I inserted a SIM card in the panel, but it doesn't work

Please make sure the SIM card is activated, make sure the PIN code is unlocked by cell phone. When you insert the SIM card, the GSM Led of the alarm is flashing once per second,indicating it's searching the network. If it flashes once every two seconds,this means the GSM signal is received. If the GSM signal is insufficient, please try to change a new SIM card, or change the location of the device