US4421951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and arrangement for signaling the transmission mode of a communication system
Assignee: AT&T Inc
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Filing: 1981-09-24
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Granted: 1983-12-20
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Expires: 2001-09-24
Abstract
Abstract The disclosed communication system operating mode signaling method and arrangement utilizes dc current signaling over the loop facility connecting a customer to a central office (CO). The dc current on the facility provides concurrent on-hook/off-hook signaling and voice/digital data operating mode signaling between the customer and CO. A current flow in a first direction over the facility signals a voice operating mode while a current flow in a second direction signals a digital data operating mode. A customer signals a change in the operating mode by reversing the direction of allowed current flow at the customer unit. The resulting interruption of the current flow is detected at the CO which responds by reversing the direction of current flow over the facility. The reappearance of current flow over the facility distinguishes a customer's change in operating mode from an on-hook condition.
Inventors
- 👤 John G. Van Bosse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:18
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/06
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
137 words
In a communication system including a subscriber unit adapted for connection over a transmission facility to a central unit, said system operating in either an analog or a digital communication mode, apparatus for signaling the communication mode between said subscriber unit and said central unit characterized in that said apparatus includes first means for providing at said central unit a first polarity dc signal over said facility representing a first operating mode, means for changing at said subscriber unit said first polarity dc signal received over said facility to signal the central unit of a change in the communication mode at said subscriber unit, and second means for providing at said central unit in response to an interruption of said first polarity dc signal a second polarity dc signal over said facility representing a second operating mode.
Claim 2
Dependent Claim
137 words
In a communication system including a subscriber unit adapted for connection over a transmission facility to a central unit, said system operating in either an analog or a digital communication mode, apparatus for signaling the communication mode between said subscriber unit and said central unit characterized in that said apparatus includes first means for providing at said central unit a first polarity dc signal over said facility representing a first operating mode, means for changing at said subscriber unit said first polarity dc signal received over said facility to signal the central unit of a change in the communication mode at said subscriber unit, and second means for providing at said central unit in response to an interruption of said first polarity dc signal a second polarity dc signal over said facility representing a second operating mode.
Claim 3
Dependent Claim
168 words
An arrangement for signaling the operating modes of a communication system, said arrangement including a subscriber unit adapted for connection over a transmission facility to a central unit characterized in that said subscriber unit includes first means for signaling a first operating mode to said central unit by allowing the reception of a first polarity dc signal over said facility, second means for signaling a second operating mode to said central unit by allowing the reception of a second polarity dc signal over said facility, means for coupling either said first signaling means or said second signaling means to said facility, and said central unit includes first means for providing a first polarity dc signal over said facility, second means for providing a second polarity dc signal over said facility, and switching means for alternating the connection of said first providing means and said second providing means to said facility in response to a dc signal interruption on said facility resulting from an operation of said coupling means.
Claim 4
Dependent Claim
168 words
An arrangement for signaling the operating modes of a communication system, said arrangement including a subscriber unit adapted for connection over a transmission facility to a central unit characterized in that said subscriber unit includes first means for signaling a first operating mode to said central unit by allowing the reception of a first polarity dc signal over said facility, second means for signaling a second operating mode to said central unit by allowing the reception of a second polarity dc signal over said facility, means for coupling either said first signaling means or said second signaling means to said facility, and said central unit includes first means for providing a first polarity dc signal over said facility, second means for providing a second polarity dc signal over said facility, and switching means for alternating the connection of said first providing means and said second providing means to said facility in response to a dc signal interruption on said facility resulting from an operation of said coupling means.
Claim 5
Dependent Claim
73 words
The invention of claim 1 or claim 2 wherein said central unit includes means responsive to a first control signal for connecting either said first providing means or said second providing means to said facility, means for detecting an interruption of a dc signal on said facility, and means responsive to said detecting means for producing said first control signal to said connecting means to interchange the providing means connected to said facility.
Claim 6
Dependent Claim
73 words
The invention of claim 3 wherein said central unit further includes means responsive to a signal received over a second facility from a remote unit for establishing a second control signal to connect either said first providing means or said second providing means to said facility, and means for transferring control of said connecting means from said first control signal of said producing means to said second control signal of said establishing means.
Claim 7
Dependent Claim
78 words
The invention of claim 1 or claim 2 wherein said central unit further includes means for comparing the operating mode of said subscriber unit with the operating mode of a remote unit connected to said central unit over a second facility and means for sending a conflict signal over said facility to said subscriber unit in response to an output from said comparing means indicating a difference in operating modes between said subscriber unit and said remote unit.
Claim 8
Dependent Claim
39 words
The invention of claim 1 or claim 2 wherein said central unit further includes means responsive to a continued interruption in the dc signal on said facility for terminating the connection between said subscriber unit and said central unit.
Claim 9
Dependent Claim
41 words
The invention of claim 1 or claim 2 wherein said central unit further includes means responsive to a dc signal interruption for transmitting a signal representing the operating mode of said subscriber unit over a second facility to a remote unit.
Claim 10
Dependent Claim
87 words
Apparatus for controlling the analog or digital communication mode of a transmission facility characterized in that said apparatus includes means responsive to a control signal for providing either a first polarity dc signal over said facility to represent a first communication mode or a second polarity dc signal over said facility to represent a second communication mode and control means for generating said control signal to interchange the existing coupling of said providing means in response to a predetermined interruption in the dc signal on said facility.
Claim 11
Dependent Claim
87 words
Apparatus for controlling the analog or digital communication mode of a transmission facility characterized in that said apparatus includes means responsive to a control signal for providing either a first polarity dc signal over said facility to represent a first communication mode or a second polarity dc signal over said facility to represent a second communication mode and control means for generating said control signal to interchange the existing coupling of said providing means in response to a predetermined interruption in the dc signal on said facility.
Claim 12
Dependent Claim
60 words
The invention of claim 8 wherein said apparatus further includes means responsive to a signal received over a second facility from a remote unit for establishing a second control signal to said providing means and means for transferring control of said providing means from said control signal of said control means to said second control signal of said establishing means.
Claim 13
Dependent Claim
72 words
The invention of claim 8 wherein said apparatus further includes means for comparing the communication mode of said subscriber unit with the communication mode of a remote unit connected to said apparatus over a second facility and means for sending a conflict signal over said facility to said subscriber in response to an output from said comparing means indicating a difference in communication modes between said subscriber unit and said remote unit.
Claim 14
Dependent Claim
24 words
The invention of claim 9 wherein said conflict signal from said sending means is a signal indicating the operating mode of said remote unit.
Claim 15
Dependent Claim
35 words
The invention of claim 8 wherein said apparatus further includes means responsive to a continued interruption in the dc signal on said facility for terminating a communication connection between said subscriber unit and said apparatus.
Claim 16
Dependent Claim
36 words
The invention of claim 8 wherein said apparatus further includes means responsive to said control means for transmitting a signal representing the communicating mode of said subscriber unit over said second facility to said remote unit.
Claim 17
Dependent Claim
18 words
The invention of claim 8 wherein said providing means includes a voice hybrid and a digital data hybrid.
Claim 18
Dependent Claim
85 words
A subscriber unit adapted to communicate in a first or a second operating mode over a transmission facility characterized in that said subscriber unit includes first means for signaling a first operating mode by allowing the reception of a first polarity dc signal over said facility, second means for signaling a second operating mode by allowing the reception of a second polarity dc signal over said facility, and means responsive to a subscriber input for switching either said first or second means to said facility.
Claim 19
Dependent Claim
85 words
A subscriber unit adapted to communicate in a first or a second operating mode over a transmission facility characterized in that said subscriber unit includes first means for signaling a first operating mode by allowing the reception of a first polarity dc signal over said facility, second means for signaling a second operating mode by allowing the reception of a second polarity dc signal over said facility, and means responsive to a subscriber input for switching either said first or second means to said facility.
Claim 20
Dependent Claim
29 words
The invention of claim 15 wherein said switching means concurrently switches communication signals to said facility from either a first operating mode means or a second operating mode means.
Claim 21
Dependent Claim
27 words
The invention of claim 15 wherein said subscriber unit further includes means for preventing the reception of said first and second polarity dc signal from said facility.
Claim 22
Dependent Claim
49 words
The invention of claim 15 wherein said subscriber unit further includes means for outputting a humanly recognizable signal from a conflict signal received over said facility to indicate a conflict in operating modes between said subscriber unit and a remote unit connected over said facility to said subscriber unit.
