The 5G Deployment Challenge - Part 4 in a Series

IEEE Future Networks Podcasts with the ExpertsFNPodcast INGR 5GDeployment Part4 Health ieeetv
An IEEE Future Directions Digital Studios Production


The 5G Deployment Challenge - Part 4 in a Series: A Panel Discussion on the Health and Safety Concerns about 5G

5G promises to usher in a new era of connectivity and productivity, but is it safe? Misconceptions about the health impacts of 5G abound, even some that imply the technology is associated with the COVID-19 pandemic. Episode 4 of “The 5G Deployment Challenge” brings together a panel of industry and technology experts including David Witkowski of INGR, and William F. Hammett and Rajat Mathur of Hammett & Edison. Our panelists offer an in-depth exploration of 5G-related health concerns, and apply a scientific perspective to the question of electromagnetic safety of cell towers, wireless installations.


Click here to listen. 
Click here to download. 


Subscribe to our feed on Apple Podcasts, Google Podcasts, or Spotify


Subject Matter Experts


DavidWitkowskiDavid Witkowski 
IEEE Senior Member
Co-chair, Deployment Working Group, International Network Generations Roadmap (INGR)
Founder & CEO, Oku Solutions LLC
Executive Director, Wireless Communications Initiative at Joint Venture Silicon Valley


William Hammett ProfileWilliam F. Hammett
President, Hammett & Edison




Rajat Mathur ProfileRajat Mathur
Vice President, Hammett & Edison





Podcast Transcript 

Intro: Welcome to the IEEE Future Networks Podcast Series – Podcast with the Experts, an IEEE Future Directions Digital Studio production. Despite 5G's potential and favorable economics deployment of the technology is proving challenging for a variety of reasons. In this episode, David Witkowski, Co-chair Deployment Working Group, INGR leads a discussion with Bill Hammett, President of Hammett & Edison, along with Vice President, the company, Raj Mathur. They share their insights on 5G deployment challenges, and offer possible solutions and building out the next generation wireless infrastructure.

David Witkowski: Hello and welcome to the podcast. I'm David Witkowski, the founder and CEO of OKU Solutions, and the Chair of the Deployment Working Group for the IEEE Future Networks Initiative. Today we're going to be talking about electromagnetic safety, RF safety, and how it applies to the deployment of cellular infrastructure in our society. I’m really pleased to be joined today by two people who have a depth of knowledge in this topic – William F Hammett is the President of Hammett & Edison, and Rajat Mathur, who's the Vice President of Hammett & Edison. Hammett & Edison is a consulting firm that works with municipalities, and with the industry to bring science and fact to the topic of electromagnetic safety of cell towers, wireless installations. Rather than try to introduce them and their storied resumes, I'm going to let them do that themselves. Bill, why don't you go ahead and tell us a little bit about yourself.

William (Bill) Hammett: Thank you, David. I'm a registered professional engineer in California and in other states as well. I manage a firm of 18. We're located in Sonoma in the San Francisco Bay Area, and a regular part of our professional practice is the calculation. the measurements and the mitigation where it's appropriate of radiofrequency exposure conditions. That's been my principal focus for 35 years and in that time we've done more than 20,000 site evaluations and McGraw Hill has published my book on this topic. As engineers, our job is really straightforward, what are the exposure levels, and how do they compare to the standards. Since we deal just in facts we work across the field, consulting for wireless carriers for cities and counties, for broadcast stations, and for private landlords.

David Witkowski: Thanks very much. Just for the purpose of the audience can you mention the name of your book, please.

Bill Hammett: Yes, the, the book has Radiofrequency Radiation Issues and Standards. Okay.

David Witkowski: Raj, why don't you go ahead and tell us about yourself.

Rajat (Raj) Mathur: I'm David great to be on this podcast. I'm really excited to talk about radiofrequency exposure and being with Hammett & Edison for 19 years now, like Bill, I'm a licensed professional electrical engineer in state of California. I have a master's degree in electrical engineering. I'm an active member of IEEE ICES (International Committee on Electromagnetic Safety), and National Committee on Electromagnetic Safety. ICES sets standards on radio frequency exposure, and I'm sure we'll talk more about that as we talk about RF exposure.

