Supporting real-time traffic with QoS in IEEE 802.11e based home networks

With fast deployment of wireless local area networks (WLANs), the ability of WLANs to support real time services with stringent quality of service (QoS) requirements has come to the fore. We evaluate the capability of QoS support in the IEEE 802.11e standard, which provides medium access control (MAC) enhancements for QoS support in 802.11. Both the enhanced distributed channel access (EDCA) and the polling based channel access modes are evaluated, and their performance under real time audio and video traffic is shown through simulations. We find that EDCA provides satisfactory service differentiation among its four access categories. However, in the presence of heavy load traffic, such as a high definition television (HDTV) signal transmission, it is more desirable to place such load under the HCF (hybrid coordination function) polling mode to avoid the adverse impact of other traffic on this class of traffic. With a hybrid polling and EDCA protocol, network capacity is effectively increased for better support of real-time audio and video transmissions in future home networks.