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Specification

3GPP TS 23.228: IP Multimedia Subsystem (IMS); Stage 2

Published 2026-10-16Updated 2026-10-16

At a glance

Title
IP Multimedia Subsystem (IMS); Stage 2
Newest version
V20.1.0 (Rel-20)
Versions indexed
9
Newest per release
Rel-16: V16.7.0 (2021-12-23); Rel-17: V17.3.0 (2021-12-23); Rel-18: V18.12.0 (2026-06-22); Rel-19: V19.8.0 (2026-09-24); Rel-20: V20.1.0 (2026-09-24)

In plain words

TS 23.228 defines stage 2, the service description for the IP Multimedia Core Network Subsystem (IMS), including elements needed to "support IP Multimedia (IM) services". It covers Access Network functionality only as it relates to providing IM services, with those aspects covered in normative Annexes. For V20.1.0, listed change subjects include IMS application-server registration procedures, binary-encoded signalling for IMS voice over NB-IoT (GEO), and NB-IoT IMS enhancements on other 3GPP accesses.

Source: 3GPP TS 23.228 V20.1.0, clause 1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/23_series/23.228/23228-k10.zip

Sources

  1. 3GPP TS 23.228 V20.1.0, clause 1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/23_series/23.228/23228-k10.zip
  2. 3GPP CR database.

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