A framework for cross-layer design of energy-conserving on-demand routing in multi-hop wireless networks

We present a scheme for conserving energy across routes in multi-hop and ad-hoc wireless networks using the IEEE 802.11 distributed coordination function (DCF) networks. The scheme is cross-layer in nature and achieves energy conservation by controlling the radio transmission power level and the rebroadcast times of route-request (RREQ) packets during path discovery. In the network layer an estimation of the end-to-end energy consumption is used to adaptively control the RREQ rebroadcast time, and the scheme incorporates a mechanism for estimating the end-to-end energy consumption of a multi-hop network without the introduction of additional control packets. In the Mac layer a variable power-data rate control algorithm changes the transmission power level between RTS-CTS and DATA-ACK packets. The maximum transmission power level and lowest data rate is used for RTS-CTS to prevent the hidden node problem, and the minimum transmission power level and highest data rate is used for DATA-ACK packets in order to save energy