BG 96 and Unsolicited Response

IoT Modules LPWA Module
1

When the modem is powered and I send “AT+QGPS=1” in roughly 30 sec and QGPSURC response appears.

Is a normal procedure?

if I make
AT+QGPSEND
and
AT+QGPS=1
QGPSURC appears in 5-10minutes.

Here is the response right after power up

[2022-10-10_15:28:23:065]AT+QGPS=1

[2022-10-10_15:28:23:065]OK
[2022-10-10_15:28:46:869]
[2022-10-10_15:28:46:869]+QGPSURC: “xtradataexpire”,0,“2022/09/25,11:00:00”

2

Hi,
that looks the gps Xtra message which the modem sends when the relevant files download ends.
See also this thread: BG95-M3 Xtra Download Failure
and chapter 1.3 of https://www.quectel.com/wp-content/uploads/2021/03/Quectel_BG96_GNSS_Application_Note_V1.3.pdf

cheers

3

Yes, indeed it is! Thank you @mgigante

Is related to gpsOneXTRA. I want to find a solution to see if the xtra file is old.
in my case AT+QGPSXTRADATA? always gives me 10800, like it’s mentioned here.

4

For BG95 (I have not used BG96),
AT+QGPSXTRADATA? returns the validity of the xtra file in minutes.
If it returns 4320, it means the file is only good for 3 days. The file needs to be renewed every 3 days.
To return the remaining period before next renewal, I use AT+QGPSCFG=“xtra_info”.
This will return the remaining period in hours. For example if it returns 29, the file will expire in 29 hours and needs to be re-downloaded.
If you enable the auto-download feature, you do not need to care about the expiry. It will re-download automatically when the xtra file expires.

5

Hi @hobby_a

I think you have new options there, in my case gives always an error message. That flag I do not see in my documentation for BG96.

I finally made Agps working on Bg96, but it uses too much traffic. So I thought to give gosonextra one more try.

What address do you use to download Xtrafile?

Thank you!

6

I don’t think the addresses for BG95 can apply to BG96. Here are the addresses for constellation GPS + Glonass:

7-day file:
http://iot1.xtracloud.net/xtra3gr.bin
http://iot2.xtracloud.net/xtra3gr.bin
http://iot3.xtracloud.net/xtra3gr.bin
3-day file:
http://iot1.xtracloud.net/xtra3gr_72h.bin
http://iot2.xtracloud.net/xtra3gr_72h.bin
http://iot3.xtracloud.net/xtra3gr_72h.bin
1-day file:
http://iot1.xtracloud.net/xtra3gr_24h.bin
http://iot2.xtracloud.net/xtra3gr_24h.bin
http://iot3.xtracloud.net/xtra3gr_24h.bin

7

I quickly looked at BG96 GNSS application note and noticed the following.
For BG96,
AT+QGPSXTRADATA? returns both <XTRA_data_durtime> and <injected_da
tatime>. You need to do the calculation to get the remaining period.

In addition, download of xtra file is different. BG95 allows the module itself to automatically download and inject the file but this option is not available for BG96.

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8

@hobby_a, so it seems that <XTRA_data_durtime> does not decrease over time? Damn…
I thought it was a trick to overcome this.

+QGPSURC: was a solution, but I’m not sure how safe it is.

9

Without AGPS, the positioning performance of BG95 is very bad compared to other standalone GNSS modules. I suppose BG96 performs the same as BG95. I did not realize that implementation of AGPS on BG96 is so user unfriendly.

10

:slight_smile: Yap, sometimes you have to dig a lot!

On GNSS it helps to synchronize the clock of the BG96 with the network time and a high gain antenna. It’s what I’m using now. I wanted something more bulky for further projects .

Thanks again for your suggestions!

11

If your device is stationary, a high gain or active antenna can bring GNSS performance to acceptable level. If your device is moving from location to location, activation of AGPS is much preferred since it boosts the cold start sensitivity by 11dB with a valid xtra file.

1 Like