Single wire return device in a fiber to the home system

• US 7,596,801 B2
• Filed: 09/25/2003
• Issued: 09/29/2009
• Est. Priority Date: 01/21/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Versteeg, William C., Wall, William E.
• Primary Examiner(s): Beliveau; Scott
• Assistant Examiner(s): LUONG, ALAN H
• Application Number:
  US10/671,151
• Publication Number:
  US 20050044576A1
• Time in Patent Office: 2,196 Days
• Field of Search: 725/105, 725/114, 725/127, 725/128, 725/129, 370/206, 370/485, 398/71, 398/138, 398/72, 398/79
• US Class Current: 725/129
• CPC Class Codes: H04H 20/69 Optical systems
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2885 Arrangements interfacing with optical systems optical network equipment H04B10/00; optical multiplexers H04J14/05 and H04J14/07
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 5/02 Channels characterised by the type of signal
• CPC Class Codes: H04N 7/173 with two-way working, e.g. subscriber sending a programme selection signal

Abstract

Systems and methods are disclosed for providing reverse signals from a plurality of DHCTs to a downstream modulator that is located in the headend facility. The present invention includes a single wire return device (SWRD) that receives RF modulated signals, dynamically determines the address of the associated modulator, and converts the signals into Ethernet signals. The Ethernet signals are subsequently provided to the headend facility via fiber cable.

Claims

1. A fiber-to-the home (FTTH) system, comprising:

at least one digital home communications terminal (DHCT) for receiving forward signals from a headend facility and for transmitting reverse RF signals to the headend facility, the reverse RF signals including header information and payload data;

a single wire and return device (SWRD) for receiving the reverse RF signals from the at least one DHCT, demodulating the reverse RF signals via an upstream demodulator, and converting the demodulated signals to Ethernet signals;

an optical network terminal (ONT) coupled to the SWRD for converting the Ethernet signals to optical signals, and for transmitting the optical signals to the headend facility via optical fiber; and

a plurality of downstream modulators located in the headend facility remote from the upstream demodulator with each downstream modulator associated with at least one corresponding DHCT and having an identification number that is inserted into the forward signals from the headend facility to identify that downstream modulator to the at least one corresponding DHCT, one of the downstream modulators associated with the at least one DHCT for receiving signals corresponding to the optical signals and for sending the forward signals downstream to the at least one corresponding DHCT via the ONT;

wherein the at least one DHCT inserts the modulator identification number received within the forward signals from the headend facility into the reverse header information, and wherein the SWRD converts the modulator identification number within the reverse header information into an Internet Protocol address to enable the reverse signals to be directed to the one downstream modulator.

2. The FTTH system of claim 1, wherein the SWRD comprises:

a diplex filter coupled for filtering forward signals and the reverse RF signals;

the upstream demodulator coupled to the diplex filter for demodulating the reverse RF signals;

a microprocessor for converting the demodulated signals to Ethernet signals; and

a switch for receiving the Ethernet signals and any additional signals from a second source, the switch for combining the signals and for providing a combined signal to the ONT.

3. The FTTH system of claim 2, wherein the SWRD converts the identification number into the Internet Protocol address via the microprocessor.

4. The FTTH system of claim 1, wherein the ONT receives the forward signals, wherein the forward signals comprise at least one of a telephone signal, Ethernet signals, data signals, and audio/video signals, and wherein the ONT provides the at least one of Ethernet signals, data signals, and audio/video signals to the SWRD and provides the telephone signals to a connected telephone.

5. A method for transmitting reverse signals in a fiber-to-the-home (FTTH) network, the FTTH network including a forward path and a reverse path, the method comprising:

receiving forward signals from a headend facility and generating a reverse RF modulated signal in a digital host communications terminal (DHCT), wherein a plurality of downstream modulators are located in the headend facility with each downstream modulator associated with at least one corresponding DHCT and having an identification number that is inserted into the forward signals from the headend facility to identify that downstream modulator, and wherein the reverse RF modulated signal includes the identification number of the downstream modulator associated with the DHCT in header information;

providing the reverse RF modulated signal via coaxial cable to a single wire return device (SWRD);

demodulating the reverse RF modulated signal via coaxial cable to a single wire return device (SWRD);

demodulating the reverse RF modulated signal via an upstream demodulator remote from the plurality of downstream modulators to provide a reverse demodulated signal;

processing the reverse demodulated signal to provide a reverse Ethernet signal, wherein the identification number is converted into an Internet Protocol address that enables the reverse Ethernet signal to be directed to the associated downstream modulator;

converting the reverse Ethernet signal to a reverse optical signal in an optical network terminal (ONT); and

receiving signals corresponding to the reverse optical signal at the associated downstream modulator located in the headend facility, wherein the downstream modulator transmits a forward signal to the at least one corresponding DHCT via the ONT in response to the received reverse optical signal.

6. The method of claim 5, wherein the DHCT stores the identification number and inserts the received identification number into the reverse header information prior to transmitting to the SWRD.

7. The method of claim 5, further comprising:

receiving the forward signals at the ONT, wherein the forward signals comprise at least one of a telephone signal, Ethernet signals, data signals, and audio/video signals, and wherein the ONT provides the at least one of Ethernet signals, data signals, and audio/video signals to the SWRD and provides the telephone signals to a connected telephone.