Cell Phones - Analog vs. Digital 173
"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?"
well... umm... the analog networks are going away (Score:5, Insightful)
Re:well... umm... the analog networks are going aw (Score:5, Funny)
Re:well... umm... the analog networks are going aw (Score:2)
Re:well... umm... the analog networks are going aw (Score:2)
Re:well... umm... the analog networks are going aw (Score:2)
Analog kills battery life. (Score:4, Insightful)
Re:Analog kills battery life. (Score:2)
Re:Analog kills battery life. (Score:2)
Re:Analog kills battery life. (Score:3, Informative)
1.9 ghz (Score:4, Insightful)
Re:1.9 ghz (Score:1, Interesting)
--
Klein bottle for sale
Re:1.9 ghz (Score:1, Funny)
Thanks for the tip!!!
Re:1.9 ghz (Score:2, Informative)
" 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.
Re:1.9 ghz (Score:1)
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)
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.
Re:1.9 ghz (Score:2)
Re:1.9 ghz (Score:5, Informative)
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.
Re:1.9 ghz (Score:2)
Which is so ironic, because in this weather I really wish I'd not lost my phone in greece.
Hold the phone!! - dump the phone company (Score:2, Interesting)
For eveyone elses phone.. (Score:3, Funny)
Digital should degrade gracefully... (Score:1)
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.
Re:Digital should degrade gracefully... (Score:1)
Re:Digital should degrade gracefully... (Score:1)
Re:Digital should degrade gracefully... (Score:1)
Good point.
Time for a little sig twiddling...
Re:Digital should degrade gracefully... (Score:1)
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)
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)
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.
Re:wow how uninformed (Score:2)
Re:wow how uninformed (Score:1)
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
Re:wow how uninformed (Score:2)
Microwave (Score:5, Insightful)
Re:Microwave (Score:1)
Re:Microwave (Score:1)
Re:Microwave (Score:2, Insightful)
Commercial? (Score:1)
Re:Commercial? (Score:2)
http://www.matthoppes.org/html/
There are no analogue networks left in Europe... (Score:5, Interesting)
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.
Re:There are no analogue networks left in Europe.. (Score:1)
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.)
You haven't been the North America lately (Score:2)
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.
You haven't been counting lately (Score:3, Informative)
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.
Re:There are no analogue networks left in Europe.. (Score:2)
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?
Re:There are no analogue networks left in Europe.. (Score:2)
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.
Re:There are no analogue networks left in Europe.. (Score:2)
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.
Re:There are no analogue networks left in Europe.. (Score:2)
Re:There are no analogue networks left in Europe.. (Score:2)
Re:There are no analogue networks left in Europe.. (Score:2)
Re:There's a reason why the US uses 1.9Ghz (Score:2)
One single biggest reason US gets any phones at all, is that there needs to be something shown for investors. Something they can hold in their hand and use.
Re:There's a reason why the US uses 1.9Ghz (Score:2)
Okay, Mister Smarty-Pants, what's our other choice over here?
- A.P.
Re:There are no analogue networks left in Europe.. (Score:2)
Cool. Might just be Orange, then. Or possibly they've changed it recently.
Re:There are no analogue networks left in Europe.. (Score:2)
That was with Vodaphone xnet200. Same sort of thing with orange too (last summer any way).
I ran up a £120 bill over summer, thanks to 3 weeks in greece, then 2 weeks driving back through europe, and calling my parents (who live in greece). Didnt use any free minutes either!
Re:There are no analogue networks left in Europe.. (Score:2)
Can someone please tell me what people find so objectionable to the idea that the caller party pays (CPP)? If I want to send someone a letter then I have to pay for the service - the paper, the envelope and, most importantly, the stamp. And, in just about every market outside of North America, the same model is applied to telephone calls.
Frankly this makes far more sense than the US model - if you want to talk to me then why should I have to pay for the priviledge of having to hear what you have to say? And how would you feel if the mail worked that way too? Can you imagine having to pay the postal service for receiving bills or junk mail?
Now, if you make lots of calls you pay more than someone who makes only a few. This makes sense - the more you use a service, the more you pay for it.
Heavy users can plan accordingly, by subscribing to a plan that has a lot of inclusive minutes and/or for which the call costs are greatly reduced (eg, a few US cents per minute).
Meanwhile, light users aren't penalised into contracts that require them to shell out big bucks for a service they don't use. Sure, they pay more for their calls, but the rates aren't that much more than those of public phones.
So in Europe, a business man who uses his phone constantly can pay a fixed monthly fee and use his phone as much as he likes whilst, on the same network, a frail grandmother who only has a phone for emergencies can go months without having to pay a single penny for the peace of mind that having a phone gives her.
How is this a bad thing?
Roaming costs? What roaming costs? It's just not an issue in Europe. Nationwide long distance? I pay one rate for all calls, irrespective of who I call or where they are.
Again, not a bad thing.
Sometimes, when things are different, it's because they are different for a very good reason.
Re:There are no analogue networks left in Europe.. (Score:2)
Agreed. It's as useful as a single currency - I still havent worked out some Italian phone cards (where you have to dial a number)
I've had a mobile for the last 5 years (of course now every 12 year old and his dog had one, I was the only person in school with a phone on GCSE results day). Naturally I dont remember peoples phone numbers now.
This was a great problem when I left my phone in greece 2 weeks ago. Got on the boat to italy, and realised I'd forgotten it when I tried to look at the time (I dont have a watch now either).
Didnt know anyones number, and after a 24 hours boat ride, spending 6 hours in venice on new years eve, isn't fun. Found an internet cafe, and sent a few emails. Couldnt make any phone calls though because I didnt know anyones number! Eventually got back to the UK and rang directory enquiries from Bristol.
A phone is great, but dont rely on it!
Re:Caller ID (Score:2)
Re:There are no analogue networks left in Europe.. (Score:2)
I'm not really sure what my phone tarriff is at the moment. I do know I get 50 minutes free in the evenings, but I use my phone quite a bit during the day. My monthly bill is about £20, anyway.
Digital != Digital (Score:2)
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)
Yay Digital... (Score:3, Funny)
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)
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...
Re:Digital Rocks (Score:2)
Same experience here (Score:2)
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.
Re:Same experience here (Score:2)
Re:Digital Rocks (Score:2)
Re:Digital Rocks (Score:2)
Instead, it is in a perfect location to draw a nice large coverage area on a map, but not actually provide service.
(I am aware of the problems and issues as you describe them and know they are real, in this particular instance that I mention that was NOT the reason for the decision.)
Microwaving your Head (Score:2, Informative)
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)
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.
Re:Old-debate (Score:2)
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.
Re:Old-debate (Score:2)
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.
The State of digital in CH (Score:1)
There are just simply no advantages in analog.. (Score:1)
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
iden phones rock!!! (Score:2)
The real skinny (Score:2)
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)
Dave
BTW, I have a perpetual energy machine to sell you, if you're interested.
Re:The real skinny (Score:2)
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.
-5 Moronic Troll? (Score:1)
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
Re:-5 Moronic Troll? (Score:1, Troll)
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)
Sure, a perfect vinyl record may theoretically sound better than a CD, but when was the last time you saw a perfect vinyl record?
Are you mentally retarded? (Score:3, Insightful)
- A.P.
Re:-5 Moronic Troll? (Score:2)
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.
Re:-5 Moronic Troll? (Score:2)
Re:-5 Moronic Troll? (Score:2)
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.
Re:-5 Moronic Troll? (Score:2)
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.
Re:-5 Moronic Troll? (Score:2)
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.
Re:-5 Moronic Troll? (Score:2)
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!
Re:-5 Moronic Troll? (Score:2)
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.
Re:-5 Moronic Troll? (Score:2)
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.
*ringring* it's the cluephone... (Score:2, Informative)
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...
Wattage my boy (Score:1)
Re:Wattage my boy (Score:2)
This is for the US market of course, but numbers elsewhere are similar.
do the math (Score:4, Interesting)
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)
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)
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.
Re:Cite some credentials, please (Score:3, Informative)
Actually, with info from the FCC, you can figure it out. For example...
Nextel Coverage Maps (Transmitter Locations) [howardforums.com]
Have fun!
Wow! (Score:2)
Thank you, sir, for proving the bar can indeed be set lower.
- A.P.
Here's an Idea (Score:1, Insightful)
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.
Re:Here's an Idea (Score:3, Funny)
Not even dogs can.
What a load (Score:5, Interesting)
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
Close? (Score:2)
Why bother with the theory anyway? If you're worried, put your egg by your phone and cook it.
In Australia (Score:2)
Power (Score:2, Informative)
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)
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.