Negotiating Simultaneous Modalities in Real-Time Communications

Document Type Expired Internet-Draft (individual)
Author Gunnar Hellstrom 
Last updated 2017-12-12 (latest revision 2017-06-10)
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In a real-time communication session, there may be a need or preference for receiving the same content in two or more simultaneous modalities. This specification extends a mechanism for human language negotiation with a mechanism for indication of preference for, or the availability of, simultaneously provided transformations of original contents. This indication enables negotiation of simultaneous modalities in real-time sessions. Applications are for example provision of both spoken and written content in a real-time call (captioning), or provision of both spoken language original and sign language interpretation of the original language in a real-time session.


Gunnar Hellstrom (

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