HFC CABLE SYSTEM WITH ALTERNATIVE WIDEBAND COMMUNICATIONS PATHWAYS AND COAX DOMAIN AMPLIFIER-REPEATERS

• US 20130332978A1
• Filed: 08/12/2013
• Published: 12/12/2013
• Est. Priority Date: 01/22/2010
• Status: Active Grant

• Current Assignee: Vecima Networks Incorporated
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Rakib, Shlomo Selim
• Granted Patent: US 9,521,464 B2
• Time in Patent Office: Days
• US Class Current: 725/127
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/106 for domestic distribution

Abstract

System and method to extend the data carrying capacity of a hybrid fiber cable (HFC) network by adding wideband RF signal capability above 1 GHz, and replacing the CATV amplifier devices with an improved type of Coax Domain Amplifier-Repeater (CDAR) device that, in addition to being a smart reconfigurable amplifier and cable signal diagnostic device, also segments the CATV cable portion of the HFC network into a series of smaller domains. The CDAR often alter RF signals from 5-865 MHz, while more freely passing RF signals over 1 GHz. Upstream capability is enhanced because the CDAR intercept 5-42 MHz upstream signals from each domain and convert to 1 GHz+ signals. Downstream capability is also enhanced because the CDAR can take efficiently encoded 1 GHz+ digital data, modulate it, and locally inject into each domain without crosstalk between domains. CDAR can use active cancellation, and active restoration techniques to improve performance.

Claims

1. A method of selectively repeating RF signals carried by a hybrid fiber cable (HFC) network with a cable head end, at least one optical fiber, at least one optical fiber node terminating on at least one CATV cable, said CATV cable connected to a plurality of branch CATV cables thus forming a CATV Tree and Branch Network, and a plurality of communication devices connected to said CATV Tree and Branch Network,

said RF signals comprising upstream RF signals with frequencies less than approximately 1 GHz, downstream RF signals with frequencies less than 1 GHz, upstream RF signals with frequencies greater than approximately 1 GHz, and downstream RF signals with frequencies greater than approximately 1 GHz;

wherein at least some of said communications devices receive downstream RF signals at frequencies less than approximately 1 GHz, and wherein at least some of said communications devices further transmit upstream RF signals at frequencies less than approximately 1 GHz;

said method comprising;

placing at least one coax domain amplifier-repeater comprising at least one processor at junctions in said at least one CATV cable, thereby partitioning said CATV cable into cable segments between said at least one coax domain amplifier-repeater, at least some of said cable segments connected to at least some of said communications devices;

and using said at least one coax domain amplifier-repeater to perform the functions of;

A;

receiving, gain adjusting, and retransmitting downstream RF signals with frequencies greater than approximately 1 GHz as downstream RF signals with frequencies greater than approximately 1 GHz;

B;

receiving, gain adjusting, and retransmitting upstream RF signals with frequencies greater than approximately 1 GHz as upstream RF signals with frequencies greater than approximately 1 GHz;

C;

receiving, gain adjusting, and retransmitting at least some downstream RF signals with frequencies less than approximately 1 GHz as downstream RF signals with frequencies less than approximately 1 GHz;

D;

receiving upstream RF signals with frequencies less than approximately 1 GHz, and either gain adjusting and retransmitting them as either upstream RF signals at the same frequency, or cancelling them and instead retransmitting either their information or their waveforms as upstream RF signals at a higher frequency.

2. The method of claim 1, wherein said coax domain amplifier-repeater additionally comprises at least one software controlled processor configured to receive control commands transmitted over said CATV cable;

wherein the functions of C;

receiving, gain adjusting, and retransmitting at least some downstream RF signals with frequencies less than approximately 1 GHz as downstream RF signals with frequencies less than approximately 1 GHz, further comprise;

active cancelling, and thereby not retransmitting, a cancellable set of selected narrowcast downstream RF signals with frequencies less than approximately 1 GHz;

wherein the functions of A;

receiving and retransmitting downstream RF signals with frequencies greater than approximately 1 GHz as downstream RF signals with frequencies greater than approximately 1 GHz, further comprise;

additionally receiving and retransmitting the information or waveforms from a substitution set of narrowcast downstream RF signals with frequencies greater than approximately 1 GHz as selected narrowcast downstream RF signals with frequencies less than approximately 1 GHz;

wherein said substitution set of narrowcast downstream RF signals are selected by said software controlled processor and said control commands.

3. The method of claim 2, wherein said active cancellation is done using information or waveforms carried by downstream RF signals with frequencies greater than approximately 1 GHz.

4. The method of claim 1, wherein:

the functions of D;

receiving upstream RF signals with frequencies less than approximately 1 GHz, and either gain adjusting and retransmitting them as either upstream RF signals at the same frequency, or cancelling them and instead retransmitting either their information or their waveforms as upstream RF signals at a higher frequency, further comprise;

receiving said upstream RF signals with frequencies less than approximately 1 GHz, cancelling them, frequency shifting them, and retransmitting them as upstream RF signals with frequencies greater than approximately 1 GHz.

5. The method of claim 1, wherein:

the functions of D;

receiving upstream RF signals with frequencies less than approximately 1 GHz, either gain adjusting and retransmitting as either upstream RF signals at the same frequency, or cancelling them and instead retransmitting either their information or their waveforms as upstream RF signals at a higher frequency, further comprise;

receiving said upstream RF signals with frequencies less than approximately 1 GHz, cancelling them, frequency shifting them, and retransmitting them as upstream RF signals with frequencies less than approximately 1 GHz but greater than 860 MHz.

6. The method of claim 1, wherein:

said downstream RF signals with frequencies less than approximately 1 GHz comprise border downstream RF signals with frequencies that are adjacent to said upstream RF signals with frequencies less than approximately 1 GHz;

further transmitting at least some of the information or waveforms contained in said border downstream RF signals as border cancellation information or waveforms using RF signals with frequencies greater than approximately 1 GHz; and

further using said border cancellation information or waveforms to actively cancel the border downstream RF signals prior to receiving said upstream RF signals with frequencies less than 1 GHz.

7. The method of claim 6, wherein:

step D;

receiving upstream RF signals with frequencies less than approximately 1 GHz, and either gain adjusting and retransmitting as either upstream RF signals at the same frequency, or cancelling them and instead retransmitting either their information or their waveforms as upstream RF signals at a higher frequency;

further comprises using said border cancellation information or waveforms to adaptively restore said upstream RF signals prior to retransmitting either their information or their waveforms at either the same frequency or higher frequency.

8. The method of claim 1, wherein said at least one optical fiber node comprises a local optical fiber node most directly connected to the CATV cable proximate said at least one coax domain amplifier-repeater;

and wherein said at least one amplifier repeater is further configured with both a node-facing cable connection that disposed in the RF signal origination direction of said local optical fiber node, and a rear-facing cable connection disposed away from the RF signal origination direction of said local optical fiber node;

wherein said at least one coax domain amplifier-repeater is configured to use said node-facing cable connection to receive downstream RF signals, and to use said rear-facing cable connection to retransmit downstream RF signals further downstream away from said local optical fiber node; and

wherein said coax domain amplifier-repeater is configured to use said rear-facing cable connection to receive upstream RF signals, and to use said node-facing cable connection to retransmit upstream RF signals further upstream towards said local optical fiber node.

9. The method of claim 1, wherein at least some of said retransmitted downstream RF signals or retransmitted upstream RF signals are retransmitted by said at least one coax domain amplifier-repeater with an adjusted RF signal intensity designed to overcome RF signal impairments on said CATV coax cable.

10. The method of claim 1, wherein said at least one optical fiber node comprises a local optical fiber node most directly connected to the CATV cable proximate said at least one coax domain amplifier-repeater;

further using said at least one amplifier repeater to analyze at least some of the received downstream RF signals or at least some of the received upstream RF signals for the effects of CATV cable induced spectrum attenuation or noise sources, and transmitting information pertaining to the effects of said spectrum attenuation or noise sources upstream over said CATV cable towards said local optical fiber node.

11. The method of claim 1, wherein said at least one coax domain amplifier-repeater uses information or waveforms derived from 1 GHz RF signals, and echo cancellation techniques, to correct at least some of the downstream RF signals or upstream RF signals for CATV cable caused signal distortion either prior to receiving or prior to transmitting.

12. The method of claim 1, wherein at least some of said coax domain amplifier-repeater devices additionally are connected to at least one HFC optical fiber;

Further using said HFC optical fiber to receive or transmit 1 GHz+ information or signals to and from said coax domain amplifier-repeater devices.

13. A method of selectively repeating RF signals carried by a hybrid fiber cable (HFC) network with a cable head end, at least one optical fiber, at least one optical fiber node terminating on at least one CATV cable, said CATV cable connected to a plurality of branch CATV cables thus forming a CATV Tree and Branch Network, and a plurality of communication devices connected to said CATV Tree and Branch Network,

said RF signals comprising upstream RF signals with frequencies less than approximately 1 GHz, downstream RF signals with frequencies less than 1 GHz, upstream RF signals with frequencies greater than approximately 1 GHz, and downstream RF signals with frequencies greater than approximately 1 GHz;

wherein at least some of said communications devices receive downstream RF signals at frequencies less than approximately 1 GHz, and wherein at least some of said communications devices further transmit upstream RF signals at frequencies less than approximately 1 GHz;

wherein said coax domain amplifier-repeater additionally comprises at least one software controlled processor configured to receive control commands transmitted over said CATV cable;

said method comprising;

placing at least one coax domain amplifier-repeater comprising at least one processor at junctions in said at least one CATV cable, thereby partitioning said CATV cable into cable segments between said at least one coax domain amplifier-repeater, at least some of said cable segments connected to at least some of said communications devices;

and using said at least one coax domain amplifier-repeater to perform the functions of;

A;

receiving, gain adjusting, and retransmitting downstream RF signals with frequencies greater than approximately 1 GHz as downstream RF signals with frequencies greater than approximately 1 GHz;

additionally receiving and retransmitting the information or waveforms from a substitution set of narrowcast downstream RF signals with frequencies greater than approximately 1 GHz as selected narrowcast downstream RF signals with frequencies less than approximately 1 GHz;

wherein said substitution set of narrowcast downstream RF signals are selected by said software controlled processor and said control commands;

B;

receiving, gain adjusting, and retransmitting upstream RF signals with frequencies greater than approximately 1 GHz as upstream RF signals with frequencies greater than approximately 1 GHz;

C;

receiving, gain adjusting, and retransmitting at least some downstream RF signals with frequencies less than approximately 1 GHz as downstream RF signals with frequencies less than approximately 1 GHz;

active cancelling, and thereby not retransmitting, a cancellable set of selected narrowcast downstream RF signals with frequencies less than approximately 1 GHz;

wherein said active cancellation is done using information or waveforms carried by downstream RF signals with frequencies greater than approximately 1 GHz;

D;

receiving said upstream RF signals with frequencies less than approximately 1 GHz, cancelling them, frequency shifting them, and gain adjusting and retransmitting them as upstream RF signals with frequencies greater than approximately 1 GHz.

14. The method of claim 13, wherein:

the functions of D;

receiving upstream RF signals with frequencies less than approximately 1 GHz, either gain adjusting and retransmitting as either upstream RF signals at the same frequency, or cancelling them and instead retransmitting either their information or their waveforms as upstream RF signals at a higher frequency, further comprise;

receiving said upstream RF signals with frequencies less than approximately 1 GHz, cancelling them, frequency shifting them, and retransmitting them as upstream RF signals with frequencies less than approximately 1 GHz but greater than 860 MHz.

15. The method of claim 13, wherein:

said downstream RF signals with frequencies less than approximately 1 GHz comprise border downstream RF signals with frequencies that are adjacent to said upstream RF signals with frequencies less than approximately 1 GHz;

further transmitting at least some of the information or waveforms contained in said border downstream RF signals as border cancellation information or waveforms using RF signals with frequencies greater than approximately 1 GHz; and

further using said border cancellation information or waveforms to actively cancel the border downstream RF signals prior to receiving said upstream RF signals with frequencies less than 1 GHz.

16. The method of claim 15, wherein:

step D;

receiving upstream RF signals with frequencies less than approximately 1 GHz, and either gain adjusting and retransmitting as either upstream RF signals at the same frequency, or cancelling them and instead retransmitting either their information or their waveforms as upstream RF signals at a higher frequency;

further comprises using said border cancellation information or waveforms to adaptively restore said upstream RF signals prior to retransmitting either their information or their waveforms at either the same frequency or higher frequency.

17. The method of claim 13, wherein said at least one optical fiber node comprises a local optical fiber node most directly connected to the CATV cable proximate said at least one coax domain amplifier-repeater;

and wherein said at least one amplifier repeater is further configured with both a node-facing cable connection that disposed in the RF signal origination direction of said local optical fiber node, and a rear-facing cable connection disposed away from the RF signal origination direction of said local optical fiber node;

wherein said at least one coax domain amplifier-repeater is configured to use said node-facing cable connection to receive downstream RF signals, and to use said rear-facing cable connection to retransmit downstream RF signals further downstream away from said local optical fiber node; and

wherein said coax domain amplifier-repeater is configured to use said rear-facing cable connection to receive upstream RF signals, and to use said node-facing cable connection to retransmit upstream RF signals further upstream towards said local optical fiber node.

18. The method of claim 13, wherein at least some of said retransmitted downstream RF signals or retransmitted upstream RF signals are retransmitted by said at least one coax domain amplifier-repeater with an adjusted RF signal intensity designed to overcome RF signal impairments on said CATV coax cable.

19. The method of claim 13, wherein said at least one optical fiber node comprises a local optical fiber node most directly connected to the CATV cable proximate said at least one coax domain amplifier-repeater;

further using said at least one amplifier repeater to analyze at least some of the received downstream RF signals or at least some of the received upstream RF signals for the effects of CATV cable induced spectrum attenuation or noise sources, and transmitting information pertaining to the effects of said spectrum attenuation or noise sources upstream over said CATV cable towards said local optical fiber node.

20. The method of claim 13, wherein said at least one coax domain amplifier-repeater uses information or waveforms derived from 1 GHz RF signals, and echo cancellation techniques, to correct at least some of the downstream RF signals or upstream RF signals for CATV cable caused signal distortion either prior to receiving or prior to transmitting.