I would like to ask you for help, for advice.
We bought two modems u-blox TOBY-L210 with evaluation board.
We would like use mentioned modems for voice testing CSFB(circuit switched fallback).
We noticed one problem if we use band LTE + 3G with following at commands:
AT+COPS=2 (deregistration SIM to network)
AT+URAT=6,3 ( 6 select: UMTS / LTE (dual mode) a 3 select: preferred LTE)
AT+COPS=0 (registration SIM to network)
We set LTE band as preferred however modem doesn’t register automatically to LTE however register to 3G instead LTE (signal for LTE is good -86dBm however signal for 3G is better -68dBm). It is not standard behavior. I attached picture.
Our firmware version is: 15.63,A01.03 (TOBY-L210-02S-00).
Our seller gave us new firmware TOBY-L210-03S-00_FW15.63_A01.50_IP however I didn’t try use this FW. Could you tell me that new FW solve our problem? Could you give us some advice (some at command for automatically preferring LTE registration) instead 2G or 3G.
Thank you Alan