Power control and rate adaptation as stochastic games for random access

In this paper, we address the random access problem from the perspective of a stochastic game. We allow selfish as well as cooperative users to select their retransmission strategies depending on several performance requirements, which involve throughput, delay and transmission costs. We first consider a simple slotted collision channel with packet capture capabilities in the presence of multiple transmissions. We formulate a random access game with possible actions of randomly choosing either to transmit or to wait, and evaluate the equilibrium transmission strategies of selfish and cooperative users. The capture effects in the communication channel can be further exploited to develop an alternative joint power control and rate adaptation game for random access. At the expense of increased system complexity, we propose to allow selfish users to choose randomly power and rate levels for retransmitting, which leads to possible performance gains over limited actions of selecting retransmission probabilities.