16.23.7 Command Procedure

Figure 16.23.7-1 depicts the basic communication between the gNB and the A-IoT CN node for the Command procedure.

The Command procedure addresses only one A-IoT device.

1. Prior to the Command procedure, the Inventory procedure as defined in clause 16.23.6 steps 1 to 6 is performed involving the concerned device and potentially other A-IoT devices.

NOTE 1: Steps 2/3/4 may happen in parallel of the Inventory procedure involving other A-IoT devices or in parallel to other command procedures targeting other A-IoT devices within the same session.

2. The A-IoT CN node initiates the Command procedure over NG-C by sending the Command Request message to the gNB in order to send a command to a single A-IoT device. The Command Request message includes the same Correlation ID and AIOTF Identifier as the ones used in its corresponding inventory procedure.

The Command Request also includes the RAN A-IoT device NGAP ID and the A-IoT NAS PDU corresponding to the targeted A-IoT device and includes some command assistance information. This command assistance information contains the estimate of expected D2R message size.

3. The gNB allocates and co-ordinates the usage of A-IoT radio resources and performs the command procedure over the A-IoT radio interface, i.e., R2D and D2R data transmission, as specified in section 16.23.5.

4. The gNB replies to the Command Request with the Command Response message including the AIOTF Identifier the Correlation ID and the RAN A-IoT device NGAP ID received in the Command Request, and the A-IoT NAS PDU received from the device.

NOTE 2: If the gNB is not able to perform the Command procedure, it rejects the request and sends a Command Failure message to the A-IoT CN node.

5. Upon completion of all the command transmission for all related devices within the session, the A-IOT CN triggers the A-IoT CN node initiated A-IoT Session Release procedure as defined in clause 16.23.8.