Coinciding with a signing-off of global standardizations for the as-yet-unlaunched 5G radio technology by 3GPP this month we get news of initial development plans for faster 6G wireless. The Center for Converged TeraHertz Communications and Sensing (ComSenTer) says it’s investigating new radio technologies that will make up 6G.
One hundred gigabits-per-second speeds will be streamed to 6G users with very low latency, the group says on its website.
For comparison, the telecommunications union ITU’s IMT-2020 has projected that 5G speeds, when that tech is eventually launched, will come in at around 20Gbps. Much slower than 6G, in other words. Those multi-gigabit 5G speeds, too, will most likely apply only to the still-in-testing high-up millimeter frequencies that will come in a second- or further-tranche of 5G. The first batch of lower-down-frequency-utilizing speeds will be slower still.
Indeed, Verizon (as well as Nokia), which has been field-trialing millimeter 5G at 28GHz for U.S. markets, is achieving throughput speeds of only 1.8Gbps, albeit with an impressive 1.5 millisecond latency. “That’s 150 times faster than you can blink your eye,” Verizon says in a media release.
Current mobile wireless network technology (4G), at frequencies below a few gigahertz, provides generally available average downloads speeds at rates below 20Mbps.
Terahertz frequency
“High frequencies, in the range of 100GHz to 1THz (terahertz),” will be used for 100Gbps 6G, the ComSenTer scientists from University of Santa Barbarasay in a release. The group created the ComSenTer center, which is part of Semiconductor Research Corporation (SRC) at their school. For spectrum comparison, Verizon’s initial 5G millimeter trials (along with Qualcomm and Novatel Wireless) that are taking place now will only go as far up the spectrum as 39GHz.
“Our center is simply the next-, next-generation of communication and sensing,” says Ali Niknejad, ComSenTer associate director and a UC Berkeley professor, on SRC’s website. It’s “something that may become ‘6G.’”
“Extreme densification of communications systems, enabling hundreds and even thousands of simultaneous wireless connections” will be part of it, the researchers claim, “with 10 to 1,000 times higher capacity than the nearer-term 5G systems and network.”
Medical imaging, augmented reality and sensing for the Internet of Things (IoT) are some of the applications the scientists say will be enhanced by faster-than-5G radios.
How terahertz 6G wireless will be accomplished
Spatial multiplexing will be an important part of the researchers’ development thrust. That’s where separate data signals are sent out in streams — the bandwidth gets efficiently reused continually. MIMO antennas, now in common use in Wi-Fi and in trials for 5G, for example, also will be used. That’s a way to maximize antennas, taking advantage of multipath. Again, it adds efficiency. Overall, terahertz should need less power and have more capacity.
Problems, though, will be encountered. Obstructions become more of an issue the higher up the spectrum — wavelengths are physically smaller. Things get in the way, so bouncing around things becomes important. That needs figuring out — for 5G still too, as well as for terahertz 6G, although Verizon says it’s getting better results than it thought it would at 5G.
“The millimeter wave signal is much more resilient than anyone expected,” Verizon’s Cynthia Grupe says in a separate press release.
But 6G exploration is worth pursuing: There are experts who say 5G won’t cope with IoT demand. 5G’s millimeter bands will be “far short of the anticipated needs,” I quoted Brown University as saying earlier this year.
“With a 10-year horizon from concept to reality, 5G has not yet been implemented in the U.S., and that makes now the best time to start thinking about what comes next,” ComSerTer says.
