Energy-efficient beaconless geographic routing in energy harvested wireless sensor networks

We propose a routing scheme called energy-efficient beaconless geographic routing with energy supply (EBGRES) for wireless sensor networks. EBGRES provides loop-free, fully stateless, energy-efficient source-to-sink routing with minimal communication overhead without the help of prior neighborhood knowledge. It locally determines the duty-cycle of each node, based on an estimated energy budget for each period, which includes the currently available energy, the predicted energy consumption and the energy expected from the harvesting device. In EBGRES, each node sends out the data packet first rather than a control message. By sending a data packet first, EBGRES performs the neighbor selection only among those neighbors that successfully received the data packet. EBGRES uses a three-way (DATA/ACK/SELECT) handshake and a timer-assignment function, the Discrete Dynamic Forwarding Delay (DDFD). We investigate the lower and upper bounds on hop count and the upper bound on energy consumption under EBGRES for source-to-sink routing. We further demonstrate the expected total energy consumption along a route toward the sink with the proposed EBGRES approach including a lower bound on energy consumption when the node density increases.