A Silence Duration Based Uplink Scheduling Algorithm for Multiple VoIP Users in M-WiMAX

This paper proposes an efficient uplink scheduling algorithm that can perfectly support various VoIP CODECs with VAD/DTX/CNG in M-WiMAX considering the variants of silence duration between different voice users, solving the problems of uplink resources wastes and overwhelmingly large overhead that caused during silence period. In our proposed algorithm, efficient schemes is proposed to implement the uplink resource interval and allocation procedure, and the BS adapts this uplink resources interval according to the reserved bit in the generic MAC header of IEEE802.16e, which is utilized to indicate voice activity of each voice user . The performance analysis of the conventional algorithms (UGS, rtPS and ertPS) as well as the one proposed in this paper is also provided. Through the numerical validations, proposed algorithm performs efficiently than the conventional algorithms over enhancement of resource utilization, total throughput, and system capacity. Also, it is proved that our algorithm can support more voice users than the conventional algorithms.