01_mobile switching system server,gateway control server

© Nokia Networks Oy

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3G Core Network

Nokia MSC Server and Gateway Control Server

Training Document


2 (47) © Nokia Networks Oy

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

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Copyright © Nokia Networks Oy 2005. All rights reserved.

Contents


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Contents

1 OBJECTIVES ................................................................................................................................4

2 INTRODUCTION..........................................................................................................................5

2.1 MSC SERVER (MSS) ................................................................................................................5 2.2 MSC SERVER (MSSU)..............................................................................................................5 2.3 GATEWAY CONTROL SERVER (GCS) .......................................................................................6 2.4 INTEGRATED MSS ....................................................................................................................7 2.5 INTEGRATED GCS ....................................................................................................................7

3 CABINET TYPES..........................................................................................................................9

3.1 MSS & GCS CABINET TYPES...................................................................................................9 3.2 MSSU CABINET TYPES...........................................................................................................12

4 FUNCTIONAL UNITS................................................................................................................13

4.1 IPCF CABINET ........................................................................................................................13 4.2 IPCG CABINET .......................................................................................................................26 4.3 IPCH CABINET .......................................................................................................................31 4.4 SOME SPECIAL UNITS IN MSSU .............................................................................................36

5 REDUNDANCY ...........................................................................................................................44

6 GLOSSARY..................................................................................................................................45



1 Objectives

After completing this module, the student should be able to:

• List the main functions of the MSS, MSSu and GCS

• Explain the main functions of each functional unit.

• List the redundancy principles for the units in MSS, MSSu and GCS.

• Explain the main difference between the standalone MSS and integrated

MSS.

Introduction


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2 Introduction

All MSC Server products are based on Nokia DX 200 hardware, which uses Intel

Pentium processors. The Integrated MSC Server is a feature in the MSCi. Thus the

HW configuration is similar to the MSCi as well. This ensures an easy and cost-

efficient upgrade for the existing MSCi elements to Integrated MSC Servers. The

standalone MSC Server is based on the DX 200 Server Platform. DX 200 Server

Platform is a new HW configuration optimised for call control. It is a pure server

configuration that utilises double computer cartridges. This minimises the floor space

requirement and maximises performance. However, all plug in units are the same as in

the DX 200 MSCi, so it also offers full synergy with other DX 200 elements.

Exact specifications for the interfaces between the modules make it possible to add

new functions without changing the system architecture and enable the system’s

remaining up-to-date throughout its long operational life.

The possibility to build different network elements, which provide different

functionalities, is a good example of the versatility of the HW architecture.

2.1 MSC Server (MSS)

The MSS is a compact standalone server product that offers processing power that is

needed when one server controls several MGWs.

Basically the MSS does not have Group Switch for switching 64 kbit/s TDM channels

but an optional small GSW can be included in the configuration if required for TDM

based SS7 signalling.

2.2 MSC Server (MSSu)

Similar to the MSS, the MSSu is also a compact standalone server product that offers

processing power that is needed when one server controls several MGWs.

The MSSu will not be a new delivery but instead it will always be upgraded from the

operator’s current MSCi.

In essence, the MSSu is a pure standalone server that does not have any TDM

interfaces.



X.25

Ext.Sync.

E1 or T1

IPControl LAN Switch

GSW

IP

CMU STU CHU OMUVLRU

O&M LAN Switch

VDU and LPT

MESSAGE BUS

SIGU BSU CCSU CMM BDCU

BSU and VLRU are partof the MSS and MSSu configuration and not furnished in GCS configuration.

Optional in MSS and GCS(not in MSSu)

ET

CLS

Figure 1 Block diagram of MSS and GCS

2.3 Gateway Control Server (GCS)

Presented in Figure 1 above is the block diagram of the GCS. It shows the interfaces

between the functional units and also the interfaces connecting the system to the

environment. A more detailed description of the functionality each unit performs is

given below in section Functional Units.

Note that GCS does not have following units:

Introduction


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• Base Station Signalling Units (BSU) is not furnished because the GCS does

not handle signalling or control traffic towards radio networks. These units

are available in MSS.

• Visitor Location Register Units (VLRU) is not furnished in the GCS because

subscriber information is handled in the visited MSS where these units are

available.

2.4 Integrated MSS

As a regular MSC can be upgraded to the Integrated MSS it can be seen that block

diagram of Integrated MSS includes all the functional units available also in a regular

MSC. Naturally here the GSW is included since this network element can also handle

user and control plane traffic on TDM lines.

2.5 Integrated GCS

The basic block diagram of the Integrated MSS also applies to the Integrated GCS

with the following exceptions:

• Base Station Signalling Units (BSU) is not furnished because the Integrated

GCS does not handle signalling or control traffic towards radio networks.

• Compact Data Service Units (CDSU) are not furnished because the Integrated

GCS does not need analogue/digital modem pool as the CS Data Interworking

Functionality is handled in the Integrated MSS or in a separate Nokia Circuit

Switched Data Server (CDS) network element.

• Visitor Location Register Units (VLRU) is not furnished in the Integrated

GCS because the subscriber information is stored in the visited MSS or the

MSC.

Note: In this document, we are focus on MSS, MSSu & GCS.



CDSU

TGFP

BDCUPAUMCCSUBSUMFSUCASU

CHU OMUSTUVLRUCMCMU

PSTN

PBX

NSS

BSS

LAN LAN LAN

VDU and LPT

X.25

ET

GSW

CCMU

MESSAGE BUS

ET

ET

ECET

CLSEXT. SYNC

VANG

O&M LAN Switch

IPET

LAN

IP Trunk

TGSU

IP

IP Control PlaneLAN Switch

IP User PlaneLAN Switch

The BSU and VLRU are partof the Integrated MSS,not the GCS.

Figure 2. Block Diagram of Integrated MSS and Integrated GCS

Cabinet Types


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3 Cabinet Types

3.1 MSS & GCS Cabinet Types

The MSC or GCS Server has three cabinet types:

• IP Cabinet F (IPCF)

• IP Cabinet G (IPCG)

• IP Cabinet H (IPCH) (Optional)

All cabinets must be installed in a fixed order side by side in a single row. It is

possible to install cabinets from left to right as shown in the illustration below or the

mirror image of it from right to left.

With base module, IPCF and IPCG0 cabinets are delivered with CMU, CMM, OMU

and CLSU units. CLBU units and LAN switches are part of each cabinets standard

configuration. To be fully operational network element, base module must be

completed with additional functional units. The minimum configuration of the MSC

Server is summarised in the table below.

Table 1 Minimum configuration (M13)

MSS Base Module 1 pcs

BSU, CP816-A/512MB 3 pcs

CHU pair, CP816-A/512MB, HDU, FDU 1 pcs

SIGU, CP816-A/512MB 3 pcs

STU pair, CP816-A/512MB 1 pcs

VLRU pair, CP816-A/512MB 1 pcs

When the two base module cabinets are configured full, the capacity can be expanded

by adding more IPCG cabinets and functional units. The use of IPCH cabinet is

optional. When used, the IPCH cabinet must be at the either end of the row. Group

Switch and CLBU are part of the standard IPCH configuration. The number of

CCSU/CASU and ET must be dimensioned case by case according to the customer's

needs.



Figure 3 MSS floor layout

Cabinet Types


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Figure 4 GCS floor layout



3.2 MSSu Cabinet Types

The MSSu features the following cabinet types:

• Main Operation and Maintenance Cabinet (MOMC)

• Visitor Location Register Cabinet (VLRC)

The MSSu floor layout is always a one-row solution.

Figure 5 The MSSu floor layout

Functional Units


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4 Functional Units

4.1 IPCF Cabinet

Figure 6 Functional unit and cartridge positions in the IPCF cabinet in the MSS



Figure 7 Functional unit and cartridge positions in the IPCF cabinet in the GCS

Functional Units


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4.1.1 Central Memory and Marker (CMM)

The CMM contains the functionality of Central Memory, Marker and Common

Channel Signalling Management Unit in the same functional unit. The MSC

Server contains two CMMs, which are located in the IPCF cabinet. The CMM

equipment is installed in a CC4C-A cartridge.

Figure 8 CMM in CC4C-A cartridge

Table 2 Plug-in units in CMM

Position ID Name Notes

F01 C105075/C08953 PSC6-/PSC6-A Power Supply for Cartridge

F02 C105007/C08951 AS7-C (M13) / AS7-A LAPD for clock control

F03 C104095 SHIM4T Empty Slot

F04 C08947 SWCOP-A Switch Control Processor (optional) Only if IPCH cabinet in use.

F05 C74990/C74920 MBIF-C (M13)/MBIF-B

F06 C74990/C74920 MBIF-C (M13)/MBIF-B

Arbitration frequency: 2,048 MHz.

MBIF-B & MBIF-C/CR is not interchangeable

C108488/C101180 CP816-A (M13) / CP710-A Pentium M Dothan processor with maximum of 1.8 GHz

frequency / Pentium®III with 800 MHz frequency

F07

C109053/C103757 MRD512A (M13)/ MR512M 512M memory

4.1.2 Cellular Management Unit (CMU)

The CMU controls the cellular radio network. The MSC Server contains two

CMUs in IPCF cabinet. They are installed in DC3C-A cartridges.



Figure 9 CMU in DC3C-A cartridge

Table 3 Plug-in units in CMU


F06 C105075 / C08953 PSC6-B / PSC6-A Power Supply for Cartridge

F07 C74990/C74920 MBIF-C (M13) /MBIF-B

F08 C74990/ C74920 MBIF-C (M13) /MBIF-B



C108488 / C101180 CP816-A (M13) / CP710-A Pentium M Dothan processor with maximum of 1.8 GHz


F09

C109053 / C103757 MRD512A (M13) / MR512M 512M memory

4.1.3 Statistical Unit (STU)

The STU collects raw traffic measurements, supervises the load of the

exchange, maintains various counters and produces statistical reports. Primarily

statistical reports are sent to IP network via OMU functional unit and FTP

protocol. Only OLCM reports and fraud reporting are transported using

redundant LAN interface available in STU. STU pair equipment is installed into

DC3C-A cartridges in IPCF cabinet. MSC Server can have only one STU pair.

Functional Units


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Figure 10 STU in DC3C-A cartridge

Table 4 Plug-in units in STU


F01 C105075 / C08953 PSC6-B /PSC6-A Power Supply for Cartridge

F02 C74990/ C74920 MBIF-C (M13) / MBIF-B

F03 C74990/C74920 MBIF-C (M13) /MBIF-B



F04 C108488/C101180 CP816-A (M13) /CP710-A Pentium M Dothan processor with maximum of 1.8

GHz frequency / Pentium®III with 800 MHz frequency

C109053/C103757 MRD512A (M13) / MR512M 512M memory

4.1.4 Charging Unit (CHU)

The CHU Collects charging data maintains various counters and produces

detailed charging records. The CHU can send charging data directly from its

redundant LAN interface to Billing Centre using FTP over TCP/IP. CHU pair

equipment is installed into CC4C-A cartridges in all MSC Server cabinets.

Maximum number of CHU pairs is three.



Figure 11 CHU pair and mass memory in CC4C-A cartridges

Table 5 Table: Plug-in units in CHU


F01 C105075 /C08953 PSC6-B / PSC6-A Power Supply for Cartridge

F02 C104095 SHIM4T

F03 C104095 SHIM4T

F04 C104095 SHIM4T

Empty Slots

F05 C74990/C104965/C

74920

MBIF-C (M13)/MBIF-CR (M13)

/MBIF-B

F06 C74990/C104965/C

74920

MBIF-C (M13)/MBIF-CR (M13)

/MBIF-B

MBIF-CR: Message bus plug-in unit with a

repeater function


MBIF-B & MBIF-C/CR is not

interchangeable

F07 C108488 / C101180 CP816-A (M13)/ CP710-A Pentium M Dothan processor with maximum of

1.8 GHz frequency / Pentium®III with 800 MHz

frequency

C109053 / C103757 MRD512A (M13)/ MR512M 512M memory

Note:

• IPCF cabinet: in CHU 0-0 MBIF-CR, in CHU 0-1 MBIF-C

• IPCG cabinets: in CHUs 1-0, 2-0 and 3-0 MBIF-CR, in CHUs 1-1, 2-1

and 3-1 MBIF-C

Functional Units


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Table 6 Plug-in units in CHU mass memory



F02 C100720 HDPU-A Hard disk adapter

F02 P01098 / P01096 / P01091 WDW73 / WDW36 / WDW18-S Hard disk unit

F04 C101810 ODPU-A Magneto Optic disk adapter

F04 P1090 MO91 Magneto Optical unit

F07 C102646 COP10T Empty Slots

4.1.5 Operation and Maintenance Unit (OMU)

The OMU handles all centralised supervision, alarm and recovery functions,

and the connections towards user interface (MMI-System). Primarily the

connections are made using IP network but V.24 interface is also available.

The OMU collects the wired alarms from the exchange as well as from the

external equipment connected to the system.

The OMU has dedicated storage devices, which serve as a storage, for example,

for the entire system software of the network element as well as for the event

buffer for intermediate storing of alarms.

The OMU provides:

• Telnet connection for MMI

• FTP and Nokia specific EMT connection to NEMU for NEMU

applications

• HTTP connections to NetAct for delivering alarms in XML format

The MSC Server contains one OMU pair and it is located in the IPCF cabinet.

The OMU equipment is installed in a CC4C-A cartridge. The OMU unit

includes also a mass memory units.



Figure 12 OMU pair and mass memory in CC4C-A cartridges

Table 7 Plug-in units in OMU



F02 C104095 SHIM4T Empty Slots

F03 C08949 SERO-A Serial Interface

F04 C08950 HWAT-A Hardware Alarm Terminal

F05 C74990/ C74920 MBIF-C (M13)/ MBIF-B

F06 C74990/C74920 MBIF-C (M13) /MBIF-B



F07 C108488 / C101180 CP816-A (M13) / CP710-A Pentium M Dothan processor with maximum of 1.8


C109053 / C103757 MRD512A (M13) /

MR512M

512M memory

Table 8 Plug-in units in Mass memory SD0




F02 P01098 / P01096 / P01091 WDW73 / WDW36 / WDW18-S Hard disk unit

Functional Units


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F04 C101810 ODPU-A Magneto Optic disk adapter

F04 P1090 MO91 Magneto Optical unit

F07 C102646 COP10T Empty Slots

Table 9 Plug-in units in Mass memory SD1




F02 P01098 / P01096 /P01091 / WDW73 /WDW36 / WDW18-S Hard disk unit

F04 C105324 D4PU-A Dummy Plug-in Unit

F05 C104095 SHIM4T

F06 C104095 SHIM4T

F07 C102646 COP10T

Empty Slots

4.1.6 Basic Data Communication Unit (BDCU)

The BDCU provides the following external connections:

• Traffic is always connected using BDCU.

• The BDCU provides network interfaces for OSI (FTAM) protocol based

O&M connections, when they are required.

• The BDCU provides SMRSE/TCP/IP connection to SMSC (X.25 is also

available).

The BDCU equipment is installed in CC4C-A cartridge. Maximum number of

BDCUs in one network element is two.



Figure 13 BDCU in CC4C-A cartridge

Table 10 Plug-in units in BDCU


F01 C105075 /C08953 PSC6-B /PSC6-A Power Supply for Cartridge

F02 C105007/C08951/C08944 AS7-C (M13) /AS7-A/AC25-A

F03 C105007/C08951/C08944 AS7-C (M13)/AS7-A /AC25-A

F04 C105007/C08951/C08944 AS7-C (M13)/AS7-A/AC25-A

X25 terminals

Optional, see note!

F05 C74990/C74920 MBIF-C (M13)/MBIF-B

F06 C74990/C74920 MBIF-C (M13)/MBIF-B


MBIF-B & MBIF-C/CR is not

interchangeable

F07 C108488 /C101180 CP816-A (M13)/CP710-A Pentium M Dothan processor with maximum of

1.8 GHz frequency / Pentium®III with 800 MHz

frequency

C109053 /C103757 MRD512A (M13) /MR512M 512M memory

Note:

• If slots F02–F04 are not equipped, SHIM4T cover plates should be

installed on these slots.

• Digital G.703 interface AS7-C/-A can be used only if MSC Server has

IPCH cabinet.

Functional Units


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4.1.7 Clock System (CLS)

Both CLBU (Clock and Alarm Buffer Unit) and CLSU (Clock System Unit) are

part of the Clock System (CLS).

The CLBU distributes the clock and synchronisation signals within the same

cabinet. The CLBU also collects the wired alarms from the units whose timing

it handles and transfers them to the OMU.

The CLSU generates the clock and synchronization signals and transmits them

further to the CLBU units in the other cabinets.

In the integrated models synchronization signal is received from external TDM

lines or from external synchronization interface in CLS.

In the standalone models without external TDM connections there is a need to

receive external synchronization signal via external synchronization interface in

CLS. This external synchronization signal is needed to ensure the accuracy of

charging and also to ensure that timestamp information in charging data and

performance data from different network elements are comparable.

The MSC Server contains one duplicated CLSU which is located in the IPCF

cabinet and three CLBUs, one in IPCF and two in IPCG0 cabinet. The CLSU

equipment is installed in the same CLOC-B cartridge. The CLBU equipment is

installed into CLAC-B cartridge.

Figure 14 CLSU in a CLOC-B cartridge & CLBU in a CLAC-B cartridge

Table 11 Plug-in units in CLSU


F00 C08825 CL2TG-S

F03 C08825 CL2TG-S

Clock and Tone

Generator



Table 12 Plug-in units in CLBU


F01 -- --

F02 -- --

F03 C08839 CLAB-S

F04 C08839 CLAB-S

Clock and Alarm Buffer

4.1.8 Switching Unit (SWU)

The SWU uses ESB20-A , which is a 20-port 10/100 BaseT/TX Ethernet LAN

Switch plug-in unit integrated into the Nokia network elements. It has an

extensive set of features such as VLAN 802.1q, Rapid Spanning Tree Protocol

802.1d (RSTP) and an SNMP agent. A set of LAN switches, integrated in the

Nokia MSC Server cabinets, provide a manageable amount of LAN interfaces

from the network element to external routers at the site. The separation of

different traffic types provides additional security and manageability.

In the MSS and GCS the ESB20-A LAN switch plug-in unit is furnished in a

separate SWU unit whereas in the integrated models and in the MSSu the

ESB20-A is furnished in STU or CHU units.

Figure 15 LAN in LASWC-A cartridge in MSS

Functional Units


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Table 13 LAN switch position in MSS cartridge


F01 C8862 PSC6 Power supply for cartridge

F02 C108885 / C108000 ESB26 / ESB20-A See Notes

F03 C108885 / C108000 ESB26 / ESB20-A IPCF cabinet

F04 C104095 SHIM4T

F05 C104095 SHIM4T

Empty Slots

Notes:

• ESB26:LAN switch unit (2 optical Gbit/s, 2 electrical Gbit/s and 2 100

Mbit/s electrical uplinks; 20 100 Mbit/s electrical downlinks)

• ESB20: LAN switch unit (2 electrical uplink and 18 downlink 10/100

Mbit/s ports)

Figure 16 LAN in LASWC-A cartridge in GCS

Table 14 LAN switch position in GCS cartridge


F01 C105075 / C08953 PSC6-B / PSC6-A Power supply for cartridge

F02 C108885 / C108000 ESB26 / ESB20-A See Notes

F03 C108885 / C108000 ESB26 /ESB20-A See Notes

F04 C104095 SHIM4T Empty slots

F05 C108885 / C108000 ESB26 /ESB20-A See notes



4.2 IPCG Cabinet

Note: *SU configurable as BSU or SIGU.

Figure 17 Functional unit and cartridge positions in the IPCG 0 cabinet in MSS

The following figure shows the functional unit and cartridge configuration of

the IPCG 0 cabinet in the GCS network element.

Functional Units


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Figure 18 Functional unit and cartridge positions in the IPCG 0 cabinet in GCS

4.2.1 Signalling Unit (SIGU)

The SIGU has the functionality of the CCSU (see above) except that the SIGU

can utilise only an IP-based signalling network, whereas the CCSU can use an

IP or a TDM-based SS7 network.



SIGUs are installed to IPCG cabinets and maximum number of SIGUs is 14

pcs. The SIGU configuration is:

Figure 19 SIGU in DC3C-A cartridge

Table 15 Plug-in units in SIGU



F02 C74990/C74920 MBIF-C(M13) /MBIF-B

F03 C74990/ C74920 MBIF-C(M13) /MBIF-B



C108488 / C101180 CP816-A(M13) / CP710-A Pentium M Dothan processor with maximum of 1.8 GHz


F04

C109053 / C103757 MRD512A(M13) / MR512M 512M memory

4.2.2 Base Station Signalling Unit (BSU)

The BSU provides BSSAP and RANAP protocols that perform the signalling

functions between radio networks and MSS. The BSU has SIGTRAN

functionality and a LAN interface which enable it to use IP for conveying

signalling messages. If the A-interface is connected directly to the Integrated

MSS, then the BSU also controls the TDM lines linked to the GERAN. The

BSU equipment is installed into DC3C-A cartridge. Maximum number of BSUs

in one MSC Server is 14 pcs. The BSU configuration is:

Functional Units


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Figure 20 BSU in a DC3C-A cartridge

Table 16 Plug-in units in BSU



F07 C74990/C74920 MBIF-C (M13) /MBIF-B

F08 C74990/ C74920 MBIF-C(M13) /MBIF-B



C108488 / C101180 CP816-A(M13) / CP710-A Pentium M Dothan processor with maximum of 1.8 GHz


F09

C109053 / C103757 MRD512A(M13) / MR512M 512M memory

4.2.3 Visitor Location Register Unit (VLRU)

The VLRU contains information of each subscriber currently served by the

MSC Server. The MSS can contain up to 8 VLRU pairs each containing a

database for up to 75,000 subscribers and 25,000 telemetric subscribers, hence

allowing a total of 600,000 + 200,000 subscribers per MSS.



VLRU pair equipment is installed into DC3C-A cartridges in IPCF and IPCG

cabinets. MSC Server can have a maximum of 8 VLRU pairs. Due to

redundancy reasons, each pair's halves are installed to separate cartridges . :

Figure 21 VLRU pair in DC3C-A cartridges

Table 17 Plug-in units in cartridges reserved for VLRUs


F01 C105075/ C08953 PSC6-B / PSC6-A Power Supply for Cartridge

F02 C74990/C74920 MBIF-C(M13) /MBIF-B

F03 C74990/ C74920 MBIF-C(M13) /MBIF-B

Arbitration frequency: 2,048 MHz.;


F04

C108488/C101180 CP816-A(M13) / CP710-A Pentium M Dothan processor with maximum of 1.8


C109053/C103757 MRD512A(M13) / MR512M 512M memory


F07 C74990/C74920 MBIF-C(M13) /MBIF-B

F08 C74990/ C74920 MBIF-C(M13) /MBIF-B

Arbitration frequency: 2,048 MHz.;


F09

C108488 / C101180

CP816-A(M13) / CP710-A Pentium M Dothan processor with maximum of 1.8 GHz frequency / Pentium®III with 800 MHz frequency

C109053 /

C103757

MRD512A(M13) / MR512M 512M memory

Functional Units


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4.3 IPCH Cabinet

Figure 22 Functional unit and cartridge positions in the IPCH cabinet



4.3.1 Common Channel Signalling Unit (CCSU)

The CCSU performs the MAP, TCAP, SCCP and ISUP signalling. CCSU

performs core INAP and CAP signalling needed in order to provide IN and

CAMEL services. For TDM based SS7 connections CCSU takes care of the

decentralised MTP functions of the SS7 signalling system, the handling of

signalling messages, and the functions related to the management of the

signalling channel. One CCSU can support 64 TDM lines.

The CCSU also contains SIGTRAN, which enables to convey the above-

mentioned signalling messages on top of IP using LAN interfaces available in

this functional unit.

In addition, the CCSU provides H.248, SIP and BICC signalling. The CCSU is

used in integrated models because of its ability to also handle TDM-based SS7.

In the standalone models SIGU is used instead to handle signalling using

SIGTRAN and CCSU is used in standalone models only in the optional IPCH

cabinet.

CCSUs can be installed into IPCH cabinet only. Maximum number of CCSUs is

10 pcs. The CCSU configuration is:

Figure 23 CCSU in CC4C-A cartridge

Functional Units


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Table 18 Plug-in units in CCSU


F01 C105075/C08953 PSC6-B /PSC6-A Power Supply for Cartridge

F02 C105007/C08951 AS7-C(M13)/AS7-A

F03 C105007/C08951 AS7-C (M13)/AS7-A

F04 C105007/C08951 AS7-C (M13)/AS7-A

CCS7 terminals

F05 C74990/C104965/C74920 MBIF-C(M13)/MBIF-CR

( M13)/MBIF-B

In CCSU 0 MBIF-CR

In CCSU 1 MBIF-C

Not interchangeable

F06 C74990/C104965/C74920 MBIF-C(M13)/MBIF-CR

( M13)/MBIF-B

In CCSU 1 MBIF-CR

In CCSU 0 MBIF-C

Not interchangeable

F07 C108488 /C101180 CP816-A (M13)/CP710-A Pentium M Dothan processor with maximum of

1.8 GHz frequency / Pentium®III with 800

MHz frequency

C109053 /C103757 MRD512A(M13)/MR512M 512M memory

4.3.2 Group Switch (GSW)

If there are TDM trunks connected directly to the MSC Server it is necessary to

have a switching fabric. The GSW is an option in the standalone models (not in

the MSSu). If the operator needs to have a direct TDM-based SS7 connection

from a standalone model, it is possible to include the optional GSW which has a

capacity of 256 TDMs. The Group switch equipment is housed in two SW1C-B

cartridges



Figure 24 GSW in SW1C-B cartridge

Table 19 Plug-in units in GSW


F00 -- --

F01 C08853 SWCSM-S Switch Control and

Switching Memory Unit

F02 C08854 SWSPS-S

F03 C08854 SWSPS-S

F04 C08854 SWSPS-S

F05 C08854 SWSPS-S

Switch Serial-Parallel-

Serial Converter

F06 C08869 PSC1-S Power supply

4.3.3 Exchange terminal (ET)

The ET performs the electrical synchronization and adaptation of an external

TDM line. It is able to do the HDB3/AMI/B8ZS coding and decoding, insert the

alarm bits in the outgoing direction, and produce the PCM frame structure. In

the MSS the ET is furnished in the optional IPCH cabinet.

Three alternative ET types without echo cancelling are available:

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Connecter Type M12 M3

E1 Euro ET2E-S ET2E-T

E1 Coax ET2E-SC ET2E-TC

T1 RJ-45 ET2A ET2A-T

Only one ET type can be used in one network element. ET plug-in units are

installed in ET4C-B or ET5C-B cartridges in the IPCH cabinet. ET4C-B

cartridge can contain up to 32 ET plug-in units. ET5C-B has room for eight ET

plug-in units. The recommended order of installing ET plug-in units is

described below but they can be added in any desired order too.

Figure 25 ET plug-in units in ET4C-B & ET5C-B cartridge

The following example shows how five ET plug-in units are installed into the

cartridge. Please note that the numbers shown in this picture's plug-in units

indicates only the order how plug-in units are added to the cartridge.



Figure 26 Example of ET configuration

When plug-in units are added later to ET cartridges, the ET plug-in unit is

installed to the first available slot using the same principle as described above.

4.4 Some Special Units in MSSu

4.4.1 Channel Associated Signalling Unit (CASU)

The CASU is installed in the network element only when Channel Associated

Signalling (CAS) is needed between the Transit MSCi and the PSTN. In the i-

series MSCs, the MFSU handles the transmission and receipt of MF signals,

while CASU takes care of the related CAS line signalling functions. If CASUs

are needed in the network element, the required minimum number is two. The

maximum number of CASUs, CCSUs, PAUs and TGSUs is 33, including a

spare unit of each type for n+1 redundancy.

4.4.2 Primary Rate Access Unit

The Primary Rate Access Unit (PAU) performs the call control and signalling

for the traffic of the ISDN PABX connected to DX 200 system by a 30B+D

interface. Of the signalling, the PAU performs the functions of levels 2 and 3 in

the seven-layer OSI model. Level 2 is generated by a LAPD (Link Access

Procedure on the D-channel) in accordance with the ITU-T Recommendations

Q920, Q921 and Q922. Level 3 is generated by the signalling network functions

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in accordance with the ITU-T Recommendation Q931. The PAU also

supervises the trunk circuits of the PABXs based on the information on the error

ratio and synchronisation of the transmission obtained from the trunk circuit

interfaces.

Two alternative protocols are available for the PBX signalling: ISDN primary

rate access 30B+D, and DPNSS 1. One PAU can handle up to 64 signalling

links and control up to 64 2 Mbit/s lines.

The basic configuration of a signalling unit includes:

• one Central Processing Unit (CPU) with memory

• two Message Bus Interfaces (MBIF)

• one AS7 pre-processor units to handle ET supervision (AS7 0).

• up to three AS7 pre-processor units to handle CAS, CCS7, LAPD and

PBX Signalling interfaces (AS7 1/2/3).

• one Power Supply (PSC6).

Figure 27 CASU, PAU or CCSU equipment in a CC3C-A cartridge.

4.4.3 Mechanical structure of MFSU(i)

The MFSU is installed in the CC4C-A or the CC3C-A cartridge (see the figures

below), and the basic configuration includes:



Configuration of the MFSU in the CC4C-A cartridge



• up to four Multifrequency Signalling Terminal units (MFSTs)

• one Power Supply for Cartridge (PSC6)

Configuration of the MFSU in the CC3C-A cartridge



• up to four Multifrequency Signalling Terminal units (MFSTs)

• one Power Supply for Cartridge (PSC6)

Figure 28 Configuration of the MFSU in the CC4C-A cartridge

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Figure 29 Configuration of the MFSU in the CC3C-A cartridge

4.4.4 Group Switch (GSW)

If there are TDM trunks connected directly to the MSC Server it is necessary to

have a switching fabric. The maximum capacity of the GSW in the integrated

models is 2048 TDMs.

The SW2C-B/A cartridge contains 2 power supply units PSC1-S, 1...8 SWSPS-

S plug-in units and 1...16 SWCSM-S plug-in units. The GSW of the MSCi and

Transit MSCi is equipped for the capacity of 2048 x 2048 PCMs and in

maximum configuration occupies four SW2C-B/A cartridges.The figure below

shows the placement of the plug-in units in the cartridge and the table that

follows indicates the number of cartridges and plug-in units needed as a

function of the number of PCM circuits.



Figure 30 Configuration of the SW2C-B/A cartridge

Table 20 Number of SW2C-B/A cartridges and plug-in units needed as a function of the number of PCM circuits.

Cartridge Plug-in units

PCM circuits SW2C SWSPS SWCSM PSC1

32 1 1 1 1

128 1 2 1 1

512 1 8 4 2

513 2 9 9 3

1 024 2 16 16 4

1 025 3 17 25 5

1 536 3 24 36 9

2 048 4 32 64 12

4.4.5 Echo cancelling and exchange terminal (ECET)

The ET with echo canceller is used for terminating TDM lines connected

directly to Integrated MSS or Integrated GCS from PSTN or PBX. One EC2ET,

EC2ET-C or EC2ET-A plug-in unit contains two ET functional units and two

Echo Canceller units. The ECETs are housed in ET4C-B / ET4C-A cartridges

positioned in ETC cabinets. One ET4C-B / ET4C-A cartridge can contain up to

16 EC2ET, EC2ET-C or EC2ET-A plug-in units.

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Figure 31 EC2ET Echo Canceller Exchange Terminal plug-in units in an ET4C-B / ET4C-A cartridge.

The cartridge on the second-lowest shelf at the right-hand side in the ETC

cabinet has a mixed configuration, with ECETs on the upper shelf and ETs on

the lower, as shown in the figure below.

Figure 32 EC2ET and ET2E plug-in units in an ET4C-B / ET4C-A cartridge.



4.4.6 Compact Data Service Unit (CDSU)

The CDSU implements the Inter Working Function (IWF) of the MSCi, CDS,

and Compact MSCi and CDS. A G.703 connection is used. The main task of the

unit is to adapt the data connection of the terminal device (i.e. laptop PC) of the

GSM Mobile Station (MS) to the:

• Public Switched Telephone Network (PSTN)

• Integrated Services Digital Network (ISDN)

The tasks of the CDSU include:

• Rate Adaption (RA)

• Radio Link Protocol (RLP) processing

• Layer 2 interface (L2R)

• Modem state control.

The CDSU offers the following GSM data services:

• Asynchronous bearer services

• Transparent synchronous bearer services

• Transparent facsimile group 3 tele-service.

