Gsm base-station-subsystem

1

รายงานการฝกอบรมหลักสูตร GSM BSS

สวนที่ 1 ขอมูลทั่วไป

รายชื่อพนักงานที่เขารับการฝกอบรม
1.1 นายสมพงษ จันทรวานิตย ผส.8 สร.
1.2 นายชัยวัฒน สุขเมฆ วศก.8 ทร.
1.3 นายวีระ ทองไพบูลย วศก.8 ทร.
1.4 นายสุรพงศ ระวังวงศ วศก.8 ทร.
1.5 นายวิโรจน แดงเจริญสุข วศก.7 นข.
1.6 นายนิวัฒน คุณกันหา นทค.7 ขต.(อน)
1.7 นายไพโรจน ปลองมาก นทค.7 ขต.(ตต)
1.8 นายสุทธิชัย จัตวาภักดี นทค.6 ขต.(อ)
1.9 นายโกศล รัตนสวางวงศ นทค.6 ขต.(ต)
1.10 นายพรชัย ตรงตระกูล นทค.6 ขต.(ก)
1.11 นายบุญโชติ แกวเทพ นทค.6 ขต.(น)
1.12 นายศรีเกษม ภุมรินทร ชทค.4 ทร.

หลักสูตรที่เขารับการฝกอบรม
ชื่อหลักสูตร (ภาษาไทย)
ชื่อหลักสูตร (ภาษาอังกฤษ) GSM BASE STATION SUBSYSTEM
เพื่อ ฝกอบรม
แหลงใหทน บริษัท ทรู มูฟ จํากัด
ุ ประเทศที่ไป จีน
ระหวางวันที่ 22 พฤษภาคม 2552 – 20 มิถุนายน 2552
ภายใตโครงการ สัญญาดําเนินการใหบริการวิทยุคมนาคมฯระหวาง กสท กับ บริษท ทรู มูฟ จํากัด
ั

สวนที่ 2 บทคัดยอ
ตามสัญญาใหดําเนินการใหบริการวิทยุคมนาคมระบบเซลลูลา DIGITAL PCN 1800 ระหวาง
กสท กับ บริษัท ทรู มูฟ จํากัด ขอที่ 15.3 ระบุให “บริษัทจะตองจัดการฝกอบรมดานเทคนิคทั้งหมดใหแก
เจาหนาที่ของ กสท. จํานวนไมนอยกวา 24 คน กับบริษัทผูผลิตเครื่องและอุปกรณในตางประเทศเปน
ระยะเวลาไมนอยกวาคนละ 30 วัน” และ 14 พฤษภาคม 2552 กสท. ไดอนุมัติใหพนักงานจํานวน 12 คน

2

เขารวมการฝกอบรมดานเทคนิคตามสัญญาดําเนินการดังกลาว ในหลักสูตร GSM BSS AND WCDMA
โดยรายละเอียดเนื้อหาหลักสูตรประกอบดวย
• GSM BSS
เนื้อหาประกอบดวยโครงสรางพื้นฐานของโครงขายระบบเซลลูลา GSM ตั้งแต Interface,
Protocols, Numbering plan, GSM Radio technologies, Signaling ตางๆ และในสวนของอุปกรณ BTS
และ BSC ไดฝกอบรมทั้ง Operation and Maintenance Training ในสวนของ Software Maintenance ได
ฝกอบรม Software BSC6000 ซึ่งเปน Software OMC ของ Huawei ที่ใช Maintenance สถานีฐานและ
BSC
• PCU
เนื้อหาประกอบดวย Operation and Maintenance PCU ซึ่งเปนระบบการใหบริการ Data บน
โครงขาย GSM
• WCDMA
เนื้อหาประกอบดวย 3G Overview, CDMA principle, WCDMA Fundamental ตลอดถึง
Hardware System Structure และ Hardware ที่เปน BSC และ BTS ยี่หอ Huawei ที่ใชงานในปจจุบัน

สวนที่ 3 ขอมูลที่ไดรับ
3.1 วัตถุประสงค
1) เพื่อใหบริษทผูรับสัมปทานปฏิบัติตามสัญญาดําเนินการใหบริการ
ั 
2) เพื่อใหพนักงาน บมจ.กสท โทรคมนาคม ไดมีความรูความเขาใจ ในเรื่อง
เทคโนโลยีการใหบริการเซลลูลา GSM มากขึ้น
3) เพื่อใหพนักงาน บมจ.กสท โทรคมนาคม ไดศึกษาดูงานยังบริษทผูผลิตอุปกรณ
ั
โครงขายโทรคมนาคม
4) เพื่อใหพนักงาน บมจ.กสท โทรคมนาคม ไดรับความรูเกี่ยวกับเทคโนโลยี
Mobile สมัยใหมเพิ่มมากขึน
้
3.2 เนื้อหาทีเ่ ปนสาระสําคัญดังตอไปนี้

3

GSM Base Station Subsystem

1. บทนํา

โทรศัพทเคลื่อนที่ระบบ GSM มีโครงสรางของโครงขายเพื่อการใหบริการดังภาพที่ 1 โดยจําแนก
ตามหนาที่ของอุปกรณออกเปน 3 สวนหลัก คือ
• MS (Mobile Station) เปนสวนติดตอกับผูใช (Subscriber)
• BSS (Base Station Subsystem) มีหนาที่จัดการและบริหารความถี่ RF เพื่อติดตอกับผูใชงาน
ผานทาง MS เชื่อมตอสัญญาณ Base Band ไปยัง Core Network เพื่อทําการหาเสนทางการ
เชื่อมตอไปยังผูใชปลายทางตอไป
• NSS (Network Station Subsystem) ทําหนาทีเปน Circuit Switching สําหรับบริการประเภท
Voice, Package switching สําหรับบริการ Data และ Network Interconnector สําหรับการเชื่อ
ตอกับโครงขายผูใหบริการอืน
่

ภาพที่ 1 แสดงโครงสรางของโครงขายโทรศัพทเคลื่อนที่ระบบ GSM

ภายใน BSS จะตองประกอบไปดวยอุปกรณอยางนอยดังนี้ BSC จํานวน 1 ชุด สวน PCU และ
BTS ขึ้นอยูกับจํานวน Traffic ของผูใชงาน และ Config ของโครงขาย หนาที่ของอุปกรณแตละสวนมีดังนี้
• BSC (Base Station Controller) ทําหนาที่ควบคุมการทํางานของระบบภายใน BSS

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• PCU (Package Control Unit) ทําหนาทีทําหนาที่ควบคุมการทํางานของวงจรในสวน
่
ของ DATA
• BTS (Base Transceiver Station) ทําหนาที่ติดตอและรับสงสัญญาณคลื่นวิทยุกับ
เครื่อง MS การควบคุมการทํางานของ BTS เปนหนาทีของ BSC
่

2. BSS Functions

หนาทีหลักของ BSS มีดังนี้
่
2.1 Radio Resource Management (RRM)
เปนหนาที่ของ BSC functions of the BSS. RRM is the procedure through which a stable
connection is established between the MS and the MSC for a call. This procedure is also used to
release the radio resources when a call is disconnected. The limited radio resources must be
dynamically allocated to maintain the stable connection between the MS and the MSC. The RRM
is mainly performed by the MS and the BSC. In addition, the RRM maintains the channel
connection when an MS is handed over to a neighbor cell.
Paging
This describes the paging procedure. Paging is a broadcast procedure used by the
network to search for an MS. On receiving a call, the GSM/GPRS network initiates broadcasting
in the location area or routing area of the paged MS. For a PS service, paging can be performed
on the basis of the location area but is mainly performed on the basis of the routing area. Which
area the paging is based on is determined by the SGSN.
Assignment
This describes the assignment procedure. Through the assignment procedure, the BSS
assigns a TCH to an MS.
Initial Access and Immediate Assignment
This describes the initial access and immediate assignment procedures. The purpose of
initial access is to set up a radio resource (RR) connection on the Um interface between an MS
and the network. The purpose of immediate assignment is to assign a signaling channel for
setting up the RR connection.

5

Authentication and Encryption
This describes the authentication and encryption procedures. Authentication and
encryption are two security mechanisms used by the GSM network to enhance network security
and data privacy.

System Information
This describes system information (SI). The SI contains the main radio network
parameters on the Um interface. These parameters include network identification parameters,
cell selection parameters, system control parameters, and network function parameters.
Handover
Handover is a procedure in which a conversation can be sustained when an MS moves
from one cell to another in order to meet the requirement of network management.
Radio Channel Management
This describes the radio channel management procedure. Radio channel management
is performed by the BSC. It consists of long-term channel configuration management and short-
term dedicated channel assignment management. The long-term management function is used
to select the channel sequence number and to configure relevant devices. The short-term
management function is used to assign and release various channels during communication.
Power Control
This describes power control. Power control aims to reduce the transmit power of the MS
or the BTS under the condition that the radio link quality is maintained and the power level of the
MS and the BSS is met. Through power control, the system interference is reduced, the
frequency spectrum efficiency is improved, and the standby time of the MS is extended.
Circuit Management
This describes the circuit management procedure. The BSC can manage the circuits on
the A interface. For example, it performs circuit assignment, circuit blocking, circuit unblocking,
circuit group blocking, and circuit group unblocking. It also operates and maintains a single
circuit or the PCM group circuits of the GEIUA/GOIUA.
TRX Management
This describes the TRX management procedure. TRX management refers to TRX status
management.

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Media Access Control
This describes Media Access Control (MAC).
Radio Link Control
This describes Radio Link Control (RLC).
2.2 Connection Management
This describes the connection management of the BSS. Connection management is a
function for the control, assignment, and management of the services provided by the network.
The services are short message services (SMSs), teleservices, and location-based services.
2.3 BTS Management
This describes the BTS management function. BTS management is a function where procedures
and messages related to the BTS are performed. The procedures and messages such as the
BTS software downloading, BTS data configuration, BTS status management, and BTS alarms
management should be performed by the peer-layer entities of the BSC and BTS.
2.4 BSS Operation and Maintenance
This describes the OM functions of the BSS. The BSS provides OM functions, such as,
performance management, BTS OM, BSC OM, clock control setting, BSC alarms, BTS alarms,
BTS commissioning, dynamic data configuration, GUI, and integrated network management
interfaces. 3 Huawei BTS

3. Huawei Base Station Subsystem
BTS ของบริษัท Huawei ที่ใชงานในระบบ GSM ซึ่งบริษทผลิตออกมาใหบริการหลายรุนดวยกันคือ
ั
BTS3012, BTS3012AE, BTS3006, BTS3006A, BTS3900, BTS3900A, DBS3900 วิธีการสังเกตดูรหัส
ของ BTS ในเบื้องตนนั้นสังเกตโดยดูทหมายเลขรุนนั้นเลข 3 หมายถึง BTS ระบบ GSM และตัวเลขสอง
ี่
หลักสุดทายจะหมายถึงจํานวน TRX สูงสุดที่สามารถติดตั้งไดภายใน Cabinet เดียวกัน สวนตัวอักษร A
หมายถึง BTS นันสามารถติดตั้งแบบ Outdoor
้

3.1 BTS 3012
BTS 3012 ออกแบบมาใชสําหรับใชงานแบบ macro cell ติดตั้งแบบ indoor จํานวน TRX ภายใน
Cabinet ติดตั้งไดสูงสุด 12 TRXs และภายใน 1 สถานีฐาน(Site) สามารถติดตั้ง BTS 3012ไดสูงสุด 6
Cabinets ทําใหรองรับจํานวน TRX สูงสุดถึง 72 TRXs รองรับการทํางานในระบบ GSM/EDGE Radio
Access Network ที่ความถี่ 850 MHz, 900 MHz, 1800 MHz, และ 1900 MHz ดังนั้น BTS 3012 จึง

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สามารถออกแบบใหรองรับไดทั้งปริมาณผูใช(Volume)และคอบคลุมพืนทีการใหบริการ(Coverage)ไดเปน
 ้ ่
อยางดีสาหรับคุณสมบัติที่สําคัญของ BTS 3012 มีดังนี้
ํ
• รองรับการทํางานแบบ Power Boost Technology (PBT) ทําใหกําลังสง TRX สูงถึง 100 w.
• ความไวของ TCH (sensitivity) ที่ -112.5 dBm (typical value in normal temperature).
• สามารถใชสญญาณนาฬิกาไดทั้ง Line Clock และ GPSรองรับการทํางานของ
ั
Transmissions E1, FE, T1, STM-1, microwave, and satellite และ Hub transmission.
3.1.1 โครงสรางพื้นฐานของ BTS 3012

BTS3012 ประกอบดวย cabinet, antenna subsystem, OM equipment, และ auxiliary
equipment ดังภาพที่ 2

ภาพที่ 2 แสดง BTS3012 Cabinet

• Cabinet เปนสวนการทํางานหลักของ BTS3012 โดยทําการประมาณผลทั้ง RF
Signal และ Baser Band Signal
• Antenna Subsystem ทําหนาที่รับและสงสัญญาณ Uplink และ Downlink กับ
MS ผานทาง Um interface
• OM Equipment เปนสวนการจัดการระบบของ BTS3012 ในระบบของ BTS3012
สามารถทํา OM ได 3 แบบดวยกันคือ Site Maintenance Terminal, Local
Maintenance Terminal และ Network iManager

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• Auxiliary Equipment เปนสวนเสริมที่ทาใหการของระบบมีความสมบูรณ
ํ
ประกอบ ดวยระบบยอยดังตอไปนี้นี้ Power Supply Converter. Monitor,
Sensor . Report และ alarm เปนตน

3.1.1.1. Physical Structure
โครงสรางทางฟสิคอลของ BTS3012 จัดไดหลายรูปแบบดวยกัน ทังนี้ขนอยูกับ
้ ึ้
จํานวน TRX ที่ใชงาน ซึง BTS3012 นั้นสามารถใชงานไดทั้ง -48 V DC และ +24 V DC
่
สําหรับในการใชงานแบบ –48V DC นั้นระบบจะตองประกอบดวย DAFU subrack,
DTRU subrack, fan subrack, common subrack, signal lightning protection
subrack, transmission subrack, and power distribution unit. แสดงคอนฟกสูงสุดที่
ใชไดใน 1 Cabinet คือ S4/4/4 configuration

ภาพที่ 3 แสดง Rack BTS3012

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(1) Transmission subrack (2) Common subrack (3) Fan subrack (4) DTRU
subrack (5) DAFU subrack (6) Power supply unit (7) Signal lightning protection
subrack
เมื่อใชงานแบบ +24 V DC นั้นระบบจะตองประกอบดวย DAFU subrack,
DTRU subrack, fan subrack, common subrack, signal lightning protection
subrack, transmission subrack, และ power distribution unit แสดงคอนฟกสูงสุดที่
ใชไดใน 1 Cabinet คือ S4/4/4 configuration

ภาพที่ 4 แสดง Fully configured BTS3012 cabinet (+24 V DC)
(1) Power subrack (2) Common subrack (3) Fan subrack (4) DTRU subrack
(5) DAFU subrack (6) Power supply unit (7) Signal lightning protection subrack

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3.1.1.2 Logical Structure

โครงสรางทาง Logical ของ BTS3012 ประกอบดวย Common Subsystem,
signal protection subsystem, double-transceiver subsystem, RF front-end
subsystem, power subsystem, environment monitoring subsystem, และ
antenna subsystem. แสดงดังรูปที่ 5

ภาพที่ 5 The logical structure of the BTS3012.

Common subsystem ติดตั้งอยูบน common subrack. ทําหนาทีควบคุม clock
่
signals ของ BTS ตรวจสอบระบบ alarms, เชื่อมตอกับโครงขายผาน Abis ประกอบดวย
DTMU, DEMU, DATU, DCSU, DCCU, DPTU, DABB, and DGPS. การคอนฟกส
แสดงดังภาพที่ 6

ภาพที่ 6 แสดง Commom subrack

− DTMU (Transmission/Timing/Management Unit for DTRU BTS )มี
หนาที่ 3 อยางคือ เชื่อมตอ Transmission บน Abis ควบคุม Timing

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และ Management BTSทํางานในโหมด active/standby ติดตั้งไดสูงสุด
2 บอรด

− DEMU(Environment Monitoring Unit for DTRU BTS) ทําหนาที่
มอนิเตอรสัญญาณจาก Alarm Sensor ตางๆเชน smoke sensor, water
sensor, temperature and humidity sensor, infrared sensor, and
door control sensor และสงรายงานไปที่ DTMU สามารถคอนฟกสบน
slot 2, 3, 4, หรือ 7

− DCSU(Combined cabinet Signal connection Unit for DTRU BTS)
ทําหนาที่สงสัญญาณ clock signals, data signals, และ control

signals จาก DTMU ไปที่ DTRU และหนาที่อีกประการหนึ่งคือเชื่อม
สัญญาณระหวาง Cabinet สําหรับกรณีที Site มีการใชงานมากกวา 1
Cabinetสามารถคอนฟกสบน slot 5 เทานัน
้

− DCCU(Cable Connection Unit for DTRU BTS)

− DATU(Antenna and TMA Control Unit for DTRU BTS) ทําหนาที่
ควบคุม RET antenna , Feeds power to the TMA ,Reports the RET
control alarm signals และ Monitors the current from the feeder

−

ภาพที่ 7 แสดงการเชื่อมตอสัญญาณบน Common Subsystem

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− Signal Protection Subsystem ทําหนาทีปองกัน E1 และ Signal
่
ตางๆจากสายฟา(Lightning) ประกอบดวยโมดูล DMLC, DELC,
and DSAC

3.2 BTS3012AE
This introduces the BTS3012AE. The BTS3012AE is an outdoor macro BTS that
supports the double-transceiver or multi-transceiver configuration. One BTS3012AE
cabinet can provide a maximum of 12 TRXs or 36 TRXs.
System Architecture

The BTS3012AE system consists of the cabinet, antenna subsystem, OM
equipment, and auxiliary equipment.

ภาพที่ 8 แสดงสถาปตยกรรมของ BTS3012AE
Overview

The BTS3012AE can be configured with the QTRU or the DTRU. The common
features are as follows:
• Supports the TCH/FS static sensitivity of -112.5 dBm (typical value in normal
temperature).

13

• Supports the Hub BTS function.
• Supports soft synchronization on the Um interface.
• Supports Flex Abis networking.
• Supports optimized Abis transmission.
• Supports rapid switchover of the ring topology.
• Supports local switching.
• Supports Abis over IP.
• Supports clock over IP.
• Supports various transmission modes such as E1, FE, T1, STM-1, microwave, and
satellite transmission.
Besides the above features, the BTS3012AE with the QTRU has the following features:
• Supports a maximum of 36 TRXs in a cabinet and 72 TRXs in cabinet groups.
• Supports the 900 MHz frequency band.
Besides the above features, the BTS3012AE with the DTRU has the following features:
• Supports a maximum of 12 TRXs in a cabinet and 36 TRXs in multiple cabinets.
• Supports the Power Boost Technology (PBT). The maximum output power of one
TRX is 100 W.
• Supports transmit diversity and four-way receive diversity.
• Supports multiple frequency bands (850 MHz, 900 MHz, 1800 MHz, and 1900
MHz) to meet requirements in different regions.

14

Application Scenario

The BTS3012AE supports the evolution to the GSM/EDGE radio access network
(GERAN). It is deployed in cities, rural areas, and suburbs with heavy traffic and wide
coverage requirements or deployed in areas where site acquisition is difficult or the cost
of an equipment room is high.

Physical Structure of the BTS3012 (for 36 TRXs)

This describes the physical structure of the BTS3012. The BTS3012 consists of
the BTS3012 cabinet, antenna subsystem, and operation and maintenance (OM)
equipment.

Physical Structure of the BTS3012 Cabinet

When the external -48 V DC power is used, the components of the BTS3012
cabinet are the DAFU subrack, QTRU subrack, fan subrack, common subrack, signal
lightning protection subrack, transmission subrack, and power distribution unit.

ภาพที่ 9 แสดง Fully configured BTS3012 cabinet (-48 V DC)

15

(1) Transmission subrack (2) Common subrack (3) Fan subrack

(4) QTRU subrack (5) DAFU subrack (6) Power distribution unit

(7) Signal lightning protection subrack

When the external +24 V DC power is used, the components of the BTS3012
cabinet are the DAFU subrack, QTRU subrack, fan subrack, common subrack, signal
lightning protection subrack, power subrack, and power distribution unit.

ภาพที่ 10 แสดง Fully configured BTS3012 cabinet (+24 V DC)

16

(1) Power subrack (2) Common subrack (3) Fan subrack

(4) QTRU subrack (5) DAFU subrack (6) Power distribution unit

(7) Signal lightning protection subrack

• DAFU subrack
The DAFU subrack is configured with the DDPU.
For details on the DAFU subrack, refer to BTS3012 RF Front-End Subsystem.
• QTRU subrack
The QTRU subrack can hold up to six QTRUs.
For details on the QTRU subrack, refer to BTS3012 Multi-Transceiver
Subsystem.
• Fan subrack
The fan subrack is configured with one fan box that holds four fans and one
fan monitoring board. The fan monitoring board detects the temperature at
the air inlets at the bottom of the cabinet and automatically adjusts the fan
speed.
For details on the fan subrack, refer to Fan Box.
• Common subrack
The common subrack is installed below the fan subrack. It holds the following
parts:
DTMU
DEMU
DATU
DCSU
DCCU
DABB

17

DPTU
DGPS
For details on the common subrack, refer to BTS3012 Common Subsystem.
• Signal lightning protection subrack
The signal lightning protection subrack is installed on top of the cabinet. It is
configured with the following boards:
DMLC
DELC
DSAC
For details on the functions of the signal lightning protection subrack, refer to
Signal Protection Subsystem of the BTS3012.
• Transmission subrack
The transmission subrack is located below the common subrack. The
transmission subrack reserves space for installing the baseband unit (BBU).
The SDH and microwave transmission equipment can be installed in the
transmission subrack.
• Power distribution unit
The power distribution unit consists of the DC lightning arrester, PGND bar,
EMI filter, and the busbar at the right of the cabinet.
For details on the power distribution unit, refer to BTS3012 Power Subsystem.
• Power subrack
The power subrack is located at the bottom of the cabinet. It consists of the
PSUs and the cable distribution area.
For details on the power subrack, refer to BTS3012 Power Subsystem.

18

Logical Structure

The logical structure of the BTS3012AE varies according to the external input
power and the configuration of transceiver units.
• ภาพที่ 11 Shows the logical structure of the BTS3012AE that uses the DC input
power. In this case, the BTS3012AE consists of the following logical
subsystems: common subsystem, signal protection subsystem, double-
transceiver subsystem, RF front-end subsystem, power subsystem,
environment monitoring subsystem, and antenna subsystem.

ภาพที่ 11 แสดง Logical structure of the BTS3012AE (DC)
• ภาพที่ 12 Shows the logical structure of the BTS3012AE that uses the AC input
power and is configured with the QTRU. In this case, the BTS3012AE consists
of the following logical subsystems: common subsystem, signal protection
subsystem, multi-transceiver subsystem, RF front-end subsystem, power
subsystem, environment monitoring subsystem, and antenna subsystem.

19

ภาพที่ 12 Logical structure of the BTS3012AE with the QTRU (AC)

• ภาพที่ 13 Shows the logical structure of the BTS3012AE that uses the AC input
power and is configured with the DTRU. In this case, the BTS3012AE consists of
the following logical subsystems: common subsystem, signal protection
subsystem, double-transceiver subsystem, RF front-end subsystem, power
subsystem, environment monitoring subsystem, and antenna subsystem.

ภาพที่ 13 Logical structure of the BTS3012AE with the DTRU (AC)

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Typical Hardware Configuration

The typical hardware configuration of the BTS3012AE is categorized into the
following two types:
• Typical hardware configuration of a single BTS3012AE cabinet
− When the transceiver subsystem is configured with the QTRU, refer to
Typical Hardware Configuration of a Single BTS3012AE Cabinet with the
QTRU for the typical hardware configuration of the BTS3012AE.
− When the transceiver subsystem is configured with the DTRU, refer to
Typical Hardware Configuration of a Single BTS3012AE Cabinet with the
DTRU for the typical hardware configuration of the BTS3012AE.
• Typical hardware configuration of BTS3012AE combined cabinets and cabinet
groups
− When the transceiver subsystem is configured with the QTRU, refer to
Typical Hardware Configuration of BTS3012AE Combined Cabinets and
Cabinet Groups with the QTRU for the typical hardware configuration of
the BTS3012AE.
− When the transceiver subsystem is configured with the DTRU, refer to
Typical Hardware Configuration of BTS3012AE Combined Cabinets and
Cabinet Groups with the DTRU for the typical hardware configuration of the
BTS3012AE.

3.3 BTS 3900
BTS3900 and BTS3900A
The BTS3900 is an indoor macro base station developed by Huawei. The
BTS3900 mainly consists of the BBU3900 and the RFUs. Compared with traditional
BTSs, the BTS3900 features simpler structure and higher integration.

The BTS3900 features:

21

• It is developed on the basis of the unified BTS platform for Huawei wireless
products and enables the smooth evolution from 2G to 3G.
• It supports the Abis IP/FE interface in hardware and enables Abis over IP through
software upgrade if required.
• It shares the BBU3900 subrack, which is the central processing unit, with the
DBS3900 to minimize the number of spare parts and reduce the cost.
• It can be flexibly installed in a small footprint and can be easily maintained with
low cost.
• It supports multiple frequency bands, such as PGSM900, EGSM900, and
GSM1800.
• It supports TX diversity (not supported by the GRFU) and PBT (not supported by
the GRFU).
• It supports 2-way and 4-way RX diversity (not supported by the GRFU) to
improve the uplink coverage.
• It supports Frequency Domain Reflectometer (FDR) , enables accurate standing
wave detection (not supported by the GRFU).
• It supports the GPRS and the EGPRS.
• It supports omnidirectional cells and directional cells.
• It supports the hierarchical cell, concentric cell, and micro cell.
• It supports multiple topologies, such as star, tree, chain, ring, and hybrid
topologies.
• It supports the A5/3, A5/2, and A5/1 encryption and decryption algorithms.
• It supports the cell broadcast SMS and point-to-point SMS.
• It supports coexistence with the BTS3X, BTS3012, and DBS3900.
• When the DRFU is configured for the BTS3900, a BTS3900 can support a
maximum of 12 carriers in the maximum cell configuration of S4/4/4. In addition,
a site configured with the BTS3900s can support a maximum of 36 carriers in the
maximum cell configuration of S12/12/12.
• When the GRFU is configured for the BTS3900, a BTS3900 can support a
maximum of 36 carriers in the maximum cell configuration of S12/12/12. In

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addition, a site configured with the BTS3900s can support a maximum of 72
carriers in the maximum cell configuration of S24/24/24.
• Supports smooth evolution from 2G to 3G through the unified BTS platform.
• Supports multiple frequency bands, such as PGSM900, EGSM900, and
DCS1800.
• Supports transmit diversity and PBT.
• Supports two-way and four-way receive diversities to improve the uplink
coverage.
• Supports the GPRS and EGPRS.
• Supports multiple network topologies, such as star, tree, chain, ring, and hybrid
topologies.
• Supports the cell broadcast SMS and point-to-point SMS.

System Architecture

The BTS3900 GSM system consists of the cabinet, antenna subsystem, OM
equipment, and auxiliary equipment. ภาพที่ Shows the BTS3900 GSM system
architecture.

ภาพที่ 14 BTS3900 GSM system architecture

23

System Architecture of the BTS3900

The BTS3900 consists of the BBU3900, RFUs, and indoor macro cabinet. The
BBU3900 and RFUs are installed in the indoor macro cabinet.

ภาพที่ 15 แสดง BTS3900 system
The BTS3900 mainly consists of the following components:
• The BBU3900 is used for baseband processing and enables interaction
between the BTS and the BSC.
• The RFU is an RF filtering unit, which performs modulation, demodulation, data
processing, and combining and dividing for baseband signals and RF signals.
• The indoor macro cabinet houses the BBU3900 and RFUs. In addition, the
indoor macro cabinet provides the functions such as power distribution, heat
dissipation, and surge protection
• The RFUs are of two types: DRFUs and GRFUs.

24

Logical Structure of the BTS3900

The BTS3900 mainly consists of the BBU and RFUs. The logical structure of the
BTS3900 consists of the RF subsystem, control subsystem, power subsystem, and
antenna subsystem.

ภาพที่ 16 แสดง Logical structure of the BTS3900

The logical subsystems of the BTS3900 are as follows:
• RF subsystem, implemented by the DRFU or GRFU
• Control subsystem whose functions are implemented by the BBU
• Power subsystem whose functions are implemented by the
following modules:
DCDU-01 Module in the BTS3900 cabinet (-48 V DC)
DCDU-01 Module and Power Subrack (DC/DC) in the BTS3900
cabinet (+24 V DC)

25

DCDU-01 Module and Power Subrack (AC/DC) in the BTS3900
cabinet (220 V AC)
• Antenna subsystem whose functions are implemented by the
following modules:
GATM
TMA
Antenna

Structure of the BTS3900 -48 V Cabinet

The BTS3900 cabinet (-48 V) uses the external -48 V DC input. The DC power is
directly led into the DCDU-01 and the DCDU-01 distributes the DC power to each
component in the cabinet. The BTS3900 -48 V cabinet can be installed alone, stacked on
another BTS3900 -48 V cabinet, or installed side by side with another BTS3900 -48 V
cabinet.
The BTS3900 -48 V cabinet consists of the following components: the DRFUs or
GRFUs, BBU, GATM, DCDU-01, and FAN unit, among which the GATM is optional.

Single Cabinet Installation

ภาพที่ 17 แสดง Typical configuration of the BTS3900 -48 V cabinet in single cabinet installation

26

Double Cabinet Installation

ภาพที่ 18 แสดง Typical configuration of two BTS3900 -48 V cabinets in side-by-side
installation

ภาพที่ 19 แสดง Typical configuration of two BTS3900 -48 V cabinets in stack

27

BTS3900/BTS3900A Configuration Principles

The BTS3900/BTS3900A is configured with RFUs. When the DRFU is configured,
a single BTS3900/BTS3900A provides a maximum of 12 carriers with the maximum cell
configuration of S4/4/4. When the GRFU is configured, a single BTS3900/BTS3900A
provides a maximum of 36 carriers with the maximum cell configuration of S12/12/12.
The BTS3900/BTS3900A is configured with the antenna system, RFUs, and BBU.

Basic Configuration Principles

• If multiple hardware configurations meet the requirements for the RNP parameter
settings, the configuration mode that supports smooth upgrades is preferred.
• The DRFU supports a maximum of two carriers and it is applicable to small- and
middle-capacity scenarios; the GRFU supports a maximum of six carriers and it
is applicable to large-capacity scenarios. The DRFU and GRFU can be
configured in the same cabinet or cell to support flexible capacity expansion.
• Wide coverage is preferred. The DRFU supports the PBT, TX diversity, and 4-way
RX diversity mode. Therefore, the DRFU can be applied to wide-coverage
scenarios.

Antenna Configuration Principles

• One dual-polarized antenna can serve a maximum of two RFUs.
• By default, RX diversity is adopted on the GSM network. That is, two feeders
connected to two single-polarized antennas or one dual-polarized antenna must
be configured in a cell.
• Each sector of the BTS must be configured with the minimum number of
antennas.
• For the 2-way RX diversity, each sector has two antenna channels; for the 4-way
RX diversity, each sector has four antenna channels.

28

RF Configuration Principles

Table 1 describes the RF configuration principles of the BTS3900.

Table 1 RF configuration principles of the BTS3900

Principle Description Example

Configuration • ANT1 and ANT2 are the TX In S3/3 configuration, three DRFUs
principles of the ports of the duplexer. They are need to be configured. The carriers
DRFU ports connected to jumpers. provided by the middle DRFU belong
• Rx1 in, Rx1 out, Rx2 in, and to different cells. That is, the Rx1 in
Rx2 out are the ports for signals port on the middle DRFU is the input
between interconnected DRFUs. port for RX diversity of carrier 1,
When two carriers provided by a which belongs to the first cell. The
DRFU belong to the same cell, input port for RX main of carrier 1 is
both Rx1 in and Rx2 in can be ANT1. The Rx2 in port is the input
the input ports for RX diversity of port for RX diversity of carrier 2,
the two carriers. When two which belongs to the second cell.
carriers provided by a DRFU The input port for RX main of carrier 2
belong to different cells, Rx1 in is is ANT2.
the input port for RX diversity of
carrier 1; Rx2 in is the input port
for RX diversity of carrier 2.
• CPRI_0 and CPRI_1 are the
ports for high-speed electrical
cables. The CPRI_1 port is
connected to the CPRI port on
the BBU or to the upper-level
RFU in the case of cascaded
RFUs. The CPRI_0 port is
connected to the lower-level RFU

29


in the case of cascaded RFUs.

Configuration • The ANT_TX/RXA port None.
principles of the supports signal reception and
GRFU ports transmission, and the ANT_RXB
port supports signal reception.
They are connected to jumpers.
• RX_INB and RX_OUTA are the
ports for signals between
interconnected GRFUs.
• CPRI_0 and CPRI_1 are the
ports for high-speed electrical
cables. The CPRI_0 port is
connected to the CPRI port on
the BBU or to the upper-level
RFU in the case of cascaded
RFUs. The CPRI_1 port is
connected to the lower-level RFU
in the case of cascaded RFUs.

Configuration • Star topology is adopted None.
principles of a between the BBU and RFUs. The
single cabinet RFUs and the high-speed CPRI
ports on the BBU have a one-to-
one relationship. That is, if slot 1
on the RFU is idle, CPRI port 1
on the BBU is also idle.
• When the DRFU is configured,

30


the maximum cell configuration
of a single cabinet is S4/4/4.
When the GRFU is configured,
the maximum cell configuration
of a single cabinet is S12/12/12.

Configuration When star and chain topology is None.
principles of adopted between the BBU and RFUs,
multiple the RFU supports 3 levels of
cabinets cascading in a chain and thus the
BBU supports a maximum of 18 (6 x
3) RFUs.

Two TRXs of one • A single DRFU does not For example, for a site in S5/4/7 cell
DRFU support the S1/1 application; configuration, nine DRFUs are
configured in however, three DRFUs support installed to meet the requirements of
one sector the S3/3 application. S6/4/8 cell configuration, but data
• When the DRFU works in TX configuration is still performed on the
PBT, TX diversity, or 4-way RX basis of the S5/4/7 cell configuration.
diversity mode, a DRFU provides
only one TRX. Therefore, you can
configure the DRFU as required.

Number of • When the number of TRXs of • S3/3/3: Number of DRFUs =
DRFUs the site is less than 12, an odd round up (9 / 2) = 5; S1/2/3:
number of TRXs can be Number of DRFUs = round up
configured for a cell. Number of [(6 + 1) / 2] = 4.
DRFUs = round up [(number of • After two TRXs are configured

31


TRXs + number of S1 cells) / 2] in one sector, the S5/5/5
• When the number of TRXs of configuration is S6/6/6. Number
the site is greater than 12, an of DRFUs = (6 + 6 + 6) / 2 = 9.
even number of TRXs should be
configured for a cell. Number of
DRFUs = round up (number of
TRXs after two TRXs are
configured in one sector / 2)

Number of • One GRFU does not server None.
GRFUs two cells. Each cell with a single
antenna can be configured with
a maximum of two GRFUs.
• One GRFU supports a
maximum cell configuration of
S6; two GRFUs supports a
maximum cell configuration of
S12. To support the configuration
larger than S12, multiple antenna
systems are used.

DRFU TRX After TRX allocation, the cells with an • In S3/5/4 configuration, S5
allocation in odd number of TRXs become can be divided into S3 + S2.
double-antenna- neighboring cells of each other. Then, the cell configuration
system mode • S5 = S3 + S2 or S5 = S2 + S3 becomes S3/(3/2)/4.
• S6 = S4 + S2 or S6 = S3 + S3 • In S2/5/5 configuration, the
• S7 = S4 + S3 or S7 = S3 + S4 first S5 is divided into S2 + S3;
the second S5 is divided into S3

32


• S8 = S4 + S4 + S2. Then, the cell
configuration becomes
S2/(2/3)/(3/2).

DRFUs at two • If the number of DRFUs is not None.
bands more than 6 in a double-band
configured in a site, the DRFUs at two bands are
site configured in the same cabinet.
If the RF cabinet is configured
with less than three 900 MHz
DRFUs and three 1800 MHz
DRFUs, the 900 MHz DRFUs are
installed in of the three slots on
the left of the RF cabinet, and the
1800 MHz DRFUs are installed in
the three slots on the right of the
RF cabinet.
• When two RF cabinets are
configured and the number of
DRFUs at each band is not more
than six, the 900 MHz DRFUs are
installed in the first RF cabinet
and the 1800 MHz DRFUs are
installed in the second RF
cabinet. The DRFUs are installed
in the slots according to the
typical S4/4/4 configuration.

33


When two RF cabinets are
configured and the number of
DRFUs at one band (for
example, 900 MHz) is greater
than six, other DRFUs at this
band share the other RF cabinet
with the DRFUs at the other band
(for example, 1800 MHz). The
mixed configuration of DRFUs at
two bands is not allowed.

Coexistence Coexistence configuration principles None.
configuration of the DRFUs and GRFUs are as
principles of the follows:
DRFUs and • The primary BCCH is carried
GRFUs on a GRFU.
• When the requirements of the
output power and number of
carriers are met and the cell
configuration is greater than S4,
a single DRFU is configured with
one TRX; when two DRFUs are
configured, one DRFU is
preferably used.
• The TX power of a DRFU and
that of a GRFU within a cell are
almost the same. The power

34


difference should not exceed 0.5
dB.
• When the DRFUs and GRFUs
are configured in one cell, 4-way
RX diversity and TX diversity are
not supported.
• The DRFUs and GRFUs are
not recommended in the same
new site.

BBU Configuration Principles

• A BBU has 6 CPRI ports and supports a maximum of 72 carriers.
• Shows the BBU slots.

ภาพที่ 20 แสดง BBU slots

35

• Table 2 describes the board configuration principles of the BBU.

Table 2 Board configuration principles of the BBU

Module or Description
Board

UBFA One UBFA must be configured.

UPEU One UPEU must be configured.
A second UPEU can be configured when the backup power is
required. The BBU, however, cannot be configured with the UPEU and the
UEIU at the same time.

UEIU One UEIU must be configured when more than two BTS3900
cabinets are configured in a single site.
In the outdoor application, one UEIU must be configured when more
than one APM30 power cabinet is configured.

GTMU One GTMU must be configured.
The GTMU is installed in slot 5 or slot 6.

UELP Not required in the BTS3900
One UELP must be configured in the BTS3900A. The UELP is
installed in slot 1.

USCU The USCU is optional and a maximum of one USCU can be
configured.
The USCU is installed in slot 0.

36

CPRI Cable Connections of the RFUs

The RFUs support various topologies: star, chain, and ring.

ภาพที่ 21 แสดง Typical topology of the DRFUs

ภาพที่ 22 แสดง Typical topology of the GRFUs

37

Table 3 describes the three typical topologies of the DRFUs.

Table 3 Three typical topologies of the DRFUs

Topology Application Scenario

Star Supports the minimum configuration scenarios

Chain Supports the maximum configuration scenarios

Ring Supports the high reliability scenarios

3.4 BTS3900A GSM

This introduces the BTS3900A GSM. The BTS3900A GSM is the fourth-generation
outdoor macro BTS developed by Huawei.

System Architecture

The BTS3900A GSM system consists of the cabinet, antenna subsystem, OM
equipment, and auxiliary equipment

ภาพที่ 23 แสดง BTS3900A GSM system architecture

38

Overview

The features of the BTS3900A GSM are as follows:
• Supports smooth evolution from 2G to 3G through the unified BTS
platform.
• Supports the Abis IP/FE port in hardware and supports Abis over IP
through software upgrade.
• Shares the BBU, which is the central processing unit, with the DBS3900
GSM to minimize the number of spare parts and reduce the cost.
• Features small size, flexible installation, easy maintenance, and low OM
cost.
• Supports multiple frequency bands, such as PGSM900, EGSM900, and
DCS1800.
• Supports transmit diversity and PBT.
• Supports two-way and four-way receive diversities to improve the uplink
coverage.
• Supports the GPRS and EGPRS.
• Supports omnidirectional cells and directional cells.
• Supports the hierarchical cell, concentric cell, and micro cell.
• Supports multiple network topologies, such as star, tree, chain, ring, and
hybrid topologies.
• Supports the A5/3, A5/2, and A5/1 encryption and decryption algorithms.
• Supports the cell broadcast SMS and point-to-point SMS.
• Supports synchronization with the BTS3012.
• Supports a maximum of 12 TRXs in a cabinet and the maximum
configuration of S4/4/4.

39

• Supports a maximum of 72 TRXs in multiple cabinets and the maximum
configuration of S24/24/24.


A single BTS3900A GSM cabinet supports the S4/4/4 configuration. The
BTS3900 GSM can support the S4/4/4 + S4/4/4 configuration through cabinet
stack. When the equipment room space is limited, the large-capacity
configuration can be used to realize the coverage of densely populated urban
areas.

Structure of the BTS3900A Cabinet

The BTS3900A cabinet consists of the RF cabinet and the APM30 power
cabinet. The RF cabinet is categorized into two types, namely 3RFU cabinet and
6RFU cabinet. The APM30 battery cabinet and APM30 transmission cabinet,
which provide backup power for a long period of time and space for user
equipment respectively, are optional for the BTS3900A.
The function modules of the BTS3900A include the DRFU, BBU, DCDU-
02, FMUA, FAN unit, and GATM, among which the GATM is optional.

40

ภาพที่ 24 แสดง Typical configuration of a BTS3900A cabinet (1)
(1) 6RFU cabinet (2) DRFU (3) FAN unit

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

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

(10) APM30 power cabinet - -

41

(1) Battery (2) 3RFU cabinet (3) DRFU

(4) FAN unit (5) FMUA (6) DCDU-02

(7) GATM (8) BBU (9) PDU

(10) Power subrack (AC/DC) (11) APM30 power cabinet -

42




(10) APM30 power cabinet (11) Battery (12) 3RFU cabinet

43




(10) APM30 power cabinet (11) DCDU-03A (12) Transmission unit

(13) APM30 transmission cabinet (14) Battery (15) APM30 battery cabinet

44

Logical Structure

The BTS3900A GSM consists of the BBU and DRFU. The BTS3900A GSM
consists of the following logical subsystems: RF subsystem, control subsystem,
power subsystem, and antenna subsystem. Figure 2 shows the logical structure
of the BTS3900A GSM.

ภาพที่ 28 แสดง Logical structure of the BTS3900A GSM

Typical Configuration of the BTS3900/BTS3900A

This lists the number of components required for the cell configuration of
S1/1/1, S2/2/2, S4/4/4, S6/6/6, S1/1/1 + S3/3/3, S2/2/2 + S2/2/2, and S4/4/4 + S4/4/4.

45

Table 4 lists the typical configuration of the BTS3900/BTS3900A.

Table 4 Typical configuration of the BTS3900/BTS3900A

Typical Number of Number of Number of Other Number of Other
Configuration DRFUs Antennas Components of the Components of the
BTS3900 BTS3900A

S1/1/1 3 3 • BTS3900 cabinet: • APM30 power
1 cabinet: 1
S2/2/2 3 3
• FAN unit: 1 • Power subrack
S4/4/4 6 3 • DCDU-01: 1 (AC/DC): 1
• BBU: 1 • PDU: 1
S2/2/2 + 6 6
S2/2/2 • Power subrack • BBU: 1
(DC/DC): 1 (+24 V • GATM: optional
DC input) • RF cabinet: 1
• Power subrack • FMUA: 1
(AC/DC): 1 (220 V AC • DCDU-02: 2
input) • FAN unit: 2
• GATM: optional

S6/6/6 9 6 • BTS3900 cabinet: • APM30 power
2 cabinet: 1
S1/1/1 + 8 6
• FAN unit: 2 • Power subrack
S3/3/3
• DCDU-01: 2 (AC/DC): 1
S4/4/4 + 12 6 • BBU: 1 • PDU: 1
S4/4/4 • Power subrack • BBU: 1
(DC/DC): 1 (+24 V • GATM: optional
DC input) • RF cabinet: 2
• Power subrack • FMUA: 2
(AC/DC): 1 (220 V AC • DCDU-02: 4

46

Table 4 Typical configuration of the BTS3900/BTS3900A

Typical Number of Number of Number of Other Number of Other
Configuration DRFUs Antennas Components of the Components of the
BTS3900 BTS3900A
input) • FAN unit: 4
• GATM: optional

3.5 DBS 3900
Introduction to the DBS3900 GSM

This introduces the DBS3900 GSM. The DBS3900 GSM is a type of multi-
transceiver distributed base station developed by Huawei.

System Architecture

The DBS3900 GSM consists of the BBU3900 GSM, RRU3004, and antenna
subsystem.

ภาพที่ 29 แสดง DBS3900 GSM system architecture

47

• The BBU3900 GSM provides physical interfaces for connections with the BSC
and RRU. It performs centralized management (OM and signaling processing)
of the entire base station system and provides the reference clock to the
system.
• The RRU3004 is an outdoor remote RF unit. It processes baseband signals and
RF signals.
• The antenna subsystem receives uplink signals and transmits downlink signals
on the Um interface.

Overview

The DBS3900 GSM has the following features:
• The maximum remote distance in cascaded mode is 40 km.
• Each RRU module carries two TRXs. The two combined RRU modules carry four
TRXs.
• Each BBU supports a maximum of 36 TRXs. It can support Abis IP through
software upgrade.
• Supports the Power Boost Technology (PBT). The maximum output power of the
TRX is 40 W at 900 MHz or 30 W at 1800 MHz.
• Supports the TCH/FS static sensitivity of -112.5 dBm (typical value in normal
temperature).
• Supports transmit diversity and four-way receive diversity.
• Supports software synchronization
• Supports E1 and T1 transmission
• Supports multiple network topologies, such as star, tree, chain, ring, and hybrid
topologies.
• Supports Flex Abis networking.
• Supports transmission sharing between the GSM system and the UMTS system.

48

• Supports AMR.
• Supports Abis transmission optimization. It supports the detection and recovery
of idle frames on the DBS and the BSC sides. Idle frames are not transmitted on
the transmission link. This saves the transmission bandwidth.
• Supports multiple frequency bands (850 MHz and 1800 MHz) to meet
requirements in different regions.


The DBS3900 GSM uses the Remote Radio Head (RRH) technology and features
flexible topology. It can be deployed in indoor coverage scenarios and outdoor
coverage scenarios, such as city street, highway, and railway.

BBU3900 GSM Module

Each BBU3900 GSM consists of five logical units: BTS interface unit, central
processing unit, high-speed interface unit, clock unit, and monitoring unit.

ภาพที่ 29 แสดง Logical structure of the BBU3900 GSM

49

For details on the logical units of the BBU3900 GSM, refer to:
• BTS Interface Unit
• Central Processing Unit
• High-Speed Interface Unit
• Clock Unit
• Monitoring Unit

RRU3004 Module

Each RRU3004 module consists of five logical units: high-speed interface
unit, signal processing unit, power amplifier (PA), dual duplexer, and low noise
amplifier (LNA).

ภาพที่ 30 แสดง Logical structure of the RRU3004
For details on the logical units of the RRU3004, refer to:
• High-Speed Interface Unit
• Signal Processing Unit

50

• PA
• Dual Duplexer
• LNA
3.6 BSC
BSC Physical Structure

This describes the physical structure of the BSC, including the cabinet,
cables, LMT computers, and alarm box.

ภาพที่ 31 แสดง Physical structure of the BSC
LMT: Local Maintenance Terminal PDF: Power Distribution Frame

Table 5 lists the components of the BSC.

Table 5 Components of the BSC

Component Introduction Description

GSM BSC control The GBCR provides For details, refer to GBCR
processing rack (GBCR) switching and processes (Configuration Type A) and GBCR

51


services for the BSC. One (Configuration Type B).
GBCR is configured in a
BSC.

GSM BSC service The GBSR processes For details, refer to GBSR Cabinet.
processing rack (GBCR) various services for the
BSC. The number of
GBSRs to be configured
depends on the traffic
volume. Zero to three
GBSRs can be configured.

BSC Cables BSC cables are classified For details, refer to BSC Cables.
into the Ethernet cable,
optical cable, and trunk
cable. The number of BSC
cables to be configured
depends on actual
requirements.

BSC LMT The LMT is a computer that For details, refer to LMT-Related
is installed with the LMT Definitions.
software package and is
connected to the OM
network of the NEs. It is
optional for the BSC.

Alarm box The alarm box can User manual delivered with the alarm
generate audible and box

52


visual alarms. It is
mandatory for the BSC.

BSC Logical Structure

Logically, the BSC system consists of the TDM switching subsystem, GE
switching subsystem, service processing subsystem, service control subsystem,
interface processing subsystem, clock subsystem, power subsystem, and
environment monitoring subsystem.

ภาพที่ 32 แสดง Logical structure of the BSC

The interface processing subsystem of the BSC provides the Pb or Gb
interface, depending on the types of PCU.

53

• When the built-in PCU is used, the interface processing
subsystem provides the Gb interface to enable the communication
between the BSC and the SGSN.
• When the external PCU is used, the interface processing
subsystem provides the Pb interface to enable the communication
between the BSC and the PCU.
The interface processing subsystem of the BSC cannot provide the Gb
interface and Pb interface simultaneously.
The interface processing subsystem supports different transmission
modes over the A interface:
• When the IP transmission is used, the A interface enables the
communication between the BSC and the MGW.
• When the TDM transmission is used, the A interface enables the
communication between the BSC and the MSC/MGW.
The interface processing subsystem of the BSC cannot support the two
transmission modes simultaneously.

BSC Hardware Configuration

This describes three types of BSC subracks, two installation modes of the
GTCS, three combination modes of BSC subracks, two types of PCU, and two
types of hardware configuration.

BSC Subracks

The BSC subracks can be classified into the following types:
• GMPS
• GEPS
• GTCS

54

Generally, both the GMPS and GEPS are referred to as the BM subrack,
and the GTCS is referred to as the TC subrack.
Both the BM subracks and the TC subracks have two interconnection modes.
• Inter-Subrack TDM Interconnections
The inter-subrack TDM interconnections between one BM subrack and
another BM subrack and between one TC subrack and another TC subrack are
established through the inter-GTNU cables. For details, refer to Physical
Structure of the BSC TDM Switching Subsystem.
• Inter-Subrack GE Interconnections
The GSCUs in the BM subracks or in the TC subracks are connected in
star topology. The subrack located in the center of the star topology is referred to
as the main subrack, and the subracks connected to the main subrack are
referred to as extension subracks. For the inter-subrack GE interconnection of
BM subracks, the GMPS must be the main subrack, and the GEPS must be the
extension subrack. For the inter-subrack GE interconnection of TC subracks, any
TC subrack can be the main subrack, and the other TC subracks must be
extension subracks. For details, refer to Physical Structure of the BSC GE
Switching Subsystem.

Installation Modes of the GTCS

The GTCS can be configured on the BSC side and on the MSC side. If
the GTCS is installed on the BSC side, the installation mode is referred to as local
GTCS. If the GTCS is installed on the MSC side, the installation mode is referred
to as remote GTCS.
• In local GTCS mode, the GSCU in the main GTCS is connected to
the GSCU in the GMPS through the crossover cable. In remote
GTCS mode, the GTCS is installed in an independent GBSR and
does not share a cabinet with the GMPS/GEPS. In addition, the

55

GSCU in the main GTCS is not connected to the GSCU in the
GMPS.

ภาพที่ 33 แสดง OM path between the GMPS and the main GTCS (in local GTCS mode)

ภาพที่ 34 แสดง OM path between the GMPS and the main GTCS (in remote GTCS mode)
As shown in Figure 33 when OM is performed on the local GTCS, the OM
information is carried by the GE link between the GSCU in the GMPS and the
GSCU in the main GTCS. The transmission rate is fast.

56

As shown in Figure 34 when OM is performed on the remote GTCS, the
OM information is carried by the E1/T1 link between the GEIUT/GOIUT in the
GMPS and the GEIUT/GOIUT in the main GTCS. The transmission rate is slow.
The application scenarios of the local GTCS and remote GTCS are as
follows: If the distance between the GSCU in the GMPS and the GSCU in the
main GTCS exceeds the maximum length of a crossover cable, the remote GTCS
should be configured. Otherwise, the local GTCS should be configured. For
example, the crossover cable can be made on site and its maximum length is
100 m. If the distance between the GMPS and the main GTCS exceeds 100 m,
the remote GTCS should be configured. Otherwise, the local GTCS should be
configured.

Configuration Modes of BSC Subracks

The BSC subracks support the following configuration modes:
• BM/TC separated
In BM/TC separated configuration mode, the BSC consists of
the GMPS/GEPS and GTCS. The GTCS can be configured on
the BSC side or on the MSC side.
Characteristics: In this configuration mode, the GTCS can be
configured flexibly. The GTCS can be configured in an
independent GBSR on the MSC side, thus saving the
transmission resources between the BSC and the MSC. The
GTCS can be configured on the BSC side and share a cabinet
with other subracks.
• BM/TC combined
In BM/TC combined configuration mode, the TC function is
performed by the GMPS or GEPS. When the TC is configured
in the GMPS, the subrack is still referred to as the GMPS. When
the TC is configured in the GEPS, the subrack is still referred to

57

as the GEPS. In BM/TC combined configuration mode, the TC
function is performed by the GDPUX.
Characteristics: Compared with the BM/TC separated
configuration mode, the BSC in BM/TC combined configuration
mode has a high density of integration. In addition, when the
capacity is the same, the BSC in BM/TC combined
configuration mode has fewer cabinets and subracks.
• A over IP
In A over IP configuration mode, the BSC consists of the
GMPS/GEPS and is not configured with the GTCS. In this case,
layer 3 of the A interface protocol stack uses IP, and the TC
function is performed by the MGW. Thus, the GTCS is not
required.
Characteristics: In A over IP configuration mode, the BSC has
few cabinets and subracks. In this case, the BSC must be
connected to the Huawei MGW.

Types of PCU

The BSC supports two types of PCU: built-in PCU and external PCU.
• The external PCU is an independent network element that provides
PS service processing functions. It communicates with the BSC over
the Pb interface, and communicates with the SGSN over the Gb
interface.
Characteristics: The external PCU requires a large floor area and is
difficult for installation and maintenance.
• The built-in PCU is the GDPUP, which provides PS service
processing functions. The GDPUP is configured in the GMPS/GEPS.

58

Application scenario: Compared with the external PCU, the built-in
PCU is a board that can be installed in a BSC subrack. The built-in
PCU features small footprint, easy cabling, and convenient
installation and maintenance.
The requirements for the configuration of the PCU vary with the
transmission modes over the Abis interface.
• When the IP protocol is used on layer 3 or HDLC protocol is used on
layer 2 of the protocol stack on the Abis interface, the BSC must use
the built-in PCU.
• When TDM transmission is used over the Abis interface, the BSC can
use either the built-in PCU or the external PCU.

BSC Hardware Configuration Types

The BSC supports two types of server: GBAM and GOMU. The
GBAM/GOMU enables the communication between the Local Maintenance
Terminal and the BSC.
• The GBAM is independent from the BSC components. It is connected
to the GSCU in the GMPS through the FE/GE port. If the GBAM is
used, it is configured in subrack 0 of the GBCR.
Characteristics: If the GBAM is used, the KVM must be configured to
serve as the operating platform for the GBAM. The GBAM occupies a
subrack in the GBCR and the cable connection of the GBAM is
complex.
• The GOMU is a type of board in the BSC. One GOMU occupies two
slots. The GOMU should be installed in slots 00 to 03 or slots 20 to 23
in the GMPS.
Characteristics: Compared with the GBAM, the GOMU requires a
small installation space. In addition, the GOMU features simple cable
connection and easy installation and maintenance.

59

The BSC hardware configuration is classified into configuration type
A and configuration type B based on the server used.
• In configuration type A, the BSC is configured with the GBAM.
• In configuration type B, the BSC is configured with the GOMU.
Compared with configuration type A, the BSC in configuration type B
can save a subrack. In addition, the cable connection is simple and
the installation and maintenance is easy.

สวนที่ 4 ขอคิดเห็นและขอเสนอแนะ
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สวนที่ 5 ความเห็นของผูบังคับบัญชาฝายที่เกี่ยวของ
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ผูประสานงาน นายวีระ ทองไพบูลย
โทร. 0-2104-4505 E-mail weera.t@cattelecom.com

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