Negotiating Human Language in Real-Time Communications

Users have various human (natural) language needs, abilities, and preferences regarding spoken, written, and signed languages. This document adds new SDP media-level attributes so that when establishing interactive communication sessions ("calls"), it is possible to negotiate (communicate and match) the caller's language and media needs with the capabilities of the called party. This is especially important with emergency calls, where a call can be handled by a call taker capable of communicating with the user, or a translator or relay operator can be bridged into the call during setup, but this applies to non-emergency calls as well (as an example, when calling a company call center). This document describes the need and a solution using new Session Description Protocol (SDP) media attributes.