TAGGING DIGITAL TELEVISION SIGNALS

• US 20160192025A1
• Filed: 08/11/2015
• Published: 06/30/2016
• Est. Priority Date: 06/10/2009
• Status: Abandoned Application

• Current Assignee: Trilithic Incorporated (Lumentum Holdings Inc.)
• Original Assignee: Trilithic Incorporated (Lumentum Holdings Inc.)
• Inventors: Bush, Terry W., Rodgers, Gregg Stephen, Emsley, Brett W.
• Application Number:
  US14/823,717
• Publication Number:
  US 20160192025A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04H 20/78 CATV [Community Antenna Television] systems
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details
• 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 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/615 Signal processing at physical level signal processing in analog two-way television systems H04N7/173

Abstract

A method and apparatus for detecting leakage of a digital CATV channel signal from a CATV system. The digital CATV channel signal is amplitude modulated with a tag signal having a frequency in the range of about 3 Hz to about 35 Hz, and coupled to the CATV system. At a point of leakage from the CATV system, the amplitude modulated digital CATV channel signal can be detected using a leakage detector capable of recovering the tag signal.

Claims

1-34. -34. (canceled)

35. A CATV system comprising:

a source of program material;

a digital modulator for modulating the program material into a digital television signal;

a channel modulator coupled to the digital modulator for modulating the digital television signal to a CATV channel frequency;

an amplitude modulator coupled to the channel modulator for amplitude modulating the CATV channel frequency signal; and

,

a CATV plant coupled to the amplitude modulator for distributing the amplitude modulated CATV channel frequency signal.

36. The system of claim 35 wherein the amplitude modulator modulates the cable channel frequency signal at a rate of between about 3 Hz and about 35 Hz.

37. The system of claim 36 wherein the amplitude modulator modulates the cable channel frequency signal at a rate of between about 10 Hz and about 23 Hz.

38. The system of claim 35 wherein the amplitude modulator modulates the cable channel frequency signal to a depth of between about 0.5 dB and 5 dB.

39. The system of claim 38 wherein the amplitude modulator modulates the cable channel frequency signal to a depth of between about 1 dB and about 3 dB.

40-77. -77. (canceled)