| 摘要 |
A communication system and a communication method arranged to obtain a diversity effect in mobile communication, to reduce the influence of multipath interference, fading or the like, to perform comparatively simple information communication such as message communication with improved reliability, and to achieve effective utilization of frequencies. A plurality of base stations having receivers are provided around an urban area within base station zones. The base stations repeatedly transmit the same message data. Receiving repeaters are provided in the urban area and small or medium suburban zones. Each receiving repeater relays a signal from a small mobile terminal via an Internet network if the output level of the mobile terminal is so low that direct transmission to one of the base stations is impossible. A 25 kHz frequency band is divided into four narrower bands of 6.25 kHz in one of the embodiments. Of frequencies f1, f2, f3, and f4 in these bands, frequencies f1 to f3 are used for "down data transmission" from the base stations to a mobile terminal while f4 is used for "up data transmission" from the mobile station to one or more of the base stations.
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