David Witkowski: Why are cellular sites generating health concerns? We know that even going back to the early days of cellular, there have been concerns about this. So the reason that we're talking about this topic today is because there's a public perception among some people that 4G and especially 5G technologies will have significant impacts on their lives specifically around their health. And I think it's notable that this has been a challenge in the industry since the early days of cellular. Why are people concerned about these new technologies what is generating that level of concern?

Raj Mathur: I think you're right about it going up and down and the concern, and generally tends to match the release of newer technology. So, in my experience when 3G or 4G was released, there was an uptick in concern regarding radio frequency exposure, and we're certainly seeing that now with 5G. I think there might be several reasons why that's happening. Maybe there's not one clear answer but maybe several things that could point to it. Specifically with 5G, it just so happened that at the same time as 5G was being developed and deployed, the FCC released, or made available, a bunch of frequencies, millimeter wave frequencies. These are frequencies that are generally higher in frequency than six gigahertz. And those frequencies, have been in use. They’re used in airport scanners they’re used by the police in speed detection and automobile collision detection, but this is probably the first time that these millimeter wave frequencies will be used for coverage purposes. Now it's important to distinguish millimeter wave and 5G there. 5G doesn't have to be deployed on millimeter wave frequencies, and we can talk more about that, but that may be one reason why there's public concern around 5G, is that really the concern is for these new millimeter wave frequencies. Another reason might be that there's just a lot of information on the Internet. Right before this podcast I did a quick search on 5G health, and there were 573 million hits, and some of that is good information, some of that is not, but it's all there and it's readily accessible to anybody. And my last point on this would be that with 5G, and this actually started maybe a little bit before 5G was being deployed, is you’re starting to see base stations go from being on taller towers and on rooftops of commercial buildings to smaller lower power sites on utility poles or light poles in residential areas sometimes. And what that does is if you are living on your residential street, you may have had a base station a couple blocks away on a commercial building, and you may know nothing about it. But now, and maybe in front of your home or on your street, now there's a proposal for a small cell, a base station on a utility pole let’s say, and now you get more active you get more interested in what is this thing why is this thing and that sort of dovetails back into going and doing Google searches, and seeing what's there and you know that brings up all kinds of information.

David Witkowski: So I definitely agree with what you've said, which is to recap one. 5G is often associated with that millimeter wave technology but in fact 5G could conceivably. In fact, we're seeing that now where it's being deployed in place of or in parallel with existing low band below one gigahertz mid band between one and six gigahertz sites that have been that have been there in some cases for 20 years, and 5G can be applied to those frequencies. And of course, engineers, know that modulation does not affect the potential health impacts. It doesn't matter if an FM transmitter has a safety zone around it where you shouldn't get closer to the antenna than a certain number of feet. It doesn't matter if that FM transmitter is playing Metallica or Mozart, the health effect is the same, the modulation has nothing to do with 5G is, is that it's modulation. At least when it comes to the air interface. So the other thing that I think you said that is very true is that because the network has been densified to provide more resources for subscribers and of course our use of cellular technology is increasing exponentially and shows no sign of slowing down the resources have to be placed closer to the users in order to provide that level of performance that people are coming to expect. So let's talk about the concerns that people have. So there are concerns about EMF health effects. And, of course, there is a safety standard, which implies that there are some effects that are instituted and guidelines that come out from the IEEE C95, which I know Raj you work on that IEEE C95 standard. What is real in these concerns and what isn't real?

Bill Hammett: Well the concerns are personal, and people are concerned in some circumstances about their own safety. There’s a couple of different ways to answer that question. In my personal and professional view, what is real, is anything below the standard, whether it's the IEEE standard or the ICNIRP standard in Europe. If exposure levels are below that standard, I think there is no health effect. I understand the standards, and the research that went into them, and the conservative nature of the safety factors. So I don't think there's any real basis for a concern if it's below the standards. Some people feel that the standards are inadequate. They may feel that they themselves are personally susceptible or particularly sensitive to electromagnetic energy, and it's not our place to tell them that, that they don't feel what they feel is true. Our role is to lay out the facts, explain how the standard is set and what it implies. And that's kind of a distinction for what is real. That is compliance with the standard, and what isn't is addressing how far below the standard people really should be concerned. There are a number of outfits that will use measurement equipment that isn't even calibrated or won't even go up as high as the standard itself, they're measuring very low levels, but they are triggered to be alarmist that is at low levels, hundreds or thousands of times below the standard, they'll still register bright red lights or top out. And this just exaggerates people's concerns and I think in terms of the standard what they're measuring what they're purporting to measure, just isn't real. Because it's all well below the standards.

David Witkowski: Having looked at the equipment that is used for measuring this and having worked on the test and measurement industry, myself, there's a huge difference between a $6,000 piece of test equipment that has a NIST traceable calibration and $125 EMF meter that you buy off of Amazon or in Home Depot. Could you describe for us what the margin is between where an effect can be measured on the human body and where the safety guidelines are set.

Raj Mathur: The FCC public limit, and the public limit for all these standards that Bill was talking about (IEEE and ICNIRP) is set with a safety factor of 50 – five zero. So, the first effects are observed at levels that are 50 times higher than the standard. And I want to just ask the question because I think it's a reasonable question, what are those effects that are observed at levels, 50 times higher than the standard? And that effect is heating, there's a one degree rise in temperature at those levels. And there’s an example of how that's actually put to use for us is a microwave oven where you have extremely high radio frequency levels inside a microwave oven. And those generate heat by vibrating the molecules generally the water molecules in the food. And that's the mechanism that heats up your food. So that's an example of what happens in extremely high radio frequency exposure. Now relating that to base stations that we're talking about are levels that ground and people's homes that we typically measure to be less than 1% of the FCC limits so that's 100 times below the FCC limit. Remember I said that the first effects were at levels, 50 times, above the limit so there's this 50 times safety factor, plus levels are 100 times below the limit so you have this massive margin in place for what people normally experienced in their day to day lives was where the first effects were observed.

David Witkowski: The margins that you describe are certainly large I think. I think an analogy probably helps here and I've used this analogy myself in some of the conversations that we've had with local governments. Imagine a speed limit on a freeway is 65 miles an hour. So we would say that that's the safe speed at which you can drive on that freeway and know that you're going to be okay. 50 times below that is 1.3 miles per hour. So we would be imagine getting on the freeway and driving 1.3 miles per hour because you have that margin that you've inserted in that. Is that a fair way to look at that? Do you think that's a reasonable analogy.

Raj Mathur: I would maybe change it slightly to say that if your studies show that the safe speed is 65, miles an hour, then you are setting a speed limit of 1.3, because that's sort of what we're doing, we're, you know we're, there's all these studies that show. Okay, what's the safe level, and then you apply a 50 times safety factor. So 65, miles per hour is what your studies show is the safe speed limit, and then you set the speed limit as at 1.3 miles an hour.

David Witkowski: So let's talk about the history of research that's been done on the effects of electromagnetic fields on living things. Bill, can you give us the history. How long has this been going on? How how many studies have been done, etc?

Bill Hammett: Sure, it's, it's, it's a good question, and it's remarkable how far back, people have been assessing and have been aware of the potential for danger at high levels. Radar in the early days of that following World War Two were a common source of high magnitude fields, and the Navy, I know did a lot of research on that topic because they had personnel working around radar facilities and wanted to know and so they started developing standards. ANSI the American National Standards Institute actually had a 1974 standard that was one of the precursors of what we have today. So it's been an actively studied field. So the research has been done is extensive and research for quality needs to really have two impacts one is it needs to be peer reviewed where a researcher will publish all of this data that's collected from the experiments and that allows other independent people to look at the data and see if they can draw the same conclusions from the same data. So that's a peer review process. Replication is the other aspect where one researcher in one institution may find what he thinks is a causal relationship, but there are lots of extraneous factors you can't account for so until another researcher in some other institution with a different set of extraneous factors they can't control for finds that same causal relationship, then it starts to have some scientific merit. So single studies are interesting, but it's only in collection with other studies seeking that the same type of investigation that you get scientific merit coming out of it to the standard setting bodies can use for establishing their standards.

David Witkowski: That's really interesting and I think that's probably one of the biggest challenges that we faced in talking to the public and to local governments, about electromagnetic safety which is understanding the difference between correlated data and causal relationships. You know there's a great book called Spurious Correlations that came out a few years ago that has a lot of funny correlations in it. You know the divorce rate in Maine correlates at 99.26% with the per capita consumption of margarine in the United States. Divorce rates in Maine and margarine are not causally related but the data is correlated but there's no relationship between those. And I think with the general public and especially with non-engineers and non-scientists, it becomes really important for us to be able to explain the difference between correlation and causation which can be a bit challenging. Research on this topic of course is ongoing. The standard for this is in fact the IEEE C95.1 standard which was just updated in 2019, Raj you're directly involved in that standard work. Could you give us an overview of the 2019 update and talk about C95 in general and how long has it been going on and what are the findings from shooting C95.1?

Raj Mathur: I have been a member of ICES for about 12 years now. You mentioned that there was a new release of the standard called C95.1, and the new release was last year in 2019, the one before that was in 2005 2006. So it wasn't involved in that, but I was extensively involved in C95.1 in 2019. And there's also a bunch of associated standards that go along with that. I'm involved with those too. The general process is that there's a literature review team that's sort of a subset of the members of ICES and these are folks who are involved in research actively involved in research, professors and researchers in the field. And so as Bill mentioned they're looking through these studies looking at peer reviewed studies replication. And then when we need which is typically twice a year, and sometimes email exchange in between they'll give us an overview off. What the latest has been in approximately the last six months, and we use that research and I should say that all these studies are at least the names and the abstracts are available for people to look at the IEEE ICES website, which lists the names and abstracts of all these studies in its standard but also, like I said on the website. And then the World Health Organization has a database of these studies as well. So if you look at that there's in the IEEE website there's almost 4,000 studies. And that's the basis for the standard and it is really quite extensive the standard I should add is available for free to download. And so I encourage your listeners to download standard. It is a long extensive and technical document. But there are certainly a bunch of sections particularly where the rationale is described where they go into real detail on all the elements that we'll look at what the research shows what the findings are and what the conclusion is and the whole bunch of studies on various aspects of radio frequency exposure, as cited in the at the end of the standard. I should add, there's other standards as well, which we've touched on the FCC standard. And there's the European standard which is called ICNIRP. And that also has been adopted by a number of countries outside Europe. Those I would say on the three big standards.

David Witkowski: And Raj, correct me if I'm wrong, but I believe me the FCC isn't doesn't have a lot of engineers working for them in fact it's mostly lawyers. I mean the IEEE is really the basis of the FCC’s standards, they derive their standard from C 95, is that correct?

Raj Mathur: Yes, partially. The FCC standard was originally set in 1996, and it was actually a congressional act, 1996 Telecommunications Act that asked the FCC to set limits, which they did. And what they did was they took two standards at the time. One was the IEEE standard, I believe it was the 1992 standard that would have been active at the time. And then another standard NCRP (National Council of Radiation Protection). Those were the two major standards, scientific standards in existence at the time. And what the FCC did was they sort of used both those standards to create the FCC standard. Since 1986, the FCC and most recently as late last year said that they've looked at the existing research on existing standards, and they find no basis to change their limits. The since that time the IEEE standard the basic restriction of the IEEE standard – the 50 times safety factor that we spoke about, is unchanged. And so, that's, I believe what the FCC is looking at that the basic restriction hasn't changed. And so they have no basis to really change their standard.

David Witkowski: So one of the things that I think causes people to react negatively to electromagnetic radiation is the use of the word radiation, especially for older people who grew up during the Cold War, they remember the duck and cover drills, the threat of Soviet nuclear weapons and all that. That nuclear age, if you will, I think, firmly cemented radiation, and the word radiation as a negative thing in people's mind. But when we talk about electromagnetic radiation. There's a difference there. Could you describe for our audience the differences between electromagnetic radiation, and these types of nuclear radiation that they may be more familiar with?

Bill Hammett: There's a huge spectrum of electromagnetic energy electromagnetic radiation and radiation as the term, just means dispersal. If you drop a pebble into a pond, the energy from that action of breaking the surface will create ripples. And those ripples radiate out from where the stone was dropped. There's no connotation to the word radiation that should be alarming, it is just a dispersal of energy. But I do want to talk about the electromagnetic spectrum which has a broad spectrum that goes from direct current is at zero and electric power coming out of the wall socket is plus minus plus minus plus minus 60 times a second. That's 60 cycles, we call it 60 hertz. That's the ELF (Extremely Low Frequency) for electric power lines running overhead operate at 60 hertz, so wavelength at 60 hertz is here to New York. I say here I'm in San Francisco, but 3,000 miles is one wavelength at power frequencies. So we don't deal in that frequency range we deal up when you get higher frequencies in radio frequencies. It's a big chunk of the electromagnetic spectrum that is good for communications. The atmosphere blocks solar radiation in the frequency range. So it's very useful. AM radio was one of the first applications of radiofrequency commercially that people might recognize a wavelength that had AM frequencies is about 1,000 feet. That includes FM and TV where wavelengths are in the order of 10 feet. That goes higher as well. And it's a packed spectrum of assigned frequencies assigned by the Federal Communications Commission for ship to shore and Aeronautical and Secret Service and police and fire it's a packed with assigned frequency bands, everybody doing their own operation in their assigned frequency bands. Above radio frequencies, is a big chunk of spectrum called infrared, and we use that to control our TVs, you have an infrared controller. If you put it behind the sofa, doesn't work real well. The wavelengths are now getting short less than an inch shorter than that. And the energy tends to travel in a very straight line. And, above infrared is a tiny sliver of this electromagnetic spectrum. We call it light, because our eyes happen to be sensitive to it. Above light is ultraviolet. And when we speak before groups, we always ask, well, what does the ultraviolet do, and people mumble and then somebody will say sunburn. That's exactly right. The ultraviolet, the wavelength is above light is so short that we'll get into molecules and break off electron. That process is called ionization very well understood principle effect of this, the high frequency radiation. During the pandemic now. A lot of people are installing ultraviolet purifiers for air you see it saw a TV special not too long ago about some restaurants putting this in and pulling air over the ultraviolet light in order to disinfect it because the wavelength is so short, it'll get in and break off electrons in the, in the virus or bacteria. Pools will often use ultraviolet light for disinfecting the pool water. Above ultraviolet is X-Rays. And I asked the question, what do they do when you go to the dentist and take an X-Ray. Well they put a lead shield over you because they know that's causing a little bit of damage and they want to minimize the amount of damage and, of course, where do they stand when they push the button. They stand around behind the wall to get even more protection. So those are examples of ionizing energy, where the, the nature of it is to get into molecules and break off electrons, and that causes a little bit of damage, and that damage adds up over time. What the carriers are using is not X-Rays, it's not ultraviolet, it's not light, is not infrared, it's down in this big chunk called radio frequencies, where wavelengths are on the order from 1,000 feet down to an inch, and that's a well understood principle. This is non ionizing energy there's nothing dangerous about it, per se. It's just a question of magnitude as Raj described earlier. High magnitudes cause an impact. That's why the FCC and all the standard setting bodies have a 50 times safety factor included for unlimited exposures 24/7.

David Witkowski: Thanks, Bill. That's an excellent overview of how photons and electromagnetic energy work across the spectrum, ranging from power all the way up, beyond visible light to X-Rays. One of the things about millimeter wave that you touched on was that it is very line of sight. And when electromagnetic radiation is line of sight, it tends to not penetrate material very well. Raj, would you please talk about how millimeter wave cellular signals behave and how they're different from the cellular signals that we're used to?

Raj Mathur: If we hone in on the radio frequency bar, which as Bill noted is non analyzing, we have the lower and we've got AM frequencies which travel really long distances and in some cases when the atmospheric conditions are right, they'll bounce off the atmosphere and travel even further. And that's because they have long wavelengths. When you get to the other end of the radio frequency spectrum where the wavelengths are shorter, the signal just doesn't travel as far. In addition, as you noted, David, it can be severely attenuated or its magnitude reduced by things like clothing by foliage, and in some cases even by rain drops, and the upshot of that for the wireless operators, is that the signals just don't go very far and so they need several sites closer together and that sort of touches on what I was talking about, right in the beginning of the podcast, with requiring sites base stations in residential areas and utility poles closer together. The other aspect of millimeter waves related to RF exposure, millimeter waves don't penetrate beyond the upper layer of the skin. They don't get into where our vital organs are. In fact there's a word for it, it’s called the skin effect at these frequencies. It's a surface effect. And so when I talked about the heating, if you had, let's say, a microwave oven that used millimeter waves, just the surface of your food would get heated up, not the inside of your food. And so, microwave ovens actually use the lower frequencies 2.3 gigahertz, because those are able to penetrate into the food and heat it up. Millimeter waves can’t do that just by the very nature of the higher frequency and shorter wavelength.

Bill Hammett: And let me add also to what Raj was saying about the deployment of sites at low elevations for the millimeter waves. Because they don't travel as far they don't put as much power into those bands. We typically see things less than 200 watts peak power out toward the horizon from a pole mounted or whether it's a light pole or utility pole in the millimeter wave bands, so they're building networks for very high capacity, because of the higher frequency and the wide bandwidth that the government has assigned to them, they get a huge data capacity and so the potential for all kinds of new uses is very enticing, but the facilities themselves are not the high power facilities that you see on rooftops or poles or along the freeways, those kinds of facilities. These are low power, short distance facilities that because of their low power are not presenting very large exposure levels in neighborhoods. That plus the inverse square law that we haven't talked about but is really a key factor as well, in terms of the energy dissipating by the square the distance the power drops exponentially, those factors of low power to start with plus the inverse square law makes the exposure levels near these new facilities going in and neighborhoods, as low as they are.

David Witkowski: Thanks both. I very much agree with what you're saying and in fact, recently I had an opportunity to demonstrate it to myself I was in one of the cities in the San Francisco Bay area where they have the millimeter wave 5G deployed. And it was the first time I had a chance to do a speed test on it. And my interaction with this site was very interesting. First of all, when I stood directly next to the pole, I did a speed test and noted that the speed was at a certain level. And then as I moved 10 feet away from the pole I did another speed test and found that in fact it was faster. And of course we know that information throughput and energy are correlated through Shannon-Hartley, which relates the ability to put information through a channel based upon a variety of factors, but primarily driven by the signal to noise ratio. So then, as I moved away from the site, I noted the speed tests were slowing down and then I walked around a corner, and the moment I walked around the corner, the signal was gone. It just completely disappeared. I think you're right in that we do want to talk about the inverse square law. So, Bill, why don't you give us an overview of what that means in the universe square law.

Bill Hammett: The inverse square law simply says that at some distance from a power source, if you double the distance that power is going to go down by a factor of four, two squared, one over two squared, it's going to go down to a quarter of the power. If you go10 times as far away, it's going to go down by a factor of 100, one over 10 squared. So the power level is dropping rapidly the phones the devices don't need much energy to operate they have tuned receivers and are good at picking up the signals. In terms of exposure conditions, the levels are dropping very rapidly. And so that is one of the factors that ensures that these facilities, do comply with the federal standard. The other factor of course is the directivity of the antenna. You mentioned when you're directly under the pole you got a certain amount of speed on the speed test and as you move to a little bit further away from the pole you got higher levels, and that's indeed the case that there's hundreds or 1000s of times less power going down and the rays going out from these antennas they're highly efficient. They want to send the energy halfway out to the next cell site to the next site in the carrier's network. So those factors all work together. Low power to start with, inverse square law and the directivity of the antenna.

David Witkowski: Okay, Bill, Raj. that was an excellent overview thank you for explaining inverse square law. This has been a great podcast I think we've covered a lot of ground today. A lot of good material here I really want to thank you for your time and for the work that you do. Bill, why don't you tell our audience how to get ahold of you if they'd like to.

Bill Hammett: Yes, I'd be happy to and I too enjoyed the conversation today it's a fascinating field. I think we had a lot of good information. We do our role is reporting and explain the facts, and the facts tend to speak for themselves. And so if people are interested, for further information about this or further discussion. We can be reached at our website, which is Always happy to have inquiries. And, again, thanks for the opportunity to participate.

David Witkowski: Thank you. And thank you, Raj for being here today. Are there any resources that you'd like to let the audience know about?

Raj Mathur: I'd like to just reiterate that there's a lot of good information available at the IEEE ICES website, including studies for those interested, there's great information at the World Health Organization site. The FCC has an RF safety page, and ICNIRP, if you're interested in international standards has some excellent information as well.

David Witkowski: Thank you both for being here today and thanks for joining the podcast, have a great day.

Close: Thank you for listening to this edition of the IEEE future networks podcast with the experts. You can discover more about the IEEE Future Networks Initiative and inquire about participating in this effort by visiting our web portal at