3GPP Scout / Reference / EMM causes / EMM cause #16

TS 24.301EMM cause

EMM cause #16: MSC temporarily not reachable

TS 24.301 V20.1.0Clause 9.9.3.9Value 16 (bits 0001 0000)Checked 2026-10-15

In plain words

The network sends this cause when the UE requests combined EPS attach or tracking area updating in a PLMN whose MSC is temporarily unreachable via EPS.

Our summary of the spec text quoted below.

What the spec says

Name in the cause table

MSC temporarily not reachable

Source: 3GPP TS 24.301 V20.1.0, clause 9.9.3.9, table 9.9.3.9.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24301-k10.zip in the 3GPP archive.

When it is used

This EMM cause is sent to the UE if it requests a combined EPS attach or tracking area updating in a PLMN where the MSC is temporarily not reachable via the EPS part of the network.

Source: 3GPP TS 24.301 V20.1.0, clause A.3. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24301-k10.zip in the 3GPP archive.

How this page was made

3GPP Scout built this page from TS 24.301 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.