Energy efficient coverage using optimized node scheduling in wireless sensor networks

In energy-limited wireless sensor networks, the sensor scheduling is an appropriate technique for minimizing node energy consumption and maximizing network coverage lifetime. The challenge is to determine an appropriate scheduling mechanism for the nodes in order to maintain sufficient count of active nodes for maximum network coverage. Existing works on coverage optimization based scheduling mechanism, do not consider the residual energy of the active nodes. RBSP considers the residual energy but ignores the active node´s battery discharge rate. In this paper, we propose OBSP (Optimized Backoff Sleep Protocol), based on battery discharge curve of active nodes to determine the scheduling mechanism of sleeping nodes. Due to battery discharge rate, OBSP avoids unnecessary and random frequent wake-ups at lower residual energy in the sleeping nodes. Thus in OBSP, sleeping nodes wake-up at required instant of time which leads to reduced energy consumption and increased network lifetime. Simulation results based on battery discharge curve show that OBSP achieves lesser energy consumption and longer network coverage lifetime as compared to PEAS and RBSP.