5.3.4A Discovery reporting – Model B procedures

23.3033GPPProximity-based services (ProSe)Release 17Stage 2TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

5.3.4A.1 Match report (non-roaming) – restricted discovery

Figure 5.3.4A.1-1: Match Report procedure for Model B restricted discovery (non-roaming)

1. When the Discoverer UE has received a ProSe Response Code over the air that matches the Discovery Response Filter it obtained from Discoverer Request procedure, and if the UE does not have a corresponding RPAUID associated with it with a valid TTL, the UE sends a Match Report (RPAUID, UE Identity, Discovery Type, Application ID, ProSe Response Code, Metadata Requested) message to the ProSe Function in the HPLMN to get the Target RPAUID. The RPAUID is the identifier that the Discoverer UE used to obtain the Discovery Response Filter(s) from the Discoverer Request procedure. The UE Identity is set to e.g. IMSI. The Application ID represents a unique identifier of the application that triggered the Discoverer Request procedure. Discovery Type is set to "restricted discovery". The ProSe Response Code is the code received over the air.

If the monitoring UE decides that it needs to obtain the latest metadata, e.g. when the Metadata Indicator allows metadata update, and the UE has noticed a change of the metadata, it includes Metadata Requested in the Match Report message.

NOTE 1: If the UE has received the Target RPAUID corresponding to the ProSe Response Code in the Discovery Response Filter in the Discovery Response message, the Match Report procedure may be skipped.

2. The HPLMN ProSe Function checks the authorization for the Discoverer UE to perform restricted discovery.

3. The HPLMN ProSe Function analyses the ProSe Response Code and identifies in the UE context of the Discoverer UE the corresponding Target RPAUID.

4.a Optionally, the ProSe Function sends a Auth Request (RPAUID, Target RPAUID, Request Type) to the ProSe Application Server. The ProSe Function locates the ProSe Application Server based on the Application ID. The Request Type is set to "restricted discovery/match". If the Metadata Requested is included in the Match Report in step 1, the ProSe Function shall send the Auth Request message.

4.b If, based on the permission setting, the RPAUID is allowed to discover the Target RPAUID, the ProSe Application Server returns a Auth Response (PDUID, Target PDUID, Response Type, metadata) message. The PDUID corresponds to RPAUID, the Target PDUID corresponds to the Target RPAUID stored in the ProSe Application Server. The Response Type is set to "restricted discovery/match ack". This message may also contain certain metadata corresponding to the Target PDUID, e.g. welcome message, etc.

4.c The ProSe Function verifies that the returned PDUID belongs to the requesting UE, and the Target PDUID is the same as the stored Target PDUID.

NOTE 2: The Auth Request and Auth Response messages may be extended with additional contents depending on the configuration on the ProSe Function and the ProSe Application Server.

NOTE 3: The Application logic triggered by the Auth Request message is out of the scope of 3GPP.

5. The ProSe Function in HPLMN returns a Match Report Acknowledgement (Application ID, Target RPAUID, validity timer, metadata (optional)) message to the UE. The UE stores the mapping between the RPAUID, the ProSe Response Code and the Application ID for the duration of the validity timer.

NOTE 4: The application client is notified of the successful discovery either by ProSe Protocol layer in the UE or by the Application Server with procedures out of the scope of 3GPP.

6. The ProSe Function in HPLMN may optionally send a Match Report Info (RPAUID, Target RPAUID, UE Identity, ProSe Response Code, Discovery Type) to the ProSe Function of the Discoveree UE. The Discovery Type is set to "restricted discovery".

5.3.4A.2 Match report (roaming/inter PLMN discovery transmission) – restricted discovery

Figure 5.3.4A.2-1: Match Report procedure for Model B restricted discovery (roaming)

1. When the Discoverer UE has received a ProSe Response Code over the air that matches a Discovery Response Filter it obtained from the Discoverer Request procedure, and if the UE does not have a corresponding RPAUID associated with it with a valid TTL, the UE sends a Match Report (RPAUID, UE Identity, Discovery Type, Application ID, ProSe Response Code, Metadata Requested, Monitored PLMN ID) message to the ProSe Function in the HPLMN to get the Target RPAUID. The RPAUID is the identifier that the Discoverer UE used to obtain the Discovery Response Filter from the Discoverer Request procedure. The UE Identity is set to e.g. IMSI. The Application ID represents a unique identifier of the application that triggered the Discoverer Request procedure. Discovery Type is set to "restricted discovery". The ProSe Response Code is the code received over the air. The Monitored PLMN ID is that of the PLMN in which the UE monitored the ProSe Response Code.

NOTE 1: How the Monitored PLMN ID is derived will be defined in RAN specifications.

NOTE 2: If the UE has received the Target RPAUID corresponding to the ProSe Response Code in the Discovery Response Filter in the Discovery Response message, the Match Report procedure may be skipped.

2. The HPLMN ProSe Function checks the authorization for the Discoverer UE to perform restricted discovery.

3. The HPLMN ProSe Function analyses the ProSe Response Code and identifies in the UE context of the Discoverer UE the corresponding Target RPAUID.

4.c The ProSe Function verifies that the returned PDUID belongs to the requesting UE, and the Target PDUID is the same as the stored Target PDUID.

NOTE 3: The Auth Request and Auth Response messages may be extended with additional contents depending on the configuration on the ProSe Function and the ProSe Application Server.

NOTE 4: The Application logic triggered by the Auth Request message is out of the scope of 3GPP.

NOTE 5: The application client is notified of the successful discovery either by ProSe Protocol layer in the UE or by the Application Server with procedures out of the scope of 3GPP.

6. The ProSe Function in HPLMN may optionally send a Match Report Info (RPAUID, Target RPAUID, UE Identity, ProSe Response Code, Discovery Type) to the ProSe Function in the HPLMN of the Discoveree UE. Discovery Type is set to "restricted discovery". If the Monitored PLMN ID is different from that of the Target PDUID, i.e. the "announcing UE" is roaming or performs inter-PLMN discovery transmission, the ProSe Function in HPLMN of the Monitoring UE may send another Match Report Info (RPAUID, Target RPAUID, UE Identity, ProSe Restricted Code, Discovery Type) to the ProSe Function of the PLMN indicated by the Monitored PLMN ID.