Jointly Optimal Congestion and Power Control for Rayleigh-Faded Channels with Outage Constraints

Abstract

We address the problem of joint congestion control and power control with link outage constraints in Rayleigh fast-fading and multihop wireless networks. Because of packet loss caused by the fast-fading-induced link outage, the data rate received successfully at the destination node (the effective rate) is much lower than the transmission rate at the source node (the injection rate). In this paper, a novel model, i.e., effective network utility maximization with power control (ENUMP), is designed to formulate this scenario. In ENUMP, the network utility is associated with the effective rate, and an effective network utility maximization formulation with link outage constraints is used. Although the original problem is non-convex and non-separable, we can still construct a distributed algorithm by applying appropriate transformations. Since in our model we sufficiently take into account the statistical variations of the signal-to-interference ratio, the power updates do not follow the instantaneous state of the fast-fading channel. Simulation results show that the optimal solution of our algorithm is close to the globally optimal solution. Besides, simulation results also verify that ENUMP achieves significant gains of the effective rate, the network utility, and the network congestion control over an existing famous model.