Research On The Network Discovery And Handoff Mechanism Based On Heterogenous Networks

With the rapid development of mobile communication technology and the improving requirements of mobile data services, various wireless networks join the family of communication. Wireless networks have been integrated with IP, and evolve to IP network. Therefore, all wireless networks could be connected to IP core network to form an inter-connecting hybrid network. This paper introduces the implications> development status and foreground of wireless networks, and analyzes3G WLAN WiMAX specially to discuss the advantages and disadvantages of them. At the same time, it introduces IPv6 briefly. Then, this paper studies the inter-communication between heterogeneous networks, mainly discusses the network discovery and handoff technologies based on heterogeneous networks' inter-connection..On the basis of IP inter-connection, besides introducing various locating technologies of different networks, the paper brings forward a kind of network locating method, which can be used for the hybrid network of WCDMA. WLAN WiMAX. The method, which leads to locate the position of terminals, is used to save power and prepare for further handoff.The paper discusses the problem of handoff in homogenous networks. It describes the handoff principle and algorithm knowledge, what' s more, it studies the horizontal handoff algorithms for WLAN and WiMAX, analyzes the disadvantage of current algorithm, and brings forward a seamless handoff algorithm. According to the algorithm, it gives the emulation result, to prove the algorithm leads to better performance.Since mobile IP supports the solution of Internet mobility, handoff in heterogeneous networks can adopt Mobile IP handoff mechanism. The paper cites the hybrid network of WCDMA and WLAN as an example, analyzes the procedure of vertical handoff, and amend the handoff algorithm. When the mobile node is in the coverage of more than two different networks, a selection needs to be made. That is which network is the best one to switch to. Finally, the paper gives a handoff control model, on the basis of which the handoff decision is made.