5.1　Packet-switch Network Architecture

5.1.1　The core network of the WCDMA system should be divided into provincial network and national backbone network，a two-layer structure.

1　The provincial network is responsible for providing subscribers with PS data access service；

2　The national backbone network is responsible for providing the interconnectivity between provincial networks of the same telecom operator，and interconnectivity for PS networks of different telecom operators.