OPTICAL FIBER-INFORMATION TRANSMISSION SYSTEM USING TRANSMISSION FORMAT OF PASTY UPPER LINK WITH CONTINUOUS LOWER LINK AND PREVIOUSLY ASSIGNED UPPER LINK PROTECTIVE BAND

摘要

PURPOSE: To provide a simple communication system by sending a signal from a master site to a viewer interface site through optical fibers by time division multiplexing and using burst time division multiplexing in other optical fibers. CONSTITUTION: A master site 10 is connected to a center office 14 through a telephone link 12 (a copper wire or optical fibers), and further, the site 10 is connected to a television transmission source 18 through a link 16. The site 10 sends a signal to a viewer interface site 30 through fibers 21 in a double optical fiber pair 20 with a continuous time division multiplexing format as continuous time division multiplexed optical signals. The site 30 is connected to the pair 30 through a local optical coupler board 35 by a private optical fiber pair 31 and sends TV information with a burst format. 'Local' mans that the board 35 is close (500 to 1000m) to the site 30 and is remote (order of 5km) from the site 10. The site 10 is connected to optical fibers 22 going from the site 30 toward a part above the pair 20.