http://www.rfc-editor.org/rfc/rfc8147.txt
RFC 8147: Next-Generation Pan-European eCall, R. Gellens, H. Tschofenig2017-05-01T23:00:00-00:00Although this specification is designed to meet the requirements of next-generation Pan-European eCall (NG-eCall), it is specified generically such that the technology can be reused or extended to suit requirements across jurisdictions.