A dynamic MBS zone framework for cost-effective inter-MBS zone handover in WiMAX networks

摘要

To synchronize multicast broadcast service (MBS) zone data transmissions, the WiMAX standard defines a coordination mechanism to coordinate data transmissions over the WiMAX network; however, the packet loss recovery procedures, which are parts of the coordination mechanism, enlarge packet transmission latency and packet buffer pool requirement. Therefore, we propose an in-frame control (IFC) scheme to decrease packet error rate and packet retransmission count, so as to reduce the packet transmission latency and packet buffer pool requirement. To support level-2 frame-offset coordination, we also propose a dynamic MBS zone (DMZ) framework that can provide data continuity between any two adjacent MBS zones. Based on the proposed DMZ framework, a seamless dynamic inter-MBS zone handover (called DMZ HO) scheme is proposed to resolve the data discontinuity (or packet loss) problem during inter-MBS zone HO. Compared to the WiMAX standard scheme, the proposed IFC scheme reduces packet error rate and packet retransmission count by 49.8 and 49.73 %, respectively. The proposed DMZ HO scheme also outperforms an overlapping zones (OLZ) scheme in terms of channel occupation time and channel bandwidth consumption (in terms of channel idle ratio). Therefore, by resolving data discontinuity, the proposed DMZ HO scheme is more cost-effective and more feasible in providing smooth multimedia content delivery services without disruption to multiple mobile stations (MSs) during HO, and thus will enhance user experience.