HUAWEI BTS3900A Hardware Structure (GSM)

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Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved.

HUAWEI BTS3900A Hardware Structure

Page1Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved.

ForewordThe BTS3900A developed by Huawei is an outdoor macro BTS

that performs the same tasks as the BTS3900. The BTS3900A

mainly consists of the BBU and DRFU. Compared with

traditional BTS, the BTS3900A features simpler structure and

higher integration


References31183199-BTS3900A GSM Documentation

BTS3900A GSM Hardware Description

BTS3900A GSM Product Description


ObjectivesUpon completion of this course, you will be able to:

Know the application scenarios of BTS3900A

Grasp the hardware structure of BTS3900A

Grasp the functions of the modules

Master typical configuration of BTS3900A

Know the networking topology of BTS3900A


Contents

1. BTS3900A Overview

2. BTS3900A Hardware Components

3. BTS3900A Signal Flow

4. Configurations of the BTS3900A

5. BTS3900A Network

6. GRFU Introduction


Location of BTS3900A

PSTN ISDN

PSPDN

Um Interface

BTS3900A

BTS3900A

BTS3900A

BTS3900A

OMC

HLR/AUC/EIR

BSC

MSC/VLR

SMC/VM

A Interface

MAPMAP

TUP,ISUPMS

MS

MS

MS: Mobile Station BTS: Base Transceiver Station BSC: Base Station Controller

HLR: Home Location Register AUC: Authentication Center EIR: Equipment Identity Register

MSC: Mobile Switching Center VLR: Visitor Location Register SMC: Short Message Center

VM: Voice Mailbox OMC: Operation and Maintenance Center


Functions and FeaturesIt supports the Abis IP/FE interface in hardware and enables Abis

over IP through software upgrade if required

It supports transmit diversity and PBT

It supports 2-antenna and 4-antenna receive diversity to improve

the uplink coverage

It supports multiple frequency bands, such as PGSM900,

EGSM900, and GSM1800

It supports the GPRS and EGPRS


Functions and FeaturesWhen the DRFU is configured, a BTS3900A can support a maximum of 12 carriers in the maximum cell configuration of S4/4/4. In addition, a site configured with the BTS3900As can support a maximum of 36 carriers in the maximum cell configuration of S12/12/12

When the GRFU is configured, a BTS3900A can support a maximum of 36 carriers in the maximum cell configuration of S12/12/12. In addition, a site configured with the BTS3900As cansupport a maximum of 72 carriers in the maximum cell configuration of S24/24/24


Contents





5. BTS3900A Network



Contents


2.1 BTS3900A Overview

2.2 BBU Unit

2.3 RF Cabinet

2.4 Power module and Components


BTS3900AThe BTS3900A consists of the AC cabinet and DC cabinet

The AC cabinet consists of the APM30H and RF cabinet, and

the BBU3900 is installed in the APM30H

The DC cabinet consists of the TMC11H and RF cabinet, the

BBU3900 is installed in the TMC11H

The RFUs are installed in the RF cabinet


Cabinet of BTS3900A

Mode Maximum Power Consumption (W)

Typical Power Consumption (W)

900 MHz 2180 1250

1800 MHz 2480 1400

Configuration Type Weight (kg)

RF cabinet (DRFUs not involved) 42

RF cabinet (DRFUs involved) 114

APM30 power distribution cabinet (BBU not involved) 54

APM30 power distribution cabinet + RF cabinet 178

APM30/TMC

RFCabinet


BTS3900A AC Cabinet The BTS3900A AC cabinet

consists of the RF cabinet and

the APM30H.

(1) RF cabinet (2) RFU (3) FAN unit

(4) FMUA (5) DCDU-02 (6) GATM

(7) BBU (8) PDU(9) Power sub-rack(AC/DC)(10)

APM30H - -


BTS3900A AC CabinetBTS3900A consists of one RF cabinet, one APM30H, one TMC11H, and one IBBS200T

(1) RF cabinet (2) RFU (3) FAN unit

(4) FMUA

(5) DCDU-02 (6) GATM

(7) BBU (8) PDU (9) Power subrack(AC/DC)

(10) APM30H

(11) DCDU-03A

(12) Transmission unit

(13) TMC11H

(14) Battery (15) IBBS200T


BTS3900A DC CabinetBTS3900A DC cabinet consists

of one RF cabinet and one

TMC11H

(1) RF cabinet

(2) RFU (3) FAN unit

(4) FMUA (5) DCDU-02 (6) GATM

(7) BBU (8) DCDU-06A (9) TMC11H


Logical Structure


Contents



2.2 BBU Unit

2.3 RF Cabinet

2.4 Power module and Components


BBUThe typical power consumption of BBU is 35W

The weight of the BBU is 12 kg at most

All the boards can be inserted from the front panel

The permissible range of power input is –38.4 V DC to –57 V DC


Working Principles of the BBU


Boards and Modules in BBUBSBC: The universal BBU Subrack Backplane type C

GTMU: The GSM Transmission, Timing and Management Unit

UBFA: The Universal BBU Fan unit type A

UPEU: The Universal Power and Environment interface Unit

UELP: The Universal E1/T1 Lightning Protection unit

UEIU: The Universal Environment Interface Unit


BSBC BoardThe BSBC provides slot 6 for the GTMU, slot 7 for a main control board that supports 3G, and slots 0 to 5 as common slots. The GTMU is 1 U high. Therefore, from the view of the front panel, the GTMU is located in slots 5 and 6

Provide backplane interfaces, communication channels, distribute clock signal and +12V power supply for the other boards


GTMUControls, maintains, and operates the BTS

Monitors the fan module and the power supply module

Distributes and manages BTS clock signals

Provides the Ethernet port for terminal maintenance

Supports four routes of E1 inputs

Provides the CPRI ports for communication with the DRFU


GTMU PortsLabel Connector

Type Description

CPRI0-CPRI5 SFP Ports for the communication between the BBU and the RF module;

support input and output of the optical and electrical signal .

ETH RJ45 Port for local maintenance and commissioning

FE0 RJ45A reserved port that performs the following function:Connects the BBU to a routing device in the equipment room through the Ethernet cable to transmit network information.

FE1 DLCA reserved port that performs the following function:Connects the BBU to a routing device in the equipment room through the optical cable to transmit network information.

USB USB A reserved port that performs the following function:Enables the automatic software upgrade from a USB disk.

TST USB Provids a reference clock for the tester.

E1/T1 DB26female

Provides the input and output of the four E1/T1 signals between the GTMU and the UELP or between the GTMU and the BSC.


GTMU Indicators LED Color Status Description

ON The board is faulty.

OFF No power supply is available or the board is faulty.

ON for 1s, OFF for 1s The board is operational.

ON for 2s, OFF for 2s The OML link is abnormal.

ON for 0.125sOFF for 0.125s The board is loading software.

ON A fault occurs in the running board.

OFF No alarm is generated.

ON The board is operational.

OFF The board is faulty.

ON This link is not used.

ON for 0.125sOFF for 0.125s A remote E1/T1 alarm is generated.

OFF This link is operational.

Green ON The CPRI link is normal.

Red ON The reception of the optical module is abnormal and an alarm is generated.

CPRI0-CPRI5

LIU0-LIU3 Green

ACT Green

ALM Red

RUN Green


UELPUELP is the E1/T1 signal lightening protection unit of BBU and it can provide protection for 4 route E1/T1 signal

Port Type Relative cables Description

INSIDE DB25 male E1 transferring cable

Transfers the four E1/T1 signals between the UELP and the GTMU

OUTSIDE DB26 male E1/T1 cableProvides the input and output of the four E1/T1 signals between the BBU and the BSC

GTMU


UPEUThe universal power and environment interface unit (UPEU) supports the -

48V /-24V DC power input, supplies power to the boards, modules, and fan

in the BBU, and provides access to multiple environment monitoring

signalsPort Type Description

MON0 RJ45 Transmitting two RS485 environment monitoring signals

MON1 RJ45 Transmitting two RS485 environment monitoring signals

EXT-ALM0 RJ45 Transmitting four dry contact

alarms

EXT-ALM1 RJ45 Transmitting four dry contact

alarms

PWR 3V3 +24 V/-48 V DC power input


UEIUUEIU is the environment interface board of BBU，it can support multi-route monitoring signal input

UEIU is optional and is only used when more ports are needed

Label Connector Type Description

MON0 RJ45 One RS485 signal

MON1 RJ45 One RS485 signal

EXT-ALM0 RJ45 Four dry contact

signals

EXT-ALM1 RJ45 Four dry contact

signals


Monitoring System


USCUThe Universal Satellite Card and Clock Unit (USCU) is compatible with six types of satellite card, provides absolute timing information and the 1 Pulse Per Second (PPS) reference clock for the main control board, and provides the RGPS ports and BITS port.

Port Description

1 GPS port Used for receiving GPS signals

2 RGPS ports Used for receiving RGPS signals

3 BITS port Connected to the BITS clock; supporting adaptive input of the 2.048 MHz and 10 MHz clocks

4 TEST port Used for testing the clock


UBFAThe universal BBU fan unit type A (2U) (UBFA) works with the air inlet box of the cabinet to form a ventilation circuit, thus cooling the entire cabinet

The UBFA module communicates with the GTMU to regulate the temperature, adjust the fan speed, and report alarms. The UBFA module is hot swappable

Label Color Status Description

0.125s ON, 0.125s OFF (Green)

The module is not registered, and no alarm is reported.

