Subcarrier modulation fiber-to-the-home/curb (FTTH/C) access system providing broadband communications

• US 6,577,414 B1
• Filed: 02/19/1999
• Issued: 06/10/2003
• Est. Priority Date: 02/20/1998
• Status: Expired due to Term

• Current Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Feldman, Robert D., Stiles, John A., Wilson, Gordon C., Wood, Thomas H.
• Primary Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US09/253,823
• Time in Patent Office: 1,572 Days
• Field of Search: 359/125, 359/167-168, 725/129
• US Class Current: 398/43
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0232 for downstream transmission
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 14/0283 WDM ring architectures
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring

Abstract

A passive optical network is provided that integrates signals carrying broadcast CATV services into a FTTH/C network that also provides high-speed Internet access and telephony. Essentially all residential telecommunications services are provided in a single network, based on a single fiber and a single simple transceiver in an optical network unit. Multiple services (e.g., analog video, digital video, cable-modem based Internet access) are multiplexed using separate rf subcarriers (subcarrier multiplexing or SCM) and the delivered signals are compatible with existing consumer appliances (e.g., TVs, VCRs, cable modems, etc.). The system and method combines a bi-directional network with dedicated upstream and downstream networks so that the most expensive and extensive portion of the network (the bi-directional outside plant infrastructure) need not be duplicated for each direction, while the use of two separate dedicated upstream and downstream networks further upstream facilitates flexible provisioning of bandwidth for each direction independently.

Claims

1. A method of delivering CATV and data signals in both an upstream and downstream direction between a headend and a service subscriber, comprising the steps of:

combining said CATV and data signals from said headend into a composite optical signal using coarse wavelength division multiplexing of two wavelengths within the same band, a first of said wavelengths being associated with said CATV signals and a second of said wavelengths being associated with said data signals;

transmitting said composite optical signal downstream over a passive optical network (PON) using coarse wavelength division multiplexing (CWDM) to separate said downstream transmission from any upstream transmissions;

converting said transmitted downstream composite optical signal to electrical signals; and

routing said electrical signals to said service subscriber for use.

2. A method as set forth in claim 1, wherein said combining step comprises the steps of:

modulating said CATV and said data signals onto subcarriers; and

combining said modulated CATV signals and said data signals into said composite optical signal via an optical combiner.

3. A method as set forth in claim 2, wherein said transmitting step comprises the step of dividing said composite optical signal into a plurality of identical composite optical signals for routing to different service subscribers.

4. A method as set forth in claim 3, further comprising the step of performing demultiplexing, ranging, and/or media access control (MAC) on said electrical signal routed to a subscriber using customer provided equipment (CPE) located in the subscriber premises.

5. A method as set forth in claim 4, further comprising the step of transmitting an upstream signal from said service subscriber to said headend using CWDM.

6. A method as set forth in claim 5, wherein said upstream transmission step comprises the steps of:

routing a first upstream electrical signal from said service subscriber to an optical-electrical converter;

converting said upstream electrical signal to an upstream optical signal;

transmitting said upstream optical signal over said PON using CWDM to separate said upstream transmission from any downstream transmissions;

converting said upstream optical signal back to a second upstream electrical signal; and

routing said second upstream electrical signal to said headend.

7. A method as set forth in claim 1, wherein said CATV signals include analog and digital broadcast television signals.

8. A method as set forth in claim 7, wherein said digital broadcast television signals are compressed to MPEG-2 format.

9. A method as set forth in claim 7, wherein said analog broadcast television signals are modulated using amplitude modulation with vistidual sideband (AM-VSB).

10. A method as set forth in claim 6, wherein said composite optical signal transmitted downstream has a wavelength of approximately 1550 nm and wherein said upstream optical signal has a wavelength of approximately 1310 nm.

11. A method as set forth in claim 1, wherein said converting step occurs on the premises of said service subscriber.

12. A method of delivering downstream CATV and data signals from a headend to a service subscriber, and for delivering upstream data signals from said service subscriber to said headend, comprising the steps of:

transmitting said downstream CATV and data signals from said headend along a dedicated downstream network to a combining node;

combining said CATV and data signals into a composite downstream optical signal and transmitting said composite downstream optical signal over a bi-directional passive optical network (PON) using coarse wavelength division multiplexing (CWDM) to separate said composite downstream optical signal from any upstream optical signals;

converting said downstream composite optical signal to downstream electrical signals;

routing said downstream electrical signals to said service subscriber for use;

wherein said combining is performed using coarse wavelength division multiplexing of two wavelengths within the same band, a first of said wavelengths being associated with said CATV signals and a second of said wavelengths being associated with said data signals.

13. A method as set forth in claim 12, wherein said upstream data signals are delivery to said headend from said service subscriber according to the following steps:

routing a first upstream electrical signal from said service subscriber to said optical-electrical converter;

converting said upstream electrical signal to an upstream optical signal;

transmitting said upstream optical signal over said bi-directional PON using CWDM to separate said upstream optical signal from any downstream optical signals;

converting said upstream optical signal to a second upstream electrical signal; and

routing said second upstream electrical signal to said headend along a dedicated upstream network.

14. A method as set forth in claim 13, wherein said converting steps occur on the premises of said service subscriber.

15. An apparatus for delivering CATV and data signals from a headend to a service subscriber, comprising:

an optical combiner connected to receive said CATV and data signals from said headend said optical combiner using coarse wavelength division multiplexing of two wavelengths within the same band, a first of said wavelengths being associated with said CATV signals and a second of said wavelengths being associated with said data signals;

a passive optical network (PON) connected to receive output from said optical combiner; and

an optical-electrical converter (OEC) connected to said PON, wherein said CATV and data signals are combined into a composite downstream optical signal and transmitted via said PON to said OEC using coarse width division multiplexing (CWDM), to separate said composite downstream optical signal from any upstream optical signals, and then delivered to said service subscriber for use.

16. An apparatus as set forth in claim 15, further comprising:

a receiver connected between said PON and said headend, said receiver receiving upstream signals from said service subscriber via said PON and routing said received upstream signals to said headend.

17. An apparatus for delivering CATV and data signals to a subscriber, comprising:

a headend;

a hub connected to said headend, said hub including a dedicated downstream network using coarse width division multiplexing to combine said CATV and data signals using two wavelengths within the same band, a first of said wavelengths being associated with said CATV signals and a second of said wavelengths being associated with said data signals and a dedicated upstream network using coarse width division multiplexing (CWDM) to separate said CATV and data signals from any upstream signals;

a passive optical network (PON) connected to said hub;

an optical-electrical converter (OEC) connected to said PON; and

customer provided equipment (CPE) connected to an output of said OEC, said CPE performing demultiplexing, ranging, and/or media access control (MAC) on a downstream signal transmitted from said headend.

18. An apparatus as set forth in claim 17, wherein said OEC is attached directly to the premises of said subscriber.

19. An apparatus as set forth in claim 17, wherein said hub comprises:

means for amplifying said CATV and data signals; and

means for combining said amplified CATV and data signals into a single composite optical signal for transmission over said PON using CWDM.

20. An apparatus as set forth in claim 19, wherein said hub further comprises a coarse wavelength division multiplexer for transmitting said single composite optical signal over said PON separate from any upstream signals.

21. An apparatus for delivering CATV and data signals to a subscriber, comprising:

a headend;

a hub connected to said headend, said hub including a dedicated downstream network and a dedicated upstream network;

a passive optical network (PON) connected to said hub;

an optical-electrical converter (OEC) connected to said PON; and

customer provided equipment (CPE) connected to an output of said OEC, said CPE performing demultiplexing, ranging, and/or media access control (MAC) on a downstream signal transmitted from said headend;

and wherein said hub further comprises;

means for amplifying said CATV and data signals;

means for combining said amplified CATV and data signals into a single composite optical signal for transmission over said PON;

a coarse wavelength division multiplexer for transmitting said single composite optical signal over said PON;

an upstream optical combiner coupled to said coarse wavelength division multiplexer;

a receiver connected to an output of said upstream optical combiner; and

a demodulator coupled to an output of said receiver, whereby an upstream signal transmitted across said PON from said subscriber is directed by said coarse wavelength division multiplexer to said upstream optical combiner and received by said receiver, where it is routed to said demodulator for conversion to an electrical signal and delivery to said headend.

22. An apparatus for delivering CATV and data signals to a subscriber, comprising:

a headend;

a hub connected to said headend, said hub including a dedicated downstream network and a dedicated upstream network;

a passive optical network (PON) connected to said hub;

an optical-electrical converter (OEC) connected to said PON; and

customer provided equipment (CPE) connected to an output of said OEC, said CPE performing demultiplexing, ranging, and/or media access control (MAC) on a downstream signal transmitted from said headend;

and wherein said hub further comprises;

means for amplifying said CATV and data signals; and

means for combining said amplified CATV and data signals into a single composite optical signal for transmission over said PON.