Controversy surrounded the US launch of 5G from AT&T and Verizon near the airport, but as travel heats up, frequent flyers are calling foul. If 5G truly interferes with aircraft as the FAA claims, why are flyers seeing it available on the tarmac where planes lane and take off, but not in the terminal? Why is their visible 5G on the runway? Is this an airport WiFi money grab or something else?

This 5G debate began in late 2021 when the FCC claimed it became aware of the FAA’s Special Airworthiness Information Bulletin (SAIB) on the “Risk of Potential Adverse Effects on Radio Altimeters” of 5G deployment in November, within days of its scheduled release. The result was AT&T and Verizon agreeing to temporary buffer zones. As travelers return to airports, many are seeing 5G on the runway at the airport. WTF? 

5G On The Runway? What’s going on?

To get one concern out of the way, no. 5G won’t crash your plane. Also, this isn’t a conspiracy to sell airport WiFi. There are certainly some 5G challenges IT leaders should be aware of like reach and signal degradation but airport 5G is different. The problem here is simply confusion around 5G as a whole, more specifically one flavor of 5G: C-Band. 

There are three versions of 5G. Those three versions are based on the spectrum that they run on; Low-band, Mid-band, and mmWave. Low-band is under 1Ghz. This is what carriers used to quickly build their nationwide 5G networks.

5G Comes In Many Flavors

Low-band isn’t much faster than today’s 4G LTE networks but offers the advantage of range and scale. mmWave is about 24Ghz+. This is the extremely fast 5G that most carriers openly market as being blazingly fast. Low-band and mmWave are not a concern for airports right now or in the foreseeable future. That leaves Mid-band, which ranges from 1Ghz – 6Ghz. Within this range is C-band which is where the concern lies. 

Mid-band has a frequency range of 1Ghz-6Ghz and within that spectrum lies C-Band. C-band operates in the 3.7-3.98GHz frequency range, which is close to the 4.2-4.4GHz used by the airplane altimeters. Due to the proximity of these ranges, it’s plausible C-Band signals can interfere with an aircraft’s altimeter. As of January 2022, the FAA has cleared about 78% of the US Commercial fleet to be safe. but due to the other 22% both AT&T and Verizon agreed to provide some C-Band buffer zones around select airports.

Differences in carriers: Verizon, T-Mobile, Sprint, AT&T

For T-Mobile users, the majority of Mid-band spectrum they received in the Sprint merger was in the 2.5Ghz frequency range, not C-band, so altimeter interference wasn’t a concern.  In practical terms, T-Mobile users are most likely to see 5G at the airport; customers are also more likely to get mid-band 5G along with mmWave as well.

AT&T and Verizon on the other hand are stuck relying on low-band and mmWave for airport 5G coverage for now. Low-band is not much faster than 4G LTE, in real-world tests, so this leaves mmWave to compete with T-Mobiles airport coverage and speed capability.  To compete, both carriers are expanding their mmWave over the next couple of years. To date, Verizon has launched mmWave, named “Ultra Wideband” 5G at eleven airports. 

AT&T appears to be a little behind Verizon with mmWave service currently at seven airports, but the company has plans to ramp up quickly to 25 by the end of 2022.  To aid in that rollout, they announced a partnership back in 2021 with Boingo to launch 5G in twelve airports.

5G and Boingo at the airport?

You may be asking your self “Why Boingo”, but it makes a lot of sense when you think about it. Boingo has spent years building WiFi networks at approximately 60 major United States with many of them utilizing Distributed Antenna Systems (DAS). AT&T will be able to connect their 5G small cells easily. Without access to these DAS systems, the buildout per location would not as efficient and would make it harder to expand quickly.

So the next time you see 5G at the airport, know it will not cause your plane to crash!  For the lucky ones at airports utilizing mid-band or mmWave you won’t have to worry about a last-minute movie download, podcast or album.

Chris Moeller is a 5G and IoT researcher at 3 Tree Tech. If you want to integrate IoT technology into your tech or need mobility infrastructure help, he’s willing to lend you his big brain. Reach out!