Over the last couple of years we’ve all finally gotten used to 4G LTE being the mobile standard our phones use… so of course, the next network tech is already in development. The wireless companies’ plans for expanding LTE networks sound simple: piggyback off spectrum that’s sitting right there, available for anyone to use, so the metaphorical pipes can be bigger. Except that could cause big problems for basically all the wireless tech we already use.

The new idea is called LTE-U, and there are a bunch of businesses fighting in Washington to have their say over how it comes to be.

What is LTE-U?
LTE-U is a new technology, still in development, that expands the networks mobile phones use to move data into the unlicensed (that’s the “U”) spectrum space.

Great! And in English, that actually means…?
The entirety of our modern data infrastructure, since the dawn of broadcast media over a century ago, relies on one basic principle of physics: information can travel through the air if you send and receive in certain parts of the electromagnetic spectrum.

The full EM spectrum is admittedly rather large, but the specific set of frequencies where radio waves travel — which includes all the bands we use for radio, broadcast TV, WiFi, and mobile communications — are fairly limited. When too many things try to use the exact same frequency in close proximity to each other, the signals interfere and nothing works. So the FCC regulates who can use which stretches of frequencies, through licensing and auctions and so forth.

For example, your favorite FM radio station has a very specific frequency you have to turn your digital dial to while you drive around. That broadcaster has a license from the FCC to use that frequency, and exactly that frequency, for radio. But WiFi is a little different. All of those wireless data networks, from public hotspots to your home router, occupy essentially the same set of waves: either the 2.4 GHz or 5 GHz band. You don’t need a license from the FCC to broadcast there, as it were; you just need your hardware (router, laptop, tablet, etc.) to meet approved specs.

So what LTE-U does is kick over some cellular device connectivity into that 5GHz band where WiFi currently lives. Because it’s unlicensed territory, anyone can use it without first going through the FCC’s licensing process.

Don’t we already have tech that moves mobile features over to WiFi?
Yes, but they’re a little different.

Sprint, T-Mobile, and AT&T all offer (or will shortly offer) WiFi calling on handsets that support the feature, including any iPhone running the latest versions of iOS. Rather than blending use of cellular tech and WiFi tech, those calls simply take place exclusively over WiFi when you dial.

It’s also slightly different from plans like Cablevision’s Freewheel service, which only operates over WiFi, and doesn’t have an LTE or cellular component at all.

LTE-U would basically bridge the two systems, drawing on the spectrum the WiFi infrastructure uses to boost LTE functionality.

What are the benefits of LTE-U?
Existing mobile tech, 4G LTE, is hitting the limits of its capability. For faster, stronger, better signals — something the rapidly expanding mobile market clearly can support and would use — businesses need new tech. So mobile manufacturers are saying, hey: look at this! We can boost existing LTE with this fancy new idea, and that will create more bandwidth that works faster and better so everyone can go stream more video, hooray.

According to Qualcomm, one of the businesses developing and pushing LTE-U, the combination of licensed and unlicensed spectrum harnessed together in aggregate makes “the end-user’s experience seamless creating a fatter data pipe whenever a data boost is needed. In essence, users get an enhanced mobile broadband experience with all of the benefits of LTE Advanced.”

In short, it’s a way of boosting networks. Consumers would get faster, more reliable mobile data and mobile businesses would get to save a lot of money, by using existing technology and infrastructure instead of having to build and deploy something entirely new.

Okay, and what are the problems with LTE-U?
That unlicensed spectrum isn’t empty; we’ve got WiFi in it. WiFi that people are using a lot. And that could pose a problem.

The technical ways in which the current iterations of LTE-U access the unlicensed spectrum can interfere with the performance of tasks over WiFi. Instead of, basically, queuing neatly in the ether and waiting their turn, LTE signals can interrupt existing WiFi transmissions. Those interruptions could lead to degraded, lower-quality data and slower response times over the network.

In other words, the worry is that if you are working along just fine streaming video to your tablet over WiFi, and someone on the other end of the room makes an LTE-U call, your video (or call, or upload, or game, or…) might stutter or cut out, which would drive every consumer crazy and have potential financial harms for some businesses.

This sounds complicated. Who’s fighting it out over what happens next?
The businesses most strongly favor of continuing to develop LTE-U as-is are the ones with a big stake in it: Qualcomm (which develops the chips that power the mobile phones), Nokia, Verizon, AT&T, and T-Mobile. Sprint did not file a comment with the FCC; however, the CTIA, a mobile industry trade group which includes Sprint among its many members, did — also in favor of LTE-U.

The groups backing LTE-U formed a new lobbying venture at the end of September to try to convince the FCC to take their side.

Businesses that stand to face harm, on the other hand, have expressed concerns to the FCC. Cablevision, which operates Freewheel exclusively over WiFi, wrote in their comments that the “incumbent licensed carriers have an economic incentive to use LTE-U and LAA [a similar technology] to undermine competition.”

The NCTA, the trade group for the cable industry (and therefore, for most of the WiFi broadband providers) is also against the current iteration. “Without a dramatic change of course, both LTE-U and LAA will gravely harm the unlicensed ecosystem,” the NCTA’s comment explains.

Consumer advocate groups, including the Open Technology Institute, Public Knowledge, Free Press, and Common Cause, also all urge caution, and back up Cablevision’s perspective that wireless carriers could use LTE-U in anticompetitive ways, and urge the FCC to push for “robust co-existence features in the tech.

At the heart of all the comments, on both sides, is the “good neighbor” principle. Proponents of LTE-U say that polite network behavior that doesn’t trample anyone else can be baked into the system from the start; opponents have their very strong doubts that, absent regulation, businesses have any incentive or desire to do so. Comments in the middle more or less say that the good neighbor behavior needs to be taken into account, and encourage the FCC to make sure it is.

But the FCC gets the final word, right? So what do they have to say?
In remarks he gave in September, FCC chairman Tom Wheeler strongly encouraged the industry — or rather, industries, mobile and cable both — to come together to create one broad-based standards process that would work for everyone.

Should the various technology businesses not feel like cooperating with each other, however, stronger FCC intervention would be called for. In the meantime, the commission has been collecting comments and information in an open docket.

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