A system of physical layer packet format and signaling methods is disclosed, wherein signaling overhead is minimized in applications where multiple users share air interface resources; improving efficiency in orthogonal frequency division multiplexing and orthogonal frequency division multiple access communication systems. In another embodiment, the method comprises providing the dielectric material, forming the feature extending into the dielectric material, forming the electrically conductive layer over the dielectric material, applying the primer to a surface of the electrically conductive layer and attaching a dielectric layer to the primer. Accordingly, a state that a feeding failure is possibly caused is detected before feeding the sheets so as to eliminate the wasteful feeding operation. In one embodiment, the grid is an iconic representation of the formatted warehoused data. In the case of a remote network device establishing a virtual channel with a local network device, a virtual channel request message is received from a local network device by a remote network device. In-situ self-calibration is performed immediately before making a measurement on the alternating current power distribution grid.