When a communication error detection apparatus according to the present invention is initially installed, it performs a detection processing of the errors based on a sampling method in which a sampling interval of packet signals at the start of detection processing is a comparatively short. The device includes a dumbbell shaped floatation member for providing buoyant resistance once submerged underwater. The server first authorizes a WLAN roaming device, and then processes a meta-data message received from a WLAN access point in which the source address of the message comprises the source address of the roaming device at the WLAN access point.