CDMA and WCDMA?

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

I've read in some of these newsgroups that GSM is moving to, or being
enhanced with WCDMA technology. What does WCDMA entail, and how does it
compare with CDMA? Will it permit users of GSM/WCDMA phones to roam to
CDMA carriers, and/or vice-versa?

I've done some cursory google searching of cdma and wcdma but could not
find anything that made enough sense to me.

Looking to be educated in these two worlds of CDMA and WCDMA.

Thank you.

Scott

 

[Joseph]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On 04 Dec 2004 00:47:22 GMT, scott@mit.edu (Scott Ehrlich) wrote:

>I've read in some of these newsgroups that GSM is moving to, or being
>enhanced with WCDMA technology. What does WCDMA entail, and how does it
>compare with CDMA? Will it permit users of GSM/WCDMA phones to roam to
>CDMA carriers, and/or vice-versa?
>
>I've done some cursory google searching of cdma and wcdma but could not
>find anything that made enough sense to me.
>
>Looking to be educated in these two worlds of CDMA and WCDMA.

CDMA and W-CDMA use the same underlying technlogy. That's where the
similarity ends. GSM uses TDMA technology, but that's about the only
relation it has to TDMA (IS-136.)

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[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

You can't roam with a CDMA phone on a WCDMA network or vice-versa. For a
starting point, go to www.gsmworld.com and browse the Wireless Evolution
section.

--

\/ L /\ D


"Scott Ehrlich" <scott@mit.edu> wrote in message
news:41b1091a$0$562$b45e6eb0@senator-bedfellow.mit.edu...

I've read in some of these newsgroups that GSM is moving to, or being
enhanced with WCDMA technology. What does WCDMA entail, and how does it
compare with CDMA? Will it permit users of GSM/WCDMA phones to roam to
CDMA carriers, and/or vice-versa?

I've done some cursory google searching of cdma and wcdma but could not
find anything that made enough sense to me.

Looking to be educated in these two worlds of CDMA and WCDMA.

Thank you.

Scott

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

Vlad Andreyev wrote:
> You can't roam with a CDMA phone on a WCDMA network or vice-versa.
> For a starting point, go to www.gsmworld.com and browse the
> Wireless Evolution section.

Is this the point?:

http://www.gsmworld.com/technology/3g/intro.shtml
" No other standard offers the flexible combination of voice and data
performance and capacity delivered by 3GSM underpinned by Wideband-CDMA. No
other standard is as open as 3GSM. No other standard delivers the economies
of scale and competitiveness for operators and vendors. "


http://www.cdmatech.com/resources/glossary_full.jsp

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

In article <xZOdncDeS5MS2yzcRVn-iA@comcast.com>,
Vlad Andreyev <vlad@atlantech.net> wrote:
>You can't roam with a CDMA phone on a WCDMA network or vice-versa. For a
>starting point, go to www.gsmworld.com and browse the Wireless Evolution
>section.

CDMA2000, which, for example, Verizon Wireless and SprintPCS use,
is a completely different protocol than WCDMA, which is the migration
path for GSM systems. They use the same underlying concept or multiple
users sharing the same frequency band using spread-spectrum techniques,
but how they do it is completely different. Totally different "languages".

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sat, 4 Dec 2004 13:47:05 -0500, CharlesH wrote
(in article <JCnsd.38751$6q2.14881@newssvr14.news.prodigy.com>):

> Subject: Re: CDMA and WCDMA?
> From: hoch@exemplary.invalid (CharlesH)
> Date: Today 1:47 PM
> Newsgroups: alt.cellular.verizon, alt.cellular.cdma, alt.cellular.gsm
>
> In article <xZOdncDeS5MS2yzcRVn-iA@comcast.com>,
> Vlad Andreyev <vlad@atlantech.net> wrote:
>> You can't roam with a CDMA phone on a WCDMA network or vice-versa. For a
>> starting point, go to www.gsmworld.com and browse the Wireless Evolution
>> section.
>
> CDMA2000, which, for example, Verizon Wireless and SprintPCS use,
> is a completely different protocol than WCDMA, which is the migration
> path for GSM systems. They use the same underlying concept or multiple
> users sharing the same frequency band using spread-spectrum techniques,
> but how they do it is completely different. Totally different "languages".

Finally someone can explain this!

Do you ever see Sprint/Verizon migrating to GSM/WCDMA?

 

[Joseph]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sat, 4 Dec 2004 22:07:43 -0500, SinghaLvr <singhalvr@charter.net>
wrote:

>On Sat, 4 Dec 2004 13:47:05 -0500, CharlesH wrote
>(in article <JCnsd.38751$6q2.14881@newssvr14.news.prodigy.com>):
>
>> Subject: Re: CDMA and WCDMA?
>> From: hoch@exemplary.invalid (CharlesH)
>> Date: Today 1:47 PM
>> Newsgroups: alt.cellular.verizon, alt.cellular.cdma, alt.cellular.gsm
>>
>> In article <xZOdncDeS5MS2yzcRVn-iA@comcast.com>,
>> Vlad Andreyev <vlad@atlantech.net> wrote:
>>> You can't roam with a CDMA phone on a WCDMA network or vice-versa. For a
>>> starting point, go to www.gsmworld.com and browse the Wireless Evolution
>>> section.
>>
>> CDMA2000, which, for example, Verizon Wireless and SprintPCS use,
>> is a completely different protocol than WCDMA, which is the migration
>> path for GSM systems. They use the same underlying concept or multiple
>> users sharing the same frequency band using spread-spectrum techniques,
>> but how they do it is completely different. Totally different "languages".
>
>Finally someone can explain this!
>
>Do you ever see Sprint/Verizon migrating to GSM/WCDMA?

It never will happen. 2G CDMA's migration path is to CDMA2000 not
W-CDMA.

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[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

In news:cqf5r0t4fkqth7i00snibhmnr1j9bm879h@4ax.com,
Joseph <JoeOfSeattle@yahoo.com> typed:
> On Sat, 4 Dec 2004 22:07:43 -0500, SinghaLvr <singhalvr@charter.net>
> wrote:
>
>> On Sat, 4 Dec 2004 13:47:05 -0500, CharlesH wrote
>> (in article <JCnsd.38751$6q2.14881@newssvr14.news.prodigy.com>):
>>
>>> Subject: Re: CDMA and WCDMA?
>>> From: hoch@exemplary.invalid (CharlesH)
>>> Date: Today 1:47 PM
>>> Newsgroups: alt.cellular.verizon, alt.cellular.cdma,
>>> alt.cellular.gsm
>>>
>>> In article <xZOdncDeS5MS2yzcRVn-iA@comcast.com>,
>>> Vlad Andreyev <vlad@atlantech.net> wrote:
>>>> You can't roam with a CDMA phone on a WCDMA network or vice-versa.
>>>> For a starting point, go to www.gsmworld.com and browse the
>>>> Wireless Evolution section.
>>>
>>> CDMA2000, which, for example, Verizon Wireless and SprintPCS use,
>>> is a completely different protocol than WCDMA, which is the
>>> migration path for GSM systems. They use the same underlying
>>> concept or multiple users sharing the same frequency band using
>>> spread-spectrum techniques, but how they do it is completely
>>> different. Totally different "languages".
>>
>> Finally someone can explain this!
>>
>> Do you ever see Sprint/Verizon migrating to GSM/WCDMA?
>
> It never will happen. 2G CDMA's migration path is to CDMA2000 not
> W-CDMA.
>
> - - - - - - - - - - - - - - - - - - - - - - - - -

VZW, Sprint, Alltel, etc which started with CDMA can upgrade their networks
to CDMA2000 incrementally since the upgrades are compatable with current
equipment.

Converting from TDMA to GSM and then from GSM to WCMA requires new equipment
for each upgrade.

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.gsm (More info?)

In alt.cellular.gsm SinghaLvr <singhalvr@charter.net> wrote:
> Finally someone can explain this!
>
> Do you ever see Sprint/Verizon migrating to GSM/WCDMA?

Doubt it. They've invested so much money in their CDMA2000x1 network.
The obvious migraqtion path to 3G/high bandwidth mobile is to upgrade to
CDMA EV-DO. For a lot of their cells I'd assume it's merely a software
upgrade.

PD

--
Paul Day Web: www.bur.st/~paul GPG Key ID: 7FF655A8

 

[Joseph]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sun, 5 Dec 2004 10:16:48 -0600, "IMHO" <nospam@nospam.net> wrote:

>VZW, Sprint, Alltel, etc which started with CDMA can upgrade their networks
>to CDMA2000 incrementally since the upgrades are compatable with current
>equipment.
>
>Converting from TDMA to GSM and then from GSM to WCMA requires new equipment
>for each upgrade.

I know you're trying to make a point, but what is it?

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[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sat, 04 Dec 2004 22:07:43 -0500, SinghaLvr wrote:

> Do you ever see Sprint/Verizon migrating to GSM/WCDMA?

IMO that would never happen.

Isn't their unique selling point the alleged superiority of CDMA over GSM?

Clear reception, etc, blah, blah, blah.

 

[Joseph]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sun, 05 Dec 2004 15:31:13 +1100, John Phillips
<flatulantdingo@deadspam.com> wrote:

>On Sat, 04 Dec 2004 22:07:43 -0500, SinghaLvr wrote:
>
>> Do you ever see Sprint/Verizon migrating to GSM/WCDMA?
>
>IMO that would never happen.
>
>Isn't their unique selling point the alleged superiority of CDMA over GSM?
>
>Clear reception, etc, blah, blah, blah.

I don't think you understand the question. The upgrade path from 2G
GSM is to W-CDMA which is a form of CDMA unrelated to what is
presently used by such carriers as Verizon and Sprint PCS.
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[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

In newst57r0l0d2hthgjch2ljn9guehvghnoiq0@4ax.com,
Joseph <JoeOfSeattle@yahoo.com> typed:
> On Sun, 5 Dec 2004 10:16:48 -0600, "IMHO" <nospam@nospam.net> wrote:
>
>> VZW, Sprint, Alltel, etc which started with CDMA can upgrade their
>> networks to CDMA2000 incrementally since the upgrades are compatable
>> with current equipment.
>>
>> Converting from TDMA to GSM and then from GSM to WCMA requires new
>> equipment for each upgrade.
>
> I know you're trying to make a point, but what is it?
>
> - - - - - - - - - - - - - - - - - - - - - - - - - -

TDMA, GSM & WCDMA are three different systems all requiring different
equipment.

CDMA thru CDMA2000 are compatable with each other - transparent to users.

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

In article <pt57r0l0d2hthgjch2ljn9guehvghnoiq0@4ax.com>,
Joseph <JoeOfSeattle@yahoo.com> wrote:
>On Sun, 5 Dec 2004 10:16:48 -0600, "IMHO" <nospam@nospam.net> wrote:
>
>>VZW, Sprint, Alltel, etc which started with CDMA can upgrade their networks
>>to CDMA2000 incrementally since the upgrades are compatable with current
>>equipment.
>>
>>Converting from TDMA to GSM and then from GSM to WCMA requires new equipment
>>for each upgrade.
>
>I know you're trying to make a point, but what is it?
>

I think their point is in the former case, the CDMA > CDMA2000 upgrade is
cheaper because the infrastructure for CDMA2000 is easier to implement
with what already exists for CDMA, whereas, in the latter case TDMA > GSM
involves a complete change of everything, and the same from GSM to WCDMA.

Please correct me if I am wrong.

Scott

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sun, 5 Dec 2004 19:00:00 -0600, "IMHO" <nospam@nospam.net> chose to add
this to the great equation of life, the universe, and everything:

>In newst57r0l0d2hthgjch2ljn9guehvghnoiq0@4ax.com,
>Joseph <JoeOfSeattle@yahoo.com> typed:
>> On Sun, 5 Dec 2004 10:16:48 -0600, "IMHO" <nospam@nospam.net> wrote:
>>
>>> VZW, Sprint, Alltel, etc which started with CDMA can upgrade their
>>> networks to CDMA2000 incrementally since the upgrades are compatable
>>> with current equipment.
>>>
>>> Converting from TDMA to GSM and then from GSM to WCMA requires new
>>> equipment for each upgrade.
>>
>> I know you're trying to make a point, but what is it?
>
>TDMA, GSM & WCDMA are three different systems all requiring different
>equipment.
>
>CDMA thru CDMA2000 are compatable with each other - transparent to users.

All true, but other posts in this thread have indicated that a transition
from CDMA2000 to WCDMA would not be transparent but would require new
equipment just as would the transition from GSM.

--
David Streeter, "an internet god" -- Dave Barry
http://home.att.net/~dwstreeter
Remove the naughty bit from my address to reply
Expect a train on ANY track at ANY time.
"I've really been burning the midday oil." - Ronald Reagan

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

David S wrote:
> On Sun, 5 Dec 2004 19:00:00 -0600, "IMHO" <nospam@nospam.net> chose
> to add this to the great equation of life, the universe, and
> everything:
>
>> In newst57r0l0d2hthgjch2ljn9guehvghnoiq0@4ax.com,
>> Joseph <JoeOfSeattle@yahoo.com> typed:
>>> On Sun, 5 Dec 2004 10:16:48 -0600, "IMHO" <nospam@nospam.net> wrote:
>>>
>>>> VZW, Sprint, Alltel, etc which started with CDMA can upgrade their
>>>> networks to CDMA2000 incrementally since the upgrades are
>>>> compatable with current equipment.
>>>>
>>>> Converting from TDMA to GSM and then from GSM to WCMA requires new
>>>> equipment for each upgrade.
>>>
>>> I know you're trying to make a point, but what is it?
>>
>> TDMA, GSM & WCDMA are three different systems all requiring different
>> equipment.
>>
>> CDMA thru CDMA2000 are compatable with each other - transparent to
>> users.
>
> All true, but other posts in this thread have indicated that a
> transition from CDMA2000 to WCDMA would not be transparent but would
> require new equipment just as would the transition from GSM.

Why in heck would anyone in their right mind want to go from CDMA2000 to
WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!?

Sure it would not be transparent, since it would be incredibily STUPID and
insane to even consider it!

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

On Sun, 5 Dec 2004 23:07:08 -0800, "Peter Pan"
<Marcs1102NOSPAM@HotmailNOSPAM.com> wrote:

>Why in heck would anyone in their right mind want to go from CDMA2000 to
>WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!?
>
>Sure it would not be transparent, since it would be incredibily STUPID and
>insane to even consider it!

Why?

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.gsm (More info?)

singha_lvr wrote:
> On Sun, 5 Dec 2004 23:07:08 -0800, "Peter Pan"
> <Marcs1102NOSPAM@HotmailNOSPAM.com> wrote:
>
>> Why in heck would anyone in their right mind want to go from
>> CDMA2000 to WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!?
>>
>> Sure it would not be transparent, since it would be incredibily
>> STUPID and insane to even consider it!
>
> Why?

WCDMA doesn't scale? Did Docomo try to deploy it 2 or 3 times?

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.gsm (More info?)

Quick wrote:
> singha_lvr wrote:
>> On Sun, 5 Dec 2004 23:07:08 -0800, "Peter Pan"
>> <Marcs1102NOSPAM@HotmailNOSPAM.com> wrote:
>>
>>> Why in heck would anyone in their right mind want to go from
>>> CDMA2000 to WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!?
>>>
>>> Sure it would not be transparent, since it would be incredibily
>>> STUPID and insane to even consider it!
>>
>> Why?
>
> WCDMA doesn't scale? Did Docomo try to deploy it 2 or 3 times?

Yes.. but they are gsm/i-mode going towards wcdma, and have never been
cdma/cdma2000.

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]

In <4sf5r0169j7sojd0uavfg17g0gg9qv64b3@4ax.com> on Sat, 04 Dec 2004 23:59:02
-0800, Joseph <JoeOfSeattle@yahoo.com> wrote:

>On Sun, 05 Dec 2004 15:31:13 +1100, John Phillips
><flatulantdingo@deadspam.com> wrote:
>
>>On Sat, 04 Dec 2004 22:07:43 -0500, SinghaLvr wrote:
>>
>>> Do you ever see Sprint/Verizon migrating to GSM/WCDMA?

No, but there is some chance that CDMA and WCDMA will merge.

>I don't think you understand the question. The upgrade path from 2G
>GSM is to W-CDMA which is a form of CDMA unrelated to what is
>presently used by such carriers as Verizon and Sprint PCS.

WCDMA is a type of CDMA only in the air interface, which is considerably
different from what's called CDMA -- the infrastructure of WCDMA is based on
GSM, and WCDMA is designed to complement GSM. Thus WCDMA is actually more GSM
than CDMA.

--
Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

GSM really resides in the higher layers of the network protocol stack. In
the lower layers - the air interface, there is currently TDMA. (Granted,
it's not exactly the same as the IS-136 version (like the old AT&T network),
but it still is TDMA.) In 3G incarnation, GSM will become UMTS in the
higher layers, and it will rely on WCDMA in the lower layers. What this
means is that the UMTS network will provide additional services to
subscribers. Because these services require higher bandwidth than what's
possible with the current TDMA system, it will be substituted with WCDMA.
While there is a lot of overlap between these terms, you have to
differentiate between the network and the air interface layers.

--

\/ L /\ D


"John Navas" <spamfilter0@navasgroup.com> wrote in message
news:%15td.9771$_3.114986@typhoon.sonic.net...
[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]

WCDMA is a type of CDMA only in the air interface, which is considerably
different from what's called CDMA -- the infrastructure of WCDMA is based on
GSM, and WCDMA is designed to complement GSM. Thus WCDMA is actually more
GSM
than CDMA.

--
Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.gsm (More info?)

Vlad Andreyev wrote:
> GSM really resides in the higher layers of the network protocol
> stack. In the lower layers - the air interface, there is currently
> TDMA. (Granted, it's not exactly the same as the IS-136 version
> (like the old AT&T network), but it still is TDMA.) In 3G
> incarnation, GSM will become UMTS in the higher layers, and it will
> rely on WCDMA in the lower layers. What this means is that the UMTS
> network will provide additional services to subscribers. Because
> these services require higher bandwidth than what's possible with the
> current TDMA system, it will be substituted with WCDMA. While there
> is a lot of overlap between these terms, you have to differentiate
> between the network and the air interface layers.

Ok...
1) Is the WCDMA air interface backward compatible with the
TDMA air interface?

2) If not, will it be able to concurrently occupy the same bandwidth?
(Will it require "throwing a switch" after which all WCDMA equipment
will work and all TDMA equipment won't?)

3) Is there any difference in the air interface for WCDMA and CDMA2000?
3a) If so, do they scale the same?

-Quick

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.gsm (More info?)

"Quick" <quick7135-news@NOSPAMyahoo.com> wrote in message
news:1102386246.247801@sj-nntpcache-5...

Ok...
1) Is the WCDMA air interface backward compatible with the
TDMA air interface?

No, they have absolutely nothing in common.

2) If not, will it be able to concurrently occupy the same bandwidth?
(Will it require "throwing a switch" after which all WCDMA equipment
will work and all TDMA equipment won't?)

Yes, they can co-exist. AT&T (now Cingular) is currently running both UMTS
(WCDMA-based) and GSM (TDMA-based) systems in 6 metro areas around the
country, both in the 1900MHz band, but in different parts of it. The
operator can allocate how much of their spectrum is occupied by which
system.

3) Is there any difference in the air interface for WCDMA and CDMA2000?
3a) If so, do they scale the same?

Yes, there is a difference. They are two totally different standards. One
has been chosen as the migration path for GSM, and the other one - as the
migration path for CDMA. What they share is the underlying concept of
simultaneously sending digital signals between multiple phones within a cell
over a spread spectrum. (I'm not sure about scaling.)

In TDMA environment, your phone receives on one frequency during a call and
transmits on another. So do several other phones at the same time, using
the same receive/transmit frequencies as yours, and you all take turn, so
that no two phones receive or transmit at the same time. There are a few of
such groups of phones in a cell, which take turn to use the same frequency.
It's quite a simple concept.

CDMA, on the contrary, is rather complicated. It uses the time and spectrum
more efficiently and, therefore, is capable of higher bandwidth. I can't go
into details, because it can make anyone's head spin, but in CDMA, your
phone actually doesn't stay on one frequency during a call but continuously
hops from one frequency to another, as do all the other phones in the cell.
This is called spread spectrum.

-Quick

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]

In <VvGsd.83493$EZ.74227@okepread07> on Sun, 5 Dec 2004 10:16:48 -0600, "IMHO"
<nospam@nospam.net> wrote:

>VZW, Sprint, Alltel, etc which started with CDMA can upgrade their networks
>to CDMA2000 incrementally since the upgrades are compatable with current
>equipment.

Likewise TDMA / GSM.

>Converting from TDMA to GSM and then from GSM to WCMA requires new equipment
>for each upgrade.

It's actually an easier hardware upgrade than from GSM to CDMA.

--
Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>

 

[Guest]

Archived from groups: alt.cellular.verizon,alt.cellular.cdma,alt.cellular.gsm (More info?)

In news:l35td.9772$_3.114997@typhoon.sonic.net,
John Navas <spamfilter0@navasgroup.com> typed:
> [POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]
>
> In <VvGsd.83493$EZ.74227@okepread07> on Sun, 5 Dec 2004 10:16:48
> -0600, "IMHO" <nospam@nospam.net> wrote:
>
>> VZW, Sprint, Alltel, etc which started with CDMA can upgrade their
>> networks to CDMA2000 incrementally since the upgrades are compatable
>> with current equipment.
>
> Likewise TDMA / GSM.
>
>> Converting from TDMA to GSM and then from GSM to WCMA requires new
>> equipment for each upgrade.
>
> It's actually an easier hardware upgrade than from GSM to CDMA.


I thought there was a different handset required for TDMA and GSM - there
are seperate plans for each.

Why have ATT, Cingular, etc required users to get new handsets for GSM?

Actually in the ATT user forum they have been talking about the need to
change to a Cingular plan AND Cingular handset to access all of the Cingular
features.

Since TDMA and GSM currently use forms of "Time Division Multiple Access" to
access their respective systems and W-CDMA uses a "Code Division Multiple
Access" - I thought there would be different handset required to access the
W-CDMA system due to the different transmission process.

As I said with VZW, Alltel, etc using CDMA - old handsets still work on
CDMA2000 and new handsets work on CDMA-1. The old handsets only display "D"
for digital, while newer phones display "D" for CDMA-1 and "1X" for
CDMA2000. Therefore the user with an old handset is not aware when the
system is upgraged and users of newer phones can tell when they are on a
CDMA-1 or CDMA-2000 system if they look at their display.