Cross-Layer Strategy for Maximizing Equilibrium Lifetime in Wireless Sensor Networks

For wireless sensor networks (WSNs), which have crucial limitation on energy as all the nodes rely on nonrenewable batteries and are often inconvenient to be replaced or recharged, the energy efficiency that has a close relationship with system longevity becomes a significant issue. In this paper, a cross-layer strategy in terms of physical layer and network layer is proposed for maximizing equilibrium lifetime of WSNs. In the proposed strategy, the residual energy ratio (RER) of individual node is taken into account and regarded as a key factor in power control and routing selection. Utilized to identify the relay capability of an intermediate node, the RER is quantized as a specific access probability, which is highly related to the contention window of each node in the end-to-end transmission link. By way of intelligent and efficient allocation of transmission power, and reasonable routing, the proposed cross-layer tactic can achieve preferable performance with energy efficiency. Simulation results prove that the cross-layer based equilibrium power control and routing (EPCR) strategy could greatly prolong the system lifetime of WSNs.