Fast Uncontrolled Handover scheme for WiMAX: Infrastructure networks

Worldwide interoperability for microwave access (WiMAX) is a wireless WAN technology with high data rate and is a candidate for the 4G network trying to provide users with mobile service. To alleviate frame loss during handover, WiMAX provides the Uncontrolled Handover for this potential problem. However, in the Uncontrolled Handover, the target Base Station (BS) needs to retrieve the information of Mobile Station from the Serving BS and the authenticator, respectively. To make matters worse, the MAC context retrieval, the AK context retrieval and the DP registration procedure are performed one after another. Therefore, the latency of the Uncontrolled Handover may be very large and may not meet the QoS requirement of some ongoing delay-sensitive services. In this paper, we propose a fast Uncontrolled Handover scheme that can minimise handover messages and accelerate handover procedure. The performance analysis shows that our scheme outperforms the NWG 1.0.0 and NWG 1.2 in average transmission delay. Besides, our scheme is compatible with the NWG specification.