Toward an all-IP-based UMTS system architecture

Looking into the future, two main drivers For the mobile telecommunications market can be identified: third-generation mobile systems (e.g., UMTS) and the Internet (e.g., the introduction of IP technologies like voice/multime dia over IF in mobile networks). UMTS is seen as the enabler of wireless mu ltimedia applications and portability of a personalized service set across network/terminal boundaries, as defined within the virtual home environment (VHE) system concept. In light of these recent evolutions, this article in vestigates the impact of the evolution toward an all-IP UMTS network archit ecture on the UMTS service architecture, which is based on the VHE concept. The article discusses two possible scenarios for supporting VoIP services in the UMTS service architecture and analyzes their applicability in on all -IP-based UMTS network. The First is based on the traditional centralized I N service architecture. The second proposes a new decentralized architectur e based on direct control of VoIP call control equipment by open service ar chitecture interfaces.