This paper presents an access-independent network architecture for supporting UMTS service capabilities. The approach is based on an enhanced B-ISDN core network with personal and terminal mobility provided by intelligent network techniques. A physical realization is presented, and the protocols corresponding to the physical interfaces are identified. Protocols are proposed for UMTS mobility and service support, and the impact on the B-UNI and IN interfaces is considered. Reflecting the vision of the ETSI global multimedia mobility (GMM) standardization framework, UMTS service support through non-UMTS access is considered. Consideration of DECT as a UMTS access technology leads to an interworking proposal that presents each DECT terminal to the core network in terms of UMTS functional entities. Access-independent usage of UMTS terminal applications motivates additional interworking in the terminal to encapsulate the access network. The desirability of an access-independent UMTS application programming interface in the terminal is indicated.

The economical estimation of B-ISDN development in metropolitan areas, with particular reference to the application of the asynchronous transfer mode (ATM) techniques is addressed. The results achieved by applying models and methods developed in the framework of RACE 1044-EPF Case Study E (Evolution Prospects for Metropolitan Public Networks) to an urban area of 2 million inhabitants. Equipment volumes are estimated as a function of different demand scenarios, equipment evolution, and network performances. Economical figures that verify the cost-effectiveness of alternative developments and the viability of alternative introduction policies of B-ISDN are derived. The economical impact of fulfilling service integrity requirements of specific demand segments is evaluated. Usable planning guidelines and evolutionary strategies as regards network architecture, system introduction, and growth policies are defined.>