Distributed Adaptive Algorithms for Optimal Opportunistic Medium Access

We examine threshold-based transmission strategies for distributed opportunistic medium access, and specifically address the problem of setting the threshold values so as to optimize the aggregate throughput utility of the various users. In the case of weighted logarithmic throughput utility (Proportional Fairness) we provide an adaptive algorithm for finding the optimal threshold values in a distributed fashion. Moreover, we discuss how the algorithm may be adapted to achieve packet-level stability with only limited exchange of queue length information among the various users. We also present numerical results to demonstrate the convergence of the proposed adaptive algorithm.