Optimization of a full duplex wideband communications system

• US 7,487,532 B2
• Filed: 08/23/2004
• Issued: 02/03/2009
• Est. Priority Date: 01/15/2003
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Fernandez, Jose M., Robertson, Neil C.
• Primary Examiner(s): Kelley; Christopher
• Assistant Examiner(s): Newlin; Timothy R
• Application Number:
  US10/923,948
• Publication Number:
  US 20050022248A1
• Time in Patent Office: 1,625 Days
• Field of Search: 725/126, 725/111, 709/227, 709/228, 709/230, 709/231, 709/234, 370/276, 370/282
• US Class Current: 725/111
• CPC Class Codes: H04H 20/63 to plural spots in a confined site, e.g. MATV [Master Antenna Television]
• CPC Class Codes: H04H 60/80 characterised by transmission among terminal devices
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04N 21/42676 for modulating an analogue carrier signal to encode digital information or demodulating it to decode digital information, e.g. ADSL or cable modem
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/4788 communicating with other users, e.g. chatting arrangements for providing for computer conferences, e.g. chat rooms, to substation in data switching networks H04L12/1813; distributed application using peer-to-peer [P2P] networks H04L67/104
• 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 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

Systems and methods are disclosed for a full duplex wideband communications system for a local (e.g. in-home) coaxial network. The system employs a Frequency-division duplex (FDD) scheme that allows identical wideband modems to communicate with each other. To achieve this, the wideband modems contain a duplexer and a switch that allows reversing the connection of the wideband transmitter and receiver to the duplexer. Each wideband modem includes a control modem that is used to control access to the wideband channels. A wideband transmitter, which may be included in a modem associated with a server set-top terminal (STT), transmits a video presentation to a wideband receiver, which may be included in a modem associated with a client STT.

Claims

1. A system for optimal transmission of high data rate signals among a plurality of full duplex wideband modems, the system comprising:

a first wideband modem for transmitting high data rate signals in a first optimized frequency, wherein prior to transmitting the high data rate signals, an optimization protocol is performed using control signals, and for receiving high data rate signals in a second optimized frequency; and

a second wideband modem for receiving the high data rate signals in the first optimized frequency,

wherein each wideband modem comprises;

a transmitter for transmitting high data rate signals;

a receiver for receiving transmitted high data rate signals;

a duplexer for combining the first optimized frequency and the second optimized frequency;

a band select switch coupled on one end to the transmitter and the receiver for selecting one of a high band or a low band in accordance with the first optimized frequency, and coupled on another end to the duplexer, wherein if the first optimized frequency is associated with one of the high band or the low band, received high data rate signals in a second optimized frequency is associated with the other band;

a control transmitter, that transmits on a third frequency, for sending control information to the second wideband modem, wherein the third frequency is outside a frequency band of the high and the low bands;

a control receiver, that receives on the third frequency, for receiving control information indicating the optimized frequencies; and

a diplexer coupled to (1) the duplexer and (2) the control transmitter and the control receiver, wherein the diplexer combines the third frequency with previously combined first and second optimized frequencies.

2. The system of claim 1, wherein the second wideband modem for transmitting high data rate signals in the second optimized frequency, wherein prior to transmitting the high data rate signals in the second optimized frequency, the optimization protocol is performed.

3. The system of claim 1, wherein the control transmitter for sending control information including signal requests in accordance with the optimization protocol, and the control receiver subsequently communicates received optimized frequency information to the wideband modem for storage and the optimized frequencies each have signal quality parameters that are ranked and stored in an order that optimizes frequency allocation among the plurality of wideband modems.

4. The system of claim 3, wherein the signal quality comprises an amplitude level, a signal to noise ratio, and a bit error rate.

5. The system of claim 3, wherein if a first optimized frequency having a high signal quality is in-use, a next optimized frequency having less signal quality is used, and wherein the optimized frequencies may be in one of the high band or the low band.

6. The system of claim 1, wherein the high data rate signals are a video presentation.

14. The system of claim 1, wherein the optimization protocol is performed in connection with at least three wideband modems that are in communication with each other simultaneously via a coaxial network to which the coaxial conductor is connected.

7. A coaxial network for communicating a video presentation, the coaxial network comprising:

a plurality of wideband modems for transmitting and receiving video presentation over a coaxial network in an optimized frequency to one or more of the plurality of wideband modems, wherein prior to transmitting video presentation, an optimization protocol is performed using control information to determine the optimized frequency, a wideband modem comprising;

a transmitter for transmitting video presentation;

a receiver for receiving video presentation from a second wideband modem;

a duplexer operably connected on one end to both the transmitter and receiver,

a band select switch coupled on one end to the transmitter and the receiver for selecting one of a high band or a low band in accordance with the optimized frequency associated with the transmitted video presentation, and coupled on another end to the duplexer;

a control transmitter, that transmits on a second frequency, for sending control information to another of the plurality of wideband modems and the control information includes information regarding the optimized frequency, wherein the second frequency is outside a frequency band of the high and the low bands;

a control receiver, that receives on the second frequency, for receiving control information from at least one of the plurality of wideband modems; and

a diplexer coupled to (1) the duplexer and (2) the control transmitter and the control receiver, wherein the duplexer combines the second frequency with the optimized frequency.

8. The coaxial network of claim 7, wherein the band select switch of one of the plurality of wideband modems and a band select switch of the second of the plurality of wideband modems communicate with each other when the band select switch is set in opposite positions.

9. The coaxial network of claim 7, wherein the control receiver of a first wideband modem receives a request for a stored video presentation from a second wideband modem, and wherein subsequently, the control transmitter of the first wideband modem transmits the control information regarding the optimized frequency to the band select switch in order to select one of the high band or the low band in accordance with the optimized frequency, and wherein the control transmitter transmits the requested information to a processor for extracting the stored video presentation for transmission via the transmitter.

10. The coaxial network of claim 7,

wherein the control information sent from a control transmitter of a first wideband modem includes signal requests to one or more second wideband modems in accordance with the optimization protocol and subsequently communicating a table of optimized frequencies that are included in one of the high band or the low band;

and

wherein the received control information, received at a control receiver in the first wideband modem includes a plurality of signals in response to the signal requests, the response signals each having a signal quality,

wherein the response signals are ranked and stored in the table from a high signal quality to a low signal quality, wherein the response signal having the high signal quality determines the optimized frequency between the first wideband modem and the one or more second wideband modems.

11. The system of claim 10, wherein the signal quality comprises an amplitude value, a signal to noise ratio, and a bit error rate of the response signal.

12. The system of claim 10, wherein if a first optimized frequency having a high signal quality in the table is in use, a next optimized frequency having less signal quality is used, and wherein the optimized frequency may be in one of the high band or the low band.

15. The coaxial network of claim 7, wherein the optimization protocol is performed in connection with at least three wideband modems that are in communication with each other simultaneously via the coaxial network.

13. A coaxial network for communicating a video presentation between a first set-top terminal and a second set-top terminal that are each located at a subscriber premises, the coaxial network comprising:

a first set-top terminal including a wideband modem for transmitting and receiving video presentation over a coaxial network in an optimized frequency to a second set-top terminal including a wideband modem, wherein prior to transmitting video presentation, an optimization protocol is performed using control signals to determine the optimized frequency, the wideband modems each comprising;

a transmitter for transmitting video presentation;

a receiver for receiving video presentation;

a duplexer operably connected on one end to both the transmitter and receiver,

a band select switch coupled on one end to the transmitter and the receiver for selecting one of a high band or a low band in accordance with the optimized frequency associated with the transmitted video presentation, and coupled on another end to the duplexer;

a control transmitter, that transmits on a second frequency, for sending control information to the second wideband modem and the control information includes information regarding the optimized frequency, wherein the second frequency is outside a frequency band of the high and the low bands;

a control receiver, that receives on the second frequency, for receiving control information from the second wideband modem; and

a diplexer coupled to (1) the duplexer and (2)the control transmitter and the control receiver, wherein the diplexer combines the second frequency with the optimized frequency, wherein a cable television (CATV) forward band and reverse band separate the optimized frequency from the second frequency.

16. The coaxial network of claim 13, wherein the optimization protocol is performed in connection with at least three wideband modems that are in communication with each other simultaneously via the coaxial network.