1

Converged Fixed-Mobile solutions:The TISPAN_NGN approach

(Sophia, 22 November 2004)

Christian Julien(ETSI Secretariat)

TC TISPAN TOchristian.julien@etsi.org

2

Agenda

1.1. TISPAN_NGN Project: Steps and TISPAN_NGN Project: Steps and RequirementsRequirements

2. TISPAN_NGN Status: architecture outline

3. How the use of 3G UMTS IMS in NGN will help Fixed-Mobile convergence for Multimedia

4. Some important issues to be taken care of

5. Summary

3

TISPAN_NGN Genesis

TISPAN: TTelecommunication and IInternet converged SServices and PProtocols for AAdvanced NNetworking

results from the combination, in September 2003, of : SPAN, formed as a Technical Body from the joining of SPS

(Services, Protocols & Switching) and NA (Network Aspects)

TIPHON, formed in 1997 as an ETSI Project to study VoIP and subsequently extended to any Telecom (including Multimedia) services over IP

TIPHON = Telecommunications and Internet Protocol Harmonization Over Networks

SPAN = Services and Protocols for Advanced Networks

4

TISPAN_NGN Synergy

The working groups of the TC TISPAN have been carefully defined to cover the needs of the industry in specific technical areas of competence

Each project follows a particular technical subject and co-ordinates across the competence groups

The following slide gives an summary of the way the new TC leads the way in standardisation

5

TISPAN_NGN Synergy

SERVICES

ARCHITECTURE

PROTOCOLS

NUMBERING &ROUTEING

QoS

TESTING

Tis

pan

_NG

N

F-M

MS

Tel

eco

m E

qu

ipm

ent

Iden

tity

Etc… as needed

NETWORK MANAGEMENT

EM

TE

L (

EM

erg

ency

TE

Lec

om

mu

nic

atio

n)

DT

M (

Dyn

amic

asy

nch

ron

ou

s T

ran

sfer

t M

od

e)

SECURITY

Projects8 Working Groups

OS

A (

Op

en S

ervi

ce A

cces

s)

6

Technical approach

Nam

ing &

Addressing

Net

wor

k &

Ser

vice

Man

agem

ent

Security

Protocols, Interworking etc.

Testing

Services

Capabilities

Architecture & Requirements

Go

als

De

finitio

nS

pecification

Typical Services and basic features

Service Capabilities (building blocks)

QoS, Security, Naming and Addressing

Architecture and Requirements

Network and Service Management (NGN OSS)

Protocol Selection and Profiling

Evaluation & Modification (“fit for purpose”)

Test Specification and Test Suites (to facilitate interoperability)

QoS

7

_NGN goals & Technical overview The Next Generation Network will eventually

provide: A multi-service multi-protocol, multi-access, IP based network

- secure, reliable and trusted• Multi-services: delivered by a common QoS enabled core

network. • Multi-access: diverse access networks; fixed and mobile

terminals,• Not one network, but different networks that interoperate

seamlessly An enabler for Service Providers to offer

• real-time and non real-time, communication services • between peers, or in a client-server configuration.

Nomadicity and Mobility• of both users and devices• inter and inter-Network Domains, eventually between Fixed and

Mobile networks

“My communications services” always reachable, everywhere, using any terminal.

8

_NGN Wide range of services

Messaging

Person-to-Person – Communication Services

Content-on-demand

Browsing Download Streaming PushBroadcast

Peer-to-Peer

Conversational Voice call Video call

Chat call Multimedia call

e-MailSMS EMS

MMS

IM

9

Conversational Streaming TV Broadcasting Messaging Web

Support of a wide variety of services

Support of fixed and mobile converged services

Control Functions

Packet-based transfer

DSL/ATMDSL/Ethernet UTRAN/GPRS

Backbone

Cable NetworkWLAN

Well defined interfaces between control and applications

Independence between control and transport

Support of a wide variety of terminals

_NGN key assumptions

10

_NGN high level Roadmap

2006

Towards a converged Wireline and Wireless NGN …

Release 3

2007 2008

Release 1 Release 2

200920052004

xDSL,WLAN FTTx Fully

Nomadic

Release 1 bringing Multimedia services Nomadicity/user-controlled roaming xDSL access focus; Access Network Attachment Subsystem

Release 2 optimizing access resources usage According to user subscription profile and service use Corporate users specific requirements …

Release 3 introducing full (inter-domain) Nomadicity Inter-network domain nomadicity/user-controlled roaming Higher bandwidth access (VDSL, FTTH, Wi-max …)

???

