Optimal Power/delay Trade-offs in Wireless Communications – Small Delay Asymptotics

In this paper we consider the optimal trade-off between average transmission power and average queueing delay for a single user transmitting data over a wireless fading channel. In particular we study the behavior of this trade-off in the regime of asymptotically large power and small delay. Our focus is on channels which require infinite power to minimize the average delay. For such channels, it is shown that the average delay decreases no faster than e P as the average power grows, where is a parameter that depends on the fading distribution and the arrival rate. We also give an sequence of policies that nearly mathc this lower bound. Several other sub-optimal policies are also discussed.