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View Full Version : TDMA, CDMA? What is that?



Shidoshi
10-11-2002, 11:22 AM
Hmm...

What's the difference between TDMA and CDMA and non-TD/CDMA phones? I live in Portugal and have never heard anything about that, I've seen it been mentioned at NokiaFree before several times but never actually looked into it.

Just really curious now :)

Thanks,
-Dave

green gerbil
10-11-2002, 10:33 PM
AMPS- Analog Cellular - Uses ESN and Nam to authenticate to tower, one channel per phone.
TDMA - Time Division Multiple Access - Uses the ESN and Nam and possibly A-key for authentication with tower before placing calls. Works on a time sharing basis. More phones go on one channel because they get a different timeslot. Basically the same thing as gsm except you cant easily change identity of the phone from one to another (no simcard).
CDMA - Code Division Multiple Access - Uses same things as above to authenticate. Uses spread spectrum to fit even more phones on a channel and is very power efficient. Instead of weird distortions and missmatched conversations, CDMA cuts out when there is a signal problem.

I still like analog the best except for the battery times :)

Shidoshi
11-11-2002, 12:17 PM
Hmm...

Thanks for your very explicit explanation, it cleared that query out for me.

I think I will also stick to analogue, however ID switching doesn't sound like a bad idea with TDMA ;)

Thanks,
-Dave

Nanda
14-11-2002, 07:09 PM
@Shidoshi

A good website that explains TDMA vs CDMA vs GSM in detail is http://www.arcx.com/sites/index.htm . It's in English though, from a bloke in Canada.

There are a couple of good sites in Portuguese about CDMA and TDMA too (they're still used in Brasil) but I don't have their links now. Besides they don't compare those systems with GSM, which would clarify a lot of things for you in Europe.

Anyways, I still reckon GSM is better than both because of its huge phone choice and universal roaming. I used to have a TDMA nokia but since I had it stolen I switched to GSM. My parents still use TDMA phones (Nok 3320) but it seems that everyone buying new phones are preferring GSM in my part of the world.

Of course, you don't have that choice, but apart from CDMA call quality in remote areas (quite common here) you're not missing much.

Hope this helps. Don't miss out that link!

Cordialmente,

Shidoshi
15-11-2002, 02:25 AM
Hmm...

I've read thoroughly the information displayed on the page that you indicated. It was very informative indeed, thank you very much Nanda and green gerbil also ;)

@Nanda:

I understand both English and Portuguese very well, however I have a much wider understanding when it comes to English ;)

Thanks,
-Dave