A new IEEE 802.11 MAC protocol with admission control for sensitive multimedia applications

Actually, the quality of service (QoS) provisioning in IEEE 802.11-based wireless network is assured by the enhanced coordination channel access (EDCA) mechanism, which lacks the aptitude to ensure: (i) an intra-QoS differentiation between the access class (AC), where flows belonging to the same service class are assigned the same MAC parameters regardless theirs respective bit rate, which leads to throughput fairness rather than perceived QoS fairness; (ii) an admission control mechanism that manages the network traffic. In this paper we propose a new MAC protocol featuring a dynamic reservation of the wireless channel (by using the TXOPlimit parameter) along with a distributed admission control mechanism. By monitoring the MAC queue, each flow computes at runtimes the TXOPlimit´s value that satisfies the application requested data rate. Meanwhile we specify a fully distributed admission control mechanism that regulates the network load and protects the admitted flows from the new ones. Simulation results show that compared to the EDCA scheme of 802.1 Ie, our protocol excels, in terms of network utilization and ability to maintain intra-QoS data rate differentiation. Further when introducing the admission control mechanism, we ensure high protection to the admitted flows, and maintain the network in steady state