REVAMPING QUALITY OF SERVICE OF VIDEO STREAMING OVER WIRELESS LAN

Abstract

Just like video streaming over a wired network, streaming can also be done over a wireless LAN. However, real-time streaming over wireless networks is a challenging proposition due to the highly variable nature of wireless links and the resource-poor nature of mobile devices. In such a context, transmission control schemes have to dynamically adapt both to the application requirements and the channel conditions. In this paper, we put forward a short review of some recent innovations, which have been devised to thoroughly revamp the Quality of Service (QoS) of video streaming over WLANs. Depending on their applications, the solutions have focused mainly on the following three network layers: Media Access Control layer (MAC), Application layer (APP) and Physical layer (PHY). In this paper, we propose an adaptive cross-layer quality-of-service (QoS) scheme for wireless channel and streaming applications. For the sake of adaptive QoS, the cross-layer architecture assumes that layer information could be exchanged between application layer and lower layers. In addition, priority-based adaptive QoS scheduling for MPEG video streams is proposed here. It considers the frame type of the MPEG-4 video file so as to efficiently provide non-similar priorities to important packets of video. IEEE 802.11e protocol assigns top priority to video applications. It does this in order to reduce delay and packets losses, which could happen due to other competing traffic. Simulation results performed with the network simulator ns-2 will show that the cross-layer architecture allows a good performance under both, light and heavy loads, while minimizing the mean packet delay and frame jitter. We aim to minimize the dropping of frames and frame jitter while gracefully degrading video quality to enable the same.