04 Cn34014en30gln1 Mgw for Mss

8/11/2019 04 Cn34014en30gln1 Mgw for Mss

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CN34014EN30GLN1 Nokia Siemens Networks 1 (63)

3G Rel4 SCNOM

MGW for MSS (U4)

Training Document


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2 (63) Nokia Siemens Networks CN34014EN30GLN1

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Contents

1 Objectives ...............................................................................................5

2 Overview of IPA2800 MGW for 3G-MSS...............................................62.1 Multimedia gateway mechanics ...............................................................72.2 New Hardware in U4 ................................................................................82.2.1 Phasing of features in Nokia MGW ..........................................................92.2.2 U4 Features ............................................................................................92.2.3 Capacity and Performance.....................................................................12

3 Nokia MGW Functional Units ..............................................................143.1 Management, Control Computer, and Data Processing Units ...............153.1.1 CACU, Control and Administrative Computer Unit.................................15

3.1.2 CM, Central Memory ..............................................................................163.1.3 ISU, Interface Control and Signalling Unit..............................................173.1.4 VANU, Voice Announcement Unit..........................................................183.1.5 SWU, ESA24 Ethernet Switch................................................................193.1.6 OMU, Operation and Maintenance and its subunits...............................203.1.7 NEMU, Network Element Management Unit and its subunits................233.1.8 TCU, Transcoding Unit...........................................................................263.2 Network Element Interface Units............................................................273.2.1 NPS1/NPS1P, Network Interface Unit STM-1........................................283.2.2 NIP1, Network Interface Unit PDH .........................................................293.2.3 NPGEP, Network Interface Unit .............................................................303.2.4 NIWU, Network Interface Unit TDM .......................................................313.2.5 IWS1E/T, Network Interface Unit STM-1/OC-3......................................333.3 Switching and Multiplexing Units............................................................343.3.1 SFU, Switching Fabric Unit ....................................................................363.3.2 MXU, Multiplexer Unit.............................................................................373.3.3 A2SU, AAL 2 Switching Unit ..................................................................393.4 Timing, Power Distribution and Hardware Management

Subsystem .............................................................................................403.4.1 TBU, Timing and Hardware Management Bus Unit ...............................413.4.2 HMS subsystem.....................................................................................443.4.3 Power Distribution Subsystem ...............................................................463.5 EHU, External Hardware Alarm Unit ......................................................47

3.5.1 EXAU, External hardware alarm panel...................................................493.5.2 CAIND, Cabinet alarm indicator .............................................................49

4 MGW Hardware Configuration ............................................................50

5 Nokia MGW Interfaces .........................................................................555.1 Physical connections in Nokia MGW......................................................555.2 ATM Backbone in Nokia MGW...............................................................565.3 IP Backbone in Nokia MGW...................................................................565.4 TDM Backbone in Nokia MGW ..............................................................57


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5.5 Nokia MGW control interface................................................................. 575.5.1 MGW control protocols (MEGACO/H.248)............................................ 585.6 Iu interface in Nokia MGW..................................................................... 58

5.7 A-interface in Nokia MGW..................................................................... 595.8 Interface towards PSTN and other TDM-based networks in

Nokia MGW ........................................................................................... 59


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1 Objectives

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

List the main functions of the MGW for MSS

Explain the main functions of each functional unit

List the redundancy principles for the function units

Identify the interfaces implemented in the MGW

Explain the MGW hardware configuration


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2 Overview of IPA2800 MGW for 3G-MSS

The 3rd Generation mobile networks will accelerate the shift towardssupporting mass-market IP-based applications that has started with 2ndGeneration systems (GSM, US-TDMA). The wireless market is undergoing aperiod of rapid change in competition, services and underlying technology,

making the choice of the network system complex. With Nokia 3G solutions,operators reduce risks by using proven concepts. Mobile networks willcontinue to evolve, from today to the 3G launch and onwards, to increase therange of available services and service capabilities.

Figure 1 MGW in MSC Server Environment

The Nokia Multimedia Gateway product can be used for transmitting andconverting the user plane traffic in both circuit-switched core networks and All-IP Mobility Core Networks as a border element between different kinds ofnetworks.The Multimedia Gateway consists of several functional elements configuredunder the gateway architecture. A number of different configurations of the

SGSN

RNCRNC

GSM

BSCBSC

WCDMA MGWMGW

ExternalIP networks

IP/ATM/TDMBackbone

MGW

PSTN/ISDN

Other PLMN

HLR

GCS -GatewayControl Server


MSC ServerMSCServer

GGSN

A

A

Iu-CS

SITGTRANH.248

H.248

BICCCS-2, SIP-T

IN/SCE APSE

SGSNSGSN

RNCRNC

GSM

BSCBSC

WCDMA MGWMGW

ExternalIP networks

IP/ATM/TDMBackbone

MGW

PSTN/ISDN

Other PLMN

HLR





MSC ServerMSCServerMSC ServerMSCServer

GGSN

A

A

Iu-CS

SITGTRANH.248

H.248

BICCCS-2, SIP-T

IN/SCE APSE


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Multimedia Gateway can be used depending on the services required by theoperator.

The main functions of the Multimedia Gateway are:

To adapt the conventional signalling (control plane) between MSCserver or Gateway Control Server (GCS) and different networkinterfaces.

To connect the user data (user plane) from ATM/IP backbone intoradio access network or circuit switched networks. Media resourcesare under control of Gateway Control Server (GCS), GCS or MSCserver via H.248 (MEGACO) protocol.

To provide tones and announcements to end users.

To perform the transcoding and signal processing for the user planewhen needed.

Typically, one control network element (CPS, GCS or MSC server) handlesseveral gateways. Therefore, Nokia Multimedia Gateway provides thepossibility to create virtual gateways in one physical gateway element so that itoffers media resources to several controlling elements. This multi-hostingfunctionality in the gateway gives operators flexibility to utilise the networkelements optimally, depending on the network architecture.

2.1 Multimedia gateway mechanics

The mechanical construction of the IPA2800 network elements is basedon M2000 mechanics platform, which follows a standard hierarchy:

Cabinets

Cooling and power supply equipment

Subracks

Plug-in units

Internal cables.

The equipment of the IPA2800 network elements is housed in IC186 orIC186-B cabinets. One cabinet has space for the cabinet-specific powerdistribution equipment, four subracks and subrack-specific coolingequipment.

All IPA2800 network elements use three types of subracks, calledSRA1-A, SRA2-A and SRBI-B. The SRA1-A is only used in the first twopositions in the A cabinet, all other positions use the SRA2-A. The onlydifference between SRA1-A and SRA2-A two subracks is that the SRA2-


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A integrates more of the subrack's internal cabling, such as signals fromthe MXUs to tributary units, into its backpanel. SRBI-B is a equippedbehind the SRA1-A and SRA2-A subracks to provide modular backplane

connections.The total number of different plug-in unit types used in a single IPA2800network element is approximately 15. The plug-in units are generallyconnected to the other parts of the system by means of backplaneconnectors. Some of the connections, however, are made from the frontpanels, normally by means of standard RJ-45 connectors. The plug-inunits of the IPA2800 network elements are designed to support hotswapping. The plug-in-units are equipped with various LED indicators formonitoring the unit's condition.

2.2 New Hardware in U4

The MX1G6 is a 1.6 Gbit/s ATM multiplexer plug-in unit. It multiplexes anddemultiplexes ATM cells and performs ATM layer and traffic managementfunctions. The MX1G6 enables to connect low speed units to the switchingfabric and improves the use of switching fabric port capacity by multiplexingtraffic from up to twenty tributary units to a single fabric port.

The main function of the SF20H plug-in unit is to switch cells from inputto output ports. Within the SF20H, switching is protocol independent.

This means that before the cells are sent to the fabric, they areencapsulated inside a special fabric frame. With a total of 32 ports, theSF20H provides a 2.5 Gbit/s serial switching fabric interface(SFPIF2G5). Several SFPIF2G5 ports can be combined for highercapacity ports.

The port interfaces can be configured for redundant network interfaceand multiplexer units. The active input is selected inside the SF20H plug-in unit, and the port redundancy of the SFPIF2G5 ports is implementedby mirroring two fabric ports together. Thus the redundant portconsumes the port capacity.

The NP2GE plug-in unit is an interface unit that is specifically designed forthe optimized use of the Internet Protocol and the packet environment.NP2GE istargeted for the multiprotocol transport Iu-CS. The primary transportmethod type used is IP over Ethernet.

NP2GE provides multiprotocol packet processing at wire speed and also offers thepossibility of using both electrical (copper) and optical (fibre) based Ethernet. Thehigh processing power of the network processor and the unit computer enable the


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NP2GE plug-in unit to process protocol and data at the line interface unit (LIU)instead of the dedicated processing units.

The IW1S1A plug-in unit supports the 2G transcoder function on the AterInterface. For efficient transmission between the plug-in unit and the Base StationController, four sub-64 kbit/s (32 kbit/s, 16 kbit/s) user data/speech channels arepacked in one time slot. The IW1S1A plug-in unit submultiplexes anddesubmultiplexes the sub-channels in both directions on the Ater interface. Afterthe desubmultiplexing, the channels are packed into ATM cells and forwarded tothe digital signal processor (DSP) pool, where the DSP adapts the 16 kbit/s and 32kbit/s sub-channels to normal 64 kbit/s time slots. The time slots are then handledlike normal A interface time slots. The ATM cells received in the submultiplexingprocess are multiplexed to the appropriate sub-channels. IW1S1A can alsoterminate one E1 line (31 time slots) SS7 signalling link.

There are few HW in U3 version removed as well by implementing new delivery ofU4, which are A2SU from AL2S-A will be replaced by CDSP-C plug in unit andSPMU will be removed completely.

2.2.1 Phasing of features in Nokia MGW

Nokia Multimedia Gateway for both MSC Server and IP MultimediaSubsystem environment is an evolution step from Multimedia Gatewaybelonging to 3G MSC. All features from previous releases and earlierarchitectures are also available in later releases.

Different functionalities become available in MGW as follows: U2: Functionality required by both 3G MSC and the first release of

Nokia MSC Server system.

U3A: STM-1/OC-3 interface for TDM use in MSC Server system.

U3B: Additional functionality for the MSC Server system release 2including possibility to use the same network element also in IPMultimedia Subsystem.

U3C: Introduces Ater and Wideband AMR functionalities

U4: New features for both the MSC Server environment and IPMultimedia Subsystem environment for the MSC Server systemrelease 3

2.2.2 U4 Features

ABNF coding for H.248 protocol.


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The U2 release only supports ASN.1 (binary) coding forH.248 messages. ABNF (text) is provided in U3B as analternative method for helping multi-vendor interoperability.

ABNF is also applied in the MGW for IMS environment. Mb interface support.

This interface is needed in IP Multimedia Subsystemenvironment. The Mb interface connects the IP MultimediaSubsystem (IMS) to MGW, which provides theinterconnection with other supported multi-access VoIPinterfaces and BSS, RAN, PSTN, or IP, ATM, or TDMbackbone.

Text Telephony Service (TTY) for 3G calls.

Text Telephony is a feature that enables text-based

communication over a speech bearer. This is mainlyintended for hearing impaired people. The text is transmittedthrough ordinary speech traffic channels

U3B TrFO

With Transcoder-free Operation (TrFO), the intention is tocompletely remove the unnecessary transcoding from thespeech path. This is achieved with an out of band signallingperforming the coded negotiation and selection throughoutthe network. Optimally, this means that speech transcodingis only performed in peer UEs (user equipment, 3G terminal).

TrFO is standardised for 3G calls only (that is, calls viaUTRAN). TrFO provides optimised speech quality andenables savings in the transmission capacity in the corenetwork. Only compressed speech samples are transmittedover the ATM/IP networks

Acoustic Echo Cancellation

Acoustic echo is generated in the uplink direction due to theacoustic coupling from the ear-piece to microphone of theUser Equipment (UE). Acoustic echo is removed by a built-inacoustic echo control device of the UE.

Sometimes the UE functionality is not sufficient, andtherefore AEC functionality is provided on the network sideby MGW.

To deal with the echo generated in the downlink direction,there is an echo canceller in MGW. The echo cancellermemorizes the voice samples sent to the PSTN and thencompares the samples to the voice samples received backfrom the PSTN. These speech samples (containing the


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by using the traditional MMLs. The MGW EM user is able tochange quickly from the configuration view to the alarm view.This reduces the time spent on finding and correcting the

fault situation in MGW. TDM to TDM semi-permanent connections

Previously only semi-permanent ATM-ATM connectionswere possible in MGW. Now it is also possible to use semi-permanent TDM-TDM connections to for example:

provide a transparent through-connection for thePBX LAPD channels

route the Gb interface (between BSC and SGSN)semi-permanently through MGW

route the O&M traffic between BSC and NetAct semi-permanently through MGW.

Support for Network subsystem configuration tool

The NSS configuration tool, Nokia ConfigurationManagement Data Mediator (CMDM) is an optionalfunctionality, and requires a separate NEMU computer unit,Medium NEMU Server hardware.

CMDM provides the operator with an opportunity to reducenetwork planning costs and ease network planning. Forexample, when configuring a bearer independent CS corenetwork environment (Nokia MSS system), CMDM provides

easy access to configuration data and tools for adding newMGWs to a MSS or for modifying existing configuration.

The network element's configuration data can be uploadedfaster, with less work hours, and without affecting thecapacity or performance of the network element. Thepossibility to download configuration data to the NE makesnetwork planning easier, and less on-site work is needed.CMDM also produces valuable network configurationdocumentation and information for optimization decisions,and an interface for comparing configuration data betweenNEs.

2.2.3 Capacity and Performance

The main capacity figures for MGW U4.0 new delivery are:

Up to 50 000 simultaneous calls, depending on the call mix. This valuecan be reached and even exceeded when the TrFO is used for 3G calls.


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2.5M BHCA

40 STM-1/OC-3 for TDM

100 000 ATM/AAL2 ports

120 000 IP ports

960 E1/T1 (IW16P1)

600 signalling links (TDM + ATM SS7 links -> 30 000messages/s/direction)


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3 Nokia MGW Functional Units

Functionality is distributed to a set of functional units capable of accomplishinga special purpose. These are entities of hardware and software or onlyhardware. Units are connected to the ATM-based switching matrix (SFU)either directly (in case of units with high traffic capacity) or via multiplexer unit

MXU (in case of units with lower traffic capacity).

Figure 2 Functional units in Multimedia Gateway


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3.1 Management, Control Computer, and DataProcessing Units

3.1.1 CACU, Control and Administrative Computer Unit

Purpose: The CACU controls the ATM switching fabrics and establishesconnections for calls. Its ATM switching management functionscomprise:

Establishment of both internal and external connections via theSFU, including ATM circuit hunting and address analysis.

Management and control of the SFU, A2SU and MXU.

Transmission resource management.

Redundancy: 2N

Type: Computer unit

Plug-in Unit: CCP18-CControl Computer, Pentium M

Interfaces: ATM interface to MXU

Location: CAMA subracks 1-2, 1 unit per subrack


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Figure 3 CACU

3.1.2 CM, Central Memory

Purpose: The CM serves as the central data storage and distribution facility inthe exchange. It also handles the centralised part of the commonchannel signalling, for example, digit analysis.

Redundancy: 2N

Type: Computer unit

Plug-in Unit: CCP18-C

Control Computer, Pentium M




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Figure 4 CM

3.1.3 ISU, Interface Control and Signalling Unit

Purpose:The ISU is responsible for core network emulation and BSS signalling

emulation towards the MSC. Its tasks include the following:

Processing of the Message Transfer Part (MTP) and SignallingConnection Part (SCCP) of both narrowband and wideband SS7

signalling All message handling and processing functions related to the signalling

channels connected to it.

Redundancy: N+1

Type: Computer unit with no sub-units

Plug-in Unit: CCP18-C


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Control Computer, Pentium M


Location: CAMA subracks 3-4, all CAMB and CAMC subracks: 1 unit persubrack

Figure 5 ISU

3.1.4 VANU, Voice Announcement Unit

Purpose: The Voice Announcement Unit (VANU) controls the announcementfunction of MGW. It stores the individual speech samples,constructs complete announcements from them and sends them tothe DSP units for further processing.

Redundancy: None or load sharing

Type: Computer unit


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Plug-in Unit: CCP18-CControl Computer, Pentium M



Figure 6 VANU

3.1.5 SWU, ESA24 Ethernet Switch

Purpose: The SWU (ESA24) is an Ethernet switch, which provides physicalLAN/Ethernet interfaces for connections between NEMU and theother units of the MGW. With two ESA24 pairs, O&M LAN andControl LAN in MGW can be physically separated.

Redundancy: None


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Type: Ethernet switch

Plug-in Unit: ESA24

Interfaces: LAN/Ethernet to OMU, ISU, NEMU and site LAN

Location: 1 unit in CAMA subracks 1-4

Figure 7 ESA 24

3.1.6 OMU, Operation and Maintenance and its subunits

Purpose: The OMU handles all the MGW's crucial upper-level systemmaintenance functions, such as hardware configurationmanagement, Hardware Management System (HMS) supervisionand the associated centralised recovery functions. In the event of afault, the OMU automatically activates appropriate recovery anddiagnostics procedures within the MGW. It also serves as aninterface between the NEMU and the other units of the exchange.


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The OMU has dedicated storage devices, which house the entiresystem software and the event buffer for intermediate storing ofalarms, along with the radio network configuration files.

Redundancy: 2N

Type: Computer unit, with a dedicated storage device unit as a sub-unit.

Plug-in Unit: CCP18-AControl Computer, Pentium M

Interfaces: ATM virtual channels to MXULAN/Ethernet via ESA24 to NEMUDuplicated Small Computer Systems Interface (SCSI)Service Terminal interfaceMultiplexer Interface

Duplicated Hardware Management System (HMS) interface


Figure 8 OMU


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Purpose: The OMU has two dedicated hard disk units which serve as aredundant storage for the entire system software, the event bufferfor intermediate storing of alarms, and the radio networkconfiguration files.Backup copies are made onto a USB memory stick that can beconnected to the CCP18-A plug-in unit's front plate. Only memorysticks can be used.FDU is the functional unit when using the USB memory stick. Noseparate configuration in the HW database is needed, because theUSB memory stick is an external device. When removing the USBmemory stick, set the state to blocked, because the system doesnot do it automatically.

Redundancy: 2N (HDS-B)

Type: Sub-unit to OMU

Plug-in Unit: HDS-B: Hard Disk Drive with SCSI Interface

Interfaces: Small Computer System Interface (SCSI)



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Figure 9. OMUs WDU

3.1.7 NEMU, Network Element Management Unit and its subunits

Purpose: The NEMU provides the following facilities:

Local user interface

Interface towards the higher level network managementsystem

O&M functionalities which are not handled by othercomputer units of the MGW, including post-processing ofperformance and fault management data, as well as SW

upgrade support Peripheral device control.

The NEMU is equipped with storage devices for storingmeasurement and statistical data, and an Ethernet hub with 12 or24 physical LAN interfaces for connections to the upper-levelnetwork management system and the site LAN. Both facilities areimplemented as separate plug-in units and described in separatesections which follow this one.


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Redundancy: None

Type: Computer unit, with dedicated storage devices and the Ethernet

Switch unit (ESA24) as sub-units.

Plug-in Unit: MCP18-BManagement Computer, Pentium M745

Interfaces: Small Computer Systems Interface (SCSI)LAN/Ethernet to NMS, OMU and Site LAN via ESA24LAN/Ethernet to OMU via ESA24USB*VDU*) The USB ports can be used to connect a keyboard, a mouse, or abootable device to NEMU.

Location: 1 unit in CAMA subrack 1

Figure 10 NEMU


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Purpose: The NEMU is equipped with dedicated hard disks which primarilyserve as a storage for the measurement and statistical data itcollects.

Redundancy: 2N (hard disk drive)

Type: Sub-unit to NEMU

Plug-in Unit: HDS-BHard Disk Drive with SCSI Interface

Interfaces: Small Computer System Interface (SCSI)


Figure 11. NEMUs HDD


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3.1.8 TCU, Transcoding Unit

Purpose: The TCU includes a number of signal processors whose main

functions are:

transcoding, that is, speech signal conversion between the codedformat used in the WCDMA Radio Access Network and the PCMformat used in the GSM network.

signal level control

discontinuous transmission.

All DSPs of the unit can be freely allocated within the MGW.

Redundancy: SN+

Type: Signal processing unit with no sub-units

Plug-in Unit: CDSP-D

Configurable Dynamic Signal Processing Platform


Location: Max. 12 units each in CAMA subracks 3-4, all CAMB and CAMCsubracks


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Figure 12 TCU

3.2 Network Element Interface Units

These units serve as the trunk network interfaces of the exchange andexecute physical layer and ATM layer functions, such as policing, statistics,Operation Administration Maintenance (OAM), buffer management andscheduling. The category comprises the following units:

NPS1/NPS1P, Network Interface Unit STM-1

NIP1, Network Interface Unit PDH

NPGEP, Network Interface Unit

NIWU, Network Interface Unit TDM

IWS1E/T, Network Interface Unit STM-1/OC-3Each network interface unit contains more than one physical interface.


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3.2.1 NPS1/NPS1P, Network Interface Unit STM-1

Purpose: Provides SDH STM-1 interfaces and handles bit timing, line

coding, and timing recovery. Typically used in connectionsbetween the MGW and the RNC.

Redundancy: NPS1: NoneNPS1P: 2N

Type: Networking Interface unit

Plug-in Unit: NP8S1Network Interface 8 x 155.52 Mbit/s STM-1

Capacity/

performance:

Eight optical STM-1/OC-3 interfaces, 155.52 Mbit/s each. The

payload capacity of one STM-1/OC-3 interface is 150.336 Mbit/s.The STM interfaces are compliant with the ITU-T G.783specifications; the OC interfaces with the ANSI T1.105specifications.While the NP8S1 plug-in unit also provisions for two STM-4/OC-12 interfaces (each with 622.08 Mbit/s total capacity and 601.344Mbit/s payload capacity), STM-4/OC-12 interfaces are notcurrently supported in MGW and RNC.

Interfaces: ATM interface to SFUClock reference output to TSS3

Location:NPS1P: 2 units in CAMA subrack 3-4, all CAMB and CAMCsubracks

NPS1: 1 unit in CAMA subrack 3-4, all CAMB and CAMCsubracks


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Figure 13 NPS1/ NPS1P

3.2.2 NIP1, Network Interface Unit PDH

Purpose: This ATM network interface unit contains PDH E1/T1/JT1interfaces with Inverse Multiplexing for ATM (IMA) function,which allows for flexible grouping of physical links to logical IMAgroups.

Redundancy: None

Type: Signal processing unit

Plug-in Unit: NI16P1AATM Network Interface 16 x PDH E1/T1/JT1

Capacity/performance:

Sixteen physical PDH electrical interfaces, each with a bandwidthof:

2048 kbit/s (E1) or 1544 kbit/s (T1/JT1)


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Interfaces: ATM interface to MXUClock reference output to TSS3

Location: 3 units in CAMA subrack 3-4 and all CAMB and CAMC subracks

Figure 14 NIP1

3.2.3 NPGEP, Network Interface Unit

Purpose: Maps IP packets to and from Ethernet frame structure includingpacket classification, forwarding, scheduling, and trafficmanagement.

Redundancy: 2N

Type: IP Interface unit

Plug-in Unit: NP2GE


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Interfaces: 2 x 1000Base-T Ethernet electrical2 x 1000Base-LX Ethernet optical

Location: 1 units in all CAMA, CAMB and CAMC subracks

Figure 15. NPGEP

3.2.4 NIWU, Network Interface Unit TDM

Purpose: The ATM network interface unit IW16P1A contains TDME1/T1/JT1 interfaces, which carry traffic at the A interface,between the MGW and the MSC. IW16P1A also provides supportfor the Ater interface towards the BSC, eliminating the need for aseparate transcoder between the MGW and BSC.

The unit also performs the user plane conversion between theTDM format and the ATM format


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Redundancy: None

Type: Network Interface unit

Plug-in Unit: IW16P1AInterworking Unit 16 x E1/T1/J1


Sixteen physical TDM electrical interfaces, each with a bandwidthof:

2048 kbit/s (E1) or 1544 kbit/s (T1/JT1)

Interfaces: ATM interface to MXURS232Clock reference output to TSS3

Location: 6 units in CAMA subrack 3-4 and in all CAMB, CAMC subracks

Figure 16 NIWU


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3.2.5 IWS1E/T, Network Interface Unit STM-1/OC-3

Purpose: The IWS1E/T unit provides STM-1/VC-12 (63 PCM) and OC-3/VC-

11 (84 PCM) interfaces and a direct interface to SDH/SONETtransmission equipment. It implements user plane conversions ofan STM-1/OC-3 user channel bit stream to an ATM user channelcell stream. It also terminates narrowband SS7 signalling links andperforms narrowband / broadband conversion. The unit supportstwo ATM protocols, AAL1 and AAL5, for internal communicationpurposes.

Redundancy: None

Type: Network Interface unit

Plug-in Unit: IW1S1PSTN Interworking Unit, E1/T1/JT1 over STM-1/OC-363 E1 (VC-12 in STM-1) or84 T1 (VC-11 in OC-3) or84 JT1 (VC-11 in OC-3)


two optical 155 Mbit/s STM-1 interfaces

Interfaces: ATM interface to MXURS232Clock reference output to TSS3

Location: 4 units in CAMA subrack 3-4 and in all CAMB, CAMC subracks


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Figure 17. IWS1E/T

3.3 Switching and Multiplexing Units

Switching and multiplexing in the MGW is based on the AsynchronousTransfer Mode (ATM) technology with full support to the various traffic typesused in the network. The units in this category are the following:

ATM Switching Fabric Units (SFUs) which are used for switching thecalls processed by the exchange

Multiplexer Units (MXUs), for connecting the low-bit-rate networkinterface units, along with the computer units and signal processingunits (which typically have small to moderate bandwidth requirements)to the ATM switch fabric

AAL 2 Switching Units (A2SUs), which ensure efficient transport ofinformation with limited transfer delay for low-to-moderate bit-rate unitsconnected to the main switch fabric.


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In addition, the units in this block provide the ATM interface which serve as themain message bus between the units in the exchange. Upper-level controlfunctions for all three units are performed by the CACU functional unit.

Figure 18 ATM connections to SFU

The SFU switching fabric has 32 ports for connections to the other units in theexchange, with an aggregate capacity of 20 Gbit/s (equivalent to 64 STM-1lines); each port, in turn, has a capacity of 1.65 Gbit/s. The connectionsthrough the ports are allocated in the following manner:

Some ports are used for the external high-bit-rate connectionsprovided by NPS1.NPS1P & NPGEP.

The other ports are used for connections to the low-bit-rate networkinterface units and the computer units via the mutually redundant MXUpairs. One MXU pair requires one port.

The equipment of the MGW is organised as groups of units around its MXUpairs, with each group connecting to a MXU pair of its own. Normally, onesuch group occupies one subrack, with the exception of the equipmentconnecting to the first MXU pair, which requires two subracks' space (CAMAsubracks 1 and 2).


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3.3.1 SFU, Switching Fabric Unit

Purpose: The ATM Switching Fabric Unit (SFU) provides part of the ATM

cell switching function. It provides 2N redundancy, fullaccessibility, and is non-blocking at ATM connection level, that is,if the input and output capacities are available, the connection canbe established. The ATM Switching Fabric supports point-to-pointand point-to-multipoint connection topologies, as well asdifferentiated handling of various ATM service categories. Highcapacity network interface units and ATM Multiplexer units areconnected to the redundant SFU.

Redundancy: 2N

Type: Switch Fabric unit

Plug-in Unit: SF20H


20 Gbit/s

Interfaces: ATM interfaces: Switch fabric interfaces for NP8S1 network interfaces Multiplexer interfaces from SFU's unit computer to OMU

(via MXUs) OMU from the unit computer of the SFU (for OAM

purposes and software uploads, via MXUs)

Location: One unit in each of CAMA subracks 1-2


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Figure 19. SFU

3.3.2 MXU, Multiplexer Unit

Purpose: The ATM Multiplexer (MXU) multiplexes traffic tributary unitstowards the switching fabric thus enabling the efficient use ofswitching resources for low bit rate network interface units andcomputer units with small to moderate bandwidth requirements.The ATM Multiplexer also includes part of the ATM layerprocessing functionality, such as policing, statistics, OAM, buffermanagement, and scheduling. Control computers, signal

processing units and low bit rate network interface units areconnected to the ATM Switching Fabric via the MXU, which is a2N redundant unit.

Redundancy: 2N

Type: ATM switching unit, subunit of SFU

Plug-in Unit: MX1G6


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1.6 Gbit/s

Interfaces: ATM interfaces to: SFU switching block SFU unit computer control computer units network interfaces TCU and A2SU connection between the passive MXU via the active one to

OMU (for OAM purposes)

Location: CAMA, CAMB, CAMC subracks: 2 units per subrack

Figure 20. MXU


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3.3.3 A2SU, AAL 2 Switching Unit

Purpose: The A2SU is an AAL Type 2 CPS minipacket switching unit, which

is used in association with the Multiplexing Unit (MXU) for facilitatingconnections between the main Switch Fabric SFU and the low-to-moderate bit-rate units (control computers, signal processing unitsand low-bit-rate network interface units). The function of the A2SU isto limit the transfer delay and ensure the general efficiency of thetransportation of information in these connections by dividing theincoming ATM cells up in AAL2 Type 2 CPS minipackets andreorganising these into new ATM cells, which it sends further.

Redundancy: SN+

Type: Switching unit, subunit of MXU

Plug-in Unit: AL2S-D / AL2S-B / AL2S-A / AL2SAAL2 Switching Unit


Location: CAMA subrack 3-4, all CAMB, CAMC subracks: 4 units per subrack


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Figure 21. A2SU

3.4 Timing, Power Distribution and HardwareManagement Subsystem

The timing, power supply and hardware management subsystems form thelowest level in the computing hierarchy of the IPA2800 network elements.Each subsystem is composed of a redundant master unit and a duplicateddata distribution/collection bus. In each case, the bus actually extends through

some lower level units to virtually all of the exchange's plug-in units, which areequipped with dedicated hardware blocks supporting the core parts of thesubsystem.

The network element's clock distribution and Hardware Managementsubsystems (TBU), use the same two types of plug-in units, namely:

TSS3, Timing and Synchronisation, SDH Stratum 3

TBUF, Timing Buffer.


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The clock system meets Stratum 3 level accuracy requirement, as defined inBellcore TA-NWT-1244 standard.

The Power Distribution Subsystem in the exchange uses two types of plug-inunits, namely:

PD30, Power Distribution Plug-in Unit 30 A

CPD120-A, Cabinet Power Distributor 120 A.

3.4.1 TBU, Timing and Hardware Management Bus Unit

The Timing and Hardware Management Bus Unit is responsible for thenetwork element synchronization, timing signal distribution and messagetransfer functions in the hardware management system. The TBU is a

duplicated functional unit that consists of two plug-in units in each subrack aswell as a serial bus spanning all plug-in units of the network element. The twoplug-in units, the Timing and Synchronisation, SDH Stratum 3 (TSS3)andTiming Buffer (TBUF)and their functions are described below.

3.4.1.1 TSS3, Timing and Synchronisation, SDH Stratum 3

Purpose: The TSS3s generate the clock signals necessary for synchronisingthe functions of the MGW. Normally, the TSS3 operates in asynchronous mode, that is, it receives an input timing referencesignal from an upper level of the network and adjusts its localoscillator to the long time mean value by filtering jitter and wander

from the timing signal. It transmits the reference to the plug-in unitsin the same subrack (all plug-in units are equipped with onboardPLL blocks), as well as to the TBUF units, which distribute thesignals to units not directly fed by the TSS3s. The TSS3 has inputsfor both synchronisation references from other network elements(via the network interfaces) and for those from external sources(options are 2,048 kbit/s, 2048 MHz or 1.54 MHz)If all synchronisation references are lost, the TSS3 can operate inplesiochronous mode, that is, by generating independently thesynchronisation reference for the units in the exchange.The TSS3s are also involved in the functioning of the HMS bus.They collect the alarms from the PIUS in the same subrack and

transfer them further to the HMS master net, which brings thealarms to the appropriate OMU.

