SIM Registraion Issue

Let me see. This got fixed. Now, facing the same issue after updating the firmware & MBPL drivers as well

ATi

Manufacturer: Sierra Wireless, Incorporated 
Model: MC7455B
Revision: SWI9X30C_02.38.00.00 rE3F3E55C03AE94 jenkins 2022/01/13 05:16:00
MEID: 35907206932248 
IMEI: 359072069322481
IMEI SV: 22
FSN: LQ101286830410 
+GCAP: +CGSM

OK
AT!uims?

!UIMS: 0

OK

AT+cpin?

+CPIN: READY

OK                                                                                                                                                                                                                                               

it shows the module can see the SIM card

Yes, now the issue is it’s not registering. After detection, it’s still on the searching mode

what is the return of the followings?

AT!ENTERCND="A710"
AT!IMPREF?
AT+CFUN?
AT!GSTATUS?
AT+CGDCONT?
AT!SELRAT?
AT!band?

AT

OK
AT!ENTERCND=“A710”

OK
AT!IMPREF?

!IMPREF:
preferred fw version: 02.38.00.00
preferred carrier name: GENERIC
preferred config name: GENERIC_002.082_000
preferred subpri index: 000
current fw version: 02.38.00.00
current carrier name: GENERIC
current config name: GENERIC_002.082_000
current subpri index: 000

OK
AT+CFUN?

+CFUN: 1

OK
AT!GSTATUS?

!GSTATUS:
Current Time: 2174 Temperature: 40
Reset Counter: 3 Mode: ONLINE
System mode: WCDMA PS state: Not attached
WCDMA band: WCDMA 900
WCDMA channel: 3022
GMM (PS) state:DEREGISTERED LIMITED SERVICE
MM (CS) state: IDLE LIMITED SERVICE

WCDMA L1 state:L1M_PCH_SLEEP LAC: 139E (5022)
RRC state: DISCONNECTED UTRAN Cell ID: 00162C64 (1453156)
RxM RSSI C0: -55 RxD RSSI C0: —
RxM RSSI C1: — RxD RSSI C1: —

OK
AT+CGDCONT?

+CGDCONT: 1,“IPV4V6”,“internet4”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0

OK
AT!SELRAT?

!SELRAT: Unknown RAT mode. Use AT!SELRAT to set band.
00000001
00000000

OK
AT!band?

Index, Name, GW Band Mask L Band Mask TDS Band Mask
00, All bands, 0002000007C00000 00000100130818DF 0000000000000000

OK

is the APN set correctly in +CGDCONT?
The AT!SELRAT is strange, can you set to LTE only?

BTW, have you checked if the supported LTE band is available in your location?

Yes, APN is set correctly.

For, AT!SELRAT to set it to LTE, I checked for that. & set to LTE only.

But, how to check the the last one, from where can I see the supported bands

you can see MC7455 specification

or you can see by

AT!Entercnd="A710"
AT!band=?

AT!Entercnd=“A710”

OK
AT!band=?
00)
0000000000800000 - B2 (1900)
0000000000400000 - B1 (2100)

OK
AT!band?

Index, Name, GW Band Mask L Band Mask TDS Band Mask
00, All bands, 0002000007C00000 00000100130818DF 0000000000000000

have you checked if the supported LTE band is available in your location?

Yes, the above two commands can be used right, for checking that. So, I posted the output of those two commands.

then have you checked with your network operator for the band supported in your location?

Network Operator informed that, it’s connecting for a while & then disconnecting on its own. Didn’t ask about the bands, but they said like this

Which band was it connected?

How to check to which band it’s currently connected

no, you cannot as you said that it is not registered now in AT!GSTATUS?

What LTE band is supported for the network operator in your area?

That needs to be asked to network operator ?

i don’t know how you can get this information…
Maybe you can also search in their website

Does this help ?