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Archived from groups: alt.cellular.verizon,alt.cellular.gsm (More info?)
[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]
In <1102447847.684377@sj-nntpcache-5> on Tue, 7 Dec 2004 11:33:31 -0800,
"Quick" <quick7135-news@NOSPAMyahoo.com> wrote:
>John Navas wrote:
>> With GSM overlay, the same "cell" (more accurately BTS*) serves both
>> TDMA and GSM users.
>>
>> * Cells are typically served by more than one BTS.
>
>That is not what I've gathered to be the point here. Let's simply
>focus on the air interface and network and user equipment.
That doesn't make sense (absent a technology agenda
, as I've explained.
What matters is whether or not there's a real and significant difference to
subscribers.
>I can be using one of the first digital StarTacs on CDMA.
>VZW can add 1xRTT and my phone still does what it
>used to do and I don't see a difference.
Likewise you can be using a TDMA phone and your carrier can add GSM overlay,
and your TDMA phone still does what it used to do and you don't see a
difference
>VZW can go
>to true 3g or CDMA2000 and my phone still does what
>it used to and I don't see a difference.
Likewise with WCDMA (UMTS) overlay; i.e., subscribers in markets where ATTWS
deployed UMTS don't see a difference.
>VZW is using all
>their spectrum efficiently
Likewise GSM and UMTS -- overlay is tuned to match subscriber demand.
>and only maintaining (for each cell)
>1 technology and the equipment for it.
That's an oversimplification that isn't really true. "The devil is in the
details."
>I get the impression that this will not be true for TDMA -> GSM
>and GSM -> WCDMA. The carrier will have to partition their
>spectrum
True, but that's not a big deal, especially from the subscriber point of view.
>and maintain separate equipment for each technology.
The equipment is actually largely common.
>At some point users will have to be told "tough luck, you have to
>get different equipment".
"At some point" any technology becomes obsolete and unusable, but that's not a
real issue here, since even ancient AMPS still has years to run, TDMA
likewise. The great majority of all customers will replace their handsets
before then, and have been migrated to more current technology in the process.
It's not a big deal.
>There will be some transitional period
>where the carrier will be using their spectrum inefficiently and
>incur the cost of maintaining "duplicate" equipment for dual or
>triple air interfaces.
Again, that's not a big deal, particularly from the subscriber point of view
-- overlay is relatively efficient.
>I still haven't heard if WCDMA will scale to the same bandwidth
>and/or user density that CDMA2000 will.
The answer depends of course on who you ask, the CDMA2000 camp or the WCDMA
camp. ;-)
This has been argued over and over, so why bring it up yet again?
Notwithstanding intense marketing (arguing) by Qualcomm, both national
carriers and most smaller TDMA carriers have and are opting for migration to
GSM over CDMA. It's a bit silly to suggest that they've all been fooled into
doing the wrong thing. ;-)
--
Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>
[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]
In <1102447847.684377@sj-nntpcache-5> on Tue, 7 Dec 2004 11:33:31 -0800,
"Quick" <quick7135-news@NOSPAMyahoo.com> wrote:
>John Navas wrote:
>> With GSM overlay, the same "cell" (more accurately BTS*) serves both
>> TDMA and GSM users.
>>
>> * Cells are typically served by more than one BTS.
>
>That is not what I've gathered to be the point here. Let's simply
>focus on the air interface and network and user equipment.
That doesn't make sense (absent a technology agenda

What matters is whether or not there's a real and significant difference to
subscribers.
>I can be using one of the first digital StarTacs on CDMA.
>VZW can add 1xRTT and my phone still does what it
>used to do and I don't see a difference.
Likewise you can be using a TDMA phone and your carrier can add GSM overlay,
and your TDMA phone still does what it used to do and you don't see a
difference
>VZW can go
>to true 3g or CDMA2000 and my phone still does what
>it used to and I don't see a difference.
Likewise with WCDMA (UMTS) overlay; i.e., subscribers in markets where ATTWS
deployed UMTS don't see a difference.
>VZW is using all
>their spectrum efficiently
Likewise GSM and UMTS -- overlay is tuned to match subscriber demand.
>and only maintaining (for each cell)
>1 technology and the equipment for it.
That's an oversimplification that isn't really true. "The devil is in the
details."
>I get the impression that this will not be true for TDMA -> GSM
>and GSM -> WCDMA. The carrier will have to partition their
>spectrum
True, but that's not a big deal, especially from the subscriber point of view.
>and maintain separate equipment for each technology.
The equipment is actually largely common.
>At some point users will have to be told "tough luck, you have to
>get different equipment".
"At some point" any technology becomes obsolete and unusable, but that's not a
real issue here, since even ancient AMPS still has years to run, TDMA
likewise. The great majority of all customers will replace their handsets
before then, and have been migrated to more current technology in the process.
It's not a big deal.
>There will be some transitional period
>where the carrier will be using their spectrum inefficiently and
>incur the cost of maintaining "duplicate" equipment for dual or
>triple air interfaces.
Again, that's not a big deal, particularly from the subscriber point of view
-- overlay is relatively efficient.
>I still haven't heard if WCDMA will scale to the same bandwidth
>and/or user density that CDMA2000 will.
The answer depends of course on who you ask, the CDMA2000 camp or the WCDMA
camp. ;-)
This has been argued over and over, so why bring it up yet again?
Notwithstanding intense marketing (arguing) by Qualcomm, both national
carriers and most smaller TDMA carriers have and are opting for migration to
GSM over CDMA. It's a bit silly to suggest that they've all been fooled into
doing the wrong thing. ;-)
--
Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>