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.