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The other unlicensed shoe has dropped and stirred confusion as it makes its first bounce.
At the end of October, a group of cable companies and big tech companies including Microsoft and Google had a meeting with Federal Communications Commission Chairman Tom Wheeler in which they complained about non-WiFi use of unlicensed spectrum. In their Ex Parte filing after the meeting, the attorneys representing those companies revealed the contents of their discussion.
What the folks in Big Cable and Big Software are complaining about is that cell phone companies might start using the same unlicensed spectrum they currently use for WiFi for another technology, a form of LTE wireless technology that works on unlicensed frequencies.
Those frequencies, which primarily are in the 2.4GHz and 5GHz bands, support WiFi, of course, but also support a wide selection of other services, including microwave ovens, drone controllers, baby monitors and security systems.
Those frequencies are not reserved for any specific service, including WiFi. You can, as long as you meet certain FCC standards for signal purity and non-interference with licensed services, do anything you want on those unlicensed bands. Despite what many might say about WiFi and other services, there are no specific standards and no standards-settings body for unlicensed spectrum.
The FCC, meanwhile, is seeking information on what to do about the competing demands for access to spectrum from WiFi and LTE-U services. The commission’s job is complicated by the commercial interests of the WiFi Alliance, which is trying to have itself declared the arbiter of all things using that part of the spectrum. In fact, the WiFi Alliance is trying to convince the FCC that it should approve all LTE-U products, just as if the LTE-U gear were WiFi gear.
Confusion is winning the day, however. This is because there are two different (and unrelated) technologies that allow people with the right mobile phones to use unlicensed frequencies. One of these is the LTE-U we’ve been discussing, which allows LTE to exist in those unlicensed frequencies alongside WiFi. The other is WiFi Calling, which allows a mobile device to connect to a WiFi access point in exactly the same way as any other WiFi device.
With WiFi Calling, which has been around for years and which existed even before there were smartphones, the phone sends your call over the WiFi connection as a data signal. T-Mobile started offering WiFi Calling a decade or so ago because it needed to give customers a way to make calls when the company had comparatively few cells available. Other cell companies, including AT&T and Sprint, are offering WiFi Calling as well, since the hardware for it already exists in phones they’re selling.
Verizon also may be offering WiFi Calling in addition to LTE-U. Many of its phones already have the capability. For example, Apple makes exactly the same iPhone for use by Verizon as it makes for T-Mobile.
LTE-U, WiFi Backers Wrangle With FCC Over Sharing Spectrum
You can change carriers on your unlocked iPhone any time you want to and it will work on any of the available networks, except that AT&T has an LTE band that the others don’t.
But despite the shared spectrum, the similarity ends there. WiFi Calling is a service that meets the technical recommendations of the WiFi Alliance, but LTE-U isn’t. On the other hand, the LTE-U Forum is working on recommended standards, including non-interference standards that will encompass WiFi. The LTE-U Forum has responded to earlier claims by the interests supporting WiFi in a letter to the FCC, claiming deficiencies in their argument.
If the pros and cons of the WiFi versus LTE-U argument were based strictly on the law and on engineering realities, this would be a relatively easy argument to settle. Sadly, the parties involved, especially on the WiFi side, are spreading fear, uncertainty and doubt as thickly as they can, making claims about LTE-U that aren’t true, pointing to fanciful scenarios and what-ifs that are pure speculation.
The reality is this. WiFi can use the 5GHz portion of the unlicensed spectrum, and many—but far from all—devices have 5GHz capability. But that portion of the spectrum is lightly used by WiFi even though it’s available because it has relatively short range and poor structure penetration. It’s important to the success of 802.11ac, but that high-speed version of WiFi only works over relatively short ranges.
It’s the 5GHz band that LTE-U is aiming at. This band is far broader than the 2.4GHz band you’re most familiar with. There’s room for a significantly greater amount of use on 5GHz than on the lower frequencies.
Interference is very unlikely to occur because of the relatively short range and poor structure penetration, but also because both WiFi and LTE-U have the ability to sense other signals on any specific frequency and move elsewhere. If there is interference, it’s the result of poor design.
Of course, there’s no shortage of poor design in WiFi, just as poor design exists in most other consumer electronics from televisions to auto entertainment systems. So the question now becomes whether the FCC should intervene to protect the poor engineering practices of one user of the spectrum to the disadvantage of another.
I’ve seen this same contest with other services over the years, and the only time any service has had the upper hand is when it’s the licensed user of spectrum that’s also being used by unlicensed users.
When that happens, the unlicensed users must give way. But here, both sides of the argument are on equal footing, with the WiFi interests trying to invent a right that doesn’t exist. The FCC should—and I think will—keep this in mind as it considers the question.