Investigating the Galaxy Nexus LTE Signal Issue
by Brian Klug on December 19, 2011 8:24 PM EST- Posted in
- Smartphones
- Verizon
- LTE
- Droid Charge
- Mobile
- galaxy nexus
- Android 4.0
It seems that each time an LTE handset comes out, there’s invariably some perceived issue with connectivity and stability. This time, focus is being placed on Verizon’s CDMA/LTE variant of the Galaxy Nexus, and the issue surrounds LTE connectivity robustness compared to the other LTE handsets out there.
I’ve been running battery life tests on our LTE Galaxy Nexus review unit since release day (a process that takes a considerable amount of time and results in our reviews posting a while behind everyone else’s), but have had some time to run tests and gauge subjective performance. I found that LTE connectivity and performance felt above average, subjectively, and noted that in a tweet. After complaints started to surface, I spent a considerable amount of time reading the threads on XDA and other places around the web trying to discern what the complaints are about. I’ve seen a couple of big misconceptions that I think really get to the heart of the matter.
First off, is some background. The Verizon CDMA/LTE Galaxy Nexus (codename “mysid”) uses a combination of Samsung CMC221 and Via Telecom CBP 7.1 for LTE and CDMA 1x/EVDO connectivity, respectively. This is virtually identical (unsurprisingly) to the Droid Charge, which used a CMC220 for LTE and the same CBP 7.1. The CMC22x family is UE Category 3, which currently is the highest for shipping devices and means it can handle up to 100 Mbps downstream with 20 MHz FDD. To date, all of the LTE basebands in Verizon LTE devices have been UE category 3 with the exception of Motorola’s devices, which are all UE category 2, but I digress. We’ve reached out to Samsung Semiconductor about what’s changed between CMC220 and 221, but doubtless the changes improve connection stability and reliability.
Speeds thus far have also been excellent. I’ve squeezed in 183 speedtests between battery life testing, and have seen some of the fastest LTE connectivity out of the Galaxy Nexus to date. After testing so many Motorola LTE devices with UE Category 2 modems, it’s refreshing to see this kind of performance out of a UE Category 3 device.
The issue that most people talk about centers around signal strength, and this is where a few misconceptions kick in. I’ve gotten a few emails and tweets and read pages on forums where people are implicitly comparing CDMA2000 1x/EVDO field strength to LTE field strength. The issue here is that on basically all of the LTE/CDMA Verizon handsets, the field under “Signal Strength” in about refers to EVDO signal strength, and not LTE signal strength. The two aren’t comparable at all for a host of reasons - different spectrum (800 MHz and 1900 MHz for 1x/EVDO as opposed to 700 MHz for LTE), and different cells (there’s some correlation, but not every Verizon base station has LTE onboard). The end result is that if you’re comparing 1x/EVDO signal strength to LTE signal strength, you’re making an absolutely meaningless apples to oranges comparison.
This is not a valid comparison - LTE versus EVDO signal strength
The Galaxy Nexus (and really just Android 4.0) now correctly reports and accommodates LTE by reporting its signal strength under “About->Status” and visualizing that as bars appropriately. Switch to EVDO on the Galaxy Nexus and signal strength appropriately changes to reflect an entirely different air interface’s signal strength. It’s nice to see people using dBm instead of bars when possible (which are effectively meaningless as a comparison metric), but now that there are multiple air interfaces on handsets, we have to be explicit about what numbers we’re actually comparing.
This reporting is a problem I’ve talked about at length in more than one LTE handset review, and to date I only know of ways to show LTE signal strength and channel quality on a few handsets. Samsung’s Droid Charge (courtesy Samsung’s excellent ServiceMode application viewed through *#0011# after some unlock trickery) and the Bionic (through logcat and grepping for the radio signal status daemon) report LTE field strength, but only if you dig for them.
Comparing LTE Signal Strength the Right Way
So how does the LTE Galaxy Nexus compare to the Droid Charge and Bionic, the two handsets we can actually view LTE signal strength in dBm on? Very closely as a matter of fact.
I have a Bionic kicking around which has to go back very soon, but fired up logcat and put the Galaxy Nexus next to it. The Bionic reports signal strength pretty constantly whereas in Android 4.0 the number has some hysteresis, but here the numbers are pretty darn close, with the Bionic hovering between -91 and -95 dBm, and the Galaxy Nexus reporting an average of -92 dBm.
Left: Motorola Droid Bionic (logcat showing LTE signal strength), Right: Galaxy Nexus
Since the Droid Charge is the only other handset I know how to show LTE signal strength on, I tracked a friend down at a local cafe with one and fired up service mode. Again, what’s shown under “About->Status” on the Droid Charge is actually EVDO signal strength. Here the Galaxy Nexus shows -107 dBm and the Droid Charge shows -108 dBm.
Left: Samsung Droid Charge (ServiceMode) Right: Galaxy Nexus
The Droid Charge is another hilarious example of why you can’t compare bars at all, as the Charge shows a positively laughable 4 out of 5 bars in an area with very low LTE signal strength, whereas the Galaxy Nexus (moreover, Android 4.0) has a very conservative and realistic strength to bars mapping. Carriers love to make things out to be better than they really are, however, and the result is this kind of hilarious visualization which portrays LTE signal as being much better than it really is if you stare at bars all day.
Verizon confirming though a tweet that there’s some sort of signal issue affecting the Galaxy Nexus confuses me, since from my perspective there isn’t any issue at all. The only real issue that exists is that the Galaxy Nexus (and really just the stock Android 4.0 signal strength to bars mapping) doesn’t line up with what Verizon has shipped on other devices, thus leading people to make apples to oranges comparisons and imagine an issue. I wager that some of this confusion is also compounded from the number of Verizon customers that are just now getting their first LTE handset with the Galaxy Nexus. It might be surprising to discover that LTE coverage right now isn't nearly as good as 1x/EVDO, but these things will improve as the carrier's LTE rollout continues. The other big disclamer is that I haven't fully investigated 1x/EVDO performance on the Galaxy Nexus, but this will end up being virtually identical to the Droid Charge.
There’s a CDMA and LTE baseband update coming with the LTE Galaxy Nexus’ 4.0.3 update as shown above, but this will likely do more to address connection stability than change the way anything is reported. Given how much attention this has gotten, however, I would not be surprised to see Google make a change to its signal strength to bars mapping for LTE and placebo away an issue that never really existed to begin with. That's also an unfortunate change, since from my perspective the Galaxy Nexus is one of the first handets that doesn't have an unrealistic mapping. In the meantime, we're still working on our Galaxy Nexus review where we'll take a complete look at the LTE/CDMA and GSM/UMTS Galaxy Nexii.
Update:
As predicted, Verizon has made a statement to The Verge and Computerworld stating that there's nothing wrong with the RF performance characteristics or baseband firmware on the LTE/CDMA Galaxy Nexus. Instead, they will upstream some changes to Android to make the device report its bars visualization in line with the rest of its 4G LTE hardware portfolio.
"[Verizon] will adjust the signal strength indicator to more closely match other Verizon Wireless devices.
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nonand - Tuesday, December 20, 2011 - link
I have two phones - A Charge and a Nexus.Sitting next to one another, the Charge is getting 4G and the Nexus 3G.
When the Nexus does finally get 4G it will often fall back to 3G with extremely poor performance.
The author makes light of the issue. Perhaps he should do a little more research before calling all of us having problems idiots.
Verizon has acknowledged an issue because there is one. I give them 10 days to resolve it or the phone goes back.
Rukkian - Tuesday, December 20, 2011 - link
I read the article and did not see anybody calling anybody an idiot. While you may have problems, he was not saying that there are not any phones with issues.I am happy to see good comparisons, and from what I see from others, it seems that the problem seems to lie in the handoff, and how the phone chooses which network to use. This is my first real smartphone (last non-feature phone was an original BB Storm) but I get better call quality than my old phone, and can keep a connection in places that most people drop (and I used to with my old phone) with verizon and other carriers.
I have left 4g off most of the time I have had the phone, as I normally do not need the extra speed and am on a limited plan, but the speeds have been pretty good, but would always like better.
nonand - Tuesday, December 20, 2011 - link
Here is what the author said...The only real issue that exists is that the Galaxy Nexus (and really just the stock Android 4.0 signal strength to bars mapping) doesn’t line up with what Verizon has shipped on other devices, thus leading people to make apples to oranges comparisons and imagine an issue. I wager that some of this confusion is also compounded from the number of Verizon customers that are just now getting their first LTE handset with the Galaxy Nexus...
I am NOT making an apples-to-oranges comparison here. And, yes, the author is implying that anyone doubting the performance of the NEXUS on LTE must be a newb. This is my 3rd Android phone.
As I sit here looking at a NEXUS and CHARGE sitting right next to one another, the Nexus has -111 dBm on LTE, and the CHARGE -95. The NEXUS will drop LTE and the CHARGE will not. To add to the confusion, in other locations these phones will have almost exactly the same signal strength and performance. Unfortunately, I don't live at the Verizon store.
There is definately something wrong here, and anyone willing to ignore it is just being ignorant. My point is that the author needs to do a little more research before making bold statements that everything is fine and anyone saying otherwise doesn't know anything.
I will gladly take up the author on his wager that there is nothing wrong with the phone except for some minor reporting issue. Perhaps he can come to my house and try out the phone.
I am happy for you, Rukkian, that your NEXUS works well where you are. I hope you are never in a place where it doesn't. I, however, just spent $400 on a phone and accessories that performs significantly worse than a CHARGE I purchased several months ago.
I hope Verizon acknowledges and addresses the issue because on all other counts this is a fantastic phone.
jersiq - Tuesday, December 20, 2011 - link
Kind of curious how you did you comparison there. RSRP is not the same as RSSI.RSRP is the energy of the reference symbols in LTE for the current cell you are on, whereas RSSI is just the received power over the entire bandwidth you are measuring, inclusive of interference. A minute difference, but a difference nonetheless.
Kiouerti - Tuesday, December 20, 2011 - link
I cannot vouchsafe for everyone but in my case the connection issue is real. Having two Nexi, one S2, and one HTC TP2 in my hand i found the following:WIFI-N: In my office I'm surrounded by WiFi networks--at any point, I can connect to at least there of them. The Nexi failed even to see the WiFi-N routers. The S2 saw it and connected immediately.
CELLULAR RADIO: In the same location the HTC TP2 had consistent connection. The Nexi could place calls and send text messages, but data was unavailable. At the same location, the S2 was inconsistent--but at least could connect most of the time.
LTE: In places where LTE is available in Phoenix, the Nexus had problems fetching data. Even voice was inconsistent. The Nexus would often refuse to fetch data, even after switching off/on the device.
Davest - Tuesday, December 20, 2011 - link
I can't speak for anyone else, but the problem that I'm having with my GNex is real. My home is on the ragged edge of the 4G range. I had a Bionic for about two months and, while the signal wasn't stellar, there were certain areas of my home where I could receive a reliable 4G signal, and I could always get very strong reception outside.Fast forward to GNex release day, when, thanks to Costco's 90-day return policy, I was able to exchange the Bionic for a GNex. The difference in signal strength is night and day. I'm not talking about how many bars show up, I'm talking about being able to get a 4G data connection at all. There's not a single place inside my house where my GNex can pick up a 4G signal. When I go outside, I can get a signal in some areas, but not in others.
Based on what I've seen on the forums, this seems to be an issue that affects those in borderline 4G areas. How much of your testing was done in such an area? By referring to "some perceived issue with connectivity and stability", and stating that "The only real issue that exists is that the Galaxy Nexus (and really just the stock Android 4.0 signal strength to bars mapping) doesn’t line up with what Verizon has shipped on other devices", you're doing a disservice to those of us who really are having a very real issue with our new phones. I don't care how many bars my phone shows; I care that I can't connect to the network at all places where other phones can.
Tabs - Tuesday, December 20, 2011 - link
Where did Brian ever say that there aren't 4G to 3G handoff issues (threshold at which it switches, hanging on the switchover etc) or that there wasn't a 3G signal strength issue?Everyone's accusing him of this on all the blogs now since the article caught on but that isn't at all what he said.
Garstud - Wednesday, January 4, 2012 - link
Brian is content with the idea that this is a indication only problem and does not seem interested in investigating the many reports of real problems here. I am one of those experiencing a real loss of 4g where i never lost it with my bionic.kkwst2 - Tuesday, December 20, 2011 - link
Well, as another anecdotal experience, I just got an LTE Nexus today and could barely get any signal in my office where I normally got great signal on my Droid X. I was able to connect long enough to activate and update to 4.0.2, but the connection was horribly unreliable.Our IT support guy had just received his Nexus late last week, so we did a comparison of the phones. In the same location on LTE, my signal strength never got above -120 dBm, compared to his at -80dBm.
Mine would not seem to be able to get a reliable CDMA signal either. When we lost LTE, his would drop back to CDMA and get 2 bars, whereas mine would show no bars and not be able to connect at all. I tried choosing CDMA preferred and rebooting with no improvement.
When I reboot the phone, it would connect OK for a few minutes and then drop the connection and never reconnect. I tried doing a *228 but the call would never go through.
I'm guessing I just got a bad unit, but seems like perhaps they are having some quality control issues. New one should arrive in a couple days....hopefully that will be better. That my coworker's works well is a little reassuring.
qualm - Tuesday, December 20, 2011 - link
http://www.phonearena.com/news/Speed-test-showdown...I know that the values that they are comparing may be the wrong ones, but I am more interested in the dropping of connection, the Nexus not be able to get LTE where the other phones are, and struggling to maintain 4g which may be draining the battery, and the fact that in almost all of the tests the Nexus was at the bottom of the download speeds.