A bulletin board system is implemented on a server computer without employing database management software. It is made from typical grip material for the application with the exception of having a smooth or textured interior and being oversized for the handle. When the third-party supplier receives a request from a wireless end-user device to purchase a video from the catalog, the third-party supplier notifies the operator network, which then delivers the video to the wireless end-user device. The hub selectively sets a bandwidth level associated with the return channel bandwidth that is available based upon one of a plurality of predetermined bandwidth levels according to a predetermined criteria. In the judgment step s6, whether the communication state is normal or abnormal is judged based on the result of the communication of the test signal between the main control unit 1 and each of the sub control units 2. The correction unit corrects an image of the certain page on the basis of the parameter determined by the determination unit.