5G-Advanced is here and these are the key features and improvements to look forward to

5G Advanced (3GPP 5G RAN Release-18) is upon us, and with it comes a new wave of 5G use cases and innovations. Release-18 aims at fulfilling the “true 5G vision” and to finally deliver on its full promise by embracing Artificial Intelligence (AI) and Machine Learning (ML) technologies to enhance existing features from previous releases (15, 16 & 17) hence boosting network performance, delivering new features, and addressing new use cases. In this article we look at some of the key features and improvements to look out for in the 5G RAN (NR) Release-18:

Network energy savings for NR in Release-18 (Low OPEX) – We expect techniques to improve network energy savings in targeted deployment scenarios.
In Release 18, 3GPP plans to enhance the coverage of physical random-access channel (PRACH) and techniques to increase UE power.
Enhanced Mobility Support – 3GPP Release 18 will introduce mechanisms and procedures for layer 1 (L1)/layer 2 (L2) based inter-cell mobility as opposed to L3 and RRC in the earlier releases. Release-18 mobility will also support “conditional handover”. In conditional handover, UE receives a handover command with a condition from the network and does not apply the command until the condition is satisfied.
MIMO Evolution – In the earlier releases, UEs with medium or high mobility experiences significant performance loss in multi-user MIMO (MU-MIMO) scenarios, partially due to outdated channel state information (CSI). Release-18 seeks to improve performance for UEs with medium or high mobility by enhancing CSI reporting.
Support for advanced UEs such as customer premise equipment (CPE), fixed wireless access (FWA) devices, and vehicular UEs, support of eight antenna ports in uplink and simultaneous multi-panel uplink transmission.
MBS (Multicast and Broadcast Service) – is a feature dedicated to delivering multicast and broadcast services efficiently. Use case examples include TV broadcasting, live video, software updates, and public safety usages. 3GPP Release 18 will extend the multicast support to UEs in RRC inactive state, introduce enhancements to enable UEs in RRC connected state to receive broadcast service and unicast service simultaneously, and study mechanisms to improve resource efficiency in RAN sharing scenarios.
Improved Positioning – 3GPP Release 18 will investigate solutions to further improve accuracy (below 20cm), integrity, and power efficiency in positioning, study sidelink positioning, and investigate positioning support for RedCap devices.
Flexible Spectrum Use – 3GPP Release 18 will introduce further enhancements to enable more flexible and efficient spectrum use for 5G deployments in various scenarios with different spectrum allocations. Some of the features that will enable flexible spectrum use include; (i) NR for spectrum less than 5MHz, (ii) NR dynamic spectrum sharing enhancement, (iii) NR multi-carrier enhancement, (iv) NR duplex operation evolution.
Diverse 5G Devices – 3GPP Release-18 will expand 5G capability to serve diverse devices across eMBB, URLLC, and mMTC usage scenarios. 3GPP Release-18 will introduce tailored functionalities to enhance and expand 5G capability to serve not only smartphones but also other diverse 5G devices, such as extended reality (XR) and cloud gaming devices, low-complexity UEs, vehicular devices, and uncrewed aerial vehicles (UAVs).
Evolved Network Topology – 3GPP Release-18 will enable a more flexible 5G network topology. 3GPP Release-18 will enhance the support of UE-to-network relay, add support for UE-to-UE relay, and study multi-path support where a UE is connected to a gNB using one direct path and one indirect path via a sidelink relay. Non-Terrestrial Network (NTN) which will utilize satellites or high-altitude platforms (e.g., airplanes, balloons, and airships) to offer connectivity services which can complement terrestrial networks by providing coverage in remote areas where terrestrial coverage is unavailable. Release-18 will also address mobility and service continuity between a terrestrial network and an NTN as well as between different NTNs.
Data driven and AI-Powered 5G – 3GPP Release-18 will not only enhance existing data collection features but also examine how AI techniques can improve air interface functions. 3GPP Release 18 will specify data collection enhancements and signaling support for a set of selective AI-based use cases, including network energy saving, load balancing, and mobility optimization. 3GPP Release-18 will also enhance NR data collection within the scope of the self-organizing network (SON)/Minimization of Drive Testing (MDT). SON automates RAN planning, configuration, management, optimization, and healing, thereby minimizing human intervention. MDT enables operators to configure normal UEs to collect and report measurement data to reduce traditional drive tests. The Release-18 work will address SON features leftover from Release-17 and data collection for random access channel (RACH) optimization. 3GPP Release-18 will also enhance the NR QoE (Quality of Experience) framework to support new types of 5G services, such as XR, cloud gaming, and MBS. QoE reflects the user’s satisfaction level with a service provided by mobile networks. A QoE report contains data of QoE metrics collected at the application layer. 3GPP Release-18 will make use of AI/ML for NR air interface to enhance performance or reduce complexity/overhead. This will establish a common AI/ML framework, identify areas where AI/ML can improve air interface functions, investigate how to describe and characterize AI/ML models, evaluate AI/ML techniques to understand their gains and complexity, and assess standardization impact. To achieve these objectives, 3GPP will focus on a set of selective use cases, including CSI feedback, beam management, and positioning. The study is expected to pave the way for other use cases leveraging AI/ML techniques in the air interface.