Efficient Self Protection Algorithms for Wireless Sensor Networks

Wireless sensor networks have been widely used in many surveillance applications. Due to the importance of sensor nodes in such applications, certain level of protection need to be provided to them. In [1], Wang, Zhang and Liu first formally introduced the self protection problem in wireless sensor networks. A wireless sensor network is p-self-protected, if at any moment, for any wireless sensor (active or non-active), there are at least p active sensors that can monitor it. [1] proved that the problem finding minimum 1-self-protection is NP-complete, and gave a centralized method with O(log n) approximation ratio. Here n is the total number of sensors in the network. In this paper, we further study the p-self-protection for wireless sensor networks and discuss several aspects that have not been considered or can not be addressed in [1]. We provide efficient centralized and distributed algorithms with constant approximation ratio for minimum p-self-protection problem in sensor networks with either homogeneous or heterogeneous sensing radius. In addition, we design efficient distributed algorithms to not only achieve pself-protection but also maintain the connectivity of all active sensors. Our simulation confirms the performances of proposed algorithms.