| The "Optimally Connected Anywhere, Anytime" vision could be realized by a network comprising a variety of interworking access systems connected to a common packet-based core network. 
Different technologies, such as WLAN, short range connectivity systems, and IMT-2000, may be present in a single device operating across various networks at any particular time. For example, a personal digital assistant (PDA) may contain multiple radio interfaces enabling it to communicate with a mobile terminal; a private or public WLAN; or a wide-area service provider, such as a mobile (cellular) network.One important element in realizing this vision of integrated services, given the emerging dominant role of packet-based applications and networks, is the development of suitable adaptive packet data transfer solutions. It should be possible to support asymmetric traffic in an efficient way. In the future operators may deploy a mix of technologies that could, at various stages in time and subject to market and regulatory considerations, incorporate cellular, WLAN, digital broadcast, satellite and other access systems. This will require the seamless interaction of these systems in order for the user to be able to receive a variety of content via a variety of delivery mechanisms depending upon the particular terminal capabilities, location and user profile. Different radio access systems will be connected via flexible core networks. In this way, an individual user can be connected via a variety of different access systems to the networks and services he desires. The interworking between these different access systems in terms of horizontal and vertical handover and seamless service provision with service negotiation including mobility, security and QoS management will be a key requirement, which may be handled in the core network or by suitable servers accessed via the core network. |
