HUAWEI GSM DBS3900 Hardware Structure-20080807-ISSUE4.0.ppt

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HUAWEI Confidential
DBS3900 is a distributed BTS solution developed by Huawei Technologies Co.,Ltd. Its baseband part and radio part can be installed independently so that it can be used to various environments with wide coverage and low cost.
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Master the Hardware structure and function of DBS3900
Master the Network topologies of DBS3900
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PSTN ISDN PSPDN
UPEA
BSBC
UBFA
UEIU
UFLP
CPRI
Sector 4 RRU Work Mode Introduction
The DBS3900 consists of the BBU3900 and the RRU3004.
The BBU3900 is an indoor baseband unit. It provides physical interfaces for connection with the BSC and RRU. It performs centralized management (OM and signaling processing) of the entire base station system and provides reference clock for the system.
The RRU3004 is an outdoor remote RF unit. It processes baseband signals and RF signals.
The Local Maintenance Terminal (LMT) and Man-Machine Interactive (MMI) can implement the maintenance of the DBS3900 through the BBU3900.
BBU3900
RRU3004
RRU3004
RRU3004
BBU3900
The BBU3900 is an indoor BTS control unit that enables interaction between the BTS and the BSC.
The BBU3900 performs the following functions:
Provides physical interfaces between the BTS and the BSC for interaction.
Provides CPRI ports for communication with the RRU3004.
Provides the USB port for downloading the BTS software.
Provides OM channels for connection to the LMT (or M2000).
Processes UL and DL data.
Provides centralized management on the entire DBS system, such as OM and signaling processing.
Provides the reference clock for the entire system.
The typical power consumption of the BBU is 35 W.
The weight of the BBU isn’t more than 10KG.
Each BBU3900 supports a maximum of 36 TRXs, and 12 cells.
The BBU is a small box with all the external ports on the front panel.
The BBU3900 boards consist of the BSBC, UEIU, GTMU, and UELP; the BBU3900 modules consist of the UBFA and the UPEU.
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BSBC Board
The BSBC is the backplane of the BBU. The BSBC provides eight board slots, two power slots, and one fan slot.
The universal BBU sub-rack backplane type C (2U) (BSBC) provides backplane interfaces for communication between boards and supplies power for boards.
The GTMU is located in slots 5 and 6, slot 7 for a main control board that supports 3G, and other ports as common slots.
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GTMU Board
The GSM transmission, timing, and management unit for BBU (GTMU) controls and manages the entire BTS. It provides interfaces related to the reference clock, power supply, OM, and external alarm collection.
The GTMU performs the following functions:
Controls, maintains, and operates the BTS
Supports fault management, configuration management, performance management, and security management
Monitors the fan module and the power supply module
Distributes and manages BTS clock signals
Provides clock input for testing
Provides the Ethernet port for terminal maintenance
Supports four E1 inputs
Port
Type
Cable
Description
ETH
Performs local maintenance and commissioning
FE0
-
A 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
-
A 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
-
A reserved port that performs the following function: Automatically upgrades the software through the USB disk
TST
E1/T1
E1/T1 cable of the BBU
Provides the input and output of the four E1/T1 signals between the GTMU and the UELP or between the GTMU and the BSC
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UBFA Module
The universal BBU fan unit type A (2U) (UBFA) communicates with the GTMU to regulate the temperature, adjust the fan speed, and report alarms. The UBFA module is hot swappable.
LED
Color
Status
Description
STATE
Green
Blinking twice per second
The board is not securely connected. An alarm is not generated.
Red
On
The board operates normally.
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UPEU Module
The universal power and environment interface unit type A (–48 V) (UPEU) supports the –48 V DC power input, supplies power to the boards, modules, and fan in the BBU, and provides access to multiple environment monitoring signals.
Port
Type
Description
MON0
RJ45 Connector
Provides the input and output of the externally collected environment monitoring signals to the GTMU according to the RS485 communications protocol
MON1
Transmits the externally collected environment monitoring signals to the GTMU through communications protocol related to the dry contact
EXT-ALM1
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UEIU Board
The universal environment interface unit (UEIU) supports multiple environment monitoring signals. The UEIU supports eight Boolean alarm signals and two RS485 environment monitoring signals.
The UEIU is optional. It is configured when the environment interfaces are insufficient.
Port
Type
Description
MON0
RJ45 Connector
Provides the input and output of the externally collected environment monitoring signals to the GTMU according to the RS485 communications protocol
MON1
Transmits the externally collected environment monitoring signals to the GTMU through communications protocol related to the dry contact
EXT-ALM1
The universal E1/T1 lightning protection unit (UELP) provides lightning protection for four E1/T1 signals.
UELP Board provides a DIP switch to set impedance of E1/T1.
Port
Type
Cable
Description
INSIDE
E1 transfer cable of the BBU
Transfers the four E1/T1 signals between the UELP and the GTMU
OUTSIDE
E1/T1 cables of the BBU
Provides the input and output of the four E1/T1 signals between the BBU and the BSC
DIP Switch
DIP Status
ON
OFF
ON
OFF
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BBU Cables
The BBU3900 cables are classified into the PGND cable, –48 V DC power cable, E1/T1 cable, E1 transfer cable, environment monitoring signal cable, CPRI signal cable between the BBU and the RRU, and BBU monitoring signal cable.
The cable connection relations of the BBU are as follows:
-48VDC power cables
E1 transfer cable
Monitoring signal cable between the OFB and the BBU
Monitoring signal cable between the APM and the BBU
(1)RJ45 Connector
The RRU3004 is an outdoor remote RF unit.
The functions of the RRU3004 are as follows:
The direct IQ modulation technique, which is directly implemented in the transmit channel, modulates the baseband signals into GSM RF signals. After being filtered and amplified, the RF signals are transmitted to the antenna for transmission, through the duplexer in the RF front-end unit.
The uplink RF signals received from the antenna go through down-conversion, amplification, analog-to-digital conversion, matched filtering, Automatic Gain Control (AGC), and then are sent to ASIC and DSP for demodulation and decoding.
Power regulation and Voltage Standing Wave Ration (VSWR) detection.
Frequency systemization and loopback test.
Generation and recovery of the clock circuitry at the CPRI interface, and the alarm detection.
RXM_OUT:RRU RX main output for RRU cascading
RXD_IN:RRU RX diversity input for RRU cascading
An RRU3004 consists of two RRU modules.
The RRU module has a modular structure. The external interfaces of the RRU module are located at the bottom of the module and in the cabling cavity.
The weight of RRU3004 is 38Kg. The RRU3004 can be installed on a wall, stand, metal pole, or tower.
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RRU Module
The RRU module has a bottom panel, a cabling cavity panel, and an area attached with LEDs.
Provides - 48VDC power supply.
Item
Label
Description
RET
TST CPRI
Connections of RRU Cables
The RRU3004 has the following cables: PGND cable, power cable, AISG multi-wire cable, AISG extension cable, CPRI optical cable, RF jumpers, Boolean input cable, and cables for cascaded RRUs.
RRU –48 V DC power cable
RRU Power cable for cascaded RRU modules
Signal cable between the electrical
ports on cascaded RRU modules
CPRI optical cable
Cascaded RF jumper
Boolean input cable
AISG multi-wire cable
AISG extension cable
Single antenna
Single antenna and double receivers
The RRU module has one TX/RX feeder and two way receiving diversities, one of the receiver is from the another RRU module of the RRU3004.
Double antennas
The RRU module has two TX/RX feeders and two way receiving diversities.
Double antennas and four receivers
Each RRU can have two TX/RX feeders, and two RRUs are combined to support four way receive diversity.
Default value: “15W”, RRU supports transmit combining or independency here, otherwise RRU supports transmit independency only.
M1800 RRU
Default value: “10W”, RRU supports transmit combining or independency here, otherwise RRU supports transmit independency only.
RRU transmit mode
Combination Solution of Two RRUs
Two RRUs are combined to share receive and transmit channels so that the configuration is more flexible. In the following figure, the cable between CPRI_W and CPRI_E are used for the TRX baseband signal interconnection, while RX_IN/OUT is only used for two way receiving diversity between two RRUs.
Interface Processing Unit
In this mode, two TRXs of RRU are both work.
In this mode, the system will work on the transmit independency or transmit combining mode automatically, according to the power mode and antenna mode.
In transmit dependency mode, TRX0 occupies channel A while TRX1 occupies channel B.
In transmit combining mode, the combining signal are transmitted through channel A.
Transmit independency
Transmit combining
In PBT mode, downlink signal are transmitted through channel A.
In this mode, only the first TRX can work.
Transmit diversity mode can improve signal the quality of downlink signal.
In this mode, the signal from the first TRX will be divided to two channels and be transmitted through channel A and channel B.
Receive diversity, RRU can work as double TRX mode.
Each TRX can receive the signal from two feeders.
In the following figurethe TRX gets the receiving signal from channel A and B of the single RRU.
It is also possible for TRX to use the channel A receiver of the other RRU in two RRUs combining solution.
The second receiving diversity signal may come from second RRU
In this mode, only the first TRX can work.
The working TRX gets the uplink signal from four feeders of two RRUs.
Only the antenna mode “Double Antennas, Four Receivers” can support “Four way receive diversity”.
The other two receiving diversity signal come from second RRU
Interface Processing
Network Topologies of the BBU
The BSC and BBUs support multiple network topologies: star, chain, tree, and ring.
E1/T1 can be used to connect BBU and BSC, or interconnect transmission equipment, optical fiber and FE cable can be used to connect BBU and Router.
Network Topologies of the RRU
The BBU and RRUs support two network topologies: star and chain.
RRU connect with BBU by optical fiber.
Network Topologies of the BBU
The BSC and BBUs support multiple network topologies: star, chain, tree, and ring.
Network Topologies of the RRU
.
The work mode and typical configuration of the RRU.
Network Topologies of the BBU and RRU.
Thank You

HUAWEI GSM DBS3900 Hardware Structure-20080807-ISSUE4.0.ppt

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