| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a synchronization method for a radio communication network system for making it possible to retain a synchronization state between a base station and a relay station even when a communication failure occurs between fixed radios. <P>SOLUTION: Mobile radios are communicably allocated at the front and back of a movable body. At least one of fixed radios is made to be a base station for synchronization, and the other radios including the mobile radios are made to be relay stations for synchronization packets. The relay station transits to a synchronization acquisition mode for waiting for receiving synchronization packets when a power supply is turned on, transits to a ground synchronization retention mode showing high synchronization accuracy and becomes capable of transmitting synchronization packets when receiving synchronization packets that are not through the mobile radio, transits to an on-vehicle synchronization retention mode showing synchronization accuracy lower than that of the ground synchronization retention mode and becomes capable of transmitting synchronization packets when receiving synchronization packets that are through the mobile radio, and transits to the ground synchronization retention mode when the relay station in the on-vehicle synchronization retention mode receives synchronization packets from the relay station in the ground synchronization retention mode. <P>COPYRIGHT: (C)2013,JPO&INPIT |
