A cable network system for bidirectionally communicating signals at an enhanced duplex frequency range, which may be between about 5 MHz and about 650 MHz. This system may include a first amplifier, which may be configured to condition an upstream signal proceeding from a subscriber premises to a headend, without necessarily conditioning a downstream signal proceeding from the headend to the subscriber premises, a second amplifier, which may be configured to condition the downstream signal without necessarily conditioning the upstream signal, and a shaping circuit, which may condition the upstream and downstream signals. This system also may simultaneously, or in an overlapping or offset manner, communicate signals at a full duplex frequency range without a diplex filter.

A radio-frequency amplifier for a cable network includes a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of the cable network and a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of the cable network. An out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to the cable receiver of the cable network and a notch filter configured to reject the amplified digitally protected video signal having the frequency in the range between 70 MHz and 130 MHz from being amplified by the return amplifier.

A radio-frequency amplifier for a cable network includes a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of the cable network and a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of the cable network. An out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to the cable receiver of the cable network and a notch filter configured to reject the amplified digitally protected video signal having the frequency in the range between 70 MHz and 130 MHz from being amplified by the return amplifier.

A network element of a cable television (CATV) network, said network element comprising one or more amplifier units for amplifying downstream signal transmission for digital output into one or more output channels; means for detecting output power of all active digital output channels; means for providing a predetermined correlation between the detected output power of said active digital output channels and a corresponding minimum bias current for said one or more amplifier units; and means for adjusting the bias current of said one or more amplifier units on the basis of the predetermined correlation.

A network element of a cable television (CATV) network, said network element comprising one or more amplifier units for amplifying downstream signal transmission for digital output into one or more output channels; means for detecting modulation error ratio (MER) of all active digital output channels; and means for reducing bias current of said one or more amplifier units from a predetermined value until the MER value reaches a predetermined minimum value.

An amplification system which includes a source of electrical audio signals, a first amplifier, a second amplifier, a plurality of loudspeakers, and a first phase of the first amplifier and a second phase of the second amplifier reproduced in parallel having a time delay between first and second phase amplification for out of phase correction. The time delay is configured to correct poor sound signals while amplifying weaker harmonics and sound signals of different frequencies, thereby adjusting sound output of the amplification system and acoustical characteristics of a room. The amplification system is useful for providing improved sound quality and increased audio efficiencies.

Systems and methods for implementing Soft-duplex functionality in an amplifier in a HFC network.

The present invention is directed to a bi-directional RF signal amplifier that includes both an active communications path and a passive communications path. The circuitry is simplified and the housing size is reduced by having one port which functions as part of the active communications path when the bi-directional RF signal amplifier is powered, and that functions as part of the passive communications path when the bi-directional RF signal amplifier is unpowered.

A method of bidirectional amplification of proprietary TDMA (Time-Division Multiple Access) data modulated signals over CATV infrastructure is described. A method of upstream/downstream switching based on carrier detection/measurement originated from the master and slave modems embodiment is described, along with upstream/downstream direction switching based on the encoded switching command detection, originating from the master modem.

A network interface device includes a passive path between an entry port and a first port. The network interface device also includes an active path between the entry port and a second port. The network interface device also includes a buffer in the active path configured to absorb, attenuate, terminate, or isolate radio-frequency (RF) signals. The network interface device also includes a switching element in the active path configured to cause the RF signals to bypass the buffer when the network interface is in a first state that exists during powered operation of the network interface device, and direct the RF signals to the buffer when the network interface device is in a second state that exists during non-powered operation or faulted operation of the network interface device.