ON CROSS-LAYER ADAPTIVE IEEE 802.11E EDCA MAC DESIGN FOR OPTIMIZED H.264 VIDEO DELIVERY OVER WIRELESS MESH NETWORKS

We present in this paper a reliable optimized transmission of H.264 video streaming over IEEE 802.11e Wireless Mesh Networks (WMNs) based on a Cross-Layer Adaptive Enhanced Distributed Channel Access (CLA-EDCA) MAC architecture. The IEEE 802.11e EDCA offers a prioritized transmission to guarantee the minimum packets delay and drop rate needed for time bound applications, such as VoIP and Video. However, the standard EDCA scheme does not adapt to the network state to support time critical applications. In order to resolve the problems associated with standard EDCA, we highlight a novel adaptive architecture so as to change the Contention Window (CW) after each successful or unsuccessful transmission according to the current network conditions. We have integrated this cross-layer adaptive scheme leveraging smart forward error correction (FEC) schemes through channel state estimation (CSE) to achieve the optimal video transmission adapting to the network conditions. We have also explored several network level metrics, including bit rate, packets delay and drop rate, to evaluate the proposed scheme in comparison with IEEE 802.11e EDCA standard. Based on these extensive simulation results, we tested H.264 video transmission with both the proposed CLA-EDCA and the standard EDCA MAC. Simulation results have confirmed that the proposed CLA-EDCA outperforms the standard IEEE 802.11e EDCA by a significant margin with smart-FEC adapting to the network conditions over WMNs.