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Spectrum shake-up to deliver more Wi-Fi, connections
Large swaths of additional unlicensed spectrum will become available in the
U.S. for connected devices, including Wi-Fi, if various proposals and schemes
by the FCC come about.
Patrick Nelson
The United States' Federal Communications Commission (FCC) wants to expand
available spectrum in order to increase bandwidth for connected devices, such
as IoT and broadband data, including those communicating via Wi-Fi. One reason
is because ISPs want to get into wireless, and they are putting pressure on.
The expansion, however, will be good for all Internet of Things (IoT), too.
A number of significant unlicensed bandwidth blocks are, or will be, available,
including at 6GHz, 5.9GHz, and 3.5GHz. Potential stumbles include that
interference mitigation needs to be resolved in a couple instances.
6GHz
In the first block, the FCC is proposing making available a large 1200
megahertz of spectrum in the 6GHz band for devices, including IoT sensors, and
Wi-Fi, which predominantly uses 2.4GHz and 5.8GHz now.
In the 6GHz proposal, formalized in October, the government agency says it
wants to implement an automated frequency coordination system for sharing the
massive 5925 to 7125 MHz slab with incumbent microwave links. At issue, and one
that the FCC is now seeking comment for and needs to be resolved before all
systems are go, is whether a computerized sharing system must be instigated for
in-building devices, such as sensors and wireless access points, as well as
outside ones — there may only be interference issues outside.
In some cases, “the unlicensed devices would be restricted to indoor operations
at lower power,” the agency says. Low power can be OK for many networking
purposes, including IoT.
5.9GHz
The second unlicensed frequency chunk that the FCC is aiming to allow
unlicensed devices to operate on is at 5.9GHz. Currently, those frequencies,
between 5850 and 5925 MHz, are allocated to automobile safety. And that’s where
things get a bit more complicated. Cars independently talking to each other, at
high speed and around corners, (called V2X, or Vehicle-to-everything) is about
to become important.
That 75 megahertz lump of spectrum, called Dedicated Short Range Communications
(DSRC), isn’t used much, though, the FCC claims. However, many in the auto
industry, think it will be used more in the future, and that interference could
be an issue if that section of the spectrum is shared.
“These safety innovations require dedicated spectrum to ensure they work right
every time, without signal interference,” said Auto Alliance, a trade body, in
a statement last month. “Millions of dollars have already been invested in this
effort.” And indeed chipsets have been developed.
Recently released FCC engineering tests, though, show that the 5.9GHz
auto-safety spec DSRC and Wi-Fi can actually work together without interference
— the unlicensed device vacates or shares the band when cars use it. The FCC
wants comments on that report, too, before anything can move forward. Though
the agency says, “We found the prototype devices reliably detected DSRC
signals.”
FCC Commissioner Mike O’Rielly is antsy to get things moving. In an October
statement, he said: “The Commission should initiate a rulemaking to reallocate
at least 45 megahertz of the band, which is completely unused today for
automobile safety.”
3.5GHz
And finally, a third block of spectrum coming on line, also suitable for
unlicensed connected device use, and the furthest down the line, is 150 MHz of
contiguous spectrum at 3550 MHz to 3700 MHz, also known as Citizen Broadband
Radio Service (CBRS). It’s being delivered through an automated sharing
agreement with incumbent Navy radar.
CBRS at 3.5GHz will be used in 5G by mobile network operators, importantly
ISPs, and for private LTE and private 5G networks, among other uses. Varying
tiers of access priority, allocated geographically at a county level, will be
determined through upcoming pay auctions, but a non-prioritized no-license tier
will exist too. Enterprises, including factories, will be able to use that for
IoT implementations if they want.
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.