MTE does not connect to the cellular carrier

After installing a SIM and the antennas and then power on the MTE for few minutes, if the POWER and SIM LEDs are on and Signal LED is completely OFF, then perform the following steps:

1. Telnet into MTE and access the command prompt.
2. Issue these commands at the prompt:
   send_ATcmd  /dev/ttyUSB2  AT+CFUN=1

   (Make sure above AT command returns OK, otherwise send command again if it does not return OK.)

   reboot

3. After reboot, check status on the signal strength LED.