ted24x

Information

Base Station System

Technical Description (TED:BSS)BS-240/241

A30808-X3247-M14-1-7618

2 A30808-X3247-M14-1-7618


InformationBase Station System

! Important Notice on Product Safety

DANGER - RISK OF ELECTRICAL SHOCK OR DEATH - FOLLOW ALL INSTALLATION INSTRUCTIONS.

The system complies with the standard EN 60950 / IEC 60950. All equipment connected to the system mustcomply with the applicable safety standards.Hazardous voltages are present at the AC power supply lines in this electrical equipment. Some components mayalso have high operating temperatures.Failure to observe and follow all installation and safety instructions can result in serious personal injuryor property damage.Therefore, only trained and qualified personnel may install and maintain the system.

The same text in German:

Wichtiger Hinweis zur Produktsicherheit

LEBENSGEFAHR - BEACHTEN SIE ALLE INSTALLATIONSHINWEISE.

Das System entspricht den Anforderungen der EN 60950 / IEC 60950. Alle an das System angeschlossenenGeräte müssen die zutreffenden Sicherheitsbestimmungen erfüllen.In diesen Anlagen stehen die Netzversorgungsleitungen unter gefährlicher Spannung. Einige Komponentenkönnen auch eine hohe Betriebstemperatur aufweisen.Nichtbeachtung der Installations- und Sicherheitshinweise kann zu schweren Körperverletzungen oderSachschäden führen.Deshalb darf nur geschultes und qualifiziertes Personal das System installieren und warten.

Caution:This equipment has been tested and found to comply with EN 301489. Its class of conformity is defined in tableA30808-X3247-X910-*-7618, which is shipped with each product. This class also corresponds to the limits for aClass A digital device, pursuant to part 15 of the FCC Rules.These limits are designed to provide reasonable protection against harmful interference when the equipment isoperated in a commercial environment.This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accor-dance with the relevant standards referenced in the manual “Guide to Documentation”, may cause harmful inter-ference to radio communications.For system installations it is strictly required to choose all installation sites according to national and local require-ments concerning construction rules and static load capacities of buildings and roofs.For all sites, in particular in residential areas it is mandatory to observe all respectively applicable electromagneticfield / force (EMF) limits. Otherwise harmful personal interference is possible.

Trademarks:

All designations used in this document can be trademarks, the use of which by third parties for their own purposescould violate the rights of their owners.

Copyright (C) Siemens AG 2005.

Issued by the Communications GroupHofmannstraße 51D-81359 München

Technical modifications possible.Technical specifications and features are binding only insofar asthey are specifically and expressly agreed upon in a written contract.

A30808-X3247-M14-1-7618 3



Reason for UpdateSummary:

First Edition for New Release BR 8.0

Details:

Chapter/Section Reason for Update

All New Release BR 8.0

Issue HistoryIssue

Number

Date of issue Reason for Update

1 01/2005 First Edition for New Release BR 8.0

4 A30808-X3247-M14-1-7618



A30808-X3247-M14-1-7618 5



This document consists of a total of 68 pages. All pages are issue 1.

Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.1 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101.2 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2 Hardware Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142.1 Board Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172.1.1 AC/DC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172.1.2 Core . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172.2 Rack Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3 Description of Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.1 Core (COBA and COSA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.1.1 Core Basis (COBA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253.1.2 Core Satellite (COSA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263.1.3 Core Link Extension (COREXT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273.2 Carrier Unit (CU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293.3 EDGE Carrier Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303.4 GMSK Carrier Units (GCU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323.5 Flexible Carrier Unit (FlexCU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323.6 Carrier Unit Output Power Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343.7 Duplexer Amplifier Multicoupler (DUAMCO). . . . . . . . . . . . . . . . . . . . . . . . 343.8 Dual Integrated Amplifier Multicoupler (DIAMCO) . . . . . . . . . . . . . . . . . . . 353.9 Filter Combiner (FICOM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353.10 Tower Mounted Amplifier (TMA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363.11 High Power Duplexer Unit (HPDU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363.12 DC Panel (DCP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373.13 Alarm Collection Terminal (ACT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373.14 AC/DC Converter (AC/DC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.14.1 DC and Battery Controller (DCBCTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.15 Overvoltage Protection and Tracer (OVPT) . . . . . . . . . . . . . . . . . . . . . . . . 403.16 Abis Connection Module (ABISCON) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.17 Abis Link Equipment (LE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.18 Cover Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.19 Backup Battery (BATTERY) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.20 Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.21 Heat Exchanger (HEX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4 Antenna Combiners and Receiving Paths . . . . . . . . . . . . . . . . . . . . . . . . . 434.1 Methods of Combining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434.1.1 Tx Attenuation of combiner units (CU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514.1.2 DUAMCO - DIAMCO GAIN (RX Path) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534.1.3 Parameters of Tower Mounted Amplifier (TMA) . . . . . . . . . . . . . . . . . . . . 544.1.4 Examples of Possible BTSE Configurations . . . . . . . . . . . . . . . . . . . . . . . . 564.2 Receiving Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 604.2.1 Antenna Diversity Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 604.2.1.1 Antenna System Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

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4.2.2 Receiver Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614.3 Transmission Diversity Time Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614.3.1 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624.4 FCC Issues (for US Market only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

5 Power Supply and Battery Backup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655.1 Support of Emergency Operation for 3rd Party BBU System . . . . . . . . . . . 66

6 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

A30808-X3247-M14-1-7618 7



IllustrationsFig. 2.1 BS-240 Indoor Cabinet and BS-241 Outdoor Cabinet (Base Racks) . . 14

Fig. 2.2 Functional Blocks of the BS-240/241. . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Fig. 2.3 Redundant COREs and their Interfaces . . . . . . . . . . . . . . . . . . . . . . . . 17

Fig. 2.4 BS-240 Base Rack and 2 Extension Racks. . . . . . . . . . . . . . . . . . . . . . 19

Fig. 2.5 BS-241 Base Shelter and 2 Extension Shelters . . . . . . . . . . . . . . . . . . 20

Fig. 2.6 Possible Configuration of Service1 Rack and Service2 Rack . . . . . . . . 21

Fig. 2.7 BS-240/241 equipped with 5 cabinets . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Fig. 3.1 Connection of major modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Fig. 3.2 COBA internal architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Fig. 3.3 Core Satellite Board (COSA) internal architecture. . . . . . . . . . . . . . . . . 27

Fig. 3.4 System with COBA4P12 and COREXT. . . . . . . . . . . . . . . . . . . . . . . . . 28

Fig. 3.5 Internal Components of the Carrier Unit . . . . . . . . . . . . . . . . . . . . . . . . 29

Fig. 3.6 FlexCU - Double ECU Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Fig. 3.7 FlexCU - Single ECU Mode - Fourfold Receive Diversity Mode . . . . . . 33

Fig. 3.8 Alarm Collection Terminal (ACTM and ACTP). . . . . . . . . . . . . . . . . . . . 38

Fig. 3.9 Example of Battery Backup Systems Connected to the AC/DC . . . . . . 41

Fig. 4.1 Overview of Combining Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Fig. 4.2 DUAMCO 2:2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Fig. 4.3 DUAMCO 4:2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Fig. 4.4 DUAMCO 8:2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Fig. 4.5 FICOM 8:1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Fig. 4.6 DIAMCO. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Fig. 4.7 HPDU. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Fig. 4.8 Configuration with HPDU, DUBIAS and TMA . . . . . . . . . . . . . . . . . . . . 50

Fig. 4.9 Configuration with Diplexer (Example) . . . . . . . . . . . . . . . . . . . . . . . . . 51

Fig. 4.10 Multi-cell (3,3,2): with 3 DUAMCO 4:2 . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Fig. 4.11 Multi-cell (3,3,2): with 2 DUAMCO 4:2 and 1 DUAMCO 2:2 . . . . . . . . . 57

Fig. 4.12 Single-cell (8,0,0): with FICOM and DIAMCO . . . . . . . . . . . . . . . . . . . . 57

Fig. 4.13 Single-cell (8,0,0): with 2 DUAMCO 4:2. . . . . . . . . . . . . . . . . . . . . . . . . 58

Fig. 4.14 Multi-cell (2,2,2): with 3 DUAMCO 2:2 . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Fig. 4.15 Single-cell (11...16,0,0): FICOMs, DIAMCOs and HPDUs in 2 Racks. . 59

Fig. 4.16 Capacity Downlink Improvements for TX Diversity . . . . . . . . . . . . . . . . 62

Fig. 4.17 BTS Rack Cabling for Transmitter Diversity Operation . . . . . . . . . . . . . 63

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TablesTab. 1.1 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Tab. 1.2 Frequency Bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Tab. 3.1 Units and Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Tab. 3.2 Carrier Unit Output Power Level (Typical and Guaranteed Values) per TRX34

Tab. 4.1 Insertion loss of FICOMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Tab. 4.2 Insertion loss of DUAMCOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Tab. 4.3 Insertion loss of BCOM, HPDU and TMA . . . . . . . . . . . . . . . . . . . . . . . . 52

Tab. 4.4 Parameters of DUAMCO - DIAMCO. . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Tab. 4.5 Parameters of 900 MHz Tower Mounted Amplifier . . . . . . . . . . . . . . . . . 54

Tab. 4.6 Parameters of 1800 MHz Tower Mounted Amplifier . . . . . . . . . . . . . . . . 55

Tab. 4.7 Parameters of 900/1800 MHz Tower Mounted Amplifier . . . . . . . . . . . . 56

Tab. 4.8 Maximum RF Power Output Values at Antenna Port . . . . . . . . . . . . . . . 64

Tab. 4.9 Maximum RF Power Output Values at Antenna Port . . . . . . . . . . . . . . . 64

A30808-X3247-M14-1-7618 9



1 IntroductionThe architecture of BS-240/241 provides maximum flexibility to develop higher capacityBTSs with reduced volume and an expanded number of 24 TRXs (48 with FlexCUcarriers) in 3 Racks with a modularity of 8 TRXs per Rack. Any operation for rack exten-sion or TRX substitution doesn’t involve service interruption.The provision of a full spec-trum of combining equipment allows high power and minimized number of antennas.High receiver sensitivity is also guaranted.

The modular architecture and the flexible internal structure, enables the BS-240/241 toprovide new GSM features such as EDGE; this platform ensures that network evolutionis as smooth as possible.

The use of the latest technology reduces power consumption and improves reliability;the reliability is also increased by the redundancy of all core modules. This is a particulararchitecture provided for customers that ask strong requirements for the best function-ality and hardware stability of their networks.Easy integration is possible in the alreadyinstalled sites, for the backward compatibility with existing SIEMENS SBS systems.High Site efficiency is assured for composite transmit power with minimal footprintrequirements.

Homogenous service throughout the network is assured by common BTS SW runningon all the platforms.

The BS-240/241 primarily consists of:• Carrier oriented boards called carrier unit (CU),• Core boards (COSA, COBA) and• Combining equipment

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1.1 Main FeaturesThe BS-240/241 is designed for max. 24 carriers (48 with FlexCU ) in 3 Racks/Sheltersplus Service Racks/Shelters, if needed.For the BS-240 the minimum configuration isone Base Rack. For the BS-241 the minimum configuration is one Rack or one BaseShelter with one Service Rack/Shelter. Service Racks/Shelters can be configured toaccommodate Backup Batteries and Link Equipment. A Service Rack/Shelter can beequipped with AC/DC Converters. Easy Rack/Shelter Extension is possible with one ortwo Extension Racks/Shelters.

The BS-240/241 can be configured for the systems GSM 850, GSM 900, GSM 1800 andGSM 1900 with the following configurations:– Single band– Dual band: GSM 900, GSM 1800; GSM 900, GSM 1900; GSM 850, GSM 1800 and

GSM 850, GSM 1900 :– Mixed cell configuration to enlarge GSM 900 cells with GSM 1800 frequencies, or

GSM 850 cells with GSM 1900 frequencies.– Single cell– Multi cell

Up to 6 cells per Rack and up to 12 cells per BTSE can be supported. A special case isthe feature “concentric cell”; one cell with 2 supply areas (inner and complete area). Thisfeature can be used in omnicells as well as in multicells with sectors.

The following combining options are supported:– Antenna combining with duplexers (DUAMCO) can be applied for 2, 4 and 8 carriers.

RF amplifier and multicoupler for the RX path are integrated– Antenna combining with Filter Combiners (FICOM) is possible for up to 8 carriers

onto one TX antenna– Cascading of multicoupler equipment (DIAMCO) is possible for up to 24 carriers– High Power Duplexer (HPDU) for reduction of the necessary numbers of antennas

in case of FICOM per cell for up to 8 carriers can be applied– Every BTSE has core equipment in the Base Rack/Shelter– Mixed Configurations of Cells/Sectors applying all types of carrier units: normal

Carrier Units (CU), EDGE Carrier Units (ECU) and Flexible Carrier Units (FlexCU).– For high capacity sites the dual-carrier FlexCU doubles the number of available

carries in a standard cabinet

Traffic Channels:– Full-Rate (FR)– Half-Rate (HR)– Enhanced Full-Rate (EFR)– Adaptive Multi Rate Codec (AMR)

Services:– GPRS– HSCSD– EDGE

Frequency Hopping and Redundancy and Support of Fault Procedures.

Abis Interface Configurations:– Configuration: Star, loop, multidrop chain and cross connect;– Change of PCM line configuration from star to multidrop or loop and vice versa is

possible without any interruption of service

A30808-X3247-M14-1-7618 11



External Abis link media can be connected:– Wire– Fiber optic– Micro-Wave

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1.2 Technical DataThe BS-240/241 family with 24 transceivers can be supplied in the following versions:– BS-240 for indoor installation.– BS-241 for outdoor installation, also equipped with: integrated power supply, battery,

microwave equipment (optional), integrated link equipment (optional), MEF filter andcross connector (optional);BS-240/241 consist in a split BTS architecture, with:- 1 Base Rack- Up to 2 Extension Racks- Up to 5 Service racks (1 Service1 and 4 Service2).

Characteristics BS-240 (indoor) BS-241 (outdoor)

Max. TRX per BTSE 24 24

(in more than one Rack)

Max. TRX per cell 24 24

(in more than one Rack)

Dimensions (HxWxD) 1600x600x450 mm(5’3”x2’x1’6”)

1750x700x650 mm(5’9”x2’4”x2’2”)

(Base Racks) (incl. Plinth)

Volume net 432 l 705 l796 l (incl. Plinth)

Maximum power consumption / Rack 1600 W 1750 W

Weight of Basic Rack in typical Configura-tion

ca. 190 kg (419 Lbs) ca. 240 kg (529 Lbs)

Weight of Extension Rack in typical Config-uration

ca. 190 kg (419 Lbs) ca. 240 kg (529 Lbs)

Weight of Service 1 in Configuration:AC/DC; F:Battery 1x (type A400/85)

ca. 264 kg (582 Lbs) ca. 314 kg (692 Lbs)

Weight of Service 2 in Configuration:F:Battery 3x (type A400/85)

ca. 490 kg (1080 Lbs) ca. 540 kg (1190 Lbs)

Temperature range -5°C to +50°C+23°F to +122°F

-33°C to +50°C-27.4˚F to +131°F

Tab. 1.1 Technical Data

A30808-X3247-M14-1-7618 13



Frequency-Band Uplink (MHz) Downlink (MHz)

GSM 850 824.2 - 848.8 869.2 - 893.8

P-GSM 900 (Primary) 890.2 - 914.8 935.2 - 959.8

E-GSM 900 (Extension) 880.2 - 914.8 925.2 - 959.8

R-GSM 900 (Railway) 876.2 - 914.8 921.2 - 959.8

GSM-RE 900 (Railway Extension) 876.2 - 901.0 921.2 - 946.0

GSM 1800 1710.2 -1784.8 1805.2 -1879.8

GSM 1900 1850.2 -1909.8 1930.2 -1989.8

Tab. 1.2 Frequency Bands

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2 Hardware ArchitectureThe BS-240/241 is designed to achieve commonality of boards to serve both GSM 850,GSM 900 with its different deviates (GSM 1800, GSM 1900) and standards selected formobile communication systems. The Fig. 2.1 shows the Base Rack Cabinets.

Fig. 2.1 BS-240 Indoor Cabinet and BS-241 Outdoor Cabinet (Base Racks)

The BTS functional blocks of the BS-240/241 are shown in Fig. 2.2

A30808-X3247-M14-1-7618 15



Fig. 2.2 Functional Blocks of the BS-240/241

CU 7

CU 0

CU 7

Base Rack

Service Rack

DUAMCO CU 0

COSA

ACTM

CAN BUS

CC-Links

FICOM

DIAMCO

HPDU

4xTX

RX

RXDIV

4xTX

RX

RXDIV

ACTC ACTP

LE 0 LE 1

BATTERY

TMA

DCB-

ACP

CTRL

ACTC

FAN

Cell 0

Cell 1

FICOM

DIAMCO

4xTX

4xTX

RX

RXDIV

Cell 1

RX

RXDIV

RX

RXDIV

ACTC ACTP

FAN

to next ext. rack

RXCA1RXCA0

BATTERY

DCB-CTRL

AC/DCAC/DC

DCP

DCP

DCP

Extension Rack

Cascading

DUBIAS

COBA

2 PCM

Ext. Sync.

2 PCM

4 PCM

Abis

Sync.

Abis

TMA

FAN

TMA

TMA

OVPT

OVPT

* not present in case of BTSE with reduced number of fans

*

*

*

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The architecture of BS-240/241 provides maximum flexibility to develop large and smallBTSs.

The BS-240/241 mainly consists of:– carrier oriented boards called carrier unit (CU),– core boards (COSA, COBA) and– combining equipment

Up to 8 PCM lines can be connected to the core boards that are scalable (COBA,COSA). In addition, also the BTS itself is scalable. It is possible to connect up to 2 Exten-sion Racks to a Base Rack.

The main communication between the modules is provided by means of bi-directionalCC-link communications between the carrier units (CU) and the core boards. The CC-link also provides an effective means to realize baseband frequency hopping.

All alarms, beside the alarms that are generated in the core and in the CU boards, aretransported via the CAN bus. Alarms of the CU boards are transmitted via CC-Link. Coreboards use their interface bus.

The carrier unit(s) provide all analog and digital signal processing including a RF powerstage necessary to process a single carrier (e.g., GSM 8 TCHs). The carrier unit(s) inter-face with the combining equipment on the one side and with the core modules on theother. The core boards provide functions common to all carriers within the BS-240/241(e.g., clock generation, O&M processing,...) as well as LAPD processing for the differentcarriers.

AC/DC AC/DC converter DCBCTRL DC and Battery ControllerACP AC Panel DCP DC PanelACTC Alarm Collection Terminal Connection module DIAMCO DI(2) Amplifier MulticouplerACTM Optional Alarm Collection Terminal for Master Rack DUAMCO Duplex Amplifier MulticouplerACTP Alarm Collection Terminal for Slave Rack FICOM Filter CombinerCAN Controller Area Network HPDU High Power DuplexerCOBA Core Basis (COBA2P8) LE Link EquipmentCOSA Core Satellite (COSA6P16) TMA Tower Mounted AmplifierCU Carrier Unit

A30808-X3247-M14-1-7618 17



2.1 Board RedundancyRedundancy in the SBS ensures survival of the system even in the event of multiple fail-ures. Modular architecture, in conjunction with the concept of split functions, guaranteesmaximum survivability with a minimum of additional hardware.

2.1.1 AC/DCThe AC/DC converter is the connection module for the BS-240/241 if supplied by mains.This module converts the AC mains voltage (Nominal Voltage: 208Vac or 230 Vac) intothe -48V supply voltage. Only one type of AC/DC module is available. It is namedAC/DCVx.

For the power supply the concept of n+1 redundancy has been implemented. N+1AC/DC converters work in load sharing operations. In case of failure and/or out ofservice of one AC/DC the remaining “n” AC/DC modules shall supply the entire BTSE-plus.

The maximum DC current to supply the equipment and the batteries installed in all theService2 racks/shelters of one BTSEplus is limited to 50 A.

2.1.2 CoreThe Core can consist of up to 2 (without redundancy) or up to 4 (with redundancy)boards, which have a common backplane. The block diagram depicts the CORE redun-dancy and the embedding of the active and the passive CORE into the BTS, and theinterrelation of both COREs.

Fig. 2.3 Redundant COREs and their Interfaces

Both COREs (COBA0/COSA0 and COBA1/COSA1) have link interfaces to the Abislines, but only one (the active CORE) can be connected.

A link is provided for the connection between the current active CORE and the LMTEvolution. In case of a CORE switch over, the connection is changed towards the newactive CORE. The same holds for the CAN bus (alarm bus), i.e., both COREs have the

CUSELIC

SELIC

PCM

RDInterf.

SwitchLogic

CORE 0CLK

Route Clock

Redundancy Link

Switch Logic Link

Route Clock(Frame Sync)

ABISCAN

LMT

µP

CUSELIC

CUSELIC

SELIC SELIC SELIC

PCM

RDInterf.

SwitchLogic

CORE 1CLK

Route Clock

µP

SELICSELIC

Switch

PCMlinkterm.

Switch

PCMLinkterm.

18 A30808-X3247-M14-1-7618



same CAN bus address where at any time at most one CORE is an active CAN busnode.

Both the active and the passive CORE have links to the carrier units (CU); in reverse,each CU is linked with both COREs. The traffic data are transmitted transparentlythrough the active CORE. Signal processing takes place only within the CUs.

The endpoints of each link are built up by SELIC ASICs (note: one SELIC containsdouble functionality), where on the CU, one SELIC serves two COREs. In the case of aswitch over, the SELICs on the active CORE are disabled by the switch logic and theSELICs on the passive one are enabled.

The RD interface (redundancy interface) is realized as a 2 Mbit/s HDLC link whichprovides a communication interface between the two main processors (mP).

The CLK of the active CORE is connected with the one on the passive CORE. It allowsthe passive CLK to be synchronized to the active one.

NOTE: the redundancy is implemented in a cold-standby mode, i.e., all calls will get lostif a CORE switch over occurs.

2.2 Rack ConfigurationThe BS-240/241 family, with 8 transceivers per Rack, is expandable up to 24 trans-ceivers in 3 Racks and can be supplied in the following different versions:– BS-240 for indoor installation– BS-241 for outdoor installation

There are 4 different types of Rack:– Base Rack/Shelter (with Core modules)– Extension Rack/Shelter (for more then 8 CU’s)– Service1 Rack/Shelter (with AC/DC modules)– Service2 Rack/Shelter (for LE and batteries)

It is possible to connect up to 3 Racks/Shelters together (1 Base Rack, 2 ExtensionRacks; the more possible Racks/Shelters called Service Rack/Shelter are not part of aRack Extension in the proprietary sense) that realizes then the performance of a 24 TRXBTSE as shown in Fig. 2.4 and Fig. 2.5:

A30808-X3247-M14-1-7618 19



Fig. 2.4 BS-240 Base Rack and 2 Extension Racks

ACOM

0

ACOM

1

ACOM

2

ACOM

3

DC-PANELACT-C

CU

2

CU

3

CU

6

CU

7

MU

CO

0

MU

CO

1

CU 0

CU 1

CU 4

CU 5

BS-240SIEMENS

ACOM

0

ACOM

1

ACOM

2

ACOM

3

CU

2

CU

3

CU

6

CU

7

MU

CO

0

MU

CO

1

CU

0

CU

1

CU

4

CU

5

BS-240SIEMENSC

OB

A 0

CO

SA

0C

OB

A 1

CO

SA

1

FAN 0 FAN 1

ACOM

0

ACOM

1

ACOM

2

ACOM

3

DC-PANELACT-C

CU

2

CU

3

CU

6

CU

7

MU

CO

0

MU

CO

1

CU 0

CU

1

CU 4

CU 5

BS-240SIEMENS

FAN 0 FAN 1

DC-PANELACT-C

FAN 0 FAN 1

FAN 2 FAN 3

FAN 4 * FAN 5*

FAN 2 FAN 3

FAN 4* FAN 5*

FAN 2 FAN 3

FAN 4* FAN 5*


20 A30808-X3247-M14-1-7618



Fig. 2.5 BS-241 Base Shelter and 2 Extension Shelters

The Fig. 2.7 shows the max possible configurations. The Base Rack and the ExtensionRacks can be located physically in any position.

The Service Rack (see the Fig. 2.6 for possible configuration) satisfies various applica-tions depending on number of CU units configured and/or number and kind of Networktermination equipment provided and the Battery Backup time required.

CU

2

CU

3

CU

6

CU

7

MU

CO

0

MU

CO

1

CU

0

CU

1

CU

4

CU

5

BS-241SIEMENS

CO

BA

0C

OS

A 0

CO

BA

1C

OS

A1

DC-PANELACT-C

FAN 0 FAN 1

FAN 2 FAN 3

FAN 4* FAN 5*

ACOM

0

ACOM

1

ACOM

2

ACOM

3

CU

2

CU

3

CU

6

CU

7

MU

CO

0

MU

CO

1

CU

0

CU

1

CU

4

CU

5

BS-241SIEMENS

DC-PANELACT-C

FAN 0 FAN 1

FAN 2 FAN 3

FAN 4* FAN 5*

ACOM

0

ACOM

1

ACOM

2

ACOM

3

CU

2

CU

3

CU

6

CU

7

MU

CO

0

MU

CO

1

CU

0

CU

1

CU

4

CU

5

BS-241SIEMENS

DC-PANELACT-C

FAN 0 FAN 1

FAN 2 FAN 3

FAN 4* FAN 5*

ACOM

0

ACOM

1

ACOM

2

ACOM

3


A30808-X3247-M14-1-7618 21



Fig. 2.6 Possible Configuration of Service1 Rack and Service2 Rack

On the digital side there is an extension of the CC links (connection between Core Back-plane and the CU’s not housed in the Base Rack) and the CAN Bus.

AC/

SIEMENS

DC-PANELACT-C

SIEMENS

FAN 0 FAN 1

DC-PANELACT-C

FAN 0 FAN 1

FAN 2 FAN 3

DC05

AC/DC00

AC/DC01

AC/DC02

AC/DC03

AC/DC04

AC + DC Distribution

AC/DC15

AC/DC10

AC/DC11

AC/DC12

AC/DC13

AC/DC14

AC + DC Distribution

1/4

Battery

1/4

Battery

LE 0

LE 1

LE 2

LE 3

LE 4

LE 5

1/4

Battery

1/4

Battery

1/4

Battery

1/4

Battery

D

CTRL

CB

D

CTRL

CB

Set Set

Set Set Set Set

22 A30808-X3247-M14-1-7618



Fig. 2.7 BS-240/241 equipped with 5 cabinets

For the BS-241 outdoor the outer parts of the cabinets are common; The rest isaccording to the provided functionality.

Extension Rack

Base Rack

Service1 Rack

Service2 Rack

Extension Rack

A30808-X3247-M14-1-7618 23



3 Description of Modules

Name Freq.Var.

Remarks

Core modules:COBACOSA

Core basisCore satellite

no Up to 8 PCM lines with COBA and COSAequipped (COBA and COSA can beequipped in the Base Rack/Shelter).

Carrier related modules:CUxECUxFlexCU

Carrier unit yes Carrier unit and EDGE and FlexCUcarrier unit can be equipped in the Baseand Extension Racks/Shelters (see alsosection Fig. 2.2)

Antenna system modules:DUAMCO2xDUAMCO4xDUAMCO8xDIAMCOxFICOMBxFICOMXxTMAxHPDUx

Duplexer 2:2Duplexer 4:2Duplexer 8:2Diversity multicouplerFilter combiner (base)Filter combiner (extension)Tower mounted amplifierHigh power duplexer

yes Antenna system modules can beequipped only in the Base and ExtensionRacks/Shelters.DIAMCO, FICOM and HPDU are notavailable for the GSM 1900 band.DUAMCO 2:2, DUAMCO 4:2 and HPDUworking in shifted primary GSM 900 bandare available.

Alarm collection modules:ACTC (part of DC-Panel)ACTMACTP

Alarm collection terminals no ACTC is equipped in every Rack/Shelter.ACTM can be equipped only in the BaseRack/Shelter. ACTP can be equipped inthe Extension or Service Racks/Shelters.

Power supply modules:AC/DCDCBCTRL

AC/DC converterDC battery controller

no AC/DC controller used for AC power canbe equipped in the Service1Rack/Shelter).Supervision of the AC/DC converter andof the connected Battery systems (inService1 and Service2 Racks/Shelters).

OVPTOVPTCOAXABISCON

Over voltage protectionand tracer.Abis Connection Module

no 100 Ω / 120 Ω line.75 Ω coaxial line. The OVPT is anoptional feature.ABISCON can be installed as alternativeto the OVPT

Abis Link Equipment:LE

Link Equipment no Link Equipment can be equipped inService1 and Service2 Racks/Shelters

Cover Parts:CP:ACOMCP:CUCP:AC/DCCP:DIAMCOCP:COBA, COSACP:ACTCP:HEX

Cover Parts have to beinserted if the respectiveactive module is notneeded in a configuration

no the air flow inside the Frame or Shelter isnot affected

Tab. 3.1 Units and Modules

24 A30808-X3247-M14-1-7618



3.1 Core (COBA and COSA)The Core has the following tasks inside the BTSE:– local controlling of the entire BTSE– generating of system clocks– providing of up to 10 Abis-interfaces to BSC or other BTSEs– routing of Abis-data to up to 48 CUs– providing an interface to the LMT Evolution/Radio Commander– handling and processing of O&M-messages

Therefore, the Core can consist of up to 2 (without redundancy) or up to 4 (with redun-dancy) boards. The following picture gives an idea of the slot-configurations:

Fig. 3.1 Connection of major modules

For a configuration with less or equal 2 PCM30/24-interfaces and no Extension Rackone COBA-board is required. The second slot can be used (by adding 1 COSA Board)for an expansion of the BTSE up to 10 Abis and 48 CU-interfaces.

Battery Backup Battery systems no up to 4 Battery systems can be equipped(in the Service1 or Service2 RackShel-ters)

Fan Central Fan unit no for forced convection cooling

Heater:HEX Single Heater

no Heater can be equipped in all typer ofShelters

Frame Compact Rack no Base, Extension, Service1 and Service2

Shelter Shelter of the Cabinet no Base, Extension, Service1 and Service2with HEX

Name Freq.Var.

Remarks

Tab. 3.1 Units and Modules

CU

2/4 Abis 4/6 Abis

COBA COSA COBA red. COSA red.

2/4 Abis 4/6 Abis

Abis

8/16 other

interfaces

CUs

OVPT

8/16CC-Link CC-Link

A30808-X3247-M14-1-7618 25



Hot Plug-in: A Hot Plug-in of the Core-boards (COBA and COSA) is possible. Thismeans, that these boards can be plugged in/out with voltage switched on and no otherHW inside the Rack is disturbed (no loss of data on other boards) or a board isdestroyed.

3.1.1 Core Basis (COBA)Two COBA boards are developed:• COBA2P8• COBA4P12

The first digit gives the number of Abis-Interfaces, the following letter the kind ofAbis-interface (e.g. P for PCM30/24), and the following digit the number of CU-inter-faces, e.g., COBA2P8 (2 PCM30/24 Abis-interfaces, 8 CU interfaces).

The COBA4P12 board permit to optimise the split of CU-links and Abis interfaces.

The primarily concepts of the COBA2P8 / COBA4P12 cards are:– Low impact on O&M software– Pin compatibility– Maintenance of the current functionality (same feature, same redundanvy concept)– Maintenance of the current LEDs signalling philosophy

The COBA is the central board of the core. The main components of this board are theBase Core Controller (BCC), the Advanced CLock Generation (ACLK), the SErial LinkInterface Controller (SELIC) that manages the external interface towards the CarrierUnits, the PCM30/24 Abis interfaces, the internal system alarm interface and also aninterface to one satellite board (COSA) for expanding the COBA.

The most important functionalities of the COBA are the local controlling of the BTSplus,the generation of the system’s clocks, the management of all the internal/external inter-faces and the routing of data to the CU. In addition the COBA handles all the O&Mmessages.

To fulfill the CORE redundancy aspects a redundant COBA can be installed. It works instandby mode. In case of a serious fault to the active COBA the redundancy algorithmswitches over the redundant one. The redundancy implemented is a "cold" one. Thismeans that when the "cold" COBA goes in service there is no synchronization of datawith the faulty one, the service is interrupted during the transition phase and all theactive calls are therefore lost. In the next "Fig. 3.2 COBA internal architecture" theinternal components of the COBA are represented.

iA mixed configuration with COBA2P8 and COBA4P12 in the same BTSE is notsupported.

26 A30808-X3247-M14-1-7618



Fig. 3.2 COBA internal architecture

The Advanced Clock Generation (ACLK) generates the system specific timing signalswhich are distributed by SELICs to the CUs.

3.1.2 Core Satellite (COSA)Two COSA boards are developed:• COSA6P16• COSA4P12

The first digit gives the number of Abis-Interfaces, the following letter the kind ofAbis-interface (e.g. P for PCM30/24), and the following digit the number of CU-inter-faces, e.g., COSA4P12 (4 PCM30/24 Abis-interfaces, 12 CU interfaces).

The primarily concepts of the COSA6P16 / COSA4P12 cards are:– Low impact on O&M software– Maintenance of the current functionality (same feature, same redundanvy concept)– Pin compatibility– Maintenance of the current LEDs signalling philosophy

The main task of the COSA board is to increase the number of the Abis-interfaces andCC-links of the Core Board (COBA) in order to provide in total up to 10 PCM30/24 portsand up to 48 Carrier Units (CU).

COSA is controlled via a satellite interface (32 bit data) by the COBA and receives theworking-clock from the COBA.

The next "Fig. 3.3 Core Satellite Board (COSA) internal architecture" shows the internalcomponents and interfaces of the COSA board:

Abis1

Abis2

SA

T-I

nter

face

DC/DC Converter

SRAM

RDLLOGIC

WATCHDOG

EEPROMsA/D-Conv. Mux

CAN-BUS, ALARMS LEDs, Redundancy Control,

Route clock

external CLK sync

CONTROLLER

BASE CORE ADVANCED

CLOCK

GENERATOR

Links to

LMT Interface

to

COSA

AlarmInterface

Flash MemoryPCM Switch

Internal Core Controller Bus

CUs

SERIALLINK

INTERFACECONTROLLER

LMT Interface

Input/Output

A30808-X3247-M14-1-7618 27



Fig. 3.3 Core Satellite Board (COSA) internal architecture

3.1.3 Core Link Extension (COREXT)The Core Link Extension board connects 4 CU ports and 2 Abis ports located atCOBA4P12 board via core backplane to the appropriate interfaces.

The COREXT is only a passive board without DC supply interface.

Two external Abis (PCM) lines are connected directly to the COREXT board. These Abis(PCM) lines are routed to the COBA4P12.

If Core redundancy is required, two COREXT boards shall be installed.

To apply the feature cross connect, either COSA4P12 or COREXT board must beinstalled in Base Rack together with COBA4P12.

Internal PCM Bus

Internal Core Controller Bus

SatelliteInterface

To COBA

PCM30/24ports PCM Switch

SerialLinkInterfaceController

To CUs

DC/DC converterRoute ControlPreselector

Bus interface to COBA

A-bis 3-8

28 A30808-X3247-M14-1-7618



Fig. 3.4 System with COBA4P12 and COREXT

The COREXT board is introduced to allow the implementation of COBA4P12 with 2further Abis links and 4 further CC links without exchange of any installed Rack hard-ware.

A30808-X3247-M14-1-7618 29



3.2 Carrier Unit (CU)The Carrier Unit (CU) is composed by an analogue recieve and transmit part with aSynthesiser and Power Amplifier (PA), by a SIgnal PROcessing unit (SIPRO) as well asa Power Supply Unit (PSU). It has two receive inputs, one for the normal path, the otherfor the diversity path. The CU contains all the functions that make up one carrier andinclude synthesiser hopping and advanced equalizer functions for high speed applicai-tons.Besides it takes care for all carrier oriented tasks. In the uplink (UL) direction twoRF signals (diversity) are received and finally converted into TRAU or PCU (for GPRS)frames and signalling data. In the downlink (DL) direction, TRAU or PCU (for GPRS)frames and signalling data are received and converted into a GMSK modulated RFsignal, which is amplified to the desired power level. The "Fig. 3.5 Internal Componentsof the Carrier Unit" shows the internal components of the Carrier Unit.

There are four variants of the CU for the different frequency bands GSM 850, R-GSM900, GSM 1800 and GSM 1900. The differences of the variants arise mainly on thePower Amplifier.

Fig. 3.5 Internal Components of the Carrier Unit

Power Amplifier and Transceiver Unit (PATRX)

The Power Amplifier and Transceiver Unit provides the main analog functions of theCU:– It receives the two (diversity) RF signals from the antenna combining equipment and

converts them down to IF. The downconverted RF signals are then transmitted toSIPRO where they are sampled and digitally downconverted to baseband.

– It receives the GMSK modulated signal from the SIPRO. The signal is then I/Qmodulated, upconverted, levelled, power amplified and transmitted to the antennacombining equipment.

– It supports the synthesizer frequency hopping– It provides an RF loop between downlink and uplink path for the unit test of the CU

The power control loop implements 6 static power steps (each 2 dB) and additional 15dynamic power levels (each 2 dB). For low output power versions of the CU, a furtherreduction of 2 dB is provided.

POWER SUPPLY UNIT

POWERAMPLIFIER

SIGNALPROCESSINGUNIT

cc

-4

puts

utputs

30 A30808-X3247-M14-1-7618



Signal Processing Unit (SIPRO)

The Signal Processing Unit contains all the digital functions of the carrier unit, includingthe following:– Signal Processing in uplink and downlink.– Control of RF on the Power Amplifier.– Baseband and synthesizer hopping.– Channel Control.– Radio Link Control.– O&M parts relevant for the Carrier Unit.– Link to the Core Board (COBA) via the CC link.– Analogic to digital conversion.– Digital to analogic conversion.– Management of the Carrier Unit Local Clock.

Due to the analogic functions, the Signal Processing Unit is specific for the differentfrequency variants. (one type for the GSM 850, GSM 900, and one for the GSM 1800,GSM 1900)

Power Supply Unit (PSU)

The Power Supply Unit (PSU) is the DC/DC converter for the CU for all applications. ThePSU generates the voltages +26/28V, +6V (only GSM 1800, GSM 1900), +12V, +5.3Vand -5.3V for the analogue circuitry and +3.35V for the digital circuitry from a -48Vprimary input voltage. The PSU is mechanically incorporated in the CU.

3.3 EDGE Carrier UnitThe EDGE Carrier Unit (ECU) is a modified CU that uses the same interfaces as theCU but supporting the EDGE functionality in uplink and downlink. In downlink direction,the signalling and traffic data are received from the Core and converted into GMSK or8-PSK modulated signal, which is amplified to the desired power level.With the ECU it is possible to mix EDGE and non EDGE timeslots on the same carrier.

The ECU carries two independent receivers (normal and diversity channel) to providethe antenna diversity function. In uplink direction, the received signal is converted toIF-band. The IF-band is converted to a digital GMSK/8PSK-signal.

The mechanical design of ECU is identical to that of CU versions.

The ECU and CU modules may be installed in any kind of mixed configurationsconcerning BS-240/241 hardware (Base/Extension Racks). Further, any cell/sectorconfiguration with a mixture of EDGE CU and “normal CUs” can be implemented.

The EDGE Carrier Unit (ECU) takes care for all carrier oriented tasks of the BTS. Inuplink (UL) direction, two RF signals (diversity) are received and finally converted intoTRAU or PCU frames (for GPRS) and signalling data. In downlink (DL) direction, TRAUframes or PCU frames (for GPRS) and signalling data are received and converted intoa GMSK or 8-PSK modulated RF signal, which is amplified to the desired power level.A BTS Rack can be equipped by any combination of ECU and CU.

Functional Structure of the EDGE Carrier Unit

The ECU unit is a new developed and enhanced CU unit which supports the GMSK and8PSK Modulation in uplink and downlink. It is a HW compatible to the CU unit and fitsinto the BTSplus Rack. A functional description of the whole receive and transmit path

A30808-X3247-M14-1-7618 31



including the EDGE Carrier Unit and the antenna combining equipment can be foundbelow.

The ECU consists of following functional subunits:

Power Amplifier and Transceiver Unit (EPATRX)

Signal Processing Unit (ESIPRO)

EDGE Power Supply Unit (EPSU)

EDGE Power Amplifier and Tranceiver Unit ( EPATRX)

The EDGE Power Amplifier and Tranceiver Unit (EPATRX) provides the main analogfunctions of the CU. In uplink direction, two (diversity) preamplified and filtered RFsignals are received from the antenna combining equipment. These signals are downconverted to IF and channel filtered in the RXFE stage. The IF signals are then trans-mitted to ESIPRO, where they are sampled and digitally down converted to baseband.In downlink direction, the GMSK or 8PSK modulated signal is received from theESIPRO, I/Q modulated and up converted by the MODUP stage, which also providesthe levelling of the output power.

The obtained RF signal is then power amplified by the module EPWRST and transmittedto the antenna combining equipment. A part of the transmitted power is fed to themodule PWRDET, which performs the power detection. This signal is used to close thedigital power loop.

The Predistortion Receiver (PDRX) down converts the transmit signal to the TX-IF forthe I/Q-Demodulation and adjusting the predistortion values. The transmitter is linear-ized by means of an adaptive digital predistortion which is applied to the basebandsignals. For the introduction of the ECU,a static predistortion was choosen for lineariza-tion of the transmit path. The HW is able to do adaptive predistortion, which can beinstalled by SW update. EPATRX is able to support synthesizer frequency hopping bythe implementation of the synthesizer modules RXLO and TXLO. The unit test of theECU is supported by the module LTL, which provides an RF loop between downlink anduplink path.

Signal Processing Unit (ESIPRO)

The EDGE Signal Processing Unit (ESIPRO) board of the BTSPLUS is a part of theEDGE Carrier Unit. It contains the following functions of the EDGE Carrier Unit:– Signal Processing in uplink and downlink– Control of RF on EPATRX– Baseband and synthesizer frequency hopping– Channel Control– Radio Link Control– O&M parts relevant for carrier unit– Link to Core via ASIC SELIC– Digital Modulation– Predistortion signal processing– Digital part of Power control– Analog to digital conversion (RXIF)– Digital to analog conversion (TX-baseband, TX-ramping)– Analog to digital conversion (PDRX)– Analog to digital conversion of Diode voltage– Analog to digital conversion of temperature– Local clock of CU

32 A30808-X3247-M14-1-7618



EPSU (Power Supply Unit)

The EDGE Power Supply Unit (EPSU) is the DC/DC converter for the ECU for all appli-cations. The EPSU generates the voltages +26V/+28V, +12V, +5,3V and -5,3V for theanalog circuitry and +3.3V for the digital circuitry from a -48V primary input voltage. Theonly interface relevant change was the change of the analog bias voltage for theEPWRSTD to +12V. The EPSU is mechanically incorporated in the ECU.

The EPSU is a slightly modified version of the PSU of the GSM CU. In this document,not all Interface names are changed to EPSU. Therefore, PSU can be seen as asynchronym for EPSU in this document.

3.4 GMSK Carrier Units (GCU)The GCU is a resembled ECU (the main sub-units are similar) which supports GMSKmodulation only, like the CU.

GCUs and CUs differ in the RF output power value for the GSM 1800 frequency band:

GCU: 53,7 W; CU: 37,1 W.

There are different variants of GCUs for the frequency bands GSM 900 and GSM 1800.

The types of GCU are the following:• GCUGV2 GMSK Carrier Unit for GSM 900 MHz• GCUDV2 GMSK Carrier Unit for GSM 1800 MHz

3.5 Flexible Carrier Unit (FlexCU)

The FlexCU is a complete two-carrier unit with the same dimension and based on theECU. Its two TRX can be configured independently, e.g. into different sectors. TheFlexCU either acts as two ECUs or as one carrier unit with so called “fourfold receivediversity”, if “Transmission Diversity Time Delay” is enabled (for operation modes seebelow).

In uplink direction four RF signals are received and converted into traffic and signallingdata. In downlink direction traffic and signalling data are received and converted into twoGMSK or 8PSK modulated signals which are amplified to the desired power level.

By using FlexCUs instead of other carrier units the number of carriers within the existingshelter(s) can be doubled. This is an ideal solution to double the capacity of BTSEs, anadvantage not only for footprint restricted BTS sites.

A working FlexCU requires about 33 % less power than two ECUs.As soon as a TRX is idle, it is switched off. With this enhanced power saving mode theoverall power consumption of an idle FlexCU (both TRX in idle state) is only 40 Watt.

The FlexCU supports all the frequency bands: GSM 850, GSM 900, GSM 1800 andGSM 1900. There exists one type for each frequency band.

These types of FlexCU are available:• FCU850V1 Flexible carrier unit for GSM 850• FCUGV1 Flexible carrier unit for (R-) GSM 900• FCUDV1 Flexible carrier unit for GSM 1800• FCUPV1 Flexible carrier unit for GSM 1900

iFlexCU modules are available from BR 8.0 onwards.

A30808-X3247-M14-1-7618 33



FlexCU Operation Modes

FlexCUs may operate in two different modes: the double and the single ECU mode.

The double ECU mode is the default configuration of a FlexCU, with full support ofMCS-1 to MCS-9 in uplink and downlink. It functions like two independent ECUs withcomplete twofold EDGE TRX functionality: Each of both transceivers shows afull-equipped main receiver and diversity receiver.

Fig. 3.6 FlexCU - Double ECU Mode

Together with a FDUAMCO (and its possibility to switch from 2:2 to 4:2 and reverse viajumper cable) it is easy to increase the capacity.

The so called fourfold receive diversity mode is the single ECU mode in which theFlexCU functions as one carrier unit with four receivers. Only one TX path is used. Whentransmit diversity is enabled, this mode is automatically activated.

The four receivers of the FlexCU are fed by four independent antennas via one(F)DUAMCO together with one DIAMCO.

The TX path is fed via the (F)DUAMCO to two of the four antennas.

The fourfold receive diversity mode enhances the receiver sensitivity of the BTSE. Thedoubled number of the RX paths leads to an enhanced diversity gain (additionally up to2.5 dB).

Fig. 3.7 FlexCU - Single ECU Mode - Fourfold Receive Diversity Mode

TX0

TX1

RX-N0RX-Div0

RX-N1RX-Div1

SignalProcessing

Combiner(s) TX0

TX1

RX-a

TX0RX-b

RX-cRX-dRX-d

RX-bRX-b

cell 1

cell 1

cell 2

TX0

TX0

RX-NRX-Div0

RX-Div1RX-Div2

SignalProcessing

Combiner(s) TX0

TX1

RX-a

TX0RX-b

RX-cRX-dRX-d

RX-bRX-bcell 1

1 carrier ofa cell

34 A30808-X3247-M14-1-7618



3.6 Carrier Unit Output Power LevelThe typical and guaranteed values of RF output power level are listed below for CUs,GCUs, ECUs and FCUs, dependent on its frequency bands and modulation types(GMSK and 8PSK).

3.7 Duplexer Amplifier Multicoupler (DUAMCO)The DUAMCO consists of two identical modules. Each module contains a duplex filter,which combines the RX and the TX path together, to be fed to a common antenna. TheDUAMCO combines 1 (see Fig. 4.2), up to 2 (see Fig. 4.3) or up to 4 (see Fig. 4.4)carriers to one antenna and consists of two branches with the following elements:• a LNA (Low Noise Amplifier) which takes care of a low system noise figure• an attenuator (in case of installed TMAs, additional gains greater than the cable

losses must be adjusted by means of the attenuator)• a second low noise amplifier• a power splitter which distributes the received band to the CUs (Carrier Units)• a transmit path which consists of:

FrequencyBand

Carrier Unit Type TypicalRF Output Power

GuaranteedRF Output Power

GMSK 8PSK GMSK 8PSK

dBm Watt dBm Watt dBm Watt dBm Watt

CU/GCU GSM 900 CUGV3 / V4 47.3 54 -- -- 47.0 50 -- --

GCUGV2 47.3 54 -- -- 47.0 50 -- --

GSM 1800 CUDV3 / V4 45.7 37 -- -- 45.4 35 -- --

GCUDV2 47.3 54 -- -- 47.0 50 -- --

GSM 1900 CUPV4 45.7 37 -- -- 45.4 35 -- --

ECU GSM 850 ECU850HPV2 48.3 68 46.3 43 48.0 63 46.0 40

ECU850V3 / V3A 48.3 68 46.3 43 48.0 63 46.0 40

GSM 900 ECUGV3 / V3A 48.3 68 46.3 43 48.0 63 46.0 40

GSM 1800 ECUDV2 47.3 54 45.3 34 47.0 50 45.0 32

ECUDHPV3 / V3A 48.3 68 45.3 34 48.0 63 45.0 32

GSM 1900 ECUPV2 47.3 54 45.3 34 47.0 50 45.0 32

ECUPHPV2 48.3 68 45.3 34 48.0 63 45.0 32

ECUPHPV3 / V3A 48.3 68 45.3 34 48.0 63 45.0 32

FlexCU GSM 850 FCU850V1 47.0 50 44.0 25 46.7 47 43.7 23

GSM 900 FCUGV1 47.0 50 44.0 25 46.7 47 43.7 23

GSM 1800 FCUDV1 47.0 50 44.0 25 46.7 47 43.7 23

GSM 1900 FCUPV1 47.0 50 44.0 25 46.7 47 43.7 23

Tab. 3.2 Carrier Unit Output Power Level (Typical and Guaranteed Values) per TRX

A30808-X3247-M14-1-7618 35



– an isolator which protects the PAs (Power Amplifiers) inside the CUs from eachother in order to assure the required intermodulation suppression

– a hybrid coupler which provides the reference signal for dynamic and static powercontrol. The corresponding not transmitted power is terminated in a load includinga heat sink (for DUAMCO 4:2 and DUAMCO 8:2)

– an ASU (Antenna Supervision Unit) which is responsible for detecting certainreflection factors at the antenna connector. The ASU detects the VSWR failureand generates a failure information towards the O&M (CAN bus interface). Thisinformation is subdivided in several levels with the following characteristics:- VSWR < 2 neither generation of warning nor of an alarm- 2 ≤ VSWR ≤ 3 generation of warning 'Antenna not Adjusted'- VSWR > 3 generation of VSWR alarm 'Antenna Faulty'.

and a common part consisting of:• a PDU (Power Distribution Unit) for two TMAs (Tower mounted Amplifier) connected

to the TMAs by means of an antenna feeder cable• an O&M interface which transmits error messages to the BTS core via a slow O&M

bus (CAN bus)

The DUAMCO amplifier has two different operation modes:– the AMCO mode where no TMA is used– in case a TMA is used the DUAMCO is configured in the MUCO mode

The PDU provides the DC power supply and the alarm supervision of the TMAs. Alarmmonitoring is done with a signalling interface between DUAMCO and TMA, modulatedonto a IF carrier at 7.86 MHz.

3.8 Dual Integrated Amplifier Multicoupler (DIAMCO)The installation of a DIAMCO Unit is required to implement two cells/sectors with RXdiversity in a Base or Extension Rack.

For the uplink direction, the DIAMCO module is used to split the RX antenna signal toseveral receiver inputs.Therefore it filters and distributes the received signals to theCarrier Units in one Rack. The DIAMCO consists of two branches constituted by:– a receive filter– a low noise amplifier (LNA) which takes care of a low system noise figure– an attenuator– a second low noise amplifier– a power splitter which distributes the received band to the CUs (Carrier Units)

and a common part constituted by:– a PDU (Power Distribution Unit) for two TMAs (Tower mounted Amplifier) connected

to the TMAs by means of an antenna feeder cable– an O&M interface which transmits error messages to the BTS core via a slow O&M

bus (CAN bus)

The DIAMCO RX amplifier has two different operation modes:– the AMCO mode where no TMA is used– in case a TMA is used the DIAMCO is configured in the MUCO mode

3.9 Filter Combiner (FICOM)With the FICOM, it is possible to combine up to 8 frequencies in downlink direction (TX)in one Rack. For the uplink direction (RX), the DIAMCO has to be used to filter and

36 A30808-X3247-M14-1-7618



distribute the received signals to the Carrier Units. The FICOM consists of remotetunable narrowband filters (TNF). The advantage of this filter combining technique is thevery low insertion loss, if e.g., 8 transmitters are combined to one antenna.

In principle, the FICOM offers the following functions:• RF Functions:

– RF Power Combining– Transmitter Spurious Signal Suppression– Isolation between inputs– Isolation output to input

• Control / Monitoring Functions:– Antenna VSWR alarm thresholds setting and status reporting– Internal Performance Monitoring– Interfacing with BTSE

• LED Display:– Antenna VSWR alarms– Tuning alarms– Presence of DC

• Lightning Protection at the RF output connector (7/16)

3.10 Tower Mounted Amplifier (TMA)The TMA connects the antenna with the BTSE in order to amplify the receive signal andpass through the transmit signal. The TMA contains two duplex filters, each on one RFconnector, to separate and combine the receive and transmit path inside the TMA. TheTMA consists of:– the RX parts of the duplex filter and– the LNA (Low Noise Amplifier) which takes care of a low system noise figure of the

RX part– the TX parts of the duplex filter

The DC power for the TMA is feed into the triplexer by the PDU (Power Distribution Unit)functionality of the DUAMCO/DIAMCO.

The Encoder/Decoder units of the TMA signalling interface generate an alarm for eachTMA separately by supervising the DC current consumption of each unit.

Note: When the TMA is used the DUAMCO/DIAMCO works in the so called MUCO(multicoupler) mode. In the MUCO mode, the DUAMCO/DIAMCO mainly works asmulticoupler to split the receive signal for the following CUs.

3.11 High Power Duplexer Unit (HPDU)The High Power Duplexer has the task of combining the TX- and the RX-path into oneantenna, in order to minimize the number of antennas when FICOM is used. The HPDUcontains a duplex filter for the transmit frequency band and for the receive frequencyband, but no Low Noise Amplifier in the RX path.

If the TMA shall be used together with a HPDU a so called BIAS-T (DUBIAS) forpowering and signalling of the TMA is required. Up to two HPDU can be integrated ontop of the Rack below the cover and also up to two HPDU could be fit in the gap betweenthe inner side wall and the Frame in the Shelter.

Note: HPDU is available for working in the P-GSM 900, GSM 1800 and GSM-PS 900.

A30808-X3247-M14-1-7618 37



3.12 DC Panel (DCP)The DC Panel contains the circuit breakers to protect the DC power lines for themodules, the ACTP, FAN units, HEX, LE units and the ACTC where the Rack/Shelteralarms will be connected. The temperature sensor is integrated in the ACTC. The frontpanel of the DC Panel for the Base Rack or shelter carries the connector for the LocalMaintenance Terminal (LMT Evolution).

3.13 Alarm Collection Terminal (ACT)The Alarm Collection Terminal contains the interface to the external alarms (Operatoralarms, Rack alarms, shelter alarms,...) and commands and a CAN-BUS interface to theCORE.

ACTC is part of the DC-Panel and therefore it is installed once in every Rack/Shelter tocollect all internal alarms. It has inputs for 16 internal alarms (1 Door, 6 Fans and 9Rack/Shelter, internal alarms, which can be defined by the operator). In the BaseRack/Shelter the ACTC is direct connected to the COBA. In all other Racks/Shelters, theACTC is connected to the ACTP.

The ACTM and ACTP contain their own DC/DC converter on board, a controller, inter-faces towards the CAN-Bus and an alarm interface for 16 Rack/Shelter alarms or siteinputs. ACTM has an additional interface for Operator Alarms (48 site inputs). ACTMand ACTP have a DIP Switch device to set the Rack address.

The tasks of the ACT are:– Collection of all alarms for units having no access to O&M BUS to CORE.– Collection of so-called cabinet specific alarms (Rack, Shelter).– Collection of so-called operator available alarms (Site Inputs).– Distribution of operator available commands (Site Outputs).– 8 bit µC (80C505C) for initialization, supervision and controlling the functions of the

ACT.– PID-EEPROM to store board data.

The physical function of the ACT is to interface the alarm and command signals betweenthe CAN-BUS and the alarm and command connectors. The ACT is designed to be usedonly one time for the Rack. So the ACT is an element without redundancy, but the BTSEis not out of service in case of a faulty ACT.

Different ACT, are available depending on the applications in the Base Rack/Shelter(ACTM) or in the Service and Extension Rack/Shelter (ACTP) as shown in Fig. 3.8.

38 A30808-X3247-M14-1-7618



Fig. 3.8 Alarm Collection Terminal (ACTM and ACTP)

1 D

oor

6 F

an

7 A

larm

s

Tem

p.S

ens

CA

N-B

us N

ode

Con

trol

ler

+ In

terf

ace

PID

DC

DC

Rack1(Extension)

ACDCController

BatteryAC

DC

CO

RE

CA

N-B

us N

ode

Mas

ter

Con

trol

ler

+ In

terf

ace

Ala

rms

Temp.Superv.

AC

OM

ACTP

1 D

oo

r

6 F

an

7 A

larm

s

Tem

p.S

ens

CA

N-B

us N

ode

Con

trol

ler

+ In

terf

ace

PIDAC

OM

ACTM

48 Site Inputs8 Site Outputs

DCDC

1 D

oo

r

6 F

an

7 A

larm

s

Tem

p.S

ens

CA

N-B

us N

ode

Con

trol

ler

+ In

terf

ace

PID

DC

DC

Rack 2(Extension)

Temp.Superv.

AC

OM

ACTP

1 D

oo

r

6 F

an

7 A

larm

s

Tem

p.S

ens

CA

N-B

us N

ode

Con

trol

ler

+ In

terf

ace

PID

DC

DC

Temp.Superv.

AC

DC

ACTP

Bat

tery

AC

DC

Con

trol

ler

Rack3(Service1)

Rack 0(Base)

CAN-Bus

A30808-X3247-M14-1-7618 39



3.14 AC/DC Converter (AC/DC)The AC/DC system consists of one or two Frames housed in the Service Rack/Shelter.Each Frame provides for AC distribution, DC distribution, EMI-filter, signal distributionbetween rectifiers and controller board via backplane. Each AC/DC Frame contains:– up to 6 rectifier modules (adapted to the actual need for specific loads) each 720W

-48VDC (N+1 redundancy to achieve 3600W+720W)– one controller board (DCBCTRL) for battery supervision, rectifier supervision, alarm

interface (see section 3.14.1)– two LVD relays for Frame.

The Service Rack/Shelter with two AC/DC Frames is intended to be used to supplyBS240/241 with more than 8 carriers.

The AC/DC tasks are:– output supplying all -48V-consumers within the BS-240/241; input supplying of 230V

AC 1 phase system for the world market and 208V AC 2 phase system (208V phaseto phase) for the US market.

– supplying external equipment with -48V– charging and supervising of different battery backup types with different capacities

and up to two battery backup systems per Service Rack/Shelter– supervising rectifiers, batteries and alarm messaging– switching off DC outputs (rectifiers as well as battery) in case of under and over

temperature– hot plug in/out– operation of two Frames in parallel

The AC/DC and the backup batteries work as an Uninterruptable Power Supply System(UPS).

3.14.1 DC and Battery Controller (DCBCTRL)The DC and Battery Controller is the supervision unit for the AC/DC Converters installedin the Frame AC/DC and for the Batteries charging of this set of AC/DCs. The DCBCTRLhas a dip switch device to adjust the frame address AC/DC frame 1 or AC/DC frame 2and the battery capacities of the connected battery system.

iDue to the maximum ambient temperature of +55 °C (+131 °F), the DCoutput power of one AC/DC module is limited to 720W.By decreasing the maximum ambient temperature to +50 °C (+122 °F),the maximum output power of one AC/DC module is increased to 800Wwithout any change in the module or in the Frame AC/DC.

40 A30808-X3247-M14-1-7618



3.15 Overvoltage Protection and Tracer (OVPT)The OVPT is responsible for lightning protection of the PCM24/PCM30 ports of the Abisinterface and the external synchronization clock input of the BS-240/241 against overvoltage. Additionally, the OVPT provides interfaces to connect PCM tracers withoutinterruption for monitoring the Abis lines. The OVPT is located outside the EMI shield inorder to terminate possible overvoltages before it enters the EMI protected area insidethe Rack.

The board performs the following tasks:– lightning protection of PCM lines– provision to connect ext. monitoring equipment without interruption. The lines are

de-coupled by resistors in order to prevent distortions.– supporting 75 Ω coax and 100 Ω/120 Ω symmetrical lines– for 75 Ω coax only a second version of the OVPT is available– provides grounding facility for the external cable shielding– provides stress relieve for the external cables

3.16 Abis Connection Module (ABISCON)The Abis Connection module provides the interface between the base cabinet and theperipheral Abis-cables and it provides also the feature for monitoring the Abis lines.

The type of Abis Connector depends on the used cable for the Abis interface• symmetrical lines with 100/120 Ohm impedance• coaxial lines 75 Ohm impedance

The ABISCON module can be installed only as alternative to the Over Voltage Protec-tion and Tracer module (OVPT).

3.17 Abis Link Equipment (LE)The link equipment acts as front end to provide the Abis interface. Different equipmentcan be used for wire or radio transmission depending on customer requirements. If a linkequipment is available at the telecommunication site, possibly no link equipment isnecessary within the BTSE. If BS-240/241 is installed away from a telecommunicationsite the link equipment must be installed inside the Service Rack/Shelter. If radio trans-mission is required, microwave equipment must be used. Also direct connections ofPCM24/30 links are possible. The number of Link Equipment, which can be installed,depends on the height of the Link Equipment.

3.18 Cover PartsAll unequipped slots in the Frames of a Rack/Shelter must be equipped with CoverParts, to reach a balanced airflow. If the complete Frame is empty, it is not necessary tocover all the empty slots.

A30808-X3247-M14-1-7618 41



3.19 Backup Battery (BATTERY)Backup batteries can be installed in the Service Racks/Shelters only. One frame AC/DCcan be connected to two battery systems with two independent connecting leads. Onebattery system can consist of up to three battery groups (one group can consist of up tofour batteries) which are always in the same Rack/Shelter due to the temperaturecontrol issues.

Besides three different types of Backup batteries with nominal capacities of 80 Ah, 85Ah and 100 Ah can be installed on the BS-240/241.

Fig. 3.9 Example of Battery Backup Systems Connected to the AC/DC

The maximum DC-Output-Power of one Frame AC/DC is limited to 3600W. Themaximum current out of one battery system is limited to 50A (respectively 2400W at48V). All battery systems connected to one or two frames AC/DC should have the samebattery capacity. See section Power Supply and Battery Backup for more details.

Battery 0

Base Frame for AC/DC Converter

DCBCTRL

AC

DC-

AC

DC-

AC

DC-

AC

DC-

AC

DC-

AC

DC-

Battery System 0

DC line (max. 50 A)

DC line (max. 50 A)

Battery System 1

Battery System 2

DC line (max. 50 A)

DC line (max. 50 A)

Battery System 3

Battery 1 Battery 2

Battery 0 Battery 1 Battery 2



Module

Module

Module

Module

Module

Module

Base Frame for AC/DC Converter

DCBCTRL

AC

DC-

AC

DC-

AC

DC-

AC

DC-

AC

DC-

AC

DC-

Module

Module

Module

Module

Module

Module

42 A30808-X3247-M14-1-7618



3.20 FanThe fan unit is responsible for creating a sufficient airflow in order to cool the inner elec-tronics using all the effects of forced convection cooling. The cooling concept is basedupon a cascaded principle of six Fan Units: two fans are responsible for each Frame.

The fans used are able to overcome the pressure drop caused by the system resistancetaking into account additional losses caused by adequate filters or Heat Exchangersused in order to establish an airflow that limits the ∆T (Temperature difference betweencritical hotspots inside the Rack and the ambient temperature) caused by the specificpower dissipation of that hotspot.

In order to keep both the acoustic noise and the power consumption of all fans at thelowest level possible, the fan speeds are (independently of each other) temperaturecontrolled via integrated sensors (NTC) that monitor the critical hotspots in order to keepthem in an acceptable range.

Furthermore, each fan delivers a fan good/fan bad signal that is processed by the COBAboard (routed via ACTC board in case of a Base Rack/Shelter or the ACTC board andCAN Bus in case of an Extension-/Service Rack/Shelter).

3.21Heat Exchanger (HEX)The BS-241 shelters can be equipped either with HEX.The heat exchangers can only be equipped on the internal side of the door of the BS-241shelter. The task of a heat exchanger is to transport the heat from inside the shelter tothe outside.

For every Frame in a base or extension shelter one heat exchanger is needed, there-fore, 3 heatexchangers are always installed in a base or extension shelter for:– ACOM Frame– Carrier Frame– Core Frame

In the service shelter we have three sections, which can be differently equipped withAC/DC modules, link equipment or backup batteries and then 1 to 3 heat exchangersare needed, according to the installation of equipment.

A30808-X3247-M14-1-7618 43



4 Antenna Combiners and Receiving Paths

4.1 Methods of CombiningIn order to serve cells with different carrier numbers, certain combinations of combiningmodules are required. These configurations provide the necessary performance in acost effective way.

For the UL (Up Link) path, antenna diversity is always considered. The required splittingfactor only depends on the maximum carrier number per cell without yielding a reson-able technical penality.

With respect to the DL (Down Link), a trade off exists between the number of antennasand the insertion loss for a given carrier number. Increasing the antenna numberdecreases the DL insertion loss introduced by hybrid combining of carriers to oneantenna port. For high carrier numbers per cell (≥5) filter combining becomes advanta-geous with respect to insertion loss but suffering from higher cost and incompatibility tosynthesizer frequency hopping.

Nevertheless, for urban sites where the cell sites are usually small a configuration witha DUAMCO 8:2 supports synthesizer frequency hopping and there is no need for addi-tional antennas. Fig. 4.1 the different combining options are shown. The relationshipbetween labels and components is shown in Fig. 2.2.

Fig. 4.1 Overview of Combining Options

2:2

2x

4:2

4x

8:2

8x

TMA

Tower Mounted

2:1

RX

High Power Duplexer

Duplex Combining

Filter Combining

HPDU2:1

TX8x 8x

2x8DUBIAS

and BIAS-T

Amplifier

44 A30808-X3247-M14-1-7618



DUAMCO (Duplexer Amplifier Multicoupler)

The DUAMCO x:y modules contain duplex filters in order to combine the transmit andreceive path to one antenna connector. The receive and transmit part of the duplex filter,respectively, provide the substantial part of the receive and transmit band filteringrequired by GSM 05.05, 11.21 and JTC J-STD-007.

The receive path consists of a LNA (Low Noise Amplifier) and a power splitter. The LNAtakes care of a low system noise figure and consists of two branches. In case ofmalfunction of one amplifier, the RX gain of the DUAMCO decreases by about 6 dB. Thepower splitter distributes the received band to the CUs (Carrier Units). A splitting factorof 4 (or 8 in case of DUAMCO 8:2) is implemented in order to feed 4 (8) CUs.

The DUAMCO amplifier has two different operation modes which can be selected bye.g. DIP switches. In the following, Mode 1 is called AMCO mode and the second modeis called MUCO mode. In the AMCO mode where no TMA (Tower mounted Amplifier) isused, the DUAMCO gain is around 19 dB. In case a TMA is used, the DUAMCO isconfigured in the MUCO mode. In the MUCO mode, the gain is reduced to about 0 dB.The exact gain of the DUAMCO to compensate the cable losses can be adjusted for thismode with a e.g., DIP switch. This adjustment is only done once during the installationof the BTSE by the service personal. The selected mode can be read by O&M SW viaCAN bus interface.

The transmit path consists of isolators, a hybrid coupler with load (for some modules)and an ASU (Antenna Supervision Unit). The isolators have to protect the PAs (PowerAmplifiers) inside the CUs from each other in order to assure the required intermodula-tion suppression. Two different hybrid couplers (2:1, 4:1) combine up to 4 carriers to oneantenna. The corresponding not transmitted power is terminated in a load includingcooler. The ASU is responsible for detecting certain reflection factors at the antennaconnector and is connected to the O&M interface.

The O&M interface of the DUAMCO transmits error messages to the BTS core via aslow O&M bus (CAN bus).

The DUAMCOs x:y are named depending on the number x of transmit connectors fedby the CUs and the number y of antenna connectors. The following figures show thedifferent DUAMCOs implemented by a set of equal sub-modules.

The DUAMCOs are implemented for seven different frequency bands: GSM 850,P-GSM 900, GSM 1800 (DUAMCO 2:2 , DUAMCO 4:2 and DUAMCO 8:2); E-GSM 900,R-GSM 900, GSM-RE 900, GSM 1900 ( DUAMCO 2:2 and DUAMCO 4:2). The divisionof the GSM 900 band (39 MHz) in two interleaved sub-bands (25 MHz each, P-GSM andGSM-RE) results from the required filter volume for the whole band.(see Tab. 1.2)

A30808-X3247-M14-1-7618 45



Fig. 4.2 DUAMCO 2:2

Fig. 4.3 DUAMCO 4:2

Rx Tx

ASU

LNA

RXCA to Rx fromTx

Control

CAN

DC interf.

TMA

DC/DC

TMA

Signall.

Rx Tx

ASU

LNA

RXCAto Rx from

Tx

AMCO

MUCO

AMCO

MUCO

LNALNA

bus

BiasTEE

BiasTEE

Module 0 Module 1

Antenna 0 Antenna 1

Antenna 0

Rx Tx

ASU

LNA

RXCAto Rx

fromTx

Control

CAN busDC interf.

TMA

DC/DC

TMA

Signall.

Rx Tx

LNA

RXCA

to RxfromTx

Antenna 1

Coupler

to/from core

ASU

CouplerAMCO

MUCO

AMCO

MUCO

LNA LNA

BIASTEE

BIASTEE

Module 0 Module 1

46 A30808-X3247-M14-1-7618



Fig. 4.4 DUAMCO 8:2

FICOM: RF Power Combining / Tuning Modes

The filter combiner (FICOM) consists of a band pass filter for filtering the transmitfrequency band, the VSWR supervision unit, as well as remotely tunable narrowbandfilters (TNF) with their control logic and the isolators for every TX input.

The low loss power addition is carried out by combining the outputs of TNFs inside theFICOM. These TNFs are remotely tuned to the channel frequency of the correspondingcarrier. The minimum number of inputs to be combined is 2. It is possible to combine amaximum number of 8 inputs by adding 'expansion modules' to the 'base module'.

A TNF is first coarse tuned to the desired channel. If RF power is supplied to the TNF itautomatically performs a fine tuning to ensure the best RF behavior. With this automatictuning process, the drift of the passband filter center frequency is compensated.

Therefore, the filter combiner can only be used with baseband frequency hopping, asretuning of the TNF frequency requires up to 5 seconds. But for a large number ofcarriers (6 or 8), baseband frequency hopping has only a negligible disadvantagecompared to synthesizer frequency hopping.

FICOM Modularity

The FICOM functions are carried out by two different types of modules. These are:– Base module 2:1– Expansion module 2:1

Each type of module is able to combine 2 carriers. But only the base module has anoutput for the completely combined signal (antenna output with 7/16 connector). Addi-tional there is a test output at every base module. Also, the reporting of the antenna

Rx Tx

ASU

LNA

RXCAto Rx

fromTx

Control

CAN busDC interf.

TMA

DC/DC

TMA

Signall.

Rx Tx

LNA

RXCAto Rx

fromTx

Coupler

to/from core

ASU

CouplerAMCO

MUCO

AMCO

MUCO

LNA LNA

BIASTEE

BIASTEE

Module 0 Module 1

Antenna 0 Antenna 1

A30808-X3247-M14-1-7618 47



VSWR status is only done by a base module. The different modules are connectedtogether by a special RF connection cable.

Therefore, the number of base modules is equal to the number of cells the FICOM hasto support. The number of expansion modules per cell depends on the total number ofcarriers per cell (2,4,6 or 8).

A FICOM Expansion module 1:1 doesn't exist any more. In case an odd number ofcarriers is recommended in one cell, only one half of the expansion module 2:1 is used.For this application, one TX port remains open.

The FICOMs are implemented for two different frequency bands: GSM-R 900 and GSM1800.

Fig. 4.5 FICOM 8:1

DIAMCO (Dual Integrated Amplifier Multicoupler)

The DIAMCO contains two sub-modules with receive filters, low noise amplifiers andpower splitters.

For the uplink direction, the DIAMCO has to be used to filter and distribute the receivedsignals to the Carrier Units. With the FICOM, it is possible to combine 8 frequencies indownlink direction (TX) in one Rack.The receive filters provide the substantial part of thereceive band filtering required by GSM 05.05, 11.21 and JTC J-STD-007.

The LNA takes care of a low system noise figure and consists of two branches. In caseof malfunction of one amplifier the RX gain of the DIAMCO decreases by about 6 dB.The power splitter distributes the received band to the CUs (Carrier Units). A splittingfactor of 8 is implemented in order to feed 8 CUs. Additionally, the DIAMCO has acascade output which is used for Rack Extension.

TNF TNF

ESN

Control

CAN busDC interf.

VS WRsupervision

Antenna

fromTx

fromTx

TNF TNF

ESN

Control

CAN busDC interf.

fromTx

fromTx

TNF TNF

ESN

Control

CAN busDC interf.

fromTx

fromTx

TNF TNF

ESN

Control

CAN busDC interf.

fromTx

fromTx

Base 2:1 Exp 2:1 Exp 2:1 Exp 2:1

48 A30808-X3247-M14-1-7618



In addition, the functionality of a PDU (Power Distribution Unit) for two TMAs is inte-grated in the DIAMCO. This is the DC power supply and the alarm supervision of theTMAs. Alarm monitoring is done with a signalling interface between DIAMCO and TMA,modulated onto a IF carrier at 7.86 MHz: This interface is identical to the interfacebetween DUAMCO and TMA.

The DIAMCO RX amplifier has two different operation modes, depending on the exist-ence of TMAs. The first mode is called AMCO mode, the second one is called MUCOmode. In the AMCO mode where no TMA is used, the DIAMCO gain is around 19 dB.In case a TMA is used, the DIAMCO is configured in the MUCO mode. In the MUCOmode, the gain is reduced to about 0 dB. The exact gain of the DIAMCO to compensatethe cable losses can be adjusted for the MUCO mode with a DIP switch. This adjustmentis only done once during the installation of the BTSE by the service personnel. Theselected mode can be read by O&M SW via CAN bus interface.

Due to the fact that TMA status information is available for the DIAMCO processor, theDIAMCO itself has to switch the RX mode according to the TMA status. Each TMA canbe switched on or off by a separate switch. This cannot be configured via O&M SW!

For Rack Extension the first DIAMCO works in the AMCO mode and the followingDIAMCO sub-modules in the MUCO mode.

The O&M interface of the DIAMCO transmits error messages to the BTS core only viathe CAN bus.

The DIAMCOs are implemented for two different frequency bands: E-GSM 900 andGSM 1800.

Fig. 4.6 DIAMCO

Antenna 0

Rx

RXCA

to Rx

Control

CAN busDC interf.

TMA

DC/DC

TMA

Signall.

Antenna 1

to/from core

Rx

RXCA

to Rx

LNA

AMCO

MUCO

LNA

LNA

AMCO

MUCO

LNA

BIASTEE

BIASTEE

Module 0 Module 1

A30808-X3247-M14-1-7618 49



High Power Duplexer (HPDU2)

The High Power Duplexer has the task of combining the TX and the RX paths into oneantenna, in order to minimize the number of antennas when FICOM is used. The HPDUcontains a duplex filter for the transmit frequency band and for the receive frequencyband, but no Low Noise Amplifier in the RX path. If the TMA is used together with aHPDU, the BIAS-T (DUBIAS) for powering and signalling of the TMA is required. Up totwo HPDU can be integrated on top of the Rack below the cover and also up to twoHPDU can be fit in the gap between the inner side wall and the Frame in the shelter. Forthe main RX path, one HPDU per cell is installed. For diversity operation, a secondreceive path has to be installed. In one Base or Extension Rack/Shelter, one or twoHPDUs can be installed and a maximum of 8 carriers can be connected to one HPDU.

Fig. 4.7 shows the standard configuration for one cell using HPDU, FICOM andDIAMCO for up to 8 carriers in one Rack.

The HPDUs are implemented for three different frequency bands: P-GSM 900, GSM1800 and GSM-PS 900 (P-GSM shifted to E-GSM).

Fig. 4.7 HPDU

BIAS-T (DUBIAS)

If the TMA is to be used together with a HPDU, a BIAS-T (DUBIAS) for powering andsignalling of the TMA is required.

The DUBIASs are implemented for two different frequency bands: R-GSM 900 andGSM 1800.

FICOM

TX-Filter

TX-Filter RX-Filter

HPDU

DIAMCO

RX-Filter RX-Filter

0 1 2 7TX

0 1 2 7RX

0 1 2 7RX

50 A30808-X3247-M14-1-7618



Fig. 4.8 Configuration with HPDU, DUBIAS and TMA

TMA TMA

DUBIAS

HPDU

TX/RX RX

FICOM

CU0 CU1 CU7

DIAMCO

RX0 RX1 RX7

Antenna Antenna

A30808-X3247-M14-1-7618 51



Diplexer

The Diplexer gives the possibility to use one Antenna Feeder Cable for both GSM 850with GSM 1900 and GSM 900 with GSM 1800 frequencies. One Diplexer is needed tocombine the 2 different frequencies at the BTSs side and the other one to separate thefrequencies near the antennas. The diplexer offers the possibility to reduce the numberof Antenna Feeder Cables in all cases where GSM 900 and GSM 1800, GSM 1900 orGSM 850 and GSM 1900 Feeder Cables have to be installed in parallel. This is e.g. thecase where an existing GSM 900 network will be extended by a GSM 1800 or GSM 1900network to implement a Dual Band Network.

Fig. 4.9 Configuration with Diplexer (Example)

4.1.1 Tx Attenuation of combiner units (CU)In the following table it is listed the typical and guaranteed combiner TX attenuation forthe GSM900 and GSM 1800/1900 system. The attenuation is assigned in decibel.

Antenna Dual Band

900 MHz1800 MHz

Diplexer

DUAMCO 2:2

(1800 MHz)

DUAMCO 2:2

(900 MHz)

Diplexer

f1 f2

f1 + f2

f1 f2

Type GSM 900 (dB) GSM 1800 (dB)

FICOM 2:1 2.3 (guaranteed: 2.7) 2.5 (guaranteed: 3.7)




Tab. 4.1 Insertion loss of FICOMs

52 A30808-X3247-M14-1-7618



Type GSM 850/900 (dB) GSM 1800/1900 (dB)

DUAMCO 2:2 1.2 (guaranteed: 2.5) 1.2 (guaranteed: 2.5)



Tab. 4.2 Insertion loss of DUAMCOs

Type GSM 900 (dB) GSM 1800 (dB)

HPDU 0.4 (guaranteed: 0.6) 0.5 (guaranteed: 0.75)

TMA 0.5 (guaranteed: 0.8) 0.5 (guaranteed: 0.8)

Tab. 4.3 Insertion loss of BCOM, HPDU and TMA

A30808-X3247-M14-1-7618 53



4.1.2DUAMCO - DIAMCO GAIN (RX Path)

DUAMCO - DIAMCO gain

DUAMCO gain GSM 850, GSM,P-GSM,GSM-RE, GSM-PS

GSM 1800, GSM1900

AMCO characteristics

Gain (ANT-RX) 20 dB +/-1.5 dB 22 dB +/-1.5 dB

Gain (ANT-RXCA) 18.5 dB +/-1.5 dB 19.5 dB +/-1.5 dB

Gain ripple +/-1 dB +/-1 dB)

MUCO characteristics

Gain (ANT-RX) 2 dB +/-1 dB 3 dB +/-1 dB

Gain (ANT-RXCA) 0.5 dB +/-1 dB 0.5dB +/-1 dB

Gain ripple +/-0.8 dB +/-0.8 dB

Attenuator characteristics

Attenuator range 0+6 dB +/-0.5 dB 0+6dB +/-0.5 dB

Step size 1 dB +/-0.3 dB 1 dB +/-0.3 dB

DIAMCO gain E-GSM GSM 1800

AMCO characteristics

Gain (ANT-RX) 20 dB +/-1.5 dB 22 dB +/-1.5 dB

Gain (ANT-RXCA) 18.5 dB +/-1.5 dB 19.5 dB +/-1.5 dB

Gain ripple +/-1 dB +/-1 dB)

MUCO characteristics

Gain (ANT-RX) 2 dB +/-1 dB 3 dB +/-1 dB

Gain (ANT-RXCA) 0.5 dB +/-1 dB 0.5dB +/-1 dB

Gain ripple +/-0.8 dB +/-0.8 dB

Attenuator characteristics

Attenuator range 0+6 dB +/-0.5 dB 0+6dB +/-0.5 dB

Step size 1 dB +/-0.3 dB 1 dB +/-0.3 dB

Tab. 4.4 Parameters of DUAMCO - DIAMCO

54 A30808-X3247-M14-1-7618



4.1.3 Parameters of Tower Mounted Amplifier (TMA)

900 MHz Tower Mounted Amplifier

Electrical System Specified Typical

Uplink RF-band 890- 915 MHz

Return Loss (ANT / BTS port) > 14 dB > 15 dB

Return Loss bypass mode > 7,7 dB > 10dB

Nominal gain 25.5 +2/- 2.5 dB at 25˚C (77˚F)25.5 +3/- 3.5 dB -33˚C to +65˚C(-27˚F to +149˚F)

25.5 +/- 1 dB at25˚C (77˚F)

Gain ripple < +/- 0.5 dB at 25˚C (77˚F)< +/- 0.8 dB -33˚C to +65˚C(-27˚F to +149˚F)

Passband ripple, max < = 0.5 dB

Insertion loss bypass mode, max. < = 5 dB max. 3.4 dB

Noise figure, max. 3.6 dB 2.8 dB

Max. input power CW 8 x 15 Watt input TMA

1 dB compression point (CP1) > = 16.5 dBm (output)

3rd order Intercept Point (IP3) on input + 1 dBm >= 6 dBm

Current consumption < = 500 mA < = 400 mA

Downlink RF- band 935 – 960 MHz

Insertion loss < = 0.8 dB < = 0.4 dB

Downlink Return Loss (ANT / BTS port) > = 18 dB >= 18.5 dBm

Return Loss (ANT / BTS port) bypass mode > = 18 dB >= 18.5 dBm

Passive Intermodulation products,max. @ ANT port

IMD3 and higher< = -108 dBm

-120 dBm

Passive Intermodulation products,max. @ BTS port

IMD3 and higher<= -108 dBm + Gain (Ant- BTS)

-100 dBm

Tab. 4.5 Parameters of 900 MHz Tower Mounted Amplifier

A30808-X3247-M14-1-7618 55



1800 MHz Tower Mounted Amplifier

Electrical System Specified Typical

Uplink RF-band 1710 - 1785 MHz

Return Loss (ANT / BTS port) > 14 dB > 16 dB

Return Loss bypass mode > 7,7 dB > 10dB

Nominal gain 25.0 +2/- 2.5 dB at 25˚C (77˚F)25.0 +3/- 3 dB -33˚C to +65˚C(-27˚F to +149˚F)

25.9 +/- 1 dB at 25˚C(77˚F)25.9 +/- 2 dB -33˚C to+65˚C (-27˚F to+149˚F)

Gain ripple < +/- 0.5 dB at 25˚C (77˚F)< +/- 0.8 dB -33˚C to +65˚C(-27˚F to +149˚F)

Passband ripple, max < = 0.5 dB

Insertion loss bypass mode, max. < = 5.2 dB max. 3.8 dB

Noise figure, max. 3.6 dB 2.5 dB

Max. input power CW 8 x 15 Watt input TMA

1 dB compression point (CP1) > = 16.5 dBm (output)

3rd order Intercept Point (IP3) on input + 1 dBm >= 4 dBm

Current consumption < = 500 mA < = 400 mA

Downlink RF- band 1805 –1880 MHz

Insertion loss < = 0.8 dB < = 0.6 dB

Downlink Return Loss (ANT / BTS port) > = 18 dB >= 18.5 dBm

Return Loss (ANT / BTS port) bypassmode

> = 18 dB >= 18.5 dBm

Passive Intermodulation products,max. @ ANT port

IMD3 and higher< = -109 dBm

-116 dBm

Passive Intermodulation products,max. @ BTS port

IMD3 and higher<= -109 dBm + Gain (Ant-BTS)

-90 dBm

Tab. 4.6 Parameters of 1800 MHz Tower Mounted Amplifier

56 A30808-X3247-M14-1-7618



The TMAs are implemented for four different frequency bands: P-GSM 900, GSM-RE900 (RE: Railway Extension; DUAMCO 2:2 and DUAMCO 4:2), GSM 1800 and GSM1900 (DUAMCO 2:2 and DUAMCO 4:2). The division of the GSM 900 band (39 MHz) intwo interleaved sub-bands (25 MHz each, P-GSM and GSM-RE) results from therequired filter volume for the whole band.(see Tab. 1.2)

4.1.4 Examples of Possible BTSE ConfigurationsIn this chapter the following examples of configurations are represented in the figuresbelow:– 3/3/2 with duplex combining (see the Fig. 4.10 and Fig. 4.11);– 8/0/0 with filter and duplex combining (see the Fig. 4.12 and Fig. 4.13):– 2/2/2 with duplex combining (see the Fig. 4.14):– only duplex or only filter combining is exclusively used within a cell

Fig. 4.10 Multi-cell (3,3,2): with 3 DUAMCO 4:2

Mechanical Size, W x H x D 172x280x191 mm (8"x11"x7.5")

Weight 4.25 kg (9 Lbs)

Antenna connector 7/ 16

BTS connector 7/ 16

General Supply Voltage Range +12V +/- 8%

Alarm functions alarming via sub-carrier to DUAMCO or DIAMCO

CIN is part of the combining units DUAMCO or DIAMCO and values are incorporated in the units specs.

Tab. 4.7 Parameters of 900/1800 MHz Tower Mounted Amplifier

RX TX RX

DUAMCO 4:2

TX

CU2CU0 CU1

CELL 0

RX TX RX

DUAMCO 4:2

TX

CU6 CU7

CELL 2

RX TX RX

DUAMCO 4:2

TX

CU5CU3 CU4

CELL 1

A30808-X3247-M14-1-7618 57



Fig. 4.11 Multi-cell (3,3,2): with 2 DUAMCO 4:2 and 1 DUAMCO 2:2

Fig. 4.12 Single-cell (8,0,0): with FICOM and DIAMCO

RX TX RX

DUAMCO 4:2

TX

CU2CU0 CU1

CELL 0

RX TX RX

DUAMCO 2:2

TX

CU6 CU7

CELL 2

RX TX RX

DUAMCO 4:2

TX

CU5CU3 CU4

CELL 1

CU4 CU5 CU6 CU7CU2 CU3

FICOMBase

Module

FICOMExpansion

Module

TX

FICOMExpansion

Module

FICOMExpansion

Module

CU0 CU1

RX RX

DIAMCO DIAMCO

58 A30808-X3247-M14-1-7618



Fig. 4.13 Single-cell (8,0,0): with 2 DUAMCO 4:2

Fig. 4.14 Multi-cell (2,2,2): with 3 DUAMCO 2:2

RX TX RX

DUAMCO 4:2

TX RX TX RX

DUAMCO 4:2

TX

CU4 CU5 CU6 CU7CU2 CU3CU0 CU1

CELL 0

RX TX RX

DUAMCO 2:2

TX

CU0 CU1

CELL 0

RX TX RX

DUAMCO 2:2

TX

CU2 CU3

CELL 1

RX TX RX

DUAMCO 2:2

TX

CU4 CU5

CELL 2

A30808-X3247-M14-1-7618 59



Fig. 4.15 Single-cell (11...16,0,0): FICOMs, DIAMCOs and HPDUs in 2 Racks

CU4 CU5 CU6 CU7CU2 CU3

FICOMBase

Module

FICOMExpansion

Module

TX

FICOMExpansion

Module

FICOMExpansion

Module

CU0 CU1

RX RX

HPDU

DIAMCO

CU12CU13CU14 CU15CU10CU11

FICOMBase

Module

FICOMExpansion

Module

TX

FICOMExpansion

Module

FICOMExpansion

Module

CU8 CU9

RX RX

DIAMCO DIAMCO

RACK 0

RACK 1

TX - Filter RX - Filter

TX- Filter RX - Filter

HPDU

DIAMCO

60 A30808-X3247-M14-1-7618



4.2 Receiving Paths

4.2.1 Antenna Diversity TechniquesBasically, There Are Two Different Diversity Combining Techniques:• Switched Combining• Maximum Ratio Combining

Switched Combining

Switched Combining simply selects one of the two receiver paths according to a givenquality criterion, such as maximum receiver gain.

Thus, in the case of correlated signals from receiver paths (and comparable gain),Switched Combining cannot improve receiver performance. A decision is usually madefor one full Um burst.

Maximum Ratio Combining

Maximum Ratio Combining provides the best combination of all available informationsfrom both receiver paths.Therefore the achievable gain is up to 3 dB.Siemens usesMaximum Ratio Combining as diversity combining technique.

4.2.1.1 Antenna System ModulesDifferent TX, RX and TX/RX antennas are provided which are connected to thecombining modules in order to serve cells with different carrier numbers. Thesecombining modules have to provide the necessary performance by using the followingmethods:– Antenna Combining

to feed several transmitter outputs to the TX antenna– Multicoupling

for splitting the RX signal for several receiver inputs– Duplexing

both Antenna Combining and Multicoupling methods are used in order to connectthe TX- and the RX-path to one antenna

The technology of the new BTSEs knows TX Combiner (FICOM), TX and RX Combiner(DUAMCO), High Power Duplexer (HPDU) and RX Multicoupler (DIAMCO). DUAMCOand DIAMCO use a Low Noise Amplifier (LNA) in the RX path, which can be set todifferent gain to establish the various configurations of the BS-240/241. Additionally, theDUAMCO and DIAMCO have power supply and supervision functionality for a TowerMounted Amplifier.

Antenna diversity is a second receive path to improve the receive quality and the gradeof service. It is important that the diversity path is configured in the same way as thenormal path, that means either, with or without TMA. Inside the Rack, it's possible thatone RX path is realized with a DUAMCO and the other with a DIAMCO or cascadedDIAMCOs.

A solution of antenna combining and multicoupling is the configuration with twoTX-/RX-antennas and two duplex combining modules. Both antennas belong to thesame cell. One antenna is used for transmission and reception, the other for transmis-sion and diversity reception. Therefore exist two transmit paths, one normal receive pathand one diversity receive path. The combining of the two transmit paths happens 'on air'.Supervision of the two antennas will be done separately for each one.

A30808-X3247-M14-1-7618 61



The principle of On Air Combining will also be used, if TX combining beyond the Rackborders is required. For e.g. to combine 24 carriers, belonging to the same cell, 3FICOMs will be used, each combines 8 carriers to one antenna. Combining of thesignals from the 3 antennas takes place 'On Air'.

4.2.2 Receiver SensitivityThe use of DUAMCOs or DIAMCOs provides a better sensitivity than the GSM require-ments at the Rack entry. The use of Tower Mounted Amplifiers (TMAs) provides a bettersensitivity than the GSM requirements at the antenna connector. The configuration withTMA is advantageous because of highest sensitivity of the RX path. One TMA is neededfor every created RX path of DUAMCO and / or DIAMCO installed and not cascaded.

Expansion of the RX path beyond the borders of the Rack or Shelter is possible bycascading of the multicoupling devices (DIAMCO or RX path of a DUAMCO). Withincreasing RF cable length, the noise figure rises and thus the RX sensitivity will bedegraded. The degradation is a little bit less than the additional cable loss.

In the configuration with antenna pre-amplifier, the true system RX sensitivity is guaran-teed at the antenna connector, including the antenna feeder cable attenuation. In theconfiguration without antenna pre-amplifier, the sensitivity is guaranteed only at the rackentry.

4.3 Transmission Diversity Time DelayGeneral

Up to BR6.0 each BTSplus CU works on its own frequency with RF output power limitedby the maximum nominal output power of the module. To achieve higher output power,a separated high power amplifier has to be used.

This feature "combines" the output signals of 2 standard carrier units (fed with the samebaseband signal) to increase the available output power. To allow the parallel CU oper-ation, their transmit signal must be de-correlated.

The parallel CU operation with de-correlated signals establish a diversity down-link path.Using down-link diversity significantly reduces the influence of signal fading.The codingschemes CS3, CS4, MCS8, and MCS9 particularly profit from such transmission diver-sity operation.

The mobile station (MS) receives an increased signal level. Applying downlink transmis-sion diversity time delay enables serving large cells, e.g., in rural areas.

By using Transmission Diversity, the downlink budget of the BTS can be significantlyimproved. This helps to balance the cell ranges of 850/900 MHz and 1800/1900 MHz inco-location scenarios.

The illustration of the downlink budget in relation to the downlink capacity is shown inthe next figure, which compares several possibilities of statically allocated CU combina-tions in one sector.

62 A30808-X3247-M14-1-7618



Fig. 4.16 Capacity Downlink Improvements for TX Diversity

4.3.1FunctionalityThe fully equipped BTS site with combined CU pairs to apply transmission diversitykeeps up with later capacity requirements and helps operate the BTS sites in temporarilyadjustable modes of operation. The Transmission Diversity mode provides the BTS siteswith double power and half capacity, and it performs using a CU pair of master and slave.Later, in case additional BTS sites get installed, the BTS sites of combined CU pairs canswitch over to normal capacity and normal power mode and release their slave CUs fromno longer needed pair-halves to make them the single CU of an additional BTS site.

Parallel CU Operation

A parallel operation of two CUs required for the parallel transmission of de-correlatedsignals is feasible and compatible with baseband hopping. The CU processes data simi-larly to baseband hopping. With difference to baseband hopping, not a single CU but apair of CUs is defined to transmit data. The CU pair operates at the same carrierfrequency. Both CUs of the pair are assigned to the same cell antenna sector, and theCUs use separate antennas. A distance preferably higher than ten lambdas separatesthe antennas when combining on-air transmissions.

The following example illustrates CU co-location in an extended circular cell thatprovides an increased cell capacity by using several different carrier frequency bands(e.g. GSM 850, GSM 900; GSM 1800, GSM 1900). CU pairs consisting of master andslave CU, apply transmission diversity time delay operation. One pair of CUs transmitson one frequency band, and the other pair of CUs transmits on another frequency band.

A30808-X3247-M14-1-7618 63



Fig. 4.17 BTS Rack Cabling for Transmitter Diversity Operation

The transmission diversity time delay feature raises an additional inaccuracy caused bythe actual timing deviation of the two transmitting CUs, due to the different length of thefeeding cables and the antenna positions. The transmission diversity time delay opera-tion can be disabled for certain burst types that are timing-sensitive, e.g., the synchro-nization channel (SCH) for Location Services (LCS). The transmission of the slave CUis disabled when such a burst type is going to be transmitted. The operator is allowed toexclude time slots or logical channels from applying the transmission diversity timedelay.

4.4 FCC Issues (for US Market only)In this chapter you find the maximum output power at the antenna connector of theBTS.These values are only relevant for the US market.

Revised FCC Certification for ECU 850

For ECUs with 869.2 and 893.8 MHz frequencies, in order to fulfil the FCC requirementsin the USA, the maximum transmitting power of the corner frequencies of the GSM 850band (channel numbers 128 and 251, i.e. 869.2 MHz and 893.8 MHz, respectively) isdecreased for all carrier units available for the U.S. market. This feature is realized persoftware.The BTS evaluates the mobile country code (MCC) provided by the BSC via the attribute"cellGlobalIdentity". If the MCC indicates “USA“, the BTS reduces the output power ofthe corner frequencies dependent on the hardware type of the carrier unit. The followingtable represents the maximum RF power output values for GMSK and 8PSK modula-tion.

64 A30808-X3247-M14-1-7618



Revised FCC Certification for ECU 1900

For ECUs with 1930.2 and 1989.8 MHz frequencies, in order to fulfil the FCC require-ments in the USA, the maximum transmitting power of the corner frequencies of theGSM 1900 band (channel numbers 512 and 810, i.e. 1930.2 MHz and 1989.8 MHz,respectively) is decreased for all carrier units available for the U.S. market. This featureis realized per software.The BTS evaluates the mobile country code (MCC) provided by the BSC via the attribute"cellGlobalIdentity". If the MCC indicates “USA“, the BTS reduces the output power ofthe corner frequencies dependent on the hardware type of the carrier unit. The followingtable represents the maximum RF power output values for GMSK and 8PSK modula-tion.

CU Type CarrierFrequency

[MHz]

ChannelNo.

Maximum RFPower Output

GMSK


8PSK

ECU850V3(A) 869.2 128 42.3 dBm = 17.0 W 45.6 dBm = 36.3 W

ECU850V3(A) 893.8 251 44.4 dBm = 27.5 W 47.2 dBm = 52.5 W

ECU850HPV2 869.2 128 42.2 dBm = 16.6 W 45.2 dBm = 33.1 W

ECU850HPV2 893.8 251 44.3 dBm = 26.9 W 46.9 dBm = 49.0 W

ECU850V2 869.2 128 40.7 dBm = 11.7 W 43.4 dBm = 21.9 W

ECU850V2 893.8 251 44.4 dBm = 27.5 W 47.2 dBm = 52.5 W

Tab. 4.8 Maximum RF Power Output Values at Antenna Port

CU Type CarrierFrequency

[MHz]

ChannelNo.


GMSK


8PSK

ECUPHPV3(A) 1930.2 512 39.9 dBm = 9.8 W 43.3 dBm = 21.4 W

ECUPHPV3(A) 1989.8 810 42.1 dBm = 16.2 W 45.7 dBm = 37.2 W

ECUPHPV2 1930.2 512 39.3 dBm = 8.5 W 42.2 dBm = 16.6 W

ECUPHPV2 1989.8 810 41.6 dBm = 14.5 W 44.3 dBm = 26.9 W

ECUPV2 1930.2 512 42.1 dBm = 16.2 W 44.7 dBm = 29.5 W

ECUPV2 1989.8 810 44.4 dBm = 27.5 W 47.1 dBm = 51.3 W

Tab. 4.9 Maximum RF Power Output Values at Antenna Port

A30808-X3247-M14-1-7618 65



5 Power Supply and Battery BackupThe AC/DC is used in the Service Rack/Shelter. It contains one or two Frames withAC/DC rectifier modules, one controller board and two LVD relays per Frame. Up to 6rectifier Modules can be inserted in one Frame; thus, the number of modules can beadapted to the actual need for specific loads. The Service Rack/Shelter with two AC/DCFrames is intended to be used to supply BTSEs with more than 8 carriers.

The AC/DC tasks are:• supplying all -48V consumers within the BTSE out of 230V AC 3 phase system for

the world market and 207V AC 2 phase system (240V phase to phase) for the USmarket

• supplying external equipment with -48V• charging and supervising of different battery types with different capacities and to

two battery backup systems per AC/DC Frame• supervising rectifiers, batteries and alarm messaging• switching off DC outputs (rectifiers as well as battery) in case of under and over

temperature• hot plug in/out• operation of two Frames in parallel

The AC/DC and the backup batteries work as an Uninterruptable Power Supply System(UPS).

The AC/DC system consists of:• Frame with AC distribution, DC Distribution, EMI-filter, signal distribution between

rectifiers and controller board via backplane• controller board with battery supervision, rectifier supervision, alarm interface,

EEPROM to store PID• up to 6 rectifier modules per Frame each 720W -48VDC (N+1 redundancy to achieve

3600W+720W).

• two LVD-Relays per AC/DC Frame

The Backup Battery guarantees continuous operation for a certain time in case of apower main breakdown or AC/DC failure. Three types of Backup Battery with nominalcapacities of 80 Ah, 85 Ah and 100 Ah are available.

The capacity of the Backup Battery can be increased further by having additionalbatteries in separate Service Racks / Shelters.

Note: The Battery Backup Time can also be extended using the feature emergencyconfiguration.

iDue to the maximum ambient temperature of +55°C (+131°F) the DCoutput power of one AC/DC module is limited to 720W.By decreasing the maximum ambient temperature to +50°C (+122°F) themaximum output power of one AC/DC module is increased to 800Wwithout any change in the module or in the Frame AC/DC.

66 A30808-X3247-M14-1-7618



5.1 Support of Emergency Operation for 3rd Party BBUSystemIn the BS-240/241 implementation the switch into emergency configuration (due to abattery discharge alarm) is triggered by an "ALARM STATUS" CAN bus message thathas been received from the CAN node of the AC/DC controller.

A special setting of the attribute "associatedString" in the command "CREATEENVABTSE" for the corresponding site input allows the operator to indicate that thesupport of emergency configuration is required for the 3rd party battery backup unitsystem.

The string indicates from which source, AC/DC CAN node or site input, the trigger forthe emergency configuration is expected. In case the string pattern is set to"##ACDC_FAULT", the trigger is expected from the site input of the correspondingENVABTSE object. In all other cases the normal behavior is maintained. For simplicity,there is no check if the string "##ACDC_FAULT" is used for more than one ENVABTSEobject.

If the operator has set the "associatedString" attribute of an ENVABTSE object to"##ACDC_FAULT" for the AC/DC alarm line, the emergency configuration is deacti-vated if all trigger sources have ceased their alarm.

A30808-X3247-M14-1-7618 67



6 AbbreviationsACP AC Panel

ACTC Alarm Collection Terminal Connection module

ACTM Alarm Collection Terminal for Master Rack

ACTP Alarm Collection Terminal for Slave Rack

AMCO Amplifier Multicoupler

AMR Adaptive Multi Rate Codec

ASIC Application Specific Integrated Circuit

ASU Antenna Supervision Unit

CC-Link Core Carrier Unit Link

COBA Core Basis

COSA Core Satellite

CU Carrier Unit

DIAMCO Diversity Amplifier Multicoupler

DL Downlink

DUAMCO Duplex Amplifier Multicoupler

ECU EDGE Carrier Unit

EDGE Enhanced Data Rates for GSM Evolution

EFR Enhanced Full-Rate

FICOM Filter Combiner

FR Full-Rate

GPRS General Packet Radio Services

GSMK Gaussian Minimum Shift Keying

HDLC High Level Data Link Control

HPDU High Power Duplexer Unit

HR Half-Rate

HSCSD High Speed Circuit Switched Data

LE Link Equipment

LMT Local Maintenance Terminal

LNA Low Noise Amplifier

LVD Low Voltage Detect

MUCO Multicoupler

NTC Negative Thermal Coefficient

O&M Operation and Maintenance

OMT Operation and Maintenance Terminal

OVPT Overvoltage Protection and Tracer

PCM Pulse Code Modulation

PDU Power Distribution Unit

PID Product Identification Data

RF Radio Frequency

SELIC Serial Link Interface Controller (ASIC)

68 A30808-X3247-M14-1-7618



TMA Tower Mounted Amplifier

TNF Tunable Narrowband Filter

TRAU Transcoding and Rate Adaption Unit

UL Uplink

UPS Uninterruptable Power Supply System

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