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Question 26/16 – Accessibility to multimedia systems and services
(Continuation of Question 26/16)


The capability to handle different information media and control actions varies within wide boundaries among users of telecommunications and multimedia services. The variation may have a cause in age-related functional limitations, in disabilities, and in other natural causes. With the ageing populations in large parts of the world, many telecom users will have sensory and motor limitations. It is important to meet this wide variety in capabilities in the original design of telecommunication services so that an increasing number of users can make benefit of the mainstream services. Legislation in many countries is also beginning to follow the trend of requiring design for all in all forms of communications services and communications devices.

Multimedia systems and services have great opportunities to provide valuable and accessible information in a way that the individual user can control, if care is taken from the beginning in inclusive design of these services, making them accessible to as many users as possible.

The accessibility activities in SG 16 and its predecessors have created the following documents:

  • Recommendation V.18 for text telephony,
  • Recommendation T.140 as the general presentation protocol for text conversation,
  • Recommendation T.134 for text conversation in the T.120 data conferencing environment,
  • Annex G to Recommendation H.323 for text conversation in H.323 packet multimedia environment.
  • Annex L to Recommendation H.324 for text conversation in low bit-rate multimedia applications
  • Recommendation F.703 – Multimedia conversation service description. Includes definitions of the accessible conversational services
  • H-series Supplement 1 – Application profile – Sign language and lip reading real time conversation using low bit rate video communication
  • Recommendation F.790 – Telecommunications accessibility guidelines for
    older persons and persons with disabilities
  • Technical Paper FSTP-TACL – Telecommunications Accessibility Checklist

Complemented by a number of additions to other Recommendations, the Total Conversation concept was founded for conversation in video, text and voice as an accessible superset of video telephony, text telephony and voice telephony.

It is the task of this Question to engage in standardization activities leading to services and systems designed for all. Consideration should be given to services in new generation networks with fixed as well as mobile features.

The group also has a task to promote and enhance accessibility as a normal part of ITU work.

Study items

Study items to be considered include, but are not limited to:

  • Sections on accessibility issues in relevant Recommendations, declaring how inclusive design is achieved, as requested by the Geneva and Tunis World Summit on the Information Society (WSIS) Phase I (2003) and II (2005), and by the United Nations Convention on the Rights of Persons with Disabilities
  • Support for wide performance limits in production, perception and control of each medium in communication services to allow for maximum usability in accordance with the principles of inclusive design. Specifically, study profiling of the latest video coding standards to fulfil sign language and lip reading needs at very low bit rates and in error prone environments
  • Specification of interfaces on communication equipment to allow various forms of user interface equipment to be attached in order to enable session and device control and media handling by people with varying capabilities and preferences (examples of what the interfaces should support include talking menus, keyboards, pointing devices, listening and viewing devices, Braille and voice call control, text conversation input and output, etc)
  • Multimedia Services including mechanisms for transformation between different media forms of the same content in order to adapt to the capabilities of end users. Such mechanisms may be automatic, for example text-to-speech, or performed by people, for example sign language interpretation
  • Mechanisms for user selectable media, including its production, storage, transport, presentation and logical linking
  • Specification of accessible services using wireless telecommunication technologies, and using wireless short range technologies for provision of convenient accessible features on communications equipment
  • Mechanisms for inter-working with mono-media services in an accessible way (e.g. text telephony and voice telephony)
  • Maintenance of the Total Conversation concept, and its inclusion in any new multimedia conversation protocol
  • Study the requirements on multimedia metadata from an accessibility point of view to encourage inclusive design in this field
  • Study emergency service access for people who need to communicate in other media than voice, e.g. text, sign language, lip reading supported speech, etc
  • Considerations on how to help measure and mitigate climate change


Tasks include, but are not limited to:

  • Coordination with other ITU-R, ITU-T and ITU-D study groups for fulfilment of accessibility requirements in their Recommendations (ongoing)
  • Coordination with other SDOs for fulfilment of accessibility requirements in their specifications (ongoing)
  • Promotion of Total Conversation defined in F.703 as a mainstream service (ongoing)
  • Develop guidance for implementers of interfaces between communication devices and user interface devices
  • Contribute to the continued harmonization and maintenance of the text telephone service, for example when new technologies are specified for PSTN transmission (ongoing)
  • Create guidelines for the design of IP phones and IP communication systems for the inclusion of accessibility features including text conversation, video and alerting and maintain interoperability with legacy text telephones
  • Develop specification in support of Total Conversation for disabilities beyond the needs of the deaf
  • Develop guidance for implementers of relay systems for deaf and speech-impaired users
  • Maintain the documents under the control of the Question.

An up-to-date status of work under this Question is found in the SG 16 work programme (




  • F.700, F.703, G.769/Y.1242, G.799.1/Y.1451.1, H.300-series, H.248, H.264, V.18, V.150-series, T.140


  • All Questions of Study Group 16

Study Groups:

  • ITU-T SG 2 on human factors
  • ITU-T SG 9 on IP Cablecom
  • ITU-T SG 12 on media quality
  • ITU-T SG 13 on NGN and IPTV
  • ITU-T SG 15 on access networks, for inclusive design in communication services
  • ITU-D SG 1 on access to telecommunication services for people with disabilities
  • ITU-D SG 2 on development and management of telecommunication services and networks and ICT applications

Other Bodies:

  • IETF in general, and specifically the SIPPING, MMUSIC, and AVT groups
  • 3GPP and 3GPP2 for mobile accessibility inclusion and co-ordination of text telephony and total conversation related issues
  • ETSI, particularly Technical Body HF (Human Factors)
  • ISO/IEC JTC1 SWG-A (Special Working Group on Accessibility)
  • Asia Pacific Telecommunity
  • G3ict (Global Initiative for Inclusive ICTs)
  • Internet Governance Forum


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Updated : 2008-12-05