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US4749247A
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Self-monitoring fiber optic link
Assignee: Mitre Corp
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Filing: 1986-04-03
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Granted: 1988-06-07
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Expires: 2006-04-03
Abstract
Abstract The self-monitoring link utilizes a GRIN lens/blazed grating combination to multiplex an optical time domain reflectometry (OTDR) signal with data signals on a fiber optic communication link. An initial average OTDR reference signature for the OTDR signal on the link is determined and is compared with a continuously determined average OTDR signature. The reference signature and the continuously determined signature are compared and a warning or alarm signal is generated when the continuously determined signature differs from the reference signature by a preselectable limit. A microprocessor is provided to adjust the preselectable limit in response to the communication link operational parameters.
Inventors
- 👤 Scott F. Large
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:12
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29304; G02B6/29305; G02B6/2931; G02B6/29379; G02B6/2938; G02B6/29382; G02B6/29385
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
85 words
Apparatus for continuously monitoring a fiber optic communications link comprising: apparatus for multiplexing an OTDR signal with at least one data signal on the fiber optic link; means for determining an initial average OTDR reference signature for the OTDR signal on the link; means for continuously determining an average OTDR signature; means for comparing the reference signature with the continuously determined signature; and means for generating a warning or alarm signal when the continuously determined signature differs from the reference signature by a preselectable limit.
Claim 2
Dependent Claim
85 words
Apparatus for continuously monitoring a fiber optic communications link comprising: apparatus for multiplexing an OTDR signal with at least one data signal on the fiber optic link; means for determining an initial average OTDR reference signature for the OTDR signal on the link; means for continuously determining an average OTDR signature; means for comparing the reference signature with the continuously determined signature; and means for generating a warning or alarm signal when the continuously determined signature differs from the reference signature by a preselectable limit.
Claim 3
Dependent Claim
22 words
The apparatus of claim 1 further including microprocessor means for adjusting the preselectable limit in response to the communication link operational parameters.
Claim 4
Dependent Claim
13 words
The apparatus of claim 2 wherein the adjusting means is responsive to temperature.
Claim 5
Dependent Claim
14 words
The apparatus of claim 2 wherein the adjusting means is responsive to equipment instability.
Claim 6
Dependent Claim
15 words
The apparatus of claim 1 wherein the multiplexing apparatus is a GRIN lens/blazed grating combination.
Claim 7
Dependent Claim
12 words
The apparatus of claim 1 including two data signals at different wavelengths.
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) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |