nrf9160, AGPS works longer than GPS

[Stas Jis]

We use nRF9160 on our own board.
The firmware "Serial lte modem" is installed on the chip with a connection to an external MCU (#define MQTT_MESSAGE_BUFFER_LEN 8192)
We tested the environment with periodic switching from AGPS to GPS.
And in tests, we constantly see that the operating time with AGPS is twice as long as with just using GPS.

Average waiting time when using AGPS: 1 minute + 10-15 seconds;
Average waiting time when using GPS: 30-40 seconds.

What could be the reason for such behavior? It was expected that the operating time with AGPS would be significantly faster than with GPS.

The command sequence for AGPS:
AT+CEREG=5
AT+CFUN=1
AT#XNRFCLOUD=1
AT#XAGPS=1,1

The command sequence for GPS:
AT+CEREG=5
AT+CFUN=31
AT#XGPS=1,1

The tests were carried out statically, without movement.

[Håkon Alseth]

Hi,

 

Average waiting time when using AGPS: 1 minute + 10-15 seconds;
Average waiting time when using GPS: 30-40 seconds.

With AGPS, you are fetching GPS data through IP, which will require a LTE paging period before you are allowed to enter eDRX or PSM successfully.

During this period, the GPS is blocked from running.

If you register for CSCON notifications, you should see when the link becomes idle (ie. when GPS will be able to run).

 

Kind regards,

Håkon

[Stas Jis]

Hi,
ie, I can not count on the fact that AGPS will work faster than just GPS?
Or have I misunderstood something?

[Håkon Alseth]

Hi,

 

Stas Jis said:

ie, I can not count on the fact that AGPS will work faster than just GPS?

You need to start the count when the GNSS is successfully able to run, ie. not blocked by the LTE link.

Stas Jis said:

Or have I misunderstood something?

AGPS downloads the ephemerides and almanac (and possibly other components too) over IP, and pushes these to the GNSS.

The problem with using IP for this is that you need to enter some sort of idle mode in the LTE link before you're able to use the GNSS.

 

Kind regards,

Håkon

[Stas Jis]

Dear Håkon Alseth,
I added the CSCON command to the sequence of commands to get the coordinates, I'm attaching a trace from the nRF9160-DK:

2022-06-20T06:57:04.907Z DEBUG modem << Ready
2022-06-20T06:57:04.920Z DEBUG modem << [00:00:00.205,627] [0m<inf> slm: Serial LTE Modem[0m
2022-06-20T06:57:04.923Z DEBUG modem << [00:00:00.224,517] [0m<dbg> slm_at_host.slm_at_host_init: UART baud: 115200 d/p/s-bits: 3/0/1 HWFC: 1[0m
2022-06-20T06:57:04.942Z DEBUG modem << [00:00:00.224,548] [0m<dbg> slm_at_host.slm_uart_configure: Set uart baudrate to: 115200, hw flow control 1[0m
2022-06-20T06:57:04.949Z DEBUG modem << [00:00:00.316,955] [0m<dbg> nrf_cloud_transport.nct_client_id_set: client_id = 50503642-3632-473c-80b9-1e142224d5ef[0m
2022-06-20T06:57:04.967Z DEBUG modem << [00:00:00.317,687] [0m<dbg> nrf_cloud_transport.nct_topics_populate: accepted_topic: 50503642-3632-473c-80b9-1e142224d5ef/shadow/g~[0m
2022-06-20T06:57:04.969Z DEBUG modem << [00:00:00.317,687] [0m<dbg> nrf_cloud_transport.nct_topics_populate: rejected_topic: $aws/things/50503642-3632-473c-80b9-1e142224d~[0m
2022-06-20T06:57:04.996Z DEBUG modem << [00:00:00.317,749] [0m<dbg> nrf_cloud_transport.nct_topics_populate: update_delta_topic: $aws/things/50503642-3632-473c-80b9-1e142224d~[0m
2022-06-20T06:57:05.000Z DEBUG modem << [00:00:00.317,749] [0m<dbg> nrf_cloud_transport.nct_topics_populate: update_topic: <log_strdup alloc failed>[0m
2022-06-20T06:57:05.003Z DEBUG modem << [00:00:00.317,779] [0m<dbg> nrf_cloud_transport.nct_topics_populate: shadow_get_topic: <log_strdup alloc failed>[0m
2022-06-20T06:57:05.031Z DEBUG modem << [00:00:00.317,810] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 1[0m
2022-06-20T06:57:05.034Z DEBUG modem << [00:00:00.317,932] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:05.036Z DEBUG modem <<                                       52 65 61 64 79 0d 0a                             |Ready..          [0m
2022-06-20T06:57:05.038Z DEBUG modem << [00:00:00.318,023] [0m<dbg> slm_fota.slm_fota_post_process: FOTA result 0,0,0[0m
2022-06-20T06:57:05.064Z DEBUG modem << [00:00:00.330,718] [0m<inf> slm_at_host: at_host init done[0m
2022-06-20T06:57:10.600Z DEBUG modem >> AT+CEREG=5
2022-06-20T06:57:10.611Z DEBUG modem << OK
2022-06-20T06:57:11.608Z DEBUG modem << [00:00:09.120,666] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:11.621Z DEBUG modem <<                                       41 54 2b 43 45 52 45 47  3d 35                   |AT+CEREG =5      [0m
2022-06-20T06:57:11.625Z DEBUG modem << [00:00:09.127,380] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:11.646Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:11.648Z DEBUG modem << [00:00:09.127,471] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:11.666Z DEBUG modem <<                                       4f 4b 0d 0a                                      |OK..             [0m
2022-06-20T06:57:15.528Z DEBUG modem >> AT+CFUN=1
2022-06-20T06:57:15.572Z DEBUG modem << OK
2022-06-20T06:57:16.536Z DEBUG modem << [00:00:14.049,072] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:16.549Z DEBUG modem <<                                       41 54 2b 43 46 55 4e 3d  31                  
2022-06-20T06:57:16.550Z DEBUG modem << +CEREG: 2,"1D6B","001B6A02",7
2022-06-20T06:57:16.568Z DEBUG modem <<     |AT+CFUN= 1       [0m
2022-06-20T06:57:16.589Z DEBUG modem << [00:00:14.049,591] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:57:16.594Z DEBUG modem << [00:00:14.088,348] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:16.598Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:16.600Z DEBUG modem << [00:00:14.088,409] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:16.601Z DEBUG modem <<                                       4f 4b 0d 0a                                      |OK..             [0m
2022-06-20T06:57:16.603Z DEBUG modem << [00:00:15.063,110] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:16.625Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:16.627Z DEBUG modem << [00:00:15.063,201] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:16.631Z DEBUG modem <<                                       2b 43 45 52 45 47 3a 20  32 2c 22 31 44 36 42 22 |+CEREG:  2,"1D6B"
2022-06-20T06:57:16.653Z DEBUG modem <<                                       2c 22 30 30 31 42 36 41  30 32 22 2c 37 0d 0a    |,"001B6A 02",7.. [0m
2022-06-20T06:57:18.003Z DEBUG modem << +CEREG: 5,"1D6B","001B6A02",7,,,"00011110","11100000"
2022-06-20T06:57:19.003Z DEBUG modem << [00:00:16.515,869] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:19.015Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:19.021Z DEBUG modem << [00:00:16.515,960] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:19.037Z DEBUG modem <<                                       2b 43 45 52 45 47 3a 20  35 2c 22 31 44 36 42 22 |+CEREG:  5,"1D6B"
2022-06-20T06:57:19.055Z DEBUG modem <<                                       2c 22 30 30 31 42 36 41  30 32 22 2c 37 2c 2c 2c |,"001B6A 02",7,,,
2022-06-20T06:57:19.072Z DEBUG modem <<                                       22 30 30 30 31 31 31 31  30 22 2c 22 31 31 31 30 |"0001111 0","1110                                      30 30 30 30 22 0d 0a                             |0000"..          [0m
2022-06-20T06:57:29.080Z DEBUG modem >> AT+CSCON=3
2022-06-20T06:57:29.094Z DEBUG modem << OK
2022-06-20T06:57:30.088Z DEBUG modem << [00:00:27.601,562] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:30.101Z DEBUG modem <<                                       41 54 2b 43 53 43 4f 4e  3d 33                   |AT+CSCON =3      [0m
2022-06-20T06:57:30.117Z DEBUG modem << [00:00:27.602,081] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:57:30.121Z DEBUG modem << [00:00:27.610,595] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:30.140Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:30.143Z DEBUG modem << [00:00:27.610,626] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:30.146Z DEBUG modem <<                                       4f 4b 0d 0a                                      |OK..             [0m
2022-06-20T06:57:31.400Z DEBUG modem >> AT+CSCON?
2022-06-20T06:57:31.414Z DEBUG modem << +CSCON: 3,1,7,4
2022-06-20T06:57:31.416Z DEBUG modem << OK
2022-06-20T06:57:32.408Z DEBUG modem << [00:00:29.921,630] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:32.421Z DEBUG modem <<                                       41 54 2b 43 53 43 4f 4e  3f                      |AT+CSCON ?       [0m
2022-06-20T06:57:32.428Z DEBUG modem << [00:00:29.922,149] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:57:32.433Z DEBUG modem << [00:00:29.930,633] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:32.449Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:32.451Z DEBUG modem << [00:00:29.930,664] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:32.468Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  33 2c 31 2c 37 2c 34 0d |+CSCON:  3,1,7,4.
2022-06-20T06:57:32.486Z DEBUG modem <<                                       0a 4f 4b 0d 0a                                   |.OK..            [0m
2022-06-20T06:57:34.388Z DEBUG modem << +CSCON: 0,7,4
2022-06-20T06:57:35.391Z DEBUG modem << [00:00:32.904,602] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:35.401Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:35.405Z DEBUG modem << [00:00:32.904,632] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:35.420Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  30 2c 37 2c 34 0d 0a    |+CSCON:  0,7,4.. [0m
2022-06-20T06:57:36.329Z DEBUG modem >> AT+CSCON?
2022-06-20T06:57:36.352Z DEBUG modem << +CSCON: 3,0,7,4
2022-06-20T06:57:36.354Z DEBUG modem << OK
2022-06-20T06:57:37.337Z DEBUG modem << [00:00:34.851,257] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:37.350Z DEBUG modem <<                                       41 54 2b 43 53 43 4f 4e  3f                      |AT+CSCON ?       [0m
2022-06-20T06:57:37.356Z DEBUG modem << [00:00:34.851,776] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:57:37.372Z DEBUG modem << [00:00:34.860,290] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:37.390Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:37.392Z DEBUG modem << [00:00:34.860,321] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:37.410Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  33 2c 30 2c 37 2c 34 0d |+CSCON:  3,0,7,4.
2022-06-20T06:57:37.412Z DEBUG modem <<                                       0a 4f 4b 0d 0a                                   |.OK..            [0m
2022-06-20T06:57:40.375Z DEBUG modem >> AT+CSCON?
2022-06-20T06:57:40.389Z DEBUG modem << +CSCON: 3,0,7,4
2022-06-20T06:57:40.391Z DEBUG modem << OK
2022-06-20T06:57:41.384Z DEBUG modem << [00:00:38.897,399] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:41.393Z DEBUG modem <<                                       41 54 2b 43 53 43 4f 4e  3f                      |AT+CSCON ?       [0m
2022-06-20T06:57:41.409Z DEBUG modem << [00:00:38.897,918] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:57:41.411Z DEBUG modem << [00:00:38.906,402] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:41.428Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:41.450Z DEBUG modem << [00:00:38.906,433] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:41.452Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  33 2c 30 2c 37 2c 34 0d |+CSCON:  3,0,7,4.
2022-06-20T06:57:41.457Z DEBUG modem <<                                       0a 4f 4b 0d 0a                                   |.OK..            [0m
2022-06-20T06:57:50.720Z DEBUG modem >> AT#XNRFCLOUD=1
2022-06-20T06:57:50.730Z DEBUG modem << OK
2022-06-20T06:57:50.818Z DEBUG modem << +CSCON: 1,7,4
2022-06-20T06:57:51.728Z DEBUG modem << [00:00:49.242,797] [0m<dbg> slm_at_host: RX
2022-06-20T06:57:51.741Z DEBUG modem <<                                       41 54 23 58 4e 52 46 43  4c 4f 55 44 3d 31       |AT#XNRFC LOUD=1  [0m
2022-06-20T06:57:51.747Z DEBUG modem << [00:00:49.243,316] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:57:51.752Z DEBUG modem << [00:00:49.243,347] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:51.768Z DEBUG modem <<                                       0d 0a 4f 4b 0d 0a                                |..OK..           [0m
2022-06-20T06:57:51.771Z DEBUG modem << [00:00:49.243,438] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 1[0m
2022-06-20T06:57:51.791Z DEBUG modem << [00:00:49.243,438] [0m<dbg> nrf_cloud.api_event_handler: NRF_CLOUD_EVT_TRANSPORT_CONNECTING[0m
2022-06-20T06:57:51.793Z DEBUG modem << [00:00:49.243,469] [0m<dbg> slm_gnss.cloud_event_handler: CLOUD_EVT_CONNECTING: status 0[0m
2022-06-20T06:57:51.796Z DEBUG modem << [00:00:49.335,235] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:51.801Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:57:51.819Z DEBUG modem << [00:00:49.335,266] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:51.822Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  31 2c 37 2c 34 0d 0a    |+CSCON:  1,7,4.. [0m
2022-06-20T06:57:51.841Z DEBUG modem << [00:00:49.784,912] [0m<dbg> nrf_cloud_transport.nct_connect: IPv4 address: 54.163.146.98[0m
2022-06-20T06:57:51.844Z DEBUG modem << [00:00:49.784,942] [0m<dbg> nrf_cloud_transport.nct_mqtt_connect: MQTT clean session flag: 1[0m
2022-06-20T06:57:54.683Z DEBUG modem << [00:00:52.386,474] [0m<dbg> nrf_cloud.nrf_cloud_run: Cloud connection request sent[0m
2022-06-20T06:57:54.696Z DEBUG modem << [00:00:52.815,826] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_CONNACK: result 0[0m
2022-06-20T06:57:54.701Z DEBUG modem << [00:00:52.815,856] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 2[0m
2022-06-20T06:57:54.721Z DEBUG modem << [00:00:52.815,856] [0m<dbg> nrf_cloud.api_event_handler: NRF_CLOUD_EVT_TRANSPORT_CONNECTED[0m
2022-06-20T06:57:54.723Z DEBUG modem << [00:00:52.815,856] [0m<inf> slm_gnss: CLOUD_EVT_CONNECTED[0m
2022-06-20T06:57:54.744Z DEBUG modem << [00:00:52.815,887] [0m<dbg> nrf_cloud_transport.nct_cc_connect: nct_cc_connect[0m
2022-06-20T06:57:54.746Z DEBUG modem << [00:00:52.816,925] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 3[0m
2022-06-20T06:57:54.750Z DEBUG modem << [00:00:53.192,810] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_SUBACK: id = 100 result = 0[0m
2022-06-20T06:57:54.752Z DEBUG modem << [00:00:53.192,810] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 4[0m
2022-06-20T06:57:54.780Z DEBUG modem << [00:00:53.192,871] [0m<dbg> nrf_cloud_transport.nct_cc_send: mqtt_publish: id = 200 opcode = 0 len = 0[0m
2022-06-20T06:57:54.789Z DEBUG modem << [00:00:53.193,695] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 5[0m
2022-06-20T06:57:55.564Z DEBUG modem << [00:00:53.425,811] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_PUBACK: id = 200 result = 0[0m
2022-06-20T06:57:55.577Z DEBUG modem << [00:00:53.425,842] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 5[0m
2022-06-20T06:57:55.584Z DEBUG modem << [00:00:53.514,770] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_PUBLISH: id = 1344 len = 317[0m
2022-06-20T06:57:55.591Z DEBUG modem << [00:00:53.517,974] [0m<dbg> nrf_cloud_transport.nct_dc_endpoint_set: nct_dc_endpoint_set[0m
2022-06-20T06:57:55.607Z DEBUG modem << [00:00:53.518,096] [0m<dbg> nrf_cloud_transport.nct_dc_endpoint_get: nct_dc_endpoint_get[0m
2022-06-20T06:57:55.628Z DEBUG modem << [00:00:53.520,385] [0m<dbg> nrf_cloud_transport.nct_cc_send: mqtt_publish: id = 301 opcode = 1 len = 395[0m
2022-06-20T06:57:55.630Z DEBUG modem << [00:00:53.522,491] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 7[0m
2022-06-20T06:57:55.632Z DEBUG modem << [00:00:53.522,521] [0m<dbg> nrf_cloud.api_event_handler: NRF_CLOUD_EVT_USER_ASSOCIATED[0m
2022-06-20T06:57:55.637Z DEBUG modem << [00:00:53.522,521] [0m<dbg> slm_gnss.cloud_event_handler: CLOUD_EVT_PAIR_DONE[0m
2022-06-20T06:57:55.657Z DEBUG modem << [00:00:54.072,814] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_PUBACK: id = 301 result = 0[0m
2022-06-20T06:57:55.659Z DEBUG modem << [00:00:54.072,814] [0m<dbg> nrf_cloud_transport.nct_dc_connect: nct_dc_connect[0m
2022-06-20T06:57:55.828Z DEBUG modem << #XNRFCLOUD: 1,0
2022-06-20T06:57:56.662Z DEBUG modem << [00:00:54.172,912] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 8[0m
2022-06-20T06:57:56.675Z DEBUG modem << [00:00:54.345,855] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_SUBACK: id = 101 result = 0[0m
2022-06-20T06:57:56.694Z DEBUG modem << [00:00:54.345,886] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 9[0m
2022-06-20T06:57:56.696Z DEBUG modem << [00:00:54.345,886] [0m<dbg> nrf_cloud.api_event_handler: NRF_CLOUD_EVT_READY[0m
2022-06-20T06:57:56.698Z DEBUG modem << [00:00:54.345,947] [0m<inf> slm_gnss: CLOUD_EVT_READY[0m
2022-06-20T06:57:56.702Z DEBUG modem << [00:00:54.346,008] [0m<dbg> slm_at_host: TX
2022-06-20T06:57:56.710Z DEBUG modem <<                                       0d 0a 23 58 4e 52 46 43  4c 4f 55 44 3a 20 31 2c |..#XNRFC LOUD: 1,
2022-06-20T06:57:56.725Z DEBUG modem <<                                       30 0d 0a                                         |0..              [0m
2022-06-20T06:58:12.868Z DEBUG modem << +CSCON: 0,7,4
2022-06-20T06:58:13.871Z DEBUG modem << [00:01:11.378,417] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:13.884Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:58:13.903Z DEBUG modem << [00:01:11.378,479] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:13.906Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  30 2c 37 2c 34 0d 0a    |+CSCON:  0,7,4.. [0m
2022-06-20T06:58:26.663Z DEBUG modem >> AT#XAGPS=1,1
2022-06-20T06:58:27.148Z DEBUG modem << OK
2022-06-20T06:58:27.161Z DEBUG modem << +CSCON: 1,7,4
2022-06-20T06:58:27.671Z DEBUG modem << [00:01:25.179,779] [0m<dbg> slm_at_host: RX
2022-06-20T06:58:27.684Z DEBUG modem <<                                       41 54 23 58 41 47 50 53  3d 31 2c 31             |AT#XAGPS =1,1    [0m
2022-06-20T06:58:27.690Z DEBUG modem << [00:01:25.180,297] [0m<dbg> slm_at_host.uart_callback: RX_DISABLED[0m
2022-06-20T06:58:27.698Z DEBUG modem << [00:01:25.657,775] [0m<dbg> slm_gnss.date_time_event_handler: DATE_TIME OBTAINED[0m
2022-06-20T06:58:27.714Z DEBUG modem << [00:01:25.660,614] [0m<inf> slm_gnss: GNSS_EVT_AGPS_REQ[0m
2022-06-20T06:58:27.716Z DEBUG modem << [00:01:25.660,644] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:27.735Z DEBUG modem <<                                       0d 0a 4f 4b 0d 0a                                |..OK..           [0m
2022-06-20T06:58:27.737Z DEBUG modem << [00:01:25.660,736] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:27.742Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:58:27.746Z DEBUG modem << [00:01:25.661,285] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:27.763Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  31 2c 37 2c 34 0d 0a    |+CSCON:  1,7,4.. [0m
2022-06-20T06:58:27.782Z DEBUG modem << [00:01:25.699,798] [0m<dbg> nrf_cloud_codec.json_send_to_cloud: Created request: {"appId":"AGPS","messageType":"DATA","data":{~[0m
2022-06-20T06:58:27.801Z DEBUG modem << [00:01:25.701,660] [0m<dbg> nrf_cloud_codec.json_send_to_cloud: Request sent to cloud[0m
2022-06-20T06:58:27.821Z DEBUG modem << [00:01:26.156,524] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_PUBACK: id = 1000 result = 0[0m
2022-06-20T06:58:29.009Z DEBUG modem << [00:01:26.511,993] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_PUBLISH: id = 1344 len = 1926[0m
2022-06-20T06:58:29.024Z DEBUG modem << [00:01:26.512,451] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 9[0m
2022-06-20T06:58:29.026Z DEBUG modem << [00:01:26.512,481] [0m<dbg> nrf_cloud.api_event_handler: NRF_CLOUD_EVT_RX_DATA[0m
2022-06-20T06:58:29.033Z DEBUG modem << [00:01:26.512,481] [0m<inf> slm_gnss: CLOUD_EVT_DATA_RECEIVED[0m
2022-06-20T06:58:29.050Z DEBUG modem << [00:01:26.650,299] [0m<dbg> nrf_cloud_transport.nct_mqtt_evt_handler: MQTT_EVT_PUBLISH: id = 1344 len = 1164[0m
2022-06-20T06:58:29.069Z DEBUG modem << [00:01:26.650,665] [0m<dbg> nrf_cloud.nfsm_set_current_state_and_notify: state: 9[0m
2022-06-20T06:58:29.071Z DEBUG modem << [00:01:26.650,726] [0m<dbg> nrf_cloud.api_event_handler: NRF_CLOUD_EVT_RX_DATA[0m
2022-06-20T06:58:29.075Z DEBUG modem << [00:01:26.650,726] [0m<inf> slm_gnss: CLOUD_EVT_DATA_RECEIVED[0m
2022-06-20T06:58:29.081Z DEBUG modem << [00:01:26.660,522] [0m<inf> slm_gnss: GNSS_EVT_BLOCKED[0m
2022-06-20T06:58:29.082Z DEBUG modem << [00:01:26.660,552] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:30.159Z DEBUG modem << [00:01:27.665,557] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:30.174Z DEBUG modem << [00:01:28.666,107] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:32.159Z DEBUG modem << [00:01:29.666,046] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:33.170Z DEBUG modem << [00:01:30.675,933] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:34.180Z DEBUG modem << [00:01:31.685,821] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:35.189Z DEBUG modem << [00:01:32.695,709] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:36.200Z DEBUG modem << [00:01:33.705,566] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:36.214Z DEBUG modem << [00:01:34.705,780] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:38.200Z DEBUG modem << [00:01:35.706,359] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:38.215Z DEBUG modem << [00:01:36.706,359] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:40.209Z DEBUG modem << [00:01:37.716,247] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:41.219Z DEBUG modem << [00:01:38.726,135] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:42.229Z DEBUG modem << [00:01:39.735,992] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:42.244Z DEBUG modem << [00:01:40.736,389] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:44.239Z DEBUG modem << [00:01:41.746,154] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:44.254Z DEBUG modem << [00:01:42.746,765] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m
2022-06-20T06:58:44.850Z DEBUG modem << +CSCON: 0,7,4
2022-06-20T06:58:45.853Z DEBUG modem << [00:01:43.362,731] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:45.867Z DEBUG modem <<                                       0d 0a                                            |..               [0m
2022-06-20T06:58:45.887Z DEBUG modem << [00:01:43.362,762] [0m<dbg> slm_at_host: TX
2022-06-20T06:58:45.889Z DEBUG modem <<                                       2b 43 53 43 4f 4e 3a 20  30 2c 37 2c 34 0d 0a    |+CSCON:  0,7,4.. [0m
2022-06-20T06:58:45.893Z DEBUG modem << [00:01:43.519,836] [0m<inf> slm_gnss: GNSS_EVT_UNBLOCKED[0m
2022-06-20T06:58:45.898Z DEBUG modem << [00:01:43.519,866] [0m<dbg> slm_gnss.gnss_event_handler: GNSS_EVT_PVT[0m

I do not understand what are the reasons for changing the mod to "inactive" and why such long pauses in time when changing the mod?

2022-06-20T06:57:29.080Z DEBUG modem >> AT+CSCON=3
2022-06-20T06:57:50.720Z DEBUG modem >> AT#XNRFCLOUD=1
2022-06-20T06:57:50.730Z DEBUG modem << OK
2022-06-20T06:57:50.818Z DEBUG modem << +CSCON: 1,7,4
....
2022-06-20T06:57:55.828Z DEBUG modem << #XNRFCLOUD: 1,0
....
2022-06-20T06:58:12.868Z DEBUG modem << +CSCON: 0,7,4
....
2022-06-20T06:58:26.663Z DEBUG modem >> AT#XAGPS=1,1
2022-06-20T06:58:27.148Z DEBUG modem << OK
2022-06-20T06:58:27.161Z DEBUG modem << +CSCON: 1,7,4
.....
2022-06-20T06:58:44.850Z DEBUG modem << +CSCON: 0,7,4

Can you explain how to use it?

You said:

The problem with using IP for this is that you need to enter some sort of idle mode in the LTE link before you're able to use the GNSS.

What is "Idle" mode for LTE and how and when should it be activated?

[Håkon Alseth]

Hi,

 

GNSS and LTE cannot run at the exact same time, but they can run concurrently.

This means that you have to wait until the LTE Link is in an idle mode before the GNSS can successfully start receiving data from satellites.

 

Please see the online power profile for an example of the time it takes to maintain the LTE link before entering PSM mode:

 Online Power Profiler for LTE 

 

Stas Jis said:

What is "Idle" mode for LTE and how and when should it be activated?

Please see this thread on intro to idle modes in LTE:

 Guidelines (LTE) 

 

Kind regards,

Håkon