An optical node assembly for cable television communications comprises at least one optical receiver, at least one optical transmitter having a single first location shaped to receive a first JXP-style component, a router board, a forward configuration board connected to the optical receiver and the router board, a return configuration board connected to the optical transmitter and the router board, at least one RF module connected to the optical receiver and the optical transmitter through the router board and having a forward circuit path and a return circuit path having a single second location shaped to receive a second JXP-style component, and at least one JXP-style component having a circuit comprising both an attenuation sub-circuit and an equalization sub-circuit, the at least one JXP-style component being inserted in at least one of the single first location and the single second location.

Devices and methods for bypassing a defective component in a combining network relaying respective upstream and downstream signals between a head end and a plurality of subscribers. The devices and methods may preferably redirect the upstream signal without redirecting the downstream signal using a wavelength-dependent filter.

There is provided an optical network device (30) comprising separate downstream and upstream signal paths (33, 34) disposed between a wavelength division multiplexing unit (16) and a signal splitting element (32, 44, 50), an optical to electrical signal converter (18) disposed in the downstream path and an electrical to optical signal converter (22) disposed in the upstream path, wherein the signal splitting element (32, 44, 50) is capable of splitting signals independent of signal frequency and is configured with an isolation of 30 to 50 dB thereby to substantially prevent leakage of downstream signals into upstream path (34). The signal splitting element is capable of splitting signals independent of signal frequency and may be a directional coupler, two-way signal splitter or hybrid coupler comprising at least two different types of coupler element.

Systems and methods for relaying upstream signals received from a plurality of subscribers to a remote head end. Some preferred embodiments include upstream transmitters in one or more Optical Network Units that may be dynamically and individually controlled to determine whether the upstream transmission is in burst mode or continuous mode.

A coaxial tap in a hybrid fiber coaxial cable distribution system serves subscribers with an RF signal.

Systems and methods for optical modulation index calibration in a CATV network.

An indexing system includes an indexing component; a redundant optical path; and a fiber tap arrangement. Multiple indexing components can be daisy-chained together in the indexing system. The redundant optical path is created between any forward port and any rearward port in the network. Multiple redundant optical paths can be created within the network. One or more tap arrangements can be disposed along each redundant optical path. Accordingly, feed signals in a bidirectional indexing environment can be supplied to each drop line along the redundant optical path from either direction without recabling.

The invention relates to a method and apparatus for evaluating a network and for predicting network performance for a higher order modulation by analyzing network signals modulated using a lower order modulation format. A margin index may be generated for the current or projected modulation formats based on displacement vectors for received symbols to indicate a margin remaining before a codeword error occurs to alert the network operator of potential performance issues before actual codeword errors occur.

A test instrument for testing RF and RFOG installations is disclosed. The test instrument is configured to test RFoG downstream power and recover an original RF signal from an optical signal generated at a head end and perform DOCSIS and RF signal tests including level, scan, carrier to noise, digital MER/BER, and full communication with CMTS.

Techniques for transmitting an optical signal through optical fiber with an improved cost effective stimulated Brillouin scattering (SBS) suppression include externally modulating a light beam emitted from a light source with a high frequency signal. The light beam is also modulated externally with an RF information-carrying signal. The high frequency signals are at least twice a highest frequency of the RF signal. The high frequency signals modulating the light source can be gain and phase adjusted by the first set of gain and phase control circuit to achieve a targeted spectrum shape. The adjusted high frequency signals then are split, providing a portion of the split signals to modulate the light source and another portion of the split signals to the second set of phase and gain control circuit for adjusting a phase/gain. The output of second set of phase and gain control circuits can be applied to the external modulator to eliminate intensity modulation caused by the corresponding high frequency signals that modulate the light source. The spread spectrum for SBS suppression or the optical transmitter's SNR is further improved by cancelling a beat between SBS suppression modulation tones and out of band distortion spectrum of information bearing RF signal.