A cross-layer oriented multi-channel MAC protocol design for QoS-centric video streaming over wireless ad hoc networks

This paper presents a cross-layer design for a QoS-centric video transmission over wireless ad hoc networks based on multi-channel MAC protocol with TDMA. First, we investigate a study of the multi-channel MAC protocol through Markov chain modeling. Based on this study, two innovative cross-layer modules are adopted for the design of multi-channel MAC protocol. In the first module, we adopt maximum latency rate (MLR) as the channel quality metric. Unlike the traditional MAC design based on network allocation vector (NAV), MLR is implemented to provide differentiated traffic so that the channel with smaller MLR time is initiated for higher priority traffic. In the second module we adopt two congestion aware metrics, namely MAC utilization and queue length of the MAC layer, to improve the congestion aware routing protocol with DSR. These two innovative modules allow the proposed MAC protocol design to achieve high performance video transmission over wireless ad hoc networks. Experimental results show that the proposed scheme outperforms the state-of-the-art schemes under multi-channel environments in wireless ad hoc networks for as much as 4.9 dB in PSNR. Such significant performance enhancement confirms that the cross-layer approach is very effective for multi-channel MAC protocol design.