Optimized power saving mechanism for wireless ad hoc networks

Power Saving is one of the most critical issues for portable devices in wireless local area network as battery power is a scarce resource. The issue becomes even more severe for wireless ad hoc networks as lack of available infrastructure could mean lack of available resources for battery recharge. IEEE 802.11 provides a mechanism known as PSM (Power saving mechanism), this mechanism achieves power saving by governing the transition of mobile stations between awake and dozing state. However, PSM puts all the stations in awake state for both broadcast and multicast data, hence those stations which are not participating in the multicasting also move to awake state and hence consume more power than what is required. In this paper we study and explain this problem for wireless ad hoc networks. We recommend a new mechanism known as OPSM (Optimized power saving mechanism) which solves the mentioned problem by storing the multicast addresses in a mapping table at each station. We also provide analytic result to verify the performance of proposed scheme.