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US4719625A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of recovering from transmission errors in a local area network by transmitting and receiving silence on all network ports

Assignee: Unisys Corp
•
Filing: 1986-03-24
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Granted: 1988-01-12
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Expires: 2006-03-24
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Abstract

Abstract A method of recovering from a transmission error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network includes the steps of: receiving on the first port, messages which are separated by idle characters and regenerating same on the second port; detecting the error during the receiving step; and responding to the detection of the error by (a) transmitting silence on both the first and second ports and (b) waiting for the receipt of silence on the ports, prior to passing any further messages through the station.

Inventors

  • 👤 John L. Bell
  • 👤 Thomas J. Dineen
  • 👤 Dennis J. Mahon

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 13:46
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/42; H04L12/437

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 104 words
A method of recovering from an error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network; said method including the steps of: receiving on said first port, messages which are separated by idle characters and regenerating same on said second port; detecting said error during said receiving step; and responding to the detection of said error by (a) transmitting silence on both said first and second ports and (b) waiting for a predetermined response on said ports to said transmitting of said silence, prior to passing any further messages through said station.
Claim 2
Independent Claim 104 words
A method of recovering from an error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network; said method including the steps of: receiving on said first port, messages which are separated by idle characters and regenerating same on said second port; detecting said error during said receiving step; and responding to the detection of said error by (a) transmitting silence on both said first and second ports and (b) waiting for a predetermined response on said ports to said transmitting of said silence, prior to passing any further messages through said station.
Claim 3
Dependent Claim 31 words
A method according to claim 1 wherein said detecting of said error includes detecting the continuous receipt of said idle characters on said first port in excess of a certain limit.
Claim 4
Dependent Claim 30 words
A method according to claim 1 wherein said detecting of said error includes detecting the continuous receipt of a message on said first port in excess of a certain limit.
Claim 5
Dependent Claim 33 words
A method according to claim 1 wherein said detecting of said error includes detecting the interruption of either said idle characters or said messages with the receipt of silence on said first port.
Claim 6
Dependent Claim 26 words
A method according to claim 1 wherein said messages have a pre-established format, and said detecting of said error includes detecting a nonconformance to said format.
Claim 7
Dependent Claim 20 words
A method according to claim 1 wherein said predetermined response includes receiving silence on both said first and second ports.
Claim 8
Dependent Claim 34 words
A method according to claim 1 wherein said predetermined response includes receiving silence on one of said ports and continuously receiving any signal except silence on the other port for a selected time interval.
Claim 9
Independent Claim 87 words
A method of recovering from an error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network; said method including the steps of: receiving on said first port, messages which are separated by idle characters and internally coupling same through said station to said second port; detecting an error during said receiving step; and responding to the detection of said error by breaking said internal coupling and transmitting silence on both said first and second ports.
Claim 10
Independent Claim 87 words
A method of recovering from an error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network; said method including the steps of: receiving on said first port, messages which are separated by idle characters and internally coupling same through said station to said second port; detecting an error during said receiving step; and responding to the detection of said error by breaking said internal coupling and transmitting silence on both said first and second ports.
Claim 11
Dependent Claim 29 words
A method according to claim 8 and further including the step of receiving silence on both said first and second ports as a precondition to reestablishing said internal coupling.
Claim 12
Dependent Claim 43 words
A method according to claim 8 and further including the step of receiving silence on one of said ports and continuously receiving any signal except silence on the other port for a selected time interval as a precondition to establishing said internal coupling.
Claim 13
Independent Claim 81 words
A method of recovering from an error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network, said method including the steps of: receiving signals on said first port, and internally coupling same through said station to said second port; detecting an error condition in said signals; and responding to the detection of said error by breaking said internal coupling and transmitting silence on both said first and second ports.
Claim 14
Independent Claim 81 words
A method of recovering from an error in a station having first and second input-output ports which are respectively coupled to two other stations in a communication network, said method including the steps of: receiving signals on said first port, and internally coupling same through said station to said second port; detecting an error condition in said signals; and responding to the detection of said error by breaking said internal coupling and transmitting silence on both said first and second ports.

References Cited (Backward Citations)

US4516121A Cited
US4542496A Cited
US4538264A Cited
US4633246A Cited
US4519070A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-01-11 1991-07-13 1992-01-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-01-11 1995-07-13 1996-01-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-01-11 1999-07-13 2000-01-12 $7700.00 Window Closed / Lapsed

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