An efficient uplink scheduling algorithm for VoIP services in IEEE 802.16 BWA systems

An efficient uplink scheduling algorithm for VoIP services is very important for supporting a large number of users with various levels of quality of service (QoS). However, conventional uplink scheduling algorithms for VoIP services in IEEE 802.16 broadband wireless access (BWA) systems cause some problems, such as waste of uplink resources, MAC overhead and unnecessary access delay. We propose an efficient uplink scheduling algorithm for VoIP services in these systems. The base station (BS) assigns uplink resources to the subscriber stations (SS) by considering voice state transitions of the SS. These voice state transitions can be informed to the BS by utilizing one reserved bit in the generic MAC header of IEEE 802.16 BWA systems. We analyze the system throughputs and the access delays of conventional algorithms and of our proposed algorithm, and show, via OPNET simulation, that, in terms of throughput, our proposed algorithm is superior to conventional algorithms in these systems.