DPHA: A Novel MAC Protocol to Enhance Network Capacity in Non-Infrastructure WLANs

Abstract

In non-infrastructure WLANs commonly used contention access protocols induce limited network capacity and poor QoS performance for real time traffics under high network load due to inherent heavy collisions. In this paper, a novel hybrid access protocol, Delegate Polling Hybrid Access (DPHA) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> protocol, in non-infrastructure WLANs is proposed to address the two problems. We proposed a hybrid access scheme to use a distributed polling-based access scheme to avoid collisions and adopt contention access scheme as complement. We designed a delegate polling scheme, making polling feasible in distributed WLAN networks through distributing polling tasks to each station consecutively rather than centralizing the tasks to an AP. We designed a polling algorithm that introduces conditional service differentiation to improve fairness and schemes to overcome imprecise queue estimation. We carry out extensive simulations to demonstrate the advantage of the four key features of our proposed DPHA protocol.