Optical data transmission system in the access network

摘要

For a transmission system serving to transmit information between a central station and a plurality of subscriber stations and vice versa, in particular for transmitting the narrowband signals in the access network of a broadband communications system, a system is proposed according to the invention in which the subscriber stations (1 to 6) are inserted in an optical loop (7) which runs from an optical transmitter (8) in the central station via these subscriber stations to an optical receiver (9) in the central station. The central station transmits information blocks in succession via the loop to the individual subscriber stations, said information blocks if necessary containing a message for the subscriber station as well as the subscriber address. So that the subscriber stations can transmit their messages to the central station in the simplest fashion, i.e. without the need for an optical transmitter, they receive constant light of a pre-defined duration (KL, Fig. 2a) in the information block addressed to them, modulate their message onto this constant light by means of a simple optical switch and forward this signal via the optical loop. If a subscriber station detects that it is addressed in the message block, it receives the message from this information block and then begins to modulate and forward the constant light. Otherwise, as soon as it receives the address, it switches to through-connection and thus forwards the remainder of the information block ... Original abstract incomplete.