BEAM AUTOMATIC SELECTION CHANGEOVER METHOD AND ITS DEVICE IN MULTI-BEAM SATELLITE COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To obtain a mobile satellite communication terminal easily in use by reducing a beam switching time so as to decrease a communication interruption time. SOLUTION: At first a data table 4 in cross reference between positions of mobile satellite communication terminals versus beams is generated in advance. A position calculation means 2 calculates a current position of a communication terminal at application of power of the communication terminal or when a prescribed key is depressed. A beam switching means 7 references data of a relevant cell in the data table 4 to decide a beam to be selected next and the beam is selected. Furthermore, a data table generating means 6 generates a data table 5 in cross reference between moving directions and beams to cross-reference a moving direction based on the current position and a beam selected next. When a terminal is moving and a channel quality measurement means 1 detects an evaluation value of the channel quality to be less than a prescribed threshold quality level, the beam switching means 7 decides and selects a beam to be selected next by using the moving direction detected by a moving direction detection means 3 and the data table 5.