Power-aware MAC for Multi-hop Wireless Networks: A cross layer approach

This paper addresses the problem of designing a power-aware Multiple Access Control (MAC) protocol for Multi-hop Wireless Networks (MHWN). The problem is formulated as a cross layer network utility maximization problem that considers the interaction of transport, MAC and physical layers in the protocol stack. Assuming physical model for successful transmission, a tractable formula for link throughput as a function of link attempt rate and power vectors is derived. Solving the problem, an algorithm for adjusting the session rate and link state i.e. link attempt rate and power, is proposed. At the session source, the algorithm adjusts the rate of the session based on the congestion signals feedback from the links in its path. At the links, the algorithm adjusts link state, based on the link congestion measure and messages received from neighboring links. Simulation results show that for a given link and at equilibrium the link state should be adjusted based on the link location in the network. This result is consistence with previous results that emphasize in MHWN, MAC should be designed by considering both time and space contention between links.