01 system description

7/27/2019 01 System Description

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Technical Manual System DescriptionM900/M1800 BTS3X Series Base Transceiver Station

Chapter 1 Introduction


1.1 Current Status and Demands of GSM Network

Since the middle 1980s, public mobile communications have witnessed two

generations of development with the further development of cellular networking

technologies and the emergence of high-capacity mobile telecommunications system.

The first generation is an analog mobile telecommunications system, which only

provides speech services using FDMA technologies.

The second generation is a digital mobile telecommunications system, which

appeared in 1990s with relevant standards including GSM, IS-95, etc. This

system is mainly used for speech services and provides low speed circuit

switched data services at the same time.

At present, GSM communications network is being applied around the world. More

and more people have recognized its big potential of development.

The market demands for the GSM network cover the following aspects:

The base transceiver station (BTS) of larger capacity is required because of the

dramatic increase in the number of mobile subscribers and the heavier traffic. Higher multiplexing ratio over the Abis interface is required due to expensive

transmission resources.

It is required to reduce the equipment room size for cost saving.

Complicated transmission mode requires powerful BTS transmission adaptability

and multiple built-in transmission equipment.

The continuous expansion of GSM system requires that BTS be expanded

flexibly and the existing investment be protected against waste during system

expansion.

Service demands of mobile subscribers keep increasing, which requires the BTS

to support more services.

Since the power supply system is unstable, power supply of BTS is required to

adapt to a wider range of voltage fluctuation and to have certain protection

mechanism which ensures fast BTS recovery after it is powered on again.

BTS is required to provide better voice quality and faster switchover.

A series of macro cell BTSs are developed by Huawei to meet the above demands.

The series of BTSs provide a network solution to convenience in maintenance,

operation and management in densely populated areas and cities with large capacity

requirement.

Huawei Technologies Proprietary

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1.2 Product Orientation

BTS3X is the series of proprietary macro cell BTS developed by Huawei. The BTS

series include:

Indoor BTS30

Indoor BTS312

Outdoor BTS3006A

Outdoor BTS3012A

The above types of BTS can meet the requirements in multiple conditions. Table 1.1

gives a brief introduction to the BTS3X series.

Table 1.1 BTS3X macro cell series

BTS3X product

model

Maximum number

of TRXs of a single

cabinet

Application

BTS30 (indoor BTS) 6 TRXs Densely populated areas and

cities

BTS312 (indoor BTS) 12 TRXs Areas with high density and large

traffic

BTS3006A (outdoor

BTS)

6 TRXs Suburb or small town with

medium traffic

BTS3012A (outdoor

BTS)

12 TRXs Area in the urban where it is

difficult to select an equipment

room

BTS30 is a highly integrated indoor macro cell BTS with low power consumption,

featuring small size, high reliability and flexible networking. It can be applied to most

of the densely populated areas and cities.

BTS312 is highly integrated indoor macro cell BTS with large capacity and low power

consumption, which saves more room to facilitate expansion. It is mainly applied to

support cells with high density and large traffic.

BTS3006A and BTS3012A are outdoor macro cell BTSs with 6 TRXs and 12 TRXs

respectively that can adapt to complex climates and electromagnetic environment.

They feature low cost, fast site construction, high environment adaptability, serving as

a major supplement to indoor BTS. They provide a complete solution to the

construction of seamless mobile communication networks.


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Chapter 2 Product Features


2.1 BTS3X Technological Characteristics

The BTS3X series are designed as a typical all-in-one BTS by taking full

consideration of the requirements in capacity, configuration, installation, power supply,

transmission, and services. This section introduces its characteristics below.

2.1.1 Integrated RF Component Technology

Expansion based on the inheritance of the investment: BTS expansion can make

the utmost us of all the antenna and feeder parts.

Modular structure with good performance: RF combiner, divider and low noise

amplifier are integrated in the combining and distribution unit (CDU). All parts for

TRX processing, which include baseband processing, RF processing, power

amplification and power supply, are integrated in one transceiver unit (TRX). The

modular structure can reduce internal cable connections, improve system

reliability and facilitate installation and maintenance.

Intelligent CDU: The CDU features fine monitor and control functions, excellent

O&M, level 2 standing wave ratio alarm, low noise amplifier alarm, tower top

amplifier (TTA) alarm, TTA power supply. It also supports auto protection against

emergency, that is, it can close transmit power when the Tx channel of the

antenna and feeder is abnormal, and can power off to bypass the low noise

amplifier (LNA) when TTA is abnormal so as to ensure normal system operation.

Receive gain can be adjusted via remote control to ensure the sensitivity of the

receive system.

2.1.2 Mature RF Technology

RF hopping and baseband frequency hopping are provided to improve system

anti-interference capability. It has good performance in practical applications.

The advanced digital RF technology is adopted to raise batch consistency,

manufacture scalability and stability of the RF system.

2.1.3 Advanced E-Abis Technology

The enhanced Abis (E-Abis) supports various transmission modes and complex

topologies. The transmission mode can be SDH, E1, microwave, or satellite.


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The E-Abis includes the following techniques:

Advanced clock phase locking (APL): solves the problem of clock jittery by using

high-precision (up to 0.1 Hz) clock and characteristic software phase lock

technique. Problems such as SDH clock phase jittery and signal out of lock

during transmission via satellite are solved.

The system can tolerate a tolerance at the bit error rate of 1E-4, that is, 2 levels

higher than the common 1E-6 bit error rate. A better and smooth voice quality

can be obtained even in transmission through microwave and satellite.

The system can tolerate an intermittent link failure of less than 2 seconds, which

makes the BTS3X more suitable for applications in unstable conditions such as

SDH transmission switching, microwave, satellite transmission, etc.

Protection against long transmission delay on the Abis to support satellites

networking.

2.1.4 Powerful O&M Functions

BTS3X can perform the following O&M functions: software downloading, BTS object

attribute configuration management, equipment management and running status

monitoring.

Local maintenance: provides man machine interface (MMI), and implement

maintenance, monitoring and management to all objects of the BTS through the

local maintenance system.

Remote maintenance: O&M network is made in the GSM system. The authorized

user can use any workstation in the network via the remote maintenance console

to perform remote O&M to BTS NEs in the system.

System state monitoring provides system running indices indication, resource

state indication.

Security management provides MS login authentication, command authority

restriction, unsecured operation indication and user group management.

Test: auto-test of functions, loop-back test.

Upgrade: automatically checks the system for upgrade. System upgrading can

be performed via remote loading. The system can be restored to its previous

version if system upgrading fails.

2.2 Advantages of BTS3X Applications

2.2.1 Large Capacity and Wide Coverage

Large capacity of a single cabinet: BTS30 and BTS3006A can support up to 6

TRXs in the full configuration mode, while both BTS312 and BTS3012A can

support up to 12 TRXs in the full configuration mode.


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When a TRX is configured, the nominal value of transmit power at the antenna

connector is 40 W. When the power boost unit (PBU) is equipped, the nominal

value of transmit power can reach 80 W; When the enhanced duplexer unit

(EDU) is adopted, the RF signal combining consumption can be reduced and theBTS coverage can be expanded.

The dual timeslot expansion function is supported. Theoretically, a maximum

coverage of 120 km can be supported.

2.2.2 Cost Reduction

It supports multiplexing of 15:1, hence greatly reducing transmission cost.

Transmission equipment such as SDH can be integrated with the cabinet,

providing a solution for future upgrade and wideband radio access and reducing

transmission equipment investment. Centralized power supply provides power to various modules in a distributed

way. BTS30 and BTS312 can provide DC +24 V, DC -48 V and AC 220 V to

satisfy different power supply requirements.

BTS3006A and BTS3012A enjoy good performance in outdoor adaptability and

reduced investment in accessories.

1) Multiple cabinet types for BTS3006A and BTS3012A are provided to cater to the

environment features of different areas. BTS3006A includes two types: the

cabinet with an air conditioner (220V AC) and the cabinet with a heat-exchanger

(110V AC with double live line). The BTS3012A includes four types: the cabinet

with an air conditioner (220V AC), the cabinet with an air conditioner (110V AC

with double live line), and the cabinet with a heat-exchanger (220V AC) and the

cabinet with a heat-exchanger (110V AC with double live line).

2) The BTS3006A and BTS3012A enjoy a wide working temperature range. The

working temperature range of the cabinet with an air conditioner is -40oC to

+55oC (environment temperature), and that of the cabinet with a heat exchanger

is -40oC to +50oC (environment temperature).

3) The cabinet supports three-phase and single-phase power supply with wide

voltage range for the 220 V power supply system: 150V AC to 276 V AC, and the

tolerant voltage is 300V AC.4) The cabinet can adopt the double live line input method for the 110V power

supply system (that is, adopt the two live lines with 120 degrees or 180 degrees

phase difference, as shown in Figure 4.1).


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Figure 4.1 110V power supply

5) Designs for waterproof, dustproof, moisture proof, acid proof, mildew proof, and

ultraviolet radiation protection meet the IP55 protection standards.

6) Two types of storage battery box can be selected: built-in storage battery box

and extended storage battery cabinet. The built-in storage battery box is

equipped inside the cabinet. For BTS3012A and BTS3006A, it can be configured

with two 12 V/100 AH and two 12 V/50 AH batteries respectively. They can

supply power to the cabinet for at least 30 and 20 minutes respectively. The

extended storage battery cabinet can be optionally configured to extend the

power supply time.

7) It supports the combined cabinet with three cabinets. BTS3012A supports up to

36 TRXs per site, BTS 3006A supports up to 18 TRXs per site. The combined

cabinet can meet large-capacity service demands.

8) Room of standard 19 inches high, 5U wide (5 44.45 mm), 300 mm deep is

reserved together with cable outlet for microwave and SDH. Small built-in

microwave and SDH transmission equipment can be equipped for diverse

demands of the customers.

Caution:

The temperature range during which the built-in transmission device of the cabinet

can work normally is 0C 55C.


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2.2.3 Smooth Evolution

The BTS3X series can support:

850M, 900M, 1800M, and 1900M services.

Mixed dual band plug-in of 900 MHz and 1800 MHz modules of 6 cells

General packet radio service (GPRS), which helps to realize smooth evolution

from 2G to 2.5G systems.

2.2.4 Multiple Transmission Modes

Multiple built-in transmission modes: 75 ohm/E1, 120 ohm/E1, and SDH. The

BTS has powerful transmission adaptability.

Room for transmission equipment such as the built-in microwave and the SDH is

reserved in the BTS3012A and BTS3006A. Transmission power is also supplied.

Users can select transmission modes according to their demands.

Note:The built-in transmission equipment in the cabinet must meet the requirement of

working long time in the environment temperature of 0 oC55 oC. You can lead out the

24 V DC/220 V DC power supply from the cabinet for the transmission equipment. If it

is the 48 V power supply, the transmission power supply module is needed.


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Chapter 3 Product Introduction


3.1 Cabinet Configuration

This section introduces the typical single cabinet configuration of BTS30, BTS312,

BTS3006A and BTS3012A. BTS3X adopts a modular RF structure. Clients can

configure the boards according to the actual site condition by following certain

configuration rule.

3.1.1 BTS30

BTS30 dimensions: 1,600 mm (H) 600 mm (W) 450 mm (D)

Figure 1.1 shows a typical single BTS30 cabinet under full configuration. In the figure,

BTS30 is configured with 3 CDUs, 6 TRXs, 4 power supply units (PSUs), 1 power

monitor unit (PMU), 2 timing/transmission and management units (TMUs), 1

transmission extension power supply unit (TES) and 1 transmission extension unit

(TEU).


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TX

RX

CDU

TX

RX

CDU

TX

RX

CDU

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

P

S

U

P

S

U

P

S

U

P

S

U U

P

M

T

M

U

T

M

U

T

U

E

T

E

S

Switch Box

Air Inlet

Fan Box

Figure 1.1 Typical configuration of BTS30

3.1.2 BTS312

BTS312 Dimensions: 1,880 mm (H) 650 mm (W) 500 mm (D)

Figure 1.1 shows a typical single BTS3012 cabinet under full configuration. In the

figure, BTS312 is configured with 6 CDUs, 12 TRXs, 6 PSUs, 1 PMU, 2 TMUs, 1 TES

and 2 TEUs.


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TX

RX

CDU

TX

RX

CDU

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

CDU

TX

RX

CDU

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

CDU

TX

RX

CDU

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

TX

RX

TRX

P

S

U

P

S

U

P

S

U

P

S

U

P

S

U

P

S

U

P

M

U

T

M

U

T

M

U

T

U

E

T

U

E

T

E

S

Switch Box

Fan Box

Air Inlet

Fan BoxFan Box

Air Trough

Figure 1.1 Typical configuration of BTS312

3.1.3 BTS3006A

BTS3006A dimensions: 1,700 mm (H) 900 mm (W) 720 mm (D)

BTS3006A can be configured with 3 CDUs, 6 TRXs, 5 PSUs, 1 PMU, 1 TCU, 1 TMU


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and 1 Abis bypass board (ABB) and other auxiliary equipment, including transmission

equipment, power lightning protection filter box in the left of the cabinet, AC/DC power

distribution box, transmission supply unit (TSU) and the built-in battery box.

Switch box

Lightningfilter box

Battery

cabin

AC power

distribution

subrack

Battery cable

inlet

Lightning

protection

subrack

TCU

TMU

ABB

PSU

PSU

PSU

PSU

PSU

PMU

EMU

IPU

TS

U

Transmission

device

subrack

CD

U

CD

U

CDU

T

RX

T

RX

T

RX

T

RX

T

RX

T

RX

Air inlet

FMU

DC power

distribution

subrack

Figure 1.1 Typical configuration of BTS3006A

In addition, BTS3006A can be configured with large capacity extended battery

cabinet. It can hold 12 batteries with nominal voltage of 2 V. The appearance of the

cabinet is shown in Figure 1.2.


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Figure 1.2Appearance of storage battery cabinet without front door

3.1.4 BTS3012A

BTS3012A dimensions: 1,700 mm (H) 1,200 mm (W) 1000 mm (D)

Figure 1.1 shows a typical single BTS3012A cabinet under full configuration. As

shown in the figure, the cabinet is configured with 6 CDUs, 12 TRXs, 6 PSUs, 1 PMU,

1 TMU, 1 TCU and 1 Abis bypass board (ABB). The auxiliary equipment cabinet can

be configured with transmission device, power lightning protection filter box at cabinet

back, AC and DC power distribution boxes, voltage regulator, EMUA, transmission

supply unit (TSU), and built-in storage battery box.


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FAN

FAN

EMUA

CDU

CDU

CDU

CDU

C

DU

C

DU

TRX

TRX

TRX

TRX

TRX

TRX

TRX

TRX

T

RX

T

RX

T

RX

T

RX

PSU

PS

U

TSU

E1 lightning

protection

subrack

AC power

distribution

subrack

DC power

distribution

subrack

Battery Cabin

TCU

T

M

U

A

B

B

Transmission

device subrack

FAN FAN

Cable Inlet

Cable

Inlet

Switch Box

PMU

PSU

PSU

PSU

PSU

PSU

Figure 1.1 Typical configuration of BTS3012A

The BTS3012A can also be configured with a large-capacity extended storage battery

cabinet, which can accommodate 12 (or 24) storage batteries with the nominal

voltage of 2 V.

3.2 BTS3X System Architecture

BTS3X supports the following functions:

Connecting with the base station controller (BSC) via the Abis interface to

coordinate with BSC in radio resource management, radio parameter

management and interface management


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Communicating with the mobile station (MS) via the Um interface to realize radio

transmission and related control between BTS and MS

Figure 1.1 shows the system architecture of BTS30/312 equipped with TEU and TES.

TRX

TRX

TRX

CDU

CDU

ECDU

FHBU

S

TTA TTA

TTA TTA

TTA TTA

PMUPSU

FMU

TDU

TMU

TEU TES

Abis

E1

Fiber(Optinal)

Common Unit Signaling Processor Unit Antenna Feeder Unit

External Alarm

Um

CBUS/TBUS/DBUS

BSC

ABB&ABA

PBU

Figure 1.1 BTS30/312 system architecture

The following further explains the above figure:

1) The boards indicated by dotted blocks are optional:

There are 2 TMU slots on BTS30/BTS312 working in active/standby mode. The

standby TMU can be configured as required. TEU and TES, if configured, provide built-in optical transmission. ABB and Abis

bypass assistant board (ABA), if configured, provide the Abis bypass function.

Because ABB and ABA must be installed in the slots hosting TEU and TES, you

have to select one of the two functions.

Generally, the triplex TTA is adopted.

2) To meet the requirements in multiple frequency bands and coverage, there are

many types of combining and distribution units, including CDU, ECDU, enhanced

duplexer unit (EDU), railway GSM enhanced combining and distribution unit

(RCDU), railway enhanced duplexer unit (REDU), multi distribution unit (MDU),

simple combining unit (SCU), and enhanced simple combining unit (ESCU).

3) The PBU only supports the power amplification of 40 W TRX at GSM900 MHz

and GSM1800 MHz.

4) TEU is the generic term for boards realizing multiple optical transmission modes.

It includes boards access SDH unit (ASU) and passive transmission board (PAT)

that provide 155 M SDH and passive optical transmission respectively.

5) The system architecture of BTS3012A and BTS3006A is similar to that of

BTS30/BTS312. They only differ in the architecture of common subsystem.

Figure 5.1 shows the logical architecture of the common subsystem when an

ABB is installed. For the BTS3012A and BTS3006A, the ABB is optional, while


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no TEU, TES, ABA or standby TMU can be configured in the cabinet.

PMUPSU

FMU

Abis

E1

Common subsystem

ABB

TMU

Figure 5.1Architecture of common subsystem in BTS3012A/BTS3006A

Note:

The Abis transmission bypass function can be performed in BTS chain networking

environment:

When the site (excluding the last level) adopting ABB is powered down, ABB is

responsible to bypass the site on the Abis transmission line so as to keep the

working of other sites on the Abis transmission line normal.

When ABB is located in the last level site of the chain networking environment, if

the site is powered down, ABB is responsible to loop back the Abis transmission

line.

The BTS3X series of BTS are composed of the following subsystems:

I. Common Subsystem

The common subsystem is composed of boards such as TMU, PSU and PMU. It

performs the following functions:

Managing and controlling other subsystems and modules

Collecting alarm information

Providing multiple basic clocks for other subsystems and modules


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Board abbreviation Full name

EMU Environment Monitor Module

EMUA Environment Monitoring Unit Analyzer

ESCU Enhanced Simple Combining Unit

MDU Multi Combining and Distribution Unit

PAT Passive Transmission Board

PBU Power Boost Unit

PMU Power Monitor Unit

PSU Power Supply Unit

RCDU Railway GSM Enhanced Combining and Distribution Unit

REDU RGSM Enhanced Duplexer Unit

SCU Simple Combining Unit

TCU Temperature Control Unit

TDU Time Distribution Unit

TEU Transmission Extension Unit

TES Transmission Extension Power Supply Unit

TMU Timing/Transmission and Management Unit

TRX Transceiver Unit


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Chapter 4 Functions

Chapter 4 Functions

4.1 Basic Functions

This section describes the basic functions of the BTS3X series.

4.1.1 Basic Software Functions

The basic software functions of the BTS3X series include:

850M, 900M, 1800M, 1900M services

EGSM, RGSM extended frequency service

All data services prescribed in Phase II+

GPRS basic services

EDGE basic services, MSC1 MSC9 coding and encoding schemes

Support of Phase I/Phase II /Phase II+ compatible LAPDm protocols

CS-1/CS-2/CS-3/CS-4 radio channel coding schemes

Phase I/Phase II/ Phase II+ compatible system information broadcasting and

resource indication

Full rate (FR), enhanced full rate (EFR), half rate (HR) data services, adaptivemultirate (AMR) services, and all the other types of FR data services

Broadcasting short messages and point-to-point short messages

Paging queue

A5/1, A5/2 encryption/decryption

Basic data dynamic configuration

Dynamic resource management

Measurement report preprocessing

10:1, 12:1 and 15:1 signaling multiplexing on the Abis interface

BCCH frequency mutual-aid

Immediate assignment combination, paging combination and paging resend

functions, boosting the radio channel utilization

Voice activity detection (VAD) based discontinuous transmission (DTX) and

discontinuous reception (DRX)

