OPTICAL RADIO TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To prevent interference without changing a carrier frequency of each system where a service area is divided into plural areas and one system covers each division area. SOLUTION: The directivity of light transmission and that of light reception of a light transmitter and a light receiver of a center 1 are made both omnidirectional in the horizontal direction. A 1st light transmitter and a 1st light receiver of the center 1 have respectively sharp light emitting and sharp light receiving directivity to make full duplex communication with the transmitter and receiver, and a 2nd light transmitter and a 2nd light receiver of the center 1 have respectively comparatively wide light emitting and light receiving directivity to make full duplex communication with a data terminal 4. The light transmitter and the light receiver of the data terminal 4 have respectively light emitting and light receiving directivity upward with prescribed spread to make full duplex communication with one repeater 3 or over.