Evolution from UPT to terminal mobility using the Vision O.N.E. call model

The introduction of the intelligent network concept means that switches can access common data from all around the network, and even within other networks. UPT makes use of these techniques to provide a simple form of mobility to users. However, the introduction of IN and ISDN into networks allows fixed switches to be developed to support users over wireless accesses. In order for this to happen the call processing architecture must be developed in such a way as to be able to introduce new software and re-use existing software easily and efficiently