Seamless integration of the seamless integrated

摘要

PROBLEM TO BE SOLVED: To provide a service which is efficient and excellent wholly by organizing a plurality of radio systems as the systems optimum for respective environments and producing a network which integrates the systems without seam. SOLUTION: The radio systems are integrated seamlessly in a network system. The architecture of a heterogeneous network is adopted for the network system, which includes at least four building blocks such as a communication terminal 40, a radio access network 41, a common core network 42 and an external network 43.