Cable television return link system with high data-rate side-band communication channels
First Claim
1. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
- an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
an Ethernet data receiver configured to receive first Ethernet data from a device external to the return path transmitter, the Ethernet data receiver configured to output the first Ethernet data in a second data stream;
first circuitry coupled to the RF signal receiver and to the Ethernet data receiver to receive and process the first data stream and second data stream and to output a third data stream;
an optical transmitter configured to convert the combined data stream into a first optical data signal for transmission over an optical fiber to the head end system;
an optical receiver configured to receive a second optical signal over the optical fiber, the optical receiver configured to convert the second optical signal into a fourth data stream;
second circuitry coupled to the optical receiver, the second circuitry configured to recover second Ethernet data from the second optical signal; and
an Ethernet data transmitter coupled to the second circuitry and configured to transmit the second Ethernet data to the external device.
2 Assignments
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Accused Products
Abstract
A Cable Television (CATV) digital return link system that provides dedicated, high-speed, full-duplex and point-to-point connections between users and the head end system is disclosed. The CATV digital return link system includes return path transmitters, intermediate hubs and a head end hub coupled to each other via a network of fiber optics cables. The return path transmitters are each coupled to a relatively large number of users via a local CATV-subtree. Signals from cable modems are transmitted via the local CATV-subtree to the return path transmitters for transmission to the head end. A number of users are individually and directly connected to the return path transmitters. Data from these directly connected users is transmitted to the head end via the network of fiber optics cables in conjunction with the RF data from the subtree. Likewise, data from the head end to these directly connected users is transmitted in the forward path direction using the digital return link system.
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Citations
20 Claims
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1. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
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an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
an Ethernet data receiver configured to receive first Ethernet data from a device external to the return path transmitter, the Ethernet data receiver configured to output the first Ethernet data in a second data stream;
first circuitry coupled to the RF signal receiver and to the Ethernet data receiver to receive and process the first data stream and second data stream and to output a third data stream;
an optical transmitter configured to convert the combined data stream into a first optical data signal for transmission over an optical fiber to the head end system;
an optical receiver configured to receive a second optical signal over the optical fiber, the optical receiver configured to convert the second optical signal into a fourth data stream;
second circuitry coupled to the optical receiver, the second circuitry configured to recover second Ethernet data from the second optical signal; and
an Ethernet data transmitter coupled to the second circuitry and configured to transmit the second Ethernet data to the external device. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A return path transmitter for use in conjunction with first and second local systems that generate first and second respective analog RF data signals to be conveyed to a head end system, the return path transmitter comprising:
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first and second RF signal receivers configured to receive and convert the first and second respective analog RF data signals into digitized RF data samples, the first and second RF signal receivers further configured to output the digitized RF data samples in first and second data streams;
an Ethernet data receiver configured to receive first Ethernet data from a device external to the return path transmitter, the Ethernet data receiver configured to output the first Ethernet data in a third data stream;
first circuitry coupled to the RF signal receivers and the Ethernet data receiver to receive and process the first, second and third data streams and to output a combined data stream;
an optical transmitter configured to convert the combined data stream into a first optical data signal for transmission over an optical fiber;
an optical receiver configured to receive a second optical signal over the optical fiber, the optical receiver configured to convert the second optical signal into a fourth data stream;
second circuitry coupled to the optical receiver, the second circuitry configured to recover second Ethernet data from the second optical signal; and
an Ethernet data transmitter coupled to the second circuitry and configured to transmit the second Ethernet data to the external device. - View Dependent Claims (8, 9, 10, 11, 12)
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13. An Ethernet connection device for use in conjunction with an RF signal receiver for a local system that generates an analog RF data signal to be conveyed to a head end system, the Ethernet data transmitter comprising:
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an Ethernet data receiver configured to receive first Ethernet data from a device external to the Ethernet connection device and the return path transmitter, the Ethernet data receiver configured to output the first Ethernet data in a first data stream;
an optical transmitter configured to convert the first Ethernet data to a first optical data signal for transmission over an optical fiber to the head end system;
an optical receiver configured to receive a second optical signal from the optical fiber, the optical receiver configured to convert the second optical signal to a second data stream;
second circuitry coupled to the optical receiver, the second circuitry configured to recover second Ethernet data and control information for the RF signal receiver from the second data stream, the second circuitry further configured to provide the control information to the RF signal receiver; and
an Ethernet data transmitter coupled to the second circuitry and configured to transmit the second Ethernet data to the external device.
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14. A transceiver card for use in a head end system of a Cable Television (CATV) system, the transceiver card comprising:
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a signal receiver for receiving a digital input signal and recovering therefrom a first data stream having an associated first data rate and a second data stream having an associated second data rate that is different from the first data rate;
the first data stream comprising a sequence of data frames, each data frame having RF data representative of a sequence of samples of an RF signal, each data frame further having Ethernet data;
a first memory device configured to store the RF data;
a second memory device configured to store the Ethernet data;
a third memory device configured to store the second data stream;
a demultiplexer for receiving the digital input signal, identifying the RF data in the first data stream and storing the RF data in the first memory device, identifying the Ethernet data in the first data stream and storing the Ethernet data in the second memory device, identifying data in the digital data stream comprising the second data stream and storing the second data stream in the second memory device;
a clock generator for generating a local sample clock having an associated sample clock rate;
first logic circuitry for reading data from the first memory device at a rate corresponding to the sample clock rate so as to regenerate the sequence of samples of the RF signal represented by the sequence of data frames comprising the first data stream;
a digital to analog converter for converting the regenerated sequence of samples at the sample clock rate into an analog signal comprising a regenerated version of the RF signal; and
second logic circuitry configured to read the Ethernet data from the second memory device and transmit the Ethernet data to a device external to the transceiver card. - View Dependent Claims (15, 16)
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17. A transceiver card for use in a head end system of a Cable Television (CATV) system, the transceiver card comprising:
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a signal receiver for receiving a digital input signal and recovering therefrom a digital data stream and an associated first clock having an associated first clock rate, the digital data stream including first, second and third data streams, the first data stream comprising a first sequence of first data frames, each first data frame having first RF data representative of a sequence of samples of a first RF signal, the second data stream comprising a second sequence of second data frames, each second data frame having second RF data representative of a sequence of samples of a second RF signal, wherein at least a subset of the first data frames and the second data frames include Ethernet data;
a first memory device configured to store the first RF data;
a second memory device configured to store the second RF data;
a third memory device configured to store the Ethernet data;
a demultiplexer configured to receive the digital data stream, to identify the first RF data in the first data frames and store the first RF data in the first memory device, to identify the second RF data in the second data frames and store the second RF data in the second memory device, and to identify the Ethernet data and store the Ethernet data in the third memory device;
a clock generator for generating a local sample clock having an associated sample clock rate;
first logic circuitry for simultaneously reading data from the first and second memory devices at a rate corresponding to the sample clock rate so as to regenerate the sequence of samples of the first RF signal represented by the sequence of first data frames comprising the first data stream and the sequence of samples of the second RF signal represented by the sequence of second data frames comprising the second data stream;
a first digital to analog converter for converting the regenerated sequence of samples of the first RF signal at the sample clock rate into an analog signal comprising a regenerated version of the first RF signal; and
a second digital to analog converter for converting the regenerated sequence of samples of the second RF signal at the sample clock rate into an analog signal comprising a regenerated version of the second RF signal; and
second logic circuitry configured to read the Ethernet data from the third memory device and transmit the Ethernet data to a device external to the transceiver card. - View Dependent Claims (18, 19, 20)
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Specification