Mobile network architectures towards UMTS

The development of the third generation mobile systems obeys, on one hand, the requirement of complete integration within the IBC framework, and is able to supply several communication features and a wide spectrum of services and, on the other hand, a transition perspective, where it can be seen as an evolution of second generation networks, namely GSM, DCS1800 and DECT. This paper addresses the Universal Mobile Telecommunications System (UMTS) technical solutions that can comply, with both integration and migration requirements in the above sense. It reports some elements of the discussion going on in European research programmes on the subject. Specifically, the main issues of the UMTS network architecture, the service evolution and the impact of radio access techniques on the fixed network infrastructure are considered. One of the most critical points considered is the definition and the implementation of mobility driven features in the B-ISDN context.