Uplink scheduling mechanism for MPEG encoded video in IEEE 802.16 MAN

MPEG coded video consists three types of periodically arranged inter-frame dependent frames: I, P, and B with different level of information and importance. When such encoded frames are transported in any wireless network, all frames are equally prone to loss. However, the effect of loss of frames is not uniform for all frame types. The effect of loss on visual quality depends on the type of the frame and position of the frame inside the GOP. So we extract these frame-position and frame-type information of every frame to develop a priority based opportunistic scheduler. In other words, the priority weight to be assigned to each frame is simply a function of frame-type and frame-position value. Every video with m number of GOPs with GOP dimension of (N, M) are fragmented into N/M + 1 layers and the frames belonging to each layer are tagged with homogeneous priority weight. Hence, this added priority determines the transmission and selective drop order of the frames residing in different layers. Performance analysis carried for this scheduler under IEEE 802.16 based system confirms the less PLR for important frame types. The proposed MPEG scheduling mechanism can be used without modification in other systems as well, provided, there is provision of QoS class based scheduling.