Saturday, June 22, 2019

"It’s Never Too Early to Think About 6G"

One way to sidestep the whole Huawei-has-the-lead-in-5G issue.
Two from IEEE Spectrum. First up, a backgrounder from last year:

May 22, 2018
Companies have barely begun deploying 5G networks, but that just means researchers are thinking about what comes next
The first thought that popped into your head as soon as you read this article’s headline was likely something along the lines of, “Wait, I thought we were still waiting on 5G.” And that’s true: This is the year 5G deployment is finally picking up steam.

But that’s precisely why ComSenTer, a multiuniversity research effort into the fundamentals of what 6G might look like, is already turning its attention to the next next generation of wireless. 5G will utilize higher frequency spectrum than previous generations in order to improve data rates. Insomuch as anyone has an idea of what 6G might look like, it’s a good bet that it will take that same tack.
“It’s not clear what 6G will be,” says Sundeep Rangan, the director of NYU Wireless, one of the institutions participating in ComSenTer. “If it is the case that 6G or other communications systems can benefit from very, very high frequency transmissions, we need to start looking at that now.”
Rangan adds that “It’s premature to say that what we’re looking at will definitely be part of 6G,” stressing that what’s being investigated now is still fundamental research.

Even so, Mark Rodwell, ComSenTer’s director and a professor at the University of California, Santa Barbara, says there are a few key demonstration projects ComSenTer is looking into. The first involves building a base station that can handle the frequency ranges expected to be part of future generations of wireless. ComSenTer, which is being funded by the Semiconductor Research Corporation, a consortium of heavy hitters like DARPA, IBM, and Intel, is focusing its efforts on the 140-gigahertz, 220-GHz, and 340-GHz frequencies—all significantly higher than the 3.4- to 3.8-GHz band being leveraged for 5G.

Rodwell envisions a base station that could emit up to a thousand beams simultaneously. “What you’re looking at is four surfaces, each capable of 250 simultaneous beams,” he says. If each beam provided 10 gigabits per second, a single base station could transfer 10 terabits every second.
The higher frequencies also present challenges for handsets. The higher-frequency receiver components must be packed more closely together, introducing a risk of overheating. Signal loss must also be addressed. “Packet loss is phenomenally extensive at these frequencies,” says Rodwell.
The third major challenge is a question of math. “When a signal comes in [from a particular] direction, it’s hitting all the antennas,” says Rodwell. “Massive numbers of beams mean a lot of number crunching. You’ve got to sort all that out.”

ComSenTer’s areas of interest overlap in many places with technologies and techniques that were developed for 5G. One of the main challenges with millimeter waves, for example, is their relatively short range and an annoying habit of being easily blocked by buildings and even people. The higher gigahertz frequencies that ComSenTer researchers will be exploring will face those problems to an even greater extent....MORE
And April 26, 2019:

Terahertz Waves Could Push 5G to 6G
At the Brooklyn 5G summit, experts said terahertz waves could fix some of the problems that may arise with millimeter-wave networks

It may be the sixth year for the Brooklyn 5G Summit, but in the minds of several speakers, 2019 is also Year Zero for 6G. The annual summit, hosted by Nokia and NYU Wireless, is a four-day event that covers all things 5G, including deployments, lessons learned, and what comes next.
This year, that meant preliminary research into terahertz waves, the frequencies that some researcher believe will make up a key component of the next next generation of wireless. In back-to-back talks, Gerhard Fettweis, a professor at TU Dresden, and Ted Rappaport, the founder and director of NYU Wireless, talked up the potential of terahertz waves.

As a quick primer on the electromagnetic spectrum, terahertz waves (despite what the name implies) occupy the 300 gigahertz to 3 terahertz band of spectrum. This means the frequencies are higher than the highest frequencies that will be used by 5G, which are known as millimeter waves, and fall between 30 and 300 GHz.

In his talk, Fettweis discussed the potential of terahertz waves and 6G to solve some of the problems of 5G. He pointed to the trend established by previous generations of wireless: While 1G provided us with mobile telephony, 2G expanded on that and addressed some of its predecessor’s shortcomings. 3G and 4G did the same with mobile data. Now that we’re moving on to 5G, which is expected to support many new applications like the Internet of Things and AR/VR, Fettweis said it was only natural that 6G will function similarly to 2G and 4G to correct the flaws of the previous generation.
As to what, exactly, terahertz waves will correct—that’s still largely unknown. Service providers around the world are only now rolling out their mobile 5G networks, and it will take time to identify the shortcomings. Even so, the physical properties of terahertz waves point to some general ways in which they could help.

Terahertz waves, as mentioned, have shorter wavelengths and higher frequencies than millimeter waves. That suggests terahertz waves should be able to carry more data more quickly, though they will not be able to propagate as far. In general, that means that the introduction of terahertz waves into mobile networks could address any areas in which 5G isn’t able to deliver high enough data throughput or low enough latency. During his talk, Fettweis revealed the results of tests in which terahertz waves were able to transmit 1 terabit per second of data for a grand total of 20 meters (yeah, not very far at all).

But if you think those results are less than impressive, they don’t dissuade Rappaport, who gave a very earnest talk on the future of terahertz waves as they relate to 6G and, dare I say it, 7G....

If interested see also:

"Ready for 6G? How AI will shape the network of the future"

Tired Of All the 5G Hype? Here's 6G

Meanwhile the cable industry appears to have attended the Nigel Tufnel school of marketing:

Ready for 10G? As wireless carriers push 5G, cable industry makes a case to keep broadband
To be followed by: