Specification
3GPP TS 29.518: 5G System; Access and Mobility Management Services; Stage 3
At a glance
- Title
- 5G System; Access and Mobility Management Services; Stage 3
- Newest version
- V20.1.0 (Rel-20)
- Versions indexed
- 10
- Newest per release
- Rel-16: V16.19.0 (2026-07-01); Rel-17: V17.18.0 (2026-07-01); Rel-18: V18.15.0 (2026-09-28); Rel-19: V19.8.0 (2026-09-28); Rel-20: V20.1.0 (2026-09-28)
In plain words
TS 29.518 specifies "the stage 3 protocol and data model for the Namf Service Based Interface", and provides message flows and an API for each service offered by the AMF. It describes services the AMF offers through the Namf service based interface to network functions including SMF, PCF and NWDAF. V20.1.0 includes 16 CRs covering native 5G security context retrieval during EPS to 5GS HO with N26, AIoT DO-A uplink notification, and one-time reports for subscriptions targeting any UE.
Source: 3GPP TS 29.518 V20.1.0, clause 1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/29_series/29.518/29518-k10.zip
Newest version in each release
| Release | Newest version | In the archive | TSG meeting |
|---|---|---|---|
| Rel-20 | V20.1.0 | 2026-09-28 | TSG CT #113 |
| Rel-19 | V19.8.0 | 2026-09-28 | TSG CT #113 |
| Rel-18 | V18.15.0 | 2026-09-28 | TSG CT #113 |
| Rel-17 | V17.18.0 | 2026-07-01 | TSG CT #112 |
| Rel-16 | V16.19.0 | 2026-07-01 | TSG CT #112 |
| Rel-15 | V15.13.0 | 2022-03-19 | TSG CT #95-e |
Source: 3GPP specification archive, versions indexed by 3GPP Scout. Each version links its official file.
Change requests in V20.1.0
V20.1.0 of TS 29.518 includes 16 CRs. The first 12 by CR number are listed.
| CR | Category | Subject | Source | Working group meeting | TSG TDoc |
|---|---|---|---|---|---|
| CR 1343 | F | Retrieval of native 5G security context from old AMF during EPS to 5GS HO with N26 | Nokia | CT4 #136 | CP-262021 |
| CR 1348 | A | Correction of OpenAPI schema | Nokia | CT4 #136 | CP-262029 |
| CR 1349 | D | Correction of CT package references in change history | Nokia | CT4 #136 | CP-262017 |
| CR 1351 rev 1 | A | Correction of NRPPa transfer failure enumeration | Nokia | CT4 #136 | CP-262019 |
| CR 1352 | F | Correction of LCS-UPP references | Nokia | CT4 #136 | CP-262017 |
| CR 1353 rev 1 | B | Clarification on handling of authorized Network Identity information | Nokia, China Mobile, Ericsson | CT4 #136 | CP-262041 |
| CR 1354 rev 1 | B | Uplink notification for AIoT DO-A devices | not listed | CP-262171 | |
| CR 1355 rev 1 | F | Specification of one-time report for subscriptions targeting any UE | Huawei, Nokia | CT4 #136 | CP-262021 |
| CR 1357 rev 1 | F | Missing re-used data type | Huawei | CT4 #136 | CP-262017 |
| CR 1359 rev 2 | A | Cancel Location in 5GS for EPS Initiated Deferred Location | not listed | CP-262160 | |
| CR 1361 rev 2 | A | Correction for Location Service Continuity for Deferred MT-LR | not listed | CP-262166 | |
| CR 1362 rev 2 | F | Clarification for Delivery of Event Report Immediate Flag not Applicable | Ericsson | CT4 #136 | CP-262017 |
Source: 3GPP CR database.
Meetings behind the latest versions
Working group meetings that agreed the CRs in V20.1.0, V19.8.0, V18.15.0:
- CT4 #136: 20 CRs
Plenary meetings:
- TSG CT #113 approved V20.1.0 (Rel-20)
- TSG CT #112 approved V20.0.0 (Rel-20)
- TSG CT #113 approved V19.8.0 (Rel-19)
Source: 3GPP CR database and specification archive, as indexed by 3GPP Scout.
Clauses changed in V20.1.0
20 clauses changed or added in V20.1.0. The 10 with the largest edits are listed. Each clause number opens Scout on that clause.
| Clause | Title | Change | CRs |
|---|---|---|---|
| 5.2.2.2.1.2 | Retrieve UE Context after successful UE authentication | changed | CR 1343 |
| 5.8.1 | Service Description | changed | CR 1366 |
| 5.8.2.1 | Introduction | changed | CR 1366 |
| 5.8.2.3 | Namf_AIoT_Notify | changed | CR 1366 |
| 6.1.6.2.23 | Type: UeContextTransferReqData | changed | CR 1343 |
| 6.1.6.2.25 | Type: UeContext | changed | CR 1343, CR 1367 |
| 6.4.6.2.7 | Type: CancelPosInfo | changed | |
| 6.6.10 | HTTP redirection | changed | |
| A.8 | Namf_AIoT API | changed | |
| A.5 | Namf_Location | changed |
Source: 3GPP Scout comparison of this version with the one before it.
Sources
- 3GPP TS 29.518 V20.1.0, clause 1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/29_series/29.518/29518-k10.zip
- 3GPP TS 29.518 V20.1.0, clause 4.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/29_series/29.518/29518-k10.zip
- 3GPP CR database.
How this page was made
The facts box and the tables come straight from the 3GPP specification archive and CR database as indexed by 3GPP Scout. An AI model (GPT-6 Luna) wrote the paragraph and named the source of each sentence. Code checked every quote word for word against the stored source text and every number against the cited source. A second AI model from another company (Claude Opus 5.5) reviewed the paragraph against the same sources. The 3GPP documents themselves govern.