Abstract
In its nearly 10-year lifespan, 5G has already made strides in communication speed and range across mobile networks. The recent releases 16 and 17 had made improvements and introduction in features relating to including multiple-input multiple-output (MIMO), beamforming, support of dynamic spectrum sharing (DSS), power saving, IoT support, and more. [1] Release 18 poises to not only enhance these features further, but also further broaden 5G's reach into device support by harnessing its fast and reliable mobile connection to service devices such as Unmanned Aerial Vehicles and XR/VR technology, while also incorporating Artificial Intelligence and Machine Learning processing into the 5G world. In this website, we will explore the new and improved 5G Evolution Technology encompassed in the latest 3GPP release, 5G Release 18.
Keywords
5G Advanced, Release 18, 3GPP, Internet of Things, Extended Reality, Cloud Gaming, Artificial Intelligence, Machine Learning, RedCap, Time as a Service, Carrier Phase Positioning, Network Sharing, Evolved Network Topology, AI in Networking, AI in Communications, ML in Networking, ML in Communications, Frequency Domain Spectrum Sharing
Introduction
In the field of mobile networking, 5G represents the fastest and most recent stage of the evolution of communications, and over the past 5 years has been widely integrated into the global mobile communications infrastructure, while efforts are ongoing to continue to improve its performance and versatility. The standardization organization overseeing 5G, 3GPP, has continued to develop 5G to extend coverage to new areas of devices, while also ensuring further reliability in its existing service performance. As the first release of the next phase of 5G, 5G Advanced, Release 18 is the latest upcoming 5G release which will bring numerous improvements to existing performance capabilities defined under previous releases, as well as a further broaden of 5G support to devices and communication, such as Non-Terrestrial Networks (NTN) and improved Vehicle to Everything (V2X) performance. In section I, we will examine the circumstances of Release 18 in the broader context of 5G development, and in section 2, we will document improvements Release 18 has made upon previous 5G releases. Finally, in Section 3, we will look at new services and features that Release 18 has brought into the 5G environment to ensure further speed, reliability, versatility, and extended coverage.
1. 5G Development
To understand what new features pertain to Release 18, we must first look at 5G Advanced, the broader developmental shift in 5G, of which Release 18 represents the beginning. Also, to contextualize the existing structure that Release 18 builds on to accomplish these goals, previous 5G releases and their features should be examined, along with a brief summary about 3GPP, the organization that makes the decisions on what to implement for 5G releases.
1.1 5G Advanced
5G Advanced is a look ahead to evolution in 5G technology, with plans of development and improvements until 2030. [2]
Specifically, 5G Release 18 represents the evolutionary transition between 5G and 5G Advanced. 5G Advanced aims to improve and introduce 5G functionality in areas such as radio, eXtended Reality (XR) support, Internet of Things (IoT) connectivity, super accurate positioning, super accurate timing, artificial intelligence (AI) and machine learning (ML). [12] 5G Advanced also aims to improve user experience in areas such as call quality through services like spatial audio calling [15] and security [14].
Under the direction of the 3GPP organization, 5G Advanced will accomplish this technological leap through improving and introducing new technologies in uplink, mobility, and energy efficiency.
1.2 3GPP
Like most other communications and networking technology standards, 5G is defined by a standardization organization, 3GPP.
3GPP, or the 3rd Generation Partnership Project, is a communications standard organization whose specifications encompass cellular, or mobile telecommunications, including 5G, which is the latest generation in its standards cycle for commercial mobile communications technologies.
3GPP began development on Release 18 in 2022, with the target release date of 2024. [12]
Prior to the definition of Release 18, 3GPP standardized and oversaw the commercial release of 5G as release 15 in April 2019, and has introduced improvements and new features in subsequent releases, 16 and 17.
1.3 Release 16 and 17
After the initial public release of 5G under Release 15, 3GPP Release 16 and 17 contained notable improvements that 5G Advanced Architecture would be built upon.
[12]
Release 16, the first official new release after 5G's public introduction, made improvements in areas including MIMO, beamforming and DSS, carrier aggregation (CA), dual connectivity (DC), industrial IoT, power saving, V2X communications, and operations in unlicensed spaces. [1] Release 16 also specifically targeted improvements in mobility through the conditional handover (CHO) and dual-active protocol stack (DAPS) for better reliability and lower interruption time. Release 17 improved areas Release 16 touched even further, with expansions in IoT optimization, moving 5G to new areas such as non-Terrestrial networks (NTN) and drones. [12] Among new technologies, Release 17 also supported reduced capability (RedCap) devices, and operation in frequency bands beyond 52 GHz [1], something that Release 18 would develop further.
With 5G expected to deliver quick, reliable, and versatile network service, 3GPP plans to continue to improve the performance of the standard under the upcoming banner of 5G advanced. Much of the features that Release 16 and Release 17 developed were crucial to the performance of 5G, and will be further expanded upon by Release 18, which will also introduce new features to continue to allow 5G to support the needs of a rapidly technologically progressing world.
Release 18 Improvements to Existing Network Infrastrucure
Release 16 and 17 brought many new enhancements to 5G performance through adoptions of new techniques and technologies in positioning, performance, timing, security, and various other improvements. Release 18 not only continues the trend of technological progress for refinements in these areas, it also continues to improve the network support to new technologies that rely on the crucial speed and performance that 5G brings.
2.1 General Improvements in Communications Performance
Like its previous iterations, Release 18 also boosted 5G support in areas of versatility and device support that Release 16 and 17 had also improved and introduced 5G connectivity. Release 18 has introduced enhancements in key network performance areas such as power management, device mobility, and transmission.
A key feature of Release 18 was its massive enhancements in MIMO performance, with strides made in beamforming, throughput, and mobility, with improvements in the latter in the area of handover events [13] with up to a 1.75x increase in performance. [6] Improved MIMO also allowed for enhancements in dynamic power aggregation in the area of carrier aggregation. [13] Thanks to new codebook compression strategies and random channel state hopping adopted by Release 18 for the strengthening of coherent joint transmission (CJT). Combined with the increase of the number of demodulation reference signal (DMRS) ports, which are used to estimate channel performance and decode incoming signals, both uplink and downlink performance is enhanced, with throughput nearly doubling. [6]
Release 18 also improved on Release 17's boosts in coverage, implementing power domain enhancements through frequency domain spectrum shaping (FDSS). [12]. 3GPP also made advances in DSS, with transmission of overlapping symbols, which, in this case, are physical downlink control channel (PDCCH) signals with LTE cell-specific reference signals (CRS). (Fig. 1) [1]
(Fig 1) Release 18's power domain enhancements. [12]
Release 18 further improved power budgeting. Previous releases had introduced the concepts of wake-up signals (WUS), changing the behavior of user equipment (UE) to only wake when triggered rather than waking periodically. Release 18 built on this system by introducing the wake-up receiver (WUR), a dedicated receiver that listens for WUS without requiring the main receiver to remain awake and listen, allowing for a timely response even with further power reductions. [4] Release 18 also generally improves power efficiency through the adoption of dynamic power adaption, a process in which the scheduler receives information regarding what power level to adjust to based on responses from user devices and data volume. Release 18 also utilizes AI and Machine Learning to optimize energy usage, which will be covered in section 2. [1]
Release 18 made strides in mobility features, resolving Release 16's issue where CHO and DAPS would not work together in tandem, inhibiting mobility performance. Release 18 resolved this issue in Layers 1-3, with random access channel (RACH)-less operation to reduce the handover in Layer 3, L1-triggered intercell mobility by using the L1/L2 signaling to dynamically switch between preconfigured candidate cells for faster cell change, and general improvements to CHO and the introduction of dual-connectivity for better performance.[12]
As release 18 continued the trend of bringing enhancements to performance through improved power budgeting, mobility, coverage, and MIMO, it also followed Release 16 and 17's progress made in the areas of timing, spatial operations, and network security.
Section 2.2 Changes in Time, Space, and Security
In order for 5G to continue to service the growing complexity of networks and communication technologies, it must also be able to improve certain areas crucial to network function and health, such as temporal and spatial operations, as well as network security.
In the area of spatial operations, Release 18 allows for super-accurate positioning through its usage of Carrier Phase Positioning (CPP). Utilizing satellites and 5G base station (gNB) transmission, Release 18 allows for networks to track objects to centimeter-level accuracy. This is further accomplished through the usage of reference devices within a network with a known location to calibrate the network's tracking and eliminate errors that could come with timing. (Fig. 2)
(Fig. 2) Devices involved Carrier Phase Positioning as defined by Release 18. [12]
3GPP also researched accurate positioning using Sidelink (SL) communication, in which device-to-device communication is utilized to calibrate positioning, and positioning for RedCap devices. [1] Sidelink positioning also better serves a wide array of applications already supported by previous 3GPP releases, such as V2X. In scenarios where a device is outside the range of a gNB, Sidelink can be exclusively used for positioning, and in cases where it is within a gNB, Sidelink can be used concurrently for better accuracy and reliability, as long as the required hardware is present, such as UEs that support SL-communication and Road Side Units (RSUs) for V2X (Fig 3). [9]
(Fig. 3) Sidelink and RSU positioning. [9]
In terms of temporal operations, Release 18 helped improve Timing as a Service (TaaS), the feature of resilient and accurate timing for time-sensitive features, by using scheduling based on the network feedback, as well as feedback on the clock quality information for the core and user devices, made to be used in tandem as an alternative to conventional methods of timing through communication between networks and satellites for calibration. (Fig. 4) [12]
(Fig. 4) Release 18 Time Calibration. [12]
Lastly, in the field of security, Release 18 continued to develop the security model introduced by previous releases. In Release 15/16, 5G Service-Based Architecture (SBA) relied on certificates to validate Network Functions. Release 18 further improves upon this by introducing automation into the process of managing said certificates, using a Certificate Management Protocol (CMP) to create, renew, and deprecate certificates. Release 18 also improved authentication involving the home network, replaced Release 16's 128-bit cryptographic algorithms with 256-bit algorithms, and increased potential vectors for delivery of roaming signal messages. [14]
For communication between users and third-party application functions (AF), Release 18 expanded authentication to roaming communications and also defined profiles for establishing secure channels between UEs and AFs. Security features were also extended to cover Machine Learning models and edge computing networks. [14]
In Release 15/16, 5G SBA relied on certificates to validate Network Functions. Release 18 further improves upon this but introducing automation into the process of managing said certificates, using a Certificate Management Protocol (CMP) to create, renew, and deprecate certificates. Release 18 also improved authentication involving the home network, replaced Release 16's 128-bit cryptographic algorithms with 256-bit algorithms, and increased potential vectors for delivery of roaming signal messages. [14]
For communication between users and third-party application functions (AF), Release 18 expanded authentication to roaming communications and also defined profiles for establishing secure channels between UEs and AFs. Security features were also extended to cover Machine Learning models and edge computing networks. [14]
The improvements that Release 18 brought to power usage, coverage, mobility, and MIMO significantly improved the performance of networks. Combined with the enhancements to network operations in positioning, timing, and security, Release 18 was able to broaden support for technologies that only recently began to adopt 5G as a means of communication, including IoT, RedCap, and XR.
Section 2.3 IoT, Redcap, and XR Support
Not only is 5G able to service devices such as cellular phones and computers with wireless communication capabilities, it has also branched into smaller devices for a wide array of uses, such as IoT and RedCap devices, as well as recently developed technologies such as Extended Reality (XR), which depend on 5G's transmission and reliability capabilities to function to their fullest potentials.
Release 18 made advancements in IoT performance by enhancing the physical layer features such as removing unnecessary feedback signals and operations for long connection times and reduced power. [8] Release 17 previously also introduced the beginning of 5G support for RedCap devices with NR-light operation, a lightweight mobile broadband that services low data output devices such as security cameras with reduced antennas and bandwidth. Release 18 optimized this further, reducing the bandwidth from 20 MHZ to 5MHZ and decreasing costs from -60% to -70%. [12] In the reduced bandwidth environment, Release 18's accurate positioning reference signals can be used through frequency hopping. [3] Release 18 also optimizes IoT performance by allowing the option to disable Hybrid Automatic Repeat reQuest feedback (HARQ) so that devices can avoid waiting for ACK/NACK signals, resulting in faster subsequent scheduling. [8]. This is especially useful for NTN satellite performance, resulting in higher data rates.
EXtended Reality, or XR, is a newly developing technology that encompasses both virtual reality (VR) and augmented reality (AR), the latter of which projects data onto an existing perception of the world. XR features require a great deal of data transmission with a short latency in order to ensure an adequate user experience, projecting high-quality images in near-real time, which would also result in significant power usage. Release 18 improves XR performance by alerting the network to XR data through QoS and congestion information, and optimizations in power usage, transmission capacity, and mobility assisting XR to reach optimal performance. [12]
These new features allowed 5G to also further service devices and technologies which had been newly introduced to 5G support, including IoT, Redcap devices, and XR performance. Release 18 also introduced a wide plethora of new features, further widening the range of 5G communication-ready devices, and integrating new capabilities to further enhance areas older features improved.
Section 3 Release 18 New Features
Thanks to Release 18's further enhancements upon its predecessors' improved features, Release 18 is able to broaden the scope of 5G performance to new devices that greatly benefit from its fast and reliable network performance. Release 18 also introduces its own significant changes, which significantly alters the structure of 5G in preparation for 5G Advanced and beyond.
3.1 5G Coverage for New Devices
With the improvements in positioning, power, and bandwidth, Release 18 opens 5G up to new devices and technologies critically dependent on these aspects for performance.
Devices such as Unmanned Aerial Vehicles require precise position and mobility data for communication. Release 18's improvements in these areas brought 5G to highly volatile-positioned devices for better and clear performance through the extension of networks, allowing networks to see the precise height, distance, and velocities of the devices. [1] Support for new mobile networking devices such as mobile integrated access backhaul and Vehicle Mounted Relay technology can assist in bringing 5G connectivity to areas suffering from disaster, which can extend the reach of mobile networks by connecting mobile stations with existing 4G infrastructure, and then converting it into 5G for on-site devices. [10] With Release 18's extended coverage capabilities, research has also been done on its ability to potentially service smart energy grids, being able to meet the critical 3ms latency demanded by the complex processes. [7]
Another still evolving technology that Release 18 brings 5G support to is Cloud Gaming. Like XR, Cloud Gaming requires high bandwidth and high power, with a large reliable stream of data to ensure an adequate gaming experience. Release 18's low latency and power efficient features allow for a far better suited 5G environment to allow for communication between hosts of Cloud Gaming software and clients, ensuring a stable connection and high quality image. [1]
With the broadening of 5G's potential support devices, it brings 5G's capabilities to mediums that greatly benefit from the superior network performance. To further increase these operational capacities and efficiencies, Release 18 introduces changes to the network structure, which further allows devices like NTN and AI support
Section 3.2 Evolved Network Topology
Through the aforementioned sidelink technology and signal repeaters, Release 18 allows for an extended coverage through the increase of the range of network signals with these devices, as well as NTN communication.
NTN communication links networks in a way that vastly expands the scope of communication between devices, with potential of ground devices to connect to devices in a non-terrestrial satellite network with ease. (Fig. 5) [1]
(Fig. 5) New Release 18 5G network Topology. [1]
In addition, repeaters that can be controlled by networks are now supported, with single-hop operations that are transparent to the UE allowing for further coverage. (Fig. 6) [11]
(Fig. 6) Network Relays introduced with Release 18. [11]
Release 18 also optimizes energy usage in networks, with the adoption of discontinuous transmission/reception (DTX/DRX) time domains for designating active and non-active cycles, saving up to 30% in energy. [13] Further improvements to power efficiency can also be observed due to enhanced Channel State Information (CSI) procedures to adapt to different network configurations.
Release 18 makes significant contributions to the network structure, greatly improving both the efficiency and reach of networks. Within the networks, it also makes performance enhancements thanks to improvements within the networks, such as with the adoption of AI and ML models for reliability and speed, even in environments not favorable towards network performance.
Section 3.3 AI/ML Model Incorporation into 5G Networking
To aid in the testing and AI model integration process, 3GPP has included tools for model management, revolving around model creation, update, and switching based on changing conditions. [5] With Artificial Intelligence and Machine Learning-backed analysis, Release 18 introduces potential optimizations in performance, mobility, and power usage [12]. Some examples of use cases include:
By training on encoders and decoders, AI and ML models are able to quickly compress CSI information, quickly changing network configurations for more efficient performance. To resolve issues caused by channel aging, which results from outdated CSI in extremely time-constrained situations, the power of predictive models work around this issue, allowing for the correct network configurations to be approximated. Predictive models can likewise be applied to beamforming, where fewer signals would be required for a more accurate and faster estimation of which beam to use, as well as anticipation for changes in future situations. Optimizations can also be made in positioning, with the use of AI Learning Models to more effectively predict locations even with Line of Sight (LOS) interference. (Fig 7) [5]
(Fig. 7) Predictive process for both the base station and device. [5]
Release 18 not only extends the trend of enhancements for 5G performance in areas started by its predecessors, but it also revolutionizes 5G in new areas of coverage, along with the incorporation of revisions to the structure of networks and adoption of new technologies such as Artificial Intelligence, updating mobile communication for the coming decade.
Section 4. Conclusion
Release 18 has made great strides in improving the performance of 5G in areas of speed, bandwidth, and power efficiency, simultaneously expanding the scope of the service to a numerous potential number of devices. But as the nature of technology implies, there always exists room for further development, much which can be built on the new and improved features of Release 18.
While Release 18 provides notable enhancements to authentication and roaming features that previous 5G releases had provided, there is still work to be done to adhere to the Zero Trust Architecture, a set of strict cybersecurity paradigms that assumes no implicit trust based on location or ownership which Release 19 has been proposed to move 5G into. [14] Although Release 18 extended sidelink communication to both the licensed and unlicensed spectrums, sidelink positioning is only standardized within licensed spectrum. For high data rate applications, future releases will likely standardize positioning in unlicensed spectrum as well for better compatibility with sidelink communication. [9] With the rise of Artificial intelligence usage internationally, AI could further improve the developments Release 18 has made in 5G communication areas such as positioning, NTN communication, low-latency XR/Cloud Gaming/Computing performance, and mobility management.
With future releases such as Release 19 focused on these potential extensions of Release 18, and as 6G approaches on the horizon, Release 18 has laid the groundwork for a truly revolutionary decade in communications.