A communication apparatus performs {HEAD ~ specific operation} before turning off {TAIL ~ the power} of the communication apparatus 
A communication apparatus performs { HEAD ~ specific operation } before turning off { TAIL ~ the power } of the communication apparatus
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH