Zoning Based MAC with Support for Recharging Process in WSN

Radio-frequency (RF) based recharging of sensor nodes is a promising way to reduce maintenance and extend the operational life of wireless sensor networks. However RF attenuation causes the network nodes with largest distance from the access point (master node) to dictate the rate of recharging which imposes unnecessary breaks in the operation of nodes closer to the master. This deteriorates the throughput of the nodes close to the master. To solve this problem we have designed location aided MAC protocol which supports recharging such that all nodes deplete their batteries at approximately the same time so that recharging pulse comes on time for all the nodes. To achieve that we have partitioned network nodes into circular zones around the master and assigned implicit priorities among the zones. Priorities decrease towards the edge of the network and regulate relative throughput among the zones. We have built probabilistic performance model to evaluate the impact of the recharging process on data communication of different zones by varying traffic load and network size.