5G NAS - Remote UE Report Response

Message Fact Sheet

Protocol	nas	Network	5g
Spec	3GPP TS 24.501	Spec Section	8.3.20
Direction	SMF to UE via AMF	Message Type	5GSM remote UE reporting

Full message name	5G NAS - Remote UE Report Response
Protocol	NAS
Technology	5G
Direction	SMF to UE via AMF
Interface	N1
Signaling bearer / channel	NAS signaling / Usually carried on the downlink NAS path for the relay UE's PDU session
Typical trigger	The SMF has received and processed a Remote UE Report and now sends the acknowledgement back to the relay UE.
Main purpose	Confirms that the network received the relay's remote UE report and completed the associated relay context handling.
Main specification	3GPP TS 24.501, 8.3.20
Release added	Release 17
Procedures where used	5G ProSe layer-3 UE-to-network relay without N3IWF, Remote UE connection and disconnection reporting, Relay PDU session maintenance

What is Remote UE Report Response in simple terms?

Remote UE Report Response is the 5GSM acknowledgement sent back to the relay UE after the SMF processes a Remote UE Report.

Confirms that the network received the relay's remote UE report and completed the associated relay context handling.

Why this message matters

Remote UE Report Response is the network's acknowledgement that it received the relay UE's remote UE report.

Where this message appears in the call flow

5G ProSe layer-3 UE-to-network relay without N3IWF

Call flow position: This is the network acknowledgement step after the relay UE sends the remote UE report.

Typical state: The SMF has already processed the report and is returning the NAS response.

Preconditions:

The relay UE sent Remote UE Report.
The SMF accepted the reported remote UE context or processed it locally.

Next likely message: The relay UE resumes normal operation or sends another report if context changes again.

Call flow position

Previous message(s): Remote UE Report, DL NAS Transport

Next message(s): Relay UE continues normal operation, Additional Remote UE Report messages if the relay context changes again

Message direction and transport

Sender and receiver: SMF to UE via AMF

Interface: N1

Domain: Core-side relay acknowledgement with access-side NAS delivery dependency

Signaling bearer: NAS signaling

Logical channel: Usually carried on the downlink NAS path for the relay UE's PDU session

Transport / encapsulation: 5GSM NAS message transported from the SMF to the relay UE through AMF mediation

Security context: Usually sent over an already protected NAS context for the relay UE's PDU session.

ASN.1 Message Syntax for 5G NAS - Remote UE Report Response

This message is not typically analyzed as ASN.1 on the wire. It is usually read as a NAS or protocol field structure instead.

This is a 5GSM NAS message defined by structured information elements in 3GPP TS 24.501 rather than ASN.1 syntax.

5G NAS - Remote UE Report Response - Example Dump

Remote UE Report Response
  Extended Protocol Discriminator: 5G Session Management
  PDU Session ID: 7
  PTI: 21
  Message Type: Remote UE Report Response

How to read this dump

The response is mostly an acknowledgement, so the key task is to correlate it with the earlier report.
Verify the same PDU session ID and PTI that were used in the remote UE report.
A simple-looking response can still be important because it confirms the network has taken note of the remote UE state change.

What to check in logs and traces

Confirm the response follows a visible Remote UE Report.
Verify `PDU Session ID` and `PTI` first so the acknowledgement matches the right report.
Check that the SMF accepted or processed the remote UE context as expected.
Correlate the response with relay access logs if the report was expected but the acknowledgement is missing.
If the relay still behaves incorrectly, inspect the earlier Remote UE Report contents rather than this response alone.

Common Issues and Troubleshooting

The response never arrives.

Likely cause: The report may not have been delivered or the network may still be processing the relay context update.

What to inspect: Check the preceding Remote UE Report, SMF logs, and relay transport path.

Next step: Validate whether the report was accepted or rejected earlier in the signaling chain.

The response arrives, but the relay context still looks wrong.

Likely cause: The response itself is only an acknowledgement; the problem is usually in the earlier report contents.

What to inspect: Check the remote UE context entries in the report and the SMF relay state.

Next step: Compare the encoded report against the expected remote UE identity and address data.

FAQ

What does Remote UE Report Response do?

It acknowledges that the network received and processed the relay UE's Remote UE Report.

Who sends Remote UE Report Response?

The SMF sends it to the relay UE via the AMF.

When is Remote UE Report Response sent?

It is sent after the SMF receives a Remote UE Report.

What are the important IEs in Remote UE Report Response?

There are no additional IEs beyond the session and transaction context; the message is essentially an acknowledgement.

Is ASN.1 used for Remote UE Report Response?

No. It is a 5GSM NAS message defined by structured information elements in 3GPP TS 24.501.

What happens if Remote UE Report Response is missing?

The relay UE may not know that the report was processed, and troubleshooting should focus on the original report path and SMF handling.

Does this message carry remote UE data?

No. The remote UE data is carried in Remote UE Report; the response mainly confirms receipt.

Related message pages

Related Procedures

Related Tools

Use This Reference in Practice

Decode this message with the 3GPP Decoder, inspect the related message database, or open the matching call flow to see where this signaling step fits in the full procedure.