The traditional constellation of networks shows a clear separation between fixed and mobile networks. Both networks have their own, firmly defined interfaces and transitions. With the convergence between cellular mobile networks and WiFi, it is possible to use all telecommunication services with one end device, regardless of the access technology used by wire or radio. Faultless switching between networks and services is controlled by service providers. This technology is implemented in Generic Access Networks
(GAN). The FMC approach, Fixed Mobile Convergence, which was developed by the European Telecommunications Standards Institute (ETSI), refers to network convergence and takes into account accessibility at any location, whether stationary or mobile, under one telephone number. According to the FMC proposals, the subscriber has only one voicebox
and receives only one bill. He has access to all types of information anywhere and at any time and can use the same services on the move as in the office or at home.Fixed Mobile Convergence takes into account terminal mobility, service mobility and personal mobility in terms of the concept
Terminal mobility allows the subscriber to take his personal terminal with him wherever he goes and to use it wherever he is. Service mobility provides the telecommunication subscriber with a set of consistent services, regardless of the terminal device, access network
and location, and personal mobility ensures that the subscriber can be reached at a number wherever he is. Thelatter involves roaming between the different networks and providing
thesame consistent services across the different networks.
In contrast to network convergence, Fixed Mobile Convergence (FMC), Fixed Mobile Integration (FMI) focuses on service convergence and combines features of different Tk services of fixed and mobile networks. And Mobile to Mobile Convergence (MMC) is functionally equivalent to FMC, except that the transition from a cellular mobile network to a WiFi network is automatic, without a service provider.