The 6G Roadmap

6G: Building Tomorrow's Wireless Tech Beyond 100 GHz

- Overview

6G networks will connect physical entities, people, and activities in a fully cyber-physical world, where the digital and physical worlds we know today merge.

This will enable entirely new ways to interact with the world around us, new possibilities for anytime, anywhere connectivity, and new ways to experience distant places and cultures. In doing so, 6G will lay the foundation for a more humane, sustainable, and efficient future society. 

Building on 5G, 6G will evolve from today's networks to meet the needs of 2030 and beyond.

The first wave of 6G will advance the technologies and use cases already introduced in the 5G era, providing essential support for key services and deployment scenarios from day one. This includes enhanced network coverage, programmable networks, and use cases such as enhanced mobile broadband (eMBB), fixed wireless access (FWA), and the Internet of Things (IoT).

As 6G develops, new network technologies will begin to redefine service possibilities, pushing the network towards a new paradigm of ultra-thin designs, unlimited connectivity, integrated sensing and communications, and seamless terrestrial, aerial, and satellite coverage. As a result, use cases such as large-scale digital twins, autonomous mobility, and wide-area mixed reality are expected to become mainstream commercial applications in the 6G era.

The most significant difference between 5G and 6G is speed. Compared to 5G, 6G will utilize more advanced radio equipment, greater capacity, and a more diverse range of radio waves, including the use of extremely high frequency (EHF) spectrum, to deliver ultra-high speeds and capacity over short distances.

While 4G speeds are measured in megabits, 5G will break the gigabit barrier, and 6G will theoretically reach terabit speeds. Most users will experience speeds exceeding 100Gbps, but this is still a transformative bit rate.

In terms of coverage, 6G has the potential to become ubiquitous. 6G satellite technology and smart surfaces that reflect electromagnetic signals will provide low-latency, multi-gigabit connectivity in areas where traditional mobile networks are difficult or cost-prohibitive. Connectivity will be available in remote areas of the Earth, in the air, and on the oceans.

- The Road to 6G: Driving the Next Wave of Connectivity

A 6G roadmap outlines the path for developing, standardizing, and deploying the sixth generation of wireless technology, which is expected to be commercially available around 2030, building on 5G Advanced capabilities. 

Key elements include enhancing spectrum efficiency, incorporating AI/ML, expanding network sensing, ensuring built-in security, and fostering cross-industry collaboration to enable a range of data-intensive applications and support global standardization efforts. 

1. Key Organizations & Initiatives: 

• Next G Alliance: A North American initiative by private industry, government, and academia working to secure leadership in 6G by defining requirements, exploring use cases, and advocating for a global 6G vision.
• National Institute of Standards and Technology (NIST): Developing a strategic roadmap to guide research investments and address challenges in 6G such as spectrum management, interference mitigation, and data privacy.
• 3GPP: An international standards body that will develop the technical specifications for 6G, starting with studies in Release 20 and continuing the evolution from 5G Advanced.

2. Key Technological Advancements: 

• Increased Capacity & Efficiency: Improving spectrum use and leveraging new frequency bands to handle a higher volume of data.
• Integrated AI/ML: Embedding artificial intelligence and machine learning for advanced network management, impairment detection, and performance optimization.
• Network Sensing: Enabling the network to "sense" its environment for applications like traffic monitoring, environmental modeling, and security alerts.
• Enhanced Security & Privacy: Designing with built-in safety and security features to protect data and systems in complex, dynamic wireless environments.
• 3D Architectures: Exploring new architectural approaches, including 3D network design, to support expanded coverage and new services.

3. Timeline & Commercialization: 

• Pre-commercial trials: Expected to begin around 2028, with early proof-of-concepts even sooner.
• Commercial deployment: The first commercial 6G services are projected to launch around 2030.

4. Industry & Societal Impact:

• Cross-sector collaboration: Roadmaps are increasingly focusing on the interdependence between technological advancements and the needs of various industry verticals, from agriculture to smart cities.
• Global Leadership: Initiatives aim to establish global standards and ensure that regions like North America remain at the forefront of next-generation mobile technology.
• Sustainability: Promoting energy efficiency and sustainable development as core tenets of 6G deployment.

- Collaborating with 6G to Create a Cyber-Physical World

6G, the next-generation cellular network, aims to seamlessly merge the physical and digital worlds, delivering ultra-high speeds, widespread coverage, and advanced connectivity. This will revolutionize the way we interact with technology and experience the world around us, potentially building a more connected, sustainable, and efficient society.

Building on the foundation of 5G, it further enhances 5G's capabilities through advanced radio equipment, expanded spectrum utilization, and the introduction of new use cases such as massive digital twins and autonomous driving.

Key points about 6G:

• Cyber-physical continuum: 6G aims to create a seamless connection between the physical and digital worlds, allowing for real-time interaction with virtual environments.
• High speeds and capacity: 6G is expected to deliver significantly higher speeds than 5G, potentially reaching terabit speeds, with improved coverage and capacity thanks to advanced radio technology.
• Advanced use cases: In addition to enhanced mobile broadband, 6G will support new applications like large-scale digital twins, autonomous vehicles, and wide-area mixed reality.
• Ubiquitous connectivity: 6G is envisioned to provide near-global coverage, utilizing satellite technology and smart surfaces to connect even remote areas.
• Evolution from 5G: 6G will build on the foundation laid by 5G, incorporating its advancements while pushing further to achieve its ambitious goals.

- Evolution of Wireless Communication to 6G 

6G is real in the sense that it is the next evolutionary step beyond 5G and is currently in the early research phase globally, though it is not yet a functional technology. 

6G aims to significantly outperform 5G with even faster speeds, lower latency, and increased bandwidth, incorporating technologies like AI, terahertz communication, and decentralized networks. 

While telecom companies are still focused on 5G, governments are funding research into 6G to gain a future technological edge, with the International Telecommunication Union (ITU) expected to play a key role in establishing its future standards. 

1. What 6G promises:

- New Spectrum and Frequencies with 6G

6G expands on 5G by moving into the Terahertz (THz) frequency band, which is above 100 GHz, to enable significantly faster speeds (up to 1000 Gbps) and lower latency than 5G. 

This shift to higher frequencies, in addition to leveraging unused spectrum, allows for new applications like high-resolution sensing, imaging, and mapping beyond traditional communications. 

1. Spectrum Evolution:

• From mmWave to THz: While 5G utilizes the millimeter wave (mmWave) bands, 6G will explore even higher frequencies in the Terahertz (THz) range, from 100 GHz up to 3 THz.
• Leveraging Unused Spectrum: The THz band represents largely unused wireless spectrum, offering vast new bandwidth for advanced applications that were not possible with previous technologies.

2. Performance Improvements:

• Data Rates: 6G is expected to achieve data rates of up to 1000 Gbps, a massive increase from 5G's peak speeds of around 20 Gbps.
• Latency Reduction: Air latency will be reduced to around 100 μs, with end-to-end (E2E) latency targeted at approximately 1 ms, significantly improving the user experience.

3. New Applications Enabled by THz Spectrum:

• Sensing and Imaging: The tiny, high-frequency signals in the THz range can enable high-resolution sensing and imaging capabilities.
• Mapping and Localization: THz waves offer potential for detailed mapping and precise localization services.
• Expanded Connectivity: Beyond traditional communications, 6G's capabilities can connect a vast array of devices and support applications that haven't even been invented yet.

[A Beautiful Sunrise over Earth]

- Key Challenges for the 6G Network

Key challenges for the 6G network include developing terahertz (THz) transceivers due to the extremely small wavelengths and the need for component innovation from semiconductor providers. 

Other major hurdles involve integrating complex terrestrial, aerial, and maritime networks, which brings new security vulnerabilities. 

Additionally, 6G will need to overcome issues with THz signal attenuation, improve the energy efficiency and scalability of networks, and develop architectures for ubiquitous intelligence and seamless global coverage. 

1. Technical & Hardware Challenges:

• Terahertz (THz) Frequency Development: The primary challenge is the creation of commercial transceivers that operate at THz frequencies, requiring significant innovation from semiconductor and electronics providers.
• Miniaturization of Components: Developing RF transistors that are physically small enough for the short wavelengths of THz signals, while also ensuring they can work effectively with THz antenna arrays, is a major challenge.
• Signal Attenuation: THz signals are prone to significant attenuation and are easily blocked by obstacles, which limits their transmission range and requires new solutions for reliable coverage.

2. Architectural & System Integration Challenges: 

• Space-Air-Ground-Sea (SAGSAG) Integration: Integrating different network segments (space, air, ground, and sea) into a seamless and robust network is a complex architectural challenge.
• Increased Complexity and Security: This high degree of integration introduces complex security risks, requiring advanced security mechanisms, impact analysis, and protocols to protect against threats.

3. Technological Innovation & Requirements:

• Ubiquitous Intelligence: 6G aims to provide global, seamless access to virtual and real worlds, requiring new network architectures and technologies to achieve ubiquitous intelligence.
• Energy Efficiency: Beyond faster speeds, 6G must significantly improve energy efficiency compared to 5G to support the massive number of devices and applications it will host.
• Scalability: The network needs to scale to support an unprecedented number of devices and a vast amount of data, demanding new levels of network capacity.

- 6G Applications for Public Safety and Critical Asset Protection

The 6G wireless standard, powered by the Terahertz (THz) spectrum and integrated artificial intelligence (AI), is expected to enable a range of advanced public safety and critical asset protection applications. The core technological advancements include ultra-low latency, unprecedented data speeds, and network-integrated sensing capabilities. 

Here is an overview of 6G applications for public safety and critical asset protection: 

1. Threat detection: 

6G networks will use an integrated sensing and communication (ISAC) system to turn the network into a real-time sensor.

• Persistent surveillance: THz imaging will enable unobtrusive security body scans for detecting hidden weapons, explosives, and other contraband, which could be implemented in public venues like airports and stadiums.
• AI-powered anomaly detection: AI and machine learning will continuously analyze network traffic and device behavior to identify threats and detect unauthorized activities, improving upon traditional intrusion detection systems.
• Enhanced surveillance: AI-enhanced threat-hunting capabilities will secure large-scale Internet of Things (IoT) ecosystems, such as smart city infrastructure, by monitoring for sophisticated cyber threats and anomalies in real-time.

2. Health monitoring: 

The low latency and high bandwidth of 6G will transform healthcare by enabling highly responsive monitoring and treatment.

• Wearable health monitoring: Compact and intelligent wearable devices will provide continuous, real-time monitoring of vital signs like heart rate and blood pressure, sending data instantly to healthcare providers.
• In-body and on-body communications: Miniaturized implants and sensors will enable in-body and on-body communication for continuous health tracking.
• Remote diagnostics and surgery: The ultra-reliable and low-latency communication (URLLC) of 6G will allow for high-quality remote consultations and real-time remote surgeries, expanding access to specialized medical care.

3. Feature and facial recognition: 

6G will power AI-driven facial and feature recognition with greater speed and reliability. 

• Enhanced security and law enforcement: Facial recognition could be used to identify suspects and track individuals in real-time by processing high-quality images from multiple cameras across different locations simultaneously.
• Biometric authentication: Beyond facial recognition, other biometric features could be used for secure and reliable identity verification.
• Resource allocation: Integrating AI will allow for intelligent and efficient network resource allocation based on real-time data analysis, which could include the use of facial and other feature recognition for specific applications.

4. Decision-making in law enforcement and social credit systems: 

The speed and intelligence of 6G could significantly impact automated decision-making processes, though this also raises complex ethical and societal concerns.

• Automated law enforcement: Ultra-low latency and real-time data analysis could be used to support automated decision-making in surveillance and policing, potentially enabling swift responses to perceived threats.
• Social credit systems: In regions that use social credit systems, 6G could enable continuous, real-time monitoring and data collection, allowing for more comprehensive scoring and evaluation based on behavioral data.
• Rapid emergency response: For mission-critical services, 6G would provide real-time data transmission for quick decision-making and coordination during emergencies.

5. Air quality and toxicity sensing: 

6G will facilitate the deployment of dense sensor networks for widespread and immediate environmental monitoring.

• Ubiquitous sensing networks: 6G can enable a vast network of wireless chemical sensors that use nanomaterials to detect toxins in real-time. This could allow for the monitoring of air quality on an urban scale.
• Autonomous monitoring: Drones and other mobile platforms equipped with sensors will be able to perform advanced air quality measurements by sampling emissions from sources like industrial plumes or wildfires.
• Targeted detection: The use of graphene-based and other advanced sensors will enable the highly sensitive detection of specific toxic gases like nitrogen dioxide.

6. Sensory interfaces:

6G's ultra-low latency will be crucial for the development of multi-sensory and tactile interfaces, blending the physical and digital worlds.

• Telemedicine and robotics: High-fidelity haptic feedback and real-time control will enable doctors to perform remote surgeries with greater precision.
• Extended reality (XR): Immersive augmented, virtual, and mixed reality experiences will be enhanced by the bandwidth and low latency required for realistic sensory inputs and interactions.
• Human-machine interaction: The tactile internet, supported by 6G, will enable advanced haptic systems that provide realistic simulations of touch, enabling remote control and manipulation of objects.

- Integrated Satellite-Terrestrial Networks Towards 6G

Integrating satellites into 6G networks offers seamless global coverage by combining terrestrial, satellite, and airborne systems into a single, comprehensive wireless architecture. Frequency Selective Surfaces (FSS) are crucial for this integration, acting as spatial filters that manage electromagnetic signals, optimizing network performance, and enabling more compact and efficient satellite technology. 

A. How FSS are enabling next-gen satellite constellations: 

For future 6G networks, FSS allow small, power-efficient satellites to manage broadband communications, addressing challenges of traditional satellite technology.

• Signal separation: FSS act as filters that separate different frequency signals, enabling a single antenna to support multiple frequency bands. This provides broadband remote sensing capabilities that previously required multiple instruments, significantly reducing the satellite's size and weight.
• Reduced size for small satellites: By enabling single-antenna, multi-frequency capabilities, FSS allow more instruments to be packed onto smaller satellite platforms, including nanosatellites. This miniaturization is crucial for deploying the massive, low Earth orbit (LEO) constellations needed for low-latency 6G.
• Anti-interference: FSS can suppress interference by selectively transmitting or reflecting electromagnetic waves in specific frequency ranges. This improves channel quality and coverage, which is vital for the reliability of 6G systems that promise high speeds and low latency.
• Enhanced efficiency: As part of Intelligent Reflecting Surfaces (IRS) and other metasurfaces, FSS can be integrated into the 6G ecosystem to improve spectrum utilization and enhance communication performance.

B. The path toward satellite-integrated 6G networks: 

The integration of satellite networks with 6G requires overcoming complex technical hurdles, including seamless communication across dynamic, three-dimensional networks.

1. Diverse network layers: 

The future network will be a three-layered structure, or space-air-ground integrated network (SAGIN), consisting of:

• Space layer: LEO and other satellites provide wide-area coverage and supplement the terrestrial network.
• Air layer: High-altitude platforms, such as drones and balloons, act as base stations in the sky to support coverage.
• Ground layer: The existing terrestrial networks of cell towers and core infrastructure.

2. Terrestrial-satellite integration: 

The goal is for devices to switch intelligently and seamlessly between terrestrial and satellite networks. Key technologies include satellite backhaul (satellites connecting remote base stations), direct-to-device communication (smartphones communicating directly with satellites), and inter-satellite links (ISLs) that use lasers to connect satellites in space.

3. Standardization efforts: 

The 3rd Generation Partnership Project (3GPP) is defining standards for Non-Terrestrial Networks (NTNs) in 6G, with standardization work already underway.

4. Addressing technical challenges: 

To realize this vision, research is focused on overcoming challenges such as signal fading, managing network mobility, and balancing network-layer demands like routing with limited satellite resources. Advances in AI and Machine Learning (ML) are expected to help optimize network traffic and resource allocation in these complex, dynamic environments.