Motorola Corporation

Stuart Baker Sanders

Vivian Therese Lund

Gary E Mastenbrook

Dennis Michael Allen

A method and apparatus for reducing ingress noise (304) in the upstream frequency band and reducing power consumption in a cable communication system (200) by not allowing signals generated in the customer premise (104) to enter the upstream frequency band on the cable network (110) unless a customer premise device (102) is attempting to establish a communication link. An RF detector (206) monitors the signals on the coaxial cable for an RF signal. The comparator (208) indicates to the logic circuit (210) when the RF signal has exceeded a minimum threshold. The logic circuit (210) determines if the subscriber premise device (102) is attempting to establish a communication link. If the subscriber premise device (102) is transmitting the logic circuit (210) closes the ingress switch (212) to connect the subscriber premise device (102) to the network.

Data communication apparatus and method thereof

A differential signal is coupled to an unbalanced port (116) from a balanced port (110) by receiving a first portion of a first phase of a differential signal at a first resonator (104) and receiving a second phase of the differential signal at a second resonator (108). The first portion of the first phase of the differential signal is coupled to a first matching element (112) and the second phase of the differential signal is coupled to a second matching element (118). The first portion of the first phase of the differential signal is coupled to a phasing element (122) through the first matching element (112) and a second portion of the first phase of the differential signal, which is a 180 degree out of representation of the second phase of the differential signal, is coupled to the phasing element (122) through the second matching element (118). The first portion of the first phase of the differential signal and the second portion of the first phase of the differential signal are combined in the phasing element (122) to produce an unbalanced signal at the unbalanced port (116).

Method and apparatus for coupling a differential signal to an unbalanced

An upstream ingress filter (300) for isolating upstream ingress noise on a bi-directional cable system having an upstream band and a downstream band for carrying upstream signals and downstream signals, respectively. The upstream ingress filter (300) includes a DC switching element (310) for changing the DC voltage on the cable system at said cable access unit and a switchable notch filter (340) that switches ON and OFF in response to the DC switching element. The notch filter isolates upstream ingress noise by attenuating upstream signals in the upstream band when the upstream ingress filter is ON. Both the DC switching element (310) and the notch filter (340) are connected in parallel to the cable (301).

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Lindenhurst, IL, United States of America

Stuart Baker Sanders