1s ON, 1s OFF (Green) The module is running properly.

1s ON, 1s OFF (Red) The module is reporting alarms.

OFF The module is powered off or the program is not loaded.

STATE

Red/Green


BBU Cables ConnectionBBU cables connection between BBU, BSC, RFU and Auxiliary equipment


BBU Hardware structure-ReviewPlease fill the board’s name in the blank of the BBU

panel


Contents



2.2 BBU Unit

2.3 RF Cabinet

2.4 Power Cabinet


RF CabinetRF Unit

DRFU

GRFU

DCDU-02

FAN Unit

FMUA

Door Sensor


RF UnitRF Unit handles modulation and demodulation between

baseband signals and RF signals, data processing, and

combining-distribution. There are two kinds RF Unit, DRFU

and GRFU

One Double Radio Frequency Unit (DRFU) provides 2 TRXs.

One GSM Radio Frequency Unit (GRFU) provides a

maximum of 6 TRXs.


Main Functions of DRFU

One double radio filter unit (DRFU) provides two TRXs

The DRFU performs modulation and demodulation between

baseband signals and RF signals, processes data, and

combines and divides signals


Working Principles of the DRFU The DRFU consists of the high-speed interface unit, signal

processing unit, power amplifier, and dual-duplexer


Ports of the DRFU Type Connector Ports Description

ANT1Port for transmitting and receiving RF signals

N female connector ANT2

Used in connection to the antenna subsystem

CPRI0 Used in connection to the BBU, or in connection to the upper-level cascaded DRFU

CPRI1 Used in connection to the lower-level cascaded DRFU

RX1 in Input port for diversity signals in antenna channel 1

RX1 out Output port of diversity signals in antenna channel 1

RX2 in Input port for diversity signals in antenna channel 2

RX2 out Output port of diversity signals in antenna channel 2

Power port 7W2 power connector PWR Receives power input

Port for transmitting RF signals between DRFUs

QMA female connector

CPRI port SFP female connector


LEDs of the DRFU LED Color Status Description

On The power input is normal, but the module is faulty.

Off No power input is available, or the module is faulty.

On for 1s Off for 1s The module is functional.

On for 0.125s Off for 0.125s The module is loading data.

On for 1s Off for 1s A fault alarm is generated.

Off No alarm is generated.

On A fault alarm is generated, need to chang another module.

On The module is functional and is correctly connected to the BBU.

Off The connection with the BBU is not established.

On for 1s Off for 1s

The DRFU is being tested on the Site Maintenance

ACT Green

ALM Red

RUN Green


LEDs of the DRFU Off No VSWR alarm is detected.

On for 1sOff for 1s

The VSWR alarm is generated only on the ANT2 port.

On for 0.125s Off for 0.125s

The VSWR alarms are generated on the ANT1 and ANT2 ports.

On The VSWR alarm is generated only on the ANT1 port.

On (green) The CPRI link is functional.

On (red) The interface module fails to receive signals.On for 1sOff for 1s (red)

The CPRI link has a loss-of-lock error.

On (green) The CPRI link is functional.

On (red) The interface module fails to receive signals.On for 1sOff for 1s (red)

The CPRI link has a loss-of-lock error.

CPRI1Red Green

CPRI0Red Green

VSWR Red


QuestionIf the ‘VSWR’ is always on, what does it mean? Can you describe the Impact on the system and the reasons?

It means only ANT1 have VSWR Alarm. Once the alarm is generated, the service carried by the TRX is totally interrupted.

The reasons list as following:The VSWR of the antenna system is too high.

The connection between the output port of the TRX and the feederis improper.

The antenna system is not in connection for the DRFU.

The DRFU is faulty.

Data configuration in BSC is incorrect.


Output power of DRFUWorking Band Frequency Range Working

ModeOutput Power (GMSK/8PSK)

Non-combination 45 W/30 W

Combination 20 W/14 W

PBT 71 W/47 W

Non-combination 40 W/26 W

Combination 18 W/12 W

PBT 63 W/42 W

GSM 1800 MHz TX: 1805-1880 MHz RX: 1710-1785 MHz

PGSM 900 MHzEGSM 900 MHz

PGSM: •TX: 935-960 MHz •RX: 890-915 MHz EGSM: •TX: 925-960 MHz •RX: 880-915 MHz


DCDU-02 ModuleThe direction current distribution unit (DCDU) provides -48 V DC power (four outputs)

Receiving -48 V DC power input

Providing -48 V DC power for boards and modules in the cabinet

DCDU-02 (four outputs) on the left

DCDU -02 (four outputs) on the right


Fan ModuleThe fan module performs the heat dissipation for the

cabinet.

One fan module is installed with two fans.

Provides forced ventilation and heat dissipation.

Supports the temperature detection.


FMUA BoardThe FMUA is a fan environment monitoring unit.

