Module is connected to China Mobile GSM1800 in Hong Kong
AT+QNWINFO
+QNWINFO: “EDGE”,“45412”,“GSM 1800”,874
Module is using Hologram SIM and APN enabled
AT+CREG?
+CREG: 0,5
OK
AT+QICSGP=1,1,“hologram”,"","",1
OK
AT+QIACT=1
OK
AT+QIACT?
+QIACT: 1,1,1,“10.95.185.2”
OK
However Xtra download failed. Any possible reasons?
AT+QGPSCFG=“xtra_download”,1
OK
+QGPSURC: “XTRA_DL”,-1
Upon re-trying, it seems download is successful after an initial GPS fix is achieved. If there is no previous fix, download will fail.
Is this how Xtra works?
Automatic download is ok for only Glonass or Galileo but not Beidou. I have tested multiple times. However I am able to manually download Beidou and inject into module successfully.
That is strange why automatic download is not successful for Beidou. I have tried trigger the download by AT command or by turning on GNSS. The download process can be triggered but the result is always +QGPSURC: “XTRA_DL”,-1
I am reading the application note of another module supplier deploying the same Qualcomm chipset and uses Xtra service.
It has stated the prerequisites to use Xtra:
since qualcomm gnss assistance service requires a valid position before assistance data is downloaded, a fix must have been collected by the modem before using qualcomm service.
So this means my finding a few days ago was correct. I failed to download initially because I did not get a fix. Once that was done download was ok except GP+BD was never successful.
Could you please confirm this prerequisite also applies to Quectel module?
Hello Stephen,
I may have more problems with Xtra and would like to combine all the questions. I am afraid I found unusual behaviour with BG95M3LAR02A03_01.009.01.009 if Xtra is disabled. Could you provide me the old FW BG95M3LAR02A03_01.005.01.005 to retest?
Thank you.
A quick follow up: Quectel has confirmed the download failure of Xtra file for Beidou. A beta firmware has been released to fix this issue. Strange that this problem has not been noticed in the very beginning.
I am wondering if we are looking at the same issue?
Could you describe the issue you found when disabling Xtra?
I am also in the process of troubleshooting an issue when doing the following with Xtra disabled. Have been experimenting with QGPSDEL with mixed results.
With QGPSDEL=1/QGPSXTRA=0:
Enable GPS
Get a fix from AT+QGPSLOC (~110Seconds)
Power down module, wait 3 minutes, wake up module,
Enable GPS
Do another fix (19seconds)(!)
Power down module again, wait 30 minutes, wake up module again
Enable GPS
Attempt a fix (Will not have a fix after 150seconds- can wait up to 5minutes and no fix will occur).
Will be good to know if we are looking at the same or similiar issue.
With Xtra disabled, BG95M3 did perform inconsistently. The fix time for each cold start could differ by significant amount.
It seems to me its acquisition is quite bad. Unlike other GNSS module which searches different constellations at the same time, it seems to look for GPS first before looking for other constellation. I have compared it with uBlox M8N and BG95M3 was really bad without Xtra.
However Xtra makes a big difference and I strongly recommend you to re-test with Xtra.