3　Network Design Requirements

3.0.1　WCDMA system architecture consists of UE，UTRAN and CN.Figure 3.0.1 shows general system architecture.

1　User equipment includes the mobile equipment and subscriber identity module；

2　UTRAN consists of Node B and RNC；

3　CN architecture is 3GPP R4 version.Shared by 2G and 3G networks，it includes a CS domain and a PS domain.CS domain equipment consists of MSC Server，GMSC Server，MGW，SG，VLR，HLR and AuC，while PS domain equipment consists of GPRS SGSN，GPRS GGSN，CG，BG and DNS.

3.0.2　WCDMA system interfaces:

1　UTRAN Interfaces:Radio interface Uu between UE and network，Iub interface between Node B and RNC，Iur interface between RNCs，Iu interface between RNC and CN（including Iu-CS to CS core network and Iu-PS to PS core network）；

2　CS core network Interfaces:Nc interface between（G）MSC Servers，Mc interface between（G）MSC Server and MGW，Nb interface between MGWs，and other MAP interfaces similar to GSM network；

3　PS core network Interfaces:Gn interface between GSNs；Gp interface between GSNs of different PLMNs；Gi interface between GGSN and PDN；Gr interface between SGSN and HLR；and Ga interface between GSN and CG.

3.0.3　WCDMA network engineering design requirements:

1　Complying with relevant national and industry technical requirements and specifications；

2　Adopting different construction principles according to the characteristics of vast land spread，uneven economic development and uneven subscriber and service distribution；

3　Adaptive to the needs of corporate development，service development，network development strategy and scope of telecom operators，as well as supporting a sustainable prospect；

4　Ensuring interoperability and connections with other networks；

5　Ensuring that the networks built are economically rational and structurally clear；

6　Finalizing the design through a comparative study of multiple design proposals；

7　Making full use of existing resources，adhering to the principle of co-location and sharing with diversified operators，minimizing redundant construction，and reducing construction and operating cost.

3.0.4　The following shall be included in WCDMA network design:

1　CS core network design；

2　PS core network design；

3　Radio access network design；

4　Trunk interface and signaling mode；

5　Numbering plan and IP address allocation；

6　Billing，network management and network security；

7　Synchronization methods；

8　Bureau and station location selection；

9　Installation and process requirements；

10　Co-location and sharing，environmental protection，energy-saving and emission reduction requirements.