Collision detection apparatus utilizing tap means connected to each transmitting optical fiber for fiber optic Local Area Networks

摘要

A fiber optic Local Area Network containing more than one transmitter-receiver combination capable of transmitting and receiving light energy over optical fibers and being deactivatable during transmission upon receiving a jam signal, a coupler means, a collision detection means for detecting when more than one transmitter is transmitting at the same time, and a plurality of optical fibers connecting the coupler means to said transmitter-receiver combinations and forming transmitting and receiving light paths there between, the collision-detection means comprising a tap means connected to each transmitting optical fiber for diverting a portion of the transmitted light energy; an optical receiver means for each optical fiber containing a tap adapted to detect that portion of an optical signal diverted by said tap means; an optical path between each tap means and a single optical receiver means; a logic means connected to said optical receiver means responsive to and adapted to transmit a predetermined signal when two or more simultaneously co-existing optical signals are detected in two or more optical receiver means; a jam signal means adapted to be activated by the predetermined signal emitted by the logic means and to transmit a jam signal to each transmitter-receiver combination, and a means in the transmitter-receiver combination to detect and is responsive to the jam signal.