| 摘要 |
PROBLEM TO BE SOLVED: To suitably select a communication system in accordance with the moving state of communication equipment of a mobile object and to provide precise information. SOLUTION: When the variation history of receiving levels and the frequency of handover are stored in a storage part 10 in each of a PDC system and a PHS system, an operation part 11 judges the moving speed of the mobile object communication equipment 31 on the basis of the variation history of the receiving levels and the frequency of handover. When the communication equipment 31 stops or its moving speed is slow, the operation part 11 selects the PHS system in which the quality of sound is fine a data communication speed is high and a transmission output is low though the cells of a base station and narrow, and executes the communication of the PHS system. When the moving speed of the communication equipment 31 is high, the operation part 11 selects the PDC system in which the cells of the base station are wide, the frequency of handover is small and communication is not frequently interrupted, and executes the communication of the PDC system. |
