A power bridge rollout service system for removing and installing a power bridge, the power bridge having a housing with an external bus assembly. The exposure apparatus allows a mask storage controller and a mask transfer device to select a mask, on which the pattern of a numeral or symbol to be imprinted is drawn, for each digit of the wafer-identifying information and carries out exposure. The base station system and a certain mobile station system communicate with each other using an overlay method that uses a spectrum hole.