1. anon(1754793)'s Avatar
    If its in the wrong place Im sure it will get moved.

    Whats the difference between GSM and(vs.) CDMA ?

    Please if you can help just put it in point form, and yes Im asking this for a reason but I have alot of things to do this morning and I cant look any of this stuff up.

    Last edited by CB.Mike-D; 10-13-09 at 11:33 AM.
    10-13-09 10:36 AM
  2. pkcable's Avatar
    I googled it for you and found a few good pages...

    CDMA vs GSM - Google Search
    10-13-09 10:50 AM
  3. _StephenBB81's Avatar
    Asking for the Difference between the 2 is pretty broad, what are you trying to learn?

    the under lying technology? the Frequencies,
    the History's the coverage maps? if you read the top 5 results from google you get tones of info, that you probably don't need to meet your needs,
    ask a specific question. and get an appropriate answer
    10-13-09 11:01 AM
  4. anon(1754793)'s Avatar
    Would anyone mind putting a few main differences in point form for me
    Like I said I dont have much time this morning to read through pages and pages of information, I dont know exactly what info I need just the general obsevations I guess.
    10-13-09 11:44 AM
  5. Motorcycle Mama's Avatar
    Is this for a school project?
    10-13-09 11:50 AM
  6. pkcable's Avatar
    Point 1
    GSM at 3G can do Data & Voice at the same time (plus many GSM devices have wifi which can do it at slower speeds too)

    CDMA even at 3G can not do voice & data at the same time. (HOWEVER with wifi, which is coming it can in wifi areas)
    Point 2
    GSM devices often come out before their CDMA counterparts. However part of this problem may be Verizon's (the main CDMA carrier) rigorous testing before certifying a device.
    Point 3
    GSM devices can be unlocked and then used on any GSM carriers providing they are the correct frequency. Some CDMA "World" phones can also be unlocked and used on GSM carriers.

    CDMA devices are locked via ESN numbers and are extremely difficult to use on another CDMA carrier. (It can only be done if an employee from the CDMA carrier adds the ESN number in to their system and generally they don't do this)
    Point 4
    Most later generation CDMA devices are 3G, when their GSM counterpart is only 2G (EDGE). An example of this is the 83XX series.
    10-13-09 12:11 PM
  7. anon(1754793)'s Avatar
    Is this for a school project?
    No its for a job, that Im hopefully going to get

    And thanks PK.
    10-13-09 05:16 PM
  8. Kirkx's Avatar
    The very big issue is coverage, if you travel outside North America or to northern Canada.

    If you travel outside North America with CDMA-only phone, it is basically dead until you come back home. GSM is used in 99% of the world outside N. America. Besides Canada and USA, CDMA is only popular in Hong Kong, South Korea, Taiwan and some parts of China (about 10%). There are also some older CDMA networks in the Caribbean, in Mexico and some CDMA pockets in completely unexpected places, which usually won't have any roaming agreements with other carriers (I've just come across one in Warsaw, Poland, although Europe, in general, is the GSM kingdom).

    Japan is a unique situation. They use a standard called W-CDMA. Only the latest CDMA BlackBerries, like Storm 9530 and Tour 9630, are designed to work on those networks.

    If you mostly stay in the US, then any standard is ok, both CDMA and GSM have similar coverage (US members, please correct me if I'm wrong here).

    Canada is a different story. GSM is available only from Rogers and they offer coverage only in heavily populated areas. If your travel takes you to Northern Ontario, Northern Quebec, Yukon, Northwest Territories or Nunavut, then forget about GSM, it doesn't exist up there, you need CDMA. Lately two biggest CDMA providers (Bell Mobility and Telus) are taking efforts to switch to GSM but it will take a few years before this task is completed network-wide.

    Many CDMA BlackBerries are designed to also work in GSM areas outside N.America, they automatically switch to whatever network is available, or you can force the switch manually. Those BlackBerry models are commonly called "world phones". You can Google "Coverage and Travel- bell.ca", select tab "International", select the phone (Tour, Storm or 8830) and you will get all info about network (CDMA/GSM) country by country.

    It seems that because GSM is the dominant world standard, CDMA is a dinosaur on the way to extinction, although it will take a while.
    Last edited by Kirkx; 10-14-09 at 05:10 AM.
    10-14-09 04:35 AM
  9. strunke's Avatar
    There is confusion here.

    Gsm is not really overtaking cdma. In fact the next generation of "gsm" uses cdma as part of the air interface.
    Classic cdma is a slightly newer and more efficient form of the tech compard to gsm. But it never caught on internationally primarily because it's parent company and creator quallcom kept it proprietary and expensive to use (royalties). Gsm doesn't have this problem. While not as efficient in spectrum and what not. It is cheaper and more economical to implement. A combination of this and the fact the carriers with it hacn'r pushed for changes that could have easily been implemented such as rium cards (sp?). It's a shame really. But the technology coming out now and what is being used as 3g by the gsm carriers has a base in cdma principles and besides the upgrade path, has little to do with gsm in and of itself. It's brand new.

    The reasons phones come out faster and on a larger scale is simple. Economies of scale. There is a bigger market for gsm phones and thus companies want to make the most money they can on new models and as soon as they can.

    The real difference is the way they both handle spectrum cdma uses pretty much all of the available. Gsm has some waist because it uses a form of tdma.

    However the death of quallcom has been highly exaggerated. As they have there hand in the ring of 3g and 4g gsm upgrade paths. Albeit a smaller hand then they did with cdma 2000 etc.

    Posted from my CrackBerry at wapforums.crackberry.com
    10-14-09 10:35 AM
  10. strunke's Avatar
    Key points...

    1. Cdma can handle more calls and data traffic then gsm can.

    2. Due to a myriad of factors as explained above. Gsm is more popular worldwide and as such can have the latest and greatest phones. Also it is easier to change out phones as needed due to Sim cards as opposed to serial numbers or what could have been rium cards.

    3. In theory Gsm has a hardline distance it can travel from a cell site. Cdma does not have this difference and can actually travel further from the site. Cdma has a phenomenon known as cell breathing, something you don't notice in the united states as a consumer. But something definately noticed say in the African cdma networks using the 450 MHz covering cast swathes of sparsely populated land. Basically in short as more and more people get on it has the potential to shrink the coverage area to maintain call quality.

    4. Gsm is an old technology that is being replaced with wcdma(not the exact same as cdma) and umts and also with some wimax.

    5. There are others but i'm typing from my blackberry SureType and am getting annoyed with going back to change all these words and acronyms. :-)

    Posted from my CrackBerry at wapforums.crackberry.com
    10-14-09 10:49 AM