5.2　Packet-switch Network Nodes

5.2.1　The WCDMA network shall include PS domain nodes of SGSN，GGSN，CG，BG and DNS.The HLRs are shared with CS domain.

5.2.2　SGSN deployment shall abide by the following principles:

1　SGSN shall support 2G GPRS and WCDMA access simultaneously.

2　SGSNs shall be deployed in high-traffic local networks，but small-traffic local networks should share one SGSN.In the same local network，one or more SGSNs may be deployed according to the growth of subscribers.For multiple SGSNs，the deployment shall be at separate bureau locations.

3　Equipment with a high-capacity and high processing ability shall be used for SGSNs.The capacity shall satisfy local and roaming subscribers needs for traffic handling and data storage.An appropriate redundancy should be considered when evaluating the processing performance of the equipment.

5.2.3　Provincial GGSN deployment shall abide by the following principles:

1　The deployment of GGSN shall comprehensively consider such factors as capacity，security，transmission conditions and access service.Each provincial network shall have at least one GGSN，and more according to the growth of traffic.Multiple GGSNs deployed for the same service shall be in a load sharing configuration.

2　GGSN should be deployed in provincial capital or local network with high traffic and outbound gateway to the external data network.

3　GGSN shall select equipment with high reliability，large capacity and high processing ability with proper redundancy.

5.2.4　Backbone GGSN deployment shall abide by the following principles:

1　The backbone GGSNs shall be deployed in cities with network interconnection points and IP bearer network backhone nodes.According to roaming traffic load，the backbone GGSNs shall be combined with provincial GGSN or independently.

2　Backbone GGSNs shall be deployed in pairs in a mutual backup configuration.

5.2.5　CG deployment shall abide by the following principles:

1　CGs should be independently deployed and shall be deployed in pairs；

2　Equipment with a high processing ability shall be selected and used for independently-deployed CGs.

5.2.6　BG deployment shall abide by the following principles:

1　BG should be deployed in cities with network interconnection points and IP bearer network backhone nodes.The deployment shall be independent and in pairs in a mutual backup configuration；

2　Equipment with a high processing ability shall be selected and used for BG.

5.2.7　Deployments of provincial network and backbone DNS shall abide by the following principles:

1　Provincial DNS should be deployed in the provinces with SGSN installation.To ensure network security，DNS shall be deployed in pairs.

2　The backbone DNSs shall be deployed in cities with IP bearer network backhone nodes.According to roaming traffic load，the backbone DNSs shall be combined with provincial DNSs or independently.