Select of Optimal Sleep State in Adaptive Smac Using Dpm

Wireless sensor networks are networks with low power nodes and limited processing. The main problem in these networks is energy. This resource is not replaceable or rechargeable. Therefore, optimal energy consumption for wsn protocols is a necessity. In a number of proposed protocols periodic sleep and wake is used for energy use reduction but these protocols result in increased end to end delay. If such delay is not acceptable for program, there will be a lot of problems such as real time programs.One of mac layer protocols that uses periodic sleep and wake for energy use reduction, is smac. Adaptive smac is an improvement on smac protocol that rather reduces its delay through early wake. In this paper an improvement has been made on adaptive smac algorithm. Thus dpm has been used in the algorithm. In used DPM, in several sleeping states, nodes remaining energy have been taken into account besides considering idle time. Also energy use is reduced in idle listening state through avoiding simultaneous wake of receiving and sending neighborhoods. Thus this algorithm helps in decreasing the delay as well as increasing the lifetime of network. KeywordsWSN, energy, DPM, Adaptive SMAC, Sleep;