NAS 5G UE to AMF 3GPP TS 24.501

5G NAS - Deregistration Request (UE Originating)

Deregistration Request (UE Originating) is the NAS message the UE sends when it wants to deregister from the 5GS.

Message Fact Sheet

Protocol	nas	Network	5g
Spec	3GPP TS 24.501	Spec Section	8.2.11
Direction	UE to AMF	Message Type	5GMM signaling

Full message name	5G NAS - Deregistration Request (UE Originating)
Protocol	NAS
Technology	5G
Direction	UE to AMF
Interface	N1
Signaling bearer / channel	NAS signaling / Dedicated NAS message, often transported through UL Information Transfer
Typical trigger	UE power off handling, SIM change, user action, or explicit service logic requiring deregistration.
Main purpose	Lets the UE explicitly request deregistration so the network can release mobility-management reachability and related context.
Main specification	3GPP TS 24.501, 8.2.11
Release added	Release 15
Procedures where used	UE-Originated Deregistration
Related timers	No dominant message-specific troubleshooting timer beyond normal NAS transaction behavior
Related cause values	Deregistration type

What is Deregistration Request (UE Originating) in simple terms?

Deregistration Request (UE Originating) is the NAS message the UE sends when it wants to deregister from the 5GS.

Lets the UE explicitly request deregistration so the network can release mobility-management reachability and related context.

Why this message matters

This is the UE asking to leave the 5G registered state.

Where this message appears in the call flow

UE-Originated Deregistration

Call flow position: Opening NAS message when the UE chooses to leave registered 5GS state.

Typical state: UE is registered before the request and moves toward deregistered state.

Preconditions:

The UE has valid NAS context.

Next likely message: Deregistration Accept (UE Originating)

Call flow position

Previous message(s): Registered-state NAS signaling

Next message(s): Deregistration Accept (UE Originating), Deregistered state

Message direction and transport

Sender and receiver: UE to AMF

Interface: N1

Domain: Core-side mobility management message

Signaling bearer: NAS signaling

Logical channel: Dedicated NAS message, often transported through UL Information Transfer

Transport / encapsulation: NAS 5GS message carried end-to-end between UE and AMF

Security context: Normally sent with valid NAS security because deregistration usually happens while the UE still has active registered context.

Message Structure Overview

This message is usually simple and procedural.
The deregistration type is the first field engineers inspect because it explains scope and intent.

Structure Syntax

This message is not typically analyzed as ASN.1 on the wire. Engineers usually inspect it as a NAS or protocol field decode rather than an ASN.1 tree.

Deregistration Request is a NAS 24.501 message, not an ASN.1-defined message.

Decoded Message Dump

Deregistration Request (UE Originating)
  Extended Protocol Discriminator: 5G Mobility Management
  Security Header Type: Integrity protected and ciphered
  Message Type: Deregistration Request (UE Originating)
  Deregistration Type: Switch off, 3GPP access

How to read this dump

Check whether the request is a normal switch-off-related case or a broader deregistration request.
Security protection should usually be present if valid NAS context still exists.

Important Information Elements

IE	Required	Description
`Deregistration type`	Yes	Explains what kind of deregistration is being requested and what access context it applies to.
`5GMM cause`	Optional	Optional cause context used in some scenarios.

Detailed field explanation

`Deregistration type`

Explains what kind of deregistration is being requested and what access context it applies to.

Presence: Required

`5GMM cause`

Optional cause context used in some scenarios.

Presence: Optional

What to check in logs and traces

Inspect Deregistration type first.
Confirm the UE was previously registered and that this is not a recovery from a failed registration.
Correlate the request with the following Deregistration Accept or with local power-off behavior.

Common Issues and Troubleshooting

UE sends Deregistration Request but the network appears to keep paging it.

Likely cause: The network may not have received or fully processed the request.

What to inspect: Check uplink transport, NAS integrity, and whether a deregistration accept followed.

Next step: Correlate later paging with AMF state and confirm whether deregistration really completed.

Detailed explanation

5G NAS - Deregistration Request (UE Originating) Explained

Deregistration Request (UE Originating) is the NAS message the UE sends when it wants to leave registered 5G service. It starts a controlled deregistration path and should be interpreted as an intentional state change, not as a reject or failure message.

For beginners, the simple meaning is: the UE is asking the network to remove its current 5G registration context.
For engineers, the message is useful because it provides the start point for a clean deregistration exchange and explains later paging and reachability behavior.

What is Deregistration Request (UE Originating) in simple terms?

The UE tells the AMF that it wants to deregister. If the network accepts that request, the procedure ends with Deregistration Accept (UE Originating).

Why this message matters

This message matters because later behavior depends on whether deregistration really completed:

the network may stop paging the UE
earlier temporary identities may stop being valid for normal reachability
later registration attempts may be treated as fresh access rather than continuation

If this message is present but the completion path is missing, engineers need to be careful about assuming deregistration really succeeded.

Where this message appears in the call flow

UE                              gNB / AMF
|--- Deregistration Request ---->|
|<-- Deregistration Accept ------|
|   UE leaves registered state   |

Transport characteristics

Direction: UE to AMF
Interface: N1
Transport on access side: usually UL Information Transfer
Security expectation: commonly protected because the UE still has valid NAS context when it starts deregistration

What Deregistration Request (UE Originating) means operationally

Operationally, this message means the UE is intentionally closing out its current 5GMM registration state. It is different from:

registration failure
radio loss
network-driven deregistration

The most important field is usually the deregistration type, because it explains the intended scope of the request.

Important Information Elements

IE	Why it matters
`Deregistration type`	Tells you what kind of deregistration the UE is asking for.

Example message dump

Deregistration Request (UE Originating)
  Extended Protocol Discriminator: 5G Mobility Management
  Security Header Type: Integrity protected and ciphered
  Message Type: Deregistration Request (UE Originating)
  Deregistration Type: Switch off, 3GPP access

How to read this dump

Read Deregistration Type first because it explains the intended scope.
Confirm the message is sent under the expected NAS protection state.
Then check whether the network answers with Deregistration Accept (UE Originating).

What to check in logs

inspect the deregistration type before looking at later state changes
verify the UE had valid registration context before the request
confirm the uplink NAS path delivered the message successfully
correlate the request with the later accept or with local UE power-off behavior

FAQ

Who sends Deregistration Request (UE Originating)?

The UE sends it when it wants to deregister from the 5GS.

Summary

Deregistration Request (UE Originating) is the NAS message the UE sends when it wants to deregister from the 5GS.

Advanced Engineer Notes

Engineers often confuse UE-originated deregistration with failure recovery or radio loss. The call-flow context matters.

Related message pages

Related Procedures

Deregistration Procedure

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.