$CW$:	Contention window	$\alpha$:	Delay time
$Ts$:	CSMA slot length	$T_P:$	preamble time
$T_c:$	Collision time	$T_{PHY}:$	physical header time
$T_{on}$:	RF transceiver power-on	$T_{MAC}:$	MAC header
$T_{CW}:$	Average back-off time	$T_{BODY}:$	MAC frame body time
$T_{data}:$	Time to transmit a data packet	$T_{FCS}:$	frame check sequence time
$T_{I-ACK}:$	Time to transmit ACK	$T_{PSIFS}:$	Short interframe spacing