Know the functions and features of BTS Know the BTS hardware structure
Base Trans Receiver Station In cellular network system, BTS is an important part to implement the
air interface functions RF Subsystem is the key part of BTS to exchange radio signals Implement the air interface functions via the antenna Provide the interface to the Common Subsystem via the interface
module. Modulates/demodulates signals
TUP,ISUP BSC A Interface MSC/VLR M AP MAP
PSTN ISDN PSPDN
BTS3012 MS BTS3012 OMC
Functions (BTS) BTS is the radio part of the BSS It implements the radio transmission and radio channel
control for its subscribers (MSs) through the air interface It also provides the wired interface functions to BSC. BTS is the radio transceiver controlled by the BSC to serve a
BTS consists of
RFS (Radio Frequency Subsystem) Common subsystem
Hardware structure (for 18TRXs)
BTS3012 Cabinet and Boards (for 18TRXs)For 18 TRXs
BTS3012 Cabinet and Boards (for 18TRXs)Subrack Board/Module Full Name Configuration Quantity in One Cabinet Full Configuration Common subrack DTMU DEMU DATU DCSU DCCU ECMB Set-on-top subrack DELC DMLC DSAC DCTB DTRU subrack DTRU DTRB DAFU subrack DCOM DDPU DFCU DFCB Fan subrack Fan box Transmission/Timing/Management Unit for DTRU BTS Environment Monitoring Unit for DTRU BTS Antenna and TMA Control Unit for DTRU BTS Combined cabinet Signal connection Unit for DTRU BTS Cable Connection Unit for DTRU BTS Enhanced Common Module Backplane for DTRU BTS E1 Signal Lightning-Protection Card for DTRU BTS Monitor Signal Lightning-Protection Card for DTRU BTS Signal Access Card for DTRU BTS Cabinet Top Backplane for DTRU BTS Double-Transceiver Unit Double-Transceiver Unit Backplane Combining Unit for DTRU BTS Dual-Duplexer Unit for DTRU BTS Filter Combiner Unit for DTRU BTS Filter Combiner Unit for DTRU BTS Fan Module 2 1 2 1 1 1 3 1 1 1 9 1 3 6 3 1 1 Minimum Configuration 1 0 0 1 1 1 1 0 1 1 1 1 0 0 0 0 1
Common Subsystem DTMU Transmission/Timing/Management Unit for DTRU BTS DEMU Environment Monitoring Unit for DTRU BTS DCSU Combined cabinet Signal connection Unit for DTRU BTS DCCU Cable Connection Unit for DTRU BTS DATU Antenna and TMA control Unit for DTRU BTS
Functions of DTMU Controls, maintains, and operates the BTS Downloads software for the BTS Provides fault management, configuration management,
performance management, and security management Provides centralized clock distribution and management of the entire BTS, and the hot backup of the clock unit Provides backup for the E1 ports and the main control unit Monitors the external fan control board and the power modules
Functions of DEMU The DEMU guarantees the normal operation of the BTS by monitoring the
surrounding environment. The DEMU performs the following functions:
Monitors the environment information sent from the smoke sensor, water sensor, temperature and humidity sensor, infrared sensor, and door control sensor. Collects alarm information and reports it to the DTMU.
Functions of DCSU The Combined cabinet Signal connection Unit for DTRU BTS (DCSU) is
placed in slot 5 of the common subrack. The DCSU is a mandatory board. Only one DCSU can be configured. The DCSU performs the following functions:
Transmits clock signals, data signals, and control signals between the main cabinet and the extension cabinet. Transmits the clock signals, data signals, and control signals from the DTMU to the DTRU ( for BTS3012) or QTRUs ( for 36TRXs).
Double transceiver subsystem (BTS3012 )
DTRU (Double Transceiver Unit) DTRB
Functions of DTRU (BTS3012 ) Baseband Processing Part
Processes the signaling, such as coding, decoding, interleaving, deinterleaving, modulation, and demodulation. Amplifies the output power. RF Transmitting Part
Modulates the baseband signals into RF signals , and performs frequency hopping. Transmit RF signal to DDPU. RF Receiving Part
Demodulates the RF signals into baseband signals, and performs frequency hopping. Divides the received RF signals and performs receive diversity.
Functional structure of DTRU (BTS3012 ) DTRU Baseband and RF Unit (DBRU) DTRU Power Amplifier Unit (DPAU) DTRU Power Supply Unit (DTPS)
DTPS 48V DC
RF Front-End Subsystem (BTS3012 ) The functions of the BTS3012 RF front-end subsystem are
performed by the boards in the DAFU subrack. The DAFU subrack can be configured with the DDPU, DCOM,
DFCU, DFCB, or the combination of these modules. DDPU (Dual Duplexer Unit for DTRU BTS) DCOM (Combining Unit for DTRU BTS) DFCU (Filter Combiner Unit for DTRU BTS) DFCB (Filter Combiner Unit for DTRU BTS)
Functions of DDPU (BTS3012 ) The DDPU performs the following functions:
Provides lightning protection through the ANT port. Detects VSWR alarms in the antenna system. Receives the gain control signals for the low noise amplifier. Transmits multiple routes of RF signals from the transmitter to the antenna. Receives signals from the antenna, amplifies and quarters these signals, and then transmits them to the receiver of the DTRU.
Switches on DCSU BoardYou can adjust the switches on the DCSU board as follow: Master cabinet:SW1-all ON SW2~SW5-all ON SW6~SW7-all OFF SW8-all ON SW9-OFF ON ON ON Others go as default.
Slave Cabinet:SW1-all OFF SW2~SW5-all ON SW6~SW7-all OFF SW8-OFF OFF ON ON SW9-OFF ON ON ON Others go as default.
Functions of DCCU The DCCU is placed in slot 6 of
the DCMB in the common subrack. The DCCU is a mandatory board. Only one DCCU can be configured. The DCCU performs the
following functions: Transfers E1 signals. Transfers the control signals for the fans. Transfers the clock signals from the DAFU subrack. Processes the power inputs through the EMI filter, and then transmits the power to the common subrack.
Functions of DATU The DATU can be installed in slot 2, 3, 4, or 7 of the
DCMB in the common subrack. The DATU is an optional board. A maximum of two DATUs can be configured. The DATU performs the following functions:
Controls the RET antenna. Provides power for the TMA over the feeder. Reports alarms related to the control of the RET antenna. Monitors the current from the feeder.
Functions of ECMB (Enhanced Common Back Plane The ECMB is the backplane for the common subrack and DTRU subrack 0. The
ECMB is a mandatory board. There are 10 slots on the ECMB. The ECMB provides power and signal circuits for the boards in the common
subrack and DTRU subrack 0. The ECMB transmits signals from the boards in the common subrack to the DCCU. The ports on the DCCU then transmit the signals to the boards in other subracks. The ECMB transmits the in-position signals of the DTRUs in DTRU subrack 0 to the DTMU. The ECMB performs the following functions:
Provides signal circuits for connecting the boards in the common subrack. Provides 48 V power circuits for the boards in the common subrack. Provides bus connection between the common subsystem and the doubletransceiver subsystem. Specifies the slot number and rack number of the DTRUs in DTRU subrack 0. Transmits the in-position signals of the DTRUs in DTRU subrack 0 to the DCCU.
Relation between boards and slot numbersBoard DTMU DEMU DATU DCSU DCCU Slots 0 and 1 Slots 2, 3, 4,or 7 Slots 2, 3, 4,or 7 Slot 5 Slot 6 Slot No.
Signal Protection Subsystem DMLC (Monitor Signal Lightning-Protection Card for DTRU BTS) DELC (E1 Signal Lightning-Protection Card for DTRU BTS) DSAC (Signal Access Card for DTRU BTS)
M L C
E L C
E L C
Functions of DMLC The DMLC is configured in slot 0, 1, or 2 of the set-onDMLC
top subrack. The DMLC is an optional board, which is used with the DEMU. Only one DMLC is required in full configuration. The DMLC performs the following functions:SWIN
Provides lightning protection for Boolean input and output signals. Provides lightning protection for analog signals that are transmitted from the smoke sensor, water sensor, door control sensor, infrared sensor, humidity and temperature sensor.SWOUT
Functions of DELC The DELC is configured in slot 0, 1, or 2 of the set-
on-top subrack. These three slots are shared by the DELC and DMLC. The DELC is a mandatory board. At least one DELC should be configured. The DELC provides lightning protection for 4
routes of E1 signals. A maximum of three DELCs can be configured to provide lightning protection for 12 routes of E1 signals.TR
The DELC performs the following functions:
Provides lighting protection for E1 signals. Transmits E1 signals to the DCCU, through which the signals are sent to the DTMU for processing.
Functions of DSACDSAC COM 2 SYNC EAC COM1 S1+S1-S2+S2-
The DSAC is placed in slot 3 of the set-on-top
subrack. The DATU is a mandatory board. Only one DSAC is required in full configuration. The DSAC performs the following functions: