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US5636203A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and system for identifying fault locations in a communications network

Assignee: MCI Corp
•
Filing: 1995-06-07
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Granted: 1997-06-03
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Expires: 2015-06-07
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Abstract

Abstract All nodes on a malfunctioned communications circuit of a communications network are enabled to identify the location of the fault causing the circuit malfunction. Upon detecting an incoming signal impairment on the circuit, each node on the circuit first assumes that the failure is on the segment of the circuit immediately upstream thereof, and accordingly sends an identifier of that fault location to its downstream nodes. Each node periodically repeats sending its identifier to its downstream nodes. A node that has sent its identifier at least a predetermined number of times without receiving a similar identifier from another node upstream thereof or without having detected a normal signal during all that time is determined to have sent out an identifier that correctly identifies the fault location on the communications circuit. If, on the other hand, a node receives a fault location identifier from a node upstream thereof before it has completed sending its identifier a predetermined number of times, then that node would stop sending its own identifier downstream. And upon receiving the same fault location identifier from an upstream node a predetermined number of times, that node further recognizes that the received identifier represents the correct location of the fault. The fault location identification process is terminated if the signal returns to the normal condition during the process.

Inventors

  • 👤 Jasvantrai C. Shah

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 18:22
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/24; H04M; H04M3/00; H04M3/08; H04M3/22; H04M3/2254; H04Q; H04Q3/00; H04Q3/0016; H04Q3/0062; H04Q3/0075; H04Q3/0079; Y; Y10; Y10S; Y10S370/00; Y10S370/901; Y10S370/902; Y10S370/903; Y10S370/907

Claims Analysis

Total Claims: 57
Claim 1
Independent Claim 131 words
In a communications network having a plurality of nodes and a plurality of communications circuits interconnecting said nodes, each of said nodes along a communications circuit having detected a fault signal caused by a fault in said communications circuit, a method for said each node along said communications circuit to identify the location of said fault in said circuit, comprising the steps of: transmitting periodically a fault location identifier originated by said each node onto said communications circuit; stopping transmission of said originated fault location identifier upon receipt of another identifier or a normal signal from an upstream node; and confirming said originated fault location identifier to be representative of the correct location of said fault if said originated fault location identifier was sent at least a predetermined number of times.
Claim 2
Dependent Claim 131 words
In a communications network having a plurality of nodes and a plurality of communications circuits interconnecting said nodes, each of said nodes along a communications circuit having detected a fault signal caused by a fault in said communications circuit, a method for said each node along said communications circuit to identify the location of said fault in said circuit, comprising the steps of: transmitting periodically a fault location identifier originated by said each node onto said communications circuit; stopping transmission of said originated fault location identifier upon receipt of another identifier or a normal signal from an upstream node; and confirming said originated fault location identifier to be representative of the correct location of said fault if said originated fault location identifier was sent at least a predetermined number of times.
Claim 3
Dependent Claim 67 words
Method of claim 1, wherein upon receipt of any incoming fault location identifier in said stopping step, the method further comprising the step of: confirming that said any received fault location identifier is representative of the correct location of said fault when the same identifier is received said predetermined number of times and no normal signal is received before the last of said predetermined number of times.
Claim 4
Dependent Claim 30 words
Method of claim 1, further comprising the step of: determining that there is no fault in said communications circuit if a normal signal is received prior to said confirming step.
Claim 5
Dependent Claim 32 words
Method of claim 2, further comprising the step of: determining that there is no fault in said communications circuit if a normal signal is received prior to either of said confirming steps.
Claim 6
Dependent Claim 32 words
Method of claim 1, wherein said transmitting step further comprises the step of: providing said fault identifier with an indicia identifying one of the nodes bracketing said fault along said communications circuit.
Claim 7
Dependent Claim 32 words
Method of claim 1, wherein said transmitting step further comprises the step of: providing said fault identifier with indicia respectively identifying both of the nodes bracketing said fault along said communications circuit.
Claim 8
Dependent Claim 50 words
Method of claim 1, wherein after said each node has detected said fault signal, said method further comprises the step of: reformatting said fault signal to another fault signal such that nodes downstream of said each node are informed of said fault when said another fault signal is broadcast thereto.
Claim 9
Dependent Claim 38 words
Method of claim 7, wherein said fault signal is a Synchronous Transport Signal Level 1 (STS-1) Alarm Indication Signal (AIS), said reformatting step further comprises the step of: asserting said AIS into an Incoming Signal Failure (ISF) signal.
Claim 10
Dependent Claim 36 words
Method of claim 7, wherein said fault signal is a Digital Service Level 3 (DS-3) Alarm Indication Signal (AIS), said reformatting step further comprises the step of: changing said DS-3 AIS into a DS-3 IDLE signal.
Claim 11
Dependent Claim 53 words
Method of claim 1, wherein said fault location identifier comprises a Synchronous Optical Network (SONET) formatted signal having a frame with an overhead byte, said method further comprising the steps of: using said overhead byte to store an indicium; deriving the identification of said fault from said indicia stored in said overhead byte.
Claim 12
Dependent Claim 36 words
Method of claim 10, wherein said deriving step further comprises the step of: using the Z4 byte in a Path Overhead (POH) of said SONET signal to derive the message channel for transmitting said fault signal.
Claim 13
Dependent Claim 51 words
Method of claim 10, wherein said fault location identifier comprises a Digital Service Level 3 (DS-3) formatted signal having an overhead bit, said method further comprising the steps of: using said overhead bit to store an indicium; deriving the identification of said fault from said indicia stored in said overhead bit.
Claim 14
Dependent Claim 32 words
Method of claim 12, wherein said deriving step further comprises the step of: using an X bit in said DS-3 overhead bit to derive the message channel for transmitting said fault signal.
Claim 15
Independent Claim 199 words
A method of identifying to all nodes of a communications path of a telecommunications network the location of a fault along said path when said fault occurs in said path, said network having a plurality of nodes interconnected by a plurality of circuits, said path including a number of said nodes interconnected by a number of said circuits, said method comprising the step of: effecting each node of said path to (i) monitor each incoming signal from nodes upstream thereof along said path; (ii) determine if said each incoming signal is an alarm signal indicating said fault; (iii) transmit an identifier to nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof; (iv) continue to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupt the transmission of said identifier upon receipt of either said other identifier or said normal signal; and (vi) conclude said fault to have occurred immediately upstream of said each node if said identifier is transmitted said predetermined number of times.
Claim 16
Independent Claim 199 words
A method of identifying to all nodes of a communications path of a telecommunications network the location of a fault along said path when said fault occurs in said path, said network having a plurality of nodes interconnected by a plurality of circuits, said path including a number of said nodes interconnected by a number of said circuits, said method comprising the step of: effecting each node of said path to (i) monitor each incoming signal from nodes upstream thereof along said path; (ii) determine if said each incoming signal is an alarm signal indicating said fault; (iii) transmit an identifier to nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof; (iv) continue to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupt the transmission of said identifier upon receipt of either said other identifier or said normal signal; and (vi) conclude said fault to have occurred immediately upstream of said each node if said identifier is transmitted said predetermined number of times.
Claim 17
Dependent Claim 44 words
Method of claim 14, further comprising the step of: effecting said each node to conclude said fault to have occurred immediately upstream of the node that sent said other identifier if said each node has received said other identifier said predetermined number of times.
Claim 18
Dependent Claim 42 words
Method of claim 14, further comprising the step of: concluding said fault not to be an actual fault if said normal signal is received before said identifier has been transmitted or said other identifier has been received said predetermined number of times.
Claim 19
Dependent Claim 33 words
Method of claim 14, further comprising the step of: providing said identifier with an indicium identifying said each node as being one of the nodes adjacent to said fault along said communications path.
Claim 20
Dependent Claim 32 words
Method of claim 14, further comprising the step of: providing said identifier with indicia respectively identifying said each node and its custodial node which together bracket said fault along said communications circuit.
Claim 21
Dependent Claim 42 words
Method of claim 14 wherein said effecting step further comprises the step of: reformatting said alarm signal into a fault signal for carrying said identifier to nodes downstream of said each node to inform said downstream nodes the location of said fault.
Claim 22
Independent Claim 239 words
A method of identifying to all nodes of a communications path of a telecommunications network the location of a malfunctioned span along said path, said network having a plurality of nodes interconnected by a plurality of spans, said path including a number of said nodes interconnected by a number of said spans, said method comprising the steps of: (a) effecting each node on either side of said malfunctioned span of said path to (i) monitor each incoming signal from nodes upstream thereof along said path; (ii) determine if said each incoming signal is an alarm signal indicating a fault; (iii) transmit an identifier to the nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof toward said malfunctioned span; (iv) continue to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupt the transmission of said identifier upon receipt of either said other identifier or said normal signal; (b) each of two adjacent nodes bracketing said malfunctioned span deciding said each adjacent node to be one of the nodes bracketing said malfunctioned span if said each adjacent node has transmitted its identifier said predetermined number of times; (c) retrieving the location of said two adjacent nodes to thereby determine the location of said malfunctioned span.
Claim 23
Independent Claim 239 words
A method of identifying to all nodes of a communications path of a telecommunications network the location of a malfunctioned span along said path, said network having a plurality of nodes interconnected by a plurality of spans, said path including a number of said nodes interconnected by a number of said spans, said method comprising the steps of: (a) effecting each node on either side of said malfunctioned span of said path to (i) monitor each incoming signal from nodes upstream thereof along said path; (ii) determine if said each incoming signal is an alarm signal indicating a fault; (iii) transmit an identifier to the nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof toward said malfunctioned span; (iv) continue to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupt the transmission of said identifier upon receipt of either said other identifier or said normal signal; (b) each of two adjacent nodes bracketing said malfunctioned span deciding said each adjacent node to be one of the nodes bracketing said malfunctioned span if said each adjacent node has transmitted its identifier said predetermined number of times; (c) retrieving the location of said two adjacent nodes to thereby determine the location of said malfunctioned span.
Claim 24
Dependent Claim 37 words
Method of claim 20, further comprising the step of: concluding said span not to be malfunctioning if said normal signal is received before either of said adjacent nodes has transmitted its identifier said predetermined number of times.
Claim 25
Dependent Claim 40 words
Method of claim 20, further comprising the step of: providing said respective identifiers of said adjacent nodes with corresponding indicia for identifying said each adjacent node to be one of the nodes bracketing said malfunctioned span along said communications path.
Claim 26
Dependent Claim 43 words
Method of claim 20 wherein said effecting step further comprises the step of: reformatting said alarm signal into a fault signal for carrying said identifier to nodes downstream of said each node to inform said downstream nodes the location of said malfunctioned span.
Claim 27
Dependent Claim 38 words
Method of claim 23, wherein said alarm signal is a Synchronous Transport Signal Level 1 (STS-1) Alarm Indication Signal (AIS), said reformatting step further comprises the step of: asserting said AIS into an Incoming Signal Failure (ISF) signal.
Claim 28
Dependent Claim 36 words
Method of claim 23, wherein said alarm signal is a Digital Service Level 3 (DS-3) Alarm Indication Signal (AIS), said reformatting step further comprises the step of: changing said DS-3 AIS into a DS-3 IDLE signal.
Claim 29
Dependent Claim 52 words
Method of claim 20, wherein said identifier comprises a Synchronous Optical Network (SONET) formatted message having a frame with an overhead byte, said method further comprising the steps of: using said overhead byte to store an indicium; deriving the identification of said malfunctioned span from said indicia stored in said overhead byte.
Claim 30
Dependent Claim 35 words
Method of claim 26, wherein said deriving step further comprises the step of: using the Z4 byte in a Path Overhead (POH) of said SONET message to derive the message channel for transmitting said identifier.
Claim 31
Dependent Claim 50 words
Method of claim 20, wherein said identifier comprises a Digital Service Level 3 (DS-3) formatted signal having an overhead bit, said method further comprising the steps of: using said overhead bit to store an indicium; deriving the identification of said malfunctioned span from said indicia stored in said overhead bit.
Claim 32
Dependent Claim 31 words
Method of claim 28, wherein said deriving step further comprises the step of: using an X bit in said DS-3 overhead bit to derive the message channel for transmitting said identifier.
Claim 33
Dependent Claim 197 words
System for identifying to all nodes of a communications path of a telecommunications network the location of a fault along said path when said fault occurs in said path, said network having a plurality of nodes interconnected by a plurality of circuits, said path including a number of said nodes interconnected by a number of said circuits, said system comprising: cross-connect means in each node of said path for (i) monitoring each incoming signal from nodes upstream thereof along said path; (ii) determining if said each incoming signal is an alarm signal indicating said fault; (iii) transmitting an identifier to nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof; (iv) continuing to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupting the transmission of said identifier upon receipt of either said other identifier or said normal signal; and (vi) concluding said fault to have occurred immediately upstream of said each node if said identifier is transmitted said predetermined number of times.
Claim 34
Dependent Claim 197 words
System for identifying to all nodes of a communications path of a telecommunications network the location of a fault along said path when said fault occurs in said path, said network having a plurality of nodes interconnected by a plurality of circuits, said path including a number of said nodes interconnected by a number of said circuits, said system comprising: cross-connect means in each node of said path for (i) monitoring each incoming signal from nodes upstream thereof along said path; (ii) determining if said each incoming signal is an alarm signal indicating said fault; (iii) transmitting an identifier to nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof; (iv) continuing to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupting the transmission of said identifier upon receipt of either said other identifier or said normal signal; and (vi) concluding said fault to have occurred immediately upstream of said each node if said identifier is transmitted said predetermined number of times.
Claim 35
Dependent Claim 44 words
System of claim 30, wherein said cross-connect means further effects said each node to conclude said fault to have occurred immediately upstream of the node that sent said other identifier if said each node has received said other identifier said predetermined number of times.
Claim 36
Dependent Claim 42 words
System of claim 30, further comprising; decision means for concluding said fault not to be an actual fault if said normal signal is received before said identifier has been transmitted or said other identifier has been received said predetermined number of times.
Claim 37
Dependent Claim 32 words
System of claim 30, further comprising: means for providing said identifier with an indicium identifying said each node as being one of the nodes adjacent to said fault along said communications path.
Claim 38
Dependent Claim 31 words
System of claim 30, further comprising: means for providing said identifier with indicia respectively identifying said each node and its custodial node which together bracket said fault along said communications path.
Claim 39
Dependent Claim 41 words
System of claim 30 wherein said effecting means further comprises: means for reformatting said alarm signal into a fault signal for carrying said identifier to nodes downstream of said each node to inform said downstream nodes the location of said fault.
Claim 40
Dependent Claim 234 words
System for identifying to all nodes of a communications path of a telecommunications network the location of a malfunctioned span along said path, said network having a plurality of nodes interconnected by a plurality of spans, said path including a number of said nodes interconnected by a number of said spans, said system comprising: means in each node on either side of said malfunctioned span of said path for (i) monitoring each incoming signal from nodes upstream thereof along said path; (ii) determining if said each incoming signal is an alarm signal indicating a fault; (iii) transmitting an identifier to the nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof toward said malfunctioned span; (iv) continuing to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupting the transmission of said identifier upon receipt of either said other identifier or said normal signal; means for deciding each of two adjacent nodes bracketing said malfunctioned span to be one of the nodes bracketing said malfunctioned span if said each adjacent node has transmitted its identifier said predetermined number of times; and means for retrieving the location of said two adjacent nodes to thereby determine the location of said malfunctioned span.
Claim 41
Dependent Claim 234 words
System for identifying to all nodes of a communications path of a telecommunications network the location of a malfunctioned span along said path, said network having a plurality of nodes interconnected by a plurality of spans, said path including a number of said nodes interconnected by a number of said spans, said system comprising: means in each node on either side of said malfunctioned span of said path for (i) monitoring each incoming signal from nodes upstream thereof along said path; (ii) determining if said each incoming signal is an alarm signal indicating a fault; (iii) transmitting an identifier to the nodes downstream thereof along said path upon detection of said alarm signal, said identifier indicating said fault to have occurred immediately upstream thereof toward said malfunctioned span; (iv) continuing to transmit said identifier a predetermined number of times so long as no other identifier from a node upstream thereof or a normal signal is received by said each node; (v) interrupting the transmission of said identifier upon receipt of either said other identifier or said normal signal; means for deciding each of two adjacent nodes bracketing said malfunctioned span to be one of the nodes bracketing said malfunctioned span if said each adjacent node has transmitted its identifier said predetermined number of times; and means for retrieving the location of said two adjacent nodes to thereby determine the location of said malfunctioned span.
