US4959862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active multichannel video processing hub for optimum transition from fiber to coax
Assignee: Sorrento Networks Inc
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Filing: 1988-04-28
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Granted: 1990-09-25
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Expires: 2008-04-28
Abstract
Abstract An active multichannel video processing hub which provides optinum transition from fiber to coaxial cable, provides optimum trading of bandwidth for signal to noise ratio. Fiber optic links have a very large bandwidth capability. Larger distances can be covered with fiber optic links without repeaters. This offers not only saving in maintenance, but has no radiation and offers bidirectional capabilities not easily achievable with coax-based trunks. Scrambled signals are transmitted over the fiber and converted to VSB-AM signals at the hub for transmission over the coaxial portion of the trunk. This keeps the bulky and complex headend scrambling equipment in one central location instead of spreading it over many hub locations. The inherent heterodyne processing capabilities of the hub permit it to link headends with different frequency plans. Also, the hub-based trunk does not obsolete existing equipment and method of operation.
Inventors
- 👤 Mircho A. Davidov
- 👤 Kamaljit Singh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:41
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/16; H04N7/22
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
86 words
A cable television distribution trunk comprising: a hub, means for frequency modulating a clear baseband video signal and a first subcarrier FM modulated audio signal to form a clear multichannel signal, means for frequency modulating a scrambled subcarrier video signal and an audio signal to form a scrambled multichannel signal, means for transmitting said clear signal and said scrambled multichannel signal to said hub, means for frequency demodulating the multichannel signals at said hub, and means for converting the demodulated multichannel signals to amplitude modulated signals.
Claim 2
Dependent Claim
86 words
A cable television distribution trunk comprising: a hub, means for frequency modulating a clear baseband video signal and a first subcarrier FM modulated audio signal to form a clear multichannel signal, means for frequency modulating a scrambled subcarrier video signal and an audio signal to form a scrambled multichannel signal, means for transmitting said clear signal and said scrambled multichannel signal to said hub, means for frequency demodulating the multichannel signals at said hub, and means for converting the demodulated multichannel signals to amplitude modulated signals.
Claim 3
Dependent Claim
30 words
A trunk as in claim 1 including means for pre-emphasizing the baseband and subcarrier video signals and means for frequency modulating said audio signals to form a composite baseband signal.
Claim 4
Dependent Claim
51 words
A trunk as in claim 2 including means for frequency modulating said composite baseband signal at an intermediate frequency, means for converting said intermediate frequency signal to a radio frequency signal, means for combining said converted multichannel signals and said radio frequency signal to form a composite radio frequency video signal.
Claim 5
Dependent Claim
23 words
A trunk as in claim 3 including an optical transmitter which is intensity modulated by said composite signal to form an optical signal.
Claim 6
Dependent Claim
25 words
A trunk as in claim 4 wherein said hub includes means for receiving said optical signal, and means for recovering said audio and video signals.
Claim 7
Dependent Claim
27 words
A trunk as in claim 1 including means for pre-emphasizing said scrambled signal and means for frequency modulating said audio signals to form a composite scrambled signal.
Claim 8
Dependent Claim
59 words
A trunk as in claim 6 including means for frequency modulating said composite scrambled signal at an intermediate frequency to form an intermediate frequency signal, means for converting said intermediate frequency signal to a radio frequency signal, and means for combining said converted scrambled multichannel signals and said radio frequency signal to form a composite radio frequency video signal.
Claim 9
Dependent Claim
23 words
A trunk as in claim 7 including an optical transmitter which is intensity modulated by said composite signal to form an optical signal.
Claim 10
Dependent Claim
27 words
A trunk as in claim 8 wherein said hub includes means for receiving said optical signal, and means for recovering said audio signal and said video signal.
Claim 11
Dependent Claim
13 words
A trunk as in claim 1 including means for globally synchronizing said trunk.
Claim 12
Dependent Claim
88 words
A multichannel cable television trunk system comprising: means for frequency modulating a baseband audio signal to form intermediate frequency (IF) audio signals, means for amplitude modulating a baseband video signal to form intermediate frequency (IF) video signals, means for scrambling said IF video and IF audio signals to form scrambled IF video and IF audio signals and control information therein, means for mixing said scrambled IF signals with local oscillator signals to form composite video and audio subcarrier signals, and means for frequency modulating said composite subcarrier signals.
Claim 13
Dependent Claim
88 words
A multichannel cable television trunk system comprising: means for frequency modulating a baseband audio signal to form intermediate frequency (IF) audio signals, means for amplitude modulating a baseband video signal to form intermediate frequency (IF) video signals, means for scrambling said IF video and IF audio signals to form scrambled IF video and IF audio signals and control information therein, means for mixing said scrambled IF signals with local oscillator signals to form composite video and audio subcarrier signals, and means for frequency modulating said composite subcarrier signals.
Claim 14
Dependent Claim
91 words
In a cable television distribution trunk including a hub, the method comprising the steps of: frequency modulating a clear baseband video signal and a first audio sub carrier signal to form a clear multichannel signal, frequency modulating a subcarrier scrambled video signal and a second audio subcarrier signal to form a scrambled multichannel signal, transmitting said clear signal and said scrambled multichannel signal to said hub, frequency demodulating the clear and scrambled multichannel signals at said hub to form demodulated signals, and converting the demodulated multichannel signals to amplitude modulated signals.
Claim 15
Dependent Claim
91 words
In a cable television distribution trunk including a hub, the method comprising the steps of: frequency modulating a clear baseband video signal and a first audio sub carrier signal to form a clear multichannel signal, frequency modulating a subcarrier scrambled video signal and a second audio subcarrier signal to form a scrambled multichannel signal, transmitting said clear signal and said scrambled multichannel signal to said hub, frequency demodulating the clear and scrambled multichannel signals at said hub to form demodulated signals, and converting the demodulated multichannel signals to amplitude modulated signals.
Claim 16
Dependent Claim
78 words
In a multichannel cable television trunk system, the method comprising the steps of: frequency modulating a baseband audio signal and amplitude modulating a baseband video signal to form intermediate frequency (IF) video and audio signals, scrambling said IF video and audio signals to form scrambled IF video and audio signals and control information therein, and mixing said scrambled signals with local oscillator signals to form composite video and audio subcarrier signals, and frequency modulating said composite subcarrier signals.
Claim 17
Dependent Claim
78 words
In a multichannel cable television trunk system, the method comprising the steps of: frequency modulating a baseband audio signal and amplitude modulating a baseband video signal to form intermediate frequency (IF) video and audio signals, scrambling said IF video and audio signals to form scrambled IF video and audio signals and control information therein, and mixing said scrambled signals with local oscillator signals to form composite video and audio subcarrier signals, and frequency modulating said composite subcarrier signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |