| 摘要 |
PROBLEM TO BE SOLVED: To prevent the radio wave delivery areas of a centralized control station from being overlapped by performing confirming processing, while using an auxiliary frequency channel before starting initial setting operation, and receiving an alarm from a terminal station under control, when that terminal station exists in the other centralized control stations around it. SOLUTION: When it is judged by carrier sence that a centralized control station does not exist around at the time of operation in a terminal station mode, radio terminals 104-109 set themselves into a centralized control station mode and function as centralized control stations. When the centralized control station mode is set, while using the auxiliary channel for transmission, a radio terminal A reports the declaration of changing itself into centralized control station mode with respect to the other radio terminals. When a terminal station B is under the control of the other centralized control station existing in the other radio terminals receiving the declaration, this radio terminal B sends an alarm command to the radio terminal A while using the auxiliary channel for transmission and prevents the radio terminal A from being set into a centralized control station mode. |
