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

• US 20050034168A1
• Filed: 09/01/2004
• Published: 02/10/2005
• Est. Priority Date: 05/28/1993
• Status: Active Grant

• Current Assignee: Comcast MO Group Incorporated (Comcast Corporation)
• Original Assignee: MediaOne Group Inc. (Comcast Corporation), U S West Inc.
• Inventors: Beveridge, Gregory J.
• Granted Patent: US 7,010,803 B2
• Time in Patent Office: Days
• US Class Current: 725/129
• 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 method for supplying selected two-way special services to a subscriber location, comprising:

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

demodulating a modulated carrier signal on a first signal path to the subscriber location in the downstream frequency range;

interdicting modulated carrier signals in the downstream frequency range on a second signal path to the subscriber location;

modulating a carrier signal in the upstream frequency range on the first signal path from the subscriber location; and

isolating modulated carrier signals in the upstream frequency range from the subscriber location on the first and second signal paths,

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

2. The method according to claim 1, further comprising supplying power to a telephone at the subscriber location through the coaxial cable system.

3. The method according to claim 1, further comprising combining video signals and the selected two-way special services on a subscriber coaxial cable system, and separating the selected two-way special services and the video signals.

4. The method according to claim 1, wherein transporting modulated carrier signals includes supplying video signals and the modulated carrier signals to the logical bus network, and converting the video and modulated carrier signals on a fiber optic transmission system to electrical signals on the coaxial cable system and converting the video electrical signals and the modulated carrier electrical signals on the coaxial cable system to optical signals on the fiber optic transmission system.

5. A method for providing video and telephony services to a subscriber, comprising:

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

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

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

modulating and demodulating the telephony signals on the network coaxial cable system;

combining the selectively delivered video signals and the demodulated telephony signals on a subscriber coaxial system; and

separating the demodulated telephony signals and the selectively transmitted video signals.

6. A method for segregating telephony services and special services in a network, the network including a central office and a transport system connected to the central office, the central office including a telephony switch and special services equipment, the transport system including a fiber optic system and a coaxial cable system connected to the fiber optic system, the method comprising:

dedicating at least one line card in the network to a subscriber;

assigning a frequency pair to the line card, the frequency pair corresponding to one of the services;

transmitting a signal including the frequency pair to and from the central office;

recognizing the frequency pair as indicative of a telephony service or a special service; and

routing a recognized telephony service to the switch and routing a recognized special service to the special services equipment.

7. The method according to claim 6, wherein assigning a frequency pair includes remotely assigning the frequency pair from the central office.

8. A method for delivering video and telephony signals to a subscriber on a coaxial cable network, comprising:

combining passband video signals and baseband telephony signals on the coaxial cable network;

splitting the signals on the coaxial cable network onto an F-fitting coaxial connector and an RJ-11 telephone jack;

blocking all telephony signals on said F-fitting connector; and

blocking all passband video signals on the RJ-11 telephone jack.

9. A method for delivering secured telephony service in a coaxial cable network, comprising:

jamming all downstream telephony signals;

isolating upstream telephony signals from one subscriber on the network to another; and

converting a selected telephony channel to a baseband telephony signal,

whereby telephony signals from a first subscriber in the upstream and downstream direction cannot be monitored by another subscriber on the network.

10. A method for delivering secured telephony service in a coaxial cable network, comprising:

eliminating all downstream telephony signals by reducing an amplitude of the signals below a noise level;

isolating upstream telephony signals from one subscriber on the network to another; and

converting a selected telephony channel to a baseband telephony signal,

whereby telephony signals to and from one subscriber on the network cannot be monitored by another subscriber on the network.