TOBY L210 problem with automatically register to prefered LTE network (instead not prefered 2G / 3G)

0 votes


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

by julo asked Oct 11
0 votes
Do you have LTE SIM card?

Are you on home network or roaming?

I really don't think this is FW related.  This is SIM card/carrier related.
by grumpy answered Oct 11

Yes I have LTE sim card. I m sure. You can see it on the picture. Problem is that SIM card is not registered topreferred  LTE network instead LTE is into 3G network. For example before call is registered in 3G network instead LTE after call is only short time few seconds in LTE and after this is again in 3G (see picture). For measurement CSFB (circuit fall back) LTE->3G/2G is important register sim card to LTE before call.

BR Alan
Hello it seems that at+cemode=2 at command solve my problem. BR Alan
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