(Informative)

To enhance its capabilities to perceive the Environment and issue better commands to Its Motion Actuation Subsystem, a CAV exchanges information via radio with Subsystems of other entities – Human-CAV Interaction and Autonomous Motion Subsystems. Such exchanges should be performed via secure channels.

V2X is the CAV component that allows the CAV Subsystems – HCIs and AMSs – to communicate to peer entities external to the Ego CAV. Ego-Remote HCI Message and Ego-Remote AMS Message include several types of information exchange.

V2X may be achieved via different communication protocols. A CAV may use multicast or unicast to send CAVs in range information it has become aware of by using the V2X communication interface. For instance, while executing a Command, the MAS of CAV may become aware of ice on the road. The AMS may decide to broadcast that information to CAVs in range.

Unicast may be used for communication between the Ego CAV and a specific CAV. Multicast Communication may be used when a CAV broadcasts large amounts of data such as the Basic Environment Descriptors (BED). The BED data format is scalable to enable transmission of the more important elements of the BED in case the number of CAVs in a particular environment is large.

Communication with Remote CAVs is managed by a Communication Device. Here is an example of the operation flow of the Communication Device communicating with Remote CAVs:

  1. Receive identities broadcasted by Remote AMSs.
  2. Establish unicast sessions with Remote AMSs.
  3. Create a list of Remote CAVs with which it has established a session.
  4. Sends the Ego CAV’s information to Remote AMSs.

Some non-vehicle equipment may perform some CAV communication functionalities. Examples are traffic lights and roadside units. units. Some vehicles may have a subset of CAV communication capabilities, such as scooters, motorcycles, bicycles, etc. possibly transmitting their GNSS position. Such vehicles may have the capability to transmit additional information, e.g., identity, model, speed.

Identification of pedestrians may be facilitated if their smartphones broadcast their Spatial Attitude.