The system 1, wherein the transmitter is inoperable to transmit data when {HEAD ~ the actual voltage supply level} of the batter is lower than {TAIL ~ the second voltage threshold} 
is lower than
The system 1 , wherein the transmitter is inoperable to transmit data when { HEAD ~ the actual voltage supply level } of the batter is lower than { TAIL ~ the second voltage threshold }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL