mgineer Blog

How Fast and Safe Will 5G Wireless Networks Be?

May 14, 2019

May 14, 2019

Jim Harrison By: Jim Harrison
Guest Blogger, Lincoln Technology Communications 

Will 5G wireless technology revolutionize everyone’s lives like “1G” did? Think of the changes cellphone usage has begotten us in just 20 years. Incredible. But, a number of people are convinced that 5G cellular will cause huge health problems.

For the record, I don’t believe 5G cellular technology will be as wonderful as companies and industry leaders are saying it’s going to be. Gosh, what a surprise. I also don’t believe it is going to cause great harm to humanity, as many people are shouting out. And, one thing I know for certain is that the web has an absolutely incredible amount of misinformation about this subject.

5G includes a number of next-generation cellphone and cellular data transfer technologies. 3G was really the first generation of cellular, and then 4G built on that. 5G takes most of Wi-Fi and 4G technology and promises increased performance by a factor of 10x to 100x. 5G wireless calls for the construction of small cells that cover an area not much larger than a football field. Multiple small cells in a given urban location would overlap and form a mesh network. It uses dual (or sometimes three) frequencies. A low band, around 600MHz, has a long reach, and a millimeter wave high band at around 38GHz supports short, very fast connections. The 38GHz band offers very high bandwidth and uses a MIMO antenna array with 8 to 32 (or more) individual antennas. The 5G MIMO antenna uses beam forming and beam steering and has full-duplex communications. Each beam goes to one user equipment (UE). Massive machine-type communication (mMTC) is a term for another operational aspect of 5G. It will make possible connections to many low-cost, low-power, long-life devices to support applications such as embedded highway sensors, parking sensors, and safety equipment. This might possibly be the true ‘revolution’ of 5G for the public.

Antennas galoreFigure 1. Antennas galore

The IEEE has a 5G track that oversees the direction of future developments that support 5G targets. These include 802.11ax and 802.11ay (WLAN), 802.15 (short-range technologies), and 802.22 (fixed wireless broadband).

How Much Faster Will 5G Be?
But will 5G be 10x or 100x faster? I’d bet it will be 10–on a good day. The only 5G smartphone currently available is offered by Verizon in the form of the midrange Motorola Moto Z3 handset, plus the 5G Moto Mod that went on sale in early April. The Mod costs an extra $200 and contains four millimeter-wave antenna array modules for 5G reception. A reporter with checked out the device in Chicago and was able to get 573Mbps download speed in some locations. Upload speeds were around 24Mbps. But that high-speed connection was very hard to find while moving through neighborhoods downtown, and was not nearly as available as Verizon had advertised. That is a 10x speed improvement over 4G. However, ping tests of that same Chicago phone showed around 20ms latency–no faster than 4G–and latency reduction, to maybe 1ms, is supposed to be the really big thing for 5G.

Samsung's Galaxy S10 5G smartphone is said to be shipping on May 16, 2019. Let’s see what its performance is like. Apparently, this handset will use the 600MHz band, along with 28GHz and 39GHz bands. Verizon has started accepting pre-orders for the $1,300 phone.

With more than three million 4G base stations, China’s big three mobile operators account for the lion’s share of the global 4G total. In the United States, over 90% of adults and more than 50% of children have cellphones. In 2017, there were 323,448 mobile wireless cell sites in the United States. Worldwide cellphone usage is said to surpass five billion. And those numbers are expected to grow. With so many mobile phones in use today, cell towers are ubiquitous, and more are springing up every day.

Are Health Concerns Over 5G Warranted?
Although the FCC permits an effective radiated power (ERP) of up to 500 watts/channel (depending on the tower height), the majority of cellular sites in urban and suburban areas operate at an ERP of 100 watts/channel or less. The towers normally have three sides and serve three transmitters. But a typical LTE site today would have 2x2 MIMO and two carriers (20MHz frequency bands) on each sector, which makes a total of 12 TRX chains. Energy use is anywhere between 250W and 500W per TRX chain.

Scientists are cautioning that before rolling out 5G, research on human health effects needs to be done to ensure the public and environment are protected, even though these cellular signals are non-ionizing radiation. Radiated power limits recommended by the International Commission on Non-Ionizing Radiation Protection have been lowered (in a draft proposal) to 0.08W/Kg-1 for whole body.

What Is EMF?
I like the (rather lengthy) technical description of this EMF given in the ICNIRP Guidelines, which states the facts and indicates the complexity level of RF interactions:

“Radio frequency EMFs consist of rapidly oscillating electric and magnetic fields…As the field propagates away from a source, it transfers power from its source, described in units of watts (W), which is equivalent to joules (J, a measure of energy) per second. When radio frequency EMF reaches a biological body, some of its power is reflected away from the body, and some is transmitted into it. This results in complex patterns of fields inside the body that are heavily dependent on the EMF source and frequency, as well as on the physical properties and dimensions of the body. These…induced electric fields…can affect the body in different ways that are potentially relevant to health.

Firstly, the induced electric field in the body exerts force on both polarized molecules (mainly water molecules) and on free moving charged particles such as electrons and ions. In both cases the EMF energy is converted to movement energy, forcing the polarized molecules to rotate and charged particles to move as a current. As the polarized molecules rotate and charged particles move, they typically interact with other polarized molecules and charged particles, causing the movement energy to be converted to heat. This heat can affect health in a range of ways. Secondly, if the induced electric field is strong and brief enough, it can exert electrical forces that are sufficient to stimulate nerves, or to cause dielectric breakdown of biological membranes, as occurs during direct current (DC) electroporation (Mir, 2008).”

5G cells mix with the othersFigure 2. 5G cells mix with the others.

RF Sources Are All Around Us
There are a lot of RF sources around. Some, like radio and TV, have been around since 1900. We have not seen a bunch of health problems in people living near these RF sources. For example, body scanners at the airport use millimeter waves. The ERP of an FM radio station is typically 5KW to 40KW.

Radar is a common source of RF energy, in frequency bands from 4GHz to 40GHz. It is not uncommon to have power levels from 50KW to over a MW – but they are pulsed with a low duty cycle. A duty cycle of 1% still yields a 1KW average power, and people on aircraft carriers, in airports, and at a dozen other types of facilities have been working around them for many years. The family boat has an x-band (10GHz) or S-band (3GHz) radar that is putting out at least 1KW as it spins around above your head.

A vintage cellphoneFigure 3. A vintage cellphone.

When smart/wireless electric meters were first being installed, there was huge pushback from some homeowners in the county I live in because of a fear of being harmed by the RF waves (and because they did not have an option of staying with the old manual meters). The RF from the meters was said to cause headaches, digestion problems, memory loss, and an increased chance of getting various cancers.

I looked into these ‘smart’ meters at that time. The PG&E SmartMeters from the electric company in my region transmit at less than 1W into the antenna. The device relays data periodically to a nearby convergence point, with each RF transmission lasting from 2 to 20 milliseconds. These intermittent signals total about 45 seconds per day. Any person who is troubled by this level of RF is going to be in terrible shape when they walk into the local coffee shop with its Wi-Fi router handling six laptops and five customers using their cellphones. But the meters made some people ill.

And, cellphones have been in mass operation since about 1998. You can see from Figure 4 that there is no corresponding rise in brain cancer to this usage. Additional data shows a flat brain cancer rate through 2016 in the U.S.

However, recently there has been data released showing a significant rise in brain cancer rates in England–in fact more than doubling from 1996 to 2015. Their rate of all brain tumors is staying about the same, but the rate of cancerous tumors is rising (and non-cancerous going down)–according to this data. The cause could be quite a number of things, but it bears watching.

A vintage cellphoneFigure 4. (A) Number of wireless phone subscribers in the United States, 1984–2006.
(B) Age-adjusted incidence of brain cancer, 1984–2006. Graphics courtesy of the National Library of Medicine.

A few epidemiology studies have reported higher rates of tumors inside the skull among people who have used cellphones heavily for 10 years or more. Of particular concern are benign Schwann cell tumors called acoustic neuromas, which affect nerve cells connecting the inner ear with structures inside the brain. These growths can, in some instances, progress to malignant cancer. But other studies have found no evidence of acoustic neuromas or brain tumors in heavy cellphone users.

Data in two studies from India indicated that persons who lived near mobile phone base stations had higher frequency of micronuclei, lowered antioxidant levels, and DNA damage in their blood lymphocytes. (Zothansiama 2017; Electromagnetic Biology and Medicine)

RF Exposure Health Studies
The U.S. National Institute of Health, National Toxicology Program has done two significant studies of rats and mice subjected to cellular modulated RF, TR-595, and TR596. A two-year study of 240 rats were exposed to whole-body GSM or CDMA-modulated 900MHz cellphone RFR at power levels of 0 (sham control), 1.5, 3.0, and 6.0W/kg, for about 18 hours/day, every day, with 50% on/off cycling. In females, there were no exposure-related effects on pregnancy status, maternal survival, or the percentage of animals that littered; however, mean body weights were significantly lower than those of the sham controls, at most time points, in the 6W/kg group.

At the end of the two-year study, an assessment showed that malignant schwannoma of the heart in the 6W/kg male group was significantly increased. At the 0, 1.5, 3, and 6W/kg RF levels, there were 0/180, 1/180, 0/180, and 5/180 instances of this condition. Five out of 180 is 2.8%.

There were some interesting inconsistencies in the findings. For example, for “adrenal medulla: benign, malignant, or complex pheochromocytoma,” the rates were 11/88, 24/90, 28/89, and 14/87–so the highest exposure had lower rates than the two lower exposures. This phenomenon occurred in a number of areas. Also, the study found some “DNA damage” in the hippocampus of males in the CDMA-modulated group only, not the GSM. No females at all exhibited this toxicology. The RF levels for the DNA analyses were not noted. Another interesting data point was the survival rates were much higher for the group with the highest RFR exposure (25/90, 45/90, 50/90, 60/90).

A study by the Ramazzini Institute (Bologna, Italy) of rats that were exposed to a 1.8GHz GSM modulated far RF field of 0, 5, 25, and 50V/m for 19 hours a day has gotten a lot of notice. Researchers estimated whole-body specific absorption rate (SAR) as 0.001W/kg at 5V/m , 0.03W/kg at 25V/m, and 0.1W/kg at 50V/m. All of these levels fall at or below U.S. standards for cell towers. The study found incidences of heart schwannomas in males at the highest dosage level (much like the NIH study, above). This study is in some dispute because of some data misgivings and the apparent fact that the animals all received a single low-dose of gamma radiation early in life, for some strange reason.

The World Health Organization’s International Agency for the Research on Cancer (IARC) has also been studying the potential health effects of exposure to RF radiation. WHO lists RF radiation as a part of Group 2B - Possibly carcinogenic to humans. For reference, coffee is also Group 2B listed. ‘Possibly carcinogenic’ means we should keep a close eye out for possible health issues–and indeed we should.

Organizations that address the potential health effects of RF radiation, include:

  • Occupational Safety and Health Administration (OSHA)
  • Federal Communications Commission (FCC)
  • World Health Organization–International Agency for Research on Cancer (WHO/IARC)
  • Centers for Disease Control and Prevention (CDC)

All electronics engineers should be aware of issues related to the safety of things we are developing. We don’t have any badges and we can’t (and don't want to) go around policing things, but we should be cognizant enough to be able to state some relevant, helpful facts in response to any inquiries. The safety, necessity, and practicality of cellular communications falls under this banner. It is not an easy subject to tackle and it’s certainly one area where care must be taken. After all, some communities are clamoring for 5G, while others are saying they don’t trust it and don’t want it.