Sometimes, if there is LTE available and the SIM is provisioned correctly, is active, there are no issues with the APN but the modem will still fail to connect to an available LTE band. In circumstances like these, use the solution below to force the modem to work with LTE only.
Before proceeding with the solution steps outlined on this article, confirm whether the FortiExtender modem is connected to the Packet Service and if it is registered on the network.
This can be confirmed by running the following:
get modem status
execute modemfw AtTest modem1 at!gstatus#
The outputs below demonstrate that the modem is being detected, but it is not attached to a packet service and not registered on the network.
If the SIM is present, has been provisioned correctly, and is active: proceed with the following steps.
Step 1: Confirm if the modem is configured to automatically choose between among supported radio technologies.
This can be performed by running the following command:
execute modemfw AtTest modem1 at!selrat#
If it is configured to automatically choose LTE, the output would look as follows.
Step 2: Confirm whether the modem is configured to allow all supported LTE bands.
This can be performed by running the following command:
execute modemfw AtTest modem1 at!band#
If it is configured to allow all supported LTE bands, the output will look like the following:
Step 3: Run the following command to open a direct serial console to the modem. This will provide access to the AT command port to run modem commands.
execute minicom /dev/ttyUSB2
Step 4: Check if the modem console is working correctly by issuing an 'AT' command as depicted below.
Step 5: Access the engineering/admin command mode to create a new profile.
Run the following command:
AT!ENTERCND="A710" .
This will unlock the privileged AT! commands.
 A710 is the modem’s engineering unlock password (sometimes called the “service code” or “command mode password”). It enables access to protected Sierra Wireless proprietary AT! commands.
Step 6: Create a new band profile named 'LTE-ONLY' and restrict it to LTE bands (i.e all LTE bands are allowed and no 2G/3G) using the command below.
AT!BAND=10,"LTE-ONLY",0000000000000000,00000100330818DF,0000000000000000
Step 7: Switch the modem to use the newly created LTE only band profile 10 using the following command.
AT!BAND=10
Step 8: Reboot or Reset the modem with the AT!RESET command.
Step 9: Break out of the modem console to the FortiExtender CLI console by issuing a 'Ctrl + C' command
Step 10: After the modem has been rebooted, issue the 'get modem status' command to confirm whether the modem is now attached to LTE-only mode and whether the FortiExtender modem is connected to the Packet Service, and if it is registered on the network.
Now, as depicted in the output. the modem is attached to LTE-only mode and the modem is connected to the Packet Service and it is registered on the network.
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