You can soon say goodbye to airplane mode — at least in Europe.

The European Commission ruled late last month to permit airlines to provide 5G connectivity to passengers on board, including for phone calls and high-speed data. E.U. member states have until the end of June 2023 to set aside 5G frequency bands for planes.

“5G will enable innovative services for people and growth opportunities for European companies,” Thierry Breton, the E.U.’s commissioner for the internal market, said in making the announcement. “The sky is no longer a limit when it comes to possibilities offered by super-fast, high-capacity connectivity.”

The E.U. move diverges sharply from the United States, where fears of 5G antennas on the ground interfering with aircraft equipment led to flight cancellations and diversions early this year. Cell carriers are still limiting 5G near airports until airlines can retrofit their planes.

Here’s why the experts said Europe’s decision is not likely to spark the end of airplane mode in U.S. skies.

Europe uses different frequencies for 5G

U.S. airlines and the Federal Aviation Administration have been concerned that 5G could interfere with planes’ radio altimeters, which measure altitude and are critical for landings in low visibility. Altimeters operate at frequencies of around 4.2 to 4.4 GHz, and certain altimeters without modern filtering technology can pick up interference from devices operating in nearby frequencies.

5G networks in the U.S. use 3.7 and 3.98 GHz, which provides relatively little “gap spacing” from the altimeter frequency, said Shrihari Pandit, co-founder and CEO of the internet provider Stealth Communications.

“If you don’t have this type of [filter] to keep the signal in sync, it can pick up background noise, like from onboard devices, and that could alter the readings,” Pandit said.

Cell carriers and the aviation industry have presented conflicting studies on how 5G affects altimeters. Airlines are retrofitting their planes to improve altimeter sensitivity or add metal shielding to reduce interference from 5G; they recently asked cell carriers for an extension from July 2023 to the end of 2023 complete the upgrades, according to Reuters.

In Europe, however, 5G operates at a frequency band of 5 GHz and above, providing significantly more gap spacing from the altimeter frequency and reducing the concern for airlines.

“There is much less prospect of interference,” Dai Whittingham, CEO of the U.K. Flight Safety Committee, told the BBC. “We have a different set of frequencies for 5G, and there are lower power settings than those that have been allowed in the U.S.”

Aircrafts are a ‘tin can’

Pandit said another concern, even in Europe, is the output power from hundreds of devices collectively searching for signal within the “tin can” of an aircraft.

Cellphones send out their strongest signals as they’re trying to connect with an antenna, meaning the “cumulative power output is going to be pretty significant,” he said.

It is unclear what impact such a powerful signal could have, but it raises concerns for electronic aircraft equipment and passengers’ health, he said. Aircraft may need even more sensitive altimeters and RF shielding to prevent leakage from the cabin into the electronics below, he noted.

Tom Wheeler, former chairman of the Federal Communications Commission and now a visiting fellow in governance studies at the Brookings Institution, said concerns over altimeter interference are largely overblown.

“The reality is that the vast, vast majority of aircraft have altimeters that are shielded from the signals,” he said, and older models are being replaced or shielded.

Wheeler also noted that aircraft are exposed to powerful radio-frequency emissions when on or near the ground and operate without any issues.

“The airplane fuselage is being exposed to all kinds of RF emissions that far trump what cellphone in seat 10C might be doing,” he said.

European airlines will rely on router-like ‘picocells’

To provide reliable service in the air, European airlines will use picocells, according to the E.U. announcement. Picocells act as mini cellphone towers that send a low power signal over a small area, such as an aircraft, reducing the need for devices to jump between towers, Wheeler said.

Those picocells will connect either to satellite networks or networks on the ground, like a WiFi router or hotspot, Pandit said.

Wheeler said advancements in picocell technology largely alleviate the technical concerns that prompted the ban on airborne cellphone use in the first place.

“The result of [picocells] was that you could use mobile devices on airplanes because they weren’t interfering with the terrestrial antennas,” he said.

Feeling the technical concerns were out of the way, Wheeler led an effort by the FCC in 2013 to consider lifting the ban on cellphone use on U.S. aircraft. But he said he quickly ran into resistance from the FAA and the airline industry over an entirely separate concern: people “yakking” on their cellphones.

In-flight calls impact the customer experience

“All hell broke loose because it turns out that airlines and the FAA had been relying on that rule to keep people from talking on their cellphones,” Wheeler said.

The regulatory proceedings over the rule eventually stalled over customer experience concerns, Wheeler said. Then-FCC chairman Ajit Pai said in 2017 he stood “with airline pilots, flight attendants, and America’s flying public against the FCC’s ill-conceived 2013 plan,” Reuters reported, and the effort officially ended in 2020.

Wheeler said the U.S. ban on cellphone use in flight stems from a “different technical reality,” but any move in the direction of the Europe in lifting it would have to also consider the passenger experience.

Pandit said he is neutral on the E.U. decision, but prefers a quiet cabin and questions the need for 5G when most airlines now offer in-flight WiFi.

“There’s definitely applications for business — you want to be connected, but I’m just wondering, isn’t WiFi sufficient?” he said. “Almost all devices that support 4G or 5G will have WiFi capability.”