A Study Of Verical Handover Strategy In Mobile Subnet Based On PMIPv6Protocol

With the continuous development of various wireless technologies, and the demands of users for access to the network at any time, Mobile Internet is moving in a direction conducive to isomerization. It has been so common that mobile terminal supports WLAN, CDMA,3G and other access technologies. Access to mobile Internet terminal is also more diverse. It not only contains a single mobile terminal, but also contains mobile subnets comprising a plurality of mobile terminals.As the key technology of the next generation network, Proxy Mobile IPv6(PMIPv6) protocol reduce the complexity of the signaling interaction and enhance network manageability. However, it is does not support network mobility and vertical handover in PMIPv6protocol, and it is not a well solution to solve this problem both here and abroad. Therefore, this paper put PMIPv6protocol, network mobility and vertical handover together to study. A scheme is designed and implemented to support network mobility and vertical handover based on PMIPv6protocol.First of all, this paper analyzes the research situation of vertical handover based on network subnet enabled PMIPv6(NS-enabled PMIPv6) at home and abroad, and then describes PMIPv6protocol, network mobility basic support protocol, and mobile handover technologies.Then, in this paper, the research content is divided into two parts. One part is how PMIPv6protocol should be performed after the occurrence of vertical handover. The other part is how mobile router determines whether to perform vertical handover. For the study contents in the first part, it puts forward vertical handover mechanism supporting NS-enabled PMIPv6. The mechanism changes signaling process of PMIPv6protocol, extends the function of protocol entity. It makes PMIPv6protocol support mobile subnet and the vertical handover.3G access module is programmed and designed in the paper. Add sending and receiving PBU sub-module when vertical handover, and expand the tunnel and routing management module.For the study contents in the second part, this paper proposes vertical handover algorithms based on NS-enabled PMIPv6. The algorithm analyzes the selection, normalization and weighting calculation of handover parameters. Then, the six modules of the algorithm is designed and implemented by procedure, which including:handover trigger management module, handover decision module, handover execution module, status monitoring of interfaces module, interfaces management module, and get information module.At last, the prototype system is designed in the paper to test the functionality and performance of vertical handover system based on NS-enabled PMIPv6. The functional testing includes protocol signaling process and handover algorithm workflow; performance testing includes handover delay and reliability of handover, etc. The results of tests show that the design of vertical handover mechanism based on NS-enabled PMIPv6has been successfully implemented and get a satisfactory performance.