With the rapid development for the technologies of mobile networks and mobile device, people are likely to access the information in Internet anytime and anywhere through different types of mobile devices.

Integration of different kinds of networks to provide people a seamless and continuous network access service become a major issue in B3G network. There are several important issues for the integration of heterogeneous networks. First, due to the different network protocols and device capabilities, protocol and message format conversion need be done. Second, the “Session Mobility”, the maintenance for the service session continuity while users roam among different networks, should be considered. Third “Personal Mobility”, a personal environment, to users while residing in different kinds of network should be achieved. Fourth, the existing network protocols should not be notified for the new infrastructure introduced to integrate the heterogeneous networks. Finally, due to the exposure of communication media and information exchanges, security issue should be considered.

In this thesis, we design and implement a Heterogeneous network Integration Support Node (HISN) for the integration of heterogeneous wireless networks integration. Then, we propose a distributed HISN network architecture. The HISN maintains the Session Mobility, Personal Mobility, and Terminal Mobility of mobile users through the Session Management mechanism.