UMTS visions and the possible evolutions of GSM networks

The aim of this paper is to discuss UMTS requirements and key technological features in relation to likely evolutions of GSM in the relevant timeframe. This also touches on the respective profiles and roles of UMTS in relation to what a migrated GSM can be in the same timeframe. This issue also reflects on possible technological paths for UMTS. To what extent is UMTS an evolution or a revolution? The answer depends on perspectives. Air interface, network architecture and services are different perspectives for the discussion on how UMTS shall be introduced. The answer depends very much on from which perspective the system is considered