Overhead analysis in WiMAX-based IPTV systems

Salient features supported by mobile WiMAX including high data rate, multicast support, guaranteed quality of service, scalability and so on makes it a promising access network for IPTV delivery. A WiMAX frame consists of data bursts and control fields. Control fields are encoded with the highest modulation and coding scheme with four repetitions in order to make sure that all the users can receive and decode them successfully. Therefore, overhead for transmitting control information has a significant impact on the overall capacity of the frame. We show by both simulation and analytical methods that with an appropriate combination of multicast and unicast TV channels and a smart scheduling policy, the total number of overhead slots can be minimized.