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

• US 7,657,919 B2
• Filed: 04/09/2004
• Issued: 02/02/2010
• 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: Alsobrook, David B., Versteeg, William C., Wall, William E., Nair, Ajith N.
• Primary Examiner(s): Beliveau; Scott
• Assistant Examiner(s): LUONG, ALAN H
• Application Number:
  US10/821,476
• Publication Number:
  US 20040257976A1
• Time in Patent Office: 2,125 Days
• Field of Search: 398/67, 398/70, 398/71, 725/62, 725/109, 725/129, 725/80, 725/105, 725/111, 725/113, 725/127, 725/128, 370/94.1, 370/94.2, 370/419, 370/206
• 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 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 for transmitting and receiving IP signals, the FTTH system including a headend facility in communication with a plurality of subscriber premises, each subscriber premises comprising:

an optical network terminal (ONT) for receiving downstream and upstream IP signals and for routing the IP signals to a coupled device or the FTTH system;

a receiving device for receiving downstream IP signals from the optical network terminal and for providing upstream IP signals to the optical network terminal, the receiving device comprising;

an Ethernet switch for routing downstream IP signals; and

a modulator for receiving downstream IP video and audio signals from the Ethernet switch, the modulator for modulating the IP video and audio signals to provide RF signals;

at least one digital home communications terminal (DHCT) for receiving the RF signals from the modulator; and

the FTTH system further comprising a reverse path, comprising;

the at least one 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;

the ONT for converting the Ethernet signals to optical signals, and for transmitting the optical signals to the headend facility via optical fiber; and

a downstream modulator located in the headend facility for receiving signals corresponding to the optical signals and for sending the forward signals downstream to the at least one DHCT via the ONT, 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 receiving device converts the modulator identification number into an Internet Protocol address indicative of the modulator identification number.

2. The FTTH system of claim 1, wherein the receiving device for providing IP data signals to a computer via a computer address.

3. The FTTH system of claim 1, wherein the optical network terminal for providing IP telephone signals to a coupled telephone.

4. The FTTH system of claim 1, the receiving device further comprising:

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

a microprocessor for converting the demodulated signals into the 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.

5. The FTTH system of claim 4, wherein the receiving device converts the identification number into the Internet Protocol number via the microprocessor.

6. The FTTH system of claim 1, wherein the modulator modulates the IP video and audio signals with quadrature amplitude modulation (QAM).

7. A fiber-to-the-home (FTTH) system for transmitting and receiving IP signals, the FTTH system including a headend facility in communication with a plurality of subscriber premises, each subscriber premises comprising:

an optical network terminal (ONT) configured to receive downstream and upstream IP signals and route the IP signals to a coupled device or the FTTH system;

a receiving device configured to receive downstream IP signals from the ONT, provide RF signals, and provide upstream IP signals to the ONT, the receiving device comprising an Ethernet switch configured to route downstream IP signals;

at least one digital home communications terminal (DHCT) configured to receive the RF signals from the receiving device, the at least one DHCT configured to transmit reverse RF signals, wherein the reverse RF signals include header information and payload data;

the receiving device is further configured to receive the reverse RF signals, demodulating the reverse RF signals, and convert the demodulated signals to Ethernet signals;

the ONT is further configured to convert the Ethernet signals to optical signals, and transmit the optical signals to a headend optical network located in the headend facility via optical fiber;

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

the FFTH system further comprising a downstream modulator located in the headend facility configured to receive signals corresponding to the optical signals from the headend optical network and to send forward signals corresponding to the IP downstream signals, the downstream modulator including the modulator identification number which is inserted into the forward signals.