Distributed Optimal Power and Rate Control in Wireless Sensor Networks

With the rapid development of wireless sensor networks, reducing energy consumption is becoming one of theimportant factors to extend node lifetime, and it is necessary to adjust the launching power of each node becauseof the limited energy available to the sensor nodes in the networks. This paper proposes a power and rate controlmodel based on the network utility maximization (NUM) framework, where a weighting factor is used to reflectthe influence degree of the sending power and transmission rate to the utility function. In real networks, nodesinterfere with each other in the procedure of transmitting signal, which may lead to signal transmission failureand may negatively have impacts on networks throughput. Using dual decomposition techniques, the NUM problem isdecomposed into two distributed subproblems, and then the conjugate gradient method is applied to solve theoptimization problem with the calculation of the Hessian matrix and its inverse in order to guarantee fast convergenceof the algorithm. The convergence proof is also provided in this paper. Numerical examples show that the proposedsolution achieves significant throughput compared with exiting approaches.