Abstract: A link probe for multimode fibers in optical networks is provided. An optical test probe signal is sent over a multimode fiber of an optical network link and a receiver converts the optical signal into an electronic signal with a trigger generated by the clock recovery section of an EDC (electronic dispersion compensation) unit. The digital signal is processed by a modified IEEE algorithm to determine a TWDP (Transmitter and Waveform Dispersion Penalty) parameter which quantifies the transmission quality of the multimode fiber and link suitability to LRM transmission.

Abstract: Methods and apparatus for supporting a plurality of modulation formats using a single transmitter are disclosed. According to one aspect of the present invention, a transmitter arrangement that provides a signal to a modulator that creates an optical data stream from the signal includes an encoder and a switching/filtering arrangement. The encoder has a state that is varied between first and second encoder states. If the state is the first encoder state, the encoder encodes the signal in a format associated with an optical duobinary (ODB) modulation format. Otherwise, the encoder does not encode the signal in the format associated with the ODB modulation format. The switching/filtering arrangement receives the signal from the encoder, and provides the signal to the modulator. If the variable state of the encoder is the first encoder state, the switching/filtering arrangement has a low bandpass configuration. Otherwise, the switching/filtering arrangement has a high bandpass configuration.

Abstract: A transponder unit which relays signals between a plurality of channels of an optical transport network and a plurality of clients. The interconnections within the transponder unit are reconfigurable for selective connections. A connection between a first client and a first network channel and a connection between a second client and a second network channel is independent of each other and may be selected so that the second client is connected to the first network channel and the first client is connected to the second network channel. Other selected connections are also possible.

Abstract: A link probe for multimode fibers in optical networks is provided. An optical test probe signal is sent over a multimode fiber of an optical network link and a receiver converts the optical signal into an electronic signal with a trigger generated by the clock recovery section of an EDC (electronic dispersion compensation) unit. The digital signal is processed by a modified IEEE algorithm to determine a TWDP (Transmitter and Waveform Dispersion Penalty) parameter which quantifies the transmission quality of the multimode fiber and link suitability to LRM transmission.