SBS Network Elements

SBS Overview Siemens

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Contents1 SBS Network Elements 31.1 Base Station Controller (BSC) 61.2 Base Transceiver Station Equipment (BTSE) 81.3 Transcoder and Rate Adapter Unit (TRAU) 91.4 Local Maintenance Terminal (LMT) 102 Interfaces 113 Link Configurations 154 SBS Documentation Overview 174.1 Guide to Documentation 194.2 System Overview Documentation 194.3 Operator Guidelines (OGL) 204.4 Operation Manuals (OMN) 204.5 Maintenance Manuals (MMN) 204.6 Command Manuals (CML) 214.7 Installation Manuals (IMN) 214.8 Installation Test Manuals (ITMN) 224.9 Acceptance Test Manuals 224.10 Output Manuals (OML) 225 Exercises 23

SBS Overview

Siemens SBS Overview

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1 SBS Network Elements


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The Siemens Base Station (SBS) consists of the following four network elements:� Base Station Controller (BSC)� Base Transceiver Station Equipment (BTSE)� Transcoding and Rate Adapter Unit (TRAU)� Local Maintenance Terminal (LMT)

There are eight different types of BTSE called BS240, BS241, BS-60, BS-61, BS-20,BS-21, BS-22 and BS-11.

Different BTSE Types

BSC TRAU

LMTBS-60

BS-61

BS-20

BS-21

BS-22

BS-11

BS-240/241

Fig. 1 SBS network elements


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The following table summarizes some characteristics of the SBS product family:

BS-11 BS-22 BS-20 BS-21 BS-60 BS-61 BSC TRAU

Volume [l] 28 177 210 399 432 1716 360 360

Powerconsumption[W]

80(1TRX)

500 470 600 1500 2160 324 476

Dimensionsd [mm] xw [mm] xh [mm]

160 x460 x415

330 x720 x775

450 x600 x775

485 x870 x945

450 x600 x1600

550 x1950 x1600

300 x600 x2000

300 x600 x2000

Weight [kg] 22(1TRX)

70 127 155 240 600 128 135

Temperaturerange [°C]

-33 to+45

-40 to+45

-5 to+45

-45 to+45

-5 to+45

-45 to+45

-5 to+45

-5 to+45

BS240 BS241Volume [l] 432 705

Power Con-sumption[W]

1610 1700

Dimensiond [mm]w [mm]h [mm]

4506001600

6507001750 (incl.plinth)

Weight [kg] 210 265

Temperaturerange [°C]

- 5 to 55 °C - 45 to 55 °C


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Capacity < BR5.0 BR5.0

Max. number of TRX 120 250

Max. number of sites 60 100

Max. number of cells 120 150

Max. Number of PCM lines towards TRAU 10 20

Max. number of PCM lines towards BTS 35 35

Max. number of PCM lines with flexiblePCMS lines configuration

not applicable 46

Max. number of LAPD links (BTSM andTRAU) at 64 kbit/s

112 112

Max. switching and processing capacity(Erl)

1000 2000

1.1 Base Station Controller (BSC)The BSC is the central control module of the SBS and provides the following majortasks:� Traffic channel (TCH) switching� Signaling information processing� Alarm monitoring.


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BTSE

TRAUMSC

BTSE

SiemensBase

Station

TRAU

BSC

BTSE

Fig. 2 BSC traffic channel switching

BTSE

TRAUMSC

BTSE

SiemensBase

Station

BSC

BTSE

Fig. 3 BSC alarm monitoring


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1.2 Base Transceiver Station Equipment (BTSE)The Base Transceiver Station Equipment (BTSE) comprises the entire radioequipment in a given site to serve a single cell or a group of cells.Maximum 6 cells (BTS), 12 TRX/cell and 24 TRX/site can be served by one BTSE.max two PCM lines between BSC and BTSE are allowed.

Omnidirectional configuration: One BTSE serves only one cell.Sectored configuration: One BTSE serves either up to 6 cells.

SiemensBaseStation

MSCBSC TRAU

BTSE

BTS BTS

Fig. 4 BTSE


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1.3 Transcoder and Rate Adapter Unit (TRAU)For each traffic channel, the TRAU adapts the different transmission rates for speechand data calls on the radio side to the standardized 64 kbit/s transmission rate at theMSC side of the system. It also maps between the different speech coding algorithmsused within the fixed network and on the radio interface.

BTSE

BSCBTSE

SiemensBase

Station

BTSE

MSC

TRAU

Fig. 5 TRAU


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1.4 Local Maintenance Terminal (LMT)The LMT may be a desktop or a laptop computer and is used for local maintenanceand operation functions at the TRAU, BSC or BTSE. It is also necessary for thecommissioning of these network elements.

LMT LMT LMT

MS MSCBTSE BSC TRAU

SBS

Fig. 6 LMT


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2 Interfaces


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BTSE, BSC and TRAU may either be separated or partially/completely collocated. Inany case, the components are interconnected by standard interfaces that areindicated in the following illustration.

BTSE

MSCBSC

BTSE

BTSE

AAsub

Abis

Um

TRAU

Fig. 7 Interfaces


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BTSE TRAUBSC

T interface

SIEMENSNIXDORF

SIEMENSNIXDORF

LAN

OMC

O interface

LMT

Fig. 8 Interfaces


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A InterfaceThe A interface is the interface between TRAU and MSC. This interface is realizedwith PCM links. Up to four PCM links can be connected between 1 TRAU and theMSC.The A interface comprises traffic channels (64 kbit/s time slots) and the CommonChannel Signaling System No. 7 (CCSS7) as a signaling link (64 kbit/s time slot).

Asub InterfaceThe Asub interface is a PCM link between the BSC and the TRAU. Four 16 kbit/schannels are multiplexed into one 64 kbit/s time slot.

Abis InterfaceThe Abis interface is a PCM link between the BSC and the BTSE.PCM timeslots can be used in either of the following ways:i) Signaling channels (16 or 64 kbit/s)ii) Traffic channels (16 kbit/s)

Um interfaceThe Um interface is the radio interface connecting the mobile stations (MS) to thespecific BTSE.

O InterfaceThe O interface is a standard interface for the interconnection of SBS and OMCbased on the CCITT X.25 and the GSM specifications. The physical layer can bebased either on a PSPDN connection between the BSC and the OMC, or on aspecific time slot embedded within the Asub and A interfaces which reaches the MSCand via a semipermanent connection the OMC.

T, Tµµµµ interfaceVia these interfaces the Local Maintenance Terminal (LMT) can be connected to thevarious SBS network elements (BSC, TRAU, or BTSE).The T interface is based on X.21+V.11 and HDLC+ proprietary layer specifications ofthe CCITT using the LAPB protocol and is used for the BSC, TRAU, BS-2x and BS-6x.

The Tµ interface is based on RS232+V.24 and is used for the BS-11.


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3 Link Configurations


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The SBS is designed for easy adaptation to a broad variety of configurations withminimum costs.In case of sector cells, each cell will be served by its own BTS although all BTS arephysically grouped together in one site (BTSE).

The following types of link configurations are possible:

Link Configuration BTSE-BSC BSC-TRAUStar X X

Multidrop chain X

Loop X

BTSEBTSE

BTSE BTSE BTSE

BTSE

BTSE

TRAU

TRAUMSC

Star

Multidrop chain

Loop

Star

BSC

BTSE

Fig. 9 Possible link configurations


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4 SBS Documentation Overview


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The SBS documentation is divided into different categories:� Guide to Documentation� System Overview Documentation� Introduction Manuals� Operation Manuals� Maintenance Manuals� Command Manuals� Installation Manuals� Installation Test Manuals� Acceptance Test Manuals� Output Manuals


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4.1 Guide to DocumentationThe Guide to Documentation is a summary of the structure and function of mobilecommunications documentation for customers and service engineers.

4.2 System Overview Documentation

4.2.1 System Description (SYD)The System Description (SYD) describes the architecture of the hardware andsoftware, the mechanical design of the network elements and the basic concept ofsetting up a connection in mobile communications.

4.2.2 Technical Description (TED)Three Technical Description (TED) documents are available for SBS:TED-OMS-B: This document describes the functions of the Operation andMaintenance Center (OMC), external and internal interfaces, hardware architecture,and software architecture.TED-NET: This document describes the PLMN.TED-BSS: This document describes the functions of the Siemens Base Station(SBS), external and internal interfaces, hardware architecture, and softwarearchitecture.


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4.3 Operator Guidelines (OGL)The Operator Guidelines (OGL) is a general guide for using the Local MaintenanceTerminal (LMT) as well as the Operation and Maintenance System (OMS-B). Whilethe LMT is the main device for local interaction with the system, the OMS-B isdedicated to the central monitoring and control of the connected BSSThe various types of SBS introduction documents are listed below:� OGL:LMT� OGL:OMS-B

4.4 Operation Manuals (OMN)The Operation Manuals (OMN) contain a description of the most useful proceduresthat can be activated from the OMC / LMT.The various types of SBS operation documents are listed below:� OMN:BSS/OMS-B� OMN:BSC

4.5 Maintenance Manuals (MMN)The Maintenance Manuals (MMN) contain a description of the actions to beperformed when an error occurs or an alarm is activated.The various types of SBS maintenance documents are listed below:� MMN:BSS/OMS-B� MMN:BSC� MMN:TRAU� MMN:BTSE BS 11� MMN:BTSE BS 20� MMN:BTSE BS 21� MMN:BTSE BS 22� MMN:BTSE BS 60� MMN:BTSE BS 61� MMN:BTSE BS240� MMN:BTSE BS241


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4.6 Command Manuals (CML)The Command Manuals (CML) contain an exhaustive description of the commandsavailable from OMC / LMT to perform actions on the network elements.The various types of SBS command documents are listed below:� CML:BSS/OMS-B� CML:BSC� CML:TRAU� CML:BTSE

4.7 Installation Manuals (IMN)The Installation Manuals (IMN) contain the instructions required for installing mobilecommunications network elements.The various types of SBS installation documents are listed below:� IMN:OMS-B� IMN:BSC� IMN:TRAU� IMN:BTSE BS 11� IMN:BTSE BS 20� IMN:BTSE BS 21� IMN:BTSE BS 22� IMN:BTSE BS 60� IMN:BTSE BS 61� IMN:BTSE BS240� IMN:BTSE BS241


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4.8 Installation Test Manuals (ITMN)The Installation Test Manuals (ITMN) contain step-by-step procedures covering allaspects of testing the correct function of newly installed network elements. Thisincludes loading the software, visual inspections and checking of jumper and switchsettings.The various types of SBS installation test documents are listed below:� ITMN:OMS-B� ITMN:BSC� ITMN:TRAU� ITMN:BTSE BS 11� ITMN:BTSE BS 20� ITMN:BTSE BS 21� ITMN:BTSE BS 22� ITMN:BTSE BS 60� ITMN:BTSE BS 61� ITMN:BTSE BS 240� ITMN:BTSE BS241

4.9 Acceptance Test ManualsA customer specific Acceptance Test Manual is offered to the customer and containsthe rules for testing the functionality of the system and the rules for checking forcorrect delivery, installation and commissioning of an individual network element inaccordance with the contract.

4.10 Output Manuals (OML)The output manuals (OML) describe all the error messages the SBS system cangenerate and propose operator actions. The various types of SBS output manualsare listed below:� OML:BSC� OML:TRAU� OML:BTSE


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5 Exercises

� List the network elements of the Siemens Base Station.� List the interfaces between the SBS network elements.� List the possible link configurations.� List the general categories of SBS documents.� Which document contains a procedure for the addition of a BTS? What is the

number of the procedure for adding a BTS?� What is the purpose of Procedure B in the MMN:BSC?� What are the permitted values for the parameter LICDTYPE in the following

command? CREATE:LICD-licdn:LICDTYPE=LICDType;

� Which document(s) contain jumper settings for the boards in the BSC?


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Documents

SBS Network Elements