2010

11

Agenda

1. TISPAN_NGN Project: Steps and Requirements

2.2. TISPAN_NGN Release 1 Status: TISPAN_NGN Release 1 Status: architecture outlinearchitecture outline

3. Why the use of IMS in NGN will help Fixed-Mobile convergence for Multimedia

4. Some important issues to be taken care of

5. Summary

12

_NGN Release 1 scope

Ongoing discussion Being consolidated meeting after meeting Stabilized at TISPAN#4 (sept.) & #4bis (nov.) meetings

Major service capabilities under consideration Real time conversationnal services (Voice, Videotelephony) Messaging (Instant Messaging, MMS), Presence Management Legacy services emulation enabling legacy PSTN/ISDN

migration towards NGN Content delivery such as VOD, Video Streaming, TV-Channel

distribution (if inputs and resources available) Network Architecture basis

ADSL access prime focus, possibly WLAN (may be deferred to Release 2)

3G/UMTS IMS sub-system reused as basis for real-time Conversationnal services (SIP-based session control)

Objective: mid-2005 Pragmatic bottom-up approach for Release 1 Not excluding Top-down (TIPHON-like) approach for preparing

future TISPAN_NGN Releases

13

_NGN architecture design principles

A sub-system oriented approach, enabling: The addition of new subsystems over the time to cover new demands and service classes.

To import subsystems from other standardisation bodies.Flexibility to adjust the architecture.

IP connectivity is provided using two subsystems:Network Attachment Subsystem (NASS)Ressource and Admission Control Subsystem (RACS)

First service-oriented subystems include:The 3GPP IMS suitably adapted to accomodate xDSL-based access networks requirements (joint effort with 3GPP), supporting multimedia services and PSTN/ISDN Simulation.

A PSTN/ISDN Emulation subsystem specifically tailored to allow TDM equipment replacement, while keeping legacy terminals unchanged.

14

_NGN Architecture overview

Other MultimediaSubsystems …

Based on3GPP IMS R6

(RTSP -based)Streaming services

(SIP -based) IP Multimedia Subsystem

(Core IMS)

IP ConnectivityAccess NetworkAnd related functionality

PS

TN

(SIP - I based)PSTN/ISDN Emulation

Subsystem

Applications

IP

Resource and Admission Control

Functionality

Core Transport Network

Access TransportNetwork

GWGWGW

Network Attachment Functionality

GW

3GPP IP-CAN

15

Resource and Admission Control Functionality

RACS

Based on3GPP IMS

IP ConnectivityAccess NetworkAnd related functionality

Network AttachmentFunctionality

NASS

Other Multimedia Components …

Streaming Services (RTSP based)

PSTN / ISDN Emulation(SIP-I based)

Applications

Core transport Network

3GPP IP-CAN

Access Transport Network

IP

3GPP Terminals

NGN Terminals

LegacyTerminals

CustomerNetworks

DataBase

Oth

er Netw

orks

“Gq”interface

“Go”interface

IP Multimedia Component (Core IMS)

(SIP based)

PS

TN

/ ISD

N

MBG

TGW

ICF

GW

GW

LegacyTerminals

NGN Terminals

LegacyTerminals

_NGN detailed overview

16

IMS introduced in 3GPP Rel5, and further enhanced in Rel6:IP Multimedia domain for call control based on SIP3GPP specifies features to fullfill operator requirements, e.g.:

•QoS control•Charging•Security•Subscription profiles•Interworking with other networks (CS/PSTN)

IMS provides building blocks allowing faster integration and deployment of IP multimedia services

IMS background (1/3)

17

IMS allows operators to have more control on the service level than with GPRS only:Service level awarenessCorrelation between the SIP application layer and the transport in PS domainAccess to services in correlation with a subscription profile (e.g. basic, silver, gold…)Better control on the packet resources used

3GPP IMS Releases:Release 5: frozen since March 2003Release 6: freezing in December 2004Release 7: Starting. Stage 1 requirements being currently defined

IMS background (2/3)

18

User IdsUser profile

security roaming

Inter-WorkingCS/PSTN

QoS policycontrol

BasicCall

Control

Service logicAPIs

SIP

charging

IMS background (3/3)

20

Signaling path Content path

LegendIMS SIP: CSCF Call State Control

Functions

Proxy- UE Interface, Local Services

Interrogating- Home Network Contact Point

Serving- Session Control, Service Invocation, AS & HSS Trigger, Charging, …

Call Flow

1 Register & find user Home

2 Register & Retrieve required S-CSCF & it’s capabilities

3 Choose correct S-CSCF

4 Register & Download IMS user Profile

5 INVITE UE#2 into call

6 Upon Acceptance, Data Path is Set-up

UMTS PACKET DOMAIN

UMTS PACKET DOMAIN

ApplicationServers

P-CSCF

I-CSCF

S-CSCF

IP MULTIMEDIA SUBSYSTEM

GGSNGGSNSGSN SGSNUE #1 UE #2

1

2 3

4

5

6

IMS Registration and Call

HSS

21

IMS

IMS Architecture

UTRAN

SGSN GGSNUE

PS Domain

I-CSCF

Go Gi

I-CSCF

P-CSCFS-CSCF

Mw

HSS

Cx

Cx

CSCFs are the IMS entities responsible of the call control: there are 3 types of CSCFs depending on their role:•P-CSCF (Proxy CSCF)•S-CSCF (Serving CSCF)•I-CSCF (Interrogating CSCF)

The PS domain provides the IP bearer to access to

the IMS, i.e. a PDP context.

The HSS holds the IMS service profile of the subscribers.

S-CSCF interconnects to external IP networks and other IMS networks.If THIG is used by the operator to hide its internal configuration, the connection to external networks goes through an I-CSCF.

Gi

Traffic Plane

Control Plane

Other IP/IMS network

Mm

22

IMS

IMS Architecture

UTRAN

SGSN GGSNUE

PS Domain

I-CSCF

Go Gi

I-CSCF

P-CSCFS-CSCF

Mw

HSS

Cx

Cx

SGWMGCF

BGCF

IMS-MGW

Legacy/PSTN

Mk

Mi

Mg

Mj

MnGi

MRF

Gi

Mr

PDF

Go

GqThose entities are responsible for interworking between IMS and CS domain/PSTN

In Release 6, the PDF can be separated from the P-CSCF. Those two entities are then connected through the Gq interface.

The MRF is used for multiparty

call control

Traffic Plane

Control Plane

Other IP/IMS network

Mm

23

Resource and Admission Control

Subsystem

PSTN/ISD

NOther

subsystems

IMS

PSTN/ISDN Emulationsubsystem

Applications

Customer Prem

ises Equipment

Service Layer

Transport Layer

Transport Functions

Network Attachment Subsystem

_NGN IMS-based subsystem

24

Core IMS use in the NGN architectureO

ther IP

Netw

orks

IP Transport (Access and Core)

T-MGF

I-BGF

AS HSS

IBCF

A-BGF

P-CSCF

S-CSCF

BGCF

I-CSCFSLF

ChargingFunctions

IWF

UE

«Core IMS »

Mw

Mw Mw/Mk/Mm

Mr

Mg

Mj

Mi

Mp MnGm

Gq

ISC Cx

Dx

Dh

Sh

Ic

Rf/Ro

Rf/RoCxIb

Ia

Id

PS

TN

/ISD

N

SGFMRFC MGCF

MRFP

Resource and Admission Control Subsystem

Network Attachment Subsystem

If

Ie

Mi

Mw

Oth

er IP N

etwo

rks

IP Transport (Access and Core)

T-MGF

I-BGF

AS HSS

IBCF

A-BGF

P-CSCF

S-CSCF

BGCF

I-CSCFSLF

ChargingFunctions

IWF

UE

«Core IMS»

Mw

Mw Mw/Mk/Mm

Mr

Mg

Mj

Mi

Mp MnGm

Gq

ISC Cx

Dx

Dh

Sh

Ic

Rf/Ro

Rf/RoCxIb

Ia

Id

PS

TN

/ISD

N

SGFMRFC MGCF

MRFP

Resource and Admission Control Subsystem

Network Attachment Subsystem

If

Ie

Mi

Mw

SIP

DIAMETER

H.248

impacted

NGNspecific

25

_NGN standards built on 3GPP IMS specs

Use the “core” IMS as one of the high-level components of the overall NGN architecture, with initial focus on xDSL

xDSL-based access networks provide access to IMS and other subsystems (e.g.; streaming)

xDSL-based access networks as a new type of IP-Connectivity Access Network for the IMS

Complement the IMS with other subsystems A resource and admission control subsystemA network attachment subsystemA PSTN/ISDN Emulation SubsystemOther multimedia subsystems and applications

26

Differences between xDSL and 3G Radio Access

Differences which impact the IMS-SIP specifications:

Wireline versus Wireless: The constraints in terms of bandwidth scarcity, security, transmission delay are different

Terminals: Less stringent requirements are likely to be placed on NGN terminals (e.g. support of IPv6, availability of USIM/ISIM, codecs...)

Location Information: Location information is different in nature and usually not available at the UE

Resource management:: Explicit resource reservation signalling not available in terminals and access network edge points; no dedicated channel for signalling

Regulatory issues: Different contexts leading to different constraints

Terminals vs Users: Users are not always tied to terminals

Details being discussed between 3GPP (IMS R6 and R7) and TISPAN

27

IP Connectivity control

IP connectivity is provided using two control subsystems, which play a role similar to the 3GPP GPRS procedures

Network Attachment SubsystemIP address allocation (e.g.; using DHCP).Authentication, taking place at the IP layerAuthorisation of network accessLocation management, taking place at the IP layer,...

Ressource and Admission Control SubsystemAdmission ControlGate Control ...

28

_PSTN/ISDN Emulation Subsystem

Resource and Admission Control

Subsystem

PSTN/ISD

NOther

subsystems

IMS

PSTN/ISDN Emulationsubsystem

Applications

Customer Prem

ises Equipment

Service Layer

Transport Layer

Transport Functions

Network Attachment Subsystem

29

Emulation vs Simulation

PSTN/ISDN service continuity in NGN: PSTN/ISDN Simulation

"Provides PSTN/ISDN service capabilities and interfaces using adaptation to an IP infrastructure"

The provision of PSTN/ISDN-like services to advanced terminals (IP-phones) or IP-interfaces. There is no strict requirement to make all PSTN/ ISDN services available or identical, although end users expect to have access to the most popular ones, possibly with different ergonomy.

PSTN/ISDN Emulation "Provides PSTN/ISDN-like service capabilities using session

control over IP interfaces and infrastructure" Mimicking a PSTN/ISDN network from the point of view of legacy

terminals (or interfaces) by an IP network, through a gateway. All PSTN/ISDN services remain available and identical (i.e. with the same ergonomics); such that end users are unaware that they are not connected to a TDM-based PSTN/ISDN.

30

_PSTN/ISDN Emulation subsystem

Two approaches under discussion: Softswitch approach ('Monolithic architecture')

•A shortcut to refer to (often already existing) implementations based on use of call control software (ported from legacy switches).

•Not requiring standardisation of the internal structure of the PSTN/ISDN emulation subsystem, only external interfaces

IMS-like approach•Re-use (all or part) of the IMS functional architecture to specify the

internal structure of the PSTN/ISDN Emulation subsystem

Towards a compromise agreement: Functional architecture, physical implementation examples

•Standardisation of external interfaces: H.248 profile, network SIP-I

An IMS-like functional architecture does not prevent the implementators to build a physical architecture using only softswitches (MGC) and media gateways (MGW).

31

IMS and PSTN/ISDN Emulation Many similarities

Two session-based control subsystems: •For supporting multimedia conversational services and PSTN/ISDN

services simulation (IMS)

•For supporting PSTN/ISDN services emulation

Above a managed IP network Supporting operators’ requirements

•Quality of service, Security, Charging capabilities, Regulatory constraints....

Clear Benefits Enables the deployment of common control platforms

•Towards a unique infrastructure for supporting multimedia services and TDM- switches replacement

Enables service convergence •new voice services available to all types of subscribers

Enables the scope of nomadism to be extended to legacy access lines.

32

SIP may also be used if the set of services to be emulated is limited and/or « downgraded » emulation is considered acceptable (e.g. second line).

_Emulation typical configurations

Z H248 ZH248SIP-I

RGW or AGW

RGW or AGW

Z H248 H248SIP-I

RGW or AGW

S/T

DSS1/IUA

Z H248

H248

SIP-I

RGW or AGW

TGW

ISUP

PSTN/ISDN

H248SIP-I

RGW or AGW

V5.2

V5.2/V5UA

ANZ H248

33

Resource and Admission Control

Subsystem

PSTN/ISD

NOther

subsystems

IMS

PSTN/ISDN Emulationsubsystem

Applications

Customer Prem

ises Equipment

Service Layer

Transport Layer

Transport Functions

Network Attachment Subsystem

_Network Attachment Subsystem

34

Main functionalitiesIP address allocation (e.g.; using DHCP).Authentication and authorisation, taking place at the IP layerAccess network configuration, based on user profiles.Location management, taking place at the IP layer

Replaces the 3GPP PS Domain / GPRS procedures for authentication and location management

Outstanding Issues Interactions between authentication at the network attachment level and at the SIP level.

Alignement with DSL Forum ArchitectureOne NASS per access network or one NASS for several access networks?

_Network Attachment Subsystem

35

a4

Service control subsystems and

applications

TE CNG

a3 a1

a2

e1

e2 e4

e3

Resource and

Admission Control

Subsystem

CLF

NACF CDCF

AMF

PDBF UAAF

_NGN NASS current architecture

36

Resource and Admission Control

Subsystem

PSTN/ISD

NOther

subsystems

IMS

PSTN/ISDN Emulationsubsystem

Applications

Customer Prem

ises Equipment

Service Layer

Transport Layer

Transport Functions

Network Attachment Subsystem

_Resource and Admission Control

37

Main Functionalities:Session Admission Control.Gate Control (including NAPT)

TISPAN R1 : No interactions between RACS in different networks

Need to support both push and pull proceduresPush mode required for ADSL-based access networks

Issues for future releases:Admission control at core network boundaries.Cooperation between peer ressource control subsystems

_NGN RACS description

38

Provides a Gq-like interface to TISPAN Subsystems and applications

Controls transport ressources at the boundary between the access and core networksUsing a Gate Control Protocol

May also control NAPT at core network boundaries TISPAN has recently approved an H.248-based

Gate Control ProfileAn alternative COPS-based or SNMP-based standards may be pushed by some vendors at a later stage

_NGN RACS status

39

Agenda

1.1. TISPAN_NGN Project: Steps and TISPAN_NGN Project: Steps and RequirementsRequirements

2.2. TISPAN_NGN Release 1 Status: architecture TISPAN_NGN Release 1 Status: architecture outlineoutline

3.3. Why the use of IMS in NGN will help Fixed-Why the use of IMS in NGN will help Fixed-Mobile convergence for MultimediaMobile convergence for Multimedia

4. Some important issues to be taken care of

5. Summary

40

Why IMS in NGN ?

IP Multimedia Substem generally fulfills the NGN requirements for conversational services

For managed, carrier operated telecom networkWith Release 6 becomes applicable to a range of access network types (3G RAN, WLAN)

IMS access (technology) independence

Whole Telecom industry benefitWill enable simple and effective interworking between Cellular and Wireline

Growing IMS market, encouraging greater usageWider choice of IMS suppliersMarket stimulation, decreasing costs (thanks to shared development/deployment costs)

…

41

Benefits of IMS use in NGN TISPAN_NGN has taken the lead in adopting 3G IMS as a key

base component in the NGN architecture It needs adaptions to support xDSL access (on-going) Still a number of issues to be addressed (Identifiers, Security,

IPv4/v6 interworking and transition …) A promissing major step to enable smooth Fixed-Mobile

convergence for Multimedia: Consolidating the IMS and Service Platforms access & transport

technology independence Enabling seamless service interworking An effective basis to support Nomadicity and Mobility features

Still a number of challenges ahead Resource optimization and transport technology evolution QoS insurance for Real time services … Identifiers, Security …

But a significant step is being taken to enable the Multimedia Fixed-Mobile convergence in TISPAN_NGN Release 1

42

Agenda

1.1. TISPAN_NGN Project: Steps and TISPAN_NGN Project: Steps and RequirementsRequirements

2.2. TISPAN_NGN Release 1 StatusTISPAN_NGN Release 1 Status

3. Why the use of IMS in NGN will help Fixed-Mobile convergence for Multimedia

4.4. Some important issues to be taken care ofSome important issues to be taken care of

5. Summary

43

_NGN IMS-related issues A promissing approach but many challenges, e.g.

Resource and QoS control in access (and end-end) QoS insurance (IP flow differenciation) Policy control (G0) interface

Services interoperability Services are not (yet) standardized in 3GPP TISPAN_NGN is intending to standardize a minimum set Interworking with Legacy networks and Platforms

Terminals IP addresses, (Line & Personal) Identifiers, SIP Client (Profile) …

IT adaptation and integration Flexible NGN-OSS Provisioning, Charging and Billing

To enable use of IT(IP)-based technology in Telecom carriers grade environment.

44

Using Gq interface in NGN

Gq Interface is located between Multimedia Subsystem(s) and Resource and Admission Control Subsystem (RACS)

Gq is used by different subsystems (not only IMS) and multiple Access Networks

Gq is used to access the following functions: Resource reservation Admission Control NAT Control Gate and Policy Control

45

Gq interface Extensions

Support for network initiated resource reservations Besides Pull Model the Push model shall be supported.

Support for requesting Address and Port Translation Parameters for NAT type of scenarios., e.g.

• interworking of different (private/public) IPv4 address spaces, query and allocate NAT bindings

• Possibly IPv4/IPv6 interworking

Gate control and service and network policy control Parameters to access those functions

46

Agenda

1.1. TISPAN_NGN Project: Steps and TISPAN_NGN Project: Steps and RequirementsRequirements

2.2. TISPAN_NGN Release 1 Status: architecture TISPAN_NGN Release 1 Status: architecture outlineoutline

3. Why the use of IMS in NGN will help Fixed-Mobile convergence for Multimedia

4. Some important issues to be taken care of

5.5. ConclusionConclusion

47

_NGN summary A strong industry demand

For new generation Multimedia services on xDSL access For preparing replacement of soon becoming obsolescent PSTN

For a first Release of specifications by mid-2005 Giving main standards directions With realistic and implementable solutions

ETSI TISPAN taking the lead to propose an architecture basis consisting of a range of subsystems: Maximizing Wireline and Cellular convergence, through adoption of

3G/UMTS IMS component for support of conversational services Access network attachment Subsystem, Resource and admission

control sub-system … preparing for next Releases TISPAN collaborating with 3GPP to accommodate Wireline

access network requirements by IMS A 1st Workshop held last June, a further one next year To coordinate the IMS specifications evolutions to support various

Wireless and Wireline access technologies Other collaborations very welcome

ITU-T NGN Focus Group, ATIS is eager to cooperate European IST projects e.g. which is considering

IMS in the scope of their system architecture too.

48

Acronyms

CSCF Call State Control Function IMS IP Multimedia Services IWF Inter-Working Function GPRS General Packet Radio Service HSS Home Subscriber Function MRF Multimedia Resource Function MGCF Media Gateway Control Function SIP Session Initiation Protocol SLF Subscriber Location Function UMTS Universal Mobile Telecom. System UTRANUniversal Telecom. Radio Access Net.

49

THANKS FOR YOUR ATTENTIONTHANKS FOR YOUR ATTENTION

Questions/Comments ?

ETSI TISPAN Portal:http://portal.etsi.org/Portal_Common/home.asp