Lecture: 04

Engineer ASAD MEHMOOD

ContentsContents

• ZXC10-BTSB Solution • ZXC10-BTSB AE

• BDS• RFS• PWS

ZTE BSSB BTS SolutionsZTE BSSB BTS Solutions• ZTE BTS consists of three subsystems

Baseband Digital Subsystem (BDS) Radio Frequency Subsystem (RFS) Power Subsystem (PWS)

• Different types of BTSs are implemented by distinct BDS or RFS. • I1 BTS = all-IP BDS + all-IP RFS

• I2 BTS = all-IP BDS + local HIRS RFS/remote RFS

• AE BTS = (HIRS + all-IP) BDS + HIRS RFS

• CBTS = all-IP BDS + all-IP RFS

ZTE BSSB BTS Solutions (Cont’d)ZTE BSSB BTS Solutions (Cont’d)ZXC10-BTSB I1 ZXC10-BTSB AE

BDS

RFS

BDS

RFS

ContentsContents

• ZXC10-BTSB Solution• ZXC10-BTSB AE

• BDS of ZXC10-BTS• RFS of ZXC10-BTS• PWS of ZXC10-BTS

BTSB AE featuresBTSB AE features• Composed of mixed HIRS+IP BDS and usually local

HIRS RFS. • Supporting at most 12 carrier sectors with two racks.• Compatible with both ZXC10-BSCB (all-IP) and ZXC10-

BSC (HIRS).• No GCM in the BDS so that Time Frequency

Subsystem (TFS) is provided in RFS for system clock and frequency generation, which includes GPSTM, FDM and TCM.

• SIM is required for transferring clock from HIRS part to IP part.

ZXC10-BTSB AE Subsystem Main ZXC10-BTSB AE Subsystem Main ContentContent

• BDS (Baseband Digital Subsystem)• TFS (Timing Frequency Subsystem)• RFS (Radio Frequency Subsystem)• PS (Power Subsystem)

Typical BDS Configuration of AETypical BDS Configuration of AE

CHM

RIM

CHM

CCM

CCM

AE BDS IP

DSM

SNM

SAM

SIM

PSMB

CHM

RIM

CHM

CHM

CCM

CCM

AE BDS IP+HIRS

DSM

SNM

SAM

SIM

RFIM

CHM

CCM

CCM

CDSU

CHM

RFIM

CHM

PSMB

PSMB

CHM

AE BDS HIRS

SAM

RFI

M

CHM

CCM

CCM

CDSU

CHM

RFI

M

CHM

PSMB

PSMB

BDS (Baseband Digital Subsystem)BDS (Baseband Digital Subsystem)

One EBDS consists of up to 4channel processing modules (CHMs), 2

communication control modules (CCM), 1 RF interface modules

(RFIM) and 1 BTS_CDSU module.

HIRS-Baseband Digital SubsystemHIRS-Baseband Digital Subsystem

Baseband Digital SubsystemBaseband Digital Subsystem• Main functions of the EBDS--HIRS

• CDMA Baseband digital data forward modulation• CDMA Baseband digital data reverse demodulation• Interface with RFS• Provide Abis Interface to BSC• control center of BTS, communication platform

• In logic, EBDS subsystem includes CCM module, CHM module and RFIM module. For the description convenience, CDSU module is described in EBDS subsystem.

Baseband Digital Subsystem-Logical StructureBaseband Digital Subsystem-Logical Structure

CCM2:1

CHM1

CHM2

CHM12. . . . . .CHM

3RFIM

2:1

C DS U

C DS U

BSC

E1CO

DI S

. . ..

TCM

G P S

I 2C

FDM

RFCM6:1

TOD 10M 16CHI P PP2S、 、

PP2S

16CHI P

10M

CDMA前 反 向数 字 基 带 数 据

BDSRS232

R FSCDMA前 反 向

模 拟 基 带 数 据

12M

CDMA Baseband Data

CCM(Communication Control module)CCM(Communication Control module)

• Main Functions:• Centralized control for data signaling route, signaling

handling, resource management and maintenance operation of whole EBDS subsystem.• Provide S_HIRS functions, served as a switching unit• Signaling processing and transfer• Maintenance and Management of modules on EBDS

Subsystem• Software downloading and data distribution• Maintenance of GPSTM, Receive the TOD message

CHM Channel Element ModuleCHM Channel Element Module

• CHM, located in the EBDS frame of ZXC10-BTS, is responsible for modulation/demodulation of the channels in CDMA. A single frame has 6 CHM modules per carrier.

• CHM implements the following functions: • In Forward link: CHM modulates voice or data frames which sent by

CCM board via transceiving interface.And then it sends the modulated signals to RFIM board.

• In Reverse link: CHM receive antenna signals which distributed by RFIM via the baseband data interface, and then it demodulates the signals into voice or data frames and sends them to CCM board for switching processing via transceiving interface

• CE is in CSM chip, each CHM include 1 or 2 CSM5000 chipset

CHMCHM Channel Element Module Channel Element Module

• 1 to 4 CSM5k chips in CHM5K for 1x, 1 chip include 64 F_CE and 32 R_CE. In 64 F_CE: 36 for voice and the left 28 for data.

X2

X1

X3

X4

X8

S1

X6

1

CSM5K

RFIM(Radio Frequency Interface Module)RFIM(Radio Frequency Interface Module)

• RFIM Functions:• RFIM is connected with EBDS and RFS. It is controlled

by CCM.• RFIM transmits and processes forward and reverse

baseband data, TRX control signaling information (configuration control and status alarm).

• Clock distribution :It receives 16Chip clock and PP2S from GPS unit ,and then distributes the clock to channel boards

SAM (Site Alarm Module)SAM (Site Alarm Module)

• For any large communication equipment, a perfect alarm system is indispensable. It must monitor the working environment of the communication equipment in real time and give a prompt response to any fault and alarm signal for timely processing and avoiding loss.• Detect the running status of the power module and fans• Environment signals such as door control, flooding,

temperature, humidity, smoke etc., • Reports the detection results to the operation and maintenance

console through the CCM for processing.

ZXC10-BTSB AE Subsystem Main ContentZXC10-BTSB AE Subsystem Main Content

• EBDS (Baseband Digital Subsystem)• TFS (Timing Frequency Subsystem)• RFS (Radio Frequency Subsystem)• PS (Power Subsystem)

FDM Frequency Distribution ModuleFDM Frequency Distribution Module• The FDM board implements the following functions:

• Receives clock signals from TCM.• Distributes 10MHz signals or distributes them after phase-

lock.• Reports the working status of this board through IIC.

FD

M M

odule

10MHz

TRX1TRX2

TRX3

TRX4TRX5TRX6

ZXC10-BTSB AE Subsystem Main ContentZXC10-BTSB AE Subsystem Main Content

• EBDS (Baseband Digital Subsystem)• TFS (Timing Frequency Subsystem)• RFS (Radio Frequency Subsystem)• PS (Power Subsystem)

RFS StructureRFS Structure

• RFS mainly enables air interface via antenna. It supports the interface with EBDS via the interface module to implement modulation transmission and demodulation receiving of CDMA signals. It also implements relative check, monitoring, configuration and control functions.

－

RF transceiver

TRX Antenna feeder system

HPARF front End

RFE

BTS test

BTM

TRX Transmitter and Receiver ModuleTRX Transmitter and Receiver Module

In TRX, two receiving interface, RX1 and RX0, are used for diversity receiving.

TRX Front PanelTRX Front PanelRUN

ALM

TRX

TX

RST

RX1

RX2

RS232

RUN Green RUN indicator.

ON: normal running (B version)Flash: normal running (C version)OFF: power-off or faulty

ALM

Red Fault indicator.

ON: any error occursFlash: IIC fault OFF: normal running or power-off

RST   Reset button. used to reset a board.

RST Reset button.When this button is pressed down, a board will be reset

TX Forward transmitting signals sent by TRX

RF IN input end of HPA

SMA RF cable

RX1 Backward receive signals of RFE

RX output end of RFE

SMA RF cable

RX2 Backward receive signals of RFE

RX output end of RFE

SMA RF cable

RS232 Test interface None None RS232 line of DB9

RFCM FunctionsRFCM Functions

• Located in the TRX Module• The data interface between the baseband

digital subsystem (RFIM) and the RF subsystem (TRX)

• D/A-A/D conversion

Attention: RFCM is inside TRX can not be seen

HPA(High Power Amplifier ModuleHPA(High Power Amplifier Module

HPA FunctionsHPA Functions• HPA performs power amplification for the

TRX forward transmission signals. • When HPA receives the forward

transmitted CDMA signals of TRX , it will amplify the power, so that the signals will radiate within the cell via the antenna after they are processed by the duplex filter of the RF front end with proper signal power to cover the planned cellular area.

RFE(Radio Front End) ModuleRFE(Radio Front End) Module

DUP: Duplexer (Receive and Transmit)DIV: Diversity (Receiving)

RFE-DIV RFE-DIV

RFE Module FunctionRFE Module Function• RFE is the bridge between the internal system of

RFS in the BTS and the external antenna of the BTS • Main Functions:

• It implements filtering and low noise amplification on small signals received by the antenna

• It implements power allocation on received signals after low noise amplification

• It provides receiving/transmission duplexing function (only for DUP)

• Performs power monitoring, providing related power detection values

ZXC10-BTSB AE Subsystem Main ContentZXC10-BTSB AE Subsystem Main Content

• EBDS (Baseband Digital Subsystem)• TFS (Timing Frequency Subsystem)• RFS (Radio Frequency Subsystem)• PS (Power Subsystem)

• PSMD: Power Distribute Module• PSMD is located in BTS system power distribution box. It distributes the

input • -48V DC power into shelves. PSMD board checks and controls the

working states• of power system and fan. • PSMC: ±12V:Provide Power for REF&TRX&FDM• PSMB: +5V:Provide Power for EBDS• PPM: +27V:Provide Power for HPA

Typical BTSB AE and ItsTypical BTSB AE and Its Principle Principle

RFE(Alpha)

TRX

RFCM

EBDS

HPA

TRX

RFCM

HPA

TRX

RFCM

HPA

TX

TX

TX

RFE(Beta)

RFE(Gamma)

RX0

RX1

RX0

RX1

RX0

RX1