Optimal feedback-based adaptive WiMax MAC for improving quality of video

WiMax based on IEEE 802.16 is an emerging wireless broadband communication technology for metropolitan area networking and is regarded as a strong competitor of cable access technologies. Among other functionalities, WiMax includes a rich set of MAC layer features that allows it to adapt to changing network and channel conditions. A well-known mechanism that has been incorporated in the physical layer of WiMax is the forward error correction (FEC). In this paper, we make use this feature to construct MAC protocol data units (MPDUs) in an adaptive manner based on the feedback about the channel conditions. We consider video as the application and use a well accepted mean opinion score (MOS) model for evaluating the video at the user end. We conduct simulation experiments to verify the performance of our adaptive MAC schemes. Simulation results reveal that the proposed adaptive scheme is able to adapt to the changing channel conditions, so the MOS for the video quality and network efficiency improve when the scheme is implemented no matter what the status of the channel is.