3GPP Scout / Reference / 5GS NAS timers / T3502

TS 24.501NAS timer

Timer T3502: 5GS mobility management, UE side

TS 24.501 V20.1.0Clause 10.2Table 10.2.1Checked 2026-10-15

In plain words

The UE starts T3502 after registration failure when the attempt counter equals 5 and initiates registration on expiry if still required.

Our summary of the spec text quoted below.

What the spec says

Timer value

Default 12 min. NOTE 1

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

At registration failure and the attempt counter is equal to 5

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

Transmission of REGISTRATION 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.

On expiry

Initiation of the registration procedure, if still required

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 5GMM-REGISTERED

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.

Note 1 of the table

NOTE 1: The value of this timer is provided by the network operator during the registration procedure.

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.

Same timer in EPS (TS 24.301)

TS 24.301 defines the corresponding timer for EPS. Its page quotes 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 line was 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.