BCSU

BCSU

DN9815194Issue 8-0 en

# Nokia Siemens Networks 1 (36)

BSC3153Nokia GSM/EDGE BSS, Rel. BSS13, BSC andTCSM, Rel. S13, Product Documentation, v.1

The information in this document is subject to change without notice and describes only theproduct defined in the introduction of this documentation. This documentation is intended for theuse of Nokia Siemens Networks customers only for the purposes of the agreement under whichthe document is submitted, and no part of it may be used, reproduced, modified or transmitted inany form or means without the prior written permission of Nokia Siemens Networks. Thedocumentation has been prepared to be used by professional and properly trained personnel,and the customer assumes full responsibility when using it. Nokia Siemens Networks welcomescustomer comments as part of the process of continuous development and improvement of thedocumentation.

The information or statements given in this documentation concerning the suitability, capacity, orperformance of the mentioned hardware or software products are given “as is” and all liabilityarising in connection with such hardware or software products shall be defined conclusively andfinally in a separate agreement between Nokia Siemens Networks and the customer. However,Nokia Siemens Networks has made all reasonable efforts to ensure that the instructionscontained in the document are adequate and free of material errors and omissions. NokiaSiemens Networks will, if deemed necessary by Nokia Siemens Networks, explain issues whichmay not be covered by the document.

Nokia Siemens Networks will correct errors in this documentation as soon as possible. IN NOEVENT WILL NOKIA SIEMENS NETWORKS BE LIABLE FOR ERRORS IN THISDOCUMENTATION OR FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO SPECIAL,DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL OR ANY LOSSES, SUCH AS BUTNOT LIMITED TO LOSS OF PROFIT, REVENUE, BUSINESS INTERRUPTION, BUSINESSOPPORTUNITY OR DATA, THAT MAYARISE FROM THE USE OF THIS DOCUMENT OR THEINFORMATION IN IT.

This documentation and the product it describes are considered protected by copyrights andother intellectual property rights according to the applicable laws.

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Other product names mentioned in this document may be trademarks of their respective owners,and they are mentioned for identification purposes only.

Copyright © Nokia Siemens Networks 2008. All rights reserved.

2 (36) # Nokia Siemens Networks DN9815194Issue 8-0 en

BCSU

Contents

Contents 3

List of tables 4

List of figures 5

Summary of changes 7

1 BCSU overview 9

2 Logical structure of BCSU 13

3 Mechanical structure of BCSU 17

4 Plug-in units of BCSU 27

5 Operation of BCSU 29

6 MC1C cartridge power supply 31

7 MC1C cartridge intermediate cabling 33

8 Power consumption of BCSU 35



Contents

List of tables

Table 1. Plug-in unit versions used in the BCSUs of different DX 200 BSCapplications 17

Table 2. The address of BCSU 34

Table 3. Power consumption of the BCSU Plug-in units 35

Table 4. Total power consumption of the BCSU with different PCU equipment 35


BCSU

List of figures

Figure 1. Interfaces of the BCSU 11

Figure 2. Functional structure of the BCSU 13

Figure 3. BCSU equipment for DX 200 BSCE – the PCU is optional 20

Figure 4. BCSU equipment for DX 200 BSCi – the PCU is optional 21

Figure 5. BCSU equipment for DX 200 BSC2E/A – the PCU is optional 22

Figure 6. BCSU equipment for DX 200 BSC2i – the PCU is optional 23

Figure 7. BCSU equipment for DX 200 BSC2 – the second PCU is optional 24

Figure 8. BCSU equipment for DX 200 BSC2i – the second PCU is optional 25



List of figures


BCSU

Summary of changes

Changes between document issues are cumulative. Therefore, the latestdocument issue contains all changes made to previous issues.

Changes between issues 7-1 and 8-0

Structure modified. The 2nd Generation Packet Control Unit (PCU2-U)added.

Sections Plug-In Units of BCSU and Operation of BCSU only contain linksto related documents.


Editorial changes.


Structure modified. Some section headings changed. Plug-in unit variantPCU-Tadded. References to plug-in units CP4C32 and CP4E32 removed.

Main functions of BSCU

Information about CCS7 interface module clarified.

Operating environment of BCSU

Minor changes to section content. Figure Interfaces of the BCSU updated.

Logical structure of BCSU

Figure Functional structure of the BCSU updated.



Summary of changes

Technical features of the AS7-X

Information about AS7-X combi functionality (LAPD and CCS7 links insame plug-in unit) clarified.

Operating environment of the PCU(-S/-T)

Information about site router/switch added. Figure Operating environmentof the PCU(-S/-T) updated.

MC1C cartridge intermediate cabling

Minor changes to section content.

Power consumption of BCSU

New section.


Online modifications. Plug-in units AS7-X, CP6MX and PCU-S added.


BCSU

1 BCSU overviewMain functions of BCSU

The Base Station Controller Signalling Unit (BCSU) handles the BSCfunctions that are highly dependent on the amount of traffic. It consists oftwo parts to handle both the A and Abis interfaces.

The BCSU is installed in the MC1C cartridge where the microcomputer ofthe BCSU is. The BCSU functional unit is composed of the CPU plug-inunit and various other plug-in units.

Depending on the application, one BCSU is enough for severaltransmitter-receivers (TRXs). In every BCSU the TRXs up to 16 arestandard. The TRXs between 16 and 32 are called Large Capacity TRXs.All the TRXs over 32 per BSCU are called High Capacity TRXs. These areused only with the BSCi and BSC2i applications. The limiting factor is theprocessing power required (especially Abis with radio measurements)rather than the amount of links that can be connected to a single unit.

By means of the frame alignment interface, the BCSU supervises the 2Mbit/s PCM lines connected to the system (time slot 0 handling). Theinterface units are connected to the switching network via 2 Mbit/sconnections. 2 Mbit/s lines for both A and Abis interfaces are handled inthe same way.

The A-interface part of the signalling unit:

. Controls the mobile and base station signalling (Base StationSystem Application Part, BSSAP).

. Takes care of the decentralised functions of the Message TransferPart (MTP).

. Takes care of the Signalling Connection Control Part (SCCP) of thesignalling system.

. Is responsible for handling the signalling messages and functionsrelated to the signalling channels that are connected to it.



BCSU overview

For the A interface, there is a CCS7 (CCITT number 7) interface module inthe unit. It consists of a signalling terminal, controlled by a processor. In theM92 mechanics BSC, there are channels as follows:

. four 64 kbit/s CCS7 channels or

. two 128 kbit/s CCS7 channels or

. one 256 kbit/s CCS7 channels

The signalling terminal is semi-permanently connected to the time slotsused for signalling.

The Abis-interface part of the signalling unit controls the logical Airinterface channels associated to TRXs and Base Stations (BTS), Abisinterface circuits and Abis signalling channels. A circuit on the Abis mapsone to one to a specific (speech/data) channel on the Air interface. Thehandover and power control algorithms also reside here, in this functionalunit.

A LAPD interface module consists of a signalling terminal which canhandle 32 (AS7–U/AS7–US) or 64 (AS7–V/AS7–VA/AS7–X) LAPD links.The bit rate of a single link can be either 16 kbit/s or 64 kbit/s. The layer 2LAPD functions are implemented by the terminal. The application-specificmessage handling is done in the microcomputer block.

The AS7–X plug-in unit is a multichannel link terminal for data or signallingusing HDLC format. The unit can handle CCS and LAPD channels at thesame time. For example, 4 CCS7 (64 kbit/s) channels and 42 LAPD (64kbit/s) channels.

Redundancy is implemented with the N+1 principle so that normally thereare n units in use; the backup unit is taken into use only if an active unitfails.

