Re: Request for joint meeting at TPAC

Good to hear from you, Janina.

We are still in the early stages of working through the WEBRTC WG schedule for TPAC 2019, but currently it would appear that the best time for a joint meeting would be on Friday afternoon.  During that portion of the agenda we will be considering WebRTC-NV Use Cases<>.    Note that within these "Next Version" use cases we have included requirements for access to raw media, which can be leveraged to enable accessibility functionality such as speech transcription, language translation and captioning.

A bit of background on the division of labor between the W3C and IETF with respect to WebRTC.

The W3C WEBRTC WG focuses on the development of APIs, while the IETF ART Area (including the RTCWEB, MMUSIC, RUM and SLIM WGs) has focused on protocol development.  In practice, this means that the IETF owns protocol development work relating to accessibility, such as the following:

OPUS WG<>:  This concluded WG developed the Opus Codec<> which is widely implemented in browsers, supports high quality stereo audio and is IBR approved for Appendix C, Section 412.4 "Digital Encoding of Speech".

RUM WG<>: The recently chartered IETF RUM WG is developing a profile of SIP and media features for use with video relay services, based on the protocols defined in the IETF RTCWEB WG. An individual submission under consideration for adoption in IETF RUM WG is available here:

MMUSIC WG<>:  Christer Holmberg has recently revived work on RTT over the WebRTC Data Channel, which is a 3GPP dependency ( ).  The approach described in this draft is also mentioned in draft-rosen-rue Section 7.2 (WebRTC data channel to RTT gateway).

SLIM WG<>: This (now concluded) WG developed RFC 8373<> "Negotiating Human Language in Real-Time Communication", which defines language negotiation (including negotiation of sign language support) in SDP. Note that SLIM WG did not get into the SIP aspects of language preference, such as mechanisms for call routing in VRS or NG emergency services.

From: Janina Sajka ( <>
Sent: Wednesday, August 14, 2019 12:36 PM
To: Bernard Aboba <>; Harald Alvestrand <>; Jan-Ivar Bruaroey <>
Cc: Dominique Hazael-Massieux <>; White, Jason J <>; Judy Brewer <>; W3C WAI Accessible Platform Architectures <>; <>; Joshue O Connor <>; Michael Cooper <>
Subject: Request for joint meeting at TPAC

Dear W3C Colleagues:

This is a request for a joint meeting from the Accessible Platform
Architectures (APA) Working Group. We note that both our WGs are meeting
Thursday and Friday at TPAC, and we would appreciate an hour of your
time on several accessibility topics of joint interest.

Most critically we in APA are concerned that implementations of WebRTC
support cann support the Real Time Text (RTT) protocol being required of
telecommunications providers in the U.S. by the Federal Communications
Commission (FCC). There are several wrinkles to this requirement,
several of which are addressed in the forwarded message below. We want
you to be fully aware of the requirements as they currently exist, and
their impact on persons who are deaf or hearing impaired (primarily).

Beyond this most immediate concern we have been developing several
accessibility related use cases we would hope you can address in future
revisions of WebRTC, if not already supported. An early draft of our
document is available here:;;sdata=32jiFG5vN5dsWJwe0%2FJpVOCfTq6sltG0bU1%2FM42kMKc%3D&amp;reserved=0

Please advise if and when we might meet during Thursday or Friday of

Thanking you in advance for your consideration,

Janina Sajka, Chair
Accessible Platform Architectures (APA) WG;;sdata=XclcZEDhwaY64mLcVR2SazzURXqOBqhBh6U4uM8bcfU%3D&amp;reserved=0

Joshue O Connor writes:
> Hi Dom,
> [with Janina and Jason - leads on APA/RQTF respectively, and Judy]
> It was good to talk earlier and hope here to unpick the question about RTT
> interoperability and how WebRTC will need to support that. [1]
> I'm outlining the 'case' here and looking forward to input from Janina,
> Jason and Judy on this, especially in light of FCC requirements. [2]
> Looking back at this, and now trying to put together a 'case' - My own
> reading of the FCC requirements is that it is referencing RTT IETF and that
> it is implicit (if not explicit ) that there will be interoperability
> requirements. For example, in the transition from TTY to RTT is that this
> the case where IETF RFC 4103 is referenced directly in the 'transitioning
> to' doc. [3]
> There were some interesting insights from Jason on a private mail - where he
> mentions for example that if running a relay service, that would need some
> level of interoperability, so that the RTT wouldn’t be handled differently
> depending on which WebRTC-based application was bringing the user into the
> conversation.  There is also interoperability with SIP and other existing
> protocols to consider.
> Jason also makes the point that it may not be sufficient for each WebRTC
> application to create its own means of real-time text handling. Should the
> question is, should this be defined and handled in WebRTC user cases for
> example?
> OK, this mail was to get the ball rolling and start to make the case for RTT
> interoperability support in WebRTC.
> Thanks and I hope this is helpful Dom - looking forward to your input
> Josh
> [1];;sdata=VICj%2B2w6f9slFx%2Fm9RnF5VvJcEZwYH1nlakZ2xX38U8%3D&amp;reserved=0
> [2];;sdata=eQJz%2FX4oPbpsF9eHQ%2BB57SHdVjczes4TBED2WQeowrw%3D&amp;reserved=0
> [3];;sdata=2%2BFT%2Bot82f%2FaUazawvrFOu7g45TR3WTIU4tiR%2BIGjjM%3D&amp;reserved=0
> --
> Emerging Web Technology Specialist/A11y (WAI/W3C)


Janina Sajka

Linux Foundation Fellow
Executive Chair, Accessibility Workgroup:;;sdata=JuocnLuk%2BvBZ3szv6gVd1RG8Mri2WuxvpiQBAcN%2FaL4%3D&amp;reserved=0

The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
Chair, Accessible Platform Architectures;;sdata=ML%2BPpPZdKGw5pE3dvmlsvz5qFSVno9W46XzB9meZR5s%3D&amp;reserved=0

Received on Thursday, 15 August 2019 20:20:10 UTC