baubiologie magazin un contributo su 5G e le ns case

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Nuove antenne e dimensioni delle celle
Quando analizziamo e valutiamo i segnali 5G, è importante considerare il nuovo design dell'antenna. Sono chiamati "intelligenti", soprattutto perché sono in grado di formare raggi di radio e microonde (i cosiddetti beamforming). Di conseguenza, la radiazione wireless non si diffonde indiscriminatamente ovunque, ma è diretta, almeno nella parte principale, verso l'utente di uno smartphone o di un altro dispositivo mobile. Le emissioni nella direzione dell'utente saranno probabilmente più elevate e quindi devono essere calcolate distanze di sicurezza maggiori per i siti di antenne cellulari. In passato, le distanze di sicurezza attorno alle antenne cellulari variavano in genere da 3 a 9 metri e ora piuttosto da 15 a 20 metri, come documentato nei certificati del sito dell'Agenzia federale tedesca delle reti.

Nuovo è anche lo schieramento molto più frequente delle cosiddette piccole celle, la cui copertura si estende a soli 200 metri. Sono, ad esempio, montati a lampioni, semafori, parchimetri su strada, pali delle utenze, bidoni della spazzatura o facciate di case, ma anche all'interno di edifici. Sebbene la potenza di trasmissione delle piccole cellule sia inferiore, le persone sono anche molto più vicine a queste antenne (piccole e quasi invisibili); inoltre, i fornitori di reti cellulari non sono tenuti ad avere un certificato del sito (a causa della bassa potenza di uscita inferiore a 10 W) perché i limiti di esposizione della 26a ordinanza federale sul controllo dell'inquinamento non si applicano qui (tuttavia, i siti devono essere segnalati a l'agenzia della rete federale tedesca).

Per ridurre l'esposizione personale, è meglio scegliere materiali da costruzione ad alta massa; nel caso di costruzioni leggere - per l'intero edificio o solo per la struttura del tetto - dovrebbe essere integrato uno strato di materiale schermante. I materiali di schermatura (vernici, tessuti, schermi), che sono stati finora comunemente utilizzati, non mostrano molta differenza nella loro efficacia di schermatura nella gamma di frequenze da circa 1 a 3 GHz rispetto alle attuali fonti di radiazione wireless come 2G , 3G, 4G, Wi-Fi, DECT, ecc. A frequenze più alte sopra i 20 GHz, i materiali in mesh come tessuti e schermi sono meno efficaci, ma i materiali da costruzione ad alta massa e i trattamenti continui di superficie come le vernici sono più efficaci.

Sarà importante garantire che dispositivi e sistemi con antenne wireless 5G (o altre tecnologie wireless) non siano installati all'interno degli edifici a meno che non possano essere disabilitati - almeno di notte, dovrebbe esserci silenzio wireless. Ove possibile, le applicazioni per la casa intelligente dovrebbero utilizzare soluzioni cablate tramite cavi di rete o sistemi bus di cavo. (Nella nuova costruzione, è necessario utilizzare una grande quantità di cavi dati.) 

Si consiglia inoltre cautela con tutti gli apparecchi elettrici dotati di funzioni wireless: fare a meno delle funzioni wireless o assicurarsi che la modalità wireless utilizzata venga trasmessa solo di rado e per brevi periodi .

In futuro, la misurazione dei segnali 5G sarà molto probabilmente piuttosto difficile a causa delle grandi fluttuazioni dei livelli di potenza, a seconda di chi trasmette la quantità di dati . Ad esempio, le emissioni dalle antenne della stazione radio base ai dispositivi mobili formeranno almeno in parte raggi. Come si dovrebbero calcolare i livelli di potenza massima basati su misurazioni casuali? E quando non c'è traffico di dati, le emissioni di 5G potrebbero persino essere completamente chiuse !? Questi aspetti presenteranno nuove sfide alle misurazioni dell'esposizione del 5G.

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5G – what is it?

5G refers to the latest generation of wireless technologies for cellular networks. This fifth generation goes well beyond basic communication between cell phones or the mobile Internet. After the first generation (1G) of analog networks (A, B, and C) in the 1960s and 1980s and the digital standards of the second generation (2G) GSM (D, E networks since 1991), the third generation (3G) UMTS/HSPA (since 2000), as well as the fourth generation (4G) LTE (since about 2010), wireless communication is now even faster (latency or response times will be about 1 millisecond). 

It is not anymore just about communication from person to person, but also from person to machine as well as from machine to machine, including such applications as the Internet of Things (IoT), smart homes, autonomous driving, telemedicine, intelligent power supply, smart metering, smart farming, or smart cities. These applications have come to infiltrate our daily lives at an accelerated pace. The new model VW Golf 8, for example, is designed to be online at all times and stay connected with the cloud. This car can also talk to other cars and to the driver’s home. The goal of 5G developers and providers is the “totally connected society.”

New bandwidths, frequencies, and pulses

5G offers many new technical advancements. Besides the previously mentioned extremely fast transmission speed, data rates are also very high. With up to 10 gigabits per second – ten times more than LTE – the electromagnetic signals require a greater bandwidth. First measurements of active 5G cell antenna sites in Germany (e.g. in Düsseldorf, Cologne, or Darmstadt) showed “frequency hills” as wide as 50 or 100 MHz. 

The initial 5G carrier frequencies will be not much different from the ones currently in use with 4G: Previous networks (2G, 3G, and 4G) mostly operated at 800 MHz, 900 MHz, 1800 MHz, 2100 MHz, and 2600 MHz and networks used inside homes such as Wi-Fi/WLAN (wireless local area network) and cordless phones (DECT) at 1900 MHz, 2.4 GHz, and 5.2–5.7 GHz. 5G networks will at first mainly use 3.4–3.7 GHz, from 2021 also 2.1 GHz. In Germany, four telecommunications providers secured those frequencies (for a total revenue of ca. 6.6 billion euro) during an auction in spring 2019. In addition to Telekom, Vodafone, and Telefonica, there is now also 1&1 Drillich.

The significantly higher frequency ranges of about 24–28 GHz and 32–33 GHz or even higher, which are often hotly debated, will most likely only become deployed in a few years.

So-called pulses – which constantly and strictly periodically switch the wireless signals on and off, several times per second – are expected to be similar to LTE because the modulations are similar (e.g. 100 Hz or 2000 Hz). There will be a new pulse of 50 Hz, at least in the frequency range about 3.5 GHz (due to the TDD modulation used). During our first measurements, these nonstop pulses could also be clearly shown, both in “zero span” mode of a spectrum analyzer and as an audio signal with broadband RF meters.

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RF spectrum analysis of 5G cell antenna sites:
(1) Spectrum of a nearly 90 MHz wide channel of a Telekom site, center frequency ca. 3.65 GHz
(2) Time analysis of the cellular signal of a Vodafone site with a clear 50 Hz pulse, center frequency ca. 3.53 GHz

New antennas and cell sizes

When we analyze and evaluate 5G signals, it is important to consider the new antenna design. They are called “smart,” especially since they are able to form beams of radio and microwaves (so-called beamforming). As a result, wireless radiation is not spread indiscriminately everywhere, but it is directed, at least the main portion of it, toward the user of a smartphone or other mobile device. The emissions in the user’s direction will be possibly higher and thus greater safety distances must be calculated for cell antenna sites. In the past, safety distances around cell antennas ranged typically from 3 to 9 meters and now rather from 15 to 20 meters, as documented in the site certificates of the German Federal Network Agency.

New is also the much more frequent deployment of so-called small cells, whose coverage extends to just 200 meters. They are, for example, mounted at street lights, traffic lights, on-street parking meters, utility poles, garbage cans, or house facades, but also inside buildings. Though the transmit power of small cells is lower, people are also much closer to these (small and almost invisible) antennas; in addition, cellular network providers are not required to have a site certificate (due to the low output power below 10 W) because the exposure limits of the 26th Federal Pollution Control Ordinance do not apply here (however, the sites are to be reported to the German Federal Network Agency).

Audio sample

Audio sample of a 5G signal from a Telekom antenna site with a clear 50 Hz pulse 

Health risks

There are hardly any research results available about risks specifically associated with the use of 5G wireless radiation. Already in 2017, more than 180 scientists and physicians from 36 countries signed an appeal. In this appeal, they warn of severe health risks associated with 5G wireless technologies and recommend putting a moratorium on the deployment of the fifth generation of wireless communication technologies until possible risks to human health and the environment have been fully researched by industry-independent scientists. They also state that it has been proven that radio-frequency electromagnetic fields are harmful to human health and the environment. The use of 5G will significantly increase the exposure to electromagnetic fields in the radio-frequency range since this new layer of signals will be added to the already existing networks of GSM, UMTS, LTE, Wi-Fi, and so on.

Since mid-band frequencies of 800, 2000, and 3500 MHz feature similar modulations and/or pulses as are found in GSM and LTE, associated risks are also expected to be similar. Should the above-described 50 Hz pulse turn out to be present at all times, this could make for more serious effects.

Regarding high-band frequencies above 20 GHz, we know rather little and rather little research has been done so far. Due to their short wavelengths, these waves hardly penetrate the body, but are absorbed at the surface of the body. First studies suggest that adverse health effects predominantly occur in eyes, skin, and sweat glands, possibly also ECG effects.

It is the official position of the Federal Office for Radiation Protection in Germany that any developments shall be closely watched, but that the compliance with the exposure limits of the 26th German Federal Pollution Control Ordinance are sufficient for now.

Will the exposure to wireless radiation increase with 5G?

Based on the currently available scientific evidence, it is not possible to answer with a clear: yes or no. Due to the higher amount of data that can be transmitted, there will certainly also be an increase in total transmissions. And with many more antennas and smaller cell sizes, people will get much closer to them. (Consequently, personal exposure levels in the immediate vicinity of small cell antennas can be higher despite the antennas’ lower output power). Because of the characteristic beamforming, it could also be possible that in some – or even many? – locations where 5G is available, but not actively used by a user, exposure levels could even be much lower compared to LTE. 

Furthermore, the higher frequencies about 3.5 GHz are typically much more strongly attenuated than those at 2 GHz or even 1 GHz, which is why in the former case indoor exposure levels could be lower. 

The pending shutdown of the UMTS networks will result in some reduction of exposure levels. So this specific type of wireless radiation, also including its pulses and risks, will disappear; however, these very frequencies will be added to 5G networks and thus exposures in this frequency band will continue to occur after all. 

In the future, possibly many new devices will operate at 5G frequencies inside buildings, which may contribute to much higher indoor exposure levels. It will be important to review on a case-by-case basis how much, how often, when, and where a given network is actively transmitting.

Caution is advised with higher frequencies, which are expected to be deployed later. As discussed earlier, in this higher frequency range, there will probably be other or additional risks.

Whether smartphones in 5G mode will emit more radiation than handsets in 2G, 3G, or 4G mode remains to be seen; 5G emission levels are currently not known or have not yet been measured by us (though the levels of intensity will most likely be similar to previous ones). 

5G satellites

Currently, there are 2000 telecommunications satellites zipping around the Earth and about 10,000 new ones are planned to be added – with 5G capabilities. From a building biology perspective, it could be an advantage that the great distance to the Earth’s surface translates into very low exposure levels (lower than 0.1 µW/m²), though admittedly everywhere.

