No L5/E5 on Pixel 4a 5G (EU model)

[Knut]

Hi all,

My Pixel 4a 5G should support dual freq, but for some reason, GPSTest does only show L1/E1 as per screenshot attached below.

This is my device info:

App version: v3.9.3 (18080-google)
Model: Pixel 4a (5G)
Android version: 11 / 30

GNSS HW Year: 2020
Raw measurements: SUPPORTED
Navigation messages: NOT_SUPPORTED
NMEA: SUPPORTED

Google Play Services App: 20.45.16 (150400-344294571)
Google Play Services Library: 12451000

Any ideas what might be wrong?

Thanks in advance,

Knut

[gpsfan]

Actually the Pixel 4A is shown as not supporting Dual-Frequency in this table : https://barbeau.medium.com/tl-dr-dual-frequency-gnss-on-android-table-of-devices-9be4bbb83a7b did you see other reports saying it did ?

Where do you see the "device info" you posted ? In the header of the NMEA log, in the "Help" screen ? I'm waiting for my Mi 10 Lite and on my Nokia 8 and I don't have all these details.

[Knut]

Hi,

if you look very closely at that table, you'll see that there are 2 Pixel 4a Models, a "4a" and a "4a 5G". The latter is supposed to support dual freq. It is quite a different piece of kit, e.g. different SoC, much larger screen, and it costs 200 $/EUR extra :-|

Regarding the info I posted, most part comes from the "Send feedback" output at the bottom of the "Settings" screen.

Here is the updated output, following an Android 11 update and a new version of the GPStest App:

App version: v3.9.5 (18082-google)

Model: Pixel 4a (5G)
Android version: 11 / 30
GNSS HW Year: 2020
Raw measurements: SUPPORTED
Navigation messages: NOT_SUPPORTED
NMEA: SUPPORTED

Google Play Services App: 20.47.14 (150400-349456378)

Google Play Services Library: 12451000

And this is the phone build:  RQ1A.210105.003 (from Android settings - Phone Info). I also tried the developer option "Force full GNSS measurements", assuming that maybe L5 measurements might be disabled for power-saving reasons, but no change in behaviour.

Best regards,

Knut

[gpsfan]

Thanks for pointing out that option in the app, it confirms that my Nokia 8 doesn't support anything, hehe...

I had indeed missed that Pixel 4a 5G version that has the 765G like the "Mi 10 Lite" and is indeed dual-band GPS capable...provided the ROM has is too. Maybe it's the "GPS Test" app that's not "compatible" with it but that seems unlikely as it's just reading the output. I'm not aware of other ways to check that is using the L5/E5 frequencies. I suppose you could log some data and see what kind of plot you're getting. Maybe with the "Galileo PVT" app ?

[andras.l...@gmail.com]

it could be ROM issue, the dual is disabled  in your ROM version somewhy. Or there is no dual band antenne design in it. It is common in certain devices, even if the SoC is dual band capable, probably they didnt design 2 bands antennas for this model. A Samsung S7 tablet has Snapdragon 865+ SoC which is dual band capable but the Samsung didnt put dual antennas into this model and it works on single band only.  So the SoC's features is limited by other hardware parts.

[gpsfan]

Just a thought, how long did you wait and did you go outside to get a good view of the sky ? Reason I'm asking is the signal levels are really low in your screenshot. On the Mi 10 Lite I received today it can take a while for L5, E5a and B2a to populate. Also make sure you have a SIM card as I'm finding AGPS data only gets downloaded through the network/4G, not through WiFi. Finally Inject PSDS doesn't seem to do anything on my Mi 10 Lite, be it over 4G or WiFi.

On Tuesday, January 19, 2021 at 4:20:35 AM UTC+1 Knut wrote:

[gpsfan]

Any luck getting L5 data showing up ? There is a new version of GPSTest you could try. Also apps like Galileo PVT or GNSS Compare show L5 info when it's available.

On Tuesday, January 19, 2021 at 4:20:35 AM UTC+1 Knut wrote:

[Sean Barbeau]

I've been told that the Pixel 4a 5G does not support E5/L5, presumably due to hardware limitations - maybe lack of antenna?

