Wireless ad-hoc sensor networks will provide one of the missing connections between the Internet and the physical world. One of the fundamental problems in sensor networks is the calculation of coverage. Exposure is directly related to coverage in that it is a measure of how well an object, moving on an arbitrary path, can be observed by the sensor network over a period of time.

In addition to the informal definition, we formally define exposure and study its properties. We have developed an efficient and effective algorithm for exposure calculation in sensor networks, specifically for finding minimal exposure paths. The minimal exposure path provides valuable information about the worst case exposure-based coverage in sensor networks. The algorithm works for any given distribution of sensors, sensor and intensity models, and characteristics of the network. It provides an unbounded level of accuracy as a function of run time and storage. We provide an extensive collection of experimental results and study the scaling behavior of exposure and the proposed algorithm for its calculation.

Note: OCR errors may be found in this Reference List extracted from the full text article. ACM has opted to expose the complete List rather than only correct and linked references.

	Abe00	Harold Abelson , Don Allen , Daniel Coore , Chris Hanson , George Homsy , Thomas F. Knight, Jr. , Radhika Nagpal , Erik Rauch , Gerald Jay Sussman , Ron Weiss, Amorphous computing, Communications of the ACM, v.43 n.5, p.74-82, May 2000  [doi>10.1145/332833.332842]
	Abi00	A. A. Abidi, G.J. Pottie, W.J. Kaiser, "Power-Conscious Design Of Wireless Circuits And Systems." Proceedings of the IEEE, vol. 88, (no. 10), pp. 1528-45, Oct. 2000.
	Adj99	William Adjie-Winoto , Elliot Schwartz , Hari Balakrishnan , Jeremy Lilley, The design and implementation of an intentional naming system, ACM SIGOPS Operating Systems Review, v.33 n.5, p.186-201, Dec. 1999
	Bal98	H. Baltes, O. Paul, O. Brand, "Micromachined Thermally Based CMOS Micro-Sensors." Proceedings of the IEEE, vol. 86, (no. 8), pp. 1660-78, Aug. 1998.
	Bra99	M.S. Braasch, A.J. Van Dierendonck, "GPS Receiver Architectures And Measurements." Proceedings of the IEEE, vol. 87, (no. 1), pp. 48-64, Jan. 1999.
	Caf98	J. Caffery Jr., G.L. Stuber, "Subscriber Location In CDMA Cellular Networks." IEEE Transactions on Vehicular Technology, vol. 47, (no. 2), pp. 406-16, May 1998.
	Caf00	J. Caffery Jr, G.L. Stuber, "Nonlinear Multiuser Parameter Estimation And Tracking In CDMA Systems." IEEE Transactions on Communications, vol. 48, (no. 12), pp. 2053-63, Dec. 2000.
	Cor90	Thomas T. Cormen , Charles E. Leiserson , Ronald L. Rivest, Introduction to algorithms, MIT Press, Cambridge, MA, 1990
	Est00	Deborah Estrin , Ramesh Govindan , John Heidemann, Embedding the Internet: introduction, Communications of the ACM, v.43 n.5, p.38-41, May 2000  [doi>10.1145/332833.332836]
	Fis99	S. Fisher, K. Ghassemi, "GPS IIF-The Next Generation." Proceedings of the IEEE, vol. 87, (no.1), pp. 24-47, Jan. 1999.
	Gib96	Elaine M. Gibson , Jerry D. Gibson, The Mobile Communications Handbook, CRC Press, Inc., Boca Raton, FL, 1998
	Gre98	W. Gregg, W. Esaias, G. Feldman, R. Frouin, S. Hooker, C. McClain, R. Woodward, "Coverage Opportunities For Global Ocean Color In A Multimission Era."" IEEE Transactions on Geoscience and Remote Sensing, vol. 36, pp. 1620-7, Sept. 1998.
	Haa00	J. Haartsen, S. Mattisson, "Bluetooth - A New Low-Power Radio Interface Providing Short-Range Connectivity." Proceedings of the IEEE, vol. 88, (no. 10), pp. 1651-61, Oct. 2000.
	Has97	Z. Haas, "On The Relaying Capability Of The Reconfigurable Wireless Networks." IEEE 47th Vehicular Technology Conference, vol. 2, pp. 1148-52, May 1997.
	Kan00	C. Kang, M. Golay, "An Integrated Method For Comprehensive Sensor Network Developement In Complex Power Plant Systems." Reliability Engineering & System Safety, vol. 67, pp. 17-27, Jan. 2000.
	Kou01	F. Koushanfar, et al. "Global Error-Tolerant Fault-Tolerant Algorithms for Location Discovery in Ad-hoc Wireless Networks." UCLA Technical Report, UCLA Computer Science Department, 2001.
	Lan00	J. Lansford, P. Bahl, ""The Design And Implementation Of HomeRF: A Radio Frequency Wireless Networking Standard For The Connected Home." Proceedings of the IEEE, vol. 88, (no. 10), pp. 1662-76, Oct. 2000.
	Lie98	K. Lieska, E. Laitinen, J. Lahteenmaki, ""Radio Coverage Optimization With Genetic Algorithms." IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, vol. 1, pp. 318-22, Sept. 1998.
	Mar90	Keith Marzullo, Tolerating failures of continuous-valued sensors, ACM Transactions on Computer Systems (TOCS), v.8 n.4, p.284-304, Nov. 1990  [doi>10.1145/128733.128735]
	Mar96	M. Marengoni, B. Draper, A. Hanson, R. Sitaraman, "System To Place Observers On A Polyhedral Terrain In Polynomial Time." Image and Vision Computing, vol. 18, pp. 773-80, Dec. 1996.
	Mas98	A. Mason, et al., "A Generic Multielement Microsystem For Portable Wireless Applications." Proceedings of the IEEE, vol. 86, (no. 8), pp. 1733-46, Aug. 1998.
	Meg01	S. Meguerdichian, F. Koushanfar, M. Potkonjak, M. Srivastava, "Coverage Problems in Wireless Add-Hoc Sensor Networks." Proceedings of IEEE Infocom, vol. 3, pp. 1380-1387, April 2001.
	Mol99	A. Molina, G.E. Athanasiadou, A.R. Nix, "The Automatic Location Of Base-Stations For Optimised Cellular Coverage: A New Combinatorial Approach." IEEE 49th Vehicular Technology Conference, vol. 1, pp. 606-10, May 1999.
	Ngu98	C. Nguyen, L. Katehi, G. Rebeiz, "Micromachined Devices For Wireless Communications." Proceedings of the IEEE, vol. 86, (no. 8), pp. 1756-68, Aug. 1998.
	Pri00	Nissanka B. Priyantha , Anit Chakraborty , Hari Balakrishnan, The Cricket location-support system, Proceedings of the 6th annual international conference on Mobile computing and networking, p.32-43, August 06-11, 2000, Boston, Massachusetts, United States  [doi>10.1145/345910.345917]
	Pot00	G. J. Pottie , W. J. Kaiser, Wireless integrated network sensors, Communications of the ACM, v.43 n.5, p.51-58, May 2000  [doi>10.1145/332833.332838]
	Rit77	S. Riter, J. MacCoy. "Automatic Vehicle Locaiton - An Overview." IEEE transaction on vehicular technology, vol. VT26, no 1, Feb 1977.
	Sha99	M. Shaw, P. Levin, J. Martel, "The Dod: Stewards Of A Global Information Resource, The Navstar Global Positioning System." Proceedings of the IEEE, vol. 87, (no. 1), pp. 16-23, Jan. 1999.
	Ten00	David Tennenhouse, Proactive computing, Communications of the ACM, v.43 n.5, p.43-50, May 2000  [doi>10.1145/332833.332837]
	Tur72	G.L. Turin, W.S. Jewell, T.L. Johnston, "Simulation Of Urban Vehicle-Monitoring Systems." IEEE Transactions on Vehicular Technology, vol. vt21, (no. 1), pp. 9-16, Feb. 1972.
	Wan92	R. Want, A. Hopper, "Active Badges And Personal Interactive Computing Objects." IEEE Transactions on Consumer Electronics, vol. 38, (no. 1), pp. 10-20, Feb. 1992.
	Yaz00	N. Yazdi, A. Mason, K. Najafi, K. Wise, "A Generic Interface Chip For Capacitive Sensors In Low-Power Multi-Parameter Micro- Systems." Sensors and Actuators A (Physical), vol. A84, (no. 3), pp. 351-61, Sept. 2000.

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