Single wire return device including a QAM modulator for downstream IP signals

• US 20040257976A1
• Filed: 04/09/2004
• Published: 12/23/2004
• Est. Priority Date: 01/21/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Inventors: Versteeg, William C., Wall, William E., Nair, Ajith N., Alsobrook, David B.
• Granted Patent: US 7,657,919 B2
• Time in Patent Office: Days
• US Class Current: 370/206
• 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 21/2221 being a cable television head-end CATV in broadcast systems H04H20/78
• CPC Class Codes: H04N 21/2381 Adapting the multiplex stream to a specific network, e.g. an Internet Protocol [IP] network transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2393 involving handling client requests scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/437 Interfacing the upstream path of the transmission network, e.g. for transmitting client requests to a VOD server flow control in data networks H04L47/10; streaming protocols, e.g. RTP or RTCP, H04L65/65; scheduling or organising the servicing of application requests in data packet switching networks H04L67/60
• CPC Class Codes: H04N 21/4381 Recovering the multiplex stream from a specific network, e.g. recovering MPEG packets from ATM cells transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• 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 7/17336 Handling of requests in head-ends

Abstract

Systems and methods are disclosed for receiving IP video and audio signals at a subscriber'"'"'s premises. A QAM modulator then modulates the IP signals and provides the modulated signals to a conventional digital home communications terminal (DHCT). Accordingly, conventional DHCTs can be used in an IP-based network.

Claims

1. A fiber-to-the-home (FTTH) system having a forward path, comprising:

a receiving device including a QAM modulator for receiving IP signals, wherein the IP signals comprise video, audio, and data signals;

the QAM modulator for receiving and modulating IP video and audio signals to provide RF video and audio signals; and

at least one digital home communications terminal (DHCT) for receiving the RF video signals.

2. The FTTH system of claim 1, wherein the receiving device further comprises a switch for providing the IP video and audio signals to the QAM modulator via a QAM modulator address, and for providing IP data signals to a computer via a computer address.

3. The FTTH system of claim 1, further comprising an optical network terminal located in close proximity to the at least one DHCT for providing the IP video and audio signals to the receiving device and for providing IP telephone signals to a coupled telephone.

4. The FTTH system of claim 1, further comprises a reverse path, comprising:

the at least one digital home communications terminal (DHCT) for transmitting reverse RF signals, the reverse RF signals including header information and payload data;

the receiving device for receiving the reverse RF signals, demodulating the reverse RF signals, and converting the demodulated signals to Ethernet signals;

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

a downstream modulator located in the headend facility for receiving the optical signals and for sending the forward signals, the downstream modulator having an identification number that is inserted into the forward signals,

wherein the at least one DHCT inserts the received modulator identification number in the reverse header information, and wherein the SWRD converts the modulator identification number into an Internet Protocol address indicative of the modulator identification number.

5. The FTTH system of claim 4, the receiving device further comprising:

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

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

the 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.

6. The FTTH system of claim 5, wherein the SWRD converts the identification number into the Internet Protocol number via the microprocessor.

7. A method for transmitting and receiving IP signals in a fiber-to-the-home (FTTH) network, the IP signals including video, audio, voice, and data signals, the FTTH network including a forward path and a reverse path, the method comprising the steps of:

receiving the IP signals at an optical network terminal;

providing the IP video and audio signals to a switch included in a single wire return device (SWRD), wherein the switch provides the IP video and audio signals to a QAM modulator in the SWRD;

modulating the IP video and audio signals to provide modulated video and audio signals for viewing on conventional DHCTs.

8. The method of claim 7, further comprising the step of providing the IP data signals to the switch, wherein the switch provides the IP data signals to a coupled computer.

9. The method of claim 7, further comprising the steps of:

generating a reverse RF modulated signal including header information in the DHCT;

providing the reverse RF modulated signal via coaxial cable to the SWRD;

demodulating the reverse RF modulated signal to provide a reverse demodulated signal;

processing the reverse demodulated signal to provide a reverse Ethernet signal;

converting the reverse Ethernet signal to a reverse optical signal in the ONT; and

receiving the reverse optical signal at a downstream modulator located in a headend facility,

wherein the downstream modulator transmits a forward signal in response to the received reverse optical signal.

10. The FTTH system of claim 9, wherein the downstream modulator includes an identification number that is inserted into signals transmitted in the forward path and stored in the DCT, and wherein the DCT inserts the received identification number into the reverse header information prior to transmitting to the SWRD.

11. The FTTH system of claim 10, wherein the SWRD converts the identification number into an Internet Protocol address that is indicative of the identification number.