{HEAD ~ The preset time window} for {TAIL ~ each sensor} can be viewed as the address of the sensor 
for
{ HEAD ~ The preset time window } for { TAIL ~ each sensor } can be viewed as the address of the sensor
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH