05 tm2110eu01tm 0003 gsn architecture

8/20/2019 05 Tm2110eu01tm 0003 Gsn Architecture

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GSN Architecture Siemens

TM2110EU01TM_00031

Contents

1 System Functions 3

1.1 System Functions 4

2 GSN Architecture 9

2.1 Serving GPRS Support Node SGSN 102.2 Gateway GPRS Support Node SGSN 18

2.3 MainStreetXpress 36140/36144 26

2.4 ATM MP Platform / 36190 28

2.5 Integration of GPRS in Existing GSM Networks 36

GSN Architecture


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Siemens GSN Architecture

TM2110EU01TM_00032


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TM2110EU01TM_00033

1 System Functions

Siemens

GPRS-Support Node

GSN

System Functions

Fig. 1


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TM2110EU01TM_00034

1.1 System Functions

In GR2.0 SGSN and GGSN nodes can be co-located (xGSN) or separate units. Theyhave to provide a large number of system functions which have to be implemented.The system functions are grouped together in the following functional areas:

Packet Handling; Packet Handling includes all functions that are necessary for uplinkand downlink transfer of packet data units by the SGSN and GGSN. In contrast toconnection-oriented networks, in packet networks such as GPRS it is necessary toroute all traffic data packets separately to their destination.

Mobility Management; GPRS Mobility Management (GMM) enables subscribers toattach themselves to the GPRS network (GPRS attach). GMM allows the protectionof the signaling data and traffic data that is to be transmitted and registers the

subscribers’ location. Traffic data can only be transmitted with an existing MMcontext. GMM functions are: attach/detach incl. P-TMSI allocation/reallocation,security (authentication & service request validation), location management, paging,GPRS subscriber database SLR (SGSN Location Register).

Session Management: Session Management SM refers to the handling of PDPcontexts in SGSN and GGSN, and in GR1.0 it covers the activation and deactivationof PDP contexts.

Protocols & Interfaces; in GR1.0 the area Protocols & Interfaces covers theimplementation of the protocols for the interfaces Gi, Gb and Gr.

Operation; in GR1.0, Operation covers the functions: Configuration Management, Accounting Management, Performance Management, Security Management as wellas Fault & Maintenance Management

Maintenance; this includes functions like those for the EWSX project: SystemMaintenance (commissioning and maintenance of operation), Trunk LineMaintenance (detection, verification and clearance of faults in the transmissionnetwork, performance measurements,...) and Application Software Maintenance(GPRS Maintenance).


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TM2110EU01TM_00035

System Functions (GR2.0)

Functions for UL- & DL-packet transmission via

SGSN & GGSN Packet Dispatching PD• Packet Routing & Transfer • SNDCP, LLC

• local TPL (throughput limiter)

• Buffer Management

Packet Handling

GPRS Mobility Management: GMM• Location (RAI, CGI) Registration & Storage (SLR: SGSN Location Register)

• MM-context prerequisite for data transmission• attach / detach• P-TMSI allocation / reallocation

• Authentication & Authorisation• Paging (PS & CS)

Mobility Management

PDP context-handling in SGSN & GGSN• Activation / De-activation

Session Management

Realises protocols for

• Gi-Interface ISP/PDN• Gn-interface SGSN/GGSN

• Gb-interface PCU/BSS• Gr-interface HLR• Gp-Interface GGSN, other PLMN

• Gs-Interface VLR• Gd-Interface SMS

Protocols & Interfaces

Network Management functions• Configuration Management• Accounting Management

• Performance Management• Security Management• Fault & Maintenance Management

(GPRS specific alarms, tests,..)

Operation

• System Maintenance• (Start / Operation maintenance)

• Trunk Line Maintenance• Application Software Maintenance

Maintenance

Fig. 2 System functions in GR2.0


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TM2110EU01TM_00036

Generation of Session Data Recording

In GPRS charging is different from GSM. In GSM the anchor MSC collects chargingdata. In GPRS billing is becoming more complex due to the fact that SGSN and

GGSN have to collect charging data. Billing is out of the scope of this course,nevertheless an overview of the Siemens solution is given.

Detailed session data are generated for the GPRS mobile subscriber during everysession transaction. The Siemens GPRS solution supports time and volumedependent charging.

All charging relevant data are collected for each GPRS MS in the SGSN and theGGSN to be processed in the Administration and Billing Center ABC. This is done bya Charging Gateway Function CGF according to the GSM standard.

The fundamental tasks of the CGF are merging charging data into records CDR,

record formatting and data transfer to the billing system.CDRs can be used for GPRS MS billing or inter operator billing via GPRS MS billinginformation.

The CGF supports e.g. charging for PDN contexts of GPRS MS.

Charging information is collected by SGSN and GGSN and therefore there are tworecord types for PDP contexts: the SGSN and the GGSN context record.

The record sequence per PDP context can consist of one or more records.Therefore each record is assigned with a unique sequence number (the last one ismarked) and a unique charging-ID CID and the GGSN address. The CID is

generated by the GGSN and passed to the SGSN. That enables the billing center tocollect all relevant records from different network nodes to charge for one activatedPDP context. The SGSN collects information related to the usage of radio network,

whereas the GGSN is responsible for charging data related to external data networks(e.g. "internet").

The SGSN PDP context record contains served subscriber related data (e.g. IMSI,GPRS MS network, RAI, LAC, CI), control data (e.g. charging ID, record sequencenumber), PLMN data (SGSN and GGSN address, PDP address and type), servicemeasurement data (record opening time, context duration, up- and downlink datavolume, QoS parameters)

The GGSN PDP context record contains served subscriber related data (e.g.IMSI,...), control data (e.g. charging ID,...), PLMN data (SGSN and GGSN address,

Access Point Name APN,...), service measurement data (record opening time,...).

The CDR does not compute subscription fees. The tariff of the operator might bechanged very often and even depend on subscriber issues and location. Due to thisfact and to offer solutions for time dependent charging the feature "tariff timeswitch" enables the ABC to charge any volume count of the CDRs as administratedin tariff periods.


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TM2110EU01TM_00037

CDR #3

CID

GGSN No.

IMSI

PDP No.

...

Generation of Session Data Recording

GPRS MS SGSN

ABC

• GPRS MS

> activates PDP context

• SGSN

> creates routing context

• GGSN > sends CID to SGSN

GGSN/SGSN:

collect charging data

• PDP No.

• PDP type (IPv4, ...)

• data volume UL / DL

• opening time/release

• IMSI

• QoS parameter

• GPRS MS HPLMN

...

CID

CDR #3

CID

SGSN No.

IMSI

PDP No....

CDR #2

CID

SGSN No.IMSI

PDP No.

...

CDR #1

CID

SGSN No.

IMSI

PDP No.

...

CDR #2

CID

GGSN No.

IMSI

PDP No.

...

CDR #1

CID

GGSN No.IMSI

PDP No.

...

GGSN

#1, #2,... : record sequence number

CID: (unique) charging IDABC: administration and billing center

CDR : charging data record

feature “ tariff time switch“

=> time dependent billing

Fig. 3 Generation of session data recording, "Charging" / "Billing"


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TM2110EU01TM_00039

2 GSN Architecture

Siemens

GPRS-Support Node

GSN

GSN Architecture

Fig. 4


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TM2110EU01TM_000310

2.1 Serving GPRS Support Node SGSN

Small / Large ConfigurationThe SGSN is responsible for the BSSs in its service area and needs interfaces toother SGSNs and GGSNs. It is a packet switch on the basis of ATM protocol.

The Siemens solution is a modular system in order to offer different configurations for the different needs of network providers.

The hardware is divided into two main parts:

ATM switching network ASN (based on EWSD SSNC V13/36190 platform),

ATM access multiplexer (based on 36140 platform).

The SGSN has to maintain connections to other network elements:

Line interface circuits LICs connect the SGSN with other SGSN (Gn) and GGSN(Gn),

LICs also provide the interfaces Gb (BSS/PCU), Gd (SMS-C), Gr (HLR), Gs (VLR),Gp (external PLMN/SGSN).

Depending on the requirements of customers and on the interface that is to berepresented different LICs are available (LIC:E1, LIC:STM1, LIC:FR, LIC:ETH)representing the different layers 1/2 (according to the OSI model).

The processors that are used in the 36190 are called main processors MP andprocessors inside the 36140 are named server processors SP.

To provide the different capacities in switching / handling of subscribers required bythe network operators the modular system will be modified in the hardwareconfiguration.

The number of LICs, SPs, and MPs used for these two options is to be found in thefollowing depiction.


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TM2110EU01TM_000311

#7 LIC

MP: SA

MP: ACC

MP: MM

ASN

Seabridge 36144 No: 1 & 2Gb

GnLIC* SP:GTP

STM1-LICSP:BSSGPFR-LIC

LIC* SP:GTP

SP:BSSGPFR-LIC STM1-LIC

E1-LIC

STM1-LICSTM1-LIC

GPRS-Node SGSN GR2.0 Small / Large Configuration

3x / 23 xMP: PD/SH

MP: SM

MP: SLT

Basic Components:

36140: ATM Access Switch

36190: EWSD SSNC V13 Platform

ASN: ATM Switching Network

LIC: Line Interface Circuits

MP: Main Processor

SP: Server Processor

PD: Packet Dispatching, SH: Session Handling,

ACC: Accounting, SLT Signaling Link Terminal

MM: Mobility Management

Gd, Gr, Gs

Interface

36140

36190

1x / 2 x

1x / 2 x1x / 4 x

1x / 2 x1x / 2 x

Fig. 5 Configuration of an SGSN, general layout, "Small / Large Configuration"


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TM2110EU01TM_000312

Block diagram of SGSN

two platforms are to be found inside the node, the ATM MP platform (EWSX,36190) and the ATM SP platform (MainStreetXpress, 36140)

the 36140 is responsible for connections to other SGSN, GGSN (Gn-interface) andto the BSSs in the service area of this SGSN (Gb-interface)

LICs provide the physical connections to other network elements and the internalinterface to the ATM MP platform. The LICs are different in hardware for differentlayer 1/2 configurations (ATM/FR, STM-1/E1/T1, ...)

Server Processors SP maintain the interfaces Gb (SP-BSSGP), Gn (SP-GTP) for the ATM SP platform

Main Processors MP are different in hardware, they are based on main processor unit type D (MPUD, Intel Pentium II, 2 GByte memory, level 2 cache 256 kByte)

The MP-SA is a stand-alone variant with OA&M interfaces (disks, Ethernet, radioclock, ALIB). This board boots the system and loads the dependent platforms.When the system is up, mainly system administration and maintenance tasks runon this platform.

MP-AP is the dependent processor platform which cannot boot up itself. Thisplatform is used to run applications.

Main Processors MP are different in software load, e.g. :

MP:PD/SH packet dispatching/session handling, MP:MM mobility management,MP:CAP Camel application part (based on MP-AP hardware),

MP:OAM operation, administration and maintenance, MP:STATS statistics for O&M (based on MP-SA hardware).

The main control processor MCP inside the 36140 is the central control unit of thissystem


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TM2110EU01TM_000313

Block Diagram of SGSN

SGSN

LIC:STM1

MCP

LIC:STM1

MP:SM

SC Switch

Commander

to GGSN

Gn-interface

to HLR/AC, SMS-C, ...

Gr-, Gd-interface,...

ATM SP

platform

ATM SP

platform

ATM MP

platform

LIC:STM1

MP:ACC

MP:OAM

MCP

LIC:STM1

36190

36140

36140

TCP/IP

MCP: Main Control Processor, SLT: Signalling Link Terminal (“SS7“),

SP: Server Processor, PD: Packet Dispatching, SH: Session Handling,

GTP: GPRS Tunneling Protocol, ACC: Accounting

to BSS

Gb-interface

MP:PD/SHLIC:E1

MP:SLT

SP:GTP

LIC:FR

SP:BSSGP

MP:MM LIC:GTP

A

S

N

Fig. 6 Block diagram of SGSN


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TM2110EU01TM_000314

Rack Layout of the SGSN "Small Configuration"

The SGSN can use racks with 7 / 8 feet height with 4 shelves per rack each (height2250 / 1930 mm, width 900 / 900 mm, depth 600 / 600 mm

One rack represents the 36190, the ATM MP platform, the other one the 36140, the ATM SP platform.

Inside the rack for the 36190 platform the two shelves in the middle are occupied bythe ATM switching network (ASN shelves). The ASN is doubled for redundancyreasons and therefore two shelves are needed.

The upper rack (SCE shelve "extension") is used for extension modules whereas theone at the bottom is reserved for the (mandatory) basic equipment (SCB "basic").

The SCE and the SCB shelf are used for Main Processors, LICs, ATM multiplexerstype E (AMXE) and devices for data storage (MDD, MOD).

The rack of the ATM SP platform contains a DC/AC converter for power supply andtwo shelves for the 36140 which is doubled for redundancy reasons too. The shelvesare equipped with LICs for the internal connection to the ATM MP platform (STM1)and for the interfaces to GGSN and BSS (FR).

This small configuration uses 1 LIC:FR, 1 SP:BSSGP, 1 LIC to GGSN, 1 SP:GTP for the ATM SP platform and 3 MP:PD/SH, 1 MP:MM inside the 36190.This provides athroughput of 3 Mbit/s sufficient for approximately 150000 subscribers or 100000

PDPs respectively. These parameters for the performance are based on theassumptions depicted in the following figure 5.


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TM2110EU01TM_000315

SG SN Basis

B r e a k e r - P a n e l

Fan-T ray

BAS _RACK S CE (0 )

M : L I C - S T M 1

M : L I C - S T M 1

M : M P - A C C

M : M P - A C C

M : M P - M M

M : M P - M M

M : A M X E 0

M : A C C G 0

M : A C C G 1

M : A M X E 1

M : M P - S L T

M : M P - S L T

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

1 0 3

1 1 5

1 2 7

1 3 9

1 5 1

1 6 3

1 7 5

1 8 7

2 1 1

2 3 1

2 5 1

2 7 1

2 9 1

3 0 3

3 1 5

3 2 7

3 3 9

3 5 1

3 6 3

3 7 5

IDF

B AS _R A C K AS N E (1 )

M : A C C G ( X 4 0 1 )

M : G M X E ( 0 )

M : A S M G 1 6 / 1 6

M : P S A G

1 1 3

1 4 1

1 6 7

1 9 3

2 1 9

2 4 1

2 7 7

2 9 5

3 2 1

3 4 7

3 7 3

B AS _R A C K AS N E (0 )

M : A C C G ( X 4 0 1 )

M : G M X E ( 0 )

M : A S M G 1 6 / 1 6

M : P S A G

1 1 3

1 4 1

1 6 7

1 9 3

2 1 9

2 4 1

2 7 7

2 9 5

3 2 1

3 4 7

3 7 3

IDF

B A S _ RA CK SC B

M : L I C

# 7

M : L I C

# 7

M : M P - S M

M : M P - S M

M : A M X E 0

M : A C C G 0

M : A L I B

M : A C C G 1

M : A M X E 1

M : M O D

0

M : M D D

0

M : M P - S A 0

M : M P - S A 1

M : M D D

1

M : M O D

1

1 0 3

1 1 5

1 2 7

1 3 9

1 5 9

1 7 9

1 9 1

2 0 1

2 2 1

2 4 3

2 7 5

2 9 9

3 1 9

3 3 9

3 6 1

Fan-Box

Breaker-Panel

Fan-Tray

36140 SGSN

L I C - F R

S P - B S S G P

L I C - S T M 1

S P - G T P

L I C *

36140 SGSN

L I C - F R

S P - B S S G P

L I C - S T M 1

S P - G T P

L I C *

DC/AC Converter

Fan-Tray

3614036190

GPRS-Node SGSN GR2.0 ‘Small Configuration’

redundancy: doubling of cards (MPs, SPs, ...) / shelves (ASN, 36140)

assumptions:

1 MP:MM

150 000 subscriber 1 MP:PD/SH

50 000 subscriber ( 60% attached )

1 MP:ACC / 1 SP:GTP

100 000 PDPs1 MP:PD/SH

1 Mbit/s throughput

configuration parameters:

150 000 subscribers, 100 000 PDPs,

3 Mbit/s throughput

Fig. 7 Rack layout of SGSN GR2.0 "Small Configuration" with ASN


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TM2110EU01TM_000316

Rack Layout of the SGSN "Large Configuration"

The SGSN can use racks with 7 / 8 feet height with 4 shelves per rack each (height2250 / 1930 mm, width 900 / 900 mm, depth 600 / 600 mm

One rack represents the 36190, the ATM MP platform, the other one the 36140, the ATM SP platform.

Inside the rack for the 36190 platform the two shelves in the middle are occupied bythe ATM switching network (ASN shelves). The ASN is doubled for redundancyreasons and therefore two shelves are needed.

The upper rack (SCE shelve "extension") is used for extension modules whereas theone at the bottom is reserved for the (mandatory) basic equipment (SCB "basic").

The SCE and the SCB shelf are used for Main Processors, LICs, ATM multiplexerstype E (AMXE) and devices for data storage (MDD, MOD).

The rack of the ATM SP platform contains a DC/AC converter for power supply andtwo shelves for the 36140 which is doubled for redundancy reasons too. The shelvesare equipped with LICs for the internal connection to the ATM MP platform (STM1)and for the interfaces to GGSN and BSS (FR).

This small configuration uses 4 LIC:FR, 2 SP:BSSGP, 1 LIC to GGSN, 2 SP:GTP for the ATM SP platform and 23 MP:PD/SH, 2 MP:MM inside the 36190 and thisprovides a throughput of 23 Mbit/s sufficient for approximately 300000 subscribers or

200000 PDPs respectively. These parameters for the performance are based on theassumptions depicted in the following figure 6.


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TM2110EU01TM_000317

SGSN Extended

Breaker-Panel

Fan-Tray

BAS_RACK SCE (0)

M : L I C - S T M 1

M : L I C - S T M 1

M : M P - A C C

M : M P - A C C

M : M P - M M

M : M P - M M

M : A M X E

0

M : A C C G 0

M : A C C G 1

M : A M X E

1

M : M P - S L T

M : M P - S L T

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

1 0 3

1 1 5

1 2 7

1 3 9

1 5 1

1 6 3

1 7 5

1 8 7

2 1 1

2 3 1

2 5 1

2 7 1

2 9 1

3 0 3

3 1 5

3 2 7

3 3 9

3 5 1

3 6 3

3 7 5

IDF

BAS_RACK ASNE(1)

M : A C C G ( X 4 0 1 )

M : G M X E ( 0 )

M : A S M G 1 6 / 1 6

M : P S A G

1 1 3

1 4 1

1 6 7

1 9 3

2 1 9

2 4 1

2 7 7

2 9 5

3 2 1

3 4 7

3 7 3

BAS_RACK ASNE(0)

M : A C C G ( X 4 0 1 )

M : G M X E ( 0 )

M : A S M G 1 6 / 1 6

M : P S A G

1 1 3

1 4 1

1 6 7

1 9 3

2 1 9

2 4 1

2 7 7

2 9 5

3 2 1

3 4 7

3 7 3

IDF

BAS_RACK SCB

M : L I C

# 7

M : L I C

# 7

M : M P - S M

M : M P - S M

M : A M X E

0

M : A C C G 0

M : A L I B

M : A C C G 1

M : A M X E

1

M : M O D

0

M : M D D

0

M : M P - S A 0

M : M P - S A 1

M : M D D

1

M : M O D

1

1 0 3

1 1 5

1 2 7

1 3 9

1 5 9

1 7 9

1 9 1

2 0 1

2 2 1

2 4 3

2 7 5

2 9 9

3 1 9

3 3 9

3 6 1

Fan-Box

SGSN Extended

Breaker-Panel

Fan-Tray

IDF

EXT-RACK SCE (3)

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : A M X E 0

M : A C C G 0

M : A C C G 1

M : A M X E 1

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

1 0 3

1 1 5

1 2 7

1 3 9

1 5 1

1 6 3

1 7 5

1 8 7

2 1 1

2 3 1

2 5 1

2 7 1

2 9 1

3 0 3

3 1 5

3 2 7

3 3 9

3 5 1

3 6 3

3 7 5

IDF

EXT-RACK SCE (2)

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : A M X E 0

M : A C C G 0

M : A C C G 1

M : A M X E 1

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

1 0 3

1 1 5

1 2 7

1 3 9

1 5 1

1 6 3

1 7 5

1 8 7

2 1 1

2 3 1

2 5 1

2 7 1

2 9 1

3 0 3

3 1 5

3 2 7

3 3 9

3 5 1

3 6 3

3 7 5

IDF

EXT-RACK SCE (1)

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - M M

M : M P - M M

M : A M X E

0

M : A C C G 0

M : A C C G 1

M : A M X E

1

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

M : M P - P D / S H - S

1 0 3

1 1 5

1 2 7

1 3 9

1 5 1

1 6 3

1 7 5

1 8 7

2 1 1

2 3 1

2 5 1

2 7 1

2 9 1

3 0 3

3 1 5

3 2 7

3 3 9

3 5 1

3 6 3

3 7 5

Fan-Box

Breaker-Panel

Fan-Tray

36140 SGSN

L I C - F R

L I C - F R

L I C - F R

L I C - F R

S P - B S S G P

L I C - S T M 1

S P - G T P

S P - B S S G P

L I C *

36140 SGSN

L I C - F R

L I C - F R

L I C - F R

L I C - F R

S P - B S S G P

L I C - S T M 1

S P - G T P

S P - B S S G P

L I C *

DC/AC Converter

Fan-Tray

GPRS-Node SGSN GR2.0 ‘Large Configuration’

36140

36190

36190

redundancy: doubling of cards (MPs, SPs, ...) / shelves (ASN, 36140)

assumptions:1 MP:MM

150 000 subscriber 1 MP:PD/SH

50 000 subscriber ( 60% attached )

1 MP:ACC / 1 SP:GTP

100 000 PDPs1 MP:PD/SH

1 Mbit/s throughput

configuration parameters:

300 000 subscribers, 200 000 PDPs,

23 Mbit/s throughput

Fig. 8 Rack layout of SGSN GR2.0 "Large Configuration" with ASN


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TM2110EU01TM_000318

2.2 Gateway GPRS Support Node SGSN

Min. / Max. Configuration

The GGSN is responsible for its interfaces to ISPs and to other SGSNs. It is a packetswitch on the basis of ATM protocol.

The GGSN-lite is a combination of 36140 and a server configuration. The 36190 isremoved of the system configuration. This GGSN-lite is a modular system andtherefore available in different configurations. The min. and the max. configurationare depicted in figures 9 and 10.

The hardware of the GGSN is divided into three main parts:

ATM access multiplexer 36140,

File Server "Centellis 4000", SPARC CPCI platform (called "Force Equipment")

HUB for connection to ABC, Switch Commander SC.

The SGSN has to maintain connections to other network elements:

Line interface circuits LICs connect the GGSN with SGSNs (Gn),

LICs also provide the interface Gi (ISP).

Depending on the requirements of customers and on the interface that is to be

represented different LICs are available (LIC:E1, LIC:STM1, LIC:ETH).


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TM2110EU01TM_000319

LIC SP:GTP

LIC

Gn

Gi

SC

ABC

RS 232

Ethernet

HDDDAT

CPCI 540File Server

SP:GTP

SP:ISPSP:ISPSP:ISPSP:ISP

SP:GTPSP:GTP

MCP

File Server

H

U

B

ABC: Administration and Billing Center, SC: Switch Commander

File Server: Storage of

Configuration, Billing Data, ...

HUB: Distribution Function

MCP: Main Control Processor,

central control unit of 36140

1x / 4x

1x / 4x

GPRS-Node GGSN GR 2.0 Min. / Max. Configuration

Fig. 9 Configuration of a GGSN, general layout, "Min. / Max. Configuration"


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TM2110EU01TM_000320

Block diagram of GGSN

the File Server collects billing information, stores configuration and system

information. It is based on a SPARC CPCI platform (Compact PCI system"Centellis 4000", SPARC Compact PCI boards)

LICs provide the physical connections to other network . The LICs are different inhardware for different layer 1/2 configurations (ETH, STM-1, ...)

10 BASE-T HUB, 10 Mbit/s for the Ethernet LAN interface to ABC and SwitchCommander SC

the 36140 is responsible for connections to other SGSN (Gn-interface) and to theISPs (Gi-interface)

Server Processors SP maintain the interfaces Gn (SP-GTP), Gi (SP-ISP) for the

ATM SP platform

The main control processor MCP inside the 36140 is the central control unit of thissystem


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TM2110EU01TM_000321

GGSN

File Server

to Internet

Gi-interface

SC Switch

Commander

ABC

to SGSN

Gn-interface,...

file

server

platform

ATM SP

platform

MCP

36140

File Server

Ethernet

LIC: Line Interface Circuit, ETH: Ethernet, STM: Synchronous Transfer Mode,

SP: Server Processor, GTP: GPRS Tunnelling Protocol, ISP: Internet Service Provider,

MCP: Main Control Processor

Block Diagram of GGSN

H

U

B

SP:ISP

SP:GTP

LIC:STM1

LIC:ETH

Fig. 10 Block diagram of GGSN


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TM2110EU01TM_000322

Rack Layout of the GGSN-lite "Min. Configuration"

The GGSN-lite can use already existing 19"-racks, racks of 7 (8) feet height.

In case of combined LAN for OAM&Accounting one HUB is needed. Some networkoperators want physically separated LANs: one hub for internal communicationbetween the 36140 and the Force Centellis cluster, another hub to connect theCentellis cluster to the outside OAM LAN, a third hub to connect the Centellis cluster to the outside Accounting LAN.

The file server is a UNIX workstation (Force Centellis Cluster, "Force PC")comprising of CPCI-boards (Compact Peripheral Component Interconnect) and datastorage devices.

The ATM access switch (36140) is doubled for redundancy reasons. Each 36140comprises of 1 SP:GTP, 1 SP:ISP, and 2 LICs. According to the assumptionsdepicted in the following figure 10 this configurations is sufficient for 50 Mbit/sthroughput, used by 100000 sessions connected to a maximum number of 6 ISPs.


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TM2110EU01TM_000323

Breaker-Panel

HUB

File Server

File Server

36140 GGSN

L I C *

L I C *

S P - I S P

L I C

S T M 1

S P - G T P

L I C *

L I C *

36140 GGSN

L I C *

L I C *

S P - I S P

L I C

S T M 1

S P - G T P

L I C *

L I C *

Fan

GGSN-lite

min. configuration

File Server (redundant):

storage of configuration,

charging data, ...

HUB:

connection to ABC,

OAM, 36140

LIC:

ETH (e.g. for OAM),

STM1 (e.g. for Gn), ...

Server Processors (SP):

1 x GTP (for Gn functions),

1 x ISP (for Gi functions),

each 36140:

1 x SP:GTP +1 x SP:ISP ==>>

50 Mbit/s throughput,

100000 sessions

6 ISPs

assumptions:

1 SP:ISP


contact to 6 ISPs1 SP:GTP

100 000 PDPs

Fig. 11 Rack layout of GGSN-lite GR2.0 "Min. Configuration"


24/38


TM2110EU01TM_000324

Rack Layout of the GGSN-lite "Max. Configuration"

The GGSN-lite can use already existing 19"-racks, racks of 7 (8) feet height.

In case of combined LAN for OAM&Accounting one HUB is needed. Some networkoperators want physically separated LANs: one hub for internal communicationbetween the 36140 and the Force Centellis cluster, another hub to connect theCentellis cluster to the outside OAM LAN, a third hub to connect the Centellis cluster to the outside Accounting LAN.

The file server is a UNIX workstation (Force Centellis Cluster, "Force PC")comprising of CPCI-boards (Compact Peripheral Component Interconnect) and datastorage devices.

The ATM access switch (36140) is doubled for redundancy reasons. Each 36140comprises of 4 SP:GTP, 4 SP:ISP, and 2 LICs. According to the assumptionsdepicted in the following figure 10 this configurations is sufficient for 200 Mbit/sthroughput, used by 400000 sessions connected to a maximum number of 24 ISPs.


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TM2110EU01TM_000325

Breaker-Panel

HUB

File Server

File Server

36140 GGSN

L I C *

S P - I S P

S P - I S P

S P - I S P

S P - I S P

S P - G T P

S P - G T P

S P - G T P

S P - G T P

L I C *

36140 GGSN

L I C *

S P - I S P

S P - I S P

S P - I S P

S P - I S P

S P - G T P

S P - G T P

S P - G T P

S P - G T P

L I C *

Fan-Tray

GGSN-litemax. configuration

File Server (redundant):

storage of configuration,

charging data, ...

HUB:

connection to ABC,

OAM, 36140

LIC:

ETH (e.g. for OAM),

STM1 (e.g. for Gn), ...

each 36140:

4 x SP:GTP +4 x SP:ISP ==>>

200 Mbit/s throughput,

400000 sessions

24 ISPs

Server Processors (SP):

4 x GTP (for Gn functions),

4 x ISP (for Gi functions),

assumptions:

1 SP:ISP


contact to 6 ISPs1 SP:GTP

100 000 PDPs

Fig. 12 Rack layout of GGSN-lite GR2.0 "Max. Configuration"


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TM2110EU01TM_000326

2.3 MainStreetXpress 36140/36144

The MainStreetXpress 36140/36144 systems are high-performance ATM accessmultiplexers.

In PO1.0 only the 36140 is used. Both have a switching capacity of 2 Gbit/s. The36144 is comprised of 5 I/O slots and is designed for smaller sites. The 36140 iscomprised of 11 I/O slots that can be used either as network or service interfaces.

The 36140 mainly consists of personality modules and service cards, power supplyand a main control processor MCP which is associated with a personality module.

Service Cards (signal processing cards):

ATM-cards support STM-1, OC-3c, T3, E3, T1, E1 physical interfaces,

Frame-Relay with E1/T1 line termination,

Ethernet LAN.

Personality Modules (I/O interfaces for service cards):

two primary functions: providing electrical connectors for power, management, datacommunication and clock units providing interfaces with an external referencesource.

BIAS (Broadband IP router and Access Server) has been defined to provide a

comprehensive set of IP functions such as RAS (Remote Access Server), DNS(Domain Name Server) and VPN (Virtual Private Network) support.

The server processors SP are based on the BIAS card and maintain the interfacesGn, Gp (SP:GTP), Gi (SP:ISP), Gb (SP:BSSGP).

Control card MCP (Main Control Processor):

houses the central control unit,

stores system software and configuration parameters,

manages system cards, interface types, protocols,

enables soft reboot,

handles faults.


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TM2110EU01TM_000327

MainStreetXpress 36140

Personality Modules: physical connections

Power

Supply

Unit

Physical

Connections

Clock Unit

Monitoring

Connector

Fiber Optic

Connector

Service Cards: signal processing, system MCP Card:

Central Control Unit

Serial

Connector

BIAS: IP functions,

e.g. IP routing (DNS)

Power

Connector

BIAS: Broadband IP router and access server

Fig. 13 The MainStreetXpress 36140, a high-performance modular ATM access multiplexer


28/38


TM2110EU01TM_000328

2.4 ATM MP Platform / 36190

The Siemens GPRS Support Node is based on EWSD V13 SSNC hardware. This isthe so called (ATM) MP platform. A variety of main processors MP and lineinterface circuits LICs realize the functions of the Siemens GSNs. The connectionsbetween the individual MPs and LICs are switched in a high-performance ATMswitching network ASN. ATM multiplexer AMX bundle the connections betweenthe LICs /MPs and the ASN.

The modules realizing corresponding functions are distributed in three variousmodule shelves:

SSNC V13 Control Shelf Basic (SCB Shelf )

SSNC V13 Control Shelf Extension (SCE Shelf )

ATM Switching Network (ASN Shelf )

For the realization of the interfaces different LICs are available depending on theinterface and the already existing network of the customer.


