CDMA BSS Hardware Description (ZTE Make)

Mechanical Features of BSC BSC has two kinds of rack:the central rack and the vocoder rack.

Central rack and vocoder rack apply standard rack and insertion boxes.

The different types of insertion box are composed of different inserted

boards.

From top to bottom, each rack contains: a power distribution insertion

box, 3~5 function insertion boxes, a fan box and dust-proof shelf.

There are four kinds of function insertion boxes:

HIRS box: consists of PSMB, NIM, NCM.

CDSU box: consists of PSMB, CDSU, CPM, TCM, GPSIM, etc.

SVBS box: consists of PSMB, SVM, SVICM.

PCFS box:consists of PSMB,PCFIM,PCF.

Max. number of broads in each function insertion box:22

Max.number of E1 links between BSC and MSC: 240 Max.number of BTS can be connected with:380 Max. number of selector/vocoder :7200 Max. traffic processing capability:5040 Erl （ 7200 x 0.7） Support soft handoff between BSC 8K、 13K QCELP and 8k EVRC vocoder Support packet data service,with a data rate up to 153.6kbps

Performance of BSC

HIRS:High-speed Interconnection Routing Subsystem

SVBS:Selector Vocoder Bank Subsystem

PCFS:Packet Control Function Subsystem

CPS:Call Processing Subsystem

CDSUS:Channel Data Service Unit Subsystem

TS:Timing Subsystem

II. Subsystems of BSC

Traffic & Signaling between each subsystem by B-HIRS

B-HIRSBSM

PCFS

CPSCDSUSBTS

SVBS

TS

MSC

PDSNA10/A11

A1/A2

Abis

voice

packet data

O&M

HIRS Subsystem is switching center and packet data exchange platform of BSC.

Functions of HIRS： Packet data switching

Timing distribution， monitor GPS

Software downloading

Operation and maintenance management on the whole BSS

HIRS

HIRS Shelf Structure

PSMB

NIM

NIM

NIM

NIM

NIM

NIM

NIM

NIM

NIM

NCM

NCM

NIM

NIM

NIM

NIM

NIM

NIM

NIM

NIM

NIM

PSMB

NCM: Network Control Module

NIM: Network Interface Module

PSMB ： Power Supply Module

NCM is the core module in HIRS shelf

When NCM is in slot 11,it must connect with port 6 of NIM in slot 9 via the internal serial bus on backplane.

When NCM is in slot 12,it must connect with port 6 of NIM in slot 14 via the internal serial bus on backplane.

2 NCM working mode: active and standby

NCM

Major functions of NCM : Gateway function:data receiving of CO bus and distribution of DIS bus,routing of data frame inside/outside of the local shelf

Distribution of software of respective modules and configuration information;

Fault detection, isolation, report and recovery in HIRS network;

GPS clock distribution;

Serving as the foreground PC of BSM to communicate with the background through 10/100Mbps Ethernet

NCM Functions

Receive/send RS-422 serial data

Receive/send data through DISCO

8＋ 1 redundancy

Clock receiving and distributing

Reports module working status to NCM via I2C bus and accepts NCM control

NIM Functions

SVBS FunctionsSVBS is the core part for enabling voice services and supporting SS7 signaling MTP1 and MTP2.

Judge and implement soft handoff: select a path in several soft handoff path by the quality for code type conversion

Code type conversion function: It enables the conversion between 64K PCM codes and variable rate of QCELP codes;

Enables echo cancellation for PCM data on the forward link

Power control

Signaling handle

SVBS Shelf Structure

PSMB

SVM

SVM

SVM

SVM

SVM

SVM

SVM

SVM

SVICM

SVICM

SVM

SVM

SVM

SVM

SVM

SVM

SVM

SVM

PSMB

SVICM: Selector Vocoder Interface Control Module

SVM: Selector Vocoder Module

PSMB ： Power Supply Module

Input and Output interface

4*E1 interfaces connected with MSC

SVBS Subsystem

Connected with NIM via RS422 port

SVICM FunctionsS-HIRS:Communicate with HIRS Network

Distribute forward traffic and signaling（ SVMSVICM NIM）Distribute reverse traffic and signaling (SVMSVICM NIM）Distribute signaling interior SVBS（ SVMSVICM ）

Receive and Distribute Clock and TOD messageManage and control SVMSignaling handlingCode type conversion between MSC and BSS via DTI