Leading -48 V DC power supply to the cabinet and supplying -48 V DC power supply for the fan module.

Collecting environment alarm information in the cabinet. The environment alarm is classified into temperature alarm, humidity alarm, smoke alarm, water immersion alarm, and door status alarm.

Supporting the detection and reporting of the temperature.


FMUA LEDsLED Color Description Status Description

Blinking once every two seconds

The board is running normally and the communication with the BBU is normal.

Blinking four times per second

There is power supply but the communication with the BBU is abnormal.

Off No power input is available.Blinking four times per second

There are alarms from both the fans on the left and right half subracks.

Blinking once every two seconds

There is an alarm from the fan on the right half subrack.

On There is a alarm from the fan on the left half subrack

Blinking once every four seconds Other alarms

Off No power input is detected.

ALARM Red

Indicates whether there are alarms

RUN Green

Indicates the running status of the board


FMUA PortsType Ports Connector Description

Power port -48 V 7W2 power connector –48 V DC power input

COM IN RJ45 connector Used in connection to the BBU or the monitoring port on the upper-level FMUA

COM OUT RJ45 connector Used in connection to the lower-level FMUATEM RJ45 connector Cabinet temperature monitoring portTEM_HUM ARRESTER RJ45 connector Used in connection to the surge protection

failure alarm port of the power distribution unitFAN0FAN1

4-pin connector Used in connection to the fan module on the left half subrack

FAN2FAN3

4-pin connector Used in connection to the fan module on the right half subrack

The first group (from left to right)

Dry contact connectors

The second group

Dry contact connectors

The third group Dry contact connectors Smoke sensor port, door status sensor port

The fourth group Dry contact connectors Water sensor ports

Extended Boolean portsBoolean port

Fan port

RS485 port


Door Status SensorThe door status sensor detects the opening and closing of the

cabinet door. It consists of two parts, the magnet part and the

switch part.

Magnet part Switch part


Contents



2.2 BBU Unit

2.3 RF Cabinet

2.4 Power Cabinet


Power Cabinet – APM30HGATM

Power Subrack(AC/DC)

PDU

APMI

AFMU

Heater

Battery

Door Status Sensor

Temperature Sensor


APM30 OverviewThe APM30 provides –48V DC power and power backup for the distributed base stations and mini base stations, and provides space for the user equipment. It also performs functions such as battery management and monitoring, and lightening protection

1. Filler panel (1U)2. Power subrack (3U)3. DC PDU (2U)4~8. 1U Filler panel9. Space for batteries (3U)


Main Functions of GATM The GSM antenna and TMA control module (GATM) is a module that controls the antenna and TMA. The GATM is optional when the DRFU module is configured.

Controls the RET antenna

Feeds power to the TMA

Reports the RET control alarm signals

Monitors the current from the feeder


Ports on the GATM

Ports Connector FunctionANT0ANT2 ANT4

SMA female Providing power for the RET antenna and transmitting control signals for the RET antenna

ANT1ANT3 ANT5

SMA female Providing power for the antenna

COM1 RJ45 Used in connection to the BBU

COM2 RJ45 Providing the extended RS485 port to be cascaded with other devices

-48 V 7W2 Receiving the -48 V power input


Power Subrack (AC/DC) The power subrack (AC/DC) consists of the PMU, PSU (AC/DC)

and the wiring unit of the power subrack (220 V).

The power subrack (AC/DC) converts the 220 V AC power to the -

48 V DC power.

1) PMU2) PSU 3) Wiring unit


Main Functions of PMU(AC/DC)The Power and Environment Monitoring Unit (PMU) provides a comprehensive function of power supply management, power distribution check, and alarm reporting.

Communicates with the GTMU through the RS232/RS422 serial port

Manages the power system and the battery charging and discharging

Detects and reports monitoring signals

1. LEDs2. Power supply test ports 3. RS232/RS422 ports 4. Battery control switch 5. COM port


Ports of PMU

Ports Function

RS232/RS422 port Used in communication with the central processing unit

Battery switch

The battery switch has two control ports ON and OFF, which are used for switching on and switching off the batteryPress and hold the port ON for 5-10 seconds to switch on the batteryPress and hold the port OFF for 5-10 seconds to switch off the battery

Power supply test port

Two power supply test holes -48V and 0V are available for measurement through an ordinary multi-meter

COM port Used in connection to the external signal transfer board

Backplane port Used in connection to the backplane


Main Functions of PSU(AC/DC)Converting 220 V AC power to -48 V DC power and supplying -48 V DC power to the DCDU

Monitoring alarms related to module faults (such as output overvoltage, no output, and fan faults), alarms related to module protection (such as over temperature protection and input overvoltage/undervoltage protection), and module out-of-position alarm

1 Power running LED 2 Protection LED 3 Fault LED

123


Power Subrack (AC/DC)—Wiring Unit

The wiring unit is connected to the external power supply through the terminals L and N wires, and leads the power to the PSU (AC/DC)through the backplane.

