Huawei Node-b Overview x4x46

Hardware Structure of the BTS3900 (-48 V) The BTS3900 cabinet that uses -48 V DC power contains the WRFU, MRFU, FAN unit, BBU, and DCDU. In addition, 2 U space is available in the cabinet for installing the equipment. The BTS3900 cabinet (-48 V) s the 3RFU typical configuration and the 6RFU full configuration, as shown in Figure 1 and Figure 2 respectively. The SLPU is optional. Figure 1 BTS3900 cabinet (-48 V) in typical configuration

Figure 2 BTS3900 cabinet (-48 V) in full configuration

BBU3900 Equipment This describes the BBU3900 equipment. It is a baseband unit that implements communication between the NodeB and the RNC. The BBU3900 has the following functions: •

Providing ports for data communication between the NodeB and the RNC

• Providing the RI interface for communication between the BBU and the RRU or the RFU • Providing USB ports, one of which facilitates NodeB upgraded when a USB disk is inserted during software installation and data configuration • Providing OM channels between the BBU and the LMT or the M2000 to operate and maintain the BBU •

Proceslink and downlink baseband signals

•

Managing the entire NodeB system in of OM and signaling processing

•

Providing the system clock

Logical Structure of the BBU3900 The BBU3900, which features a modular design, consists of the transport subsystem, baseband subsystem, control subsystem, and power module. Figure 1 shows the logical structure of the BBU3900. Figure 1 Logical structure of the BBU3900

Transport Subsystem The transport subsystem has the following functions: • Providing physical ports for data communication between the NodeB and the RNC • Providing OM channels between the BBU3900 and the OMC (LMT or M2000) for operation and maintenance

Baseband Subsystem The baseband subsystem processes uplink and downlink baseband data. The functions of the baseband subsystem are performed by the following modules: • Uplink baseband data processing module: Consists of the demodulation unit and the decoding unit. In this module, uplink baseband data is processed into despreading soft decision symbols after access channel searching, access channel demodulation, and dedicated channel demodulation. The symbols are then sent to the RNC through the transport subsystem after decoding and Frame Protocol (FP) processing. • Downlink baseband data processing module: Consists of the modulation unit and the coding unit. The module receives the service data from the transport subsystem and sends the service data to the FP processor for FP processing. The signals are finally sent to the interface module after encoding, transport channel mapping, physical channel generating, framing, spreading, modulation, and power control combination. In the baseband subsystem, the BBU3900 has an integrated RI interface module that connects the BBU3900 to the RRU.

Control Subsystem The control subsystem manages the entire NodeB. The subsystem performs OM, processes signaling, and provides the system clock. • The OM module has functions such as equipment management, configuration management, alarm management, software management, and commissioning management. • The signaling processor has functions such as NodeB Application Part (NBAP) signaling processing, Access Link Control Application Part (ALCAP) processing, Stream Control Transmission Protocol (SCTP) processing, and logical resource management. • The clock module has functions such as providing a phase-locked line clock extracted from the Iub interface (the clock is extracted from an E1, optical port, or FE), a GPS clock, or an external clock. The BBU3900 extracts the clock from the Iub interface and then provides a system clock for the NodeB after frequency dividing, phase locking, and phase adjusting.

Power Module The power module converts -48 V or +24 V DC power into the power required by the boards and provides a port to connect to an external monitoring device.

Ports on the BBU3900 This describes the ports on the mandatory and optional boards of the BBU3900.

Ports on the Mandatory Boards of the BBU3900 Board WMPT

Port

Connector

Quantity

Description

E1 port

DB26

1

One port s four E1s.

FE electrical port

RJ45

1

-

Board

Port

Connector

Quantity

Description

FE optical port

SFP

1

-

USB port for loading

USB

1

Port for software loading

USB port for test

USB

1

Port for test

Commissioning port

RJ45

1

Port for local maintenance of the NodeB

GPS port

SMA

1

-

WBBP

RI

SFP

3

-

UPEU

PWR

3V3

1

Port for leading in -48 V DC or +24 V DC power

MON0

RJ45

1

MON1

RJ45

1

Providing two RS485 monitoring ports and connecting to external monitoring devices

EXT-ALM0

RJ45

1

EXT-ALM1 port

RJ45

1

Providing eight dry alarm inputs and connecting to external alarm devices

Ports on the Optional Boards of the BBU3900 Board UELP

UFLP

Port

Connector

Quantity

Description

INSIDE

DB25

1

Port for four E1/T1 inputs

OUTSIDE

DB26

1

Port for four E1/T1 outputs

FE0 and FE1 (INSIDE)

RJ45

2

Connecting to either the WMPT or UTRP

FE0 and FE1 (OUTSIDE)

RJ45

2

Connecting to external devices.

Board

Port

Connector

Quantity

Description The FE0 (OUTSIDE) connects to the FE0 (INSIDE) and the FE1 (OUTSIDE) connects to the FE1 (INSIDE).

USCU

UTRP

UEIU

RGPS port

DB8

3

Connecting to the RGPS signal cable

BITS port

SMA

1

Connecting to the BITS clock

Clock test port

SMA

1

Port for testing clock signal output

Antenna port for the satellite card

SMA

1

RF signal input terminal of the satellite card

E1/T1 port

DB26

2

Providing eight ATM over E1s or eight IP over E1s

STM-1/OC-3 port

SFP

1

Providing one unchannelized STM-1/OC-3

MON

RJ45

1

MON1 port

RJ45

1

Connecting to external monitoring devices

EXT-ALM0 port

RJ45

1

EXT-ALM1

RJ45

1

Connecting to external alarm devices

Logical Structure of the WRFU/MRFU The WRFU/MRFU, which features a modular design, consists of the interface module, transceiver (TRX), Power Amplifier (PA), filter, and Low Noise Amplifier (LNA). Figure 1 shows the logical structure of the WRFU/MRFU.

Figure 1 Logical structure of the WRFU/MRFU

Interface Module The functions of the interface module are as follows: • Receiving downlink baseband data from the BBU • Transmitting uplink baseband data to the BBU • Forwarding the data sent from the cascaded WRFUs/MRFUs

TRX The TRX provides two RX channels and one TX channel for RF signals. • The RX channels perform the following functions: 

Down-conversion of the received signals to IF signals



Amplification of the IF signals



Analog-to-digital conversion



Digital down-conversion



Matched filtering



Digital Automatic Gain Control (DAGC)

• The TX channel performs the following functions: 

Shaping and filtering of downlink spread spectrum signals



Digital-to-analog conversion



Up-conversion of the IF signals to the TX band

PA The PA adopts the DPD and A-Doherty technologies to amplify low-power RF signals from the TRX.

Filter The filters consist of a duplex filter and an RX filter. The filters perform the following functions: • The duplex filter multiplexes one RX and one TX signals over RF channels so that they can share one antenna channel. In addition, it filters RX and TX signals. • The RX filter filters one RX signal.

LNA The LNA amplifies the signals received from the antenna system.

Ports on the WRFU/MRFU The external ports of the WRFU/MRFU are located at the bottom of the module and in the cabling cavity. The ports on the WRFU/MRFU are the power port, transmission ports, RF ports, and commissioning port. Table 1 Ports on the WRFU/MRFU Port Type

Connector Type

Quantity

Remarks

-48 V DC power input port

3V3

1

Power port

RI port

SFP female

2

Transmission port for BBU cascading

Interconnection port for receiving RF signals

QMA female

2

Transmission port for WRFU/MRFU cascading

Port for transceiving antenna signals

DIN

2

RF port

Commissioning port

RJ45

1

Reserved for fan monitoring

Functions of the WRFU/MRFU The WRFU is the WCDMA RF filter unit, and the MRFU is the multi-carrier RF filter unit. The WRFU/MRFU performs the following functions: • The WRFU/MRFU, which adopts the direct frequency conversion technology, modulates the baseband signals to the WCDMA TX band. After filtering and amplification, the baseband signals are transmitted to the antenna system through the duplex filter. • The WRFU/MRFU receives uplink RF signals from the antenna system and then down-converts the received signals to IF signals. After amplification, analog-to-digital conversion, digital down-conversion, matched filtering, automatic gain control (AGC), the IF signals are sent to the BBU for further processing.

•

Power control and Voltage Standing Wave Ratio (VSWR) detection

•

Reverse power detection

•

Frequency synthesis and loopback test

• Generation of the RI clock, recovery of the RI clock of lost synchronization, and alarm detection