US4095045A
Expired / Lapsed
US
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Method and apparatus for signaling in a communication system
Assignee: General Datacomm Inc
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Filing: 1977-01-19
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Granted: 1978-06-13
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Expires: 1997-01-19
Abstract
Abstract A method and apparatus are disclosed for using a specified pattern of signal events for signaling in a digital communication system. Illustratively, detection of a first event in a control signal activates timing apparatus which looks for a second event in a control signal within a specified time "window" and at least one additional event in either a data or a control signal within a specified time period. Preferably, the first event is a drop in one of the carrier detect or request to send signals and the second event is a rise in the same signal. The additional event illustratively is reception of two identical data characters, each representing an address and an operation code. Each of these two characters must be received and compared for verification within the specified time period in order to produce an output control signal decoded from the operation code. This signal may be used for any application such as the activation of a terminal to receive data, the initiation of a test sequence, or a change of the network configuration.
Inventors
- 👤 Charles P. Johnson
- 👤 Frederick A. Lucas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:38
CPC Classifications
H; H04; H04L; H04L12/00; G; G06; G06F; G06F13/00; G06F13/38
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
150 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, a signal detection method comprising the steps of: detecting a first signal event transmitted from said signal source to said terminal; detecting a second signal event transmitted from said signal source to said terminal, said second signal event being detected within a specified time interval commencing after said first event; detecting thereafter at least one additional signal event transmitted from said signal source to said terminal, said additional signal event being detected within a time limit related to either said first or said second event, at least one of said first, second and additional signal events occurring in a control signal; and producing an output signal indicating that said second event and said additional event were detected within the time interval and time limit specified.
Claim 2
Dependent Claim
150 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, a signal detection method comprising the steps of: detecting a first signal event transmitted from said signal source to said terminal; detecting a second signal event transmitted from said signal source to said terminal, said second signal event being detected within a specified time interval commencing after said first event; detecting thereafter at least one additional signal event transmitted from said signal source to said terminal, said additional signal event being detected within a time limit related to either said first or said second event, at least one of said first, second and additional signal events occurring in a control signal; and producing an output signal indicating that said second event and said additional event were detected within the time interval and time limit specified.
Claim 3
Dependent Claim
54 words
The method of claim 1 wherein: the step of detecting at least one additional event comprises the step of receiving a data signal representative of an operation code; and the step of producing an output signal comprises the steps of decoding said operation code and providing an output signal representative of said operation code.
Claim 4
Dependent Claim
78 words
The method of claim 1 wherein: the step of detecting at least one additional event comprises the steps of: receiving a first data signal representative of an operation code; receiving a second data signal representative of the same operation code; and comparing the two operation codes; and the step of producing an output signal comprises the decoding said operation code if the two operation codes are the same; and providing an output signal representative of said operation code.
Claim 5
Dependent Claim
82 words
The method of claim 1 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the step of detecting at least one additional event comprises the steps of: receiving a data signal representative of an address and an operation code; and verifying said address; and the step of producing an output signal comprises the steps of: decoding said operation code if the address is verified; and providing an output signal representative of said operation code.
Claim 6
Dependent Claim
120 words
The method of claim 1 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the step of detecting at least one additional event comprises the steps of: receiving a first data signal representative of an address and an operation code; verifying said address; receiving a second data signal representative of an address and an operation code; verifying said address in the second data signal; and comparing the two operation codes; and the step of producing an output signal comprises the the steps of: decoding said operation code only if the address is again verified and the two operation codes are the same; and providing an output signal representative of said operation code.
Claim 7
Dependent Claim
98 words
The method of claim 1 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the step of detecting at least one additional event comprises the steps of: receiving data signals representative of at least two addresses and two operation codes; verifying each of the addresses received; and comparing the operation codes; and the step of producing an output signal comprises the steps of: decoding said operation code only if the addresses are verified and the operation codes are the same; and providing an output signal representative of said operation code.
Claim 8
Dependent Claim
24 words
The method of claim 1 wherein the first and second events are transitions in a control signal from one binary signal level to another.
Claim 9
Dependent Claim
18 words
The method of claim 1 wherein the first and second events are detected in the same control signal.
Claim 10
Dependent Claim
31 words
The method of claim 1 wherein the communication system is an in-band communication system and the first and second events take place in the carrier detect or request to send signal.
Claim 11
Dependent Claim
57 words
The method of claim 1 wherein the communication system is an in-band communication system, the first event is a drop in the carrier detect or request to send signal, the second event is a rise in the carrier detect or request to send signal, and said at least one additional signal is at least one data character.
Claim 12
Dependent Claim
145 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, a method for detecting at the terminal an operating instruction transmitted from the signal source, said method comprising the steps of: detecting a first signal event in a control signal received at said terminal; detecting a second signal event in a control signal received at said terminal, said second signal being detected within a specified time interval commencing after said first event; detecting thereafter at least one data character transmitted from the signal source and received at said terminal, said data character being detected within a time limit related to either said first or said second event; decoding an operation code in said data character; and producing an output signal representative of the operating instruction embodied in said operation code.
Claim 13
Dependent Claim
145 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, a method for detecting at the terminal an operating instruction transmitted from the signal source, said method comprising the steps of: detecting a first signal event in a control signal received at said terminal; detecting a second signal event in a control signal received at said terminal, said second signal being detected within a specified time interval commencing after said first event; detecting thereafter at least one data character transmitted from the signal source and received at said terminal, said data character being detected within a time limit related to either said first or said second event; decoding an operation code in said data character; and producing an output signal representative of the operating instruction embodied in said operation code.
Claim 14
Dependent Claim
65 words
The method of claim 11 wherein: the step of detecting at least one data character comprises the steps of: receiving a first data signal representative of an operation code; receiving a second data signal representative of the same operation code; and comparing the two operation codes; and the step of decoding said operation code is performed only if the two operation codes are the same.
Claim 15
Dependent Claim
68 words
The method of claim 11 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the step of detecting at least one data character comprises the steps of: receiving a first data signal representative of an address and an operation code; and verifying said address; and the step of decoding said operation code is performed only if the address is verified.
Claim 16
Dependent Claim
108 words
The method of claim 11 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the step of detecting at least one data character comprises the steps of: receiving a first data signal representative of an address and an operation code; verifying said address; receiving a second data signal representative of an address and an operation code if the address is verified; verifying said address in the second data signal; and comparing the two operation codes; and the step of decoding said operation code is performed only if the address is again verified and the two operation codes are the same.
Claim 17
Dependent Claim
82 words
The method of claim 11 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the step of detecting at least one data character comprises the steps of: receiving data signals representative of at least two addresses and two operation codes; verifying each of the addresses received; and comparing the operation codes; and the step of decoding said operation code is performed only if the addresses are verified and the operation codes are the same.
Claim 18
Dependent Claim
24 words
The method of claim 11 wherein the first and second events are transitions in the control signal from one binary signal level to another.
Claim 19
Dependent Claim
18 words
The method of claim 11 wherein the first and second events are detected in the same control signal.
Claim 20
Dependent Claim
32 words
The method of claim 11 wherein the communication system is an in-band data communication system and the first and second events take place in the carrier detect or request to send signal.
Claim 21
Dependent Claim
155 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, apparatus for detecting a signal comprising: means for detecting a first signal event transmitted from said signal source to said terminal; means for detecting a second signal event transmitted from said signal source to said terminal, said second signal even being detected within a specified time interval commencing after said first event; means for detecting thereafter at least one additional signal event transmitted from said signal source to said terminal, said additional signal being detected within a time limit related to either said first or said second event, at least one of said first, second and additional signal events occurring in a control signal; and means for producing an output signal indicating that said second event and said additional event were detected within the time interval and time limit specified.
Claim 22
Dependent Claim
155 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, apparatus for detecting a signal comprising: means for detecting a first signal event transmitted from said signal source to said terminal; means for detecting a second signal event transmitted from said signal source to said terminal, said second signal even being detected within a specified time interval commencing after said first event; means for detecting thereafter at least one additional signal event transmitted from said signal source to said terminal, said additional signal being detected within a time limit related to either said first or said second event, at least one of said first, second and additional signal events occurring in a control signal; and means for producing an output signal indicating that said second event and said additional event were detected within the time interval and time limit specified.
Claim 23
Dependent Claim
52 words
The apparatus of claim 19 wherein: the means for detecting at least one additional event comprises means for receiving a data signal representative of an operation code; and the means for producing an output signal comprises means for decoding said operation code and providing an output signal representative of said operation code.
Claim 24
Dependent Claim
101 words
The apparatus of claim 19 wherein: the means for detecting at least one additional event comprises: means for receiving a data signal representative of an operation code; means for storing a first such data signal; and means for comparing said first such data signal with a second such data signal representative of an operation code; and the means for producing an output signal comprises the the steps of: means for decoding said operation code if the operation codes represented by the first and second data signals are the same; and means for providing an output signal representative of said operation code.
Claim 25
Dependent Claim
84 words
The apparatus of claim 19 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the means for detecting at least one additional event comprises: means for receiving a data signal representative of an address and an operation code; and means for verifying said address; and the means for producing an output signal comprises: means for decoding said operation code if the address is verified; and means for providing an output signal representative of said operation code.
Claim 26
Dependent Claim
147 words
The apparatus of claim 19 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the means for detecting at least one additional event comprises: means for receiving a data signal representative of an address and an operation code; means for verifying said address; means for storing that portion of a first such data signal which is representative of an operation code; and means for comparing that portion of the first such data signal which is representative of an operative code with that portion of a second data signal representative of an operation code; and the means for producing an output signal comprises: means for decoding said operation code only if an address in the second data signal is verified and the two operation codes are the same; and means for providing an output signal representative of said operation code.
Claim 27
Dependent Claim
96 words
The apparatus of claim 19 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the means for detecting at least one additional event comprises: means for receiving a data signal representative of at least two addresses and two operation codes; means for verifying each of the addresses received; and the means for producing an output signal comprises: means for decoding said operation code only if the addresses are verified and the operation codes are the same; and means for providing an output signal representative of said operation code.
Claim 28
Dependent Claim
24 words
The apparatus of claim 19 wherein the first and second events are transitions in a control signal from one binary signal level to another.
Claim 29
Dependent Claim
18 words
The apparatus of claim 19 wherein the first and second events are detected in the same control signal.
Claim 30
Dependent Claim
32 words
The apparatus of claim 19 wherein the communication system is an in-band data communication system and the first and second events take place in the carrier detect or request to send signal.
Claim 31
Dependent Claim
59 words
The apparatus of claim 19 wherein the communication system is an in-band data communication system, the first event is a drop in the carrier detect or request to send signal, the second event is a rise in the carrier detect or request to send signal, and said at least one additional signal event is at least one data character.
Claim 32
Dependent Claim
151 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, apparatus at the terminal for detecting an operating instruction transmitted from the signal source, said apparatus comprising: means for detecting a first signal event in a control signal received at said terminal; means for detecting a second signal event in a control signal received at said terminal, said second signal event being detected within a specified time interval commencing after said first event, means for detecting thereafter at least one data character transmitted from the signal source and received at said terminal, said data being detected within a time limit related to either said first or said second event; means for decoding an operation code in said data character; and means for producing an output signal representative of the operating instruction embodied in said operation code.
Claim 33
Dependent Claim
151 words
In a digital communication system using data and control signals and comprising a signal source, at least one communication channel and at least one terminal, apparatus at the terminal for detecting an operating instruction transmitted from the signal source, said apparatus comprising: means for detecting a first signal event in a control signal received at said terminal; means for detecting a second signal event in a control signal received at said terminal, said second signal event being detected within a specified time interval commencing after said first event, means for detecting thereafter at least one data character transmitted from the signal source and received at said terminal, said data being detected within a time limit related to either said first or said second event; means for decoding an operation code in said data character; and means for producing an output signal representative of the operating instruction embodied in said operation code.
Claim 34
Dependent Claim
85 words
The apparatus of claim 29 wherein: The means for detecting at least one data character comprises: means for receiving a data signal representative of an operation code; means for storing the first such data signal resentative of an operation code; and means for comparing said first such data signal with a second such data signal representative of an operation code; and the means for decoding an operation code is activated only if the operation codes represented by the first and second series are the same.
Claim 35
Dependent Claim
68 words
The apparatus of claim 29 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the means for detecting at least one data character comprises: means for receiving a data signal representative of an address and an operation code; and means for verifying said address; and the means for decoding said operation code is activated only if the address is verified.
Claim 36
Dependent Claim
130 words
The apparatus of claim 29 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the means for detecting at least one data character comprises: means for receiving a data signal representative of an address and an operation code; means for verifying said address; means for storing that portion of a first such data signal which is representative of an operation code; and means for comparing that portion of the first such data signal which is representative of an operation code with that portion of a second data signal representative of an operation code; and the means for decoding an operation code is activated only if an address in the second data signal is verified and the two operation codes are the same.
Claim 37
Dependent Claim
86 words
The apparatus of claim 29 wherein: the communication system is a polled network in which at least some terminals are individually addressed; the means for detecting at least one data character comprises: means for receiving a data signals representative of at least two addresses and two operation codes; means for verifying each of the addresses received; and means for comparing the operation codes; and the means for decoding an operation code is activated only if the addresses are verified and the operation codes are the same.
Claim 38
Dependent Claim
24 words
The apparatus of claim 29 wherein the first and second events are transitions in a control signal from one binary signal lever to another.
Claim 39
Dependent Claim
18 words
The apparatus of claim 29 wherein the first and second events are detected in the same control signal.
Claim 40
Dependent Claim
33 words
The apparatus of claim 29 wherein the communication system is an in-band data communication system in which the first and second events take place in the carrier detect or request to send signal.
References Cited (Backward Citations)
US3549809A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |