I noted in my review of the LG/Google Nexus 4 that the device included hardware necessary for LTE on at least some of its bands, namely bands 1 (2100 MHz), 2 (1900 MHz), and 4 (AWS 1700/2100) based on what I saw in my teardown. Enabling LTE on a given device requires everything in the cellular chain to include support — the cellular baseband to support it must be present and loaded with the appropriate software, the transceiver must be the appropriate kind, and finally the right power amplifiers (PAs) have to be in place for the wider channel bandwidths that LTE brings (up to 20 MHz) over WCDMA  (5 MHz). 

 
Nexus 4 on Band 4 LTE (Left), Band Preference Setting in *#*#4636#*#* (Right)

In the case of the Nexus 4, the hardware includes the latest and greatest cellular hardware from Qualcomm with MDM9215M, its third generation 28nm Category 3 LTE multimode baseband, and a WTR1605L transceiver. I tore down the Nexus 4 to ascertain whether PAs were present that could work with LTE, and saw indeed that at least bands 4, 2, and 1 did have Avago power amplifiers (A5704, A5702, and ACPM–7251) which noted support for LTE. The remaining piece of the puzzle was software stack, both in Android and inside the version of the AMSS (Advanced Mobile Subscriber Software) running onboard MDM9215M.

Recently some Nexus 4 owners in Canada posted on XDA that they had working LTE support on Band 4 if they enabled the appropriate "Preferred Network Type" in the dropdown menu there. This menu is inside "Phone Info" which has been part of Android forever and can be accessed on almost every Android phone either by dialing *#*#4636#*#* (INFO) or using an app called Phone Info which launches that activity directly. 

Recently, Anritsu graciously loaned me an MD8475A signaling tester and LTE/WCDMA/CDMA2000 base station emulator for me to test and evaluate devices with. I tested the Nexus 4 on DC-HSPA+ for the review but didn't think to try testing LTE on the appropriate bands since Google and the FCC documents are both explicit about only WCDMA/GSM being present. I tested for LTE on all the bands that the Nexus 4 includes UMTS support for, starting with 5 MHz wide LTE channels. It appears that Nexus 4 only has support for LTE on Band 4 (AWS) with bandwidths up to 20 MHz in fact. I put together a table for easier parsing. If a band isn't listed, it isn't supported. Update: Lots of people have asked me to test some additional bands (3, 7, 20) because of their international relevance, these unsurprisingly are not supported given the fact that there are no PAs present for them. I've updated the table to be explicit however.

Nexus 4 LTE Band Coverage
E-UTRA (LTE) Band Number Commonly Known Frequency (MHz) Bandwidths Supported
1 2100 No Support
2 1900 No Support
3 1800 No Support
4 1700/2100 5, 10, 20 MHz
5 850 No Support
7 2600 No Support
8 900 No Support
20 800 No Support

Because testing the 2x2 MIMO configuration requires cabling up the Nexus 4 to the antenna leads directly, and my LG-appropriate antenna connectors haven't arrived yet, I only can test with a 1x1 configuration. The Nexus 4 does include Rx diversity for every band, and thus it's entirely possible on Band 4 that users will see the full 2x2 MIMO rates (37 Mbps on 5 MHz, 73 on 10 MHz, 100 Mbps on 20 MHz), but I can't confirm it directly. For the 1x1 configuration I could test, however, I saw the expected ~75 Mbps on 20 MHz FDD LTE which is very close to the maximum of 75.376 as shown. 

The conclusion is that the Nexus 4 at present curiously includes the software profile on MDM9215M that enables support for LTE on Band 4 (AWS), and users only need to set the appropriate network type preference in Android to use it. None of the other bands that there are even power amplifiers for have LTE support, which is unfortunate for users in places where carriers aren't running LTE on AWS, such as the USA. For example, in the USA, AT&T previously discussed plans for LTE on Band 4 but has only rolled out LTE on Band 17 to date, and is rumored to be turning to refarming its PCS (1900 Band 2) and Cellular (850 Band 5) holdings for additional LTE capacity, perhaps in the stead of AWS. T-Mobile US however will use AWS for LTE. Nexus 4 LTE support is definitely unofficial (and somewhat surprising) at this point, but if you're lucky enough to be in a place where your carrier has rolled it out on Band 4, it's just a setting away.

 
Still working on Android 4.2.1...

Update: This morning an update started rolling out to the Nexus 4, 7, and 10. I suspected initially that Google would quickly disable LTE on band 4 on the Nexus 4 for regulatory reasons (or file a Class II permissive change with the FCC). Interestingly enough the OTA going out to the Nexus 4 bringing it to build JOP40D doesn't disable LTE on band 4 or change the baseband software version at all. I was able to make the device attach the same was as I was previously. This update does fix the missing December option for birthdays in the People application, however. 

Source: XDA Developers

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  • Eug - Friday, November 23, 2012 - link

    As a Fido customer, I am tickled pink, since it should support LTE on the Nexus 4.

    However, it's currently moot, since I can't even order the Nexus 4. :(
    Reply
  • Zink - Friday, November 23, 2012 - link

    Here are some tests on my commute today with my Nexus 4 in LTE only mode. This is in Waterloo, Ontario on Koodo (Bell towers).
    http://www.imgur.com/MCWXo.png
    Reply
  • bplewis24 - Friday, November 23, 2012 - link

    So basically what this means is, the Nexus 4 in Canada is currently the best possible phone money can buy. And it's $300 off contract.

    I'm jelly.
    Reply
  • psygone - Friday, November 23, 2012 - link

    Good upload speeds and ping times. Did you need an LTE sim or have to change your APN to work on Koodo? Reply
  • Zink - Friday, November 23, 2012 - link

    The phone set up the APN automatically when I put in the SIM that came with my GSII. I deleted the proxy settings because they blocked speedtest but other than that I just clicked LTE only and this is what happened. Reply
  • Fiercé - Friday, November 23, 2012 - link

    Fantastic work Brian. Articles like this are why many come to AnandTech I'm sure.

    As an aside, can you quickly look into the Podcast naming schema, meta data and tag usage?

    Right now, the Podcast tag is missing from Episodes 5-7 (though a search for "podcast" brings up all of them), and the recent Episodes 9 and 10 are going under a weird "Anand Shimpi1's Album" on my phone. Episodes 1-8 went into "Anand Shimpi's Album" as a comparison.

    Also, a picture of the AnandTech logo wouldn't hurt either. In addition to aesthetic cleanliness with the rest of ones Album view, those sidelong glances at the screen from people sitting beside a smartphone user on a train or plane lead to curious Google searches and new listeners.

    Again, brilliant work. Be the wheat, not the chaff!
    Reply
  • Eudoxus - Friday, November 23, 2012 - link

    This is fantastic news. Even if the LTE eats the battery, I can always turn it off when I don't need it.

    Mr. Klug, you have made sitting on the backorder list for a Nexus 4 in Canada infinitely less painful. I didn't really believe this news until I saw it here.
    Reply
  • Mannberg - Friday, November 23, 2012 - link

    Does this mean if we could flash an AMSS (Advanced Mobile Subscriber Software) that has support for bands 4, 2, and 1 to the MDM9215M we would have LTE on band 4, 2 an 1? Reply
  • Mannberg - Friday, November 23, 2012 - link

    Is it possible to take the AMSS software from an LTE enabled Optimus G? Reply
  • descendency - Friday, November 23, 2012 - link

    I think the hardware is missing for bands 2 and 1. Reply

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