Redundancy: 2N

Type: Functional unit with TBUF units as sub-units

Plug-in Unit: TSS3Timing and Synchronisation, SDH Stratum 3


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Interfaces: Synchronisation reference interfaces:three line inputs (from STM-1 or TDM lines)two external inputs (2,048 kbit/s, 2048 MHz, 1.54 MHz

eight outputs to cabinet timing busesone output to subrack timing busAlarm interfaces:one input from PIUs in same subrackone output to OMU via HMS Master Net

Location: One unit in each of CAMA subracks 1-2

3.4.1.2

3.4.1.3 TBUF, Timing Buffer

Purpose: The TBUF unit is a clock buffer which distributes thesynchronisation signals generated by the TSS3s to plug-in units notdirectly fed by the TSS3s.Like the TSS3s, the TBUFs are also involved in the functioning ofthe HMS bus. They collect the alarms from the PIUS in the samesubrack and and transfer them further to the HMS master net, whichbrings the alarms to the appropriate OMU.

Redundancy: 2N

Type: Functional unit, sub-unit of the TSS3

Plug-in Unit: TBUFTiming Buffer

Interfaces: Synchronisation reference interfaces:

one input from TSS3 or another TBUF

one output to subrack timing bus

one output to another TBUFAlarm interfaces:

one input from PIUs in same subrack

one output to OMU via HMS Master Net

Location: One unit in each of CAMA subracks 1-2;two units in all other CAMA, CAMB and CAMC subracks.


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TSS3 TBUF

Figure 22. TBU

3.4.1.4 Connection principle and redundancy for the timing and synchronisationdistribution bus routing

The MGW has two separate timing and synchronisation distribution buses toensure 2N redundancy for the intermal timing signal distribution. Each bus hasits own system clock (a TSS3 plug-in unit), distribution cabling and timingbuffers (TBUF plug-in units).

The two TSS3 units backing each other up are placed in different subracks(subracks 1 and 2), each of which is powered by a power supply plug-in unit ofits own to ensure redundancy for the power supply. Each of these subracks isalso equipped with a TBUF plug-in unit, which connects the equipment in thesubrack to the other clock distribution bus. The CAMA subracks 3 and 4 andall CAMB subracks, on the other hand, have all two separate TBUF unitswhich connect to different clock distribution buses by means of cables of their

own.

The clock distribution principle in the exchange is shown in the figure below.


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Figure 23 Routing of the duplicated clock distribution bus

3.4.2 HMS subsystem

The hardware management subsystem has three hierarchically organisedlayers of equipment. The highest level in the hierarchy is formed by theHardware Management Master Nodes (HMMNs), one in each OMU, whichcontrol the whole subsystem. The TSS3s and TBUFs in the subracks haveseparate Hardware Management System Bridge nodes (HMSBs), which formthe next, intermediate level in the hierarchy. As the name suggests, they serveas bridges which connect HMMNs to the lowest-level blocks in the hierarchy,

Hardware Management System Slave Nodes (HMSSs). Implemented asdedicated hardware blocks in all plug-in units, the latter are independent fromthe other blocks of the plug-in unit, for example, in terms of the power supply.

A block diagram which illustrates the HMS subsystem implementation isshown in the figure below.


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Figure 24 Block diagram of the HMS subsystem

The MGW has also two mutually redundant hardware management buses,which are implemented by means of the same plug-in units as the timing andsynchronisation buses, that is, the TSS3s and the TBUFs. The routing of thehardware management buses, however, differs somewhat from that of thetiming and synchronisation buses.

The Hardware Management Bus is organised in such a way that the TSS3sand TBUFs are on an equal level of the subsystem; both act as parallel HMSbridges which connect the plug-in units in the same subrack to the HMSmaster net, which brings the alarms to the appropriate OMU.


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Figure 25. Routing of the duplicated HMS bus

3.4.3 Power Distribution Subsystem

Purpose: The Power Distribution Subsystem distributes the -48V power fromthe rectifiers or batteries to the equipment inside the MGW cabinets.This subsystem consists of two CPD120-A power distribution panelsat the top of each cabinet, one PD30 power distribution plug-in unitin each subrack and the associated cabling. See the Cable Lists fora visual representation of the power feed to each subrack.The PD30 unit also controls the cooling equipment of its own

subrack on the basis of messages sent by the OMU.

Redundancy: Power distribution subsystem is duplicated by providing twoindependent feeding input branches from cabinet level to plug-inunit level.

Type: Subsystem

Plug-in Unit: CPD120-ACabinet Power Distributor 120 A


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PD30Power Distribution Plug-in Unit 30 A

Interfaces: One input for each of the two CPD120-AsFour outputs to subracks in CPD120-AOutputs to four groups of plug-in units (in PD30)Fan tray control and alarm interface

Location: Either one CPD120-A unit or CPD120-A units at the top of eachcabinet; one PD30 plug-in unit in each subrack

PD30

Figure 26 Power distribution system

3.5 EHU, External Hardware Alarm Unit

Purpose: The purpose of External Hardware Alarm Unit is to receive externalalarms and send indications of them as messages to OMU-locatedexternal alarm handler via HMS.A second function is to drive the optional External Hardware Alarmpanel (EXAU-A / EXAU), the cabinet integrated lamp, CAIND alarmindicator located on the top of CAMA cabinet and possible otherexternal equipment.


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Redundancy: None

Type: Functional Unit

Plug-in Unit:EHATExternal Hardware Alarm Terminal

Interfaces:

Interfaces include 32 voltage controlled inputs, 8 current controlledinputs, 16 general purpose 20 mA current outputs. Connections toexternal devices via cabling panel 1 located in the rear of the CAMAcabinet.

Location: One unit per network element, in CAMA subrack 2,3

Figure 27. EHU


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3.5.1 EXAU, External hardware alarm panel

The optional peripheral EXAU provides a visual alarm of the fault indications

of the MGW. The EXAU panel is located in the telecommunications siterooms, outside the network element.

3.5.2 CAIND, Cabinet alarm indicator

The CAIND is located on the top of CAMA cabinet and provides a visual alarmindicating the network element with a fault.


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4 MGW Hardware Configuration

The MGW have three different equipment cabinets, namely:Cabinet Module A (CAMA)Cabinet Module B (CAMB)Cabinet Module C (CAMC)

The subracks are assigned with numbers starting from 1 at the top of eachcabinet and ending to 4 at its bottom. The following figure shows all theequipment cabinets and cabling cabinets in the MGW.

Figure 28 MGW cabinets and subracks


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The configurations of the MGW support left-to-right or alternatively right-to-leftcabinet installation as shown by the figure below. The cabinets must alwaysbe installed into a single row.

Figure 29 MGW cabinet instillation (U4.0)

All the MGW configurations have the CAMA cabinet, and the first twosubracks in the CAMA cabinet (the base module) are the same for allconfigurations. All other subracks are equipped according to the configurationand capacity needed, the main difference between the configurations beingthe number of TCU/A2SU units as well as type and number of interface units.

The minimum configuration of the MGW features only the CAMA cabinetwhere subracks 1-2 are fully equipped and subracks 3-4 are partiallyequipped. TBU and PD30 units are always equipped to empty subracks in allthree cabinets.

For expansion, the MGW provides roughly two kinds of capacities that can beincreased: interface capacity and user plane processing (DSP) capacity.Expanded capabilities can be obtained by adding new cabinets and the


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necessary plug-in units in the empty subracks according to the chosenconfiguration. The processing capacity of the MGW is increasedby adding TCUs, ISUs and MXUs. The interface capacity is then added

independently by adding NIWU, NIP1, NPS1P/NPS1, NPGEP andIWS1E/IWS1T units.

Figure 30. CAMA subrack 1 (base module)


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Figure 31. CAMA subrack 2 (base module)

In U4.0, there are three subrack configuration alternatives. The main

difference between the subrack configurations is the number ofTCU/A2SU units and number and type of interface units.

Subrack configuration with IWS1E/T

Subrack configuration with NIWU/NIP1

Subrack configuration with TCU

General principles

NIWU/NIP1 and IWS1E/T units cannot be equipped in the samesubrack at the same time

NIP1 units are equipped before NIWU units.

ISUs cannot be equipped in a subrack without an MXU pair:

Units are equipped in index order

The index order of TCU/A2SU units runs from subrack tosubrack, top to bottom


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The index order of NIWU units runs in two sets: from slots 1-3 / subrack to subrack, top to bottom, from slots 4-6 /subrack to subrack, top to bottom

The index order of IWS1E/T units runs in two sets: from slots1-3 / subrack to subrack, top to bottom slot 4, subrack tosubrack, top to bottom

ISUs are equipped in index order starting from the lowestindex, up to the last subrack where MXUs are equippedadditional ISUs are equipped in CAMA subrack 1-2

Figure 32 Equipment in CAMB subracks 14


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5 Nokia MGW Interfaces

5.1 Physical connections in Nokia MGW

Since Nokia MGW can be used in both 2G and 3G environment, it providesflexible alternatives for both TDM- and packet-based interfaces. MGWprovides the possibility to combine both ATM and IP interfaces in one elementaccording to network demands. All interface types can be scaledindependently, thus making it possible to have only those interfaces which arerequired in each element

ATM used for:

Iu-interface

ATM backbone

TDM used for:

A-interface

PSTN

IP used for:

IP user plane to backbone

SIGTRAN H.248 control

MGWMGW

TDME1/T1/JT1

STM-1/OC3

IP

Ethernet

ATM

E1/T1/JT1 (IMA)

STM-1/OC3

Figure 33. Multimedia Gateway interfaces


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5.2 ATM Backbone in Nokia MGW

The Nb reference point in the 3GPP model describes the interface betweentwo MGWs. Nokia gateway utilises several ATM adaptation layer protocols formedia transport:

AAL1 PVC/SVC for circuit-switched data and for PCM-coded speech

AAL2 for compressed speech and for non-real-time data transport

AAL5 PVC/SVC carries user and control data and transports IP traffic

ATM forum has specified UNI 4.0 and this protocol is used for creating SVCconnections from gateway to border ATM backbone element.

Physical connection is STM-1 VC-3 or VC-4 confirming ITU-T G.957 S-1.1.Four STM-1 interfaces per unit are provided, and transmission medium issingle mode fiber.

5.3 IP Backbone in Nokia MGW

Nokia Multimedia Gateway provides the possibility to use IP backbonenetworks as such for transporting media for circuit-switched connectionsbetween gateways (Nb reference point). In All-IP mobility core networks, theIP backbone is used to transport speech traffic between the GGSN andMultimedia Gateway (Gi reference point). The natural choice for transmittingmedia over IP in backbone connections is the IP over SDH/Sonet.

Media over the IP backbone is transferred using the real time protocol (RTP).RTP provides end-to-end delivery services for data with real-timecharacteristics, such as interactive audio. These services include payload type

identification, sequence numbering, time stamping and delivery monitoring.This makes RTP an ideal protocol for real-time applications such as voice overIP (VoIP).The network interface unit in the Nokia Multimedia Gateway provides 2 GigabitEthernet interfaces (2 x 1000 Base-T Ethernet electrical or optical)


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MGW

2*1GB

NPGEPIP

Backbone

IP BB interface for userplane

NPGEP (PIU:NP2GE)

2*1GB Electrical or Optical

Ethernet

IP BB interface for userplaneNPGEP (PIU:NP2GE)

2*1GB Electrical or Optical

Ethernet

SFU

Figure 34. IP connectivity for user plane

5.4 TDM Backbone in Nokia MGW

Nokia Multimedia Gateway can be easily adapted to the existing mobileenvironment by using the existing TDM-based transmission network also inthe Nb interface. If the existing transmission network is cost-efficient, and ifthere are no other reasons (such as need for more capacity) for changing thetransmission network type, it does not prevent the operator from taking the

Rel.4 network into use.

Upgrading to the Rel.4 level inevitably requires changes in the networkbecause the control plane and user plane traffic are separated. The TDMbackbone makes it possible to reduce the number of simultaneous changeswhen upgrading the network to the Rel.4 level. This way, the Rel.4deployment can be divided into several easily controllable phases, thuslowering, for example, schedule risk in the network installation phase.Changing the backbone to a packet-based one for reaching all Rel.4 benefitscan then be scheduled to a later phase according to operator-specific plans.

5.5 Nokia MGW control interface

The Mc reference point in the 3GPP model describes the interface betweenthe MGCF and the Multimedia Gateway, between the MSC Server andMultimedia Gateway, and between the GMSC Server and MultimediaGateway. It is fully compliant with the H.248 standard work carried out by theIETF MEGACO workgroup.


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5.5.1 MGW control protocols (MEGACO/H.248)

MGCP and MEGACO/H.248 are protocols used between the Media Gateway

Controller and the Media Gateway. The MEGACO protocol is also known asH.248 as it is being developed co-operatively between the IETF MEGACOworkgroup and the ITU-T. Currently, Nokia officially supports MEGACO asdefined by the ITU.

The gateway supports the MEGACO protocol to perform the following tasks:

reserve and connect terminations

connect or release echo canceller to terminations

connect or release of tones and announcements to terminations

send/receive DTMF tones

5.6 Iu interface in Nokia MGW

The Iu-CS interface is used to interconnect the UMTS RAN towards the NokiaMultimedia Gateway. The interface is ATM-based, either STM-1 or TDMconnections can be used (as in Multimedia Gateway Rel.99). Theseconnections can be used to Iu-CS traffic. Also Iu-PS traffic towards packet

core can be routed via the same physical medium to Multimedia Gateway andcross-connected in the Multimedia Gateway to SGSN.

