The FCC Releases Needed Spectrum

The FCC made two moves in the last week concerning spectrum. Chairman Ajit Pai announced intentions to vote later this month to release the entire 1,200 MHz band of 6 GHz spectrum for unlicensed usage. They also awarded special temporary authority for 33 WISPs to use 45 MHz out of the 5.9 GHz band to boost rural fixed broadband during the COVID-19 crisis.

It’s expected that the recommendation for the 6 GHz spectrum will be approved unanimously by FCC Commissioners. This announcement is huge news. This would increase the bandwidth available for WiFi by almost a factor of 5. The WiFi band already carries far more data than any other swath of spectrum and this bolsters WiFi for the next few decades. The order proposes to uses for the new spectrum. The entire 1,200 MHz of frequency would be released for indoor usage at low power. 850 MHz of the band would be released at standard power levels and can be used outdoors in hot spots and for point-to-multipoint fixed wireless networks.

The cellular carriers have been lobbying hard to have some of the bandwidth sold as licensed spectrum. Instead, the FCC order would allocate it all to public use, but allows anybody, including the cellular carriers to use the spectrum subject to automated frequency coordination. That’s the system that senses existing use of the spectrum before allowing a second interfering use. The cellular carriers might elect to use this spectrum heavily, on an as-needed basis, in urban areas, but likely won’t bother in rural areas – freeing this bandwidth mostly for rural broadband usage.

This is big news because until this announcement there was still the possibility that some of the spectrum would be allocated to a licensed auction. The Chairman did say that he was considering making this all public spectrum a year ago, but a decision was never official until now. This is big news for the whole WiFi industry as well, since any spectrum allocated to licensed spectrum would have been off-limits for indoor WiFi use. As I’ve written in other blogs, this new spectrum, along with the introduction of WiFi 6 technology means a massive upgrade in capability for home and office WiFi performance. This should enable multiple simultaneous large-bandwidth uses of bandwidth within the home or office without interference. WiFi 6 also uses techniques that cut down on interference from neighboring hotspots.

The second action by the FCC is interesting. They granted special temporary authority to 33 rural WISPs to use 45 MHz of the 5.9 GHz spectrum for the next 60 days. This will allow these WISPs to beef up rural bandwidth during the COVID-19 crisis. The WISPs report that they are seeing a 35% increase in traffic volumes along with a requests for more bandwidth due to students and employees suddenly working from homes.

The extra bandwidth will allow these ISPs to boost bandwidth since they use software-defined radios that already work in the nearby 5 GHz WiFi spectrum band. I would expect the FCC to continue the temporary use of the spectrum if shelter-in-place extends in some places past the 60-day window.

These temporary uses of the spectrum might presage a more permanent use of this spectrum band. The 5.9 GHz spectrum was set aside many years ago for vehicle-to-vehicle communications. The self-driving and assisted driving vehicle technology has advanced much more slowly than originally anticipated, plus some car manufacturers are using a different spectrum solution for communicating from car to car. The FCC was already considering splitting the spectrum band and cutting the amount of spectrum available to vehicles in half, with the rest likely going to public auction. The cellular carriers claim that they still only have half of the mid-range spectrum they need to support full deployment of 5G, and the FCC seems likely to grab this spectrum for that purpose.

We Need Public 5G Spectrum

Last October the FCC issued a Notice for Proposed Rulemaking that proposed expanding WiFi into the 6 GHz band of spectrum (5.925 to 7.125 GHz). WiFi has been a huge economic boon to the country and the FCC recognizes that providing more free public spectrum is a vital piece of the spectrum puzzle. Entrepreneurs have found a myriad of inventive ways to use WiFi that go far beyond what carriers have provided with licensed spectrum.

In much of the country the 6 GHz spectrum is likely to be limited to indoor usage due to possible outdoor interference with Broadcast Auxiliary Service, where remote crews transmit news feeds to radio and TV stations, and Cable Television Relay Service, which cable companies used to transmit data within a cable company. The biggest future needs for WiFi are going to be indoors, so restricting this spectrum to indoor use doesn’t feel like an unreasonable limitation.

However, WiFi has some inherent limitations. The biggest problem with the WiFi standard is that a WiFi network will pause to allow any user to use the bandwidth. In a crowded environment with a lot of devices the constant pausing adds latency and delay in the system, and in heavy-use environments like a business hotel the constant pauses can nearly shut down a WiFi network. Most of us don’t feel that interference today inside our homes, but as we add more and more devices over time, we will recognize the inherent WiFi interference into our network. The place where WiFi interference is already a big concern is in heavy wireless environments like hospitals, factories, airports, business hotels, and convention centers.

Many of our future computing needs are going to require low latency. For instance, creating home holograms from multiple transmitters is going to require timely delivery of packets to each transmitter. Using augmented reality to assist in surgery will require deliver of images in real time. WiFi promises to get better with the introduction of WiFi 6 using the 802.11ax standard, but that new standard does not eliminate the innate limitations of WiFi.

The good news is that we already have a new wireless standard that can create a low-latency dedicated signal paths to users. Fully implemented 5G with frequency slicing can be used to satisfy those situations where WiFi doesn’t meet the need. It’s not hard to picture a future indoor network where a single router can satisfy some user needs using the WiFi standard with other uses satisfied using 5G – the router will choose the best standard to use for a given need.

To some degrees the cellular carriers have this same vision. They talk of 5G being used to take over IoT needs instead of WiFi. They talk about using 5G for low latency uses like augmented reality. But when comparing the history of the cellular networks and WiFi it’s clear that WiFi has been used far more creatively. There are thousands of vendors working in today’s limited WiFi spectrum that have developed a wide array of wireless services. Comparatively, the cellular carriers have been quite vanilla in their use of cellular networks to deliver voice and data.

I have no doubt that AT&T and Verizon have plans to offer million-dollar 5G solutions for smart factories, hospitals, airports and other busy wireless environments. But in doing so they will tap only a tiny fraction of the capability of 5G. If we want 5G to actually meet the high expectations that the industry has established, we ought to create a public swath of spectrum that can use 5G. The FCC could easily empower the use of the 6 GHz spectrum for both WiFi and 5G, and in doing so would unleash wireless entrepreneurs to come up with technologies that haven’t even been imagined.

The current vision of the cellular carriers is to somehow charge everybody a monthly subscription to use 5G – and there will be enough devices using the spectrum that most people will eventually give in and buy the subscription. However, the big carriers are not going to be particularly creative, and instead are likely to be very restrictive on how we use 5G.

The alternate vision is to set aside a decent slice of public spectrum for indoor use of 5G. The public will gain use of the spectrum by buying a 5G router, with no monthly subscription fee – because it’s using public spectrum. After all, 5G is a just standard, developed worldwide and is not the proprietary property of the big cellular companies. Entrepreneurs will jump on the opportunity to develop great uses for the spectrum and the 5G standard. Rather than being held captive by the limited vision of AT&T and Verizon we’d see huge number of devices using 5G creatively. This could truly unleash things like augmented reality and virtual presence. Specialty vendors would develop applications that make great strides in hospital health care. We’d finally see smart shopping holograms in stores.

The public probably doesn’t understand that the FCC has complete authority over how each swath of spectrum is used. Only the FCC can determine which spectrum can or cannot be used for WiFi, 5G and other standards. The choice ought to be an easy one. The FCC can let a handful of cellular companies decide how society will use 5G or they can unleash the creativity of thousands of developers to come up with a myriad of 5G applications. We know that creating public spectrum creates immense societal and economic good. If the FCC hadn’t set aside public spectrum for WiFi we’d all still have wires to all our home broadband devices and many of the things we now take for granted would never have come to pass.