As much of a pain as it is having 2 different digital standards, allowing
the market to experiment with CDMA on a mass scale was actually good.
Everything in the future is going to go to a "CDMA-type" standard, including
GSM when it upgrades to its 3G UMTS format. Unfortunately Verizon will still
be incompatible with Cingular.
CDMA has the advantage that it's inherently data-friendly. The digitized
audio information is mixed with a unique digital sequence "Walsh Code"
that's about a 100 times higher frequency, and combined with 100 or so other
conversations all at the same time. The receiver knows its assigned "Walsh
Code", and filters appropriately so that only the intended conversation
drops out. The advantage is there's a continous data stream, with no
interruptions, which data packets like.
TDMA/GSM on the other hand, works by time slicing. Multiple conversations
are put into multiple time slots, and pulled out of aequence at the right
time by the receiver. This is fine for voice but causes havoc for data,
which requires the GPRS add-on to make it work.
The analogy is the United Nations cocktail party, where everyone's trying to
be heard. With TDMA/GSM each couple speaks in turn, and then shuts up while
other couples get their turn to talk. With CDMA everyone talks at once, but
speaks in their own native language from back home so the other
conversations sound like background noise.
Sorry, this diverged a bit but I couldn't resist.
Nat
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Carleton MacDonald
Sent: Thursday, 2007 March 15 22:47
To: U.S. Metric Association
Subject: [USMA:38229] RE: Brand New Phone, 12 Hour Time.
Well, there is something related - CDMA is another case of the USA doing
things differently than 80% of the rest of the world ...
Wonder which is actually better.
Carleton
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Michael Payne
Sent: Thursday, March 15, 2007 23:07
To: U.S. Metric Association
Subject: [USMA:38224] RE: Brand New Phone, 12 Hour Time.
Not that this has much to do with metric, but I switched from Cingular to
T-Mobile just over a year ago and I've found the coverage with T-Mobile
better using a GSM phone, I also use my phone worldwide.
Michael Payne
----- Original Message -----
From: "Nat Hager III" <[EMAIL PROTECTED]>
To: "U.S. Metric Association" <[email protected]>
Sent: Friday, 16 March 2007 02:59
Subject: [USMA:38222] RE: Brand New Phone, 12 Hour Time.
>>> You actually cared about TDMA coverage and left Cingular because of
>>> that?
>
> Wow, you deserve the 12 hour time then. hahahaha.. Of course, maybe
> I'm
> spoiled because I'm in Seattle. Home of both AT&T Wireless (before
> Cingular
> bought them) and T-Mobile.
>>>
>
> You bet. In 2005 Cingular GSM coverage was only slightly better than
> T-Mobile, in 2004 it was experimental on the weaker 1900 MHz band only, my
> phone switched to TDMA half the time.
>
> Nat
>
>
>
