An Internet draft, describing a solution for “Data-only emergency calls”, has been issued by the members of the ECRIT (Emergency Context Resolution with Internet Technologies) working group of IETF (Internet Engineering Task Force), on February the 14th, 2014.
This solution uses the CAP message as a container for emergency data such as alerts sent by sensors or alerts sent by vehicles after a crash. The CAP messages are transmitted using the SIP MESSAGE extension.
This draft complements a previous Internet draft issued by the former working group ATOCA (Authority-to-Citizen Alert), on the use of the SIP Event Package for CAP messages distribution, expired on April the 21st, 2011.

Links:
http://tools.ietf.org/html/draft-ietf-ecrit-data-only-ea-07
http://tools.ietf.org/html/draft-ietf-atoca-cap-00