Abstract: This article provides an overview of the fifth generation of cellular communications (5G) and beyond. It presents the transmission techniques of current 5G communications and those expected of future developments, namely a brief study of non-orthogonal multiple access (NOMA) using the single carrier with frequency domain equalization (SC-FDE) block transmission technique, evidencing its added value in terms of spectral efficiency.
The new 5G services are enabled by innovative techniques like millimeter wave (mmWave) technology and massive Multiple Input, Multiple Output (MIMO) in addition to traditional microwave communication methods. These advancements significantly enhance network capacity, speed, and reliability. While 5G is currently instrumental in the early stages of the Fourth Industrial Revolution, 6G is designed to introduce a broader spectrum of new services, such as VR, AR, holographic technologies, the advanced IoT, AI-enhanced applications, wireless BCI, and the ability to handle increased speeds. The current research on systems beyond 5G indicates that these applications shall be supported by new MIMO techniques and make use of terahertz (THz) bands.
INTRODUCTION As the digital revolution accelerates, connectivity remains its beating heart. The arrival of fifth-generation mobile networks—commonly known as 5G—has ushered in a new era of ultra-fast, low-latency, high-capacity wireless communication. But even as 5G continues to roll out globally, researchers, engineers, and policymakers are already looking ahead to what lies beyond: 6G and the future of ubiquitous, intelligent connectivity. As seen in Figure 1 the Fourth Industrial Revolution comprises other parameters besides robots and artificial intelligence The context of the Fourth Industrial Revolution.
Robots need to communicate and to sense the environment (using sensors and communications), for which the Internet of things (IoT) is employed (all over the Internet protocol (IP)). The IoT generates massive quantities of data (big data) that will be processed with artificial intelligence to generate knowledge; that is, the data supports human decision-making, as well as decisions made by the robots. These new technologies will originate a deep modification of society with great impact on the human way of life, as well as on the employment market.
Understanding 5G: The Foundation of Modern Wireless
5G is more than just a faster version of 4G LTE. It represents a fundamental leap in wireless technology, enabling not just improved speed but also the capacity to handle massive numbers of connected devices and ultra-reliable, low-latency communications.
Key Features of 5G:
Massive Machine-Type Communications (mMTC): 5G networks can connect up to 1 million devices per square kilometer, enabling a truly connected Internet of Things (IoT) ecosystem.
Enhanced Mobile Broadband (eMBB): 5G offers peak download speeds of up to 10 Gbps, making it ideal for applications such as 4K/8K streaming, virtual reality (VR), and high-performance gaming.
Ultra-Reliable Low Latency Communication (URLLC): Latency in 5G can be as low as 1 millisecond, which is critical for mission-critical applications such as autonomous vehicles, remote surgeries, and industrial automation.
Current Applications and Use Cases of 5G
The deployment of 5G has already begun to transform multiple sectors, from healthcare and manufacturing to entertainment and transportation.
1. Smart Cities and Infrastructure:
5G is key to the development of smart cities, where everything from traffic lights and waste management to energy systems and public safety can be monitored and optimized in real-time. Its ability to support massive IoT deployments is essential for managing urban environments efficiently.
2. Healthcare Innovation:
With its low latency and high reliability, 5G is facilitating remote diagnostics, robotic surgeries, and telemedicine. During the COVID-19 pandemic, 5G-enabled healthcare devices helped provide services in underserved and remote areas.
3. Autonomous Vehicles:
Self-driving cars require real-time communication with other vehicles, traffic systems, and cloud servers. 5G’s low-latency communication makes such instant data exchange feasible and safe.
4. Industrial Automation (Industry 4.0):
Factories are deploying 5G-enabled sensors and robotic systems to increase productivity and ensure worker safety. Predictive maintenance, quality control, and supply chain management are becoming more efficient thanks to real-time analytics powered by 5G.
5. Immersive Entertainment and Media:
5G enhances AR/VR experiences by reducing lag and improving streaming quality. This is particularly important for gaming, virtual concerts, and immersive media, where user experience depends heavily on network performance.
Challenges in 5G Deployment
Despite its promise, 5G is not without challenges. Its full potential will take time to realize, and several barriers need to be addressed.
1. Infrastructure Costs:
Unlike 4G, 5G relies heavily on small cell technology, which requires denser networks of base stations. Building this infrastructure is both capital-intensive and time-consuming, particularly in rural or underdeveloped regions.
2. Spectrum Availability:
5G operates across multiple frequency bands (low, mid, and high). The high-frequency millimeter waves (mmWave) offer greater speeds but have limited range and poor penetration. Efficiently managing spectrum allocation and overcoming these physical limitations remains a hurdle.
3. Regulatory and Security Concerns:
The global rollout of 5G has sparked geopolitical debates over infrastructure vendors and national security. Moreover, the increased number of connected devices poses new cybersecurity challenges that require robust and scalable solutions.
4. Energy Consumption:
While 5G is more efficient in terms of data transmitted per unit of energy, the sheer number of base stations and devices will increase total energy usage, raising environmental and sustainability concerns.
Looking Ahead: The Road to 6G
In the context of communications, 5G represents a significant shift in how we approach connectivity, aligning with the foundational principles of the Fourth Industrial Revolution and its impact on businesses and society. This can be rephrased as: “5G, in the realm of communication, signifies a fundamental change in the technological landscape, driven by the needs of the Fourth Industrial Revolution and its influence on organizations and communities. The future digital society, in the scope of increasing automation, namely the digital society of 2030 and beyond, comprises more and more connected devices (IoT), including sensors, vehicles, aerial drones, and data. While 5G supports autonomous vehicles, the increasing number of sensors per vehicle requires higher speeds of communications and lower latencies. Society and organizations demand new services to be included in 6G, such as the following:
- Augmented reality (AR) and extended reality (XR),
- Artificial intelligence (AI)-infused applications,
- Wireless brain–computer interactions (BCI),
- Holographic services,
- The integration of communications with localization, mapping, and remote control,
- Emerging eHealth applications,
- Improved autonomous vehicles,
- More efficient support of IoT, namely smart cities and smart houses, supporting an extremely high number of low-power devices,
- Support of flying vehicles and increased mobility speed.
In addition, 6G aims to have higher energy efficiency and more efficient strategies of energy- harvesting, so that the autonomy of user equipment can be increased, despite its demanding applications.
In addition, 6G aims to have higher energy efficiency and more efficient strategies of energy- harvesting, so that the autonomy of user equipment can be increased, despite its demanding applications.
These new services and capabilities to be supported by 6G continue to require more efficient networks with increased data rates, lower latencies, more efficient spectral efficiencies, increased energy efficiencies, and improved network capacities. Some of the foreseen requirements for 6G include:
- Nomadic peak data rates of at least 1 Tbps (100 times higher than 5G).
- Mobile data rates of 1 Gbps (10 times higher than 5G).An energy efficiency 10 to 100 times better than 5G;
- A spectral efficiency 5 to 10 times better than 5G.
While 5G requirements are achieved based on mm-wave and m-MIMO techniques, 6G must incorporate new concepts and frequency bands not yet considered for cellular communications.
What Will 6G Offer?
- Terahertz (THz) Communication:
6G may use even higher frequencies (100 GHz to 10 THz), potentially allowing data rates of up to 1 Tbps. This would enable fully immersive extended reality (XR), real-time holograms, and seamless human-machine interaction. - AI-Native Networks:
While 5G incorporates AI for optimization, 6G is expected to be AI-native. Networks will be self-learning and self-healing, offering predictive quality of service and enhanced user personalization. - Quantum-Secure Communication:
With the rise of quantum computing, current encryption methods may become obsolete. 6G networks may incorporate quantum communication protocols to ensure ultra-secure data transmission. - Global Connectivity:
6G aims to integrate terrestrial networks with satellite communications and airborne platforms (like drones and balloons) to offer global, uninterrupted coverage—even in remote areas. - Human-Centric and Context-Aware:
6G is expected to prioritize human experience and contextual awareness, adapting dynamically to individual needs, emotions, and intentions.
Potential Use Cases for 6G
- Remote Presence: Users could experience real-time holographic interactions, blurring the line between physical and digital presence.
- Brain-Computer Interfaces: 6G may support neural interfaces that allow humans to control devices using thought, enhancing accessibility and productivity.
- Environmental Monitoring: Massive-scale sensors could track climate conditions, air quality, and natural disasters with greater accuracy and speed.
Preparing for the Future: Policy, Collaboration, and Innovation
Realizing the vision of 5G and beyond requires more than just technological innovation—it demands global collaboration, forward-thinking policy, and ethical oversight.
1. Global Standardization:
Harmonizing spectrum policies and technical standards will be essential for seamless global 6G deployment. Organizations like 3GPP, ITU, and IEEE will play a central role.
2. Public-Private Partnerships:
To accelerate innovation and infrastructure deployment, governments and private companies must collaborate more deeply. Public funding for research, especially in less commercially viable areas, will be vital.
3. Ethical Considerations:
With increased connectivity comes increased surveillance potential. Protecting privacy, ensuring equity in access, and preventing algorithmic bias are crucial societal considerations that must be embedded in the design of future networks.
4. Workforce Readiness:
The telecommunications sector will require a new generation of skilled workers trained in AI, cybersecurity, advanced hardware, and ethical tech development. Investing in education and upskilling will be a national priority for many countries.
Conclusion: Building the Future, Today
5G is not the endpoint—it’s the beginning of a new digital age. It lays the groundwork for unprecedented innovations, but its real power lies in its potential to transform societies and economies.
As we look toward 6G and beyond, we must align technological advancement with human values, sustainable development, and global collaboration. The future of connectivity isn’t just about faster downloads or smarter devices; it’s about creating a world where information flows freely, inclusively, and securely, empowering everyone to participate in the digital society.
The road ahead is both challenging and exciting. As the building blocks of 6G start to take shape, now is the time for policymakers, technologists, researchers, and citizens to come together to shape the future of communication—for everyone, everywhere.
