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US 6,888,883 B1Granted
Method and apparatus for reducing noise leakage from a cable modem
AssigneeCisco Technology, Inc.
InventorsAlejandro H. Schwartzman, Charles J. Naegeli
Life of this patent
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AssigneeCisco Technology, Inc.
InventorsAlejandro H. Schwartzman, Charles J. Naegeli
Estimating the term…
Apparatus and methods are disclosed for reducing noise leakage on the upstream channel from a cable modem. Noise leakage from cable modems, such as from a persistently enabled amplifier or other components in the modem, can accumulate on an upstream channel and reduce the overall signal-to-noise ratio of signals sent to the headend. In order to significantly reduce such noise leakage and to provide termination of the cable plant in the modem when the modem is not transmitting data, a cable modem arranged to improve its isolation is disclosed. The modem contains an upstream transmitter having a control line on which the upstream transmitter can emit a control signal. The modem also includes a switch component capable of being enabled and disabled by the control signal on the control line. The control signal from the upstream transmitter to the switch component enables the switch component thereby allowing a data signal to be transmitted on an upstream channel. The switch component includes two switches. One switch is a series switch used to enable and disable the transmission of data. Another switch is a shunt for providing termination of the cable plant. The cable modem also includes an amplifier for amplifying the data signal from the upstream transmitter before being transmitted on the upstream channel.
A cable modem capable of reducing noise leakage on the upstream channel in a cable plant comprising:
A method of reducing noise leakage from a cable modem onto a cable plant, the method comprising:
The method of clam 10 wherein the amplifier is activated before the switch is activated, and the switch is deactivated before the amplifier is deactivated.
A method of reducing noise leakage from a cable modem onto a cable plant the method comprising:
An apparatus for reducing noise leakage from a cable modem onto a cable plant, the apparatus comprising:
A method of reducing noise leakage from a cable modem onto a cable plant, the method comprising:
A method of reducing noise leakage from a cable modem onto a cable plant, the method comprising:
An apparatus for reducing noise leakage from a cable modem onto a cable plat, the apparatus comprising:
Dependencies are inferred from the claim text.