Total Conversation
Encyclopedia
In telecommunication
, Total Conversation encompasses the use of a Total Conversation service which is defined in ITU-T
recommendation F.703 as “An audiovisual conversation service providing bidirectional symmetric real-time transfer of motion video, text and voice between users in two or more locations”.
In simple terms, a Total Conversation service allows people in two or more locations to:-
all in real-time.
principles applied to telecommunication field. This concept brings communication services to the broadest range of population including deaf people, hard or hearing people but also people who have speech impairment, people with cognitive impairement, elderly people, children, and also ... regular users. It is an enhancement of call services that provides a better experience to all. Total Conversation uses video, text and audio. These media can be combined or not depending on the type of profile used : many user profiles have to be taken into account. Such methodology is named Universal Design.
One of the important outcome of the project is the delivery of a technical document describing how Total Conversation should be implemented. This is done in the deliverable D3.2 Platform Specification. This document targets the videophone manufacturers but also the electronic communication regulators and people working on next generation emergency services (NG 112 in Europe)
Technical protocols used by Total Conversation are
(* Use of Common Alerting Protocol
may be also considered to share information with Emergency Services.)
Total Conversation defines three basic services
The currently most common implementation environment is native SIP as described above.
Total Comnversation can also be implemented in other call control environments.
One such environment is IP Multimedia Subsystem
(IMS) in its IMS Multimedia Telephony service.
Firstly, Total Conversation can be defined as a pragmatic selection of existing standards related to (Session Initiation Protocol
with the selection of audio, video and text codecs. It is a private initiative of services provider and technology vendors seeking interoperability in the broadtest sense.
Secondly, this can apply to existing and deployed SIP platform rather than future or next generation networks.
Thirdly, IMS is much more ambitious and define a whole architecture, including all internal interfaces and billing and physical infrastructure. Theses standards are more suitable for large telecommunication operators and their equipment vendors. This complexity has consequences:
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, Total Conversation encompasses the use of a Total Conversation service which is defined in ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
recommendation F.703 as “An audiovisual conversation service providing bidirectional symmetric real-time transfer of motion video, text and voice between users in two or more locations”.
In simple terms, a Total Conversation service allows people in two or more locations to:-
- see each other;
- hear each other; and
- send text to each other,
- mixing or not those different modes,
all in real-time.
Application of Total Conversation
- Conference call for businesses will need to use audio and text and may use video to share documents.
- Deaf people using sign languageSign languageA sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...
would be more than satisfied to call each other with video. - Deaf people using sign languageSign languageA sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...
can also call, and be called by hearing people using Video Relay ServiceVideo Relay ServiceA Video Relay Service , also sometimes known as a Video Interpreting Service, is a videotelecommunication service that allows deaf, hard-of-hearing and speech-impaired individuals to communicate over video telephones and similar technologies with hearing people in real-time, via a sign language...
. - Hard of hearing people to call each other directly with voice and text and even video for lip-reading.
- Hard of hearing and deaf people who do not use sign languageSign languageA sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...
(orally and late deafned) need to access a Text Relay Service with an audio plus text call in order to be able to speak but also to receive captions. - Text only call is the only way to make a call for deafblind user using braille display.
- Text call mixed to audio feedback is the only way to make a call for speech disabled user
- video, text and audio combined call is the only suitable way to make a call for cognitive disabled user.
- Text only call might be convenient in situation when audio communication is not permitted, available or dangerous (noisy situation, low bandwith).
- Support and hot line might be contacted with an audio only call and add a video stream if the user needs to show the actual issue he or she is facing on a device.
Total Conversation and Universal Design
Total Conversation is a straightforward application of Universal DesignUniversal design
Universal design refers to broad-spectrum ideas meant to produce buildings, products and environments that are inherently accessible to both people without disabilities and people with disabilities....
principles applied to telecommunication field. This concept brings communication services to the broadest range of population including deaf people, hard or hearing people but also people who have speech impairment, people with cognitive impairement, elderly people, children, and also ... regular users. It is an enhancement of call services that provides a better experience to all. Total Conversation uses video, text and audio. These media can be combined or not depending on the type of profile used : many user profiles have to be taken into account. Such methodology is named Universal Design.
Available implementations
A number of European companies including 4CTel, Aupix, IVèS and Omnitor but also Orange Labs produced implementations. These are mostly used to provide user-to-user calls and Relay Services for deaf and Hard of hearing people.The REACH112 European Project
The REACH112 include most of these companies mentioned above and several European companies offering services to deaf people as well as Emergency services. It is named after the "112" number which is the European emergency number like the 911 in the USA. The purpose of the project is to establish pilots in five countries in order to test Total Conversation on the field with several thousands users and for three usages:- European wide person to person calls
- Total Conversation Relay Services for deaf people
- Total Conversation used for emergency calls.
One of the important outcome of the project is the delivery of a technical document describing how Total Conversation should be implemented. This is done in the deliverable D3.2 Platform Specification. This document targets the videophone manufacturers but also the electronic communication regulators and people working on next generation emergency services (NG 112 in Europe)
Purpose of these specifications
These specifications describe:- An interconnection interface between Total Conversation Service Providers including Relay Services.
- A user to network interface for videophone manufacturers.
- A call interface for Next Generation Emergency Services in Europe Europe including an information sharing capability.
Technical protocols used by Total Conversation are
- Session Initiation ProtocolSession Initiation ProtocolThe Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
for call signalling, - T.140 with an RFC 4103. for Real-Time Text (RTT)
- Video codecs H.263H.263H.263 is a video compression standard originally designed as a low-bitrate compressed format for videoconferencing. It was developed by the ITU-T Video Coding Experts Group in a project ending in 1995/1996 as one member of the H.26x family of video coding standards in the domain of the ITU-T.H.263...
and preferably H.264. - Audio codec ITU-T G.711 and other as commonly used in VoIP calls.
(* Use of Common Alerting Protocol
Common Alerting Protocol
The Common Alerting Protocol is an XML-based data format for exchanging public warnings and emergencies between alerting technologies. CAP allows a warning message to be consistently disseminated simultaneously over many warning systems to many applications...
may be also considered to share information with Emergency Services.)
Total Conversation defines three basic services
- seamless multimedia person to person calls including the ability to call regular telephone users.
- the ability to invoke a relay service by deaf or hard of hearing persons,
- the ability to call emergency services in Total Conversation mode.
Conversation Totale and IP Multimedia Subsystem
Total Conversation basically provides a multi-media call services with specific media enabled.The currently most common implementation environment is native SIP as described above.
Total Comnversation can also be implemented in other call control environments.
One such environment is IP Multimedia Subsystem
IP Multimedia Subsystem
The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...
(IMS) in its IMS Multimedia Telephony service.
Firstly, Total Conversation can be defined as a pragmatic selection of existing standards related to (Session Initiation Protocol
Session Initiation Protocol
The Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
with the selection of audio, video and text codecs. It is a private initiative of services provider and technology vendors seeking interoperability in the broadtest sense.
Secondly, this can apply to existing and deployed SIP platform rather than future or next generation networks.
Thirdly, IMS is much more ambitious and define a whole architecture, including all internal interfaces and billing and physical infrastructure. Theses standards are more suitable for large telecommunication operators and their equipment vendors. This complexity has consequences:
- Very little UMTS release 5 networks fully supporting IMS are in production
- Multimedia call services defined by MMTEL are not translated in actual usable services on the market. An industry led initiative called Rich Communication Suite finally plans to do this .. when IMS will be rolled out in the networks.
- Rolling out a Native SIP Total Conversation services needs investments that are very reduced compared to the IMS equivalent. However, the implementations in both environments are close enough that interoperability between the two is an easy task.