3GPP Scout / Reference / 5GS NAS timers / Timers T3521 and T3522

TS 24.501NAS timer

Timers T3521 and T3522: DEREGISTRATION REQUEST retransmission

TS 24.501 V20.1.0Clause 10.2Tables 10.2.1 and 10.2.2Checked 2026-10-15

Covers

TS 24.501 words these values in parallel, so they share this page. Each has its own section with the spec text and a plain explanation.

Timer T3521: 5GS mobility management, UE side

5GS mobility management, UE sideTable 10.2.1

In plain words

The UE starts T3521 when it sends DEREGISTRATION REQUEST for a procedure not due to switch off and retransmits the request on expiry.

Our summary of the spec text quoted below.

Timer value

15s NOTE 7 NOTE 8 In WB-N1/CE mode, 45s For access via a satellite NG-RAN cell, 27s NOTE 12

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

Started when

Transmission of DEREGISTRATION REQUEST message when de-registration procedure is not due to a "switch off"

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

On expiry

Retransmission of DEREGISTRATION REQUEST message

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

Stopped when

DEREGISTRATION ACCEPT message received

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

State

5GMM-DEREGISTERED-INITIATED

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

Timer T3522: 5GS mobility management, AMF side

5GS mobility management, AMF sideTable 10.2.2

In plain words

The AMF starts T3522 when it sends DEREGISTRATION REQUEST and retransmits the request on expiry.

Our summary of the spec text quoted below.

Timer value

6s In WB-N1/CE mode, 24s For access via a satellite NG-RAN cell, 11s NOTE 12

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

Started when

Transmission of DEREGISTRATION REQUEST message

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

On expiry

Retransmission of DEREGISTRATION REQUEST message

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

Stopped when

DEREGISTRATION ACCEPT message received

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

State

5GMM-DEREGISTERED-INITIATED

Source: 3GPP TS 24.501 V20.1.0, clause 10.2, table 10.2.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.

Same timers in EPS (TS 24.301)

TS 24.301 defines the corresponding timers for EPS. Their pages quote the EPS wording.

How this page was made

3GPP Scout built this page from TS 24.501 V20.1.0 as indexed on 2026-10-15. The quotes are copied from the spec, and code checks each one against the stored text and the 3GPP archive file before publishing. The plain-words lines were written by an AI model (GPT-6 Sol) and checked against the quotes by a second AI model from another company (Claude Opus 5.5). The official 3GPP text governs.