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Roaming between GSM and CDMA

Viewing 15 posts - 1 through 15 (of 31 total)
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  • #36794

    Hello all,

    I would like to know, is it possible to have a roaming contract between GSM and CDMA network?

    Thanks for yr concerns


    i think it is not posible to do, because they quitely technology, frequency, mobile equipment …


    Yes it is possible…

    Currently applicable to WCDMA Networks.In which user have to select the mode.Used in Europeon Countrys for Testing.Not yet commercialised.

    I dont know much abt CDMA 2000 where they dont use SIM Cards.



    Yeah, you are right, Scot.

    Plz kindly tell me, which site or documents about roaming between GSM and CDMA I have to refer to?

    Do u know any information concerning to WCDMA and CDMA 2000? or do u know any related material?

    Is it true that both WCDMA and CDMA 2000 are 3G?

    Does the subscriber of WCDMA network use SIM card?

    Thank you


    I didnt gone for any search yet.

    Very busy my friend.

    Better can you check some sites of GSM 3G Operators ?




    The roaming is a possibility between the GSM and CDMA networks and in some networks in SE asia, trials are on. Basically this requires the CDMA handsets to be equipped with R-UIM (similar to the SIM cards in GSM) and some other support as the reciever. On the core network side there is an additional component called Network Interface controller (NIC) that helps in authentication. This is still in very primitive stage and a lot needs to happen.

    On the second query, there is no CDMA 3X or WCDMA in CDMA world now. UMTS, WDMA, GSM 3G all refer to one of the same thing where access technology is CDMA (with 5MHz carrier) and core is GSM.

    The CDMA will not go to CDMA 3X (or WCDMA). After CDMA 1X there is 1X-EVDO and then 1X-EVDV.

    so the dream of consolidation of GSM and CDMA network is quite far. Unless some good results come outof these trial, we need to wait till 4G.


    Thanks Scot and Pankaj for your information.

    Does anyone else has other comments?


    prabhakar verma

    Pankaj , would like to comment as to where you read the stuff you are mentioning..
    Cause only recently they have created a Hand-set capable of working as dual CDMA as well as GSM , and i doubt to the concept of R-UIM and NIC.
    If the handset’s are capable of working as a dual one..
    then only the changes in the Signalling messages in accordance to the format used between CDMA and GSM , the roaming could be possible..
    Awaiting your comment in this topic

    prabhakar verma

    More on it..
    all you require is an interworking unit to do the coversion between the MAP messages(GSM) and IS41D messages(CDMA)


    The NIC that i mentioned is probably you are refering as conversion unit. In that unit you do not convert the GSM MAP messages to IS-41 or visa versa, what it does it that it provides the authentication support for the mobiles, and emulates a HLR for that.

    i doubt that the mobile that you are talking about is available commercially. Any ways i will be more then happy to see any information on that.

    Lastly the RUIM is very much in there as that is the current mechanism to provide plastic roaming between CDMA and GSM.


    hi all,
    clearly roaming is possible between GSM and CDMA

    CDMA Customers without SIM cards and customers of operators that do not have a roaming
    agreement can rent a PDC (2G) handset. The mobile handset number will be different in this case

    more information plz visit


    hi MISA

    Regarding roaming between GSM and CDMA, the answer is yes and did not have to wait 4G or 3G and it’s available right now with GSM1X (u can refer to The product and technology built by Qualcom and it’s already complete trial by China Unicom( according to news)…



    Hi Mohsin

    Thnak you for the information


    IS41D and GSM – MAP Protocal Interworking is currenly used in INDIA for SMS-Interworking between CDMA2000 and GSM Networks.

    For this the CDMA Operator is using a “SPECIAL UNIT” to do the CONVERSION JOB.

    Any Idea abt this Equipment.

    May be integrated with the the SMS-SC of CDMA Network in RELIANCE/TATA ?

    John Chen

    Is there any one can providing me a description or a structure pictures to talking about this cross roaming between CDMA and GSM. Thank you

Viewing 15 posts - 1 through 15 (of 31 total)
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