A practical layer 3 admission control and adaptive scheduling (L3-ACAS) for cots wlans

We propose a practical approach to provide QoS over the existing best-effort Commercial On The Shelf (COTS) IEEE802.11 WLANs using Layer 3 Admission Control and Adaptive Scheduling (L3-ACAS) scheme. This approach enables operators with existing large-scale WLAN deployments to offer QoS control over their networks with minimal disruption, capital expenditure (CAPEX) or infrastructure upgrade. Extensive simulation studies show that with this scheme, the total goodput, flows throughput ratio, packets delay and jitter of the real-time applications such as VoIP and real-time video can be improved significantly. We have also successfully implemented a testbed to evaluate our architecture using the existing COTS hardware and the open source Linux components.