NIM

SVICM

Ugateway

SVCSVM1 SVM

7SVM8

CODISC_BUS

SVBS

DTI

MSC

时钟

I2C

Clockdistribution

RS422

4*E1

4*HW

Structure of SVICM

transcoding between PCM and QCELP

reverse outer-loop power control

soft handoff

handle layer 3 of Abis interface and layer 2 of IS-95 signaling

assign the timeslot

SVM － Selector & Vocoder Module

A SVM contain 1 SVP and 15 SVEs. SVICM receive traffic data from the RS-422 port of NIM then forward to

SVM,SVP forward to SVE,SVE transcoding to PCM and send through

HW,in other direction,SVE transcoding PCM to QCELP or EVRC,then

send to SVP,then to SVICM,and then NIM.

Structure of SVM

HW interface

SVE1

SVE2

SVE15

Data Interface

maintenance bus

clock interface

SV

P

PCFS

Each BSC can support 10 PCFS subsystems.

Each PCFS subsystem comprises 1 PCFIM board and 8 PCF boards.

Each PCFS subsystem is connected with the PDSN via PCFIM board, and

provides a 10M/100M self-adaptive physical Ethernet interface through the

PCFIM board.

Each PCFS subsystem can carry 4000 PPP connections (Dormant+Active),

and 240 activated PPP connections (total number of active ones).

PCFS Functions

To Select a service path with best quality among multiple soft handoff paths for

data GRE encapsulation.

Enables adaptation between GRE data packets and RLP data packets;.

To establish, configure and maintain A8 and A10 links via A9 and A11 interfaces.

To establish PPP link between MS and PDSN to enable packet data service

transmission.

Input and Output Interface

PCFS provides a 10M/100M fast Ethernet interface to be connected with

PDSN.

PCFS provides a RS422-port to be connected with HIRS switching

network.

CPS is a joint point of BSS system’s resource management and call signaling protocol processing.

CPS comprises two modules:CPM and PAM.

CPS

Handle the signaling of Abis interface

Radio resource maintenance,management and distribution

Trunk resource management

provides A signaling interface. It fulfills A interface startup and re-startup, A interface protective switching, activation of failing data link, control of link labels, and delivery of A messages.

Control over loading of BSS;produce the message of A and ABIS interface:establish the signaling link to CCM and SVICM

Manage the database of BSS,include the parameters of BSS system,ground circuit resource,traffic channel resource,calling record,performances record,handoff record and so on.

CPS Functions

Hardware feature of CPMAccording to the software function of CPM,CPM should have the Hardware features below：CPS sub-system is a joint point of BSS system’s resource management and call signaling protocol processing,processing all the signaling,so the CPM should be powerful.

The CPM is 1+1 hot standby

PAM Functions

monitor the running status of the power supply modules in the BSC-side frames and the equipment room environment signals, including temperature, humidity, smoke, and so on.

report the result to the background operation and maintenance console through the NCM for processing;

provides duplex RS232 and RS485 interfaces for the connection of external monitoring devices and alarm box.

CDSU Subsystem

1. Convert signal between RS-422 interface and non-channelized E1,transfer signaling and traffic data between BSC and BTS.

2. BSC-CDSU and BTS-CDSU, have the same hardware structure

Timing SubsystemAccording to the CDMA standard,BSC and BTS independently synchronization the timing signal provided by GPS.

Timing subsystem provides such timing signal:* PP2S* 16chips： 19.6608MHz* TOD message

GPSTM

HIRS1

NCM

NCM

HIRS2

NCM

NCM

SVICM

SVICM

19. 6608MHz,10MHz, PP2S,

Tod

19. 6608MHz,10MHz, PP2S,

Tod

1. 2288MHz,PP2S, Tod

1. 2288MHz,PP2S, Tod

1. 2288MHz, PP2S, Tod, Tx_cl ock,

Rx_cl ock

1. 2288MHz, PP2S,8kHz, 2MHz, 50Hz,

Tod

NIM

NIM SVM

SVM

1. 2288MHz, PP2S, Tod, Tx_cl ock,

Rx_cl ock

1. 2288MHz, PP2S,8kHz, 2MHz, 50Hz,

Tod

BSC_CDSU

CPM

GPSTM

GPSTMBP

TCM

Timing distributing of BSC