A new inter-node priority access enhancement scheme for IEEE_802.11 WLANs

Because of their wide proliferation, IEEE 802.11 WLANs are expected to support multimedia applications such as voice and broadband video transmissions, which normally have strict bounded transmission delay or minimum link rate requirement. Service differentiation can be applied to media traffic transmitted by the same node using the 802.11e EDCA (Enhanced Distributed Channel Access) protocol. However, the EDCA mode does not offer user differentiation, which can be viewed as a deficiency in multi-access wireless networks. In this paper, we propose a new inter-node priority access scheme for IEEE 802.11e networks which is compatible with the EDCA scheme. The proposed scheme deploys inter-node priority for channel access to complement the existing EDCA inter-frame priority. This provides true QoS control across multiple users within the same coverage area of an access point. We provide performance evaluations to compare the proposed access model with the basic EDCA 802.11 MAC protocol mode to elucidate the quality improvement achieved for multimedia communication over 802.11 WLANs.