A study of QoS-aware MAC protocol with network adaptation

A number of QoS-aware medium access control (MAC) schemes have been introduced to extend the legacy IEEE 802.11 MAC protocol which has not guaranteed any service differentiation. However, none of those schemes fulfill both QoS features and channel efficiency although these support the service differentiation based on priority. This paper presents a novel MAC scheme for enhancements of both QoS and medium efficiency. In the proposed scheme, referred to as enhanced distributed coordination function with network adaptation (EDCF-NA), we modify the existing backoff algorithm and employ a new mechanism called inter frame space (IFS) control. These newly developed methods use smart factors denoted by ACK rate, which is involved by the entire network faults such as collisions and drops, and network load threshold (TH). In addition, our approaches are evaluated by NS-2 simulations and compared the performance of other MAC protocols