Cross-Layer Optimized Congestion, Contention and Power Control in Wireless Ad Hoc Networks

Despite some scepticism, cross-layer optimization has largely been accepted as an indispensable part of protocol design for wireless networks. In this respect, generalized network utility maximization (GNUM) has become a widely employed systematic approach for understanding the interconnections between layers and designing efficient cross-layer protocols. In this paper we adopt the GNUM approach and propose a cross-layer optimized congestion, contention and power control algorithm for transport, MAC (medium access control) and physical layers respectively. First we develop an abstract MAC layer model to capture the effects of multiple access in a wireless medium, then express the effective link capacities by relating physical layer capacities to the MAC layer model through average interference. Secondly we construct the GNUM based congestion, contention and power control problem, and devise a primal-based distributed algorithm to solve it. Results show that distributed algorithm obtains very similar results with the centralized one.