Distributed Maximum Lifetime Routing in Wireless Sensor Networks Based on Regularization

The maximum lifetime routing problem in wireless sensor networks has received increasing attention in recent years. One way is to formulate it as a linear programming problem by maximizing the time at which the first node runs out of energy subject to the flow conservation constraints. The solutions in this problem correspond to the rates allocated to each link. In this paper, we first show that, under certain conditions, the solutions of this problem are not unique for some network topologies. Given the feasible solutions set, one can further define a secondary optimization problem by minimizing the end-to-end packet transfer delay or power consumption. Rather than solving two sequential optimization problems, in this paper, we propose the use of a regularization method which can jointly maximize the network lifetime and minimize another objective (e.g., packet delay). We describe the fully distributed implementation and provide performance comparisons with other algorithms.