Quality of service provisioning for real-time services in wireless LANs

This paper addresses issues on how to support both real-time and non-real-time communication services in a wireless LAN. Unpredictable wireless channel errors may cause applications with real-time traffic to receive degraded quality of services due to packet losses. We propose scheduling algorithms that can take advantages of point coordination function (PCF) of a wireless LAN to support quality of service provisioning for real-time services. Specifically, we consider two types of service differentiation: (1) absolute delay differentiated services; and (2) proportional differentiated fair bandwidth services, for real time communication. At the same time, our proposed schemes also try to accommodate best-effort traffic to minimize the delay experienced by best traffic. One challenging issue involved is to consider the packet loss due to channel bit errors. We also establish conditions to admit a new real-time connection. Preliminary performance evaluation of the proposed schemes is conducted to demonstrate how one of proposed scheme works as well as to study its effectiveness.