System and method for spectral node splitting in a hybrid fiber optic-coaxial cable network

• US 7,209,497 B2
• Filed: 11/26/2001
• Issued: 04/24/2007
• Est. Priority Date: 11/26/2001
• Status: Expired due to Fees

• Current Assignee: ATX Networks Incorporated (United Communications Group, Inc.)
• Original Assignee: Xtend Networks Ltd. (National Vision Holdings, Inc.)
• Inventors: Weinstein, Hillel, Orbach, Zeev
• Primary Examiner(s): Jung; Min
• Application Number:
  US10/497,064
• Publication Number:
  US 20050063424A1
• Time in Patent Office: 1,975 Days
• Field of Search: 370/535, 370/537, 725/127, 725/119, 725/149, 398/66, 398/116
• US Class Current: 370/535
• CPC Class Codes: H04H 20/69 Optical systems
• CPC Class Codes: H04H 60/97 using uplink of the CATV systems
• 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 7/10 Adaptations for transmission by electrical cable H04N7/12 takes precedence
• CPC Class Codes: H04N 7/104 Switchers or splitters
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission

Abstract

A system and method for spectral node splitting in cable TV network based on hybrid fiber-coax architecture is disclosed. Two-way optical signals carrying video and/or multimedia content are received at a signal distribution node. Portions of the received signals are processed according to the functionality the direction thereof. Certain frequency ranges are passed intact while specific different downstream and specific different upstream frequency bands are converted in a manner as to be allowed to be multiplexed into an extended broadband signal. The frequency bands within the extended broadband signal are distributed selectively among separate branches of the network. The frequency bands dedicated to the upstream traffic are received selectively from the separate network branches to be back converted and transmitted upstream to the network controller.

Claims

1. In a communications network accommodating at least two subscribers linked via at least one communications network branch to at least one content distribution unit, the content distribution unit feeding a two-way radio frequency signal to the at least one communications network branch, a system of spectrally splitting the at least one distribution unit in order to replace the at least one communications network branch by at least two separate communications network branches, the system comprising the elements of:

at least one extended converter unit to receive via an at least one optical signal conduit an at least one two-way optical signal carrying content information having a pre-determined transmission frequency bandwidth, to form a RF signal having a substantially extended transmission spectrum bandwidth, to convert pre-determined downstream portions of the at least one two-way optical signal into at least two different pre-determined RF transmission frequency bands, and to introduce the at least two converted different RF bands into a multiplexed downstream RF signal having a substantially extended transmission spectrum bandwidth; and

at least two extended broadband amplifiers to selectively pass at least two pre-determined RF bands from the multiplexed RF signal having a substantially extended transmission spectrum bandwidth downstream to the at least two different communications network branches; and

at least one back converter unit to receive via the at least one communications network branch at least one branch-specific RF signal, to extract from the at least one branch-specific RF at least one predetermined upstream frequency band, to convert the at least one branch-specific upstream RF band to a predetermined upstream frequency band, and to introduce the converted upstream RF band into the multiplexed RF signal having a substantially extended transmission bandwidth to be delivered upstream to the at least one content distribution unit.

2. The system of claim 1 wherein, the at least one extended converter unit comprises the elements of:

a first converter unit to convert the first predetermined frequency band associated with the at least one optical signal into the first RF band and to introduce the first converted RF band into the multiplexed RF signal having a substantially extended frequency bandwidth; and

a second converter unit to convert the second predetermined frequency band associated with the at least one optical signal into the second RF band and to introduce the second converted RF band into the multiplexed RF signal having a substantially extended frequency bandwidth; and

a third converter unit to convert the third predetermined frequency band associated with the at least one optical signal into the third RF band and to introduce the third converted RF band into the multiplexed RF signal having a substantially extended frequency bandwidth.

3. The system of claim 2, wherein the at least one extended converter unit further comprises the elements of:

a first splitter unit to separate the first, the second, and the third upstream frequency bands; and

a second splitter unit to combine the first, the second, and the third up-converted downstream frequency bands; and

a CATV amplifier unit to drive a CATV signal into the first converter unit.

4. The system of claim 2 wherein, the first converter unit comprises the elements of:

a triplexer unit to multiplex the up-converted downstream frequency bands and the CATV signal into a multiplexed extended signal and to de-multiplex the upstream frequency bands from the multiplexed extended signal; and

an upstream amplifier unit to drive the first upstream frequency band; and

an upstream filter unit for filtering the first upstream frequency band; and

an upstream frequency converter unit to down-convert the first upstream frequency band; and

a downstream frequency converter unit to up-convert the first downstream frequency band; and

a downstream filter unit for filtering the first downstream frequency band; and

a downstream amplifier unit to drive the combined downstream frequency bands; and

a voltage controlled oscillator to control the upstream frequency controller and the downstream frequency controller.

5. The system of claim 2 wherein, the second converter unit comprises elements substantially identical to the elements constituting the first converter unit.

6. The system of claim 5 wherein the operational parameters associated with the elements of the second converter unit are pre-determined for the appropriate handling of the second downstream band and the second upstream band.

7. The system of claim 2 wherein the third converter unit comprises elements substantially identical to the elements constituting the first converter unit.

8. The system of claim 7 wherein the operational parameters associated with the elements of the third converter unit are pre-determined for the appropriate handling of the third downstream band and the third upstream band.

9. The system of claim 1, wherein the at least one extended back converter unit comprises the elements of:

a first back converter unit to extract the first upstream frequency band from the first branch-specific frequency spectrum, to convert the first upstream frequency band and to introduce the first converted upstream frequency band into the multiplexed extended frequency band to be delivered to the at least one distribution unit; and

a second back converter unit to extract the second upstream frequency band from the second branch-specific frequency spectrum, to convert the second upstream frequency band and to introduce the second converted upstream frequency band into the multiplexed extended frequency band to be delivered to the at least one distribution unit; and

a third back converter unit to extract the third upstream frequency band from the third branch-specific frequency spectrum, to convert the third upstream frequency band and to introduce the third converted upstream frequency band into the multiplexed extended frequency band to be delivered to the at least one distribution unit.

10. The system of claim 9 wherein, the first back-converter unit comprises elements substantially identical to the elements constituting the extended converter unit.

11. The system of claim 10 wherein, the second back-converter unit comprises elements substantially identical to the elements constituting the first back-converter converter unit.

12. The system of claim 11 wherein, the third back-converter unit comprises elements substantially identical to the elements constituting the first back-converter converter unit.

13. The system of claim 11 wherein the operational parameters associated with the elements of the second back-converter unit are pre-determined for the appropriate handling of the second downstream band and the second upstream band.

14. The system of claim 12 wherein the operational parameters associated with the elements of the third back-converter unit are pre-determined for the appropriate handling of the third downstream band and the third upstream band.

15. The system of claim 1 wherein the communications network is a cable TV system based on a hybrid fiber-optic infrastructure.

16. The system of claim 1 wherein the communications network is a satellite communications network.

17. The system of claim 1 wherein the communications network is a Local Area Network network.

18. The system of claim 1 wherein the communications network is a Wide Area Network.

19. The system of claim 1 wherein the extended converter unit comprises one or more converter units.

20. In a communication network accommodating at least two subscribers linked via at least one communications network branch to at least one content distribution unit, the content distribution unit feeding a two-way RF signal to the at least one communications network branch, a method of spectrally splitting the at least one content distribution unit in order to replace the at least one communications network branch by at least two separate communications network branches, the method comprising the steps of:

receiving at least two optical signals carrying encoded content information in at least two predefined different downstream frequency bands; and

converting the at least two pre-defined downstream frequency band to at least two pre-determined converted frequency band within the combined broadband signal; and

converting the at least two pre-defined upstream frequency band to the at least two pre-determined frequency band within the combined broadband signal; and

multiplexing the CATV signal and the at least two converted downstream frequency band into a combined broadband signal having a substantially extended frequency range; and

selectively distributing the converted downstream frequency bands within the combined broadband signal to separate communications network branches; and

selectively receiving at least two upstream frequency bands included in the combined broadband signal and transmitted from separate communications network branches; and

converting the at least two upstream frequency bands to pre-defined frequency bands.

21. The method of claim 20 further comprises the steps of:

determining the size and the frequency ranges of the converted downstream frequency bands in the combined broadband signal; and

determining the size and the frequency ranges of the converted upstream frequency ranges in the combined broadband signal.

22. The method of claim 20 further comprises the steps of:

receiving an optical signal containing an encoded CATV signal in a pre-defined frequency band; and

distributing the CATV portion of the combined broadband signal into separate communications network branches; and

transmitting the converted upstream frequency bands to the network plant.

23. The method of claim 20 wherein the combined broadband signal is having an extended frequency range of about 5 MHz to 3 GHz.

24. The method of claim 20, wherein the converted downstream frequency ranges are multiplexed into the combined broadband signal over a frequency range of about 1 GHz to 2 GHz.

25. The method of claim 20 wherein the converted upstream frequency ranges are multiplexed into the combined broadband signal over a frequency range of about 2 GHz to 3 GHz.

26. The method of claim 20 wherein the combined broadband signal is formed by attaching to the CATV transmission spectrum of about 5 to 860 MHz a supplementary frequency band of about 1 to 2 GHz to hold the converted downstream frequency ranges and the converted upstream frequency ranges.

27. The method of claim 20 wherein the downstream frequency bands are allocated a frequency bandwidth of about 160 MHz to 200 MHz.

28. The method of claim 20 wherein the upstream frequency bands are allocated a frequency bandwidth of about 30 MHz.