The method 1, wherein the increasing or decreasing the volume level by using {HEAD ~ volume control buttons} of {TAIL ~ a remote controller} comprises: 
of
The method 1 , wherein the increasing or decreasing the volume level by using { HEAD ~ volume control buttons } of { TAIL ~ a remote controller } comprises :
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH