US3749845A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital data communication system
Assignee: AT&T Inc
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Filing: 1971-08-27
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Granted: 1973-07-31
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Expires: 1991-08-27
Abstract
Abstract A digital data transmission system comprising a plurality of interconnected switching units, each such unit having connected thereto at least one transmission loop, and each such loop having at least one digital device attached thereto. The system provides controllable buffering of digital data thereby allowing digital devices having different data transfer speeds and storage capabilities to communicate asynchronously. The system allocates communication resources upon request but only creates actual communication paths when the requesting device is transmitting data. Thus system resources need not remain committed between bursts of data.
Inventors
- 👤 A Fraser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:09
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/28; H04L12/46; H04L12/4637; H04L5/00; H04L5/02
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
47 words
A data transmission system for a plurality of digital devices comprising: means for virtually allocating transmission paths upon request from any of said digital devices to any other of said digital device; and means for activating said virtually allocated transmission paths only when data is actually transmitted.
Claim 2
Dependent Claim
47 words
A data transmission system for a plurality of digital devices comprising: means for virtually allocating transmission paths upon request from any of said digital devices to any other of said digital device; and means for activating said virtually allocated transmission paths only when data is actually transmitted.
Claim 3
Dependent Claim
67 words
A digital data transmission syStem, including a plurality of transmission loops, each including at least one digital device, comprising: means for virtually allocating a transmission path from a digital device in one loop to a digital device in another loop comprising a plurality of asynchronous links; and means for activating particular ones of said links only when data is actually available at said particular ones for transmission.
Claim 4
Dependent Claim
67 words
A digital data transmission syStem, including a plurality of transmission loops, each including at least one digital device, comprising: means for virtually allocating a transmission path from a digital device in one loop to a digital device in another loop comprising a plurality of asynchronous links; and means for activating particular ones of said links only when data is actually available at said particular ones for transmission.
Claim 5
Dependent Claim
43 words
A data transmission system comprising: means for receiving requests to virtually allocate communication paths; means for storing descriptions of requested communication paths; and means for using the stored descriptions to create the requested communication paths only when data is actually available for transmission.
Claim 6
Dependent Claim
43 words
A data transmission system comprising: means for receiving requests to virtually allocate communication paths; means for storing descriptions of requested communication paths; and means for using the stored descriptions to create the requested communication paths only when data is actually available for transmission.
Claim 7
Dependent Claim
50 words
A data transmission system comprising: means for receiving requests to establish communication paths; means for storing descriptions of requested communication paths comprising a plurality of asynchronous links; and means for activating particular ones of the plurality of links only when data is actually available at the particular ones for transmission.
Claim 8
Dependent Claim
50 words
A data transmission system comprising: means for receiving requests to establish communication paths; means for storing descriptions of requested communication paths comprising a plurality of asynchronous links; and means for activating particular ones of the plurality of links only when data is actually available at the particular ones for transmission.
Claim 9
Independent Claim
68 words
A system for providing data communication between a plurality of digital devices comprising: means for receiving requests for the use of communication paths from each one of said plurality of digital devices; means for virtually allocating communication paths in response to said requests and prior to actual use of said paths; and means for actually connecting said virtually allocated communication paths at the time data is actually transmitted.
Claim 10
Independent Claim
68 words
A system for providing data communication between a plurality of digital devices comprising: means for receiving requests for the use of communication paths from each one of said plurality of digital devices; means for virtually allocating communication paths in response to said requests and prior to actual use of said paths; and means for actually connecting said virtually allocated communication paths at the time data is actually transmitted.
Claim 11
Dependent Claim
110 words
A digital data transmission system comprising: a first switching unit; a first digital device attached to said first switching unit; a second switching unit connected to said first switching unit; a second digital device attached to said second switching unit; means for virtually allocating a first transmission path between said first digital device and said first switching unit; means for virtually allocating a second transmission path between said first switching unit and said second switching unit; means for virtually allocating a third transmission path between said second switching unit and said second digital device; and means for selectively activating each of said first, second, and third virtually allocated transmission paths.
