Performance evaluation of multicast routing protocol in WiMAX multi-hop relay environment

Abstract

Multicast/Broadcast Service (MBS) in WiMAX refers to the ability of the WiMAX network to provide flexible and efficient mechanisms to send common content to multiple users who are sharing radio resources. WiMAX multi-hop relay technology is a key enabler to expand WiMAX infrastructure to eliminate blind spots in coverage and to enhance user throughput with a lower capital expenditure and operational expenditure. To support MBS in a WiMAX multi-hop relay network, one must consider several design issues such as the dynamic relay topology discovery in response to the mobility of the relay station, the dynamic group membership management, the service activation due to join/leave operations of MBS users, the radio resource allocation and the connection management to support these dynamic behaviors. This thesis studies and develops a WiMAX relay architecture, its relay protocol and the optimal multicast algorithms to solve the above issues. To resolve the above-mentioned issues, we have created a model for our multi-hop WiMAX relay architectures. This model incorporates an inter-layer protocol design that would allow the IP layer to use its IGMP/PIM snooping capability together with WiMAX MAC layer relay protocols. Among the MBS server, the WiMAX BS (Base Station) and the MS (Mobile Station), we adopted existing IETF protocols (including IGMP and PIM) to implement some common multicast procedures at the networks layer in order to provision MBS service. To support dynamic formation of a relay network topology, we have proposed and implemented a BS-oriented source-routing protocol to automatically discover the relay path. Finally, we have implemented our MBS in an OPNET simulator, and verified their operations. We have also evaluated the performance of the video and voice applications in WiMAX relay networks under different network sizes, and discussed their performances. The performance results demonstrate the Point to Multi-Point characteristic of WiMAX.