Tradeoff Between Lifetime and Rate Allocation in Wireless Sensor Networks: A Cross Layer Approach

This paper studies the tradeoff between energy consumption and application performance in wireless sensor networks by investigating the interaction between network lifetime maximization and rate allocation problems. To guarantee the individual performance of sensor nodes, we adopt the network utility maximization (NUM) framework to ensure certain fairness on source rates of sensor nodes. We formulate the network lifetime maximization problem and fair rate allocation problem as constrained maximization problems, and combine them by introducing a system parameter, which characterizes the tradeoff between the two problems. Using Lagrange dual decomposition, the original problem is vertically decomposed into three subproblems: a rate control problem at the transport layer, a contention resolution problem at the MAC Layer, and a cross-layer energy conservation problem. The first and second subproblems jointly solve the congestion problem in sensor networks via congestion prices, and fully distributed algorithms are derived. Furthermore, they are coupled with the cross layer energy conservation problem to solve the network lifetime maximization problem via energy prices. For the third subproblem, we first propose a partially distributed algorithm where network lifetime is a global information, and then by exploring the similarity between max-min rate allocation and network lifetime maximization in sensor networks, we approximate the latter by the NUM framework, and hence formulate the tradeoff problem in the unified NUM framework. As a result, a fully distributed algorithm is derived for the energy conservation problem.