Note that this page shows only those active (i.e. not yet completed) WIs where C1 is the sole responsible group.
There may be other active WIs for which this group holds joint responsibility, particularly hierachically higher WIs which comprise WIs from several groups: such WIs are not shown on this page.
| 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 |
| 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: 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: 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 |
| 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 |
| Building Block: CT aspects of CIoT | CIoT-CT | Rel-13 |
| Work task: CT1 aspects of CIoT | CIoT-CT | 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: 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 |
| Work task: CT1 aspects of Double Resource Reuse for Multiple Media Sessions | DRuMS-CT | Rel-13 |
| 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 |
| 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 |
| 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 |
| Work task: CT1 part of PCRF based solution | PCSCF_RES | Rel-12 |
| Feature or Study Item: Deleted - IMS Registration Control | IMS_RegCon | Rel-12 |
| Work task: CT1 part of CT impacts of codec for Enhanced Voice Services | EVS_codec-CT | 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 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: 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 |
| 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 |
| Feature or Study Item: Coordination of Video Orientation | CVO | Rel-12 |
| Feature or Study Item: Extended IMS media plane security features | eMEDIASEC | 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: 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: 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: 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 |
| 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 |
| Feature or Study Item: IMS Emergency Session Enhancements | IESE | Rel-10 |
| 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: CT1 part of Transfer of ETSI business trunking specifications | IMS_Corp2 | Rel-12 |
| 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: 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 |
| 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: 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: 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: 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 |
| 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 |
| 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: 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 |
| 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 |
| 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 |
| 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: 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 |
| 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: 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 |
| 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 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: 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: Full Support of Multi-Operator Core Network by GERAN | Full_MOCN-GERAN | Rel-11 |
| 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 |
| 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: PS domain and IMS impacts for supporting IMS Emergency calls (EMC1) | EMC1 | Rel-7 |
| Building Block: CT1 part of IMS Signalling Activated Trace | ISAT | Rel-14 |
| Building Block: Stage 3 for MBMS_Mcservices | MBMS_Mcservices | Rel-15 |
| 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 |
| 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 XRM | XRM | 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 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 Application enablement for AI/ML services | AIML_App | Rel-19 |
| Building Block: CT aspects of Application enablement for mobile metaverse services | Metaverse_App | 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 |
