5 disruptions that tomorrow’s 6G mobile networks will bring

It may seem early to speak about how sixth generation (6G) mobile networks would be a disruptive force in the future, when much of the world is still rolling out many of today’s state-of-the-art 5G networks right now.

In Singapore, 5G networks are being progressively rolled out by telecommunications operators. They are expected to offer nationwide coverage by 2025.

Yet, research on 6G networks has already begun around the world, even if experts estimate that their rollouts will be about a decade away.

That is a long time but don’t forget the telecom industry has always been pushing hard for technologies to meet growing demands for bandwidth, which has been roughly doubling every two years.

To see how fast and far we have come, we only have to look back at the three generations of mobile technologies introduced in the past two decades.

The rollout of 3G started around 2001, moving on to the commercial deployment of 4G in 2009, then on to the installation of 5G networks today. Along the way, Wi-Fi has seen speeds go up multi-fold as well.

Still, despite all those new developments and the increasing number of mobile communication technology options, the hunger for bandwidth remains insatiable. That is why the sector has started to prepare for the next step – 6G.

To be sure, these are early days. International 6G standards are still in development. But one thing is clear: 6G will leave its predecessors far behind, especially when it comes to speed and latency. 

Here are five disruptive features you can expect from tomorrow’s 6G networks.

1. Speeds of up to 100Gbps

For most people, mobile broadband networks are just a means to stream movies and television series on the go or to download large files quickly. What they need is speed.

We keep on sharing more – and increasingly large – (video) files over the internet. People watch more than one billion hours of YouTube videos every day. And three-quarters of YouTube users access the platform using a mobile device.  

What is key for people, is to be able to access those downloads anytime, anywhere – and to watch videos in the highest possible resolution. Enter mobile broadband. 

6G networks will continue to build on that trend, featuring a projected download speed of no less than 100Gbps. That is 10 times faster than the (theoretical) download speed of a 5G network and 300 times faster than the downlink speed today’s most advanced 4G networks can accommodate.      

2. Latency of just a few microseconds

People’s mobile experience depends on more than the amount of data that they can (quickly) download. For many applications, the network’s latency, that is, the lag in data transfer, is an equally important factor.  

When watching live TV programmes, for example, latency can make or break the customer experience. After all, no one wants to miss out on that crucial penalty kick during the final of the World Cup.  

Admittedly, the introduction of 5G networks (and their latency of less than 1 millisecond) should already put an end to such hiccups. Still, 6G proposes even lower latency of just a few microseconds.    

Such low signal delay will be particularly necessary to support the growing number of Internet of Things (IoT) applications. Think of closed-loop control systems that independently control machines and complex industrial processes based on real-time sensor data; or time-sensitive medical IoT applications, such as the processing and interpretation of electrocardiogram or electroencephalogram signals.  

3. Ten million connected devices per km²

The power of the IoT is determined by the number of connected sensors and devices. Here as well, enormous growth is projected.

Market research company Statista predicts that by 2025, the IoT will consist of nearly 31 billion devices, compared with 12 to 13 billion devices today. With this ever-increasing number of devices, comes the challenge of connecting as many as possible to the Internet (per m² or km²). This number is referred to as the connection density.

Today’s 4G networks achieve a connection density of about 100,000 devices per km². 5G does a lot better already, allowing the connection of one million devices per km². And with the introduction of 6G networks, the figure of 10 million connected devices per km² comes well within reach. 

It is important to note that when moving to 6G, a network’s connection density should instead be expressed in km³. After all, a third dimension – height – will become increasingly important as the number of drones deployed increases. They, too, will be a fundamental part of tomorrow’s internet.    

4. Frequencies of 100GHz (and more)

The higher the frequency, the more bandwidth is available. So to achieve the bandwidths necessary for 6G, we will need to tap into higher radio frequencies.  

For example, 4G networks are limited to frequencies of up to 2.5GHz, while 5G networks operate in the 28GHz and 39GHz bands. And the next generations of mobile networks – including 6G – are expected to depend on frequencies above 100GHz.    

5. Energy consumption of less than 1 nanojoule per bit

With the higher radio frequencies used in 6G, energy use becomes a big factor. Today’s chip technology is not yet able to operate in those frequency bands in an energy-efficient manner, so there needs to be a way to create energy-smart devices. 

Telecom powerhouse Ericsson stated in a recent report that mobile networks' energy consumption is indeed likely to increase dramatically – at the expense of both the environment and networks’ total deployment cost. 

To overcome the impact, there needs to be new hardware and software to cut consumption by a factor of between 10 and 20. Researchers have set the goal of reducing 6G’s energy consumption to less than 1 nanojoule (10-9 joules) per bit.

They have placed high hopes on new “III-V” semiconductor materials – such as indium phosphide (InP) – even though those do not yet lend themselves to being integrated onto a computer chip made of silicon.

Hence, research today is focused on hybrid approaches that combine III-V materials with Complementary Metal Oxide Semiconductor (CMOS) technologies. Critical here are the reliability and stability of these building blocks for the next big mobile revolution.

Indeed, one brick at a time, researchers are already laying the foundation for a future mobile technology that will efficiently and cost-effectively operate at much higher speeds than today.

ABOUT THE AUTHOR:

Michael Peeters is the vice-president for research and development for connectivity at Imec, a Belgium-based research and development and innovation hub that specialises in nanoelectronics and digital technologies.