Seeing at lte and CDMA are two different techs what happens

Discussion in 'iPhone' started by SilentLoner, Oct 13, 2012.

  1. SilentLoner macrumors 65816

    SilentLoner

    Joined:
    Dec 29, 2007
    #1
    When you switch between the two. Does the CDMA chip activate and switch on then? Do you need the nano sim if you want to use it for just 3G/2G. I'm on about the iPhone 5.
     
  2. dontwalkhand macrumors 601

    dontwalkhand

    Joined:
    Jul 5, 2007
    Location:
    Phoenix, AZ
    #2
    Nano SIM is required at all times as it is so a C-SIM. Removing the SIM, will remove all service from your phone just like a normal GSM phone.

    But sounds like you got the rest right. CDMA is always running for voice. LTE for data only.
     
  3. SilentLoner thread starter macrumors 65816

    SilentLoner

    Joined:
    Dec 29, 2007
    #3
    That's cool. I find the differences fascinating. What is different between a c-sim and sim?
     
  4. tymaster50 macrumors 68030

    tymaster50

    Joined:
    Oct 3, 2012
    Location:
    New Jersey
    #4
    you ever notice when you switch to LTE it stalls for a little then the status bar says LTE after 5-50 seconds(depends on your area)? That's because it is turning on the lte signal since it is a seperate chip and then finding a signal strong enough to replace the 3g one.
     
  5. sdsvtdriver macrumors 65816

    Joined:
    Jul 31, 2008
    Location:
    Southern California
    #5
    No, there's no "separate chip". the i5 uses Qualcomm's single radio chip for this device, hence the good battery life compared to many other devices that have to use separate radio chips.
     
  6. tymaster50 macrumors 68030

    tymaster50

    Joined:
    Oct 3, 2012
    Location:
    New Jersey
    #6
    There is a chip in the iPhone 5 for LTE. MDM9615M modem is the name of it
     
  7. dontwalkhand macrumors 601

    dontwalkhand

    Joined:
    Jul 5, 2007
    Location:
    Phoenix, AZ
    #7
    C-SIM is a SIM card that is for CDMA, it still is compatible with GSM, for when you're roaming. In essence it is a normal GSM SIM with extensions to allow for usage of the SIM on CDMA.
     
  8. sdsvtdriver macrumors 65816

    Joined:
    Jul 31, 2008
    Location:
    Southern California
    #8
    This chip also does EVDO and HSPA+, amongst others. It isn't just an LTE chip. Other devices have a dedicated chip for LTE and another chip for EVDO or HSPA+ which kills battery life.
     

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