If someone wants to log the GNSSAntennaInfo on a Pixel 4a 5g using the latest GPSTest beta version and share the file it should confirm that.

Sean

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[gpsfan]

Hopefully @Knut can try that new version. It would seem like a big oversight if they hadn't used the proper antenna given they are pushing their Urban Canyon technology on the Pixel 5 and...Pixel 4a 5G with the L5 band being the big breakthrough https://android-developers.googleblog.com/2020/12/improving-urban-gps-accuracy-for-your.html !

[Knut]

Hi,

sorry, very busy at work in recent weeks. I did try Galileo PVT and GNNS compare, all show no L5/E5 info, in line with GPSTest.

@Sean, thanks for the hint, will try that.

@gpsfan, yes, it seems strange, also given the delta price between the 4a and 4a 4G would suggest that their BOM should be able to carry a 2nd antenna (and RF front-end). I briefly considered trading the phone up for a Pixel 5, but that would have been another 200EUR of delta cost... On the other hand, die Google themselves ever advertise the 4a 5G as Dual-Freq capable?

Cheers,

Knut

[Sean Barbeau]

FYI, I've added a feature to report the number of GNSS antennas and carrier frequencies for those antennas to the GPSTest Device Database (https://bit.ly/gpstest-device-database) to the GPSTest master branch on GitHub to make reporting this info easier. I'll try to get another release out soon with it.

(an aside, apparently this API has a bug on the Pixel 5 and incorrectly reports antennas with carrier frequencies L1 and L2 - see https://github.com/barbeau/gpstest/issues/483. So I'd be interested to see the output of the Pixel 4a 5G)

Sean

[Sean Barbeau]

I've release v3.9.8 with this feature to Google Play beta, also available via direct download here:

https://github.com/barbeau/gpstest/releases/tag/v3.9.8

You can also see the number of antennas and antenna carrier frequencies in the email text when sending a feedback email.

Sean

[Knut]

Sean,

my device now shows up in your database...

Most intriguingly, it says 2 antennae, even though the Dual-Frequency property is reported as "not supported" and antenna frequencies are reported as L1,L2, so there appears to be the same bug as on the Pixel 5 you mentioned above.

What I can't see though is the csv file with the actual Antenna capabilities, in my gnss_log folder there is only a file called gnss_log_2021_02_12xxxxx.txt and the first lines are:

# Header Description:
#
# Version: v3.9.8 (18085-google), Manufacturer: Google, Model: Pixel 4a (5G), GNSS HW Year: 2020, Platform: 11, API Level: 30
#
# Raw GNSS measurements format:
#   Raw,ElapsedRealtimeMillis,TimeNanos,LeapSecond,TimeUncertaintyNanos,FullBiasNanos,BiasNanos,BiasUncertaintyNanos,DriftNanosPerSecond,DriftUncertaintyNanosPerSecond,HardwareClockDiscontinuityCount,Svid,TimeOffsetNanos,State,ReceivedSvTimeNanos,ReceivedSvTimeUncertaintyNanos,Cn0DbHz,PseudorangeRateMetersPerSecond,PseudorangeRateUncertaintyMetersPerSecond,AccumulatedDeltaRangeState,AccumulatedDeltaRangeMeters,AccumulatedDeltaRangeUncertaintyMeters,CarrierFrequencyHz,CarrierCycles,CarrierPhase,CarrierPhaseUncertainty,MultipathIndicator,SnrInDb,ConstellationType,AgcDb,CarrierFrequencyHz
#
# Location fix format:
#   Fix,Provider,Latitude,Longitude,Altitude,Speed,Accuracy,(UTC)TimeInMs
#
# Navigation message format:
#   Nav,Svid,Type,Status,MessageId,Sub-messageId,Data(Bytes)
#
# NMEA format (for [NMEA sentence] format see https://www.gpsinformation.org/dale/nmea.htm):
#   NMEA,[NMEA sentence],(UTC)TimeInMs
#
# GnssAntennaInfo format (https://developer.android.com/reference/android/location/GnssAntennaInfo):
#   GnssAntennaInfo,CarrierFrequencyMHz,PhaseCenterOffsetXOffsetMm,PhaseCenterOffsetXOffsetUncertaintyMm,PhaseCenterOffsetYOffsetMm,PhaseCenterOffsetYOffsetUncertaintyMm,PhaseCenterOffsetZOffsetMm,PhaseCenterOffsetZOffsetUncertaintyMm,PhaseCenterVariationCorrectionsArray,PhaseCenterVariationCorrectionUncertaintiesArray,PhaseCenterVariationCorrectionsDeltaPhi,PhaseCenterVariationCorrectionsDeltaTheta,SignalGainCorrectionsArray,SignalGainCorrectionUncertaintiesArray,SignalGainCorrectionsDeltaPhi,SignalGainCorrectionsDeltaTheta

followed by NMEA messages in case I switch NMEA logging on... GNSS Antenna Info logging is switched on in settings...

Maybe I'm misunderstanding sth here, and that very last line is already the Antenna Info?

Cheers,

Knut

[Sean Barbeau]

Thanks! Yes, interesting - looks like the same bug as Pixel 5 exists on Pixel 4a 5g for the antenna info, as it should only report one antenna. I'll update the Google ticket with this info.

Hmmm, not sure why you're not seeing the antenna info in the CSV file if you have that option enabled. You should see a line that starts with GNSSAntennaInfo as shown in the bottom lines of the example here:

https://github.com/barbeau/gpstest/blob/master/LOGGING.md#data-output---csv

If you enable logging to JSON it will be a separate file. 

Sean

To view this discussion on the web visit https://groups.google.com/d/msgid/gpstest_android/3173207e-b538-42ee-9d60-c88af2452aa2n%40googlegroups.com.

[Knut]

Ok, some stupidity on my side, I guess, now the antenna info shows up in the log.txt and the .json. Frequencies reported and L1 and L2...

Why should the Pixel 5 only report one antenna? I thought that phone would indeed support dual freq (but L1+L5 and not L2)

GnssAntennaInfo,1575.42,1.2,0.1,3.4,0.2,5.6,0.3,[11.22 33.44 55.66 77.88; 10.2 30.4 50.6 70.8; 12.2 34.4 56.6 78.8],[0.1 0.2 0.3 0.4; 1.1 1.2 1.3 1.4; 2.1 2.2 2.3 2.4],60.0,120.0,[9.8 8.7 7.6 6.5; 5.4 4.3 3.2 2.1; 1.3 2.4 3.5 4.6],[0.11 0.22 0.33 0.44; 0.55 0.66 0.77 0.88; 0.91 0.92 0.93 0.94],60.0,120.0

GnssAntennaInfo,1227.6,3.4,0.2,5.6,0.3,1.2,0.1,[55.66 77.88; 11.22 33.44; 56.6 78.8; 12.2 34.4],[0.3 0.4; 1.1 1.2; 2.1 2.2; 0.1 0.2],180.0,90.0,[7.6 6.5; 5.4 4.3; 1.3 2.4; 9.8 8.7],[0.91 0.92; 0.55 0.66; 0.11 0.22; 0.93 0.94],180.0,90.0

[Sean Barbeau]

Re: the log, I think I know what happened - the output from the app writing the file is buffered, so if you grab the file off the device while the app is running, you can end up with a partial file if the buffer in the app hasn't been flushed. You can force the flush of the buffer by killing the app (e.g., via the Back button), and then if you refresh your file view you should get the complete file. I should add something on this in the logging docs.

>Why should the Pixel 5 only report one antenna? I thought that phone would indeed support dual freq (but L1+L5 and not L2)

Sorry, yes, my last message wasn't very clear - the Pixel 5 and Pixel 4a 5G seem to suffer from the same bug as they are both outputting the exact same antenna data (including the various characteristics, which should vary per device model). The Pixel 5 should output 2 antennas (L1 and L5 carrier frequencies), and the Pixel 4a 5G should output 1 antenna (L1 carrier frequency). Instead they are both outputting 2 antennas (L1 and L2 carrier frequencies).

Sean

To view this discussion on the web visit https://groups.google.com/d/msgid/gpstest_android/42377e15-0ec8-49cb-967b-c09bf3bdd561n%40googlegroups.com.

[Knut]

confirmed, indeed buffering must have been the issue. This last example was logged successfully after I killed the app...