Performance Evaluation of IEEE 802.11 MAC Layer in Supporting Delay Sensitive Services
Providing QoS requirements like good throughput and minimum access delay are challenging tasks with regard to 802.11 WLAN protocols and Medium Access Control (MAC) functions. IEEE 802.11 MAC layer supports two main protocols: DCF (Distributed Coordination Function) and EDCF (Enhanced Distributed Coordination Function). During the evaluation of EDCF, the performance of various access categories was the determining factor. Two scenarios, with same Physical and MAC parameters, one implementing the DCF and other EDCF, were created in the network simulation tool (OPNET MODELER) to obtain the results. The results showed that the performance of EDCF was better in providing QoS for real-time interactive services (like video conferencing) as compared to DCF, because of its ability to differentiate and prioritize various services.