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

• US 6,862,349 B1
• Filed: 09/23/1996
• Issued: 03/01/2005
• Est. Priority Date: 05/28/1993
• Status: Expired due to Fees

• Current Assignee: Comcast MO Group Incorporated (Comcast Corporation)
• Original Assignee: MediaOne Group Inc. (Comcast Corporation), U S West Inc.
• Inventors: Beveridge, Gregory Joseph
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US08/717,982
• Time in Patent Office: 3,081 Days
• Field of Search: 379/54, 379/53, 379/157, 455/5, 370/95.1, 370/110.1, 348/14
• US Class Current: 379/157
• CPC Class Codes: H04H 20/69 Optical systems
• CPC Class Codes: H04H 60/94 Telephonic networks for accessing the Internet H04H60/84
• CPC Class Codes: H04K 2203/14 for the transfer of light or images, e.g. for video-surveillance, for television or from a computer screen
• CPC Class Codes: H04K 2203/16 for telephony
• CPC Class Codes: H04K 3/68 using passive jamming, e.g. by shielding or reflection shielding of apparatus or components against electric or magnetic field H05K9/00
• CPC Class Codes: H04K 3/825 by jamming
• 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 21/6137 involving transmission via a telephone network, e.g. POTS
• CPC Class Codes: H04N 21/6187 involving transmission via a telephone network, e.g. POTS
• CPC Class Codes: H04N 21/64723 Monitoring of network processes or resources, e.g. monitoring of network load traffic related reporting in data switching networks H04L43/062
• 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 selected two-way special 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 modulated carrier signals in a downstream and upstream frequency range to said subscriber location; and

a selective delivering device electromagnetically connected to said logical bus network, said selective delivering device interdicting modulated carrier signals in said downstream frequency range on said second signal path and isolating modulated carrier signals in said upstream frequency range on said first and second paths, said selective delivering device demodulating selected modulated carrier signals in the downstream frequency range on said first signal path and modulating carrier signals in the upstream frequency range on said first signal path wherein said carrier 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 network to deliver one or more selected two-way special services to a subscriber location.

3. A system according to claim 1 further including means, operatively associated with said coaxial cable network, for supplying power to a subscriber telephone through said coaxial cable network.

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

means for providing modulated telephony signals to and from a combined network transmission system, said combined network transmission system including a fiber optic transmission system and a network coaxial cable system;

means, operatively associated with said combined network transmission system, for supplying video signals on said combined network transmission system;

means, operatively associated 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 simultaneously 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;

means, operatively associated with said combined network transmission system, for selectively delivering said video signals;

means, operatively associated with said network coaxial cable system, for providing demodulated telephony signals;

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

means, operatively associated with said subscriber coaxial system for separating said demodulated telephony signals from said selectively delivered video signals.

5. A system according to claim 4 further including:

means, operatively associated with said network coaxial cable system, for furnishing power; and

means, operatively associated with said network coaxial cable system, for transforming said power.

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

a transport network including a fiber optic system and a coaxial cable system;

means, associated with said transport network, for modulating/demodulating a baseband telephony signal;

means, associated 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;

a modulator/demodulator connected to said coaxial cable system;

means, connected to said interdiction device and said modulator/demodulator device, for combining a noninterdicted video signal and said baseband telephony signal; and

means, connected to said combining means, for separating said noninterdicted video signal from said baseband telephony signal.

7. A video and telephony 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 associated with said fiber optic transmission system;

a video provisioning system associated with said fiber optic transmission system;

an interdiction unit operatively associated with said coaxial cable system; and

a modulator/demodulator operatively associated with said coaxial cable system;

whereby telephony signals and video signals on said coaxial cable system are interdicted such that only selected telephony signals are transmitted to and from said telephones.

8. A network according to claim 7 further including:

means, operatively associated with said coaxial cable system, for combining an interdicted video signal and a demodulated telephony signal on a subscriber coaxial cable system; and

means, operatively associated with said subscriber coaxial cable system, for separating said interdicted video signal from said demodulated telephony signal.

9. A network according to claim 7 further including means, operatively associated with said coaxial cable system, for supplying power to said telephones.

10. A telephony network comprising:

a central office including a digital switch and a special service equipment;

a transport system operatively connected to said switch, said transport system including a fiber optic system and a coaxial cable system connected to said fiber optic system;

a plurality of line cards operatively associated with said coaxial cable system;

each said line card including a preselected frequency pair assigned thereto, said preselected frequency pair corresponding exclusively to either a telephony service or a special service;

means, associated with said digital transport system, for recognizing said assigned frequency pair; and

whereby a signal from said line card is routed to said digital switch if said assigned frequency pair is recognized as a telephony service and a signal for said line card is routed to said special service equipment if said assigned frequency pair is recognized as a special service.

11. A network according to claim 10 wherein said line card is included in a BBP device adjacent to a subscriber location.

12. A network according to claim 10 further including means, associated with said transport system, for remotely assigning said frequency pair.

13. An apparatus for delivering video and baseband telephony signals to a subscriber on a coaxial cable network comprising:

a network interface;

a baseband below passband unit connected to said network interface;

a signal combiner operatively associated with said baseband below passband unit, said combiner including at least one pair of L-filters to allow baseband telephony signals to be added to passband video signals; and

a signal splitter connected to said coaxial cable network, said splitter including a high pass filter and a low pass filter such that said high pass filter permits transmission of all passband signals and blocks all telephony signals, and said low pass filter blocks all passband signals and permits transmission of all telephony signals.

14. A device for selective delivery of telephony signals in a coaxial cable network such that said telephony signals from a particular subscriber can not be monitored by another subscriber on said network said device comprising:

an interdiction device connected to said coaxial cable network to jam selected video signals and all telephony signals, said interdiction device including;

a jamming oscillator connected to said coaxial cable network;

an amplifier connected to said coaxial cable network;

a forward coupler connected to said coaxial cable network; and

a modulator/demodulator connected to said coaxial cable network to derive selected baseband telephony signals for said particular subscriber.

15. A device for selective delivery of telephony signals in a coaxial cable network comprising:

an interdiction device connected to said coaxial cable network, said interdiction device including;

a negative trap connected to said coaxial cable network;

an amplifier effectively connected to said coaxial cable network;

a forward coupler connected to said coaxial cable network; and

a modulator/demodulator connected to said coaxial cable network;

whereby said interdiction device eliminates all telephony signals and said modulator/demodulator device derives selected baseband telephony signals for a particular subscriber such that said baseband telephony signals for said particular subscriber can not be monitored by a different subscriber on said network.