Method and apparatus for delivering secured telephone service in hybrid coaxial cable network

• US 5,469,495 A
• Filed: 12/16/1994
• Issued: 11/21/1995
• Est. Priority Date: 05/28/1993
• Status: Expired due to Term

• Current Assignee: Comcast MO Group Incorporated (Comcast Corporation)
• Original Assignee: U.S. West Advanced Technologies, Inc.
• Inventors: Beveridge, Gregory J.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Chernoff, Michael B.
• Application Number:
  US08/357,558
• Time in Patent Office: 340 Days
• Field of Search: 379/406, 379/407, 379/414, 379/417, 379/194, 379/195, 379/56, 379/413, 359/179, 359/173, 359/123, 359/124, 359/125, 359/118, 359/137, 359/171, 359/174, 359/176, 359/177, 370/110.1, 348/12, 348/13, 348/14, 348/16, 348/17, 348/6, 348/7, 348/8, 380/6, 380/7, 380/8, 455/26.1, 455/4.2, 455/1
• US Class Current: 379/56.2
• CPC Class Codes: H04H 20/12 Arrangements for observation, testing or troubleshooting
• CPC Class Codes: H04H 20/79 using downlink of the CATV systems, e.g. audio broadcast via CATV network
• CPC Class Codes: H04H 60/94 Telephonic networks for accessing the Internet H04H60/84
• CPC Class Codes: H04H 60/97 using uplink of the CATV systems
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/205 Eavesdropping prevention - indication of insecurity of line or network
• CPC Class Codes: H04M 3/303 and using PCM multiplexers, e.g. pair gain systems
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 9/025 Time division multiplex systems, e.g. loop systems
• CPC Class Codes: H04N 7/17354 in an intermediate station common to a plurality of user terminals
• CPC Class Codes: H04Q 11/02 for frequency-division multiplexing H04Q11/0001 takes precedence

Abstract

A hybrid coaxial cable network employing interdiction to ensure privacy in telephony communications. The video and telephony signals are secured such that telephony and interactive video signals to and from a subscriber do not appear on the network at any other undesired subscriber location.

Claims

1. A system for providing telephony services to a subscriber location comprising:

a logical bus network including a coaxial cable network having at least a first signal path and a second signal path to and from said subscriber location for transporting telephony signals in a downstream frequency range and an upstream frequency range;

a selective delivering device electromagnetically connected to said logical bus network, said selective delivering device jamming telephony signals in said downstream frequency range on said second signal path and isolating telephony signals in said upstream frequency range on said first and second signal paths, said selective delivering device demodulating selected baseband telephony signals in the downstream frequency range on said first signal path and modulating baseband telephony signals in the upstream frequency range on said first signal path wherein said baseband telephony signals to and from said subscriber location cannot be monitored at another subscriber location on said logical bus network.

2. A system according to claim 1 wherein said selective delivering device includes:

an interdiction device operatively associated with said network to allow only preselected frequency signals to be transmitted upstream or downstream on said network; and

a modulator/demodulator operatively associated with said coaxial cable system to deliver one or more selected baseband telephony signals to a subscriber location.

3. A method for supplying telephony services to a subscriber location comprising:

transporting telephony signals in an upstream frequency range and a downstream frequency range over a logical bus network including a coaxial cable system; and

interdicting said telephony signals on said coaxial cable system, said step of interdicting including;

demodulating a baseband telephony signal on a first signal path to said subscriber location in said downstream frequency range;

jamming telephony signals in said downstream frequency range on a second signal path to said subscriber location;

modulating a telephony signal in said upstream frequency range on said first signal path from said subscriber location;

isolating telephony signals in said upstream frequency range from said subscriber location on said first and second signal paths;

wherein modulated telephony signals to and from said subscriber location cannot be monitored at another subscriber location on said logical bus network.

4. A method according to claim 3, further including the steps of:

combining video signals transported on said subscriber coaxial cable system with a demodulated telephony signal; and

separating said demodulated telephony signals from said video signals.

5. A method for providing telephony services according to claim 3 wherein said step of transporting includes:

supplying video signals and telephony signals to said network; and

converting said video and telephony signals on a fiber optic transmission system to electrical signals on said coaxial cable system and converting said video signals and said telephony electrical signals on said coaxial cable system to optical signals on said fiber optic transmission system.

6. A system for providing video and telephony services to a subscriber comprising:

a telecommunications system for providing telephony signals to and from a logical bus network transmission system, said logical bus network transmission system including a fiber optic transmission system and a network coaxial cable system;

a video system electromagnetically connected to said logical bus network transmission system, for supplying video signals on said logical bus network transmission system;

a converter electromagnetically connected with said fiber optic transmission system, for converting said telephony and video optical signals on said fiber optic transmission system to telephony electrical signals and video electrical signals on said network coaxial cable system, and for converting said video and said telephony electrical signals on said network coaxial cable system to video and telephony optical signals on said fiber optic transmission system;

a video delivery system electromagnetically connected with said logical bus network transmission system, for selectively delivering said video signals;

a modulator demodulator electromagnetically connected with said network coaxial cable system, for providing modulated demodulated telephony signals;

a combiner electromagnetically connected with said selectively delivering means and said providing means, for combining said selectively delivered video signal and said modulated demodulated telephony signals onto a coaxial cable system of said subscriber;

a separator electromagnetically connected with said subscriber coaxial system for separating said modulated demodulated telephony signals from said selectively delivered video signals; and

an interdiction device to prevent access 19 all except selected telephony signals at a subscriber location such that telephony signals to or from one subscriber location cannot be monitored at a second subscriber location on said local bus network.

7. A method for providing video and telephony services to a subscriber over a logical bus network, said method comprising:

supplying a set of video signals and a modulated telephony signal to a fiber optic transmission system;

converting optical signals on said fiber optic transmission system to electrical signals on a network coaxial cable system and converting electrical signals on said network coaxial cable system to signals on said fiber optic transmission system;

selectively delivering said video signals on said network coaxial cable system;

interdicting said telephony signals on said coaxial cable system, said step of interdicting including;

demodulating a baseband telephony signal on a first signal path to said subscriber location in a downstream frequency range;

jamming telephony signals in said downstream frequency range on a second signal path to said subscriber location;

modulating a telephony signal in an upstream frequency range on a first signal path from said subscriber location;

isolating telephony signals in said upstream frequency range from said subscriber location on said first and second signal paths; and

wherein modulated telephony signals to and from said subscriber location be monitored at another subscriber location on said logical bus network;

combining said selectively delivered video signal and said demodulated telephony signal on a subscriber coaxial system; and

separating said demodulated telephony signal and said selectively transmitted video signal.

8. A system for delivering video and telephony services to a subscriber comprising:

a logical bus network including a fiber optic system and a coaxial cable system;

a modulating/demodulating device in said logical bus network for modulating/demodulating a baseband telephony signal;

a video system electromagnetically connected with said fiber optic system, for supplying a video signal on said fiber optic system;

an optical/electrical signal converter connected to said fiber optic system and said coaxial cable system;

an interdiction device, connected to said coaxial cable system said interdiction device jamming telephony signals in a downstream frequency range on a second signal path and isolating telephony signals in an upstream frequency range on a first and said second signal paths, said interdiction device demodulating selected baseband telephony signals in the downstream frequency range on said first signal path and modulating baseband telephony signals in the upstream frequency range on said first signal path wherein said baseband telephony signals to and from said subscriber location cannot be monitored at another subscriber location on said logical bus network;

a signal combiner connected to said interdiction device for combining a video signal and said baseband telephony signal; and

a signal separator connected to said signal combiner, for separating said video signal from said baseband telephony signal.

9. A video and telephony logical bus network including a plurality of telephones operatively connected thereto comprising:

a fiber optic transmission system;

a coaxial cable transmission system connected to said fiber optic transmission system;

a telephone switching system electromagnetically connected to said fiber optic transmission system;

a video provisioning system electromagnetically connected to said fiber optic transmission system; and

an interdiction device, connected to said coaxial cable system said interdiction device jamming telephony signals in a downstream frequency range on a second signal path and isolating telephony signals in an upstream frequency range on a first and said second signal paths, said interdiction device demodulating selected baseband telephony signals in the downstream frequency range of said first signal path and modulating baseband telephony signals in the upstream frequency range on said first signal path wherein said baseband telephony signals to and from said telephone at a subscriber location cannot be monitored at another subscriber location on said logical bus network.

10. A network according to claim 9 further including:

a combiner unit electromagnetically connected with said coaxial cable system, for combining an interdicted video signal and a demodulated telephony signal on a subscriber coaxial cable system; and

a separator unit electromagnetically connected with said subscriber coaxial cable system, for separating said interdicted video signal from said demodulated telephony signal.

11. A system for providing telephony services to a subscriber location comprising:

a logical bus network including a downstream frequency range and an upstream frequency range on a coaxial cable network having at least a first signal path and a second signal path to and from said subscriber location;

a selective delivering device electromagnetically connected to said logical bus network, said selective delivering device negatively trapping telephony signals in said downstream frequency range on said second signal path and isolating telephony signals in said upstream frequency range on said first and second signal paths, said selective delivering device demodulating selected baseband telephony signals in the downstream frequency range on said first signal path and modulating baseband telephony signals in the upstream frequency range on said first signal path wherein said baseband telephony signals to and from said subscriber location cannot be monitored at another subscriber location on said logical bus network.

12. A method for supplying telephony services to a subscriber location comprising:

transporting telephony signals in an upstream frequency range and a downstream frequency range over a logical bus network including a coaxial cable system; and

`interdicting said telephony signals on said coaxial cable system such that said signals are secured, said step of interdicting including;

demodulating a baseband telephony signal on a first signal path to said subscriber location in said downstream frequency range;

negatively trapping telephony signals in said downstream frequency range on a second signal path to said subscriber location;

modulating a telephony signal in said upstream frequency range on said first signal path from said subscriber location;

isolating telephony signals in said upstream frequency range from said subscriber location on said first and second signal paths; and

wherein modulated telephony signals to and from said subscriber location cannot be monitored at another subscriber location on said logical bus network.