AAL2 is supported over Iu-CS for user plane and that traffic is routed todestination network interface (another Iu, PSTN, or ATM/IP backbone) directlyfrom the Multimedia Gateway.AAL5 is used for control plane. This RANAP signalling is routed from the RNCto the Multimedia Gateway where it is extracted and sent to the MSC Server(typically) over Ethernet.

Physical connection is STM-1 supporting VC-4 and 3 x VC-3 formatsconforming ITU-T standard G.957 S-1.1. Eight STM-1 interfaces per unit are

provided, and transmission medium is single mode fiber.

Another option is to use TDM interfaces for ATM connectivity. Up to 16E1/T1/JT1 ATM interfaces can be used to form one ATM IMA (Inverse MultipleAccess) interface over conventional PCM connections where the bandwidthrequirements are low and capacity and cost optimisation is necessary.


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SFU

NPS1

RNC/MGW

RNC

SDH/Sonet

MGW

NIP1

MXU

18*E1 in oneIMA group

RNC

STS1

Iu & ATM BB Interface

NPS1/NPS1P (PIU:NP8S1)

8*STM-1/OC-3 interfaces

per unit


NPS1/NPS1P (PIU:NP8S1)

8*STM-1/OC-3 interfaces

per unit


NIP1 (PIU:NI16P1A)

16*E1/T1/JT1 interface with

IMA function per unit


NIP1 (PIU:NI16P1A)

16*E1/T1/JT1 interface with

IMA function per unit

Figure 35. Iu interface options

5.7 A-interface in Nokia MGW

The A-interface belongs to the family of SS7 signalling system and is used fortransmission of speech, data and signalling between MSC and BSS. A-interfaces are connected either to the MSC Server or to Multimedia Gateway,depending on the operator needs.

If the A-interface is connected to Multimedia Gateway, then BSSAP signallingis routed to MSC Server and handled there.

The physical interface used is E1/T1/JT1.

5.8 Interface towards PSTN and other TDM-basednetworks in Nokia MGW

Multimedia Gateway typically serves as an interconnect point between twodifferent types of networks, providing an interconnection for both signallingand media between TDM-based and packet (or cell)-based networks.


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All TDM-based networks are considered identical in the Multimedia Gatewayfrom the signalling point of view. In case a call is routed from a packet-basednetwork towards the PSTN interface, then echo cancellers are connected from

Multimedia Gateway to the speech path to prevent the electrical echogenerated by the interconnection.

Signalling towards other TDM networks is handled using SS7 standards.

ISUPThe ISDN user part (ISUP) provides facilities for handling the ISDN bearerservices (including Telephony) and supplementary services for voice and dataapplications. The Message Transfer Part is used to carry the information of theISUP message.

MAP

The mobile application part (MAP) protocol is specifically designed for non-calltransactions between the GSM switching and database elements that supportthe roaming of mobile subscribers.

TUPThe telephone user part (TUP) provides facilities for handling telephone callcontrol functions in national and international networks. The Message TransferPart is used to carry the information of TUP messages.

The physical interface towards other TDM networks is E1/T1/JT1.

Alternatively, STM-1 VC-12 (STS-3 VC-11) is provided for environmentswhere large interconnect points are desired. STM-1 VC-12 allows connectingof 63 E1 interfaces (or alternatively 84 T1 interfaces) over a single fiber.


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Glossary

2G 2ndGeneration mobile phone network

3G 3rd

Generation mobile phone network

3GPP Third Generation Partnership Project

AAL ATM Adaptation Layer

AEMF ATM Equipment Management Function

AMR Adaptive Multi-rate Speech Codec

ATM Asynchronous Transfer Mode

BSSAP Base Station Subsystem Application Part

CACU Control and Administrative Computer Unit

CAMA Cabinet Module A

CAMB Cabinet Module B

CAMC Cabinet Module C

CM Central Memory

CMISE Common Management Information Service Element

CORBA Common Object Request Brokerage Architecture

CPS Connection Processing Server

CPU Central Processing Unit

CS Circuit Switched

DSP Digital Signal Processing

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

HMMN Hardware Management Master Node

HMS Hardware Management System

HMSB Hardware Management System Bridge node

HMSS Hardware Management System Slave Node

HSS Home Subscriber Server

IMAInverse Multiplexing for ATM


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IMSIInternational Mobile Subscriber Identification

INIntelligent Network

INAP Intelligent Network Application PartIP

Internet ProtocolIP-NIU

can be either IPFE/IPFEP, IPGE/IPGEP or IPGO/IPGOPISU

Interface Control and Signalling UnitIWS1

Network Interface Unit STM-1/OC-3M3UA

MTP3 User AdaptationMAP

Mobile Application PartMGCF

Media Gateway Control Function

MGWMultimedia Gateway

MMIMan Machine Interface

MMLMan Machine Language

MSCMobile Switching Centre

MSSMSC Server

MSSuUpgraded MSC Server

MTPMessage Transfer Part

NEMU

Network Element Management UnitNIP1

Network Interface Unit PDHNIS1

Network Interface Unit STM-1NIWU

Network Interface Unit TDMNPC

Network Parameter Control ( used in NNI)OAM

Operations, Administrations and MaintenanceO&M

Operation & MaintenanceOMU

Operational And Maintenance Unit

PDH Plesiochronous Digital HierarchyPLMN

Public Land Mobile NetworkPSTN

Public Switched Telephone NetworkPVC

Permanent Virtual ConnectionRAN

Radio Access NetworkRANAP

Radio Access Network Application Part


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RNCRadio Network Controller

RTPReal Time Protocol

SCCP Signalling Connection PartSCSI

Small Computer Systems InterfaceSCTP

Stream Control Transmission ProtocolSDH

Synchronous Digital HierarchySIGTRAN

Signalling TransportSIP

Session Initiated ProtocolSPMU

Signal Processing Management UnitSS7

Signalling System # 7SVC

Switched Virtual ConnectionTBU

Timing and Hardware Management Bus UnitTBUF

Timing BufferTMSI

Temporary Mobile Subscriber InformationT-SGW

Transport Signalling GatewayTSS3

Timing and Synchronisation, SDH Stratum 3UE

User EquipmentUMTS

Universal Mobile Telecommunication SystemUPCUsage Parameter Control ( used in UNI )

USBUniversal Serial Bus

UTRANUMTS Terrestrial Radio Access Network

VANUVoice Announcement Unit

VC-3/ VC-4/VC12

Virtual Container , structural part of an STM-1 frame consisting of pathoverhead and a container

VMSSVisited MSC Server

04 Cn34014en30gln1 Mgw for Mss

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