US5229998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing the low-frequency component of jitter in a digital data transmission system
Assignee: Telediffusion de France ets Public de Diffusion
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Filing: 1991-05-30
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Granted: 1993-07-20
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Expires: 2011-05-30
Abstract
Abstract A digital data transmission system comprises at its input a higher order multiplexer receiving at least one stream of digitized data organized into blocks and at a specific timing, said multiplexer transmitting each block of data in a digital multiplex to the output of the transmission system via a digitized data transmission channel subject to a variable multiplexing delay. To reduce the low-frequency component of the jitter in a timing signal reconstituted at the output of the system, the multiplexing delay is measured for the current transmission of a block of data in the multiplex and the measured multiplexing delay is compared with a reference value to determine a multiplexing delay offset and if necessary to defer said current transmission. The measurement and comparison are repeated for the next transmission of a block of data in the multiplex using in the comparison the multiplexing offsets determined for previous transmissions.
Inventors
- 👤 Alain Weisser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:14
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/062; H04J3/0632; H04J3/0626; H04J3/0629
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
155 words
Method of reducing the low-frequency component of the jitter in a timing signal reconstituted at the output of a digital data transmission system of the type comprising at its input a higher order multiplexer receiving at least two streams of digitized data organized into blocks and at a specific timing, said multiplexer transmitting each block of data in a digital multiplex to the output of the transmission system via a digitized data transmission channel subject to a variable multiplexing delay, in which method: a) the multiplexing delay is measured for the current transmission of a block of data in the multiplex, b) the measured multiplexing delay is compared with a reference value to determine a multiplexing delay offset and selectively defer said current transmission, c) stages a) and b) are repeated for the next transmission of a block of data in the multiplex using in stage b) the multiplexing delay offsets determined for previous transmissions.
Claim 2
Dependent Claim
155 words
Method of reducing the low-frequency component of the jitter in a timing signal reconstituted at the output of a digital data transmission system of the type comprising at its input a higher order multiplexer receiving at least two streams of digitized data organized into blocks and at a specific timing, said multiplexer transmitting each block of data in a digital multiplex to the output of the transmission system via a digitized data transmission channel subject to a variable multiplexing delay, in which method: a) the multiplexing delay is measured for the current transmission of a block of data in the multiplex, b) the measured multiplexing delay is compared with a reference value to determine a multiplexing delay offset and selectively defer said current transmission, c) stages a) and b) are repeated for the next transmission of a block of data in the multiplex using in stage b) the multiplexing delay offsets determined for previous transmissions.
Claim 3
Dependent Claim
43 words
Method according to claim 1 wherein the use in stage c) of the multiplexing delay offsets determined for previous transmissions consists in successively accumulating said multiplexing delay offsets and compensating for the accumulative result when comparing the multiplexing delay with said reference value.
Claim 4
Dependent Claim
19 words
Method according to claim 1 wherein said multiplexing delay reference value is greater than the maximum multiplexing delay value.
Claim 5
Dependent Claim
20 words
Method according to claim 1 wherein the multiplexing delay is measured by means of a counter incremented by clock pulses.
Claim 6
Dependent Claim
19 words
Method according to claim 4 wherein the multiplexing delay reference value represented by a predetermined number of clock pulses.
Claim 7
Dependent Claim
36 words
Method according to claim 5 wherein the transmission of a block of data in the multiplex is deferred if the count value of said counter is not at least equal to the multiplexing delay reference value.
Claim 8
Dependent Claim
19 words
Method according to claim 5 wherein the multiplexing delay time reference value is the value when said counter overflows.
Claim 9
Dependent Claim
39 words
Method according to claim 5 wherein the multiplexing delay offset is determined by subtracting from the value of the counter when the block of data is transmitted in the multiplex the count value representing the multiplexing delay reference value.
Claim 10
Dependent Claim
34 words
Method according to claim 4 wherein the multiplexing delay offsets are accumulated by successively carrying forward a multiplexing delay offset for the transmission into the measured multiplexing delay for transmission of the next block.
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) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |