Localized Distance-Sensitive Service Discovery in Wireless Sensor and Actor Networks IEEE Transactions on Computers, Vol. 58, No. 9, September 2009 Xu Li, Nicola Santoro, and Ivan Stojmenovic 1 postdoctoral fellow at SITE, University of Ottawa, and CNRS/INRIA, France. 2 University of Waterloo, Canada 3 University of Ottawa, Canada. Outline Introduction iMesh Protocol Performance Evaluation Conclusions Introduction Destination Static sensor Moving object Introduction A In this work, the authors propose a novel solution to address the distance-sensitive service discovery problem energy saving timely response Information Mesh Construction Service Provider (SP) Service Consumer (SC) A B C Information Mesh Construction Blocking Rule A common node u of the residing rows/columns of two SPs a and b (ab) stops the further propagation of the information of a, iff |ua| > |ub| |ua| = |ub| colline(a, b) |ua| = |ub| ~colline(a, b) horizon(b) a b u b u a Information Mesh Construction c b a d Extension Rule A node u, at which an SP-node a orthogonally blocks another SP-node b, sends the information of a to b along the backward path from which it receives bs information. The information of a does not travel all the way to b but stops at the point where the path intersects the bisector between a and b. c b a u Extension area d Information mesh in an arbitrary sensor network no void areas Information mesh in an arbitrary sensor network In the presence of void areas Performance Evaluation Evaluation Metrics Total Number of Construction Messages (TNCM): the total number of messages transmitted in the network for information mesh construction Number of Construction Messages per SP (NCMSP): the average number of messages generated by an SP for the purpose of information mesh construction Number of Search Messages per SC (NSMSC): average number of lookup messages generated by an arbitrary SC (reply messages are not counted) Performance Evaluation grid networks of size:32 32, 45 45, , 100 100 SPs are randomly scattered in the network. Percentage of SPs (PSP) in the network varying from 0.1 to 1.5 percent. Message overhead 10,000 nodes iMesh versus Quorum size 10,000 iMesh versus Quorum size 1,000 PDOCC iMesh-AiMesh-B Conclusions In this work, the authors formalize the distance-sensitive service discovery problem information blocking rule information extension rule. Extended to different node densities different topological holes Thank You ~