Work item:
J.ACDN-MIS
Subject/title:
Accessibility Capability Discovery and Negotiation for Multimedia and Immersive Services
Status:
Under study
Approval process:
AAP
Type of work item:
Recommendation
Version:
New
Equivalent number:
-
Timing:
2027-10 (Medium priority)
Liaison:
IRG-AVA
Supporting members:
Ministry of Communications India, Telecom Regulatory Authority of India, Centre for Development of Telematics
Summary:
This Recommendation specifies a standardized runtime mechanism that enables multimedia and immersive service endpoints and platforms to dynamically discover user accessibility preferences and negotiate supported capabilities. TR.CUP provides an initial context.
Existing standards such as H.702, F.790, W3C timed-text, MPEG/DVB descriptors, 3GPP multimedia, and IETF signalling protocols provide important elements for accessibility (profiles, guidelines, captions/subtitles, and metadata), but none define a cross-domain runtime discovery and negotiation mechanism. Current solutions remain static, domain-specific, or fragmented, leading to inconsistent user experiences and limited interoperability across IPTV, OTT, conferencing, and XR environments.
To address these gaps, this Recommendation defines:
a) A metadata schema for describing accessibility preferences, device capabilities, and service features.
b) Signalling methods, including messages, exchanges, and state machines, for discovery, negotiation, confirmation, and status updates.
c) Conformance points and interworking requirements to ensure interoperability across heterogeneous platforms.
d) Fall-back procedures when preferred accessibility features are unavailable.
The Recommendation is applicable to live and on-demand media, conferencing, IPTV/OTT players, XR runtimes, and virtual worlds. By providing a language- and modality-independent negotiation framework, it enhances interoperability and promotes consistent delivery of accessible experiences for persons with disabilities and other users with diverse accessibility needs.
Comment:
-
Historic references: