Handover Delay Reduction and Buffer-Based Data Recovery Scheme for Inter Multicast Broadcast Service Zone

Multicast broadcast service (MBS) is one of the important features supported by Mobile WiMAX to efficiently transmit data common to a group of users. As MBS services are usually delay-sensitive applications, the concept of the MBS zone is also introduced to provide better quality of service (QoS) for mobile users. However, the large inter- MBS zone handover delay and frame offsets between adjacent MBS zones cause large packet loss, but this problem is little studied. In this paper, we propose an improvement on the inter-MBS zone handover procedure to greatly reduce the handover delay. Furthermore, we also propose a data recovery scheme for inter-MBS zone handover by using an additional multicast connection as a recovery channel for each MBS service to minimize the packet loss. Simulation results show that our proposed schemes achieves almost zero packet loss when the number of recovery channels is the same with the number of MBS sessions.