On the power efficiency of sensory and ad-hoc wireless networks

This paper discusses the power efficiency of a communications channel, i.e., the maximum bit rate that can be achieved per unit power (energy rate). For AWGN channels, it is well known that power efficiency is attained in the low SNR regime. In this paper we show that for a random sensory, or ad-hoc, wireless network with n users (nodes), with high probability converging to one as n grows, the power efficiency scales at least by a factor of √n. In other words, each user in a wireless channel with n nodes can support the same communications rate as a single user system, but by expending only 1/√n the energy.