Max-min length-energy-constrained routing in wireless sensor networks

We consider the problem of inter-cluster routing between cluster heads via intermediate sensor nodes in a hierarchical sensor network. Sensor nodes having limited and unreplenishable power resources, both path length and path energy cost are important metrics affecting sensor lifetime. In this paper, we model the formation of length and energy constrained paths using a game theoretic paradigm. The Nash equilibrium of our routing game corresponds to the optimal length-energy-constrained (LEC) path. We show that this path can be computed in polynomial time in sensor networks operating under a geographic routing regime. We then define a simpler team version of this routing game and propose a distributed nearly-stateless energy efficient inter-cluster routing protocol that finds optimal routes. This protocol balances energy consumption across the network by periodically determining a new optimal path consistent with associated energy distributions. Simulation results testify to the effectiveness of the protocol in producing a longer network lifetime.