Cross-layer congestion and contention control for wireless ad hoc networks

We consider joint congestion and contention control for multihop wireless ad hoc networks, where the goal is to find optimal end-to-end source rates at the transport layer and per-link persistence probabilities at the medium access control (MAC) layer to maximize the aggregate source utility. The primal formulation of this problem is non-convex and nonseparable. Under certain conditions, by applying appropriate transformations and introducing new variables, we obtain a decoupled and dual-decomposable convex formulation. For general non-logarithmic concave utilities, we develop a novel dualbased distributed algorithm using the subgradient method. For logarithmic utilities, we introduce two modified algorithms: a heuristic one with linearly regularized log rate adjustments and a penalty-based one by adding a quadratic term to the linear objective. For both logarithmic and non-logarithmic utilities, our solutions enjoy the benefits of cross-layer optimization while maintaining the simplicity and modularity of the traditional layered architecture.