The gNB-CU initiates the procedure by sending a POSITIONING MEASUREMENT REQUEST message to the gNB-DU, indicating in the TRP List IE the TRP(s) from which measurements are requested. The gNB-DU node shall use the included information to configure positioning measurements by the indicated TRP(s). If at least one of the requested measurements has been successful for at least one of the TRPs, the gNB-DU shall reply with the POSITIONING MEASUREMENT RESPONSE message.
If the Positioning Report Characteristics IE is set to "OnDemand", the gNB-DU shall return the corresponding measurement results in the Positioning Measurement Result List IE in the POSITIONING MEASUREMENT RESPONSE message, and the gNB-CU shall consider that this reporting has been terminated by the gNB-DU.
If the Positioning Report Characteristics IE is set to "Periodic", the gNB-DU shall initiate the corresponding measurement, and it shall reply with the POSITIONING MEASUREMENT RESPONSE message without including any measurement results in the message. The gNB-DU shall then periodically initiate the Positioning Measurement Report procedure for the corresponding measurements, with the requested reporting periodicity.
If the Measurement Beam Information Request IE is included in the POSITIONING MEASUREMENT REQUEST message, the gNB-DU node shall include the Measurement Beam Information IE in the Measurement Result IE of the POSITIONING MEASUREMENT RESPONSE message
If the gNB-DU is unable to provide the requested positioning measurements for any of the TRPs in the TRP List IE of the POSITIONING MEASUREMENT REQUEST message, it shall respond with a POSITIONING MEASUREMENT FAILURE message.
If the gNB-DU receives a POSITIONING MEASUREMENT REQUEST message containing an LMF Measurement ID corresponding to an ongoing positioning measurement, it shall consider the procedure as failed and initiate local error handling.