On the longest vulnerable path inside a sensor network from boundary regions

One of the most fundamental problems in wireless sensor network is coverage problem. Higher coverage contributes to improving the quality of services provided by a sensor network. In this paper, we have investigated the coverage problem in heterogeneous sensor network from an intruder's point of view. We argue that a well covered area may still be vulnerable if there exist some paths that can be traversed without being discovered by any sensors. After defining vulnerable paths and weak points and demonstrating their properties we present an efficient algorithm with O(n log n) time complexity to find the longest vulnerable path from a given boundary point in non overlapping sensing regions. We claim that further sensor deployment based on the algorithm reduces vulnerability of the system and improves the quality of service significantly. We present simulation results to support our claim.