%%% -*-BibTeX-*- %%% ==================================================================== %%% BibTeX-file{ %%% author = "Nelson H. F. Beebe", %%% version = "1.13", %%% date = "06 April 2012", %%% time = "18:41:07 MDT", %%% filename = "tosn.bib", %%% address = "University of Utah %%% Department of Mathematics, 110 LCB %%% 155 S 1400 E RM 233 %%% Salt Lake City, UT 84112-0090 %%% USA", %%% telephone = "+1 801 581 5254", %%% FAX = "+1 801 581 4148", %%% URL = "http://www.math.utah.edu/~beebe", %%% checksum = "13411 8568 46572 434603", %%% email = "beebe at math.utah.edu, beebe at acm.org, %%% beebe at computer.org (Internet)", %%% codetable = "ISO/ASCII", %%% keywords = "ACM Transactions on Sensor Networks; %%% bibliography; TOSN", %%% license = "public domain", %%% supported = "yes", %%% docstring = "This is a COMPLETE BibTeX bibliography for %%% ACM Transactions on Sensor Networks (CODEN %%% ????, ISSN 1550-4859 (print), 1550-4867 %%% (electronic)), covering all journal issues %%% from 2005 -- date. The journal is published %%% quarterly in February, May, August, and %%% November, and the first issue was published %%% in August 2005. %%% %%% At version 1.13, the COMPLETE journal %%% coverage looked like this: %%% %%% 2005 ( 12) 2008 ( 26) 2011 ( 18) %%% 2006 ( 17) 2009 ( 45) 2012 ( 9) %%% 2007 ( 22) 2010 ( 54) %%% %%% Article: 203 %%% %%% Total entries: 203 %%% %%% The journal Web page can be found at: %%% %%% http://www.acm.org/tosn/ %%% %%% The journal table of contents page is at: %%% %%% http://portal.acm.org/browse_dl.cfm?idx=J981 %%% %%% Qualified subscribers can retrieve the full %%% text of recent articles in PDF form. %%% %%% The initial draft was extracted from the ACM %%% Web pages. %%% %%% ACM copyrights explicitly permit abstracting %%% with credit, so article abstracts, keywords, %%% and subject classifications have been %%% included in this bibliography wherever %%% available. Article reviews have been %%% omitted, until their copyright status has %%% been clarified. %%% %%% bibsource keys in the bibliography entries %%% below indicate the entry originally came %%% from the computer science bibliography %%% archive, even though it has likely since %%% been corrected and updated. %%% %%% URL keys in the bibliography point to %%% World Wide Web locations of additional %%% information about the entry. %%% %%% BibTeX citation tags are uniformly chosen %%% as name:year:abbrev, where name is the %%% family name of the first author or editor, %%% year is a 4-digit number, and abbrev is a %%% 3-letter condensation of important title %%% words. Citation tags were automatically %%% generated by software developed for the %%% BibNet Project. %%% %%% In this bibliography, entries are sorted in %%% publication order, using ``bibsort -byvolume.'' %%% %%% The checksum field above contains a CRC-16 %%% checksum as the first value, followed by the %%% equivalent of the standard UNIX wc (word %%% count) utility output of lines, words, and %%% characters. This is produced by Robert %%% Solovay's checksum utility." %%% } %%% ==================================================================== @Preamble{"\input bibnames.sty"} %%% ==================================================================== %%% Acknowledgement abbreviations: @String{ack-nhfb = "Nelson H. F. Beebe, University of Utah, Department of Mathematics, 110 LCB, 155 S 1400 E RM 233, Salt Lake City, UT 84112-0090, USA, Tel: +1 801 581 5254, FAX: +1 801 581 4148, e-mail: \path|beebe@math.utah.edu|, \path|beebe@acm.org|, \path|beebe@computer.org| (Internet), URL: \path|http://www.math.utah.edu/~beebe/|"} %%% ==================================================================== %%% Journal abbreviations: @String{j-TOSN = "ACM Transactions on Sensor Networks"} %%% ==================================================================== %%% Bibliography entries: @Article{Zhao:2005:I, author = "Feng Zhao", title = "Introduction", journal = j-TOSN, volume = "1", number = "1", pages = "1--2", month = aug, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Li:2005:NPS, author = "Qun Li and Daniela Rus", title = "Navigation protocols in sensor networks", journal = j-TOSN, volume = "1", number = "1", pages = "3--35", month = aug, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Xing:2005:ICC, author = "Guoliang Xing and Xiaorui Wang and Yuanfang Zhang and Chenyang Lu and Robert Pless and Christopher Gill", title = "Integrated coverage and connectivity configuration for energy conservation in sensor networks", journal = j-TOSN, volume = "1", number = "1", pages = "36--72", month = aug, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Lazos:2005:SRL, author = "Loukas Lazos and Radha Poovendran", title = "{SeRLoc}: {Robust} localization for wireless sensor networks", journal = j-TOSN, volume = "1", number = "1", pages = "73--100", month = aug, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{He:2005:FTI, author = "Guanghui He and Rong Zheng and Indranil Gupta and Lui Sha", title = "A framework for time indexing in sensor networks", journal = j-TOSN, volume = "1", number = "1", pages = "101--133", month = aug, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Nguyen:2005:KBL, author = "Xuanlong Nguyen and Michael I. Jordan and Bruno Sinopoli", title = "A kernel-based learning approach to ad hoc sensor network localization", journal = j-TOSN, volume = "1", number = "1", pages = "134--152", month = aug, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Ledeczi:2005:CSU, author = "{\'A}kos L{\'e}deczi and Andr{\'a}s N{\'a}das and P{\'e}ter V{\"o}lgyesi and Gy{\"o}rgy Balogh and Branislav Kusy and J{\'a}nos Sallai and G{\'a}bor Pap and Sebesty{\'e}n D{\'o}ra and K{\'a}roly Moln{\'a}r and Mikl{\'o}s Mar{\'o}ti and Gyula Simon", title = "Countersniper system for urban warfare", journal = j-TOSN, volume = "1", number = "2", pages = "153--177", month = nov, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Prabh:2005:ECD, author = "K. Shashi Prabh and Tarek F. Abdelzaher", title = "Energy-conserving data cache placement in sensor networks", journal = j-TOSN, volume = "1", number = "2", pages = "178--203", month = nov, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Liu:2005:IKP, author = "Donggang Liu and Peng Ning", title = "Improving key predistribution with deployment knowledge in static sensor networks", journal = j-TOSN, volume = "1", number = "2", pages = "204--239", month = nov, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Huang:2005:FFA, author = "Qingfeng Huang and Sangeeta Bhattacharya and Chenyang Lu and Gruia-Catalin Roman", title = "{FAR}: {Face-Aware Routing} for mobicast in large-scale sensor networks", journal = j-TOSN, volume = "1", number = "2", pages = "240--271", month = nov, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Zhang:2005:UBL, author = "Honghai Zhang and Jennifer C. Hou", title = "On the upper bound of {$\alpha$}-lifetime for large sensor networks", journal = j-TOSN, volume = "1", number = "2", pages = "272--300", month = nov, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Zhang:2005:ODS, author = "Xin Zhang and Stephen B. Wicker", title = "On the optimal distribution of sensors in a random field", journal = j-TOSN, volume = "1", number = "2", pages = "301--306", month = nov, year = "2005", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Dec 27 07:32:01 MST 2005", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{He:2006:VIS, author = "Tian He and Sudha Krishnamurthy and Liqian Luo and Ting Yan and Lin Gu and Radu Stoleru and Gang Zhou and Qing Cao and Pascal Vicaire and John A. Stankovic and Tarek F. Abdelzaher and Jonathan Hui and Bruce Krogh", title = "{VigilNet}: {An} integrated sensor network system for energy-efficient surveillance", journal = j-TOSN, volume = "2", number = "1", pages = "1--38", month = feb, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Aug 28 07:01:48 MDT 2006", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Costa:2006:DWM, author = "Jose A. Costa and Neal Patwari and Alfred O. {Hero III}", title = "Distributed weighted-multidimensional scaling for node localization in sensor networks", journal = j-TOSN, volume = "2", number = "1", pages = "39--64", month = feb, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Aug 28 07:01:48 MDT 2006", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Law:2006:SBB, author = "Yee Wei Law and Jeroen Doumen and Pieter Hartel", title = "Survey and benchmark of block ciphers for wireless sensor networks", journal = j-TOSN, volume = "2", number = "1", pages = "65--93", month = feb, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Aug 28 07:01:48 MDT 2006", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Carbunar:2006:RCD, author = "Bogdan C{\u{a}}rbunar and Ananth Grama and Jan Vitek and Octavian C{\u{a}}rbunar", title = "Redundancy and coverage detection in sensor networks", journal = j-TOSN, volume = "2", number = "1", pages = "94--128", month = feb, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Aug 28 07:01:48 MDT 2006", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Li:2006:LTC, author = "Xiang-Yang Li and Wen-Zhan Song and Yu Wang", title = "Localized topology control for heterogeneous wireless sensor networks", journal = j-TOSN, volume = "2", number = "1", pages = "129--153", month = feb, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Aug 28 07:01:48 MDT 2006", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Chakrabarti:2006:CPO, author = "Arnab Chakrabarti and Ashutosh Sabharwal and Behnaam Aazhang", title = "Communication power optimization in a sensor network with a path-constrained mobile observer", journal = j-TOSN, volume = "2", number = "3", pages = "297--324", month = aug, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Lazos:2006:SCH, author = "Loukas Lazos and Radha Poovendran", title = "Stochastic coverage in heterogeneous sensor networks", journal = j-TOSN, volume = "2", number = "3", pages = "325--358", month = aug, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Fragouli:2006:CCT, author = "Christina Fragouli and Tarik Tabet", title = "On conditions for constant throughput in wireless networks", journal = j-TOSN, volume = "2", number = "3", pages = "359--379", month = aug, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Devarajan:2006:DMC, author = "Dhanya Devarajan and Richard J. Radke and Haeyong Chung", title = "Distributed metric calibration of ad hoc camera networks", journal = j-TOSN, volume = "2", number = "3", pages = "380--403", month = aug, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Ramachandran:2006:DDF, author = "Umakishore Ramachandran and Rajnish Kumar and Matthew Wolenetz and Brian Cooper and Bikash Agarwalla and Junsuk Shin and Phillip Hutto and Arnab Paul", title = "Dynamic data fusion for future sensor networks", journal = j-TOSN, volume = "2", number = "3", pages = "404--443", month = aug, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Funke:2006:SID, author = "Stefan Funke and Alexander Kesselman and Ulrich Meyer and Michael Segal", title = "A simple improved distributed algorithm for minimum {CDS} in unit disk graphs", journal = j-TOSN, volume = "2", number = "3", pages = "444--453", month = aug, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Agarwal:2006:SOS, author = "Pankaj K. Agarwal and David Brady and Ji{\v{r}}{\'\i} Matou{\v{s}}ek", title = "Segmenting object space by geometric reference structures", journal = j-TOSN, volume = "2", number = "4", pages = "455--465", month = nov, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Jindal:2006:MSC, author = "Apoorva Jindal and Konstantinos Psounis", title = "Modeling spatially correlated data in sensor networks", journal = j-TOSN, volume = "2", number = "4", pages = "466--499", month = nov, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Zhu:2006:LES, author = "Sencun Zhu and Sanjeev Setia and Sushil Jajodia", title = "{LEAP+}: {Efficient} security mechanisms for large-scale distributed sensor networks", journal = j-TOSN, volume = "2", number = "4", pages = "500--528", month = nov, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Arici:2006:PEB, author = "Tarik Arici and Toygar Akgun and Yucel Altunbasak", title = "A prediction error-based hypothesis testing method for sensor data acquisition", journal = j-TOSN, volume = "2", number = "4", pages = "529--556", month = nov, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Cao:2006:SLC, author = "Qing Cao and Tarek Abdelzaher", title = "Scalable logical coordinates framework for routing in wireless sensor networks", journal = j-TOSN, volume = "2", number = "4", pages = "557--593", month = nov, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Goldberg:2006:VIE, author = "David H. Goldberg and Andreas G. Andreou and Pedro Juli{\'a}n and Philippe O. Pouliquen and Laurence Riddle and Rich Rosasco", title = "{VLSI} implementation of an energy-aware wake-up detector for an acoustic surveillance sensor network", journal = j-TOSN, volume = "2", number = "4", pages = "594--611", month = nov, year = "2006", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Huang:2007:DPE, author = "Chi-Fu Huang and Yu-Chee Tseng and Hsiao-Lu Wu", title = "Distributed protocols for ensuring both coverage and connectivity of a wireless sensor network", journal = j-TOSN, volume = "3", number = "1", pages = "??--??", month = mar, year = "2007", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "5", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Ramachandran:2007:ACA, author = "Iyappan Ramachandran and Arindam K. Das and Sumit Roy", title = "Analysis of the contention access period of {IEEE} 802.15.4 {MAC}", journal = j-TOSN, volume = "3", number = "1", pages = "??--??", month = mar, year = "2007", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "4", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Su:2007:CAA, author = "Xun Su", title = "A combinatorial algorithmic approach to energy efficient information collection in wireless sensor networks", journal = j-TOSN, volume = "3", number = "1", pages = "??--??", month = mar, year = "2007", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "6", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Tiwari:2007:EEW, author = "Ankit Tiwari and Prasanna Ballal and Frank L. Lewis", title = "Energy-efficient wireless sensor network design and implementation for condition-based maintenance", journal = j-TOSN, volume = "3", number = "1", pages = "??--??", month = mar, year = "2007", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "1", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Trigoni:2007:WSR, author = "Niki Trigoni and Yong Yao and Alan Demers and Johannes Gehrke and Rajmohan Rajaraman", title = "Wave scheduling and routing in sensor networks", journal = j-TOSN, volume = "3", number = "1", pages = "??--??", month = mar, year = "2007", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "2", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Yoon:2007:CAC, author = "Sunhee Yoon and Cyrus Shahabi", title = "The {Clustered AGgregation (CAG)} technique leveraging spatial and temporal correlations in wireless sensor networks", journal = j-TOSN, volume = "3", number = "1", pages = "??--??", month = mar, year = "2007", CODEN = "????", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Sat Apr 14 11:10:02 MDT 2007", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "3", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Zamalloa:2007:AUA, author = "Marco Z{\'u}{\~n}iga Zamalloa and Bhaskar Krishnamachari", title = "An analysis of unreliability and asymmetry in low-power wireless links", journal = j-TOSN, volume = "3", number = "2", pages = "7:1--7:??", month = jun, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1240226.1240227", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:12 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Experimental studies have demonstrated that the behavior of real links in low-power wireless networks (such as wireless sensor networks) deviates to a large extent from the ideal binary model used in several simulation studies. In particular, there is a large transitional region in wireless link quality that is characterized by significant levels of unreliability and asymmetry, significantly impacting the performance of higher-layer protocols. We provide a comprehensive analysis of the root causes of unreliability and asymmetry. In particular, we derive expressions for the distribution, expectation, and variance of the packet reception rate as a function of distance, as well as for the location and extent of the transitional region. These expressions incorporate important environmental and radio parameters such as the path loss exponent and shadowing variance of the channel, and the modulation, encoding, and hardware variance of the radios.", acknowledgement = ack-nhfb, articleno = "7", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "communication theory; hardware variance; probability theory; transitional region; wireless link", } @Article{Yoon:2007:TST, author = "Suyoung Yoon and Chanchai Veerarittiphan and Mihail L. Sichitiu", title = "Tiny-sync: {Tight} time synchronization for wireless sensor networks", journal = j-TOSN, volume = "3", number = "2", pages = "8:1--8:??", month = jun, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1240226.1240228", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:12 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Time synchronization is a fundamental middleware service for any distributed system. Wireless sensor networks make extensive use of synchronized time in many contexts (e.g., data fusion, TDMA schedules, synchronized sleep periods, etc.). We propose a time synchronization method relevant for wireless sensor networks. The solution features minimal complexity in network bandwidth, storage as well as processing, and can achieve good accuracy. Especially relevant for sensor networks, it also provides tight, deterministic bounds on offset and clock drift. A method for synchronizing the entire network is presented. The performance of the algorithm is analyzed theoretically and validated on a realistic testbed. The results show that the proposed algorithm outperforms existing algorithms in terms of precision and resource requirements.", acknowledgement = ack-nhfb, articleno = "8", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "sensor networks; time synchronization", } @Article{Brass:2007:BCT, author = "Peter Brass", title = "Bounds on coverage and target detection capabilities for models of networks of mobile sensors", journal = j-TOSN, volume = "3", number = "2", pages = "9:1--9:??", month = jun, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1240226.1240229", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:12 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article we analyze the capabilities of various models of sensor networks with the Boolean sensing model for mobile or stationary sensors and targets, under random or optimal placement, independent or globally coordinated search, and stealthy or visible sensors. For each model we give an upper bound for the capabilities under any strategy, and a search strategy which at least asymptotically matches that bound. To ensure comparability of these models, we present them using the same parameters: the sensing radius $r$, sensor placement density $\lambda$, as well as the travel distance $l$ of each sensor and $d$ of the target. By this we obtain a complete analysis of the geometric coverage and detection capabilities of the various models of sensor networks, where we abstract from issues like communication and power management.", acknowledgement = ack-nhfb, articleno = "9", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Boolean sensing model; coverage capabilities; foundations of sensor networks; mobile sensors; search strategies; sensor deployment", } @Article{Gelenbe:2007:DMP, author = "Erol Gelenbe", title = "A diffusion model for packet travel time in a random multihop medium", journal = j-TOSN, volume = "3", number = "2", pages = "10:1--10:??", month = jun, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1240226.1240230", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:12 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We consider a wireless network in which packets are forwarded opportunistically from the source towards the destination, without accurate knowledge of the direction that they should take. A Brownian motion model that includes the effect of packet losses, and subsequent retransmission after a time-out, is used to compute the average travel time of the packet. The results indicate that the average travel time is always finite provided that a time-out is used, and that there is an element of randomness in the manner in which successive nodes are being chosen. We show that the average packet travel time can be minimized by a judicious choice of the time-out, and its optimum value in turn depends on other system parameters such as packet-loss probabilities. We present simulations that illustrate the analytical results.", acknowledgement = ack-nhfb, articleno = "10", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "ad hoc networks; autonomic communications; diffusion process; packet travel time; sensor networks; simulation; wireless networks", } @Article{Xing:2007:MPC, author = "Guoliang Xing and Chenyang Lu and Ying Zhang and Qingfeng Huang and Robert Pless", title = "Minimum power configuration for wireless communication in sensor networks", journal = j-TOSN, volume = "3", number = "2", pages = "11:1--11:??", month = jun, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1240226.1240231", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:12 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article proposes the minimum power configuration (MPC) approach to power management in wireless sensor networks. In contrast to earlier research that treats different radio states (i.e., transmission/reception/idle) in isolation, MPC integrates them in a joint optimization problem that depends on both the set of active nodes and the transmission power. We propose four approximation algorithms with provable performance bounds and two practical routing protocols. Simulations based on realistic radio models show that the MPC approach can conserve more energy than existing minimum power routing and topology control protocols. Furthermore, it can flexibly adapt to network workload and radio platforms.", acknowledgement = ack-nhfb, articleno = "11", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "ad hoc networks; energy efficiency; minimum power configuration; sensor networks; wireless communications", } @Article{Cheng:2007:CBP, author = "Maggie X. Cheng and Lu Ruan and Weili Wu", title = "Coverage breach problems in bandwidth-constrained sensor networks", journal = j-TOSN, volume = "3", number = "2", pages = "12:1--12:??", month = jun, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1240226.1240232", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:12 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Recent research in sensor networks highlights the low-power mode operation of sensor networks. In wireless sensor networks, network lifetime can be extended by organizing sensors into mutually exclusive subsets and alternatively activating each subset. Coverage breach occurs when a subset fails to cover all the targets. In bandwidth-constrained sensor networks, coverage breach is more likely to happen because when active sensors periodically send data to the base station, contention for channel access must be considered. Channel bandwidth imposes a limit on the cardinality of each subset. To make efficient use of both energy and bandwidth with minimum coverage breach requires optimal arrangement of sensor nodes.\par This article addresses three coverage breach problems related to the low-power operation of wireless sensor networks where channel bandwidth is limited. The three coverage breach problems are formulated using integer linear programming models. A greedy approximation algorithm and a heuristic based on the LP-relaxation method are proposed. Effects of changing different network resources on sensor network coverage are studied through simulations. One consistent result is that when the number of sensors increases, network lifetime can be improved without loss of network coverage only if there is no bandwidth constraint; with bandwidth constraints, network lifetime may be improved further at the cost of coverage breach.", acknowledgement = ack-nhfb, articleno = "12", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "coverage; coverage breach; energy efficiency; network lifetime; scheduling; sensor networks", } @Article{Girod:2007:ESE, author = "Lewis Girod and Nithya Ramanathan and Jeremy Elson and Thanos Stathopoulos and Martin Lukac and Deborah Estrin", title = "Emstar: {A} software environment for developing and deploying heterogeneous sensor-actuator networks", journal = j-TOSN, volume = "3", number = "3", pages = "13:1--13:??", month = aug, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1267060.1267061", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:25 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Recent work in wireless embedded networked systems has followed heterogeneous designs, incorporating a mixture of elements from extremely constrained 8- or 16-bit ``Motes'' to less resource-constrained 32-bit embedded ``Microservers.''\par Emstar is a software environment for developing and deploying complex applications on such heterogeneous networks. Emstar is designed to leverage the additional resources of Microservers by trading off some performance for system robustness in sensor network applications. It enables fault isolation, fault tolerance, system visiblity, in-field debugging, and resource sharing across multiple applications.\par In order to accomplish these objectives, Emstar is designed to run as a multiprocess system and consists of libraries that implement message-passing IPC primitives, services that support networking, sensing, and time synchronization, and tools that support simulation, emulation, and visualization of live systems, both real and simulated. We evaluate this work by discussing the Acoustic ENSBox, a platform for distributed acoustic sensing that we built using Emstar. We show that by leveraging existing Emstar services, we are able to significantly reduce development time while achieving a high degree of robustness. We also show that a sample application was developed much more quickly on this platform than it would have been otherwise.", acknowledgement = ack-nhfb, articleno = "13", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Emstar; Real code simulation; sensor networks; TinyOS", } @Article{Zhu:2007:IHH, author = "Sencun Zhu and Sanjeev Setia and Sushil Jajodia and Peng Ning", title = "Interleaved hop-by-hop authentication against false data injection attacks in sensor networks", journal = j-TOSN, volume = "3", number = "3", pages = "14:1--14:??", month = aug, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1267060.1267062", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:25 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Sensor networks are often deployed in unattended environments, thus leaving these networks vulnerable to false data injection attacks in which an adversary injects false data into the network with the goal of deceiving the base station or depleting the resources of the relaying nodes. Standard authentication mechanisms cannot prevent this attack if the adversary has compromised one or a small number of sensor nodes. We present three interleaved hop-by-hop authentication schemes that guarantee that the base station can detect injected false data immediately when no more than $t$ nodes are compromised, where $t$ is a system design parameter. Moreover, these schemes enable an intermediate forwarding node to detect and discard false data packets as early as possible. Our performance analysis shows that our scheme is efficient with respect to the security it provides, and it also allows a tradeoff between security and performance. A prototype implementation of our scheme indicates that our scheme is practical and can be deployed on the current generation of sensor nodes.", acknowledgement = ack-nhfb, articleno = "14", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "authentication; filtering false data; interleaved hop-by-hop; sensor networks", } @Article{Hua:2007:ARS, author = "Cunqing Hua and Tak-Shing Peter Yum", title = "Asynchronous random sleeping for sensor networks", journal = j-TOSN, volume = "3", number = "3", pages = "15:1--15:??", month = aug, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1267060.1267063", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:25 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Sleeping scheduling is a common energy-conservation solution for sensor networks. For application whereby coordination of sleeping among sensors is not possible or inconvenient, random sleeping is the only option. In this article, we study the asynchronous random sleeping(ARS) scheme whereby sensors (i) do not need to synchronize with each other, and (ii) do not need to coordinate their sleeping schedules. The stationary coverage probability and the expected coverage periods for ARS are derived. For surveillance application, we derive in addition the detection probability and detection delay distribution. The correctness of our results is validated through extensive simulations. We compare ARS with other synchronous and asynchronous sleeping scheduling algorithms and show that ARS offers better performance in terms of detection delay in the lower duty-cycle regime. We also conduct simulations to demonstrate that our results can be a good approximation for clock drifting case.", acknowledgement = ack-nhfb, articleno = "15", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy conservation; event detection; k-coverage; random sleeping; sensor network", } @Article{Huang:2007:SPK, author = "Dijiang Huang and Deep Medhi", title = "Secure pairwise key establishment in large-scale sensor networks: {An} area partitioning and multigroup key predistribution approach", journal = j-TOSN, volume = "3", number = "3", pages = "16:1--16:??", month = aug, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1267060.1267064", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:25 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Existing pairwise key establishment schemes for large-scale sensor networks are vulnerable to various passive or active attacks. We classify attacks as selective node capture attacks, node fabrication attacks, and insider attacks. In order to improve the security robustness of random key predistribution and pairwise key establishment schemes against these attacks, we propose a five-phase pairwise key predistribution and pairwise key establishment approach by using area partitioning and multigroup key predistribution. Our security performance studies show that our proposed approach is resilient to selective node capture and node fabrication attacks, and restricts the consequence of any insider attack to a minimal level.", acknowledgement = ack-nhfb, articleno = "16", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "insider attack; node fabrication; selective node capture; sensor", } @Article{Hoang:2007:CBC, author = "Anh Tuan Hoang and Mehul Motani", title = "Collaborative broadcasting and compression in cluster-based wireless sensor networks", journal = j-TOSN, volume = "3", number = "3", pages = "17:1--17:??", month = aug, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1267060.1267065", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:25 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Achieving energy efficiency to prolong the network lifetime is an important design criterion for wireless sensor networks. In this article, we propose a novel approach that exploits the broadcast nature of the wireless medium for energy conservation in spatially correlated wireless sensor networks. Since wireless transmission is inherently broadcast, when one sensor node transmits, other nodes in its coverage area can receive the transmitted data. When data collected by different sensors are correlated, each sensor can utilize the data it overhears from other sensors to compress its own data and conserve energy in its own transmissions. We apply this idea to a class of cluster-based wireless sensor networks in which each sensing node transmits collected data directly to its cluster head using time division multiple access (TDMA). We formulate the problem in which sensors in each cluster collaborate their transmitting, receiving, and compressing activities to optimize their lifetimes. We show that this lifetime optimization problem can be solved by a sequence of linear programming problems. We also propose a heuristic scheme which has low complexity and achieves near optimal performance. Important characteristics of wireless sensor networks such as node startup cost and packet loss due to transmission errors are also considered. Numerical results show that by exploiting the broadcast nature of the wireless medium, our control schemes achieve significant improvement in the sensors' lifetimes.", acknowledgement = ack-nhfb, articleno = "17", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "broadcast communications; clustering; data compression; data gathering; lifetime optimization; sensor networks; spatial correlation", } @Article{Wan:2007:OTM, author = "Chieh-Yih Wan and Shane B. Eisenman and Andrew T. Campbell and Jon Crowcroft", title = "Overload traffic management for sensor networks", journal = j-TOSN, volume = "3", number = "4", pages = "18:1--18:??", month = oct, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1281492.1281493", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:34 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "There is a critical need for new thinking regarding overload traffic management in sensor networks. It has now become clear that experimental sensor networks (e.g., mote networks) and their applications commonly experience periods of persistent congestion and high packet loss, and in some cases even congestion collapse. This significantly impacts application fidelity measured at the physical sinks, even under light to moderate traffic loads, and is a direct product of the funneling effect; that is, the many-to-one multihop traffic pattern that characterizes sensor network communications. Existing congestion control schemes are effective at mitigating congestion through rate control and packet drop mechanisms, but do so at the cost of significantly reducing application fidelity measured at the sinks. To address this problem we propose to exploit the availability of a small number of all wireless, multiradio virtual sinks that can be randomly distributed or selectively placed across the sensor field. Virtual sinks are capable of siphoning off data events from regions of the sensor field that are beginning to show signs of high traffic load. In this paper, we present the design, implementation, and evaluation of Siphon, a set of fully distributed algorithms that support virtual sink discovery and selection, congestion detection, and traffic redirection in sensor networks. Siphon is based on a Stargate implementation of virtual sinks that uses a separate longer range radio network (based on IEEE 802.11) to siphon events to one or more physical sinks, and a short-range mote radio to interact with the sensor field at siphon points. Results from analysis, simulation and an experimental 48 Mica2 mote testbed show that virtual sinks can scale mote networks by effectively managing growing traffic demands while minimizing any negative impact on application fidelity. Additionally, we show the scheme is competitive with respect to energy consumption compared to a network composed of only motes.", acknowledgement = ack-nhfb, articleno = "18", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "simulations; system design; testbeds", } @Article{Tague:2007:CSA, author = "Patrick Tague and Radha Poovendran", title = "A canonical seed assignment model for key predistribution in wireless sensor networks", journal = j-TOSN, volume = "3", number = "4", pages = "19:1--19:??", month = oct, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1281492.1281494", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:34 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "A promising solution for trust establishment in wireless sensor networks is the assignment of cryptographic seeds (keys, secrets, etc.) to sensor nodes prior to network deployment, known as key predistribution. In this article, we propose a canonical seed assignment model for key predistribution characterizing seed assignment in terms of the probability distribution describing the number of nodes receiving each seed and the algorithm for seed assignment. In addition, we present a sampling framework for seed assignment algorithms in the canonical model. We propose a probabilistic $k$-connectivity model for randomly deployed secure networks using spatial statistics and geometric random graph theory. We analyze key predistribution schemes in the canonical model in terms of network connectivity and resilience to node capture. The analytical results can be used to determine the average or worst-case connectivity or resilience to node capture for a key predistribution scheme. Furthermore, we demonstrate the design of new key predistribution schemes and the inclusion of existing schemes in the canonical model. Finally, we present a general approach to analyze the addition of nodes to an existing secure network and derive results for a well-known scheme.", acknowledgement = ack-nhfb, articleno = "19", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "key establishment; key predistribution; network models; sensor networks", } @Article{Wang:2007:SPP, author = "Dan Wang and Qian Zhang and Jiangchuan Liu", title = "The self-protection problem in wireless sensor networks", journal = j-TOSN, volume = "3", number = "4", pages = "20:1--20:??", month = oct, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1281492.1281495", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:34 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Wireless sensor networks have recently been suggested for many surveillance applications, such as object monitoring, path protection, or area coverage. Since the sensors themselves are important and critical objects in the network, a natural question is whether they need certain level of protection, so as to resist the attacks targeting on them directly. If this is necessary, then who should provide this protection, and how it can be done?\par We refer to the above problem as self-protection, as we believe the sensors themselves are the best (and often the only) candidates to provide such protection. In this article, we for the first time present a formal study on the self-protection problems in wireless sensor networks. We show that, if we simply focus on enhancing the quality of field or object covering, the sensors might not necessarily be self-protected, which in turn makes the system extremely vulnerable. We then investigate different forms of self-protections, and show that the problems are generally NP-complete. We develop efficient approximation algorithms for centrally controlled sensors. We further extend the algorithms to fully distributed implementation, and introduce a smart sleep-scheduling algorithm that minimizes the energy consumption.", acknowledgement = ack-nhfb, articleno = "20", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "coverage; protection; sensor networks", } @Article{Zheng:2007:LUB, author = "Yunhui Zheng and David J. Brady and Pankaj K. Agarwal", title = "Localization using boundary sensors: {An} analysis based on graph theory", journal = j-TOSN, volume = "3", number = "4", pages = "21:1--21:??", month = oct, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1281492.1281496", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:34 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We consider sensors, such as fibers, lasers, and pyroelectric motion detectors, that fire when objects cross a boundary. A moving object can be localized by analyzing sequences of boundary crossings. We consider the number of distinct sequences and object positions that can be achieved using boundary sensors in one- and two-dimensional spaces. For 1D systems we use representations of sensor sequences on graphs to derive limits on the number of object locations that can be monitored by a given sensor population and sequence length. For 2D systems we show that in certain circumstances the ratio of the number of unique sensor sequences to the number of unique object paths is exponential in the sequence length and we argue that the probability of unique identification is high for sufficiently large sequences. We also prove the triangle grid can track an object with error limited to a small neighborhood.", acknowledgement = ack-nhfb, articleno = "21", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "boundary sensor; deployment graph; deployment sequence; sensor sequence; sequence graph", } @Article{Kansal:2007:RMM, author = "Aman Kansal and William Kaiser and Gregory Pottie and Mani Srivastava and Gaurav Sukhatme", title = "Reconfiguration methods for mobile sensor networks", journal = j-TOSN, volume = "3", number = "4", pages = "22:1--22:??", month = oct, year = "2007", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1281492.1281497", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:34 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Motion may be used in sensor networks to change the network configuration for improving the sensing performance. We consider the problem of controlling motion in a distributed manner for a mobile sensor network for a specific form of motion capability. Mobility itself may have a high resource overhead, hence we exploit motility, a constrained form of mobility, which has very low overheads but provides significant reconfiguration potential. We present an architecture that allows each node in the network to learn the medium and phenomenon characteristics. We describe a quantitative metric for sensing performance that is concretely tied to real sensor and medium characteristics, rather than assuming an abstract range based model. The problem of determining the desirable network configuration is expressed as an optimization of this metric. We present a distributed optimization algorithm which computes a desirable network configuration, and adapts it to environmental changes. The relationship of the proposed algorithm to simulated annealing and incremental subgradient descent based methods is discussed. A key property of our algorithm is that convergence to a desirable configuration can be proved even though no global coordination is involved. A network protocol to implement this algorithm is discussed, followed by simulations and experiments on a laboratory test bed.", acknowledgement = ack-nhfb, articleno = "22", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "actuation; coverage; mobile or actuator systems; mobility control; motion coordination; network protocols; spatial resolution", } @Article{Ning:2008:MAA, author = "Peng Ning and An Liu and Wenliang Du", title = "Mitigating {DoS} attacks against broadcast authentication in wireless sensor networks", journal = j-TOSN, volume = "4", number = "1", pages = "1:1--1:??", month = jan, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1325651.1325652", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:44 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Broadcast authentication is a critical security service in wireless sensor networks. There are two general approaches for broadcast authentication in wireless sensor networks: digital signatures and $\mu$TESLA-based techniques. However, both signature-based and $\mu$TESLA-based broadcast authentication are vulnerable to Denial of Services (DoS) attacks: An attacker can inject bogus broadcast packets to force sensor nodes to perform expensive signature verifications (in case of signature-based broadcast authentication) or packet forwarding (in case of $\mu$TESLA-based broadcast authentication), thus exhausting their limited battery power. This paper presents an efficient mechanism called message-specific puzzle to mitigate such DoS attacks. In addition to signature-based or $\mu$TESLA-based broadcast authentication, this approach adds a weak authenticator in each broadcast packet, which can be efficiently verified by a regular sensor node, but takes a computationally powerful attacker a substantial amount of time to forge. Upon receiving a broadcast packet, each sensor node first verifies the weak authenticator, and performs the expensive signature verification (in signature-based broadcast authentication) or packet forwarding (in $\mu$TESLA-based broadcast authentication) only when the weak authenticator is valid. A weak authenticator cannot be precomputed without a non-reusable (or short-lived) key disclosed only in a valid packet. Even if an attacker has intensive computational resources to forge one or more weak authenticators, it is difficult to reuse these forged weak authenticators. Thus, this weak authentication mechanism substantially increases the difficulty of launching successful DoS attacks against signature-based or $\mu$TESLA-based broadcast authentication. A limitation of this approach is that it requires a powerful sender and introduces sender-side delay. This article also reports an implementation of the proposed techniques on TinyOS, as well as initial experimental evaluation in a network of MICAz motes.", acknowledgement = ack-nhfb, articleno = "1", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "broadcast authentication; DoS attacks; security; sensor networks", } @Article{Krasniewski:2008:EED, author = "Mark D. Krasniewski and Rajesh Krishna Panta and Saurabh Bagchi and Chin-Lung Yang and William J. Chappell", title = "Energy-efficient on-demand reprogramming of large-scale sensor networks", journal = j-TOSN, volume = "4", number = "1", pages = "2:1--2:??", month = jan, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1325651.1325653", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:44 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "As sensor networks operate over long periods of deployment in difficult to reach places, their requirements may change or new code may need to be uploaded to them. The current state-of-the-art protocols (Deluge and MNP) for network reprogramming perform the code dissemination in a multihop manner using a three-way handshake where metadata is exchanged prior to code exchange to suppress redundant transmissions. The code image is also pipelined through the network at the granularity of pages. In this article we propose a protocol called Freshet for optimizing the energy for code upload and speeding up the dissemination if multiple sources of code are available. The energy optimization is achieved by equipping each node with limited nonlocal topology information which it uses to determine the time when it can go to sleep since code is not being distributed in its vicinity. The protocol to handle multiple sources provides a loose coupling of nodes to a source and disseminates code in waves each originating at a source with a mechanism to handle collisions when the waves meet. The protocol's performance with respect to reliability, delay, and energy consumed is demonstrated through analysis, simulation, and implementation on the Berkeley mote platform.", acknowledgement = ack-nhfb, articleno = "2", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Deluge; network reprogramming; sensor networks; three-way handshake; wireless communication", } @Article{Wang:2008:SLC, author = "Chen Wang and Li Xiao", title = "Sensor localization in concave environments", journal = j-TOSN, volume = "4", number = "1", pages = "3:1--3:??", month = jan, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1325651.1325654", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:44 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In sensor network localization, multihop based approaches have been proposed to approximate the shortest paths to Euclidean distances between pairwise sensors. A good approximation can be achieved when sensors are densely deployed in a convex area, where the shortest paths are close to straight lines connecting pairwise sensors. However, in a concave network, the shortest paths may deviate far away from straight lines, which leads to erroneous distance estimation and inaccurate localization results. To solve this problem, we propose an improved multihop algorithm that can recognize and filter out the erroneous distance estimation, and therefore achieve accurate localization results even in a concave network.", acknowledgement = ack-nhfb, articleno = "3", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "concave; localization; multihop; sensor networks", } @Article{Gupta:2008:EGC, author = "Himanshu Gupta and Vishnu Navda and Samir Das and Vishal Chowdhary", title = "Efficient gathering of correlated data in sensor networks", journal = j-TOSN, volume = "4", number = "1", pages = "4:1--4:??", month = jan, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1325651.1325655", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:44 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article, we design techniques that exploit data correlations in sensor data to minimize communication costs (and hence, energy costs) incurred during data gathering in a sensor network. Our proposed approach is to select a small subset of sensor nodes that may be sufficient to reconstruct data for the entire sensor network. Then, during data gathering only the selected sensors need to be involved in communication. The selected set of sensors must also be connected, since they need to relay data to the data-gathering node. We define the problem of selecting such a set of sensors as the connected correlation-dominating set problem, and formulate it in terms of an appropriately defined correlation structure that captures general data correlations in a sensor network.\par We develop a set of energy-efficient distributed algorithms and competitive centralized heuristics to select a connected correlation-dominating set of small size. The designed distributed algorithms can be implemented in an asynchronous communication model, and can tolerate message losses. We also design an exponential (but nonexhaustive) centralized approximation algorithm that returns a solution within $O(\log n)$ of the optimal size. Based on the approximation algorithm, we design a class of centralized heuristics that are empirically shown to return near-optimal solutions. Simulation results over randomly generated sensor networks with both artificially and naturally generated data sets demonstrate the efficiency of the designed algorithms and the viability of our technique --- even in dynamic conditions.", acknowledgement = ack-nhfb, articleno = "4", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "correlated data; energy efficiency; topology control", } @Article{Karenos:2008:CBC, author = "Kyriakos Karenos and Vana Kalogeraki and Srikanth V. Krishnamurthy", title = "Cluster-based congestion control for sensor networks", journal = j-TOSN, volume = "4", number = "1", pages = "5:1--5:??", month = jan, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1325651.1325656", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:44 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In wireless sensor networks, multiple flows from data collecting sensors to an aggregating sink could traverse paths that are largely interference coupled. These interference effects manifest themselves as congestion, and cause the flows to experience high packet loss and arbitrary packet delays. This is particularly problematic in event-based sensor networks (such as those in disaster recovery missions) where some flows are of greater importance than others and require a higher fidelity in terms of packet delivery and timeliness. In this paper we present COMUT (COngestion control for MUlti-class Traffic), a distributed cluster-based mechanism for supporting multiple classes of traffic in sensor networks. COMUT is based on the self-organization of the network into clusters, each of which autonomously and proactively monitors congestion within its localized scope. The clusters then exchange appropriate information to facilitate system wide rate control where, each data source, depending on the relative importance of its data flow and the experienced congestion en route the sink, is coerced into controlling its rate. Our simulation results demonstrate that (i) our techniques are highly effective in dealing with multiple, interfering flows and in achieving high delivery ratios and low delays compared to traditional approaches, (ii) operate successfully over multiple underlying routing protocols, (iii) provide higher throughput to higher importance flows, (iv) are responsive to failures and, finally, (v) achieve substantial energy savings due to the considerable reduction in packet drops via the effective regulation of the network load.", acknowledgement = ack-nhfb, articleno = "5", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "clusters; rate control; real time; sensor networks", } @Article{Sengul:2008:APB, author = "Cigdem Sengul and Indranil Gupta and Matthew J. Miller", title = "Adaptive probability-based broadcast forwarding in energy-saving sensor networks", journal = j-TOSN, volume = "4", number = "2", pages = "6:1--6:??", month = mar, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1340771.1340772", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:53 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Networking protocols for multihop wireless sensor networks (WSNs) are required to simultaneously minimize resource usage as well as optimize performance metrics such as latency and reliability. This article explores the energy-latency-reliability tradeoff for broadcast in WSNs by presenting a new protocol called PBBF. Essentially, for a given reliability level, energy and latency are found to be inversely related and our study quantifies this relationship at the reliability boundary. Therefore, PBBF offers an application designer considerable flexibility in the choice of desired operation points. Furthermore, we propose an extension to dynamically adjust the PBBF parameters to minimize the input required from the designer.", acknowledgement = ack-nhfb, articleno = "6", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "broadcast; probabilistic protocols; sensor network", } @Article{Nath:2008:SDR, author = "Suman Nath and Phillip B. Gibbons and Srinivasan Seshan and Zachary Anderson", title = "Synopsis diffusion for robust aggregation in sensor networks", journal = j-TOSN, volume = "4", number = "2", pages = "7:1--7:??", month = mar, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1340771.1340773", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:53 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Previous approaches for computing duplicate-sensitive aggregates in wireless sensor networks have used a tree topology, in order to conserve energy and to avoid double-counting sensor readings. However, a tree topology is not robust against node and communication failures, which are common in sensor networks. In this article, we present synopsis diffusion, a general framework for achieving significantly more accurate and reliable answers by combining energy-efficient multipath routing schemes with techniques that avoid double-counting. Synopsis diffusion avoids double-counting through the use of order- and duplicate-insensitive (ODI) synopses that compactly summarize intermediate results during in-network aggregation. We provide a surprisingly simple test that makes it easy to check the correctness of an ODI synopsis. We show that the properties of ODI synopses and synopsis diffusion create implicit acknowledgments of packet delivery. Such acknowledgments enable energy-efficient adaptation of message routes to dynamic message loss conditions, even in the presence of asymmetric links. Finally, we illustrate using extensive simulations the significant robustness, accuracy, and energy-efficiency improvements of synopsis diffusion over previous approaches.", acknowledgement = ack-nhfb, articleno = "7", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "query processing; sensor networks; synopsis diffusion", } @Article{Sugihara:2008:PMS, author = "Ryo Sugihara and Rajesh K. Gupta", title = "Programming models for sensor networks: {A} survey", journal = j-TOSN, volume = "4", number = "2", pages = "8:1--8:??", month = mar, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1340771.1340774", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:53 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Sensor networks have a significant potential in diverse applications some of which are already beginning to be deployed in areas such as environmental monitoring. As the application logic becomes more complex, programming difficulties are becoming a barrier to adoption of these networks. The difficulty in programming sensor networks is not only due to their inherently distributed nature but also the need for mechanisms to address their harsh operating conditions such as unreliable communications, faulty nodes, and extremely constrained resources. Researchers have proposed different programming models to overcome these difficulties with the ultimate goal of making programming easy while making full use of available resources. In this article, we first explore the requirements for programming models for sensor networks. Then we present a taxonomy of the programming models, classified according to the level of abstractions they provide. We present an evaluation of various programming models for their responsiveness to the requirements. Our results point to promising efforts in the area and a discussion of the future directions of research in this area.", acknowledgement = ack-nhfb, articleno = "8", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "programming models and languages; survey; taxonomy", } @Article{Chitnis:2008:AML, author = "Laukik Chitnis and Alin Dobra and Sanjay Ranka", title = "Aggregation methods for large-scale sensor networks", journal = j-TOSN, volume = "4", number = "2", pages = "9:1--9:??", month = mar, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1340771.1340775", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:53 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The ability to efficiently aggregate information --- for example compute the average temperature --- in large networks is crucial for the successful employment of sensor networks. This article addresses the problem of designing truly scalable protocols for computing aggregates in the presence of faults, protocols that can enable million node sensor networks to work efficiently. More precisely, we make four distinct contributions. First, we introduce a simple fault model and analyze the behavior of two existing protocols under the fault model: tree aggregation and gossip aggregation. Second, since the behavior of the two protocols depends on the size of the network and probability of failure, we introduce a hybrid approach that can leverage the strengths of the two protocols and minimize the weaknesses; the new protocol is analyzed under the same fault model. Third, we propose methodology for determining the optimal mix between the two basic protocols; the methodology consists in formulating an optimization problem, using models of the protocol behavior, and solving it. Fourth, we perform extensive experiments to evaluate the performance of the hybrid protocol and show that it usually performs better, sometimes orders of magnitude better, than both the tree and gossip aggregation.", acknowledgement = ack-nhfb, articleno = "9", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "fault tolerance; in-network processing and aggregation; modeling faults; sensor fusion and distributed inference", } @Article{Shrivastava:2008:DCS, author = "Nisheeth Shrivastava and Subhash Suri and Csaba D. T{\'o}th", title = "Detecting cuts in sensor networks", journal = j-TOSN, volume = "4", number = "2", pages = "10:1--10:??", month = mar, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1340771.1340776", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:53 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We propose a low-overhead scheme for detecting a network partition or cut in a sensor network. Consider a network $S$ of $n$ sensors, modeled as points in a two-dimensional plane. An $\epsilon$-cut, for any $0 < \varepsilon < 1$, is a linear separation of $\varepsilon n$ nodes in $S$ from a distinguished node, the base station. Our main result is that, by monitoring the status of just $O(1/\epsilon)$ nodes in the network, the base station can detect whenever an $\epsilon$-cut occurs. Furthermore, this detection comes with a deterministic guarantee that every reported cut has size at least $\epsilon n / 2$. Besides this combinatorial result, we also propose efficient algorithms for finding the $O(1 / \epsilon)$ nodes that should act as sentinels, and report on our simulation results, comparing the sentinel algorithm with two natural schemes based on random sampling.", acknowledgement = ack-nhfb, articleno = "10", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "computational geometry; distributed algorithms; network failure", } @Article{Liu:2008:GBK, author = "Donggang Liu and Peng Ning and Wenliang Du", title = "Group-based key predistribution for wireless sensor networks", journal = j-TOSN, volume = "4", number = "2", pages = "11:1--11:??", month = mar, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1340771.1340777", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:50:53 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Many key predistribution techniques have been developed recently to establish pairwise keys between sensor nodes in wireless sensor networks. To further improve these schemes, researchers have also proposed to take advantage of the sensors' expected locations and discovered locations to help the predistribution of the keying materials. However, in many cases, it is very difficult to deploy sensor nodes at their expected locations or guarantee the correct location discovery at sensor nodes in hostile environments. In this article, a group-based deployment model is developed to improve key predistribution. In this model, sensor nodes are only required to be deployed in groups. The critical observation in the article is that the sensor nodes in the same group are usually close to each other after deployment. This deployment model is practical; it greatly simplifies the deployment of sensor nodes, while still providing an opportunity to improve key predistribution. Specifically, the article presents a novel framework for improving key predistribution using the group-based deployment knowledge. This framework does not require the knowledge of the sensors' expected or discovered locations and is thus suitable for applications where it is difficult to deploy the sensor nodes at their expected locations or correctly estimate the sensors' locations after deployment. To seek practical key predistribution schemes, the article presents two efficient instantiations of this framework, a hash key-based scheme and a polynomial-based scheme. The evaluation shows that these two schemes are efficient and effective for pairwise key establishment in sensor networks; they can achieve much better performance than the previous key predistribution schemes when the sensor nodes are deployed in groups.", acknowledgement = ack-nhfb, articleno = "11", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "group-based deployment; key predistribution; pairwise key establishment; security; sensor networks", } @Article{Zamalloa:2008:EGR, author = "Marco Z{\'u}{\~n}iga Zamalloa and Karim Seada and Bhaskar Krishnamachari and Ahmed Helmy", title = "Efficient geographic routing over lossy links in wireless sensor networks", journal = j-TOSN, volume = "4", number = "3", pages = "12:1--12:??", month = may, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1362542.1362543", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:51:03 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Recent experimental studies have shown that wireless links in real sensor networks can be extremely unreliable, deviating to a large extent from the idealized perfect-reception-within-range models used in common network simulation tools. Previously proposed geographic routing protocols commonly employ a maximum-distance greedy forwarding technique that works well in ideal conditions. However, such a forwarding technique performs poorly in realistic conditions as it tends to forward packets on lossy links. Based on a recently developed link loss model, we study the performance of a wide array of forwarding strategies, via analysis, extensive simulations and a set of experiments on motes. We find that the product of the packet reception rate and the distance improvement towards destination (PRR $\times d$) is a highly suitable metric for geographic forwarding in realistic environments.", acknowledgement = ack-nhfb, articleno = "12", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "blacklisting; geographic routing; wireless sensor networks", } @Article{Jourdan:2008:OSP, author = "Damien B. Jourdan and Nicholas Roy", title = "Optimal sensor placement for agent localization", journal = j-TOSN, volume = "4", number = "3", pages = "13:1--13:??", month = may, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1362542.1362544", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:51:03 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article we consider deploying a sensor network to help an agent navigate in an area. In particular the agent uses range measurements to the sensors to localize itself. We wish to place the sensors in order to provide optimal localization accuracy to the agent. We begin by considering the problem of placing sensors in order to optimally localize the agent at a single location. The Position Error Bound (PEB), a lower bound on the localization accuracy, is used to measure the quality of sensor configurations. We then present RELOCATE, an iterative algorithm that places the sensors so as to minimize the PEB at that point. When the range measurements are unbiased and have constant variances, we introduce a coordinate transform that allows us to obtain a closed-form solution to minimizing the PEB along one coordinate. We also prove that RELOCATE converges to the global minimum, and we compute the approximate expected rate of convergence of the algorithm. We then apply RELOCATE to the more complex case where the variance of the range measurements depends on the sensors location and where those measurements can be biased. We finally apply RELOCATE to the case where the PEB must be minimized not at a single point, but at multiple locations, so that good localization accuracy is ensured as the agent moves through the area. We show that, compared to Simulated Annealing, the algorithm yields better results faster on these more realistic scenarios. We also show that by optimally placing the sensors, significant savings in terms of number of sensors used can be achieved. Finally we illustrate that the PEB is not only a convenient theoretical lower bound, but that it can actually be closely approximated by a maximum likelihood estimator.", acknowledgement = ack-nhfb, articleno = "13", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "localization; sensor placement; target location; tracking; ultra-wideband (UWB)", } @Article{Wang:2008:PNC, author = "Dan Wang and Qian Zhang and Jiangchuan Liu", title = "Partial network coding: {Concept}, performance, and application for continuous data collection in sensor networks", journal = j-TOSN, volume = "4", number = "3", pages = "14:1--14:??", month = may, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1362542.1362545", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:51:03 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Wireless sensor networks have been widely used for surveillance in harsh environments. In many such applications, the environmental data are continuously sensed, and data collection by a server is only performed occasionally. Hence, the sensor nodes have to temporarily store the data, and provide easy and on-hand access for the most updated data when the server approaches. Given the expensive server-to-sensor communications, the large amount of sensors and the limited storage space at each tiny sensor, continuous data collection becomes a challenging problem.\par In this article, we present partial network coding (PNC) as a generic tool for these applications. PNC generalizes the existing network coding (NC) paradigm, an elegant solution for ubiquitous data distribution and collection. Yet PNC allows efficient storage replacement for continuous data, which is a deficiency of the conventional NC. We prove that the performance of PNC is quite close to NC, except for a sub-linear overhead on storage and communications. We then address a set of practical concerns toward PNC-based continuous data collection in sensor networks. Its feasibility and superiority are further demonstrated through simulation results.", acknowledgement = ack-nhfb, articleno = "14", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "network coding; random linear coding; sensor networks", } @Article{Ganeriwal:2008:RBF, author = "Saurabh Ganeriwal and Laura K. Balzano and Mani B. Srivastava", title = "Reputation-based framework for high integrity sensor networks", journal = j-TOSN, volume = "4", number = "3", pages = "15:1--15:??", month = may, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1362542.1362546", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:51:03 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Sensor network technology promises a vast increase in automatic data collection capabilities through efficient deployment of tiny sensing devices. The technology will allow users to measure phenomena of interest at unprecedented spatial and temporal densities. However, as with almost every data-driven technology, the many benefits come with a significant challenge in data reliability. If wireless sensor networks are really going to provide data for the scientific community, citizen-driven activism, or organizations which test that companies are upholding environmental laws, then an important question arises: How can a user trust the accuracy of information provided by the sensor network? Data integrity is vulnerable to both node and system failures. In data collection systems, faults are indicators that sensor nodes are not providing useful information. In data fusion systems the consequences are more dire; the final outcome is easily affected by corrupted sensor measurements, and the problems are no longer visibly obvious.