The PSU (AC/DC) converts the input AC power into the -48 V DC power.

The DPMU monitors the operating status of the PSU (AC/DC).

The wiring unit provides -48 V DC power outputs through LOAD1(-), LOAD2(-), and RTN(+).


PDU ModuleThe PDU (Power Distribution Unit) performs AC or DC power distribution

Supplies two AC power outputs with the maximum current of 10 A to the heaters of the power cabinet and the heating film of the battery cabinet

Provides 10 DC power outputs to meet the DC power requirements of the distributed base station or the separated base station

Reports the surge protection alarms of the AC or DC output power


PDU PortsSN Description

1 For the 110 VAC dual-live-wire input, use L2 For the single-phase 220 VAC/three-phase 220 VAC input, use N1 and N2

2 For the 110 VAC dual-live-wire input, use L1 For the single-phase 220 VAC/three-phase 220 VAC input, use L1, L2 and L3 3 AC output wiring terminals (Lout1, Lout2)

4 AC output wiring terminals (Nout1, Nout2)

5 AC input MCB

6 AC output MCB (controls the power supply to the heating film or heaters)

7 DC output MCBs (SW0-SW9)

8 DC output wiring terminals (LOAD0-LOAD9)


APMI BoardThe APMI board refers to APM Power Monitor unit Interface

board

Transfers the APM30 serial port communication signals, Boolean

input/output signals, and EMI signals.

Protects the dry contact input/output signals and RS485 signals

(connected to the BBU/BTS)


APMI PortsPort Connector Type Quantity Function

RS422 RJ45 connector 1 Connecting the monitoring signal cable between the PMU and the APMI

TX+, TX-, RX+, RX-

2-pin molex connector 2 Connecting the monitoring signal cable between the APMI and the BBU

IN1-IN3 2-pin molex connector 3 Connecting the dry contact alarm input cableOUT1 2-pin molex connector 1 Connecting the optical coupling alarm output cable


AFMU BoardProvides DC power supply to the APMI and AFMU boards through the DC power port

Supplies DC power to the two fans at the top of the cabinet and reports the alarms of the fans

Reports the alarms of the internal ambient temperature sensor, air inlet temperature sensor, and air outlet temperature sensor


AFMU Ports and LEDsSN Port Function

1 ALMConnecting the monitoring signal cable between the

AFMU and the APMI

2 DC INPUT

Connecting the DC power cable of the AFMU

LED Silkscreen Color Status Description

ON steady About 1 minute after the AC or DC power-on

1s ON and 1s OFF The system is working properly.

0.125s ON0.125s OFF

The serial port communication is disrupted. The other communication is normal.

OFF steady The system is not powered on.ON steady An alarm is generated.

OFF steady No alarm is generated, or the system is not powered on.

Alarm LED ALM Red

Operation LED RUN Green


HeaterThe heater functions in the low-temperature environment to

provide suitable working temperature for the batteries in the

power cabinet or transmission cabinet.

When the internal temperature of the cabinet is lower than 5℃, the heater starts to work; when the internal temperature

is higher than 15℃, the heater stops working.


BatteryThe power cabinet can house 1 to 3 groups of -48 V 12 AH

batteries, which can form the -48 V 12 AH battery group

system, the -48 V 24 AH system, or the -48 V 36 AH system.


Door Status SensorThe door status sensor is made up of two parts, the

magnet part and the switch part.


Temperature SensorThe temperature sensors of the APM30 consist of the air inlet temperature sensor, internal ambient temperature sensor, and the air outlet temperature sensor


Question Would you please describe Power Distribution Modes of

BTS3900A?


IBBS200T OverviewThe IBBS200T provides long-time backup power for the

BTS3900A. It is used outdoors.


TMCThe TMC can accommodate the transmission equipment

of the user. It is used outdoors.

1 Filler panel2 Inner air circulation fan

3 HEUA 4 DCDU-03

5 Outer air circulation fan

6 Core of the heat exchange


Contents





5. BTS3900A Network



BTS3900A Signal FlowThe signal flow of the BTS3900A consists of the traffic

signal flow and the signaling flow of the BTS.

DL traffic signal flow

UL traffic signal flow

Signaling flow


Traffic Signal FlowThe DL traffic signal flow is transmitted from the BSC to the MS

through the BTS3900A. The BBU and RFUs work together to

process the DL traffic signals

Opposite to the DL traffic signal flow, the UL traffic signal flow is

transmitted from the MS to the BSC through the BTS3900A. The

BBU and RFUs work together to process the UL traffic signals

BBU DRFUE1

CPRI

DBUSCBUSFHBU

S

RF

BSC


Signaling FlowThis describes the BTS3900A signaling flow on the Abis

interface. The BBU serves as the control unit and works with

the RFUs to process the signaling.

BBU DRFUE1 CPRI

DBUSCBUS

FHBUS

BSC


Contents





5. BTS3900A Network



Contents

4. Configurations of the BTS3900A 4.1 Configuration Principle

4.2 Antenna Mode

4.3 Transmit Mode and Receive Mode

4.4 Typical Configuration


Basic Configuration PrinciplesThe DRFU supports a maximum of two carriers and it is applicableto small- and middle-capacity scenarios;

The GRFU supports a maximum of six carriers and it is applicableto large-capacity scenarios.

The DRFU and GRFU can be configured in the same cabinet or cell to support flexible capacity expansion.

Wide coverage is preferred. The DRFU supports the PBT, TX diversity, and 4-way RX diversity mode. Therefore, the DRFU can be applied to wide-coverage scenarios.


Antenna Configuration PrinciplesOne dual-polarized antenna can serve a maximum of two RFUs.

By default, RX diversity is adopted on the GSM network. That is,

two feeders connected to two single-polarized antennas or one

dual-polarized antenna must be configured in a cell.

Each sector of the BTS must be configured with the minimum

number of antennas.

For the 2-way RX diversity, each sector has two antenna channels;

for the 4-way RX diversity, each sector has four antenna channels.


DRFU Configuration PrinciplesA single DRFU does not support the S1/1 application; however, three DRFUs support the S3/3 application

When the DRFU works in TX PBT, TX diversity, or 4-way RX diversity mode, a DRFU provides only one TRX.

When only DRFU are configured, One BTS3900A can support a maximum of 12 carriers in the maximum cell configuration of S4/4/4. A site configured with the BTS3900As can support a maximum of 36 carriers in the maximum cell configuration of S12/12/12


Contents


4.2 Antenna Mode




DRFU Antenna ModeSingle Feeder

Single Feeder (1TX + 1RX), for one DRFU configuration

Single Feeder (1TX + 2RX), for two DRFUs configuration

Double Feeder

Double Feeder (1TX + 1RX), for one DRFU configuration



Double Feeder (2TX + 4RX), for two DRFUs configuration


Signal Feeder

Single Feeder (1TX + 1RX) Single Feeder (1TX + 2RX)

TX/RX TX/RXTX/RX


Double Feeder

Double Feeder (1TX + 1RX) Double Feeder (1TX + 2RX)

TX RX TX/RX RX


Double Feeder

Double Feeder (2TX + 2RX) Double Feeder (2TX + 4RX)

TX/RX TX/RX TX/RX TX/RXTX/RX TX/RX


Contents


4.2 Antenna Mode




Transmit Mode and Receive Mode

DRFU transmit mode

Transmit independency or combining

PBT

Dynamic PBT

Diversity transmitter

DRFU receive mode

Main diversity receiver

Four diversity receiver


DRFU Internal Structure2 TRXs and 2 duplexers are integrated in DRFU module which can be connected to antenna directly

The RX_IN and RX_OUT port of DRFU can support the receiving signal interconnection between 2 DRFUs, so that the 2 DRFUs can share different feeders

Interface Processing Unit

DUP

DUP

CPRI-0

CPRI-1

ANTA

ANTB

RX-IN

RX_OUT


Transmit IndependencyIn transmit independency mode, TRX0 occupies channel A

while TRX1 occupies channel B

CPRI0

CPRI1

Interface Processing U

nit

ANT1

ANT2

DUP

DUP


Transmit Combining In transmit combining mode，the two TRXs are combined

and transmitted through channel A

CPRI0

CPRI1


nit

ANT1

ANT2

DUP

DUP


PBTIn PBT mode, only the TRX0 can work

PBT mode can improve the transmitting power

In PBT mode，only channel A is used by downlink signal

CPRI0

CPRI1


nit

ANT1

ANT2

DUP

DUP


Dynamic PBTDynamic PBT is a mode based on the operation of timeslots, compared with static PBT, it brings the balance between capacityand coverage and does not cause the 50% decrease of capacity

The subscriber occupies a TS under the detection of measure report. When the quality is lower than a threshold, the same No. of TS of the adjacent TRX will be used as the secondary TS by the subscriber to start PBT. (The former subscriber in the secondaryTS will handover) When the quality is higher than a threshold, the PBT will be canceled and the secondary TS will be released


The Principle of Dynamic PBT

TimeslotsTimeslots TRXsTRXs

Good qualityGood quality

Poor qualityPoor quality

Signal qualitySignal quality

No signalNo signal


Transmit DiversityIn Transmit diversity mode, only the TRX0 can work

Transmit diversity mode improves the quality of downlink signal

In Transmit diversity mode，the signal from the TRX0 is divided to 2 channels and be transmitted through ANTA and ANTB

CPRI0

CPRI1


nit

ANT1

ANT2

DUP

DUP


QuestionWhen configuring ‘Transmit Mode’, ‘Transmit Independency or Combining ’ can be chosen. How can we know whether ‘Transmit Independency’ or ‘Transmit Combining’ is used?

It will be decided by antenna mode. When 2 TRXs are used in one DRFU,

If the antenna mode is ‘Single antenna’ or ‘Double antenna(1TX)’, the transmit mode must be ‘Transmit Independency’

If the antenna mode is ‘Double antenna(2TX)’, the transmit mode must be ‘Transmit Combining’


Main Diversity receiverIn this mode，both of the 2 TRXs can work

Each TRX receives the signal from 2 feeders

In the following figure，the TRX gets the receiving signal from channel A and B of the single DRFU

It is also possible for TRX to share the receiving channels with another DRFU

If only one ANT channel is used,

TRX can also use the ANT

channel of other DRFU through RX-in to ensure 2 way receiving

CPRI0

CPRI1


nit

ANT1

ANT2

DUP

DUP

RX-IN

RX_OUT


Four Diversity ReceiverIn this mode, only the first TRX can work

The working TRXs get the uplink signals from 4 ANT ports of 2

DRFUsCable connection

for sharing the receiving signals

CPRI0

CPRI1

Interface Processing

Unit

ANT1

ANT2

DUP

DUP

RX-INRX_OUT

CPRI0

CPRI1

Interface Processing

Unit

ANT1

ANT2

DUP

DUP

RX-INRX_OUT


Receiver Sensitivity of BTS3900A

Receive Mode Operating Frequency Band

Static Sensitivity (Typical Value)

900 MHz -113 dBm

1800 MHz -113 dBm

900 MHz -116 dBm

1800 MHz -116 dBm

900 MHz -118.5 dBm

1800 MHz -118.5 dBmFour-way receive

diversity

Two-way receive diversity

Receive independency

The following table lists the static receiver sensitivity of theBTS3900A


Contents


4.2 Antenna Mode




DRFU S1/S2 ConfigurationS1 Configuration

TX mode: Transmit Independency or Combining

RX mode: Main diversity receiver

Antenna mode: Double antenna(1TX+2RX)

S1 ConfigurationTX mode: Transmit diversity



S2 ConfigurationTX mode: Transmit Independency or Combining




DRFU S2/S3/S4 ConfigurationS2 Configuration

TX mode: PBT


Antenna mode: Single antenna(1TX+2RX)

S3/S4 Configuration

TX mode: Transmit Independency or

Combining




DRFU S5/S6 ConfigurationS5/S6 Configuration


Combining


Antenna mode

DRFU0: Single antenna(1TX+2RX)


DRFU2: Double antenna(1TX+2RX)


DRFU S7/S8 ConfigurationS7/S8 Configuration


Combining




DRFU S3/3 ConfigurationS3/3 Configuration


Combining


Antenna mode


DRFU1: Double antenna(2TX+4RX)



Contents





5. BTS3900A Network



BTS Star TopologyThe star topology applies to common areas, especially densely

populated areas, such as cities

In the star topology, each site is directly connected to the BSC


BTS Chain TopologyThe chain topology applies to sparsely populated areas in strip-

like terrain, such as areas along highways and railway tracks

The chain topology reduces cost in transmission equipment,

construction, and transmission link lease


BTS Tree TopologyThe tree topology applies to areas where network structures, site distribution, and subscriber distribution are complicated

The tree topology requires fewer transmission cables compared with the star topology


BTS Ring TopologyThe ring topology applies to common scenarios. Due to its strongself-healing capability, the ring topology is preferred if permitted by the routing

If there is a breaking point in the ring, the ring breaks into two chains at the breaking point automatically. In this way, the BTSs preceding and following the breaking point can work normally despite the breaking point; thus improving the robustness of the system


DRFU Topologies ConfigurationThe DRFU supports

various network

topologies: star, chain,

and ring


Contents





5. BTS3900A Network



Introduction of GRFUGRFU is based on multi-carrier technology, one GRFU can support six TRXs at most.

GRFU performs modulation and demodulation between baseband signals and RF signals, processes data, and combines and divides signals.

The main new features and functions of GRFU

Inner Bias-Tee Integration of feeder current to TMA.

Provides power sharing. Improves the network coverage, reduces the interference and power consumption and save the device cost.


Multi-carrier TechnologyThe principle of multi-carrier technology: multiple carriers share one power amplifier and one RF channel.

Baseband pool replaced independent baseband unit. Improve the integration.

Digital IF combination replaced Analog RF combination. There isn’t combination loss.