Building biology recommendations

Everybody is encouraged both to raise awareness in a factual and constructive way among family members, friends, and coworkers and to campaign against 5G antennas or for installations with the lowest emissions possible. (Unfortunately, many of the 5G antennas will not be subject to approval so that actions in this regard may be limited.) The consumer protection organizations “Diagnose Funk” and “Kompetenzinitiative,” which fight against wireless radiation pollution, are here to help you, but also need your support.

To reduce your personal exposure, it is best to choose high-mass building materials; in the case of lightweight construction – for the entire building or just the roof structure – a layer of shielding material should be integrated. Shielding materials (paints, fabrics, screens), which have been in common use to date, do not show much of a difference in their shielding effectiveness in the frequency range from around 1 to 3 GHz compared to current sources of wireless radiation such as 2G, 3G, 4G, Wi-Fi, DECT, etc. At higher frequencies above 20 GHz, mesh materials such as fabrics and screens are less effective, but high-mass building materials and continuous surface treatments such as paints are more effective.

If in doubt, have exposure levels verified by measurements; looking up the EMF Monitor at the German Federal Network Agency (or equivalent databases of cellular antennas in other countries) can already reveal important information.

It will be important to ensure that devices and systems with 5G wireless antennas (or other wireless technologies) are not installed inside buildings unless they can be disabled – at least at night, there should be wireless silence. Whenever possible, smart home applications should use hardwired solutions via network cables or cable bus systems. (In new construction, an abundance of data cables should be run.) Caution is also advised with all electrical appliances that come equipped with wireless functions: Either do without wireless functions or make sure that the wireless mode used only transmits infrequently and for short periods.

From a building biology perspective, it is generally recommended not only to focus on 5G, but also to consider other stress factors (e.g. ELF electric and magnetic fields, static electric and magnetic fields, formaldehyde, radioactivity, etc.) and to always take a holistic approach to problem solving, measurements, and mitigation. 

Summary

Many things regarding 5G are not yet known, but enough to use caution and to reduce one’s exposure to 5G radiation as much as possible. One thing is for sure, the introduction of 5G will lead to an increased personal exposure in various situations, at work, in public, or even at home. It is possible, as discussed above, that wireless radiation levels may drop compared to current levels. The how and where of exposure levels must be verified on a case-by-case basis, preferably with measurements.

The main goal of the building biology approach is to keep the sleep environment as free of wireless radiation exposure as possible, also including 5G. With regard to indoor wireless sources, main strategies include prudent avoidance, shutting off devices, or keeping a safe distance; with regard to outdoor wireless sources, shielding measures are in order.

How to measure 5G

Ideally, spectrum analyzers are used to measure 5G signals, which allow for the most detailed measurements. Depending on the situation, broadband RF meters can also be used. In the latter case, there will be certain measurement errors due to “crest factors” similar to LTE and even higher bandwidths, but they should all be manageable in the context of building biology assessments.

In any case, the measurement device must cover the frequencies used: Since many 5G applications will transmit around 3.4-3.7 GHz, spectrum analyzers or broadband RF meters must at least detect up to 4 GHz. For higher frequencies above 10 GHz, there are no broadband meters available as of yet and only very few building biology professionals own spectrum analyzers that can detect such high frequencies.

In the building biology community, experience with 5G measurements is still rare. Owing to the low traffic on 5G networks at this time, first measurements should be treated with caution. In the future, measuring 5G signals will be most likely rather difficult because of the great fluctuations in power levels, depending on who transmits how much data where. For example, emissions from base station antennas to mobile devices will at least partly form beams. How should one calculate maximum power levels based on random measurements? And when there is no data traffic, 5G emissions may even be shut off completely!? These aspects will present new challenges to 5G exposure measurements.

This is a translation of „5G aus baubiologischer Sicht„

Author
Dr. Manfred Mierau is a biologist (Diplom-Biologe) and works as a Building Biology Professional in Aachen, Germany.

Translator
Katharina Gustavs is a Building Biology Professional in Victoria, Canada, who translated the Building Biology Online Course IBN.
info@katharinaconsulting.com
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