Abstract :
The evolving third generation of mobile communication, Universal Mobile Telecommunication System (UMTS), foresees global provision of a broad variety of services with data rates of up to 2 Mbit/s, seamlessly integrated in different mobile and fixed networks. In addition to terrestrial networks, satellite systems (S-UMTS) are expected to ensure global coverage. Within the time schedule of UMTS no satellite system will be able to provide 2 Mbit/s rates for mobile phones. However, the evolving new LEO and MEO type satellite systems are expected to provide voice and low data rate (below 64 kbit/s) services to multimode terminals by the end of the century. An integration of these systems into UMTS seems feasible and is evaluated by different EU-ACTS projects (INSURED, SINUS). The TOMAS project in contrast focuses on high quality multimedia services and other high bit rate applications, which can be provided by geostationary satellites in the global cell of the UMTS. The terminals will not be handheld mobile phones but highly portable notebook-sized satellite terminals, but the services should be compatible with UMTS. The TOMAS main objectives are to demonstrate and evaluate applications and components of S-UMTS requiring higher bit rates (on a global platform). The emphasis is, however, on the end user´s perspective. Therefore within TOMAS an `Inter-Trial Testbed´ will be set up, which will enable TOMAS and other ACTS and non-ACTS projects to test components and applications in real end-user trials, using existing ESA/EMS and Inmarsat geostationary satellites with data rates up to 2 Mbit/s
