A composite ceramic of the present invention includes granular alumina particles having an aspect ratio of 3 or less, granular zirconia particles having an aspect ratio of 3 or less, and a columnar crystal having an aspect ratio of 3 or more, the columnar crystal including a complex metal oxide containing an alkaline-earth metal element and aluminum element. A transmitter transmits at least two data packets via two or more antennas. One or more of those facial features are selected and superimposed on the target image. The loss of direct communication between any two nodes in an optical network can occur because of obscuration of the atmospheric path between the two nodes.