Host Qs: MAC-Independent Traffic Differentiation in 802.11-Based WLANs

In this paper, we address the problem of Quality of Service (QoS) support in the current generation of IEEE 802.11 WLANs. We propose and investigate a novel approach, called Host Qs, aiming at LLC-layer differentiation of traffic depending on its QoS requirements. The approach is based on creating one LLC queue for each traffic category and on scheduling queue service according to the concept of "virtual contention" among different priorities, within the wireless station. The frame at the head of the LLC queue winning the contention is delivered to the MAC layer and handled according to the access functions of the MAC layer. We have implemented the proposed mechanism on an Open-Source Access Point using a Prism2 chipset on a Linux box. Several experiments have been performed to show the effectiveness of the approach in presence of multimedia and data traffic.