2024 Summer

With the new issue of 5G++ Waves Magazine, we wish you a safe and productive year!
The primary goals of this magazine are to demonstrate some of the most recent 5G/6G technical developments and to analyze potential future research directions for mobile communications. Also, we outline the evolution, driving trends, and key requirements of wireless systems.

FOREWORD

The time we live in is an exciting inflection point for 5G and the way telecommunications networks are built and consumed. Initial problems and challenges have been solved and 5G is well deployed across the world, laying the foundation for experimentation, new ideas, and innovation.5G is now a mainstream technology and a global success. This new generation arrived during a turbulent time in the global environment. Telco operators are rapidly deploying 5G as a necessary capacity boost for their cellular networks and using the new technology to maintain their profitability. We are only experiencing the first wave of 5G services, just the surface of what is available with 5G.
As we transition from the 5G epoch, a new horizon beckons with the advent of 6G, seeking a profound fusion with novel communication paradigms and emerging technological trends, bringing once-futuristic visions to life along with added technical intricacies. Therefore, 6G is not expected to be just another step in the evolutionary ladder of wireless technology; but an ambitious leap towards an interconnected, intelligent, and immersive future.
6G will be more than just another wireless network. And the challenge of 6G is to further develop and integrate wireless communications, sensor technology and cloud computing into a seamless whole. Information and communications technologies will further merge, i.e. the processing of large amounts of data will take place in distributed systems in the network and not necessarily in the end-user device, leading to challenging data rate and latency requirements. Computing power could be offloaded to the cloud or edge networks separate from the devices (thus allowing cheaper terminals). To enable new and fascinating applications and use cases, a 6G network needs to be much more efficient in all areas than today’s 5G New Radio networks. The following technology components will be an essential part of accomplishing this goal: THz communications, joint communications and sensing, artificial intelligence and machine learning, reconfigurable intelligent surfaces, photonics and visible light communications. Besides these revolutionary concepts, some evolutionary technology components are also under discussion for possible inclusion in the 6G standard. 6G will continue on the path started with 5G towards an optimized service based network topology and unified 3D-architecture, allowing tight integration of different variants and ultimately becoming a network of networks. 6G will use new application-driven approaches impacting network architecture, network topology and distributed computing and thus become a network of networks. It is necessary to extend network coverage three-dimensionally and include the vertical direction in addition to horizontal deployments. Such ubiquitous communications could be realized with non-terrestrial networks (NTN), which would utilize drones (high-altitude platform stations (HAPS) in the stratosphere at an altitude of 20 km) and low earth orbit (LEO) satellite constellations acting as mobile base stations in the sky and leading to a unified network architecture.
The development of 6G vision, applications, technologies and standards has already become a popular research theme in academia and the industry. We provide a comprehensive survey of the current 5G+ developments.  We discuss a number of fundamental aspects, including new scope and approach, that need to be considered in design and development of the next generation of standards and technologies.We highlight the societal and technological trends. Emerging applications to realize the demands raised by driving trends are discussed subsequently. We also elaborate the requirements that are necessary to realize the emerging applications. Then we present the key enabling technologies in detail. We also outline current research projects and activities including standardization efforts towards the development of 6G. Finally, we summarize lessons learned from state-of-the-art research and discuss technical challenges. 6G developments are expected to progress along with the deployment and commercialization of 5G networks, and the final developments of 4G Long Term Evolution (LTE), being LTE-C, which followed LTE-Advanced and LTE-B. The vision for 6G is envisaged to be framed by 2022 - 2023 to set forth the 6G requirements and evaluate the 6G development, technologies, standards, etc. Standardization bodies such as the International Telecommunication Union (ITU) and 3rd Generation Partnership Project (3GPP) are expected to develop the specifications to develop 6G by 2026 - 2027. Network operators will start 6G research and development (R&D) work by this time to do 6G network trials by 2028 - 2029, to launch 6G communication networks by 2030. The way future wireless standards and technologies are developed will be crucial. There is a need to broaden, align, and rationalize the scope of standards and technology development.

Highlights

Novel and differentiated services with expanded market opportunities and novel experience:

   Mobile Internet eMBB, Broadband connectivity

   Massive MTC,   Massive IoT

   Ultra-reliable LLC (low-latency communication)

   UltraHD and 3D streaming media in Interactive XR services

   Perception Engineering    Intergated Sensing&Communication

Standardisation roadmap, Specification, Development (prototyped, validated, trialed and piloted 5G), Experimentation / Pilots

Verticals

 5G-MAG   5G MediaHub   

Verticals towards 2030   

LTE and 5G-based private cellular networks come in many different shapes and sizes, including isolated end-to-end NPNs in industrial and enterprise settings, local RAN equipment for targeted cellular coverage, dedicated on-premise core network functions, virtual sliced private networks, secure MVNO (Mobile Virtual Network Operator)  platforms for critical communications, and wide area networks for application scenarios such as PPDR (Public Protection & Disaster Relief) broadband, smart utility grids, railway communications and A2G (Air-to-Ground) connectivity. However, it is important to note that equipment suppliers, system integrators, private network specialists, mobile operators and other ecosystem players have slightly different perceptions as to what exactly constitutes a private cellular network. While there is near universal consensus that private LTE and 5G networks refer to purpose-built cellular communications systems intended for the exclusive use of vertical industries and enterprises, some industry participants extend this definition to also include other market segments – for example, 3GPP-based community and residential broadband networks deployed by non-traditional service providers. Another closely related segment is multi-operator or shared neutral host infrastructure, which may be employed to support NPN services in specific scenarios.
  • AI-on-5G kickstarts Industry 4.0
  • Autonomous systems in Real and Virtual Worlds
  • Multi-energy SmartCity (KPI)

Trustworthy AI

As we continue evolving beyond 5G, the landscape is becoming more complex. With such rapid technological advancement, maintaining public trust is key to sustainable development.Trustworthy AI is comprised of three main components, which must be met throughout the AI system’s life cycle
  • lawful, complying with all applicable laws; 
  • ethical, ensuring adherence to ethical principles and values including fairness and respect to human autonomy;  
  • robust, both from a technical and social perspective by taking into account the context and environment in which it operates.

Innovators and ecosystem

We believe that the continuing evolution of the mobile industry, and the underlying technologies, must be guided by the imperative to satisfy fundamental needs facing the society at large, and the telecoms industry. The need to manage complexity, drive efficiency, and reduce costs is now paramount, in the 5G roadmap and the path towards 6G.Ecosystem as a path to 6G.  The old notion of value chains will be replaced by value creation network pointing out to deep network economy - a continuously optimizing frontier of applications, services, and products. It also means that our immediate environment is becoming increasingly smart, self-sustained and green. 

InnovationLab   Academy

Machine learning 

3GPP  RAN3 identified three main use cases for which AI/ML based solutions would be investigated:

• Network energy saving: where the energy consumption improvements for the whole radio access network may be achieved by actions such as traffic offloading, coverage modification and cell deactivation.• Load balancing: where the objective is to distribute load effectively among cells or areas of cells in a multi frequency/multi-RAT deployment to improve network performance based on load predictions.• Mobility optimization: where satisfactory network performance during mobility events is preserved while optimal mobility targets are selected based on predictions of how UEs may be served.

Open Call  

State of 5G 2023  6G White papers   6G Magazine: 1 2 3 4 5 6  5Green

Webinar Series

   5G EU ecosystem forum   6G Channel   6G Summit   6G Summit EU   6G World      6G Channel Program   R&I   Media Production over 5G NPN   UoM2018/2020/2022   ATHENS2020/2022   SIRS2020   
  • Welcome & Introduction
  • Presentation & Discussion
  • Questions
  • Closing remarks

SPECIJALISTIČKA OBUKA

5G/5G+ MOBILNE MREŽE: Od istraživanja do tržišta   PKS 17. јun 2022. 11:00-12:00Building the Road to 6G: From 5G-Advanced to Beyond-5G & 6G  19 May 2023 10:00 am-2:30 pm EDT

Essential skills for early career academic eesearchers

Seminar 4: Conference and Workshop presentation skills   IEEE Mauritius Section  16.12.2022 11:00-12:00

Wireless Summit

Keynotes

Radio interfaces specifications in mobile broadband communication

ITU-R  IMT-2000                 3G                2000.ITU-R  IMT-Advanced      4G       Jan. 2012.ITU-R  IMT-2020                 5G      Feb. 2021.ITU-R  IMT-2030                 6G      Nov. 2022.

5G System standards in mobile broadband communications

3GPP Specifications Vocabulary 3GPP  Release 15  5G Phase 1        Start June 2016  - Stage3 Mar. 2019 - EndDate June 20193GPP  Release 16  5G Phase 2        Start Mar. 2017   - Stage3 July  2020 - EndDate July  2020 3GPP  Release 17  5G Transformation  Start June  2018 - Stage3 Mar. 2022 - EndDate June 20223GPP  Release 18   5G-Advanced Start Oct. 2019   - Stage3 Dec. 2023  - EndDate June 20243GPP  Release 19   5G-Advanced Start June 2021  - Workshop June 2023 - Jan.  2024 - 20253GPP  Release 20   5G-Advanced transfromation3GPP  Release 21   6G 2028.

Open RAN transformation

O-RAN Alliance   O-RAN   Open5GO-RAN promotes virtualized RANs in design, deployment, and operations where disaggregated components are connected via open interfaces and optimized by intelligent controllers. Open-RAN deployments are based on disaggregated, virtualized and software-based components, connected through open and well-defined interfaces, and interoperable across different vendors. Disaggregation and virtualization enable flexible deployments, based on cloud-native principles. This increases the resiliency and reconfigurability of the RAN. Open and interoperable interfaces also allow operators to onboard different equipment vendors, which opens the RAN ecosystem to smaller players. Finally, open interfaces and software-defined protocol stacks enable the integration of intelligent, data-driven closed-loop control for the RAN.

Industrial 5G testbeds & trials

UK Programme

5.5G Vision

5.5G represents a 10-fold improvement in performance over 5G in every department. That means 10 Gbps headline connection speeds, 10 times the number of IoT connections – which translates to 100 billion in total – and reducing latency by a factor of 10.Networks also need to consume a tenth of the energy that they consume today on a per Terabyte basis, and they need to be 10x more intelligent, which means supporting level 4 autonomous driving, and making operations and maintenance (O&M) more efficient by a factor of, you guessed it: 10.With these capabilities in place, 5.5G networks will enable a boom in immersive interactive experiences, like VR gaming in 24K resolution, and glasses-free 3D video, predicts Huawei. It expects the installed user base of these services will grow 100-fold to 1 billion. On the enterprise side, the vendor expects the number of private cellular networks to increase from 10,000 today to 1 million by 2030.

6G architecture landscape

5GPP   6G Connecting a cyber-physical world
Congested spectrum.  Spectrum congestion occurs when multiple users or devices attempt to access the same portion (or band) of spectrum. The effect of congestion is to degrade communications throughput, to increase latency and, in the worst cases, to completely block a transmission from reaching its intended recipient.Contested spectrum.  In a contested spectrum, adversaries actively attempt to deny friendly forces the ability to utilize the spectrum, while continuing to use the spectrum themselves. The usual term for denying or degrading the RF spectrum is jamming.Cooperative spectrum sharing.  In a cooperative environment, multiple users of the spectrum are aware of each other and cooperate to enable maximum utilization of the spectrum and actively work together to reduce conflicts and activities that may degrade the channel.Cognitive spectrum sharing.  Cognitive systems are a form of sharing, but utilize artificial intelligence (AI) and machine learning (ML). An AI/ML system detects and recognizes its operating environment in order to adjust the operating modes of the radio dynamically and autonomously, and learns from the results of its actions and its operating framework. A cognitive radio is a form of wireless communications in which a transmitter or receiver can logically detect which communications channels are in use and which are not and can transfer communications to the unused channels. This permits optimum use of the available radio frequencies within a given spectrum space, while minimizing interference with other users.
2G to 6GThroughput. The data rate supported by each generation has increased significantly over time. 2G networks had a throughput of 9.6 Kbps to 236 Kbps, 3G increased this range to 384 Kbps to 42 Mbps, and 4G further improved it from 100 Mbps to 1 Gbps. 5G has made a massive leap with a throughput of 10 Gbps to 20 Gbps, while 6G is expected to reach an impressive 100 Gbps to 1 Tbps.Speed. The average user experience in terms of speed has also improved with each generation. 2G networks provided speeds of around 20-40 Kbps, 3G increased this range to 500 Kbps to 2 Mbps, and 4G delivered speeds of 10-50 Mbps. With 5G, users can expect speeds between 50 Mbps and 10 Gbps. 6G is projected to offer speeds from 1 Gbps to 100 Gbps.Latency. Latency, or the time it takes for a signal to travel from the sender to the receiver, has decreased significantly with each generation. 2G had a latency of 300-1000 ms, 3G reduced this to 100-500 ms, and 4G further decreased it to 30-100 ms. 5G has dramatically lowered latency to 1-10 ms, and 6G is expected to achieve sub-millisecond latency.Spectrum efficiency. The ability to transmit more data using the same spectrum has improved. 2G had low spectrum efficiency, while 3G and 4G made significant improvements. 5G has very high spectrum efficiency thanks to massive MIMO and beamforming technologies. 6G is expected to push the limits of spectrum efficiency even further with the use of THz frequencies and advanced network architectures.
5G generation of mobile networks offers faster data speeds and lower latency than previous generations of mobile networks. It is designed to support a wide range of applications and services, including high-definition video streaming, virtual and augmented reality, and the Internet of Things (IoT). Some of the key features of 5G networks include:
  • High speeds.  5G networks are designed to offer faster data speeds than previous generations of mobile networks, potentially reaching speeds of up to 10 gigabits per second (Gbps).
  • Low latency.  Latency refers to the amount of time it takes for a signal to be transmitted from one device to another. 5G networks are designed to have significantly lower latency than previous generations of mobile networks, potentially reaching levels as low as a few milliseconds.
  • Increased capacity.  5G networks are designed to support a larger number of devices and connections, which is expected to enable new applications and services such as the IoT.
  • Enhanced coverage.  5G networks are expected to offer improved coverage and reliability compared to previous generations of mobile networks.
5G networks are currently being deployed in many countries around the world, and they are expected to become more widely available over the coming years. However, it is important to note that the availability and capabilities of 5G networks can vary depending on the specific location and infrastructure.
6G is the next generation of mobile networks that is expected to offer faster data speeds, lower latency, and more advanced capabilities than current 5G networks. It is still in the development phase. Some of the expected improvements of 6G over 5G include:
  • Higher speeds.  6G is expected to offer data speeds that are significantly faster than 5G, potentially reaching speeds of up to 1 terabit per second (Tbps).
  • Lower latency.  6G is expected to have significantly lower latency than 5G. 
  • More advanced capabilities.  6G is expected to incorporate a range of advanced technologies, such as holographic communications, which would allow for the transmission of 3D images and other immersive media. It is also expected to support a wider range of frequencies, including higher and lower bands, which could improve coverage and capacity.

6G technology is expected to be the next generation of wireless communication, following the 5G standard. It aims to achieve data rates up to 1 Tbps, ultra-low latency of less than 1 ms, and connection density of 10 million devices per square kilometer. Operating in the sub-THz to THz frequency range (100 GHz to 3 THz), 6G aims to be 10 times more energy efficient than its predecessor, 5G.Potential applications of 6G include smart cities with improved urban planning, energy management, transportation, and security. Industry 4.0 will benefit from advanced automation, real-time data analysis, and predictive maintenance. The healthcare sector may see innovations such as remote surgery, real-time health monitoring, and personalised medicine. Extended reality (XR) and autonomous vehicles will also see significant advancements, thanks to the capabilities of 6G technology.However, several challenges must be overcome before 6G becomes a reality. Spectrum allocation in the THz frequency bands, ensuring device compatibility, and managing energy consumption for high-performance devices are some key obstacles. In addition, robust security measures must be implemented to protect sensitive data and user privacy. Developing and deploying the necessary infrastructure and establishing global standards for 6G technology and its applications are also critical steps in the realisation of 6G networks.
Contrary to popular belief, 3GPP is not a standards organization, but a partnership project consisting of seven organizational partners that have agreed to collaborate to produce global technical reports followed by technical specifications on how next-generation networks should be built and implemented. Technical Reports (TRs) are the results of studies performed by the 3GPP group, which are then distilled in Technical Specification (TS) documents that are the standard itself. Essentially, 3GPP is a collaborative effort, with  stakeholders from around the world meeting to distill years of research into commonly agreed upon technical specifications that later become national standards and, eventually, the hardware and software that powers the mobile telecoms market.3GPP working groups splitting the topics to be standardized in numerous parallel activities and in a hierarchical manner. The focus area of communication systems is organized in three high level groups, called Technical Specification Groups (TSG), which are: Radio Access Network (RAN), Service and System Aspects (SA), Core Network and Terminals (CT). Each TSG is made of a different number of so called TSG Working Groups (WG), The WGs operate in a 3-steps cycle of activities called Stage 1 - Stage 2 - Stage 3, each one partially overlapping in time with the others and feeding the next one in the row with its outcome. A set of parallel activities on different features, and spanning a defined time window, is the so-called Release. Each release usually lasts 1 to 2 years. The releases in 3GPP are indexed contiguously.3GPP bodies started to work on the definition of the 5G system in 2016. Release 15 specifies 5G Phase 1, which introduces a new radio transmission technique and other key concepts such as an industry-grade reliability, an extended modularity, or a faster response time.Release 15  5G Phase 1 foundations (eMBB, uRLLC, mMTC)                           [from 1Q 2016 to 4Q 2018]Release 16  5G Phase 2  introduces standalone (SA) deployment and expanding to new verticals                            [from 3Q 2018 to 1Q 2020 ]Release 17  5G further enhancements to the foundational aspects and verticals (NR-RedCap, NTN)                           [from 2Q 2020 to 2Q 2022]Release 18  in full flight as 5G reaches its mid-point!?                           [ Stage 2 Functional Freeze Dec. 2021]                           [ Stage 2 Functional Freeze March 2023]                           [ Stage 3 Freeze  December 2023]                           [ Protocol Coding Freeze  March 2024]Release 19, 20   5G-Advanced evolve the system to its fullest capabilities in transformation to 6G Release 21, 22, 23  6G requirements, study items, work items, R21 normative work, evolution
  • Release 15 3GPP was delivered in 2018 and was the first official specification that described a full 5G network. To accelerate the adoption of 5G globally and taking into consideration that many mobile operators aimed to launch 5G in 2018, 3GPP decided to split R15 in two “drops.” An early drop included Non-Standalone (NSA), allowing 5G radio networks to be connected to 4G core networks, thus allowing the faster deployment of the new generation. A late drop included Standalone SA, which also fully specified the 5G core network as well. R15 includes the specifications for 5G NR (New Radio), the air interface used for 5G networks. Release 15 also includes new features and enhancements for LTE, the air interface used for 4G networks, as well as other technical improvements and enhancements. Release 15 represents the current state of the art in cellular network technology, and it forms the basis for the deployment of 5G networks around the world. Future releases of 3GPP specifications will build on the foundations established in Release 15 and introduce new features and capabilities to support the continued evolution of wireless telecommunications.
  • Release 16 was published in 2020 and includes further enhancements and improvements to the 5G NR (New Radio) air interface, as well as new features and capabilities for LTE, the air interface used for 4G networks. R16 is the full 5G specification, which enables the advanced use cases and applications 5G has promised, including enterprise services and network slicing. R16 built upon the success of R15, which provided the foundation for consumer and enterprise services. This new release provided efficiency and expansion improvements to R15 specifications, predominantly in the enterprise domain. It  supports for new applications and services, such as the Internet of Things (IoT) and mission-critical communication. Some of the key areas of focus for Release 16 include enhanced mobile broadband, ultra-reliable low-latency communication, and massive machine-type communication. Release 16 will also include support for new frequency bands and other technical enhancements to support the continued evolution of cellular networks.
  • Release 17 was published in March 2022 and includes further enhancements and improvements to the 5G NR (New Radio) air interface. R17 was frozen in March 2022 and will be followed by Release 18 that is aimed to fully freeze in December 2023 or soon after. These two releases will introduce several organic improvements to the cellular standard, as well as new radical features that aim to introduce significant value for enterprise applications.The development of Release 17 will be guided by the evolving needs and requirements of the wireless industry, and will build on the foundations established in previous releases of 3GPP specifications. 3GPP Release 17 reached Stage 3 functional freeze (system design completion) in March 2022 (the scope of the Release was approved in December 2019). Release 17 wraps up the first phase of the technology evolution in the 5G decade. 
  • Release 18 addresses more 5G-Advanced, which is what the industry is calling some of the tech that comes between 5G and 6G. Work for Release 18 begins in the second quarter of 2022. Release 18 is the inaugural standard release for 5G-Advanced, and we expect a couple more releases following it to be focused on 5G. If the transition from 4G to 5G is an indication of when 6G will start (i.e. the same ~10-year cadence), then the normative work on 6G will likely begin in the Release 21 timeframe. The 5G technology space is beginning its 5G-Advanced technical evolution, which will see an increased focus on extended reality (XR), artificial intelligence (AI), machine learning (ML), and increased sustainability efforts hitting the market starting in 2024. The firm cited standards body 3GPP recently approving its Release-18 package at the end of 2021 year, which marked the official start of work on 5G-Advanced. That specification package has a preliminary freeze date of December 2023, at which point vendors should be able to start pushing those approved updates into commercial equipment. ABI Research predicts 5G-Advanced radios will start gaining traction in the market between 2024 and 2026. The firm expects the consumer infrastructure market will lead the space, with 75% of 5G base stations serving the market being upgraded to the 5G-Advanced specification by 2030. The enterprise infrastructure market will lag, hitting about half of that upgrade ratio. In 5G-Advanced, extended reality (XR) applications will promise monetary opportunities to both the consumer markets with use cases like gaming, video streaming, as well as enterprise opportunities such as remote working and virtual training. Therefore, XR applications are a major focus of 3GPP working groups to significantly improve XR-specific traffic performance and power consumption for the mass market adoption. nother noticeable feature is AI/ML, which will become essential for future networks given the predictive rapid growth in 5G network usage and use case complexities, which can’t be managed by legacy optimization approaches with presumed models. System-level network energy saving is also a critical aspect as operators need to reduce the deployment cost but assure network performance for various use cases.
  • Before R18, Artificial Intelligence (AI) and Machine Learning (ML) related projects in 3GPP focused on enabling network automation or data collection for various network functions. Network Data Analytics Function (NWDAF) was introduced in R15 providing network slice analysis capabilities. It was later expanded to providing data collection and exposure in 5G core in R16, and to enable UE application data collection in R17. Similarly, projects on Self Organizing Network (SON) and Minimization of Drive Tests (MDT) have been defining data collection procedures for various NR features over releases starting from R16. How the network would use that collected data has always been left to implementation. In R17 a RAN3-led study on further enhanced data collection investigated the high-level principles of RAN intelligence enabled by AI. R18 RAN1-led study on AI/ML for NR Air Interface, as the central subject of this article, explores the benefits of augmenting the air interface with features enabling improved support of AI/ML based algorithms for enhanced performance and/or reduced complexity or overhead.
  • IVAS codec is scheduled for 3GPP R18. 3GPP SA4 is now closing this gap with the standardization of its codec for Immersive Voice and Audio Services (IVAS). IVAS will not only introduce immersion into the traditional voice service, it will also address the demand for more general immersive multimedia services. Service applications include, but are not limited to, conversational voice, multi-stream teleconferencing, VR conversational and user generated live and non-live content streaming, AR/MR.  An IVAS codec candidate is currently being developed. Once chosen, IVAS codec standardization will follow the traditional rigorous approach based on permanent documents (Pdocs), all agreed in 3GPP. Key Pdocs are design constraints and performance requirements. These ensure the standardized codec can be implemented on relevant UEs and that it is suitable for the intended service applications. Any new codec undergoes a rigid selection process in which it must meet all 3GPP-agreed requirements. The process includes selection testing in which the quality of the candidate is formally evaluated against the performance requirements. A significant budget – in excess of a million euros – is dedicated to testing the IVAS codec.
  • Release 19 and subsequent iterations will specify forward-looking concepts and technologies that will expand the reach and utility of cellular networks well beyond today’s limitations. Some examples include: support for much higher frequencies (up to THz), more advanced radio interfaces (including full duplex), joint sensing and communication, energy harvesting and passive IoT, cognitive access across many wireless technologies, including Wi-Fi, satellite, and cellular. 

Enhancement of key capabilities from IMT-Advanced to IMT-2020. 

The importance of key capabilities in different usage scenarios.

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.  The first 5G-Advanced networks are expected to be deployed commercially around 2025.  

5G evolution is now entering the 5G-Advanced era, starting with 3GPP Release 18.  The preparation for 5G-Advanced was ongoing during 2021, leading to specification work starting in 2022 and reaching completion around the end of 2023 and start of 2024 for the various items.

Sustainability 

   6G dimensions and KPI requirements

   Key enablers and research challenges

   Methods and technologies to harness new spectrum

   Intelligent Reflecting Surface (IRS) and Smart dust (material needs to be electronically adjustable, or controllable; when radio devices are used to point a signal at a surface, it needs to be capable of directing it to the desired target)

   Green networking

The status-quo is no option due to overall accumulation of environmental crises (climate change, destruction of biodiversity, pollution) and likely future energy crises (energy efficiency, reduce energy overconsumption and uses) in coming years . 

Reduction of energy consumption through standards formulation

Over the years, the 3GPP has made significant effort to reduce energy consumption from one generation of cellular technology to the next. The energy efficiency of network elements and user devices is improved through enhancement in data transmission, reduction of control-signaling overhead, and improvement in link adaption.3GPP has placed some emphasis on ‘power saving’ and ‘5G energy efficiency’. This represents an important shift from viewing energy savings through the lens of terminals and broadening the scope to a network-wide approach. Without standardised backing, it becomes difficult to implement sustainable policies.

O-RAN network energy saving

There are several approaches to improving EE in mobile networks, and it can be worked on at different layers. EE is usually defined as a ratio between the average user throughput and average power consumption. 

  • Direct EE improvement at the highest level is simply by switching off the whole BS (i.e., putting the BS into the sleep mode). Lower level EE optimization relate to the individual BSs’ components like improvement of power amplifier efficiency, or adjusting the number of active antennas. Improvement of the EE can also be focused on some protocol-specific features like dynamic power allocation for the pilot signals, adaptation of DRX (discontinuous reception) parameters, or intelligent blanking of resource blocks under specific network conditions. Finally, EE gains can be obtained by switching off individual component carriers.
  • Indirect EE optimization can be based on e.g., load balancing between neighboring cells, or between frequency bands within the same cell. The energy-efficient load balancing is achieved, through intelligent traffic steering, e.g., by a combination of dynamic switching users between cells and frequency bands not utilizing some of them, and adaptive power allocation. 

The implementation of the above-mentioned representative algorithms aiming at EE improvements in 5G networks requires access to: some specific data, e.g., power consumption, traffic volume, user throughputs; and control actions. Recently, O-RAN ALLIANCE has released the updated version of its Use Case Detailed Specification:

  • load-dependent Base Station On/Off switching
  • antenna selection for M-MIMO
  • user association and power allocation

Transition from VNF to CNF in agnostic to deployment environment. Kubernetes become the de-facto standard for automating and orchestrating cloud-native functions (CNFs) and containers. 

vRAN/open RAN – operators’ primary considerations

As operators embark on their journey, it is getting clear that it will be a two-step process. First, a single vendor vRAN with open interfaces. Second, multi-vendor open RAN. This approach minimizes the system integration burden and enables smooth migration. They are also realizing that outlandish cost-saving claims of open RAN are not true. If at all, the initial deployments will be more expensive. But, the hope is that without vendor lock-in, the second step might bring cost savings.vRAN/open RAN comprises of three parts. First is the Central Unit (CU), which manages Radio Resource Control and Packet Data Convergence Protocol functions. The Second is the Distributed Unit (DU), which manages Radio Link Control, Medium Access Control, and PHY. And third is the Radio Unit (RU), which manages digital-to-analog conversion, MIMO antenna management, and others.From a protocol perspective, CU manages Layer-3 and part of Layer-2. DU manages part of Layer-2 and part of Layer-1. RU manages the remaining portion of Layer-1. The complexity, latency constraints, and processing needs drastically increase as you move down from Layer-3 to Layer-1. In fact, Layer-2 and 1 together consume almost 90% of the processing power of RAN.The crucial Layer-1 functionality is divided into two parts: Low-Phy and High-Phy. Low-Phy is managed by Radio Unit (RU). The High-Phy, which includes the most demanding functions such as demodulation, beamforming, channel coding, and Forward Error Correction (FEC), is managed by DU. These functions are highly latency-sensitive and consume a significant portion of the 90% processing power mentioned above.High-Phy is where 5G rubber hits the road and is the essence of 5G radio technology. High-Phy functions make or break vRAN/open RAN. RAN vendors spend years, if not decades, on optimizing the performance of these functions. They also offer the opportunity for vendors to differentiate.It’s pretty clear that a combination of dedicated, optimized in-line Accelerator for High-Phy (and networking), ASICs for RU, and COTS host servers for everything else is the most optimal compute configuration for vRAN/open RAN. Then the question for operators becomes how to choose the best vendor for their network. That boils down to whoever offers the best performance (processing power, capacity, and power consumption), advanced features such as 64T64R massive MIMO, beam steering, beamforming techniques, carrier aggregation, etc., in a standard compliant and virtualized architecture. Also, vendors’ track record and experience in cellular infrastructure matter.Obviously, whichever vendor scores high on these parameters will win in the marketplace. The beauty of open RAN is that operators have the luxury of selecting the best of the breed, be it COTS, Accelerators, cloud providers, and others, for a true multi-vendor open RAN. However, that creates system integration challenges.

C-RAN vs D-RAN

Centralized RAN (C-RAN) and Distributed RAN (D-RAN) are two different architectural concepts for radio access networks (RANs) in mobile communication systems. These concepts define the organization and distribution of various RAN components, including baseband processing units (BBUs), remote radio heads (RRHs), and antennas. C-RAN and D-RAN architectures aim to meet different objectives, and each has its advantages and challenges.
Centralized RAN (C-RAN) ArchitectureThe Centralized RAN (C-RAN) architecture, sometimes referred to as Cloud RAN, is a network topology in which baseband processing units (BBUs) are centralized and pooled together in a single location. The BBUs are then connected to remote radio heads (RRHs) at the cell sites through high-capacity, low-latency fronthaul connections. C-RAN architecture relies on virtualization technologies to consolidate BBUs, enabling resource sharing and dynamic allocation among multiple cell sites.Advantages of C-RAN:
  • Resource pooling and dynamic allocation: C-RAN allows for more efficient use of resources by sharing processing capabilities among multiple cell sites. This approach enables operators to allocate resources dynamically based on network demands, reducing the overall operational costs and energy consumption.
  • Enhanced coordination and interference management: Centralizing BBUs simplifies the coordination among cell sites, enabling advanced interference management techniques such as coordinated multipoint (CoMP) and coordinated scheduling. This results in improved network performance and enhanced user experience.
  • Simplified network management and maintenance: C-RAN architecture simplifies network management by consolidating the majority of the processing equipment in a central location. This reduces the need for on-site maintenance and enables centralized software updates and fault management.
  • Scalability: C-RAN supports network scalability by allowing operators to add new BBUs or cell sites without needing significant infrastructure modifications. This helps operators quickly adapt to changes in network demands or deploy new technologies, such as 5G.
Challenges of C-RAN:
  • Fronthaul requirements: The C-RAN architecture relies on high-capacity, low-latency fronthaul connections to link the centralized BBUs and remote RRHs. These stringent fronthaul requirements can be challenging to meet and may require significant investment in fiber infrastructure.
  • Virtualization and real-time processing challenges: The implementation of C-RAN architecture requires advanced virtualization technologies that can support real-time processing requirements. This can be challenging to achieve in practice, especially considering the strict latency requirements of some mobile applications.
C-RAN DeploymentNetwork Planning and Design:
  • Analyze network coverage, capacity, and performance requirements.
  • Identify suitable locations for central BBU pools and cell sites.
  • Design the C-RAN topology, including BBU-RRH connections and fronthaul links.
  • Estimate the required number of BBUs, RRHs, and antennas.
Infrastructure and Equipment Selection:
  • Choose the appropriate virtualization technologies for BBU pooling.
  • Select suitable C-RAN-capable BBUs, RRHs, and antennas.
  • Determine the required fronthaul technology (e.g., CPRI, eCPRI, Ethernet) and fiber infrastructure.
BBU Pool Deployment:
  • Establish the central BBU pool location(s) with adequate power, cooling, and security.
  • Install the virtualized BBU equipment and integrate it with the network management system.
  • RRH and Antenna Deployment:
  • Install RRHs and antennas at the cell sites, ensuring proper alignment and connectivity.
  • Connect the RRHs to the BBU pool via fronthaul links, adhering to latency and capacity requirements.
Network Configuration and Optimization:
  • Configure radio parameters, cell site coordination, and resource allocation.
  • Optimize the network for coverage, capacity, and interference management.
  • Perform drive testing and verification to ensure network performance meets design specifications.
Integration with the Core Network:
  • Integrate the C-RAN with the existing core network infrastructure.
  • Configure necessary network elements and interfaces for seamless communication.
Network Management and Maintenance:
  • Monitor network performance and perform regular maintenance tasks.
  • Implement centralized software updates and fault management.

Distributed RAN (D-RAN) ArchitectureThe Distributed RAN (D-RAN) architecture, also known as Traditional RAN, is a network topology in which the baseband processing units (BBUs) are co-located with the radio frequency (RF) components at the cell sites. In this architecture, each cell site has its BBU, which is responsible for processing the baseband signals and managing the radio resources for that specific site.Advantages of D-RAN:
  • Lower fronthaul requirements: D-RAN architecture does not rely on high-capacity, low-latency fronthaul connections, as the BBUs are co-located with the RF components at the cell sites. This reduces the need for extensive fiber infrastructure and simplifies network deployment.
  • Network resiliency: In D-RAN, each cell site operates independently, providing inherent resiliency to network failures or outages. If one cell site experiences a failure, it does not affect the operation of other cell sites, maintaining overall network performance.
Challenges of D-RAN:
  • Less efficient resource utilization: D-RAN architecture does not support resource pooling or dynamic allocation among cell sites.
D-RAN DeploymentNetwork Planning and Design:
  • Analyze network coverage, capacity, and performance requirements.
  • Identify suitable locations for cell sites.
  • Design the D-RAN topology, including cell site distribution and backhaul links.
  • Estimate the required number of BBUs, RRHs, and antennas.
Infrastructure and Equipment Selection:
  • Select suitable D-RAN-capable BBUs, RRHs, and antennas.
  • Determine the required backhaul technology (e.g., microwave, fiber) and infrastructure.
  • Cell Site Deployment:
  • Install BBUs, RRHs, and antennas at the cell sites, ensuring proper alignment and connectivity.
  • Connect the cell sites to the core network via backhaul links, adhering to capacity requirements.
Network Configuration and Optimization:
  • Configure radio parameters, cell site coordination, and resource allocation.
  • Optimize the network for coverage, capacity, and interference management.
  • Perform drive testing and verification to ensure network performance meets design specifications.
Integration with the Core Network:
  • Integrate the D-RAN with the existing core network infrastructure.
  • Configure necessary network elements and interfaces for seamless communication.
Network Management and Maintenance:
  • Monitor network performance and perform regular maintenance tasks.
  • Implement software updates and fault management on a per-cell-site basis.
Four D2D scenarios are shown. The first one is about local data sharing where data caching in one device can be shared with other devices in proximity. In the second scenario, called relaying, D2D communication can play a key role to improve network availability (i.e. to extend the coverage area) via a D2D based relay. This is especially important for the use cases related to public safety and those including both indoor and outdoor users. The third scenario, called single or multi-hop local proximity communication, is the one considered in the 3rd Generation Partnership Project (3GPP) Release 12. In this scenario, the devices within proximity can set up a peer-to-peer link or multicast link that does not use the cellular network infrastructure. One of the particular applications is the public safety service. The last scenario is D2D discovery (considered in 3GPP Release 12 as well), which refers to a process that identifies whether a UE is in proximity of another UE.