Multimedia Gateways& H.248/ MEGACO

ITU Workshop on IP Networking & MEDIACOM-2004

April 26, 2001

Presented by-

Clifford Sayre, Lucent Technologies

2

Multimedia Gateways

• This presentation is the joint work of several teams:

• NTT DoCoMo– Takashi Suzuki - (ITU-T SG 16 delegate)

• NTT DoCoMo Communications Laboratories USA– Muhammad Mukarram Bin Tariq– Shahid Shoaib

• Lucent Technologies– Clifford Sayre - (ITU-T SG 16 delegate)

3

Overview

• Introduction to IMT-2000 & New Capabilities

• Emerging Wireless Multimedia Applications

• H.324M/ 3G-324M Standard for Wireless Multimedia

• Interworking with the ITU-T H.3XX Series

• MEGACO/H.248 as Key Element in Interworking Gateway

4

Features of IMT-2000

• High Speed Data and Video Transmission– Maximum bit rate: 384kbps (outdoor), 2Mbps (Indoor)

• Global Mobility

• High quality transmission– Appropriate quality for each application can be provided– From 10-3 to 10-6

• Improved Frequency Efficiency– The same frequency band can accommodate a greater number of

users

• The network platform for the Mobile Multimedia Applications– Video Phone– Video Mail– Video Distribution (streaming / download)

5

Bearers of IMT-2000 and the Type of Services

• Audio/Video Application over Circuit Switched Bearer– Based on 3GPP 3G-324M– Various applications with 3G-324M

» Video phone» Video mail / Video answering» Audio/Visual content distribution

• Interworking between 3G-324M and other networks– Important to launch mobile multimedia successfully

BearersBearers Services to be CoveredServices to be CoveredType of BearersType of Bearers

Voice Communication

Packet

Voice

Non-specified Digital

Audio ／ Video Communication

Internet

Video phone (3GPP 3G-324M)

Internet

Circuit Switched

Packet Switched

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Packet SwitchedPacket SwitchedMobile NetworkMobile NetworkPacket SwitchedPacket SwitchedMobile NetworkMobile Network

Circuit Switched Circuit Switched Mobile NWMobile NW

Circuit Switched Circuit Switched Mobile NWMobile NW

InternetInternetInternetInternet

Interworking Between Multimedia Terminals

• Interworking with Multimedia terminal on the Internet• Interworking with Multimedia terminal on the PS mobile network

• 3G-324M – H.323/SIP Interworking

MGC

MG

SS7SS7SS7SS7

H.248

33G-324MG-324MMT (PS)MT (PS)(SIP/H.323)(SIP/H.323)

H.323/SIPH.323/SIP

7

3GPP 3G-324M Overview

• ITU-T developed H.324 Mobile extension (H.324M)– H.324 Annex C has been established in ’98.2– Improved error robustness

» Error robust multiplexing (H.223 Annex A ~ C)

» Efficient transport of H.245 control messages

• 3GPP extended H.324 Annex C– 3G-324M has been established in ’99.12– Specified the audio/video CODECs suitable for Wireless Network

» Mandatory support of AMR speech CODEC

» Mandatory support of H.263 baseline

» Optionally but recommended support of MPEG-4 Simple Profile @ Level 0– Specified the multiplexing for Wireless Network

» Mandatory support of H.223 Level 2 (Annex B)– Added several clarifications

» Based on the interoperability test carried out by the interested companies

» Described in 3G-324M Implementor’s Guide

8

Building Blocks of 3G-324M/ H.324M

• H.223 multiplexed bitstream is mapped onto digital channel

• Bearer control messages are delivered as in-band data

• Modem/Mode negotiation is not applied

H.2

23 A

nnex

BBearer Control

H.245

Audio CODECAMR

Call Control

Wir

eles

s N

etw

ork

I/F

Video CODECH.263/MPEG-4

Out-band

In-band

WirelessNetwork

9

H.323H.3233G-324M3G-324M

Interworking With H.323

• Interworking with H.323 system requires:– Mapping of Call Control Signaling– Mapping of Bearer Control Signaling (I.e. H.245)– Conversion of Media Transport Format– Media Transcoding

H.2

23 A

nnex

B

Bearer ControlH.245

Audio CODECAMR

Call Control

Wir

eles

s N

etw

ork

I/F

Video CODECH.263/MPEG-4

Q.931/H.225.0

Bearer ControlH.245

Audio CODEC

Video CODEC

TC

PR

TP

/UD

P

IP

10

Interworking with SIP

• Interworking with SIP requires:– Mapping of Call Control /Bearer Control Signaling to SIP/SDP– Conversion of Media Transport Format– Media Transcoding

SIPSIP3G-324M3G-324M

H.2

23 A

nnex

B

Bearer ControlH.245

Audio CODECAMR

Call Control

Wir

eles

s N

etw

ork

I/F

Video CODECH.263/MPEG-4

SIP/SDP

Audio CODEC

Video CODEC

TC

P o

r U

DP

RT

P/U

DP

IP

11

Interworking & Gateway Decomposition

• Requirements for gateway

– Decomposed GW shall be able to achieve the same interworking functionalities as Monolithic GW

– Able to communicate with any 3G-324M/ H.324M compliant terminal

– Easy to achieve compatibility between MG and MGC from different vendors

– Less interactions between MG and MGC are better» For compatibility between MG and MGC» For reduction of signaling traffic (to accommodate tens of millions

of customers)

12

Gateway Configuration

• Proposed configuration– H.248/ MEGACO protocol for MGC to MG control– MGC for call control/ signaling– MG for media stream processing– MG or MGC for media stream control (H.245) varying with application– Advantages

» Distributed architecture

» Scalability

» Synergy with converged voice/data network architectures

• H.248/ MEGACO advantages for multimedia– Support for multiple terminations in a call context– Media descriptors for voice & video signals– Packages provide flexibility for extensions & customization– ITU-T SG 16 to standardize packages for H.324M support

13

Configuration of 3G-324M – H.323 Gateway

MG

TD

M

H.245

LC:Logical ChannelNT:Network Termination

H.245 NT*

*

*

MGC

CallControl H.225.0*

3G-324Mwireless

H.323IP

ResourceControl

•Add/Delete H.245 termination•Rough Resource Control(max. no of audio/video termination)

•Add/Delete H.245 termination•Rough Resource Control(max. no of audio/video termination)

LC

LC

H.223 Audio

Video

NT

NT

•Control Audio/Video streams•Based on H.245 signaling•Follow the limitations set by MGC

•Control Audio/Video streams•Based on H.245 signaling•Follow the limitations set by MGCH.248

Bearer Control (H.245) in MGBearer Control (H.245) in MG

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MG

MGC

Other Configuration

TD

M

H.245

LC:Logical ChannelNT:Network Termination

*

*

*

CallControl H.225.0*

3G-324Mwireless

H.323IPLC

LC

H.223 Audio

Video

NT

NT

H.248

Bearer Control (H.245) in MGCBearer Control (H.245) in MGC

H.245H.245ResourceControl

Backhaul of H.245

15

Complementary Standards

• Complementary standards from different organizations enable:

– Wireless multimedia telephony– Interworking between wireless multimedia and ITU-T H.3XX series

• ITU-T Standards– Circuit switched standards such as H.324M– Packet switched standards such as H.323– Interworking standards such as H.246

• Joint IETF & ITU-T– Media gateway control with MEGACO/ H.248

• IETF Standards– IP/ packet standards such as SDP, RTP, & TCP

• 3GPP Standards– Wireless standards such as 3G-324M & GSM-AMR speech

• ISO/ MPEG Standards– Multimedia standards such as MPEG-4 video

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Summary

• Emerging wireless multimedia applications– Based on 3G-324M/ H.324M– Supported as 3GPP circuit switched service

• Interworking to other networks– Scenarios for H.3XX series terminals– Scenarios for other terminals, such as SIP terminals

• Gateways to support interworking– Flexible architecture with MGC & MG elements– H.248/ MEGACO protocol for MGC to MG control

• Complementary standards help support interworking scenarios

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Multimedia Gateways

• Back up slides and additional information

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H.324M Transport Via IP Tunneling

IP-based Core IP-based Core NWNW

IP-based Core IP-based Core NWNWCircuit Circuit

Switched Switched Radio Access Radio Access

NWNW

Circuit Circuit Switched Switched

Radio Access Radio Access NWNW

MGC

MG

H.248

33G-324MG-324M

Circuit Circuit Switched Switched

Radio Access Radio Access NWNW

Circuit Circuit Switched Switched

Radio Access Radio Access NWNW

MGC

MG

H.248

33G-324MG-324M

IP tunneling of IP tunneling of 3G-324M stream3G-324M stream

• 3G-324M audiovisual call via IP-based core network

• Save the resource of MG and core network by multiplexing audio and video stream into one connection

• Enable precise audio and video synchronization between GWsBearer Independent Call Bearer Independent Call

ControlControlBearer Independent Call Bearer Independent Call

ControlControl

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Configuration of tunneling gateway

• Gateway for tunneling

MG

TD

M

LC:Logical ChannelNT:Network

NT

MGC

*

3G-324M MG

ResourceControl

H.223

H.248

*

MGC

3G-324M