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Cell Phones - Analog vs. Digital 173

Posted by Cliff from the "can-you-hear-me-now?" dept.
matth asks: "So which is better? Analog or Digital for your cell phone? The cell phone companies would like you to believe Digital is better... but is it really?" matth makes his, in this article. Would you care to make yours?

"The point of digital is that it takes alot less power to transmit and if you've got 1 bar or 5, the signal should sound the same.. and there in lies the problem.. with the should. With an analog phone as your signal strength begins to go below 1 bar you start to hear static but you can still understand the person your talking to, though you may need to 'yell over the static'. However, with a digital system when the signal fades, there's no yelling because the signal isn't there, and packets that should be getting to your phone, just get dropped. As a result, Aunt Martha's 'Hello' on a crummy analog connection can still be made out.. but on a digital connection of the same strength might sound like 'He...o' with a gap of silence in the middle. (See my Cell-Phone Switch parody commercial on this site for an example if you don't know what I'm talking about).

Cell phone companies are boasting about how digital is good, but is it really? Analog signals work on the 900MHz band, which goes very well through houses, trees, your neighbors dog, etc. Analog works on the 1.9GHz frequency, which does not go through houses, walls, metal, trees, well at all. The question now becomes, why are they moving to 1.9GHz? The signal length is smaller, and therefore antenas on the phones can be smaller without worrying about chopping the signal from it's full height. However, the cell phone companies need to cover the area better for there to be as much coverage, especially in the city where there is lots of Multi-path (bounces and signal inversions), and buildings to go through. This is the same reason that your 900MHz portable (land line) phone will go further then your 1.2GHz portable phone.. (or it should anyway, but alot of companies are making illegal 1.2GHz phones and putting them on the market).

In addition, back to Aunt Martha, as long as her 'Hello' usually sounds like her 'Hello' on a land line, what difference does it make right? Well, unfortunately, the digital standards we have today are from years past. And while they work, they are by no means clear. If you are looking for clarity, you'll want to stick with an analog phone. For data communications, digital is the way to go. Cell phone companies will tell you that if you're in analog you won't get your voice mail notification and such, but the truth is they COULD do it if they wanted to. They just want you to switch over to digital. Why? For one, it takes less bandwidth off of their access points, so they can get more subscribers on per access point. Each analog cell antenna can carry only 56 simultaneous phone conversations, which just doesn't cut it in heavily populated areas. With digital they compress the signal and as a result can get many more people on a sectoral antenna. Digital cell phones use extreme compression of the sound that they transmit. The compression algorithms used are lossy; they're specifically designed around transmission of human voice to human ears, and take advantage of what the human ear will tolerate and what it won't.

What about the pros for digital? Digital is a bit more secure then analog as you can't hear it just by setting a scanner to the correct frequency, you also have to un-encode it from the digital, and smooth the signal out.

On last thing, the digital system works on 1.9GHz... your home microwave works on 2.4GHz.. It's close enough, you still want to hold that phone next to your head? Remeber what happens to an egg when you put it in the microwave, and then decide.

So with all that said, which do I prefer? I prefer the analog since it has better coverage, and the analog phone will keep the connection better in fringe areas. Digital phones are an all or nothing proposition. They either work or they won't. Analog phones can swish and cut out, without dropping the call. What do Slashdot readers use and like and why?"
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Cell Phones - Analog vs. Digital More

Cell Phones - Analog vs. Digital

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  • In a few years, the analog networks will be completely gone. Hell, a good number of phones sold today do not support analog.

  • Analog kills battery life. (Score:4, Insightful)

    by recursiv ( 324497 ) on Thursday January 09, 2003 @08:14PM (#5051438) Homepage Journal
    For all its good points, what's the point of analog if I can't use my phone because the battery is dead?
    • I am not entirely sure that analog by itself uses so much more battery than digital. However, I can only present this piece of anecdotal evidence. My dads old phone was a hybrid that could use either analog or digital. When it could only find analog service, it would use that but it would continually search for digital service because it 'preferred' it. The problem was, digital service was not available in the area. The phone would seek fruitlessly and waste its battery. This was the explanation given to him when he asked why his phone battery lasted so much longer when he traveled into other service areas where digital was available. I have no idea who exactly who told him this. Maybe this was just a lie. The parent post is modded up so people tend to agree that analog phones have worse battery life, but maybe the seeking for digital is the reason and not the power consumption of the technology?
      • no. according to the specifications of my phone (panasonic allure) in standby mode (not talking, but in service) it lasts 7 days in standby mode, and 8 hours in analog.
      • Analog mode transmission at 900Mhz maxes at 3W broadcast compared to a couple hundred mW for most digital phones (they vary by encoding method and distance to tower). Most phones today with analog mode won't get near the 3W output but they will still be several times higher than their digital mode, add to that the fact that broadcasted power does not come linearly and analog mode can easily drain the battery 10X faster than digital mode.

  • 1.9 ghz (Score:4, Insightful)

    by hawkbug ( 94280 ) <psxNO@SPAMfimble.com> on Thursday January 09, 2003 @08:15PM (#5051447) Homepage
    Yeah, I realize that microwaves are 2.4 ghz, etc. Cell phones are 1.9, yes. However, if there is proof that cell phones cause cancer, or some other awful problem - we haven't seen it yet. Does your head warm up when you're on the phone? Yes. Does it harm you? Don't know, and we might not know for some time.

    • Re:1.9 ghz (Score:1, Interesting)

      by Anonymous Coward
      If your head feels warm when you're on the phone, it's only because you're holding a lump of plastic next to it. Try holding a cassette-tape or pocket calculator up to your ear for 10 or 15 minutes and it will get just as warm. Chances are you never noticed this effect before, because sane people don't usually walk around with casette tapes or pocket calculators pressed to their ears.

      --
      Klein bottle for sale ... inquire within.

      • Re:1.9 ghz (Score:1, Funny)

        by Anonymous Coward
        So THAT is why people have been looking at me funny when I go into the Big Blue Room!

        Thanks for the tip!!!

      • Re:1.9 ghz (Score:2, Informative)

        by hawkbug ( 94280 )
        Sorry, but you're wrong - I suggest you read this [cellular.co.za]. The important part for you to read:

        " It concluded that the radio frequency signals emitted by phones generated heat in the brain, but said it was not clear whether this could have other biological effects, such as triggering cancer. "

        When I said your head gets hot, this is what I was talking about. I doubt a tape player puts off enough raditation to heat your brain.
    • Keep in mind that the reason why microwaves heat things up is that they prey on a *specific* resonance frequency for water molecules. Microwaves starting a little ways off of this frequency, to either side, aren't going to vibrate the water molecules and hence not heat anything up.

      This is not to say that the energy carried in the waves can't be turned into heat somehow, but the mechanism that microwaves use to do this just plain doesn't work. You *can't* make a microwave oven in the communications frequencies just by bombarding it with high power microwaves.

      -Jeff

      • Re:1.9 ghz (Score:2, Informative)

        by Anonymous Coward
        While you are correct that 2.4GHz is a resonant frequency of water, and thus the most efficient at causing materials with water to warm quickly, it is NOT true to say that off center frequencies will not warm things up.

        If you doubt this, ask the guys that have to scrape dead birds from the tops of buildings with microwave transmitters. For that matter, consider the name of the first microwave oven - the "radarange" or, more accurately, "RADAR range". Early RF engineers figured out you could heat with radio frequencies pretty early on. If you put enough power behind it, you can make nearly any RF frequency toast something.

        Where I work, we test a lot of prototype radar systems - and there are alarms and lighted perimeters all across the roof to keep people from walking in front of these beasties when they are transmitting. I can't tell you the exact frequencies, but I can tell you they aren't 2.4GHz either.

        The trick with cell phones is that they are low power, and don't hit any known resonant frequencies of body tissues or water.
      • Keep in mind that the reason why microwaves heat things up is that they prey on a *specific* resonance frequency for water molecules.
        Sorry to burst your bubble, but that's only a myth. You can actually warm water with a wide range of frequencies: every water molecule has a built-in electric polarization, and therefore flips back and forth as the ambient electric field changes. As it flips, there's a little drag from nearby molecules, and energy is dissipated as heat. The key to getting lots of heat is to use an intense field--microwave oven use on the order of a hundred thousand volts per meter!

      • Re:1.9 ghz (Score:5, Informative)

        by The_Laughing_God ( 253693 ) on Friday January 10, 2003 @12:52AM (#5052806)
        While one will indeed find this "fact" listed in many places, including a few physics texts, it may well be a fallacy. I've looked up the frequency absorption spectrum of water, and 2450 MHZ was not a peak. Unfortunately my "classic" paper link is now dead (I'd really appreciate a currently active and stable link even if it supercedes the paper I had and proves me wrong)

        The best I can do right now is " Absorption Spectrum of H2 18O in the Range 12 400...14 520 cm-1 [ucl.ac.uk] [Journal of Molecular Spectroscopy 216, 77-80 (2002)]

        Moreover, anyone with equipment to measure the relevant range can see that microwaves are not tuned to a tight band. The frequency of any one oven varies far more than any the reasonable expectation for an absorption band in that range (depending on temperature, use, etc.) and the variance between ovens is greater still.

        That's actually one specific reason why a resonance frequency is not used: the increase in efficiency that would result from picking an absorption peak (vs. simply reflecting the microwaves around inside the cavity 10-1000 times until a significant fraction is absorbed) simply wouldn't have been worth the effort and cost of precisely tuning each unit (at the time when microwaves first came out) Further, we are all aware of the accounts (admittedly potentially apocryphal) that relate the discovery of microwave cookery to an accidental exposure to a military radar dish. Military radars (excluding weather radars) generally avoid the water bands, because water vapor in the air would limit range.

        I don't mean to criticize the Original Poster, since that "information" can indeed be found in reputable sources. I'd simply rather not see it repeated if it obscures and incorrectly explains the operation of microwave ovens and EM radiation.

        Finally, even if the microwave radiation from a oven *did* operate on a resonance absorption band for water, the total power of a cell phone is tiny (mW-W). One would get orders of magnitude more tissue heating by stepping out into the sun or even another person (both things some techie types seem to avoid). In the absence of any specific epidemiological or other significant evidence of specific tissue or cellular disorders caused by the specific frequency bands used by cellular phones, their radiation can *only* be expected to produce nonspecific tissue heating.

        Before you worry about microwaves, worry about other sources of energy like sunlight. Microwaves onlt *seem* "spookier" to certain people, while sunlight is far stronger in many, many specific bands than celphones over their entire range.

        It might be wise to say say IANAMD, but I *am* an MD (with a degree in molecular biology). That doesn't make me an authority on epidemiology or molecular properties, but I like to think it does give me a small edge.
    • Does your head warm up when you're on the phone? Yes.

      Which is so ironic, because in this weather I really wish I'd not lost my phone in greece.
  • Just in case you missed this excellent post by Hemos last evening here it is again: Posted by Hemos. http://slashdot.org/article.pl?sid=03/01/08/213625 4&mode=thread&tid=98 It's "a good article that describes how we, the consumers, can play the role of competitors to the vendors of products and services we buy. The author draws a parallel between FedEx's ZapMail failure and current situation with VoIP and WiFi in regard to the phone companies." I agree with the article. The jist is: you don't see anyone replacing digital phones with analog. Instead we are buying WI-Fi and 802.11 etc. and using VOIP to ease the use/spread of our digital materials. If we all buy enough of these network enhancers we just might be able to do away with outragous telephone bills from the Baby Bells.

  • For eveyone elses phone.. (Score:3, Funny)

    by zcat_NZ ( 267672 ) <zcat@wired.net.nz> on Thursday January 09, 2003 @08:21PM (#5051482) Homepage
    ..I much prefer analog. You need tome rather fancy equipment to eavesdrop on digital cellphones, but I can listen in on analog cellphones using just a very old Motorola and a small strip of tinfoil.

  • But it seems there's something missing from the standards... like that. :-)

    Why is it that these networks don't simply break the bits per byte of sound up? IE: For every 8 samples of sound (assuming it's 8-bit sound), the bits are interleaved. This way if a byte is missing, the sound is still present, but at a lower quality.

    Is there some technical reason this isn't done that I'm missing? I'd much rather my phone go from 8-bit sound quality, to 7-bit, to 6-bit, etc, etc, rather than just dropping out altogether.
    • Latency.. if you spread the bits out, you have to have a delay in the audio so you can collect them all together again. GSM already has a small (about 100ms I think) delay, which is hardly noticable, but anything longer gets to be quite distracting.

    • Also, shoes, assuming they are leather, would actually be considered red meat.
    • Digital schemes like CDMA (IS-95/cdmaOne) and WCDMA (UMTS) already perform interleaving. Interleaving helps prevent you from losing a large set of consecutive data from the end-user's perspective. Instead, you lose a little data spread out over a longer time. The voice quality degrades gracefully rather than harshly.

      Interleaving works best against fading - that is, when your signal strength drops down a little in the short term (i.e. for 5 ms). Longer term loss of signal like when you go behind a building is called shadowing, and is not protected by interleaving. So when your signal drops out, you may be experiencing long-term shadowing, and interleaving won't help a bit.

      Dave

  • Digital phone frequencies (Score:3, Informative)

    by QuantumET ( 54936 ) on Thursday January 09, 2003 @08:27PM (#5051520)
    On the frequency point... Digital cell phones use (at least GSM phones do, don't know the CDMA frequencies) both 900 MHz bands and 1.8 GHz bands (1.9 GHz in the US, because the 1.8 GHz band is reserved for .mil use in the US). It depends on what the base stations in the area are using.

    In general, digital signals can get through a much worse signal-to-noise ratio (after all, all you have to pick up is a 0 or 1), and should therefore be more robust than analog, especially with basic error correction thrown in. You'd need to compare the transmission/reception power levels to see if the digital phone is really doing worse. If the digital base station is transmitting at X watts, and the analog base station is transmitting at 3X watts, yeah, the analog might come through better.

    Of course, better battery life isn't a bad thing either...

  • wow how uninformed (Score:4, Interesting)

    by XO ( 250276 ) <blade.eric@NospAM.gmail.com> on Thursday January 09, 2003 @08:34PM (#5051550) Homepage Journal
    If your analog phones signal drops below maybe -3- bars out of 5, you're gonna get static. If you have 1 bar or less of signal on an analog phone, no amount of screaming is going to help you. I can make a crystal clear digital call, on Verizon's network usually with 1 bar or more. I get a bit of dropping on 0 bars, but whenever the signal is THAT low, it should switch to analog ALREADY.

    NOT all Digital systems operate at 1.9GHz either - Verizon's network is mostly 800MHz. (Also incorrect when he states that AMPS [analog] operates on 900MHz, it is in the 800 band) Digital phones are at -variable- power, anywhere up to 300mw. Analog phones run at 600mw for handhelds, and 3W for the larger mounted and bag phones.

    Granted, with a 3W transmitter, I'd take call quality from an analog phone any day, but unless you're in a really crappy area, a digital handheld should outperform any analog handheld. At least, a good digital handheld.
    Plus, any good digital handheld should also be a good analog handheld if it needs to be.

    The Analog network will be going away in a few years, except for areas where there is NO digital coverage.

    Use high quality phones. Verizon and AT&T have decent quality control for their phones, and strict standards as to what they will approve to be used on their network [i'd be willing to be Verizon is a bit higher than AT&T, since they don't have 8 million different handsets available]. T-Mobile, Sprint and Cingular's QC for phones is considerably inferior, though I have no personal experience with AT&T, T-Mobile, or Cingular's inner workings. I can't speak for Nextel at all, but I don't know anyone who personally wants to carry a phone as big and heavy as the analog ones from 5 years ago on their hips just to have neat walkie talkie functions.
    • Actualy Nextel phones aren't that big any more. They have been small for quite sometime. iDen is a Digital network as well. In fact, they also have a color one available and also introduced a RIM Blackberry unit complete with Cell Phone and Direct Connect features. I live in Columbus, OH and was able to talk back to Columbus from Lexington, KY. Direct Connect will soon be (if it is not already) Nation wide. A walkie talkie that lets me talk from one coast to the next...nice. Although I have a Verizon phone and I did notice that in between the big cities on my trip like between Knoxville and Lexington and Lexington and Cincy have no Digital coverage....jus AMPS but the Verizon phone worked. Web Browser did not as it needs the digital network but I could make ad recieve calls. AMPS will be around a while longer.
      • They're still pretty big and clunky, even the smaller ones. At least, compared to, say, a Samsung 310, or even Motorola's CDMA phones..

        Pretty sure the direct connect function operates to anyone on the Nextel network.. no matter what area.. but I don't know how much that extends. Obviously the coverage map they last showed me (which showed everywhere in the U.S. covered) is incorrect.

        But, I have no personal experience with them. I imagine since Motorola runs the network, Motorola builds the handsets, Motorola does it all, that the quality and compatibility is way up there. Unlike say, the Nokia 21xx CDMA phones, where they apparently tried to homebrew their own CDMA chipset, and it failed miserably. lol

      • iDen SUCKS, it is a battery hog, not sure if it's their digital mode sucks or the direct connect that does but none of the Nextel phones has a standby time of over 72hours wtf is with that? I hate the fact that I have a HUGE cellphone(i550 Plus) that has to be charged twice a week, yeah the i1000 is smaller but it doesn't have any better standby time. What I really want is 140 hours standby minimum and the cool speakerphone feature from the i1000 in a phone the size of my ATT Nokia.

  • Microwave (Score:5, Insightful)

    by linuxwrangler ( 582055 ) on Thursday January 09, 2003 @08:36PM (#5051568)
    The microwave comparison is bunk. First, microwave frequencies are chosen to be those best absorbed by food (ie. resonant with molecules such as H2O). Second, the power level of your phone is, at max output, a bit over a watt. The microwave is 600 to 1000 watts beamed into an enclosed space. It's like saying that you shouldn't play with a nerf launcher because getting hit with a rocket-propelled grenade is dangerous.
  • See my Cell-Phone Switch parody commercial on this site for an example if you don't know what I'm talking about
    You have a Cell-Phone Switch parody commercial on Slashdot? Where? You didn't give any links to it. Or did you just rip this article off from another site and submit it to slashdot without giving proper credit?

  • There are no analogue networks left in Europe... (Score:5, Interesting)

    by Gordonjcp ( 186804 ) on Thursday January 09, 2003 @08:44PM (#5051594) Homepage
    ... perhaps that answers your question.

    Seriously, guys, get with the rest of the world. Even if it's just this one thing. In Europe GSM phones use either 900MHz or 1800MHz - why are you trying to push 1900MHz? Just use one of the normal frequencies.

    US mobile phone networks seem really limited - if you go outside a given area, you might have coverage, but it's more likely you'll have to pay a fortune for it. In Europe, I can leave the UK and travel to damn near any other European country, and use the same phone. If I'm in Romania, my phone works just the same as it would in Scotland. Local calls cost about the same, international calls cost about the same. If you want to phone me, in Romania, dial the international dialling code for Romania then my mobile number. Simple as that.

    Just use GSM, and get it the same as the rest of the world.
    • US mobile phone networks seem really limited

      My Verizon Wireless phone only gets an analog signal in Orlando. Heck it also only gets analog in Peoria (next to the Verizon building) and in Canada. In analog mode most conversations are unintelligible, calls frequently fail to complete and the battery gives me a whopping talk time of 12 minutes. (It also gets so hot it almost burns.)

    • True there is more cell phone coverage in Europe than in the US. However the US has a lot less people. There are places where there is still NO coverage, no analog, no digital, not even a a smile land line phone for miles. However if people actually live in the area there is some form of coverage. True it may be analog in some areas, but there is cell phones and land lines to nearly everyone.

      It shows that you have not been to North america lately. I have cell coverage until I really get out there. I get it when camping on an island. Sure I eventially get out of my digital only coverage area, but only when traveling well outside of the areas I normally travel. Most months I do not go out of my coverage area, and often when I do I get coverage back again at my destination.

      P.S. I have a GSM cell phone however that means nothing to me. It is just an engineering protocol, and I frankly don't care what protocol my phone uses, I care that my phone works, and it does.

      • True there is more cell phone coverage in Europe than in the US. However the US has a lot less people.

        Hmmm, I guess this is is straying off-topic but I have to correct you on that. The population of the European Union right now is roughly 280 million. This will rise to around 360 million once the new members (mostly former Eastern Bloc states) join.

        Compare that to the US population of roughly 300 million. Hardly "a lot less people" is it?

        True, Europe is more densely populated than the US but most as Americans live in urban areas (cities, towns) it doesn't make that much difference.

        Sure, if you live in a remote area of Utah then you're not going to find network coverage everywhere but the same is true of some places in Europe. However, it is fair to say that the percentage of land where you can't find coverage is far greater for the US than it is for the majority of Europe.
    • Try a stinking dual-band phone.

      We have GSM already.
      We also have CDMA.
      We also have AMPS.
      We also have CDPD.

      Radio anyone?
      Choose OTA, XM, or Sirius

      TV?
      OTA, Cable, DirecTV, Echostar (Dish)

      Internet?
      Dial-Up (gobs of providers), DSL, IDSN, Satellite, Radio (802.11), Ricochet, Wireless (2.5G), Cable

      Phone?
      In my area, Qwest, McLeodUSA, or TelcomStar

      Wireless?
      In my area:
      AT&T, Sprint, Verizion, T-Mobile, Cingular, Nextel, Cricket, Qwest, more

      See a trend?
      • Err, I hate to rain on your parade but you can walk into any phone store in Europe and buy a tri-band phone on a choice of networks that will work virtually anywhere in the world (including the US).

        And as for radio, internet, and other telephone, the choices are just as varied as those you've oulined - those services and services and technologies do exist outside of the US and have done for some time.
    • Seriously, guys, get with the rest of the world.

      Okay, you've never travelled in North America, have you. You really don't understand how far people are apart here. You need population density to make these kinds of networks worthwhile, or they aren't economically feasible. Simply put, analog towers service fewer simultaneous users, but cover a much larger range. Therefore, if you have lower population density, analog suits you better.

      To illustrate population density differences, check out the CIA world factbook, and divide the population of the U.S. by the area, then do the same with some European countries.

      U.S.: 30 people per km^2
      Romania: 97 people per km^2
      France: 110 people per km^2
      Germany: 238 people per km^2
      U.K.: 248 people per km^2

      You see, the U.S. can't offer digital service to it's entire population unless the entire population lives in urban areas.

      Compare that to where I'm from - Canada, at 3.5 people per km^2. However, Canadians tend to be urban dwellers, with around 80% living in cities in the more moderate climates, so our cell phone coverage is similar to the U.S., with digital coverage to most people, but analog coverage to the rest of the populated areas.

      It's similar to the automobile phenomenon... I've heard many Europeans can't believe how many cars we own in North America, but again due to population density, public transportation just won't take you where you want to go. The country is huge. If we wanted to do a "road trip" to visit relatives on the east coast, that would be a 25 hour drive, and I live near Toronto! Visiting my relatives in Vancouver would be a 40 hour drive! Of course, I'd probably fly...

      So anyway, I guess size does matter.
  • Just trying to say analog vs. digital misses the fact that there are several types of digital - the most common in the US being CDMA and TDMA. I have no scientific surveys but it seems that my friends on CDMA systems are much less happy than those with TDMA.

    It's true that quality vs. signal strength on analog is, well, analog. It gets worse and worse as the strength goes down. On digital it's digital. Once you reach a certain threshold you are suddenly screwed. I have had times where I could converse, however poorly, on analog when I could not at all on digital (just select analog only on the phone's menu in those cases).

    Overall, I think the quality committment of the company (enough capacity, well-placed sites, proper maintenance, etc.) is a much bigger factor than analog or digital.

  • Stick with analog (Score:4, Funny)

    by phreaknb ( 611492 ) <phreakinb@c[ ]ast.net ['omc' in gap]> on Thursday January 09, 2003 @08:48PM (#5051618) Homepage
    Stick with analog. The human ear cannot hear digital, only analog, so there isnt much better quality unless you have super ears.

  • Yay Digital... (Score:3, Funny)

    by Anonymous Coward on Thursday January 09, 2003 @08:54PM (#5051648)
    With an analog phone...you may need to 'yell over the static'

    As someone who's heard way to many insensative a#%holes have conversations in movie theaters, restaurants and the like, the fact that you can't 'shout over the static' with digital is a feature, not a drawback.

  • Digital Rocks (Score:3, Interesting)

    by topham ( 32406 ) on Thursday January 09, 2003 @08:56PM (#5051656) Homepage

    I've had a Digital phone for several years. The first would switch between digital and analog, the second is GSM, so digital only.

    You know what? It rocks. I've never had significant issues with it except at a client site that is not served well. (The 'local' tower is not local and the buildings in the town where the client resides are sufficient to block the signal entirly. This was a screwup on the part of the cellular company.

    Anybody that bitches about the sound quality on digital should either find a new provider, or get their hearing checked. I've never had to yell into my phone, and, with the odd bit of noise I've only occasionaly had to ask people to repeat themselves. (and that is because I wasn't paying attention :)

    I was using a TDMA Startac, but have since switched to a Nokia 8390 GSM phone. Works great and the coverage is similar or identical to my TDMA. I also notice that less people yell into their phones these days...

    • You should visit Philadelphia sometime. I have a friend who has gone thru two companies and 4 phones. His calsl always suck to me. Dropped words and sentences. Calls being cut off. he gets slightly better reception outside but if I had his phone troubles I'd get rid of the cell all together and wait til something a but better came out.
      • Using Cingular, my analog service was far superior to digital. With digital, I had to constantly move around my apartment to keep a conversation going. Sometimes I'd not even get a ring - I'd move the phone and "1 missed call, you have voicemail" would appear on-screen - yet the phone was within reach all evening, ringer on Loud.

        It was enough to make me drop service althogether. I don't think I'll go back to Cingular when I'm ready to try a cell phone again - but that will be a long time.
      • but you see, thats entirely my point. The problem isn't analog or digital, it's the damn cellular companies and their stupidity with antenna placement. (especially in the problem I have at the client I mentioned. The ground is FLAT, it's a small town, but the largest in the area, and instead of putting the tower close to town they put it too far away. It made their coverage map look good though.
  • Sure, the digital signals are very close in frequency to microwaves. So what? Microwaves are usually about 1000 watts. And we all know that watts is the actual measure of power. So, what is the 'power' rating of your cell phone?

    Look here to find out: http://www.cnet.com/wireless/0-5939521.html I'll bet it's a lot less than your microwave. In addition, a microwave is a specially designed metal box that does it's best to make sure all that power gets into the food, your cell phone has at least a 180 degrees that isn't pointed at your head.

    Digital signals are better, it helps to relieve congestion on the airways, it reduces the power of signals needed and increases battery life. Plus it's a hell of a lot easier to get IP working over it. (IP does dropped packets a lot better than garbled packets).

    If radiation is really your concern. Get a head set. Bluetooth might not be the best idea. :)

  • Old-debate (Score:5, Informative)

    by jquirke ( 473496 ) on Thursday January 09, 2003 @09:06PM (#5051725)
    I don't know what the point of this article is. It is re-iterating (in some cases exaggerating) stuff we already knew. The rest of the world had this discussion at least 10 years ago. As a result, we standardized on GSM.

    In Australia we discouraged the use of Analog phones in the mid 90s, and the analog networks were shutdown in 99.

    Before this time GSM was gaining huge momentum, with three GSM networks rapidly expanding their coverage. The majority of the urban population were pleased with the technology, however the rural population were less than amused. As a result, CDMA technology was deployed by Telstra which is a digital system, but offering performance characteristics closer to analog.

    One problem with GSM in rural areas is the timing advance issue, which limits the maximum range of dedicated mode (2-way communication) to about 35km, typically. The GSM range limitation is not, contrary to popular belief, a power output limitation.

    I'm getting a little offtopic here, but I'll quickly explain the problem: The timing advance problem is a result of using fine-grained timeslots. The timing advance parameter is the number of symbol periods the MS (phone) must advance the transmission to avoid colliding with other timeslots. The maximum value is 63 symbol periods, which was chosen to allow the MS plenty of time to measure other cells when not transmitting and receiving.

    Additionally, GSM offers Short-Messaging-Service, GPRS (packet switched data), far more efficient spectrum use, EDGE (high speed GPRS using 8PSK modulation).

    The population and population density of the US is far better for deploying GSM networks than Australia, so if Australia can do it, I can't see why the US can't.
    • Something I forgot to comment on, was your comparison of voice quality.

      I'm not sure which standard you are referring to, but have you heard the quality of the EFR (enhanced full rate) codec on GSM? I would easily say that overall it sounds much crisper and cleaner than any analog technology.
    • Australia has 2 major cities 3 minor ones and just about no other population centers. Sydney or Melbourne are big cities (one of the two will be the largest English speaking cities in the world by 2012 when they both will be bigger than London) GSM works well in the big cities because they are high density (higher than most US cities). The demographics just aren't the same. The city density in the US midwest is lower than smaller towns in Australia and they are spread out much differently. Victoria and Missouri have about the same area and same population but there are about 10 times as many areas in Missouri that have a population density to support a small airport. In GSM terms that means more towers where the Analog systems work much better.

      GSM was designed so that one countries signal would not work in a bordering country. If you had tried GSM in Europe before the roaming agreements came in, you would find that the cell towers were quite selective near the borders of other countries. The signal was fine, the cell just wouldn't accept a signal that was in the wrong time slot because it was too far away and in a different countries area.

      When they turned off the Analog system in Australia, many farmers lost their mobile phones since the CDMA stuff just didn't work as far away. With the exception of the big cities, the analog system worked very well for what it needed to do.
  • I just recently bought a Seimens S something or other and it SUCKS! I have never had worse quality from any phone. The phone retails for $250, good thing I didn't pay that much. The internet features never work, every person I talk to says that I am cutting out, and the signal is absolute trash; it will shut off when I answer, when I am in the house, in the car. I have to stand outside to make a friggin call. If you are in the Chapel Hill, NC area go for analog or stay away from Cingular. I have never had a digital phone that worked past 10 feet of the inside of a building. My analog had no such problem. Is this a problem with my provider or are the digital networks just not up to par yet?
  • You can get digital phones in all brands - 900MHz, 1800MHz and 1900MHz, so the microwave-point (which, is also not valid because of the _very_ low power emitted) and the longer signal are not valid.

    The soundquality is also overall better in a digital network.

    And besides, if you want to do something geeky, you'll definetly need a digital signal to transmit data. =P
  • One digital phone I'm really satisfied is Nextel, which uses the IDEN protocol. It's basically the same as TDMA, with the 2-way radio feature added in. With the 2way radio, you have a number of benefits -- much cheaper (they are billed out at 1/10 second intervals), and you don't get tied up in a long conversation with someone when you just need a bit of info. That is, since communication with the radio feature is half duplex, the person your conversing with will tend to give you the facts quickly, then release the key in order to get the reply. Whereas, if you call someone, it tends to turn into a long useless conversation. Therefore, it's about as efficient as doing SMS messages.
  • Sprint used to have a pretty big campaign advertising "Digital Clarity", but that's bullshit. The tests I've done say that analog sounds better. This doesn't mean it IS better, however. Digital networks are way cheaper to set up and run. Which, believe it or not, they do pass the savings on to you. This is why Sprint can offer what ammounts to $0.10 a minute peak and infinite offpeak usage (and tmobile is even cheaper).

    As for me, I'm content with the sound quality of my digital phone (unless my reception is bad, people I'm talking to can't tell I'm on a cell phone) - but I'm very happy with the price.

    And as for microwaving your brain, the analog phones put out a lot more power than than the digital ones - but the figures for american phones are like 600mW and 200mW [arpansa.gov.au](analog and digital) compared to the 1000KW a typical microwave oven will output (sucking about 1.5KW of electricity to do it) - hardly a reasonable comparison.

    • Re:The real skinny (Score:2, Informative)

      by dgmartin98 ( 576409 )
      Hey Buddy!! - How do you generate 1 MW of energy out of 1.5 kW of electricty? Despite popular belief, microwave ovens don't "nuke" our food.

      Dave

      BTW, I have a perpetual energy machine to sell you, if you're interested.
      • I suppose he meant 1kW.

        But you can get 1MW from a 1.5kW power supply, IF you have suitable equipment.

        For example if you take in 1.5kW for 1000 seconds and accumulate 1.5 megajoules, and then release all of it over 1.5 seconds you generate 1MW of power.

        That's the sort of thing they do for hot fusion stuff or artificial lightning generators.

        I'm sure you can find other examples yourself.

        AFAIK from some popular theories there is a perpetual energy machine, it's called the Universe.
  • How can I moderate this frontpage news item as (-5 Moronic Troll)?

    I mean, part of the informations are just false, the opinions are presented as facts, and the important factors that caused the switch to digital cell phones are conveniently avoided.

    (like the max number of users per cell, min and max cell sizes, signal degradation in transit and several more)

    Robert
    • Hmm the reality is that analog WOULD sound better. You have to realize that analog is real sound. Basically there is the carrier signal and then the actual data signal. Digital is digitized signal and the carrier signal. When your carrier signal goes in analog you get static, but in digital you get nothing. Either way you get H**lo or H lo. Analog always sounds better though. Look at records vs CD. Many people complained that records were better than cd sound wise. But it does not matter in the end records are on the way out and cd's are in and there is a new digital format coming to replace the old digital.

      There is just no way in winning in this debate. Analog will always sound clearer. In digital you have the sample rate. This means that in a signal how many parts of that signal will I get? Digital purposesly drops parts of sound. If you have a basic sine wave. In digital you will have part of that way. The sample points. In analog you have the whole wave. If you have a higher sample speed you get more points. Live with it!

      It sounds to me like he has sprint service. Sprint in my area sucks butt. AT&T is better in my area. This is not true for everyone. ASK people you know which service they have better luck with.

      • Re:-5 Moronic Troll? (Score:2, Insightful)

        by damiam ( 409504 )
        Analog may have the "whole wave", but with digital you always get the exact signal that was sent. If you record a sound without any background hiss and play it back digitally, you'll get the same clear sound. With analog, there's no guarentee of anything.

        Sure, a perfect vinyl record may theoretically sound better than a CD, but when was the last time you saw a perfect vinyl record?

      • The signal in an analog phone is still converted into digital pulses at some point along its journey. There's no escaping it. You're either woefully uninformed, or just a really bad troll.

        - A.P.
      • Um, I have to disagree. Analog is NOT always better than digital. It depends on MANY factors including bandwidth, noise, signal strength, etc. In a high noise or low signal strength environment (or combination) digital will sound better. Period. I left analog behind years ago and would NEVER go back.

        I recently (last month) drove across the US with my dual analog / digital phone and in the few analog areas that I hit the service was terrible (didn't help any that it sucked my batteries at a rate 10 times faster than digital.)

        I guess if you are sitting next to a cell tower analog would sound better, but in REAL WORLD conditions it is worse.
        • I'm talking about pure sound itself not cell phones. Obvioulsy nobody here has ever taken any kind of singal class.
          • We're talking about cell phones, not pure sound. And many of us have taken signal processing and data transmission classes.

            Digital sound does not suffer from signal degradation. Hold true for communications, CD/vinyl, whatever. You only need two samples per cycle to accurately reproduce a sine wave...once enough samples are taken, the output sound will become identical to the analog waveform for all practical purposes. You don't have to go much higher than CD quality to fool the audiophiles; the CD sample rate was a compromise between widely acceptable quality and the cost of manufacture.
            • 2 samples for a sound wave??? sounds more like a triangle wave. Real sound is not just 1 sound wave. There is noise that is lost that makes up the rest of the sound. Thus if I have a varing signal, like voice, and I sample it, I loose the noise. That is what calculus is all about. You have a wave and you APPROXIMATE the area under the curve. There is NO way today, that a 100% reproduction of an analog signal can be done digitally. If I sample at point a and point b, and between these two points is a spike, then I have to guess what that is. Did you also take numerical analysys? Remember the trapizoidal rule?????

              The reason that everyone is going digital is because it is cheaper. It is cheaper to send a digital signal down the calbe line than analog signal. It is less lossy in terms of distance, where analog needs boosters digital is better over distance.

              If your a BSEE its no wonder your looking for a job.

              • You're obviously not a BSEE, or any type of engineer for that matter. I'm not even sure you're an adult.

                This may surprise you, but calculus (specifically integration) is not the end of mathematics. The Nyquist theorem states that in order to accurately reproduce a frequency, the sample rate must be twice or more than the frequency. Using just two samples per waveform, the sine wave can be reconstructed.

                And if you remember Fourier transforms, you'll realize that any waveform can be broken down into component sine waves. With enough samples, the original waveform can be reconstructed with practically no measurable difference from the analog source. And, yes, with today's technology, quite possible and commonly done.

                No, the digitally-reproduced waveform is not going to be 100% the same. It will be something like 99.999%. And I'd like to see you get that with an analog signal, taking into account the capacitance and inductance effects of the transmission line, thermal noise from resistances, and analog processing done with parts that commonly are 10% away from specified value.

                I'm not worried about what your opinion is of my competence. Any other electrical engineer knows what I just told you.
                • "This may surprise you, but calculus (specifically integration) is not the end of mathematics. The Nyquist theorem states that in order to accurately reproduce a frequency, the sample rate must be twice or more than the frequency. Using just two samples per waveform, the sine wave can be reconstructed."

                  Okay you now have the frequency, how do you know what the max / min amplitude is? Its offset from 0 axis?

                  If you remember forier transforms then your realize that these are only approximations as well.

                  "No, the digitally-reproduced waveform is not going to be 100% the same. It will be something like 99.999%. "

                  I think it is less than that, but my point is just that. THERE IS SOME LOSS and what that is YOU cant say.

                  Also note, yes I am a BSEE, but I'm not for hire, I'm employed!! I wouldnt hire an artogant a**hole like you!

                  • The universally accepted meaning of the word "sample" is a measurement of amplitude at a given time. Using two or more samples per cycle, a sine wave can be accurately reconstructed according to amplitude, frequency, and "offset from the 0 axis" (phase, if you actually mean offset from the y axis along the x axis).

