A New Hybrid Medium Access Mechanism with Integrated QoS Support for Wireless LANs

Modern wireless networks need to integrate different types of traditional and multimedia traffic. This paper proposes a new WLAN access mechanism as an alternative to the HCF (Hybrid Coordination Function) scheme defined by the IEEE 802.1 le workgroup to provide QoS in wireless LANs. POHA (Priority Oriented Hybrid Access) is a complete medium control protocol, it combines a polling based and a TDM A access scheme, provides QoS for all types of communications, adapts to the dynamic conditions of modern WLANs, optimizes channel utilization and station feedback, provides medium contention fairness, eliminates collisions, differentiates traffic based on priorities, supports dynamic resource assignment, and instantly negotiates the quality levels of the offered traffic streams trying to support multiple streams with best possible quality. POHA, compared with HCF, exhibits generally superior performance.