Omnidirectional cell and directional cell

Chain, tree, star and ring networking modes supported

Support of locked, fast pull-in, holdover and free run clock modes

Synchronous, asynchronous and quasi-synchronous handover

Um interface tracing and internal interface tracing

Remote and local loading of software


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Chapter 4 Functions

Dynamic and static power control

Support of satellite transmission and support of 16 k signaling transmission on

the Abis interface

Support of extended cell functions Uplink frequency scanning

Support of Huawei power control algorithm II

Multi-cell configuration with up to 12 cells

Timeslot-based baseband frequency hopping and RF hopping

Support of class 3 handsets with large power

Support Adaptive Multi-Rate (AMR), support AMR FR and AMR HR

4.1.2 Basic Hardware Functions

Basic hardware functions of BTS3X series include:

Eight E1 ports and twelve antenna feeders ports

Support of battery management

Support of both 900 MHz and 1800 MHz modules in one cell, in total for 6 cells

Lightning protection at trunk ports, power ports, and RF ports

E1 bypass function after the power-off of the BTS3X

BTS3X bar code report and software/hardware version report of some boards

The TMU auto-check of the central frequency of the crystal oscillator

Clock backup and switchover of master and slave clocks

Clock fast pull-in mode E1 self-loop test and RF self-loop test

4.2 Networking Functions

BTS3X has flexible networking modes. It can support multiple transmission modes:

E1, SDH, HDSL, microwave and satellite transmission.

4.2.1 E1 Networking

When networked via E1, BTS3X supports star, tree and chain networking. E1

networking is shown in IFigure 1.1, IIFigure 1.1, and IIIFigure 1.1, where each line

indicates a bi-directional E1 line.


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Chapter 4 Functions

I. Star Networking

BSC

BTS

BTS

BTS

Figure 1.1 BTS3X E1 star networking

II. Tree Networking

BSC

BTS

BTS

BTS

BTS

Figure 1.1 BTS3X E1 tree networking

III. Chain Networking

BSC BTS BTS BTS

Figure 1.1 BTS3X E1 chain networking


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Chapter 4 Functions

IV. Ring Networking

BSC BTS BTS BTS

Figure 1.1 BTS3X E1 chain networking

4.2.2 SDH Networking

When networked via SDH, BTS3X supports chain and ring networking. SDH

networking is shown in IFigure 1.1 and IIFigure 1.1, where each line indicates an E1,

and each pair of lines indicates a pair of optical fibers.

I. Chain Networking

Figure 1.1 BTS3X SDH chain networking

II. Ring Networking

Figure 1.1 BTS3X SDH ring networking

4.2.3 Satellite Transmission Networking

In areas lacking transportation facilities, ordinary BTS cannot satisfy the requirements

due to restriction of conventional transmission technology. Therefore, GSM services

cannot be provided. Adopting the satellite transmission networking mode in these

areas will make the transmission effective and economic. Figure 1.1 shows the

satellite transmission networking.


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Chapter 4 Functions

PCH: Paging Channel

RACH: Random Access Channel

AGCH: Access Grant Channel

PPCH: Packet Paging channel PRACH: Packet Random access channel

PRAGCH: Packet Access grant channel

PTCCH: Packet Timing advance control channel

SDCCH/8: Stand-alone Dedicated Control Channel, eight of them mapped on a

separate basic physical channel

SACCH/C8: Slow SDCCH/8 Associated Control Channel

SACCH/TF: Slow TCH/F Associated Control Channel

FACCH/F: Full rate Fast Associated Control Channel

SDCCH/4: Stand-alone Dedicated Control Channel, four of them mapped on the

same basic physical channel as the CCCH

SACCH/C4: Slow, SDCCH/4 Associated Control Channel

CBCH: Cell Broadcast Channel

II. Channel Combinations Supported

TCH/F + FACCH/F + SACCH/TF

TCH/H(0,1) + FACCH/H(0,1) + SACCH/TH(0,1)

TCH/H(0,0) + FACCH/H(0,1) + SACCH/TH(0,1) + TCH/H(1,1)

FCCH+SCH+BCCH+CCCH

FCCH+SCH+BCCH+CCCH+SDCCH/4+SACCH/C4 BCCH+CCCH

SDCCH/8+SACCH/8

SDCCH/8+SACCH/8+CBCH

FCCH+SCH+BCCH+CCCH+SDCCH/4+SACCH/C4+CBCH

PBCCH+PCCCH+PDTCH+PACCH+PTCCH

PCCCH+PDTCH+PACCH+PTCCH

PDTCH+PACCH+PTCCH

Note:CCCH=PCH+RACH+AGCH

PCCCH=PPCH+PRACH+PAGCH

4.3.2 Diversity Receiving

A radio channel is a random time-variable channel with fading features. The diversity


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Chapter 4 Functions

requirement, the static power control should be adjusted so as to raise the maximum

output power of dynamic power control.

4.3.5 Discontinuous Transmission

There are two transmission modes in the GSM system:

One is the normal mode, in which noise has the same transmission quality as

voice.

The other is discontinuous transmission (DTX) mode, in which MS only sends

the encoded background noise that is called "comfortable noise".

The utilization of DTX can meet the requirement for system measurement and can

make the called feel that the call is not disconnected.

BTS3X adopts voice activation detection (VAD) technology to distinguish voice from

noise.

4.3.6 AMR

BTS3X supports Adaptive Multi Rate (AMR). AMR is a set of multiple voice Codec

algorithms. Different Codec algorithm generates different rate voice code stream. The

BTS and MS can automatically choose a proper Codec algorithm according to the

actual radio environment to adjust the rate. Thus the voice quality of the radio

communication system is improved.


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Chapter 5 Reliability Design


5.1 System Reliability Design

I. Rating-Lowering Design

The strict rating-lowering design is applied to power and easily overheated devices to

make the electrical stress and temperature stress in practical utilization lower than the

set rating. This postpones the degradation of parameters and prolongs their life span.

II. Heat Design

Through parts selection, circuit design, structure design, and heat dissipation design,

the impact of temperature change on product performance is reduced and reliable

operation of the product in a wider temperature range is ensured.

III. EMC Design

Electromagnetic compatibility (EMC) design prevents equipment from inhibited

degradation caused by electromagnetic transmission of other equipment in the same

electromagnetic environment. It also prevents other equipment, subsystems, and

systems in the same electromagnetic environment from inhibited degradation caused

by the electromagnetic transmission of the equipment.

IV. System Fault Monitoring and Handling

The system can auto-test and diagnose software and hardware fault, and report

alarms. It can record and output the fault records for print. It collects environment

conditions and report alarms when it detects problems. When TMU is faulty, the

system can test the major faults and report alarms while keeping the communication

between BTS and BSC.

V. System Fault Protection

A fault of any module will not lead to destructive fault of other modules. Major faults

can be reported in time.

VI. System Maintainability Design

Reasonable BTS internal cabling facilitates board replacement during fault handling.


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During board replacement, you can only disconnect the cables of the faulty boards.

When replacing boards, main boards can be plugged in or pulled out from the front of

the cabinet.

By indicator states, you can judge whether the equipment operation is normal.

VII. Running Environment Protection Design

The system provides the following functions for the PSU and the transmit power

equipment:

Input over- and under-voltage protection

Output over-voltage protection

Output short-circuited protection

Output overload protection Excess temperature protection

For the DC input transmit power, it has input reverse polarity protection to guarantee

system safety.

5.2 Hardware Reliability Design

5.2.1 Board Coding Key Design

When a functional board is mistakenly inserted into the slot of the functional board of

another kind, the mistakenly inserted board cannot make normal contact with the

backplane. The coding key is adopted to protect the equipment against damage.

5.2.2 Power System Reliability Design

I. Uninterrupted Power Supply Design

For BTS using AC power supply, the outdoor BTS can work for some time by using

the storage battery equipped to keep the operation of equipment during this time

when external mains supply is powered off. The BTS sends mains supply power off

alarm signal to the BAM in the meantime, and handles the alarm according to the

actual situation.

BTS3006A/BTS3012A has built-in transmit power to provide -48 V power for

transmission equipment. To improve reliability, 1+1 backup working mode may be

adopted for the transmit power. When one of the modules is faulty, it automatically

exits the power supply system, while another module provides output to all -48V load

and sends the module faulty alarm information to the BAM.


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II. Distributed Power Supply Design

Distributed power supply for load is adopted inside the system. The key power supply

path, AC/DC part, adopts N+1 backup working mode. If one of the modules in AC/DC

part is faulty, alarm information can be sent to the BAM, and onsite hot swappable

replacement is supported.

5.2.3 Abis Communication Bypass Design

When BTS is in chain networking environment and its power fails, the Abis

transmission bypass board in the BTS can bypass the transmission line of the TMU

board internally, hence avoiding long-time service disruption of all the sites under this

BTS.

5.3 Software Reliability Design

I. Scheduled Check of Key Resources

For software resources in the system, the verifying mechanism for long-time

occupation is applied among the modules. In case of resources unavailable due to

software exception, the verifying mechanism can ensure the release of unavailable

resources and the output of various logs and alarms.

II. Fault Isolation Feature

Software design features module fault isolation. The error in some software module is

only restricted in the module and does not lead to fault in other software modules.

The software can tolerate faults and correct errors. Abnormal operation of minor

software does not cause system restart or reset.

III. Data Check

Consistency check of user input data guarantees the correctness of reference

relation among the data. When the system detects data modification failure in some stage, it will restore

the related data to the initial state for data consistency.

IV. Process Monitoring

During software operations, output channels are provided for internal software errors

and part of hardware errors, which is defined as the process monitoring mechanism.

This mechanism can monitor the running state of tasks, handle system abnormalities

and report to the external devices.


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Chapter 6 O&M System


6.1 O&M Architecture

6.1.1 Overview

As shown in Figure 1.1, BTS can provide two maintenance modes:

Local maintenance

Remote maintenance

Local Maintenance

Console

Remote Maintenance

Console

MMI

MMI

BTS

BTS

BSC

Abis

Abis

OMC

Server

Hub

Remote Maintenance

Console

Figure 1.1 BTS O&M structure

6.1.2 Local Maintenance

Local maintenance refers to the maintenance mode in which PCs are connected to

BTS through serial port cables and implement maintenance operations to the BTS, as

shown in 6.1.1 IFigure 1.1.

The local maintenance console can only be accessed after the local maintenancesoftware is loaded to PCs. The BTS local maintenance is carried out based on

different logical objects of the BTS, including site, cell, carrier, and baseband. Direct

operations can also be performed on boards. Real-time alarm messages can be

obtained at the same time.

6.1.3 Remote Maintenance

Remote maintenance is performed through OMC. PCs are connected to BSC via

OMC network and are connected subsequently to BTS via the Abis interface, as


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shown in 6.1.1 IFigure 1.1.

The remote maintenance console can only be accessed via OMC Shell of the

workstation (WS). The user interface of the BTS remote maintenance console uses

topological structure, where names, categories, locations, numbers, equipment types

and running states (normal, alarm, etc.) of all NEs in the mobile network can be

browsed. You can specify an NE to be maintained and check its detailed performance

data, alarm data and configuration data. You can also implement operations and

maintenance on certain types of NEs through the topological map.

6.2 O&M Functions

The BTS3X O&M system provides powerful O&M functions to meet your

requirements in equipment performance and maintenance. These functions include:

Security management

Alarm management

Maintenance management

Performance measurement and test

6.2.1 Security Management

Various remote maintenance operations can be implemented through the O&M

system. The system provides powerful security management to execute O&M control

over the equipment in order to avoid unauthorized operations that may affect normal

performance of the equipment.

To perform operations and maintenance on the BTS, you have to log in and go

through authentication. The system provides an authorization system on multiple

levels to ensure that only authorized users can execute relevant commands for O&M.

Meanwhile, dialog boxes are prompted before any important O&M command is

executed to get confirmation for the potential problems due to the operations.

6.2.2 Alarm Management

The BTS O&M system provides highlighted alarm windows and powerful real-time

alarm management functions, such as collection, clearing, query, processing, saving,

explanation, prompting, shielding, filtering, acknowledging, and analyzing. Besides, it

provides an on-line help information system and stage filtering system to help you

quickly locate faults. It also provides alarm recovery methods.


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6.2.3 Maintenance Management

The operation & maintenance center (OMC) implements management over the whole

BSS through BSC. For the OMC, the BTS is highly visible. BTS can check and locateinternal errors so that BSC can implement maintenance to it without knowing the

internal structure of each BTS.

6.2.4 Performance Measurement and Test

The O&M system can implement performance measurement and test to the entities

so as to collect BTS running states data and perform accurate analysis on the running

states.


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Chapter 7 Technical Specifications


7.1 Engineering Specifications of BTS3X Cabinet

The cabinet engineering specifications of BTS30 are shown in Table 1.1.

Table 1.1 BTS30 cabinet engineering specifications

Parameter Specifications

Cabinet dimensions Height 1600 mm

Width 600 mm

Depth 450 mm

Weight 180 kg (a single cabinet under full configuration)

Power consumption 1200 W (a single cabinet under full configuration)

Working environment

temperature

-5C to +45C

Working environment relative

humidity

15% to 85%

Clock Frequency: 1.3 107 Hz, with precision higher than

0.05 ppm at delivery

Temperature drift: < 5 10-8 (0C to 70C)

Annual aging rate:< 1 10-7

Input power supply 220 V AC: 150 V AC to 280 V AC/47 Hz to 63 Hz

-48 V DC: 40 V DC to -60 V DC

24 V DC: 19 V DC to 29 V DC

Security performance In compliance with IEC60950 standard

Earthquake-proof

performance

In compliance with IEC Class 4M3 standard

EMC In compliance with ETS 300-342-3 corresponding

standard


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The cabinet engineering specifications of BTS312 are shown in Table 1.2.

Table 1.2 BTS312 cabinet engineering specifications



Width 650 mm

Depth 500 mm

Weight 330 kg (a single cabinet under full configuration)

Power consumption 2400 W (a single cabinet under full configuration)

Working environment

temperature

-5C to +45C

Working environment

relative humidity

15% to 85%

Clock Frequency: 1.3 107 Hz, with precision higher than

0.05 ppm at delivery



Input power 220 V AC: 150 V AC to 280 V AC/47 Hz to 63 Hz.

-48 V DC -40 V DC to -60 V DC

24 V DC: 19 V DC to 29 V DC

Security In compliance with IEC60950 standard

Earthquake-proof

performance


EMC In compliance with ETS 300-342-3 related standard

The cabinet engineering specifications of BTS3006A are shown in Table 1.3.


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Table 1.3 BTS3006A cabinet engineering specifications



Width 900 mm

Depth 720 mm

Weight 390 kg (a single cabinet under full configuration,

including built-in batteries)

250 kg (assembly cabinet)

Power consumption 1900W (when the heat exchanger is not working)

2300W (when the heat exchanger is exchanging

the heat)

3500W (when the heat exchanger is heating the

cabinet)

Working environment

temperature

-40C +50C

Storage temperature -40C +70C

Working environment

relative humidity

5% 100%

Clock Frequency: 1.3 107Hz, with precision at delivery

higher than 0.05 ppm

Temperature drift:


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Earthquake-proof

performance



Waterproof and dustproof

performance

In compliance with IP55 standard

The cabinet engineering specifications of BTS3012A are shown in Table 1.4.

Table 1.4 BTS3012A cabinet engineering specifications



Width 1200 mm

Depth 1000 mm

Weight 650 kg (a single cabinet under full configuration,

including storage batteries)

420 kg (assembly cabinet)

Power consumption Power consumption of a full configuration cabinet:

3500 W (when the air conditioner/the heat

exchanger is not working)

5500 W (when the air conditioner is cooling the

cabinet)

6100 W (when the air conditioner is heating the

cabinet)

4150 W (when the heat exchanger is exchangingthe heat)

6240 W (when the heat exchanger is heating the

cabinet)

Working environment

temperature

Cabinet with an air conditioner: -40C to +55C

Cabinet with an heat exchanger: -40C to +45C

Storage battery cabinet: -20C to +45C


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Startup temperature BTS3012A can be started at -40C. The startup time

is less than 2 hours after the BTS is heated to -10

C.

Storage temperature -40C to +70C

Working environment

relative humidity

5% to 95%

Clock Frequency: 1.3 107 Hz, with precision at delivery

higher than 0.05 ppm



Input power Normal working voltage: 90 V AC to 276 V AC/47 Hz

to 53 Hz

Tolerant voltage: 300V AC

Security In compliance with IEC60950 standard

Earthquake-proof

performance



Waterproof and dustproof

performance

In compliance with IP55 standard

7.2 Performance Specifications of BTS3X Cabinet

The performance specifications of BTS3X cabinet are shown in Table 1.1.

Table 1.1 Performance specifications of BTS3X cabinet

Performance

classification


System indices Channel capacity 8CH/TRX


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Performance

classification


Frequency band GSM850:

Uplink: 824 MHz to 849 MHz

Downlink: 869 MHz to 894 MHz

GSM900:



GSM1800:

Uplink: 1,710 MHz to 1,785 MHz

Downlink: 1,805 MHz to1,880 MHz

GSM1900:

Uplink: 1,850 MHz to 1,910 MHz

Downlink: 1,930 MHz to1,990 MHz

RGSM:



Receiving

performance

Static receive

sensitivity

GSM850: -110dBm

GSM900: -110dBm

GSM1800: -109dBm

GSM1900: -109dBm

RGSM: -110dBm

Block feature Satisfies requirement of GSM11.21 protocol

Anti-interference

feature

Satisfies requirement of GSM11.21 protocol

Intermodulation

suppression



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Performance

classification


Stray radiation Satisfies requirement of GSM11.21 protocol

Transmitting

performance

Maximum transmit

power of each

TRX

40W TRX: 46.0 dBm

60W TRX: 47.8 dBm

40W TRX + PBU: 49.0 dBm

ETR: 46.0 dBm (8PSK)/47.8 dBm (GMSK)

Absolute transmit

power precision

2 0.5 dB (temperature within normal

range)

2 1 dB (temperature out of normal

range)

Static power

control range

Level 0 to 10

Dynamic power

control range

Level 0 to 15

Transmit spectrum Satisfies requirement of GSM11.21 protocol

Intermodulationsuppression


Stray radiation Satisfies requirement of GSM11.21 protocol

Frequency error 0.05 ppm

Phase error 5 (rms)

20 (peak)

7.3 External Physical Interfaces

The external physical interfaces of BTS30 and BTS312 are shown in Table 1.1.


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Table 1.1 External physical interfaces of BTS30 and BTS312

Interface Type Quantity Function realized

Abis interface E1 8 pairs

Provides 75 ohm/120ohm E1 interface

Supports cascading

Provides O&M link

(OML)

STM-1 2 pairs Provides SDH optical

transmission

interface

Supports cascading

Provides OML

Clock interface

(CLK)

FCLK 1 FCLK test port

13 MCLK 1 13 MHz clock test port

SYNC 1 External synchronization

input end (satellite)

Maintenance

interface

MMI Serial

port

1 Provides local

maintenance channel

Power and

grounding

Power supply 3 power input

modes

-48 VDC input power

+24VDC input power

220 VAC input power

Grounding 1 PGND

Feeder cable

interface

RF signal 12 Feeder input port

Combined cabinet

interface

Data bus

interface

2 Data bus interface

DCF1 and DCF2

Clock bus

interface

2 Combined cabinet clock

bus interface CKB1 and

CKB2

Combined

cabinet

cascading

interface

6 CDU combined cabinet

cascading interface


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Management

signal interface

Alarm 2 External alarm

interface EAC1 and

EAC2

Can be connected to

environment monitor

Storage

battery

management

1 Connects to storage

power pool signal

PWRC

The external physical interfaces of BTS3006A are shown in Table 1.2.

Table 1.2 BTS3006A external physical interfaces


Abis interface E1 4 pairs Provides 75 ohm/120 ohm

E1 interface

Supports cascading

Provides OML

Clock interface(CLK)



Maintenance

interface

MMI serial

port

1 Provides near end maintenance

channel

Power and

grounding

Power supply 1 It can be used as the input port

for 220 V AC/110V AC power

supply.

PGND 1 1 grounding interface

Feeder cable

interface

RF signal 6 Feeder input interface

The external physical interfaces of BTS3012A are shown in Table 1.3.


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Table 1.3 BTS3012A external physical interfaces


Abis interface E1 4 pairs

Provides 75-ohm/120-ohmE1 interface

Supports cascading

Provides OML

Clock interface

(CLK)



Maintenance

interface

MMI serial

port

1 Provides near end maintenance

channel

Power and

grounding

Power supply 1 It can be used as the input port

for 220 V AC/110V AC power

supply.

PGND 1 1 grounding interface

Feeder cable

interface

RF signal 12 Feeder input interface

01 system description

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