Rel-18

Radio Link Protocol (RLP) for Circuit Switched Data

Specifies RLP for circuit switched data transmission within a PLMN, covering Layer 2 functionality and protocol conversi

Service Change and UDI Fallback (SCUDIF) for CS Multimedia

Describes SCUDIF feature for UDI/RDI multimedia calls, enabling fallback to speech and service change during CS calls.

GERAN PLMN Connection Types

Defines PLMN connection types for GERAN, bridging service specifications and detailed network capabilities for GSM/3G ne

Sy Reference Point for Spending Limit Reporting

Stage 3 specification of Sy reference point between PCRF and OCS for policy counter status reporting and spending limit

PLMN-PSTN/ISDN Interworking for CS Services

Defines MSC/IWF requirements for circuit-switched interworking between PLMN and PSTN/ISDN, including voice and data call

TAF for Synchronous Bearer Services

Defines Terminal Adaptation Functions (TAF) for synchronous bearer services in PLMN, covering rate adaptation and ITU-T

Terminal Adaptation Functions for PLMN

Defines terminal adaptation functions for connecting non-voice terminals to PLMN, covering A/Gb and Iu modes.

Terminal Adaptation Functions for MT

Defines interfaces and Terminal Adaptation Functions (TAF) for Mobile Terminations to enable asynchronous bearer service

IMS Multimedia Telephony Communication Service

Defines protocols for multimedia telephony (MMTel) over IMS, including basic communication and supplementary services.

CS Bearer Services in UMTS

Defines circuit switched bearer services for UMTS, covering transparent/non-transparent data, bearer capabilities, and h

UMTS Facsimile Group 3 Teleservice

Describes real-time fax group 3 service in UMTS using non-transparent network support for Teleservices 61 and 62.

SIP-I CS Core Interworking with External Networks

Specifies interworking between SIP-I based CS core and external SIP-I, ISUP, BICC networks, and IMS with out-of-band tra

S9 Reference Point for Policy and Charging Control

Stage 3 specification for S9 reference point between H-PCRF and V-PCRF in roaming scenarios.

Np Reference Point Stage 3 Specification

Defines the Np interface between RCAF and PCRF for RAN user plane congestion reporting and policy control in 3GPP networ

Nt Reference Point Protocol for Background Data Transfer

Defines Diameter-based Nt application between SCEF and PCRF for background data transfer policy negotiation and event mo

CS-SIP-I Interworking Procedures

Defines interworking between 3GPP CS domain (BICC/ISUP) and external SIP-I networks, including control plane and MGW con

St Reference Point for Traffic Steering Control

Defines REST-based St interface between PCRF and TSSF for provisioning traffic steering control information in 4G networ

Ns Reference Point Protocol for Congestion Reporting

Defines Diameter-based protocol between SCEF and RCAF for RAN congestion status reporting, including one-time and contin

Multiplexer Protocol between UE and TE

Defines multiplexing protocol for multiple simultaneous sessions (voice, data, SMS, etc.) over serial interface between

Optimal Media Routeing in IMS

Defines OMR procedures for IMS entities to optimize media path by manipulating SDP attributes.

TE-MT Interworking for Packet Domain

Defines requirements for TE-MT interworking over R-reference point for GPRS/UMTS packet services, including protocols an

MB2 Reference Point Protocol for GCS

Defines protocol for MB2 between GCS AS and BM-SC for MBMS bearer management and TMGI allocation.

Nb UP Protocol for CS Core Network

Specifies user plane protocol between Media Gateways in BICC-based CS core network, based on Iu UP protocol.

SIP Transfer of Tariff Information

Specifies real-time transfer of tariff info between CDP and CGP using SIP for IMS charging.

Nb Interface Bearer Transport and Control

Specifies bearer data transport and control protocols between MGWs in CS core network over Nb Interface.

Gw and Gwn Reference Points for PFD Management

Stage 3 specification for Gw/Gwn interfaces between PFDF and PCEF/TDF for Packet Flow Description retrieval and provisio

PC2 Reference Point Stage 3 Specification

Specifies the stage 3 procedures and functional requirements for the PC2 reference point between the ProSe Function and

IM/CPM and SMS Service Level Interworking

Specifies protocol details for interworking between Instant Messaging or Chat Sessions and SMS over CS/PS and IP network

Nu Reference Point Stage 3 Specification

Stage 3 specification of Nu reference point between PFDF and SCEF for provisioning of Packet Flow Descriptions (PFDs) an

Rate Adaptation Functions for PLMN BSS

Defines rate adaptation functions for BSS transcoders and IWF to adapt radio interface data rates to 64 kbit/s A-interfa

VoLTE Roaming Architecture and Signalling Flows

Describes end-to-end use cases and signalling flows for voice over IMS with local breakout roaming architecture.

Rate Adaptation for GSM/EDGE Mobile Stations

Defines rate adaptation functions for adapting terminal interface data rates to MS-BSS interface rates in GSM/EDGE netwo

Diameter Usage within 3GPP

Common principles, rules, and recommendations for consistent Diameter protocol usage across 3GPP WGs.

UDR for Policy, Application & Exposure Data

Specifies stage 3 usage of Nudr_DataRepository service for policy, application, and structured exposure data in 5G Core.

NR UE Demodulation Performance Requirements

Specifies minimum demodulation performance requirements for NR UE receivers, covering conducted and radiated tests for F

NR UE Radio Transmission and Reception

Specifies minimum RF requirements for NR UE supporting CA, DC, V2X in FR1/FR2.

T8 Reference Point Protocol for SCEF

Defines HTTP/JSON APIs for SCEF to expose 3GPP network capabilities to SCS/AS, enabling monitoring, device triggering, a

Session Management Policy Control Service Stage 3

Stage 3 specification for 5G Session Management Policy Control Service, defining protocols and procedures for policy and

CAPIF Protocol for 3GPP Northbound APIs

Specifies the Common API Framework (CAPIF) protocol for northbound APIs, including service discovery, publishing, securi

Nsmf_EventExposure Service

Defines stage 3 of SMF event exposure service for 5G, allowing NF consumers to subscribe to PDU session events and recei

MCLoc Protocol Specification

Specifies protocols for Mission Critical Location Management service (MCLoc) supporting public safety and specialized co

IVAS Codec Fixed-Point C Code

Fixed-point C code for IVAS codec, rendering, error concealment, and jitter buffer management.

SIP-Based User Configuration of Supplementary Services

Defines a SIP-based protocol framework for user configuration of IMS supplementary services using Request-URI in INVITE

Wireless LAN control plane protocol for trusted WLAN access to EPC

Specifies procedures of the Wireless LAN control plane protocol for trusted WLAN access to EPC

IMS Messaging Service Using SIP, SDP, MSRP

Specifies protocol details for immediate and session-based messaging in IMS, covering page-mode and MSRP-based conferenc

IMS Service Continuity Protocol Details

Protocol details for IMS Service Continuity using SIP/SDP and CS domain protocols for session continuity across access n

Flexible Alerting (FA) Supplementary Service

Defines protocol details for Flexible Alerting in IMS, enabling call branching to multiple group members simultaneously.

IMS Call Control Protocol based on SIP/SDP

Defines call control protocol for IP Multimedia Core Network subsystem using SIP and SDP, covering interfaces between UE

Access Traffic Steering, Switching and Splitting (ATSSS)

Specification of procedures for ATSSS between UE and network across 3GPP and non-3GPP access

Communication Continuity Management Object

Defines a management object for VCC, SC, and inter-UE transfer settings, compatible with OMA DM 1.2.