Patent ID: 8301134

Claim:
A main device of a cordless telephone system configured to perform communication with at least one additional device, each of the at least one additional device comprising: a search unit configured to search intermittently for a radio wave generated from the main device; and a search stopping unit configured to stop execution of the search unit after a state in which the search unit does not receive a radio wave continues for a predetermined time, wherein the main device comprises: a radio wave generating unit configured to generate the radio wave; an operation stopping unit configured to stop an operation of the radio wave generating unit; and a temporary returning unit configured to recover temporarily the operation of the radio wave generating unit to generate a radio wave and configured to stop the operation of the radio wave generating unit after the at least one additional device executes multiple searches by using the search unit after stopping the operation of the radio wave generating unit, but before the predetermined time elapses, wherein the temporary returning unit comprises: a recovery unit configured to recover the operation of the radio wave generating unit; a judging unit configured to judge whether communication with the at least one additional device is established after the recovery of the operation by the recovery unit; and a re-stop unit configured to stop the operation of the radio wave generating unit under a condition that the judging unit judges that communication with all of the at least one additional device is established, wherein the search unit is configured to execute searches a predetermined number of times within the predetermined time, and wherein the temporary returning unit is configured to recover temporarily the operation of the radio wave generating unit to generate a radio wave while the at least one additional device executes a search corresponding to the predetermined number-th search, which is counted from the stoppage of the operation of the radio wave generating unit by the operation stopping unit or the re-stop unit, by using the search unit.