Impact of Power and Rate Selection on the Throughput of Ad Hoc Networks

With the advance of wireless technology, wireless devices are capable of adjusting transmit power and physical (PHY) layer data-rate. In this paper, we investigate the problem of how to adjust the power level and the PHY rate in order to maximize the network throughput in wireless ad hoc networks. Solving this problem can help compute the network capacity of ad hoc networks, which has drawn a lot of attention recently. In our study, we find that there exist intertwined relationships among maximum network throughput, power, and PHY rate. These intertwined relationships make computing the maximum network throughput a difficult problem. To get around the coupled relationships among power, PHY rate and network throughput, we take a simulation-based optimization approach, i.e., use a recursive randomized algorithm to find the solution. We study the convergence and complexity of our algorithm. Our results show that our algorithm always converges and the computation complexity is polynomial. The simulations also show that our algorithm can iteratively improve the network throughput, given an initial feasible power and rate setting.