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TM2110EU01TM_000329

SGSN

GSN

SCE: SSNC V13 Control shelf Extended

SCB: SSNC V13 Control shelf Basic

LICAMXATM

Multi-plexer ASN

ATM

SwitchingNetworkMP

MP

LIC(SS7)

LIC

Gr, Gd, Gs

MP(OAM)

SCB shelf

SCE shelf

ASN shelf

BCT

MP: Main Processor LIC: Line Interface Circuit

BCT: Basic Craft Terminal ATM SP platform = 36140

AMX

ATM SP platform

ATM MP platform hardware

Fig. 14 ATM MP platform (36190)


30/38


TM2110EU01TM_000330

2.4.1 ATM Switching Network ASN

The ATM switching network ASN is the core of the GPRS node. It consists of the ATM multiplexer/demultiplexer AMX and the ASN core. The latter comprises a further multiplexer and concentration level GMX (ASN multiplexer for the ASN) and the ASNcore module ASNG (ASNH). The two multiplexer level AMX and GMX concentratethe data traffic in the direction of the ASN core module and thus enable the ASN coremodules to be used efficiently. The ASN function consists in switching through ATMcells between the LICs and the MPs.

ATM Multiplexer AMX:

It comprises the ATM Multiplexer modules Type E AMXE and a ASN Controller and

Clock Generator module ACCG. The AMXE concentrate the data traffic coming fromthe LICs and MPs onto (max. 16) STM-1 equivalent ATM interfaces (each with155 Mbit/s) in the direction of the ASN core.

ASN Controller and Clock Generator ACCG

The ACCG monitors and controls all switching modules of the ASN (AMXE, GMX:E, ASN type F, G, H). Every one of these is controlled by the ACCGs viamicroprocessor bus interface and does not have own control functions. An ACCGmodule also contains the Clock Generator Unit CGU which supplies the clock for all

ASN modules and the peripheral LIC and MPU units.

ATM Multiplexer for ASN GMX

The GSN comprises up to 8 Multiplexer type E for the ASN GMX:E. These multiplexthe data stream incoming from the AMXE (max. 16 x 155 Mbit/s) into 2.4 Gbit/s(STM-16 equivalent) in the direction of the ASN Core module and vice versa.

ASN Switching Core Module

The ASN core is housed in the ASN subrack and contains a switching network. It iscontrolled by an ASN controller and clock generator module ACCG. The task of the

ASN switching core module is to through-connect ATM cells. Cells incoming from anyinput can be relayed to any output. 2 ASN types are planned: ASNG with a maximumflow rate of 40 Gbit/s and ASNH with a maximum of 60 Gbit/s.

The ASN Core (ASNG + GMX + ACCG) is housed in separate ASN Shelves (with1+1 redundancy) and is powered by a Power Supply unit type A PSA. The AMX(AMXE + ACCG) is housed in the shelves SCE and SCB.


31/38


TM2110EU01TM_000331

ATM Switching Network ASN

ACCGASN Controller

& Clock Generator

AMXATM Multiplexer

ASNSwitching

Core Module

PSAPower Supply Unit

Type A

• ATM Switching Network

• switching of ATM cells: user data & signalling,

LIC & MP signalling

• ASNG: max. 40 Gbit/s• ASNH: max. 60 Gbit/s

AMXEATM

Multiplexer

type E

•

••

ACCGASN Controller

& Clock Generator

GMXATM Multiplexer

GMX:EMultiplexer

type Efor the ASN

1

GMX:EMultiplexer

type E

for the ASN

8

•

•

•

LIC

LIC

MPU

MPU

••

•

•••

155

Mbit/s(STM-1)

155Mbit/s

(STM-1)

•

•

•

2.4

Gbit/s(STM-16)

2.4Gbit/s

(STM-16)

ASN Shelf SCB & SCE Shelves

Fig. 15 Structure and function of the elements in the SCB, SCE and ASN shelves of the 36190


32/38


TM2110EU01TM_000332

2.4.2 Hardware Configuration: GSN Rack & Shelves

The individual modules of the GSN in GR1.0 are integrated into the shelves of theGSN rack, as can be seen below:

SSNC V13 Control Shelf Basic (SCB Shelf)

The SCB Shelf contains:

1 MP-SA, for MP:OAM/ACC/LM-functions (MPU SA 00 / 01)

max. 2 MP-AP (MPU 00 / 01 and MPU 10 / 11)

max. 1 LIC in 1+1 redundancy (LIC) for SS7

2 ATM multiplexer module type E AMXE (AMXE 00 / 01) 2 ASN controller & clock generator ACCG (ACCG 00 / 01)

1 alarm indication module type B ALIB (ALIB)

2 magnetic disc device MDD (MDD 00 / 01)

2 magneto-optical disc device MOD (MOD 00 / 01)

SSNC V13 Control Shelf Extended (SCE Shelf)

The SCE shelf contains:

max. 8 MPC-AP (LIC/MPU 00 / 01 ... 70 / 71)

max. 8 LIC in 1+1 redundancy or 16 independent LICs (LIC/MPU 00 / 01...70/71)

2 AMXE (AMXE 00 / 01)

2 ACCG (ACCG 00 / 01)

ATM Switching Network Shelf (ASN Shelf)

The ASN Shelf contains the ASN core modules:

