When {TAIL ~ execution} of the communication task can be extended, {HEAD ~ the communication apparatus} extends execution of the communication task to a later time 
When { TAIL ~ execution } of the communication task can be extended , { HEAD ~ the communication apparatus } extends execution of the communication task to a later time
OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH