Basics of Cdma

Part1 Basic knowledge of CDMA

Agenda
1. Architecture of CDMA system/ Coverage Area Structure 2. Interface between different entities 3. Numbering plan

Architecture of CDMA system
MS Um Abis A B OMC

BT S

BSC

MSC

VLR D HLR H

BSS
C

MSS

AUC

•MS: •BSC: •BTS: •MSC: •VLR: •HLR: •AUC: •OMC:

Mobile Station Base Station Controller Base Transceiver Station Mobile Switching Center Visitor Location Register Home Location Register Authentication Center Operation and Maintenance Center

1.Main components of CDMA
•MSS (Mobile Switching Sub-system) •BSS (Base Station Sub-system) •MS (Mobile Station) •OMC (Operation and Maintenance Center)

1.1 Base Station Sub-system
•Function It provides trunks between wireless part and fixed part of PLMN network. ---BSC BSC performs the controlling function and management.

---BTS BTS is in charge of wireless transmission.

1.2 Mobile Switching Sub-system
•Function —CDMA switching function —Manage mobile subscriber data —Manage database for mobile service —Interface between CDMA network and other network (such as PSTN, other PLMN etc.). •It includes 4 function units: ---MSC ---HLR ---VLR ---AUC

1.2.1 Mobile Switching Center(MSC) •It is responsible for setting up, managing and clearing connections as well as routing the calls to the proper user. • It provides the network interfaces, the charging function and the function of processing the signaling. • MSC gets data for call handling from 3 databases: VLR/HLR/AUC • GMSC(gateway):When a non-CDMA end subscriber calls a CDMA subscriber, the call will first be routed to a GMSC. •It can process the No. 7 signaling between BSS and MSC, and realizes the auxiliary radio resource management and mobile management.

1.2.2 Visitor Location Register(VLR) •VLR is a dynamic database used by MSC for information index. It stores all related information of mobile subscribers that enter its coverage area, which enables MSC to set up incoming and outgoing