Service differentiation extensions for elastic and real-time traffic in 802.11 wireless LAN

QoS in wireless networks has a special relevance due to the scarce bandwidth available in such networks. This contribution addresses this issue by extending the MAC protocol of the IEEE 802.11 wireless LAN standard. The extension is divided in two steps. In the first step, real-time traffic is distinguished from elastic traffic by a priority scheduling approach in order to meet the delay requirements of, for example, voice communication. In the second step, service differentiation is introduced for elastic traffic, based on a relative differentiation model. In this model, a high priority service always receives a higher throughput than a low priority one. The proposed architecture has been validated via simulation. Results for real-time traffic show that the proposed approach leads to sufficiently low delays if admission control is properly applied. Elastic traffic achieves the desired differentiation in all simulated scenarios.