US3770913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for remote supervision of two-way repeater stations in multichannel pcm telecommunication path
Assignee: Italtel SpA
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Filing: 1972-01-31
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Granted: 1973-11-06
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Expires: 1992-01-31
Abstract
Abstract A multichannel PCM telecommunication path, extending between two terminal stations, comprises a d-c service line common to m parallel channels which are divided into two groups for transmission in opposite directions. A plurality of cascaded repeating stations, with m repeaters each, are inserted in that path and are each provided with a single band-pass filter designed to pass a test frequency individual to any repeating station. The test frequency is established by an unbalanced interrogation code which is iteratively transmitted over a given channel from a control post at one terminal over an outgoing channel and returned thereto over an incoming channel in a loop closed at the other terminal in response to the code. The filtered-out test frequency can be fed to the control post via the service line from the outputs of the two repeaters in the closed loop by way of two transformers and respective diodes which are inversely biased by a d-c potential on the service line, the polarity of this potential being reversible at the control post to select either of these repeaters for testing.
Inventors
- 👤 R Camiciottoli
- 👤 D Marchini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:27
CPC Classifications
H; H04; H04B; H04B17/00; H04B17/40; H04B17/401; H04B17/406
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
279 words
A system for the individual testing of n sets of repeaters at respective repeating stations, including two groups of repeaters at each station respectively serving m/2 outgoing channels and m/2 incoming channels of a PCM signal path extending from a control terminal by way of said repeaters to a remote terminal, comprising: a service line common to said channels extending from said control terminal along said path to all said repeating stations; a generator of recurrent test codes individually assigned to each of said stations at said control terminal; selector means at said control terminal for connecting said generator to any of said outgoing channels; monitoring means at said remote terminal responsive to the arrival of a test code over any one of said outgoing channels for connecting same in a loop to an associated incoming channel whereby the test code successively traverses a first repeater at each of said stations serving the outgoing channel and a second repeater at each of said stations serving the incoming channel; detector means at each of said stations connected between the outputs of all the repeaters thereof and said service line for ascertaining the appearance of the assigned test code and converting same into a response signal transmitted to said control terminal via said service line; indicator means for said response signal connected to said service line at said control terminal; and switchover means at each repeating station inserted between said detector means and the two groups of m/2 repeaters thereof, said switchover means being operable from said control terminal via said service line for selectively connecting either of said groups to said detector means to the exclusion of the other group.
Claim 2
Independent Claim
279 words
A system for the individual testing of n sets of repeaters at respective repeating stations, including two groups of repeaters at each station respectively serving m/2 outgoing channels and m/2 incoming channels of a PCM signal path extending from a control terminal by way of said repeaters to a remote terminal, comprising: a service line common to said channels extending from said control terminal along said path to all said repeating stations; a generator of recurrent test codes individually assigned to each of said stations at said control terminal; selector means at said control terminal for connecting said generator to any of said outgoing channels; monitoring means at said remote terminal responsive to the arrival of a test code over any one of said outgoing channels for connecting same in a loop to an associated incoming channel whereby the test code successively traverses a first repeater at each of said stations serving the outgoing channel and a second repeater at each of said stations serving the incoming channel; detector means at each of said stations connected between the outputs of all the repeaters thereof and said service line for ascertaining the appearance of the assigned test code and converting same into a response signal transmitted to said control terminal via said service line; indicator means for said response signal connected to said service line at said control terminal; and switchover means at each repeating station inserted between said detector means and the two groups of m/2 repeaters thereof, said switchover means being operable from said control terminal via said service line for selectively connecting either of said groups to said detector means to the exclusion of the other group.
Claim 3
Dependent Claim
19 words
A system as defined in claim 1 wherein said switchover means comprises a pair of relatively inverted electronic gates.
Claim 4
Dependent Claim
41 words
A system as defined in claim 2 wherein said gates are a pair of oppositely poled diodes, said control terminal being provided with biasing means selectively operable to apply a blocking potential for either of said diodes to said service line.
Claim 5
Dependent Claim
25 words
A system as defined in claim 1 wherein said detector means comprises a band-pass filter tuned to a low-frequency component of the assigned test code.
Claim 6
Dependent Claim
30 words
A system as defined in claim 4 wherein each repeater is provided with an output circuit including a low-pass filter for said component connected in tandem with said band-pass filter.
Claim 7
Dependent Claim
31 words
A system as defined in claim 5 wherein said band-pass filter is provided with two input transformers connected in parallel to the output circuits of the repeaters of saiD groups, respectively.
Claim 8
Dependent Claim
26 words
A system as defined in claim 6 wherein said switchover means comprises a pair of relatively inverted diodes inserted between said transformers and said band-pass filter.
Claim 9
Dependent Claim
47 words
A system as defined in claim 7 wherein said service line has two conductors and each of said stations includes a common biasing circuit for said diodes connected across said conductors, said control station being provided with a source of reversible biasing potential connectable across said conductors.
Claim 10
Dependent Claim
15 words
A system as defined in claim 8 wherein said biasing circuit bypasses said band-pass filter.
Claim 11
Dependent Claim
21 words
A system as defined in claim 9 wherein said biasing circuit includes an adjustable resistor in parallel with said band-pass filter.
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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |