5G pro­vides faster con­nection speeds to more devices simul­ta­ne­ously, and to more types of devices. Pexels.

Amid the various con­spiracy the­ories sur­rounding the intro­duction of 5G — the fifth gen­er­ation of broadband cell net­works — Asso­ciate Editor Allison Schuster sat down with Assistant Pro­fessor of Physics Timothy Dolch to set the record straight. 

Q: What is 5G?

Dolch: 5G refers to the fifth gen­er­ation of cel­lular net­works. It pro­vides faster con­nection speeds to more devices simul­ta­ne­ously, and to more types of devices. Such net­works are cur­rently under con­struction. 

Q: How do 5G towers work?

Dolch: The idea is that the tra­di­tional structure of towers cov­ering geo­graphical cells will be sup­ple­mented with a more dis­tributed network of smaller base sta­tions. In the old cell tower model, if you are in a par­ticular geo­graphic cell defined by tower loca­tions, you are assigned a unique fre­quency. But the signals you and the tower send back and forth are still very spread out in terms of direction. 5G base sta­tions, on the other hand, will use MIMO (mul­tiple input mul­tiple output) tech­nology to send radio signals in a par­ticular user’s direction.

Q: How will 5G rev­o­lu­tionize cel­lular data usage and wireless tech­nology?

Dolch: In some cases, it may be so fast, reliable, and acces­sible that people won’t feel the need for their own indi­vidual wireless net­works at home anymore. That would be after 5G-com­patible hardware becomes standard across many devices — mobile devices, laptops, etc. The greater number of devices that a 5G network can handle will also accel­erate the devel­opment of the Internet of Things (IoT). This gener­i­cally refers to the numerous “smart” devices that require a con­stant internet con­nection to work. So early cel­lular net­works were designed for (audio) phones, later net­works were designed for data con­nec­tions to smart­phones, and the 5G network is designed for smart devices in general.

Q: Is 5G safe?

Dolch: Yes. First, radio waves are the lowest energy part of the elec­tro­mag­netic spectrum. The high-energy parts of the elec­tro­mag­netic spectrum, such as x‑rays, are what destroy cel­lular struc­tures, leading to cancer. This is called ion­izing radi­ation. Radio waves are not ion­izing radi­ation. Second, radio wave prop­a­gation follows an inverse square law, meaning that if you double the dis­tance to a radio trans­mitter, the waves are one quarter the intensity; if you triple the dis­tance, they’re one ninth the intensity, and so on. Occa­sionally radio waves do interact with a com­ponent of life —namely, with water. This is how a microwave oven works. There is a spe­cific fre­quency of radio waves that happens to be the res­o­nance fre­quency of the water mol­ecule. So when enough radio waves of this fre­quency hit water, the water vibrates on the mol­e­cular scale, meaning, the water on the macroscale heats up. And voila, a hot lunch. Due to the inverse square law and the fact that cel­lular net­works don’t use this par­ticular fre­quency, the worst effect that could happen is that a few, weak radio waves at the water fre­quency (leaking over from other fre­quencies) might warm the water in our bodies slightly. But whether such an effect happens to any appre­ciable degree and how it could lead to other health problems is still very spec­u­lative. For example, it’s already quite clear that the long-term health risks from even a mild case of COVID-19 are far, far worse than any­thing related to radio waves. And because of the direc­tional nature of some 5G base sta­tions, you might actually get less exposure from 5G net­works, because radio waves aren’t being need­lessly broad­casted in all direc­tions.

Q: How do you protect yourself from wireless radi­ation?

Dolch: I think it’s unlikely that you’ll need pro­tection, for the reasons we just dis­cussed. Suppose for the sake of argument that a sys­tematic, long-term health problem was even­tually shown to occur in people due to cel­lular net­works. Well, in that unlikely case, it would have come from your devices having actively used the network, not from the network’s radio signals having been broad­casted in your envi­ronment. So if you’re worried, just use your mobile devices less — which is probably a good thing anyway!

Q: Why has 5G spurred so much con­tro­versy?

Dolch: To my mind, there are some legit­imate con­cerns that have nothing to do with health. Weather satel­lites now look at weak microwave emission from water vapor in the atmos­phere, an important advance in weather fore­casting. Having active 5G net­works every­where might interfere with these mea­sure­ments. Second, one 5G-related company obtained a license to use the spectrum near the GPS fre­quencies. This means that if you’re trying to get your coor­di­nates via GPS near a lot of 5G broad­casting, there might be too much local noise to catch the signal from GPS satel­lites. The avi­ation industry, for example, has been very worried about this. You can change GPS receivers to get around the problem, but that’s a big job to implement.