Comparison by Simulation of Energy Consumption and WSN Lifetime for LEACH and LEACH-SM

Extending the period of operation (lifetime) of wireless sensor networks (WSNs) is one of the most critical issues. Lifetime limitations are due to limited energy resources. Available research results reveal that significant improvement in WSN lifetime can be achieved by using spares (spare nodes). At the moment of WSN deployment, the minimum required coverage of WSN targets is assured by primaries (primary nodes). Spares, if activated, would provide an above-threshold (more than required), redundant target coverage, so they can be switched off initially. They are ready to be switched on when any primary exhausts its energy. The spares must be properly managed. Mismanagement includes redundant and above-threshold coverage, which increase transmission of redundant data to cluster heads (collecting information from regular nodes, that is, primary nodes that are not cluster heads). Therefore, mismanaged spares can shorten WSN lifetime instead of extending it. We measured WSN lifetime by simulating the behavior of a single node. This paper presents the impact of spares and duration of the Nap interval of cluster heads on the WSN lifetime. We generate results based on different executions representing different scenarios.