Roughly every 10 years, we get a new cellular communication standard. In 2000, we got 3G. In 2010, we got 4G (LTE). And in 2019, we had 5G shoved down our collective throats (indeed, demand for the 5G transition has been nothing like the demand for the 4G transition). But already the industry is looking ahead to 6G and a 2030-ish launch.
While this may seem way too early, the amount of research and collective bargaining over specifications that go into a new telecommunications standard means the R&D folks get started early. Especially because with 6G we’re going to have to make advances across several different fields, from computer science to physics. It will not be a fast process.
Before we get into the advances that need to happen, let’s talk about what 6G will enable. That requires a quick history lesson in cellular standards.
All of the different generations are created by the GSMA, a standards organization that governs the telecommunications industry. The committee that governs these standards, the 3GPP, sets milestones along the way.
We’re currently in release 17 of the 5G standard, which began with release 15. Around the midpoint of each generational shift, we move from XG to XG- Advanced. So, I’m already being briefed about upcoming 5G-Advanced technologies in preparation for 6G.
And yes, those are a lot of Gs and even more technical jargon. But I’m trying to make clear to y’all that the jump from 5G to 6G won’t be a big leap, but rather a series of highly negotiated steps every couple of years. This will allow the industry to prepare and test new technology — and dream up good use cases and test those use cases — while readying for the new generation. It makes for bad headlines, but good tech policy.
Thanks to all those Gs and related technical jargon, we already have a sense of what we want from 6G. The generational milestones typically come in pairs, with the odd numbers introducing a new concept and the even generations refining it. So in 1G, we got analog voice service while in 2G, that was digitized. In 3G, we started down the path of data, which was subsequently perfected in 4G. In 5G, we are focused on connecting a lot of things and doing so with low latency, which will be refined in 6G.
“One of the key notions of 6G will be the combining of the digital, physical, and virtual worlds,” said John Smee, VP of engineering and wireless research at Qualcomm. “This will enable new types of devices but the data will be digitized.” Work on AR and VR devices with 5G has just gotten underway, he added, but with 6G those devices will come into their own, much like smartphones took a huge leap when they moved from 3G to 4G.
First, however, there needs to be a lot of research, in six areas. First up is better machine learning. Right now 5G is hard, like rocket science hard, because it requires multiple transmitters and multiple antennas on both the transmitter and the receivers. Unlike the traditional single cell tower serving thousands of devices, as data rates and the number of devices being used have increased, carriers have had to add more transmitters. So now we have towers, small cells, and even access points for buildings that are similar to Wi-Fi access points but are designed for 5G.
And many of these transmitters have a lot more antennas trying to orient and send radio signals to the antennas on nearby devices. This requires a lot of math, especially when the devices move around. Plus, with 5G we added new spectrum bands for licensed cellular, and that means even more options for data transmission.
Every new option means a new potential path for your data, and every path has to be calculated and optimized by processors in the transmitters and devices, in real time. Those paths change in response to movement, any other devices around you — even the weather conditions. With 6G, all of those factors are multiplied. That is why we hear so much about machine learning for 5G radios and devices. We’ll need even better ML algorithms when it comes to 6G.
Because 6G will likely use terahertz spectrum, we’re also going to need new silicon technologies to build and test terahertz radios. With 5G, we added millimeter-wave radios to the licensed spectrum arsenal (we still use traditional licensed spectrum for 5G as well). That was a challenge, but using terahertz radios will be even more difficult, according to Charles Schroeder, technology fellow at National Instruments, which builds test equipment for engineers.
The military and medical industries have long used millimeter-wave radios, so the technology to build and test those radios was already established, if not yet optimized, Schroeder said. But because no one is currently using terahertz spectrum, researchers need to start finding the right materials and testing equipment today.
We won’t just need new radios for new spectrum. We’ll need more ways to handle spectrum sharing to go along with our increased use of radio waves that are already used by other government agencies at least some of the time. We can’t make new spectrum, but we can share it, which is how we’ll continue to add bandwidth for wireless communication.
Smee adds that we’ll also need new, more distributed network architectures for 6G because devices will need to communicate at low latency directly with one another, not just back to a tower and then to the cloud and finally, back to another device.
To deliver on the convergence of the physical, digital, and the virtual and bring the use cases for 6G to fruition, Smee said the industry will need better research into things like digital twins and shrinking electronics. He also indicated that researchers will — and indeed, should — be focusing more on the resiliency of these networks. That’s because they will become ever more important to the regular functioning of society. It’s also because the networks will be under greater threat. Those threats will come from Mother Nature in the form of climate change, and also from mankind, as research into quantum computing makes network security more prone to hacks and hacking becomes more lucrative.
It’s probably a good thing that 6G is still so far off.