Claim 12
Dependent Claim
110 words
A digital data transmission system comprising: a first switching unit; a first digital device attached to said first switching unit; a second switching unit connected to said first switching unit; a second digital device attached to said second switching unit; means for virtually allocating a first transmission path between said first digital device and said first switching unit; means for virtually allocating a second transmission path between said first switching unit and said second switching unit; means for virtually allocating a third transmission path between said second switching unit and said second digital device; and means for selectively activating each of said first, second, and third virtually allocated transmission paths.
Claim 13
Dependent Claim
47 words
The digital data transmission system of claim 6 wherein each of the three means for virtually allocating a transmission path further comprises: means for storing parameters characterizing the data which is to be transmitted; and means for initiating the virtual allocation of the next succeeding transmission path.
Claim 14
Dependent Claim
100 words
The digital data transmission system of claim 6 wherein said means for selectively activating each of said first, second, and third virtually allocated transmission paths further comprises: means for activating said first virtually allocated transmission path only when said first digital device is actually transmitting data; means for activating said second virtually allocated transmission path only when said first switching unit is actually retransmitting data received from said first digital device; means for activating said third virtually allocated transmission path only when said second switching unit is actually retransmitting that data received from said retransmission by said first switching unit.
Claim 15
Dependent Claim
51 words
The digital data transmission system of claim 8 wherein each of the three means for activating a transmission path further comprises: means for receiving incoming data which is to be retransmitted on said transmission path; means for storing said incoming data; and means for retransmitting said data on said transmission path.
Claim 16
Dependent Claim
34 words
The digital data transmission system of claim 9 wherein said means for storing said incoming data further comprises: means for selectively limiting the total amount of incoming data which is stored at any time.
Claim 17
Dependent Claim
49 words
ThE digital data transmission system of claim 10 wherein said selectively limiting means further comprises: means for causing the device that is transmitting said incoming data to cease transmission when the amount of said incoming data that has not been retransmitted on said transmission path reaches a prespecified value.
Claim 18
Independent Claim
42 words
A system for transmitting data between digital devices comprising: a plurality of interconnected program-controlled switching units; at least one program-controlled terminal interface unit attached to each one of said plurality of interconnected program-controlled switching units for communication therewith by a digital device.
Claim 19
Independent Claim
42 words
A system for transmitting data between digital devices comprising: a plurality of interconnected program-controlled switching units; at least one program-controlled terminal interface unit attached to each one of said plurality of interconnected program-controlled switching units for communication therewith by a digital device.
Claim 20
Dependent Claim
31 words
The system of claim 12 further comprising: means for selectively limiting the amount of buffering that said system provides in each switching unit for each digital device that is attached thereto.
Claim 21
Dependent Claim
33 words
The system of claim 13 further comprising: means for selectively limiting the minimum amount of data that said system permits each digital device attached thereto to transmit in a single burst of transmission.
Claim 22
Dependent Claim
32 words
The system of claim 14 further comprising: means for selectively limiting the minimum amount of data that said system transmits to each digital device attached thereto in a single burst of transmission.
Claim 23
Dependent Claim
26 words
The system of claim 14 further comprising: means for selectively limiting the rate at which said system permits each digital device attached thereto to transmit data.
Claim 24
Dependent Claim
25 words
The system of claim 15 further comprising: means for selectively limiting the rate at which said system transmits data to each digital device attached thereto.
Claim 25
Independent Claim
53 words
The method of transmitting data comprising the steps of: receiving requests for the use of transmission resources from transmitting devices; storing descriptions of the transmission resources necessary to honor the received requests; committing transmission resources to particular transmitting devices in accordance with the stored descriptions only at the time data is actually transmitted.
Claim 26
Independent Claim
53 words
The method of transmitting data comprising the steps of: receiving requests for the use of transmission resources from transmitting devices; storing descriptions of the transmission resources necessary to honor the received requests; committing transmission resources to particular transmitting devices in accordance with the stored descriptions only at the time data is actually transmitted.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |