Sony Xperia Z3 might not be compatible with T-Mo’s 700MHz band after all

Earlier this month, we got wind that the rumored Sony Xperia Z3 would support band 12 LTE. If so, it would be compatible with the 700MHz spectrum acquired by T-Mobile from Verizon recently. It would join both the Samsung Galaxy Tab 4 8.0 and the unreleased Galaxy Avant as being one of the first devices to support the lower frequency network. But there’s a problem. As indicated in the device’s FCC filing and SAR report, it apparently doesn’t support the full range of 700MHz spectrum required to work on T-Mo’s.

The Z3 – or whatever this mystery device is – only supports band 12 on 704-716 / 734-746 MHz. This excludes the lower A-block spectrum, making it incompatible with the network T-Mobile will be rolling out at some point later this year. However, it’s important to note the possibility that this device’s network capabilities are being engineered for an entirely different market north of the border, in Canada. Both Telus and Bell use Band 12 in these frequencies. 

Now, there’s a small chance that the device is being prepped for use on AT&T’s band 17 LTE network which has the required frequencies, but isn’t band 12. If AT&T’s band 17 network started advertising band 12 support, it could be possible for the Sony smartphone to make use of its 700MHz airwaves. In order to make that a reality though, it would need to implement a technology named Multi-Frequency Band Indicator or MFBI. This allows carriers to declare multiple band IDs for the same set of frequencies.

Our reader, and fellow tech blogger Neal (aka @det_conan_kudo on Twitter) helped us out a lot in discovering this and states:

For example, if T-Mobile launches LTE on PCS, it’ll natively use the Band 2 ID, since that is supported for its devices. However, T-Mobile could also use MFBI to additionally declare that it is a Band 25 LTE network, allowing Band 25 LTE devices (Sprint LTE devices) to connect to its PCS LTE network. T-Mobile is unlikely to do this, of course, but it could. What it will do in the future is use MFBI to support the upcoming band ID that will support AWS-3 frequencies (which are up for auction on November 13) and AWS-1 frequencies (which T-Mobile uses now).
This device is effectively worthless for either T-Mobile US and AT&T on 700MHz because T-Mobile doesn’t control any Lower 700MHz spectrum within those frequencies and AT&T doesn’t have MFBI on its network to allow it to connect (it won’t have it until late next year, according to some rumors).

So, for now, we’ll assume that any Z3 device that may or may not be released at this year’s IFA event in Berlin in September won’t be compatible with T-Mobile’s band 12 network.

Thanks, Neal.

Image Credit: EvLeaks

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  • Bryan Pizzuti

    That 700 MHz A-block is really turning into a bust.


      If you think T-Mobile doesn’t have handsets in the works that will use it you are sadly pessimistic.

      • Bryan Pizzuti

        That band has been around a while now. No one’s using it, and there’s no devices for it. I wish it was useful, but perhaps it just isn’t.

        • Moby

          This is false information. U.S. Cellular has been using band 12 devices since early 2013. However, since that is a CDMA carrier, those devices can’t be used on T-Mobile. T-Mobile has only owned their band 12 spectrum for a brief period. And they are commissioning devices for band 12, that they said from the beginning would be out before the end of the year.

    • Chris

      A company doesn’t buy a spectrum and then few months later that block of spectrum is in use. Doesn’t happen that way and never will. A company already has plans in improving their towers, spectrum use, etc. on that year, do you seriously think that by buying a spectrum all of their already planned projects would just go to the trash in favor of the new spectrum? No, they would have to go back and think it through on what the integration plan would be.

  • Hamster

    “The Z3 – or whatever this mystery device is – only supports band 12 on 704-716 / 734-746 MHz.”

    That’s not band 12 at all. That’s band 17.

    • Hamster

      Granted, band 17 is a subset of band 12, but the phrasing is bad. Something either supports band 12 or doesn’t. It’s not a partial thing. Band 12 is A/B/C blocks and band 17 is B/C.

    • Moby

      Right. The device NEVER supported band 12. If you look at the link to the FCC report in the initial Tmonews article, it clearly had an exhibit called Test Report LTE B17. Never mentioned B12. Then the other exhibit referenced in the original Tmonews article, “Test Report Re-Use Confirmation” clearly said the following about the device: “FCC ID: PY7PM-0800 supports LTE B5, 7, 13 and 17 and doesn’t support LTE B12 ”

      I don’t know how much more clearly they needed to make it. The people at tmonews reported something that was clearly not shown in the FCC filing.

      • Hamster

        Right. They seem to have some confusion about what they reported originally. The original report simply showed evidence of a variant of the PY7PM-0800 that would support band 12 with the ID PY7PM-0801. The 0800 was always lacking band 12.

        This could easily be a situation where the 0800 is the international model and the 0801 is the North American model.

        • The device in question has FCC ID PY7-PM-0801. It has Band 12 for only the Band 17 frequencies.

          Take a look at the SAR report for yourself:

        • Hamster

          Ah, you found something for the 801. Well done.

          That said it’s not exactly clear to me that it means what you think it means. It seems to be written a little oddly. It says it has a low transmit frequency of 704, but then uses 704 as the center frequency for a 10Mhz channel in the SAR test (in Part 3c) which would perfectly line up its frequency range of 699 – 716 along with the test of a 10Mhz channel with 711 as the center frequency.

          Confusion aside, I still feel confident this will be A-block compatible because, as I said, doing tests labeled Band 12 on a Band 17-only device doesn’t make sense.

          The transmit range on the on Part 1 doesn’t even make sense for a Band 17 device though as it says it stops at 711 while Band 17 goes to 716. The transmit range doesn’t make sense to me unless the high and low are taken as center frequencies, rather than actual limits. Granted that doesn’t match up with how the other LTE bands are marked — perhaps that’s because of the different bandwidths between the tested Bands.

  • Hamster

    Moreover, the filing’s report re-use still specifies a second variant of the device that is band-12 friendly. No idea where or if the filing for the variant in question “PY7PM-0801” is, though.

  • Laststop311

    Will the galaxy note 4 support band 12? I have a galaxy note 2 and I want my next phone to be band 12 compatible as I live near cleveland ohio which sits in an area covered by the 700mhz purchase. I mean my note 2 still runs very well and I’ll gladly wait for the note 5 but I hope the note 4 does i mean if the galaxy avant can support it no reason the note 4 cant.

  • LTEstyles

    Anyone have the link to the full LTE bands for the T-Mobile version of the Z3?