Shweta Shrivastava

Performance analysis of persistent scheduling for VoIP in WiMAX networks

WiMAX networks based on Release 1.0 were known for efficient support of data traffic, but were considered inefficient for VoIP capacity, i.e. for supporting a large number of simultaneous VoIP users, due to large control overhead associated with VoIP. Persistent Scheduling is a mechanism that was adopted in Mobile WiMAX Release 1.5 to reduce MAP (control) overhead for VoIP traffic and improve VoIP capacity. This paper presents a performance analysis of persistent scheduling in WiMAX. Our simulation results show that persistent scheduling can increase VoIP Capacity by 15%.

Group Resource Allocation for Increasing VoIP Capacity over WiMAX

High demand for mobile voice puts forth the requirement of high VoIP capacity over WiMAX networks. Although WiMAX networks are well-known for high-speed internet access on the go, VoIP capacity over WiMAX is low due to large control overhead. In this paper, we propose Group Resource Allocation (GRA) mechanism that reduces the control overhead and hence increases VoIP Capacity over WiMAX. In GRA multiple users are provided allocation as a group. Grouping is based on common traffic and channel characteristics and uses bitmaps to signal resource allocation information to users. Grouping of users and use of bitmaps reduces control overhead. Simulation results show that a 40% gain in VoIP capacity over WiMAX can be achieved with Group Resource Allocation.