5G-Advanced R18&R19->R20

The next step in the development of cellular technologies, 5G-Advanced refers to a suite of technologies that will be introduced with Release 18 of the 3GPP standards. Release 18 is due to be finalised in June 2024, paving the way for vendors to start supplying commercial solutions to mobile network operators for deployment in late 2025 onwards. Following the first major wave of deployments in 2026, 5G-Advanced capabilities promise to transform every aspect of the services mobile network operators (MNOs) provide for their customers.

5G-Advanced Use Cases are presentedin order to illuminate recent advancements, industry standards, and emerging technologies, offering a comprehensive understanding of both the current state and the future direction of this field.

Metaverse evolution. The metaverse is a dynamic and evolving concept in the realm of digital technology, characterized by its capacity to transcend strict definitions. It represents a partial or fully immersive digital networked experience that seamlessly interconnects people, places, objects, and information in real time, going beyond the confines of the physical world. At its core, the metaverse holds vast potential to augment the human experience, impacting social interactions, healthcare, education, gaming and creating new avenues for business through virtual economies and currencies.
As such, the metaverse experience is accessible through a variety of XR/3D devices or conventional 2D screens using WebXR technologies. The metaverse’s essence lies in its ability to transform our digital interactions and experiences, promising to reshape the way we live, work, and connect in the modern age.
RedCap. Supporting RedCap devices is introduced in NR Rel-17. The use cases that motivate the specification work on NR RedCap include wearables (e.g., smart watches, wearable medical devices, AR/VR goggles, etc.), industrial wireless sensors, and video surveillance. These three use cases put some generic requirements on the system, such as reduced device complexity, compact form factor, and support for FR1 and FR2. The table below specifies such use case specific requirements.
Integrated Communication and Sensing (ICAS). Joint communication and sensing (JCAS), on a high level, can be defined as integrating the functionalities of communication and sensing into the same system or network. The integration of sensing and communication with JCAS could be at different levels, from loosely coupled to fully integrated, shared spectrum, shared hardware, to shared signal processing module and network protocol stacks, and even using the same waveform for both communications and sensing. In this integrated way, sensing functionality can be introduced as a service with a low incremental cost as it leverages on equipment and spectrum anyway deployed for communication purposes. Overall, JCAS can extend the capability of cellular network from “listen and talk” to “see and feel”. From a device perspective, they can sense their surroundings, and exchange their sensing results through communication links. From a network perspective, the widely deployed base stations for legacy cellular service could be re-used for wide area seamless RF sensing. In addition, combining the AI, communications, positioning and sensing capabilities, the cellular network could intelligently fuse the physical world with digital world and provide a variety of new services for consumers and industry customers.
Ambient IoT. Ambient IoT represents an innovative device category that exclusively relies on harvested environmental energy, ensuring both cost-effectiveness and simplicity. These devices are intentionally designed without the need for battery replacements, alleviating the maintenance burden. Ambient IoT stands as the most budget-friendly, uncomplicated, and power-efficient tier of devices. Its affordability facilitates the connection of numerous objects and items to networks, allowing for a multitude of applications

The major focus for 2023 has been completing work and finalizing Release 18, which is the first official release supporting 5G Advanced. Release 18 aims to drive a balanced 5G evolution across key technology areas while also taking into consideration the ways 5G Advanced will evolve in Release 18, Release 19, and beyond. This evolutionary approach has led to many study items being defined and set up as work items in later releases. Major topics covered in Release 18 include MIMO enhancements, in particular for uplink and mobility scenarios, NR-Light (RedCap) evolution, evolved duplexing, and artificial intelligence (AI) and machine learning (ML) data-driven designs. The MIMO enhancement uplink improvement aims to improve the user experience when trying to upload content in crowded locations, a common pain point for customers. And RedCap looks to provide a low-power solution for devices like sensors and wearables.In parallel to the work being done in Release 18, the first plenary meeting was held in June 2023 to discuss the package of projects that will be included in Release 19. This package will be approved at the December ’23 RAN plenary (RAN #102) with a target timeframe of 18 months for the duration of Release 19. The primary focus of Release 19 will be 5G-Advanced, and again, this release will be all about balance between short-term fixes and long-term feature development, mobile broadband evolution versus the expansion of vertical use cases, and device evolution versus network evolution. An initial list of topics for consideration for Release 19 was drafted in June and further narrowed down at the RAN plenary in September 2023 (Figure 2). After the September meeting, seven items were identified for RAN Working Group 1 (RAN1), five for RAN Working Group 2 (RAN2), and three for RAN Working Group 3 (RAN3). The full list of all items and more details can be found in the RAN chair’s guidance RP-231540.

The RAN1 topics include AI and ML for the air interface, ambient IoT, network energy savings, and an exploration of new spectrum (7-24 GHz). AI/ML and the inclusion of items related to improving energy efficiency are obvious inclusions based on current industry trends. And like energy savings items, ambient IoT could also be considered part of the green movement for wireless. An ideal ambient IoT device would be a device that could harvest energy from the RF radiation in the atmosphere and would not need a battery.
These devices are still a research concept, but the 3GPP is looking for ways to construct the protocol to allow for minimal up time, the most efficient design of a wake-up signal, and the lowest overall power required for the device to communicate with the network.
The most time units (TUs), or the estimated amount of time that the 3GPP will dedicate to focusing on a specific item, in RAN1 is four for AI/ML for the air interface. This makes sense, given the efforts to look at AI/ML in Release 18, which included AI for channel state information (CSI) enhancements, beam management, and positioning. This work will be carried into Release 19, and some new topics are likely to emerge as well. Network energy savings remain a significant effort and are likely to be carried forward into Release 19. The largest effort in Release 18 was the MIMO evolution, and again, to no surprise, MIMO evolution is listed for Release 19, although with only 1-2 TUs reserved.
RAN2’s topics include enhancements for extended reality (XR) and non-terrestrial networks (NTN) evolution for NR and IoT. There will also be overlap and cross-working group efforts needed between RAN1 and RAN2 for ambient IoT and AI/ML for the air interface. RAN3 items include AI/ML for next-generation RAN (NG-RAN), self-organizing networks (SON) / minimization of drive test (MDT) enhancements, and additional topological enhancements, as well as cross-working group efforts for ambient IoT. The development cycle for RAN Working Group 4 (RAN4), which focuses on radio performance and protocol aspects, trails RAN1, 2, and 3 by a few months. A similar discussion will be had to look at candidate items for RAN4 during the December plenary.

Release 19 is important because it will also serve as a bridge to 6G. Release 20 is anticipated to be the first official release to include 6G study items, but there is strong interest in initiating some studies sooner for important topics like channel modeling for 7-24 GHz and integrated sensing and communications (ISAC).

5G-Advanced is set to evolve the 5G system to its fullest capabilities. It will comprise a large set of innovations offering a plethora of benefits for network and system operators, end-users and verticals. 5G-Advanced will include features that will be specified in 3GPP Release 18 and beyond, including, among others, improved coverage and capacity, enhanced end-user experience and expanded capabilities beyond connectivity. It will introduce enhancements needed for more demanding applications, such as mobile extended reality and haptic applications. 5G-Advanced will inject more intelligence into the network, utilizing machine learning to adapt to the environment, boost performance and manage complex optimizations. It will also bring mobile broadband to new classes of devices (e.g. extended reality, reduced capability devices, new sidelink innovations, reduced bandwidth operation) and open 5G to new sectors. Energy efficiency will be central to 5G-Advanced, both in maximizing device battery life and in reducing network power consumption. The world’s first 5G New Radio (NR) solution was standardized by 3GPP in Release 15. NR is highly flexible and enables significant improvements in three main service domains: enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), and massive machine type communications (mMTC). These are achieved by a new User Equipment (UE), Radio Access Network (RAN) and 5G Core (5GC) design that includes numerous innovations. Among others, the RAN includes a new beam-based physical layer design with scalable numerology that allows operation up to mmWave carrier frequencies and supports massive MIMO, new channel coding schemes, and flexible frame structures. The Layer-2 RAN protocol design includes decoupling of higher layer functions from real-time constraints, avoiding duplicated functions, supporting front-haul interface splits, and flexible QoS. Among others, this is achieved by moving functionalities such as packet reordering and concatenation from the Radio Link Control (RLC) protocol layer to the Packet Data Convergence Protocol (PDCP), meaning that the tasks of the PDCP and RLC layers can be completed before fast scheduling decisions are made at the Medium Access Control (MAC) to trigger fast transmissions at the physical layer. 5G NR saw its first commercial deployments in 2019, using dual connectivity with LTE and the Evolved Packet Core (EPC) core network (so-called Non-Standalone (NSA) NR deployments), with the full 5G experience including the 5GC becoming available from 2020 when Standalone (SA) 5G networks started to be rolled out. 5G SA also enables deployment of private 5G networks for verticals.Since the creation of 3GPP NR Release 15, the 5G standard has further evolved in Releases 16 and 17, introducing enhancements particularly for Industrial IoT (IIoT) and wider expansion of the 5G ecosystem, including innovations to support time sensitive communication (TSC), enhanced MIMO, small data transmission (SDT), UE energy saving, and many more. 5G evolution is now entering the 5G-Advanced era, starting with 3GPP Release 18. In July 2021, 3GPP held its first RAN workshop where potential innovations for 5G-Advanced were discussed, with companies submitting more than 500 proposals. In September 2021, 3GPP also discussed numerous potential innovations for the 5G-Advanced system architecture and services. In December-2021, 3GPP agreed on the scope of many Release 18 study and work items, while additional Release 18 items for UE and base station RF and performance requirements are expected to be decided in March-2022.The first 5G-Advanced networks are expected to be deployed commercially around 2025. 5G-Advanced will provide a foundation for more demanding applications such as truly mobile extended reality services. It will also inject more intelligence into the network, utilizing machine learning (ML) to adapt to its environment. As with previous 5G releases, 5G-Advanced will boost fundamental radio and system performance, but it will also bring mobile broadband to new classes of devices and enhance support for novel use cases. As will be described in greater detail in the forthcoming sections, device innovations for 5G-Advanced are projected to include reduced capability devices, new sidelink innovations, reduced bandwidth operation, and eventually also making device satellite connectivity a commonplace feature. 5G-Advanced will be fully backward compatible, so it will be able to coexist with the current 5G NR Releases 15-17, including the ability to serve legacy 5G UEs.

In June 2022, 3GPP Rel-17 was introduced, heralding significant enhancements to existing applications, complementing the advancements in data speeds, reduced latency, and ultra-reliability.Rel-17 brings major enhancements to existing applications, complementing the previously mentioned enhancements.

5G-Advanced started with 3GPP Release 18 and shifts up to the next gear with Release 19. It will fine-tune the important themes from Release 18 - such as improved energy efficiency, better coverage-capacity and improved mobility performance – as well as putting in place the foundations of a bridge for a smooth evolution to 6G, including channel modeling, duplex evolution, and the development of a more extensive AI/ML framework. Essentially, Release 19 will offer unprecedented performance to commercial mobile network operators as well as private enterprises, resulting in improved end-user experience and superior operational excellence. We expect standardization of Release 19 to complete by the end of 2025, with commercial availability of the first Release 19 features in the field approximately one year after the standard’s completion.

3GPP Rel-18 5G-Advanced RAN featuresThe first release of 5G-Advanced as per 3GPP Rel-18 will cover interesting topics like the inclusion of AI/ML within RAN and even air interface. This is part of the automation framework, which is getting more advanced within the 5G system and is accompanied by other relevant features like enhancements to QoE and SON/MDT. Other set of topics include novel architectural aspects, like Mobile IAB, UAV, Network Controlled Repeaters, Sidelink, and NTN. In the IoT sector, also aspects like coverage enhancements, Small data transmission, RedCap, positioning, or NTN within the IoT area are dealt with. Finally, the MBB related features include MIMO and CA enhancements along with MBS and XR enhancements.
The current timeline for the Rel-18 is as follows:

Stage 1 – Dec. 2021 (an overall service description from the user’s standpoint
Stage 2 Functional freeze – March 2023 (overall description of the organization of the network functions to map service requirements into network capabilities)
Stage 3 Freeze – December 2023 (the definition of switching and signalling capabilities needed to support services defined in stage 1)
Protocol Coding Freeze (ASN1 and Open API) – March 2024

The current set of WI/SI (Work Items/Study items) for 3GPP Rel-18 RAN features is split into four RAN working groups (WGs) as per the figure below. As per the above description, the first release of 5G-Advanced as per 3GPP Rel-18 will cover interesting topics like the inclusion of AI/ML within RAN and even air interface. This is part of the automation framework, which is getting more advanced within the 5G system and is accompanied by other relevant features like enhancements to QoE and SON/MDT. Other set of topics include novel architectural aspects, like Mobile IAB, UAV, Network Controlled Repeaters, Sidelink, and NTN. In the IoT sector, also aspects like coverage enhancements, Small data transmission, RedCap, positioning, or NTN within the IoT area are dealt with. Finally, the MBB related features include MIMO and CA enhancements along with MBS and XR enhancements.

5G-Advanced in 3GPP SA2. On the 20th of December 2021, 3GPP SA TSG approved a total of 28 Work-/Study-Items (WIs/SIs) for the SA2 Rel-18 at the SA plenary meeting #94e (SP-94e). 3GPP Rel-18 is the first release of the 5G-Advanced standard. The approved projects include TSN, NW slicing, support for edge computing, NW automation, location services, AI and ML-based services, XR services to name a few.The current set of accepted WIs/SIs (Work Items/Study items) for 3GPP Rel-18 SA2 features is shown on the figure below. Those are discussed in detail in the following section. Summing up the above, Rel-18 set of features from the SA2 perspective could be grouped into several main topics like:

Enhanced Services, including: XR, Enhanced IMS, MBS, Priority Services, Ranging-based Services, LCS
Advanced IoT Use Cases, including: UAS/UAV, RedCap, Satellite, Personal IoT, TSC, DetNet
Architectural Aspects, including: Satellite backhaul, NPN, SFC, ProSe enhancements, Sidelink Positioning, Mobile Relays, Wireless-Wireline Convergence
Automation and Optimization, including: AI/ML in CN, Edge computing, NW Automation, NW Slicing

Preparation for Release 19 was kicked off in June 2023 with large workshops for radio access network (RAN) and service and system aspects (SA) with close to 200 different stakeholders from across the wireless industry. The features emerging for 5G-Advanced Release 19 build on the foundations of Release 18. Among others, these features will offer refinements for services such as extended reality (XR), while at the same time improving on the radio and system performance. The important themes from Release 18 – such as improved energy efficiency, better coverage, and improved mobility performance – will be carried over into the Release 19 specifications.In December 2023, 3GPP formally approved the first package of 5G-Advanced Rel-19 RAN and SA items, with more to come in March 2024 when Release 19 items led by the RAN working group responsible for radio performance and requirements will be approved. Release 19 will also include new themes that can be regarded as preparatory steps towards 6G, which we refer to as 6G-bridge topics.

3GPP Release-19 is the second release of the 5G-Advanced standard. Early workshops on this release were held in June 2023 discussing hundreds of submissions. The original assumption was that 3GPP Rel-19 would primarily focus on investing in the 5G-Advanced commercial deployments to further improve performance and address critical needs by continuing balanced evolutions between:

mobile broadband evolution vs. further vertical domain expansion,
immediate vs. longer-term commercial needs,
device vs. network evolution.

During the plenary TSGs #100 (Technical Specification Groups) meetings, 3GPP started the process of deciding what will be worked on within Rel-19. The content of Rel-19 was decided at the December 2023 TSGs (#102). The currently included items (both work- and study items, WIs/SIs) cover, among others, topics like:

mobile metaverse and extended reality (XR)
AI/ML model transfer
edge computing and mission-critical communications
Satellite access, UAV (Unmanned Aerial Vehicle), and FMRCS (Future Mobile Railway Communications System) communications extensions
Ambient IoT and integrated sensing
energy efficiency enhancements
network sharing and NPN (Non-Public Network)
multiple studies on security (e.g., for NPN, RTC – Real Time Communications, satellite access, and zero trust)
multiple studies on management aspects (e.g., NTN – Non-Terrestrial Network, IAB – Integrated Access and Backhaul, network sharing, RedCap – Reduced Capability, and Digital Twin).

The current 3GPP releases with an open status (subject to active 3GPP work) are:

Release 18, whose start date was 09.2019, and the end date is scheduled on 06.2024 (i.e., to be completed on SA#104)
Release 19, with a start date of 06.2021, and a completion date of 12.2025 during SA#110.

Both of them relate to the 5G-Advanced system (dates and corresponding meeting IDs):

RAN1 completion (functional freeze) of Rel-18 during RAN1 #101 in Q3 2023, and targeting the completion of Rel-19 features by RAN1 #108 in Q2 2025;
RAN2/3/4 completion (functional freeze) of Rel-18 during RAN2/3/4 #102 in Q4 2023, and targeting the completion of Rel-19 features by RAN2/3/4 #109 in Q3 2025;
SA (System Architecture)/CT (Core Network and Terminals) completion (functional freeze) of Rel-18 during SA/CT #103 in Q1 2024, and targeting completion of Rel-19 features by SA/CT #109 in Q3 2025;
ASN1 freeze of Rel-18 in Q2 2024 (SA#104) and Rel-19 ASN1 freeze in Q4 2025 (SA#110).

The general direction of 3GPP Rel-19 is expansion towards vertical applications. The set of features could be grouped into several main topics:

5G support for cutting-edge use cases and services, like XR or metaverse;
5G architectural aspects for industrial scenarios and service robots;
Enhancements of the architecture for Satellite and UAV support, as well as novel network-sharing scenarios;
AI/ML enhancements to be supported within the 5G system;
Energy efficiency is a big topic itself, with the recent items targeting encapsulating service criteria;
Support for IoT-related features, like ambient devices and integrated communications and sensing;
Advancements in various aspects of security for, e.g., NPN or mission-critical services.

3GPP Rel-19 features (WIs): Let me now touch upon some of those items with more details. The descriptions of the below Study Items (feasibility studies/technical analysis on a particular topic) and Work Items (inormative specification work) are based on SIDs and WIDs (Study / Work Item Description) from https://portal.3gpp.org/#/55935-work-planSumming up the above, the general direction of 3GPP Rel-19 is expansion towards vertical applications. The set of features could be grouped into several main topics:

5G support for cutting-edge use cases and services, like XR or metaverse
5G architectural aspects for industrial scenarios and service robots
Enhancements of the architecture for Satellite and UAV support, as well as novel network-sharing scenarios
AI/ML enhancements to be supported within the 5G system
Energy efficiency is a big topic itself, with the recent items targeting encapsulating service criteria
Support for IoT-related features, like ambient devices and integrated communications and sensing
Advancements in various aspects of security for, e.g., NPN or mission-critical services.

6G discussion in 3GPP

3GPP is expected to develop an input to the IMT-2030 process.Initial 6G discussion in 3GPP RAN:

First (very brief) 6G timeline discussion in RAN#101 (September’2023)
Triggered by the liaison from ITU-R WP5D in RP-231518: On completion of draft new Recommendation ITU-R M.[IMT.FRAMEWORK FOR 2030 AND BEYOND]
High-level considerations for 6G timeline discussed in RAN#102 (December’2023), including a TSG-wide joint session, resulting in the endorsed way forward in RP-233985
Additional considerations for 6G timeline discussed in RAN#103 (March’2024), including another TSG-wide joint session, resulting in the endorsed way forward in RP-240823

First 3GPP TSG-wide 6G workshop: March 10–11th 2025

Right before the planned Rel-19 RAN1 functional freeze (June 2025).
Details TBD (e.g., whether to have a joint or separate workshop across TSGs, how to handle contributions, etc.)
TSG#107 plenary meetings are to be scheduled subsequently in the same week

Studies for 6G in 3GPP: from Release 20
RAN plenary work is split into an ITU focused SI (study item) and General RAN SI

IMT-2030 discussion is expected in RAN from 09/24 to 12/24
RP SI Rel-20 focusing on ITU–IMT-2030: approval 12/24 until 06/25
RP SI Rel-20 focusing on 6G General (e.g., radio requirements and KPIs) : approval 03/25 (after WS), until 06/26

RAN WGs in Rel-20For 5G-Advanced: 18-month. Assuming no delay of Rel-19

Stage-1 freeze : Jun 2025
Stage-2 freeze : Jun 2026 (>=80%); Sep 2026 (100%)
Stage-3 freeze : Mar 2027
ASN.1/OpenAPIfreeze: June 2027

For 6G SI: 21 months

RAN1 starts in 3Q/25 until 1Q/27
RAN2/3/4 start in 4Q/25 until 2Q/27

IMT-2030 submission and normative work for 6G in 3GPP are expected to start from Release 21

Release 21 is expected to produce the 1stset of 3GPP 6G technical specifications, and will be the release for IMT-2030 submission before 2030
Release 21 is expected to be delivered with a single drop (i.e., a single code freeze)
Release 21 timeline is to be decided no later than June 2026
However, ASN.1/OpenAPIfreeze date is no earlier than March 2029