International Telecommunication Union

Plenary Session on ITU-T Standards15th Biennial TDI International Conference –

Las Vegas, Nevada, USA

Total Conversation through ITU-T Total Conversation through ITU-T Standards:Standards:

Sign, Type, and Speak – You DecideSign, Type, and Speak – You Decide

Paul E. JonesCisco Systems, Inc.

In the beginning, communication devices for the deaf opened a whole new world for the users of those devices.

But times change…

Friends and family were able to carry on conversations over long distances, helping to maintain and even strengthen those relationships.

They enabled people to communicate in ways that were never possible before.

Without question, the introduction of the telecommunication devices for the deaf enriched everyone's lives.

314-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

And so do the modes of communication!

414-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

It’s All AboutTotal Conversation

o The ITU-T is working on standards that bring about the convergence of• Voice telephony• Video telephony• Text telephony

o These standards aim to enable what it calls “Total Conversation”

514-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Defining the Multimedia Service

o The ITU-T defined a series of service specifications and included text and video as components of the multimedia services (F.700 and F.703)

614-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Popular Multimedia Systems

o H.323 – Multimedia communication over packet-switched networks (Internet)

o SIP – Session Initiation Protocol (Internet) (IETF)

o H.320 - Multimedia communication over ISDN

o H.324 – Multimedia communication over low bit-rate links (phone lines and mobile phones)

714-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Problems with These Systems Identified

o Multimedia systems had largely focused only on voice and video

o There was a lack of support for text (or at least acceptable text)

o Video support often did not take into consideration the needs of the deaf

814-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

More Standards

o H Series Supplement 1 – Raised awareness about sign language and lip reading as it relates to video quality

o T.140 – Standard to allow Unicode for textual conversation• IETF RFC 2793 defines the transport

of T.140 over IP networks• Used by both H.323 and SIP systems

914-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Integration

o During the 1997 – 2000 timeframe, the ITU-T worked to add support for real-time text communication to the popular multimedia systems

o Acceptable video support was more of an educational exercise… and the ITU-T has made an effort to educate!

1014-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

…But Still Segregated

o The video conferencing systems in use today are:• Largely used between two parties

who have the same equipment• Not “tied into” the larger public

communications networkso Further integration is required

1114-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

The VoIP Revolution

o Since the late 1990s, the communications industry has been heavily focused on “voice over IP” or “VoIP”

o The basic idea is to simply use the Internet Protocol (IP) to carry voice, video, and data communications (sounds simple enough, huh?)

1214-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

The VoIP Revolution (cont)

o VoIP is still in its infancy, as compared to the mature public switched telephone network (PSTN)

o Even so, a large number of telephone calls are carried over IP networks today

o Unfortunately, multimedia communication services (the video and textual components) have been slower to “take off”

1314-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Bridging Two PSTN Networks over an IP Network

Service Provider IP Core Network

H.323 PSTN Gateways

GK GK GK

“Directory” Gatekeepers

GKGK

H.248 PSTN Gateways

MGCMGC

GKGK

“Text over IP” – V.toipScheduled for approval in January 2004

1414-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

ToIP Objectives

o Allow for character-by-character text communication

o Allow for simultaneous two-way conversation, along with voice and video (inherent limitations of the PSTN an obstacle)

o Standardize on an international character set (Unicode)

o Support all standard TTY device types defined in ITU-T V.18

o Enable different device types to communicate through each other by using the gateways as “interworking” devices (see next slide)

1514-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Interworking TTY Types through the use of T.140

Baudot DeviceV.21 Device

IP Network

T.140 bridges the gap

1614-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Building Bridges to the Enterprise and Residence

Service Provider IP Core Network

GK

Residence

Enterprise

GK

H.323 PSTN Gateways

GK GK GK

“Directory” Gatekeepers

GKGK

H.248 PSTN Gateways

MGCMGC

Audio and Video Terminals and TTYs

GKGK

1714-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

Ultimate Goals

o To allow any device to support the transmission of video and/or text signals

o To allow a user on a PC connected to an IP network to chat with a user on a legacy PSTN TTY device

o To improve communications with the widespread adoption of video

o To allow a user with a wireless PDA to communicate with anybody in the world

o To not require special tools for communications

1814-16 July 2003 15th Biennial TDI International Conference – Las Vegas, Nevada, USA

ITU-T

ITU-T Standards…

Enable Video, Text, and Voice Communications.

So you can Sign, Type, or Speak.

You Decide!