This document specifies general technical details related to the access layer of the ITS station reference architecture specified in ISO 21217 including:

— the service access point (SAP) of a communication interface (CI) as provided by the communication adaptation layer (CAL) for communication, named IN-SAP, and related service primitives and service primitive functions;

— the SAP provided by the CI management adaptation entity (MAE) for management of the communication interface, named MI-SAP, and related service primitives by reference to ISO 24102‑3, and service primitive functions.