Patent US5408350A successfully refreshed from Google Patents.
US5408350A
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Bidirectional transmission system, especially one using optical fiber, employing a single carrier for both transmission directions
Assignee: Alcatel CIT SA
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Filing: 1994-09-21
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Granted: 1995-04-18
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Expires: 2014-09-21
Abstract
Abstract This bidirectional transmission system, especially one using optical fiber, between a source terminal and a user terminal employing a single carrier for both transmission directions obtained from a source in the source terminal characterized in that it comprises for each transmission direction means for modulating one parameter of said carrier, this parameter being intensity for the two directions and subject in all cases to the condition that the modulation applied first for transmission in the downward direction from the source terminal to the user terminal the depth of modulation is sufficiently high to leave sufficient power for application of the second modulation to which that applied second can be applied for transmission in the upward direction from the user terminal to the source terminal.
Inventors
- 👤 Philippe Perrier
- 👤 Olivier Gautheron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:29
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/25; H04B10/2587
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
189 words
Bidirectional transmission system, employing a transmission medium, between a source terminal and a user terminal employing a single carrier for both transmission directions obtained from a source in said source terminal, said system comprising means within said source terminal for applying a first intensity modulation to said carrier to provide a signal for transmission in a downward direction from said source terminal to said user terminal, and means within said user terminal for applying a second intensity modulation for transmission in an upward direction from said user terminal to said source terminal, subject in all cases to the condition that for said first intensity modulation, the depth of modulation is sufficiently small to always leave sufficient power for application of said second intensity modulation wherein said user terminal comprises means for separating said signal received from said source terminal into first and second parts each including said first intensity modulation; means for detecting said first intensity modulation in said first part; and means for applying said second intensity modulation to said second part and for transmitting the intensity modulated second part in said upward direction over said transmission medium.
Claim 2
Dependent Claim
189 words
Bidirectional transmission system, employing a transmission medium, between a source terminal and a user terminal employing a single carrier for both transmission directions obtained from a source in said source terminal, said system comprising means within said source terminal for applying a first intensity modulation to said carrier to provide a signal for transmission in a downward direction from said source terminal to said user terminal, and means within said user terminal for applying a second intensity modulation for transmission in an upward direction from said user terminal to said source terminal, subject in all cases to the condition that for said first intensity modulation, the depth of modulation is sufficiently small to always leave sufficient power for application of said second intensity modulation wherein said user terminal comprises means for separating said signal received from said source terminal into first and second parts each including said first intensity modulation; means for detecting said first intensity modulation in said first part; and means for applying said second intensity modulation to said second part and for transmitting the intensity modulated second part in said upward direction over said transmission medium.
Claim 3
Dependent Claim
19 words
System according to claim 1 characterized in that it comprises a single transmission medium for transmission in both directions.
Claim 4
Dependent Claim
139 words
System according to claim 1 characterized in that the first intensity modulation applied for transmission in the downward direction is effected so that it appears in said first part between a low level Pb relatively far from the zero level and a high level Ph, the second intensity modulation applied for transmission in the upward direction is effected upon said second part between a level Po near the zero level and the level Pb, the decision threshold (sd 2 ) of the optical receiver of the user terminal is adjusted to a value substantially equal to half the sum of the level values Pb and Ph and the decision threshold (sd 1 ) of the optical receiver of the source terminal is adjusted to a value substantially equal to half the sum of the level values Po and Pb.
Claim 5
Dependent Claim
13 words
System according to claim 1 wherein said transmission medium is an optical fiber.
Claim 6
Dependent Claim
22 words
System according to claim 1 wherein said first intensity modulation and said second intensity modulation are at substantially the same bit rate.
References Cited (Backward Citations)
US3584220A
Cited
US3989942A
Cited
US3943284A
Cited
FR2558025A1
Cited
EP0227164A2
Cited
US4763326A
Cited
WO1987006084A1
Cited
GB2196809A
Cited
US5010586A
Cited
US4956877A
Cited
US4955086A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-04-17 | 1998-10-17 | 1999-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-17 | 2002-10-17 | 2003-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-17 | 2006-10-17 | 2007-04-18 | $7700.00 | Window Closed / Lapsed |