| Feature or Study Item: Supporting Globally Routable User Agent URIs in IMS | GRUU | Rel-7 |
| Feature or Study Item: Access Class Barring and Overload Protection | ACBOP | Rel-7 |
| Feature or Study Item: System enhancements for Fixed Broadband access to IMS | FBI | Rel-7 |
| Feature or Study Item: Support of SMS over generic 3GPP IP access | SMSIP | Rel-7 |
| Feature or Study Item: Evolution of Policy Control and Charging | PCC | Rel-7 |
| Feature or Study Item: Combinational Services | CSICS | Rel-7 |
| Work task: CT1 PS domain aspects to support IMS Emergency sessions | EMC1 | Rel-7 |
| Building Block: Emergency Call Enhancements for IP& PS Based Calls – stage 3 | EMC1 | Rel-7 |
| Building Block: Maintenance of TISPAN R1 | MAINT_R1 | Rel-7 |
| Feature or Study Item: IMS Stage 3 IETF Protocol Alignment | IMSProtoc | Rel-7 |
| Feature or Study Item: Mobility between 3GPP-WLAN Interworking and 3GPP Systems | IWLAN_Mob | Rel-8 |
| Building Block: AS/MRFC Stage 2 | MRFC_TS | Rel-8 |
| Building Block: Issues for CT1 TR 24.801 | SAES | Rel-8 |
| Building Block: CT1 aspects of IMS_Corp | IMS_Corp | Rel-8 |
| Building Block: CT1 part of Stage 3 for I-WLAN NSP | IWLANNSP | Rel-8 |
| Feature or Study Item: 3GPP2 Input to Common IMS | CIMS_3GPP2 | Rel-8 |
| Building Block: CS Fallback in EPS | SAES-CSFB | Rel-8 |
| Feature or Study Item: Maintenance of TISPAN documentation | MAINTISP | Rel-8 |
| Work task: Documentation of TISPAN R1 and R2 in CT1 | REDOC_TIS-C1 | Rel-8 |
| Feature or Study Item: Home NodeB / eNodeB | HomeNB | Rel-8 |
| Work task: Stage 3 for SRVCC in EPS | SAES-SRVCC | Rel-8 |
| Work task: CT1 aspects - Stage 3 for ICSRA | ICSRA | Rel-8 |
| Building Block: Stage 3 CIMS_3GPP2 | REDOC_3GPP2 | Rel-8 |
| Work task: IMS CAT SS | CAT-SS | Rel-8 |
| Work task: Stage 3 security aspects for MIPv4 Access | SAES-SA-FP_n3GPP | Rel-8 |
| Building Block: CT1 part of GBAPush | GBAPush | Rel-8 |
| Building Block: Stage 3 IMS Service Continuity | IMS-Cont | Rel-8 |
| Feature or Study Item: IMS Restoration Procedures | IMS_RP | Rel-8 |
| Building Block: CT1 aspects of Mobility between 3GPP-WLAN Interworking and 3GPP Systems | IWLAN_Mob | Rel-8 |
| Building Block: Transfer of data during an emergency call | EData | Rel-8 |
| Building Block: CT1 aspects of ETWS | ETWS | Rel-8 |
| Building Block: SAE for Interoperation between LTE and legacy cellular PS accesses | SAES-SA-FP_3GPP | Rel-8 |
| Building Block: SAE for support for non-3GPP accesses | SAES-SA-FP_n3GPP | Rel-8 |
| Feature or Study Item: Earthquake and Tsunami Warning System | ETWS | Rel-8 |
| Feature or Study Item: IMS Multimedia Telephony and Supplementary Services | IMSTSS | Rel-8 |
| Building Block: General aspects of IMS Sup Services | IMSSS-Gal | Rel-8 |
| Feature or Study Item: Security Enhancements for IMS | IMS-Sec | Rel-8 |
| Building Block: IMS Inter-working aspects in Support of Cable Regulatory requirements | PktCbl-Intw | Rel-8 |
| Work task: CT1,CT3 aspects of PktCbl-Interwork | PktCbl-Intw | Rel-8 |
| Building Block: Single Radio Voice Call Continuity for 3GPP (SRVCC) | SAES-SRVCC | Rel-8 |
| Building Block: Stage 3 for PNM | PNM | Rel-8 |
| Building Block: Deleted - Actual Requirements of PNM | PNM | Rel-8 |
| Building Block: Stage 2 for PNM | PNM | Rel-8 |
| Work task: Stage 2/3 for Network selection procedures | SAES | Rel-8 |
| Work task: Stage 3 for Session management, bearer control and QoS aspects | SAES-LTE | Rel-8 |
| Work task: Stage 3 (CT1) for SAE impact on services, network functions and capabilities | SAES | Rel-8 |
| Work task: Deleted - Interoperability | SAES-St3-interop | Rel-8 |
| Feature or Study Item: Enhancements for Voice Group Call Service (VGCS) Applications (EVA) | EVA | Rel-8 |
| Work task: Deleted - Protocol impact of FBI for TISPAN R2 | FBI2-TISP2-c1 | Rel-8 |
| Work task: CT1 part of Service Level Tracing in IMS | OAM8-Trace | Rel-8 |
| Feature or Study Item: Study on AS-MRFC media server control protocol | MRFC | Rel-8 |
| Feature or Study Item: Personal Network Management | PNM | Rel-8 |
| Feature or Study Item: Value-Added Services for Short Message Service | VAS4SMS | Rel-9 |
| Building Block: LCS Control Plane Solution for EPS | LCS_EPS-CPS | Rel-9 |
| Building Block: CT1 aspects of Access Network Discovery and Selection Function enhancements | eANDSF | Rel-9 |
| Building Block: CT1 aspects of Multiple PDN Connection to the Same APN for PMIP-based Interfaces | MUPSAP | Rel-9 |
| Work task: CT1 aspects of IMS Media Plane Security | MEDIASEC_CORE | Rel-9 |
| Feature or Study Item: System aspects of vocoder rate adaptation for LTE | LTEimp-Vocoder | Rel-9 |
| Feature or Study Item: Enhancements of IMS Customized Alerting Tone (CAT) Service | eCAT | Rel-9 |
| Building Block: Stage 3 for Enhancements of IMS Customized Alerting Tone (CAT) Service | eCAT-SS | Rel-9 |
| Feature or Study Item: IMS Stage 3 IETF Protocol Alignment - phase 3 | IMSProtoc3 | Rel-9 |
| Building Block: Stage 3 for Service Specific Access Control in EPS | SSAC | Rel-9 |
| Building Block: Stage 3 for IMS Customized Ringing Signal (CRS) Service | CRS | Rel-9 |
| Feature or Study Item: 128 bit encryption for GSM and GPRS | A5/4-GEA4 | Rel-9 |
| Work task: CT1 aspects of Control Plane LCS in the EPC | LCS_EPS-CPS | Rel-9 |
| Building Block: CT1 aspects of IMS Stage 3 - IETF Protocol Alignment - phase 3 | IMSProtoc3 | Rel-9 |
| Building Block: CT1 part of Cell Broadcast protocol Base Station Controller – Cell Broadcast Centre | CEBRO | Rel-9 |
| Building Block: CT1 part of 128 bit encryption for GSM and GPRS | A5/4-GEA4 | Rel-9 |
| Work task: CT1 part of Stage 3 for Network Improvements for Machine-Type Communications | NIMTC-CN | Rel-10 |
| Work task: CT1 part of Stage 3 for IP Flow Mobility and seamless WLAN offload | IFOM-CT | Rel-10 |
| Feature or Study Item: AT Commands for IMS-configuration | AT_IMS | Rel-10 |
| Building Block: CT aspects of Multi Access PDN Connectivity | MAPCON-St3 | Rel-10 |
| Building Block: Stage 3 for IMS Emergency Session Enhancements | IESE | Rel-10 |
| Feature or Study Item: Single Radio Voice Call Continuity (SRVCC) enhancements (Stage 3) | eSRVCC | Rel-10 |
| Feature or Study Item: Single Radio Voice Call Continuity (SRVCC) in alerting phase (Stage 3) | aSRVCC | Rel-10 |
| Work task: CT1 aspects of Multi Access PDN Connectivity | MAPCON-St3 | Rel-10 |
| Building Block: CT1 part of Stage 3 for SRVCC enhancements | eSRVCC | Rel-10 |
| Building Block: CT aspects of Single Radio Voice Call Continuity (SRVCC) in alerting phase (Stage 3) | aSRVCC | Rel-10 |
| Feature or Study Item: IMS Service Continuity – Inter Device Transfer enhancements | IMS_SC_eIDT | Rel-10 |
| Feature or Study Item: Tightened Link Level Performance Requirements for Single Antenna MS | TIGHTER | Rel-10 |
| Feature or Study Item: Advice of Charge (AoC) service support enhancements | eAoC | Rel-10 |
| Building Block: Stage 2/3 for Local IP Access | LIPA | Rel-10 |
| Building Block: CN aspects of Single Radio Video Call Continuity for 3G-CS | vSRVCC-CT | Rel-11 |
| Building Block: Stage 3 for Transit Inter Operator Identifier for IMS Interconnection Charging in multi operator environment | IOI_IMS_CH | Rel-11 |
| Feature or Study Item: enhanced Nodes Restoration for EPC (Stage 2/3) | eNR_EPC | Rel-11 |
| Feature or Study Item: Reference Location Information (Stage 3) | RLI | Rel-11 |
| Feature or Study Item: IMS Stage 3 IETF Protocol Alignment - phase 5 | IMSProtoc5 | Rel-11 |
| Feature or Study Item: Single Radio Voice Call Continuity from UTRAN/GERAN to E-UTRAN/HSPA | rSRVCC | Rel-11 |
| Building Block: CN Stage 3 for Full Support of Multi-Operator Core Network by GERAN | Full_MOCN-GERAN | Rel-11 |
| Work task: CT1 part of CT aspects of Roaming Architecture for Voice over IMS with Local Breakout | RAVEL-CT | Rel-11 |
| Building Block: CT aspects of Network-provided Location information for IMS (Stage 3) | NWK-PL2IMS-CT | Rel-11 |
| Building Block: Deleted - CT1 part of Enhancement of the Protocols for SMS over SGs | PROTOC_SMS_SGs | Rel-11 |
| Work task: CT1 part of Stage 3 for GBA extensions for re-use of SIP Digest credentials | GBA-ext-St3 | Rel-11 |
| Feature or Study Item: S2a Mobility based On GTP and WLAN access to EPC | SaMOG_WLAN | Rel-11 |
| Work task: CT1 part of Stage 3 for Advanced IP Interconnection of Services | IPXS | Rel-11 |
| Work task: CT1 part of Stage 3 BB1: Reachability Aspects of SIMTC | SIMTC-ReachCSPS | Rel-11 |
| Work task: Deleted - Stage 3 (CS+PS) Signalling Optimizations of SIMTC | SIMTC-Sig | Rel-11 |
| Work task: Stage 3 CS aspects for SIMTC | SIMTC-CS | Rel-11 |
| Work task: Deleted - CT1 part of Stage 3 Signalling Optimizations of SIMTC | SIMTC-Sig | Rel-11 |
| Work task: Stage 3 (CS+PS) Extended Access Barring for UTRAN and E-UTRAN | SIMTC-RAN_OC | Rel-11 |
| Work task: CT1 part of Stage 3 BB I: BBF interworking with home routed traffic for WLAN and H(e)NB | BBAI_BBI-CT | Rel-11 |
| Work task: CT1 part of Stage 3 BB II: BBF interworking with offload in access network for WLAN and for H(e)NB | BBAI_BBII-CT | Rel-11 |
| Building Block: CT aspects for Single Radio Voice Call Continuity from UTRAN/GERAN to E-UTRAN/HSPA (Stage 3) | rSRVCC-CT | Rel-11 |
| Building Block: CS Fallback in EPS - Phase 2 | SAES2-CSFB | Rel-11 |
| Building Block: Stage 3 for Inclusion of Media Resource Broker | MRB | Rel-11 |
| Work task: CT1 part for Single Radio Voice Call Continuity from UTRAN/GERAN to E-UTRAN/HSPA | rSRVCC-CT | Rel-11 |
| Building Block: CT1 part of Support of ALT-C attribute | ALTC | Rel-12 |
| Feature or Study Item: Impacts of RFC7044 for introduction of the new History-Info header field | HISTORY_CT | Rel-12 |
| Building Block: CT aspects of Smart Congestion Mitigation in E-UTRAN (Stage 3) | SCM_LTE-CT | Rel-12 |
| Building Block: PCRF based solution | PCSCF_RES | Rel-12 |
| Building Block: HSS based solution | PCSCF_RES | Rel-12 |
| Building Block: Common for HSS & PCRF solutions | PCSCF_RES | Rel-12 |
| Feature or Study Item: Network Initiated USSD Simulation Services in IMS | USSI-NET | Rel-12 |
| Building Block: CT impacts of codec for Enhanced Voice Services | EVS_codec-CT | Rel-12 |
| Work task: CT1 part of Group Communication System Enablers for LTE | GCSE_LTE-CT | Rel-12 |
| Feature or Study Item: Enhanced S2a Mobility Over trusted WLAN access to EPC | eSaMOG | Rel-12 |
| Feature or Study Item: Optimized Offloading to WLAN in 3GPP-RAT Mobility | WORM | Rel-12 |
| Feature or Study Item: Network-provided Location information for IMS Trusted WLAN Access Network (TWAN) case | NETLOC_TWAN | Rel-12 |
| Building Block: CT part: Downlink Multi Carrier GERAN | DMCG | Rel-12 |
| Building Block: CT aspects of Web Real Time Communication (WebRTC) Access to IMS | IMS_WebRTC-CT | Rel-12 |
| Feature or Study Item: Transfer of ETSI business trunking specifications | IMS_Corp2 | Rel-12 |
| Feature or Study Item: Support of ALT-C attribute | ALTC | Rel-12 |
| Feature or Study Item: Smart Congestion Mitigation in E-UTRAN | SCM_LTE | Rel-12 |
| Work task: Stage 3 for BB1: Policy and Charging Control for supporting traffic from fixed terminals and NSWO traffic from 3GPP UEs in fixed broadband access networks | P4C-F-CT3 | Rel-12 |
| Work task: CT1 part of CT aspects of IMS Business Trunking for IP-PBX in Static Mode of Operation (Stage 3) | BusTI-CT | Rel-12 |
| Building Block: CT1 part of Updating IMS to conform to RFC 6665 | UP6665 | Rel-12 |
| Work task: CT1 part of Stage 3 for Enhanced S2a Mobility Over trusted WLAN access to EPC | eSaMOG-St3 | Rel-12 |
| Building Block: Stage 3 for SMS submit and delivery without MSISDN in IMS | SMSMI-CT | Rel-12 |
| Feature or Study Item: Dual Radio VCC enhancements (Stage 2/3) | eDRVCC | Rel-12 |
| Building Block: Stage 2 for Diameter based interface between SGSN and SMS central functions | Dia_SGSN_SMS | Rel-12 |
| Feature or Study Item: Mobile Station Receive Diversity (MSRD) for Voice Services over Adaptive Multi-user channels on One Slot (VAMOS) | MSRD_VAMOS | Rel-12 |
| Feature or Study Item: IMS-based Telepresence | IMS_TELEP | Rel-12 |
| Feature or Study Item: Downlink Multi Carrier GERAN | DMCG | Rel-12 |
| Work task: CT1 part of CT aspects of Extended IMS media plane security features | eMEDIASEC-CT | Rel-12 |
| Feature or Study Item: Reporting Enhancements in Warning Message Delivery (Stage 2/3) | REP_WMD | Rel-12 |
| Building Block: CT1 part of Reporting Enhancements in Warning Message Delivery (Stage 2) | REP_WMD-CT1 | Rel-12 |
| Feature or Study Item: Single Radio Voice Call Continuity (SRVCC) before ringing (Stage 3) | bSRVCC | Rel-12 |
| Feature or Study Item: IMS Stage 3 IETF Protocol Alignment - phase 6 | IMSProtoc6 | Rel-12 |
| Building Block: CT1 part of IMS Stage 3 IETF Protocol Alignment - phase 6 | IMSProtoc6 | Rel-12 |
| Feature or Study Item: SAE Protocol Development - Phase 3 | SAES3 | Rel-12 |
| Building Block: SAE Protocol Development (Stage 3) - Phase 3 | SAES3-CT1 | Rel-12 |
| Building Block: CS Fallback in EPS - Phase 3 | SAES3-CSFB | Rel-12 |
| Building Block: SAE for support for non-3GPP accesses - Phase 3 | SAES3-non3GPP | Rel-12 |
| Feature or Study Item: IM-SSF Application Server Service Data Descriptions (Stage 2/3) | IMS_SSFDD | Rel-12 |
| Building Block: Stage 2 for IM-SSF Application Server Service Data Descriptions | IMS_SSFDD | Rel-12 |
| Feature or Study Item: Diameter based interface between SGSN and SMS central functions (Stage 2/3) | Dia_SGSN_SMS | Rel-12 |
| Feature or Study Item: Tunneling of UE Services over Restrictive Access Networks (Stage 2/3) | TURAN | Rel-12 |
| Building Block: CT1 part of Single Radio Voice Call Continuity (SRVCC) before ringing | bSRVCC | Rel-12 |
| Feature or Study Item: LIPA Mobility and SIPTO at the Local Network | LIMONET | Rel-12 |
| Building Block: SAE Protocol Development (Stage 3) - Phase 4 | SAES4 | Rel-13 |
| Building Block: CS Fallback in EPS - Phase 4 | SAES4-CSFB | Rel-13 |
| Building Block: SAE for support for non-3GPP accesses - Phase 4 | SAES4-non3GPP | Rel-13 |
| Building Block: CT1 aspects of Mobile Equipment Identity signalling over WLAN | MEI_WLAN | Rel-13 |
| Feature or Study Item: Authentication Signalling Improvements for WLAN | ASI_WLAN | Rel-13 |
| Feature or Study Item: Message interworking during PS to CS SRVCC | mSRVCC | Rel-13 |
| Building Block: CT1 aspects of Message interworking during PS to CS SRVCC | mSRVCC | Rel-13 |
| Feature or Study Item: Retry restriction for Improving System Efficiency | RISE | Rel-13 |
| Work task: Call Control – On Network | MCPTT-CT | Rel-13 |
| Work task: Call Control – Off Network | MCPTT-CT | Rel-13 |
| Work task: Floor Control – On Network | MCPTT-CT | Rel-13 |
| Work task: Floor Control – Off Network | MCPTT-CT | Rel-13 |
| Building Block: CT1 aspects of IMS Stage-3 IETF Protocol Alignment | IMSProtoc7 | Rel-13 |
| Building Block: Interworking solution for Called IN number and original called IN number ISUP parameters | INNB_IW | Rel-13 |
| Work task: CT1 part of Stage 3 for Application specific Congestion control for Data Communication | ACDC-CT | Rel-13 |
| Work task: CT1 aspects of system architecture enhancements for TV service | AE_enTV-CT | Rel-14 |
| Feature or Study Item: Study on MBMS usage for mission critical communication services | FS_MBMS_MCservices | Rel-14 |
| Feature or Study Item: Stage-3 SAE Protocol Development - Phase 5 | SAES5 | Rel-14 |
| Building Block: SAES5 CS Fallback in EPS | SAES5-CSFB | Rel-14 |
| Building Block: SAES5 for support for non-3GPP accesses | SAES5-non3GPP | Rel-14 |
| Work task: CT1 aspects of evolution to and interworking with eCall in IMS | EIEI-CT | Rel-14 |
| Work task: CT1 aspects for Non-IP for Cellular Internet of Things for EC-EGPRS | NonIP_GPRS-CT | Rel-14 |
| Building Block: deleted -CT1 aspects of MTSI Extension on Multi-stream | MMCMH-CT | Rel-14 |
| Work task: CT1 aspects of MMCMH_Enh | MMCMH_Enh-CT | Rel-14 |
| Building Block: CT1 aspects of IMS Stage-3 IETF Protocol Alignment | IMSProtoc8 | Rel-14 |
| Building Block: SAE Protocol Development (Stage 3) - Phase 5 | SAES5 | Rel-14 |
| Work task: CT1 aspects of EWE | EWE-CT | Rel-14 |
| Work task: CT1 aspects for PWDIMS | PWDIMS-CT | Rel-14 |
| Building Block: CT1 aspects of IOC_UE_conf | IOC_UE_conf | Rel-14 |
| Feature or Study Item: IMS Stage-3 IETF Protocol Alignment | IMSProtoc8 | Rel-14 |
| Building Block: CT1 part of IMS Signalling Activated Trace | ISAT | Rel-14 |
| Building Block: CT aspects of EVS in 3G Circuit-Switched Networks | EVSoCS-CT | Rel-13 |
| Building Block: CT1 aspects of Enhanced P-CSCF discovery using signalling for access to EPC via WLAN | ePCSCF_WLAN | Rel-13 |
| Building Block: CT1 aspects of Warning Status Report in EPS | WSR_EPS | Rel-13 |
| Feature or Study Item: Stage-3 SAE Protocol Development - Phase 4 | SAES4 | Rel-13 |
| Feature or Study Item: IMS Stage-3 IETF Protocol Alignment | IMSProtoc7 | Rel-13 |
| Feature or Study Item: Enhanced P-CSCF discovery using signalling for access to EPC via WLAN | ePCSCF_WLAN | Rel-13 |
| Feature or Study Item: Interworking solution for Called IN number and original called IN number ISUP parameters | INNB_IW | Rel-13 |
| Work task: CT1 part of CT aspects of voice over E-UTRAN Paging Policy Differentiation | voE_UTRAN_PPD-CT | Rel-13 |
| Building Block: CT aspects of voice over E-UTRAN Paging Policy Differentiation | voE_UTRAN_PPD-CT | Rel-13 |
| Feature or Study Item: Support of EVS in 3G Circuit-Switched networks | EVSoCS | Rel-13 |
| Feature or Study Item: QoS End-to-end Multimedia Telephony Service for IMS (MTSI) extensions (Stage 3) | QOSE2EMTSI | Rel-13 |
| Building Block: Stage 3 for MBMS_Mcservices | MBMS_Mcservices | Rel-15 |
| Feature or Study Item: voice over E-UTRAN Paging Policy Differentiation | voE_UTRAN_PPD | Rel-13 |
| Feature or Study Item: Application specific Congestion control for Data Communication | ACDC | Rel-13 |
| Work task: Broadcast – Call Control and Floor Control | MCPTT-CT | Rel-13 |
| Work task: Group management | MCPTT-CT | Rel-13 |
| Work task: Identity management | MCPTT-CT | Rel-13 |
| Work task: Management Object | MCPTT-CT | Rel-13 |
| Work task: Configuration management | MCPTT-CT | Rel-13 |
| Feature or Study Item: Support of Real-time Transport Protocol (RTP) / Real-time Transport Control Protocol (RTCP) multiplexing (signalling) in IMS | RTCP_MUX | Rel-13 |
| Building Block: CT1 part of Support of RTP / RTCP multiplexing (signalling) in IMS | RTCP_MUX | Rel-13 |
| Building Block: CT1 aspects of MCPTTProtoc1 | MCPTTProtoc1 | Rel-14 |
| Work task: CT1 aspects of eDecor | eDecor-CT | Rel-14 |
| Work task: CT1 aspects of SEW2 | SEW2-CT | Rel-14 |
| Feature or Study Item: AT Commands for CIoT | AT_CIoT | Rel-14 |
| Building Block: CT Aspects of RobVoLTE | RobVoLTE-CT | Rel-14 |
| Work task: CT1 Aspects of V8 | V8-CT | Rel-14 |
| Work task: CT1 aspects of V2X Services | V2X-CT | Rel-14 |
| Building Block: CT1 aspects of SIP Reason header extension | REAS_EXT | Rel-14 |
| Work task: CT1 aspects of ERP | ERP-CT | Rel-14 |
| Building Block: Stage 3 for Application specific Congestion control for Data Communication | ACDC-CT | Rel-13 |
| Building Block: CT1 aspects of P-CSCF Restoration Enhancements with WLAN | PCSCF_RES_WLAN | Rel-13 |
| Building Block: CT Aspects of QoS End-to-End MTSI Extensions | QOSE2EMTSI-CT | Rel-13 |
| Work task: CT1 Aspects of QoS End-to-End MTSI Extensions | QOSE2EMTSI-CT | Rel-13 |
| Work task: CT1 aspects of Double Resource Reuse for Multiple Media Sessions | DRuMS-CT | Rel-13 |
| Work task: Stage 3 CN aspects of SIPTO at the Local Network | LIMONET-SIPTO | Rel-12 |
| Work task: Deleted - Stage 3 CN aspects of LIPA Mobility | LIMONET-LIPA-del2 | Rel-12 |
| Feature or Study Item: Introduction of ER-GSM band for GSM-R | RT_ERGSM | Rel-12 |
| Feature or Study Item: Short Message Service (SMS) submit and delivery without MSISDN in IMS | SMSMI | Rel-12 |
| Feature or Study Item: Operator Policies for IP Interface Selection | OPIIS | Rel-12 |
| Building Block: Deleted - CT1 part for Security aspects of Public Warning System | PWS_Sec-del4 | Rel-12 |
| Feature or Study Item: Codec for Enhanced Voice Services | EVS_codec | Rel-12 |
| Building Block: (IETF) CT1 aspects of IMS Stage-3 IETF Protocol Alignment | IMSProtoc7 | Rel-13 |
| Building Block: CT aspects of enhancements to Proximity-based | eProSe-Ext-CT | Rel-13 |
| Work task: CT1 aspects of enhancements to Proximity-based | eProSe-Ext-CT | Rel-13 |
| Building Block: CT aspects of IP Flow Mobility support for S2a and S2b Interfaces | NBIFOM-CT | Rel-13 |
| Work task: CT1 aspects of IP Flow Mobility support for S2a and S2b Interfaces | NBIFOM-CT | Rel-13 |
| Work task: CT1 aspects of Monitoring Enhancements | MONTE-CT | Rel-13 |
| Work task: CT1 aspects of Group based Enhancements | GROUPE-CT | Rel-13 |
| Work task: CT1 Aspects of Video Enhancements by Region-Of-Interest information signalling | ROI-CT | Rel-13 |
| Work task: CT1 aspects of EVS in 3G Circuit-Switched Networks | EVSoCS-CT | Rel-13 |
| Building Block: Stage 3 for Operator Policies for IP Interface Selection | OPIIS-CT | Rel-12 |
| Building Block: CT aspects of Tunneling of UE Services over Restrictive Access Networks (Stage 3) | TURAN-CT | Rel-12 |
| Work task: Deleted - CT1 aspects of CT aspects of IMS registration control (Stage 2/3) | IMS_RegCon-CT1 | Rel-12 |
| Work task: CT1 part of CT aspects of Coordination of Video Orientation | CVO-CT | Rel-12 |
| Work task: CT1 part of CT aspects of End-to-End Multimedia Telephony Service for IMS (MTSI) extensions | E2EMTSI-CT | Rel-12 |
| Building Block: CT1 part of CT Aspects of Signalling of Image Size | SIS_CT | Rel-12 |
| Feature or Study Item: Proxy Call Session Control Function (P-CSCF) restoration enhancements (Stage 2/3) | PCSCF_RES | Rel-12 |
| Building Block: CT aspects of Coordination of Video Orientation | CVO-CT | Rel-12 |
| Building Block: CT aspects of End-to-End Multimedia Telephony Service for IMS (MTSI) extensions | E2EMTSI-CT | Rel-12 |
| Feature or Study Item: CT aspects of Signalling of Image Size (Stage 2/3) | SIS_CT | Rel-12 |
| Building Block: Deleted - CT aspects of IMS registration control | IMS_RegCon-CT | Rel-12 |
| Work task: CT1 part of Stage 3 for SMS submit and delivery without MSISDN in IMS | SMSMI-CT | Rel-12 |
| Building Block: Stage 3 for Dual Radio VCC enhancements | eDRVCC | Rel-12 |
| Building Block: CT1 part of Introduction of ER-GSM band for GSM-R | RT_ERGSM | Rel-12 |
| Work task: CT1 part of Stage 3 CN aspects of SIPTO at the Local Network | LIMONET-SIPTO-CT1 | Rel-12 |
| Work task: Deleted - CT1 part of CN aspects of LIPA Mobility | LIMONET-LIPA-del3 | Rel-12 |
| Building Block: CT1 part of IMS Emergency PSAP Callback | EMC_PC | Rel-12 |
| Feature or Study Item: IMS Emergency PSAP Callback (Stage 3) | EMC_PC | Rel-12 |
| Building Block: Stage 3 of User Controlled Spoofed Call Treatment | SPECTRE-CT | Rel-14 |
| Work task: CT1 Aspects of Determination of Completeness of Charging Information in IMS | CH14-DCCII-CT | Rel-14 |
| Work task: CT1 aspects of Enhancements for Mission Critical Push To Talk | MCImp-eMCPTT-CT | Rel-14 |
| Work task: CT1 aspects of MCData | MCImp-MCDATA-CT | Rel-14 |
| Work task: CT1 aspects 3 of MCVideo | MCImp-MCVIDEO-CT | Rel-14 |
| Work task: CT1 aspects of extended architecture enhancements for Cellular Internet of Things | CIoT_Ext-CT | Rel-14 |
| Work task: CT1 aspects of PS Data Off | PS_DATA_OFF-CT | Rel-14 |
| Feature or Study Item: Group Communication System Enablers for LTE | GCSE_LTE | Rel-12 |
| Feature or Study Item: Policy and Charging Control for supporting fixed broadband access networks | P4C | Rel-12 |
| Feature or Study Item: IMS Business Trunking for IP-PBX in Static Mode of Operation | BusTI | Rel-12 |
| Feature or Study Item: WLAN Network Selection for 3GPP Terminals | WLAN_NS | Rel-12 |
| Feature or Study Item: Deleted - IMS Registration Control | IMS_RegCon | Rel-12 |
| Work task: CT1 part of PCRF based solution | PCSCF_RES | Rel-12 |
| Work task: CT1 part of CT impacts of codec for Enhanced Voice Services | EVS_codec-CT | Rel-12 |
| Work task: CT1 part of Stage 3 for Dual Radio VCC enhancements | eDRVCC | Rel-12 |
| Building Block: CT1 introduction of MS capability support for MS supporting MSRD for VAMOS | MSRD_VAMOS | Rel-12 |
| Building Block: CT aspects of IMS Business Trunking for IP-PBX in Static Mode of Operation (Stage 3) | BusTI-CT | Rel-12 |
| Feature or Study Item: Updating IMS to conform to RFC 6665 (Stage 3) | UP6665 | Rel-12 |
| Building Block: Stage 3 for Enhanced S2a Mobility Over trusted WLAN access to EPC | eSaMOG-St3 | Rel-12 |
| Building Block: CT aspects of Optimized Offloading to WLAN in 3GPP-RAT Mobility (Stage 3) | WORM-CT | Rel-12 |
| Feature or Study Item: IMS Operator Determined Call Barring enhancements (Stage 3) | eIODB | Rel-12 |
| Building Block: CT aspects of WLAN Network Selection for 3GPP Terminals (Stage 3) | WLAN_NS-CT | Rel-12 |
| Feature or Study Item: Signalling Improvements for Network Efficiency (Stage 3) | SINE | Rel-12 |
| Building Block: CT aspects of Network-provided Location information for IMS Trusted WLAN Access Network (TWAN) case (Stage 3) | NETLOC_TWAN-CT | Rel-12 |
| Work task: CT1 part of Stage 3 for BB1: Policy and Charging Control for supporting traffic from fixed terminals and NSWO traffic from 3GPP UEs in fixed broadband access networks | P4C-F-CT3 | Rel-12 |
| Feature or Study Item: WLAN/3GPP Radio Interworking | UTRA_LTE_WLAN_interw | Rel-12 |
| Feature or Study Item: New Training Sequence Codes (TSC) for GERAN | NewToN | Rel-12 |
| Work task: CT1 aspects for Dedicated Core Networks CT aspects | DECOR-CT | Rel-13 |
| Work task: CT1 aspects 3 for Enhancements to WebRTC interoperability | eWebRTCi-CT | Rel-13 |
| Work task: CT1 aspects for MCPTT protocol aspects | MCPTT-CT | Rel-13 |
| Building Block: IMS Profile to support MCPTT | MCPTT-Prof | Rel-13 |
| Work task: CT1 aspects of extended DRX cycle | eDRX-CT | Rel-13 |
| Work task: CT1 aspects of Support of Emergency services over WLAN – phase 1 | SEW1-CT | Rel-13 |
