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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
6
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
14
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
16
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
17
Multimedia Gateways
• Back up slides and additional information
18
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
19
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
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