A Dynamical Games Approach to Transmission-Rate Adaptation in Multimedia WLAN

This paper considers the scheduling, rate adaptation, and buffer management in a multiuser wireless local-area network (WLAN) where each user transmits scalable video payload. Based on opportunistic scheduling, users access the available medium (channel) in a decentralized manner. The rate adaptation problem of the WLAN multimedia networks is then formulated as a general-sum switching control dynamic Markovian game by modelling the video states and block fading channel qualities of each user as a finite states Markovian chain. A value iteration algorithm is proposed to compute the Nash equilibrium policy of such a game and the convergence of the algorithm is also proved. We also give assumptions on the system so that the Nash equilibrium transmission policy of each user is a randomization of two pure policies with each policy nondecreasing on the buffer state occupancy. Based on this structural result, we use the policy gradient algorithm to compute the Nash equilibrium policy.