hello all
I'm having a very weird problem this this gsm modem.I'm using it on a school project to seend sms via arduino. My problem is if I connect it at home it blinks 6 times and register successfully at the operator and is ready to seend sms.I developed the all the code at home and today I get all those stuff to school and for my surprise the modem wont register there.It just blink 5 times and nothing more.The possibility of be bad signal from the operator is low since I have good cover on my phone which is the same operator that the sim card on the modem.
I dont belive in witches but I cant figure out what could be 
I have a possibility and I would like to share opinions ?
Could the modem just be working in a 3G network and this way wont register at the school?( I will test if there have a a good cover on 3g network)
Could the modem need to receive some AT command to change it from 800 Mhz to 1800Mhz(Dual band operation) or disable 3g operating band ?
Thanks for your time
