what are the main differences in these and why does the reception differ between the two?
also, what is PCS… i asked a friend who had it and he didn’t know
Chief’s Domain - http://www.seas.ucla.edu/~ravi
PCS is nothing more than “Personal Cellular Service”. Is it anything more than a digital phone? My friends in the field tell me “no”.
I’m no expert, so I can’t sling the correct acronyms and details. In general, trtanscribing a digital transmission to something you can listen to involves only deciding whether each particular bit is one or zero. There’s a fairly large difference between one and zero. So a perfect signal is transcribed perfectly, a slightly-to-somewhat degraded signal is transcribed perfectly, a poor signal is transcribed with a few errors, and a lousy signal is transcribed as garbage.
On the other hand, every degradation in an analog signal is potetntially an error in what you hear, although sophisticated filters and signal processors can mask a lot of the errors before they get to you.
Bottom line: under perfect conditions it doesn’t matter, but under imperfect conditions digtial systems almost always perform better.
jrf
Go to Usenet or DejaNews and look up the alt.cellular newsgroup to get plenty of info.
Also look in www.point.com
Basically, digital uses the 1’s and 0’s to handle data like a computer does. Phone companies can compress/code the data just like a computer can, allowing them to handle more users than they could with analog phones. This lowers the cost per user.
Digital also lets you use extra features such as caller ID.
Digital uses less power so batteries last longer.
Analog uses more power and has longer range.
Digital systems typically use analog as backup for when you get away from the larger cities.
I work in wireless. The above answers are right. An analog signal is transmitted by radio waves. A digital signal is transmitted by binary code. This allows for scrambling & digitizing, so that there’s better security (although, still not completely secure). Less power is used, so you have longer battery life. Clearer signal.
Most companies that sell digital, now, sell technology that allows the phone to switch between digital and analog. The phones we sell switch from 1.9 digital to 800 mghz digital to analog, whichever signal is stronger, without the user having to end the call or drop the call. Some other companies sell something that snaps onto the phone that allows the user to use both systems, but the user has to end the call when snapping the little thing on. I’ve never used one of these, so I don’t know much about this device.
This isn’t entirely true; I have caller ID on my ancient analog phone.
Here’s what I know:
With analog, you get a signal of varying quality from good to bad.
With digital, there is very little leeway. You pretty much get a clear signal or nothing.
Here’s what I thought:
PCS is digital that uses a higher frequency and more “links” since they have shorter range.
Feel free to get me up to speed if I’ve missed something.
I think some of the confusion comes from those stupid commercials that try to make a distinction between “cellular” and “PCS digital”. Is there really a difference?
Here’s what I think I know. Let’s distinguish between these two things: signal and information. In other words, there are digital & analog information (data), and digital & analog signaling techniques (transmission). We can have:
[list type=A]
[li]Digital data transmitted with digital signals (e.g., a word doc from RAM to disk).[/li][li]Digital Data via analog signaling (e.g., transferring a file from your PC to work via a modem)[/li][li]Analog data via analog signaling (e.g., your voice over the phone)[/li][li]Analog data via digital data (e.g., your voice recorded via a sound card and stored on disk in a computer)[/li][/list]
ALL signals transmitted via “airwaves” are inherently analog (electro-magnetic). A digital phone takes your analog voice and converts it into digital information and encodes it in an analog signal for transmission.
The advantages stated in the previous posts are correct: error checking & correcting, compression and so forth. This is of particular interest these days since people are interested in having access to inherently digital information (email, etc.).
Digital is not inherently better for analog data. Consider talking to your granny over a bad connection. Over traditional lines, you can still distinguish “hello” even with a high level of static. Information has been successfully transmitted. On a digital phone, you’d get squat. (This, of course, is a re-statement of what someone said earlier.)
Tinker
oops!
The last item in the list should read “analog info via digital signals”.
RealPlayer would be a better example than the one I gave previously.
well, no. PCS stands for Personal Communications Services. they want to make the distinction between it and analog cellular.
what is essential is invisible to the eye -the fox
And now we have (just for good measure and added confusion) digital and analog hard-wired telephones.
Recently, my office installed new telephones for several of us with new features, including instantaneous called ID. Problem was, these were digital phones, operating on new digital lines, and those of us with modems, cordless phones, etc. found that they no longer worked. They had to come back, take out the digital phones, change the lines back to analog, and give us new phones. I still have Caller ID, but now it’s much slower to identify the caller.
Computers in the future may weigh no more than 15 tons.
-Popular Mechanics, 1949
Those have been around for some time. Lots of hotels have them. I’ve fried two analog modems. Many people who travel a lot (my travel has gone down a lot in the last few years) carry adapters (around $200 at places like Road Warrior).
“Cellular” means any of several possible systems, including “PCS digital”. The ads are trying to make a distinction between analog cellular and PCS digital cellular. There are several varieties of analog cellular (one of which is available in the US) and several varieties of digital cellular (IIRC two of which are available in the US).
jrf
Hmm, yes…how does one get one’s computer to do the dialing for you if your phone line is digital? My built-in modem expects a plain old (analog) telephone line. I wouldn’t mind purchasing a digital modem, if such a thing exists, although all I really need is something that will send the button-key information (1,2,3,4,5,6,7,8,9,0,*,#) – in particular, since typical modems want to “hang up” the line and start from dial tone, whereas I just want the computer to do the equiv of me hitting the telephone button if told to do so by a script on my computer (or even by me hitting the key on the numerical keypad).
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