Cellular Connectivity

We’ve already outlined much of what there is to say about the combination of Qualcomm’s MDM6600 and Motorola’s on Wrigley LTE baseband inside the Droid Bionic review, but it still bears going over. Just like the Bionic, MDM6600 handles 1x voice and data, EVDO Rev.A 3G data, and Wrigley supplies LTE connectivity. In fact, the RAZR has a virtually identical cellular architecture to the Bionic, at least as far as I can tell. There’s the same Infineon transciever for LTE, Skyworks 700 MHz power amp, and combination MCP DRAM+NAND packages for the MDM6600 and Wrigley basebands.


Motorola Wrigley LTE baseband, Intel/Infineon transceiver, Skyworks PA encircled in blue, green, and red respectively. (Original image courtesy iFixit)

I wasn’t totally satisfied in the Bionic piece that I proved the Wrigley baseband was UE Category 2, so I did some more poking this time with the RAZR and found the same exact architecture for administration and configuration as previously. Wrigley is actually a very interesting little part, consisting of an ARM926EJ-S running at 380 MHz:

cat /proc/cpuinfo
Processor       : ARM926EJ-S rev 5 (v5l)
BogoMIPS        : 189.57
Features        : swp half thumb fastmult edsp java 
CPU implementer : 0x41
CPU architecture: 5TEJ
CPU variant     : 0x0
CPU part        : 0x926
CPU revision    : 5
Hardware        : Wrigley 3G DatacardLTE

Oddly enough there are many places where it refers to itself as a “3G Datacard” even though it’s clearly designed only to work with LTE. The thing is just running GNU Linux:

uname -a
Linux localhost 2.6.29-omap1 #2 Tue Oct 25 20:02:46 CDT 2011 armv5tejl GNU/Linux

The reality is that almost all black boxes inside mobile phones end up revealing something similar at their heart if you poke around enough. If we were counting the number of ARM parts onboard your average smartphone I wouldn’t be surprised to see at least 4 or 5 different ARM cores.

Anyhow, the RAZR doesn’t have a nice mib default xml file that nicely spells out the LTE UE category like the Bionic did, but the default set of mibs being set does include the Verizon EARFCN of 5230 which corresponds to LTE band 13. After lots of poking around, I found a way to query the UE category directly:

shell@(unknown):/system/bin$ iwaconfig -g -x 33163
MOID 0x818b  Name LTE_MGMT_RRC_UE_CATEGORY   MIB OID 
  value=2 [0x02]

So life is good and our earlier claims that Motorola Wrigley (with lots of TI references inside) is indeed LTE UE Category 2. As a reminder, other devices based on MDM9x00, LG L2000, and Samsung’s CMC220 are UE Category 3.

FCC UE Category for RAZR

Oddly enough, just like the Bionic the official FCC filing summary information for the LTE side of the RAZR erroneously states that it is UE Category 1. As usual we get the normal pretty diagram with the location of antennas, and interestingly enough the LTE antenna is up at the top on the RAZR instead of in a combined module at the very bottom.

FCC Diagram

We’ve been doing a pretty good job keeping track of cellular throughput by running a bunch of speedtests, getting that data off, and making some graphs. The RAZR isn’t spared this treatment at all, and I ran 510 tests on Verizon 4G LTE in my own market in Tucson AZ and while on a trip to Los Angeles, CA.

Downstream Stats (Mbps)
Avg: 14.701; Max: 36.267; Min: 0.068, StDev: 6.594
 
Upstream Stats (Mbps)
Avg: 6.912; Max: 20.719; Min: 0.084, StDev: 3.707
 
Latency Stats (ms)
Avg: 80.990; Max: 196; Min: 34, StDev: 17.499

Downstream Upstream Latency

The histograms themselves look a lot like what we’ve seen already out of Verizon’s 4G LTE network on other smartphones, which again uses 10 MHz FDD on LTE band 13. I’ve seen numerous other people hit speeds above 50 Mbps on category 3 devices in favorable network conditions, but obviously the RAZR being category 2 does preclude it hitting those speeds.

Like the Bionic, the RAZR also gives you a nice and easily accessible network option to use either LTE/CDMA or just CDMA. Unfortunately again there’s no way to force data on only LTE and avoid handing over, but in practice I rarely saw the RAZR do a hard handover unless network conditions completely precluded using LTE.

I was pleased with myself when I used the Bionic that it was possible to look at LTE signal power (RSCP) and the channel quality indicator (CQI) by just running logcat and grepping the radio status daemon that Motorola wrote for updating their bar visualization. Unfortunately in this newer version of Blur that logging debug output and functionality is no longer, and if you look closely you’ll also notice they went from 4 bars to 5. There’s another way to view those metrics but it involves having shell on the baseband and directly querying the MIBs that correspond to all the LTE signal quality figures of merit. It’s still possible but much more involved. The upside of course is that I was able to confirm the RAZR correctly reports those bars based on signal power and quality, unlike most of the other LTE handsets which just look at power.

Lastly, the Droid RAZR XT912 Motodev page notes that the phone has WCDMA 850/900/1900/2100 connectivity courtesy of the MDM6600. However, the shipping Droid RAZR has WCDMA disabled and corresponding lines commented out inside build.prop for the WCDMA components. Considering the existence of the RAZR XT910 (sans “Droid”) with WCDMA and GSM I think it’s fairly easy to predict that a world mode variant with LTE is coming sooner rather than later. I wouldn’t mind having a RAZR that works on AT&T WCDMA, that’s for sure.

WiFi, GPS, Audio and Speakerphone Camera - Stills and Video
POST A COMMENT

76 Comments

View All Comments

  • JonnyDough - Saturday, December 17, 2011 - link

    I should probably mention too that when I got my phone (through Verizon) that I had mobile hotspot, it was one of the reasons I got the phone. Of course, a month later they had made it pay-to-use and blocked me from it with an update. Its kind of like the whole ISP industry putting caps on it because they quote "can't afford" to not do it. Laugh. ArsTechnica had a whole article on that. Its a really good read. Reply
  • loribeth - Tuesday, December 27, 2011 - link

    Don't worry, the hot spot connection is a known Razor issue, or at least that is what I have read doing a Google search. I just dropped my hot spot, today. I also got a refund of al charges since my purchase. It will connect, but will immediately disconnect. Reply
  • Shinobi_III - Saturday, December 17, 2011 - link

    The razr screen might look bad under a microscope, but compared with the SGS2, the colours are so much better, and no banding at all.

    The SGS2 with it's supposedly better layout, looks like sh*t next to a razr in the real world displaying photos or even most games that happen to have a color fade.
    Reply
  • anandtech pirate - Sunday, December 18, 2011 - link

    It’s a bit odd to see the Epic Touch getting better battery life with Wimax than with 3G. Could this be related to a bad Sprint signal at your test location? Sprint 3G data speeds have been terrible in many locations for the past 6 months. Reply
  • victorjr - Sunday, December 18, 2011 - link

    This is what should be called Review! "Reviews" done by other sites are a joke. We can decide with much more success. We can read facts and not only biased opinions. Anandtech is the place I have been for years. This will continue. Cant wait to the Galaxy Nexus review. Reply
  • iSayuSay - Sunday, December 18, 2011 - link

    I don't want to start another flame because I actually feel this Razr is a damn fine phone (apart from it's not bundled with ICS yet), but truly .. Apple just did it again.

    Some hi-end Android now start to use a user un-effin-replacable battery in pursue of thinness and the ability of using hi grade material..

    Adobe start to drop future support on Mobile Flash plugin.

    Some Android now bundled with software or apps which basically iTunes wannabe with all syncing, copying, and not-so-free device managing, something most people bash on iPod and iPhones?

    And I'm sure more and more Android handset going to adapt microSIM on their phone. Just like this phone.

    Long story short, somehow .. smartphone trend start to follow something that most people hate .. the iPhone
    Reply
  • lexluthermiester - Sunday, December 18, 2011 - link

    Had to deal with two iPhones with batteries that stopped holding a charge and a few friends have had to deal with similar problems with their iPads. Sealing the battery inside gives the manufacturer an opportunity cut corners in the battery department. Totally unacceptable. Reply
  • doobydoo - Tuesday, January 17, 2012 - link

    Thankfully you're in a tiny minority. And you can get dodgy batteries whether it's removable or not. Reply
  • georgekn3mp - Monday, December 19, 2011 - link

    I have had the HTC ReZound for a month now, and did not like the width and height of the Razr (or the screen compared to true HD 720p on the ReZound) and hope to see a Galaxy nexus review soon even if Anad never publishes one for the ReZound. I researched all 3 before buying the ReZound and found it was best for my needs and wants for a halo phone.

    Even if the SunSpider and Vellamo tests on GNex beat the ReZound..I am not switching. I love my first smartphone...with a non-Pentile HD 720p display, dual-core at 1.5ghz, a better 8MP camera with f2.2 lens and not as big a bezel. I like the phone dimensions on Rezound better anyway...I can swipe my thumbs all the way across holding it one-handed and can't on GNex.

    So the only thing GNex has that ReZound does not is Android 4.0 (and that will happen eventually). So NFC is crippled anyway without the Google Wallet. Heh, all that waiting for a GNex which is already sporting outdated hardware....I bet both the Razr and ReZound beat it when they get Ice Cream Sandwich...just have to wait long enough.
    Reply
  • Rowlf - Monday, December 19, 2011 - link

    I just came back from the verizon store in an attempt to escape apple hell. I so desperately wanted the RAZR or galaxy nexus to be a replacement for my old iphone. The razr and nexus seemed to be choking on this review or anywhere on anandtech. Scrolling was not smooth and the nexus even crashed once. I tried the newest iphone just for kicks and it had no problems. Was it the demo floor model?

    Also the nexus seemed to be half as bright as my old phone. Yes I made sure brightness was as maximum and auto brightness was off. Was it the demo model?

    Do I need to go to a different verizon store? Is that as good as it gets at this time and I should be looking or waiting for something else?
    Reply

Log in

Don't have an account? Sign up now