                    And I did state that there would be some loss. My point was that, with current and available technology, the loss can be reduced to nearly unmeasurable levels. It merely depends on how much processing and equipment you want to invest. Analog components are continually far off from specified values, subject to noise, and guaranteeing a perfect, lossless copy across a transmission line is almost a joke.

                    I'm not seeing where you think I'm arrogant. Just pointing out some facts. If you don't understand what I just said (which is first or second year engineering material) then you have some serious gaps you need to study up on. At least if you plan to speak authoritatively on this subject.

                    I'm also employed, just in a mechanical engineering position at the present time. My education prepared me well enough, so that I am able to pick up the skills I need pretty quickly. I'd like a more EE-based job, perhaps I'll get yours after your superiors get tired of your attitude.
                    • I guess you must have missed your numerical analysys classes then.

                      You task: given 2 points recreate a sine wave:

                      point 1 -> x=2, y=1

                      point 2 -> x=3, y=4

                      Well?

                      So how do you determine that given these two points that it IS indeeed a sine wave and not a straight line? Or a triangle wave? YOU CANT. That is my point.

                      Yes if you take enough sameples then yes you get closer to duplicating the original wave.

                      When you are dealing with voice and CD data this is ueually possible. The problem is that if you loose enough of these points (as in shotty transmission) then you loose the sound, where as with analog if you loose the same 'sample' then you may stil have sound.

                      Also if you did take signals then you would know that there is a carrier wave and there is a signal that gets put on this carrier wave. In the case of AM and FM signals the carrier wave and analog sound wave get 'combined' (amplidtude modulation or frequency modulation) to one wave which is then transmitted and then take apart. if you loose 1 milliseconds of this sound every 5 milliseconds you will still have a sound and you will be able to make it out. In digital if you have a sample point ever 5 millisec (bad sample I know) and you drop the same 1 millisecond point on that sample point, YOU have LOST your sound entireley and cannot reproduce your sound.

                      This is what the original poster was talking about. In analog phones if you have a bad connection you can often make out what the other end is saying, but in digital you either have sound or you don't.

                      Go back to school and learn this all over again and loose some of the attitude and maybe you will have a job in the field again.

  • Here - Qualcomm [cdmatech.com]

    and here - for a CDMA FAQ [rr.com]

    and here [cdg.org] for why CDMA is better than analog along with a whole lot of other shit as to why dropped calls are far less frequent on digital networks as opposed to analog ones...

  • Analog phones are typically 1.5-5 watt transmitters, digital phones run anywhere from .6-1.5 watts. So the egg frying is actually worse on analog (Both penetrate your skull pretty easily) So if you want range or your provider has long distances betwwen towers, analog is the way to go. But if you want features beyond basic voice mail, time to move to digital.
    • Other than the fact that your numbers are WRONG, it IS true that digital phones operate at a lower power. Max power for analog is 3W for a bag phone and I think .6 or .8W for a hand-held. Digital I think maxes at .6W (it may be even less.)

      This is for the US market of course, but numbers elsewhere are similar.

  • do the math (Score:4, Interesting)

    by aminorex ( 141494 ) on Thursday January 09, 2003 @10:55PM (#5052258) Homepage Journal
    Many responders observe that the 600 mW of a phone
    is about 1e-3 or less of the power of an oven, but
    neglect to consider that you don't hold an oven
    against your skull (hopefully). Holding a cell
    at 600mW 5mm from your skull is like holding an
    oven magnetron 6 inches from your skull, in terms
    of the power density over the surface area at the
    nearest point. I don't do either. I use a headset.

    • Re:do the math (Score:3, Insightful)

      by cybermace5 ( 446439 )
      Creative math there.

      Assuming the magnetron and cell phone have identical spherical radiation patterns, the energy from the magnetron would be about seven times more than the cell phone.

      Additionally, the magnetron will penetrate much deeper: 5mm deep into your skull, the cell phone's power will be 400% less, and the magnetron's power will be 15% less. That assumes zero blocking effects from the tissue.

      Paranoia and hearsay does not equal fact.

  • Cite some credentials, please (Score:4, Interesting)

    by Gus ( 2568 ) on Thursday January 09, 2003 @11:12PM (#5052353) Homepage
    What exactly are the author's qualifications, beyond being a consumer? Here are a few points I'd like to see addressed:

    • Statements about signal penetration indicate some knowledge of RF Engineering. Has the author ever worked in Radio Frequency engineering?
    • Statements of coverage area indicate a knowledge of how the wireless companies have deployed sites. Which carriers have shared this information with the author?
    • Is there any evidence that isn't anecdotal in the author's statements?
    Since no credentials are given for the author, I am quite curious to see if this is an amateur opinion or an educated one. Being a technical field, only the latter matters.

    There are a lot of things to dislike about wireless companies - the weak regulatory bodies that have failed to force standardization or universal coverage, or the amount the industry is steered by market analysts with no experience or knowledge of the field both spring to mind. But the adoption of digital technologies is not one of them.

  • Just when I thought last night's CD player Ask Slashdot was the worst ever.

    Thank you, sir, for proving the bar can indeed be set lower.

    - A.P.

  • Here's an Idea (Score:1, Insightful)

    by The Donald ( 525605 )
    Digital cell phones use extreme compression of the sound that they transmit. The compression algorithms used are lossy; they're specifically designed around transmission of human voice to human ears, and take advantage of what the human ear will tolerate and what it won't.

    My repsonse to this is so what? I don't need to stream lossless audio down my cell phone. I want the person on the other end to hear me somewhat clear. If they tune the codec to human voice, around the 150 KHZ range, that's fine.

  • What a load (Score:5, Interesting)

    by Sentry21 ( 8183 ) on Friday January 10, 2003 @12:29AM (#5052690) Journal
    I've been using various digital cellphones lately, from an LG-T520 to an Audiobox 9000 or something (stupid loaner phone while I'm getting some repairs done to my LG), and here's my refutations of what's the dilly, yo:

    However, with a digital system when the signal fades, there's no yelling because the signal isn't there, and packets that should be getting to your phone, just get dropped. As a result, Aunt Martha's 'Hello' on a crummy analog connection can still be made out.. but on a digital connection of the same strength might sound like 'He...o' with a gap of silence in the middle.

    Even with the worst digital signal I could find, I've never had a problem at all hearing someone else's voice. I've been told that some voicemail I left once dropped out a word, but that's the only comment I've ever had. Other than that, no problems.

    he question now becomes, why are they moving to 1.9GHz?

    Among the other reasons mentioned, it provides more bandwidth as well, which means a lot of things - more users, more data, more whatever you're sending.

    However, the cell phone companies need to cover the area better for there to be as much coverage, especially in the city where there is lots of Multi-path (bounces and signal inversions), and buildings to go through.

    I live in Fredericton, NB. We have digital, but barely, since the telco just decided fairly recently to cover the area with digital. There isn't great digital coverage, but see my comment above for the impact this has made. The worst problem I've had is that I get bumped to analog (usually four or five out of six bars) when I'm in a basement room two minutes' walk from daylight, or I get no signal whatsoever, in worse circumstances. Even if digital coverage were hopeless, my phone can not only fall back to Analog from digital, it can do so in the middle of a call. It can't fall forward to digital during a call, but that's ok.

    In addition, back to Aunt Martha, as long as her 'Hello' usually sounds like her 'Hello' on a land line, what difference does it make right? Well, unfortunately, the digital standards we have today are from years past. And while they work, they are by no means clear. If you are looking for clarity, you'll want to stick with an analog phone.

    I don't know about you, but my phone uses 3G CDMA (hooray Qualcomm), which is a fairly new standard, and most people (even people who KNOW that my only phone is a cellphone) often ask whose house I'm at - because I sound like I'm on a land line, and everyone knows cellphones are horrible, right?

    Another related comment: I was standing in Starbucks, of all places, surrounded by a crowd and with the espresso machine going, while I was on my cellphone, but the person on the other end could only hear me. When I wasn't talking, there was no sound. When I was, there was only me. Hooray active noise reduction. That being said, it was the phone itself doing it, and not CDMA's built-in anti-background filter (though that can't have hurt).

    The compression algorithms used are lossy; they're specifically designed around transmission of human voice to human ears, and take advantage of what the human ear will tolerate and what it won't.

    Don't forget to mention that, in the case of CDMA, it just doesn't transmit while you're talking, and doesn't recieve when the other person isn't. This saves battery power, bandwidth, radiation, everything. Analog, on the other hand, is always doing what it's doing all the time, by nature of it being a connection, as opposed to packets.

    What about the pros for digital? Digital is a bit more secure then analog as you can't hear it just by setting a scanner to the correct frequency, you also have to un-encode it from the digital, and smooth the signal out.

    Not to mention battery life. I can go for literally a week and a half without charging my phone, as long as I'm not stuck in that stupid room in the forestry building I had class in last semester. When I am, and I get bumped to analog, my battery drains almost 80% in a day. This is partly because I get poor reception, but even in one-bar digital areas, I don't have any sorts of issues (and I should know, Chapters/Starbucks is one such area).

    On last thing, the digital system works on 1.9GHz... your home microwave works on 2.4GHz.. It's close enough, you still want to hold that phone next to your head? Remeber what happens to an egg when you put it in the microwave, and then decide.

    Oh yeah, and by the way, wireless networking is going to give you testicular cancer, because it uses 2.4 GHz, just like your home microwave. And it'll fry your brain! And eat your fish! And salt your lawn! Fearmongering is pathetic, let's get real.

    I use and like my 3G CDMA LG T520, serviced by Telus Communications, 800 MHz digital network by Aliant Telecom. Rare dropped packets, rare analog service, even though there are very few towers around here, and yet the data service is entirely reliable. They're putting up a 1900 MHz digital tower soon, which will provide us with '1x service' (the full 3G shebang), but in the meantime, my phone rocks anyway, and will gladly switch from 1900 MHz digital to 800 MHz digital to analog depending on what it can find.

    So why is there such a complaint? Are people getting stuck with digital-only phones? Do Americans have to make this choice actively when they get a cellphone? Every phone Telus sells is 3G CDMA, tri-mode, and cool to boot. No old-school audiobox, no Nokia phones, just good-looking, good-working, sturdy, quality phones, and you know what? They work great, even here.

    --Dan
  • 1.9Ghz and 2.4Ghz. Close? 500 cycles per second. 25%. But then again 2+2=5 for very large values of 2...

    Why bother with the theory anyway? If you're worried, put your egg by your phone and cook it.

  • ...the analog networks have totally disappeared. The 3 cell providers here (Optus, Telstra and Vodafone) have ceased all anolog service. You can't buy an analog phone here. I assumed it was the same in the US. The only place there is an anolog service of some sort is in the outback (but that barely exists).

  • Power (Score:2, Informative)

    by 91degrees ( 207121 )
    the digital system works on 1.9GHz... your home microwave works on 2.4GHz.. It's close enough, you still want to hold that phone next to your head?

    You have a 850W mobile phone!? This is just a pile of FUD. The 900MHz analogue signals are at a higher power than digital, and since they're at a lower frequency will penetrate further into the skull.

  • Holy FUD Batman! (Score:5, Informative)

    by Andy Dodd ( 701 ) <atd7NO@SPAMcornell.edu> on Friday January 10, 2003 @10:45AM (#5054563) Homepage
    So many things are misinformed/wrong about this...

    Most have been posted by others, such as:

    a) Digital can be in the 800 MHz band (same as analog) in addition to 1.9 GHz, and most of Verizon's CDMA network is low-band. 1.9 GHz is used because we ran out of 800 MHz spectrum.

    b) Analog typically takes 3x as much power. Digital is good for the handset battery and good for your head. Digital phones peak at 200 mW, analogs are 600 mW for handsets, and some portables are 3W units. Analog is actually better for the provider power consumption wise - Analog FM signals can be amplified with around 70-80% efficiency or more, as opposed to around 14% for the absolute latest CDMA amplifiers. (FM signals do not need a linear amplifier, while CDMA requires an ultra-linear amplifier.)

    c) RF cannot directly harm your body. (i.e. changing DNA nucleotides) The only way RF can harm your body is by heating it. Who cares if 1.9 GHz is close to 2.4 GHz? It's 200 milliwatts, which will cause negligible heating even if it is more efficiently absorbed than 800 MHz radiation. If RF were that dangerous, half of my coworkers would be dead after 10+ years of developing microwave transmitters and amplifiers. Yes, you have to be careful, and 45W of microwave directly into your body can do serious damage, but 200 milliwatts can't do diddly, even if you directly touch the antenna.

    d) The author is severely wrong about quality vs. signal strength with analog vs. digital. Even at 4 bars of signal, an analog signal will have static. At 1-2, it will be almost unintelligible. I can get crystal-clear connections at 1 bar of signal, sometimes even 0 (i.e. on the verge of losing a connection) with my CDMA phone.

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