IMS Architecture: Past, Present and Future

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(No Transcript)
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IMS Architecture Past, Present and Future

• By Dhananjay Shukla and Vinay Rao
• Centillium Communications Inc.

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IMS Architecture Past, Present and Future

• Introduction
• What is IMS?
• Convergence and IMS Drivers
• IMS Evolution
• IMS Origins
• Who is involved?
• ITU IMT-2000 Framework
• 3GPP
• About 3GPP
• Standards Releases
• IMS Reference Architecture
• 3GPP2
• About 3GPP2
• Standards Releases
• MMD Architecture

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IMS Architecture Past, Present and Future

• 3GPP/3GPP2
• Differences
• Harmonized Architecture
• Evolution from Wireless to Wireline
• NGN TISPAN
• About TISPAN
• Standards
• Architecture

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What is IMS?

• IP Multimedia Subsystem IMS is an architectural
  framework for delivering IP multimedia services
  to end users.
• IMS provides a network-independent, common
  service delivery environment for both wireless
  and fixed network users.
• IMS standards define common signaling and media
  interfaces that are open, vendor independent, and
  abstract the underlying network complexities.

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Convergence and IMS Drivers

• Convergence
• Fixed, mobile, broadband
• Convergence is a reality
• IMS motivations
• New services and revenue
• Fast time-to-market
• Harmonized (any terminal)
• Lower infrastructure cost
• IMS technology components
• IP (while keeping legacy)
• SIP
• Multimedia high compression/quality and
  adaptation
• Any access and IMS arch support

FIXED
IMS
BROADBAND
MOBILE
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IMS Evolution

• IMS evolved from early packet data over mobile
  wireless architectures called 3G.IP to provide
  internet services over mobile networks.
• IMS was incorporated into 3GPP standards efforts
  first appearing in Release 5.
• IMS was incorporated into 3GPP2 standards efforts
  as part of Multimedia Domain MMD.
• ETSI-TISPAN and ITU-T also incorporated IMS into
  their Next-Generation-Network NGM Wireline
  standards developments.
• Other consortia such as OMA are involved in
  specifying IMS services.

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IMS Origins
2006
2005
2004
2003
2002
2001
Rel. 5.0 IMS
Rel. 6.0 IMS
Rel. 7.0 IMS
Rel. 4.0
Rel. 0 MMD
Rel. A MMD
Rel. B MMD
Rel. 2.0 NGN
Rel. 1.0 NGN
Rel. 1.0 NGN FG
Other
OMA
IP multimedia subsystem (IMS), multimedia
domain (MMD), Next Generation Network (NGN)
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Who is involved?
Standards Organization or Consortium Scope or Focus Standards Contribution
Internet Engineering Task Force (IETF) All IP networks SIP, SDP, RTP, DIAMETER, etc
Third-Generation Partnership Project (3GPP) UTRA, GSM, GPRS, EDGE, UMTS, W-CDMA, etc IP Multimedia Subsystem IMS
Third-Generation Partnership Project 2 (3GPP2) CDMA2000, etc Multimedia Domain MMD
European Telecom Standards Institute (ETSI) Next-generation wireline networks NGN effort by TISPAN
International Telecommunication Union (ITU-T) IMT-2000 and Next-generation wireline networks Framework for 3G efforts, FG-NGN effort by ITU-T SG13 NGN, etc
Open Mobile Alliance Mobile Services and Applications Instant Messaging, OMA-POC, Presence, etc
CableLabs Cable IP Networks PacketCable 2.0 project
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ITU IMT-2000 Framework
The 5 IMT 2000 terrestrial interfaces agreed by
ITU-R
UMTS
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3GPP About 3GPP

• The 3rd Generation Partnership Project (3GPP) -
  Collaboration agreement formalized in December
  1998 by signing of The 3rd Generation
  Partnership Project Agreement.
• Collaboration agreement brings together as
  Organizational Partners, a number of
  telecommunications standards bodies from around
  the world, namely ETSI (Europe), ARIB/TTC
  (Japan), CCSA (China), ATIS (North America) and
  TTA (South Korea).
• 3GPP scope is to specify a global (3G) mobile
  phone system under ITU's IMT-2000 framework.
• 3GPP specs are based on evolved GSM specs.
• 3GPP standardization encompasses Radio, Core
  Network and Service architectures.

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3GPP Standards Releases

• Release '99
• functionally frozen December 1999. Defines UTRA
  and many other initial features
• The basis for early 3G deployment
• Release 4
• functionally frozen March 2001. Enhancements to
  Release '99 plus separation of control plane from
  user plane in core network
• First steps towards IP-based operation
• Also defines the low chip rate TDD mode
  (TD-SCDMA)
• Release 5
• functionally frozen March/June 2002. This release
  introduces
• IMS - IP-based Multimedia Services
• HSDPA - High Speed Downlink Packet Access
• Release 6
• functionality frozen September/ December2004
• Includes 2nd phase of IMS, High Speed Uplink,
  plus many other features designed to deliver the
  full 3G experience
• Release 7
• Stage 1 Dec 2005 Stage 2 2nd half 2006 Stage
  3 mid-2007
• Enhanced uplink, other spectrum multiple input
  multiple output antennas (MIMO), Advanced Global
  Navigation Satellite System concept, IMS
  emergency call handling, e-call, back-up
  algorithms (UEA2 and UIA2)

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3GPP IMS Reference Architecture
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IMS Reference Architecture

• IMS reference architecture is based on
  multi-standard and multi-industry architecture.
• IMS reference architecture is being defined by
  all major wireless and wireline standards bodies
  including, 3GPP, 3GPP2, ETSI-TISPAN, IETF, WiMAX
  Forum, OAM and others.
• IMS reference architecture unifies
  next-generation services across the user
  applications, user devices, access networks, and
  core network.
• IMS provides an infrastructure for multimedia
  services such as telephony, video, multimedia
  messaging and games for one-to-one or
  one-to-many multimedia communications.

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IMS Architecture Simplified view

• Simplified View Three Layers

AS
Service Layer
MRF
HSS
CSCF
MFCF/ MGC
Control Layer
PSTN/PLMN
IP
Access Layer
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IMS Architecture Session Control Layer

• Session Control Layer
• consists of network control servers for managing
  calls, establishing sessions and making
  modifications.
• two main elements the call session control
  function (CSCF) and the home subscriber server
  (HSS).
• the call session control function (CSCF) handles
  end-point registration and inspect/routing the
  SIP signaling messages to the application server.
  The CSCF is also responsible for interoperating
  with the access layers.
• the home subscriber server (HSS) maintains the
  end users service profile. The service profile
  includes date such as registration information,
  roaming and end users preferences.

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IMS Architecture Service Layer

• Service/Application Layer
• provides value-added services using application
  and content servers.
• two main elements the Application Server (AS)
  and the Media Resource Function (MRF).
• the application server (AS) is responsible for
  call flows, database accesses and user interface
  interactions.
• the MRF provides the media processing capability
  for the application layer. It has two
  componenets media resource function controller
  (MRFC) and media resource function processor
  (MRFP).
• the MRFC is a signaling plane node (SIP user
  agent to the S-CSCF) and the MRFP is a media
  plane node (provides all media-related functions).

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3GPP2 About 3GPP2

• The Third Generation Partnership Project 2
  (3GPP2) is a collaboration of North American and
  Asian interests also under the framework of ITUs
  IMT-2000.
• Collaboration brings together as Organizational
  Partners, Five Standards Development
  Organizations, namely, ARIB (Japan) CCSA
  (China)TIA (North America) TTA (Korea) and TTC
  (Japan) with market representation by CDMA
  development group, IPv6 forum, International 450
  association.
• 3GPP2 specs are based on evolving
  ANSI/TIA/EIA-41 specs commonly known as CDMA2000
• Four Technical Specifications Groups
• TSG-A (Access Network Interfaces)
• TSG-C (cdma2000)
• TSG-S (Services and Systems Aspects)
• TSG-X (Core Networks)

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3GPP2 MMD Architecture
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3GPP/3GPP2 Differences

• 3GPP
• Mandates IPv6
• Special GPRS procedure is used for Address.
• GGSN and P-CSCF need to be located in the same
  network.
• 3GPP uses GPRS packet services
• Smart cards are mandatory
• 3GPP doesnt allow HTTP digest authentication
• IP Multimedia Subsystem IMS

• 3GPP2
• Allows both IPv4 and IPv6
• DHCP or P-CSCF address on MS/R-UIM for IP
  Address.
• PDSN and P-CSCF allowed to be located in
  different networks (e.g., PDSN in visiting
  network and P-CSCF in home network.)
• 3GPP2 uses packet data service and Mobile IP
• Smart Cards are optional
• 3GPP2 allows HTTP digest authentication.
• Multimedia Domain MMD
• IMS CDMA Packet Data

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3GPP/3GPP2 Harmonized Architecture
IP MULTIMEDIA SUBSYSTEM
IP MULTIMEDIA SUBSYSTEM
P-CSCF
S-CSCF
P-CSCF
S-CSCF
I-CSCF
I-CSCF
APP SRV
APP SRV
3GPP GPRS Core Network
3GPP2 Packet Data Subsystem
PDSN
GGSN
SGSN
MIP HA
CORE NETWORK
RADIO ACCESS NETWORK (RAN)
3GPP RAN
3GPP2 RAN
NODE-B
RNC
BSC
BTS
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Evolution from Wireless to Wireline
Source Cisco Paper - Supporting the IP
Multimedia Subsystem for Mobile, Wireline, and
Cable Providers.
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TISPAN About TISPAN

• Telecoms and Internet converged Services and
  Protocols for Advanced Networks TISPAN
• ETSI core competence centre for fixed networks
  and for migration from switched circuit networks
  to packet-based networks with an architecture
  that can serve in both.
• Responsible for all aspects of standardisation
  for present and future converged networks
  including the NGN (Next Generation Network) and
  including, service aspects, architectural
  aspects, protocol aspects, QoS studies, security
  related studies, mobility aspects within fixed
  networks, using existing and emerging
  technologies.

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TISPAN 3GPP Collaboration

• Building upon the work already done by 3GPP in
  creating the SIP-based IMS (IP Multimedia
  Subsystem), TISPAN and 3GPP are now working
  together to define a harmonized IMS-centric core
  for both wireless and wireline networks.
• This harmonized All IP network has the
  potential to provide a completely new telecom
  business model for both fixed and mobile network
  operators.
• Access independent IMS will be a key enabler for
  fixed/mobile convergence, reducing network
  installation and maintenance costs, and allowing
  new services to be rapidly developed and deployed
  to satisfy new market demands.

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TISPAN NGN Standards

• NGN Release 1 was launched by TISPAN in December
  2005, providing the robust and open standards
  that industry can use as a reliable basis for the
  development and implementation of the first
  generation of NGN systems.
• Terminology, Strategy, QoS, Security, NNA
  Identification, ENUM
• Requirements, General architecture, Early
  services and protocols
• Detailed architecture, Base services/protocols,
  3GPP endorsements
• Operations Support Systems, Congestion control,
  NGN user data, PSTN/ISDN emulation
• TISPAN is now working on NGN Release 2 (due
  sometime this year), with a focus on enhanced
  mobility, new services and content delivery with
  improved security and network management.
• Content delivery Streaming, IP-TV, VoD
• Optimized resource usage
• Corporate users specific requirements

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TISPAN NGN Architecture
Diagram from ETSI TISPAN Ref.
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TISPAN New 3G-NGN MGW Function

• TISPAN NGN functional architecture Rel. 1.
• Media Gateway Function (MGF)
• The residential MGF (R-MGF) is located on
  customer premises.
• The access MGF (A-MGF) resides on the network
  operators premises (IP access network or core
  network).
• The trunking MGF (T-MGF) resides in the
  boundary between an IP core network and the
  PSTN/ISDN.

From Rel 1. Doc Same as IMS-MGW in 3GPP
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TISPAN New 3G-NGN MRFP Function

• TISPAN NGN functional architecture Rel. 1.
• Media Resource Function Processor (MRFP)
• Specialized resource processing functions beyond
  those available in media gateway functions
• Multimedia conferences
• Multimedia announcements
• IVR capabilities
• Media content analysis

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IMS Common Platform FMC MGW/MRFP Vision

• Common HW/SW IMS MGW/MRFP
• Safeguards future network deployments
• Accelerates delivery of real-time multimedia
  services
• Enables fixed mobile convergence today!
• Single, all-in-one, common software
• PSTN
• NGN-VoIP
• GSM/W-CDMA/3GPP
• CDMA2000/3GPP2
• Next-gen session boarder controller (SBC) with
  media functions.
• Media services
• Announcements/rec
• Rich conf.
• Rich and programmable tones
• Video and other (roadmap)

PSTN/ PLMN
IP
MTA
BB Access
IMS-MGW MGF
MGCF
Other Blocks
MRFP
MRFC
IMS
Bearer
3GPP (WCDMA) ( TD-SCDMA China) 3GPP2 (CDMA
Evolution)
Control


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Whats in store?
2009
2008
2007
2006
2005
Rel. 8.0
Rel. 7.0
Rel. 2.0 NGN
Rel. 3.0 NGN
Rel. 2.0 NGN FG
IP multimedia subsystem (IMS), multimedia
domain (MMD), Next Generation Network (NGN)
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Standard updates in the works -1

• 3GPP
• Rel 7.0 Stage 3 Mid-2007
• IMS Emergency Call handling, eCall, Backup
  algorithms, etc.
• Rel. 8.0
• Security related updates Multimedia Priority
  Service, Voice Group Call Service VGCS
  enhancements for public safety and public
  warning,
• Emergency Calling Data transfer, etc
• IMS updates for Packet Cable,
• 3GPP2
• IMS Bridge
• IMS/MMD Superstructure

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Standard updates in the works -2

• ETSI TISPAN NGN Release 3.0 based on 3GPP Rel.
  7.0
• Inter-network domain nomadicity
• User-controlled roaming
• Higher bandwidth access
• Fully nomadic (WiMAX, VDSL..)
• ITU NGN FG Release 2.0

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Glossary of Terms

• CSCF Call Session Control Function
• P-CSCF Proxy Call Session Control Function
• I-CSCF Interrogating Call Session Control
  Function
• S-CSCF Serving Call Session Control Function
• GPRS General Packet Radio Service
• GGSN Gateway GPRS Support Node
• SGSN Serving GPRS Support Node
• PDSN Packet Data Serving Node
• MIP HA Mobile IP Home Agent
• RNC Radio Network Controller
• BTS Base Transceiver Subsystem
• BSC Base Station Controller