On maximum lifetime routing in Wireless Sensor Networks

Lifetime maximization is an important optimization problem specific to wireless sensor networks (WSNs) since they operate with limited energy resources which are therefore eventually depleted. This paper considers first the problem of routing in a WSN with the objective of lifetime maximization based on a simple model for battery dynamics. Specifically, we discuss the equivalence of two different formulations and solutions in the existing literature. We then revisit a related problem, the optimal allocation of a total energy amount over all nodes so as to maximize network lifetime. We prove that this is equivalent to a shortest path problem on a weighted graph and can therefore be efficiently solved. Finally, we present a more realistic model for battery dynamics, and numerically solve the lifetime maximization problem. The empirical results obtained indicate that, while a static routing policy is not expected to be optimal, such a policy is a good approximation of the optimal dynamic routing policy.