- Communication Profile Handler (CPH);
- Content Subscription Handler (CSH);
- Facilities Services Handler (FSH).
These functionalities are used by ITS-S application processes (ITS-S-AP) to communicate with other ITS-S application processes and share information. These functionalities describe
- how lower-layer communication services assigned to a given data flow are applied to the service data units at the various layers in the communication protocol stack (CPH, see 6.2.3),
- how content from data dictionaries can be published and subscribed to by ITS-S application processes (CSH, see 6.2.5),
- how well-known ITS station facilities layer and management services can be applied to application process data units (FSH, see 6.2.4), relieving (ITS-S) application processes from having to implement these services on their own,
- how service access points (SAP) primitives specified in ISO 24102‑3 are used,
- service primitives for the exchange of information between ITS-S application processes and the ITS station facilities layer (FA-SAP), and
- a set of communication requirements and objectives (profiles) using the methods defined in ISO/TS 17423 to select the level of performance (best effort or real-time, etc.), confidence and security (authentication, encryption, etc.) for information exchange between ITS stations, such as data provision, event notification, roadside configuration, map update.