The requirements for IMT-2000 network evolution

摘要

IMT-2000 system will Start in 2001 spring and it enables high-speed data communication with range from 144kbps to 2Mbpa. A surge of i-mode users proves high demand to ease-access to the Internet and utilize its resource on mobile environment. NTT DoCoMo is researching how to evolve IMT-2000 system with the following three requirements; 1) service flexibility, extension, cost reduction, 2) harmonization mobile and IP service, 3) IP extension for mobile communication. We described the brief of IMT-2000 packet switching system for mobile communication and its problems such as traffic congestion on gateway node and detour routing mechanism. Then we explained the key technologies; network architecture consisting of two separate layers, call control layer and transport layer, IP nobility and open service architecture to solve these problems and meet the above requirements.