A 6G Terahertz Economy by 2030?

Researchers predict 6G to be thousand times faster than 5G, and that could be a real game changer

On 7November 2020, China successfully launched the world’s ‘first 6G satellite’ into space, with it the world took the first step into the Terahertz era, even before the millimeter wave 5G technology was yet to be fully launched in every country. In addition to Earth observations, the 6G satellite will test a high-frequency terahertz communication payload that could send data at speeds several times faster than 5G – 2020 became Year-Zero for 6G.

What makes 6G look more promising is the jump to Terahertz (THz) communications as we move from Megahertz (MHz) in 4G to Gigahertz (GHz) in 5G with mmWave spectrum. The spectrum range that is being proposed for 6G communications is between 300GHz and 3THz. This indeed will be a step change as the industry aims for terabit throughputs, microsecond latencies, and capacities never seen before.

The obvious question is why do we need 6G when 5G ‘s full potential is yet to be realized? Researchers have promised that 6G will be 1000 times faster than 5G, by the time it is launched in 2030. What will this speed of data communication do for us? The use cases straddle everything from HoloPortation to real-time remote surgery.

Figure 1: The 6G Use Case Roadmap – A vision for the future

A simple full-body human-size 3D hologram (tens of gigapixels in size) will require a Tbps bandwidth to transport it. With advanced compression techniques, 6G architecture and related radio capabilities, we should be aiming to transmit this high-res hologram over a mobile link, also termed as HoloPortation! It will extend the reality spatially and transform how we communicate with each other. Lower microsecond-level latencies could unlock real-time tactile applications such as almost zero-lag remote collaborative surgeries, real-time remote control of machines, and more.Further, high-resolution digital twins or digital replicas will be used for interaction between the digital and physical worlds through mixed-reality devices and the power of AI.

6G also has some key sustainability goals attached to it aligned with the UN goals. It aims to meet the transmission requirements of exponential data growth without increasing the energy usage of networks. Evolving towards 2030, connectivity will likely be regarded as a basic human right for accessing equal education, business, and health opportunities. Stressed by the pandemic beginning in 2020, there is currently a strong societal, economic, and political drive to continue the expansion of mobile networks for providing full global coverage and closing the digital divide to rural and remote areas.

The world wants to move to the Internet of Experiences or Everything (IoE). It would revolve around interactions between three worlds: a human world of our senses, bodies, intelligence, and values; a digital world of information, communication, and compute; and a physical world of objects, organisms and processes. Development will be intense around the interactions between these worlds; through connected intelligence, enabling machines to communicate without limits; immersive communication, removing distance as a limit for human experience; twinning of the physical sensing/actuators and programmable digital representations; and finally the fundamental ambition of a sustainable world, enabled by network technology.

Europe and the US are already gearing up for 6G. Major communications providers AT&T, Verizon, and T-Mobile, along with others, joined the newly formed Alliance for Telecommunications Industry Solutions (ATIS) Next G Alliance, an industry initiative that will advance North American mobile technology leadership in 6G and beyond over the next decade. On January this year the European Commission launched 12 Hexa-X program its research project to define the future of 6G.

Each successive generation of cellular service has offered benefits over its predecessor. 4G improved over 3G services by adding mobile broadband internet access. Such service enabled mobile web access and mobile IP voice, gaming, and videoconferencing applications. Similarly, the main advantage of 5G services over 4G is that 5G offers greater bandwidth, resulting in faster transmission and download speeds. 5G’s capabilities enable many new applications. Those include mobile video streaming, intelligent edge, and greater use of the Internet of Things (IoT).

6G will be significantly faster than 5G. Both make use of higher frequencies of the wireless spectrum. Higher frequencies allow more data to be transmitted faster. How much faster will 6G be over 5G? A commonly stated goal for 6G is for it to be 1,000 times faster than 5G. That will depend on the transmission technologies and broadcast frequencies used.

Latency differences are another aspect used to compare these services. 4G latency is about 50 milliseconds. Current 5G deployments are touting latencies of less than 30 milliseconds. Still, providers expect to reduce that to 10 milliseconds and lower (some say it could possibly be sub-1 millisecond) using techniques such as network slicing. The anticipated 6G bandwidth and latency characteristics will spawn uses in a variety of innovative application areas, including augmented reality (AR) and virtual reality (VR), holographic telepresence, eHealth (healthcare delivered remotely), autonomous vehicles, Industry 4.0, and robotics.

This will require Artificial Intelligence (AI) technology to be an integral part of 6G networks – to develop methodology, algorithms, and architectural requirements for an AI-native network, through AI-driven air interface and AI governance. 6G networks should be designed to incorporate AI operation to optimize network performance, as well as operate to optimize AI performance for other services. Key targets here are to embed AI functionality into the signal processing chain and develop suitable learning methods. Governance and protocols for secure AI needs to be developed for the integration of AI into trustworthy network systems. Further, intelligent orchestration covering dynamic resource management, data-driven optimization, and intent-based operation will be developed to streamline operations of future networks. The potential of node programmability will be studied for improved development speed and flexibility.

AI/Machine Learning (ML) will bring a major disruption to future networks from impacting the design of air interface, data processing, network architecture and management towards computing for achieving superior performance. It will become essential for the end-to-end network automation dealing with the complexity of orchestration across multiple network domains and layers. Network intelligence will help to improve energy efficiency and ensure service availability by performing optimizations that are challenging for traditional algorithms with AI/ML approaches and carrying out system management tasks autonomously with AI/Machine Reasoning (MR).

However, an autonomous system can only be successful if it is trusted by humans and can be understood and explained. It is extremely critical to establish suitable mechanisms for trustworthy AI. For example: the system needs to be able to explain its actions and why it ended up in its current state; the intelligent system should (i) act lawfully, respecting all applicable laws and regulations (ii) be ethical, respecting the right principles and values, and iii) be technically robust while considering its social environment. Last but not the least, the system must involve humans when needed.