— 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 ε-cut, for any 0 < ε < 1, is a linear separation of εn nodes in S from a distinguished node, the base station. We show that the base station can detect whenever an ε-cut occurs by monitoring the status of just O(1 ε ) nodes in the network. Our scheme is deterministic and it is free of false positives: no reported cut has size smaller than 1 2 εn. Besides this combinatorial result, we also propose efficient algorithms for finding the O( 1 ε ) nodes that should act as sentinels, and report on our simulation results, comparing the sentinel algorithm with two natural schemes based on sampling.
Nisheeth Shrivastava, Subhash Suri, Csaba D. T&oac