3GPP Scout / Reference / EMM causes / EMM cause #39

TS 24.301EMM cause

EMM cause #39: CS service temporarily not available

TS 24.301 V20.1.0Clause 9.9.3.9Value 39 (bits 0010 0111)Checked 2026-10-15

In plain words

The network sends this cause to the UE when O&M reasons temporarily prevent a CS fallback or 1xCS fallback request from being served. The network also sends it when it aborts a mobile terminating CS fallback call during call establishment.

Our summary of the spec text quoted below.

What the spec says

Name in the cause table

CS service temporarily not available

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 when the CS fallback or 1xCS fallback request cannot be served temporarily due to O&M reasons or a mobile terminating CS fallback call is aborted by the network during call establishment (see 3GPP TS 29.118 [16A]).

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.