The Data Service Cartridge (DS1C-B/A) is 1/3 shelf wide. It is a cartridge for

DX 200 hardware and its physical dimensions are: 240 mm(width) x 262

mm(height) x 300 mm (depth).

In its maximum configuration, the DS1C-B/A cartridge can contain 10 plug-in

units:

• one PSC6 plug-in unit (power supply)

• one DSCO plug-in unit (control unit)

• eight DSMA-S plug-in units

The equipping of the cartridge depends on the application. There are three

options for the CDSU:

• a Normal Speed Data Service Unit with Data Interface, NDSD Pool, or

an UDI Pool

• a Normal Speed Data Service Unit with Modems, NDSM Pool, or a

Modem Pool)

• a Compact Data Service Unit Pool, CDSU Pool, or a General Pool

(which combines both of the above).

The CDSU supports, when fully equipped, 32 simultaneous calls (no matter

whether the call is using single or multi-slot configuration in the air interface).

If the CDSU hardware is configured as

• NDS; it supports 32 simultaneous modem/fax calls.

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• NDSD; it supports 32 simultaneous UDI calls

• CDSU; it supports 32 simultaneous modem/fax/UDI calls.

In the NDSM and CDSU mode the use of channels is dynamic (modem, fax,

UDI), that is, the reserved channel is configured based on the received call set

up request. So, for example, the CDSU can serve simultaneously any number of

modem/fax/UDI calls (the total number of calls per CDSU is limited to 32).

Figure 33 Configuration of the plug-in units of the NDSM Modem and CDSU General pool

Figure 34 Configuration of the plug-in units of the NDSD UDI pool



5 Redundancy

REDUNDANCY

BDCU N

BSU N+1

CASU N+1

CDSU N

CCMU 2N

CCSU N+1

CHU 2N

CM 2N

CMM 2N

CMU 2N

ESB20 2N

ET N

IPET N

M 2N

MB 2N

MFSU N+1/L

OMU 2N

PAU N+1

SIGU N+1

STU 2N

TGFP 2N

TGSU N+1

VLRU 2N

Table 21 Redundancy methods of functional units

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6 Glossary

2G 2nd

Generation mobile phone network

3G 3rd Generation mobile phone network

3GPP Third Generation Partnership Project

AC Apply Charging

ACR ApplyChargingReport

API Application Programming Interface

APSE Application Server

AUC Authentication Centre

BSSAP Base Station Subsystem Application Part

CAMEL Customised Applications for Mobile Network Enhanced Logic

CAP CAMEL Application Part

CDR Charging Data Record

CHU Charging Unit

CM Central Memory

CMISE Common Management Information Service Element

CORBA Common Object Request Brokerage Architecture

CPS Connection Processing Server

CPU Central Processing Unit

CUE Continue

CS Circuit Switched

DCN Data Communications Network

DP Detection Point

DTMF Dual Tone Multifrequency

EDGE Enhanced Data Rates For GSM

FTP File Transfer Protocol

GCS Gateway Control Server

GERAN GSM/EDGE Radion Access Network

GPRS General Packet Radio Service

GSM Global System For Mobile Communications

GSW Group Switch

HLR Home Location Register



HSS Home Subscriber Server

IDP Initial DP operation

IMS IP Multimedia Subsystem

IMSI International Mobile Subscriber Identification

IN Intelligent Network

INAP Intelligent Network Application Part

IP Internet Protocol

ISUP ISDN User Part

LA Location Area

M Marker

M3UA MTP3 User Adaptation

MAP Mobile Application Part

MGCF Media Gateway Control Function

MGW Multimedia Gateway

MMI Man Machine Interface

MML Man Machine Language

MS Mobile Station

MSC Mobile Switching Centre

MSS MSC Server

MSSu Upgraded MSC Server

NEMU Network Element Management Unit

O&M Operation & Maintenance

OMU Operational And Maintenance Unit

PLMN Public Land Mobile Network

PSTN Public Switched Telephone Network

PVC Permanent Virtual Connection

RAN Radio Access Network

RANAP Radio Access Network Application Part

RNC Radio Network Controller

RTP Real Time Protocol

SCP Service Control Point

SCTP Stream Control Transmission Protocol

SIGTRAN Signalling Transport

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SIP Session Initiated Protocol

SMSC Short Message Service Centre

SPVC Soft Permanent Virtual Connection

SRR Service Routing Register

SSP Service Switching Point

SS7 Signalling System # 7

STU Statistical Unit

SVC Switched Virtual Connection

TMSI Temporary Mobile Subscriber Information

T-SGW Transport Signalling Gateway

UE User Equipment

UMTS Universal Mobile Telecommunication System

USB Universal Serial Bus

USSD Unstructured Supplementary Services Data

UTRAN UMTS Terrestrial Radio Access Network

VLR Visitor Location Register

VMSS Visited MSC Server

01_mobile switching system server,gateway control server

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