W3C activity

The proposal for a W3C working group on this issue is found below. This is a copy of an early draft, and is not necessarily reflective of what's currently being proposed to the W3C leadership.

Existing WGs related to this:

The official site for the charter is at http://www.w3.org/2010/12/webrtc-charter.html - this copy, correct as of Feb 3, 2001, is here purely for convenience.

W3C Ubiquitous Web Domain

[DRAFT] Web Real-Time Communications Working Group Charter

Status: this is a draft charter based on ongoing discussions with Harald Alvestrand, following up on the RTC Web Workshop in October 2010.

The mission of the Web Real-Time Communications Working Group, part of the Rich Web Client Activity, is to define client-side APIs to enable Real Time Communications in Web browsers.

These APIs should enable building applications that can be run inside a browser, requiring no extra downloads or plugins, that allow communication between parties using audio, video and supplementary real-time communication, without having to use intervening servers (unless needed for firewall traversal, or for providing intermediary services).

Join the Web Real-Time Communications Working Group.

End date28 February 2013
ConfidentialityProceedings are public
Initial ChairsHarald Alvestrand
Initial Team Contacts
(FTE %: 10)
François Daoust
Usual Meeting ScheduleTeleconferences: Weekly 
Face-to-face: 3-4 per year


Enabling real-time communications between Web browsers require the following client-side technologies to be available:

  • API functions to explore device capabilities, e.g. camera, microphone, speakers (currently in scope for the Device APIs & Policy Working Group)
  • API functions to capture media from local devices (camera and microphone) (currently in scope for the Device APIs & Policy Working Group)
  • API functions for encoding and other processing of those media streams,
  • API functions for establishing direct peer-to-peer connections, including firewall/NAT traversal
  • API functions for decoding and processing (including echo cancelling, stream synchronization and a number of other functions) of those streams at the incoming end,
  • Delivery to the user of those media streams via local screens and audio output devices (partially covered with HTML5)

Success Criteria

To advance to Proposed Recommendation, each specification is expected to have two independent implementations of each feature defined in the specification.

To advance to Proposed Recommendation, interoperability between the independent implementations (that is, bidirectional audio and video communication between the implementations) should be demonstrated.

Out of Scope

The definition of the network protocols used to establish the connections between peers is out of scope for this group; in general, it is expected that protocols considerations will be handled in the IETF.

The definition of codecs for audio and video is out of scope.


Recommendation-Track Deliverables

The working group will deliver specifications that cover at least the following functions, unless they are found to be fully specified within other working groups' finished results:

Media Stream API
API functions to manipulate media streams for interactive real-time communications, connecting various processing functions to each other, and to media devices and network connections, including media manipulation functions for e.g. allowing to synchronize streams.
Audio Stream API
An extension of the Media Stream API to process audio streams, to enable features such as automatic gain control, mute functions and echo cancellation.
Video Stream API
An extension of the Media Stream API to process video streams, to enable features such as bandwidth limiting, image manipulation or "video mute".
Functional Component API
API functions that allow to query for the components present in an implementation, instantiate them, and connect them to media streams.
P2P Connection API
API functions to establish peer-to-peer connections between Web browsers, independent of the network protocols used to establish the connections between peers.

The working group may decide to group the specified functions in one or more specifications.

While the specified APIs will not constrain implementations into supporting a specific profile, they will be compatible with the Profile that will be specified by the IETF @@@ Working Group.

The specified APIs and the requirements on their implementation must offer functionality that ensures that users' expectations of privacy and control over their devices are met - this includes, but is not limited to, ensuring that users are assured at all times that they know what media they are transmitting, and are able to find out who they are transmitting media to.

Similarly, all the deliverables must address issues of security - this includes, but is not limited to, ensuring that arbitrary UDP packets cannot be sent to arbitrary destinations and ports.

Other Deliverables

A comprehensive test suite for all features of a specification is necessary to ensure the specification's robustness, consistency, and implementability, and to promote interoperability between User Agents. Therefore, each specification must have a companion test suite, which should be completed by the end of the Last Call phase, and must be completed, with an implementation report, before transition from Candidate Recommendation to Proposed Recommendation. Additional tests may be added to the test suite at any stage of the Recommendation track, and the maintenance of a implementation report is encouraged.

Other non-normative documents may be created such as:

  • Primers
  • Requirements and use case document for specifications.
  • Non-normative group notes

Given sufficient resources, this Working Group should review other working groups' deliverables that are identified as being relevant to the Working Group's mission.


Note: The actual production of some of the deliverables may follow a different timeline. The group will document any schedule changes on the group home page.

TODO: depends on charter review and actual group starting date.

Dependencies and Liaisons

W3C Groups

HTML Working Group
The HTML Working Group defines a number of markup elements and APIs that serves as the basis on which the RTC APIs will be developed; in particular, the outcome of this group might require extensions to the <audio> and <video> tags
Web Applications Working Group
Some of the Web Applications Working Group APIs (such as the Web Sockets API) are likely to serve as inspiration or starting points for the APIs developed by the RTC Working Group.
Device APIs & Policy Working Group
The DAP Working Group on Media Capture APIs will require coordination across the two groups.
Web Notifications Working Group
The abilty of notifying users of incoming communications made possible by the work in the Web Notifications Working Group will be critical to the deployment of Web Real Time Communications.
Audio Incubator Group
The API under development in the Audio Incubator Group is relevant to the expected work on an Audio Stream API
WAI Protocols and Formats Working Group
Reviews from the WAI PF Working Group will be required to ensure the APIs allow to create an accessible user experience.

External Groups

IETF @@@ group on related protocol
The RTC APIs developed by this group will build upon the protocols and formats developed in the IETF @@@ Working Group.
One possible audio codec for use with this API is the one being developed in the IETF.


To be successful, the Web Real-Time Communications Working Group is expected to have 10 or more active participants for its duration. Effective participation to Web Real-Time Communications Working Group is expected to consume one work day per week for each participant; two days per week for editors. The Web Real-Time Communications Working Group will allocate also the necessary resources for building Test Suites for each specification.

Participants are reminded of the Good Standing requirements of the W3C Process.


This group primarily conducts its work on the public mailing list @@@.

The group uses a Member-confidential mailing list for administrative purposes and, at the discretion of the Chairs and participants of the group, for Member-only discussions in special cases when a particular participant requests such a discussion.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the Web Real-Time Communications Working Group home page.

Decision Policy

As explained in the Process Document (section 3.3), this group will seek to make decisions when there is consensus. When the Chair puts a question and observes dissent, after due consideration of different opinions, the Chair should record a decision (possibly after a formal vote) and any objections, and move on.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the Web Real-Time Communications Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Dominique Hazaël-Massieux, based on initial input from Harald Alvestrand

Copyright ©2011 W3C® (MITERCIMKeio), All Rights Reserved.

$Date: 2011/02/03 22:14:05 $

Subpages (1): API proposals