{HEAD ~ a cooling unit} to perform {TAIL ~ a cooling process} to lower a temperature of a light source when an instruction for turning off the power of the communication apparatus is received 
to perform
{ HEAD ~ a cooling unit } to perform { TAIL ~ a cooling process } to lower a temperature of a light source when an instruction for turning off the power of the communication apparatus is received
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH