a-Coverage Scheme for Wireless Sensor Networks

The problem of prolonging system lifetime in wireless sensor networks (WSNs) while guaranteeing the entire coverage of the interest zone is very challenging mainly due to constraint-energy of sensors that composed these networks. In most applications, system lifetime is defined as the time elapsed until the last sensor dies. However, this evaluation should not be used in some critical applications such as intrusion detection and surveillance applications, where coverage ratio must be raised enough. Thus, to fulfill successfully the objective of deploying WSNs for these types of applications, it is often required that ratio of alive sensors should be higher than a certain value alpha-coverage. In this paper, we propose an efficient alpha-coverage scheme to maximize the ratio of alive sensors that is necessary to guarantee the entire coverage of the interest region. This scheme is based on substantial performance gains of scheduling and broad casting solutions proposed to prolong system lifetime in WSNs. Simulation results show that our scheme prolongs considerably network lifetime when compared with LEACH [1] and LEACH-C [2].