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Cellular Phone Forum / General / GSM / December 2004CDMA and WCDMA?
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 >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 [quoted text clipped - 5 lines] > >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.) - - - - - - - - - - - - - - - - - - - - - - - - - - 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.  Signature\/ L /\ D 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 > 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 >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". > Subject: Re: CDMA and WCDMA? > From: hoch@exemplary.invalid (CharlesH) [quoted text clipped - 10 lines] > 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? > 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. >> Do you ever see Sprint/Verizon migrating to GSM/WCDMA? > [quoted text clipped - 3 lines] > >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. - - - - - - - - - - - - - - - - - - - - - - - - - - >>> 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. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular 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. Signature\/ L /\ D 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. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > GSM really resides in the higher layers of the network protocol > stack. In the lower layers - the air interface, there is currently [quoted text clipped - 7 lines] > 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 >> GSM really resides in the higher layers of the network protocol >> stack. In the lower layers - the air interface, there is currently [quoted text clipped - 11 lines] >1) Is the WCDMA air interface backward compatible with the > TDMA air interface? No. >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?) WCDMA is designed to coexist with GSM, including seamless call handoff. >3) Is there any difference in the air interface for WCDMA and CDMA2000? Yes. >3a) If so, do they scale the same? No. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular 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 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 SignaturePaul Day Web: www.bur.st/~paul GPG Key ID: 7FF655A8 >> Subject: Re: CDMA and WCDMA? >> From: hoch@exemplary.invalid (CharlesH) [quoted text clipped - 14 lines] > >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. - - - - - - - - - - - - - - - - - - - - - - - - - - >>> Subject: Re: CDMA and WCDMA? >>> From: hoch@exemplary.invalid (CharlesH) [quoted text clipped - 21 lines] > > - - - - - - - - - - - - - - - - - - - - - - - - - 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. >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? - - - - - - - - - - - - - - - - - - - - - - - - - - >> VZW, Sprint, Alltel, etc which started with CDMA can upgrade their >> networks to CDMA2000 incrementally since the upgrades are compatable [quoted text clipped - 6 lines] > > - - - - - - - - - - - - - - - - - - - - - - - - - - TDMA, GSM & WCDMA are three different systems all requiring different equipment. CDMA thru CDMA2000 are compatable with each other - transparent to users. >>> VZW, Sprint, Alltel, etc which started with CDMA can upgrade their >>> networks to CDMA2000 incrementally since the upgrades are compatable [quoted text clipped - 9 lines] > >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. SignatureDavid 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 > 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 [quoted text clipped - 18 lines] > 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! >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? >> Why in heck would anyone in their right mind want to go from >> CDMA2000 to WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!? [quoted text clipped - 3 lines] > > Why? WCDMA doesn't scale? Did Docomo try to deploy it 2 or 3 times? >>> Why in heck would anyone in their right mind want to go from >>> CDMA2000 to WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!? [quoted text clipped - 5 lines] > > 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. >>> Why in heck would anyone in their right mind want to go from >>> CDMA2000 to WCDMA?!?!?!?!? Who is even considerring it?!?!?!?!?!? [quoted text clipped - 5 lines] > >WCDMA doesn't scale? Did Docomo try to deploy it 2 or 3 times? DoCoMo had some teething problems with WCDMA, like most new technologies, but WCDMA is now pretty solid. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular >> WCDMA doesn't scale? Did Docomo try to deploy it 2 or 3 times? > > DoCoMo had some teething problems with WCDMA, like most new technologies, but > WCDMA is now pretty solid. Who's docomo? >>> WCDMA doesn't scale? Did Docomo try to deploy it 2 or 3 times? >> >> DoCoMo had some teething problems with WCDMA, like most new technologies, but >> WCDMA is now pretty solid. > >Who's docomo? "Google is your friend!" http://www.google.com/search?q=docomo SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > Subject: Re: CDMA and WCDMA? > From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 13 lines] > "Google is your friend!" > http://www.google.com/search?q=docomo According to google: 1) Some Japanese network company (I can't read the page ...) 2) A private hobby site 3) A Public Wireless LAN access service for Japanese-speaking residents in the United States (http://www.docomo-usa.com/intro/index.html) 4) A cell phone manufacturer (http://www.gizmodo.com/gadgets/cellphones/nec/docomo-nec-900il-025631.php) I'll assume one of the above .... did I miss any? >> Subject: Re: CDMA and WCDMA? >> From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 28 lines] > > I'll assume one of the above .... did I miss any? "DoCoMo is Japan's leading mobile communications operator" http://www.nttdocomo.com/ >>> Who's docomo? >> [quoted text clipped - 4 lines] > >1) Some Japanese network company (I can't read the page ...) That's it. >2) A private hobby site > [quoted text clipped - 5 lines] > >I'll assume one of the above .... did I miss any? Indeed you did, the English link right below the first link: <http://www.nttdocomo.co.jp/english/index.shtml> In other words, if you'd spent as much time actually looking as being a s-a, you would have gotten your answer. ;-) SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > In other words, if you'd spent as much time actually looking as being a s-a, > you would have gotten your answer. ;-) What the heck is an a-s-a? Sorry I missed the link .... sheesh. Would typing "Foreign phone company" have been that much harder than "go look up a link and figure out which one applies". Sorry to take up so much of your time with a question. >> In other words, if you'd spent as much time actually looking as being a s-a, >> you would have gotten your answer. ;-) [quoted text clipped - 7 lines] > >Sorry to take up so much of your time with a question. Sorry to have wasted time trying to help you. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > Subject: Re: CDMA and WCDMA? > From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 18 lines] > > Sorry to have wasted time trying to help you. Insult a person and try to cloak it in philanthropy. Nice. On Sun, 5 Dec 2004 23:07:08 -0800, "Peter Pan" <Marcs1102NOSPAM@HotmailNOSPAM.com> chose to add this to the great equation of life, the universe, and everything: >> 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 [quoted text clipped - 15 lines] >Sure it would not be transparent, since it would be incredibily STUPID and >insane to even consider it! Maybe some idealistic idiot might think the public would benefit if all cell phones in the world used the same standard... (Yeah, I know, different frequency bands, but that's a trivial thing to manage in the handset.) SignatureDavid 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 say what it occurs to me to say when I think I hear people say things. More I cannot say." - The Ruler of the Universe >On Sun, 5 Dec 2004 23:07:08 -0800, "Peter Pan" ><Marcs1102NOSPAM@HotmailNOSPAM.com> chose to add this to the great equation [quoted text clipped - 25 lines] >(Yeah, I know, different frequency bands, but that's a trivial thing to >manage in the handset.) Manageable, but not trivial. SignatureBest 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] > [quoted text clipped - 29 lines] > > Manageable, but not trivial. First off (from about the middle of this one), no one said anything about transitioning from CDMA2000 to WCDMA. The discussion is about getting to 3G and beyond. The CDMA migration is parrallel and independent from the GSM migration. Now about a single standard. Europe has traditionally gone this route. They do it by government regulation. The governments own most of the public networks and tightly control most everything else. ...Europe has always been a leader in deploying cutting edge networking technology and public networks... (<- smiley in case you didn't catch the drift) there are tradeoffs -Quick >First off (from about the middle of this one), no one said anything >about transitioning from CDMA2000 to WCDMA. The discussion >is about getting to 3G and beyond. The CDMA migration is parrallel >and independent from the GSM migration. The actual issue is convergence of CDMA2000 and WCDMA. Unfortunately, such efforts have gone nowhere. >Now about a single standard. Europe has traditionally gone this route. >They do it by government regulation. The governments own most of the public [quoted text clipped - 5 lines] > >there are tradeoffs By any measure, Europe (and Asia) got it right in mobile -- the US has paid a stiff price for chaos. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > First off (from about the middle of this one), no one said anything > about transitioning from CDMA2000 to WCDMA. The discussion > is about getting to 3G and beyond. The CDMA migration is parrallel > and independent from the GSM migration. > > -Quick Actually Quick, that exact question *WAS* asked and answered (okay.. made fun of).... While the later discussion was about something else, the original question was: > 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?!?!?!?!?!? > Actually Quick, that exact question *WAS* asked and answered (okay.. > made fun of).... While the later discussion was about something else, [quoted text clipped - 3 lines] >> transition from CDMA2000 to WCDMA would not be transparent but would >> require new equipment just as would the transition from GSM. Ok... I'm not going to look back through it. The above makes reference to "..but other posts...". I didn't remember any "other posts" making a reference to a transition from CDMA2000 to WCDMA. I certainly could have missed it since John says the whole thing is about convergence of the two. -- you think he just substituted "transition" for "convergence"? -Quick >> Actually Quick, that exact question *WAS* asked and answered (okay.. >> made fun of).... While the later discussion was about something else, [quoted text clipped - 12 lines] > > -Quick Beats me, and you and others gave good info that the above Q was NOT correct, and that CDMA2000 and WCDMA where NEVER going to be implemented together on the same cell. I just saw my reply being pasted in posts without the original question and thought I'd correct the record. >>> Actually Quick, that exact question *WAS* asked and answered (okay.. >>> made fun of).... While the later discussion was about something else, [quoted text clipped - 10 lines] >> convergence of the two. -- you think he just substituted >> "transition" for "convergence"? >Beats me, and you and others gave good info that the above Q was NOT >correct, and that CDMA2000 and WCDMA where NEVER going to be implemented >together on the same cell. I just saw my reply being pasted in posts without >the original question and thought I'd correct the record. <http://www.rysavy.com/Articles/3G/3g.htm> But what about the differences between CDMA2000 and WCDMA? If the goal of IMT-2000 is a single worldwide standard, can these two versions of CDMA be harmonized into a single standard? That is the very question being addressed by the CDMA Operators Harmonization Group that is developing the Global 3G CDMA standard (G3G). Since there are some irreconcilable differences between CDMA2000 and WCDMA in the radio portion, the approach is a modular architecture as shown in Figure 4. This approach allows any of three airlink technologies to be used in a network, including WCDMA, 3XRTT, and a time-division duplex form of spread spectrum. In addition to the three types of airlinks, the architecture recognizes that network infrastructures may be based on either GSM-MAP protocols or ANSI-41 protocols. G3G will give operators flexibility in choosing the airlink and network infrastructure that best addresses their particular needs. One issue in harmonizing CDMA data is that WCDMA is based on GPRS protocols, which use the GPRS tunneling protocol (GTP) to forward IP packets to the mobile station. Mobility management is also handled by specific GPRS protocols. CDMA2000, however, is based on the Mobile IP standard. Any harmonized CDMA standard should ideally be based on the same set of tunneling and mobility standards. For this reason, the European Telecommunications Standards Institute (ETSI), responsible for GSM and GPRS, has started an investigation of how GPRS/EDGE could integrate Mobile IP. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > <http://www.rysavy.com/Articles/3G/3g.htm> > > But what about the differences between CDMA2000 and WCDMA? If the > goal of IMT-2000 is a single worldwide standard, can these two > versions of CDMA be harmonized into a single standard? [snip] Wow, this was a post? on alt. ? > For this reason, the European Telecommunications > Standards Institute (ETSI), responsible for GSM and GPRS, has > started an investigation of how GPRS/EDGE could integrate Mobile > IP. see, see, what did I tell you... ETSI... blew it with GSM... had to try to patch it up with GPRS/EDGE and now they're going to try to wedge mobile IP into it to save their bacon. They should give it up, scrap everything, do without for a few years and start fresh with CDMA2000. :) -Quick >TDMA, GSM & WCDMA are three different systems all requiring different >equipment. > >CDMA thru CDMA2000 are compatable with each other - transparent to users. In fact the respective upgrade paths are more similar than different. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular >>VZW, Sprint, Alltel, etc which started with CDMA can upgrade their networks >>to CDMA2000 incrementally since the upgrades are compatable with current [quoted text clipped - 4 lines] > >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 >>>VZW, Sprint, Alltel, etc which started with CDMA can upgrade their networks >>>to CDMA2000 incrementally since the upgrades are compatable with current [quoted text clipped - 11 lines] > >Please correct me if I am wrong. TDMA > GSM doesn't require "a complete change of everything" -- GSM overlay of TDMA can be accomplished within the same hardware platform (depending on how old it is). SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular >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. SignatureBest 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] > [quoted text clipped - 8 lines] > > 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. AT&T and Cingular required different handsets for their "TDMA" and GSM systems, because they are different and incompatible. What's commonly referred to as "TDMA" is actually the IS-136 system. Both the "SIM-less" IS-136 and the SIM-card GSM systems are based on the slightly different versions of the Time Division Multiple Access technology, as you point out. The two systems co-exist peacefully, and the operators allocate parts of their spectrum to each one. There are a few GAIT (GSM ANSI Interoperability Team) handsets that support both the systems. Recently, WCDMA has been added to the mix in some markets, and now there are handsets that support GSM and UMTS (WCDMA). Signature\/ L /\ D In news:l35td.9772$_3.114997@typhoon.sonic.net, John Navas <spamfilter0@navasgroup.com> typed: > [POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE] > [quoted text clipped - 11 lines] > > 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. > AT&T and Cingular required different handsets for their "TDMA" and GSM > systems, because they are different and incompatible. What's commonly [quoted text clipped - 49 lines] > when they are on a CDMA-1 or CDMA-2000 system if they look at their > display. Which supports what I initally posted: CDMA - phones continue to work as systems are upgraded. TDMA, GSM, & W-CDMA - New phone required for each system upgrade/change. Well, this is based on the assumption (or fact) that older CDMA networks are instantaneously and completely replaced with backwards-compatible newer ones, as opposed to the operators running the old and the new networks simultaneously during the transition period, which is what's happening in the GSM world. I don't know that much about CDMA, so I'm not sure how it's done. Either way, if you have an old CDMA phone, you won't be able to use any of the features offered by a newer CDMA network, so you would have to get a new phone for that. The Sprint PCS "Vision" handsets are an example, I think. For operators, however, different upgrade paths do come at different prices. Signature\/ L /\ D Which supports what I initally posted: CDMA - phones continue to work as systems are upgraded. TDMA, GSM, & W-CDMA - New phone required for each system upgrade/change. I had an old Digital/Analog phone which showed "D" everywhere when not in Analog. I got a new 3G phone and noticed that there were areas on VZW & Alltel that were "D" (CDMA-1) and others that were "1X" (CDMA-2000). Then after a while all the "D" areas changed to "1X". With CDMA the carriers just upgrade the cell sites with compatible newer ones. There is no difference in the Over-The-Air interface. For making & recieving calls any phone (new or old) works. For web browsing, sending messages, taking pictures, etc, it actually depends on what functions are on the phone. The new phones range from very basic to all the bells and whistles. > Well, this is based on the assumption (or fact) that older CDMA > networks are instantaneously and completely replaced with [quoted text clipped - 8 lines] > are an example, I think. For operators, however, different upgrade > paths do come at different prices. >I had an old Digital/Analog phone which showed "D" everywhere when not in >Analog. I got a new 3G phone and noticed that there were areas on VZW & >Alltel that were "D" (CDMA-1) and others that were "1X" (CDMA-2000). Then >after a while all the "D" areas changed to "1X". With CDMA the carriers >just upgrade the cell sites with compatible newer ones. There is no >difference in the Over-The-Air interface. ... In fact there are big differences. It's just that these differences are transparent to older handsets, just as GSM overlay is transparent to older TDMA handsets. SignatureBest 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] > [quoted text clipped - 9 lines] > are transparent to older handsets, just as GSM overlay is transparent > to older TDMA handsets. TDMA & GSM are transparent to each other as well as to CDMA, IDEN & Amps. Actually FIVE different incompatable systems. >>> I had an old Digital/Analog phone which showed "D" everywhere when >>> not in Analog. I got a new 3G phone and noticed that there were [quoted text clipped - 10 lines] >TDMA & GSM are transparent to each other as well as to CDMA, IDEN & Amps. >Actually FIVE different incompatable systems. If you had a point I missed it. SignatureBest 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] > [quoted text clipped - 14 lines] > > If you had a point I missed it. CDMA handsets can make and receive calls on all CDMA cell sites. Any CDMA cell site added regardless of technology benefits all users. TDMA phones will only make calls on a TDMA cell site. GSM phones will only make calls on a GSM cell site. Adding GSM cell sites does not benefit TDMA users. >>> TDMA & GSM are transparent to each other as well as to CDMA, IDEN & >>> Amps. Actually FIVE different incompatable systems. >> >> If you had a point I missed it. > >CDMA handsets can make and receive calls on all CDMA cell sites. That is of course a truism. Just like any other technology. >Any CDMA cell site added regardless of technology benefits all users. Not necessarily. It's not that simple. >TDMA phones will only make calls on a TDMA cell site. >GSM phones will only make calls on a GSM cell site. >Adding GSM cell sites does not benefit TDMA users. With GSM overlay, the same "cell" (more accurately BTS*) serves both TDMA and GSM users. * Cells are typically served by more than one BTS. SignatureBest 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] > [quoted text clipped - 19 lines] > > * 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. 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. VZW can go to true 3g or CDMA2000 and my phone still does what it used to and I don't see a difference. VZW is using all their spectrum efficiently and only maintaining (for each cell) 1 technology and the equipment for it. I get the impression that this will not be true for TDMA -> GSM and GSM -> WCDMA. The carrier will have to partition their spectrum and maintain separate equipment for each technology. At some point users will have to be told "tough luck, you have to get different equipment". 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. I still haven't heard if WCDMA will scale to the same bandwidth and/or user density that CDMA2000 will. -Quick >> With GSM overlay, the same "cell" (more accurately BTS*) serves both >> TDMA and GSM users. [quoted text clipped - 3 lines] >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. ;-) SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular On Tue, 07 Dec 2004 21:11:36 GMT, John Navas <spamfilter0@navasgroup.com> chose to add this to the great equation of life, the universe, and everything: >>> With GSM overlay, the same "cell" (more accurately BTS*) serves both >>> TDMA and GSM users. >>> >>> * Cells are typically served by more than one BTS. I probably should know, but what's a BTS? >>VZW is using all >>their spectrum efficiently > >Likewise GSM and UMTS -- overlay is tuned to match subscriber demand. Ah, but with CDMA, it's not overlay, it's co-use. >>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." Explain. >>I get the impression that this will not be true for TDMA -> GSM >>and GSM -> WCDMA. The carrier will have to partition their [quoted text clipped - 14 lines] >before then, and have been migrated to more current technology in the process. >It's not a big deal. Most, but not all. Some will eventually be forced to get new phones when the old infrastructure is turned off. With the CDMA upgrade path, the very first CDMA phone ever sold will work on a CDMA2000 cell (or BTS?), and the very first CDMA cell ever installed can support the latest and greatest phones, all without partitioning any spectrum. >>There will be some transitional period >>where the carrier will be using their spectrum inefficiently and [quoted text clipped - 3 lines] >Again, that's not a big deal, particularly from the subscriber point of view >-- overlay is relatively efficient. It is statistically improbable, but definitely possible, that at any given moment, the proportion of users within range of a given cell will be so skewed in favor of one system or the other (TDMA or GSM (or WCDMA)) that they will fill the equipment for that particular system to capacity under circumstances where a single system, or a backwards-compatible system such as CDMA, would not overload. SignatureDavid 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 could end up being the music industry's worst nightmare: a smart gal with a fat bank account who is unafraid to go down in flames fighting for a principle." - Courtney Love, in the Los Angeles Times, on her legal fight against Universal Music Group challenging the business practices of major record labels >On Tue, 07 Dec 2004 21:11:36 GMT, John Navas <spamfilter0@navasgroup.com> >chose to add this to the great equation of life, the universe, and [quoted text clipped - 6 lines] > >I probably should know, but what's a BTS? <http://www.mobileguru.co.uk/Mobile_Technology_globe.html>: Base Station Sub-system (BSS) The Base Station function is divided into two main functional elements, the Base Station Controller (BSC) which also includes the Transcoder Unit (TCU), and the Base Transceiver System (BTS). The BSC can control several BTS units. Each BTS will consist of a number of transceivers (TRX) and will serve a cell or a number of cells. The BSC unit also performs transcoding functions to convert between 64Kbps channel rate used in the Switching System and the 16Kbps channel rate for GSM traffic. >>>VZW is using all >>>their spectrum efficiently >> >>Likewise GSM and UMTS -- overlay is tuned to match subscriber demand. > >Ah, but with CDMA, it's not overlay, it's co-use. In general, that's not a substantial difference. >>>and only maintaining (for each cell) >>>1 technology and the equipment for it. [quoted text clipped - 3 lines] > >Explain. Both GSM and CDMA are evolving technologies, with upgrades needed to incorporate improvements. >>"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 [quoted text clipped - 7 lines] >very first CDMA cell ever installed can support the latest and greatest >phones, all without partitioning any spectrum. As I wrote, that's not a real issue. >>>There will be some transitional period >>>where the carrier will be using their spectrum inefficiently and [quoted text clipped - 10 lines] >circumstances where a single system, or a backwards-compatible system such >as CDMA, would not overload. There are worst case conditions for any technology, and I could easily attack CDMA for such weaknesses as poor call quality due to overload, dropped calls due to cell "shrinkage," etc. I don't, because squabbling over such small details is silly -- in general, GSM and CDMA are comparably "good," and differences in technology are usually overwhelmed by other issues (e.g., coverage, system loading). SignatureBest 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] > [quoted text clipped - 8 lines] >transparent to older handsets, just as GSM overlay is transparent to older >TDMA handsets. The various CDMA protocols can co-exist on the same frequency band. Don't the TDMA-GSM-WCDMA carriers have to partition their bandwidth among the various protocols? Specifically, I've heard that TDMA (IS-136) service on the (former) AT&T Wireless network in the San Francisco Bay Area is really getting bad (fast busies) as more and more of the band is reassigned to GSM. Similar to trying to use AMPS on any of the cellular providers; not many AMPS channels left. >> [POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE] >> [quoted text clipped - 18 lines] > is reassigned to GSM. Similar to trying to use AMPS on any of the > cellular providers; not many AMPS channels left. Exactly. I can't seem to convince John Navas that statically partitioning your bandwidth is a big deal (the fact that the provider can adjust the allocation only mitigates the problem to some extent). Then, at some point, you will have to tell hundreds of thousands, if not millions, of very fickle and vocal customers that they have to do an equipment upgrade. -Quick >>> In fact there are big differences. It's just that these differences >>> are transparent to older handsets, just as GSM overlay is [quoted text clipped - 12 lines] >your bandwidth is a big deal (the fact that the provider can adjust the >allocation only mitigates the problem to some extent). In practice it's simply not a big deal -- given allocation according to actual demand (as measured by the system itself), it could only be a big deal if the carrier has run out of capacity, an issue that would overwhelm the significance of allocation. >Then, at some >point, you will have to tell hundreds of thousands, if not millions, of very >fickle and vocal customers that they have to do an equipment upgrade. Actually you don't, as I've explained. With all due respect, this is the same kind of CDMA "FUD" that Qualcomm has been spreading for years, but which the real world has shown to not be a real issue. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > Actually you don't, as I've explained. > > With all due respect, this is the same kind of CDMA "FUD" that Qualcomm has > been spreading for years, but which the real world has shown to not be a real > issue. What involvement (if any) does Qualcomm have with WCDMA? >> Actually you don't, as I've explained. >> [quoted text clipped - 3 lines] > >What involvement (if any) does Qualcomm have with WCDMA? Patent licensing. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > Subject: Re: CDMA and WCDMA? > From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 13 lines] > > Patent licensing. Thank you. So in essence ... the entire world will be at Qualcomm's doorstep at some point in the future .... >>> What involvement (if any) does Qualcomm have with WCDMA? >> >> Patent licensing. > >Thank you. You're welcome. >So in essence ... the entire world will be at Qualcomm's doorstep at some >point in the future .... I think that's a bit of an overstatement. :) SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > Subject: Re: CDMA and WCDMA? > From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 15 lines] > > I think that's a bit of an overstatement. :) Just a little bit ..... :-) But you get the idea .... capturing the market of both CDMA networks and GSM networks ... kinda nice from Qualcomm's perspective. >> Subject: Re: CDMA and WCDMA? >> From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 17 lines] >of both CDMA networks and GSM networks ... kinda nice from Qualcomm's >perspective. Except it didn't capture the market -- Qualcomm is pushing CDMA2000, not WCDMA, which is considerably different. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular >> Subject: Re: CDMA and WCDMA? >> From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 19 lines] >of both CDMA networks and GSM networks ... kinda nice from Qualcomm's >perspective. Actually it does Qualcomm little good. The GSM versions were carefully spec'd to avoid almost all of the Qualcom patents >>> Subject: Re: CDMA and WCDMA? >>> From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 22 lines] >Actually it does Qualcomm little good. The GSM versions were carefully >spec'd to avoid almost all of the Qualcom patents I thought that they finally gave up and arranged some cross-licensing aggreements between the Qualcomm CDMA patents and the GSM patents. It IS true that there are a LOT of gratuitous differences between WDCMA and CDMA2000 in an effort to avoid Qualcomm's patents, but there were some which they couldn't work around. But one difference is unrelated to the patent issue: CDMA2000 depends on all of the cell sites in a system to have very closely synchronized clocks, which is done using GPS receivers at the cell site. But it was politically unacceptable for the GSM Consortium to use a protocol which has dependencies on the U.S. Department of Defense, who operates the GPS satellites. >I thought that they finally gave up and arranged some cross-licensing >aggreements between the Qualcomm CDMA patents and the GSM patents. It [quoted text clipped - 6 lines] >for the GSM Consortium to use a protocol which has dependencies on the >U.S. Department of Defense, who operates the GPS satellites. I seriously doubt that was actually a consideration. :) More likely is the fact that it's hard to maintain such close timing where GPS signals aren't readily available (e.g., underground). Differences between WCDMA and CDMA2000 include: * Chip rate * Frame duration * Asynchronous versus synchronous * Base station acquisition/detection * Forward link pilot * Antenna beam form * Single carrier versus multicarrier spreading * Transmit diversity * Underlying network SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > Subject: Re: CDMA and WCDMA? > From: John Navas <spamfilter0@navasgroup.com> [quoted text clipped - 28 lines] > * Transmit diversity > * Underlying network This thread is really an education. Does anyone know of a reference site (or 2 or 3) that documents all of these technologies, their similarities, their differences, which ones work with which, etc? (CDMA, GSM, WCDMA, EDGE, 1X, EV DO, etc.) Other than google, I'm looking for something that maybe helped you in the past .... >This thread is really an education. > [quoted text clipped - 4 lines] >Other than google, I'm looking for something that maybe helped you in the >past .... http://gsmworld.com/technology/ http://www.cdg.org/technology/3g.asp http://www.itu.int/home/imt.html http://www.3g.co.uk/ http://www.3gpp.org/ http://www.3g-generation.com/ http://www.3gamericas.org/ http://www.3gtoday.com/ http://www.umts-forum.org/ http://www.umtsworld.com/ http://www.umtscongress.com/ http://www.cellular.co.za/ SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > http://gsmworld.com/technology/ > http://www.cdg.org/technology/3g.asp [quoted text clipped - 8 lines] > http://www.umtscongress.com/ > http://www.cellular.co.za/ I have some reading to do. I am in your debt. :-) >[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE] > [quoted text clipped - 12 lines] >fact that it's hard to maintain such close timing where GPS signals aren't >readily available (e.g., underground). It's the cell sites that have to be tightly synchronized with GPS, and I think at least part of them (the antenna) is always above ground :-). The phones get the timing info from the cell site(s) they are registered on. BTW, this use of GPS for synchronizing cell sites (from the beginning of CDMA) is completely unrelated to the GPS E-911 location functionality in some newer phones. > Differences between WCDMA and CDMA2000 include: > >* Chip rate >* Frame duration >* Asynchronous versus synchronous So this is how they avoid the clock synchronization requirement. I was wondering about that. >* Base station acquisition/detection >* Forward link pilot >* Antenna beam form >* Single carrier versus multicarrier spreading >* Transmit diversity >* Underlying network The WCDMA network is essentially extending the current GSM network to support high speed data and such, isn't it? Thanks for the list of differences. Some of these are indeed non-trivial. >The WCDMA network is essentially extending the current GSM network to >support high speed data and such, isn't it? And of course change the GSM to CDMA technology. -- John S. e-mail responses to - john at kiana dot net >>The WCDMA network is essentially extending the current GSM network to >>support high speed data and such, isn't it? > >And of course change the GSM to CDMA technology. Nope. GSM refers to entire infrastructure, and UMTS is based on enhanced GSM infrastructure. The air interface for UMTS is WCDMA, instead of the TDMA-type air interface for GSM, but that difference is a relatively small part of the total system. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular >The air interface for UMTS is WCDMA, Exactly my point. All the carriers are moving toward a CDMA type of sustem. The rest of it definatly varies, but it is still CDMA. -- John S. e-mail responses to - john at kiana dot net >>The air interface for UMTS is WCDMA, > >Exactly my point. That wasn't what you said (wrote). >All the carriers are moving toward a CDMA type of sustem. > >The rest of it definatly varies, but it is still CDMA. The differences between UTMS and CDMA2000, including the air interfaces, far outweigh the similarities. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular >>I seriously doubt that was actually a consideration. :) More likely is the >>fact that it's hard to maintain such close timing where GPS signals aren't [quoted text clipped - 3 lines] >and I think at least part of them (the antenna) is always above ground >:-). ... Not for underground service; e.g., subways, underground shopping malls. >>* Underlying network > >The WCDMA network is essentially extending the current GSM network to >support high speed data and such, isn't it? UMTS (which uses WCDMA) is based on extensions to GSM infrastructure. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > >>I seriously doubt that was actually a consideration. :) More likely is the > >>fact that it's hard to maintain such close timing where GPS signals aren't [quoted text clipped - 5 lines] > > Not for underground service; e.g., subways, underground shopping malls. There doesn't seem to cause a problem with Verzion having very good underground service. They are the only cell service available underground on the Washington DC Metro, and the NEC rail tunnels under the Hudson River into New York City. SignatureCharles >There doesn't seem to cause a problem with Verzion having very good >underground service. They are the only cell service available >underground on the Washington DC Metro, and the NEC rail tunnels under >the Hudson River into New York City. Sure, you make exclusive deals with the Port Authority and DC Metro so you're the only one and of course you'll have it to the exclusion of anyone else. What's so new or odd about that? - - - - - - - - - - - - - - - - - - - - - - - - - - > Sure, you make exclusive deals with the Port Authority and DC Metro so > you're the only one and of course you'll have it to the exclusion of > anyone else. What's so new or odd about that? Who said it was odd? I just mentioned that it worked underground. If they have exclusive agreements that may explain why they have service and the others don't, but it does not negate the fact that Verizion works undergound with the GPS synced CDMA. I was reading today that the Bush administration plans to turn off GPS if there is a national emergency. I wonder how that would effect the CDMA service? I'd guess that would disrupt it? SignatureCharles >> Sure, you make exclusive deals with the Port Authority and DC Metro so >> you're the only one and of course you'll have it to the exclusion of [quoted text clipped - 4 lines] >and the others don't, but it does not negate the fact that Verizion >works undergound with the GPS synced CDMA. There are ways other than GPS to provide time reference for CDMA. >I was reading today that the Bush administration plans to turn off GPS >if there is a national emergency. ... And another silly Internet Myth takes wing. SignatureBest regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES: John Navas <http://navasgrp.home.att.net/#Cingular > >I was reading today that the Bush administration plans to turn off GPS > >if there is a national emergency. ... > > And another silly Internet Myth takes wing. It was reported in an article in today's Washington Post. http://www.washingtonpost.com/wp-dyn/articles/A4326-2004Dec16.html I don't doubt it. I don't think it is a myth. SignatureCharles >> >I was reading today that the Bush administration plans to turn off GPS >> >if there is a national emergency. ... [quoted text clipped - 4 lines] > >http://www.washingtonpost.com/wp-dyn/articles/A4326-2004Dec16.html Registration required -- no thanks. >I don't doubt it. I don't think it is a myth. What's a silly myth (no matter what the source) is the notion that GPS would ever be "turned off". The military already has the (classified) ability to deny access to GPS from non-military receivers in given regional area(s), but that would only be used in actual theaters of military conflict. In other words, it would take an actual serious attack for it to be used in the USA. In that case, the least of your worries would be CDMA cell phone service :), particularly since cellular base stations are designed to maintain time sync during limited periods of external time reference outage. <http://www.nytimes.com/aponline/national/AP-Positioning-Satellites.html>: Any shutdown of the network inside the United States would come under only the most remarkable circumstances, said a Bush administration official who spoke to a small group of reporters at the White House |
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