QoS algorithms for IEEE 802.11e implementation

In this paper, we analyze the issues involved in developing a system based on the IEEE 802.11e draft proposal, which defines medium access control (MAC) procedures to support wireless LAN with QoS requirements. However, for scheduler design, the standard provides informative and normative guidelines only. This paper concentrates on design of a scheduler that adapts with the varying channel conditions. We describe the interactions of this scheduler with other components in the system. The functionality of the scheduler is extended to include rate adaptation information. Through extensive simulations, we study the performance enhancement in terms of throughput offered by the adaptive scheme for traffic streams. Results also show the suitability of the scheme in offering QoS guarantees for networks handling both integrated and differentiated traffic using hybrid coordination function (HCF) defined in the draft.