An integrated multiple access and hierarchical coding scheme for video communication on wireless networks

A Medium Access Control (MAC) protocol of the Reservation Random Access (RRA) family is integrated with a hierarchial video-coding scheme, to realize effective real-time video services over the up-link of a mobile wireless network. For every picture or for each group of contiguous pictures (GOP), the encoder generates an information lion set organized in hierarchical layered structure. The base layer contains the information needed to a low quality video; the others layers contain data, which, if received and decoded, can enhance the video quality. The basic idea is to reserve bandwidth only to grant the transmission of base layer information, and modify the MAC scheme to manage the video enhancement data together with voice/data streams, by adaptively transmitting the incremental video information only if the performances of other traffic classes will not drop below a certain threshold. The aim of this proposal is the improvement of the video stream quality in low load conditions, without a significant reduction of other traffic classes performance during high load periods. Several simulation results show the effectiveness of the proposed method.