Internet Engineering Task Force SIPPING WG Internet Draft Charlton/Gasson/ Document: draft-charlton-deaf-req-00.txt Gybels/Spanner/ van Wijk October 2001 RNID/Ericsson Expires: April 2002 Category: Informational User Requirements for SIP in support of deaf, hard of hearing and speech-impaired individuals Status of this Memo This document is an Internet-Draft and is subject to all provisions of Section 10 of RFC2026[1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Table of Contents 1. Abstract........................................................2 2. Terminology and Conventions Used in this Document...............2 3. Introduction....................................................3 4. Purpose and Scope...............................................3 5. Background......................................................4 6. Deaf, Hard of Hearing and Speech-impaired Requirements for SIP.........................................................4 Introduction....................................................4 6.1. Connection without Difficulty..............................4 6.2 User Profile................................................5 6.3 Intelligent Gateways........................................5 6.4 Inclusive Design............................................5 6.5 Resource Management.........................................6 6.6 Confidentiality and Security................................6 7. Some Real World Scenarios.......................................6 7.1 Transcoding Service.........................................7 7.2 Media Service Provider......................................7 7.3 Sign Language Interface.....................................8 7.4 Synface Support for Voice Calls.............................8 8. Some Suggestions for Service Providers and User Agent Manufacturers...................................................8 9. Acknowledgements................................................9 10. Author's Addresses..............................................9 References and Notes...............................................10 Charlton/Gasson/Gybels/Spanner/van Wijk [Page 1 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 1. Abstract This document aims to present a set of SIP user requirements that support communications for deaf, hard of hearing and speech-impaired individuals. These user requirements address the current difficulties of deaf, hard of hearing and speech-impaired individuals in using communications facilities, while acknowledging the multi-functional potential of SIP-based communications. A number of issues related to these user requirements are further raised in this document. Also included are some real world scenarios and some technical requirements to show the robustness of these requirements on a concept-level. 2. Terminology and Conventions Used in this Document In this document, the key words "MUST", "MUST NOT","REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in RFC2119[2] and indicate requirement levels for compliant SIP implementations. For the purposes of this document, the following terms are considered to have these meanings: Abilities: A person's capacity for communicating which could include a hearing or speech impairment or not. The terms Abilities and Preferences apply to both caller and call-recipient. Preferences: A person's choice of communication mode. This could include any combination of media stream, e.g., text, audio, video. The terms Abilities and Preferences apply to both caller and call-recipient. Relay Service: A third-party or intermediary in deaf, hard of hearing and speech-impaired communications. See the definition for Transcoding Services. Transcoding Services: A human or automated third party acting as an intermediary in any session between two other User Agents (being a User Agent itself), and transcoding one stream into another (e.g., voice to text or vice versa). Textphone: Sometimes called a TTY (teletypewriter), TDD (telecommunications device for the deaf) or a minicom, a textphone enables a deaf, hard of hearing or speech-impaired person to place a call to a telephone or another textphone. Some textphones use the V18 protocol as a standard for communication with other textphone communication protocols world-wide. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 2 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 User: A deaf, hard of hearing or speech-impaired individual. A user is otherwise referred to as a person or individual, and users referred to as people. Note: For the purposes of this document, a deaf, hard of hearing, or speech-impaired person is an individual who chooses to use SIP because it can minimize or eliminate constraints in using common communication devices. As SIP promises a total communication solution for any kind of person, regardless of ability and preference, therefore there is no attempt to specifically define deaf, hard of hearing or speech-impaired in this document. 3. Introduction The background for this document is the recent developments of SIP and SIP-based communications, and a growing awareness of deaf, hard of hearing and speech-impaired issues in the technical community. The SIP capacity to simplify setting up, managing and tearing down communication sessions between all kinds of User Agents has specific implications for deaf, hard of hearing and speech-impaired individuals. As SIP enables multiple sessions with translation between multiple types of media, these requirements aim to provide the standard for recognising and enabling these interactions, and for a communications model that includes any and all types of SIP-networking abilities and preferences. 4. Purpose and Scope The scope of this document is to first present a current set of user requirements for deaf, hard of hearing and speech-impaired individuals through SIP-enabled communications. These are then followed some real world scenarios in SIP-communications that could be used in a test environment, and some concepts on how these requirements can be developed by service providers and User Agent manufacturers. These recommendations make explicit the needs of a currently often disadvantaged user-group and attempts to match them with the capacity of SIP. It is also not the intention here to prioritise the needs of the deaf, hard of hearing and speech-impaired in a way that would penalise other individuals. These requirements aim to encourage developers and manufacturers worldwide to consider the specific needs of deaf, hard of hearing and speech-impaired individuals. This document presents a world-vision where deafness, hard of hearing or speech impairment are no longer a barrier to communication. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 3 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 5. Background Deaf, hard of hearing and speech-impaired people are currently sometimes unable to use commonly available communication devices. Although this is documented[3], this does not mean that developers or manufacturers are always aware of this. Communication devices for the deaf, hard of hearing and speech-impaired are currently often primitive in design, expensive, and non-compatible with progressively designed, cheaper and more adaptable communication devices for other individuals. Additionally, non-technical human communications for the deaf, hard of hearing and speech-impaired (sign languages, lip reading) are non-standard around the world. Intermediary or third-party services (e.g. transcoding services) for enabling the hearing impaired full access to modern facilities and services are currently sometimes limited, although their value is undeniable as compared to the previous complete unavailability of such transcoding services. Yet communication methods in recent decades have proliferated: email, mobile phones, video streaming, etc. These methods are an advance in the development of data transfer technologies between devices. Developers and advocates of SIP agree that this is a protocol that not only anticipates the growth in communications between convergent networks in real time, but also fulfils the potential of the Internet as a communications and information forum. Further, that these developments allow a standard of communication that can be applied throughout all networking communities, regardless of abilities and preferences. 6. Deaf, Hard of Hearing and Speech-impaired Requirements for SIP Introduction The user requirements in this section are provided for the benefit of service providers, User Agent manufacturers and any other interested party in the development of products and services for the deaf, hard of hearing and speech-impaired. The user requirements are as follows: 6.1 Connection without Difficulty This requirement states: Whatever the preferences and abilities of the user and User Agent, there SHOULD be no difficulty in setting up SIP sessions. These sessions could include multiple proxies, call routing decisions, transcoding services, e.g., TypeTalk[4] or other media processing, and could include multiple simultaneous or alternative media streams. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 4 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 This means that any User Agent in the conversation space (including transcoding services) SHOULD be able to add or remove a media stream from the call without having to tear it down and re-establish it. 6.2 User Profile This requirement states: Deaf, hard of hearing and speech-impaired user abilities and preferences (i.e., user profile) MUST be communicable by SIP, and these abilities and preferences MUST determine the handling of the session. The User Profile for a deaf, hard of hearing and speech-impaired person might include: - How media streams are received and transmitted (text, voice, video, or any combination) - Redirecting specific media streams through a transcoding service (e.g., TypeTalk) - Roaming (for example, a deaf person accessing their User Profile from a web-interface at an Internet café) - Anonymity, that is, not revealing that a deaf person is calling, even through a transcoding service (for example, TextDirect informs the call-recipient that there is an incoming text call without saying that a deaf person is calling). Part of this requirement is to ensure that deaf, hard of hearing and speech-impaired people can keep their preferences and abilities confidential from others, to avoid possible discrimination or prejudice, while still being able to establish a SIP session. 6.3 Intelligent Gateways This requirement states: SIP SHOULD support a class of User Agents to perform as gateways for legacy systems designed for deaf, hard of hearing and speech-impaired people. For example, an individual could have a SIP User Agent acting as a gateway to a PSTN legacy textphone. 6.4 Inclusive Design This requirement states: Where applicable, design concepts for communications (devices, applications, etc.) MUST include the abilities and preferences of deaf, hard of hearing and speech-impaired people. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 5 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 Transcoding services and User Agents MUST be able to connect with each other regardless of the provider or manufacturer. This means that new User Agents MUST be able to support legacy protocols through appropriate gateways. 6.5 Resource Management This requirement states: User Agents SHOULD be able to identify the content of a media stream in order to obtain such information as the cost of the media stream, if a transcoding service can support it, etc. User Agents SHOULD be able to choose among transcoding services and similar services based on their capabilities (e.g., whether a transcoding service carries a particular media stream), and any policy constraints they impose (e.g., charging for use). It SHOULD be possible for User Agents to discover the availability of alternative media streams and to choose from them. 6.6 Confidentiality and Security This requirement states: All third-party or intermediaries (transcoding services) employed in a session for deaf, hard of hearing and speech-impaired people MUST offer a confidentiality policy. All information exchanged in this type of session MUST be secure, that is, erased before confidentiality is breached, unless otherwise required by legal intercept[5]. This means that transcoding services (e.g., interpretation, translation) MUST publish their confidentiality and security policies. 7. Some Real World Scenarios These scenarios are intended to show some of the various types of media streams that would be initiated, managed, directed, and terminated in a SIP-enabled network, and shows how some resources might be managed between SIP-enabled networks, transcoding services and service providers. To illustrate the communications dynamic of these kinds of scenarios, each one specifically mentions the kind of media streams transmitted, and whether User Agents and Transcoding Services are involved. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 6 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 7.1 Transcoding Service In this scenario, a hearing person calls the household of a deaf person and a hearing person. 1. A voice conversation is initiated between the hearing participants: ( Phone A) <-----Voice ---> ( Phone B) 2. During the conversation, the hearing person asks to talk with the deaf person, while keeping the voice connection open so that voice to voice communications can continue if required. 3. A Relay Service is invited into the conversation. 4. The Relay Service transcodes the hearing person's words into text. 5. Text from the hearing person's voice appears on the display of the deaf person's User Agent. 6. The deaf person types a response. 7. The Relay Service receives the text and reads it to the hearing person: ( ) <------------------Voice----------------> ( ) (Phone A ) -----Voice---> (Voice To Text ) -Text-> (Phone B ) ( ) <----Voice---- (Service Provider) <-Text- ( ) 8. The hearing person asks to talk with the hearing person on the other side. 9. The Relay Service withdraws from the call. 7.2 Media Service Provider In this scenario, a deaf person wishes to listen to a Radio program through a text stream of the program's audio stream. 1. The deaf person attempts to establish a connection to the radio broadcast, with User Agent preferences set to receiving audio stream as text. 2. The User Agent of the deaf person queries the radio station User Agent on whether a text stream is available, other than the audio stream. 3. However, the radio station has no text stream available for a deaf listener, and responds in the negative. 4. As no text stream is available, the deaf person's User Agent requests a Voice-To-Text transcoding service (e.g., TypeTalk) to come into the conversation space. 5. The transcoding service User Agent identifies the audio stream as a radio broadcast. However, the policy of the transcoding service is that it does not accept radio broadcasts because it would overload their resources far too quickly. 6. In this case, the connection fails. Alternatively, continuing from 2 above: 3. The radio station does provide text with their audio streams. 4. The deaf person receives a text stream of the radio program. Note: To support deaf, hard of hearing and speech-impaired, service providers are encouraged to provide text with audio streams. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 7 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 7.3 Sign Language Interface In this scenario, a deaf person enables a VisiCAST Avatar by setting up a User Agent to receive audio streams as XML data that will operate an avatar for sign-language. For outgoing communications, the deaf person types text that is transcoded into an audio stream for the other conversation participant. For example: ( ) --Voice--> ( VoiceToVisiCast ) --XMLData--> ( ) ( hearing ) ( deaf ) ( Party A ) <--Voice-- ( Text To Voice ) <---Text--- ( Party B ) ( ) ( Service Provider ) ( ) 7.4 Synface Support for Voice Calls In order to receive voice calls, a hard of hearing person uses the Synface Avatar software on a PC. Synface software processes voice (audio) stream data and displays an animated face that a hard of hearing person can lip read. During a conversation, the hard of hearing person uses Synface as support for understanding the audio stream. For example: ( ) <-----Voice-----> ( hard of ) -Voice-> ( PC with ) ( hearing ) ( hearing ) ( Synface ) ( Party A ) ( party B ) ( software) ( ) ( ) ( ) 8. Some Suggestions for Service Providers and User Agent Manufacturers This section is included to encourage service providers and user agent manufacturers in developing products and services that can be used by as wide a range of individuals as possible, including the deaf, hard of hearing and speech-impaired. - Service providers and User Agent manufacturers can offer to a deaf, hard of hearing and speech-impaired person the possibility of being able to hide their specific preferences and abilities from being made public in any transaction. - If a User Agent performs auditory signalling, for example a pager, it could also provide another signalling method, for example, visual or sensory. - Service providers who allow the user to store specific setting or preferences and abilities (i.e., user profile) might consider storing these setting in a central repository, accessible no matter the location of the user and regardless of the User Agent used at that time or location. - If there are several transcoding services available, the User Agent can be set to select the most economical/highest quality service. - The service provider can show the cost per minute and any minimum charge of a transcoding service call before a session starts, allowing the user a choice of engaging in the service or not. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 8 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 - Service providers are encouraged to offer an alternative stream with audio streams, for example, text or data streams that operate avatars, etc. - All services for interpreting, transliterating, or facilitating communications for deaf, hard of hearing and speech-impaired people are required to: - Keep information exchanged during the transaction strictly confidential - Enable information exchange literally and simply, without deviating and compromising the content - Facilitate communication without bias, prejudice or opinion - Match skill sets to the requirement of the individual - Behave in a professional and appropriate manner - Be fair in claiming compensation for services - Strive to improve the skill-sets used for their services. 9. Acknowledgements The authors would like to thank the following individuals for their contributions to this draft: Arnoud van Wijk, Ericsson David R. Oran, Cisco Mark Watson, Nortel Networks Brian Grover, RNID Anthony Rabin, RNID Michael Hammer, Cisco Henry Sinnreich, Worldcom Rohan Mahy, Cisco Julian Branston, Cedalion Hosting Services 10. Author's Addresses Nathan Charlton, RNID, nathan.charlton@rnid.org.uk Mick Gasson, RNID, mike.gasson@rnid.org.uk Guido Gybels, RNID, Guido.Gybels@rnid.org.uk Mike Spanner, RNID, mike.spanner@rnid.org.uk 19-23 Featherstone Street London EC1Y 8SL Tel: +44-20 7296 8000 Textphone: +44-20 7296 8001 Fax: +44-20 7296 8199 Arnoud van Wijk Ericsson EuroLab Netherlands BV P.O. Box 8 5120 AA Rijen The Netherlands Fax: +31-161-247569 Email: Arnoud.van.Wijk@eln.ericsson.se Comments can be sent to the SIPPING mailing list. Charlton/Gasson/Gybels/Spanner/van Wijk [Page 9 of 10]SIP for deaf, hard of hearing and speech-impaired October 2001 References and Notes 1. Bradner, S., "The Internet Standards Process -- Revision 3", BCP9, RFC 2026, October 1996. 2. S. Bradner, "Key words for use in RFCs to indicate requirement levels". Request for Comments 2119, Internet Engineering Task Force. March 1997. 3. Moore, Matthew, et al. "For Hearing People Only: Answers to Some of the Most Commonly Asked Questions About the Deaf Community, Its Culture, and the Deaf Reality". MSM Productions Ltd., 2nd Edition, September 1993. 4. TypeTalk is a UK based Relay Service with human operators performing text to voice and voice to text transcoding services. 5. This requirement recognises emerging regulatory conditions world-wide that allow for the surveillance and interception of electronic mail by legal authorities. Full Copyright Statement "Copyright (C) The Internet Society 2001. All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Expires: April 2002 Charlton/Gasson/Gybels/Spanner/van Wijk [Page 10 of 10]