Mile Hi: Why It's Suddenly Safe to Use Cell Phones on Planes

When the Federal Communications Commission said earlier this month it would consider allowing airplane passengers to use their cell phones in flight, people basically freaked out. After all, no one—not even FCC chairman Tom Wheeler—wants to be stuck next to a stranger gabbing their way from New York to Los Angeles.

But despite the backlash, the proposal to allow in-flight calls cleared its first hurdle yesterday, and the FCC explained that the issue in question here isn't about etiquette (as Wheeler said: "We're not the Federal Courtesy Commission") but rather about keeping up with the latest technology. The commission claims that previous concerns that wireless signals would interfere with cellular networks on the ground or airplanes' navigation systems are outdated.

"There is a need to recognize that there is a new technology," Wheeler told a congressional panel. "This is a technical rule. It is a rule about technology. It is not a rule of usage."

So then, what is this new technology that allows us to safely converse 40,000 feet in the air at 500 hundred miles an hour? For one, it's not actually that new; some airlines in Europe already permit cell phone use. If the FCC overturns the currrent ban, airlines in the US could choose to adopt the systems being used across the pond. Here’s how it would work.

Airplanes allowing in-flight cell phone use are equipped with picocells—basically a mini cell tower—that collects the signals from all the phones on board and beams it to a communications satellite in orbit, which then relays it to a base station on the ground to connect to a cell network.

But let's back up a bit and look at how cell phones work normally. Our mobile phones transmit radio signals to and from ground stations with antennas. The base station’s coverage area is called a cell, and the more cells, the stronger the network. Picocells, the game-changing technology for in-flight calls, came along in the early 2000s when everyone started ditching the landline. They're basically mini base stations typically used to boost a cell signal or extend it to hard-to-reach areas. If you stick one on an airplane, you've got a micro, mobile cellular network in the sky.

To connect the onboard network with the folks you’re chatting with on the ground, an antenna on top of the plane routes the signal to a communications satellite, which patches it through to a terrestrial base station. Per FAA rules, the equipment is rigged to control the transmission so it doesn’t try to directly contact cell networks on the ground, which would interfere with those signals.

That fear of interference is one of the reasons the FCC has kept the 1991 ban on in-flight cell phone use up until now. The other is the worry that radio transmissions beaming around from the plane to the satellite and back to Earth would interfere with the aircraft's communications and navigation equipment, which also rely on radio signals. But according to the FCC, that's no longer a risk.

"Where there is new onboard technology that eliminates that potential for interference, there is no need for an interference rule," Wheeler said yesterday. "We are the expert technical agency, and new technology removes the technical justification of this rule."

Basically, since the antenna on the picocell is so close to the phones onboard that it's communicating with, the output power can be very low. FAA restrictions mandate that cell signals are at their lowest transmitting power level, minimizing the risk that the transmission will get all tangled up in the aircraft equipment signals.

Unsurprisingly, the groups pushing the FCC to overturn the current ban are the telecom companies who would provide this satellite communications equipment; there’s a lot of money to be made extending wireless use to skies—the final frontier. But others are still skeptical about the idea. On the same day the FCC voted to consider allowing in-flight calls, the US Department of Transportation piped up and threatened to instate its own ban. Not because talking and texting in the sky it's potentially unsafe, but because it's potentially annoying as hell.