Adaptive rate control scheme for handoff and its performance evaluation in mobile multimedia networks

An adaptive rate control scheme based on QoS priority for handoff success in WCDMA networks is proposed. Our scheme improves the call drop rate by adaptively managing the data rates of existing lower priority users when resources are insufficient. We describe a way that a resource can be dynamically allocated. We evaluate the performance variation in terms of a system capacity and a call dropping probability and the delay of downgraded traffic by the proposed scheme. The results show our scheme increases system capacity and decreases the call dropping probability at the cost of small delay of the data traffic. The proposed scheme has a better system utilization than guard channel (GC) scheme and it can be implemented independently of GC scheme for maximizing system performance. This scheme can also be used for the call admission control (CAC) to decrease call blocking and improve handoff control.