Huawei Technologies CBTS3612-1900 CDMA Base Station User Manual

Download:
Mirror Download [FCC.gov]
Document ID	358829
Application ID	UDOkvkNf1oS7Fg/sOmRSVg==
Document Description	User Manual
Short Term Confidential	No
Permanent Confidential	No
Supercede	No
Document Type	User Manual
Display Format	Adobe Acrobat PDF - pdf
Filesize	152.78kB (1909750 bits)
Date Submitted	2003-09-22 00:00:00
Date Available	2003-09-19 00:00:00
Creation Date	2003-09-12 07:27:41
Producing Software	Acrobat Distiller 5.0 (Windows)
Document Lastmod	2003-09-15 14:28:32
Document Title	User Manual

HUAWEI
Airbridge cBTS3612 CDMA Base Station
User Manual
System Description
HUAWEI
Airbridge cBTS3612 CDMA Base Station
User Manual
Local Maintenance Terminal
HUAWEI
Airbridge cBTS3612 CDMA Base Station
User Manual
BTS Maintenance
1.5cm
User Manual
Airbridge cBTS3612 CDMA Base Station
7cm Font: Arial 22pt ,
Product name: Bold
5.3cm
0.7cm
5cm
4cm
HUAWEI
Ver: T2-03016020030125-C-1.21
BOM: 31013260
2.5cm, Font: Arial, 9
pt
Huawei Technologies Co., Ltd.
Administration Building, Huawei Technologies
Co., Ltd., Bantian, Longgang District,
Shenzhen, P. R. China
Postal Code: 518129
Website: http://www.huawei.com
BOM: 31013260
15.7cm
User Manual
User Manual
Airbridge cBTS3612 CDMA Base Station
Airbridge cBTS3612 CDMA Base Station
User Manual
User Manual
Airbridge cBTS3612 CDMA Base Station
Airbridge cBTS3612 CDMA Base Station
10cm
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
1. 16K Cover for hectograph; Font: Arial 22 pt; Product name: Bold
Airbridge cBTS3612
CDMA Base Station
User Manual
HUAWEI
1. System Description
2. Local Maintenance Terminal
3. BTS Maintenance
Airbridge cBTS3612 CDMA Base Station
User Manual
V100R002
Airbridge cBTS3612 CDMA Base Station
User Manual
Manual Version
T2-030160-20030125-C-1.21
Product Version
V100R002
BOM
31013260
Huawei Technologies Co., Ltd. provides customers with comprehensive technical support
and service. Please feel free to contact our local office, customer care center or company
headquarters.
Huawei Technologies Co., Ltd.
Address: Administration Building, Huawei Technologies Co., Ltd.,
Bantian, Longgang District, Shenzhen, P. R. China
Postal Code: 518129
Website: http://www.huawei.com
Email: support@huawei.com
© 2003 Huawei Technologies Co., Ltd.
All Rights Reserved
No part of this document may be reproduced or transmitted in any form or by any
means without prior written consent of Huawei Technologies Co., Ltd.
Trademarks
, HUAWEI, C&C08, EAST8000, HONET,
, ViewPoint, INtess, ETS, DMC,
TELLIN, InfoLink, Netkey, Quidway, SYNLOCK, Radium,
M900/M1800,
TELESIGHT, Quidview, Musa, Airbridge, Tellwin, Inmedia, VRP, DOPRA, iTELLIN,
HUAWEI OptiX, C&C08 iNET, NETENGINE, OptiX, SoftX, iSite, U-SYS, iMUSE,
OpenEye, Lansway, SmartAX are trademarks of Huawei Technologies Co., Ltd.
Notice
The information in this document is subject to change without notice. Every effort
has been made in the preparation of this document to ensure accuracy of the
contents, but all statements, information, and recommendations in this document
don't constitute the warranty of any kind, express or implied.
About This Manual
Version
The product version corresponds to the manual is Airbridge cBTS3612 CDMA Base
Station V100R002.
Contents
This User Manual gives a systematic introduction on the technical principles, structures
and maintenance methods of Airbridge cBTS3612 CDMA Base Station (cBTS3612
hereafter).
It is divided into three modules:
Module 1 System Description
This module introduces the technical principles, software and hardware structures,
functions, networking configurations and performance indices of cBTS3612.
Module 2 Local Maintenance Terminal
This module introduces how to use the cBTS3612 local maintenance terminal. First is
the guide to the local maintenance terminal, second is the detailed introduction of the
local commands, including configuration commands and maintenance commands.
Module 3 BTS Maintenance
This module introduces how to maintain the cBTS3612 BTS, including routine
maintenance instructions, fault analysis and location, component replacement and
component description.
Target Readers
The manual is intended for the following readers:
Installation engineers & technicians
Operation & maintenance personnel
Conventions
This document uses the following conventions:
I. General conventions
Convention
Description
Arial
Normal paragraphs are in Arial.
Arial Narrow
Warnings, cautions, notes and tips are in Arial Narrow.
Terminal Display
Terminal Display is in Courier New; message input by the user
via the terminal is in boldface.
II. Command conventions
Convention
Description
boldface font
Command keywords (which must be input unchanged) are in boldface.
italic font
Command arguments for which you supply values are in italics.
[]
Elements in square brackets [ ] are optional.
{ x | y | ... }
Alternative keywords are grouped in braces and separated by vertical bars. One is
selected.
[ x | y | ... ]
Optional alternative keywords are grouped in square brackets and separated by
vertical bars. One (or none) is selected.
{ x | y | ... } *
Alternative keywords are grouped in braces and separated by vertical bars. A
minimum of one and maximum of all can be selected.
[ x | y | ... ] *
Optional alternative keywords are grouped in square brackets and separated by
vertical bars. Many (or none) are selected.
A line starting with an exclamation mark is comments.
III. GUI conventions
Convention
Description
<>
Message entered via the terminal is within angle brackets.
[]
MMIs, menu items, data table and field names are inside square brackets [ ].
Multi-level menus are separated by forward slashes (/). Menu items are in
boldface. For example, [File/Create/Folder].
IV. Keyboard operation
Format
Description

Press the key with key name expressed with a pointed bracket, e.g.
, , , or.

Press the keys concurrently; e.g. means the three keys should
be pressed concurrently.

Press the keys in turn, e.g. means the two keys should be pressed
in turn.
[Menu Option]
The item with a square bracket indicates the menu option, e.g. [System]
option on the main menu. The item with a pointed bracket indicates the
functional button option, e.g.  button on some interface.
[Menu1/Menu2/Menu3]
Multi-level menu options, e.g. [System/Option/Color setup] on the main
menu indicates [Color Setup] on the menu option of [Option], which is on
the menu option of [System].
V. Mouse operation
Action
Description
Click
Press the left button or right button quickly (left button by default).
Double Click
Press the left button twice continuously and quickly.
Drag
Press and hold the left button and drag it to a certain position.
VI. Symbols
Eye-catching symbols are also used in this document to highlight the points worthy of
special attention during the operation. They are defined as follows:
Caution, Warning, Danger: Means reader be extremely careful during the operation.
Note Comment, Tip, Knowhow, Thought: Means a complementary description.
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Table of Contents
Table of Contents
1 System Overview .............................................................................................................. 1-1
1.1 Brief Introduction ....................................................................................................... 1-1
1.2 System Features ....................................................................................................... 1-3
1.2.1 Advanced Technology and Excellent Performance............................................ 1-3
1.2.2 Protecting User Investment .............................................................................. 1-4
1.2.3 Convenient Operation and Maintenance........................................................... 1-4
1.2.4 Flexible Networking Mode................................................................................ 1-5
1.2.5 Reliable Power Supply System ........................................................................ 1-5
1.2.6 Multi-band supported ....................................................................................... 1-6
1.3 Technical Index ......................................................................................................... 1-6
1.4 External Interface...................................................................................................... 1-9
1.4.1 Overview......................................................................................................... 1-9
1.4.2 Um Interface ................................................................................................. 1-10
1.4.3 Abis Interface ................................................................................................ 1-14
1.4.4 OML Interface ............................................................................................... 1-18
1.4.5 LMF Interface................................................................................................ 1-18
1.4.6 System Synchronization Interface.................................................................. 1-18
1.4.7 BTS Test Interface ........................................................................................ 1-18
1.4.8 Remote Maintenance Serial Port .................................................................... 1-19
1.4.9 Environment Alarm Interface.......................................................................... 1-19
1.5 Reliability Design .................................................................................................... 1-19
1.5.1 Hardware Reliability Design ........................................................................... 1-20
1.5.2 Software Reliability Measures ........................................................................ 1-23
2 Hardware Architecture ...................................................................................................... 2-1
2.1 Overview .................................................................................................................. 2-1
2.2 Baseband Subsystem................................................................................................ 2-5
2.2.1 Overview......................................................................................................... 2-5
2.2.2 Control & Clock Module (BCKM) ...................................................................... 2-7
2.2.3 Control Interface Module (BCIM).................................................................... 2-10
2.2.4 Channel Processing Module (BCPM) ............................................................. 2-12
2.2.5 Resource Distribution Module (BRDM) ........................................................... 2-14
2.2.6 Baseband Backplane Module (CBKM)............................................................ 2-17
2.2.7 E1 Surge Protector (BESP)............................................................................ 2-19
2.2.8 Fan Module (BFAN)....................................................................................... 2-20
2.3 RF Subsystem ........................................................................................................ 2-24
2.3.1 Overview....................................................................................................... 2-24
2.3.2 BTS Transceiver Module (BTRM)................................................................... 2-25
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Table of Contents
2.3.3 BTS High Power Amplifier Module (BHPA) ..................................................... 2-28
2.3.4 BTS Transceiver Backplane Module (BTBM) .................................................. 2-30
2.3.5 Combining Duplexer Unit (CDU)..................................................................... 2-31
2.3.6 Duplexer Filter Unit (DFU) ............................................................................. 2-33
2.3.7 Dual Duplexer Unit (DDU).............................................................................. 2-35
2.3.8 Receive LNA Distribution Unit (RLDU)............................................................ 2-37
2.3.9 BTS RF Fan Module (BRFM) ......................................................................... 2-39
2.4 Antenna & Feeder Subsystem ................................................................................. 2-43
2.4.1 Overview....................................................................................................... 2-43
2.4.2 RF Antenna & Feeder.................................................................................... 2-43
2.4.3 Dual-Satellite Synchronization Antenna & Feeder ........................................... 2-47
2.5 Power Supply Subsystem ........................................................................................ 2-50
2.5.1 Overview....................................................................................................... 2-50
2.5.2 General Structure .......................................................................................... 2-51
2.5.3 Technical Indices .......................................................................................... 2-51
2.5.4 Power Supply Monitoring ............................................................................... 2-54
2.5.5 BTS Direct Current Switchbox (BDCS) ........................................................... 2-55
2.6 Environment Monitoring........................................................................................... 2-55
2.6.1 Alarm Box Input ............................................................................................. 2-56
2.6.2 Alarm Indicator .............................................................................................. 2-56
2.6.3 Interface for Actuators ................................................................................... 2-57
2.6.4 Communication ............................................................................................. 2-57
2.7 Lightning Protection System .................................................................................... 2-57
2.7.1 Overview....................................................................................................... 2-57
2.7.2 Lightning Protection for DC............................................................................ 2-59
2.7.3 Lightning Protection for Trunk Line ................................................................. 2-60
2.7.4 Lightning Protection for Antenna & Feeder Port .............................................. 2-62
3 Software Architecture ....................................................................................................... 3-1
3.1 Overall Architecture................................................................................................... 3-1
3.2 Module Description ................................................................................................... 3-2
3.2.1 Main Control Software ..................................................................................... 3-2
3.2.2 O&M Software................................................................................................. 3-4
3.2.3 Clock Software................................................................................................ 3-6
3.2.4 BCIM Software ................................................................................................ 3-7
3.2.5 BCPM Software............................................................................................... 3-8
3.2.6 BRDM Software .............................................................................................. 3-9
3.2.7 BTRM Software ............................................................................................. 3-10
4 System Function ............................................................................................................... 4-1
4.1 Transmission Networking .......................................................................................... 4-1
4.2 Call Procedure .......................................................................................................... 4-3
4.2.1 Speech Service Call Procedure........................................................................ 4-3
4.2.2 Data Service Call Procedure............................................................................ 4-6
ii
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Table of Contents
4.3 Signaling Processing ................................................................................................. 4-9
4.4 Baseband Processing.............................................................................................. 4-11
4.5 RF Functions .......................................................................................................... 4-13
4.5.1 Power Control ............................................................................................... 4-13
4.5.2 Handoff ......................................................................................................... 4-15
4.5.3 Flexible Configuration .................................................................................... 4-15
4.5.4 Radio Configuration and Channel Support ...................................................... 4-16
4.5.5 Easy Installation and Operation...................................................................... 4-21
4.5.6 Diversity Receiving ........................................................................................ 4-21
4.5.7 Cell Breath.................................................................................................... 4-22
4.6 Operation and Maintenance..................................................................................... 4-22
4.6.1 Software Loading .......................................................................................... 4-22
4.6.2 Interface Management ................................................................................... 4-23
4.6.3 Test Management ......................................................................................... 4-24
4.6.4 Status Management ...................................................................................... 4-24
4.6.5 Event Reporting and Processing .................................................................... 4-25
4.6.6 Equipment Management ................................................................................ 4-26
4.6.7 Site Configuration.......................................................................................... 4-28
4.6.8 Operation Status Tracing............................................................................... 4-29
4.6.9 Other Functions............................................................................................. 4-29
5 System Configuration ....................................................................................................... 5-1
5.1 Overview .................................................................................................................. 5-1
5.1.1 Basic/Extended Cabinet Configuration ............................................................. 5-1
5.1.2 Baseband Subrack Configuration ..................................................................... 5-4
5.1.3 Power Supply Subrack Configuration ............................................................... 5-6
5.1.4 RF Modules Configuration ............................................................................... 5-6
5.1.5 Configuration of Antenna Parts ........................................................................ 5-7
5.2 Typical Configurations ............................................................................................... 5-8
5.2.1 Typical Configuration of cBTS3612 for 450MHz Band ....................................... 5-8
5.2.2 Typical Configuration of cBTS3612 for 800MHz Band ..................................... 5-14
5.2.3 Typical Configuration of cBTS3612 in 1900MHz Band..................................... 5-21
Appendix A Technical Performance of Receiver and Transmitter ..................................... A-1
A.1 Performance of Receiver...........................................................................................A-1
A.1.1 Frequency Coverage.......................................................................................A-1
A.1.2 Access Probe Acquisition ................................................................................A-1
A.1.3 R-TCH Demodulation Performance..................................................................A-1
A.1.4 Receiving Performance ...................................................................................A-9
A.1.5 Limitations on Emissions ...............................................................................A-10
A.1.6 Received Signal Quality Indicator (RSQI).......................................................A-11
A.2 Performance of Transmitter.....................................................................................A-11
A.2.1 Frequency Requirements ..............................................................................A-11
A.2.2 Modulation Requirements..............................................................................A-12
iii
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Table of Contents
A.2.3 RF Output Power Requirement ......................................................................A-12
A.2.4 Limitations on Emissions ...............................................................................A-13
Appendix B EMC Performance ........................................................................................... B-1
B.1 EMI Performance......................................................................................................B-1
B.2 EMS Performance ....................................................................................................B-2
Appendix C Environment Performance .............................................................................. C-1
C.1 Ambient Temperature and Humidity.......................................................................... C-1
C.2 Cleanness ............................................................................................................... C-1
C.3 Illumination .............................................................................................................. C-2
C.4 Atmospheric Condition ............................................................................................. C-2
Appendix D Electromagnetic Radiation.............................................................................. D-1
D.1 Introduction ............................................................................................................. D-1
D.2 Maximum Permissible Exposure (MPE) .................................................................... D-1
D.3 Estimation of Exposure to Electromagnetic Fields ..................................................... D-3
D.4 Calculation of Safe Distance .................................................................................... D-3
D.5 Location of Base Station Antennas ........................................................................... D-4
D.5.1 Exclusion Zones ............................................................................................ D-4
D.5.2 Guidelines on Arranging Antenna Locations .................................................... D-4
Appendix E Standard Compliance .......................................................................................E-1
E.1 Um Interface.............................................................................................................E-1
E.2 Abis Interface ...........................................................................................................E-1
E.3 Lightning Protection ..................................................................................................E-2
E.4 Safety ......................................................................................................................E-3
E.5 EMC.........................................................................................................................E-3
Appendix F Abbreviation ..................................................................................................... F-1
iv
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
1 System Overview
This chapter firstly presents an outline of the cBTS3612 base station system, and
then briefs the system features, technical indices and external interfaces, followed
by an introduction to the system reliability design in aspects of hardware and
software.
1.1 Brief Introduction
The cdma2000 1X mobile communication system comprises the Base Station
Subsystem (BSS) and the Core Network (CN). The BSS comprises the Base
Transceiver Station (BTS), Base Station Controller (BSC) and Packet Control
Function (PCF), while the CN comprises the packet domain network and circuit
domain network. The equipment of packet domain interworks with Internet, and that
of the circuit domain interworks with the conventional PLMN and PSTN/ISDN. The
system's operation and maintenance is implemented via the integrated mobile
network management system (iManager M2000).
The position of BTS in CDMA system is as shown in Figure 1-1.
Mobile Network
Management System
MS
SoftSite
BTS
Ab
is
SoftSite
BSC/PCF
A10/A11
BTS
SDH
MS
BTS
A3/A7
/A2
A1
SoftSite
BTS
Abis
MS
A1/A2
BTS
PLMN
Circuit Domain
Network
Equipment
BSC/PCF
MS: Mobile Station
BSC: Base Station Controller
PLMN: Public Land Mobile Network
PCF: Packet Control Function
BSS: Base Station Subsystem
Internet
A10
/A1
BTS
Packet Domain
Network Equipment
BTS: Base Transceiver Station
ISDN: Integrated Service Data Network
PSTN: Public Switched Telephone Network
Softsite: Soft Site
CN: Core Network
Figure 1-1 Network structure of cdma2000 1X mobile communication system
1-1
PSTN/ISDN
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
cBTS3612 is located between the Base Station Controller (BSC) and the Mobile
Station (MS) in the cdma2000 1X mobile communication system.
Under the control of the BSC, the cBTS3612 serves as the wireless transceiving
equipment of one cell or multiple logical sectors. Connecting to BSC via the Abis
interface, it assists the BSC on the radio resource management, radio parameter
management and interface management. It also implements, via the Um interface,
the radio transmission between the BTS and the MS, as well as related control
functions.
cBTS3612 cabinet is shown in Figure 1-2.
Baseband subrack
Fan subrack
Power subrack
RF subrack
CDU/RLDU subrack
RF subrack
Figure 1-2 cBTS3612 cabinet
cBTS3612 has the following functions:
I. Interface function
Um interface supports IS2000 Release A. It is fully compatible with IS -95A/B.
The physical layer supports a rate as high as 307.2kbit/s.
Hard handoff, soft handoff and softer handoff are supported.
Quick forward power control, slow forward power control, quick reverse power
control and reverse open-loop power control are available.
1-2
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Support omni-cell, directional 3 sectors and 6 sectors configurations.
Abis interface supports E1/T1 trunk mode and optical fiber transmission mode
(optical fiber transmission mode will be available in the coming version). E1/T1
trunk mode supports as many as 16 E1/T1 trunk lines and optical fiber
transmission mode will support 2 pairs of STM -1 optical fibers.
Chain, star and tree networking modes are supported.
Softsite (ODU3601C) can be extended afar via optical fibers.
II. Basic functions of operation and maintenance
Software downloading
Abis interface management
Air interface (Um) management
Test management
Status management
Event report handling
Equipment management
Data configuration management
BTS operation tracing
Telnet logon
1.2 System Features
cBTS3612 features large capacity, high integration and low power consumption.
One cabinet can accommodate as many as 12 sector carriers. It can satisfy the
customer's
demands
on
capacity,
configuration,
installation,
power
supply,
transmission and service. It's a typical "All In One" BTS. Its features are highlighted
as follows:
1.2.1 Advanced Technology and Excellent Performance
cBTS3612 integrates the following technologies to improve its performances:
Based on well-developed Huawei ATM platform and cell switching & broadband
processing technology, standard interface and open application is enabled.
Designed with the resource pool concept, which helps increase the availability
of hardware resources and the system's fault-tolerance.
Equipped with the digital intermediate frequency technology to enhance
wireless signal transmitting and receiving capability.
Designed with the technology of diversity receiving to improve the radio signal
receiving performance.
Supporting remote installation of the SoftSite via optical fibers, thus making
networking more flexible.
1-3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Equipped with the blind mate technology on the radio frequency module for
convenient maintenance.
Intelligent fans with prolonged service life and reduced noise.
1.2.2 Protecting User Investment
The cBTS3612 is compatible with IS -95A/B and cdma2000 1X, and can be
upgraded to cdma2000 1X EV smoothly. When the network is upgraded from IS-95
to cdma2000 1X, or from cdma2000 1X to cdma2000 1X EV, the user's investment
can be saved.
The cBTS3612 features large-capacity design, modular structure and high
integration. A single cabinet can accommodate up to 12 sector carriers. It also
supports 36 sector carriers with three fully configured cabinets combined together.
Its baseband processing employs the resources pool design to reduce equipment
redundancy and improve reliability.
Its Abis interface supports 16 E1s or 2 STM-1 optical interfaces (in the coming
version), oriented to future high-speed data service.
Its excellent inheritance capability guarantees the original antenna and feeder
components can be used in the event of BTS expansion or upgrade. The
components include DU, RLDU, antenna, feeder and the optional TMA (The TMA
only applies to 19000MHz band). The DU includes CDU, DFU and DDU, the
difference between these 3 DUs will be introduced in "2.3 RF Subsystem".
1.2.3 Convenient Operation and Maintenance
Emergency serial ports are provided for the boards, so that the alarm information
can be reported in the case of communication link fault.
Real-time status query, online board test and system fault locating as well as system
restart functions are provided.
Telnet Server is provided so that the user can log in to the BTS via the local
Ethernet interface in the standard Telnet mode to perform O&M.
Modem dial-up is supported so that the remote O&M can be performed.
All boards of baseband subrack support hot plug/unplug for the sake of ready
maintenance, upgrade and expansion.
Blind mate of the radio frequency module guarantees that all operations can be
done at the front side of the equipment. During expansion and configuration, wiring
at the back need not be modified.
1-4
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Its modularized structure reduces the internal connections and improves the
reliability of the system, and thus makes the installation and maintenance easier.
In the case of whole BTS interruption due to power supply or transmission causes,
the cBTS3612 system can restart automatically right after the faults are cleared.
1.2.4 Flexible Networking Mode
I. Networking for large capacity and wide coverage
A single cabinet supports as many as 12 sector carriers. 3 cabinets can be
combined to provide a maximum capacity of 36 sector carriers.
Large-capacity trunk. Abis interface of BTS supports as many as 16 E1s
transmission. The coming version will support STM -1 optical transmission in
ATM mode at Abis interface and provide two STM -1 ports for Abis interface
trunk.
Support multiple BTS configurations such as omni 4 carriers, 1%3, 2%3, 12%3,
6%6(carrier%sector) configurations.
II. Supporting multiple BTS networking modes such as chain, star and tree
Refer to "4.1 Transmission Networking" for details.
III. Soft BTS networking (the SoftSite will be available in the coming version)
In this networking mode, the baseband unit adopts the centralized processing mode.
The baseband signals and maintenance information are transferred through the fiber
to the SoftSite (ODU3601C). The SoftSite can be applied indoors, outdoors or
underground.
The SoftSite, small in size, is equipped with built-in power supply, temperature
regulator and monitoring device. It can be used in severe environments, e.g.
outdoors. The feeder loss of the SoftSite is trivial, making large coverage for macro
cells possible.
SoftSites in the chain-networking mode are applicable to highways and subways. A
maximum of 6 SoftSites can be connected in serial in one pair of optical fibers.
1.2.5 Reliable Power Supply System
The DC/DC power supply with -48V DC power input, and +27V DC output is
adopted. The whole power supply system is composed of 5 modules in full
configuration, with automatic current equalization function, 4+ 1 redundancy, meeting
the requirement of 8000W power supply.
1-5
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Current equalization hot backup, centralized management, and decentralized power
supply are enabled. It makes the power supply system safer and more reliable. It
provides automatic alarming through monitoring interface for the power fan, input
under-voltage, output over-voltage, overheat and protection against reverse
connection. This ensures the reliability of the power system. Remote power on/off
function enables unattended BTS operation and remote maintenance.
1.2.6 Multi-band supported
Now the cBTS3612 base station support the following band class specified in
TIA/EIA-97-D Recommended Minimum Performance Standards for cdma2000
Spread Spectrum Base Stations.
Band Class 0 (800 MHz Band).
Band Class 1 (1900 MHz Band).
Band Class 5 (450 MHz Band).
To support the different band classes, RF modules with different specifications
should be configured in cBTS3612 base station.
1.3 Technical Index
I. Structure and environment indices
Cabinet dimensions (Top set excluded)
Power supply
Operational environment
Equipment room noise
1800mm x 800mm x 650mm (H x W x D)
-48V DC (-40 - -60V DC)
Temperature: -5°C ~ 50°C
Relative humidity: 5% ~ 90%
70dB A (With intelligent fan control. The noise varies with the
ambient temperature)
Note:
In terms of environment adaptability, cBTS3612 conforms to the following specifications: IEC 60721-3
series, IEC 60068-2 and ETS 300 019-2 series. For details, please refer to Appendix C Environment
Performance.
Equipment room noise is In compliance with ETS 300 753 Noise Requirement for telecommunication
equipment and base station environment. When the inside temperature of cBTS3612 equipment room
is 50âC, the equipment noise is less than 70dBA, and when the temperature is 25âC, the equipment
noise is less than 60dBA.
1-6
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
II. Clock indices
Frequency stability
<±5 x 10-8
Annual aging rate
<±5 x 10-10
III. System capacity
Full configuration of one cabinet
12 sector-carriers
Full configuration of three cabinets 36 sector-carriers
IV. Power consumption and cabinet weight
Site configuration
S(1/1/1)
S(2/2/2)
S(4/4/4)
Power consumption (W)
<1500
<2800
<5500
Cabinet weight (kg)
351
388
550
V. Transmitter indices
450MHz Band
460 - 470MHz
Working band
Channel bandwidth
1.23MHz
Channel precision
25kHz
Frequency tolerance
±0.05ppm
Transmitting power
20W (The maximum value measured at the cabinet-top
feeder port)
800MHz Band
869 - 894MHz
Working band
Channel bandwidth
1.23MHz
Channel precision
30kHz
Frequency tolerance
±0.05ppm
Transmitting power
20W (The maximum value measured at the cabinet-top
feeder port)
1900MHz Band
1-7
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
1930 - 1990MHz
Working band
Channel bandwidth
1.23MHz
Channel precision
50kHz
±0.05ppm
Frequency tolerance
20W (The maximum value measured at the cabinet-top
feeder port)
Transmitting power
VI. Receiver indices
450MHz Band
450 - 460MHz
Working band
Channel bandwidth
1.23MHz
Channel precision
25kHz
Better than -126dB (RC3, main and diversity receiving)
Sensitivity of signal receiver
800MHz Band
824 - 849MHz
Working band
1.23MHz
Channel bandwidth
30kHz
Channel precision
Better than –127dBm (RC3, main and diversity receiving)
Sensitivity of signal receiver
1900MHz Band
1850 - 1910MHz
Working band
1.23MHz
Channel bandwidth
50kHz
Channel precision
Better than –126dBm (RC3, main and diversity receiving)
Sensitivity of signal receiver
VII. Rate configuration on Um interface
Rate configuration
Mode 1
Mode 2
Mode 3
Mode 4
Forward
RC1
RC2
RC3 or RC4
RC5
1-8
Reverse
RC1
RC2
RC3
RC4
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
VIII. EMC indices
ETSI EN 300 386 Electromagnetic compatibility and Radio spectrum Matters (ERM)
- Telecommunication network equipment - ElectroMagnetic Compatibility (EMC)
requirements is the universal EMC standard of telecommunication equipment. The
EMC indices of the cBTS3612 comply with ETSI EN 300 386 V1.2.1 (2000 – 03).
IX. System reliability
MTBF (hour)
100000
MTTR (hour)
99.999%
Availability (A)
Note:
The performance of cBTS3612 base station satisfies or excels TIA/EIA-97-D: Recommended Minimum
Performance Standards for cdma2000 Spread Spectrum Base Stations.
1.4 External Interface
1.4.1 Overview
The external interfaces of cBTS3612 are shown in Figure 1-3.
1-9
User Manual
Airbridge cBTS3612 CDMA Base Station
Test
equipment
Environment
alarm box
Satellite Synchronization
interface
Environment
alarm interface
Test
interface
Um
BSC
BTS
interface
System Description
System Overview
OMC
Abis interface OML interface
Ethernet
interface
MS
Remote maintenance serial port
PSTN
LMF
MODEM
Figure 1-3 BTS external interface
Um interface: interface with MS.
Abis interface: interface with BSC.
OML interface: interface with the remote OMC. It shares the transmission
resources with Abis interface.
LMF interface: interface with BTS local maintenance console.
System synchronization interface: including GPS/GLONASS antenna interface
and system external synchronization interface. When GPS/GLONASS is not
available and there is other clock synchronization equipment, the clock
synchronization output of the equipment can be connected with the external
synchronization interface of BTS system.
BTS test interface: interface for BTS test, providing such signals as 10MHz and
2s signal.
Remote maintenance serial interface: another interface to remote console. This
is a standby maintenance interface can be used when the active maintenance
link between OMC and BTS is interrupted.
Environment alarm interface: interface with environment alarm collection box.
1.4.2 Um Interface
I. Overview
In Public Land Mobile Network (PLMN), MS is connected with the fixed part of the
network through the radio channel, which enables the subscribers to be connected
1-10
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
with the network and to enjoy telecommunication services. To implement
interconnection between MS and BSS, systematic rules and standards should be
established for signal transmission on radio channels. The standard for regulating
the radio channel signal transmission is called radio interface, or Um interface.
Um interface is the most important interface among the many interfaces of CDMA
system. Firstly, standardized radio interface ensures that MSs of different
manufacturers are fully compatible with different networks. This is one of the
fundamental conditions for the roaming function of CDMA system. Secondly, radio
interface defines the spectrum availability and capacity of CDMA system.
Um interface is defined with the following features:
Channels structure and access capacity.
Communication protocol between MS and BSS.
Maintenance and operation features.
Performance features.
Service features.
II. Um interface protocol model
Um interface protocol stack is in 3 layers, as shown in Figure 1-4.
Figure 1-4 Um interface layered structure
1-11
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Layer 1 is the physical layer, i.e. the bottom layer. It includes various physical
channels, providing a basic radio channel for the transmission of higher layer
information.
Layer 2 is the data link layer, including Medium Access Control (MAC) sublayer
and Link Access Control (LAC) sublayer. The cdma2000 MAC sublayer
performs the mapping between logic channels and physical channels, and
providing Radio Link Protocol (RLP) function. The cdma2000 LAC sublayer
performs such functions as authentication, Automatic Repeat Request (ARQ),
addressing and packet organization.
Layer 3 is the top layer. It performs Radio Resource Management (RM),
Mobility Management (MM) and Connection Management (CM) through the air
interface.
III. Physical layer
1) Operating band
Band
Forward Band
Reverse Band
460 - 470MHz
450 - 460MHz
Duplex
Space
10MHz
Channel
Wideth
1.23
MHz
Carrier Space
450MHz
800MHz
869 - 894 MHz
824 - 849 MHz
45MHz
1.23 MHz
1.25 MHz
1900MHz
1930 - 1990 MHz
1850 - 1910 MHz
80MHz
1.23 MHz
1.25 MHz
1.23 MHz
2) Physical layer function
Service bearer: the physical channel in the physical layer provides bearer for
the logic channel of the higher layer.
Bit error check: the physical layer provides a transmission service with error
protection, including error checking and error correction.
User identification: the physical layer provides an exclusive ID for every user by
code division.
3) Radio configuration
The cdma2000 physical layer supports multiple Radio Configurations (RCs).
Different RCs support different traffic channel data rates. For detailed introduction,
please refer to Section 4.5.4 Radio Configuration and Channel Support.
IV. Data link layer
Data link layer at Um interface includes two sublayers: MAC and LAC. The purpose
of introducing MAC and LAC is to:
Support higher level services (signaling, voice, packet data and circuit data).
Support data services of multiple rates.
Support packet data service and circuit data service of higher quality (QoS ).
1-12
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Support multi-media service, i.e. processing voices, packet data and circuit
data of different QoS levels at the same time.
1) MAC sublayer
To support data service and multi-media service, cdma2000 1X provides powerful
MAC layer to ensure the reliability of services. MAC layer provides two important
functions:
Radio Link Protocol (RLP ), ensuring reliable transmission on the radio link.
Multiplex function and QoS function, with diversified services and higher service
quality.
2) LAC sublayer
LAC layer performs such functions as Automatic Repeat Request (ARQ),
authentication and addressing.
V. Layer 3
The higher layer signaling performs the functions such as radio resource
management, mobility management and call control management on air interface.
1) Radio resource management
It is mainly used to establish, operate and release radio channels, and help to
realize soft handoff, softer handoff and hard handoff.
2) Mobility management
It is mainly used to support the mobility features of the mobile user, performing such
functions as registration, authentication and Temporary Mobile Subscriber Identifier
(TMSI) re-allocation.
3) Connection management
It is mainly used to setup, maintain and terminate calls.
VI. Power control
Um interface utilizes power control technology to reduce the system interference
and improve the system capacity. There are forward power control and reverse
power control available.
1) Forward power control supports closed-loop power control
Forward power control includes power control based on power measurement report,
control based on EIB, and quick forward power control.
Forward closed-loop power control means that MS checks the quality of received
frames and received power, makes judgment and sends request to BTS for
1-13
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
controlling BTS transmitting power. Then BTS adjusts its transmitting power
according to the request. Power control command is sent at a rate of 50bit/s or
800bit/s.
2) Reverse power control includes open-loop power control and closed-loop power
control.
Reverse open-loop power control means that MS adjusts its transmit power as
the received power changes.
Reverse closed-loop power control means that BTS compares the received MS
transmit power with the preset power control threshold and sends power control
command based on the comparison. MS changes its transmit power as
required by the received power control command. Power control commands are
transmitted on F-TCH at a rate of 800bit/s.
For more information about power control, please refer to Section 4.5.1 Power
Control.
VII. Handoff
Um interface supports many handoff technologies. It supports three types of handoff
in traffic channel communication:
1) Hard handoff: MS breaks the connection with the old BTS before establishing
connection with a new BTS.
2) Soft handoff: MS establishes connection with a new BTS while maintaining the
connection with the existing one.
3) Softer handoff: soft handoff that occurs between different sectors of the same
BTS.
Soft handoff technology can improve the rate of handoff success, reduce call drops
and effectively improve the system performance.
For more information, please refer to Section 4.5.2 Handoff.
1.4.3 Abis Interface
I. Overview
Abis interface is defined as the interface between BSC and BTS, the two functional
entities in the Base Station Subsystem (BSS ). It is the interface defined for BTS
accessing BSC via the terrestrial link.
1-14
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
1) Composition of Abis interface
Abis interface consists of three parts: Abis traffic, Abis signaling and OML signaling,
as shown in Figure 1-5.
Abis traffic is the interface connecting SDU of BSC and the channel processing unit
of BTS. It is used to bear user traffic.
Abis signaling is the signaling transmission channel between BSC and BTS. It is
used to control the cell setup, transmission of messages in paging channels and
access channels, and call setup & release.
OML signaling is used to perform operation and maintenance. It is defined by
equipment manufacturers. On Abis interface, there is a transparent channel used to
bear OML between OMC and OMU of BTS.
SPU
SDU
MC
CEs
OML
OMU
alin
ign
sS
Abi
ic
Traff
Abis
Abis Interface
OM
Abis
Signa
ling
Abis
Traffic
BSC
OMU CEs MC
BTS
BTS
SPU：Signaling Process Unit
SDU：Selection/Distribution Unit
MC： Main Control
CEs： Channel Elements
OMU ：Operation & Maintenace Unit
Figure 1-5 Composition of Abis interface
2) Protocol stack of Abis interface
The protocol stack used by Abis signaling and the signaling for operation &
maintenance is as follows:
Abis Signaling Application/OAM Application
TCP
IP
AAL5
ATM
Physical Layer
1-15
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Protocol stack used by Abis traffic is as follows:
Abis Traffic
SSSAR
AAL2
ATM
Physical Layer
II. Physical layer
The physical layer of Abis interface can use E1/T1 interface or STM -1 interface.
With E1/T1 interface used, its physical electric parameters comply with CCITT
G.703 recommendations. The multiple E1/T1 trunk lines transmit ATM cells by
means of Inverse Multiplexing on ATM (IMA).
III. Data link layer
ATM is used in the data link layer of Abis interface.
Adaptation of Abis signaling is performed on the basis of AAL5, and is borne in IP
Over ATM (IPoA ) mode. At Abis interface, Abis signaling path connects the main
control software (MC) and SPU of BSC via Permanent Virtual Circuit (PVC) to
transmit Abis signaling. So it is with the transmission path of signaling that performs
operation & maintenance. It also uses PVC to connect OMU of BTS and BSC, which
will forward it to OMC transparently. BSC does not process any signaling that
performs operation and maintenance.
Adaptation of Abis traffic is performed on the basis of AAL2. At Abis interface,
BCPM uses several PVCs to connect the channel processing unit of BTS and SDU
of BSC, for BTS to transmit the uplink data received from the air interface to BSC,
and for BSC to transmit the downlink data to be transmitted via the air interface to
BTS.
IV. Layer 3 - traffic management
At Abis interface, Abis signaling and Abis traffic are in the domain of traffic
management. Specifically, Abis traffic management includes the following functions:
1) BTS logic operation & maintenance function
Resource status indication: with this function, BTS requests logic configuration
from BSC, reports logic status to BSC and checks logic resource regularly.
Cell configuration: with this function, BSC configures logic parameters of cells
for BTS, including cell pilot Pseudo Noise (PN) offset, sector gain, common
channel number and parameter.
Overhead message updating: with this function, BSC configures or update
overhead message to BTS.
1-16
User Manual
Airbridge cBTS3612 CDMA Base Station
Cell breath control function.
Cell blocking function.
Radio measurement report function.
System Description
System Overview
2) Common channel management procedure
Paging channel management procedure: it is used to transmit paging channel
messages from BSC to MSs through Abis interface.
Access channel management procedure: it is used to transmit access channel
messages received on the access channel of BTS to BSC through Abis interface.
3) Procedure of dedicated channel setup and release
It is used to control the setup and release of dedicated radio channel and Abis
interface terrestrial channel.
Abis interface supports the setup and release of various dedicated channels
specified
in
IS95A/B
and
cdma2000
1X,
specifically
including
IS95-FCH,
IS95-SCCH, IS2000-FCH, IS2000-DCCH and IS2000-SCH.
Each radio channel is allocated with one AAL2 link on Abis interface to bear user
traffic data.
Caution:
Softer handoff is only allocated with one AAL2 link on Abis interface.
4) Traffic channel bearing procedure
BTS needs to process Abis interface frame protocol, to transmit the data received
from the reverse traffic channel on the air interface to BSC and the data from BSC
through the forward traffic channel at the air interface.
Traffic channel bearing procedure also performs functions such as AAL2 traffic
matching, time adjustment of traffic data frame, reverse outer loop power control
adjustment and forward power control adjustment.
5) Power control
Abis interface supports various power controls. Power control is performed through
parameter configuration. Power control falls into 4 types: quick forward closed-loop
power control, slow forward closed-loop power control, quick reverse closed-loop
power control and reverse open-loop power control.
1-17
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
1.4.4 OML Interface
OML interface is between BTS and remote OMC. It is actually one of the Abis
interface applications, but in the application layer, OML interface is between BTS
and the remote OMC. OML interface shares resources of Abis interface, including
physical layer, ATM, AAL5 and TCP/IP. For details, please refer to the introduction to
Abis interface.
OML interface is used for OMC to perform operation and maintenance to BTS. It is
defined by equipment manufacturers. On Abis interface, it is a transparent path.
1.4.5 LMF Interface
LMF interface is the interface between BTS and Local Maintenance Function (LMF).
Its interface protocol stack is shown as below:
LMF Signaling Application (self- defined)
TCP
IP
Data Link Layer
Physical Layer (10/100 Base-T)
1.4.6 System Synchronization Interface
System synchronization interface includes GPS/GLONASS antenna interface and
system external synchronization interface.
1) GPS/GLONASS antenna interface: GPS is in compliance with ICD200c:
IRN-200C-001-IRN-200C-004: Interface Control Document of GPS. GLONASS is in
compliance with GPS/GLONASS Receiver Interface Language (GRIL).
2) System external synchronization interface: the external synchronization interface
without GPS/GLONASS is in compliance with the requirement of CDMA Digital
Cellular Mobile Communication Network GPS/GLONASS Dual-Mode Receiver and
Base Station Interface Specifications.
1.4.7 BTS Test Interface
BTS test interface provides 10MHz and 2s signals that may be necessary for
testers.
1-18
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
1.4.8 Remote Maintenance Serial Port
Remote maintenance serial port is an RS-232 serial port, connected with PSTN via
an external Modem. It is used for emergency maintenance by dial-up with a Modem
when OML between OMC and BTS is interrupted.
1.4.9 Environment Alarm Interface
Environment alarm interface is an RS-485 serial port connected with the external
environment alarm collection box, performing a centralized monitoring to the
environment. A communication protocol defined by Huawei is used between BTS
and the environment alarm collection box. Therefore, supported environment alarm
collection box should be used for the BTS.
1.5 Reliability Design
Reliability design of a system is shown in the stability and reliability of the product
during operation.
Huawei cBTS3612 is designed based on reference to the following standards:
YD/T 1029-1999 800MHz General Technical Specifications of CDMA Digital
Cellular Mobile Communication Network Equipment
YD/T 1030-1999 800MHz Technical Requirement for Interface of CDMA Digital
Cellular Mobile Communication Network
TIA/EIA/IS-97D Minimum Performance Standard of CDMA Base Station
Huawei product reliability design index and related technical specifications
The design of boards is in strict accordance with the requirement of above
standards pertaining to reliability design, with measures taken to improve the
reliability. In addition, some key parts of the system are designed with redundancy
(such as active/standby mode and resource pool) to improve the reliability of the
system.
System reliability indices are:
MTBF: 100000 hours
MTTR: 1 hour
1-19
A : 99.999%
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
Note:
Reliability refers to the product capability of performing specified functions in the specified conditions
and specified time.
There are 3 main indices to describe the reliablity of a system:
MTBF: Mean Time Between Failures, normally applicable to recoverable systems.
MTTR: Mean Time To Repair, inlcuding the time of fault checking, isolation, unit replacement and
recovery.
A: Availability , a comprehensive index to measure the system availability.
1.5.1 Hardware Reliability Design
cBTS3612 is designed with substantial hardware reliability, such as board
active/standby operation, load sharing and redundancy configuration. In addition,
system maintainability is improved with fault detection and isolation technology on
the board and system. In respect of hardware reliability, the following considerations
have been taken:
I. De-rating design
To improve system reliability and prolong the service life of components,
components are carefully selected and strictly tested, and less stress (electrical
stress and temperature stress) is to be borne than its designed rating.
II. Redundancy design
Redundant configuration of key units is applied in the BTS system. The system or
equipment will not fail unless the specified sets of units fail. In the BTS system,
common measures such as active/standby and load-sharing modes are adopted,
e.g. for BCIM, BCPM and BCKM.
III. Selection and control of components
The category, specifications and manufacturers of the components are carefully
selected and reviewed according to the requirements of the product reliability and
maintainability. The replaceability and normalization of components is one of the
main factors for the decision, which help to reduce the types of components used
and hence improve the availability of the system.
1-20
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
IV. Board level reliability design
Many measures have been taken to improve the board reliability. Moreover, the
system reliability is improved through the redundancy design of key parts.
Key circuits are designed by Huawei, which lays the foundation of high
reliability.
The hardware WATCHDOG is equipped for the board, and the board can
automatically reset in case of fault.
The board is provided with the functions of over-current and over-voltage
protection and the function of temperature detection.
The board also provides emergency serial port, and can keep contact with the
main control board in case of emergency.
Strict thermal analysis and simulation tests are conducted during the design of
boards for the purpose of ensuring longtime operation.
The board software and important data is stored in the non-volatile memory, so
that the board can be restarted when the software upgrading fails.
V. Overvoltage and overcurrent protection
The BTS system provides various means of over-voltage and over-current
protection.
Over-voltage and over-current hardware protection is provided for the DC/DC
power supply module.
For secondary power supply to boards, slow-start is employed to prevent the
great impact on the whole power supply load when the boards are powered on.
Fuse is installed for each board against over-current.
For E1 interface circuit, serial-port circuit and network interface circuit,
protection measures are taken in accordance with the corresponding design
specifications of Huawei.
VI. Power supply reliability
The reliability of power supply is improved by means of over-current and
over-voltage protection, internal temperature adjustment, and redundancy backup.
VII. Fault detection, location and removal
The BTS system is equipped with the functions of self-detection and fault diagnosis
that can record and output various fault information. The common software and
hardware faults can be corrected automatically.
The hardware fault detection functions include fault locating, isolating and automatic
switchover. The maintenance engineers can identify the faulty boards easily with the
help of the maintenance console.
1-21
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
When faults occur to software, certain automatic error-correction function will be
executed, including restarting and reloading.
The BTS system also provides manual and automatic re-initialization of different
levels, and supports the reloading of configuration data files and board execution
programs.
VIII. Fault tolerance
When faults occur, the system usually will not be blocked, as the BTS system
provides the E1 connection in conformity with the IMA protocol, and has certain line
backup capabilities.
The boards of important devices in the system have been backed up, ensuring that
the BTS system can switch the service from the faulty board to a normal board, or
perform reconfiguration of the system.
The system will make a final confirmation on a hardware fault through repeated
detection, thus avoiding the system reconfiguration or QoS deterioration due to
contingent faults.
IX. Thermal design
The influence of temperature on the BTS system has been considered in the design
of the system. Thermal design primarily concerns the selection of components,
circuit design (including error tolerance, drift design and derating design), structure
design and heat dissipation, so that the BTS system can work reliably in a wide
range of temperatures.
The first consideration in thermal design is to balance the heat distribution of the
system. Corresponding measures are taken in the place where heat is more likely to
be accumulated.
X. Maintainability
The purpose of maintainability design is to define the workload and nature of the
maintenance, so as to cut the maintenance time. The main approaches adopted
include
standardization,
modularization,
error
prevention,
and
testability
improvement which can simplify the product maintenance work.
XI. EMC design
The design ensures that cBTS3612 will not degrade to an unacceptable level due to
the electromagnetic interference from other equipment in the same electromagnetic
environment. At the same time, cBTS3612 will not cause other equipment in the
1-22
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
same electromagnetic environment to degrade to an unacceptable level due to the
EMI from it.
XII. Lightning protection
To eliminate the probability of lightning damage on the BTS system, proper
measures are taken in the following three aspects:
Lightning protection for DC power supply
Lightning protection for BTS trunk lines
Lightning protection for antenna and feeder system
For details, please refer to "2.7 Lightning Protection System".
1.5.2 Software Reliability Measures
Software reliability mainly includes protection performance and fault tolerance
capability.
I. Protection performance
The key to improve software reliability is to reduce software defects. Software
reliability of BTS is ensured in the whole process from system requirement analysis,
system design to system test.
Starting from the requirement analysis, software development process goes under
regulations such as CMM (Capability Mature Mode), which aim to control faults in
the initial stage.
In software design, much attention is devoted to the designing method and
implementation: the software is designed in a modular structure, and in a loose
coupling mechanism. When a fault occurs to one module, other modules will not be
affected. In addition, preventive measures such as fault detection, isolating and
clearing are also important in improving the system reliability. Other effective
methods include code read-through, inspection, and unit test.
Various software tests are necessary to improve the software reliability. Test
engineers participate the whole software develop process, from unit test to system
test. They make plans strictly compliant with the demand of the upper level flow,
which ensure the improvement of software reliability. Additionally, test plans are
improved with the tests and become more and more applicable.
II. Fault tolerance capability
Fault tolerance capability of the software system means that the whole system
would not collapse when a minor software fault occurs, i.e. the system has the
1-23
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
System Overview
self-healing capability. The fault tolerance of software is represented in the following
aspects:
All boards work in a real-time operating system of high reliability.
Important data on BCKM are backed up on real-time basis. Operation is
switched to the standby board when a fault occurs.
When a fault occurs to some transmission links, traffic borne on them can be
transferred to other links smoothly.
Each board's software on the board has a static backup on BCKM.
If software loading fails, the system can return to the version that was loaded
successfully last time.
Important operations are recorded in log files.
Different authority levels are provided for operations, to prevent users from
performing unauthorized operations.
Prompts are given for the operations that will cause system reboot (such as
reset operation), which requests the operator to confirm it before executing
such operation.
1-24
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
2 Hardware Architecture
The beginning of this chapter briefs cBTS3612 hardware architecture, followed by
the details of four subsystems: baseband, RF, antenna & feeder, and power supply
system. This chapter also covers BTS environment monitoring and lightning
protection systems.
2.1 Overview
In cdma2000 1X mobile communication system, BTS functions as a radio relay. One
end is connected with MS through Um interface and the other end connected with
BSC through Abis interface.
The architecture of BTS is as shown in Figure 2-1.
Um interface
BSC
Abis interface
BCIM
BCPM
BHPA
CDU
BTRM
RLDU
RF receive/ transmit
antenna
LMF
BFMM
RS232
Ethernet port
Emergency
serial port
Clock bus
Backplane
bus
Modem
Test interface
RS485
High-speed data bus
Optical fiber
Test
equipment
RS485
Um interface
BCKM
BRDM
...
Environment alarm RS485
collection
External
synchronization
BBFM
CDU
BTRM
RLDU
RF receive/ transmit
antenna
Optical fiber
GPS/GLONASS receive antenna
RS485
Baseband
subsystem
BHPA
BHPA
BBFM
RF subsystem
RS485
-48VDC
GND
POWER
Power supply
subsystem
Figure 2-1 BTS architecture
2-1
+27VDC
GND
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Note:
In Figure 2-1, the duplexer is CDU, and actually the right duplexer should be selected according to the
band class BTS supported. CDU applies to 800MHz band and 450MHz band, DFU applies to
450MHz band, and DDU applies to 1900MHz band, as for the difference between the CDU, DFU and
DDU, please refer to "2.3
RF Subsystem".
BTS is mainly composed of baseband subsystem, RF subsystem, antenna & feeder
subsystem (which comprises RF receive/transmit antenna and GPS/GLONASS
receive antenna) and power supply subsystem. Baseband subsystem in physical
structure also carries a clock synchronization unit, receiving GPS/GLONASS clock
and providing system time, synchronous clock and frequency reference.
I. Baseband subsystem
The main functions of baseband subsystem are: processing Abis interface protocol,
modulating/demodulating baseband data, channel encoding/decoding, processing
protocols
of
physical
layer
and
MAC
layer
on
air
interface,
system
operation/maintenance and connecting baseband data optical interface of RF
module.
Baseband subsystem is located in the BTS baseband subrack. It consists of BTS
Control & Clock Module (BCKM), BTS Resource Distribution Module (BRDM), BTS
Channel Processing Module (BCPM ), BTS Control Interface Module (BCIM ) and
CDMA Baseband Backplane Module (CBKM). Functions of all boards are
highlighted as follows:
1) BCKM
At most 2 BCKMs are configured in hot standby. BCKM receives GPS signals (or
other synchronization satellite signals), generates local clock and provides time
signals 16%1.2288MHz, 10MHz, PP2S for the boards in the system. This is mainly
the responsibility of the clock module of BCKM. Besides clock signal, BCKM also
provides main control function for channel resources. Its MPU module performs a
number of operations and functions such as resource management, equipment
management,
performance
monitoring,
configuration
management,
software
downloading, MPU active/standby switchover, operation & maintenance (O&M),
environment monitoring interface, as well as board control inside the system.
2) BRDM
BRDM is logically located between BTRM and BCPM. The data sent by BTRM
module are sent to BRDM via the optical fiber. Then BRDM distributes the data
before sending them to BCPMs via the high-speed data bus. BRDM can also build
2-2
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
daisy chains for BCPMs. The BRDM connects via the shorter daisy chain provided
to BCPM to form a standard daisy chain, which helps to improve the utilization ratio
of channel resource and facilitates the flexible configuration of channel capacity for
each sector carrier. BRDM exchanges O&M information with BCKM through the
backplane bus. The emergency serial port of BRDM is attached on the UART of the
backplane as a standby node.
3) BCPM
BCPM processes BTS baseband signals, both for the forward traffic and reverse
traffic. For forward traffic, it performs functions such as encoding (convolutional code,
TURBO code), interleaving, spectrum spreading, modulation and data multiplexing.
For reverse traffic, it performs functions such as demultiplexing, demodulation,
de-interleaving and decoding (convolutional code, TURBO code). Regarding the
user data flow, BCPM is between BRDM and BCIM.
4) BCIM
BCIM transfers data between BTS and BSC, including voices, data and O&M
commands. With the Inverse Multiplexing on ATM (IMA) technology, BCIM
multiplexes the BTS uplink data to IMA link set that is composed of multiple E1s,
and then transmits it to BSC via coaxial or optical fiber. Inversely, it can also
demultiplex the IMA link set signals from BSC into an ATM cell flow and transmit it to
BTS boards via the backplane bus.
5) CBKM
CBKM performs interconnection of high-speed data links between boards in the
baseband part and the interconnection of various management and control signals
of boards.
II. RF subsystem
BTS RF subsystem is composed of five parts: BTS Transceiver Module (BTRM),
BTS High Power Amplifier Module (BHPA ), BTS Transceiver Backplane Module
(BTBM), Duplexer Unit and Receive LNA Distribution Unit (RLDU). Functions of all
parts are briefed as follows:
1) BTRM
BTRM consists of BTS Intermediate Frequency Unit (BIF U), and BTS Radio
up/down-conversion Unit (BRCU). Its functions are as follows:
BIF U: BIFU performs such functions as A/D conversion in the reverse receiving path
and D/A conversion in the forward transmitting path, digital frequency up/down
-conversion, received signal filtering, baseband molded signal filtering, Digit
Automatic Gain Control (DAGC), uplink & downlink RF Automatic Gain Control
2-3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
(AGC), multiplexing/demultiplexing of forward & reverse orthogonal (IQ) signals,
clock recovery and RF module operation & maintenance.
BIFU also performs the control over BTRM, including power-on initialization,
function configuration, alarm collection and reporting, and processing of O&M
related messages.
BRCU: BRCU is composed of 5 logic functional units: main/diversity transmit unit,
main/diversity receive unit and frequency source unit.
Transmit unit realizes analog up-conversion and spurious suppressed filtering
for transmitted signals output by BIFU.
Main/diversity receive unit realizes analog frequency down-conversion, channel
selective filtering and rec eived nose coefficient control for BTS main/diversity
received signals output by RLDU.
Frequency source unit is responsible for the synthesis of the low phase noise,
high-stability local oscillation signals that are necessary for the analog
frequency conversion in transmit and receive paths.
2) BHPA
BHPA performs high power linear amplification for a transmitted carrier signal,
checks its own working status in real time and generates alarm. It is composed of
main signal power amplification unit and signal detection alarm unit. Signal detection
is to check whether the input is too excited, whether the temperature is too high or
whether the gain is lowered strikingly (device failure).
3) BTBM
BTBM performs structure support and signal communication between BTRM and
BHPA.
4) Duplexer Unit
There are following three types of Duplexers. They can be configured according to
actual requirements.
Combiner and Duplexer Unit (CDU): combining and filtering of two transmitting
carriers, transmitting and receiving signals duplexing and isolating, and diversity
receiving signal filtering. CDU operates at 800MHz band and 450MHz band.
Duplex er and Filter Unit (DFU): transmitting and receiving signal duplexing, isolating
and filtering of one channel, diversity receiving signal filtering. DFU operates at
450MHz band.
Dual Duplexer Unit (DDU): transmitting and receiving signals duplexing, isolating
and filtering of two channels, It does not provide combining function. DDU operates
at 1900MHz band.
2-4
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
6) RLDU
RLDU performs low noise amplification and division of the receiving signals,
providing standing wave alarm and forward power checking voltage output, checking
the physical connection of the antenna port and monitoring whether the output of
BRCU, BHPA signals is normal.
III. Antenna & feeder subsystem
BTS antenna & feeder subsystem includes two parts: RF antenna & feeder and
dual-satellite synchronization antenna & feeder. The former mainly transmits the
modulated RF signals and receives MS information while the latter provides precise
synchronization for CDMA system.
IV. Power supply subsystem
Power supply subsystem consists of power input component (EMI filter, lightning
arrester of power supply), high power DC/DC power supply module, power
distribution box, medium/low power DC/DC power supply module for boards (or
modules ).
The power supply subsystem provides power for the whole BTS.
2.2 Baseband Subsystem
2.2.1 Overview
The baseband subsystem is one of the major parts of BTS. Its structure is shown in
Figure 2-2.
2-5
User Manual
Airbridge cBTS3612 CDMA Base Station
BSC
E1
BCKM
...
BCIM
System Description
Hardware Architecture
Other functional
units
Emergency serial port
Clock bus
Backplane bus
BCPM
High-speed
data bus
BRDM
Optical fiber
BTRM
Figure 2-2 Structure of baseband subsystem
Baseband subsystem is connected with BSC through Abis interface provided by
BCIM. The transmission in this subsystem is performed through E1 trunk (The
coming version will provide STM-1 optical transmission). BRDM and BTRM are
connected by optical fiber to support RF module extended afar mode.
Baseband subsystem also provides some other interfaces through BCKM:
LMF interface: 10/100 Base-T interface, connecting Local Maintenance
Function (LMF).
Remote maintenance serial port: The interface is an RS232 serial port,
connected with PSTN via an external Modem. When OML between OMC and
BTS is interrupted, maintenance can be performed through telephone line
dial-up connection.
GPS/GLONASS antenna interface: It is used to receive clock signal from
GPS/GLONASS.
System external synchronization interface: When GPS/GLONASS is not
available, it makes the system clock synchronized with external clock.
Fan module interface: It is connected with fan module through RS485 serial
port, monitoring the fan module.
Environment alarm interface: It is connected with an external environment
alarm collection box, providing environment monitoring alarm information of the
equipment and monitoring information of the primary power supply.
Power monitoring interface: It is connected with power supply module, reporting
various alarm information of the power supply.
Test interface: It is an interface for BTS test, providing 10MHz and 2s signals.
2-6
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Baseband subsystem is physically located in the baseband subrack, powered by
power supply subsystem (in the power subrack). Boards generate their own 3.3V,
1.8V power through the distributed power supply module.
The configuration of baseband subrack (including board position) is as shown in
Figure 2-3.
1 2 3 4
5 6 7 8 9
10
11
12 13 14 15 16 17 18 19 20 21
Figure 2-3 Baseband subrack configuration
Baseband subrack supports the following boards:
BCIM: BTS control interface module, to be inserted in E1 interface slot,
providing Abis interface for connection with BSC and supporting E1/T1
transmission. In the coming version, BCIM slot can also accommodate BEOM
(BTS Electric-Optical Module) to support STM-1 optical transmission.
BCPM: BTS channel process board, processing the data of CDMA forward
channel and reverse channel.
BRDM: BTS resource distribution module, connecting BCPM and RF module,
realizing the control of resource pool for BCPM.
BCKM: BTS control & clock board, providing clock for BTS system and realizing
the control of BTS system resource.
2.2.2 Control & Clock Module (BCKM)
I. Overview
BCKM is located in the baseband subrack of BTS. BCKM performs two major
functions: main control module (MPU, Main Processing Unit) and clock module (CLK,
Clock) functions. Here MPU performs Abis interface signaling processing, O&M
management, while CLK provides reference clock signals for the whole BTS system.
Main functions of BCKM:
MPU module provides BTS system with a hardware control platform, on which
the operating system and system software are running to implement control
and management tasks of BTS system.
2-7
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Perform operation and maintenance via the backplane bus for other boards in
the baseband subrack, realizing in-band signaling communication.
Connected with Local Maintenance Function (LMF) through the 10/100M
compatible Ethernet interface.
The active/standby asynchronous serial port serves as a path for out-band
signaling backup. MPU functions as the main node and other boards function
as the standby nodes. When a fault occurs to the in-band signaling path,
signaling communication can be maintained with this standby path.
Provide an interface connected with Modem in compliance with RS232 serial
communication standard, realizing remote maintenance and monitoring in case
of OML link failure.
Connected with an external monitoring module in compliance with RS485
standard,
collecting
and
processing
the
equipment
room
environment
information (such as fire alarm/water soaking/temperature/ humidity).
CLK unit is the clock source of BTS system, providing working clock for all
boards. It provides high precision oscillation clock and can be synchronized
with an external clock (such as GPS clock).
BCKM provides active/standby switchover function, working in active/standby
mode in the system. When a fault occurs to the active BCKM, the standby
BCKM is switched to active status under the control of specific software. A fault
occurring to either MPU or CLK module of the BCKM will result in the
switchover of the whole BCKM.
II. Structure and principle
The structure of BCKM module is as shown in Figure 2-4.
Other
functional units
...
BCKM
External
communication
unit
Clock module
CBKM
MPU module
Backplane bus
module
Power supply
module
Figure 2-4 Structure of BCKM module
2-8
Backplane
bus
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
BCKM comprises the following parts:
1) MPU module
MPU controls logic circuits to initialize components. It realizes control and
management over BTS system through system software.
2) Clock module
Clock module is the clock source of BTS, providing working clock for boards. Clock
module is available in two modes: external synchronization mode (locked mode) and
free oscillation mode (holdover mode). The clock module can provide high-precision
oscillation clock (voltage control constant temperature crystal oscillator) or be
synchronized with external clock source (GPS, GLONASS, external synchronization
equipment ).
3) Backplane bus module
The communication port of the Central Processing Unit (CPU) is connected with
other boards of BTS through the backplane bus module, processing or transmitting
O&M signaling from other boards of BTS (BRDM, BCPM and BCIM ).
4) External communication module
External communication module utilizes the multiple communication control ports
provided by the main control CPU to implement functions such as LMF interface,
external monitoring
module interface, debugging interface, and out-of-band
signaling serial port.
5) Power supply module
BCKM includes two isolated secondary power supply modules, converting +27V
voltage into +5V, +3.3V and +2.5V for various modules of local board.
III. Interface
LMF interface (10/100 Base-T)
Remote maintenance serial port (RS232)
Environment alarm interface (RS485)
GPS/GLONASS antenna port
2s and 10MHz test port
Inter-board interface, and interfaces with other boards in the baseband subrack.
IV. Index
The board size is 460mm%233.35mm, powered with +27V, power consumption
<20W.
2-9
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
2.2.3 Control Interface Module (BCIM)
I. Overview
BCIM is located in BTS baseband subrack. It is a functional entity for the connection
of BTS and BSC. Its major functions are as follows:
In uplink direction, backplane bus receives O&M command from BCKM and
traffic data from BCPM, and transmit ATM cells on the multiple E1 links with
IMA technology in compliance with G.804 standards to BSC.
In downlink direction, it receives ATM cells distributed on the multiple E1 links
from BSC, multiplexes them into a single ATM cell flow with IMA technology
and finally sends them to corresponding processing boards through the
backplane bus.
Each BCIM provides 8 E1 links, which can support at most 4 IMA link sets. In
BTS, there are two BCIMs, providing physical interfaces to BSC in load sharing
mode. At most 16 E1 links can be provided.
It communicates with BSC through IMA state machine program on the local
board, and monitors the working status of E1 link and ensuring the
implementation of IMA protocol.
It transmits O&M command through backplane bus or out-band signaling serial
port, reports the status information of the local board to BCKM and provides
interface for board maintenance and network management.
II. Structure and principle
The structure of BCIM is as shown in Figure 2-5.
Data bus
RS232
Backplane
bus module
CPU module
IMA module
Control bus
Clock module
Figure 2-5 Structure of BCIM module
2-10
Power supply
module
E1
...
Backplane
bus
BCKM
BESP
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
BCIM comprises the following parts:
1) IMA module
The purpose of IMA is to inversely multiplex an ATM cell flow based on cells into
multiple physical links for transmission. Another purpose is to remotely multiplex the
cell flows transmitted on different physical connections into a single ATM cell flow.
In uplink direction, IMA module receives AAL2 traffic cells from BCPM and AAL5
signaling cells from BCKM through the backplane bus. It splits the ATM cell flow into
cells, transmits them on multiple E1 link according to G.804 standard before sending
them to BSC.
In downlink direction, it receives ATM cells from BSC that are distributed on multiple
E1 trunk lines, inversely multiplexes them into a single ATM cell flow. Then it sends
AAL2 traffic cells to BCPM and AAL5 signaling cells to BCKM through the backplane
bus
2) CPU module
The main control CPU on BCIM implements such functions as initialization of
devices on BCIM, IMA protocol processing, executing OAM function of IMA, as well
as E1 trunk line management and communication with BCKM.
3) Backplane bus module
BCIM communicates with other boards in the baseband part through the backplane
bus module, including control information communication with BCKM and traffic data
communication with BCPM.
4) Power supply module
The power supply module implements DC/DC power conversion from +27V to 3.3V.
5) Clock module
It provides working clock for the local board.
III. Interface
E1 interface
Interface with BSC
Backplane bus interface
Interface with other boards in the bas eband part.
RS-232 serial port
As an emergency serial port, it is connected with UART as a standby node, used for
communicating with BCKM when other part of the board is faulty.
2-11
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
IV. Index
The
board
size
is
460mm%233.35mm,
powered
with
+27V,
power
consumption<10W.
2.2.4 Channel Processing Module (BCPM)
I. Overview
BCPM is logically located between BRDM and E1 interface board on BTS. BCPM is
the service processing board of the system with 12 equipped in full configuration.
Data of various forward channel traffic and reverse channel traffic are processed by
this board. BCPM also processes digital signals, including encoding/decoding
baseband signals and one-time modulation and demodulation of baseband signals.
In addition, it processes high layer control signals. The main functions are as
follows:
In forward direction, after ATM cell data from the network side are processed by
the high performance processor, BCPM performs functions such as encoding
(convolutional code, TURBO code), interleaving, spread spectrum, modulation
and data multiplexing, and converts them into high-speed signals. Then the
signals are processed by a dedicated processing chip and transmitted through
the radio interface side of the channel processing board.
In reverse direction, data received by BCPM are demultiplexed, demodulated,
de-interlaced and decoded (convolutional code, TURBO code). Then under the
control of the high performance processor, the data are sent to BSC via E1
interface in the form of ATM cells.
BCPM
supports
in-board
and
inter-board
daisy
chains,
forming
resource-processing pool.
High performance processor, two kernels, internal cache, level-2 cache can be
attached externally at the same time to improve processing capacity.
II. Structure and principle
BCPM module comprises the following parts as shown in Figure 2-6:
2-12
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
BCPM
BRDM
High-speed
data bus
Data bus
Multiplex/demultiplex
module
Baseband
processing module
Control bus
Backplane
bus
Data bus
Backplane bus
module
Clock module
CPU module
RS232
BCKM
Power module
Figure 2-6 Structure of BCPM module
1) Multiplex/demultiplex module
In forward direction, baseband data in the channel processing board are multiplexed
into high-speed signals and sent to radio side in the form of differential signals. In
reverse direction, the high-speed differential signals are demultiplexed and sent to
baseband processing chip.
2) Baseband processing module
The QUALCOMM new generation processing chip is used to perform forward and
reverse baseband data processing. With the help of in-board and inter-board data
daisy chains, channel processing capability is increased greatly. Maximal 6 sectors
can be supported.
3) CPU module
The high performance control CPU on BCPM mainly processes the forward &
reverse high-speed traffic data and control data and reports board status. At the
network side, the processing module receives control signaling, receives/transmits
ATM cells and communicates with BSC through E1 interface. At the radio side, it
controls the dedicated baseband processing chip to generate orthogonal (IQ) data.
After multiplexing, the data pass BRDM as high-speed differential signals, to
implement data exchange with radio side.
2-13
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
4) Backplane bus module
BCPM communicates with other boards in the BTS baseband part through
backplane bus, including control information communication with BCKM and traffic
data communication with E1 interface board.
5) Clock module
The clock module performs double-frequency phase-locking to the clock signals
from the backplane, provides clock for boards, and drives and co-phases the clock
signals generated on the local board, to get satisfactory clock signals.
6) Power supply module
It performs DC/DC power conversion from +27V to 3.3V.
III. Interface
High-speed data bus interface
Interface with BRDM.
Backplane bus interface
Interface with other boards of baseband part
RS232 serial port
As an emergency serial port, it is connected with UART as a standby node, used for
communicating with BCKM when other part of the board is faulty.
IV. Index
The board size is 460mm%233.35mm, powered with +27V, power consumption
<30W.
2.2.5 Resource Distribution Module (BRDM)
I. Overview
BRDM is logically located between BTRM and BCPM, providing path for orthogonal
data connection (IQ) and exchange between the two so as to support the flexible
configuration relation between BCPM and BTRM. BRDM also support daisy chain
cascading between BCPMs.
Data from BTRM are sent to BRDM through optical fiber. BRDM distributes the data
before sending them to BCPMS via the high-speed data bus. BRDM can also build
daisy chains for BCPMs. BRDM connects via the short daisy chain provided to the
BCPM to form standard daisy chain. This can help to improve the utilization ratio of
2-14
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
channel resource and facilitates the flexible configuration of the channel capacity of
each sector carrier.
BRDM has the following functions and features:
Six pairs of optical interfaces provide high-speed data paths to BTRM.
When it is necessary to extend optical interfaces, BRDM board can be inserted
in BCPM slot.
16 pairs of high-speed data bus interfaces are prvoded for connection with 16
BCPM slots through the backplane.
Flexible data distribution and exchange between BTRM and BCPM are
enabled.
Flexible data exchange between BCPMs is enabled. It can be cascaded to form
daisy chains, so BCPM resource pool can be achieved. Resource pool
improves the utilization ratio of channel resource and makes the configuration
of channel capacity of each sector carrier flexible.
It exchanges O&M information with BCKM through the backplane bus or
emergency serial port.
It forwards and receives O&M information of BTRM via optical fiber and
provides O&M link between the baseband subrack and BTRM.
II. Structure and principle
The structure of BRDM module is as shown in Figure 2-7.
BRDM
BTRM
BTRM
BTRM
BTRM
BTRM
BTRM
Optical
Optical
Optical
Optical
module
Optical
module
High-speed
data
interface
Optical
module
Optical
Optical
module
Optical
Optical
module
Optical
High-speed
data
interface
Switching
module
High-speed
data
interface
High-speed
data
interface
High-speed
data
interface
Optical
module
Power supply
module
High-speed
data
interface
CPU
module
Clock
module
Figure 2-7 Structure of BRDM module
2-15
Bus
interface
module
4 high-speed
data buses
4 high-speed
data buses
4 high-speed
data buses
4 high-speed
data buses
BCPM
BCPM
BCPM
BCPM
Backplane
bus
RS232
BCKM
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
As shown in Figure 2-7, BRDM board is composed of optical module, high-speed
data interface module, switching module, CPU module, bus interface module, power
supply module and clock module.
Optical module
This module converts optical signal into electrical signal.
BRDM can be classified into single-mode BRDM and multi-mode BRDM according
to different type of optical module. The single-mode BRDM can be further classified
into two kinds, namely 10km and 70km, according to the transmission capability of
the optical module.
The multi-mode BRDM is used to connect with BTRM in the cabinet, while the
single-mode BRDM is used to cascade SoftSite (ODU3601C).
Equipped with 6 optical modules, the multi-mode BRDM provides 6 pairs of optical
fiber ports. Equipped with 3 optical modules, the single-mode BRDM provides 3
pairs of optical fiber ports.
High-speed data interface module
High-speed data interface module mainly performs rate conversion of high-speed
signals, for the convenient processing of the switching module.
Switching module
Switching module segments and paste data as required. It is a core processing
module of this board. Data from BTRM are sent to this board, where the switching
module will distribute and paste them before sending to BCPM. The switching
module can also provide daisy chain cascading for the BCPMs through the
distribution and pasting of data.
CPU module
CPU module processes O&M information and configures switching parameters. The
O&M information from BCKM is sent to this board via the bus interface module.
Then CPU module processes the information and sends the necessary O&M
information to the corresponding BTRMs. The parameters of the switching module
should also be configured by CPU module.
Bus interface module
This module performs conversion of interface between the board and the backplane,
and provides a path for the O&M information between this board and the backplane.
Power supply module
This module converts the input DC +27V power into digital +3.3V, +1.8V and analog
+3.3V powers for the modules on the local board.
2-16
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Clock module
The clock module provides 2S, 16%1.2288MHz, 100%1.2288MHz clocks for the local
board.
III. Interface
Optical interface
They are on the front panel, 6 pairs altogether. They are connected with BTRMs,
transmitting orthogonal (IQ) data and O&M information.
High-speed data interface
The interfaces are connected with 16 service slots through the backplane, for
transmitting orthogonal (IQ) data.
Backplane bus interface
It is used for transmitting O&M information between the BCKMs.
Clock interface
It is connected with BCKM via the backplane. It receives 2S, 16 %1.2288MHz clock
signals and clock active/standby selection signal.
RS232 serial port
As an emergency serial port, it is connected with UART as a standby node, used for
communicating with BCKM when other part of the board is faulty.
Power interface
Led out from the power connector on the backplane, the interface is connected with
+27V power, +27V power ground and PGND.
IV. Index
The
board
size
is
460mm%233.35mm,
powered
with
+27V,
power
consumption<45W.
2.2.6 Baseband Backplane Module (CBKM)
I. Overview
CBKM is used to make interconnection of high-speed data links among the boards
of baseband part, and exchanges various management and control information of
boards with high-speed backplane technology.
Specifically, the backplane:
Realizes interconnection of various signals between boards.
Supports hot plug/unplug of all boards.
Supports active/standby switchover of BCKM.
2-17
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Leads in system power and provides distributed power to all boards.
Leads in the signal monitoring line for fan subrack and power subrack.
Provides protection against misplug.
II. Structure
Functional units in CBKM are as shown in Figure 2-8.
2 3 4
B B B B B
C C C C C
I I P P P
M M M M M
5 6 7 8 9
10
11
12 13 14 15 16 17 18 19 20 21
Figure 2-8 Functional units of all slots in CBKM
A backplane includes the connector and board slot.
Connector part includes a slot for test board, input connector of backplane +27V
power/ground, and 3 DB37 D-connectors. Power input connector, D-connector are
all crimped devices.
Slots of the backplane are defined as follows:
Slots 0~1 are for BCIMs.
Sots 10~11 are for BCKMs.
Slots 8~9, 12~ 13, 20~21 are for BRDMs.
Slots 2~7, 14~ 19 are for BCPMs.
III. Interface
The interfaces between the backplane and external devices include:
System power interface
Remote maintenance serial port
Environment alarm interface
Fan alarm serial port in baseband subrack
System external synchronization interface
16 E1 interfaces
IV. Index
CBKM size: 664mm%262mm.
2-18
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
2.2.7 E1 Surge Protector (BESP)
I. Overview
BESP is placed in the upper part of BTS. It is a functional entity for BTS to
implement lightning protection with E1 trunk line. Two identical BESPs are installed
for each cabinet in consideration of limited space on top of the equipment and the
convenience of installation and dismounting. The 8 pairs of lightning protection units
are used to discharge the transient high voltage on the sheath and core of E1 trunk
line to PGND.
II. Structure and principle
Board structure is as shown in Figure 2-9.
BESP
Level-2
Level-1
protection protection
PGND
Level-2
Level-1
protection protection
Interface
DB25
...
4 E1s
BSC
PGND
Interface
DB37
Interface
DB25
...
4 E1s
...
BCIM
...
8 E1s
BSC
Level-2 Level-1
protection protection
PGND
Figure 2-9 Structure of BESP
The board consists of three parts: DB25 connector, lightning protection unit and
DB37 connector.
When the BTS E1 trunk line is struck by the lightning, high voltage will arise first on
DB25. The high voltage will spread to the lightning protection units. The lightning
protection units have two protection levels: air discharge tube and voltage limit mesh.
2-19
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
The air discharge tube discharges the high voltage to the ground and lowers the
voltage to less than 600V. Then the voltage limit mesh further lowers the voltage to
less than 30V.
III. Interface
E1interface
Interface with BSC (DB25).
Connection with BCIM (DB37)
IV. Index
Board size: 140mm%120mm
Bearable surge current: >10kA (common mode), >5KA (differential mode)
Output residual voltage: <30V.
2.2.8 Fan Module (BFAN)
BFAN is installed right under the baseband subrack, serving as a part of the blower
type cooling system of the baseband subrack. The fan module consists of two fan
boxes, each of which has 4 fan units (24V DC brush-free fan), and one BTS Fan
Monitor Module (BFMM). Fan enclosure is used for installation of fan boxes. The
outside of the fan enclosure is the BTS Fan Block Interface Board (BFNB) that
provides a system interface. The structure of BFAN is as shown in Figure 2-10.
2-20
User Manual
Airbridge cBTS3612 CDMA Base Station
(1) Fan box 2
(4) Fan enclosure
(7) Power input interface
(2) Fan box 1
(5) BFNB
(8) Blind mate connector
System Description
Hardware Architecture
(3) LED indicator
(6) System signal interface
(9) BFMM
Figure 2-10 Structure of BFAN
I. BTS Fan Monitor Module (BFMM)
1) Overview
BFMM is built in the fan box. It communicates with BCKM and receives instructions
from BCKM. It can perform PWM speed adjustment on the fan units and report
board status information to BCKM when it is queried. BFMM can guarantee a safe
and proper cooling system and lower system noise. Its main functions are as
follows:
Control rotating speed of the fans.
Check whether fan units are in position and report their information.
Check and report fan unit blocking alarm.
Drive fan operating status indicator.
Communicate with the Main Control Unit (MCU) of BCKM and report in-board
status information.
2) Structure and principle
BFMM's position is as shown in Figure 2-10. Its function is as shown in Figure 2-11.
2-21
User Manual
Airbridge cBTS3612 CDMA Base Station
Temperature collection module
Communication module
System Description
Hardware Architecture
Fan drive module
Main control unit
Fan-in-position & fault
detection module
Switch value alarm module
Indicator drive module
Power supply module
Figure 2-11 Illustration of BFMM
Power supply module:
System input DC power is +27V, board power consumption is less than 5W.
Main Control Unit (MCU):
MCU controls the fans and communicates with BCKM. Specifically, it generates
control PWM signal according to the instruction sent from BCKM to control the
speed of fans. MCU can also detect fan alarm signal and in-board logic alarm signal,
and report them to BCKM. It generates panel indicator signal.
Communication module:
It performs serial communication with BCKM.
Fan driving module:
PWM control signal generated in MCU provides controlled power input for fans by
isolating driving circuits.
Fan in position and fault detection module:
This module isolates the fan-in-position signal and fan blocking alarm signal, then
convert them into logic level for MCU to sample and analyze.
Temperature collection module:
The module collects the ambient temperature information of BFMM in real time,
which is realized by MCU in query operation.
Indicator driving module:
When functional alarm (such as communication interruption in main control mode)
occurs to the board or fan blocking alarm occurs to the motor, this module provides
LED optical alarm interface inside the fan block, to drive the LED indicator on the
fan block front panel.
2-22
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
3) Interface
Power interface
It is used to lead in working power for BFMM.
Communication serial port 0, 1
Serial port communication ports 0 and 1 provide access for system active/standby
serial port. When the system has only one serial port, only port 0 is used.
LED indicator driving output interface
This is the driving interface for LED status indicator on the panel of the fan box.
Fan unit driving interface
Maximally 6 such interfaces are provided. They also serve as the interfaces for
fan-in-position detection and fan blocked detection.
4) Index
The size of BFMM: 280mm%35mm.
+27V power supply, power consumption <5W.
II. BTS Fan block iNterface Board (BFNB)
1) Overview
BFNB provides electrical connection between the fan box and the system. On one
hand, it provides blind mate interface for the fan box. On the other hand, it provides
the system with power interface and serial communication interface.
2) Structure and principle
BFNB's position is shown in Figure 2-10.
BFNB implements interface conversion function. Refer to "3) Interface" for the
definition of interface.
BFNB's structure is shown in Figure 2-12.
(1) MOLEX connector
(2) Large 3PIN power socket
Figure 2-12 Illustration of BFNB structure
2-23
(3) DB-15 signal socket
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
3) Interface
Fan box electrical interface
Power supply ports and serial port communication ports are provided for the two fan
boxes through MOLEX connectors.
System power supply interface
The interface leads in system power through big 3-pin connector.
System serial communication interface
External serial communication interface is provided through DB -15.
4) Index
The size of BFNB: 380mm%30mm.
2.3 RF Subsystem
2.3.1 Overview
The structure of RF subsystem is as shown in Figure 2-13.
To antenna &
feeder
f1
BRDM
BTRM
BHPA
DFU
To antenna &
feeder
f0
BRDM
BTRM
BHPA
CDU
f2
BRDM
BTRM
BHPA
RLDU
BRDM: Resource Distribution Module
CDU: Combining Duplexer Unit
BTRM: Transceiver Module
DFU: Duplexer Filter Unit
Figure 2-13 Structure of RF subsystem
2-24
BHPA: High Power Amplifier Unit
RLDU: Receive LNA Distribution Unit
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Note:
The above figure illustrates the RF configuration for 450MHz band. For 800MHz band, the duplexer
would be CDU. For 1900MHz band, the duplexer would be DDU.
In forward link, it performs power adjustable up-conversion and linear power
amplification to the modulated transmission signals, filtering the transmission signals
to meet the corresponding air interface standard.
In reverse link, it filters the signals received by the BTS antenna to suppress
out-band interference, and then performs low-noise amplification, noise factor
adjustable frequency down-conversion, and channel selective filtering.
2.3.2 BTS Transceiver Module (BTRM)
BTRM is in charge of modulating/demodulating of baseband signal, Analog/Digital
and Digital/Analog (AD/DA) conversion, digital up/down conversion and radio
up/down conversion.
I. Structure and principle
BTRM consists of BTS Intermediate Frequency Unit (BIFU) and BTS Radio up-down
Converter Unit (BRCU). Its structure is shown in Figure 2-14.
BIFU
BRCU
BHPA
BHPA
PSU
PSU
Demultiplexer/multiplexer
Optical interface
BTRM
CPU
FIR
DAGC
Clock
Down
converter
ADC
Filter
Down
converter
ADC
Filter
Main receiver
RLDU
Diversity receiver
RLDU
Local oscillator
FIR
+27V
Up
converter
DAC
Filter
Transmitter
Power
Figure 2-14 Structure of BTRM
2-25
BHPA
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
1) BTS Intermediate Frequency Unit (BIFU)
BIFU consists of up-c onverter, down-converter, multiplexer/demultiplexer, optical
interface, clock, CPU, and power supply sub-unit. It is in charge of the conversion
between the analog intermediate frequency signals and the digital baseband signals,
and the control of the MTRB. The functions of each sub-unit are as below:
Up-converter
The up-converter accomplishes the wave filtering, digital up-conversion and
digital-analog conversion of the signals in the transmit path.
On receiving the baseband I/Q signals that have been de-multiplexed, it performs
digital up-conversion after baseband filtering. Then the digital intermediate
frequency signals are converted into analog intermediate frequency signals after
digital-analog conversion and wave filtering. At last, the analog intermediate
frequency signals are sent to the transmitter in BRCU via radio frequency (RF)
interface. BRCU.
The
Down-converter
down-converter
accomplishes
the
analog-digital
conversion,
digital
down-conversion and baseband filtering of the signals in the receive path.
On receiving the analog intermediate frequency signals via the radio interface, it
converts them into digital intermediate frequency signals via analog-digital
conversion. Then the digital intermediate frequency signals are converted into
baseband I/Q signals via digital down-conversion and baseband filtering. As last, the
I/Q signals are transmitted to the demultiplexer/multiplexer.
Demultiplexer/multiplexer
Under the control of the CPU, the demultiplexer/multiplexer de-multiplexes the
forward I/Q signals, and multiplexes the reverse I/Q signals. At the same time, it
multiplexes/de-multiplexes the operation & maintenance (O&M) signals of the OML.
Optical interface
The optical interface performs channel coding and decoding, and accomplishes
optical-electrical signal conversion and electrical-optical signal conversion. It is the
interface between the BIFU and the BRDM of the upper-level BTS, and the interface
between the BIFU and the MTRM (Micro-bts Transceiver Module) in the lower-level
SoftSite.
Clock
The clock generates all the clocks needed by the BIFU, which include the clocks for
up/down conversion, analog-digital conversion (ADC), and digital-analog conversion
(DAC), and other working clocks. At the same time, it also provides the reference
clock for the BRCU.
2-26
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
CPU
The CPU is in charge of the control of BTRM, which includes the initialization upon
power-on, alarm collecting and reporting, and processing operation & maintenance
related messages.
Power supply
With input voltage of +27V, the power supply sub-unit provides power supply to
BIFU and BRCU.
2) BTS Radio up-down Converter Unit (BRCU)
BRCU consists of transmitter, main/diversity receiver and local oscillator. It
up-converts, amplifies the intermediate frequency signals output by BIFU, and
performs
spuriousness-suppression
wave
filtering.
It
also
performs
analog
down-conversion, amplification of BTS main/diversity receiving signal input from the
RLDU, and channel-selection wave filtering. The functions of each sub-unit are as
below．
Transmitter
When receiving the modulated analog intermediate frequency signals output by
BIFU, the transmitter converts them to specified RF band via two times of
up-conversions.
Before
and
after
the
up-conversion,
wave
filtering,
signal
amplification and power control are performed, so as to ensure the RF signals
output meet the protocol requirements on power level, Adjacent Channel Power
Radio (ACPR) and spuriousness.
Main/diversity receiver
It converts the RF signals output by RLDU to specified intermediate frequency
signals via down-conversion, and performs wave filtering, signal amplification and
power control before/after the down-conversion, so as to ensure the intermediate
frequency signals output can be received by BIFU.
Local oscillator
It consists of the intermediate frequency source and transmit/receive RF synthesizer.
The intermediate frequency source generates the local frequency signals for
intermediate frequency up-conversion in transmit path. The RF synthesizer
generates the local frequency signals for the up-conversion of the transmit path and
the local frequency signals for the down-conversion of main/diversity receive path.
II. Interface
There
are
interfaces
between
BTRM
and
descriptions of each interface are given as below:
2-27
BHPA/ RLDU/BRDM/PSU.
The
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
BTRM -BHPA RF interface
The RF transmitting signal is output via this interface to BHPA, where the signal is
amplified and then outputted.
BTRM -BHPA RS485 interface
This interface is used to transfer alarm and control signal, and power detection
signal.
BTRM -RLDU RF interface
The main/diversity RF receiving signal output by RLDU is received via this interface.
BTRM -BRDM optical interface
Baseband data are transmitted or received via this interface.
+27V power supply interface
This interface is used to provide power supply to BTRM.
III. Index
Supported frequency band: 450MHz band, 800MHz band, 1900MHz band
Power supply: +27V
Power consumption: 51W
Module size: L%W%T=460mm%233.5mm%64mm
2.3.3 BTS High Power Amplifier Module (BHPA)
I. Overview
BHPA is located in RF subrack of BTS cabinet, and used for amplifying the RF
modulation signals output by BTRM. Its main functions are:
RF power amplification: perform power amplification for the RF modulation
signals from BTRM.
Over-temperature alarm: when the temperature of power amplifier base board
exceeds a specified threshold, BBFM will process the over-temperature alarm
signal generated by HPAU and report it to BTRM.
Over-excited alarm: when the power level of BHPA input RF signal exceeds a
specified threshold, BBFM will process the over-excited alarm signal generated
by HPAU and report it to BTRM.
Gain decrease alarm: when the gain of the power amplifier drops over 6dB,
BBFM will process the gain decrease alarm signal generated by HPAU and
report it to BTRM.
Fan monitoring: BBFM is installed in BHPA, performing such functions as fan
alarm and power amplifier alarm signal processing & reporting, and fan speed
adjustment.
2-28
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
II. Structure and principle
The structure of BHPA module includes the following parts, as shown in Figure 2-15:
RF input
BTRM
Power
amplification
Coupler
Circulator
RF output
CDU
Sampling
port
HPAUz
Alarm
circuit
BDCS
+27VDC
Alarm signal
BBFM
BHPA
Alarm signal
BTBM
BTRM
Figure 2-15 Block diagram of BHPA module
1) High Power Amplifier Unit (HPAU)
HPAU mainly consists of two parts: power amplifier and alarm circuit. The power
amplifier amplifies the RF signals from BTRM. The amplified RF signals are then
sent to CDU or DFU via BTBM. Alarm circuit monitors the power amplifier status and
generates over-temperature alarm, over-excited alarm and gain decrease alarm
signals when necessary. The alarm signals will be sent to BBFM, where they will be
processed and reported to BTBM. The coupler is used to couple the RF output
signals to the sampling port for test purpose.
The output power of HPAU can be adjusted by controlling the RF output signal of
BTRM.
2) BTS BTRM Fan Monitor (BBFM)
BBFM processes fan alarm signals and power amplifier alarm signals, and sends
them to BTRM via BTBM, and then BTRM will report them to upper level. BBFM can
adjust the fan speed based on the ambient temperature and the actual BHPA output
power in order to lower the noise of fans.
III. Interface
External interfaces of the BHPA module are D-type combination blind mate
connectors, including:
2-29
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
RF interface
The RF interface of BHPA has one input port and one output port. They are
connected respectively with BTRM RF output port via BTBM and CDU/DFU/DDU RF
input port via coaxial cable.
Power supply interface
Interface with BTS Direct Current Switch box (BDCS).
Alarm interface
Interface with BTRM. Fan alarm signals and power amplifier alarm signals are sent
via BTBM to BTRM.
IV. Index
Supported frequency band: 450MHz band, 800MHz band, 1900MHz band
Max. average output power: ¦ 40W (for 450MHz band and 1900MHz band)
¦ 30W (for 800MHz band)
Power supply: +27V
Power consumption: <380W
Module size: L%W%T=460mm%233.5mm%64mm
2.3.4 BTS Transceiver Backplane Module (BTBM)
BTBM interconnects six BTRMs and six BHPAs. It provides six sets of 2mm
connectors for BTRM, six sets of 24W7 combination D-type blind mate connectors
for BHPA, and three DB9 connectors for RLDU alarm collection, and six sets of
temperature sensors.
The above parts form three independent function groups, as shown in Figure 2-18.
BTRM 2mm connector
Each set of 2mm connectors includes one 5%22pin A-connector and three 3-socketN-connectors. A-connector transfers RLDU alarm signals from DB9 connector and
RS485 interface message from BHPA 24W7 combination D-connector. N-connector
transfers the main/diversity input/ output RF signal of BTRM and +27V DC power
signal needed by BTRM.
BHPA 24W7 D-type combination blind mate connector
Each 24W7 D-type combination blind mate connector includes 2 coaxial contacts
(transferring BHPA input/output
RF signals), 2 high-current
power contacts
(transferring +27V power supply and PGND signals), one set of RS485 signal
contacts and a group of contacts for temperature sensor signals.
DB9 connector
There are 3 angled DB9 connectors on BTBM for 3 RLDUs alarm signals transferred
to BTRM.
2-30
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Temperature sensor
There are 6 temperature sensors for the 6 BHPA slots, used for sensing the air
temperature at each BHPA air outlet. They will convert the information into current
and send to BFMM on BHPA for processing. In this way, fan speed is controlled in
real time.
RS485
RS485
2mmA/N
connector
24W7DB
connector
RS485
Temperature sensor
RS485
Temperature sensor
RLDU alarm signal
DB9 connector
Functional group 1
Figure 2-16 Functional blocks of BTBM
Index
Board size: L%W%T= 664mm%262mm%3mm
2.3.5 Combining Duplexer Unit (CDU)
I. Overview
CDU mainly has the following functions:
Combine two carrier signals from the two BHPAs into one signal.
Isolation and filtering of receiving and transmitting signals.
Filtering of transmitting signals so as to suppress BTS spurious emissions.
Filtering of receiving signals so as to suppress the interference from outside the
receive band.
Key internal parts of CDU include isolator, 2-in-1 combiner, duplexer, and directional
coupler.
II. Structure and principle
CDU structure is as shown in Figure 2-17.
2-31
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Pr-OUT
Pf-OUT
TX1
Isolator
TX2
Isolator
Combiner
Duplexer
Directional
coupler
RXM-OUT
TX/RXM-ANT
TX-Test
RXM-Test
Figure 2-17 Structure of CDU
Isolator
There are two isolators at each input port of the combiner in CDU. They are used to
isolate the two carriers from two input ports.
2-in-1 combiner
The combiner is a narrow band cavity filtering combiner. In comparison with
broadband combiner, it features lower insertion loss and effective isolation.
Duplexer
The duplexer is used to isolate transmitted signals and received signals, suppress
transmission spurious and reduce antenna quantity.
Directional coupler
The directional coupler couples forward/reverse power to RLDU, and monitors the
antenna VSWR.
III. Interface
CDU is a module shared by transmit and receive path of the BTS. It has interfaces
with other modules both in the transmitting and receiving paths. Its external
interfaces include a set of 8W8 D-type combination blind mate connectors on the
backside, and a set of N-connectors and SMA connectors on the front side. The
interface signals include:
2-32
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
RF signals between CDU combiner input ports and BHPA output ports. They
are transferred through the blind mate connectors on the backside.
BTS transmitting signals, which are transferred to the cabinet-top antenna
interface through the RF cable connected with the N-connector at the front side
of CDU.
BTS receiving signals, which are transferred from the cabinet-top antenna
interface through the RF cable connected with the N-connector on the front side
of CDU.
BTS receiving signals output from the duplexer. They are sent to RLDU via the
blind mate connector on the backside.
Forward/reverse coupled RF signals, which are sent to RLDU via the blind
mate connector on the backside.
Forward/reverse coupled test signals, which are outputted through the standard
SMA connector on the front side of CDU.
IV. Index
Number of combined channels: 2
Supported frequency band: 450MHz band, 800MHz band
Module size: L%W%H=450mm%100mm%344.8mm
2.3.6 Duplexer Filter Unit (DFU)
I. Overview
DFU mainly fulfills the following functions:
Isolation and filtering of transmitting and receiving signals for the single carrier.
Filtering of diversity receiving
signals in order to suppress out-band
interference.
Key parts of DFU includes low-pass filter, duplexer, diversity receive filter and
directional coupler.
II. Structure and principle
DFU structure is shown in Figure 2-18.
2-33
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
S RXD-TEST
Low-pass filter Diversity receive filter
RXD-OUT
N RXD-ANT
Low-pass filter
TX
S TX-TEST
Duplexer
Directional coupler
N TX/RXM-ANT
RXM-OUT
Pf-OUT
Pr-OUT
S RXM-TEST
D-SUB
N N-Type
SMA-Type
Figure 2-18 Structure of DFU
Low-pass filter
At the transmitting signal input port and main/diversity receiving signal output port,
there are three low-pass filters used for low-pass filtering of transmitting and
main/diversity receiving signals.
Duplexer
The duplexer is used to isolate transmitting and receiving signals, suppress
transmission spurious and reduce antenna quantity.
Diversity receive filter
The diversity receive filter of DFU is a separate path. Signals received by the
diversity antenna must be filtered by the diversity receive filter in DFU before being
sent to the low-noise amplifier in RLDU for amplification.
Directional coupler
The directional coupler couples forward/reverse power for RLDU, and monitors the
antenna VSWR.
III. Interface
DFU is a module shared by transmit and receive path of the BTS. It has interfaces
with other modules in the transmit and receive paths. Its external interfaces include
a set of 8W8 D-type combination blind mate connectors on the backside, and a set
of N connectors and SMA connectors on the front side. The interface signals
include:
The signals between DFU and BHPA, which are transferred through the blind
mate connectors on the backside.
2-34
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
BTS transmitting signals, which are transferred to the cabinet-top antenna
interface through the RF cable connected with the N-connector at the front side
of the module.
BTS receiving signals, which are transferred from the cabinet-top antenna
interface to DFU for filtering through the RF cable connected with the
N-connector on the front side of the module.
BTS receiving signals output from the duplexer and diversity receive filter. They
are sent to RLDU via the blind mate connector on the backside.
Forward/reverse coupled RF signals, which are sent to RLDU via the blind
mate connectors on the backside.
Forward/reverse coupled test signals, which are outputted through the standard
SMA connector on the front side.
IV. Index
Supported frequency band: 450MHz band
Module size: L%W%H=450mm%100mm%344.8mm
2.3.7 Dual Duplexer Unit (DDU)
I. Overview
DDU completes the following functions:
Isolation and low-pass filtering of two receiving and transmitting signals.
Providing two DC feeds to T-type tower-top amplifier.
Voltage Standing Wave Ratio (VSWR) test on transmit channels in both
forward and backward directions.
Coupling test of transmitting and receiving signals.
Key components within DDU include Bias-T DC feed connector, low-pass filter,
duplexer, and bi-directional coupler.
II. Structure and principle
DDU structure is shown in Figure 2-19.
2-35
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Pr1-OUT D
Pf1-OUT D
BIAS T
TX1 D
BIAS T
LPF
COUPLER
RXM-OUT D
TX1-TEST
TX/RXM-ANT
RXM-TEST
DUPLEXER
LPF
Pr2-OUT D
Pf2-OUT D
TX2 D
BIAS T
BIAS T
LPF
COUPLER
RXD-OUT D
LPF
D-SUB
TX2-TEST
TX/RXD-ANT
RXD-TEST
DUPLEXER
N N-Type
S SMA-Type
Figure 2-19 Structure of DDU
Low-pass filter
The low-pass filter is used to suppress the high-order harmonic wave. The low-pass
filter on receive channel also functions to suppress the interference from the
transmit channel.
Duplexer
The duplexer is used to isolate transmitting signals and receiving signals, suppress
transmission spurious and reduce antenna quantity.
Bi-directional coupler
The bi-directional coupler couples forward/reverse power for RLDU, and monitors
the antenna VSWR.
T-type feed connector
This connector receives the RF signals and divides/combines DC feeds, so that the
RF signals and DC go through different channels, realizing the DC supply to the
tower-top amplifier.
III. Interface
DDU is a module shared by the transmitting and receiving paths of the BTS. It has
interfaces with other modules both in the transmitting and receiving paths. Its
external interfaces include a set of 8W8 DB combination blind mate connectors on
the backside, and a set of N-connectors and SMA connectors on the front. The
interface signals include:
2-36
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Signals between transmit input port and BHPA port. They are transferred
through the blind mate connectors on the back side.
Transmitting signals, which are transferred to the cabinet -top antenna port
through the RF cable connected with the N-connector at the front side of DDU.
Receiving input signals, which are transferred from the cabinet-top antenna port
through the RF cable connected with the N-connector on the front side of DDU.
Signals output from the receive filter. They are sent to RLDU via the blind mate
connector on the back side.
Transmitting forward/reverse coupled RF signals, which are sent to RLDU via
the blind mate connector on the back side.
Transmitting and receiving coupled test signals, which are outputted through
the standard SMA connector on the front side of DDU.
IV. Index
Supported frequency band: 1900MHz band
Module size: L%W%T=450mm%100mm%344.8mm
2.3.8 Receive LNA Distribution Unit (RLDU)
I. Overview
RLDU consists of Low Noise Amplifier), distribution unit, configuration switch and
alarm monitoring circuit. Its main functions are:
Low noise amplification and distribution for BTS receiving signals.
Built-in electronic RF switch supports multiple BTS configurations (3 sectors or
6 sectors).
Antenna VSWR monitoring and alarming, BTS forward RF power detecting,
LNA running status monitoring and alarming.
II. Structure and principle
RLDU structure is shown in Figure 2-20.
2-37
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
RXBD-IN
RXBM-IN
RXAD-IN
RXAM-IN
RXAM-TEST
VSWR and power
check
RXBM-TEST
APf-IN
APr-IN
BPf-IN
BPr-IN
RXAM1
RXAM2
RXAD1
Switch distribution
module
LNA
module
RXAD2
RXAM3/RXBM1
RXAM4/RXBM2
RXAD3/RXBD1
RXAD4/RXBD2
Power supply
DC-IN
PWR
S/W
VSWR check processing
Forward power output
DB15
Figure 2-20 Structure of RLDU
1) Receiving signal low noise amplification and distribution unit
There are 4 LNAs and distributors inside RLDU, which can process 4 signals. The 4
LNAs have the same specifications such as gain, noise factor and dynamic, so the 4
receive paths are balanced.
2) Configuration switch unit
The electronic switches inside RLDU are designed for supporting different BTS
configurations. When the BTS is configured in 3-sector mode, the electronic
switches can be set to make RLDU operate in a single-sector mode that has two
main/diversity receiving paths (Each path provides 1-in-4 output to support 1~4
carriers configuration for each sector). When the BTS is configured in 6-sector mode,
the electronic switches can be set to make RLDU operate in two-sector mode each
of which having 4 main/diversity receive paths (Each path provides 1-in-2 output,
supporting 1~2 carriers configuration for each sector).
3) Antenna VSWR and LNA status monitoring unit
The transmitted forward/reverse power coupling signals from CDU or DFU or DDU
are processed in the antenna VSWR monitoring circuit inside RLDU. When the
VSWR of transmitting antenna exceeds a specified threshold, alarm will occur. At
the same time, RLDU also converts transmit coupling power signal into DC level
signal through its RF power detecting circuits. Through this DC level signal, any
2-38
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
exception of transmit signal power of antenna can be monitored in real time. LNA
status monitoring circuit monitors the voltage and current of the 4 LNAs inside
RLDU. It gives alarm when fault t is found.
III. Interface
RLDU is the reverse link function module of the BTS, which interfaces with
CDU/DFU and BTRM in both input side and output side through the two sets of 8W8
D-type combination blind mate connectors on the backside of the module.
1) Interface signals between RLDU and CDU/DFU/DDU are:
Main/diversity path receiving RF signals outputted from two CDU/DFU/DDU
receive filters. They are amplified and distributed by RLDU.
CDU/DFU/DDU coupling RF signal, which are used for antenna VSWR
monitoring and forward power detecting.
2) Interface signals between RLDU and BTRM are:
Main/diversity path receiving RF signals transmitted to BTRM after being
amplified and distributed.
Antenna VSWR, LNA status monitoring alarm signals and forward power
detecting voltage signals, which are outputted to BRCU by RLDU through a
DB15 interface on the front side of the module and transferred to BIFU for
processing.
3) The +27V DC power is necessary for RLDU. It is provided directly by the
secondary power supply module in the BTS through a MOLEX power connector on
the front side of the module.
IV. Index
Supported frequency band: 450MHz band, 800MHz band, 1900MHz band
Power supply: +27VDC
Power consumption <50W
Module size: L%W%H= 450mm%180mm%50mm
2.3.9 BTS RF Fan Module (BRFM)
BRFM mainly consists of BBFM, BBFL and fans. The following is the introduction to
BBFM and BBFL.
I. BTS BTRM FAN Monitor (BBFM)
1) Overview
BBFM collects and analyzes the temperature information of BHPA module and
adjust the fan speed in real time to lower the system noise, so as to prolong
2-39
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
equipment service life and improve the external performance of the overall system
on the premise that the system works in a safe thermal status. The Pulse Wide
Modulation (PWM) control signal regarding the fan speed can be generated by the
MCU of the local board or configured by the control unit of BTRM module. At the
same time, BBFM reports to BCKM the gain decrease, over-temperature,
over-excited alarm and fan failure alarm of BHPA, to ensure the reliability of BHPA
module. Specifically, it functions to:
Control fan speed, monitor and report fan alarm.
Monitor and report BHPA alarm.
Drive fan monitor indicator module.
Collect temperature information of BHPA module.
Communicate with BTRM module.
2) Structure and principle
BBFM
BHPA
Figure 2-21 Position of BBFM in BHPA module
The structure of BBFM is shown in Figure 2-22.
2-40
Blind mate
connector
Fan cover
The position of BBFM in BHPA module is as shown in Figure 2-21.
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
BBFM
HPAU
Interface
circuit
Panel indicator
driving alarm
signal isolation
circuit
Temperature
collection
PWM
Modulation
circuit
BHPA
MCU
External
temperature
collection
Communication
interface
Watchdog
Fan cover
Serial port
BTRM
Figure 2-22 Structure of BBFM module
MCU module
The MCU module collects and analyzes the temperature information to generate
PWM signal for controlling the fan speed, receives alarm signals generated by
BHPA module and fan alarm signals and reports to BTRM module, generates panel
indicator signal and communicates with BTRM module.
BHPA interface module
This moduloe isolates and drives the interface with BHPA.
Temperature information collection module
This module collects the temperature information of BHPA module in real time,
which is implemented by MCU in query operation.
Panel indicator driving and alarm signal isolation module
It is used to drive the panel indicator and isolate fan alarm signals.
Communication module
The module performs serial communication with BTRM module.
Power supply module
The input power of BFMM is +27V, power consumption is 3.5W (including power for
the fans ).
3) Interface
BHPA interface
Interface with BHPA module, used for BHPA alarm monitoring.
Serial communication interface
Interface used to report the alarm of the fans and BHPA module.
2-41
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Interface with the fan cover
Including fan alarm signal, panel indicator, and fan power interface.
4) Index
Size of BBFM: 200.0mm%55.0mm.
II. BTS BTRM FAN Lamp Module (BBFL)
1) Overview
BBFL has three RUN indicators to indicate the running status of BTRM module, fans
and BHPA module. The board is connected with BBFM via the fan cover interface. It
is an auxiliary board.
2) Structure and principle
The structure of BBFL is shown in Figure 2-23.
BTRM indicator
LED1
LED2
LED3
Fan 2 interface
Fan 1 interface
FAN indicator
BHPA indicator
Fan cover port (connect to BBFM)
Figure 2-23 Structure of BBFL module
BBFL consists of the following parts:
Fan 1 interface module
It is a 4pin ordinary socket connector connected with Fan 1, including power supply
input port and fan alarm output port.
Fan 2 interface module
It is a 4pin ordinary socket connector connected with Fan 2, including power supply
input port and fan alarm output port,
2-42
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Fan cover port interface module
It is connected with the fan cover of BBFM.
3) Panel indicator
LED1: BTRM operating signal
LED2: Fan operating signal
LED3: BHPA operating signal
4) Index
Size of BBFL: 55.0mm%25.0mm.
2.4 Antenna & Feeder Subsystem
2.4.1 Overview
BTS antenna & feeder subsystem consists of two parts: RF antenna & feeder, and
dual-satellite synchronization antenna & feeder. The former transmits the modulated
RF signals
and
receives
MS
signals,
while
the
latter
provides
precise
synchronization for CDMA system.
2.4.2 RF Antenna & Feeder
RF antenna & feeder of the BTS is composed of outdoor antenna, jumper from
antenna to feeder, feeder, and the jumper from feeder to cabinet -top, as shown in
Figure 2-24.
2-43
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Antenna
Sector
α
Jumper
Sector
β
Sector
γ
Feeder
Jumper
BTS cabinet
Figure 2-24 Structure of RF antenna & feeder
I. Antenna
Antenna is the end point of transmitting and start point of receiving. Type, gain,
coverage pattern and front-t o-rear ratio of the antenna can affect the system
performance. The network designer should choose antenna properly based on the
subscriber number and system coverage.
1) Antenna gain
Antenna gain is the capability of the antenna to radiate the input power in specific
directions. Normally, the higher gain, the larger coverage. But there may be blind
area in the vicinity.
2) Antenna pattern
Antenna pattern describes the radiation intensity of the antenna in all directions. In
the field of telecommunication, it usually means a horizontal pattern. BTS antenna is
available in two types: 360â omni antenna and directional antenna. The directional
antenna includes the following types: 120â , 90â , 65â and 33â .
3) Polarization
Polarization is used to describe the direction of the electrical field. The mobile
communication
system
often
uses
uni-polarization
antennas.
Bi-polarization
antennae have been used recently to reduce the quantity of antennae. The two
polarization directions are perpendicular to each other.
2-44
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
Normally Bi-polarization directional antenna is used in directional cell. Comparing
with the uni-polarization directional antenna, the bi-polarization directional antenna
is cost-effective, space saving and easy to install. However, uni-polarization omni
antenna is still adopted in omni cell.
4) Diversity technology
Electrical wave propagation in urban area has the following features:
Field intensity value changes slowly with places and times. It changes in the
rule of logarithmic normal distribution, which is called slow attenuation.
Field intensity transient value attenuates selectively since it is multi-path
transmission. The attenuation rules falls in Rayleigh distribution, which is called
fast attenuation.
Either fast attenuation or slow attenuation impairs the quality of communication or
even interrupts the conversation. Diversity technology is one of the most effective
technologies to tackle the attenuation problem. Diversity receiving and combining
technology can be used to minimize the attenuation when there is little correlation
between the two attenuated signals. There are polarized diversity and space
diversity. In the present mobile communication system, horizontal space diversity
and polarized diversity are both supported. Theoretical conclusion shows that space
diversity is effective when the distance between two antennae is over 10
wavelengths. Polarized diversity facilitates antenna installation and saves space,
therefore it is used more and more extensively.
5) Antenna isolation
The receiving/transmitting antenna must be installed with sufficient isolation to
minimize the effect on the receiver. The isolation space is subject to the out-band
noise of the transmitter and the sensitivity of the receiver. Please refer to cBTS3612
Installation Manual for details.
II. Feeder
Normally, the standard 7/8 inch or 5/4 inch feeders are used to connect the outdoor
antenna and indoor cabinet. In the site installation, 7/16 DIN connectors are needed
based on the actual length of feeders. Three grounding cable clips for lightning
protection should be applied at the tower top (or building roof), feeder middle, and
the wall hole where feeder enter indoors. If the feeder is excessively long, additional
cable clips are needed.
Since 7/8 inch feeder should not be bent, the tower top (or building roof) antenna
and the feeder, indoor cabinet and the feeder should be connected via jumpers. The
specifications of Huawei standard jumpers are 1/2 inch, 3.5m long, with 7/16DIN
connectors.
2-45
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
III. Lightning arrester (Optional)
When the cBTS3612 is configured for 1900MHz band, the lightning arrester is
necessary, but for the other bands, it is not necessary.
The lightning arrester is used to prevent damage of lightning current to the antenna
and feeder system. Usually, there are two kinds of lightning arresters. The first type
uses the microwave principle to conduct the low frequency lightning current to the
ground so as to sink the current. The second one is a discharging tube, when the
voltages at both ends of the discharging tube reach a certain value, the tube
conducts to sink the large current. The second technique is used in cBTS3612.
Lightning arrester should be installed close to the BTS cabinet, for details, please
refer to cBTS3612 Installation Manual.
IV. Tower-top Amplifier (Optional)
When the cBTS3612 is configured for 1900MHz band, the tower-top amplifier is
optional, for the other bands, it is not necessary.
Tower-top amplifier is used to further improve the signal quality. Normally it is
installed close to the antennas, consisting of triplex filter and low noise amplifier.
The triplex filter is actually a device composed of two duplex filters.
Signals from the antennas first pass through the triplex filter to filter out the out-band
interference, then the low noise amplifier amplifies the weak signals. Finally the
amplified signals are sent over the low loss cable to the BTS.
The purpose of the tower top amplifier is to enhance the receiving sensitivity of the
base station. So the tower-top amplifier is required to have a low noise coefficient.
The power of the signals received on the antenna varies greatly with the distance
between the MS and the base station. This requires that the tower- top amplifier
have a greater dynamic range.
Besides, the tower-top amplifier also has the by-pass function in case of DC power
failure.
The DC power supply of tower-top amplifier is fed through the center conductor of
the receiving feeder by DDU. Since it is an outdoor device, so a reliable waterproof
sealing is required.
The tower-top amplifier can operate under -40 C~60 C.
2-46
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
2.4.3 Dual-Satellite Synchronization Antenna & Feeder
I. Overview
Many important features of CDMA system are closely related with global satellite
navigation system and are much dependent on it. If global satellite navigation
system does not work for a long time, the whole network will collapse. In
consideration of the system security and reliability, BTS receives the signals of GPS
system or of GLONASS system through the dual-satellite synchronization antenna &
feeder, to implement radio synchronization. In this way, the whole network can
operate normally without any adverse effect when GPS or GLONASS system is not
available. The following describes the application of GPS and GLONASS in CDMA
system.
1) GPS
CDMA network can be synchronized with GPS. GPS is a high precision global
positioning system set up by American Navy Observatory. It is a all-weather satellite
navigation system based on high frequency radio. It provides 3D-position
information, so users can attain high precision information about position, speed and
time. The 3D-position is accurate to less than 10 yard (approx. 9.1m) in space and
less than 100ns in time. The received signal is processed and used as the master
reference frequency.
The whole system consists of three parts: space part, land control part and user
part.
Space part is a group of satellites 20,183 kilometers high, orbiting the earth at a
speed of 12 hours/circle. There are 24 satellites together, running on 6 orbits. The plane of
each orbit is at a 55â angle with the equator.
The land control part consists of a main control center and some widely distributed
stations. The land control network tracks the satellites and controls their orbits
accurately. It also corrects astronomical data and other system data from time to
time and transmits to users through the satellites.
The user part includes the GPS receivers and their supporting equipment. The
CDMA system is actually a GPS user utilizing the timing function of GPS. GPS
satellites are synchronized with a cesium atom clock group on the land. Therefore,
GPS timing signal is steady and reliable. The frequency is in a long-term stability of
cesium atom clock level. BTS provides a highly stable crystal clock, which is stable
on a short-term base. The crystal clock together with GPS signals ensures the clock
absolute stability and reliability of CDMA system.
2-47
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Hardware Architecture
2) GLONASS
GLONASS is a global satellite navigation system developed by the former Soviet
Union and inherited by Russia. It is of a similar structure to GPS. There are 24
satellites distributed on 3 orbits. The inclination of the orbit is 64.8â and the height is
18840~19940 km. The satellites go around the earth one circle every 11 hours 15
minutes and 44 seconds. Satellites are identified with frequency division
multi-address, i.e. different satellites use different frequencies. Since the inclination
of the orbits is greater than that of GPS, the visibility at high latitude area (over 50â )
is better than that of GPS. The design service life of the present satellites is 3~4
years. The service life of the new generation GLONASS will be 5 years, with
enhanced functions of inter-satellite data communication and autonomous running.
At present, only 19 satellites are working in the constellation and some of them are
not working well. The coverage is not as large as GPS system.
The user equipment receives C/A code, P code and two carrier signals modulated
from the navigation data L1: 1602MHz + 4.00 MHz
(ITU Class A Requirement)
> 4.00 MHz
(ITU Class B Requirement)
Spurious requirement
-45 dBc / 30 kHz
-60 dBc / 30 kHz; Pout ≥ 33 dBm
-27 dBm / 30 kHz; 28 dBm ≤ Pout < 33 dBm
-55 dBc / 30 kHz; Pout < 28 dBm
-13 dBm / 1 kHz;
9 kHz < f < 150 kHz
-13 dBm / 10 kHz;
150 kHz < f < 30 MHz
-13 dBm/100 kHz;
30 MHz < f < 1 GHz
-13 dBm / 1 MHz;
1 GHz < f < 5 GHz
-36 dBm / 1 kHz;
9 kHz < f < 150 kHz
-36 dBm / 10 kHz;
150 kHz < f < 30 MHz
-36 dBm/100 kHz;
30 MHz < f < 1 GHz
-30 dBm / 1 MHz;
1 GHz < f < 12.5 GHz
Table A-26 Conducted Spurious Emissions Performance (1900MHz band)
Offset from carrier central frequency
885 kHz~1.25 MHz
1.25 MHz~1.98 MHz
1.98 MHz~2.25 MHz
2.25 MHz~4.00 MHz
> 4.00 MHz
(ITU Class A Requirement)
Spurious requirement
-45 dBc / 30 kHz
-60 dBc / 30 kHz; Pout ≥ 33 dBm
-27 dBm / 30 kHz; 28 dBm ≤ Pout < 33 dBm
-55 dBc / 30 kHz; Pout < 28 dBm
-55dBc/30kHz， Pout¦33dBm
-22dBm/30kHz， 28dBm ≤ Pout < 33dBm
-50dBc/30kHz， Pout < 28dBm
-13dBm/1MHz
-13 dBm / 1 kHz;
9 kHz < f < 150 kHz
-13 dBm / 10 kHz;
150 kHz < f < 30 MHz
-13 dBm/100 kHz;
30 MHz < f < 1 GHz
-13 dBm / 1 MHz;
1 GHz < f < 5 GHz
A-13
System Description
Appendix A Technical Performance of Receiver
and Transmitter
User Manual
Airbridge cBTS3612 CDMA Base Station
II. Radiated spurious emissions
In compliant with local radio specifications.
A-14
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix B EMC Performance
Appendix B EMC Performance
ETSI EN 300 386 Electromagnetic Compatibility and Radio Spectrum Matters (ERM);
Telecommunication network Equipment. ElectroMagnetic Compatibility (EMC)
Requirements are the EMC standards of telecommunication equipment globally
applicable. EMC Performance of BTS comply with ETSI EN 300 386 V1.2.1
(2000-03). They are described in two aspects: EMI (EelectroMagnetic Interference)
and EMS (ElectroMagnetic Sensitivity).
B.1 EMI Performance
1) Conductive emission (CE) at DC input/ output port
CE performance indices are listed in Table B-1.
Table B-1 CE index at -48V port
Threshold (dB µV)
Frequency range
0.15 ~ 0.5MHz
0.5 ~ 5MHz
5 ~ 30MHz
Average
56~ 46
46
50
Quasi-peak
66~ 56
56
60
2) Radiated emission (RE)
RE performance indices are listed in Table B-2.
Table B-2 RE performance requirement
Band (MHz)
Threshold of quasi-peak (dB µV/m)
30 ~ 1000
1000 ~ 12700
61.5
67.5
& Note:
Test place is arranged according to ITU -R 329-7 [1].
B-1
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix B EMC Performance
B.2 EMS Performance
1) R-F anti-electromagnetic interference (80 MHz~1000MHz )
Values of RF anti-EMI test are listed in Table B-3.
Table B-3 Values of RF anti-EMI test
Test port
Test level
Whole cabinet
3V/m
Performance class
& Note:
Test method is the same as IEC1000-4-3 [9].
2) Voltage drop anti-interference
Among all test items of EMS, the requirement for resisting continuous interference
test is class A and the requirement for resisting transient interference test is class B.
Requirement for power drop and level interruption is shown in Table B-4.
Table B-4 Requirement for power drop and level interruption
Test port
Test level
Performance class
Drop 30%
Last for 10ms
AC port
When there is backup power, A
When there is no backup power, the communication link
need not be maintained. It can be re-created and the
user data can be lost.
When there is backup power, A
When there is no backup power, the communication link
need not be maintained. It can be re-created and the
user data can be lost.
Drop 60%
Last for 100ms
Drop over95%
Last for 5000ms
& Note:
Test method is the same as IEC61000-4-11 [13].
3) Electrostatic discharge (ESD)
Requirement for ESD test level is shown in Table B-5.
B-2
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix B EMC Performance
Table B-5 Requirement for ESD test level
Discharge mode
Contact
Air
Test level
2kV, 4kV
2kV, 4kV, 8kV
Performance class
& Note:
1. Test method is the same as IEC 61000-4-2 [5].
2. ESD should be performed to all exposed surface of equipment to be tested except those to be
protected as required by the user's document.
4) RF conductive anti-interference
In CDMA equipment, the port where a cable of more than 1 meter may be connected
to, including control port, DC input/output port and the input/output port of the
connection line when cabinets are combined, should satisfy the requirement for RF
conductive anti -interference. Voltage level is shown in Table B-6.
Table B-6 Voltage level
Test port
Voltage level
DC line port
AC line port
Signal line port and control line port
3V
Performance class
& Note:
Test method is the same as IEC61000-4-6 [9] .
5) Surge
For CDMA equipment, the DC power input port, indoor signal line of more than 3 m,
control line (such as E1 trunk line, serial port line) and the cable that may be led out
to the outdoor should all satisfy the requirement for surge interference level. The test
level is shown in Table B-7.
Table B-7 Test level
Test port
AC port
Control line, signal line
Test level
Line~ line, 2kV
Line~ ground, 4kV
Line~ line, 0.5kV
Line~ ground, 1kV
B-3
Performance class
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix B EMC Performance
Test port
Control line, signal line (outdoors)
Test level
Performance class
Line~ line, 1kV
Line~ ground, 2kV
& Note:
The test method is the same as IEC61000-4-5 [11].
6) Common-mode fast transient pulse
The signal & data line between CDMA cabinets and that connected with other
systems (such as E1 trunk line), control line and cable connected to DC input/output
port, should be the requirement for fast transient pulse anti-interference level. The
threshold value is shown in Table B-8.
Table B-8 Threshold value
Test port
Test level
Signal control line port
DC line input/ output port
AC line input port
0.5kV
1kV
2kV
Performance class
& Note:
Performance class A: it means that BTS can withstand the test without any damage and it can run
normally in the specified range. There is not any change in the software or data (all data in the storage
or the data being processed) related to the tested switching equipment. Equipment performance is not
lowered.
Performance class B: it means that BTS can withstand the test without any damage. There is no
change in the software or the data in storage. Communication performance is lowered a little, but in the
tolerance (as defined for different products). The existing communication link is not interrupted. After
the test, the equipment can recover to the normal status before the test automatically without any
interference of the operator.
Performance class C: some functions of BTS are lost temporarily during the test, but they will recover
to normal performance in a specific period after the test (normally the shortest time needed for system
reboot). There is no physical damage or system software deterioration.
Performance class R: after the test, there is no physical damage or fault (including software corruption)
with BTS. Protection equipment damage caused by external interference signal is acceptable. When
the protection equipment is replaced and the running parameters are re-configured, the equipment can
operate normally.
B-4
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix C Environment Performance
Appendix C Environment Performance
In compliance with ETSI, environmental conditions of products include requirements
in three aspects: operation environment, transportation environment and storage
environment.
C.1 Ambient Temperature and Humidity
1) Operation environment
In
compliance
with
the
environmental
level
specified
in
IEC60721-3-3
3K3/3Z2/3Z4/3B1/3C2/3S3/3M1 and ETS 300 019-2-3 T3.1. The normal running
temperature should be in the range of -5âC~+50 âC, and that of humidity in the range
of 5%~ 90% .
2) Storage environment
In compliance with IEC60721-3-1 1K4/1Z2/1Z3/1B2/1C2/1S3/M2 and IEC 300
019-2-1 T1.2 "Weather Protection, No Temperature Control" level. Normal storage
temperature should be in the range of -25âC ~+55âC, and that of humidity in the
range of 10%~100%.
3) Transportation environment
In compliance with IEC60721-3-2 2K4/2B2/2C2/2S2/2M2 and IEC 300 019-2-2 T2.3
"Public Transportation" level. Normal transportation temperature should be in the
range of -40âC ~+70âC, and that of humidity in the range of 5%~ 100%.
C.2 Cleanness
1) Operation environment
In compliance with IEC60721-3-3 3K3/3Z2/3Z4/3B1/3C2/3S3/3M1 and ETS 300
019-2-3 T3.1 environment level:
Precipitable particle
Floating particle
Gravel
15
0.4
300
m2h
mg/m3
mg/m3
2) Storage environment
In compliance with IEC60721-3-1 1K4/1Z2/1Z3/1B2/1C2/1S3/M2 and IEC 300
019-2-1 T1.2 "Weather protection, no temperature level" level:
Precipitable particle
Floating particle
Gravel
20
300
C-1
m2h
mg/m3
mg/m3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix C Environment Performance
3) Transportation environment
In compliance with IEC60721-3-2 2K4/2B2/2C2/2S2/2M2 and IEC 300 019-2-2 T2.3
"Public Transportation" level.
Precipitable particle
Floating particle
Gravel
m2h
mg/m3
mg/m3
No requirement
100
C.3 Illumination
1) Operation environment
In compliance with IEC60721-3-3 3K3/3Z2/3Z4/3B1/3C2/3S3/3M1 and ETS 300
019-2-3 T3.1 environment level. In normal operation, solar radiation should not
exceed 700W/m , thermal radiation should not exceed 600W/m , and illumination
should satisfy the requirement for working visibility and comfort.
2) Storage environment
In compliance with IEC60721-3-1 1K4/1Z2/1Z3/1B2/1C2/1S3/M2 and IEC 300
019-2-1 T1.2 "Weather Protection, No Temperature Control" level. In normal storage
place, the solar radiation should not exceed 1120W/m , thermal radiation should not
exceed 600W/m , and illumination should satisfy the requirement for working
visibility and comfort.
3) Transportation environment
In compliance with IEC60721-3-2 2K4/2B2/2C2/2S2/2M2 and IEC 300 019-2-2 T2.3
"Public Transportation" level. In normal transportation conditions, the solar radiation
should not exceed 1120W/m , thermal radiation should not exceed 600W/m , and
illumination should satisfy the requirement for working visibility and comfort.
C.4 Atmospheric Condition
1) Operation environment
In compliance with IEC60721-3-3 3K3/3Z2/3Z4/3B1/3C2/3S3/3M1 and ETS 300
019-2-3 T3.1 environment level:
Atmospheric pressure
Wind speed
SO 2
H 2S
Cl2
HCl
NOx
NH3
HF
O3
70~ 106
0.3~ 1.0
0.1 ~ 0.5
0.1 ~ 0.3
0.1 ~ 0.5
0.5 ~ 1.0
1.0 ~ 3.0
0.01 ~ 0.03
0.05 ~ 0.1
C-2
kPa
m/s
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix C Environment Performance
2) Storage environment
In compliance with IEC60721-3-1 1K4/1Z2/1Z3/1B2/1C2/1S3/M2 and IEC 300
019-2-1 T1.2 "Weather Protection, No Temperature Control" level:
Atmospheric press
Wind speed
SO 2
H 2S
Cl2
HCl
NOx
NH3
HF
O3
70~ 106
30
0.3~ 1.0
0.1 ~ 0.5
0.1 ~ 0.3
0.1 ~ 0.5
0.5 ~ 1.0
0.5 ~ 3.0
0.01 ~ 0.03
0.05 ~ 0.1
KPa
m/s
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
3) Transportation environment
In compliance with IEC60721-3-2 2K4/2B2/2C2/2S2/2M2 and IEC 300 019-2-2 T2.3
"Public Transportation" level.
Atmospheric pressure
Wind speed
SO 2
H 2S
Cl2
HCl
NOx
NH3
HF
O3
70~ 106
20
0.5
No requirement
0.5
0.03
0.1
C-3
kPa
m/s
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
mg/m3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix D Electromagnetic Radiation
Appendix D Electromagnetic Radiation
D.1 Introduction
Base Transceiver Station (BTS) emit RF radiation (Radiation Hazard). Although
there is no scientific evidence of possible health risks to persons living near to base
stations some recommendations are giving below for the installation and operation
of base station transceivers. Ope rators of base station transceivers are required to
obey the local regulation for erecting base station transceivers.
The Federal Communications Commission (FCC), are imposing MPE ( maximum
permissible exposure) limits. FCC CFR part 1, subpart I, section 1.1307 requires
operator to perform a Enviromenta Assemessmet (EA). Equipment listed in the table
1 of before mentioned part are subjected to routine environmental evaulation. For
facilities and operations licensed under part 22, licensees and manufactuere are
required tto ensure that their facility and equipment comply with IEEE C95.1-1991.
The objective of the Environmental Evaluation is to ensure that human exposure to
RF energy does not go beyond the maximum permissible levels stated in the
standard. Therefore certain sites do not require an evaluation by nature of its design.
It could be that the antennas are placed high enough thereby resulting in extremely
low RF fields by the time it reaches areas that would be accessible to people.
Environmental evaluations are required, for Paging and Cellular Radiotelephone
Services, Part 22 Subpart E and H;
Non-rooftop antennas: height of radiation center < 10m above ground level and
total power of all channels > 1000 W ERP (1640 W EIRP)
Rooftop antennas: total power of all channels > 1000 W ERP (1640 W EIRP)
D.2 Maximum Permissible Exposure (MPE)
Maximum permissible exposure (MPE) refers to the RF energy that is acceptable for
human exposure, given the scientific research to date. It is broken down into two
categories, Controlled and Uncontrolled. Controlled limits are used for persons such
as installers and designers that are in control of the hazard and exposed to energy
for limited amounts of time per day. Occupational/controlled limits apply in situations
in which are persons are exposed as a consequence of their employment provided
those persons are fully aware of the potential for exposure and can exercise control
over their exposure. Limits for occupational/controlled exposure also apply in
situations
when
an
individual
D-1
is
transient
through
location
where
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix D Electromagnetic Radiation
occupational/controlled limits apply provided he or she is made aware of the
potential for exposure.
Uncontrolled limits are used for general public. General population/uncontrolled
exposure apply in situations is which the general public may be exposed, or in which
persons that are exposed as a consequence of their employment may not be fully
aware of the potential for exposure or can not exercise control over their exposure.
The exposure levels can be expressed in terms of power density, electric field
strength, or magnetic field strength, as averaged over 30 minutes for the general
public and 6 minutes for trained personnel. The exposure criteria is frequency
dependent, and a chart covering the range from 3 kHz to 100 GHz can be found in
NCRP No.86 (references IEEE C95.1-1991). Below are the limits.
Limits for Occupational/Controlled Exposure
Frequency Range
Electric Field
Strength (E) (V/m)
(MHz)
Magnetic Field
Strength (H) (A/m)
Power Density (S)
(mW/cm2 )
0.3-3.0
614
.63
(100)*
3.0-30
1842/f
4.89/f
(900/f2 )*
30-300
61.4
0.163
1.0
300-1500
--
--
f/300
1500-100,000
--
--
Limits for General Population/Uncontrolled Exposure
Frequency Range
Electric Field
Strength (E) (V/m)
(MHz)
Magnetic Field
Strength (H) (A/m)
Power Density (S)
(mW/cm2 )
0.3-3.0
614
1.63
(100)*
3.0-30
842/f
2.19/f
(180/f2 )*
30-300
27.5
0.073
0.2
300-1500
--
--
f/1500
1500-100,000
--
--
1.0
Power
S=
density
[mW/cm ]
f [ MHz ] 880
= 2 .9 mW / cm
300
300
D-2
for
controlled
area
at
880
MHz
User Manual
Airbridge cBTS3612 CDMA Base Station
Power
S=
density
System Description
Appendix D Electromagnetic Radiation
[mW/cm ]
for
uncontrolled
area
at
880
MHz
f [ MHz ] 880
= 0. 58 mW / cm
1500
1500
D.3 Estimation of Exposure to Electromagnetic Fields
Below method describes a theoretical approach to calculate possible exposure to
electromagnetic radiation around a base station transceiver antenna. Precise
statements are basically only possible either with measurements or complex
calculations considering the complexity of the environment (e.g. soil conditions, near
buildings
and
other
obstacles)
which
causes
reflections,
scattering
of
electromagnetic fields.
The maximum output power (given in EIRP) of a base station is usually limited by
license conditions of the network operator.
A rough estimation of the expected exposure in power flux density on a given point
can be made with the following equation. The calcualtions are based on FCC OET
65 Appendix B.
S=
P(W ) ∗ Gnumeric
4 ∗ r 2 ( m) ∗ π
Whereas:
P = Maximum output power in W of the site
G numeric = Numeric gain of the antenna relative to isotropic antenna
R = distance between the antenna and the point of exposure in meters
D.4 Calculation of Safe Distance
Calculations can be made on a site by site basis to ensure the power density is below
the limits given above, or guidelines can be done beforehand to ensure the minimum
distances from the antenna is maintained through the site planning.
r=
1.64 * Gd * Pt
4πS
Whereas:
r = distance from the antenna [m]
D-3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix D Electromagnetic Radiation
Gd = Antenna gain relative to half wave dipole
Pt
= Power at the antenna terminals [W]
S = power density [W/m2] see also MPE Limits
Note: 1mW/cm2 = 10W/m2
D.5 Location of Base Station Antennas
Base stations antennas, the source of the radiation, are usually mounted on
freestanding towers, with a height up to 30 m or on a tower on the top of buildings or
in less cases to the side of the building. Generally the height of the antenna position
does not fall below 10 m. The power usually is focused into a horizontal main beam
and slightly downward tilted. The remaining pow er goes into the weaker beams on
both side of the main beam. The main beam however does not reach ground level
until the distance from the antenna position is around 50 – 200 m.
The highest level of emission would be expected in close vicinity of the antenna and
in line of sight to the antenna.
D.5.1 Exclusion Zones
1)
Antenna location should be designed so that the public cannot access areas
where the RF radiation exceeds the levels as described above. .
2)
If there are areas accessible to workers that exceed the RF radiation exceeds
the levels as described above make sure that workers know where these areas
are, and that they can (and do) power-down (or shut down) the transmitters
when entering these areas. Such areas may not exist; but if they do, they will be
confined to areas within 10 m of the antennas.
3)
Each Exclusion zone should be defined by a physical barrier and by a easy
recognizable sign warning the public or workers that inside the exclusion zone
the RF radiation might exceed national limits.
D.5.2 Guidelines on Arranging Antenna Locations
1)
For roof-mounted antennas, elevate the transmitting antennas above the height
of people who may have to be on the roof.
2)
For roof-mounted antennas, keep the transmitting antennas away from the
areas where people are most likely to be (e.g., roof access points, telephone
service points, HVAC equipment).
3)
For roof-mounted directional antennas, place the antennas near the periphery
and point them away from the building.
D-4
User Manual
Airbridge cBTS3612 CDMA Base Station
4)
System Description
Appendix D Electromagnetic Radiation
Consider the trade off between large aperture antennas (lower maximum RF)
and small aperture antennas (lower visual impact).
5)
Take special precautions to keep higher-power antennas away from accessible
areas.
6)
Keep antennas at a site as for apart as possible; although this may run contrary
to local zoning requirements.
7)
Take special precautions when designing "co-location" sites, where multiple
antennas owned by different companies are on the same structure. This applies
particularly to sites that include high-power broadcast (FM/TV) antennas. Local
zoning often favors co-location, but co-location can provide "challenging" RF
safety problems.
8)
For roof-mounted antennas, elevate the transmitting antennas above the height
of people who may have to be on the roof.
9)
For roof-mounted antennas, keep the transmitting antennas away from the
areas where people are most likely to be (e.g., roof access points, telephone
service points, HVAC equipment).
10) Take special precautions for antenna sites near hospital and schools.
D-5
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix E Standard Compliance
Appendix E Standard Compliance
E.1 Um Interface
I. Physical layer
TIA/EIA IS-2000-2-A: Physical Layer Standard for cdma2000 Spread Spectrum
Systems
II. MAC layer
TIA/EIA IS -2000-3-A: Medium Access Control (MAC) Standard for cdma 2000
Spread Spectrum Systems
III. Service capability
TSB2000: Capabilities Requirements Mapping for cdma2000 standards
IV. System performance
TIA/EIA -97-D: Recommended Minimum Performance Specification for cdma2000
Spread Spectrum Base Station
E.2 Abis Interface
I. Physical layer
1)
E1 interface
E1 Physical Interface Specification, September 1996
2)
SDH STM -1
ANSI T1.101: Synchronization Interface Standard
ITU-T G.707: (3/96) Network node interface for the synchronous digital hierarchy
(SDH)
ITU-T G.703: (10/98) Physical/electrical characteristics of hierarchical digital
interfaces
ITU-T G.957: Optical interface for equipment and systems relating to the
synchronous digital hierarchy
E-1
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix E Standard Compliance
ITU-T G.958: Digital line systems based on the synchronous digital hierarchy for use
on optical fiber cables
3)
ATM
AF-PHY -0086.001: Inverse Multiplexing for ATM(IMA) Specification Version 1.1
ATM Forum af-phy-0064.000
ATM Forum af-phy-0130.000
ATM on Fractional E1/T1, October 1999
II. ATM layer
ANSI T1.627-1993: Telecommunications broadband ISDN-ATM Layer Functionality
and specification
III. ATM adaptation layer
ITU-T recommendation I.366.2: B-ISDN ATM Adaptation Layer Type 2 Specification
ITU-T I.363.5: B-ISDN ATM Adaptation Layer 5 Specification: Type 5 AAL
IV. TCP/IP
RFC791: Internet Protocol
RFC793: Transport Control Protocol
V. Abis interface high layer protocol
3GPP2 A.R0003: Abis interface technical report for cdma2000 1X Spread Spectrum
System
VI. Self-defined standard
cdma2000 1X Abis Interface High Layer Protocol
E.3 Lightning Protection
IEC 61312-1(1995) Protection Against Lightning Electromagnetic Impulse Part I:
General Principles
IEC 61643-1(1998) Surge Protective devices connected to low-voltage power
distribution systems
ITU-T K.11 (1993) Principles of Protection Against Over-voltage and
Over-current.
ITU-T
K.27
(1996)
Bonding
Telecommunication Building
E-2
Configurations
and
Earthing
Inside
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix E Standard Compliance
ETS 300 253(1995) Equipment Engineering; Earthing and bonding of
telecommunication equipment in telecommunication centers
E.4 Safety
IEC60950 Safety of information technology equipment Including Electrical
Business Equipment
IEC60215 Safety requirement for radio transmitting equipment
CAN/CSA-C22.2 No 1-M94 Audio, Video and Similar Electronic Equipment
CAN/CSA-C22.2 No 950-95 Safety of Information Technology Equipment
Including Electrical Business Equipment.
UL 1419 Standard for Professional Video and Audio Equipment
73/23/EEC Low Voltage Directive
UL 1950 Safety of information technology equipment Including Electrical
Business Equipment
IEC60529 Classification of degrees of protection provided by enclosure (IP
Code).
E.5 EMC
TS 25.113v3.1.0; 3rd Generation Partnership Project; Technical Specification
Group Radio Access Networks; Base station EMC
ITU-R Rec. SM.329-7: "Spurious emissions"
TS 25.141; 3rd Generation Partnership Project; TSG RAN WG4; UTRA (BS)
FDD; Base station conformance testing (FDD)
TS 25.142; 3rd Generation Partnership Project; TSG RAN WG4; Base station
conformance testing (TDD)
TS 25.104; 3rd Generation Partnership Project; TSG RAN WG4; UTRA (BS)
FDD; Radio transmission and reception
TS 25.105; 3rd Generation Partnership Project; TSG RAN WG4; UTRA (BS)
TDD; Radio transmission and reception
E-3
User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
Appendix F Abbreviation
Appendix F Abbreviation
3GPP2
A1/A2/A5
A3/A7
A8/A9
A10/A11
AAA
AAL2
AAL5
Abis
AC
AC
A/D
ADC
AGC
ANSI
ARQ
ATM
AUC
BPSK
BAM
BBFL
BBFM
BCIM
BCKM
BCPM
BDCS
BEOM
BESP
BFAN
BFMM
BFNB
BHPA
BICM
BIFU
BPLI
BRCU
BRDM
BRFM
BS
BSC
BSS
BTBM
BTEM
BTRM
BTS
CCITT
CBKM
CDMA
CDU
CE
CLI
CLK
CM
3rd Generation Partnership Project 2
Availability
Interface between BSC and MSC
Interface between BSCs
Interface between BSC and PCF
Interface between PCF and PDSN
Authorization, Authentication and Accounting
ATM Adaptation Layer 2
ATM Adaptation Layer 5
Interface between BSC and BTS
Authentication Center
Alternating Current
Analog/Digital
Analog Digit Converter
Automatic Gain Control
American National Standards Institute
Automatic Repeat Request
Asynchronous Transfer Mode
Authentication
Binary Phase Shift Keying
Back Administration Module
BTS BTRM FAN Lamp Module
BTS BTRM FAN Monitor
BTS Control Interface Module
BTS Control & Clock Module
BTS Channel Process Module
BTS Direct Current Switchbox
BTS Electric-Optical Module
BTS E1 Surge Protector
BTS FAN Module
BTS Fan Monitor Module
BTS Fan Block Interface Board
BTS High Power Amplifier Unit
BTS Intermediate Frequency Control Module
BTS Intermediate Frequency Unit
BTS Power & Lighting protection lamp Indicator board
BTS Radio Up-Down Conv erter Unit
BTS Resource Distribution Module
BTS RF Fan Module
Base Station
Base Station Controller
Base Station Subsystem
BTS Transceiver Backplane Module
BTS Test Module
BTS Transceiver Module
Base Transceiver Station
International Telephone and Telegraph Consultative Committee
CDMA Backplane Module
Code Division Multiple Access
Combining Duplexer Unit
Channel Element
Command Line Interpreter
Clock
Connection Management
F-1
User Manual
Airbridge cBTS3612 CDMA Base Station
CMM
CN
CPU
CRC
CTC
D/A
DAC
DC
DAGC
DCE
DDU
DFU
EMC
EMI
EMS
EIA
EIB
EIR
ESD
ETS
ETSI
FA
F-APICH
F-ATDPICH
F-BCH
FCACH
FCC
F-CCCH
FCH
F-DCCH
F-DD
FER
F-FCH
F-PCH
F-PICH
F-QPCH
F-SCCH
F-SCH
F-SYNCH
F-TCH
F-TDPICH
FTP
GLONASS
GPM
GPS
GRIL
GUI
HA
HDLC
HLR
HPAU
HPBW
HPSK
ICP
ID
IEC
System Description
Appendix F Abbreviation
Capability Mature Mode
Core Network
Central Processing Unit
Cyclic Redundancy Check
Common Transmit Clock
Digit/Analog
Digit Analog Converter
Direct Current
Digit Automatic Gain Control
Data Communications Equipment
Dual Duplex er Unit
Duplex er and Filter Unit
Electro Magnetic Compatibility
Electro Magnetic Interference
Electro Magnetic Sensitivity
Electronics Industry Association
Erasure Indicator Bit
Equipment Identity Register
Electrostatic Discharge
European Telecommunication Standards
European Telecommunication Standards Institute
Foreign Agent
Forward Assistant Pilot Channel
Forward Transmit Diversity Assistant Pilot Channel
Forward Broadcast Channel
Forward Common Assignment Channel
Federal Communications Commission
Forward Common Control Channel
Fundamental Channel
Forward Dedicated Control Channel
Frequency Division Duplex
Frame Error Rate
Forward Fundamental Channel
Forward Paging Channel
Forward Pilot Channel
Forward Quick Paging Channel
Forward Supplemental Code Channel
Forward Supplemental Channel
Forward Sync Channel
Forward Traffic Channel
Forward Transmit Diversity Pilot Channel
File Transfer Protocol
Global Navigation Satellite System
General Paging Message
Global Position System
GPS/GLONASS Receiver Interface Language
Graphics User Interface
Home Agent
High level Data Link Control
Home Location Register
High Power Amplifier Unit
Half Power Beam Width
Hybrid Phase Shift Keying
IMA Control Protocol
IDentification
International Electrotechnical Commission
F-2
User Manual
Airbridge cBTS3612 CDMA Base Station
IEEE
IF
IMA
IP
IPOA
ISDN
ITC
ITU
ITU -R
ITU -T
IWF
JTAG
LAC
LED
LMF
LNA
MAC
MC
MCPA
MCU
Mcps
MM
MMI
MOC
Modem
MPU
MS
MSC
MT0
MTC
MT1
MTBF
MTRB
MTTR
OAM
OEM
OMC
OML
OMU
OCXO
OQPSK
OTD
PCB
PCF
PCH
PDSN
PGND
PLL
PLMN
PMRM
PN
PP2S
PPP
PRM
PSPDN
PSTN
System Description
Appendix F Abbreviation
Institute of Electrical and Electronics Engineers
Intermediate Frequency
Inverse Multiplexing for ATM
Internet Protocol
IP over ATM
Integrated Services Digital Network
Independent Transmit Clock
International Telecommunications Union
International Telecommunications Union- Radiocommunication Sector
International Telecommunications Union-Telecommunication Standardization Sector
Interwork Function
Joint Test Action Group
Link Access Control
Light Emitting Diode
Local Maintenance Function
Low-Noise Amplifier
Medium Access Control
Message Center
Multi-Carrier Power Amplifier
Main Control Unit
Million chips per second
Mobility Management
Man Machine Interface
Mobile Originated Call
Modulator-Demodulator
Micro Process Unit
Mobile Station
Mobile Switching Center
Mobile Terminal 0
Mobile Terminated Call
Mobile Terminal 1
Mean Time Between Failures
Micro-bts Transceiver Board
Mean Time To Repair
Operation & Maintenance
Original Equipment Manufacturer
Operation & Maintenance Center
Operation & Maintenance Link
Operation & Maintenance Unit
Oven voltage Control Oscillator
Offset Quadrature Phase Shift Keying
Orthogonal Transmit Diversity
Printed Circuit Board
Packet Control Function
Paging Channel
Packet Data Service Node
Protection Ground
Phase-Locked Loop
Public Land Mobile Network
Power Measurement Report Message
Pseudo Number
Pulse Per 2 Seconds
Peer-Peer Protocol
Paging Response
Packet Switched Public Data Network
Public Switched Telephone Network
F-3
User Manual
Airbridge cBTS3612 CDMA Base Station
PSU
PVC
PVP
PWM
QIB
QoS
QPCH
QPSK
R-ACH
RC
RC1
RC2
RC3
RC4
R-CCCH
R-DCCH
R-EACH
RF
R-FCH
RLDU
RLP
RM
RNC
R-PC
R-PICH
R-SCCH
R-SCH
RSQI
R-TCH
SCH
SDH
SID
SME
SDU
SPU
SSSAR
STM -1
STS
TA
TA
TAm
TCP
TDD
TDMA
TE1
TE2
TIA
TMSI
TRX
Um
UNI
UTC
UART
VCI
VLR
VPI
System Description
Appendix F Abbreviation
Power Supply Unit
Permanent Virtual Channel
Permanent Virtual Path
Pulse-Width Modulation
Quality Identification Bit
Quality of Service
Quick Paging Channel
Quadrature Phase Shift Keying
Reverse Access Channel
Rate Configuration
Rate Configuration 1
Rate Configuration 2
Rate Configuration 3
Rate Configuration 4
Reverse Common Control Channel
Reverse Dedicated Control Channel
Reverse Enhanced Access Channel
Radio Frequency
Reverse Fundamental Channel
Receive LNA Distribution Unit
Radio Link Protocol
Radio Management
Radio Network Controller
Reverse Power Control subchannel
Reverse Pilot Channel
Reverse Supplemental Code Channel
Reverse Supplemental Channel
Receive Signal Quality Indicator
Reverse Traffic Channel
Supplemental Channel
Synchronous Digital Hierarchy
System Identification
Signaling Message Encryption
Selection/Distribution Unit
Signaling Process Unit
Special Service Segmentation and Reassemble
Synchronization Transfer Mode 1
Space Time Spreading
Timing Advance
Terminal Adapter
Mobile Terminal Adapter
Transport Control Protocol
Time Division Duplex
Time Division Multiple Access
Terminal Equipment 1
Terminal Equipment 2
Telecommunications Industry Association
Temp Mobile Subscriber Identifier
Transceiver
Interface between BTS and MS
User Network Interface
Universal Coordinated Time
Universal Asynchronous Receiver/Transmitter
Virtual Channel Identifier
Visitor Location Register
Virtual Path Identifier
F-4
User Manual
Airbridge cBTS3612 CDMA Base Station
VSWR
System Description
Appendix F Abbreviation
Voltage Standing Wave Radio
F-5

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.4
Linearized                      : No
Create Date                     : 2003:09:12 07:27:41Z
Modify Date                     : 2003:09:15 14:28:32+02:00
Page Count                      : 204
Creation Date                   : 2003:09:12 07:27:41Z
Mod Date                        : 2003:09:15 14:28:32+02:00
Producer                        : Acrobat Distiller 5.0 (Windows)
Metadata Date                   : 2003:09:15 14:28:32+02:00