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US4475187A
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Broad band exchange system to minimize crosstalk using threshold value multiplex circuits
Assignee: Siemens AG
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Filing: 1982-02-19
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Granted: 1984-10-02
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Expires: 2002-02-19
Abstract
Abstract In a broad-band communications system, whose subscriber lines are preferably formed by light wave guides, and by way of which television broad-band signals are transmitted as pulse-modulated signals, for television program distribution, each television program is supplied, in a plurality of time channels, to time channel individual inputs in program source individual switching planes of a broad-band switching arrangement. In order to increase the blocking attenuation, crosspoint switches which lead to one and the same output are connected via multiplex logic linking elements to the output in question of the broad-band switching arrangement. When a crosspoint switch is blocked, the broad-band signal in question then experiences the cascaded blocking attenuation of a crosspoint switch and a threshold value multiplex circuit. The crosspoint switches and the threshold value multiplex circuits are preferably formed by logic linking elements constructed in accordance with ECL technology.
Inventors
- 👤 Udo Barabas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:25
CPC Classifications
H; H04; H04N; H04N21/00; H04N21/20; H04N21/23; H04N21/236; H04N21/2365; H04N21/40; H04N21/43; H04N21/434; H04N21/4347; H04N7/00; H04N7/22; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04J; H04J2203/00; H04J2203/0001; H04J2203/0003
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
196 words
A broad-band exchange system for selectively connecting broad-band signal sources to subscriber stations which receive broad-band signals, comprising: a crosspoint matrix including a plurality of crosspoint switches arranged in a plurality of switching planes and in columns and rows in each of said switching planes; a plurality of broad-band signal sources each assigned to a respective switching plane and each including scanning means operable to provide signals in a plurality of time channels equal in number to the number of channels which can be simultaneously connected to a subscriber station; input means including a plurality of input logic circuits each connecting the crosspoint switches of a respective row to receive signals of a respective channel of the signal source assigned to that respective switching plane; output means including a plurality of threshold value multiplex circuits each connected to the crosspoint switches of a column of a respective switching plane, and a plurality of subscriber output lines each connected to the threshold value multiplex circuits of corresponding columns of each switching plane, each of said threshold value multiplex circuits having a threshold value which cannot be overshot by signals which are blocked by an appertaining crosspoint switch.
Claim 2
Dependent Claim
196 words
A broad-band exchange system for selectively connecting broad-band signal sources to subscriber stations which receive broad-band signals, comprising: a crosspoint matrix including a plurality of crosspoint switches arranged in a plurality of switching planes and in columns and rows in each of said switching planes; a plurality of broad-band signal sources each assigned to a respective switching plane and each including scanning means operable to provide signals in a plurality of time channels equal in number to the number of channels which can be simultaneously connected to a subscriber station; input means including a plurality of input logic circuits each connecting the crosspoint switches of a respective row to receive signals of a respective channel of the signal source assigned to that respective switching plane; output means including a plurality of threshold value multiplex circuits each connected to the crosspoint switches of a column of a respective switching plane, and a plurality of subscriber output lines each connected to the threshold value multiplex circuits of corresponding columns of each switching plane, each of said threshold value multiplex circuits having a threshold value which cannot be overshot by signals which are blocked by an appertaining crosspoint switch.
Claim 3
Dependent Claim
43 words
The broad-band exchange system of claim 1, wherein: said scanning means comprises means for scanning at a frequency corresponding to the number of time channels and providing modulated signals representing the scan values to the associated time channels of the associated switching plane.
Claim 4
Dependent Claim
66 words
The broad-band exchange system of claim 1, wherein: said scanning means comprises means for scanning at a scanning rate which corresponds to a single time channel; and means including a plurality of serially-connected delay devices and a plurality of taps for distributing the signal in a stepped manner by one time channel each, and said taps connected to said input means of the associated switching plane.
Claim 5
Dependent Claim
21 words
The broad-band exchange system of claim 1, wherein: each of said threshold value multiplex circuits comprises a multiplex logic linking element.
Claim 6
Dependent Claim
47 words
The broad-band exchange system of claim 1, wherein: each of said threshold value multiplex circuit includes a threshold value switch and an output which is connected to the respective subscriber output line in common with the outputs of other threshold value multiplex circuits of different switching planes.
Claim 7
Dependent Claim
58 words
The broad-band exchange system of claim 1, wherein: each of said threshold value multiplex circuits comprises a first input which is connected to those of said crosspoint switches which are not of adjacent rows and a second input which is connected to those crosspoint switches which are not of adjacent rows but alternate with the first-mentioned adjacent rows.
Claim 8
Dependent Claim
14 words
The broad-band exchange system of claim 1, wherein: said crosspoint switches are ECL switches.
Claim 9
Dependent Claim
16 words
The broad-band exchange system of claim 1, wherein: said threshold value multiplex circuits are ECL switches.
Claim 10
Dependent Claim
20 words
The broad-band exchange system of claim 1, wherein: said crosspoint switches and said threshold value multiplex circuits are ECL switches.
Claim 11
Dependent Claim
17 words
The broad-band exchange system of claim 1, wherein: said crosspoint switches comprise AND gates and NOR gates.
Claim 12
Dependent Claim
70 words
The broad-band exchange system of claim 1, wherein: said input logic circuits each comprise continuously unlocked logic linking elements including chain-connected elements some of which provide negation, some of said crosspoint switches, in the case of 2n-2 negations where n=1, 2 . . . , comprise AND gates; and others of said crosspoint switches, in the case of 2n-1 negations, where n=1, 2 . . . , comprise NOR gates.
References Cited (Backward Citations)
US4345273A
Cited
US4382266A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |