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5G won’t cope, terahertz will provide more bandwidth
Researchers say 5G won't be able to accommodate the growing demand for
bandwidth. Terahertz-frequency networks, with their larger capacity and smaller
power needs, will be the better option.
Patrick Nelson
Terahertz data links promise significant advantages over existing
microwave-based wireless data transmissions, and the technology will ultimately
beat out the upcoming 5G millimeter frequencies if progress continues on it,
researchers say.
The reason for the optimism is that terahertz is more capacious than existing
radio bands. It’s also less power hungry, and new technical advances are being
made in it.
The latest terahertz-level advance, announced this week by scientists at Brown
University, is the ability to bounce the mega-bandwidth-carrying waves of
energy around corners. Quashing that line-of-sight requirement introduces a
level of robustness not seen before.
"I think moving into terahertz frequencies will be the future of wireless
communications," says Shaghik Atakaramians, an optical engineer who is part of
a separate, multi-university Australian group developing a new, magnetism-based
platform for the radiation-based terahertz technology. She was quoted in a
press release this week related to a paper his group published in APL Photonics.
Scientists are bullish on terahertz. The Brown University team says
yet-to-be-launched super-carrier 5G isn’t going to be able to cope, partly
because of projected growth in the Internet of Things (IoT).
Upcoming 5G “will not be sufficient to keep pace with the rapidly increasing
global demand for bandwidth,” the Brown University scientists say in their
invited article, also published by APL Photonics this month.
Those researchers claim shorter wavelength terahertz, which is found between
radio spectrum and infrared, will have about 100 times the data capacity of
microwaves. (Microwaves are what we use now for cellular and Wi-Fi.) And the
researchers say the alternative, upcoming 5G’s peak data throughput of a few
gigabits per second, will not be enough. 5G’s millimeter bands will be “far
short of the anticipated needs,” they claim.
Moving forward with terahertz
Other scientific progress that’s been made in terahertz recently includes
multiplexing. I reported on that in 2015, as well as on the feasibility of
chips capable of the high frequencies needed for terahertz.
Additionally, Harvard University late last year said it has been exploring
using infrared laser technology to create terahertz.
The problem, though, is that terahertz implementation isn’t easy. The “channel
characteristics” are not “well established,” the Brown University researchers
explain. That’s because the frequencies (95 GHz and above) are actually beyond
known characteristics — there are no FCC service rules, for example, they say.
Trouble issues can include power loss and signal degradation. Much like the
high end of microwave, obstructions block paths because the waves are so small
they can’t get around things like they can in traditional radio.
Even water droplets, as one gets in rain and fog, can cause issues with
microwave. With terahertz, any object could simply stop it, and any attempt to
get around that would use too much power, it has been thought. That’s why Brown
University’s discovery of a way to bounce the signal off walls and the ground,
and thus handle difficult environments in a power-friendly way, is important.
“You can imagine that if your line-of-site path is blocked, you could think
about bouncing it off the ground to get there,” says Daniel Mittleman, a
professor in Brown University’s School of Engineering, in a press release.
Interestingly, the researchers say transmitting over grass will be better than
concrete for focus and interference reduction because grass holds water. That
absorbs terahertz and stops the principal beam from fanning out and getting
corrupted. Eco-networking, perhaps?
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Patrick Nelson was editor and publisher of the music industry trade publication
Producer Report and has written for a number of technology blogs. Nelson wrote
the cult-classic novel Sprawlism.