A-GNSS not working in location sample

[heisenbug]

I've testing out the GNSS and Location samples. According to documentation, A-GNSS is enabled by default in the location sample but I am not able to confirm this both through the logs and the code.

When running the GNSS example with A-GNSS enabled, I can clearly see the FW connecting to LTE, GNSS requesting A-GNSS data, and FW downloading the data. The impact on getting a location is also visible.

I cannot see the same in the location example. Even in code, Location sample executes a print out when LOCATION_EVT_GNSS_ASSISTANCE_REQUEST event occurs instead requesting data from the cloud.

Am I missing something here in the Location sample? How can I get A-GNSS working with the location sample?

[dejans]

Hi,

Which NCS version do you use?

Have you tried unmodified sample?

Can you show complete application log from location sample?

Best regards,
Dejan

[heisenbug]

I am using the unmodified location sample from NCS v2.9.0. The sample output is below:

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
Location sample started

Connecting to LTE...
+CEREG: 2,"7EF4","0648BF0C",7
+CSCON: 1
+CEREG: 5,"7EF4","0648BF0C",7,,,"11100000","11100000"
Connected to LTE
%XTIME: "4A","5240428193054A","01"
Waiting for current time
Requesting location with short GNSS timeout to trigger fallback to cellular...
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,5070,265,40,11,8088,10332
[00:00:11.161,315] <inf> nrf_cloud_info: Device ID: nrf-351901936411614
[00:00:11.168,731] <inf> nrf_cloud_info: IMEI:      351901936411614
[00:00:11.278,106] <inf> nrf_cloud_info: UUID:      50525631-3738-4f4d-800c-13280a5bc58d
[00:00:11.286,926] <inf> nrf_cloud_info: Modem FW:  mfw_nrf9160_1.3.6
[00:00:11.293,731] <inf> nrf_cloud_info: Protocol:          REST
[00:00:11.300,140] <inf> nrf_cloud_info: Download protocol: HTTPS
[00:00:11.306,640] <inf> nrf_cloud_info: Sec tag:           16842753
[00:00:11.313,385] <inf> nrf_cloud_info: Host name:         api.nrfcloud.com
[00:00:20.266,235] <inf> location: Method specific timeout expired
[00:00:20.273,162] <inf> location: Location retrieval failed using 'GNSS', trying with 'Cellular' next
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,5070,265,36,6,19606,5070,247,36,6,0,19392
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,19392,5070,265,44,14,19507,1,0
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,19392,5070,265,36,6,19686,1,1,5070,247,36,6,0
+CSCON: 0
+CSCON: 1
Got location:
  method: Cellular
  latitude: *********
  longitude: ***********
  accuracy: 788.0 m
  date: 2025-04-24
  time: 18:39:59.248 UTC
  Google maps URL: https://maps.google.com/?q=*********,***********

Requesting location with the default configuration...
+CSCON: 0
[00:02:50.049,041] <inf> location: Method specific timeout expired
[00:02:50.055,572] <wrn> location: GNSS timed out possibly due to too short GNSS time windows
[00:02:50.065,124] <inf> location: Location retrieval failed using 'GNSS', trying with 'Cellular' next
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,5070,265,40,11,168395,5070,247,40,11,0,48249
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,48249,5070,265,40,9,169525,1,0
%NCELLMEAS: 0,"0648BF0C","302720","7EF4",432,48249,5070,265,39,8,174795,1,0,"062BBA2A","302490","FA64",65535,0,2225,337,27,22,175647,0,0,"062BBA2A","302490","FA64",65535,0,66711,337,20
+CSCON: 1
Got location:
  method: Cellular
  latitude: *********
  longitude: ***********
  accuracy: 497.0 m
  date: 2025-04-24
  time: 18:42:35.234 UTC
  Google maps URL: https://maps.google.com/?q=*********,***********

Requesting low accuracy GNSS location...
+CSCON: 0
Got location:
  method: GNSS
  latitude: *********
  longitude: ***********
  accuracy: 10.3 m
  date: 2025-04-24
  time: 18:44:41.048 UTC
  Google maps URL: https://maps.google.com/?q=*********,***********

Requesting high accuracy GNSS location...
Got location:
  method: GNSS
  latitude: *********
  longitude: ***********
  accuracy: 6.3 m
  date: 2025-04-24
  time: 18:44:45.168 UTC
  Google maps URL: https://maps.google.com/?q=*********,***********

Requesting 30s periodic GNSS location with cellular fallback...
Got location:
  method: GNSS
  latitude: *********
  longitude: ***********
  accuracy: 11.2 m
  date: 2025-04-24
  time: 18:44:47.304 UTC
  Google maps URL: https://maps.google.com/?q=*********,***********

[dejans]

Hi,

I see that you can get GNSS location and your log is similar to what is shown in the location sample. You could potentially try to increase GNSS fix timeout value using CONFIG_GNSS_FIX_TIMEOUT_SECONDS as shown in the Note in nrf_cloud_multi_service sample.

Best regards,
Dejan

[heisenbug]

What exactly triggers an A-GNSS request from the modem? Is it just a matter of how long it takes to acquire satellites.

I've also ran the Cellular: GNSS sample and that doesn't have a problem getting request for A-GNSS data. I've also ran the modem shell sample and I can see the A-GNSS request in that sample as well so this is why the location sample is confusing.