Claim 23
Dependent Claim
121 words
In a communication system including a subscriber unit adapted for connection over a transmission facility to a central unit, said system operating in either an analog or digital communication mode, a method of signaling the communication mode between said subscriber unit and said central unit characterized by the steps of (a) providing at said central unit a first polarity dc signal over said facility representing a first operating mode, (b) interrupting at said subscriber unit said first polarity dc signal over said facility to represent a change in the communication mode at said subscriber unit, and (c) providing at said central unit in response to said interrupting step a second plarity dc signal over said facility representing a second communication mode.
Claim 24
Dependent Claim
121 words
In a communication system including a subscriber unit adapted for connection over a transmission facility to a central unit, said system operating in either an analog or digital communication mode, a method of signaling the communication mode between said subscriber unit and said central unit characterized by the steps of (a) providing at said central unit a first polarity dc signal over said facility representing a first operating mode, (b) interrupting at said subscriber unit said first polarity dc signal over said facility to represent a change in the communication mode at said subscriber unit, and (c) providing at said central unit in response to said interrupting step a second plarity dc signal over said facility representing a second communication mode.
Claim 25
Dependent Claim
125 words
In a communication system including a subscriber unit connected over a transmission facility to a central unit, said system operating in either an analog or a digital communication mode, a method of signaling the communication mode between said subscriber unit and said central unit characterized by the steps of (a) providing at said central unit a first polarity dc signal over said facility representing the establishment of a first communication mode, (b) providing at said central unit a second polarity dc signal over said facility representing the establishment of a second communication mode, and (c) alternating between steps (a) and (b) in response to a predetermined interruption of the dc signal on said facility representing a change in the communication mode at said subscriber unit.
Claim 26
Dependent Claim
125 words
In a communication system including a subscriber unit connected over a transmission facility to a central unit, said system operating in either an analog or a digital communication mode, a method of signaling the communication mode between said subscriber unit and said central unit characterized by the steps of (a) providing at said central unit a first polarity dc signal over said facility representing the establishment of a first communication mode, (b) providing at said central unit a second polarity dc signal over said facility representing the establishment of a second communication mode, and (c) alternating between steps (a) and (b) in response to a predetermined interruption of the dc signal on said facility representing a change in the communication mode at said subscriber unit.
Claim 27
Dependent Claim
62 words
The method of claim 20 further including the steps of establishing the connection of either said first polarity dc signal or said second polarity dc signal to said facility in response to a signal received over a second facility from a remote unit and transferring control of said providing steps (a) and (b) from said alternating step (c) to said establishing step.
Claim 28
Dependent Claim
63 words
The method of claim 20 further including the steps of comparing the communicating mode of said facility with a communicating mode of a second facility connected to said central unit and sending a conflict signal over said facility to said subscriber unit in response to a difference in communicating modes between said facility and said second facility as determined by said comparing step.
Claim 29
Independent Claim
76 words
A method for controlling the analog or digital communication mode of a transmission facility characterized by the steps of providing either a first polarity dc signal over said facility to represent a first communication mode or a second polarity dc signal over said facility to represent a second communication mode and interchanging the dc signal coupled to said facility during the providing step in response to a predetermined interruption in the dc signal on said facility.
Claim 30
Independent Claim
76 words
A method for controlling the analog or digital communication mode of a transmission facility characterized by the steps of providing either a first polarity dc signal over said facility to represent a first communication mode or a second polarity dc signal over said facility to represent a second communication mode and interchanging the dc signal coupled to said facility during the providing step in response to a predetermined interruption in the dc signal on said facility.
Claim 31
Independent Claim
68 words
A method of signaling a change in the analog or digital communication mode of a transmission facility characterized by the steps of (a) signaling a first communicating mode by receiving a first polarity dc signal over said facility, (b) signaling a second communicating mode by receiving a second polarity dc signal over said facility, and (c) switching between steps (a) and (b) in response to a subscriber input.
Claim 32
Independent Claim
68 words
A method of signaling a change in the analog or digital communication mode of a transmission facility characterized by the steps of (a) signaling a first communicating mode by receiving a first polarity dc signal over said facility, (b) signaling a second communicating mode by receiving a second polarity dc signal over said facility, and (c) switching between steps (a) and (b) in response to a subscriber input.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |