OPTICAL COMMUNICATIONS SYSTEM UTILIZING FREQUENCY DIVISION MULTIPLEXING

摘要

Overhead information is transmitted from a first node to a second node in an optical fiber communications system using a separate frequency band. A control channel containing the overhead information if frequency division multiplexed with electrical low-speed channels to form an electrical high-speed channel, which is converted from electrical to optical form to form an optical high-speed channel. The optical high-speed channel is transmitted over the optical fiber to the second node. In addition, attenuation caused by dispersion in an optical fiber communications system is compensated. The power of each low-speed channel is adjusted to compensate for the estimated attenuation caused by dispersion. In addition, two nodes in an optical fiber communications system are synchronized by transmitting a reference signal between the two. The reference signal (or a harmonic of the reference signal) is generated at one node and then transmitted across an optical fiber to the other node. Both nodes are synchronized to the reference signal, thus synchronizing each node to the other. In one embodiment, the refrence signal is combined with the electrical low-speed channels using frequency division multiplexing.