Multimedia traffic over WLANs: QoS support and performance evaluation

Multimedia traffic support over Wireless Local Area Networks (WLANs) witnessed a huge demand recently with market fusion toward personal smart digital devices. Bandwidth utilization, minimum delay and jitter are some of the critical requirements to provide real-time applications with good quality of service (QoS) level. In this paper, we evaluate the performance of the traditional IEEE 802.11 standard in supporting multimedia traffic, in particular audio and video streams. Furthermore, we evaluate the performance of the IEEE 802.11e standard which targets QoS support in WLANs. Extensive simulation scenarios were conducted using ns-2 to evaluate the standards under different traffic loads, parameters values, and different topologies. The exhibited results show the enhancement that IEEE 802.11e offers to applications that require high QoS in terms of network throughput, medium utilization, collision rate, jitter, and packet access delay. However, it is noted that video traffic received delay optimization more than the audio traffic under this standard. For this purpose, we propose a modified scheme of the IEEE 802.11e to optimize the delay and jitter of audio traffic. The simulation results proved the efficiency of the proposed scheme in enhancing the performance of the audio traffic while preserving the good performance of the video traffic gained by the original standard.