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Thread: Why companies chose/choose CDMA over GSM

  1. #46
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    Sadly, RUIM is going dead.
    When China first tried to lauch 2G, it considered CDMA at that time. But Qualcom was too greedy and screwed up the good chance. Then China decide to go with GSM.
    I don't know what deal China Unicom made with Qualcom, but they lauched a CDMA network later. In China, cellular provider didn't subsidize the handset and people like to change the phone once a while. Thus China Unicom tried to push the standardization of RUIM which makes the CDMA phone work just the same way as GSM phone to the consumer, but unique to elsewhere in the world. Thinking of the large population of China and potential large number of subscribers, Unicom expected to make the RUIM a world standard for CDMA. However due to the poor marketing, Unicom didn't gain as many subscribers in CDMA as they expected. To implement the RUIM, the phone manufactures have to have a different design, which keeps the CDMA phone price high. Not every CDMA phone has a brother with RUIM, this limits the choices of CDMA phones in China. High price, less choices make CDMA market worse.
    Recently, I heard Unicom is considering of using normal CDMA phones instead of those with RUIM ones. This could bring the story of RUIM to an end.
    As to 3G, China wants to implement its own standard TD-SCDMA. Thus the government waited and waited with 3G license still in hand.

    Quote Originally Posted by Abbott
    For China, you are right. When I wrote my previous post, I didn't consider China. I didn't because I heard that 85%+ of Internet traffic is in English. So I only really considered the USA, the UK, Australia, New Zealand, and Canada.

    The UK doesn't have CDMA. The other countries I listed seem to be the same way about CDMA as it is in the US.

    However, when I say this I don't mean disrespect towards China. For the record, even though I'm a U.S. native, my mother is an immigrant from Taiwan. She came here for school, met my father, and didn't move back.

    But, I did assume that most people here are located in English speaking countries, so what I wrote applied to that (except the UK, where there's no CDMA as far as I know).


    I can only hope that the CDMA carriers in the U.S. and elsewhere will start using RUIM, or switch to GSM. However, I doubt it since it would increase consumer control and choice.

    CDMA as a technology isn't bad, but the implementation is horrible (RUIM not being used except in China).

  2. #47
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    Quote Originally Posted by photonth
    Sadly, RUIM is going dead.
    When China first tried to lauch 2G, it considered CDMA at that time. But Qualcom was too greedy and screwed up the good chance. Then China decide to go with GSM.
    I don't know what deal China Unicom made with Qualcom, but they lauched a CDMA network later. In China, cellular provider didn't subsidize the handset and people like to change the phone once a while. Thus China Unicom tried to push the standardization of RUIM which makes the CDMA phone work just the same way as GSM phone to the consumer, but unique to elsewhere in the world. Thinking of the large population of China and potential large number of subscribers, Unicom expected to make the RUIM a world standard for CDMA. However due to the poor marketing, Unicom didn't gain as many subscribers in CDMA as they expected. To implement the RUIM, the phone manufactures have to have a different design, which keeps the CDMA phone price high. Not every CDMA phone has a brother with RUIM, this limits the choices of CDMA phones in China. High price, less choices make CDMA market worse.
    Recently, I heard Unicom is considering of using normal CDMA phones instead of those with RUIM ones. This could bring the story of RUIM to an end.
    As to 3G, China wants to implement its own standard TD-SCDMA. Thus the government waited and waited with 3G license still in hand.
    And what are they going to do with the old R-UIM phones?

    And, the image of normal CDMA phones in China is pretty negative. Independent shops that charge anywhere from $5-$50 for activation and a mixed bag of post-activation service (Unicom will support network functions, but if they think the problem lies in the activation or the phone itself they won't handle it) currently faces people that wish to use their own phones from Korea/USA in China.

    Oh, and try to tell me "less choice" after a look at the local market. CDMA phones in China range from the cheap to the high-end; China actually gets quite a few phones that the US doesn't. It's not any more expensive than Korea either, not with a sliding scale of subsidies that have been implemented (buy a bigger plan, get a bigger subsidy). Also, look at Chinese service plans and tell me if it costs more in the US or China. The US shouldn't be as expensive as it is.

  3. #48
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    Quote Originally Posted by zephxiii
    I've ran into a few papers that state CDMA capacity, is just slightly more than GSM now with AMR, and supposedly could be higher, depending on air interface configuration. Also initial CDMA capacity wasn't as much as it was hyped up to be initially.

    http://www.rysavy.com/Articles/GSM_v...city_71802.pdf

    http://www.3gamericas.org/PDFs/Webcast/PeterRysavy.pdf

    Accuracy questionable of coarse
    Thanks for those links.

    Of course, there is the opposite question -- why would a consumer choose one system over the other? It has come up many times (including briefly in this thread in a post by Abbot), but I thought that advances in each technology had wiped out a lot of the differences. Nope, as I found out recently.

    I originally went with GSM years ago because its higher voice quality. I wanted a landline replacement, and CDMA at the time sounded like a medoicre VOIP connection. Plus, the few friends that I had on CDMA found out the hard way that, when the network is crowded, everyone's voice quality becomes so muddied that no one can understand what's being said. On GSM, you either got through with good quality or not. If not, you re-dialed a couple of times until you got through.

    I recently got an additional prepaid CDMA phone because one place that I needed to be once a week happened to only have good coverage via CDMA. Oh, there's that same old mediocre-VOIP voice quality again.

    While AMR has allowed GSM to achieve higher capacity when needed, the degradation in voice quality is still acceptable. My GSM carrier is expected to fill that one coverage hole this summer, so I can happily ditch the CDMA phone then.

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    Quote Originally Posted by Ian Brantford
    Of course, there is the opposite question -- why would a consumer choose one system over the other?
    Joe Consumer doesn't know CDMA from GSM. They just want service and a device. They'll never see, much less move a SIM. And customers are conditioned to phones being "T-Mobile" or "Sprint" phones, rather then "Motorola" or "LG" phones. Which means they're not choosing CDMA or GSM. They're choosing a phone and service.

    Sad, isn't it?
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  5. #50
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    Quote Originally Posted by npaladin2000
    Joe Consumer doesn't know CDMA from GSM. They just want service and a device. They'll never see, much less move a SIM. And customers are conditioned to phones being "T-Mobile" or "Sprint" phones, rather then "Motorola" or "LG" phones. Which means they're not choosing CDMA or GSM. They're choosing a phone and service.

    Sad, isn't it?
    Well, yes. However, just because most consumers don't know why things are different doesn't mean that a choice cannot be made on advertiseable factors. Some carriers justifiably claim better call clarity, or wider coverage, etc.

    I think that ads that showed a person switching a SIM card from his/her "beater" phone after snowboarding to a "fashion" phone would be worthwhile if it were targetted well. For instance, the youth market has finally taken up text messaging in North America. I don't see why it couldn't be exploited for other useful advantages too.

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    Quote Originally Posted by Ian Brantford
    Well, yes. However, just because most consumers don't know why things are different doesn't mean that a choice cannot be made on advertiseable factors. Some carriers justifiably claim better call clarity, or wider coverage, etc.

    I think that ads that showed a person switching a SIM card from his/her "beater" phone after snowboarding to a "fashion" phone would be worthwhile if it were targetted well. For instance, the youth market has finally taken up text messaging in North America. I don't see why it couldn't be exploited for other useful advantages too.

    Except there isn't a carrier in the USA that wants ANY of their customers to be able to swap their phones, hence locked phones, and ESN whitelists.

  7. #52
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    Quote Originally Posted by Ian Brantford
    Well, yes. However, just because most consumers don't know why things are different doesn't mean that a choice cannot be made on advertiseable factors. Some carriers justifiably claim better call clarity, or wider coverage, etc.
    I find this to be an interesting point because such factors are no longer an issue where I live. Customers here expect every network to have the same sort of coverage quality i.e. blanket and excellent. Now I realise the UK is much smaller than the U.S. and hence easier to provide service to, however, if the U.S. were using a single standard it would allow the networks there, in theory at least, to have a greater roaming capacity, this increasing their coverage area and, one imagines, call quality.
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  8. #53
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    Quote Originally Posted by Ian Brantford
    Thanks for those links.

    Of course, there is the opposite question -- why would a consumer choose one system over the other? It has come up many times (including briefly in this thread in a post by Abbot), but I thought that advances in each technology had wiped out a lot of the differences. Nope, as I found out recently.

    I originally went with GSM years ago because its higher voice quality. I wanted a landline replacement, and CDMA at the time sounded like a medoicre VOIP connection. Plus, the few friends that I had on CDMA found out the hard way that, when the network is crowded, everyone's voice quality becomes so muddied that no one can understand what's being said. On GSM, you either got through with good quality or not. If not, you re-dialed a couple of times until you got through.

    I recently got an additional prepaid CDMA phone because one place that I needed to be once a week happened to only have good coverage via CDMA. Oh, there's that same old mediocre-VOIP voice quality again.

    While AMR has allowed GSM to achieve higher capacity when needed, the degradation in voice quality is still acceptable. My GSM carrier is expected to fill that one coverage hole this summer, so I can happily ditch the CDMA phone then.
    ^ A very important and valid point for me. The difference in voice quality is quite amazing.Whenever I use a friends CDMA phone its sounds so "digitised'!

    Years ago I too did not know the difference between GSM and CDMA, I then started to travel to Europe and wondered why my Telus phone would not roam there. I switched to Rogers for their much nicer phones and choices. I thought it was really cool to be able use my Rogers locked phone overseas, until I saw my enormous roaming bill when I got home. Thats when my eyes opened to unlocked phones and the even wider choices available online. For these reasons I would never go back to CDMA.

    No-one here has mentioned Japan and its CDMA usage?

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    Japan's CDMA is different from the rest of the world, so it can't really be compared. It is far better than the US, though- about on par with Korea. I mean, I wouldn't mind carrier lock-in to Verizon with phones like the W41T available.

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    I have no technical data. This is just my opinion. I had Cingular for 6 years. This year I got with Amp'd for two months lol. Now I am with Verizon. I like the sound quality and coverage better with Verizon. i live in the USA. Nashville TN

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    Quote Originally Posted by yangj08
    Japan's CDMA is different from the rest of the world, so it can't really be compared. It is far better than the US, though- about on par with Korea. I mean, I wouldn't mind carrier lock-in to Verizon with phones like the W41T available.
    This is just ignorant.
    NTT DoCoMo's 2G(MOVA) uses TDMA based PDC(Personal Digital Cellular), 3G(FOMA) uses wCDMA (not same as UMTS at first, but modified to conform fully with UMTS now)
    au/kddi uses cdmaOne as 2G, cdma2000 as 3G
    TU-KA, a subsidiary of KDDI, provides PDC
    Softbank Mobile, former Vodafone KK/J-phone, 2G as PDC, 3G as wCDMA
    Willcom,uses PHS (XiaoLingtong)
    So what CDMA is different from the rest of the world? PDC? Of course it's different, but it's not CDMA. 3G(wCDMA or CDMA2000)? It is same, the Japanese just started the service earlier than the rest of the world.
    The CDMA system used in South Korea is also same as the one in the US.

    BTW, when talking about less choices of cdma handset in my previous post, it's comparing with gsm handset. I never claim China has less cdma phone choices than US.
    Last edited by photonth; 08-04-2007 at 04:31 PM.

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    Quote Originally Posted by batman420
    I have no technical data. This is just my opinion. I had Cingular for 6 years. This year I got with Amp'd for two months lol. Now I am with Verizon. I like the sound quality and coverage better with Verizon. i live in the USA. Nashville TN
    Sound quality has a lot to do with the phone (speaker). GSM full rate sound quality is better than CDMA in my experience, and when you hit 3G on ATT, you just went up another level in sound quality.

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    Quote Originally Posted by photonth
    This is just ignorant.
    NTT DoCoMo's 2G(MOVA) uses TDMA based PDC(Personal Digital Cellular), 3G(FOMA) uses wCDMA (not same as UMTS at first, but modified to conform fully with UMTS now)
    au/kddi uses cdmaOne as 2G, cdma2000 as 3G
    TU-KA, a subsidiary of KDDI, provides PDC
    Softbank Mobile, former Vodafone KK/J-phone, 2G as PDC, 3G as wCDMA
    Willcom,uses PHS (XiaoLingtong)
    So what CDMA is different from the rest of the world? PDC? Of course it's different, but it's not CDMA. 3G(wCDMA or CDMA2000)? It is same, the Japanese just started the service earlier than the rest of the world.
    The CDMA system used in South Korea is also same as the one in the US.

    BTW, when talking about less choices of cdma handset in my previous post, it's comparing with gsm handset. I never claim China has less cdma phone choices than US.
    I'm pretty sure you just mentioned "the use of CDMA in Japan" and not "all the networks used in Japan". Oh, and the difference is that the Rx/Tx frequencies are reversed for au/kddi's network, something that generally keeps them from working on other non-Japanese CDMA networks. Also, they use a non-standard ESN system (5 letters followed by 6 numbers) which standard CDMA does not use.
    Last edited by yangj08; 08-04-2007 at 09:48 PM.

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    Quote Originally Posted by photonth
    This is just ignorant.
    .....
    So what CDMA is different from the rest of the world?
    It's completely incompatible with the rest of the world because of the inversion of up and down links.
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    There are a few phones which do both KDDI Au's version and everyone else's version of CDMA. KDDI sells several such phones. SKT has several which will switch to JCDMA (SCH V920 is one of these and there about half a dozen others.)

    I had heard from a manager at QCOM that KDDI was going to switch to the standard RX/TX frequencies. So far, there is no evidence of this.
    Bugwart

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