GPS Lock Lost and Not Recovering

IoT Modules LTE Standard Module
1

I am using the Quectel EC25-E module (Firmware version: EC25EFAR08A07M4G) in my device for both LTE and GPS functionality.

I have configured the GPS to output NMEA sentences via the dedicated USB port. I am operating GPS in Mobile Station Based mode (A-GPS using SUPL).

Below are the AT commands I use to configure and start GPS:

AT+QGPSEND
AT+QGPSCFG="gpsnmeatype",31
AT+QGPSCFG="plane",0
AT+QGPSSUPLURL="supl.google.com:7276"
AT+QGPS=2

Issue description:

  • Upon starting GPS, the module successfully acquires a fix, and I receive valid NMEA data with latitude and longitude.
  • However, after running for some time, the GPS lock is lost.
  • Once the lock is lost, it is not recovering back
  • NMEA output continues but shows no valid fix data (e.g. empty fields or “no fix” status).

I would like to understand:

  1. What could cause GPS lock to be lost and not recover in this scenario?
  2. Is there any additional configuration or AT commands I should use to ensure stable long-term GPS operation in Mobile Station Based mode?
  3. Should I periodically stop and restart the GPS session to maintain reliability? Is there any such approaches that I can use?
  4. Are there any known firmware limitations or bugs in version EC25EFAR08A07M4G related to GPS operation or SUPL assistance?

Module Details:

  • Module: Quectel EC25-E
  • Firmware version: EC25EFAR08A07M4G
  • GPS operating mode: Mobile Station Based (AT+QGPS=2)
  • SUPL Server: supl.google.com:7276

Thanks for the support in advance.

Best regards,
Anoop M