Operating environment of BCSU

The BCSU is part of the decentralised call control section in the DX 200system. The BCSU is connected to the microcomputer network of theexchange through the message bus interface of its microcomputer and tothe CCS and LAPD channels by semipermanent connections via theGroup Switch (GSW). The control connection between the trunk circuitinterfaces (ET) and the BCSU is also implemented by semipermanentconnections. The BCSU is connected to the Clock Equipment (CLS) of theexchange by the 8 MHz and 8 kHz timing signals. The BCSU is connected


BCSU

to the Operation and Maintenance Unit (OMU) and the Marker and CellularManagement Unit (MCMU) by the timing and GSW switch-over controlsignal CGS. The BCSU is also connected to the OMU by the message busclock alarm MBAL and the card control loop CCL.

The LAN interface provides an Ethernet interface according to IEEE802.3.This interface is located at the CPU.

Figure 1. Interfaces of the BCSU

For more information, see:


Mechanical structure of BCSU

Plug-in units of BCSU

Operation of BCSU


TIMING

TRUNK CIRCUITS

DN9986407

MCMU

OMU

LAN SWITCHOR

ROUTER

GSW

CLS

ET

ET

MESSAGE BUS

CCL

MBAL

LAN

BCSUCGS

SIGNALLING

TRUNK CIRCUITSUPERVISION



BCSU overview


BCSU

2 Logical structure of BCSU

The BCSU is composed of the following functional blocks, as shown in thefigure below:

. a microcomputer

. an SS7 (Signalling System number 7) interface

. a LAPD (Link Access Protocol on the D-Channel) interface

. a trunk circuit supervision interface

. a message bus interface

. a Packet control Unit (PCU)

Figure 2. Functional structure of the BCSU

GROUP SWITCH

BCSU

DMC BUSMicro-

computer

SS7interface

1

0MB ETDN03529077

PCUinterfaces

Trunk circuitcontrol/

LAPD interface

Message businterface




Microcomputer with message bus interface

The microcomputer of the BCSU is a general-purpose microcomputerused in the DX 200 system. It is composed of a Central Processing Unit(CPU) and two Message Bus Interface plug-in units (MBIF-T/UA). Thetasks of the microcomputer in the BCSU include the call control of thetrunk circuit traffic, the supervision of the trunk circuits, and the functionsabove CCS level 2, excluding the management of the signalling networkand the monitoring of the signalling traffic.

SS7 (Signalling System number 7) interface

The equipping of the Signalling System number 7 (SS7) interface includesone AS7-U/-US/-VA or AS7-V or AS7-X (S10 first deliveries) plug-in unit.The capacity of the AS7-U or AS7-US is four SS7 channels and that of theAS7-V, AS7-VA, and AS7–X is 16 SS7 channels. The interface performsthe functions associated with the control, supervision, and messagetransmission of the SS7 channels.

LAPD interface

The equipping of the LAPD interface includes one AS7-U/-US/-VA or AS7-V or AS7-X (S10 first deliveries) plug-in unit. The capacity of the AS7-U orAS7-US is 32 LAPD channels and that of the AS7-V, AS7-VA, and AS7–Xis 64 LAPD channels. The layer 2 LAPD functions are implemented byAS7-U/-US/-VA or AS7-V.

Trunk circuit supervision interface

The trunk circuit supervision interface is composed of an AS7-U/-US/-VAor AS7-V (BSC2, BSC2i) or AFS-T (BSCE, BSCi) or AS7-X (S10 firstdeliveries) plug-in unit. This plug-in unit collects and processes theinformation obtained from the exchange terminals, indicating the operatingstate of the trunk circuits and the error ratio of the transmission. Thecapacity of the interface is 32 PCM trunk circuits (AS7-U/-US) or 64 PCMtrunk circuits (AS7-V or AS7-VA).

Packet control unit (PCU)

The PCU unit performs all the data processing tasks related to (E)GPRStraffic. It implements both packet-switched traffic oriented Gb and Abisinterfaces in the BSC, handled by the Packet Control Unit (PCU/PCU-S/PCU-T plug-in unit).


BCSU

2nd generation packet control unit (PCU2–U)

The 2nd generation Packet Control Unit (PCU2-U) is available as an optionon the S11.5 level. This option increases the unit's packet switched traffichandling capacity. It implements the packet-switched traffic oriented Gbover IP and Abis interfaces in the BSC.





BCSU

3 Mechanical structure of BCSU

The BCSU is installed in the MC1C cartridge, which contains plug-in unitslots for:

. one CPU plug-in unit

. two MBIF-T/UA plug-in units

. two AS7-U + one AFS-T plug-in units, or three AS7-U/-US + oneAFS-T plug-in unit, or three AS7-U/-US plug-in units, or three AS7-Xplug-in units

. one or two PCU(-S/-T) plug-in units (optional) or PCU2–U (S11.5)

The BSCi and BSC2i contain different plug-in unit variants (in the BCSU)than the BSCE and BSC2.

The table below lists the variants used in the different applications. Theunits which must be replaced with different units in the upgrade fromBSCE/BSC2 to BSCi/BSC2i are marked as Removed in columns BSC2i,upgrade and BSCi, upgrade.

Table 1. Plug-in unit versions used in the BCSUs of different DX 200 BSCapplications

PIU BSC2A/E BSC2i,upgrade

BSC2i,firstdelivery

BSCE BSCi,upgrade

CP4xxx,CP4HL

1)

Used Removed - Used Removed

CP6LX

2)

- Used Used - Used

CP6MX Used

3)

Used

3)

Used Used

3)

Used

3)




Table 1. Plug-in unit versions used in the BCSUs of different DX 200 BSCapplications (cont.)

PIU BSC2A/E BSC2i,upgrade

BSC2i,firstdelivery

BSCE BSCi,upgrade

MBIF-T

4)

Used Removed - Used Removed

MBIF-UA

5)

- Used Used - Used

AS7-U/-US Used Used - Used Used

AS7-V/-VA - Used Used - Used

AFS-T - - - Used Used

AS7-X - - Used - -

PCU(-S/T) Used Used Used Used Used

PCU2–U Used Used Used Used Used

PSC3 Used Used Used Used Used

1) Removed if SMLC option used


3) Required by SMLC option


5) Required by SMLC option

The cartridge has its own power supply (PSC3) which generates the +5 Vand -5 V voltages needed by the plug-in units.

All interconnection cables to the cartridge are connected at the rearconnectors, except for the PCM circuit cables, which are connected to thefront connectors of PCU/-S/-T plug-in units.

The following figures show the equipping of the MC1C cartridge withBCSU. The dimensions of the MC1C are: 262 mm (depth) x 260 mm(width) x 170 mm (height).


BCSU

The MBIF, AS7, and AFS plug-in units are constructed on 233.4 mm x 160mm circuit boards. The MBIF is connected to the rear panel of the subrackby two 64-pin male connectors. The AS7 and AFS are connected to therear panel by two 2 x 32-pin connectors.

The CPU plug-in units used in the BSCE and BSC2 (CP4HX and CP4HL)are constructed on the circuit boards CPIO and CP3x (x = B, C, or D),whose dimensions are 233.4 mm x 160 mm. The CP4HX plug-in units are66 mm wide and the CP4HL is 44 mm wide. It is connected to the rearpanel of the subrack by two 64-pin connectors mounted on the CPIOboard.

Starting with the release S11, all computer units of the BSC must have atleast 128 MB of memory. This applies to both M92 and M98 mechanics.Therefore only CPU plug-in unit variants CP4HX and CP4HL are allowedin S11 M92 BSC. No other CPU486 plug-in variants may be used.

Note

Only MM32M-S memory modules are supported with the S11.5upgrade.

The CPU plug-in unit used in the BSCi and BSC2i (CP6LX) is constructedon a single circuit board, whose dimensions are 233.4 mm x 160 mm. Theunit is 51 mm wide. It is connected to the rear panel of the subrack by two64-pin connectors.

The PCU(-S/-T) plug-in unit consists of a mother board and a daughterboard. The mother board is constructed on a double Euro size 233.4 mm x160 mm board. The daughter board is constructed on a 85 mm x 120 mmboard. It is fastened onto the mother board with three 8-mm bushings.Signals are connected between the mother board and the daughter boardvia a 400-pin PGGA connector.

GPRS option

The figures below present the GPRS option in BSC applications.




Figure 3. BCSU equipment for DX 200 BSCE – the PCU is optional

DN0194067

MBIF

MBIF

PSC3

AS7

AS7

AS7

AFS

AS7

PCU

::::::::::::::::::::::::::::::::::

CPU

::::::::::::::::::::::::::::::::::

02 03 04 05 06 08 100100 07 09


BCSU

Figure 4. BCSU equipment for DX 200 BSCi – the PCU is optional

DN0194055

MBIF

MBIF

PSC3

AS7

AS7

AS7

::::::::::::::::::::::::::::::::::

::::::::::::::::::::::::::::::::::

CPU

AS7

AS7

PCU

AS7

AFS

02 03 04 05 06 08 100100 07 09




Figure 5. BCSU equipment for DX 200 BSC2E/A – the PCU is optional

DN0194079

MBIF

MBIF

PSC3

AS7

AS7

AS7

AS7

AS7

PCU

::::::::::::::::::::::::::::::::::

CPU

::::::::::::::::::::::::::::::::::

02 03 04 05 06 08 100100 07 09


BCSU

Figure 6. BCSU equipment for DX 200 BSC2i – the PCU is optional

Second PCU for GPRS/EDGE option

The figures below present the second PCU for GPRS/EDGE option in theBSC2 and BSC2i applications.

DN0194043

MBIF

MBIF

PSC3

AS7

AS7

AS7

::::::::::::::::::::::::::::::::::

::::::::::::::::::::::::::::::::::

CPU

AS7

AS7

PCU

02 03 04 05 06 08 100100 07 09




Figure 7. BCSU equipment for DX 200 BSC2 – the second PCU is optional

DN0195039

MBIF

MBIF

PSC3

AS7

AS7

AS7

AS7

AS7

PCU

::::::::::::::::::::::::::::::::::

CPU

::::::::::::::::::::::::::::::::::

PCU

02 03 04 05 06 08 100100 07 09


BCSU

Figure 8. BCSU equipment for DX 200 BSC2i – the second PCU is optional

DN0195027

MBIF

MBIF

PSC3

AS7

AS7

AS7

:::::::::::::::::::::::::::::

:::::::::::::::::::::::::::::

CPU

AS7

AS7

PCU

PCU

02 03 04 05 06 08 100100 07 09





BCSU

4 Plug-in units of BCSU

For more information on the individual plug-in units of BCSU, see thefollowing Plug-in Unit Descriptions:

Central Processing Unit, CPU

CP6MX

CP6LX

Message Bus Interface, MBIF

MBIF-UA, MBIF-V

MBIF-T

AS7 Interface

AS7-V

AS7-VA

AS7-U, AS7-US

AS7-X

Packet Control Unit, PCU

PCU2-U

PCU-S

PCU-T

Power Supply for Cartridge, PSC3

PCS3



Plug-in units of BCSU


BCSU

5 Operation of BCSU

For more information on the operation of the individual plug-in units of theBCSU, see the following Plug-in Unit Descriptions:

Intermediate cabling of MC1C cartridge


Power supply for MC1C cartridge

MC1C cartridge power supply

Jumper settings of the plug-in units

Jumper Settings of CP6LX

Jumper Settings of CP4HL and CP4HX

Jumper Settings of MBIF-UA, MBIF-V

Jumper Settings of MBIF-T

Jumper Settings of AS7-V

Jumper Settings of AS7-X

Jumper Settings of AFS-T

Jumper settings of PCU2-U

Jumper Settings of PCU-T and PCU-S

Jumper settings of AS7-U C08530 / AS7-US C08905

Front panel switches and LED indicators for CPU

Operation of CP6LX



Operation of BCSU

Operation of CP6MX

Front panel LED indicators for MBIF

Operation of MBIF-UA, MBIF-V

Operation of MBIF-T

Front panel LED indicators for AS7

Operation of AS7-U

Operation of AS7-X

Front panel LED indicators for AFS-T

Operation of AFS-T

Front panel LED indicators for PCU

Operation of PCU2-U

LED indicators of PCU-T

Front panel LED indicators for PSC3

Operation of PSC3


BCSU

6 MC1C cartridge power supplyPower supply PSC3

The PSC3 has three forward DC-DC converters, which generate thevoltages of +5V, +3.3V, and -5V. The output and input are galvanicallyseparated from each other.

The converters have common input voltage filtering, a start-up circuit,over-voltage and under-voltage protection of the input, and an alarm circuitin the output.

The plug-in units in the MC1C cartridge operate with +5V and -5Voperating voltages, except for the AS7–V, which has an onboard converterfor converting the 5V voltage to 3.3V.

The MC1C cartridge has its own power supply to convert the +5V voltagesfrom 48 VDC input voltage, which is lead to the cartridge throughconnector PL1.



MC1C cartridge power supply


BCSU

7 MC1C cartridge intermediate cablingMC1C cartridge intermediate cabling

The placement of the intermediate cables associated with the MC1Ccartridge is shown in the Interconnection Cables lists in the SiteDocuments.

The message bus cables are attached to the connectors on the rear of thecartridge. The connectors for the message bus are the same to which theMBIF plug-in units are equipped on the front side of the cartridge.Connector 03S1 is used for message bus number 0 and 04S1 formessage bus number 1.

Basic timing signals from the clock equipment and the change-over signalof the GSW are lead to the MC1C cartridge through a cable connected toconnector 10S7 at the rear of the cartridge. Wired alarms from thecartridge (power supply alarm and clock alarm) are also lead out from thecartridge through the connector (10S7).

Internal PCM signals are led to the BCSU cartridge through rearconnectors in location 05V1 from GSWB 0 and location 05V4 from GSWB1. Internal PCM signals to the PCU plug-in units are led to the frontconnectors in location xxR1 from GSWB 0 and xxR3 from GSWB 1 (xxstands for the PCU plug-in unit slot).

Settings

The following settings are made in the MC1C cartridge by using jumperedconnectors (1/4) placed on the rear connectors of the cartridge.

. the address of the BCSU is set by placing jumpered connectors (1/4)according to the following table to locations B01S5 and B01S7:




Table 2. The address of BCSU

Plug-in unit Address

BCSU 0 MBADD 30

BCSU 1 MBADD 31

BCSU 2 MBADD 32

BCSU 3 MBADD 33

BCSU 4 MBADD 34

BCSU 5 MBADD 35

BCSU 6 MBADD 36

BCSU 7 MBADD 37

BCSU 8 MBADD 38

. The transmission frequency of the message bus is set to 2 MHz(BSCE and BSC2) or to 8 MHz (BSCi, BSC2i) by equipping theMBFRE02 connector to location B01S1.

. BCSU is set to the slave for change over of the GSW by equippingthe CSADD00 connector to location B01S3.

. Cross-connection of internal PCM signals in the BCSU isimplemented by equipping the PCMCO01 connector to locationB05Y1.


BCSU

8 Power consumption of BCSU

The tables below give the power consumption per Plug-in unit and also thetotal power consumptions per system with different PCU equipment.

Table 3. Power consumption of the BCSU Plug-in units

Plug-in unit Power consumptionper plug-in unit (W)

CP6MX, CP6LX (BCSi, BSC2i) 20

CP4HX, CP4HL (BSCE, BSC2) 18.5

MBIF-U/UA x 2 9.3

AS7–U, AS7–US, AS7–V 5.2

AS7–VA 8.6

AS7–X 8.9

AFS-T 3.6

PCU-S 10

PCU-T 12

PCU2–U 12

Table 4. Total power consumption of the BCSU with different PCU equipment

System Total powerconsumption (W)

BSCE 61 W

BSCE with PCU2–U 61 W

BSC2 77 W

BSC2 with PCU2–U 77 W

BSCi 82 W




Table 4. Total power consumption of the BCSU with different PCU equipment(cont.)

System Total powerconsumption (W)

BSCi with PCU2–U 82 W

BSC2i 82 W

BSC2i with PCU2–U 82 W


BCSU

BCSU

Documents

internal pcm

nokia siemens

total power

central processing

message bus

packet control

message bus

optional bcsu