Single-carrier Technology Multi-carrier Technology


Ports of GRFU

Port Type Label Connector Type Description

ANT_RXB

DIN connector

ANT_TX/RXA

DIN connector

CPRI0 SFP female connector

Connecting to the BBU, or the upper-level RFU during the cascading.

CPRI1 SFP female connector

Connecting to the lower-level RFU during the cascading.

RX_INBQMA female connector

Input port of diversity signals in the antenna channel.

RX_OUTA

QMA female connector

Output port of diversity signals in the antenna channel.

Power supply port PWR 3V3 power connector Feeding power.

Monitoring port MON RJ45 connector Monitoring port.

Interconnection port for RF receive signals

CPRI

Connecting to the antenna subsystem.Port for transceiving RF signals


LEDs of GRFULED Color Status Description

ON The power input is normal, but the module is faulty.

OFF There is no power supply, or the module is faulty.

1s ON1s OFF The module is running properly.

0.2s ON 0.2s OFF

The software is being loaded to the module.

1s ON1s OFF A fault alarm is generated.

OFF No alarm is generated.

ON The module is functional and is correctly connected to the BBU.

OFF The connection with the BBU is not set up.

OFF No VSWR alarm is generated.

ON The VSWR alarm is generated on the ANT_TX/RX port.

VSWR Red

ACT Green

ALM Red

RUN Green


LEDs of GRFU

ON (Green) The CPRI link is normal.

ON (Red) The interface module fails to receive signals.

1s ON 1s OFF(Red) The CPRI link is out of lock.

ON (Green) The CPRI link is normal.

ON (Red) The interface module fails to receive signals.

1s ON,1s OFF (Red) The CPRI link is out of lock.

CPRI1

RedGreen

CPRI0

RedGreen


Compare GRFU with DRFU

Port Type GRFU Relative position DRFU Relative

positionANT_TX/RXA lower

upper

lowerupper

upper

lower

existence

ANT_RXB

upperANT1

ANT2

CPRI0CPRI1

Rx_1 in

Rx_1 out

Rx_2 in

CPRI0

Rx_2 out

lower

upperlowerCPRI1

RX_INB

RX_OUTA

Non

existenceMON

Port for

transceiving

RF signals

CPRI

Interconnectio

n

port for RF

Receive

signals

Monitoring

port


Output power of GRFUThe output power of different configuration is also configured

differently

Frequency bands ConfigurationOutput power（GMSK/8PSK

）S1 80W/53W

S3 31W/20W

S4 27W/17W

S6

S2 40W/26W

S5 18W/12W

PGSM 900MHz / GSM1800MHz

16W/10W


Limitation of GRFUIf the frequency interval of a cell is outside the range of 15MHz, 2 GRFUs can be considered to be used and the range of frequency for each GRFU also should be within15MHz.

Generally, it is suggested that the number of carriers should be set to 2 GRFUsaveragely if 2 GRFUs are used in a cell. For example: S8 should be configured as 4+4 when 2 GRFU are used.

GRFU supports whole frequency band of PGSM 900MHz, high 45MHz frequency band and low 45MHz frequency band of DCS1800MHz.

GRFU DL UL

Whole 25MHz frequency band of 900MHz 935-960MHz 890-915MHz

Low 45MHz of 1800MHz 1805-1850MHz 1710-1755MHz

High 45MHz of 1800MHz 1835-1880MHz 1740-1785MHz


Configuration Principle of GRFU The DRFU and GRFU can be configured in the same cabinet.

When the GRFU is configured, a single BTS3900A provides a maximumof 36 carriers with the maximum cell configuration of S12/12/12. In addition, a site configured with the BTS3900As cansupport a maximum of 72 carriers, with the maximum cell configuration of S24/24/24.

One GRFU does not serve two cells.

Each cell with a single antenna can be configured with a maximum of two GRFUs.


Transmit Mode and Receive Mode of GRFU

GRFU Transmit Mode

Transmit independency or combining

GRFU Receive Mode

Main diversity receiver


GRFU S2-S6 ConfigurationS2-S6 Configuration


Combining




GRFU S7-S12 ConfigurationS7-S12 Configuration

TX mode: Transmit Independency

or Combining


Antenna mode:

Single antenna(1TX+2RX)


DRFU＆GRFU ConfigurationDRFU＆GRFU Configuration


Combining


Antenna mode:

GRFU: Single antenna(1TX+2RX)

DRFU: Single antenna(1TX+2RX)


DRFU＆GRFU ConfigurationDRFU＆GRFU Configuration


Combining


Antenna mode:

GRFU: Double antenna(1TX+2RX)

DRFU: Double antenna(1TX+2RX)


SummaryBTS3900A functions and features

BTS3900A hardware structure, including RF cabinet, APM30

and components

Working mode, configuration principles, RF cable

configurations, typical configurations

BTS networking topology and RFU connection

Documents

HUAWEI BTS3900A Hardware Structure (GSM)