Canonical Atlas record
Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP)
S1AP
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Release evolution
Use indexed version, Work Item and Change Request evidence to see what changed around this specification. This is an evidence trail, not a clause-by-clause normative diff.
Release ledger
Rel-19 snapshot
35 indexed Change Requests · 3 connected Work Items.
Showing 12 CR records from the available cross-release sample. Browse release CR records (JSON) →
CR 1984 rev.3 — Correction on Error Indication procedure
CR 1977 — Rapporteur corrections
CR 1975 rev.2 — Correction on the MME Name IE in the S1 REMOVAL RESPONSE message
CR 1963 rev.5 — Support of Full eNB as Regenerative Payload
CR 1956 rev.3 — Time Reference Distribution Information in S1AP
CR 1962 rev.4 — X2 TNL address exchange
CR 1964 rev.2 — Correction on UE Radio Capability Retrieval
CR 1984 — Correction on Error Indication procedure
CR 1956 rev.2 — Time Reference Distribution Information in S1AP
CR 1984 rev.1 — Correction on Error Indication procedure
CR 1969 — Add support for S1 context Suspend/Resume procedures in LTE/NTN (Store-and-Forward)
CR 1962 — X2 TNL address exchange
Version history
Showing 60 of 127 indexed versions.
Atlas classifications
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Work Items
Rel-4 RAN improvements
Rel-5 RAN improvements
Provisioning of IP-based multimedia services
(Small) Technical Enhancements and Improvements for Rel-5
Rel-6 RAN improvements
Rel-6 Charging Management
Rel-7 RAN improvements
Mp (MRFC - MRFP) interface
Rel-8 RAN improvements
Flexible Alerting
Stage 3 FA
Stage 1 FA
UTRA HNB
UTRAN Architecture for 3G HNB
Rel-8 LTE 3G Long Term Evolution - Evolved Packet System RAN part
LTE eUTRAN Interfaces
HSPA VoIP to WCDMA/GSM CS continuity
(Small) Technical Enhancements and Improvements for Rel-8
Enhanced Home NodeB / eNodeB
Home NB and Home eNB enhancements - RAN3 aspects
Rel-9 RAN improvements
LTE TDD Home eNodeB RF Requirements
Support for IMS Emergency Calls over LTE
Positioning Support for LTE
MBMS support in LTE
Public Warning System
Public Warning System (PWS) RAN aspects
Rel-9 Self-Organizing Networks (SON)
(Small) Technical Enhancements and Improvements for Rel-9
Deleted - Support of WiMAX - LTE Mobility
HNB and HeNB Mobility Enhancements
Core part: HNB and HeNB Mobility Enhancements
Local IP Access and Selected Internet IP Traffic Offload
Core part: Carrier Aggregation for LTE
Perf. part: Carrier Aggregation for LTE
Relays for LTE
Core part: Relays for LTE
Security for LTE Relay Nodes (Stage 2)
Minimization of Drive Tests for E-UTRAN and UTRAN
Core part: Minimization of Drive Tests for E-UTRAN and UTRAN
RAN mechanisms to avoid CN overload due to Machine-Type Communications
Stage 2 for SIPTO for macro networks
Stage 2/3 for SIPTO for macro networks
LTE Self Optimizing Networks (SON) enhancements
Core part: LTE Self Optimizing Networks (SON) enhancements
(Small) Technical Enhancements and Improvements for Rel-10
Core part: Enhanced Inter-Cell Interference Control (ICIC) for non-Carrier Aggregation (CA) based deployments of heterogeneous networks for LTE
Enhancements for Multimedia Priority Service
Core part: Further enhancements to H(e)NB mobility - Part 1
Core part: Further enhancements to H(e)NB mobility - Part 2
Study on further enhancements for HNB and HeNB
Network-Based Positioning Support for LTE
Core part: Network-Based Positioning Support for LTE
Core part: LTE Carrier Aggregation Enhancements
Core part: Network Energy Saving for E-UTRAN
Rel-11 Security small Enhancements
Core part: RAN overload control for Machine-Type Communications
Further Self Optimizing Networks (SON) enhancements
Core part: Further Self Optimizing Networks (SON) enhancements
(Small) Technical Enhancements and Improvements for Rel-11
Core part: Further Enhanced Non CA-based ICIC for LTE
Core part: Enhancement of Minimization of Drive Tests for E-UTRAN and UTRAN
Core part: Further enhancements for HeNB mobility-X2-GW
Core part: Further enhancements to H(e)NB mobility - Part 3
Study on LTE-HRPD (High Rate Packet Data in 3GPP2) inter-RAT SON
Core part: Group Call eMBMS congestion management for LTE
Core part: HetNet Mobility enhancements for LTE
Deleted - CT1 aspects of CT aspects of IMS registration control (Stage 2/3)
Core part: Low cost & enhanced coverage MTC UE for LTE
LIPA Mobility and SIPTO at the Local Network
RAN aspects for SIPTO at the Local Network
Core part: RAN aspects for SIPTO at the Local Network
Deleted - Core part: Carrier based HetNet ICIC for LTE
Core part: LTE Device to Device Proximity Services
LTE-HRPD (High Rate Packet Data in 3GPP2) inter-RAT SON
Core part: LTE-HRPD (High Rate Packet Data in 3GPP2) inter-RAT SON
Core part: E-UTRA Small cell enhancements - Physical layer aspects
Core part: Dual connectivity for LTE
Core part: Further Enhancements to LTE TDD for DL-UL Interference Management and Traffic Adaptation
Core part: Further MBMS operations support for E-UTRAN
Core part: RAN enhancements for Machine-Type and other mobile data applications Communications
TR on Security aspects of Machine-Type Communications
Reporting Enhancements in Warning Message Delivery (Stage 2/3)
Public Warning System - Reset/Failure/Restart in Warning Message Delivery in LTE
Core part: PWS - Reset/Failure/Restart in Warning Message Delivery in LTE
(Small) Technical Enhancements and Improvements for Rel-12
Core part: RAN aspects for improvements to CS/PS coordination in UTRAN Shared Network
Core part: Dedicated Core Networks
Study on further Enhancements of Minimization of Drive Tests for E-UTRAN
Core part: LTE Carrier Aggregation Enhancement Beyond 5 Carriers
Further LTE Physical Layer Enhancements for MTC
Core part: Further LTE Physical Layer Enhancements for MTC
Dual Connectivity enhancements for LTE
Core part: Extension of Dual Connectivity in E-UTRAN
Enhanced LTE Device to Device Proximity Services
Core part: Enhanced LTE Device to Device Proximity Services
Core part: Further Enhancements of Minimization of Drive Tests for E-UTRAN
Core part: RAN enhancements for extended DRX in LTE
Core part: Narrowband Internet of Things (IOT)
RAN aspects of RAN Sharing Enhancements for LTE
Core part: RAN aspects of RAN Sharing Enhancements for LTE
(Small) Technical Enhancements and Improvements for Rel-13
Core part: Self Organizing Networks (SON) for Active Antenna System (AAS) based deployments
Core part: Flexible eNB-ID and Cell-ID in E-UTRAN
Core part: Support for V2V services based on LTE sidelink
Core part: LTE-based V2X Services
Core part: Voice and Video Enhancement for LTE
Enhancements of NB-IoT
Core part: Enhancements of NB-IoT
(Small) Technical Enhancements and Improvements for Rel-14
Core part: RAN aspects of eDECOR for UMTS and LTE
5G System - Phase 1
Historical association · verification pendingEnhanced QoE Reporting for MTSI
Enhanced LTE Support for Aerial Vehicles
LTE Advanced inter-band CA (4DL/4UL) of Band 41C and Band 42C
Stopped - Core part: Signalling reduction to enable light connection for LTE
Core part: Bluetooth/WLAN measurement collection in LTE Minimization of Drive Tests (MDT)
Quality of Experience (QoE) Measurement Collection for streaming services in E-UTRAN
Core part:Quality of Experience (QoE) Measurement Collection for streaming services in E-UTRAN
Core part: UL data compression in LTE
Core part: Even further enhanced MTC for LTE
Core part: Further NB-IoT enhancements
Separation of CP and UP for Split Option 2 of NR
New Radio Access Technology
Core part: New Radio Access Technology
5G V2X with NR sidelink
Core part: 5G V2X with NR sidelink
Core part: Direct data forwarding between NG-RAN and E-UTRAN nodes for inter-system mobility
Additional MTC enhancements for LTE
Core part: Additional MTC enhancements for LTE
Core part: Even further mobility enhancement in E-UTRAN
Additional enhancements for NB-IoT
Core part: Additional enhancements for NB-IoT
Core part: NR_IAB
Core part: Support of NR Industrial Internet of Things (IoT)
Core part: NR mobility enhancements
SON (Self-Organising Networks) and MDT (Minimization of Drive Tests) support for NR
Core part: SON (Self-Organising Networks) and MDT (Minimization of Drive Tests) support for NR
Core part: NR-based access to unlicensed spectrum
Optimisations on UE radio capability signalling
Historical association · verification pendingOptimisations on UE radio capability signalling NR/E-UTRA Aspects
Core part: Optimisations on UE radio capability signalling NR/E-UTRA Aspects
(Small) Technical Enhancements and Improvements for Rel-16
Historical association · verification pendingNB-IoT/eMTC support for Non-Terrestrial Networks
Core part: NB-IoT/eMTC support for Non-Terrestrial Networks
Support for Multi-SIM devices for LTE/NR
Core part: Support for Multi-SIM devices for LTE/NR
Additional enhancements for NB-IoT and LTE-MTC
Core part: Additional enhancements for NB-IoT and LTE-MTC
Enhancement of data collection for SON (Self-Organising Networks)/MDT (Minimization of Drive Tests) in NR and EN-DC
Core part: Enhancement of data collection for SON (Self-Organising Networks)/MDT (Minimization of Drive Tests) in NR standalone and MR-DC (Multi-Radio Dual Connectivity)
Core part: Extending current NR operation to 71GHz
Core part: NR_redcap
(Small) Technical Enhancements and Improvements for Rel-17
Core part: User Plane Integrity Protection support for EPC connected architectures
IoT (Internet of Things) NTN (non-terrestrial network) enhancements
Core part: IoT (Internet of Things) NTN (non-terrestrial network) enhancements
Core part: Enhanced support of reduced capability NR devices
(Small) Technical Enhancements and Improvements for Rel-18
Core part: Non-Terrestrial Networks (NTN) for Internet of Things (IoT) Phase 3
(Small) Technical Enhancements and Improvements for Rel-19
Subscription control for reference time distribution in EPS
NR to LTE mobility restriction
Historical association · verification pendingHarmonized Standard
Location Services
Lawful Interception for GSM Features transposed to UMTS
(Small) Technical Enhancements and Improvements for R99
UMTS
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