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