Which Phones Make Your Head Glow?

[Ed Hansberry]

<a href="http://www.fcc.gov/oet/rfsafety/sar.html">According to the FCC</a>, a phones SAR rating is "a value that corresponds to the relative amount of RF energy absorbed in the head of a user of a wireless handset. The FCC limit for public exposure from cellular telephones is an SAR level of 1.6 watts per kilogram (1.6 W/kg)" I'm not really sure what that means. Per kilogram of what? Phone, brain matter? It would seem having a fat head would make you less susceptible to this radiation which, by the way, has not been shown to have any harmful effects on your gray matter. The safety of those around you while you drive and talk, however, is not in any way assured.<br /><br />So, back to the point of this article, which is to show you a bunch of numbers so you can go "hmmm..." but not really glean anything useful unless you know the difference between an Ohm, Watt, Volt, Amp and know how to measure all of them in picoseconds. (The particularly astute among you will know I made some of that up.) CNet has made a list of the <a href="http://msn-cnet.com.com/4520-6602_7-5020356-1.html?tag=lnav">lowest SAR rated phones</a> in the US, which includes a few Windows Mobile devices, and the <a href="http://msn-cnet.com.com/4520-6602_7-5020357-1.html">10 phones voted most likely</a> to to cause you to lose memory as cells are slowly cooked by the low powered microwave you talk on every day, most of which are Motorola phones, and one Palm Treo 650, all scoring above 1.50 striving to hit the maximum "safe" level of 1.6 W/kg. Other phones of interest:<br /><br />• <a href="https://gullfoss2.fcc.gov/prod/oet/forms/blobs/retrieve.cgi?attachment_id=594776&native_or_pdf=pdf">Palm Treo 700w</a> - 1.26<br />• <a href="https://gullfoss2.fcc.gov/prod/oet/forms/blobs/retrieve.cgi?attachment_id=594776&native_or_pdf=pdf">Palm Treo 700p</a> - 1.48<br />• <a href="https://gullfoss2.fcc.gov/prod/oet/forms/blobs/retrieve.cgi?attachment_id=555665&native_or_pdf=pdf">HTC Wizard</a> - Way low, three values given at .233, .184 or .079, depending on what radios are on.<br />• HTC Universal - Unknown. Not for sale in the US so they didn't need FCC approval I guess. No telling what that beast is pumping out. ;)<br />• <a href="https://gullfoss2.fcc.gov/prod/oet/forms/blobs/retrieve.cgi?attachment_id=562893&native_or_pdf=pdf">HTC Tornado </a>- Levels between .59 and .83<br /><br />So, I have no idea what all that really means, and be honest, you don't either, but those PalmOS devices sure do crank out the juice. 8O That's my new leave-them-bewildered comment at the counter as someone reaches for a Treo 700p. "Hey, great device, but it approaches the maximum safe radiation dose allowed by the FCC, and almost 20% more radioactive than this Treo 700w, and the 700w can actually multitask." :devilboy:

[xdev]

"that beast" is pumping out 0.172

[Mick]

The PPC-6601 (WM2003SE), which is what I have, is listed as having the lowest SAR. It also has better reception than any other Sprint phone I have owned, which suggests that you do not need to have a high SAR to have good reception.
Mick

[sooby77]

I think it is typical that CDMA phones do pump out those radiation. That's the characteristics of the transmiision network.

[Mark Johnson]

This issue is why I'm shopping for a bluetooth headset. I figure that even if Samsung has set the power level all the way up to "Deep Fry" I'll be OK if it's not actually next to my head...

[Janak Parekh]

I think it is typical that CDMA phones do pump out those radiation. That's the characteristics of the transmiision network.
Hmm? CDMA, if anything, tries to reduce power output to the minimum required. If you look at the ten-highest CNET link, many of the phones listed are GSM.

--janak

[rich2741]

First, as Janak pointed out, a lot of modern cell phones tend to be intelligent in their output levels (dead batteries drive paying customers nuts just as much as no connection [same result]). Just what's needed to do the job; ramp up or down as needed.

Second, the highest output levels (ERP: Effective Radiated Power) of these phones are nada in reality for adults. Try standing atop a busy RF site and getting your PDA wiped clean from the saturation of RF energy; that's something to worry about. The levels are set so as not to adversley impact children (who shouldn't need/have one anyway, but whatever) who have developing immune systems. Most people don't even realize their phones are working all the time; as they pass from cell-to-cell the phone is polled by the site, even when you are not making a call, but the power use is very low.

Third, the whole trick to cell phone systems is reception sensitivity and selectivity, not transmitter power. The receivers in our cell phones and at the cell sites are truly modern marvels. Between that and the uber-plotted site locations for maximum connectivity for the biggest mass of people, you should all be very thankful.

Lastly, GSM is the way to go when selecting a phone. Oh, and I wouldn't consider ANY cell phone service to actually be called 'microwave' [think about the nomenclature] transmissions, more like 'point-to-multipoint UHF'.

Anyway, no one is getting their brains zapped by cell phones. The energy and frequency just aren't enough.

Richard Driskill
Electromagnetic Spectrum Authority, retired

[Sven Johannsen]

Oh, and I wouldn't consider ANY cell phone service to actually be called 'microwave' [think about the nomenclature] transmissions, more like 'point-to-multipoint UHF'.

Oh, I don't know about that. It's reasonable well accepted that microwave, when it comes to RF thought, spans 300MHz to 300GHz, which does span UHF, SHF and EHF. UHF being at the bottom there. Of course when most folks think of microwave they think of the oven which operates at around 2.4GHz, which would be UHF if you made a radio at that frequency. My JasJar has an operating mode at 2.1Ghz, not that far of of what we use to cook stuff. Even the low end 850MHz is within the label microwave.

Not that I am concerned about my phone's radiation, but calling it microwave, though capitalizing on the connotation, is accurate. I'd just file this away so if I have a problem with cancer at some point, I have someone to sue ;)

[Cybrid]

This issue is why I'm shopping for a bluetooth headset. I figure that even if Samsung has set the power level all the way up to "Deep Fry" I'll be OK if it's not actually next to my head...
And what makes you think that a BT radio (2.4Ghz) is just more than slightly better? Where-as a phone might at some point be returned to your belt when not in use...(lead jockstrap anyone?) you are keeping the head set in your ear semi permanently...lower levels but more prolonged exposure...


The above is pure sarcasm. Meant to amuse but not much else, it should in no way ever be considered scientific or even objective.

[eagle63]

Lastly, GSM is the way to go when selecting a phone.

huh??

[rich2741]

Just by chance I happened to revisit this thread! Cool, I get to clear up some misconceptions and a personal selection reason...

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Regarding the term "microwave" -

The technical use of the word "microwave" has been bastardized by the unknowning [just like the technical term "Gigabyte" (decimal / base 10) which equals 1,000,000,000 bytes] -versus- "Gibibyte" (binary / base 2... which is the number system used by computers) which equals 1,073,741,824 bytes], and the genie is not likely to be placed back in the bottle, but here goes anyway.

"Microwave" is a indication of a energy wave's physical size in the electromagnetic spectrum.

The wavelength of RF energy is defined in metric; normally expressed in megameters (300 Hertz), myriameters (3 kiloHertz), kilometers (300 kiloHertz), hectometers (3 MegaHertz), dekameters (30 MegaHertz), meters (300 MegaHertz), decimeters (3 GigaHertz), centimeters (30 GigaHertz), millimeters (300 GigaHertz), micrometers (300 TeraHertz), nanometers (300 PetaHertz), angstroms (3 ExaHertz), picometers (300 ExaHertz), X-units (3 ZettaHertz), and femtometers (300 ZettaHertz).

It can also be expressed in terms of time passed in the numbers of waves passing over a given time period, and is refered to as "Cycle time" or cycles per second (CPS), but most commonly known as "frequency", which is expressed in Hertz: second (Hertz/Hz), millisecond (kiloHertz/kHz), microsecond (MegaHertz/MHz), nanosecond (GigaHertz/GHz), picosecond (TerraHetz/THz), femtosecond (PetaHertz/PHz), attosecond (ExaHertz/EHz), zeptosecond (ZetaHertz/ZHz), and yoctosecond (YottaHertz/YHz).

When we talk about the 'very small' (not a technical term!) wavelengths, we express it in "angstroms" (100 millionths of a centimeter). As an example, the frequency of 983.5710564304461 MHz is exactly one foot in size which equals 47244094488.0 angstroms. It's simply easier to use numbers with a smaller metric scale in that size spectrum, and that is why angstroms are delegated to use only the high end of the spectrum.

But... the transfer of technical nomenclature to the public was dumbed down because it either sounded cool to relay by a quasi-literate tech, or dreamed up by some marketing slug. Furthermore, wavelengths were once commonly referred to in banding segments like - microwave, shortwave, mediumwave, longwave, and in a technical sense was ambiguous and even incorrect.

So... the term "microwave" is actually technical. "Micro" denotes a specific length, either in time or space, and refers to "micrometer". In this case it is attached (literally) to the word "wave", which tells us that we are measuring a length in the domain of physical distance between two points along the basepoint (node-to-node-to-node).

Ergo, the technical microwave (being a micrometer wave; since all measurements are based upon the meter in this field) segment resides between 300 TeraHertz and 299.999999999999999 PetaHertz, which starts in the area of infrared LASER's and concludes in the area just beyond soft X-rays.

Is this going to change the use of the word in the common domain? Nope. But now you know.

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Regarding the power level of Bluetooth -

The name Bluetooth is taken from the 10th century Danish King Harald Blatand - or Harold Bluetooth in English. It is a 2.402 to 2.480 GHz (79 hops, 1 MHz steps) WPAN using GFSK with a nominal asymmetrical throughput of 728 kbit/s (or 432 kbit/s if symmetrical) with a variety of link ranges -
Class 3 (short): 10 centimeters (3.937007874 inches) [ 0 dBm]
Class 2 (ordinary): 10 meters (32.80839895 feet) [ 4 dBm] (which is 1mW, with auto-reductions via RSSI)
Class 1 (long) 100 meters (328.0839895 feet) [20 dBm].

1 mW will impact zip. It is so weak, -it- can be effected by other waves.


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Regarding GSM as the selected phone system -

The comment meant that out of any of the common cellphone services available, I'd recommend GSM because it is functional in the majority of nations around the globe which offer cellular service. Either a (cellphone) system works (according to a Standard) or it doesn't, but nothing is perfect.

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I hope this helped take a little confusion out of the points raised.

Richard Driskill
Electromagnetic Spectrum Authority (retired)