Why is the GPS operation always blocked

RE: Why is the GPS operation always blocked

Albrecht Markus Schellenberger — Mon, 30 Aug 2021 07:50:13 GMT

Hello,

my apologies for the late reply. I was on vacation for the last couple of weeks.

[quote user="duxinglang"]Is there any other way to keep the network connection and enable the GPS function properly? [/quote]

Yes. The GPS socket can be used while the LTE socket is released which happens after it has entered RRC idle. For this, your network provider has to support PSM and you have to configure your device requesting PSM to the network accordingly.

Regards,

Markus

RE: Why is the GPS operation always blocked

duxinglang — Tue, 24 Aug 2021 09:59:16 GMT

Does this mean that when I need to start GPS, I have to disconnect the NB connection? This will cause my device to disconnect from the background. Is there any other way to keep the network connection and enable the GPS function properly?

RE: Why is the GPS operation always blocked

Albrecht Markus Schellenberger — Thu, 22 Jul 2021 11:28:48 GMT

Thanks for elaborating!

[quote user="duxinglang"]In order to prevent the modem from automatically registering the network repeatedly, I turned off the modem and then turned it back on when the GPS needed to be started.[/quote]

Turning on the modem with AT+CFUN=1 will also enable the LTE socket which will block the GPS socket from running during the connection attempt(s).

I would recommend you instead to turn on the modem with AT+CFUN=31 or disable the LTE socket using AT%XSYSTEMMODE=0,0,1,0

Regards,

Markus

RE: Why is the GPS operation always blocked

duxinglang — Thu, 22 Jul 2021 10:52:00 GMT

I'm sorry I didn't make it clear. What I meant was that the device failed to register with the NB network through the modem because the SIM was not activated. In order to prevent the modem from automatically registering the network repeatedly, I turned off the modem and then turned it back on when the GPS needed to be started.

RE: Why is the GPS operation always blocked

Albrecht Markus Schellenberger — Tue, 20 Jul 2021 05:58:45 GMT

[quote user="duxinglang"]but because of the SIM card, the Modem returned a connection failure, so I closed the modem, and then reset AT+CFUN=1 to turn on the modem when the GPS was needed.[/quote]

I do honestly not think that this sounds about right. What kind of connection failure does the modem return?

[quote user="duxinglang"]I don't think there should be any NB operation to block the GPS in this case. [/quote]

The thing is that, as long as the LTE socket is not in RRC idle, the GPS socket will not run.

Regards,

Markus

RE: Why is the GPS operation always blocked

duxinglang — Mon, 19 Jul 2021 10:52:43 GMT

Yes, I registered the NB network when the system was initialized, but because of the SIM card, the Modem returned a connection failure, so I closed the modem, and then reset AT+CFUN=1 to turn on the modem when the GPS was needed. I don't think there should be any NB operation to block the GPS in this case.

RE: Why is the GPS operation always blocked

Albrecht Markus Schellenberger — Fri, 16 Jul 2021 13:47:15 GMT

Hello,

My assumption here would be that the GPS socket is blocked by the LTE socket, since LTE always is prioritised.

Could you please check your network registration status (or alternatively read modem parameters)? It would be good to confirm that the network has allowed the device entering PSM.

Another idea could be enabling modem sleep and/or periodic TAU notifications.

Regards,

Markus