PDU Mode
AT+CSMS=1
+CSMS: 1,1,1
OK
Set PDU mode.
AT+CMGF=0
OK
AT+CNMI=2,2,0,0,0
OK
Message is received from network.
+CMT: "",70
06816000585426000480980600F170110370537284...
Send positive acknowledgement to the network.
AT+CNMA=0
OK
Message is received from network.
+CMT: "",70
06816000585426000480980600F170110370537284...
Send negative acknowledgment (Unspecified error) to the network.
AT+CNMA=2,3<CR>
> 00FF00 <Ctrl-Z>
OK