| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability by suppressing mutual interference so as to permit a DS(direct spreading) radio equipment and an FH(frequency hopping) radio equipment to co-exist and also arranging the respective radio equipment in places being proper to their characteristics. SOLUTION: The FH-system radio master equipments 33 and 34 for hopping a frequency and radio slave equipment 331-33n and 241-34n are arranged in radio wave zones A and B where narror band disturbance easily occurs, the DS-system radio master equipment 35 for direct spreading modulation and the radio slave equipments 351-35n are arranged in the radio wave zone C where the jam of people and a multi-pass easily occur, the DS radio eqipments detect reception electric field strength in spreading band width before transmission so as to start transmission only when recognized that the detected reception electric field strength does not exceed a prescribed level and the FH radio equipments detect reception electric field strength in present hopping frequency band width before transmission so as to start transmission only when recognized that the detected reception electric field strength does not exceed the prescribed level. |
