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US4954965A Expired / Lapsed US ⏱️ 0.0 years remaining

Enhanced frame utilization for CSMA/CD communication protocol

Assignee: International Business Machines Corp
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Filing: 1989-02-09
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Granted: 1990-09-04
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Expires: 2009-02-09
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Abstract

Abstract In a CSMA/CD communication protocol, data to be sent from one device on a communication network to another is put into frames, or predetermined sized pieces of information. One of the fields in a frame, the pad field, is used to make the total size of the frame large enough to ensure that a collision anywhere in the network with another frame is detected by the senders. The pad field is further used to identify when a data record will be continued in the next frame and also to identify when multiple data records are being sent in the same frame.

Inventors

  • 👤 John M. Johnson
  • 👤 James A. Rocke
  • 👤 Divakara K. R. Udupa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 04:31
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; H04L12/413

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 147 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for determining when data from a single record is put into more than one different frame to be transmitted: means coupled to the frame generating means for inserting in said frames indications to identify the different frames which contain data from the single record; means coupled to said frame generating means for inserting in said frames indications to differentiate between data records contained in the same frame; and means coupled to the identifying means for transmitting said frames to the other node.
Claim 2
Independent Claim 147 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for determining when data from a single record is put into more than one different frame to be transmitted: means coupled to the frame generating means for inserting in said frames indications to identify the different frames which contain data from the single record; means coupled to said frame generating means for inserting in said frames indications to differentiate between data records contained in the same frame; and means coupled to the identifying means for transmitting said frames to the other node.
Claim 3
Independent Claim 158 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for inserting a more bit in a pad field of a frame to indicate that there is more data in a record; means coupled to the frame generating means for inserting a record number in the pad field of a frame to indicate an ordering of data in a record; means coupled to the network for receiving at least one frame from the network; means coupled to the frame receiving means for assembling a record from data contained in multiple frames, each of said frames having a more bit and a record number.
Claim 4
Independent Claim 158 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for inserting a more bit in a pad field of a frame to indicate that there is more data in a record; means coupled to the frame generating means for inserting a record number in the pad field of a frame to indicate an ordering of data in a record; means coupled to the network for receiving at least one frame from the network; means coupled to the frame receiving means for assembling a record from data contained in multiple frames, each of said frames having a more bit and a record number.
Claim 5
Independent Claim 111 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for detecting short record; means coupled to the frame generating means for combining short records in a frame to be transmitted; and means coupled to the frame generating means for inserting representations of record lengths of said combined records in a pad field of said frame.
Claim 6
Independent Claim 111 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for detecting short record; means coupled to the frame generating means for combining short records in a frame to be transmitted; and means coupled to the frame generating means for inserting representations of record lengths of said combined records in a pad field of said frame.
Claim 7
Dependent Claim 62 words
The device of claim 3 further comprising: means coupled to the network for receiving at least one frame from the network; means coupled to the frame receiving means for detecting if there are record length representations in the pad field; and means coupled to the frame receiving means for assembling records in a received frame in accordance with the record length representations.
Claim 8
Dependent Claim 15 words
The device of claim 4 wherein up to 4 records are transmitted to a frame.
Claim 9
Dependent Claim 21 words
The device of claim 5 wherein the record length is compatible with a single line of text displayable on a CRT.
Claim 10
Dependent Claim 22 words
The device of claim 5 wherein the record length is compatible with a single line of text printable by a printing device.
Claim 11
Independent Claim 211 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for inserting a more bit in a pad field of a frame to indicate that there is more data in a record; means coupled to the frame generating means for inserting a record number in the pad field of a frame to indicate an ordering of data in a record; means coupled to the network for receiving one or more frames from the network; means coupled to the frame receiving means for assembling a record from data contained in multiple frames, each of said frames having a more bit and a record number. means coupled to the frame generating means for detecting short records; means coupled to the frame generating means for combining short records in a frame to be transmitted; and means coupled to the frame generating means for inserting representation of record lengths of said combined records in a pad field of said frame.
Claim 12
Independent Claim 211 words
A device for transferring data between nodes coupled to a network having a carrier sense multiple access/collision detect protocol for such data transfer, the device at each node comprising: means for identifying data records to be transferred to another node; means coupled to the identifying means for generating frames containing data from the data records to be transmitted; means coupled to the frame generating means for inserting a more bit in a pad field of a frame to indicate that there is more data in a record; means coupled to the frame generating means for inserting a record number in the pad field of a frame to indicate an ordering of data in a record; means coupled to the network for receiving one or more frames from the network; means coupled to the frame receiving means for assembling a record from data contained in multiple frames, each of said frames having a more bit and a record number. means coupled to the frame generating means for detecting short records; means coupled to the frame generating means for combining short records in a frame to be transmitted; and means coupled to the frame generating means for inserting representation of record lengths of said combined records in a pad field of said frame.
Claim 13
Dependent Claim 24 words
The device of claim 8 wherein the more bit and record number comprise a single predetermined byte of the pad field of each frame.
Claim 14
Dependent Claim 55 words
The device of claim 8 further comprising: means coupled to the frame generating means for indicating optimal frame size; means coupled to the frame generating means for combining records to maintain an optimal size frame; and means coupled to the frame generating means for breaking records into multiple frames to maintain an optimal size frame.
Claim 15
Dependent Claim 20 words
The device of claim 8 wherein the representations of field length each comprise a predetermined byte of the pad field.

References Cited (Backward Citations)

US4543654A Cited
US4688035A Cited
US4757460A Cited
US4745559A Cited
US4750137A Cited
US4771391A Cited
US4837679A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-09-03 1994-03-05 1994-09-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-09-03 1998-03-05 1998-09-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-09-03 2002-03-05 2002-09-04 $7700.00 Window Closed / Lapsed

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