\par In this article, we investigate a generalized and unified approach for providing information about the data accuracy in sensor networks. Our approach is to allow the sensor nodes to develop a community of trust. We propose a framework where each sensor node maintains reputation metrics which both represent past behavior of other nodes and are used as an inherent aspect in predicting their future behavior. We employ a Bayesian formulation, specifically a beta reputation system, for the algorithm steps of reputation representation, updates, integration and trust evolution. This framework is available as a middleware service on motes and has been ported to two sensor network operating systems, TinyOS and SOS. We evaluate the efficacy of this framework using multiple contexts: (1) a lab-scale test bed of Mica2 motes, (2) Avrora simulations, and (3) real data sets collected from sensor network deployments in James Reserve.", acknowledgement = ack-nhfb, articleno = "15", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Bayesian formulation; beta reputation system; reputation; sensor networks", } @Article{Crespi:2008:TTA, author = "Valentino Crespi and George Cybenko and Guofei Jiang", title = "The theory of trackability with applications to sensor networks", journal = j-TOSN, volume = "4", number = "3", pages = "16:1--16:??", month = may, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1362542.1362547", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:51:03 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article, we formalize the concept of tracking in a sensor network and develop a quantitative theory of trackability of weak models that investigates the rate of growth of the number of consistent tracks given a temporal sequence of observations made by the sensor network. The phenomenon being tracked is modelled by a nondeterministic finite automaton (a weak model) and the sensor network is modelled by an observer capable of detecting events related, typically ambiguously, to the states of the underlying automaton. Formally, an input string of symbols (the sensor network observations) that is presented to a nondeterministic finite automaton, M, (the weak model) determines a set of state sequences (the tracks or hypotheses) that are capable of generating the input string. We study the growth of the size of this candidate set of tracks as a function of the length of the input string. One key result is that for a given automaton and sensor coverage, the worst-case rate of growth is either polynomial or exponential in the number of observations, indicating a kind of phase transition in tracking accuracy. These results have applications to various tracking problems of recent interest involving tracking phenomena using noisy observations of hidden states such as: sensor networks, computer network security, autonomic computing and dynamic social network analysis.", acknowledgement = ack-nhfb, articleno = "16", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "multiple hypotheses; sensor networks; tracking", } @Article{Jaggi:2008:NOA, author = "Neeraj Jaggi and Koushik Kar and Ananth Krishnamurthy", title = "Near-optimal activation policies in rechargeable sensor networks under spatial correlations", journal = j-TOSN, volume = "4", number = "3", pages = "17:1--17:??", month = may, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1362542.1362548", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Jun 16 17:51:03 MDT 2008", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We address the problem of optimal node activation in a sensor network, where the optimization objective is represented as a global time-average utility function over the deployment area of the network. Each sensor node is rechargeable, and can hold up to K quanta of energy. When the recharge and/or discharge processes in the network are random, the problem of optimal sensor activation is a complex stochastic decision question. For the case of identical sensor coverages, we show the existence of a simple threshold policy which is asymptotically optimal with respect to the energy bucket size K, that is, the performance of this threshold policy approaches the optimal performance as K becomes large. We also show that the performance of the optimal threshold policy is robust to the degree of spatial correlation in the discharge and/or recharge processes. We then extend this approach to a general sensor network where coverage areas of different sensors could have complete, partial or no overlap with each other. We demonstrate through simulations that a local information based threshold policy, with an appropriately chosen threshold, achieves a performance which is very close to the global optimum.", acknowledgement = ack-nhfb, articleno = "17", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "coverage; energy-efficiency; rechargeable sensors; sensor activation; sensor networks; spatial correlations", } @Article{Xu:2008:DWS, author = "Wenyuan Xu and Wade Trappe and Yanyong Zhang", title = "Defending wireless sensor networks from radio interference through channel adaptation", journal = j-TOSN, volume = "4", number = "4", pages = "18:1--18:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387664", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Radio interference, whether intentional or otherwise, represents a serious threat to assuring the availability of sensor network services. As such, techniques that enhance the reliability of sensor communications in the presence of radio interference are critical. In this article, we propose to cope with this threat through a technique called channel surfing, whereby the sensor nodes in the network adapt their channel assignments to restore network connectivity in the presence of interference. We explore two different approaches to channel surfing: coordinated channel switching, in which the entire sensor network adjusts its channel; and spectral multiplexing, in which nodes in a jammed region switch channels and nodes on the boundary of a jammed region act as radio relays between different spectral zones. For coordinated channel switching, we examine an autonomous strategy where each node detects the loss of its neighbors in order to initiate channel switching. To cope with latency issues in the autonomous strategy, we propose a broadcast-assisted channel switching strategy to more rapidly coordinate channel switching. For spectral multiplexing, we have devised both synchronous and asynchronous strategies to facilitate the scheduling of nodes in order to improve network fidelity when sensor nodes operate on multiple channels. In designing these algorithms, we have taken a system-oriented approach that has focused on exploring actual implementation issues under realistic network settings. We have implemented these proposed methods on a testbed of 30 Mica2 sensor nodes, and the experimental results show that channel surfing, in its various forms, is an effective technique for repairing network connectivity in the presence of radio interference, while not introducing significant performance-overhead.", acknowledgement = ack-nhfb, articleno = "18", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Channel Surfing; Jamming; Radio Interference", } @Article{Yin:2008:ARU, author = "Jie Yin and Qiang Yang and Dou Shen and Ze-Nian Li", title = "Activity recognition via user-trace segmentation", journal = j-TOSN, volume = "4", number = "4", pages = "19:1--19:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387665", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "A major issue of activity recognition in sensor networks is automatically recognizing a user's high-level goals accurately from low-level sensor data. Traditionally, solutions to this problem involve the use of a location-based sensor model that predicts the physical locations of a user from the sensor data. This sensor model is often trained offline, incurring a large amount of calibration effort. In this article, we address the problem using a goal-based segmentation approach, in which we automatically segment the low-level user traces that are obtained cheaply by collecting the signal sequences as a user moves in wireless environments. From the traces we discover primitive signal segments that can be used for building a probabilistic activity model to recognize goals directly. A major advantage of our algorithm is that it can reduce a significant amount of human effort in calibrating the sensor data while still achieving comparable recognition accuracy. We present our theoretical framework for activity recognition, and demonstrate the effectiveness of our new approach using the data collected in an indoor wireless environment.", acknowledgement = ack-nhfb, articleno = "19", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Activity recognition; motion patterns; segmentation", } @Article{Chatterjea:2008:DSO, author = "Supriyo Chatterjea and Tim Nieberg and Nirvana Meratnia and Paul Havinga", title = "A distributed and self-organizing scheduling algorithm for energy-efficient data aggregation in wireless sensor networks", journal = j-TOSN, volume = "4", number = "4", pages = "20:1--20:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387666", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Wireless sensor networks (WSNs) are increasingly being used to monitor various parameters in a wide range of environmental monitoring applications. In many instances, environmental scientists are interested in collecting raw data using long-running queries injected into a WSN for analyzing at a later stage, rather than injecting snap-shot queries containing data-reducing operators (e.g., MIN, MAX, AVG) that aggregate data. Collection of raw data poses a challenge to WSNs as very large amounts of data need to be transported through the network. This not only leads to high levels of energy consumption and thus diminished network lifetime but also results in poor data quality as much of the data may be lost due to the limited bandwidth of present-day sensor nodes. We alleviate this problem by allowing certain nodes in the network to aggregate data by taking advantage of spatial and temporal correlations of various physical parameters and thus eliminating the transmission of redundant data. In this article we present a distributed scheduling algorithm that decides when a particular node should perform this novel type of aggregation. The scheduling algorithm autonomously reassigns schedules when changes in network topology, due to failing or newly added nodes, are detected. Such changes in topology are detected using cross-layer information from the underlying MAC layer. We first present the theoretical performance bounds of our algorithm. We then present simulation results, which indicate a reduction in message transmissions of up to 85\% and an increase in network lifetime of up to 92\% when compared to collecting raw data. Our algorithm is also capable of completely eliminating dropped messages caused by buffer overflow.", acknowledgement = ack-nhfb, articleno = "20", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "cross-layer optimization; in-network data aggregation; scheduling; self-organizing; spatio-temporal correlation; Wireless sensor network", } @Article{Lai:2008:OBE, author = "Wei Lai and Ioannis C. Paschalidis", title = "Optimally balancing energy consumption versus latency in sensor network routing", journal = j-TOSN, volume = "4", number = "4", pages = "21:1--21:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387667", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We consider wireless sensor networks with nodes switching ON (awake) and OFF (sleeping) to preserve energy, and transmitting data over channels with varying quality. The objective is to determine the best path from each node to a single gateway. The performance metrics we are interested in are: the expected energy consumption, and the probability that the latency exceeds a certain threshold. Under Markovian assumptions on the sleeping schedules and the channel conditions, we obtain the expected energy consumption of transmitting a packet on any path to the gateway. We also provide an upper (Chernoff) bound and a tight large deviations asymptotic for the latency probability on each path. To capture the trade-off between energy consumption and latency probability, we formulate the problem of choosing a path to minimize a weighted sum of the expected energy consumption and the exponent of the latency probability. We provide two algorithms to solve this problem: a centralized stochastic global optimization algorithm, and a distributed algorithm based on simulated annealing. The proposed methodology can also optimize over the fraction of time that sensor nodes remain ON (duty cycle).", acknowledgement = ack-nhfb, articleno = "21", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy and resource management; latency; routing; Sensor networks; sleeping schedule", } @Article{Malan:2008:IPK, author = "David J. Malan and Matt Welsh and Michael D. Smith", title = "Implementing public-key infrastructure for sensor networks", journal = j-TOSN, volume = "4", number = "4", pages = "22:1--22:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387668", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a critical evaluation of the first known implementation of elliptic curve cryptography over F$_{2 {\em p\/}}$ for sensor networks based on the 8-bit, 7.3828-MHz MICA2 mote. We offer, along the way, a primer for those interested in the field of cryptography for sensor networks. We discuss, in particular, the decisions underlying our design and alternatives thereto. And we elaborate on the methodologies underlying our evaluation.\par Through instrumentation of UC Berkeley's TinySec module, we argue that, although symmetric cryptography has been tractable in this domain for some time, there has remained a need, unfulfilled until recently, for an efficient, secure mechanism for distribution of secret keys among nodes. Although public-key infrastructure has been thought impractical, we show, through analysis of our original implementation for TinyOS of point multiplication on elliptic curves, that public-key infrastructure is indeed viable for TinySec keys' distribution, even on the MICA2. We demonstrate that public keys can be generated within 34 seconds and that shared secrets can be distributed among nodes in a sensor network within the same time, using just over 1 kilobyte of SRAM and 34 kilobytes of ROM. We demonstrate that communication costs are minimal, with only 2 packets required for transmission of a public key among nodes. We make available all of our source code for other researchers to download and use. And we discuss recent results based on our work that corroborate and improve upon our conclusions.", acknowledgement = ack-nhfb, articleno = "22", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Diffie--Hellman; DLP; ECC; ECDLP; elliptic curve cryptography; MICA2; motes; sensor networks; TinyOS; TinySec", } @Article{Song:2008:LPP, author = "Hui Song and Sencun Zhu and Wensheng Zhang and Guohong Cao", title = "Least privilege and privilege deprivation: {Toward} tolerating mobile sink compromises in wireless sensor networks", journal = j-TOSN, volume = "4", number = "4", pages = "23:1--23:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387669", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Mobile sinks are needed in many sensor network applications for efficient data collection, data querying, localized sensor reprogramming, identifying, and revoking compromised sensors, and other network maintenance. Employing mobile sinks however raises a new security challenge: if a mobile sink is given too many privileges, it will become very attractive for attack and compromise. Using a compromised mobile sink, an adversary may easily bring down or even take over the sensor network. Thus, security mechanisms that can tolerate mobile sink compromises are essential. In this article, based on the {\em principle of least privilege}, we first propose an efficient scheme to restrict the privilege of a mobile sink without impeding its ability to carry out any authorized operations for an assigned task. In addition, we present an extension to allow conditional trajectory change due to unexpected events. To further reduce the possible damage caused by a compromised mobile sink, we propose efficient message forwarding schemes for deleting the privilege assigned to a compromised mobile sink immediately after its compromise has been detected. Through detailed analysis, simulation, and real implementation, we show that our schemes are secure and efficient, and are highly practical for sensor networks consisting of the current generation of sensors.", acknowledgement = ack-nhfb, articleno = "23", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "key management; key revocation; Least privilege; pairwise key; sensor networks", } @Article{Pattem:2008:ISC, author = "Sundeep Pattem and Bhaskar Krishnamachari and Ramesh Govindan", title = "The impact of spatial correlation on routing with compression in wireless sensor networks", journal = j-TOSN, volume = "4", number = "4", pages = "24:1--24:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387670", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The efficacy of data aggregation in sensor networks is a function of the degree of spatial correlation in the sensed phenomenon. The recent literature has examined a variety of schemes that achieve greater data aggregation by routing data with regard to the underlying spatial correlation. A well known conclusion from these papers is that the nature of optimal routing with compression depends on the correlation level. In this article we show the existence of a simple, practical, and static correlation-unaware clustering scheme that satisfies a min-max near-optimality condition. The implication for system design is that a static correlation-unaware scheme can perform as well as sophisticated adaptive schemes for joint routing and compression.", acknowledgement = ack-nhfb, articleno = "24", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "analytical modeling; correlated data gathering; Sensor networks", } @Article{Edara:2008:ANP, author = "Pavan Edara and Ashwin Limaye and Krithi Ramamritham", title = "Asynchronous in-network prediction: {Efficient} aggregation in sensor networks", journal = j-TOSN, volume = "4", number = "4", pages = "25:1--25:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387671", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Given a sensor network and aggregate queries over the values sensed by subsets of nodes in the network, how do we ensure that high quality results are served for the maximum possible time? The issues underlying this question relate to the fidelity of query results and lifetime of the network. To maximize both, we propose a novel technique called {\em asynchronous in-network prediction\/} incorporating two computationally efficient methods for in-network prediction of partial aggregate values. These values are propagated via a tree whose construction is cognizant of (a) the coherency requirements associated with the queries, (b) the remaining energy at the sensors, and (c) the communication and message processing delays. Finally, we exploit {\em in-network filtering\/} and {\em in-network aggregation\/} to reduce the energy consumption of the nodes in the network. Experimental results over real world data support our claim that, for aggregate queries with associated coherency requirements, a prediction-based, asynchronous scheme provides higher quality results for a longer amount of time than a synchronous scheme. Also, whereas aggregate dissemination techniques proposed so far for sensor networks appear to have to trade-off quality of data for energy efficiency, we demonstrate that this is not always necessary.", acknowledgement = ack-nhfb, articleno = "25", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Aggregation; coherency; energy efficient; prediction; query processing", } @Article{Yap:2008:MWA, author = "Kok-KIONG Yap and Vikram Srinivasan and Mehul Motani", title = "{MAX}: {Wide} area human-centric search of the physical world", journal = j-TOSN, volume = "4", number = "4", pages = "26:1--26:??", month = aug, year = "2008", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1387663.1387672", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We propose MAX, a system that facilitates human-centric search of the physical world. Instead of organizing objects a priori, it allows humans to search for and locate them as needed. Designed for the following objectives: (i) human-centric operation, (ii) privacy, and (iii) efficient searching of any tagged object, MAX provides location information in a form natural to humans, that is, with reference to identifiable landmarks (such as, ``on the dining table'') rather than precise coordinates. In the system, all physical objects --- from documents to clothing --- can be tagged, users then locate objects using an intuitive search interface. To make searching efficient, MAX adopts a hierarchical architecture consisting of tags (bound to objects), substations (bound to landmarks), and base-stations (bound to localities). Tags can be marked as either public or private, with private tags searchable only by the owner. MAX also provides for privacy of physical spaces. It requires minimal initial configuration, and is robust to reconfiguration of the physical space. We also present a methodology to design energy-optimal and delay-optimal query protocols for a variety of device choices, this optimizes system performance, and affords insight into the appropriate actions for various scenarios. We have implemented a simple prototype of MAX, demonstrating the feasibility of the system for human-centric search over several locations across a wide area. We contend that a MAX-like search system will enable sharing (e.g., books on a college campus) and trading (e.g., buying and selling used books) of physical resources, and will be the engine for a host of new applications.", acknowledgement = ack-nhfb, articleno = "26", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Human-centric; landmark-based localization; physical world; search", } @Article{Li:2009:CNL, author = "Li Li and Thomas Kunz", title = "Cooperative node localization using nonlinear data projection", journal = j-TOSN, volume = "5", number = "1", pages = "1:1--1:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464421", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Cooperative node localization schemes that employ nonlinear data reduction often deliver higher network node position accuracy compared to many other approaches. Other advantages of such algorithms are that they require only a minimum number of anchor nodes (if we require absolute locations) and that they can be applied under both range-based and range-free conditions. This article presents a novel cooperative node localization scheme, applying an efficient neural network nonlinear projection method called Curvilinear Component Analysis (CCA). A thorough comparative performance study of the proposed scheme in different mission-critical operational network scenarios is conducted. Compared with another leading cooperative node localization algorithm, MDS-MAP, which employs Multi-Dimensional Scaling (MDS), the proposed CCA-MAP approach significantly improves position estimate accuracy in many of the scenarios. We also propose a new local edge model for range-free distance matrix approximation that considerably enhances the performance for both MDS-MAP and CCA-MAP in certain irregular network configurations which are very challenging for node positioning.", acknowledgement = ack-nhfb, articleno = "1", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "curvilinear component analysis; Localization; multi-dimensional scaling; nonlinear mapping; simulations", } @Article{Chen:2009:SRP, author = "Yingying Chen and Konstantinos Kleisouris and Xiaoyan Li and Wade Trappe and Richard P. Martin", title = "A security and robustness performance analysis of localization algorithms to signal strength attacks", journal = j-TOSN, volume = "5", number = "1", pages = "2:1--2:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464422", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Recently, it has been noted that localization algorithms that use signal strength are susceptible to noncryptographic attacks, which consequently threatens their viability for sensor applications. In this work, we examine several localization algorithms and evaluate their robustness to attacks where an adversary attenuates or amplifies the signal strength at one or more landmarks. We study both point-based and area-based methods that employ received signal strength for localization, and propose several performance metrics that quantify the estimator's precision, bias, and error, including H{\"o}lder metrics, which quantify the variability in position space for a given variability in signal strength space. We then conduct a trace-driven evaluation of a set of representative algorithms, where we measured their performance as we applied attacks on real data from two different buildings. We found the median error degraded gracefully, with a linear response as a function of the attack strength. We also found that area-based algorithms experienced a decrease and a spatial-shift in the returned area under attack, implying that precision increases though bias is introduced for these schemes. Additionally, we observed similar values for the average H{\"o}lder metric across most of the algorithms, thereby providing strong experimental evidence that nearly all the algorithms have similar average responses to signal strength attacks with the exception of the Bayesian Networks algorithm.", acknowledgement = ack-nhfb, articleno = "2", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Localization; robustness; sensor networks; signal strength attacks; susceptibility", } @Article{Jung:2009:SNL, author = "Deokwoo Jung and Thiago Teixeira and Andreas Savvides", title = "Sensor node lifetime analysis: {Models} and tools", journal = j-TOSN, volume = "5", number = "1", pages = "3:1--3:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464423", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article presents two lifetime models that describe two of the most common modes of operation of sensor nodes today, trigger-driven and duty-cycle driven. The models use a set of hardware parameters such as power consumption per task, state transition overheads, and communication cost to compute a node's average lifetime for a given event arrival rate. Through comparison of the two models and a case study from a real camera sensor node design we show how the models can be applied to drive architectural decisions, compute energy budgets and duty-cycles, and to preform side-by-side comparison of different platforms. Based on our models we present a MATLAB Wireless Sensor Node Platform Lifetime Prediction and Simulation Package (MATSNL). This demonstrates the use of the models using sample applications drawn from existing sensor node measurements.", acknowledgement = ack-nhfb, articleno = "3", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "duty cycle; event arrival rate; Node lifetime; schedule-driven node; semi-Markov Chain; trigger driven node", } @Article{Hu:2009:DEH, author = "Wen Hu and Nirupama Bulusu and Chun Tung Chou and Sanjay Jha and Andrew Taylor and Van Nghia Tran", title = "Design and evaluation of a hybrid sensor network for cane toad monitoring", journal = j-TOSN, volume = "5", number = "1", pages = "4:1--4:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464424", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article investigates a wireless acoustic sensor network application --- monitoring amphibian populations in the monsoonal woodlands of northern Australia. Our goal is to use automatic recognition of animal vocalizations to census the populations of native frogs and the invasive introduced species, the cane toad. This is a challenging application because it requires high frequency acoustic sampling, complex signal processing, wide area sensing coverage and long-lived unattended operation.\par We set up two prototypes of wireless sensor networks that recognize vocalizations of up to ninth frog species found in northern Australia. Our first prototype consists of only resource-rich Stargate devices. Our second prototype is more complex and consists of a hybrid mixture of Stargates and inexpensive, resource-poor Mica2 devices operating in concert. In the hybrid system, the Mica2s are used to collect acoustic samples, and expand the sensor network coverage. The Stargates are used for resource-intensive tasks such as fast Fourier transforms (FFTs) and machine learning.\par The hybrid system incorporates four algorithms designed to account for the sampling, processing, energy, and communication bottlenecks of the Mica2s (1) high frequency sampling, (2) thresholding and noise reduction, to reduce data transmission by up to 90\%, (3) sampling scheduling, which exploits the sensor network redundancy to increase the effective sample processing rate, and (4) harvesting-aware energy management, which exploits sensor energy harvesting capabilities to extend the system lifetime.\par Our evaluation shows the performance of our systems over a range of scenarios, and demonstrate that the feasibility and benefits of a hybrid systems approach justify the additional system complexity.", acknowledgement = ack-nhfb, articleno = "4", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "acoustic; application; high frequency sampling; hybrid; Sensor networks; solar energy", } @Article{Dietrich:2009:LWS, author = "Isabel Dietrich and Falko Dressler", title = "On the lifetime of wireless sensor networks", journal = j-TOSN, volume = "5", number = "1", pages = "5:1--5:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464425", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Network lifetime has become the key characteristic for evaluating sensor networks in an application-specific way. Especially the availability of nodes, the sensor coverage, and the connectivity have been included in discussions on network lifetime. Even quality of service measures can be reduced to lifetime considerations. A great number of algorithms and methods were proposed to increase the lifetime of a sensor network --- while their evaluations were always based on a particular definition of network lifetime. Motivated by the great differences in existing definitions of sensor network lifetime that are used in relevant publications, we reviewed the state of the art in lifetime definitions, their differences, advantages, and limitations. This survey was the starting point for our work towards a generic definition of sensor network lifetime for use in analytic evaluations as well as in simulation models --- focusing on a formal and concise definition of accumulated network lifetime and total network lifetime. Our definition incorporates the components of existing lifetime definitions, and introduces some additional measures. One new concept is the ability to express the service disruption tolerance of a network. Another new concept is the notion of time-integration: in many cases, it is sufficient if a requirement is fulfilled over a certain period of time, instead of at every point in time. In addition, we combine coverage and connectivity to form a single requirement called connected coverage. We show that connected coverage is different from requiring noncombined coverage and connectivity. Finally, our definition also supports the concept of graceful degradation by providing means of estimating the degree of compliance with the application requirements. We demonstrate the applicability of our definition based on the surveyed lifetime definitions as well as using some example scenarios to explain the various aspects influencing sensor network lifetime.", acknowledgement = ack-nhfb, articleno = "5", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "connectivity; coverage; lifetime; longevity; Sensor networks", } @Article{Law:2009:EEL, author = "Yee Wei Law and Marimuthu Palaniswami and Lodewijk Van Hoesel and Jeroen Doumen and Pieter Hartel and Paul Havinga", title = "Energy-efficient link-layer jamming attacks against wireless sensor network {MAC} protocols", journal = j-TOSN, volume = "5", number = "1", pages = "6:1--6:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464426", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "A typical wireless sensor node has little protection against radio jamming. The situation becomes worse if energy-efficient jamming can be achieved by exploiting knowledge of the data link layer. Encrypting the packets may help to prevent the jammer from taking actions based on the content of the packets, but the temporal arrangement of the packets induced by the nature of the protocol might unravel patterns that the jammer can take advantage of, even when the packets are encrypted.\par By looking at the packet interarrival times in three representative MAC protocols, S-MAC, LMAC, and B-MAC, we derive several jamming attacks that allow the jammer to jam S-MAC, LMAC, and B-MAC energy efficiently. The jamming attacks are based on realistic assumptions. The algorithms are described in detail and simulated. The effectiveness and efficiency of the attacks are examined. In addition, we validate our simulation model by comparing its results with measurements obtained from actual implementation on our sensor node prototypes. We show that it takes little effort to implement such effective jammers, making them a realistic threat.\par Careful analysis of other protocols belonging to the respective categories of S-MAC, LMAC, and B-MAC reveals that those protocols are, to some extent, also susceptible to our attacks. The result of this investigation provides new insights into the security considerations of MAC protocols.", acknowledgement = ack-nhfb, articleno = "6", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "clustering; denial-of-service attacks; expectation maximization; jamming; MAC protocols", } @Article{Bruck:2009:LRS, author = "Jehoshua Bruck and Jie Gao and Anxiao (Andrew) Jiang", title = "Localization and routing in sensor networks by local angle information", journal = j-TOSN, volume = "5", number = "1", pages = "7:1--7:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464427", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Location information is useful both for network organization and for sensor data integrity. In this article, we study the anchor-free 2D localization problem by using local angle measurements. We prove that given a unit disk graph and the angles between adjacent edges, it is NP-hard to find a valid embedding in the plane such that neighboring nodes are within distance 1 from each other and non-neighboring nodes are at least distance \sqrt 2/2 away. Despite the negative results, however, we can find a planar spanner of a unit disk graph by using only local angles. The planar spanner can be used to generate a set of virtual coordinates that enable efficient and local routing schemes such as geographical routing or approximate shortest path routing. We also proposed a practical anchor-free embedding scheme by solving a linear program. We show by simulation that it gives both a good local embedding, with neighboring nodes embedded close and non-neighboring nodes far away, and a satisfactory global view such that geographical routing and approximate shortest path routing on the embedded graph are almost identical to those on the original (true) embedding.", acknowledgement = ack-nhfb, articleno = "7", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "embedding; geographical routing; localization; planar spanner subgraph; Sensor networks; wireless networks", } @Article{Zhou:2009:VRC, author = "Zongheng Zhou and Samir R. Das and Himanshu Gupta", title = "Variable radii connected sensor cover in sensor networks", journal = j-TOSN, volume = "5", number = "1", pages = "8:1--8:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464428", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "One of the useful approaches to exploit redundancy in a sensor network is to keep active only a small subset of sensors that are sufficient to cover the region required to be monitored. The set of active sensors should also form a connected communication graph, so that they can autonomously respond to application queries and/or tasks. Such a set of active sensors is known as a connected sensor cover, and the problem of selecting a minimum connected sensor cover has been well studied when the transmission radius and sensing radius of each sensor is fixed. In this article, we address the problem of selecting a minimum energy-cost connected sensor cover, when each sensor node can vary its sensing and transmission radius; larger sensing or transmission radius entails higher energy cost.\par For the aforesaid problem, we design various centralized and distributed algorithms, and compare their performance through extensive experiments. One of the designed centralized algorithms (called CGA) is shown to perform within an {\em O\/} (log {\em n\/}) factor of the optimal solution, where {\em n\/} is the size of the network. We have also designed a localized algorithm based on Voronoi diagrams which is empirically shown to perform very close to CGA and, due to its communication-efficiency, results in significantly prolonging the network lifetime. We also extend the aforementioned algorithms to incorporate fault tolerance. In particular, we show how to extend the algorithms to address the minimum energy-cost connected sensor {\em k\/} -cover problem, in which every point in the query region needs to be covered by at least {\em k\/} distinct active sensors. The CGA preserves the approximation bound in this case. We also propose a localized topology control scheme to preserve {\em k\/} -connectivity, and use it to extend the Voronoi-based approach to computing a minimum energy-cost {\em k\/}$_1$ -connected {\em k\/}$_2$ -cover. We study the performance of our proposed algorithms through extensive simulations.", acknowledgement = ack-nhfb, articleno = "8", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "connectivity; coverage; energy conservation; sensor networks; Topology control", } @Article{Vicaire:2009:ALT, author = "Pascal Vicaire and Tian He and Qing Cao and Ting Yan and Gang Zhou and Lin Gu and Liqian Luo and Radu Stoleru and John A. Stankovic and Tarek F. Abdelzaher", title = "Achieving long-term surveillance in {VigilNet}", journal = j-TOSN, volume = "5", number = "1", pages = "9:1--9:??", month = feb, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1464420.1464429", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:22:49 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Energy efficiency is a fundamental issue for outdoor sensor network systems. This article presents the design and implementation of multidimensional power management strategies in VigilNet, a major recent effort to support long-term surveillance using power-constrained sensor devices. A novel tripwire service is integrated with an effective sentry and duty cycle scheduling in order to increase the system lifetime, collaboratively. The tripwire service partitions a network into distinct, nonoverlapping sections and allows each section to be scheduled independently. Sentry scheduling selects a subset of nodes, the sentries, which are turned on while the remaining nodes save energy. Duty cycle scheduling allows the active sentries themselves to be turned on and off, further lowering the average power draw. The multidimensional power management strategies proposed in this article were fully implemented within a real sensor network system using the XSM platform. We evaluate key system parameters using a network of 200 XSM nodes in an outdoor environment, and an analytical probabilistic model. We evaluate network lifetime using a simulation of a 10,000-node network that uses measured XSM power values. These evaluations demonstrate the effectiveness of our integrated approach and identify a set of lessons and guidelines, useful for the future development of energy-efficient sensor systems. One of the key results indicates that the combination of the three presented power management techniques is able to increase the lifetime of a realistic network from 4 days to 200 days.", acknowledgement = ack-nhfb, articleno = "9", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "and longevity; Applications of sensor and actuator networks; connectivity; coverage; energy and resource management; energy conservation; network protocols; sensor networks; tracking", } @Article{Li:2009:UCM, author = "Mo Li and Yunhao Liu", title = "Underground coal mine monitoring with wireless sensor networks", journal = j-TOSN, volume = "5", number = "2", pages = "10:1--10:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498916", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Environment monitoring in coal mines is an important application of wireless sensor networks (WSNs) that has commercial potential. We discuss the design of a Structure-Aware Self-Adaptive WSN system, SASA. By regulating the mesh sensor network deployment and formulating a collaborative mechanism based on a regular beacon strategy, SASA is able to rapidly detect structure variations caused by underground collapses. We further develop a sound and robust mechanism for efficiently handling queries under instable circumstances. A prototype is deployed with 27 mica2 motes in a real coal mine. We present our implementation experiences as well as the experimental results. To better evaluate the scalability and reliability of SASA, we also conduct a large-scale trace-driven simulation based on real data collected from the experiments.", acknowledgement = ack-nhfb, articleno = "10", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "coal mine; structure monitoring; underground; Wireless sensor networks", } @Article{Lim:2009:DLA, author = "Hyuk Lim and Jennifer C. Hou", title = "Distributed localization for anisotropic sensor networks", journal = j-TOSN, volume = "5", number = "2", pages = "11:1--11:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498917", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article, we address the issue of localization in anisotropic sensor networks. Anisotropic networks differ from isotropic networks in that they possess properties that vary according to the direction of measurement. Anisotropic characteristics result from various factors such as the geographic shape of the region (nonconvex region), different node densities, irregular radio patterns, and anisotropic terrain conditions. In order to characterize anisotropic features, we devise a linear mapping method that projects one embedding space built upon proximity measures into geographic distance space by using the truncated singular value decomposition (SVD) pseudo-inverse technique. This transformation retains as much topological information as possible and reduces the effect of measurement noise on the estimates of geographic distances. We show via simulation that the proposed localization method outperforms DV-hop, DV-distance, and MDS-MAP, and makes robust and accurate estimates of sensor locations in both isotropic and anisotropic sensor networks.", acknowledgement = ack-nhfb, articleno = "11", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Localization; sensor networks; singular value decomposition", } @Article{Zhu:2009:SSF, author = "Xianjin Zhu and Rik Sarkar and Jie Gao", title = "Segmenting a sensor field: {Algorithms} and applications in network design", journal = j-TOSN, volume = "5", number = "2", pages = "12:1--12:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498918", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The diversity of the deployment settings of sensor networks is naturally inherited from the diversity of geographical features of the embedded environment, and greatly influences network design. Many sensor network protocols in the literature implicitly assume that sensor nodes are deployed inside a simple geometric region, without considering possible obstacles and holes in the deployment environment. When the real deployment setting deviates from that, we often observe degraded performance. Thus, it is highly desirable to have a generic approach to handle sensor fields with complex shapes. In this article, we propose a segmentation algorithm that partitions an irregular sensor field into nicely shaped pieces such that algorithms and protocols that assume a nice sensor field can be applied inside each piece. Across the segments, problem dependent structures specify how the segments and data collected in these segments are integrated. Our segmentation algorithm does not require any extra knowledge (e.g., sensor locations) and only uses network connectivity information. This unified spatial-partitioning approach makes the protocol design become flexible and independent of deployment specifics. Existing protocols are still reusable with segmentation, and the development of new topology-adaptive protocols becomes much easier. We verified the correctness of the algorithm on various topologies and evaluated the performance improvements by integrating shape segmentation with several fundamental problems in network design.", acknowledgement = ack-nhfb, articleno = "12", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "flow complex; network design; sensor networks; Shape segmentation; topology-adaptive protocols", } @Article{Manulis:2009:SMF, author = "Mark Manulis and J{\"o}rg Schwenk", title = "Security model and framework for information aggregation in sensor networks", journal = j-TOSN, volume = "5", number = "2", pages = "13:1--13:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498919", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Information aggregation is an important operation in wireless sensor networks (WSNs) executed for the purpose of monitoring and reporting environmental data. Due to the performance constraints of sensor nodes the in-network form of the aggregation is especially attractive since it allows saving expensive resources during frequent network queries. Easy accessibility of networks and nodes and almost no physical protection against corruptions raise high security challenges. Protection against attacks aiming to falsify the aggregated result is considered to be of prime importance.\par In this article we design the first general framework for secure information aggregation in WSNs focusing on scenarios where aggregation is performed by one of its nodes. The framework achieves security against node corruptions and is based solely on the symmetric cryptographic primitives that are more suitable for WSNs in terms of efficiency. We analyze performance of the framework and unlike many previous approaches increase confidence in it by a rigorous proof of security within the specially designed {\em formal security model.\/}", acknowledgement = ack-nhfb, articleno = "13", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Aggregation; framework; in-network processing; provable security; wireless sensor network", } @Article{Huang:2009:SSF, author = "Pei Huang and Hongyang Chen and Guoliang Xing and Yongdong Tan", title = "{SGF}: {A} state-free gradient-based forwarding protocol for wireless sensor networks", journal = j-TOSN, volume = "5", number = "2", pages = "14:1--14:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498920", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Limitation on available resources is a major challenge in wireless sensor networks. Due to high rates of unexpected node/link failures, robust data delivery through multiple hops also becomes a critical issue. In this article we present a state-free gradient-based forwarding (SGF) protocol to address these challenges. Nodes running SGF do not maintain states of neighbors or network topology and thus can scale to very large networks. Without using routing tables, SGF builds a cost field called {\em gradient\/} that provides each node the direction to forward data. The maintenance of gradient is purely driven by data transmissions and hence incurs little overhead. To adapt to transient channel variations and topology changes, the forwarder of a routing node is selected opportunistically among multiple candidate nodes through a distributed contention process. Simulation results show that SGF achieves significant energy savings and outperforms several existing data forwarding protocols in terms of packet delivery ratio and end-to-end delay.", acknowledgement = ack-nhfb, articleno = "14", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy conservation; gradient; power control; robust performance; Sensor networks; state-free", } @Article{Kulathumani:2009:TDS, author = "Vinodkrishnan Kulathumani and Anish Arora and Mukundan Sridharan and Murat Demirbas", title = "{Trail}: {A} distance-sensitive sensor network service for distributed object tracking", journal = j-TOSN, volume = "5", number = "2", pages = "15:1--15:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498921", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Distributed observation and control of mobile objects via static wireless sensors demands timely information in a {\em distance-sensitive\/} manner: Information about closer objects is required more often and more quickly than that of farther objects. In this article, we present a wireless sensor network protocol, Trail, that supports distance-sensitive tracking of mobile objects for in-network subscribers upon demand. Trail achieves a find time that is linear in the distance from a subscriber to an object, via a distributed data structure that is updated only locally when the object moves. Notably, Trail does not partition the network into a hierarchy of clusters and clusterheads, and as a result Trail has lower maintenance costs, is more locally fault tolerant, and it better utilizes the network in terms of load balancing and minimizing the size of the data structure needed for tracking. Moreover, Trail is reliable and energy efficient, despite the network dynamics that are typical of wireless sensor networks. Trail can be refined by tuning certain parameters, thereby yielding a family of protocols that are suited for different application settings such as rate of queries, rate of updates, and network size. We evaluate the performance of Trail by analysis, simulations in a 90 \times 90 sensor network, and experiments on 105 Mica2 nodes in the context of a pursuer-evader control application.", acknowledgement = ack-nhfb, articleno = "15", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "applications of sensor actuator networks; data storage and query; Distributed tracking; energy efficiency; fault tolerance; network protocol; scalability", } @Article{Kulkarni:2009:EEM, author = "Sandeep Kulkarni and Limin Wang", title = "Energy-efficient multihop reprogramming for sensor networks", journal = j-TOSN, volume = "5", number = "2", pages = "16:1--16:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498922", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Reprogramming of sensor networks is an important and challenging problem, as it is often necessary to reprogram the sensors in place. In this article, we propose MNP, a multihop reprogramming service designed for sensor networks. One of the problems in reprogramming is the issue of message collision. To reduce the problem of collision, we propose a sender selection algorithm that attempts to guarantee that in a given neighborhood there is at most one source transmitting the program at a time. Furthermore, our sender selection is greedy in that it tries to select the sender that is expected to have the most impact. We use pipelining to enable fast data propagation. MNP is energy efficient because it reduces the active radio time of a sensor node by putting the node into ``sleep'' state when its neighbors are transmitting a segment that is not of interest. We call this type of sleep contention sleep. To further reduce the energy consumption, we add noreq sleep, where sensor node goes to sleep if none of its neighbors is interested in receiving the segment it is advertising. We also introduce an optional init sleep to reduce the energy consumption in the initial phase of reprogramming. Finally, we investigate the performance of MNP in different network settings.", acknowledgement = ack-nhfb, articleno = "16", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy efficiency; network reprogramming; Sensor networks", } @Article{Manohar:2009:PCS, author = "Pallavi Manohar and S. Sundhar Ram and D. Manjunath", title = "Path coverage by a sensor field: {The} nonhomogeneous case", journal = j-TOSN, volume = "5", number = "2", pages = "17:1--17:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498923", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We analyze the statistical properties of the coverage of a one-dimensional path induced by a two-dimensional nonhomogeneous random sensor network. Sensor locations form a nonhomogeneous Poisson process and sensing area for the sensors are circles of random independent and identically distributed radii. We first characterize the coverage of a straight-line path by the nonhomogeneous one-dimensional Boolean model. We then obtain an equivalent M$_{{\em t\/}}$ /G$_{{\em t\/}}$ /{\infty}, queue whose busy period statistics is the same as the coverage statistics of the line. We obtain {\em k\/} -coverage statistics for an arbitrary point and a segment on the {\em x\/} -axis. We provide upper and lower bounds on the probability of complete {\em k\/} -coverage of a segment. We illustrate all our results for the case of the sensor deployment having a ``Laplacian'' intensity function.", acknowledgement = ack-nhfb, articleno = "17", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Analysis; k -coverage of paths; nonhomogeneous queues; nonhomogeneous sensor deployment; sensor network", } @Article{Lazos:2009:AET, author = "Loukas Lazos and Radha Poovendran and James A. Ritcey", title = "Analytic evaluation of target detection in heterogeneous wireless sensor networks", journal = j-TOSN, volume = "5", number = "2", pages = "18:1--18:??", month = mar, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1498915.1498924", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:16 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article, we address the problem of target detection in Wireless Sensor Networks (WSNs). We formulate the target detection problem as a line-set intersection problem and use integral geometry to analytically characterize the probability of target detection for both stochastic and deterministic deployments. Compared to previous work, we analyze WSNs where sensors have heterogeneous sensing capabilities. For the stochastic case, we evaluate the probability that the target is detected by at least {\em k\/} sensors and compute the free path until the target is first detected. For the deterministic case, we show an analogy between the target detection problem and the problem of minimizing the average symbol error probability in 2D digital modulation schemes. Motivated by this analogy, we propose a heuristic sensor placement algorithm, called DATE, that makes use of well-known signal constellations for determining good WSN constellations. We also propose a heuristic called CDATE for connected WSN constellations, that yields high target detection probability.", acknowledgement = ack-nhfb, articleno = "18", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "heterogeneous; Target detection; wireless sensor networks", } @Article{Kho:2009:DCA, author = "Johnsen Kho and Alex Rogers and Nicholas R. Jennings", title = "Decentralized control of adaptive sampling in wireless sensor networks", journal = j-TOSN, volume = "5", number = "3", pages = "19:1--19:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525857", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The efficient allocation of the limited energy resources of a wireless sensor network in a way that maximizes the information value of the data collected is a significant research challenge. Within this context, this article concentrates on adaptive sampling as a means of focusing a sensor's energy consumption on obtaining the most important data. Specifically, we develop a principled information metric based upon Fisher information and Gaussian process regression that allows the information content of a sensor's observations to be expressed. We then use this metric to derive three novel decentralized control algorithms for information-based adaptive sampling which represent a trade-off in computational cost and optimality. These algorithms are evaluated in the context of a deployed sensor network in the domain of flood monitoring. The most computationally efficient of the three is shown to increase the value of information gathered by approximately 83\%, 27\%, and 8\% per day compared to benchmarks that sample in a na{\"\i}ve nonadaptive manner, in a uniform nonadaptive manner, and using a state-of-the-art adaptive sampling heuristic (USAC) correspondingly. Moreover, our algorithm collects information whose total value is approximately 75\% of the optimal solution (which requires an exponential, and thus impractical, amount of time to compute).", acknowledgement = ack-nhfb, articleno = "19", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Adaptive sampling algorithm; decentralized decision mechanism; Gaussian process regression; information metric", } @Article{Castelluccia:2009:EPS, author = "Claude Castelluccia and Aldar C-F. Chan and Einar Mykletun and Gene Tsudik", title = "Efficient and provably secure aggregation of encrypted data in wireless sensor networks", journal = j-TOSN, volume = "5", number = "3", pages = "20:1--20:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525858", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Wireless sensor networks (WSNs) are composed of tiny devices with limited computation and battery capacities. For such resource-constrained devices, data transmission is a very energy-consuming operation. To maximize WSN lifetime, it is essential to minimize the number of bits sent and received by each device. One natural approach is to aggregate sensor data along the path from sensors to the sink. Aggregation is especially challenging if end-to-end privacy between sensors and the sink (or aggregate integrity) is required. In this article, we propose a simple and provably secure encryption scheme that allows efficient additive aggregation of encrypted data. Only one modular addition is necessary for ciphertext aggregation. The security of the scheme is based on the indistinguishability property of a pseudorandom function (PRF), a standard cryptographic primitive. We show that aggregation based on this scheme can be used to efficiently compute statistical values, such as mean, variance, and standard deviation of sensed data, while achieving significant bandwidth savings. To protect the integrity of the aggregated data, we construct an end-to-end aggregate authentication scheme that is secure against outsider-only attacks, also based on the indistinguishability property of PRFs.", acknowledgement = ack-nhfb, articleno = "20", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Authentication; cryptography; privacy; pseudorandom functions; secure data aggregation; stream ciphers; wireless sensor networks", } @Article{Cevher:2009:ASN, author = "Volkan Cevher and Lance M. Kaplan", title = "Acoustic sensor network design for position estimation", journal = j-TOSN, volume = "5", number = "3", pages = "21:1--21:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525859", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In this article, we develop tractable mathematical models and approximate solution algorithms for a class of integer optimization problems with probabilistic and deterministic constraints, with applications to the design of distributed sensor networks that have limited connectivity. For a given deployment region size, we calculate the Pareto frontier of the sensor network utility at the desired probabilities for {\em d\/} -connectivity and {\em k\/} -coverage. As a result of our analysis, we determine (1) the number of sensors of different types to deploy from a sensor pool, which offers a cost vs. performance trade-off for each type of sensor, (2) the minimum required radio transmission ranges of the sensors to ensure connectivity, and (3) the lifetime of the sensor network. For generality, we consider randomly deployed sensor networks and formulate constrained optimization technique to obtain the localization performance. The approach is guided and validated using an unattended acoustic sensor network design. Finally, approximations of the complete statistical characterization of the acoustic sensor networks are given, which enable average network performance predictions of any combination of acoustic sensors.", acknowledgement = ack-nhfb, articleno = "21", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Bayesian experimental design; dynamic programming; sensor networks", } @Article{Luo:2009:DIE, author = "Liqian Luo and Qing Cao and Chengdu Huang and Lili Wang and Tarek F. Abdelzaher and John A. Stankovic and Michael Ward", title = "Design, implementation, and evaluation of {EnviroMic}: {A} storage-centric audio sensor network", journal = j-TOSN, volume = "5", number = "3", pages = "22:1--22:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525860", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article presents the design, implementation, and evaluation of {\em EnviroMic}, a low-cost experimental prototype of a novel distributed acoustic monitoring, storage, and trace retrieval system designed for disconnected operation. Our intended use of acoustic monitoring is to study animal populations in the wild. Since a permanent connection to the outside world is not assumed and due to the relatively large size of audio traces, the system must optimally exploit available resources such as energy and network storage capacity. Towards that end, we design, prototype, and evaluate distributed algorithms for coordinating acoustic recording tasks, reducing redundancy of data stored by nearby sensors, filtering out silence, and balancing storage utilization in the network. For experimentation purposes, we implement EnviroMic on a TinyOS-based platform and systematically evaluate its performance through both indoor testbed experiments and an outdoor deployment. Results demonstrate up to a four-fold improvement in effective storage capacity of the network compared to uncoordinated recording.", acknowledgement = ack-nhfb, articleno = "22", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "acoustics; applications; distributed storage; group management; Sensor networks", } @Article{De:2009:DAM, author = "Pradip De and Yonghe Liu and Sajal K. Das", title = "Deployment-aware modeling of node compromise spread in wireless sensor networks using epidemic theory", journal = j-TOSN, volume = "5", number = "3", pages = "23:1--23:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525861", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Motivated by recently surfacing viruses that can spread over the air interfaces, in this article, we investigate the potentially disastrous threat of node compromise spreading in wireless sensor networks. We assume such a compromise originating from a single infected node, can propagate to other sensor nodes via communication and pre-established mutual trust. We focus on the possible epidemic breakout of such propagations where the whole network may fall victim to the attack. Using epidemic theory, we model and analyze this spreading process and identify key factors determining potential outbreaks. In particular, we perform our study on random graphs precisely constructed according to the parameters of the network, such as distance, key sharing constrained communication and node recovery, thereby reflecting the true characteristics therein. Moreover, a comparative study of the epidemic propagation is performed based on the effects of two types of sensor deployment strategies, viz., uniform random and group-based deployment. The analytical results provide deep insights in designing potential defense strategies against this threat. Furthermore, through extensive simulations, we validate the model and perform investigations on the system dynamics. Our analysis and simulation results indicate that the uniform random deployment is more vulnerable to an epidemic outbreak than the group based deployment strategy.", acknowledgement = ack-nhfb, articleno = "23", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "epidemic theory; group-based deployment; random graph; Random key predistribution; sensor networks", } @Article{Maierbacher:2009:LCC, author = "Gerhard Maierbacher and Jo{\~a}o Barros", title = "Low-complexity coding and source-optimized clustering for large-scale sensor networks", journal = j-TOSN, volume = "5", number = "3", pages = "24:1--24:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525862", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We consider the distributed source coding problem in which correlated data picked up by scattered sensors has to be encoded separately and transmitted to a common receiver, subject to a rate-distortion constraint. Although near-to-optimal solutions based on Turbo and LDPC codes exist for this problem, in most cases the proposed techniques do not scale to networks of hundreds of sensors. We present a scalable solution based on the following key elements: (a) distortion-optimized index assignments for low-complexity distributed quantization, (b) source-optimized hierarchical clustering based on the Kullback--Leibler distance and (c) sum-product decoding on specific factor graphs exploiting the correlation of the data.", acknowledgement = ack-nhfb, articleno = "24", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Distributed source coding; hierarchical clustering; quantizer design; source and correlation models", } @Article{Ni:2009:SND, author = "Kevin Ni and Nithya Ramanathan and Mohamed Nabil Hajj Chehade and Laura Balzano and Sheela Nair and Sadaf Zahedi and Eddie Kohler and Greg Pottie and Mark Hansen and Mani Srivastava", title = "Sensor network data fault types", journal = j-TOSN, volume = "5", number = "3", pages = "25:1--25:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525863", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This tutorial presents a detailed study of sensor faults that occur in deployed sensor networks and a systematic approach to model these faults. We begin by reviewing the fault detection literature for sensor networks. We draw from current literature, our own experience, and data collected from scientific deployments to develop a set of commonly used features useful in detecting and diagnosing sensor faults. We use this feature set to systematically define commonly observed faults, and provide examples of each of these faults from sensor data collected at recent deployments.", acknowledgement = ack-nhfb, articleno = "25", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Data integrity; fault; sensor network", } @Article{Wettergren:2009:OPD, author = "Thomas A. Wettergren and Russell Costa", title = "Optimal placement of distributed sensors against moving targets", journal = j-TOSN, volume = "5", number = "3", pages = "26:1--26:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525864", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article addresses the problem of deploying a sparse network of sensors for surveillance of moving targets. The sensor networks of interest consist of sensors which perform independent binary detection on a target, and report detections to a central node for fusion. An optimization framework is developed for placement of sensors within a bounded search region, given sensor performance characteristics, prior information on anticipated target characteristics, and a distributed detection criteria. Individual sensor performance is represented parametrically as are priors on target dynamics. Several numerical examples are included that illustrate the utility of the optimization approach.", acknowledgement = ack-nhfb, articleno = "26", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "coverage; optimization; Sensor networks", } @Article{Rajamani:2009:IGA, author = "Vasanth Rajamani and Sanem Kabadayi and Christine Julien", title = "An interrelational grouping abstraction for heterogeneous sensors", journal = j-TOSN, volume = "5", number = "3", pages = "27:1--27:??", month = may, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1525856.1525865", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:23:43 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In wireless sensor network applications, the potential to use cooperation to resolve user queries remains largely untapped. Efficiently answering a user's questions requires identifying the correct set of nodes that can answer the question and enabling coordination between them. In this article, we propose a {\em query domain\/} abstraction that allows an application to dynamically specify the nodes best suited to answering a particular query. Selecting the ideal set of heterogeneous sensors entails answering two fundamental questions --- {\em how\/} are the selected sensors related to one another, and {\em where\/} should the resulting sensor coalition be located. We introduce two abstractions, the {\em proximity function\/} and the {\em reference function}, to precisely specify each of these concerns within a query. All nodes in the query domain must satisfy any provided proximity function, a user-defined function that constrains the relative relationship among the group of nodes (e.g., based on a property of the network or physical environment or on logical properties of the nodes). The selected set of nodes must also satisfy any provided reference function, a mechanism to scope the location of the query domain to a specified area of interest (e.g., within a certain distance from a specified reference point). In this article, we model these abstractions and present a set of protocols that accomplish this task with varying degrees of correctness. We evaluate their performance through simulation and highlight the tradeoffs between protocol overhead and correctness.", acknowledgement = ack-nhfb, articleno = "27", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "clustering; energy-efficiency; Heterogeneous sensor networks; proximity functions; querying abstraction", } @Article{Kamat:2009:TPW, author = "Pandurang Kamat and Wenyuan Xu and Wade Trappe and Yanyong Zhang", title = "Temporal privacy in wireless sensor networks: {Theory} and practice", journal = j-TOSN, volume = "5", number = "4", pages = "28:1--28:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614380", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Although the content of sensor messages describing ``events of interest'' may be encrypted to provide confidentiality, the context surrounding these events may also be sensitive and therefore should be protected from eavesdroppers. An adversary armed with knowledge of the network deployment, routing algorithms, and the base-station (data sink) location can infer the temporal patterns of interesting events by merely monitoring the arrival of packets at the sink, thereby allowing the adversary to remotely track the spatio-temporal evolution of a sensed event. In this paper we introduce the problem of temporal privacy for delay-tolerant sensor networks, and propose adaptive buffering at intermediate nodes on the source-sink routing path to obfuscate temporal information from the adversary. We first present the effect of buffering on temporal privacy using an information-theoretic formulation, and then examine the effect that delaying packets has on buffer occupancy. We observe that temporal privacy and efficient buffer utilization are contrary objectives, and then present an adaptive buffering strategy that effectively manages these tradeoffs. Finally, we evaluate our privacy enhancement strategies using simulations, where privacy is quantified in terms of the adversary's mean square error.", acknowledgement = ack-nhfb, articleno = "28", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "privacy; security; Sensor networks; temporal privacy", } @Article{Liu:2009:CEE, author = "Sha Liu and Kai-Wei Fan and Prasun Sinha", title = "{CMAC}: {An} energy-efficient {MAC} layer protocol using convergent packet forwarding for wireless sensor networks", journal = j-TOSN, volume = "5", number = "4", pages = "29:1--29:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614381", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Low duty cycle operation is critical to conserve energy in wireless sensor networks. Traditional wake-up scheduling approaches either require periodic synchronization messages or incur high packet delivery latency due to the lack of any synchronization. To simultaneously achieve the seemingly contradictory goals of energy efficiency and low latency, the design of a new low duty-cycle MAC layer protocol called Convergent MAC (CMAC) is presented. CMAC avoids synchronization overhead while supporting low latency. By using zero communication when there is no traffic, CMAC allows sensor nodes to operate at very low duty cycles. When carrying traffic, CMAC first uses anycast to wake up forwarding nodes, and then converges gradually from route-suboptimal anycast with unsynchronized duty cycling to route-optimal unicast with synchronized scheduling. To validate our design and provide a usable module for the research community, CMAC has been implemented in TinyOS and evaluated on the Kansei testbed consisting of 105 XSM nodes. The results show that CMAC at 1\% duty cycle significantly outperforms BMAC at 1\% in terms of latency, throughput and energy efficiency. The performance of CMAC is also compared with other protocols using simulations, in which the results show for 1\% and lower duty cycles, CMAC exhibits similar throughput and latency as CSMA/CA using much less energy, and outperforms SMAC, DMAC and GeRaF in almost all aspects.", acknowledgement = ack-nhfb, articleno = "29", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Aggressive RTS; anycast; CMAC; convergent forwarding; MAC; wireless sensor networks", } @Article{Shrivastava:2009:TTB, author = "Nisheeth Shrivastava and Raghuraman Mudumbai and Upamanyu Madhow and Subhash Suri", title = "Target tracking with binary proximity sensors", journal = j-TOSN, volume = "5", number = "4", pages = "30:1--30:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614382", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We explore fundamental performance limits of tracking a target in a two-dimensional field of binary proximity sensors, and design algorithms that attain those limits while providing minimal descriptions of the estimated target trajectory. Using geometric and probabilistic analysis of an idealized model, we prove that the achievable spatial resolution in localizing a target's trajectory is of the order of 1/{\rho} {\em R}, where {\em R\/} is the sensing radius and {\rho} is the sensor density per unit area. We provide a geometric algorithm for computing an economical (in descriptive complexity) piecewise linear path that approximates the trajectory within this fundamental limit of accuracy. We employ analogies between binary sensing and sampling theory to contend that only a ``lowpass'' approximation of the trajectory is attainable, and explore the implications of this observation for estimating the target's velocity. We also consider nonideal sensing, employing particle filters to average over noisy sensor observations, and geometric postprocessing of the particle filter output to provide an economical piecewise linear description of the trajectory. In addition to simulation results validating our approaches for both idealized and nonideal sensing, we report on lab-scale experiments using motes with acoustic sensors.", acknowledgement = ack-nhfb, articleno = "30", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "binary sensing; distributed algorithms; fundamental limits; Sensor networks; target tracking", } @Article{Lederer:2009:CBL, author = "Sol Lederer and Yue Wang and Jie Gao", title = "Connectivity-based localization of large-scale sensor networks with complex shape", journal = j-TOSN, volume = "5", number = "4", pages = "31:1--31:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614383", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We study the problem of localizing a large sensor network having a complex shape, possibly with holes. A major challenge with respect to such networks is to figure out the correct network layout, that is, avoid global flips where a part of the network folds on top of another. Our algorithm first selects landmarks on network boundaries with sufficient density, then constructs the landmark Voronoi diagram and its dual combinatorial Delaunay complex on these landmarks. The key insight is that the combinatorial Delaunay complex is provably {\em globally rigid\/} and has a {\em unique\/} realization in the plane. Thus an embedding of the landmarks by simply gluing the Delaunay triangles properly recovers the faithful network layout. With the landmarks nicely localized, the rest of the nodes can easily localize themselves by trilateration to nearby landmark nodes. This leads to a practical and accurate localization algorithm for large networks using only network connectivity. Simulations on various network topologies show surprisingly good results. In comparison, previous connectivity-based localization algorithms such as multidimensional scaling and rubberband representation generate globally flipped or distorted localization results.", acknowledgement = ack-nhfb, articleno = "31", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Combinatorial Delaunay Complex; Embedding; Graph Rigidity; Localization; Sensor Networks", } @Article{Shi:2009:OBS, author = "Yi Shi and Y. Thomas Hou", title = "Optimal base station placement in wireless sensor networks", journal = j-TOSN, volume = "5", number = "4", pages = "32:1--32:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614384", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Base station location has a significant impact on network lifetime performance for a sensor network. For a multihop sensor network, this problem is particularly challenging due to its coupling with data routing. This article presents an approximation algorithm that can guarantee (1 - \epsilon)-optimal network lifetime performance for base station placement problem with any desired error bound \epsilon > 0. The proposed (1 - \epsilon)-optimal approximation algorithm is based on several novel techniques that makes it possible to reduce an infinite search space to a finite-element search space for base station location. The first technique used in this reduction is to discretize cost parameter (associated with energy consumption) with performance guarantee. Subsequently, the continuous search space can be broken up into a finite number of subareas. The second technique is to exploit the cost property of each subarea and represent it by a novel notion called fictitious cost point, each with guaranteed cost bounds. We give a proof that the proposed base station placement algorithm is (1- \epsilon)-optimal. This approximation algorithm is simpler and faster than a state-of-the-art algorithm and represents the best known result to the base station placement problem.", acknowledgement = ack-nhfb, articleno = "32", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Approximation algorithm; base station placement; network lifetime; sensor network", } @Article{Mathur:2009:ULP, author = "Gaurav Mathur and Peter Desnoyers and Paul Chukiu and Deepak Ganesan and Prashant Shenoy", title = "Ultra-low power data storage for sensor networks", journal = j-TOSN, volume = "5", number = "4", pages = "33:1--33:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614385", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Local storage is required in many sensor network applications, both for archival of detailed event information, as well as to overcome sensor platform memory constraints. Recent gains in energy efficiency of new-generation NAND flash storage have strengthened the case for in-network storage by data-centric sensor network applications. We argue that current storage solutions offering a simple file system abstraction are inadequate for sensor applications to exploit storage. Instead, we propose Capsule --- a rich, flexible and portable object storage abstraction that offers stream, file, array, queue and index storage objects for data storage and retrieval. Further, Capsule supports checkpointing and rollback of object state for fault tolerance. Our experiments demonstrate that Capsule provides platform independence, greater functionality and greater energy efficiency than existing storage solutions.", acknowledgement = ack-nhfb, articleno = "33", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "embedded systems; energy efficiency; file system; flash memory; objects; sensors; storage system", } @Article{Paschalidis:2009:RDS, author = "Ioannis Ch. Paschalidis and Dong Guo", title = "Robust and distributed stochastic localization in sensor networks: {Theory} and experimental results", journal = j-TOSN, volume = "5", number = "4", pages = "34:1--34:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614386", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a robust localization system allowing wireless sensor networks to determine the physical location of their nodes. The coverage area is partitioned into regions and we seek to identify the region of a sensor based on observations by stationary clusterheads. Observations (e.g., signal strength) are assumed random. We pose the localization problem as a composite multihypothesis testing problem, develop the requisite theory, and address the problem of optimally placing clusterheads. We show that localization decisions can be distributed by appropriate in-network processing. The approach is validated in a testbed yielding promising results.", acknowledgement = ack-nhfb, articleno = "34", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "hypothesis testing; information theory; localization; optimal deployment; Sensor networks; testbed", } @Article{Deng:2009:MDF, author = "Jing Deng", title = "{Multihop\slash Direct Forwarding (MDF)} for static wireless sensor networks", journal = j-TOSN, volume = "5", number = "4", pages = "35:1--35:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614387", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The success of Wireless Sensor Networks (WSNs) depends largely on efficient information delivery from target areas toward data sinks. The problem of data forwarding is complicated by the severe energy constraints of sensors in WSNs. In this work, we propose and analyze a data forwarding scheme, termed Multihop/Direct Forwarding (MDF), for WSNs where sensor nodes forward data traffic toward a common data sink. In the MDF scheme, a node splits outgoing traffic into at most two branches: one is sent to a node that is {\em h\/} units away; the other is sent directly to the data sink. The value of {\em h\/} is chosen to minimize the overall energy consumption of the network. The direct transmission is employed to balance the energy consumption of nodes at different locations and to avoid the so-called hot spot problem in data forwarding. In order to calculate its traffic splitting ratio, a node only needs to know the distance toward the common data sink and that of the farthest node. Our analytical and simulation results show that the MDF scheme performs close to, in terms of energy efficiency and network lifetime, the optimum data forwarding rules, which are more complex and computation intensive.", acknowledgement = ack-nhfb, articleno = "35", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Energy efficient; multihop forwarding; wireless sensor networks", } @Article{Lachenmann:2009:MLG, author = "Andreas Lachenmann and Klaus Herrmann and Kurt Rothermel and Pedro Jos{\'e} Marr{\'o}n", title = "On meeting lifetime goals and providing constant application quality", journal = j-TOSN, volume = "5", number = "4", pages = "36:1--36:??", month = nov, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1614379.1614388", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:11 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Most work in sensor networks tries to maximize network lifetime. However, for many applications the required lifetime is known in advance. Therefore, application quality should rather be maximized for that given time. {\em Levels}, the approach presented in this article, is a programming abstraction for energy-aware sensor network applications that helps to meet such a user-defined lifetime goal by deactivating optional functionality.\par With this programming abstraction, the application developer defines so-called {\em energy levels}. Functionality in energy levels is deactivated if the required lifetime cannot be met otherwise. The runtime system uses data about the energy consumption of different levels to compute an optimal level assignment that maximizes each node's quality for the time remaining.\par As described in this paper, {\em Levels\/} includes a completely distributed coordination algorithm that balances energy level assignments and keeps the application quality of the network roughly constant over time. In this approach, each node computes its schedule based on those of its neighbors.\par As the evaluation shows, applications using {\em Levels\/} can accurately meet given lifetime goals with only small fluctuations in application quality. In addition, the runtime overhead both for computation and for communication is negligible.", acknowledgement = ack-nhfb, articleno = "36", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "coordination; energy; lifetime goal; programming abstraction; Wireless sensor network", } @Article{Gandhi:2009:CEM, author = "Sorabh Gandhi and Subhash Suri and Emo Welzl", title = "Catching elephants with mice: {Sparse} sampling for monitoring sensor networks", journal = j-TOSN, volume = "6", number = "1", pages = "1:1--1:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653761", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We propose a scalably efficient scheme for detecting large-scale physically correlated events in sensor networks. Specifically, we show that in a network of {\em n\/} sensors arbitrarily distributed in the plane, a sample of {\em O\/} (1/\epsilon log 1/\epsilon) sensor nodes ({\em mice\/}) is sufficient to catch any, and {\em only those}, events that affect \Omega (\epsilon {\em n\/}) nodes ({\em elephants\/}), for any 0 \par While nearly optimal in theory, due to implicit constant factors, these ``scale-free'' bounds still prove too large in practice if applied blindly. We therefore propose heuristic improvements and perform empirical parameter tuning to counter the pessimism inherent in these theoretical estimates. Using a variety of data distributions and event geometries, we show through simulations that the final scheme is eminently scalable and practical, say, for {\em n\/} \geq 1000. The overall simplicity and generality of our technique suggests that it is well suited for a wide class of sensornet applications, including monitoring of physical environments, network anomalies, network security, or any abstract binary event that affects a significant number of nodes in the network.", acknowledgement = ack-nhfb, articleno = "1", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Chen:2009:MGQ, author = "Ai Chen and Ten H. Lai and Dong Xuan", title = "Measuring and guaranteeing quality of barrier coverage for general belts with wireless sensors", journal = j-TOSN, volume = "6", number = "1", pages = "2:1--2:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653762", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Sensors may fail due to various reasons such as heat, malicious activity, environmental hazards, extended use, and lack of power. As more and more sensors fail, certain desired properties such as barrier coverage will diminish and eventually fall below a desired level. In such a case, the network will have to be repaired. It is therefore desirable to have mechanisms to monitor network properties. In this article, we are interested in measuring the quality of barrier coverage, which is known to be an appropriate model of coverage for movement detection applications such as intrusion detection.\par In the literature, researchers only consider whether or not a sensor network provides barrier coverage. This is equivalent to measuring its quality as either 0 or 1. We believe quality of barrier coverage is not binary and propose a metric for measuring it. If the measured quality is short of a desired value, we further identify all local regions that need to be repaired. The identified regions are minimal in the sense that if one of them is not repaired then the resulting network will still be short of quality. We also discuss how to actually repair a region.", acknowledgement = ack-nhfb, articleno = "2", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "barrier coverage; measuring; quality; repairing; Wireless sensor networks", } @Article{Jurdak:2009:DBO, author = "Raja Jurdak and Antonio G. Ruzzelli and Gregory M. P. O'hare and Russell Higgs", title = "Directed broadcast with overhearing for sensor networks", journal = j-TOSN, volume = "6", number = "1", pages = "3:1--3:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653763", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The efficient management of scarce network resources, including energy and bandwidth, represents a central challenge for wireless sensor networks. The current trend in resource management relies on the introduction of control mechanisms, such as control message exchanges, node-specific addressing, and storage of partial network state information. These mechanisms typically incur communication and processing overhead that does not scale well for larger or denser networks. Instead of introducing control mechanisms for network resource management, this article proposes and evaluates a Directed Broadcast with Overhearing (DBO) approach for sensor networks that combines directed broadcast at the network layer with CSMA and packet overhearing at the MAC layer. Through avoidance of control messaging and exchange of network state information, DBO trades off limited packet duplication overhead for control messaging overhead. This article introduces an analytical model that provides the basis for DBO evaluation and for analysis of the approach's transient packet retransmissions, route convergence, and energy consumption in the average and worst cases. We also present the model implementation details and the simulation experiments that explore the suitability of DBO for networks of different sizes with three different radio models that vary the width of grey regions, and we compare DBO's energy consumption against conventional unicast beacon-based and snooping-based routing protocols. The results indicate that DBO's route convergence requires an average of five hops for ideal radio reception, seven hops for narrow grey regions, and twelve hops for wide grey regions. These results confirm that DBO shifts energy consumption from critical nodes near the base station to nodes near the source. The overall energy consumption of limited packet duplication overhead with DBO compared to unicast routing shrinks for medium- to large-size networks, rendering it more favorable than conventional communication approaches for large and dense sensor networks.", acknowledgement = ack-nhfb, articleno = "3", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "architecture; Cross-layer; directed broadcast; overhearing; protocols; sensor networks", } @Article{Ruj:2009:KPU, author = "Sushmita Ruj and Bimal Roy", title = "Key predistribution using combinatorial designs for grid-group deployment scheme in wireless sensor networks", journal = j-TOSN, volume = "6", number = "1", pages = "4:1--4:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653764", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We propose a new grid-group deployment scheme in wireless sensor networks. We use combinatorial designs for key predistribution in sensor nodes. The deployment region is divided into square regions. The predistribution scheme has the advantage that all nodes within a particular region can communicate with each other directly and nodes which lie in a different regions can communicate via special nodes called agents which have more resources than the general nodes. The number of agents in a region is always three, whatever the size of the network. We give measures of resiliency taking the Lee distance into account. Apart from considering the resiliency in terms of fraction of links broken, we also consider the resiliency as the number of nodes and regions disconnected when some sensor are compromised. This second measure, though very important, had not been studied so far in key predistribution schemes which use deployment knowledge. We find that the resiliency as the fraction of links compromised is better than existing schemes. The number of keys preloaded in each sensor node is much less than all existing schemes and nodes are either directly connected or connected via two hop paths. The deterministic key predistribution schemes result in constant-time computation overhead for shared key discovery and path key establishment.", acknowledgement = ack-nhfb, articleno = "4", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Combinatorial design; deployment; key predistribution; Lee distance; secure communication; transversal design", } @Article{Sadek:2009:EEC, author = "Ahmed K. Sadek and Wei Yu and K. J. Ray Liu", title = "On the energy efficiency of cooperative communications in wireless sensor networks", journal = j-TOSN, volume = "6", number = "1", pages = "5:1--5:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653765", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Cooperative communications represent a potential candidate to combat the effects of channel fading and to increase the transmit energy efficiency in wireless sensor networks with the downside being the increased complexity. In sensor networks the power consumed in the receiving and processing circuitry can constitute a significant portion of the total consumed power. By taking into consideration such overhead, an analytical framework for studying the energy efficiency trade-off of cooperation in sensor networks is presented. This trade-off is shown to depend on several parameters such as the receive and processing power, the required quality-of-service, the power amplifier loss, and several other factors. The analytical and numerical results reveal that for small distance separation between the source and destination, direct transmission is more energy efficient than relaying. The results also reveal that equal power allocation performs as well as optimal power allocation for some scenarios. The effects of the relay location and the number of employed relays on energy efficiency are also investigated in this work. Moreover, there are experimental results conducted to verify the channel model assumed in the article.", acknowledgement = ack-nhfb, articleno = "5", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "cooperative communications; diversity; energy efficiency; power allocation; Sensor networks", } @Article{Eisenman:2009:BMS, author = "Shane B. Eisenman and Emiliano Miluzzo and Nicholas D. Lane and Ronald A. Peterson and Gahng-Seop Ahn and Andrew T. Campbell", title = "{BikeNet}: {A} mobile sensing system for cyclist experience mapping", journal = j-TOSN, volume = "6", number = "1", pages = "6:1--6:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653766", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present BikeNet, a mobile sensing system for mapping the cyclist experience. Built leveraging the MetroSense architecture to provide insight into the real-world challenges of people-centric sensing, BikeNet uses a number of sensors embedded into a cyclist's bicycle to gather quantitative data about the cyclist's rides. BikeNet uses a dual-mode operation for data collection, using opportunistically encountered wireless access points in a delay-tolerant fashion by default, and leveraging the cellular data channel of the cyclist's mobile phone for real-time communication as required. BikeNet also provides a Web-based portal for each cyclist to access various representations of her data, and to allow for the sharing of cycling-related data (for example, favorite cycling routes) within cycling interest groups, and data of more general interest (for example, pollution data) with the broader community. We present: a description and prototype implementation of the system architecture based on customized Moteiv Tmote Invent motes and sensor-enabled Nokia N80 mobile phones; an evaluation of sensing and inference that quantifies cyclist performance and the cyclist environment; a report on networking performance in an environment characterized by bicycle mobility and human unpredictability; and a description of BikeNet system user interfaces.", acknowledgement = ack-nhfb, articleno = "6", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Applications; bicycling; recreation; systems", } @Article{Rajasegarar:2009:EAW, author = "Sutharshan Rajasegarar and James C. Bezdek and Christopher Leckie and Marimuthu Palaniswami", title = "Elliptical anomalies in wireless sensor networks", journal = j-TOSN, volume = "6", number = "1", pages = "7:1--7:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653767", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Anomalies in wireless sensor networks can occur due to malicious attacks, faulty sensors, changes in the observed external phenomena, or errors in communication. Defining and detecting these interesting events in energy-constrained situations is an important task in managing these types of networks. A key challenge is how to detect anomalies with few false alarms while preserving the limited energy in the network. In this article, we define different types of anomalies that occur in wireless sensor networks and provide formal models for them. We illustrate the model using statistical parameters on a dataset gathered from a real wireless sensor network deployment at the Intel Berkeley Research Laboratory. Our experiments with a novel distributed anomaly detection algorithm show that it can detect elliptical anomalies with exactly the same accuracy as that of a centralized scheme, while achieving a significant reduction in energy consumption in the network. Finally, we demonstrate that our model compares favorably to four other well-known schemes on four datasets.", acknowledgement = ack-nhfb, articleno = "7", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "anomaly detection; Elliptical anomalies; multivariate analysis; outlier detection; security; wireless sensor networks", } @Article{Cheng:2009:DAN, author = "Bing Hwa Cheng and Lieven Vandenberghe and Kung Yao", title = "Distributed algorithm for node localization in wireless ad-hoc networks", journal = j-TOSN, volume = "6", number = "1", pages = "8:1--8:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653768", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a distributed algorithm for node localization based on the Gauss--Newton method. In this algorithm, each node updates its own location estimate using the pairwise distance measurements and the local information it receives from the neighboring nodes. Once the location estimate is updated, the sensor node broadcasts the updated estimate to all the neighboring nodes. A distributed and scalable local scheduling algorithm for updating nodes in the network is presented to avoid the use of the global coordinator or a routing loop. We analytically show that the proposed distributed algorithm converges under certain practical assumptions of the network. The performance of the algorithm is evaluated using both simulation and experimental results. Quantitative comparisons among different distributed algorithms are also presented.", acknowledgement = ack-nhfb, articleno = "8", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Distributed optimization; Gauss--Newton; node localization", } @Article{Wang:2009:SST, author = "Ronghua Wang and Wenliang Du and Xiaogang Liu and Peng Ning", title = "{ShortPK}: {A} short-term public key scheme for broadcast authentication in sensor networks", journal = j-TOSN, volume = "6", number = "1", pages = "9:1--9:??", month = dec, year = "2009", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1653760.1653769", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:24:34 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Broadcast authentication is an important functionality in sensor networks. Energy constraints on sensor nodes and the real-time nature of the broadcasts render many of the existing solutions impractical: previous works focusing primarily on symmetric key schemes have difficulties in achieving real-time authentication. Public Key Cryptography (PKC), however, can satisfy the real-time requirements, and recent trends indicate that public key is becoming feasible for sensor networks.\par However, PKC operations are still expensive computations. It is impractical to use PKC in the conventional ways for broadcast authentication in sensor networks. To reduce costs, we propose {\em ShortPK}, an efficient Short-term Public Key broadcast authentication scheme. The basic idea is to use short-length public/private keys, but limit their lifetime to only a short period of time. To cover a long period of time, we need to use many public/private key pairs; distributing these public keys to sensors is a challenging problem. We describe a progressive key distribution scheme that is secure, efficient, and packet-loss resilient. We compare our scheme with the traditional 160-bit ECC public key schemes, and show that our scheme can achieve a significant improvement on energy consumption.", acknowledgement = ack-nhfb, articleno = "9", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "communication; public key; Sensor networks", } @Article{Xu:2010:CGM, author = "Xiaochun Xu and Nageswara S. V. Rao and Sartaj Sahni", title = "A computational geometry method for localization using differences of distances", journal = j-TOSN, volume = "6", number = "2", pages = "10:1--10:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689240", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a computational geometry method for the problem of estimating the location of a source in the plane using measurements of distance-differences to it. Compared to existing solutions to this well-studied problem, this method is: (a) computationally more efficient and adaptive in that its precision can be controlled as a function of the number of computational operations, and (b) robust with respect to measurement and computational errors, and is not susceptible to numerical instabilities typical of existing linear algebraic or quadratic methods. This method employs a binary search on a distance-difference curve in the plane using a second distance-difference as the objective function. We show the correctness of this method by establishing the unimodality of directional derivative of the objective function within each of a small number of regions of the plane, wherein a suitable binary search is supported. The computational complexity of this method is {\em O\/} (log (1/ {\em {\gamma}\/})), where the computed solution is guaranteed to be within a distance {\gamma} of the actual location of the source. We present simulation results to compare this method with existing DTOA localization methods.", acknowledgement = ack-nhfb, articleno = "10", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "distance-difference triangulation; DTOA localization; geometric search; sensor networks", } @Article{Nordio:2010:IQE, author = "Alessandro Nordio and Carla-Fabiana Chiasserini and Emanuele Viterbo", title = "The impact of quasi-equally spaced sensor topologies on signal reconstruction", journal = j-TOSN, volume = "6", number = "2", pages = "11:1--11:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689241", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "A wireless sensor network with randomly deployed nodes can be used to provide an irregular sampling of a physical field of interest. We assume that a sink node collects the data gathered by the sensors and uses a linear filter for the reconstruction of a bandlimited scalar field defined over a {\em d\/} -dimensional domain. Sensors' locations are assumed to be known at the sink node, up to a certain position error. We then take the mean square error (MSE) of the reconstructed field as performance metric, and evaluate the effect of both uniform and quasi-equally spaced sensor layouts on the quality of the reconstructed field. We define a parameter that provides a measure of the regularity of the sensors deployment, and, through asymptotic analysis, we derive the MSE in the case of different sensor spatial distributions. For two of them, an approximate closed form expression is obtained. We validate our analysis through numerical results, and we show that an excellent match exists between analysis and simulation even for a small number of sensors.", acknowledgement = ack-nhfb, articleno = "11", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "irregular sampling; performance evaluation; Sensor networks; signal reconstruction", } @Article{Sang:2010:LAO, author = "Lifeng Sang and Anish Arora and Hongwei Zhang", title = "On link asymmetry and one-way estimation in wireless sensor networks", journal = j-TOSN, volume = "6", number = "2", pages = "12:1--12:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689242", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Link asymmetry is one of the unique challenges that wireless sensor networks pose in the design of network protocols. We observe, based on testbed experiments, that a substantial percentage of links are asymmetric, many are even unidirectional. We also find that the reliability of synchronous acknowledgments is considerably higher than that of asynchronous messages. Thus the norm of estimating link quality bidirectionally via asynchronous beacons underestimates the link reliability of asymmetric links. This leads us to investigate how to exploit asymmetric links in order to improve network functions such as convergecast routing in sensor networks via one-way link estimation. We propose a new one-way link metric ETF (for the {\em expected number of transmissions over forward links\/}) and present a local procedure for its estimation. We use ETF to identify reliable forward links, and we use dynamic retransmission thresholding for error control. Via experiments on testbeds of CC1000 radios and CC2420 radios (an IEEE 802.15.4-compliant radio), we quantify the performance improvement in ETF as compared with ETX. We also study the performance improvement of ETF over ETX when no special mechanism is employed to discover asymmetric links or to control retransmissions.", acknowledgement = ack-nhfb, articleno = "12", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "link estimation; routing; Sensor network", } @Article{Reddy:2010:UMP, author = "Sasank Reddy and Min Mun and Jeff Burke and Deborah Estrin and Mark Hansen and Mani Srivastava", title = "Using mobile phones to determine transportation modes", journal = j-TOSN, volume = "6", number = "2", pages = "13:1--13:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689243", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "As mobile phones advance in functionality and capability, they are being used for more than just communication. Increasingly, these devices are being employed as instruments for introspection into habits and situations of individuals and communities. Many of the applications enabled by this new use of mobile phones rely on contextual information. The focus of this work is on one dimension of context, the transportation mode of an individual when outside. We create a convenient (no specific position and orientation setting) classification system that uses a mobile phone with a built-in GPS receiver and an accelerometer. The transportation modes identified include whether an individual is stationary, walking, running, biking, or in motorized transport. The overall classification system consists of a decision tree followed by a first-order discrete Hidden Markov Model and achieves an accuracy level of 93.6\% when tested on a dataset obtained from sixteen individuals.", acknowledgement = ack-nhfb, articleno = "13", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Activity classification; mobile phones; transportation mode inference", } @Article{Carbunar:2010:QPW, author = "Bogdan Carbunar and Yang Yu and Weidong Shi and Michael Pearce and Venu Vasudevan", title = "Query privacy in wireless sensor networks", journal = j-TOSN, volume = "6", number = "2", pages = "14:1--14:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689244", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Existing mechanisms for querying wireless sensor networks leak client interests to the servers performing the queries. The leaks are not only in terms of specific regions of interest but also of client access patterns. In this article we introduce the problem of preserving the privacy of clients querying a wireless sensor network owned by untrusted organizations. We first propose an efficient protocol, SPYC, that ensures full client privacy in settings where the servers providing access to the network are honest-but-curious and whose collaboration does not extend beyond well-defined administrative purposes. Furthermore, we study the same query privacy problem in a setting where servers exhibit malicious behavior or where powerful external attackers have access to sensor network traffic information. In this setting we propose two metrics for quantifying the privacy achieved by a client's query sequence. We then extend SPYC with a suite of practical algorithms, then analyze the privacy and efficiency levels they provide. Our TOSSIM simulations show that the proposed extensions are communication efficient while significantly improving client privacy levels.", acknowledgement = ack-nhfb, articleno = "14", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "data integrity; Data storage and query processing; privacy; security", } @Article{Ni:2010:DRS, author = "Jinfeng Ni and Li Zhou and Chinya V. Ravishankar", title = "Dealing with random and selective attacks in wireless sensor systems", journal = j-TOSN, volume = "6", number = "2", pages = "15:1--15:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689245", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a framework for analyzing the effects of random and selective compromises (using order statistics) in sensor networks. We discuss the problem of ensuring data integrity at the source and during transit in sensor networks, and present an analysis of the reliability of reports from mobile collectors. No analysis has appeared in the literature of source integrity for mobile nodes, or of selective attacks in sensor networks. We address transit data integrity by presenting mGKE, a key establishment scheme for general group-based sensor deployments, and present a detailed analytical and experimental comparison of mGKE with current schemes. mGKE outperforms current methods in terms of resilience, connectivity, and memory and communication overhead.", acknowledgement = ack-nhfb, articleno = "15", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Attack models; fault tolerance; mobile sensors", } @Article{Srinivasan:2010:ESL, author = "Kannan Srinivasan and Prabal Dutta and Arsalan Tavakoli and Philip Levis", title = "An empirical study of low-power wireless", journal = j-TOSN, volume = "6", number = "2", pages = "16:1--16:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689246", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present empirical measurements of the packet delivery performance of the latest sensor platforms: Micaz and Telos motes. In this article, we present observations that have implications to a set of common assumptions protocol designers make while designing sensornet protocols --- specifically --- the MAC and network layer protocols. We first distill these common assumptions in to a conceptual model and show how our observations support or dispute these assumptions. We also present case studies of protocols that do not make these assumptions. Understanding the implications of these observations to the conceptual model can improve future protocol designs.", acknowledgement = ack-nhfb, articleno = "16", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "802.15.4; low-power wireless networks; metrics; Wireless link; wireless measurement study; wireless protocol design", } @Article{Ingelrest:2010:SAS, author = "Fran{\c{c}}ois Ingelrest and Guillermo Barrenetxea and Gunnar Schaefer and Martin Vetterli and Olivier Couach and Marc Parlange", title = "{SensorScope}: {Application-specific} sensor network for environmental monitoring", journal = j-TOSN, volume = "6", number = "2", pages = "17:1--17:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689247", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "SensorScope is a turnkey solution for environmental monitoring systems, based on a wireless sensor network and resulting from a collaboration between environmental and network researchers. Given the interest in climate change, environmental monitoring is a domain where sensor networks will have great impact by providing high resolution spatio-temporal data for long periods of time. SensorScope is such a system, which has already been successfully deployed multiple times in various environments (e.g., mountainous, urban). Here, we describe the overall hardware and software architectures and especially focus on the sensor network itself. We also describe one of our most prominent deployments, on top of a rock glacier in Switzerland, which resulted in the description of a micro-climate phenomenon leading to cold air release from a rock-covered glacier in a region of high alpine risks. Another focus of this paper is the description of what happened behind the scenes to turn SensorScope from a laboratory experiment into successful outdoor deployments in harsh environments. Illustrated by various examples, we point out many lessons learned while working on the project. We indicate the importance of simple code, well suited to the application, as well as the value of close interaction with end-users in planning and running the network and finally exploiting the data.", acknowledgement = ack-nhfb, articleno = "17", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Architecture; deployment; environmental monitoring; implementation; wireless sensor network", } @Article{Zhu:2010:FTR, author = "Mengxia Zhu and Song Ding and Qishi Wu and R. R. Brooks and N. S. V. Rao and S. S. Iyengar", title = "Fusion of threshold rules for target detection in wireless sensor networks", journal = j-TOSN, volume = "6", number = "2", pages = "18:1--18:??", month = feb, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1689239.1689248", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Tue Mar 16 15:25:00 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We propose a binary decision fusion rule that reaches a global decision on the presence of a target by integrating local decisions made by multiple sensors. Without requiring a priori probability of target presence, the fusion threshold bounds derived using Chebyshev's inequality ensure a higher hit rate and lower false alarm rate compared to the weighted averages of individual sensors. The Monte Carlo-based simulation results show that the proposed approach significantly improves target detection performance, and can also be used to guide the actual threshold selection in practical sensor network implementation under certain error rate constraints.", acknowledgement = ack-nhfb, articleno = "18", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "binary decision fusion; Chebyshev inequality; false alarm rate; Hit rate; ROC curve; wireless sensor network", } @Article{Ko:2010:HNU, author = "Teresa Ko and Shaun Ahmadian and John Hicks and Mohammad Rahimi and Deborah Estrin and Stefano Soatto and Sharon Coe and Michael P. Hamilton", title = "Heartbeat of a nest: {Using} imagers as biological sensors", journal = j-TOSN, volume = "6", number = "3", pages = "19:1--19:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754415", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a scalable end-to-end system for vision-based monitoring of natural environments, and illustrate its use for the analysis of avian nesting cycles. Our system enables automated analysis of thousands of images, where manual processing would be infeasible. We automate the analysis of raw imaging data using statistics that are tailored to the task of interest. These ``features'' are a representation to be fed to classifiers that exploit spatial and temporal consistencies. Our testbed can detect the presence or absence of a bird with an accuracy of 82\%, count eggs with an accuracy of 84\%, and detect the inception of the nesting stage within a day. Our results demonstrate the challenges and potential benefits of using imagers as biological sensors. An exploration of system performance under varying image resolution and frame rate suggest that an {\em in situ\/} adaptive vision system is technically feasible.", acknowledgement = ack-nhfb, articleno = "19", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "computer vision; image network; sensor network; system deployment", } @Article{Saukh:2010:BRL, author = "Olga Saukh and Robert Sauter and Matthias Gauger and Pedro Jos{\'e} Marr{\'o}n", title = "On boundary recognition without location information in wireless sensor networks", journal = j-TOSN, volume = "6", number = "3", pages = "20:1--20:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754416", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Boundary recognition is an important and challenging issue in wireless sensor networks when no coordinates or distances are available. The distinction between inner and boundary nodes of the network can provide valuable knowledge to a broad spectrum of algorithms. This article tackles the challenge of providing a scalable and range-free solution for boundary recognition that does not require a high node density. We explain the challenges of accurately defining the boundary of a wireless sensor network with and without node positions and provide a new definition of network boundary in the discrete domain. Our solution for boundary recognition approximates the boundary of the sensor network by determining the majority of inner nodes using geometric constructions, which guarantee that for a given {\em d}, a node lies inside of the construction for a {\em d\/} -quasi unit disk graph model of the wireless sensor network. Moreover, such geometric constructions make it possible to compute a guaranteed distance from a node to the boundary. We present a fully distributed algorithm for boundary recognition based on these concepts and perform a detailed complexity analysis. We provide a thorough evaluation of our approach and show that it is applicable to dense as well as sparse deployments.", acknowledgement = ack-nhfb, articleno = "20", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "boundary definition; boundary recognition; d-quasi unit disk graphs; unit disk graphs; wireless sensor networks", } @Article{Ning:2010:DST, author = "Xu Ning and Christos G. Cassandras", title = "Dynamic sleep time control in wireless sensor networks", journal = j-TOSN, volume = "6", number = "3", pages = "21:1--21:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754417", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Idle listening is a major source of energy waste in wireless sensor networks. It can be reduced through Low-Power Listening (LPL) techniques in which a node is allowed to sleep for a significant amount of time. In contrast to conventional fixed sleep time policies, we introduce a novel dynamic sleep time control approach that further reduces control packet energy waste by utilizing known data traffic statistics. We propose two distinct approaches to dynamically compute the sleep time, depending on the objectives and constraints of the network. The first approach provides a dynamic sleep time policy that guarantees a specified average delay at the sender node resulting from packets waiting for the end of a sleep interval at the receiver. The second approach determines the optimal policy that minimizes total energy consumed. In the case where data traffic statistics are unknown, we propose an adaptive learning algorithm to estimate them online and develop corresponding sleep time computation algorithms. Simulation results are included to illustrate the use of dynamic sleep time control and to demonstrate how it dominates fixed sleep time methods. An implementation of our approach on a commercial sensor node supports the computational feasibility of the proposed approach.", acknowledgement = ack-nhfb, articleno = "21", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy management; learning; low-power listening; stochastic processes", } @Article{Wang:2010:EED, author = "Jing Wang and Yonghe Liu and Sajal K. Das", title = "Energy-efficient data gathering in wireless sensor networks with asynchronous sampling", journal = j-TOSN, volume = "6", number = "3", pages = "22:1--22:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754418", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "A low sampling rate leads to reduced congestion and hence energy consumption in the resource-constrained wireless sensor networks. In this article, we propose asynchronous sampling that shifts the sampling time instances of sensor nodes from each other. For lossy data gathering scenarios, the proposed approach provides more information about the physical phenomena in terms of increased entropy at a low sampling rate. For lossless data gathering scenarios, on the other hand, the sampling rate is lowered without sacrificing critical knowledge required for signal reconstruction. As lower sampling rates lead to smaller energy consumption for processing and transmitting the collected sensory data, the proposed asynchronous sampling strategies are capable of achieving a better trade-off between the lifetime of the network and the quality of collected information. In addition to mathematical analysis, simulation results based on real data also verify the benefits of our asynchronous sampling.", acknowledgement = ack-nhfb, articleno = "22", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "asynchronous sampling; data gathering; energy efficiency; models; temporal-spatial correlation; wireless sensor networks", } @Article{Sharma:2010:SFD, author = "Abhishek B. Sharma and Leana Golubchik and Ramesh Govindan", title = "Sensor faults: {Detection} methods and prevalence in real-world datasets", journal = j-TOSN, volume = "6", number = "3", pages = "23:1--23:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754419", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Various sensor network measurement studies have reported instances of transient faults in sensor readings. In this work, we seek to answer a simple question: How often are such faults observed in real deployments? We focus on three types of transient faults, caused by faulty sensor readings that appear abnormal. To understand the prevalence of such faults, we first explore and characterize four qualitatively different classes of fault detection methods. Rule-based methods leverage domain knowledge to develop heuristic rules for detecting and identifying faults. Estimation methods predict ``normal'' sensor behavior by leveraging sensor correlations, flagging anomalous sensor readings as faults. Time-series-analysis-based methods start with an a priori model for sensor readings. A sensor measurement is compared against its predicted value computed using time series forecasting to determine if it is faulty. Learning-based methods infer a model for the ``normal'' sensor readings using training data, and then statistically detect and identify classes of faults.\par We find that these four classes of methods sit at different points on the accuracy/robustness spectrum. Rule-based methods can be highly accurate, but their accuracy depends critically on the choice of parameters. Learning methods can be cumbersome to train, but can accurately detect and classify faults. Estimation methods are accurate, but cannot classify faults. Time-series-analysis-based methods are more effective for detecting short duration faults than long duration ones, and incur more false positives than the other methods. We apply these techniques to four real-world sensor datasets and find that the prevalence of faults as well as their type varies with datasets. All four methods are qualitatively consistent in identifying sensor faults, lending credence to our observations. Our work is a first step towards automated online fault detection and classification.", acknowledgement = ack-nhfb, articleno = "23", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "data integrity; fault detection; fault prevalence; sensor networks; statistical techniques", } @Article{Shen:2010:EDD, author = "Chung-Ching Shen and William L. Plishker and Dong-Ik Ko and Shuvra S. Bhattacharyya and Neil Goldsman", title = "Energy-driven distribution of signal processing applications across wireless sensor networks", journal = j-TOSN, volume = "6", number = "3", pages = "24:1--24:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754420", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Wireless sensor network (WSN) applications have been studied extensively in recent years. Such applications involve resource-limited embedded sensor nodes that have small size and low power requirements. Based on the need for extended network lifetimes in WSNs in terms of energy use, the energy efficiency of computation and communication operations in the sensor nodes becomes critical. Digital Signal Processing (DSP) applications typically require intensive data processing operations and as a result are difficult to implement directly in resource-limited WSNs. In this article, we present a novel design methodology for modeling and implementing computationally intensive DSP applications applied to wireless sensor networks. This methodology explores efficient modeling techniques for DSP applications, including data sensing and processing; derives formulations of Energy-Driven Partitioning (EDP) for distributing such applications across wireless sensor networks; and develops efficient heuristic algorithms for finding partitioning results that maximize the network lifetime. To address such an energy-driven partitioning problem, this article provides a new way of aggregating data and reducing communication traffic among nodes based on application analysis. By considering low data token delivery points and the distribution of computation in the application, our approach finds energy-efficient trade-offs between data communication and computation.", acknowledgement = ack-nhfb, articleno = "24", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "DSP; energy efficiency; network lifetime; speech recognition; wireless sensor networks", } @Article{Zhang:2010:DMM, author = "Zhiguo Zhang and Ajay D. Kshemkalyani and Sol M. Shatz", title = "Dynamic multiroot, multiquery processing based on data sharing in sensor networks", journal = j-TOSN, volume = "6", number = "3", pages = "25:1--25:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754421", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Applications that exploit the capabilities of sensor networks have triggered significant research on query processing in sensor systems. Energy constraints make optimizing query processing particularly important. This article addresses multiroot, multiquery optimization for region queries. The work focuses on application-layer issues exploiting query semantics. The article formulates three algorithms: a na{\"\i}ve algorithm, without data sharing, and a static and heuristic data-sharing algorithm. The heuristic algorithm allows sharing of partially aggregated results of preconfigured geographic regions and exploits the location attribute of sensor nodes as a grouping criterion. Simulation studies indicate the potential for significant energy savings with the proposed algorithms.", acknowledgement = ack-nhfb, articleno = "25", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "distributed query processing; geographic coverage; multiquery optimization; sensor networks", } @Article{Lee:2010:NLO, author = "Huang Lee and Abtin Keshavarzian and Hamid Aghajan", title = "Near-lifetime-optimal data collection in wireless sensor networks via spatio-temporal load balancing", journal = j-TOSN, volume = "6", number = "3", pages = "26:1--26:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754422", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In wireless sensor networks, periodic data collection appears in many applications. During data collection, messages from sensor nodes are periodically collected and sent back to a set of base stations for processing. In this article, we present and analyze a near-lifetime-optimal and scalable solution for data collection in stationary wireless sensor networks and an energy-efficient packet exchange mechanism. In our solution, instead of using a fixed network topology, we construct a set of communication topologies and apply each topology to different data collection cycles. We not only use the flexibility in distributing the traffic load across different routes in the network (spatial load balancing), but also balance the energy consumption in the time domain (temporal load balancing). We show that this method achieves an average energy consumption rate very close to the optimal value found by network flow optimization techniques. To increase the scalability, we further extend our solution such that it can be applied to networks with multiple base stations where each base station only stores part of the network configuration, cooperating with each other to find a global solution in a distributed manner. The proposed methods are analyzed and evaluated by simulations.", acknowledgement = ack-nhfb, articleno = "26", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "distributed algorithms; energy-efficient data collection; lifetime optimization; routing and scheduling design; wireless sensor networks", } @Article{Padhy:2010:UBA, author = "Paritosh Padhy and Rajdeep K. Dash and Kirk Martinez and Nicholas R. Jennings", title = "A utility-based adaptive sensing and multihop communication protocol for wireless sensor networks", journal = j-TOSN, volume = "6", number = "3", pages = "27:1--27:??", month = jun, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1754414.1754423", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:19 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article reports on the development of a utility-based mechanism for managing sensing and communication in cooperative multisensor networks. The specific application on which we illustrate our mechanism is that of GlacsWeb. This is a deployed system that uses battery-powered sensors to collect environmental data related to glaciers which it transmits back to a base station so that it can be made available world-wide to researchers. In this context, we first develop a sensing protocol in which each sensor locally adjusts its sensing rate based on the value of the data it believes it will observe. The sensors employ a Bayesian linear model to decide their sampling rate and exploit the properties of the Kullback--Leibler divergence to place an appropriate value on the data. Then, we detail a communication protocol that finds optimal routes for relaying this data back to the base station based on the cost of communicating it (derived from the opportunity cost of using the battery power for relaying data). Finally, we empirically evaluate our protocol by examining the impact on efficiency of a static network topology, a dynamic network topology, the size of the network, the degree of dynamism of the environment, and the mobility of the nodes. In so doing, we demonstrate that the efficiency gains of our new protocol, over the currently implemented method over a 6 month period, are 78\%, 133\%, 100\%, and 93\%, respectively. Furthermore, we show that our system performs at 65\%, 70\%, 63\%, and 70\% of the theoretical optimal, respectively, despite being a distributed protocol that operates with incomplete knowledge of the environment.", acknowledgement = ack-nhfb, articleno = "27", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "adaptive sampling; cost of communication; data gathering; dynamic environment; energy efficiency; network lifetime; sensor networks", } @Article{Puccinelli:2010:RDD, author = "Daniele Puccinelli and Martin Haenggi", title = "Reliable data delivery in large-scale low-power sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "28:1--28:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777407", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In data collection applications of low-end sensor networks, a major challenge is ensuring reliability without a significant goodput degradation. Short hops over high-quality links minimize per-hop transmissions, but long routes may cause congestion and load imbalance. Longer links can be exploited to build shorter routes, but poor links may have a high energy cost. There exists a complex interplay among routing performance (reliability, goodput, energy efficiency), link estimation, congestion control, and load balancing; we design a routing architecture, Arbutus, that exploits this interplay, and perform an extensive experimental evaluation on testbeds of 100-150 Berkeley motes.", acknowledgement = ack-nhfb, articleno = "28", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "congestion control; load balancing; routing; wireless sensor networks", } @Article{Dong:2010:SRV, author = "Jing Dong and Kurt E. Ackermann and Brett Bavar and Cristina Nita-Rotaru", title = "Secure and robust virtual coordinate system in wireless sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "29:1--29:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777408", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Virtual Coordinate System (VCS)-based routing provides a practical, efficient, and scalable means for point-to-point routing in wireless sensor networks. Several VCS-based routing protocols have been proposed in the last few years, all assuming that nodes behave correctly. However, many applications require deploying sensor networks in adversarial environments, making VCS-based routing protocols vulnerable to numerous attacks.\par In this article, we study the security of VCS-based routing protocols, with a focus on the unique component of VCS-based routing protocols, the virtual coordinate system. We first identify the security requirements of a correctly functioning VCS-based routing protocol and a set of novel attacks that can result in the violation of each of the identified requirements. The attacks target the underlying virtual coordinate system and can be mounted with low resources. However, they are epidemic in nature and are highly destructive to system performance. We then propose lightweight defense mechanisms designed specifically for resource-constrained sensor networks against each of the identified attacks. The proposed techniques require only local information on sensor nodes and take into account the unreliable nature of wireless links and network churn. Finally, we evaluate experimentally the impact of the attacks and the effectiveness of our defense mechanisms using a well-known VCS-based routing protocol, BVR. Our experiments show that the proposed techniques successfully mitigate all the identified attacks under a realistic link model and even at a high level of network churn.", acknowledgement = ack-nhfb, articleno = "29", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "beacon vector routing; routing; secure beacon vector routing; security; sensor network routing; virtual coordinate system", } @Article{Gao:2010:CLC, author = "Jie Gao and Radu Sion and Sol Lederer", title = "Collaborative location certification for sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "30:1--30:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777409", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Location information is of essential importance in sensor networks deployed for generating location-specific event reports. When such networks operate in hostile environments, it becomes imperative to guarantee the correctness of event location claims. In this article we address the problem of assessing location claims of untrusted (potentially compromised) nodes. The mechanisms introduced here prevent a compromised node from generating illicit event reports for locations other than its own. This is important because by compromising ``easy target'' sensors (say, sensors on the perimeter of the field that's easier to access), the adversary should not be able to impact data flows associated with other (``premium target'') regions of the network.\par To achieve this goal, in a process we call {\em location certification}, data routed through the network is ``tagged'' by participating nodes with ``belief'' ratings, collaboratively assessing the probability that the claimed source location is indeed correct. The effectiveness of our solution relies on the joint knowledge of participating nodes to assess the truthfulness of claimed locations. By collaboratively generating and propagating a set of ``belief'' ratings with transmitted data and event reports, the network allows authorized parties (e.g., final data sinks) to evaluate a metric of trust for the claimed location of such reports. Belief ratings are derived from a data model of observed past routing activity. The solution is shown to feature a strong ability to detect false location claims and compromised nodes. For example, incorrect claims as small as 2 hops (from the actual location) are detected with over 90\% accuracy.\par Finally, these new location certification mechanisms can be deployed in tandem with traditional secure localization, yet do not require it, and, in a sense, can serve to minimize the need thereof.", acknowledgement = ack-nhfb, articleno = "30", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "location certification; security; sensor networks; systems", } @Article{Venkatasubramanian:2010:PVB, author = "Krishna K. Venkatasubramanian and Sandeep K. S. Gupta", title = "Physiological value-based efficient usable security solutions for body sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "31:1--31:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777410", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "A Body Sensor Network (BSN) is a network of economically powered, wireless, wearable, and implanted health monitoring sensors, designed to continually collect and communicate health information from the host they are deployed on. Due to the sensitive nature of the data collected, securing BSNs is important for privacy preservation and protecting the host from bodily harm.\par In this article, we present Physiological Value-based Security (PVS), a usable and efficient way of securing intersensor communication schemes for BSNs. The PVS scheme distributes the key used for securing a particular message along with the message itself, by hiding it using physiological values. In this way, it not only eliminates the need for any explicit key distribution, but also reduces the number of keys required at each node to meet all its secure communication requirements.\par We further demonstrate the use of the PVS scheme in securing {\em cluster\/} topology formation in BSNs. Traditional protocols for cluster formation do not consider security and are therefore susceptible to malicious attacks. We present a PVS-based cluster formation protocol which mitigates these attacks. Performance analysis of the protocol shows that compared to cluster formation protocols secured with non-PVS-based key distribution schemes, it performs efficiently.", acknowledgement = ack-nhfb, articleno = "31", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "body sensor networks; efficiency; environmentally-coupled security; physiological values; secure cluster formation; usable security", } @Article{Wang:2010:DEE, author = "Zijian Wang and Eyuphan Bulut and Boleslaw K. Szymanski", title = "Distributed energy-efficient target tracking with binary sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "32:1--32:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777411", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Target tracking is a typical and important cooperative sensing application of wireless sensor networks. We study it in its most basic form, assuming a binary sensing model in which each sensor returns only 1-bit information regarding target's presence or absence within its sensing range. A novel, real-time and distributed target tracking algorithm is introduced. The algorithm is energy efficient and fault tolerant. It estimates the target location, velocity, and trajectory in a distributed and asynchronous manner. The accuracy of the algorithm is analytically derived under an ideal binary sensing model and extensive simulations of ideal, imperfect, and faulty sensing models show that the algorithm achieves good performance. It outperforms other published algorithms by yielding highly accurate estimates of the target's location, velocity, and trajectory.", acknowledgement = ack-nhfb, articleno = "32", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "binary sensor networks; distributed algorithms; energy efficient; target tracking", } @Article{Vedantam:2010:ADE, author = "Satish Vedantam and Urbashi Mitra and Ashutosh Sabharwal", title = "Asymptotic distortion exponents for the estimation of time-varying channels in multihop sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "33:1--33:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777412", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The problem of time-varying channel estimation in multihop sensor networks is examined. Two relay processing methods are explored: amplify-and-forward and encode-and-forward. Bounds on the end-to-end distortion for all internode channel estimates are computed for these two relay processing schemes. Performance is analyzed via the asymptotic limit of the decay rate of the end-to-end distortion with respect to SNR at high SNR. It is also established that asymptotically in SNR, amplify-and-forward can outperform encode-and-forward and in fact can achieve the maximum possible distortion exponent (distortion decay rate) order of unity. Linear and many-to-one topologies are then examined and it is shown that orthogonal access in the many-to-one network is optimal.", acknowledgement = ack-nhfb, articleno = "33", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "communication and estimation; joint communication and estimation; rate distortion theory", } @Article{Paek:2010:TAT, author = "Jeongyeup Paek and Ben Greenstein and Omprakash Gnawali and Ki-Young Jang and August Joki and Marcos Vieira and John Hicks and Deborah Estrin and Ramesh Govindan and Eddie Kohler", title = "The {Tenet} architecture for tiered sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "34:1--34:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777413", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Most sensor network research and software design has been guided by an architectural principle that permits multinode data fusion on small-form-factor, resource-poor nodes, or {\em motes}. While we were among the earliest promoters of this approach, through experience we found that this principle leads to fragile and unmanageable systems and explore an alternative. The {\em Tenet architecture\/} is motivated by the observation that future large-scale sensor network deployments will be {\em tiered}, consisting of motes in the lower tier and {\em masters}, relatively unconstrained 32-bit platform nodes, in the upper tier. Tenet constrains multinode fusion to the master tier while allowing motes to process locally-generated sensor data. This simplifies application development and allows mote-tier software to be reused. Applications running on masters {\em task\/} motes by composing task descriptions from a novel tasklet library. Our Tenet implementation also contains a robust and scalable networking subsystem for disseminating tasks and reliably delivering responses. We show that a Tenet pursuit-evasion application exhibits performance comparable to a mote-native implementation while being considerably more compact. We also present two real-world deployments of Tenet system: a structural vibration monitoring application at Vincent Thomas Bridge and an imaging-based habitat monitoring application at James Reserve, and show that tiered architecture scales network capacity and allows reliable delivery of high rate data.$^1$", acknowledgement = ack-nhfb, articleno = "34", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "motes; network architecture; sensor networks; tiered network", } @Article{Zhang:2010:RPA, author = "Lei Zhang and Ligang Liu and Craig Gotsman and Steven J. Gortler", title = "An as-rigid-as-possible approach to sensor network localization", journal = j-TOSN, volume = "6", number = "4", pages = "35:1--35:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777414", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We present a novel approach to localization of sensors in a network given a subset of noisy inter-sensor distances. The algorithm is based on ``stitching'' together local structures by solving an optimization problem requiring the structures to fit together in an ``As-Rigid-As-Possible'' manner, hence the name ARAP. The local structures consist of reference ``patches'' and reference triangles, both obtained from inter-sensor distances. We elaborate on the relationship between the ARAP algorithm and other state-of-the-art algorithms, and provide experimental results demonstrating that ARAP is significantly less sensitive to sparse connectivity and measurement noise. We also show how ARAP may be distributed.", acknowledgement = ack-nhfb, articleno = "35", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "as-rigid-as-possible; embedding; localization; sensor networks", } @Article{Rowaihy:2010:SMA, author = "Hosam Rowaihy and Matthew P. Johnson and Ou Liu and Amotz Bar-Noy and Theodore Brown and Thomas La Porta", title = "Sensor-mission assignment in wireless sensor networks", journal = j-TOSN, volume = "6", number = "4", pages = "36:1--36:??", month = jul, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1777406.1777415", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Thu Jul 15 18:24:44 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "When a sensor network is deployed, it is typically required to support multiple simultaneous missions. Schemes that assign sensing resources to missions thus become necessary. In this article, we formally define the sensor-mission assignment problem and discuss some of its variants. In its most general form, this problem is NP-hard. We propose algorithms for the different variants, some of which include approximation guarantees. We also propose distributed algorithms to assign sensors to missions which we adapt to include energy-awareness to extend network lifetime. Finally, we show comprehensive simulation results comparing these solutions to an upper bound on the optimal solution.", acknowledgement = ack-nhfb, articleno = "36", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "mission assignment; resource allocation; wireless sensor networks", } @Article{Kusy:2010:RDS, author = "Branislav Kus{\'y} and Isaac Amundson and Janos Sallai and Peter V{\"o}lgyesi and Akos L{\'e}deczi and Xenofon Koutsoukos", title = "{RF} {Doppler} shift-based mobile sensor tracking and navigation", journal = j-TOSN, volume = "7", number = "1", pages = "1:1--1:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806896", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Mobile wireless sensors require position updates for tracking and navigation. We present a localization technique that uses the Doppler shift in radio transmission frequency observed by stationary sensors. We consider two scenarios. In the first, the mobile node is carried by a person. In the second, the mobile node controls a robot. In both approaches the mobile node transmits an RF signal, and infrastructure nodes measure the Doppler-shifted frequency. Such measurements enable us to calculate the position and velocity of the mobile transmitter. Our experimental results demonstrate that this technique is viable and accurate for resource-constrained mobile sensor tracking and navigation.", acknowledgement = ack-nhfb, articleno = "1", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Doppler effect; localization; navigation; Sensor networks; tracking", } @Article{Zhang:2010:RTD, author = "Jun Zhang and Xiaohua Jia and Guoliang Xing", title = "Real-time data aggregation in contention-based wireless sensor networks", journal = j-TOSN, volume = "7", number = "1", pages = "2:1--2:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806897", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We investigate the problem of delay constrained maximal information collection for CSMA-based wireless sensor networks. We study how to allocate the maximal allowable transmission delay at each node, such that the amount of information collected at the sink is maximized and the total delay for the data aggregation is within the given bound. We formulate the problem by using dynamic programming and propose an optimal algorithm for the optimal assignment of transmission attempts. Based on the analysis of the optimal solution, we propose a distributed greedy algorithm. It is shown to have a similar performance as the optimal one.", acknowledgement = ack-nhfb, articleno = "2", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "CSMA/CA; data aggregation; delay constrained transmission; real-time traffic; Sensor networks", } @Article{Kwon:2010:RLS, author = "Youngmin Kwon and Kirill Mechitov and Sameer Sundresh and Wooyoung Kim and Gul Agha", title = "Resilient localization for sensor networks in outdoor environments", journal = j-TOSN, volume = "7", number = "1", pages = "3:1--3:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806898", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The process of determining the physical locations of nodes in a wireless sensor network is known as {\em localization}. Self-localization is critical for large-scale sensor networks, because manual or assisted localization is often impractical due to time requirements, economic constraints, or inherent limitations of the deployment scenarios. We propose scalable solutions for reliably localizing wireless sensor networks in environments conducive to several types of ranging errors. We follow a hybrid hardware-software approach for acoustic ranging or radio interferometry to acquire internode distance measurements, and a resilient self-localization algorithm to compute the node location estimates. The acoustic ranging method improves on previous work, extending the practical measurement range up to 35 m in grassy outdoor environments, achieving a distance-invariant median measurement error of about 1\% (33 cm). The localization algorithm is based on {\em least-squares scaling\/} with soft constraints. Empirical evaluation using ranging results obtained from sensor network field experiments and simulations confirms that our approach is more resilient than multidimensional scaling (MDS) algorithms against large-magnitude ranging errors and sparse range measurements: conditions that are common in large-scale outdoor sensor network deployments.", acknowledgement = ack-nhfb, articleno = "3", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "least-squares scaling; localization; MDS; multidimensional scaling; multilateration; Wireless sensor networks", } @Article{Sugihara:2010:SCS, author = "Ryo Sugihara and Rajesh K. Gupta", title = "Speed control and scheduling of data mules in sensor networks", journal = j-TOSN, volume = "7", number = "1", pages = "4:1--4:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806899", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Unlike traditional multihop forwarding among stationary sensor nodes, use of mobile devices for data collection in wireless sensor networks has recently been gathering more attention. The use of mobility significantly reduces the energy consumption at sensor nodes, elongating the functional lifetime of the network. However, a drawback is an increased data delivery latency. Reducing the latency through optimizing the motion of data mules is critical for this approach to thrive. In this article, we focus on the problem of motion planning, specifically, determination of the speed of the data mule and the scheduling of the communication tasks with the sensors. We consider three models of mobility capability of the data mule to accommodate different types of vehicles. Under each mobility model, we design optimal and heuristic algorithms for different problems: single data mule case, single data mule with periodic data generation case, and multiple data mules case. We compare the performance of the heuristic algorithm with a naive algorithm and also with the multihop forwarding approach by numerical experiments. We also compare one of the optimal algorithms with a previously proposed method to see how our algorithm improves the performance and is also useful in practice. As far as we know, this study is the first of a kind that provides a systematic understanding of the motion planning problem of data mules.", acknowledgement = ack-nhfb, articleno = "4", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Controlled mobility; linear programming; motion planning; scheduling; simulation", } @Article{Hu:2010:TTW, author = "Wen Hu and Hailun Tan and Peter Corke and Wen Chan Shih and Sanjay Jha", title = "Toward trusted wireless sensor networks", journal = j-TOSN, volume = "7", number = "1", pages = "5:1--5:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806900", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article presents the design and implementation of a trusted sensor node that provides Internet-grade security at low system cost. We describe trustedFleck, which uses a commodity Trusted Platform Module (TPM) chip to extend the capabilities of a standard wireless sensor node to provide security services such as {\em message integrity, confidentiality, authenticity}, and {\em system integrity\/} based on RSA public-key and XTEA-based symmetric-key cryptography. In addition trustedFleck provides secure storage of private keys and provides platform configuration registers (PCRs) to store system configurations and detect code tampering. We analyze system performance using metrics that are important for WSN applications such as computation time, memory size, energy consumption and cost. Our results show that trustedFleck significantly outperforms previous approaches (e.g., TinyECC) in terms of these metrics while providing stronger security levels. Finally, we describe a number of examples, built on trustedFleck, of symmetric key management, secure RPC, secure software update, and {\em remote attestation}.", acknowledgement = ack-nhfb, articleno = "5", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "public key (PK); remote attestation; RSA; TPM; trusted computing; Wireless sensor networks", } @Article{Miller:2010:RER, author = "Chris Miller and Christian Poellabauer", title = "Reliable and efficient reprogramming in sensor networks", journal = j-TOSN, volume = "7", number = "1", pages = "6:1--6:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806901", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Retasking and remote programming of sensor networks is an essential functionality to make these networks practical and effective. As the availability of more capable sensor nodes increases and new functional implementations continue to be proposed, these large collections of wireless nodes will need the ability to update and upgrade the software packages they are running. In order to do this, the new binary file must be distributed to all nodes in the network. Making a physical connection with each individual node is impractical in large wireless networks. Standard flooding mechanisms are too energy-costly and computationally expensive and they may interfere with the network's current tasks. A reliable method for distributing new code or binary files to every node in a wireless sensor network is needed. We propose a reprogramming/retasking framework for sensor networks that is energy efficient, responsive, and reliable, while maintaining a stable network.", acknowledgement = ack-nhfb, articleno = "6", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Broadcast; energy efficiency; minimum energy broadcast; reliable distribution; reprogramming; retasking; sensor networks", } @Article{Lim:2010:RRP, author = "Jun Bum Lim and Beakcheol Jang and Suyoung Yoon and Mihail L. Sichitiu and Alexander G. Dean", title = "{RaPTEX}: {Rapid} prototyping tool for embedded communication systems", journal = j-TOSN, volume = "7", number = "1", pages = "7:1--7:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806902", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Advances in microprocessors, memory, and radio technology have enabled the emergence of embedded systems that rely on communication systems to exchange information and coordinate their activities in spatially distributed applications. However, developing embedded communication systems that satisfy specific application requirements is a challenge due to the many tradeoffs imposed by different choices of underlying protocols and their parameters. Furthermore, evaluating the correctness and performance of the design and implementation before deploying it is a nontrivial task due to the complexity of the resulting system. This article presents the design and implementation of RaPTEX, a rapid prototyping tool for embedded communication systems, especially well suited for wireless sensor networks (WSNs), consisting of three major subsystems: a toolbox, an analytical performance estimation framework, and an emulation environment. We use a hierarchical approach in the design of the toolbox to facilitate the composition of the network stack. For fast exploration of the tradeoff space at design time, we build an analytical performance estimation model for energy consumption, delay, and throughput. For realistic performance evaluation, we design and implement a hybrid, accurate, yet scalable, emulation environment. Through three use cases, we study the tradeoff space for different protocols and topologies, and highlight the benefits of using RaPTEX for designing and evaluating embedded communication systems for WSNs.", acknowledgement = ack-nhfb, articleno = "7", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "analytical performance modeling; rapid prototyping tool; RaPTEX; real code simulation; TinyOS; Wireless sensor networks", } @Article{Wang:2010:MLL, author = "Chao Wang and Parameswaran Ramanathan and Kewal K. Saluja", title = "Modeling latency --- lifetime trade-off for target detection in mobile sensor networks", journal = j-TOSN, volume = "7", number = "1", pages = "8:1--8:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806903", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Two important measures of performance for the surveillance applications of the mobile sensor networks are detection latency and system lifetime. Previous work on modeling detection delay has assumed that sensor measurements are delivered to the fusion center with zero delay. Such approaches can require excessive energy, resulting into reduced lifetime. This article argues that a trade-off between detection latency and system lifetime can be made by employing an energy aware transmission scheme. The article formulates the trade-off as an optimization problem, and presents an analytic method to model both detection latency and system lifetime. The model is substantiated by using simulation.", acknowledgement = ack-nhfb, articleno = "8", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy efficiency; Mobile sensor networks; target detection", } @Article{Kalpakis:2010:ESA, author = "Konstantinos Kalpakis", title = "Everywhere sparse approximately optimal minimum energy data gathering and aggregation in sensor networks", journal = j-TOSN, volume = "7", number = "1", pages = "9:1--9:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806904", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We consider two related data gathering problems for wireless sensor networks (WSNs). The MLDA problem is concerned with maximizing the system lifetime $T$ so that we can perform $T$ rounds of data gathering with in-network aggregation, given the initial available energy of the sensors. The $M^2$ EDA problem is concerned with minimizing the maximum energy consumed by any one sensor when performing $T$ rounds of data gathering with in-network aggregation, for a given $T$.\par We provide an effective algorithm for finding an everywhere sparse integral solution to the $M^2$ EDA problem which is within a factor of $\alpha = 1+ 4 n / T$ of the optimum, where $n$ is the number of nodes. A solution is everywhere sparse if the number of communication links for any subset $X$ of nodes is $O(X)$, in our case at most $4 |X|$. Since often $T = \omega(n)$, we obtain the first everywhere sparse, asymptotically optimal integral solutions to the $M^2$ EDA problem. Everywhere sparse solutions are desirable since then almost all sensors have small number of incident communication links and small overhead for maintaining state.\par We also show that the MLDA and $M^2$ EDA problems are essentially equivalent, in the sense that we can obtain an optimal fractional solution to an instance of the MLDA problem by scaling an optimal fractional solution to a suitable instance of the $M^2$ EDA problem. As a result, our algorithm is effective at finding everywhere sparse, asymptotically optimal, integral solutions to the MLDA problem, when the initial available energy of the sensors is sufficient for supporting optimal system lifetime which is $\omega(n)$.", acknowledgement = ack-nhfb, articleno = "9", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Energy management; in-network aggregation; lifetime maximization; sparsity communication topology; wireless sensor networks", } @Article{Langendoen:2010:AMPa, author = "Koen Langendoen and Andreas Meier", title = "Analyzing {MAC} protocols for low data-rate applications", journal = j-TOSN, volume = "7", number = "1", pages = "10:1--10:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1806895.1806905", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:33:47 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The fundamental wireless sensors network (WSN) requirement to be energy-efficient has produced a whole range of specialized medium access control (MAC) protocols. They differ in how performance (latency, throughput) is traded off for a reduction in energy consumption. The question ``which protocol is best?'' is difficult to answer because (i) this depends on specific details of the application requirements and hardware characteristics involved, and (ii) protocols have mainly been assessed individually with each outperforming the canonical S-MAC protocol, but with different simulators, hardware platforms, and workloads. This article addresses that void for low data-rate applications where collisions are of little concern, making an analytical approach tractable in which latency and energy consumption are modeled as functions of key protocol parameters (duty cycle, slot length, number of slots, etc.). By exhaustive search we determine the Pareto-optimal protocol settings for a given workload (data rate, network topology). Of the protocols compared we find that WiseMAC strikes the best latency versus energy-consumption tradeoff across the range of workloads considered. In particular, its random access scheme in combination with local synchronization not only minimizes protocol overhead, but also maximizes the available channel bandwidth.", acknowledgement = ack-nhfb, articleno = "10", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Energy efficiency; performance modeling; sensor networks", } @Article{Martin:2010:KPH, author = "Keith M. Martin and Maura B. Paterson and Douglas R. Stinson", title = "Key predistribution for homogeneous wireless sensor networks with group deployment of nodes", journal = j-TOSN, volume = "7", number = "2", pages = "11:1--11:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824767", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Recent literature contains proposals for key predistribution schemes for sensor networks in which nodes are deployed in separate groups. In this article we consider the implications of group deployment for the connectivity and resilience of a key predistribution scheme. We propose a flexible scheme, based on the structure of a resolvable transversal design. We demonstrate that this scheme permits effective trade-offs between resilience, connectivity and storage requirements within a group-deployed environment as compared with other schemes in the literature, and show that group deployment can be used to increase network connectivity, without increasing storage requirements or sacrificing resilience.", acknowledgement = ack-nhfb, articleno = "11", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Group-based deployment; key predistribution; wireless sensor networks", } @Article{Liaskovitis:2010:LRS, author = "Periklis G. Liaskovitis and Curt Schurgers", title = "Leveraging redundancy in sampling-interpolation applications for sensor networks: {A} spectral approach", journal = j-TOSN, volume = "7", number = "2", pages = "12:1--12:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824768", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "An important class of sensor network applications aims at estimating the spatiotemporal behavior of a physical phenomenon, such as temperature variations over an area of interest. In such a scenario, the network essentially acts as a distributed sampling system. However, unlike in the event detection case, the notion of sensing range is largely meaningless for sampling-interpolation applications. As a result, existing techniques to exploit sensing redundancy in event detection settings, which rely on the existence of such sensing range, become unusable. Instead, this article presents a new method to exploit redundancy for the sampling class of applications by selecting a suitable set of sensors to act as sampling points. Through online estimation of process characteristics, sufficiently accurate interpolation can be achieved. We illustrate an algorithm to obtain multiple disjoint sets and demonstrate significant reductions in the number of active sensors for a wide range of synthetic sensor data.", acknowledgement = ack-nhfb, articleno = "12", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "energy efficiency; Hilbert space; sampling; sensing topology management; Sensor networks; sensor selection; spatial monitoring", } @Article{Machado:2010:CPC, author = "Renita Machado and Wensheng Zhang and Guiling Wang and Sirin Tekinay", title = "Coverage properties of clustered wireless sensor networks", journal = j-TOSN, volume = "7", number = "2", pages = "13:1--13:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824769", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article studies clustered wireless sensor networks (WSNs), a realistic topology resulting from common deployment methods. We study coverage in {\em naturally clustered\/} networks of wireless sensor nodes, as opposed to WSNs where clustering is facilitated by selection. We show that along with increasing the vacancy in random placement of nodes in a WSN, it also alters the connectivity properties in the network. We analyze varying levels of redundancy to determine the probability of coverage in the network. The phenomenon of clustering in networks of wireless sensor nodes raises interesting questions for future research and development. The article provides a foundation for the design to optimize network performance with the constraint of sensing coverage.", acknowledgement = ack-nhfb, articleno = "13", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "clustering; coverage; Wireless sensor networks", } @Article{Jurcik:2010:DWC, author = "Petr Jurcik and Anis Koub{\^a}a and Ricardo Severino and M{\'a}rio Alves and Eduardo Tovar", title = "Dimensioning and worst-case analysis of cluster-tree sensor networks", journal = j-TOSN, volume = "7", number = "2", pages = "14:1--14:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824770", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Modeling the fundamental performance limits of Wireless Sensor Networks (WSNs) is of paramount importance to understand their behavior under the worst-case conditions and to make the appropriate design choices. This is particular relevant for time-sensitive WSN applications, where the timing behavior of the network protocols (message transmission must respect deadlines) impacts on the correct operation of these applications. In that direction this article contributes with a methodology based on Network Calculus, which enables quick and efficient worst-case dimensioning of static or even dynamically changing cluster-tree WSNs where the data sink can either be static or mobile. We propose closed-form recurrent expressions for computing the worst-case end-to-end delays, buffering and bandwidth requirements across any source-destination path in a cluster-tree WSN. We show how to apply our methodology to the case of IEEE 802.15.4/ZigBee cluster-tree WSNs. Finally, we demonstrate the validity and analyze the accuracy of our methodology through a comprehensive experimental study using commercially available technology, namely TelosB motes running TinyOS.", acknowledgement = ack-nhfb, articleno = "14", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Cluster-tree; IEEE 802.15.4; network calculus; network dimensioning; sensor networks; worst-case analysis; ZigBee", } @Article{Mottola:2010:AWS, author = "Luca Mottola and Gian Pietro Picco and Matteo Ceriotti and {\c{S}}tefan Gun{\u{a}} and Amy L. Murphy", title = "Not all wireless sensor networks are created equal: {A} comparative study on tunnels", journal = j-TOSN, volume = "7", number = "2", pages = "15:1--15:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824771", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Wireless sensor networks (WSNs) are envisioned for a number of application scenarios. Nevertheless, the few in-the-field experiences typically focus on the features of a specific system, and rarely report about the characteristics of the target environment, especially with respect to the behavior and performance of low-power wireless communication. The TRITon project, funded by our local administration, aims to improve safety and reduce maintenance costs of road tunnels, using a WSN-based control infrastructure. The access to real tunnels within TRITon gives us the opportunity to experimentally assess the peculiarities of this environment, hitherto not investigated in the WSN field. We report about three deployments: (i) an operational road tunnel, enabling us to assess the impact of vehicular traffic; (ii) a nonoperational tunnel, providing insights into analogous scenarios (e.g., underground mines) without vehicles; (iii) a vineyard, serving as a baseline representative of the existing literature. Our setup, replicated in each deployment, uses mainstream WSN hardware, and popular MAC and routing protocols. We analyze and compare the deployments with respect to reliability, stability, and asymmetry of links, the accuracy of link quality estimators, and the impact of these aspects on MAC and routing layers. Our analysis shows that a number of criteria commonly used in the design of WSN protocols do not hold in tunnels. Therefore, our results are useful for designing networking solutions operating efficiently in similar environments.", acknowledgement = ack-nhfb, articleno = "15", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "link quality; low-power wireless communications; network topologies; topology characterization; tunnel environment; Wireless sensor networks", } @Article{Strasser:2010:DRJ, author = "Mario Strasser and Boris Danev and Srdjan {\v{C}}apkun", title = "Detection of reactive jamming in sensor networks", journal = j-TOSN, volume = "7", number = "2", pages = "16:1--16:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824772", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "An integral part of most security- and safety-critical applications is a dependable and timely alarm notification. However, owing to the resource constraints of wireless sensor nodes (i.e., their limited power and spectral diversity), ensuring a timely and jamming-resistant delivery of alarm messages in applications that rely on wireless sensor networks is a challenging task. With current alarm forwarding schemes, blocking of an alarm by jamming is straightforward and jamming is very likely to remain unnoticed. In this work, we propose a novel jamming detection scheme as a solution to this problem. Our scheme is able to identify the cause of bit errors for individual packets by looking at the received signal strength during the reception of these bits and is well-suited for the protection of reactive alarm systems with very low network traffic. We present three different techniques for the identification of bit errors based on: predetermined knowledge, error correcting codes, and limited node wiring. We perform a detailed evaluation of the proposed solution and validate our findings experimentally with Chipcon CC1000 radios. The results show that our solution effectively detects sophisticated jamming attacks that cannot be detected with existing techniques and enables the formation of robust sensor networks for dependable delivery of alarm notifications. Our scheme also meets the high demands on the energy efficiency of reactive surveillance applications as it can operate without introducing additional wireless network traffic.", acknowledgement = ack-nhfb, articleno = "16", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Jamming detection; reactive jamming; sensor networks", } @Article{Paschalidis:2010:SAD, author = "Ioannis Ch. Paschalidis and Yin Chen", title = "Statistical anomaly detection with sensor networks", journal = j-TOSN, volume = "7", number = "2", pages = "17:1--17:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824773", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We seek to detect statistically significant temporal or spatial changes in either the underlying process the sensor network is monitoring or in the network operation itself. These changes may point to faults, adversarial threats, misbehavior, or other anomalies that require intervention. To that end, we introduce a new statistical anomaly detection framework that uses Markov models to characterize the ``normal'' behavior of the sensor network. We develop a series of Markov models, including tree-indexed Markov chains which can model its spatial structure. For each model, an anomaly-free probability law is estimated from past traces. We leverage large deviations techniques to develop optimal anomaly detection rules for each corresponding Markov model, assessing whether its most recent empirical measure is consistent with the anomaly-free probability law. A series of simulation results, some with real sensor data, validate the effectiveness of the proposed anomaly detection algorithms.", acknowledgement = ack-nhfb, articleno = "17", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "anomaly detection; large deviations; Sensor networks", } @Article{Yau:2010:QMS, author = "David K. Y. Yau and Nung Kwan Yip and Chris Y. T. Ma and Nageswara S. V. Rao and Mallikarjun Shankar", title = "Quality of monitoring of stochastic events by periodic and proportional-share scheduling of sensor coverage", journal = j-TOSN, volume = "7", number = "2", pages = "18:1--18:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824774", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We analyze the quality of monitoring (QoM) of stochastic events by a periodic sensor which monitors a point of interest (PoI) for $q$ time every $p$ time. We show how the amount of information captured at a PoI is affected by the proportion $q/p$, the time interval $p$ over which the proportion is achieved, the event type in terms of its stochastic arrival dynamics and staying times and the utility function. The periodic PoI sensor schedule happens in two broad contexts. In the case of static sensors, a sensor monitoring a PoI may be periodically turned off to conserve energy, thereby extending the lifetime of the monitoring until the sensor can be recharged or replaced. In the case of mobile sensors, a sensor may move between the PoIs in a repeating visit schedule. In this case, the PoIs may vary in importance, and the scheduling objective is to distribute the sensor's coverage time in proportion to the importance levels of the PoIs. Based on our QoM analysis, we optimize a class of periodic mobile coverage schedules that can achieve such proportional sharing while maximizing the QoM of the total system.", acknowledgement = ack-nhfb, articleno = "18", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "mobile coverage; periodic scheduling; proportional sharing; Sensor network", } @Article{Langendoen:2010:AMPb, author = "Koen Langendoen and Andreas Meier", title = "Analyzing {MAC} protocols for low data-rate applications", journal = j-TOSN, volume = "7", number = "2", pages = "19:1--19:??", month = aug, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1824766.1824775", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:03 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The fundamental WSN requirement to be energy-efficient has produced a whole range of specialized Medium Access Control (MAC) protocols. They differ in how performance (latency, throughput) is traded off for a reduction in energy consumption. The question ``which protocol is best?'' is difficult to answer because (i) this depends on specific details of the application requirements and hardware characteristics involved, and (ii) protocols have mainly been assessed individually with each outperforming the canonical S-MAC protocol, but with different simulators, hardware platforms, and workloads. This article addresses that void for low data-rate applications where collisions are of little concern, making an analytical approach tractable in which latency and energy consumption are modeled as a function of key protocol parameters (duty cycle, slot length, number of slots, etc.). By exhaustive search we determine the Pareto-optimal protocol settings for a given workload (data rate, network topology). Of the protocols compared we find that WiseMAC strikes the best latency vs. energy-consumption trade-off across the range of workloads considered. In particular, its random access scheme in combination with local synchronization does not only minimize protocol overhead, but also maximizes the available channel bandwidth.", acknowledgement = ack-nhfb, articleno = "19", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Energy efficiency; performance modeling; sensor networks", } @Article{Paek:2010:RRC, author = "Jeongyeup Paek and Ramesh Govindan", title = "{RCRT}: {Rate-controlled} reliable transport protocol for wireless sensor networks", journal = j-TOSN, volume = "7", number = "3", pages = "20:1--20:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807049", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Emerging high-rate applications (imaging, structural monitoring, acoustic localization) will need to transport large volumes of data concurrently from several sensors. These applications are also loss-intolerant. A key requirement for such applications, then, is a protocol that reliably transports sensor data from many sources to one or more sinks without incurring congestion collapse. In this article, we discuss RCRT, a rate-controlled reliable transport protocol suitable for constrained sensor nodes. RCRT uses end-to-end explicit loss recovery, but places all the congestion detection and rate adaptation functionality in the sinks. This has two important advantages: efficiency and flexibility. Because sinks make rate allocation decisions, they are able to achieve greater efficiency since they have a more comprehensive view of network behavior. For the same reason, it is possible to alter the rate allocation decisions (for example, from one that ensures that all nodes get the same rate, to one that ensures that nodes get rates in proportion to their demands), without modifying sensor code at all. We evaluate RCRT extensively on a 40-node wireless sensor network testbed and show that RCRT achieves 1.7 times the rate achieved by IFRC and 1.4 times that of WRCP, two recently proposed interference-aware distributed rate-control protocols. We also present results from a 3-month-long 19-node real world deployment of RCRT in an imaging application and show that RCRT works well in real long-term deployments.", acknowledgement = ack-nhfb, articleno = "20", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "centralized; congestion control; reliable; Sensor networks; tiered network; transport protocol", } @Article{Chin:2010:ILL, author = "Jren-Chit Chin and Nageswara S. V. Rao and David K. Y. Yau and Mallikarjun Shankar and Yong Yang and Jennifer C. Hou and Srinivasagopalan Srivathsan and Sitharama Iyengar", title = "Identification of low-level point radioactive sources using a sensor network", journal = j-TOSN, volume = "7", number = "3", pages = "21:1--21:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807050", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Identification of a low-level point radioactive source amidst background radiation is achieved by a network of radiation sensors using a two-step approach. Based on measurements from three or more sensors, a geometric difference triangulation method or an $N$-sensor localization method is used to estimate the location and strength of the source. Then a sequential probability ratio test based on current measurements and estimated parameters is employed to finally decide: (1) the presence of a source with the estimated parameters, or (2) the absence of the source, or (3) the insufficiency of measurements to make a decision. This method achieves specified levels of false alarm and missed detection probabilities, while ensuring a close-to-minimal number of measurements for reaching a decision. This method minimizes the ghost-source problem of current estimation methods, and achieves a lower false alarm rate compared with current detection methods. This method is tested and demonstrated using: (1) simulations, and (2) a test-bed that utilizes the scaling properties of point radioactive sources to emulate high intensity ones that cannot be easily and safely handled in laboratory experiments.", acknowledgement = ack-nhfb, articleno = "21", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "detection and localization; Point radioactive source; sequential probability ratio test", } @Article{Zheng:2010:ODD, author = "Rong Zheng and Khuong Vu and Amit Pendharkar and Gangbing Song", title = "Obstacle discovery in distributed actuator and sensor networks", journal = j-TOSN, volume = "7", number = "3", pages = "22:1--22:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807051", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Distributed active sensing is a new sensing paradigm, where active sensors (aka actuators) as illuminating sources and passive sensors as receivers are distributed in a field, and collaboratively detect events of interest. In this paper, we study the fundamental properties of distributed actuator and sensor networks (DASNs) in detecting and localizing obstacles. A novel notion of ``exposure'' is defined, which quantifies the dimension limitations in detectability. Using simple geometric constructs, we propose polynomial-time algorithms to compute the exposure and bounding regions where the center of the obstacles may lie.", acknowledgement = ack-nhfb, articleno = "22", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Active sensing; conflict regions; exposure; Segment Voronoi Diagram", } @Article{Djidjev:2010:AAC, author = "Hristo N. Djidjev", title = "Approximation algorithms for computing minimum exposure paths in a sensor field", journal = j-TOSN, volume = "7", number = "3", pages = "23:1--23:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807052", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The exposure of a path $p$ in a sensor field is a measure of the likelihood that an object traveling along $p$ is detected by at least one sensor from a network of sensors, and is formally defined as an integral over all points $x$ of $p$ of the sensibility (the strength of the signal coming from $x$) times the element of path length. The minimum exposure path (MEP) problem is, given a pair of points $x$ and $y$ inside a sensor field, to find a path between $x$ and $y$ of minimum exposure. In this article we introduce the first rigorous treatment of the problem, designing an approximation algorithm for the MEP problem with guaranteed performance characteristics. Given a convex polygon $p$ of size $n$ with $O(n)$ sensors inside it and any real number $\epsilon > 0$, our algorithm finds a path in $p$ whose exposure is within a $1 + \epsilon$ factor of the exposure of the MEP, in time $O(n / \epsilon^2 \psi \log n)$, where $\psi$ is a geometric characteristic of the field. We also describe a framework for a faster implementation of our algorithm, which reduces the time by a factor of approximately $\theta (1 / \epsilon)$, while keeping the same approximation ratio.", acknowledgement = ack-nhfb, articleno = "23", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "approximation algorithms; coverage; minimum exposure paths; Sensor networks; shortest paths", } @Article{Schmid:2010:ICP, author = "Thomas Schmid and Roy Shea and Zainul Charbiwala and Jonathan Friedman and Mani B. Srivastava and Young H. Cho", title = "On the interaction of clocks, power, and synchronization in duty-cycled embedded sensor nodes", journal = j-TOSN, volume = "7", number = "3", pages = "24:1--24:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807053", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The efficiency of the time synchronization service in wireless sensor networks is tightly connected to the design of the radio, the quality of the clocking hardware, and the synchronization algorithm employed. While improvements can be made on all levels of the system, over the last few years most work has focused on the algorithmic level to minimize message exchange and in radio architectures to provide accurate time-stamping mechanisms. Surprisingly, the influences of the underlying clock system and its impact on the overall synchronization accuracy has largely been unstudied.\par In this work, we investigate the impact of the clocking subsystem on the time synchronization service and address, in particular, the influence of changes in environmental temperature on clock drift in highly duty-cycled wireless sensor nodes. We also develop formulas that help the system architect choose the optimal resynchronization period to achieve a given synchronization accuracy. We find that the synchronization accuracy has a two region behavior. In the first region, the synchronization accuracy is limited by quantization error, while int he second region changes in environmental temperature impact the achievable accuracy. We verify our analytic results in simulation and real hardware experiments.", acknowledgement = ack-nhfb, articleno = "24", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "clocks; duty-cycling; Oscillator; temperature effects; time synchronization", } @Article{Peleg:2010:LSC, author = "David Peleg and Liam Roditty", title = "Localized spanner construction for ad hoc networks with variable transmission range", journal = j-TOSN, volume = "7", number = "3", pages = "25:1--25:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807054", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article presents an algorithm for constructing a spanner for ad hoc networks whose nodes have {\em variable\/} transmission range. Almost all previous spanner constructions for ad hoc networks assumed that all nodes in the network have the same transmission range. This allowed a succinct representation of the network as a unit disk graph, serving as the basis for the construction. In contrast, when nodes have variable transmission range, the ad hoc network must be modeled by a general disk graph. Whereas unit disk graphs are undirected, general disk graphs are directed. This complicates the construction of a spanner for the network, since currently there are no efficient constructions of low-stretch spanners for general directed graphs. Nevertheless, in this article it is shown that the class of disk graphs enjoys (efficiently constructible) spanners of quality similar to that of unit disk graph spanners. Moreover, it is shown that the new construction can be performed in a localized fashion. Our results use only simple packing arguments, hence all algorithms work for every metric space of constant doubling dimension.", acknowledgement = ack-nhfb, articleno = "25", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "Directed graphs; distributed algorithms; spanners", } @Article{Ling:2010:APA, author = "Yibei Ling and Chung-Min Chen and Shigang Chen", title = "Analysis of power-aware buffering schemes in wireless sensor networks", journal = j-TOSN, volume = "7", number = "3", pages = "26:1--26:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807055", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We study the power-aware buffering problem in battery-powered sensor networks, focusing on the fixed-size and fixed-interval buffering schemes. The main motivation is to address the yet poorly understood size variation-induced effect on power-aware buffering schemes. Our theoretical analysis elucidates the fundamental differences between the fixed-size and fixed-interval buffering schemes in the presence of data-size variation. It shows that data-size variation has detrimental effects on the power expenditure of the fixed-size buffering in general, and reveals that the size variation induced effects can be either mitigated by a positive skewness or promoted by a negative skewness in size distribution. By contrast, the fixed-interval buffering scheme has an obvious advantage of being eminently immune to the data-size variation. Hence the fixed-interval buffering scheme is a risk-averse strategy for its robustness in a variety of operational environments. In addition, based on the fixed-interval buffering scheme, we establish the power consumption relationship between child nodes and parent node in a static data-collection tree, and give an in-depth analysis of the impact of child bandwidth distribution on the parent's power consumption.\par This study is of practical significance: it sheds new light on the relationship among power consumption of buffering schemes, power parameters of radio module and memory bank, data arrival rate, and data-size variation, thereby providing well-informed guidance in determining an optimal buffer size (interval) to maximize the operational lifespan of sensor networks.", acknowledgement = ack-nhfb, articleno = "26", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "algorithm analysis; Power-aware buffering schemes", } @Article{Efrat:2010:FDA, author = "Alon Efrat and David Forrester and Anand Iyer and Stephen G. Kobourov and Cesim Erten and Ozan Kilic", title = "Force-directed approaches to sensor localization", journal = j-TOSN, volume = "7", number = "3", pages = "27:1--27:??", month = sep, year = "2010", CODEN = "????", DOI = "http://doi.acm.org/10.1145/1807048.1807057", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Oct 8 18:34:21 MDT 2010", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "As the number of applications of sensor networks increases, so does the interest in sensor network localization, that is, in recovering the correct position of each node in a network of sensors from partial connectivity information such as adjacency, range, or angle between neighboring nodes. In this article, we consider the anchor-free localization problem in sensor networks that report possibly noisy range information and angular information about the relative order of each sensor's neighbors. Previously proposed techniques seem to successfully reconstruct the original positions of the nodes for relatively small networks with nodes distributed in simple regions. However, these techniques do not scale well with network size and yield poor results with nonconvex or nonsimple underlying topology. Moreover, the distributed nature of the problem makes some of the centralized techniques inapplicable in distributed settings. To address these problems we describe a multiscale dead-reckoning (MSDR) algorithm that scales well for large networks, can reconstruct complex underlying topologies, and is resilient to noise. The MSDR algorithm takes its roots from classic force-directed graph layout computation techniques. These techniques are augmented with a multiscale extension to handle the scalability issue and with a dead-reckoning extension to overcome the problems arising with nonsimple topologies. Furthermore, we show that the distributed version of the MSDR algorithm performs as well as, if not better than, its centralized counterpart, as shown by the quality of the layout, measured in terms of the accuracy of the computed pairwise distances between sensors in the network.", acknowledgement = ack-nhfb, articleno = "27", fjournal = "ACM Transactions on Sensor Networks (TOSN)", keywords = "force-directed; node localization; Sensor networks", } @Article{Holland:2011:OPL, author = "Matthew Holland and Tianqi Wang and Bulent Tavli and Alireza Seyedi and Wendi Heinzelman", title = "Optimizing physical-layer parameters for wireless sensor networks", journal = j-TOSN, volume = "7", number = "4", pages = "28:1--28:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921622", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "28", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Chan:2011:SFP, author = "Aldar C-F. Chan and Claude Castelluccia", title = "A security framework for privacy-preserving data aggregation in wireless sensor networks", journal = j-TOSN, volume = "7", number = "4", pages = "29:1--29:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921623", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "29", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Panta:2011:EIC, author = "Rajesh Krishna Panta and Saurabh Bagchi and Samuel P. Midkiff", title = "Efficient incremental code update for sensor networks", journal = j-TOSN, volume = "7", number = "4", pages = "30:1--30:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921624", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "30", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Krause:2011:RSP, author = "Andreas Krause and Carlos Guestrin and Anupam Gupta and Jon Kleinberg", title = "Robust sensor placements at informative and communication-efficient locations", journal = j-TOSN, volume = "7", number = "4", pages = "31:1--31:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921625", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "31", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Wan:2011:EEC, author = "Chieh-Yih Wan and Shane B. Eisenman and Andrew T. Campbell", title = "Energy-efficient congestion detection and avoidance in sensor networks", journal = j-TOSN, volume = "7", number = "4", pages = "32:1--32:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921626", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "32", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Wang:2011:OSM, author = "Guiling Wang and Mary Jane Irwin and Haoying Fu and Piotr Berman and Wensheng Zhang and Tom La Porta", title = "Optimizing sensor movement planning for energy efficiency", journal = j-TOSN, volume = "7", number = "4", pages = "33:1--33:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921627", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "33", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Keeler:2011:MFG, author = "Holger P. Keeler and Peter G. Taylor", title = "A model framework for greedy routing in a sensor network with a stochastic power scheme", journal = j-TOSN, volume = "7", number = "4", pages = "34:1--34:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921628", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "34", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Cai:2011:CSD, author = "Haiyan Cai and Xiaohua Jia and Mo Sha", title = "Critical sensor density for partial connectivity in large area wireless sensor networks", journal = j-TOSN, volume = "7", number = "4", pages = "35:1--35:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921629", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "35", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Zhu:2011:SNL, author = "Yuanchen Zhu and Steven J. Gortler and Dylan Thurston", title = "Sensor network localization using sensor perturbation", journal = j-TOSN, volume = "7", number = "4", pages = "36:1--36:??", month = feb, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1921621.1921630", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Mar 28 11:54:52 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "36", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Sugihara:2011:PPD, author = "Ryo Sugihara and Rajesh K. Gupta", title = "Path Planning of Data Mules in Sensor Networks", journal = j-TOSN, volume = "8", number = "1", pages = "1:1--1:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993043", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "1", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Wang:2011:MMR, author = "Xiaorui Wang and Xiaodong Wang and Xing Fu and Guoliang Xing", title = "{MCRT}: Multichannel Real-Time Communications in Wireless Sensor Networks", journal = j-TOSN, volume = "8", number = "1", pages = "2:1--2:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993044", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "2", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Dereszynski:2011:SMD, author = "Ethan W. Dereszynski and Thomas G. Dietterich", title = "Spatiotemporal Models for Data-Anomaly Detection in Dynamic Environmental Monitoring Campaigns", journal = j-TOSN, volume = "8", number = "1", pages = "3:1--3:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993045", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "3", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Sarkar:2011:HSG, author = "Rik Sarkar and Xianjin Zhu and Jie Gao", title = "Hierarchical Spatial Gossip for Multiresolution Representations in Sensor Networks", journal = j-TOSN, volume = "8", number = "1", pages = "4:1--4:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993046", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "4", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Singh:2011:MTT, author = "Jaspreet Singh and Rajesh Kumar and Upamanyu Madhow and Subhash Suri and Richard Cagley", title = "Multiple-Target Tracking With Binary Proximity Sensors", journal = j-TOSN, volume = "8", number = "1", pages = "5:1--5:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993047", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "5", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{He:2011:PPP, author = "Wenbo He and Xue Liu and Hoang Viet Nguyen and Klara Nahrstedt and Tarek Abdelzaher", title = "{PDA}: Privacy-Preserving Data Aggregation for Information Collection", journal = j-TOSN, volume = "8", number = "1", pages = "6:1--6:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993048", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "6", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Francesco:2011:DCW, author = "Mario Di Francesco and Sajal K. Das and Giuseppe Anastasi", title = "Data Collection in Wireless Sensor Networks with Mobile Elements: {A} Survey", journal = j-TOSN, volume = "8", number = "1", pages = "7:1--7:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993049", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "7", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Busnel:2011:ADT, author = "Yann Busnel and Leonardo Querzoni and Roberto Baldoni and Marin Bertier and Anne-Marie Kermarrec", title = "Analysis of Deterministic Tracking of Multiple Objects Using a Binary Sensor Network", journal = j-TOSN, volume = "8", number = "1", pages = "8:1--8:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993050", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "8", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Wang:2011:DSS, author = "Qian Wang and Kui Ren and Shucheng Yu and Wenjing Lou", title = "Dependable and Secure Sensor Data Storage with Dynamic Integrity Assurance", journal = j-TOSN, volume = "8", number = "1", pages = "9:1--9:??", month = aug, year = "2011", CODEN = "????", DOI = "http://dx.doi.org/10.1145/1993042.1993051", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Mon Sep 5 17:03:48 MDT 2011", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", acknowledgement = ack-nhfb, articleno = "9", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Ayday:2012:DAA, author = "Erman Ayday and Farshid Delgosha and Faramarz Fekri", title = "Data authenticity and availability in multihop wireless sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "10:1--10:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140523", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Security services such as data confidentiality, authenticity, and availability are critical in wireless sensor networks (WSNs) deployed in adversarial environments. Due to the resource constrain's of sensor nodes, the existing protocols currently in use in adhoc networks cannot be employed in WSNs. In this article, we propose a protocol called location-aware network-coding security (LNCS) that provides all the aforementioned security services. By dividing the terrain into nonoverlapping cells, the nodes take advantage of the location information to derive different location-binding keys. The key idea in LNCS is that all the nodes involved in the protocol collaborate in every phase. We employ random network coding in order to provide data availability significantly higher than that in other schemes. A hash tree-based authentication mechanism is utilized to filter the bogus packets enroute. We provide a comparison between our scheme and previously proposed schemes. The results reveal significant improvement in data availability while maintaining the same level of data confidentiality and authenticity.", acknowledgement = ack-nhfb, articleno = "10", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Shirmohammadi:2012:SLS, author = "Babak Shirmohammadi and Camillo J. Taylor", title = "Self-localizing smart camera networks", journal = j-TOSN, volume = "8", number = "2", pages = "11:1--11:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140524", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article describes a novel approach to localizing networks of embedded cameras and sensors. In this scheme, the cameras and the sensors are equipped with controllable light sources (either visible or infrared), which are used for signaling. Each camera node can then determine automatically the bearing to all of the nodes that are visible from its vantage point. By fusing these measurements with the measurements obtained from onboard accelerometers, the camera nodes are able to determine the relative positions and orientations of other nodes in the network. The method uses angular measurements derived from images, rather than range measurements derived from time-of-flight or signal attenuation. The scheme can be implemented relatively easily with commonly available components, and it scales well since the localization calculations exploit the sparse structure of the system of measurements. Additionally, the method provides estimates of camera orientation which cannot be determined solely from range measurements. The localization technology could serve as a basic capability on which higher-level applications could be built. The method could also be used to automatically survey the locations of sensors of interest, to implement distributed surveillance systems, or to analyze the structure of a scene, based on images obtained from multiple registered vantage points. It also provides a mechanism for integrating the imagery obtained from the cameras with the measurements obtained from distributed sensors.", acknowledgement = ack-nhfb, articleno = "11", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Karumbu:2012:DOE, author = "Premkumar Karumbu and Venkata K. Prasanthi and Anurag Kumar", title = "Delay optimal event detection on ad hoc wireless sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "12:1--12:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140525", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "We consider a small extent sensor network for event detection, in which nodes periodically take samples and then contend over a random access network to transmit their measurement packets to the fusion center. We consider two procedures at the fusion center for processing the measurements. The Bayesian setting, is assumed, that is, the fusion center has a prior distribution on the change time. In the first procedure, the decision algorithm at the fusion center is network--oblivious and makes a decision only when a complete vector of measurements taken at a sampling instant is available. In the second procedure, the decision algorithm at the fusion center is network--aware and processes measurements as they arrive, but in a time-causal order. In this case, the decision statistic depends on the network delays, whereas in the network--oblivious case, the decision statistic does not. This yields a Bayesian change-detection problem with a trade-off between the random network delay and the decision delay that is, a higher sampling rate reduces the decision delay but increases the random access delay. Under periodic sampling, in the network--oblivious case, the structure of the optimal stopping rule is the same as that without the network, and the optimal change detection delay decouples into the network delay and the optimal decision delay without the network. In the network--aware case, the optimal stopping problem is analyzed as a partially observable Markov decision process, in which the states of the queues and delays in the network need to be maintained. A sufficient decision statistic is the network state and the posterior probability of change having occurred, given the measurements received and the state of the network. The optimal regimes are studied using simulation.", acknowledgement = ack-nhfb, articleno = "12", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Chang:2012:PRS, author = "Shih-Ying Chang and Yue-Hsun Lin and Hung-Min Sun and Mu-En Wu", title = "Practical {RSA} signature scheme based on periodical rekeying for wireless sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "13:1--13:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140526", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Broadcast is an efficient communication channel on wireless sensor networks. Through authentic broadcast, deployed sensors can perform legitimate actions issued by a base station. According to previous literature, a complete solution for authentic broadcast is digital signature based on asymmetric cryptography. However, asymmetric cryptography utilizes expensive operations, which result in computational bottlenecks. Among these cryptosystems, Elliptic Curve Cryptography (ECC) seems to be the most efficient and the most popular choice. Unfortunately, signature verification in ECC is not efficient enough. In this article, we propose an authentic broadcast scheme based on RSA. Unlike conventional approaches, the proposed scheme adopts short moduli to enhance performance. Meanwhile, the weakness of short moduli can be fixed with rekeying strategies. To minimize the rekeying overhead, a Multi-Modulus RSA generation algorithm, which can reduce communication overhead by 50\%, is proposed. We implemented the proposed scheme on MICAz. On 512-bit moduli, each verification spends at most 0.077 seconds, which is highly competitive with other public-key cryptosystems.", acknowledgement = ack-nhfb, articleno = "13", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Cao:2012:ITM, author = "Zhen Cao and Hui Deng and Zhi Guan and Zhong Chen", title = "Information-theoretic modeling of false data filtering schemes in wireless sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "14:1--14:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140527", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "False data filtering schemes are designed to filter out false data injected by malicious sensors; they keep the network immune to bogus event reports. Theoretic understanding of false data filtering schemes and guidelines to further improve their designs are still lacking. This article first presents an information-theoretic model of false data filtering schemes. From the information-theoretic view, we define the scheme's filtering capacity C$_{F i}$ as the uncertainty-reduction ratio of the target input variable, given the output. This metric not only performs better than existing metrics but also implies that only by optimizing the false negative rate and false positive rate simultaneously, can we promote a scheme's overall performance. Based on the investigation from the modeling efforts, we propose HiFi, a hybrid authentication-based false data filtering scheme. HiFi leverages the benefits of both symmetric and asymmetric cryptography and achieves a high filtering capacity, as well as low computation and communication overhead. Performance analysis demonstrates that our proposed metric is rational and useful, and that HiFi is effective and energy efficient.", acknowledgement = ack-nhfb, articleno = "14", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Sun:2012:QCC, author = "Xusheng Sun and Edward J. Coyle", title = "Quantization, channel compensation, and optimal energy allocation for estimation in sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "15:1--15:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140528", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "In clustered networks of wireless sensors, each sensor collects noisy observations of the environment, quantizes these observations into a local estimate of finite length, and forwards them through one or more noisy wireless channels to the cluster head (CH). The measurement noise is assumed to be zero-mean and have finite variance, and each wireless hop is modeled as a binary symmetric channel (BSC) with a known crossover probability. A novel scheme is proposed that uses dithered quantization and channel compensation to ensure that each sensor's local estimate received by the CH is unbiased. The CH fuses these unbiased local estimates into a global one, using a best linear unbiased estimator (BLUE). Analytical and simulation results show that the proposed scheme can achieve much smaller mean square error (MSE) than two other common schemes, while using the same amount of energy. The sensitivity of the proposed scheme to errors in estimates of the crossover probability of the BSC channel is studied by both analysis and simulation. We then determine both the minimum energy required for the network to produce an estimate with a prescribed error variance and how this energy must be allocated amongst the sensors in the multihop network.", acknowledgement = ack-nhfb, articleno = "15", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Erdem:2012:EPH, author = "U{\u{g}}ur Murat Erdem and Stan Sclaroff", title = "Event prediction in a hybrid camera network", journal = j-TOSN, volume = "8", number = "2", pages = "16:1--16:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140529", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "Given a hybrid camera layout-one containing, for example, static and active cameras-and people moving around following established traffic patterns, our goal is to predict a subset of cameras, respective camera parameter settings, and future time windows that will most likely lead to success the vision tasks, such as, face recognition when a camera observes an event of interest. We propose an adaptive probabilistic model that accrues temporal camera correlations over time as the cameras report observed events. No extrinsic, intrinsic, or color calibration of cameras is required. We efficiently obtain the camera parameter predictions using a modified Sequential Monte Carlo method. We demonstrate the performance of the model in an example face detection scenario in both simulated and real environment experiments, using several active cameras.", acknowledgement = ack-nhfb, articleno = "16", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Eswaran:2012:UBB, author = "Sharanya Eswaran and Archan Misra and Flavio Bergamaschi and Thomas La Porta", title = "Utility-based bandwidth adaptation in mission-oriented wireless sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "17:1--17:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140530", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "This article develops a utility-based optimization framework for resource sharing by multiple competing missions in a mission-oriented wireless sensor network (WSN) environment. Prior work on network utility maximization (NUM) based optimization has focused on unicast flows with sender-based utilities in either wireline or wireless networks. In this work, we develop a generalized NUM model to consider three key new features observed in mission-centric WSN environments: (i) the definition of the utility of an individual mission (receiver) as a joint function of data from multiple sensor sources; (ii) the consumption of each sender's (sensor) data by multiple missions; and (iii) the multicast-tree-based dissemination of each sensor's data flow, using link-layer broadcasts to exploit the ``wireless broadcast advantage'' in data forwarding. We show how a price-based, distributed protocol (WSN-NUM) can ensure optimal and proportionally fair rate allocation across multiple missions, without requiring any coordination among missions or sensors. We also discuss techniques to improve the speed of convergence of the protocol, which is essential in an environment as dynamic as the WSN. Further, we analyze the impact of various network and protocol parameters on the bandwidth utilization of the network, using a discrete-event simulation of a stationary wireless network. Finally, we corroborate our simulation-based performance results of the WSN-NUM protocol with an implementation of an 802.11b network.", acknowledgement = ack-nhfb, articleno = "17", fjournal = "ACM Transactions on Sensor Networks (TOSN)", } @Article{Ilyas:2012:DPA, author = "Muhammad U. Ilyas and Hayder Radha", title = "A dynamic programming approach to maximizing a statistical measure of the lifetime of sensor networks", journal = j-TOSN, volume = "8", number = "2", pages = "18:1--18:??", month = mar, year = "2012", CODEN = "????", DOI = "http://dx.doi.org/10.1145/2140522.2140531", ISSN = "1550-4859 (print), 1550-4867 (electronic)", ISSN-L = "1550-4859", bibdate = "Fri Apr 6 18:38:19 MDT 2012", bibsource = "http://portal.acm.org/; http://www.math.utah.edu/pub/tex/bib/tosn.bib", abstract = "The inherent many-to-one flow of traffic in wireless sensor networks (WSNs) produces a skewed distribution of energy consumption rates, leading to the early demise of those sensors that are critical to the ability of surviving nodes to communicate their measurements to the base station. Numerous previous approaches aimed at balancing the consumption of energy in wireless networks are either too complex or do not address problems unique to the flow of traffic in WSNs. In this article, we propose the use of a dynamic programming algorithm (DPA), an operational, low-complexity algorithm, used in conjunction with four different route discovery algorithms. We perform complexity analysis, statistical evaluation of changes in power consumption rates effected, and verify spatial redistribution of energy consumption of sensors in the network. Our results on multihop networks of 100 randomly placed nodes show that, on average, the two best performing variants of DPA yield a reduction of up to 28\% and 36\% in power consumption rate variance at the cost of raising average power consumption by 15\% and 21\%, respectively. Computational complexities of DPA variants range from $O(N^3)$ to $O(N^4)$, which is significantly lower than linear search of the solution space of $O(N!^{N i})$. Analysis by diffusion plots shows that DPA reduces power consumption of sensors that experience the highest power consumption under the shortest path routes.", acknowledgement = ack-nhfb, articleno = "18", fjournal = "ACM Transactions on Sensor Networks (TOSN)", }