Mirko,
now A1 Bulgaria NB-IoT ( band 8, 900MHz ) work with 3GPP rev 14
my boards use module BC66NB-04 STD
and connections is OK
first searching ~70 seconds, all next … connect for 4 seconds to cell
IF you can not connect:
APN is wrong
Bad antena, Bad signal, No NB cell nearby
IMEI = 00000000
Follow this ( firmware 7 & 10 ):
AT+CFUN=0 // disable modem
AT+CGSN=0 // check your IMEI, if is 00…00, you will never connect
AT+CGSN=1
AT*MCGDEFCONT=“IP”,“your-iot-apn” // store APN to NVDM
AT+QRST=1 // reset the module
///////
AT+CEREG=1 // fast enter this
AT+CEREG? // repeat … to show status
AT+CEREG? +CEREG: 1,2 OK
+CEREG: 1
+IP: 10.66.154.157 // connected to cell