Location Determination has been a fundamental requirement in many wireless sensor network applications. Various schemes have been proposed to solve this problem. These schemes depend on the measurement of physical quantities such as time of flight, angle of arrival, time difference of arrival and signal strength for location determination. Measurements in the real world are also affected by environmental conditions and contain unavoidable errors. Statistical techniques such as MMSE have been shown to be tolerant towards such errors. However in hostile environments, attackers can alter the measurements significantly to render these proposed schemes useless. Security mechanisms such as authentication and encryption can thwart external attacks such as eavesdropping and spoofing. However, attacks specific to location determination schemes differ from conventional security attacks and have been shown to be successful even when adequate security mechanisms are in place. Recently AR-MMSE, LMS and Voting-based schemes have been proposed to resist these attacks. A technique has also been proposed for detection of attacker nodes. This thesis presents the design and implementation of a nesC [[8] library that achieves secure and robust location determination using these techniques and provides a simple interface that can be used by high level applications. A working system was built using Cricket sensors to evaluate the feasibility of the techniques along with basic security mechanisms. We measure the tradeoffs between the time required for computation, memory consumption and the accuracy of the estimated location. We also measure the accuracy of the estimated location under various degrees of attack for both 2-dimensional and 3- dimensional scenarios. Our experimental results show that in a 2-dimensional system, even with 2 malicious Beacon Nodes out of 8, the maximum increase in error is less than 8 cm for all three techniques when the maximum error is 2 cm without any malicious Beacon Nodes. In case of 3-dimensional system with 1 malicious Beacon Node out of 8, the maximum increase is less than 20 cm with maximum error of about 10 cm when no malicious Beacon Nodes are present.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-01062006-120251 |
| Date | 06 January 2006 |
| Creators | Shah, Pratik |
| Contributors | Dr. Douglas Reeves, Dr. Peng Ning, Dr. Ting Yu |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-01062006-120251/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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