Enhanced uplink scheduling algorithm based on frame duration for VoIP over M-WiMAX

In order to solve the uplink resource wastes during silence period and optimize the system VoIP capacity, this paper proposes an enhanced uplink scheduling algorithm that can successfully support various DTX VoIP CODECs over M-WiMAX based on the CODEC frame duration. Efficient schemes is proposed to implement the uplink resource interval and allocation procedure, by adaptation of uplink resource intervals of BS according to the reserved bit in the generic MAC header of IEEE802.16e, which is utilized to indicate voice activity of each voice user. Performance comparisons between the conventional algorithms (UGS, rtPS and ertPS) and the proposed algorithm are given. Further, numerical validations are given to prove the efficiency of the proposed algorithm over enhancement of resource utilization, total throughput, increment of system capacity, and number of voice users supported.