International Journal of Advanced Technology in Engineering and Science (IJATES)
IEEE 802.11e introduced traffic and service differentiation at the MAC layer to achieve QoS in delivering multimedia streams, by putting flow deadlines. Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel access (HCCF) are two MAC functions in IEEE 802.11e to support QoS in multimedia transactions. MMDSR and its various versions use EDCA as proper access mechanism in mobile ad-hoc networks because of no centralized access point. EDCA based on prioritization of traffic which leads to a selfish action problem. Pooling scheme seems better but pure HCCA also cannot be a good solution as previous research proved that it has good real time performance and QoS support with CBR traffic only.