Optimal flow control for utility-lifetime tradeoff in wireless sensor networks

In this paper, we study the utility-lifetime tradeoff in wireless sensor networks (WSNs) by optimal flow control. We consider the flow control in a more practical way by taking into account link congestion and energy efficiency in our network model, and formulate it as a constrained multi-objective optimization problem. Because of the variable coupling in the objective function, auxiliary variables are introduced to decouple it. We introduce the concept of inconsistent coordination price to balance the energy consumption of the sensor nodes. Based on the congestion price and inconsistent coordination prices, a distributed algorithm using gradient projection is proposed to solve the optimization problem. The convergence of the algorithm is also proved. Numerical results show the convergence of our algorithm, the tradeoff of utility and lifetime, as well as the necessity of considering link congestion in WSNs. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.