Research Of The Roaming From Wi-Fi To Wimax In IEEE802 Heterogeneous Networks

With the popularity of internet and the rapid development of mobile communication technology, People hope to access to a network conveniently in routine living and commercial activities by moving method. However, whichever coverage of Wi-Fi or Wimax is much limited. Wi-Fi standard could provide broad wireless service which could access to internet in nearby areas and cover with indoors. Wimax is a wireless access technologies of broad wman. Wi-Fi and Wimax have many advantages of broad wireless data service, but they have differences in coverage which cause great complement in application layer. meanwhile, Wi-Fi,Wimax, a series of standards define merely air interface specifications which provide flexibility for upper application layer.Our courtry's dimensionality is vast, the transmission environment and the demand of services is multiform. In allusion to the characteristics of Wi-Fi, Wimax's data rate and coverage and according to mutual benefit principles, it's significant that we research organic merging of Wi-Fi, Wimax's application mode for developing prosperously Chinese information industry. We could foresee, with the popularity of Wi-Fi, Wimax technology and the decline of equipment's cost, the application mode of hotspot echoplex and terminal access would be combined gradually. The roaming between heterogeneous networks will be drawn up a programme resolving the matter that mobile terminal devices switch from a base station to another base station or from a kind of 802 network to another kind of 802 network.I work over physics layer and data link layer of Wi-Fi and Wimax which belong to broad wireless access technologies and choose the project of connecting isomerous networks which is based on Internet, by which we create uniform core network for roaming in heterogeneneous networks. we study deeply functional entities, basic framework, and work process of mobile IP protocol and bring forward a upswing project of mobile IP which is dead against disfigurement of current mobile IP. Lastly, I put forward the roaming project in heterogeneous networks of Wi-Fi, Wimax which is based on the improved project of mobile IP and research into the arithmetic which is in support of switching from a base station to another base station or from a kind of network to another kind of network when data link is triggered. Subsequently, I introduce a refined arithmetic.