This International Standards specifies FAST services, i.e. FAST networking & transport layer protocols for single-hop communications, N-hop broadcast communications, ITS-MUX, and ITS station-internal forwarding, FAST service for 15628 CI (DSRC CI) support, FAST service for 15628 application support, and the related support of the MN-SAP and MF-SAP. This International Standard references ISO 24102 for related specifications of FAST ITS service announcement, and groupcast management. NOTE Formerly “FAST ITS service announcement?? was referred to as “FAST service advertisement??. The name is being changed in order to align with terminology specified in ISO 21217. Wherever practicable, this International Standard has been developed by reference to suitable extant standards, adopted by selection.