Claim 42
Dependent Claim 36 words
System of claim 36, further comprising: means for deciding said span not to be malfunctioning if said normal signal is received before either of said adjacent nodes has transmitted its identifier said predetermined number of times.
Claim 43
Dependent Claim 39 words
System of claim 36, further comprising: means for providing said respective identifiers of said adjacent nodes with corresponding indicia for identifying said each adjacent node to be one of the nodes bracketing said malfunctioned span along said communications path.
Claim 44
Dependent Claim 45 words
System of claim 38 wherein said means in said each node further comprises: means for reformatting said alarm signal into a fault signal for carrying said identifier to nodes downstream of said each node to inform said downstream nodes the location of said malfunctioned span.
Claim 45
Dependent Claim 39 words
System of claim 36, wherein said alarm signal is a Synchronous Transport Signal Level 1 (STS-1) Alarm Indication Signal (AIS); and wherein said means in said each node further converts said AIS into an Incoming Signal Failure (ISF) signal.
Claim 46
Dependent Claim 36 words
System of claim 36, wherein said alarm signal is a Digital Service Level 3 (DS-3) Alarm Indication Signal (AIS); wherein said means in said each node further converts said DS-3 AIS into a DS-3 IDLE signal.
Claim 47
Dependent Claim 50 words
System of claim 36, wherein said identifier comprises a Synchronous Optical Network (SONET) formatted message having a frame with an overhead byte, said system further comprising: an indicium stored in said overhead byte; means for deriving the identification of said malfunctioned span from said indicia stored in said overhead byte.
Claim 48
Dependent Claim 31 words
System of claim 42, wherein said deriving means further uses the Z4 byte in a Path Overhead (POH) of said SONET message to derive the message channel for transmitting said identifier.
Claim 49
Dependent Claim 48 words
System of claim 36, wherein said identifier comprises a Digital Service Level 3 (DS-3) formatted signal having an overhead bit, said system further comprising: an indicium stored in said overhead bit; means for deriving the identification of said malfunctioned span from said indicia stored in said overhead bit.
Claim 50
Dependent Claim 27 words
System of claim 44, wherein said deriving means further uses an X bit in said DS-3 overhead bit to derive the message channel for transmitting said identifier.
Claim 51
Dependent Claim 127 words
In a communications network having a plurality of nodes and a plurality of communications circuits interconnecting said nodes, each of said nodes along a communications circuit having detected a fault signal caused by a fault in said communications circuit, apparatus in said each node for identifying the location of said fault in said circuit, comprising: means for transmitting periodically a fault location identifier originated by said each node onto said communications circuit; means for stopping transmission of said originated fault location identifier upon receipt of another identifier or a normal signal from an upstream node; and means for confirming said originated fault location identifier to be representative of the correct location of said fault if said originated identifier was sent at least a predetermined number of times.
Claim 52
Dependent Claim 127 words
In a communications network having a plurality of nodes and a plurality of communications circuits interconnecting said nodes, each of said nodes along a communications circuit having detected a fault signal caused by a fault in said communications circuit, apparatus in said each node for identifying the location of said fault in said circuit, comprising: means for transmitting periodically a fault location identifier originated by said each node onto said communications circuit; means for stopping transmission of said originated fault location identifier upon receipt of another identifier or a normal signal from an upstream node; and means for confirming said originated fault location identifier to be representative of the correct location of said fault if said originated identifier was sent at least a predetermined number of times.
Claim 53
Dependent Claim 60 words
Apparatus of claim 46, wherein upon receipt of any incoming fault location identifier, further comprising: means for confirming that said any received fault location identifier is representative of the correct location of said fault when the same identifier is received said predetermined number of times and no normal signal is received before the last of said predetermined number of times.
Claim 54
Dependent Claim 39 words
Apparatus of claim 46, further comprising: means for determining that there is no fault in said communications circuit if a normal signal is received prior to said originated fault location identifier having been sent said predetermined number of times.
Claim 55
Dependent Claim 27 words
Apparatus of claim 46, further comprising: an indicium identifying one of the nodes bracketing said fault along said communications circuit being provided in said fault location identifier.
Claim 56
Dependent Claim 27 words
Apparatus of claim 46, further comprising: indicia respectively identifying both of the nodes bracketing said fault along said communications circuit being provided in said fault location identifier.
Claim 57
Dependent Claim 48 words
Apparatus of claim 46, said apparatus further comprising: means for reformatting said fault signal to another fault signal such that nodes downstream of said each node are informed of said fault when said another fault signal is broadcast thereto after said each node has detected said fault signal.

References Cited (Backward Citations)

US3500202A Cited
US4604745A Cited
US5095482A Cited
US5233600A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-06-02 2000-12-02 2001-06-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-06-02 2004-12-02 2005-06-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-06-02 2008-12-02 2009-06-03 $7700.00 Window Closed / Lapsed

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