| Building Block: CT1 part of IMS Operator Determined Call Barring enhancements | eIODB | Rel-12 |
| Work task: CT1 part of Stage 3 for BB3: UE Power Consumptions Optimizations (UEPCOP) | MTCe-UEPCOP-CT1 | Rel-12 |
| Work task: CT1 part of Network-provided Location information for IMS Trusted WLAN Access Network (TWAN) case | NETLOC_TWAN-CT | Rel-12 |
| Feature or Study Item: Coordination of Video Orientation | CVO | Rel-12 |
| Feature or Study Item: Extended IMS media plane security features | eMEDIASEC | Rel-12 |
| Work task: CT1 part of Stage 3 for USSD simulation service in IMS | USSI | Rel-11 |
| Work task: CT1 aspects of Single Radio Video Call Continuity for 3G-CS | vSRVCC-CT | Rel-11 |
| Building Block: CT1 part of IMS Stage 3 IETF Protocol Alignment - phase 5 | IMSProtoc5 | Rel-11 |
| Building Block: Stage 3 for Advanced IP Interconnection of Services | IPXS | Rel-11 |
| Building Block: Stage 2/3 for CS aspects for SIMTC | SIMTC-CS | Rel-11 |
| Building Block: BB1: Stage 3 (CS+PS) Reachability Aspects of SIMTC | SIMTC-ReachCSPS | Rel-11 |
| Work task: Deleted - Stage 3 (CS+PS) CN-based requirements and Power Considerations of SIMTC | SIMTC-CN_Pow | Rel-11 |
| Building Block: RAN overload control for Machine-Type Communications | SIMTC-RAN_OC | Rel-11 |
| Building Block: Stage 2/3 for Support for 3GPP Voice Interworking with Enterprise IP-PBX | VINE-CT1 | Rel-11 |
| Building Block: Stage 3 BB I - Core Network impacts: BBF interworking with home routed traffic for WLAN and H(e)NB | BBAI_BBI-CT | Rel-11 |
| Building Block: Stage 3 BB II - Core Network impacts: BBF interworking with offload in access network for WLAN and for H(e)NB | BBAI_BBII-CT | Rel-11 |
| Building Block: CT1 part of Reference Location Information (Stage 3) | RLI | Rel-11 |
| Feature or Study Item: SAE Protocol Development - Phase 2 | SAES2 | Rel-11 |
| Feature or Study Item: GCSMSC and GCR Redundancy for VGCS/VBS (Stage 2/3) | RT_VGCS_Red | Rel-11 |
| Feature or Study Item: Inclusion of Media Resource Broker (Stage 2/3) | MRB | Rel-11 |
| Building Block: CT1 part of New Training Sequence Codes (TSC) for GERAN (Stage 3) | NewToN | Rel-12 |
| Work task: CT1 part of CT aspects of Web Real Time Communication (WebRTC) Access to IMS | IMS_WebRTC-CT1 | Rel-12 |
| Work task: CT1 part of CT aspects of Proximity-based Services | ProSe-CT | Rel-12 |
| Building Block: Stage 3 for IMS Overload Control | IOC | Rel-11 |
| Building Block: CT1 part of Enhanced T.38 FAX support | MMTel_T.38_FAX | Rel-11 |
| Work task: CT1 part of CT aspects of Network-provided Location information for IMS | NWK-PL2IMS-CT | Rel-11 |
| Building Block: Stage 2/3 for SMS in MME architecture option and related PS-only service subscription | SIMTC-PS_Only | Rel-11 |
| Feature or Study Item: AT commands for Universal Resource Identifier (URI) support | ATURI | Rel-11 |
| Work task: CT1 part of Stage 2/3 for SMS in MME architecture option and related PS-only service subscription | SIMTC-PS_Only | Rel-11 |
| Feature or Study Item: IMS Overload Control | IOC | Rel-11 |
| Feature or Study Item: IMS Operator Determined Call Barring | IODB | Rel-11 |
| Feature or Study Item: Enhanced T.38 FAX support (Stage 3) | MMTel_T.38_FAX | Rel-11 |
| Work task: CT1 part of Stage 3 for IMS Overload Control | IOC | Rel-11 |
| Building Block: CT1 part of IMS Operator Determined Call Barring | IODB | Rel-11 |
| Building Block: BB1: Policy and Charging Control for supporting traffic from fixed terminals and NSWO (Non Seamless WLAN Offload) traffic from 3GPP UEs in fixed broadband access networks (P4C-F) | P4C-F | Rel-12 |
| Building Block: CT part for IMS Telepresence (Stage 2/3) | IMS_TELEP | Rel-12 |
| Work task: TR on CT part of IMS Telepresence (Stage 2/3) | IMS_TELEP | Rel-12 |
| Work task: CT1 part of IMS Telepresence (Stage 3) | IMS_TELEP | Rel-12 |
| Building Block: CT aspects of Extended IMS media plane security features (Stage 2/3) | eMEDIASEC-CT | Rel-12 |
| Building Block: CT aspects of Data Identification in Access Network Discovery and Selection Function (ANDSF) Stage 3 | DIDA-CT | Rel-11 |
| Building Block: CT aspects of Roaming Architecture for Voice over IMS with Local Breakout (Stage 3) | RAVEL-CT | Rel-11 |
| Feature or Study Item: Roaming Architecture for Voice over IMS with Local Breakout | RAVEL | Rel-11 |
| Work task: Deleted - CT1 part of CT aspects of LOcation-Based Selection of gaTEways foR WLAN | LOBSTER-CT | Rel-11 |
| Work task: Deleted - CT1 part of CN aspects of Mobility based On GTP & PMIPv6 for WLAN access to EPC | SaMOG_WLAN-CN | Rel-11 |
| Building Block: Stage 3 for GBA extensions for re-use of SIP Digest credentials | GBA-ext-St3 | Rel-11 |
| Building Block: CT1 part of Transfer of ETSI business trunking specifications | IMS_Corp2 | Rel-12 |
| Work task: Deleted - CT1 part of Stage 3 CN-based requirements and Power Considerations of SIMTC | SIMTC-CN_Pow | Rel-11 |
| Work task: TR on Stage 3 BB I for BBAI; UE to network protocols | BBAI_BBI-CT | Rel-11 |
| Work task: TR on Stage 3 BB II for 3GPP System to Fixed Broadband Access Network Interworking; UE to network protocols | BBAI_BBII-CT | Rel-11 |
| Building Block: SAE Protocol Development (Stage 3) - Phase 2 | SAES2 | Rel-11 |
| Building Block: CT1 part of GCSMSC and GCR Redundancy for VGCS/VBS | RT_VGCS_Red | Rel-11 |
| Building Block: Stage 2 for Inclusion of Media Resource Broker | MRB | Rel-11 |
| Building Block: CN aspects of Mobility based On GTP & PMIPv6 for WLAN access to EPC | SaMOG_WLAN-CN | Rel-11 |
| Feature or Study Item: Generic Bootstrapping Architecture (GBA) extensions for re-use of SIP Digest credentials | GBA-ext | Rel-11 |
| Building Block: CT1 part of enhanced Nodes Restoration for EPC | eNR_EPC | Rel-11 |
| Feature or Study Item: Support of RFC 6140 in IMS | GINI | Rel-11 |
| Feature or Study Item: Deleted - Enhancement of the Protocols for SMS over SGs (Stage 3) | PROTOC_SMS_SGs | Rel-11 |
| Building Block: CN part of Stage 3 for Network Improvements for Machine-Type Communications | NIMTC-CN | Rel-10 |
| Work task: Stage 3 for SIPTO for macro networks | SIPTO | Rel-10 |
| Work task: Stage 3 for Local IP Access | LIPA | Rel-10 |
| Building Block: Stage 3 for IP Flow Mobility and seamless WLAN offload | IFOM-CT | Rel-10 |
| Building Block: Stage 3 for Optimal Media Routing | OMR | Rel-10 |
| Feature or Study Item: Completion of Communications on Not Logged-in | CCNL | Rel-10 |
| Feature or Study Item: Local IP Access and Selected Internet IP Traffic Offload | LIPA_SIPTO | Rel-10 |
| Building Block: Stage 2/3 for SIPTO for macro networks | SIPTO | Rel-10 |
| Feature or Study Item: IP Flow Mobility and seamless WLAN offload | IFOM | Rel-10 |
| Feature or Study Item: Enabling Coder Selection and Rate Adaptation for UTRAN and E-UTRAN for Load Adaptive Applications | ECSRA_LAA | Rel-10 |
| Feature or Study Item: Optimal Media Routing | OMR | Rel-10 |
| Building Block: CT aspects of CIoT | CIoT-CT | Rel-13 |
| Work task: CT1 aspects of CIoT | CIoT-CT | Rel-13 |
| Feature or Study Item: Enhancements for Multimedia Priority Service | eMPS | Rel-10 |
| Feature or Study Item: Support for BroadBand Forum Accesses Interworking | BBAI | Rel-11 |
| Work task: CT1 part of Stage 3 CS aspects for SIMTC | SIMTC-CS | Rel-11 |
| Work task: CT1 part of Stage 3 Extended Access Barring for UTRAN and E-UTRAN | SIMTC-RAN_OC | Rel-11 |
| Work task: CT1 part of Stage 3 for Inclusion of Media Resource Broker | MRB | Rel-11 |
| Feature or Study Item: Transit Inter Operator Identifier for IMS Interconnection Charging in multi operator environment | IOI_IMS_CH | Rel-11 |
| Feature or Study Item: Single Radio Video Call Continuity for 3G-CS | vSRVCC | Rel-11 |
| Work task: CT1 part of Common for HSS & PCRF solutions | PCSCF_RES | Rel-12 |
| Feature or Study Item: Study on impacts on UE-Core Network signalling from Energy Saving | FS_UE-CN_ES | Rel-11 |
| Feature or Study Item: Advanced IP Interconnection of Services | IPXS | Rel-11 |
| Feature or Study Item: System Improvements to Machine-Type Communications | SIMTC | Rel-11 |
| Feature or Study Item: Unstructured Supplementary Service Data (USSD) simulation service in IMS | USSI | Rel-11 |
| Feature or Study Item: Network-provided Location information for IMS (NETLOC) | NWK-PL2IMS | Rel-11 |
| Work task: CT1 part of CN Stage 3 for Full Support of Multi-Operator Core Network by GERAN | Full_MOCN-GERAN | Rel-11 |
| Building Block: Stage 3 for USSD simulation service in IMS | USSI | Rel-11 |
| Building Block: CT1 aspects of VAS4SMS Interface and Signalling Flow | VAS4SMS | Rel-9 |
| Feature or Study Item: IMS Services Centralization and Continuity | IMS_SCC | Rel-9 |
| Building Block: Single Radio Voice Call Continuity (SRVCC) support for IMS Emergency Calls | IMS_EMER_GPRS_EPS-SRVCC | Rel-9 |
| Feature or Study Item: Cell Broadcast protocol Base Station Controller – Cell Broadcast Centre (BSC-CBC) | CEBRO | Rel-9 |
| Building Block: Stage 3 for Support of Personal Area Networks and Enhancements to Personal Network Management | PAN_EPNM | Rel-9 |
| Feature or Study Item: Multiple PDN Connection to the Same APN for PMIP-based Interfaces | MUPSAP | Rel-9 |
| Feature or Study Item: IMS Media Plane Security | MEDIASEC | Rel-9 |
| Feature or Study Item: Completion of IMS Restoration Procedures | eIMS_RP | Rel-9 |
| Building Block: CT1 aspects of Completion of IMS Restoration Procedures | eIMS_RP | Rel-9 |
| Work task: CT1 aspects of SRVCC support for IMS Emergency Calls | IMS_EMER_GPRS_EPS-SRVCC | Rel-9 |
| Building Block: Stage 3 for Public Warning System | PWS-St3 | Rel-9 |
| Work task: CT1 aspects of Stage 3 for Public Warning System | PWS-St3 | Rel-9 |
| Building Block: Stage 3 - Enhancements for Completion of Communications Supplementary service | eMMTel-CC | Rel-9 |
| Work task: Stage 3 for Enhancements to IMS Centralized Services | IMS_SCC-ICS | Rel-9 |
| Work task: Stage 3 for IMS Service Continuity Enhancements: Service, Policy, Interactions and Inter UE Transfer | IMS_SCC-SPI | Rel-9 |
| Building Block: Stage 3 for IMS Emergency Calls over GPRS and EPS | IMS_EMER_GPRS_EPS | Rel-9 |
| Work task: CT1 aspects - Stage 3 for IMS Emergency Calls over GPRS and EPS | IMS_EMER_GPRS_EPSC1 | Rel-9 |
| Feature or Study Item: 3GPP IMS Conferencing Management Object (MO) | IMS_ConfMO | Rel-9 |
| Feature or Study Item: UICC access to IMS Specification | IMS-UICC-S | Rel-10 |
| Building Block: CT1 part of UICC access to IMS Specification | IMS-UICC-S | Rel-10 |
| Feature or Study Item: Formalization of WLAN Files | FoWF | Rel-10 |
| Feature or Study Item: S2b Mobility based on GTP | SMOG | Rel-10 |
| Building Block: CT1 part for TIGHTER | TIGHTER | Rel-10 |
| Feature or Study Item: Support for 3GPP Voice Interworking with Enterprise IP-PBX | VINE | Rel-11 |
| Feature or Study Item: Data Identification in Access Network Discovery and Selection Function (ANDSF) | DIDA | Rel-11 |
| Building Block: CN aspects of Enabling Coder Selection and Rate Adaptation for UTRAN and E-UTRAN for Load Adaptive Applications | ECSRA_LAA-CN | Rel-10 |
| Building Block: Stage 3 on enhancements for Multimedia Priority Service | eMPS-CN | Rel-10 |
| Building Block: Stage 3 for S2b Mobility based on GTP | SMOG-St3 | Rel-10 |
| Building Block: CT1 part - AoC enhancements (Stage 3) | eAoC | Rel-10 |
| Feature or Study Item: AT Commands for USIM Application Toolkit (USAT) | AT_UICC | Rel-10 |
| Work task: CT1 part of Stage 3 for SIPTO for macro networks | SIPTO | Rel-10 |
| Work task: CT1 part of Stage 3 for Local IP Access | LIPA | Rel-10 |
| Work task: CT1 part of Stage 3 for Optimal Media Routeing | OMR | Rel-10 |
| Feature or Study Item: Support of Multi-Operator Core Network by GERAN | MOCN-GERAN | Rel-10 |
| Work task: CT1 part of CN aspects of Enabling Coder Selection and Rate Adaptation for UTRAN and E-UTRAN for Load Adaptive Applications | ECSRA_LAA-CN | Rel-10 |
| Work task: CT1 part on Stage 3 on enhancements for Multimedia Priority Service | eMPS-CN | Rel-10 |
| Work task: CT1 part of Stage 3 for S2b Mobility based on GTP | SMOG-St3 | Rel-10 |
| Building Block: CT1 part of Stage 3 for Support of Multi-Operator Core Network by GERAN | MOCN-GERAN | Rel-10 |
| Feature or Study Item: Full Support of Multi-Operator Core Network by GERAN | Full_MOCN-GERAN | Rel-11 |
| Building Block: CT1 part of Stage 3 for MESSIW | MESSIW | Rel-8 |
| Building Block: Deleted - CT1 part of Enhancement of interworking between MTSI and CS networks | MTSI_eMHI | Rel-8 |
| Building Block: Core Network Impacts for A-Interface User Plane over IP | AoIP-CN | Rel-8 |
| Building Block: IMS Restoration Procedures (CT1) | IMS_RP | Rel-8 |
| Building Block: AS/MRFC Stage 3 | MRFC_TS | Rel-8 |
| Feature or Study Item: Generic Bootstrapping Architecture Push Function | GBAPush | Rel-8 |
| Building Block: CT1 part of Stage 3 for IMS-Sec | IMS-Sec | Rel-8 |
| Feature or Study Item: IMS Service Continuity | IMS-Cont | Rel-8 |
| Building Block: Flexible Alerting | FA | Rel-8 |
| Work task: Deleted - CT1 aspects of SAES | SAES-St3 | Rel-8 |
| Building Block: SAE for LTE access | SAES-LTE | Rel-8 |
| Building Block: Deleted - CT1 aspects of Local Call Local Switch | LCLS-CN | Rel-10 |
| Feature or Study Item: Multi Access PDN Connectivity | MAPCON | Rel-10 |
| Feature or Study Item: Network Improvements for Machine-Type Communications | NIMTC | Rel-10 |
| Feature or Study Item: IMS System enhancements for corporate network access | IMS_Corp | Rel-8 |
| Work task: Stage 3 for Access to the EPC via non-3GPP access networks | SAES-SA-FP_n3GPP | Rel-8 |
| Work task: Stage 3 for Mobility management based on DSMIPv6 | SAES-SA-FP_n3GPP | Rel-8 |
| Work task: Stage 3 for Inter-system mobility between E-UTRAN and CDMA2000 | SAES-SA-FP_3GPP | Rel-8 |
| Feature or Study Item: IMS Stage 3 IETF Protocol Alignment - phase 2 | IMSProtoc2 | Rel-8 |
| Feature or Study Item: Paging Permission with Access Control (PPACR) | PPACR | Rel-8 |
| Building Block: CT1 aspects of IMS Stage 3 IETF Protocol Alignment - phase 2 | IMSProtoc2 | Rel-8 |
| Building Block: High level and common (for all accesses) functions | EPS-ComF | Rel-8 |
| Work task: Stage 3 security aspects for DSMIPv6 Access | SAES-SA-FP_n3GPP | Rel-8 |
| Feature or Study Item: IMS Centralized Service control | ICSRA | Rel-8 |
| Feature or Study Item: IMS Enhancements for support of Packet Cable access | PktCbl | Rel-8 |
| Work task: CT1 aspects of PktCbl-Sec | PktCbl-Sec | Rel-8 |
| Building Block: IMS Enhancements for Cable Client Types and Deployment Models | PktCbl-Deploy | Rel-8 |
| Work task: CT1 aspects of PktCbl-Deploy | PktCbl-Deploy | Rel-8 |
| Building Block: Stage 3 - IMS Inter-UE Transfer enhancements | IMS_SC_eIDT | Rel-10 |
| Building Block: CT1 part of Stage 3 for Completion of Communications on Not Logged-in | CCNL | Rel-10 |
| Feature or Study Item: IMS Stage 3 IETF Protocol Alignment - phase 4 | IMSProtoc4 | Rel-10 |
| Work task: Stage 3 for security aspects of LTE Access | SAES-LTE | Rel-8 |
| Feature or Study Item: Rel-8 Operations, Administration, Maintenance and Provisioning (OAM&P) | OAM8 | Rel-8 |
| Building Block: Rel-8 Trace Management | OAM8-Trace | Rel-8 |
| Work task: CT1 aspects of Stage 3 PNM | PNM | Rel-8 |
| Feature or Study Item: Multimedia Priority Service | PRIOR_EMR | Rel-8 |
| Building Block: IMS Enhancements for Security Requirements in Support of Cable Deployments | PktCbl-Sec | Rel-8 |
| Building Block: CT1 part of Stage 3 for PRIOR | PRIOR_EMR | Rel-8 |
| Building Block: Deleted - CT aspects of SAES | SAES-St3 | Rel-8 |
| Work task: Stage 3 for UE Non-Access-Stratum (NAS) mobility procedures in idle and active mode | SAES-LTE | Rel-8 |
| Work task: Deleted - UE to EPC NAS signalling (incl. MBMS and QoS aspects) | SAES-St3-sig | Rel-8 |
| Feature or Study Item: Customized Alerting Tone (CAT) service | CAT | Rel-8 |
| Feature or Study Item: I-WLAN Network Selection Principle (NSP) | IWLANNSP | Rel-8 |
| Feature or Study Item: Service-Level Interworking for Messaging Services | MESSIW | Rel-8 |
| Feature or Study Item: eCall Data Transfer | EData | Rel-8 |
| Building Block: CT1 aspects of EVA | EVA | Rel-8 |
| Building Block: CT aspects of WLAN/3GPP Radio Interworking (Stage 2/3) | UTRA_LTE_WLAN_interw-CT | Rel-12 |
| Feature or Study Item: Indication of NNI Routeing scenarios in SIP requests | NNI_RS | Rel-12 |
| Feature or Study Item: Unstructured Supplementary Service Data (USSD) method selection (Stage 3) | USSD_MS | Rel-12 |
| Building Block: CT aspects of Group Communication System Enablers for LTE | GCSE_LTE-CT | Rel-12 |
| Building Block: CT1 part of Impacts of RFC7044 for introduction of the new History-Info header field | HISTORY_CT | Rel-12 |
| Work task: CT1 part of CT aspects of WLAN/3GPP Radio Interworking (Stage 3) | UTRA_LTE_WLAN_interw-CT | Rel-12 |
| Building Block: CT1 part of Indication of NNI Routeing scenarios in SIP requests | NNI_RS | Rel-12 |
| Work task: CT1 part of HSS based solution | PCSCF_RES | Rel-12 |
| Feature or Study Item: GERAN support for GERAN - 3G Long Term Evolution interworking | GELTE | Rel-8 |
| Feature or Study Item: AoIP (A-interface over IP) | AoIP | Rel-8 |
| Feature or Study Item: 3GPP System Architecture Evolution Specification - Evolved Packet System (non RAN aspects) | SAES | Rel-8 |
| Building Block: CT1 part of GERAN support for GERAN - 3G Long Term Evolution interworking | GELTE | Rel-8 |
| Building Block: Stage 3 of ServID | ServID | Rel-7 |
| Building Block: Stage 3 of GRUU | GRUU | Rel-7 |
| Building Block: Procedural aspects of NSP | NSP-CR | Rel-7 |
| Building Block: Stage 3 for SMSIP | SMSIP-St3 | Rel-7 |
| Feature or Study Item: Mp (MRFC - MRFP) interface | Mp | Rel-7 |
| Building Block: Rx reference point for PCC CT3 aspects | PCC-Rx | Rel-7 |
| Feature or Study Item: Selective Disabling of UE Capabilities | SDoUE | Rel-7 |
| Feature or Study Item: Support of Personal Area Networks and Enhancements to Personal Network Management | PAN_EPNM | Rel-9 |
| Feature or Study Item: Multi-Media Telephony Service enhancements | eMMTel | Rel-9 |
| Feature or Study Item: Enhanced Home NodeB / eNodeB | EHNB | Rel-9 |
| Feature or Study Item: Public Warning System | PWS | Rel-9 |
| Work task: CT1 IMS aspects to support IMS Emergency sessions | EMC1 | Rel-7 |
| Work task: PCC-Rx CT1 aspects | PCC-Rx-Gx-c1 | Rel-7 |
| Feature or Study Item: Interoperability between VGCS/VBS and A/Gb flexibility | VGCSFlex | Rel-7 |
| Feature or Study Item: Enhancements of VGCS for public authority officials | EVGCS | Rel-7 |
| Building Block: Stage 3 CN aspects of ACBOP | ACBOP | Rel-7 |
| Building Block: Stage 3 for CSICS CN aspects | CSICS | Rel-7 |
| Building Block: Architecture and protocol aspects | EVGCS | Rel-7 |
| Building Block: Protocol aspects | IVGCS | Rel-7 |
| Building Block: WLAN-PNA - Stage 3 | WLANPNA-st3 | Rel-7 |
| Work task: CT1 aspects of EVGCS | EVGCS | Rel-7 |
| Work task: CT1 aspects of IVGCS | IVGCS | Rel-7 |
| Work task: CT1 aspets for WLAN-PNA | WLANPNA-st3 | Rel-7 |
| Feature or Study Item: IMS Support of Conferencing | IMSconf | Rel-7 |
| Building Block: TISPAN Rel 1 related aspects | FBI-TIS1 | Rel-7 |
| Building Block: PacketCable Related aspects | FBI-PCBL | Rel-7 |
| Building Block: Stage 3 of SDoUE | SDoUE | Rel-7 |
| Building Block: Stage 3 of MTSI | MTSI | Rel-7 |
| Feature or Study Item: Multimedia Telephony Service for IMS | MTSI | Rel-7 |
| Feature or Study Item: CSI Terminating Session handling | CSItermS | Rel-7 |
| Feature or Study Item: Routeing of MT-SMS via the HPLMN | SMSviaH | Rel-7 |
| Building Block: Stage 3 CT1 on support of QoS over 3GPP/WLAN Interworking | WLANQOS | Rel-7 |
| Feature or Study Item: Support for IMS Emergency Calls over GPRS and EPS | IMS_EMER_GPRS_EPS | Rel-9 |
| Feature or Study Item: Customized Ringing Signal | CRS | Rel-9 |
| Work task: CT aspects of SRVCC support for IMS Emergency Calls | IMS_EMER_GPRS_EPS-SRVCC | Rel-9 |
| Building Block: CN aspects of IMS Media Plane Security | MEDIASEC_CORE | Rel-9 |
| Building Block: CT1 aspects - Support of Home NB and Home eNB enhancements | EHNB-CT1 | Rel-9 |
| Feature or Study Item: Definition of Ml interface for Control Plane LCS (Stage 3) | EMC2 | Rel-9 |
| Feature or Study Item: Security enhancements | SEC7 | Rel-7 |
| Building Block: HTTPS connection between a UICC and a NAF | SEC7-HSUN | Rel-7 |
| Feature or Study Item: Identification of Communication Services in IMS | ServID | Rel-7 |
| Building Block: CAT Service in 3GPP CS domain | CAT-3G_CS | Rel-8 |
| Building Block: CSG and Idle Mode Mobility for LTE Home eNodeB | HomeNB-LTE | Rel-8 |
| Building Block: CSG and Idle Mode Mobility for 3G Home NodeB | HomeNB-3G | Rel-8 |
| Work task: CT1 part of CAT Service in 3GPP CS domain | CAT-3G_CS | Rel-8 |
| Work task: Stage 3 for Mobility management based on MIP v4 | SAES-SA-FP_n3GPP | Rel-8 |
| Work task: Stage 3 CIMS_3GPP2 (CT1) | REDOC_3GPP2 | Rel-8 |
| Building Block: IMS CAT Supplementary Service | CAT-SS | Rel-8 |
| Work task: Stage 3 FA | FA | Rel-8 |
| Feature or Study Item: IMS Emergency Session Enhancements | IESE | Rel-10 |
| Building Block: Maintenance of TISPAN R2 | MAINT_R2 | Rel-8 |
| Building Block: Call Completion on Busy Subscriber (CCBS)/Call Completion on Non-Reachable (CCNR) on IMS | CCBS_CCNR | Rel-8 |
| Work task: CT1 part of Stage 3 CCBS_CCNR | CCBS_CCNR | Rel-8 |
| Building Block: Communication Wait on IMS | CW_IMS | Rel-8 |
| Work task: CT1 part of Stage 3 CW-IMS | CW_IMS | Rel-8 |
| Building Block: CT1 part of Network Attachment Subsystem (NASS) Bundled Authentication | NBA | Rel-8 |
| Feature or Study Item: Interworking between User-to-User Signalling (UUS) and SIP | UUSIW | Rel-8 |
| Building Block: CT1 part of Stage 3 MGCF UUSIW | UUSIW | Rel-8 |
| Building Block: Stage 3 for PPACR (CT1) | PPACR-CT1 | Rel-8 |
| Feature or Study Item: Support of Overlap signalling | Overlap | Rel-8 |
| Building Block: Stage 3 Overlap (CT1) | Overlap | Rel-8 |
| Work task: Stage 3 for Inter-system mobility between E-UTRAN and non 3GPP accesses | SAES-SA-FP_n3GPP | Rel-8 |
| Work task: Stage 3 for Inter-system mobility between E-UTRAN and 2G/3G | SAES-SA-FP_3GPP | Rel-8 |
| Feature or Study Item: AS/MRFC Stage 2 and 3 | MRFC_TS | Rel-8 |
| Work task: CT1 part of Stage 3 for CS Fallback in EPS | SAES-CSFB | Rel-8 |
| Work task: Deleted - Stage 3 for ICSRA – I1 interface | ICSRA | Rel-8 |
| Work task: CT1 part of Core Network Impacts for A-Interface User Plane over IP | AoIP-CN | Rel-8 |
| Building Block: Stage 3 for ICSRA – Protocol, Addressing, Subscriber Data | ICSRA | Rel-8 |
| Feature or Study Item: Service Specific Access Control in EPS | SSAC | Rel-9 |
| Feature or Study Item: Access Network Discovery and Selection Function enhancements | eANDSF | Rel-9 |
| Building Block: Stage 2/3 for IMS Service Continuity Enhancements: Service, Policy and Interactions | IMS_SCC-SPI | Rel-9 |
| Building Block: Stage 2/3 for IMS Centralized Services | IMS_SCC-ICS | Rel-9 |
| Building Block: Stage 2 for Support of Personal Area Networks and Enhancements to Personal Network Management | PAN_EPNM | Rel-9 |
| Building Block: Stage 3 - IMS Centralized Services support via I1 interface | IMS_SCC-ICS_I1 | Rel-9 |
| Feature or Study Item: LCS for LTE and EPS | LCS_LTE_EPS | Rel-9 |
| Feature or Study Item: PS domain and IMS impacts for supporting IMS Emergency calls (EMC1) | EMC1 | Rel-7 |
| Building Block: Stage 2 modifications for VGCS improvements | IVGCS | Rel-7 |
| Feature or Study Item: Voice Call Continuity between CS and IMS (incl. I-WLAN) | VCC | Rel-7 |
| Feature or Study Item: Enhancements to support QoS provisioning over 3GPP/WLAN Interworking | WLANQOS | Rel-7 |
| Feature or Study Item: WLAN Interworking – Private Network access from WLAN 3GPP IP Access | WLANPNA | Rel-7 |
| Building Block: SAES6 for support for non-3GPP accesses | SAES6-non3GPP | Rel-15 |
| Building Block: SAE Protocol Development (Stage 3) - Phase 6 | SAES6 | Rel-15 |
| Work task: CT1 aspects of VoWLAN | VoWLAN-CT | Rel-15 |
| Work task: CT1 aspects of ProSe_WLAN_DD | ProSe_WLAN_DD_Stage3 | Rel-15 |
| Work task: CT1 aspects of PS Data Off Phase 2 | PS_DATA_OFF2-CT | Rel-15 |
| Building Block: C1 aspects of 5GS_OTAF | 5GS_OTAF | Rel-16 |
| Work task: CT1 aspects of IABARC | IABARC | Rel-16 |
| Work task: CT1 aspects of Multi-device and multi-identity | MuD | Rel-16 |
| Work task: CT1 aspects of ePWS | ePWS | Rel-16 |
| Work task: Study on stages 2 and 3 of enhancements of ePWS | ePWS | Rel-16 |
| Feature or Study Item: Protocol enhancements for Mission Critical Services | MCProtoc16 | Rel-16 |
| Work task: CT1 aspects of 5WWC | 5WWC | Rel-16 |
| Feature or Study Item: Stage-3 5GS NAS protocol development | 5GProtoc16 | Rel-16 |
| Feature or Study Item: Stage-3 SAE Protocol Development for Rel16 | SAES16 | Rel-16 |
| Building Block: Stage-3 SAE Protocol Development for Rel16 general aspects | SAES16 | Rel-16 |
| Building Block: Stage-3 SAE Protocol Development for Rel16 for CS Fallback in EPS | SAES16-CSFB | Rel-16 |
| Building Block: Stage-3 SAE Protocol Development Rel16 for support for non-3GPP accesses | SAES16-non3GPP | Rel-16 |
| Building Block: Stage-3 5GS NAS protocol development general aspects | 5GProtoc16 | Rel-16 |
| Building Block: Stage-3 5GS NAS protocol development for support for non-3GPP accesses | 5GProtoc16-non3GPP | Rel-16 |
| Feature or Study Item: IMS Stage-3 IETF Protocol Alignment | IMSProtoc16 | Rel-16 |
| Feature or Study Item: Signalling Improvements for Network Efficiency in 5GS | SINE_5G | Rel-16 |
| Building Block: CT aspects of eMCData2 | eMCData2 | Rel-16 |
| Feature or Study Item: Withdrawal of TS 24.323 from Rel-11, Rel-12, Rel-13 | ISAT-MO-WITHDRAW | Rel-16 |
| Work task: CT1 aspects of Vertical_LAN | Vertical_LAN | Rel-16 |
| Work task: CT1 aspects of 5G_CIoT | 5G_CIoT | Rel-16 |
| Work task: CT1 aspects of 5G_eLCS | 5G_eLCS | Rel-16 |
| Work task: CT1 aspects of eNS | eNS | Rel-16 |
| Work task: CT1 aspects of ATSSS | ATSSS | Rel-16 |
| Work task: CT1 aspects of PARLOS | PARLOS | Rel-16 |
| Work task: CT1 Aspects of E2E_DELAY | E2E_DELAY | Rel-16 |
| Building Block: CT aspects of enh2MCPTT | enh2MCPTT-CT | Rel-16 |
| Feature or Study Item: Video enhancement of IMS CAT/CRS/announcement services | eIMSVideo | Rel-16 |
| Work task: CT1 Aspects of 5G_URLLC | 5G_URLLC | Rel-16 |
| Building Block: CT1 aspects of IMSProtoc16 | IMSProtoc16 | Rel-16 |
| Feature or Study Item: Stage 3 for MC Communication Interworking with Land Mobile Radio Systems | MCCI_CT | Rel-16 |
| Work task: CT1 aspects of RACS | RACS | Rel-16 |
| Work task: CT1 aspect of 5G_SRVCC | 5G_SRVCC | Rel-16 |
| Work task: Stopped - CT1 aspects of VBCLTE | VBCLTE | Rel-16 |
| Work task: CT1 aspects of xBDT | xBDT | Rel-16 |
| Work task: CT1 aspects of MONASTERY2 | MONASTERY2 | Rel-16 |
| Work task: CT1 aspects of V2XAPP | V2XAPP | Rel-16 |
| Work task: CT1 aspects of eV2XARC | eV2XARC | Rel-16 |
| Work task: CT1 aspects of SEAL | SEAL | Rel-16 |
| Work task: CT1 aspects of eIMS5G_SBA | eIMS5G_SBA | Rel-16 |
| Work task: CT1 aspects of RDSSI | RDSSI | Rel-17 |
| Building Block: CT1 aspects of enhancement of RAN Slicing for NR | NRslice | Rel-17 |
| Building Block: Stage 3 of MuDE | MuDe | Rel-17 |
| Feature or Study Item: Stage-3 5GS NAS protocol development 17 | 5GProtoc17 | Rel-17 |
| Feature or Study Item: Protocol enhancements for Mission Critical Services | MCProtoc17 | Rel-17 |
| Feature or Study Item: Stage-3 SAE Protocol Development | SAES17 | Rel-17 |
| Building Block: Stage 3 (CT1) of eCPSOR_CON | eCPSOR_CON | Rel-17 |
| Building Block: CT1 aspects of IMS Stage-3 IETF Protocol Alignment | IMSProtoc17 | Rel-17 |
| Building Block: CT1 aspects of FS_eIMS5G2 | FS_eIMS5G2 | Rel-17 |
| Feature or Study Item: Mission Critical system migration and interconnection | MCSMI_CT | Rel-17 |
| Feature or Study Item: Modifying PASSporT signing and verification for Spoofed calls | SPECTRE_Ph3 | Rel-17 |
| Building Block: CT aspects of AKMA_TLS | AKMA_TLS | Rel-17 |
| Building Block: CT1 aspects of NSWO | NSWO_5G | Rel-17 |
| Building Block: CT1 aspects of 5MBS | 5MBS | Rel-17 |
| Work task: CT1 aspects of TEI17_SE_RPS | TEI17_SE_RPS | Rel-17 |
| Work task: CT1 aspects for enabling MSGin5G Service | 5GMARCH | Rel-17 |
| Building Block: CT1 aspects of ING_5GS | ING_5GS | Rel-17 |
| Work task: CT1 aspects of MINT | MINT | Rel-17 |
| Work task: CT1 aspects of TEI17_N3SLICE | TEI17_N3SLICE | Rel-17 |
| Building Block: CT1 aspects of NB-IoT/eMTC Non-Terrestrial Networks in EPS | IoT_SAT_ARCH_EPS | Rel-17 |
| Feature or Study Item: Multi-device enhancements for device transfers | MuDTran | Rel-17 |
| Building Block: CT1 aspects of NR_redcap | ARCH_NR_REDCAP | Rel-17 |
| Work task: Stage 3 for TEI17_IMSGID | TEI17_IMSGID | Rel-17 |
| Building Block: Stage 3 CT1 for eCryptPr | eCryptPr | Rel-17 |
| Work task: CT1 aspects for EDGEAPP | EDGEAPP | Rel-17 |
| Building Block: Stage 3 aspects of enh3MCPTT | enh3MCPTT-CT | Rel-17 |
| Building Block: CT1 Aspects of Application Layer Support for Uncrewed Aerial Systems (UAS) | UASAPP | Rel-17 |
| Building Block: CT1 aspects of eV2XARC_Ph2 | eV2XARC_Ph2 | Rel-17 |
| Building Block: CT1 aspects of eSEAL | eSEAL | Rel-17 |
| Building Block: CT1 aspects of MCOver5GS | MCOver5GS | Rel-17 |
| Building Block: CT1 aspects of NBI17 | NBI17 | Rel-17 |
| Building Block: CT1 aspects of SMS_SBI | SMS_SBI | Rel-17 |
| Work task: CT1 aspects of AKMA | AKMA-CT | Rel-17 |
| Building Block: CT aspects of eMCData3 | eMCData3 | Rel-17 |
| Work task: CT1 aspects of eNS_Ph2 | eNS_Ph2 | Rel-17 |
| Work task: CT1 aspects of 5G eEDGE | eEDGE_5GC | Rel-17 |
| Work task: CT1 aspects of 5G_eLCS_ph2 | 5G_eLCS_ph2 | Rel-17 |
| Work task: CT1 aspects of ATSSS_Ph2 | ATSSS_Ph2 | Rel-17 |
| Work task: CT1 aspects of support of enhanced Industrial IoT | IIoT | Rel-17 |
| Work task: CT1 aspects of Enabling Multi-USIM Devices | MUSIM | Rel-17 |
| Work task: CT1 aspects of eNPN | eNPN | Rel-17 |
| Work task: CT1 aspects for ID_UAS | ID_UAS | Rel-17 |
| Work task: CT1 aspects of 5G_ProSe | 5G_ProSe | Rel-17 |
| Work task: CT1 aspects of eV2XAPP | eV2XAPP | Rel-17 |
| Work task: CT1 aspects on TEI17_SAPES | TEI17_SAPES | Rel-17 |
| Feature or Study Item: CT aspects of Enhanced Mission Critical Communication Interworking with Land Mobile Radio Systems | eMCCI_CT | Rel-17 |
| Building Block: CT aspects of enh3MCPTT | enh3MCPTT-CT | Rel-17 |
| Work task: CT1 aspects of 5GC architecture for satellite networks | 5GSAT_ARCH-CT | Rel-17 |
| Building Block: CT aspects of eMONASTERY2 | eMONASTERY2 | Rel-17 |
| Building Block: Stage-3 5GS NAS protocol development 17 general aspects | 5GProtoc17 | Rel-17 |
| Building Block: Stage-3 5GS NAS protocol development 17 non-IETF aspects | 5GProtoc17-non3GPP | Rel-17 |
| Building Block: Stage-3 SAE Protocol Development general aspects | SAES17 | Rel-17 |
| Building Block: Stage-3 SAE Protocol Development CSFB aspects | SAES17-CSFB | Rel-17 |
| Building Block: Stage-3 SAE Protocol Development non 3GPP aspects | SAES17-non3GPP | Rel-17 |
| Work task: CT1 aspects of MPS2 | MPS2 | Rel-17 |
| Building Block: Stage 3 of eMONASTERY2 | eMONASTERY2 | Rel-17 |
| Building Block: CT1 aspects of PAP/CHAP protocols usage in 5GS | PAP_CHAP | Rel-17 |
| Building Block: Study on the CT aspects of Support for Minimization of service Interruption | FS_MINT-CT | Rel-17 |
| Building Block: CT aspects of RDSSI | RDSSI | Rel-17 |
| Building Block: CT1 aspects of IVAS_Codec | IVAS_Codec | Rel-18 |
| Building Block: CT1 aspects of EDGE_Ph2 | EDGE_Ph2 | Rel-18 |
| Building Block: CT1 aspects of NSCALE | NSCALE | Rel-18 |
| Building Block: CT1 aspects of XRM | XRM | Rel-18 |
| Building Block: CT1 aspects of Mission Critical ad hoc group Communications | MC_AHGC | Rel-18 |
| Building Block: CT aspects of enh4MCPTT | enh4MCPTT | Rel-18 |
| Building Block: CT1 aspects of MPS_WLAN | MPS_WLAN | Rel-18 |
| Building Block: CT1 aspects of MBS support for V2X services | TEI18_MBS4V2X | Rel-18 |
| Building Block: Stopped – CT1 aspects of Slice-based PLMN Selection | PLMNsel_NS | Rel-18 |
| Building Block: CT aspects of 5GSAT_Ph2 | 5GSAT_Ph2 | Rel-18 |
| Building Block: CT aspects of PINAPP | PINAPP | Rel-18 |
| Building Block: CT aspects of UAS Ph2 | UAS_Ph2 | Rel-18 |
| Building Block: CT aspects of Ranging_SL | Ranging_SL | Rel-18 |
| Building Block: CT aspects of 5GFLS | 5GFLS | Rel-18 |
| Building Block: CT1 aspects of GMEC | GMEC | Rel-18 |
| Building Block: CT aspects of Network Slicing Phase 3 | eNS_Ph3 | Rel-18 |
| Building Block: CT aspects of NG_RTC | NG_RTC | Rel-18 |
| Building Block: CT aspects of ATSSS_Ph3 | ATSSS_Ph3 | Rel-18 |
| Building Block: CT aspects of ADAES | ADAES | Rel-18 |
| Building Block: CT aspects of 5GMARCH_Ph2 | 5GMARCH_Ph2 | Rel-18 |
| Building Block: CT aspects of VMR | VMR | Rel-18 |
| Building Block: CT1 aspects of Mission Critical Services over 5MBS | MCOver5MBS | Rel-18 |
| Building Block: CT1 aspects of Mission Critical Services over 5GProSe | MCOver5GProSe | Rel-18 |
| Building Block: CT1 aspects of NBI18 | NBI18 | Rel-18 |
| Building Block: Stage-3 5GS NAS protocol development 18 non 3GPP aspects | 5GProtoc18-non3GPP | Rel-18 |
| Building Block: Stage-3 SAE Protocol Development CSFB | SAES18-CSFB | Rel-18 |
| Building Block: Stage-3 SAE Protocol Development non 3GPP | SAES18-non3GPP | Rel-18 |
| Building Block: CT1 aspects of IMSProtoc18 | IMSProtoc18 | Rel-18 |
| Building Block: Stage-3 5GS NAS protocol development 18 general aspects | 5GProtoc18 | Rel-18 |
| Building Block: Stage-3 SAE Protocol Development general | SAES18 | Rel-18 |
| Feature or Study Item: MPS for Supplementary Services | MPSSupServ | Rel-18 |
| Building Block: CT1 aspects of MCGWUE | MCGWUE | Rel-18 |
| Building Block: CT1 aspects of UAS Ph2 | UAS_Ph2 | Rel-18 |
| Building Block: CT1 aspects of VMR | VMR | Rel-18 |
| Building Block: CT1 aspects of Ranging_SL | Ranging_SL | Rel-18 |
| Building Block: CT1 aspects of Network Slicing Phase 3 | eNS_Ph3 | Rel-18 |
| Building Block: CT1 aspects of 5GFLS | 5GFLS | Rel-18 |
| Building Block: CT1 aspects of PINAPP | PINAPP | Rel-18 |
| Building Block: CT1 aspects of PIN | PIN | Rel-18 |
| Building Block: CT1 aspects of 5GMARCH_Ph2 | 5GMARCH_Ph2 | Rel-18 |
| Building Block: CT1 aspects of ADAES | ADAES | Rel-18 |
| Building Block: CT1 aspects of ATSSS_Ph3 | ATSSS_Ph3 | Rel-18 |
| Building Block: CT1 aspects of UEConfig5MBS | UEConfig5MBS | Rel-18 |
| Building Block: CT1 aspects of NG_RTC | NG_RTC | Rel-18 |
| Building Block: CT1 aspects of 5GSAT_Ph2 | 5GSAT_Ph2 | Rel-18 |
| Building Block: CT1 aspects for 5MBS_Ph2 | 5MBS_Ph2 | Rel-18 |
| Building Block: CT1 aspects of SENSE | SENSE | Rel-18 |
| Building Block: Mission critical system migration and interconnection enhancements | eMCSMI_IRail | Rel-18 |
| Building Block: CT aspects of UASAPP_Ph2 | UASAPP_Ph2 | Rel-18 |
| Building Block: CT aspects of V2XAPP_Ph3 | V2XAPP_Ph3 | Rel-18 |
| Building Block: CT aspects of SEALDD | SEALDD | Rel-18 |
| Building Block: CT aspects of 5G_ProSe_Ph2 | 5G_ProSe_Ph2 | Rel-18 |
| Building Block: CT aspects of TEI18_SDNAEPC | TEI18_SDNAEPC | Rel-18 |
| Building Block: CT aspects of SEAL_Ph3 | SEAL_Ph3 | Rel-18 |
| Building Block: CT aspects of Seamless UE context recovery | SUECR | Rel-18 |
| Building Block: CT aspects of 5WWC_Ph2 | 5WWC_Ph2 | Rel-18 |
| Building Block: CT1 aspects of UASAPP_Ph2 | UASAPP_Ph2 | Rel-18 |
| Building Block: CT1 aspects of 5G_eLCS_Ph3 | 5G_eLCS_Ph3 | Rel-18 |
| Building Block: CT1 aspects of 5G_ProSe_Ph2 | 5G_ProSe_Ph2 | Rel-18 |
| Building Block: CT1 aspects of SEAL_Ph3 | SEAL_Ph3 | Rel-18 |
| Building Block: CT1 aspects of SEALDD | SEALDD | Rel-18 |
| Building Block: CT1 aspects of NR_REDCAP_Ph2 | NR_REDCAP_Ph2 | Rel-18 |
| Building Block: CT1 aspects of eMCSMI_IRail | eMCSMI_IRail | Rel-18 |
| Building Block: CT1 aspects of V2XAPP_Ph3 | V2XAPP_Ph3 | Rel-18 |
| Building Block: CT1 aspects of EDGEAPP_Ph2 | EDGEAPP_Ph2 | Rel-18 |
| Building Block: CT1 aspects of eNPN_Ph2 | eNPN_Ph2 | Rel-18 |
| Building Block: CT1 aspects of eUEPO | eUEPO | Rel-18 |
| Building Block: CT1 aspects of 5WWC_Ph2 | 5WWC_Ph2 | Rel-18 |
| Building Block: CT1 aspects of Seamless UE context recovery | SUECR | Rel-18 |
| Building Block: CT1 aspects of Detnet | DetNet | Rel-18 |
| Building Block: CT1 aspects of TEI18_IPv6PD | TEI18_IPv6PD | Rel-18 |
| Building Block: CT1 aspects of TEI18_SDNAEPC | TEI18_SDNAEPC | Rel-18 |
| Building Block: CT1 aspects of TRS_URLLC | TRS_URLLC | Rel-18 |
| Building Block: CT1 aspects of MCProtoc18 | MCProtoc18 | Rel-18 |
| Building Block: CT Aspects of Application Layer Support for Uncrewed Aerial Systems (UAS), Phase 3 | UASAPP_Ph3 | Rel-19 |
| Feature or Study Item: Enhanced Mission Critical Location Management | enhMCLoc | Rel-19 |
| Building Block: Stage-3 5GS NAS protocol development 18 general aspects | 5GProtoc19 | Rel-19 |
| Building Block: Stage-3 5GS NAS protocol development 18 non 3GPP aspects | 5GProtoc19-non3GPP | Rel-19 |
| Building Block: Stage-3 SAE Protocol Development general | SAES19 | Rel-19 |
| Building Block: Stage-3 SAE Protocol Development non 3GPP | SAES19-non3GPP | Rel-19 |
| Work task: CT1 aspects for Enabling Edge Applications Phase 3 | EDGEAPP_Ph3 | Rel-19 |
| Building Block: CT1 aspects of Rel-19 Enhancements of 3GPP Northbound and Application Layer Interfaces and APIs | NBI19 | Rel-19 |
| Building Block: CT1 aspects of IMS Stage-3 IETF Protocol Alignment | IMSProtoc19 | Rel-19 |
| Building Block: CT1 aspects of Protocol enhancements for Mission Critical Services | MCProtoc19 | Rel-19 |
| Building Block: CT1 aspects of Enhancement of controlling RAT utilization | ECRATU | Rel-19 |
| Work task: CT1 Aspects of Application Layer Support for Uncrewed Aerial Systems (UAS), Phase 3 | UASAPP_Ph3 | Rel-19 |
| Building Block: CT aspects of SEAL DD (Data Delivery) Phase 2 | SEALDD_Ph2 | Rel-19 |
| Building Block: CT aspects of Railways specific Enhancements to Mission Critical Services | FRMCS_Ph5 | Rel-19 |
| Building Block: CT aspects of integration of satellite components in the 5G architecture Phase 3 | 5GSAT_Ph3_ARCH | Rel-19 |
| Building Block: CT aspects of Multi-Access (ATSSS_Ph4) | MASSS | Rel-19 |
| Building Block: CT aspects of ProSe support in NPN | TEI19_ProSe_NPN | Rel-19 |
| Building Block: CT aspects of System architecture for Next Generation Real time Communication services Phase 2 | NG_RTC_Ph2 | Rel-19 |
| Building Block: CT aspects of Proximity-based Services in 5GS Phase 3 | 5G_ProSe_Ph3 | Rel-19 |
| Building Block: CT aspects of Vehicle Mounted Relays Phase 2 | VMR_Ph2 | Rel-19 |
| Feature or Study Item: Alignment of eCall over IMS with CEN | eCallCEN | Rel-19 |
| Building Block: Study on MINT support in EPS for 5G-only national roaming UE | FS_MINT_Ph2 | Rel-19 |
| Work task: CT1 aspects of Proximity-based Services in 5GS Phase 3 | 5G_ProSe_Ph3 | Rel-19 |
| Work task: CT1 aspects of integration of satellite components in the 5G architecture Phase 3 | 5GSAT_Ph3_ARCH | Rel-19 |
| Work task: CT1 aspects of Application enablement for AI/ML services | AIML_App | Rel-19 |
| Work task: CT1 aspects of Enhanced application layer support for location services | eLSAPP | Rel-19 |
| Work task: CT1 aspects of Multi-Access (ATSSS_Ph4) | MASSS | Rel-19 |
| Work task: CT1 aspects of Application enablement for mobile metaverse services | Metaverse_App | Rel-19 |
| Work task: CT1 aspects of MPS for IMS Messaging and SMS services | MPS4msg | Rel-19 |
| Work task: CT1 aspects of System architecture for Next Generation Real time Communication services Phase 2 | NG_RTC_Ph2 | Rel-19 |
| Work task: CT1 aspects of SEAL DD (Data Delivery) Phase 2 | SEALDD_Ph2 | Rel-19 |
| Work task: CT1 aspects of indirect network sharing | TEI19_NetShare | Rel-19 |
| Work task: CT1 aspects of ProSe support in NPN | TEI19_ProSe_NPN | Rel-19 |
| Work task: CT1 aspects of UAS, UAV and UAM Phase 3 | UAS_Ph3 | Rel-19 |
| Work task: CT1 aspects of Identifying non-3GPP Devices Connecting behind a UE or 5G-RG | UIA_ARC | Rel-19 |
| Work task: CT1 aspects of Vehicle Mounted Relays Phase 2 | VMR_Ph2 | Rel-19 |
| Work task: CT1 aspects of Railways specific Enhancements to Mission Critical Services | FRMCS_Ph5 | Rel-19 |
| Feature or Study Item: NAS layer overhead reduction for data transfer using CP CIoT | NORDAT_CP | Rel-19 |
| Building Block: CT aspects for enabling MSGin5G Service phase 3 | 5GMARCH_Ph3 | Rel-19 |
| Building Block: CT aspects of security for mobility over non-3GPP access to avoid full primary authentication | Non3GPPMob_Sec | Rel-19 |
| Work task: CT1 aspects for application enablement for satellite access Phase 3 | 5GSAT_Ph3_App | Rel-19 |
| Work task: CT1 aspects of Extended Reality and Media service (XRM) Phase 2 | XRM_Ph2 | Rel-19 |
| Work task: CT1 aspects of Application enablement for XRM Services Phase 2 | XRM_Ph2_App | Rel-19 |
| Work task: CT1 aspects for enabling MSGin5G Service phase 3 | 5GMARCH_Ph3 | Rel-19 |
| Building Block: CT1 aspects of bSRVCC_MT | bSRVCC_MT | Rel-15 |
| Feature or Study Item: Enhancements to Call spoofing functionality | eSPECTRE | Rel-15 |
| Building Block: CT1 aspects of eSPECTRE | eSPECTRE | Rel-15 |
| Work task: CT1 aspects of MONASTERY | MONASTERY | Rel-15 |
| Work task: CT1 aspects of INOBEAR | INOBEAR-CT | Rel-15 |
| Building Block: CT1 aspects of PV_VBC | PC_VBC | Rel-15 |
| Feature or Study Item: Protocol enhancements for Mission Critical Services | MCProtoc15 | Rel-15 |
| Building Block: Stage 3 of enhMCPTT | enhMCPTT-CT | Rel-15 |
| Building Block: Stage 3 of eMCData | eMCData-CT | Rel-15 |
| Work task: CT1 aspects of eMCVideo | eMCVideo-CT | Rel-15 |
| Work task: CT1 aspects of IMSo5G | 5GS_Ph1-IMSo5G | Rel-15 |
| Work task: CT1 aspects of EDCE5 | EDCE5-CT | Rel-15 |
| Work task: Study on 5G Network selection | 5GS_Ph1-CT | Rel-15 |
| Work task: Study on 5G Mobility management | 5GS_Ph1-CT | Rel-15 |
| Work task: Study on 5G Session management | 5GS_Ph1-CT | Rel-15 |
| Work task: Study on 5G Non-3GPP access networks | 5GS_Ph1-CT | Rel-15 |
| Work task: Study on 5G Interworking with EPC | 5GS_Ph1-CT | Rel-15 |
| Work task: Study on 5G System core network impact on services, network functions and capabilities | 5GS_Ph1-CT | Rel-15 |
| Work task: Study on 5G Network slicing | 5GS_Ph1-CT | Rel-15 |
| Work task: CT1 aspects of 5G System - Phase 1 (normative work) | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G Network selection | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G Mobility management | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G Session management | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G Non-3GPP access networks | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G Interworking with EPC | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G System core network impact on services, network functions and capabilities | 5GS_Ph1-CT | Rel-15 |
| Work task: 5G Network slicing | 5GS_Ph1-CT | Rel-15 |
| Feature or Study Item: AT Commands for CIoT-Ext | AT_CIoT-Ext | Rel-15 |
| Work task: CT1 aspects of FS_PC_VBC | FS_PC_VBC | Rel-15 |
| Work task: Stopped - CT1 aspects of LTE_LIGHT_CON | LTE_LIGHT_CON-CT | Rel-15 |
| Building Block: CT1 aspects of IMS Stage-3 IETF Protocol Alignment | IMSProtoc9 | Rel-15 |
| Work task: CT1 aspects of eCNAM | eCNAM-CT | Rel-15 |
| Feature or Study Item: Stage-3 SAE Protocol Development - Phase 6 | SAES6 | Rel-15 |
| Building Block: SAES6 CS Fallback in EPS | SAES6-CSFB | Rel-15 |
