When either a front-side sensor or a rear-side sensor of a subject vehicle detects an obstacle entering a certain distance range of multiple distance ranges within a detection zone close to the subject vehicle, a micro-computer causes a warning unit to warn with a buzzer in a primary warning pattern that is prepared for each distance range. In one embodiment the trench structure is created by forming sets of trenches with a lithographic mask and filling the sets of trenches with sets of step spacer blocks comprising two alternating spacer materials which are separately removable from each other. If the HTC enabling field is enabled, then an HTC field is sent that announces a sounding frame and a type of channel estimation feedback expected from a receiving station. The invention further relates to the inbred and hybrid genetic complements of plants of variety CV443328. The source ATM may use secret information associated with the common software program andor hardware and other randomly generated information to securely encrypt the secret encryption keys.