SATELLITE COMMUNICATION SYNCHRONIZING SYSTEM

PURPOSE:To change a switch pattern without disconnecting satellite lines, by performing the change of the switch pattern of satellite switches and the change of a line assignment pattern of satellite switches synchronously with each other. CONSTITUTION:A switch pattern change command issued from a command device of a satellite command station 106 is indicated to a controlling circuit 310 of a communication satellite 101. The circuit 310 changes the switch pattern synchronously with a superframe. Meanwhile, a synchronism controller 302 of a reference station 104 transmits an initial acquisition to the satellite 101. This signal is switched by a satellite switch 309 and is turned back to the controller 302. By this turned-back signal, the synchronism for the frame cycle of the switch is established. The signal turned back from the satellite 101 is changed by the change of the switch pattern. This change is detected to establish the synchronism for the superframe by the controller 302. The controller 302 indicates a superframe corresponding to the change of the switch pattern to a time division multiple access TDMA device 303 of an earth station 105.