Total Conversation through ITUT Standards: Sign, Type, and Speak You Decide

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Total Conversation through ITU-T StandardsSign,
Type, and Speak You Decide

• Paul E. Jones
• Cisco Systems, Inc.

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In the beginning, communication devices for the
deaf opened a whole new world for the users of
those devices.
They enabled people to communicate in ways that
were never possible before.
Friends and family were able to carry on
conversations over long distances, helping to
maintain and even strengthen those relationships.

Without question, the introduction of the
telecommunication devices for the deaf enriched
everyone's lives.
But times change
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And so do the modes of communication!
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Its All AboutTotal Conversation

• The ITU-T is working on standards that bring
  about the convergence of
• Voice telephony
• Video telephony
• Text telephony
• These standards aim to enable what it calls
  Total Conversation

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Defining the Multimedia Service

• 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)

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Popular Multimedia Systems

• H.323 Multimedia communication over
  packet-switched networks (Internet)
• SIP Session Initiation Protocol (Internet)
  (IETF)
• H.320 - Multimedia communication over ISDN
• H.324 Multimedia communication over low
  bit-rate links (phone lines and mobile phones)

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Problems with These Systems Identified

• Multimedia systems had largely focused only on
  voice and video
• There was a lack of support for text (or at least
  acceptable text)
• Video support often did not take into
  consideration the needs of the deaf

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More Standards

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

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Integration

• During the 1997 2000 timeframe, the ITU-T
  worked to add support for real-time text
  communication to the popular multimedia systems
• Acceptable video support was more of an
  educational exercise and the ITU-T has made an
  effort to educate!

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But Still Segregated

• 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
  networks
• Further integration is required

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The VoIP Revolution

• Since the late 1990s, the communications industry
  has been heavily focused on voice over IP or
  VoIP
• The basic idea is to simply use the Internet
  Protocol (IP) to carry voice, video, and data
  communications (sounds simple enough, huh?)

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The VoIP Revolution (cont)

• VoIP is still in its infancy, as compared to the
  mature public switched telephone network (PSTN)
• Even so, a large number of telephone calls are
  carried over IP networks today
• Unfortunately, multimedia communication services
  (the video and textual components) have been
  slower to take off

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Bridging Two PSTN Networks over an IP Network
Directory Gatekeepers
Service Provider IP Core Network
H.323 PSTN Gateways
H.248 PSTN Gateways
Text over IP V.toip Scheduled for approval in
January 2004
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ToIP Objectives

• Allow for character-by-character text
  communication
• Allow for simultaneous two-way conversation,
  along with voice and video (inherent limitations
  of the PSTN an obstacle)
• Standardize on an international character set
  (Unicode)
• Support all standard TTY device types defined in
  ITU-T V.18
• Enable different device types to communicate
  through each other by using the gateways as
  interworking devices (see next slide)

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Interworking TTY Types through the use of T.140
IP Network
Baudot Device
V.21 Device
T.140 bridges the gap
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Building Bridges to the Enterprise and Residence
H.248 PSTN Gateways
Directory Gatekeepers
Residence
Service Provider IP Core Network
Enterprise
H.323 PSTN Gateways
Audio and Video Terminals and TTYs
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Ultimate Goals

• To allow any device to support the transmission
  of video and/or text signals
• To allow a user on a PC connected to an IP
  network to chat with a user on a legacy PSTN TTY
  device
• To improve communications with the widespread
  adoption of video
• To allow a user with a wireless PDA to
  communicate with anybody in the world
• To not require special tools for communications

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ITU-T Standards
Enable Video, Text, and Voice Communications. So
you can Sign, Type, or Speak. You Decide!