On selection of optimal transmission power for ad hoc networks

This paper investigates the problem of selecting an energy-efficient transmission power for ad hoc networks. Specifically, we examine how to determine a network-wide transmission power that minimizes global energy consumption, with desired lower bounds on capacity and connectivity. Based on recent empirical measurements of energy consumption in wireless modems, we derive an analytical model for network-wide energy consumption, parameterized by density, packet size, MAC protocol and radio characteristics. We then use this model to derive the optimal transmission power at which end-to-end energy consumption is minimized. As the selection of transmission radius not only influences energy consumption but also bandwidth, latency, and network connectivity, we discuss the tradeoff between these metrics and demonstrate that the "average neighbourhood size" is a useful parameter for finding the optimal balance point. Based on this discussion, we present a practical scheme for choosing a transmission power that can make an informed tradeoff between energy efficiency, capacity, latency, and connectivity.