Research On End-To-End Handoff Mechanism Based On 802.16 Access Network

The WiMAX standardized by the IEEE802.16 Working Group aims at achieving global network interworking under fixed and mobile broadband wireless access environment. The technical advantages of WiMAX determine that WiMAX technology will have a vast scope of good market prospects. Up to now, the IEEE 802.16 standards only concern the functions such as MAC layer, physical layer and the handoff technology of MAC layer, etc., but how to solve the problems on handoff of upper layer is still not described. Therefore, it is very important for in-depth study of the WiMAX on end-to-end network handoff mechanism.SIP is used by IP Multimedia Subsystem proposed by the 3GPP organization for session control. Due to the SIP's mobility support, it is convenient to create and modify an end-to-end session in IMS. In the field of study of end-to-end network handoff, SIP also has the natural advantage of the technology and broad market prospects.On the basis of study of WiMAX and SIP, a new mechanism using SIP to achieve end-to-end handoff under IEEE802.16e access networks is proposed in this thesis. The mechanism adopts a cross-layer design of handoffs, which means that the MAC layer handoff procedure can be interleaved with that of the application layer. During the handoff at link layer, the session modification at application layer is triggered. Therefore, the handoff process speeds up and the handoff delay is reduced and the success rate of handoff is improved. A simulation based on NS2 platform is done, including integrating SIP modules with WiMAX protocol modules on NS2, extending some of the messages of SIP to support session mobility. Finally a SIP session establishment procedure based on WiMAX access is completed.