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Clue Status Pages

ControLling mUltiple streams for tElepresence (Concluded WG)
Art Area: Barry Leiba, Murray Kucherawy | 2011-Jan-11 — 2020-Mar-17 

2020-03-15 charter

ControLling mUltiple streams for tElepresence (clue)


 Current Status: Active

     Paul Kyzivat <pkyzivat@alum.mit.edu>
     Roni Even <ron.even.tlv@gmail.com>

 Applications and Real-Time Area Directors:
     Barry Leiba <barryleiba@computer.org>
     Alexey Melnikov <aamelnikov@fastmail.fm>
     Adam Roach <adam@nostrum.com>

 Applications and Real-Time Area Advisor:
     Adam Roach <adam@nostrum.com>

 Mailing Lists:
     General Discussion: clue@ietf.org
     To Subscribe:       https://www.ietf.org/mailman/listinfo/clue
     Archive:            https://mailarchive.ietf.org/arch/browse/clue/

Description of Working Group:

    In the context of this WG, the term telepresence is used in a general
    manner to describe systems that provide high definition, high quality
    audio/video enabling a "being-there" experience.  One example is an
    immersive telepresence system using specially designed and special
    purpose rooms with multiple displays permitting life size image
    reproduction using multiple cameras, encoders, decoders, microphones
    and loudspeakers.

    Current telepresence systems are based on open standards such as RTP,
    SIP, H.264, the H.323 suite. However, they cannot easily interoperate
    with each other without operator assistance and expensive additional
    equipment which translates from one vendor to another. A major factor
    limiting the interoperability of telepresence systems is the lack of a
    standardized way to describe and negotiate the use of the multiple
    streams of audio and video comprising the media flows.

    The WG will create specifications for SIP-based conferencing systems
    to enable communication of information about media streams so that a
    sending system, receiving system, or intermediate system can make
    reasonable decisions about transmitting, selecting, and rendering
    media streams. This enables systems to make choices that optimize user

    This working group is chartered to specify the following information
    about media streams from one entity to another entity:

    * Spatial relationships of cameras, displays, microphones, and
      loudspeakers - relative to each other and to likely positions of

    * Viewpoint, field of view/capture for
      camera/microphone/display/loudspeaker - so that senders and
      intermediate devices can understand how best to compose streams for
      receivers, and the receiver will know the characteristics of its
      received streams

    * Usage of the stream, for example whether the stream is presentation,
      or document camera output

    * Aspect ratio of cameras and displays

    * Which sources a receiver wants to receive.  For example, it might
      want the source for the left camera, or might want the source chosen
      by VAD (Voice Activity Detection)

    Information between sources and sinks about media stream capabilities
    will be exchanged.

    The working group will define the semantics, syntax, and transport
    mechanism for communicating the necessary information. It will
    consider whether existing protocols for signaling, messaging and
    transport are adequate or need to be extended. Any extensions to IETF
    protocols will be done in appropriate WGs, for example extensions to
    SDP in MMUSIC.

    The scope of the work includes describing relatively static relations
    between entities (participants and devices). It also includes handling
    more dynamic relationships, such as specifying the audio and video
    streams for defined speakers. Specifying the location of the current
    speakers relative to display microphones needs to be provided
    dynamically as speakers move.

    As part of the receiver telling the sender what it wants dynamically,
    explicit receiver notification to the sender of the desired video
    stream and video pause will be considered.

    The scope includes both systems that provide a fully immersive
    experience, and systems that interwork with them and therefore need to
    understand the same multiple stream semantics.

    The focus of this work is on multiple RTP audio and video streams.
    Other media types may be considered, however development of
    methodologies for them is not within the scope of this work.

    Interoperation with SIP and related standards for audio and video is
    required.  However, backwards compatibility with existing
    non-standards compliant telepresence systems is not required.

    This working group is not currently chartered to work on issues of
    continuous conference control including: far end camera control, floor
    control, conference roster. The working group may identify
    interoperability obstacles in existing open standards. If so, the WG
    will develop requirements to be communicated to other IETF WGs or
    Standards Forums, or recharter as appropriate.

    Reuse of existing protocols and backwards compatibility with
    SIP-compliant audio/video endpoints are important factors for the
    working group to consider. The work will closely coordinate with the
    appropriate areas (e.g., OPS and SEC), and working groups including

Goals and Milestones:
  Done     - Submit informational draft to IESG on use cases
  Done     - Submit informational draft to IESG on requirements
  Done     - Submit standards track draft to IESG on Framework
  Done     - Submit standards track draft to IESG on Data Model
  Done     - Submit standards track draft to IESG on CLUE Protocol
  Done     - Submit standards track draft to IESG on CLUE Data Channel
  Done     - Submit standards track draft to IESG on Usage of RTP
  Done     - Submit standards track draft to IESG on Overall Signaling     and usage of SDP

All charter page changes, including changes to draft-list, rfc-list and milestones:

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