In this paper, a utility-based joint power and rate adaptive algorithm (UPRA) is proposed to alleviate the influence of channel variation by using softened signal-to-interference-and-noise ratio (SINR) requirements. The transmission power and rate of each user will be adjusted to maximize its own net-utility according to the states of channel, which results in a balance between the effective transmission rate and power consumption. Although the UPRA works based on a non-cooperative game, cooperation among users can be achieved so that the throughput of the whole network will be improved. The convergence of the algorithm has also been studied in both feasible and infeasible cases.

Joint power and rate adaptation mechanisms based on hard signal-to-interference-and-noise ratio (SINR) thresholds might suffer from variations of channel conditions. We propose a utility-based joint power and rate adaptation mechanism (UPRA) that is flexible against channel variations. Our mechanism selects power and rate by trading off among transmission rates, frame error rate and power consumption. By setting soft SINR requirement (utility) and considering the penalty of power consumption (cost), balancing could be achieved. The scheme is based on the non-cooperative game theory resulting in cooperation among nodes. This framework provides a promising policy when both the power and rate are controllable. Simulation results show significant improvements on throughput and energy consumption over the algorithm based on hard SINR thresholds.

To provide differentiated service is one of important issues in the design of wireless ad hoc networks. Traditionally, the provisioning of the differentiated service to different types of traffic streams is mainly supported at the medium access control layer with strict priority scheduling or weighted priority scheduling. In this paper, we propose a novel solution, named as Power-Controlled Rate-Adaptive medium access control (PCRA-MAC) scheme, to provide differentiated service by cross-layer consideration and design. The PCRA-MAC scheme exploits the features of multi-rate and power adjustable wireless transceiver system to achieve different transmission rates to support differentiated service. To the best of our knowledge, the PCRA-MAC scheme is the first and the only MAC scheme that generates different transmission rates for different types of traffic by tuning transmission power. Simulation experiments have proved that the PCRA-MAC scheme can effectively supports differentiated service in the wireless ad hoc networks.