1 ATM switching network core module type G ASNG

max. 8 ATM multiplexer type E for the ASN GMX:E

1 ACCG

1 power supply unit type A PSA


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TM2110EU01TM_000333

SCE Shelf SSNC V13 Control Shelf Extended

1

2

3

4

5

1

2

3

4

5

D

C

L I C

/ M P U

0 0

A C

C G

0 0

A C C G

0 1

A M

X E 0 1

PITCH 103 115 127 139 163 175 187 207 247 287267 299 359

L I C

/ M P U

0 1

L I C

/ M P U

1 0

L I C

/ M P U

1 1

L I C

/ M P U

2 0

L I C

/ M P U

2 1

L I C

/ M P U

3 0

L I C

/ M P U

3 1

A M

X E 0 1

A M

X E 0 0

151 227 239 311 323 335 347 371 389

L I C

/ M P U

4 0

L I C

/ M P U

4 1

L I C

/ M P U

5 0

L I C

/ M P U

5 1

L I C

/ M P U

6 0

L I C

/ M P U

6 1

L I C

/ M P U

7 0

L I C

/ M P U

7 1

E1 / DS1

STM1

E1 / DS1

STM1

max. 8 MP-AP or

max. 8 LIC (1+1) or 16 independent LIC2 ACCG

ASN Controller &

Clock Generator

2 AMXEATM Multiplexer

module type E

Fig. 16 Configuration of the SCE shelf in the base rack of the GSN


34/38


TM2110EU01TM_000334

2.4.3 Further Modules in the GSN (in Shelf SCB)

Alarm Indication Module Type B ALIB

The ALIB can handle up to 16 external alarms. The internal and external alarms arecollected in the alarm collecting module ALCM which is a part of the breaker panel.The external alarms are relayed to the ALIB, whereas the internal alarms areforwarded to a ACCG n the SCB shelf or to an ACCG in the first SCE shelf of a rack.

Magneto-Optical Disc device MOD

The MOC enables loading of software and configuration files into the MP:SA. It isalso used to store older software versions.

Magnetic Disc Device MDD

The MDD is used as off-board mass memory for the MP-SA. It has ca capacity of 2.1 GByte and is required in every possible configuration.


35/38


TM2110EU01TM_000335

1

2

3

4

5

1

2

3

4

5

D

C

L I C

/ M P U

0 0

M P U

1 0

M P U

1 1

A M X E 0 0

A

C C G 0

0

A L I B

A

C C G 0

1

A

M X E 0 1

M

O D

0 0

M

D D

0 0

M

P U

S A

0 0

M

D D

0 1

M

P U

S A

0 1

M O D

0 1

PITCH 103 115 127 139 159 179 191 201 221 251247 275 299 319 339 361 103

L I C

/ M P U

0 1

SCB Shelf

SSNC V13 Control Shelf Basic

1 MP-SA

(MP:OAM/ACC/LM)

2 MDD

Magnetic Disc DeviceMP-SA mass storage (2,1 GByte)

2 MOD

Magneto-Optical Disc device

loads SW & configuration data

in MP-SA (2,1 GByte)

1 / 2 MP-AP

0 / 1 + 1 LIC

1 ALIB

Alarm Indication module type Bcollects (max. 16) external alarms

2 ACCG

ASN Controller &

Clock Generator

2 AMXE

ASN Multiplexer

module type E

Fig. 17 Configuration of the SCB shelf in the base rack of the GSN


36/38


TM2110EU01TM_000336

2.5 Integration of GPRS in Existing GSM Networks

The GPRS support nodes are linked to the GSN network architecture via interfaceGb. Transmission is performed by Frame Relay via E1/DS1.

An E1 line (for PCM30) has 32 channels at 64 kbit/s (total: 2.048 Mbit/s). Onechannel is used for synchronization, the rest for signaling and traffic.

A DS1 line (for PCM24) has 24 channels at 64 kbit/s (total: 1.544 Mbit/s).

There are different ways of implementing interface Gb for contacting the combinedSGSN /GGSN node with the BSS:

NUC (Nailed Up Connection) via MSC: a direct link via an MSC. Each NUC is used to

connect a BSC (PCU) to the GSN. Only an E1/DS1 time slot can be used for an NUC(MSC-dependent). This means that up to 31 / 24 BSCs (PCUs) can be contacted viaan E1/DS1 line from the GSN. The peak rate via interface Gb is therefore 64 kbit/s for one BSC (PCU).

NUC via MSC via a Frame Relay network. Each NUC is used to connected a BSC tothe FR network. In all other respects the same as 1).

Using a Frame Relay network (without going via an MSC). Several channels (max.31/24) at 64 kbit/s each can be used to link a BSC (PCU) to a GSN. Therefore amaximum of approx. 2 or 1.5 Mbit/s can be transferred.

Direct connection with Frame Relay. An E1/DS1 line exists as a direct connection(dedicated line) between GSN and BSC (PCU). Therefore a maximum of 2 or 1.5 Mbit/s can be transferred.


37/38


TM2110EU01TM_000337

Gb-Interface

configuration

P

C

UBSC Frame Relay

network

GSN

MSC E1/DS1-Line

E1/DS1-Line

E1/DS1-Line

E1/DS1-Line

1

2

3

4

multiple nailed-upcircuits, each 64 kbit/s

dedicated Frame Relay

resources

1) Nailed Up Connection NUC via MSC;

1 TS je NUC max. 64 kbit/s via Gb; but 31 BSCs (PCUs) via 1 E1/DS1 lines

2) NUC via MSC via FR network (compare 1)

3) through FR network; 1max. 31/24 * 64 kbit/s max. 2 / 1,5 Mbit/s

4) direct lines via FR ; (compare 3)

Fig. 18 Gb interface configurations: direct access to the BSS/PCU or via circuit switched MSC


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05 tm2110eu01tm 0003 gsn architecture

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