We are using BG95-M3 in our device, configured with
AT+QCFG="nwscanmode" command to search for RATs both GSM and LTE (
scan_mode=0). However, we see that when the modem connects to GSM, it strongly tends to stay connected with this RAT after many subsequent network connections (even with power down/up sequence in between), although LTE becomes and stays available. Then only forcing the modem with
AT+QCFG="nwscanmode" command to search only for LTE (
scan_mode=3), will result with modem being connected to LTE.
The problem with such forcing to LTE is that:
- we do not know if LTE is currently available, and
- we have very limited battery usage constraints.
As a result, we cannot just try each time assuming that LTE could be available to wait for network timeout connection from modem, only to switch it back to GSM after such try.
Is there a way to somehow change the RAT priorities internally in the modem, to make it try searching for LTE in a more efficient way? How does this network RAT searching actually work - does modem try to search for another RAT (especially more efficient RAT) itself, or is it up to the host to make such decisions?