04 - ims overview

www.convergencetechnologycenter.org DUE 402356

Vincente D’IngianniDirector of Professional ServicesBinary Systems, [email protected]

IMS Overview

2 www.convergencetechnologycenter.org

Contents

What is IMS? Basic Principles IMS building blocks IMS Architecture Why all the excitement? Who needs IMS Problems Conclusions


What is IMS?

IMS is an architecture, it is not a protocol.

Open-systems architecture that supports a range of IP-based services over both Private and Carrier networks, employing both wireless and fixed access technologies.

IMS is defined by 3GPP.


Basic Principles

Access Independence

Different Network Architectures

Terminal and user mobility

Extensive IP-based services


IMS Building Blocks

1. An all-IP Core Network (CN)

2. An all-IP Radio Access network (RAN)

3. Multimedia call control based on SIP

4. Quality of Service (QoS) support for IP


Management

Provisioning

Charging

NumberMapping

MGW

SG/MGCF

CSCF

MRF

HSSSIP, IP

Control Layer

AS ASSIP / OSA / CAMEL

Application Layer

IP/MPLS PSTN/PLMN

GERAN, UTRAN, WLAN, xDSL,...

Connectivity & Access Layer

IMS Architecture

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HSS: Home Subscriber Server

CSCF: Call Session Control Function:

S-CSCF: Serving CSCF

I-CSCF: Interrogating CSCF

P-CSCF: Proxy CSCF

BGCF: Breakout Gateway Control Function

MGCF: Media Gateway Control Function

AS: Application Server

SCP: Service Control Point

MGW: Media Gateway

MRFC: Multimedia Resource Function Controller

MRFP: Multimedia Resource Function Processor

Applications and Services

AS

SCP

Mobile

UE

GERAN

UTRAN

SGSN

IM-SSF

OSA-SCS

CSCF

HSS

SGW

Operator 1

CSCF BGCF

Operator 2

BGCF

MGCF

MRFC MRFP

GGSN

Multimedia IP

Networks

CS Domain- or -PSTN- or -

Legacy- or -

External

MGW

SGW

AlternativeAccess

Network

IMS Architecture


Vertical vs. Horizontal Architecture

Terminal TerminalNetwork

logic

Se

rvic

e 1

Se

rvic

e 2

Se

rvic

e 3

Replicated - not reusable

Application logicCommon functions

Routing

Terminal TerminalNetwork

logic

Replication of common functions

Se

rvic

e 1

Se

rvic

e 2

Se

rvic

e 3

Routing

Common functions


Imagine starting a voice call on you home phone and transferring it seamlessly to your mobile as you drive to work.

Imagine sending a multimedia message from your car that later appears on your TV screen.

Imagine watching a movie on that same TV, pausing it in mid-show and then watching it on a wireless PDA as you relax in the garden.

Imagine having a cell phone conversation with two or three friends and simultaneously sharing a video of the football match you are attending.

Imagine that all of the above can be done with a single account, on a single log-in with multiple devices over any number of access networks

These are only a few examples of seamless multimedia services that IMS will allow users to access “anywhere” at “anytime”

Why all of the excitement?


Who needs IMS?

Fixed Network Users want Multimedia Conferencing Voice over IP Streaming Services

Mobile Network Users want Push-to-X Location Based Services Mobile Gaming


Who needs IMS?

Network Providers want

Fixed Mobile Convergence One service - one implementation for all

access types New Business Models


An everyday scenario

Daniel

Jacqueline

In a taxi from the airport... Walking to the office...

Mobile phone call Mobile phone call

Mobile phone Mobile phoneVincente

Gerry



Daniel

Jacqueline

In a taxi from the airport...Walking to the office...

Activates Video mode Views Images on his mobile

Mobile phone Mobile phoneVincente

Gerry



Vincente Daniel

Gerry Jacqueline

In a taxi from the airport... Walking to the office...

Mobile phone Mobile phone

Buddy list > select project work groupInitiate PTT session

In the office... In the office...Office PC

Join PTT session Join PTT session

Join PTT session

Fixed line phone



Daniel

Jacqueline

At the hotel... Walking to the office...

Laptop Computer Mobile phone

Buddy list > personal listInvite others to Videoconference

In the office... In the office...Office PC Fixed line phone

Join Videoconference

Join VideoconferenceJoin Videoconference

Vincente

Gerry



Daniel

Jacqueline

At the hotel... Walking to the office...

Laptop Computer Mobile phone

Participates in Videoconference


Participates in Videoconference

Participates in VideoconferenceOpens presentation and shares it with his colleagues

Vincente

Gerry



Vincente Daniel

Gerry Jacqueline

At the hotel... Arrived in the office...

Laptop Computer Office PC


Switches from Mobile to PCParticipates in Videoconference

Participates in VideoconferenceParticipates in Videoconference


Problems and open issues

Architecture complexity. Guarantees of QoS. IETF and 3GPP standardisation co-operation. SIP and IMS architecture are not mature enough

to guarantee fully functioning network. Terminal complexity.


There is still work to be done....

The current work in 3GPP is still unfinished and the discussion with IETF has just been started.

The specification work still continue now.


Selected Acronyms

3G Third Generation

3GPP(2) Third Generation Partnership Project (2)

API Application Programming Interface

AS Application Server

BGCF Breakout Gateway Control Function

CAMEL Customised Applications for Mobile Enhanced Logic

CSCF Call Session Control Function

BICN Bearer Independent Core Network

GGSN Gateway GPRS Support Node

GPRS General Packet Radio Service

GSM Global System for Mobility

IMS IP Multimedia Subsystem

IP Internet Protocol

IP-CAN IP- Connectivity Access Network

ISIM IMS Subscriber Identity Module

IWF Inter-Working Function

LAN Local Area Network

QoS Quality of Service

RACS Resource and Admission Control Subsystem

RAN Radio Access Network

SCM Session Control Manager

SGSN Serving GPRS Support Node

SIP Session Initiation Protocol

SLA Service Level Agreement

UMTS Universal Mobile Terrestrial Access

04 - ims overview

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