Understanding LTE

Discussion in 'iPhone' started by n8236, Oct 8, 2012.

  1. n8236 macrumors 65816

    Mar 1, 2006
    So, we know there are two model numbers for the iPhone 5 (A1428 and A1429). A1428 is from AT&T and A1429 being from the rest.

    Does anyone know if there are any hardware differences besides the A1429 having a CDMA chip?

    We know they use different LTE bands, but is that because of a software/firmware or hardware difference?

    The bottom line is, will there be a solution where all LTE bands will be accepted.
  2. n8236 thread starter macrumors 65816

    Mar 1, 2006
  3. stevedusa macrumors regular

    Jun 12, 2012
    Most likely the hardware. Keep in mind for that RF is not very simple thing to master into small physical spaces. The biggest challenge is the physical antenna that does the transmit and receiving.

    The differences between these models are the LTE band they can operate on, other than that? They are identical. Qualcomm is the one that made the iPhone 5's RF chips and either they couldn't fit all existing (and expending) LTE bands together or the FCC frowns upon the Idea.
  4. Dwalls90 macrumors 601


    Feb 5, 2009
    This will probably give you what you're looking for.

    There is no software/firmware that can amend this, as it's hardwired into the wireless chip.

    Unfortunately, 4G LTE is way bigger of a spectrum scatter than 3G ever was, and it took us a few years to get a world 3G iPhone. Maybe we will see a true "world" 4G LTE iPhone next year.
  5. Gav2k macrumors G3


    Jul 24, 2009
    It's 110% hardware. There isn't a chip on the market that covers the whole spectrum yet.
  6. CyBeRino macrumors 6502a

    Jun 18, 2011
    The hardware in the three different models is mostly identical. In the A1429s, it is identical and the difference is software. (The one chip handles CDMA, EV-DO, UMTS, HSPA, GSM and LTE, and it's in all models. The software disables CDMA in the GSM A1429 model).

    The difference between A1428 and A1429 lies in the amplifiers for the LTE radio. Those are set-up so the device will work with AT&T's LTE frequencies. This requires physically slightly different hardware. The chip itself can handle all of them, but the supporting hardware can't. And it can only support a certain amount of bands at the same time.

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