An edge narrowing method for a display panel is disclosed. Each transmitted frame is stored after a full compressdecompress cycle, and difference data representing the difference between the stored frame and the incoming new frame is transmitted. Consequently, cracks, weak spots and other defects in the protective stack are to a large extent avoided. The method also includes determining one or more receiver locations of one or more receivers to provide a system wherein signals from the transmitter device reach at least one of the receiver locations.