The 6G Roadmap

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

- Overview

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

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

6G will build on 5G, evolving 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 the necessary 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, driving networks towards a new paradigm of ultra-slim design, unlimited connectivity, integrated sensing and communications, and seamless ground, air and satellite coverage. Therefore, use cases such as large-scale digital twins, autonomous mobility, and wide-area mixed reality are expected to become commercial mainstream in the 6G era. 

The most obvious difference between 5G and 6G is speed. 6G will use more advanced radio equipment and greater capacity and diversity of airwaves than 5G, including the use of extremely high frequency (EHF) spectrum, to deliver ultra-high speeds and massive capacity over short distances. 

4G speeds are discussed in megabits, while 5G will break the gigabit barrier and 6G will deliver theoretical terabit speeds. Most users will get over 100Gbps, but this is still a transformative bitrate.

In terms of coverage, 6G may become ubiquitous. 6G satellite technology and smart surfaces that reflect electromagnetic signals will provide low-latency, multi-gigabit connectivity in parts of the world where traditional mobile networks are difficult or too expensive. Remote areas of the planet, the sky and the oceans can all be connected.

While 5G already leverages artificial intelligence (AI) for optimization, dynamic resource allocation and data processing, ultra-low latency of less than one millisecond and decentralized architecture means 6G will be able to deliver integrated intelligence everywhere. In fact, Japanese operator NTT DoCoMo believes that 6G will achieve AI  similar to the human brain. 

6G will also be more efficient and consume less power than its predecessor. Due to the expected growth in data generation, energy efficiency is critical for a more sustainable mobile industry.

- 5G Evolution - On The Path to 6G

Sixth generation (6G) wireless communication networks promise to integrate land, air and maritime communications into a robust network that is more reliable, faster, and can support a large number of devices with ultra-low latency requirements.

Researchers across the globe are proposing cutting-edge technologies such as artificial intelligence (AI)/machine learning (ML), quantum communication/quantum machine learning (QML), blockchain, terahertz and mmWave communications, tactile internet, non-orthogonal multiple Address access (NOMA), small cell communication, fog/edge computing, etc. as key technologies to achieve beyond 5G (B5G) and 6G communication.

Is 6G real? Yes. And no. Yes, 6G (or whatever it’s eventually called) will eventually replace 5G, but 6G is not yet a functioning technology, and is instead in the early research phase. Mobile telecom companies are much too focused on 5G to deal with 6G in any significant way, although early research projects have begun thanks to funding from governments that want to gain an edge.  

How fast will 6G be? We don’t know how fast 6G will be yet, but estimates have it around 100 times faster than 5G. The final standards that will define what a 6G connection is will probably be down to the International Telecommunication Union (ITU). The ITU recently nailed down the standards for 5G (which it refers to as IMT-2020) after more than eight years of work, and is expected to start a similar process for 6G soon.

It’ll be like 5G, but more so. Even higher speeds, even lower latency, and masses of bandwidth. Researchers and scientists are talking about 6G going beyond a “wired” network, with devices acting as antennas using a decentralized network not under the control of a single network operator. If everything connects using 5G, 6G will set these connected devices free, as higher data speeds and lower latency make instant device-to-device connection possible. 

- New Spectrum and Frequencies with 6G

6G requires massive performance improvements as compared to 5G. While 5G was designed to achieve peak speeds of 20 Gbps and utilize frequencies up to 100 GHz, 6G is expected to achieve data rates of up to 1000 Gbps and utilize frequencies up to 3 THz. Latency is also expected to be improved massively with air latency targeted to be around 100 μs, end-to-end (E2E) latency of around 1 ms which would be result in user experience latency of less than 10 ms. User experience latency is the sum of all latency components in the entire communication channel.

Just as the jump from 4G to 5G represents an expansion of spectrums used and introduction of new frequencies, so will the evolution between 5G and 6G communications. Whereas 5G leverages mmWave in the microwave frequency range, 6G will take advantage of even smaller wavelengths at the Terahertz (THz) band, which is typically referred to as 100 GHz to 3 THz.

By exploring the capabilities of wireless signals in the largely unused range above 100 gigahertz -- or the proposed 6G spectrum - can enable applications outside the classical definition of communications. The tiny signals at this range, referred to as millimeter waves, or mmWaves, can allow for imaging, mapping, localization and higher data-rate communications to connect multiple devices and even applications that haven’t yet been invented.

- New Challenges with 6G

The 6G wireless communication network is expected to integrate the terrestrial, aerial, and maritime communications into a robust network which would be more reliable, fast, and can support a massive number of devices with ultra-low latency requirements. 

Just as there have been, and will continue to be, many challenges with 5G, so will there be many new challenges with 6G.  One of those challenges will be developing commercial transceivers at the to-be utilized THz frequencies. This is largely an area in which electronics component providers will need to innovate. For example, semiconductor providers will need to deal with extremely small wavelengths and correspondingly small physical size of RF transistors and how they will interwork with element spacing of THz antenna arrays.

The researchers around the globe are proposing cutting edge technologies such as artificial intelligence (AI)/machine learning (ML), quantum communication/quantum machine learning (QML), blockchain, tera-Hertz and millimeter waves communication, tactile Internet, non-orthogonal multiple access (NOMA), small cells communication, fog/edge computing, etc., as the key technologies in the realization of beyond 5G and 6G communications. 

- Potential New Applications of 6G

Features of the 6G spectrum will make for some interesting applications and multiplicative effects. Potential applications for Terahertz spectrum include sensing, imagine, wireless cognition, For example:

• Wireless cognition: Robotic control and drone fleet control;
• Sensing: Air quality detection, personal health monitoring, gesture detection and touchless smartphones, explosive detection and gas sensing;
• Imaging: See in the dark, HD resolution video radar, Terahertz security body scanning;
• Communication: Wireless fiber backhaul, intra-device radio communication, connectivity in data centers, information shower;
• Centimeter-level positioning.

6G will have big implications for many government and industry approaches to public safety and critical asset protection, such as the following: 

• Threat detection
• Health monitoring
• Feature and facial recognition
• Decision-making in areas like law enforcement and social credit systems
• Air quality measurements
• Gas and toxicity sensing, and
• Sensory interfaces that feel like real life

Improvements in these areas will also benefit smartphone and other mobile network technology, as well as emerging technologies such as smart cities, autonomous vehicles, virtual reality and augmented reality.

- The Future of Global Satellite Broadband Networks

6G is expected to integrate with satellites. Integrating terrestrial, satellite, and airborne networks into a single wireless system will be crucial for 6G. 

Orbital broadband networks will need large constellations of small satellites to relay transmissions effectively and at lower power consumption than today’s larger satellites. This is where the technologies of wireless transmission absorption and refraction – known as frequency selective surfaces (FSS) – come to play a major role in increasing efficiency over any previous satellite wireless technology. 

FSS are used in Earth observation satellites to separate signals, which are collected by single reflector antennas. For these, FSS provide broadband remote sensing capability by enabling the instrument to work over a large frequency bandwidth. So, one instrument replaces many that were required in the past, thus reducing the footprint of each satellite (useful for nanosatellites) or [packing] more equipment onto a larger platform. FSS are an optimal solution to be used for future satellite broadband communications systems.