EP0224212A2
Expired / Lapsed
EP
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Dial tone detection arrangement with a detection notification feature
Assignee: AT&T Inc
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Filing: 1986-11-21
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Granted: —
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Expires: 2006-11-21
Abstract
Abstract A dial tone detection arrangement for a PBX which provides a dial tone detection notification feature to a calling party (100-1) is disclosed. The disclosed arrangement relieves the calling party (100-1) from the burden of aurally monitoring the receiver of the station set while waiting for receipt of dial tone from the central office ( C.O.) (130). The dial tone detection arrangement utilizes an algorithm to establish a connection between a dial tone detection circuit (107-1) of the PBX and a trunk port (109-1) connected to a C.O. (130) via a switching network (104). The dial tone detection circuit (107-1) monitors the C.O. (130) via the trunk port (109-1) for the presence of dial tone indicative of C.O. availability. The calling party (100-1) may now go "on-hook". Upon detecting dial tone from the C.O., the calling station (100-1) is notified. In response to this notification, the calling party (100-1) goes "off-hook" and a call connection is established between the calling (100-1) and called stations. (FIG. 1).
Inventors
- 👤 Jeffrey Allen Cromwell
- 👤 Robert Lawrence Ducharme
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 02:38
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/02; H04M3/42; H04M3/48; H04Q; H04Q3/00; H04Q3/58; H04Q3/62; H04Q3/625
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
173 words
In a switching system comprising; a plurality of stations, a plurality of trunk ports connected to a central office and a switching network; a method for providing central office dial tone notification to a calling one of each plurality of stations; said method comprising the steps of: 1) requesting [generating a service request] a call connection from said one calling station to [request] said central office [for serving said call]; 2) establishing a first path between one of said trunk ports and a dial tone detection circuit via said switching network to detect a dial tone from said central office; [indicating when said central office is available to serve said call]; 3) responding to a presence of said central office dial tone [said dial tone detection] to transmit to said one calling station on indication to said availability of said central office; and 4) establishing a second path from said one calling station via said switching network to said one of said trunk ports connected to said central office for serving said call.
Claim 2
Dependent Claim
173 words
In a switching system comprising; a plurality of stations, a plurality of trunk ports connected to a central office and a switching network; a method for providing central office dial tone notification to a calling one of each plurality of stations; said method comprising the steps of: 1) requesting [generating a service request] a call connection from said one calling station to [request] said central office [for serving said call]; 2) establishing a first path between one of said trunk ports and a dial tone detection circuit via said switching network to detect a dial tone from said central office; [indicating when said central office is available to serve said call]; 3) responding to a presence of said central office dial tone [said dial tone detection] to transmit to said one calling station on indication to said availability of said central office; and 4) establishing a second path from said one calling station via said switching network to said one of said trunk ports connected to said central office for serving said call.
Claim 3
Dependent Claim
53 words
The method of claim 1 wherein the step of establishing a first path includes the steps of: 1) seizing concurrently said one of said trunk ports and said dial tone detection circuit; and 2) assigning a network time slot to interconnect said one of said trunk ports to said dial tone detection circuit.
Claim 4
Dependent Claim
60 words
The method of claim 1 wherein said step of establishing a first path is in combination with the steps of: 1) activating a decremental timer to begin decrementing from a specified allotted time period within which to detect said central office dial tone [from said central office]; and 2) abandoning said call connection request when said decremental timer fully decrements.
Claim 5
Dependent Claim
64 words
The method of claim 1 wherein said step of establishing a second path is in combination with the steps of: 1) disengaging an interconnection between said dial tone detection circuit and said switching network to remove a portion of said first established path; and 2) utilising said assigned network time slot to interconnect said one calling station to said one of said trunk ports.
Claim 6
Dependent Claim
31 words
The method of claim 1 wherein the step of transmitting includes the step of: activating an indicator at said one calling station to provide an indication of said dial tone detection.
Claim 7
Dependent Claim
29 words
The method of claim 5 wherein the step of activating includes the step of: providing an audible indication at said one calling station to indicate said dial tone detection.
Claim 8
Dependent Claim
29 words
The method of claim 5 wherein the step of activating includes the step of: providing a visual indication at said one calling station to indicate said dial tone detection.
Claim 9
Dependent Claim
127 words
In a switching system where a calling station requests a call connection to a called station served by a central office; a method for providing central office dial tone notification to said calling station, said method comprising the steps of: 1) establishing a first path between a trunk port connected to said central office and a dial tone detection circuit via a switching network to detect a dial tone from said central office; 2) responding to a presence of said central office dial tone to transmit to said calling station an indication of said availability of said central office; and 3) establishing a second path from said calling station via said switching network to said trunk port connected to said central office for serving said call connection.
Claim 10
Dependent Claim
127 words
In a switching system where a calling station requests a call connection to a called station served by a central office; a method for providing central office dial tone notification to said calling station, said method comprising the steps of: 1) establishing a first path between a trunk port connected to said central office and a dial tone detection circuit via a switching network to detect a dial tone from said central office; 2) responding to a presence of said central office dial tone to transmit to said calling station an indication of said availability of said central office; and 3) establishing a second path from said calling station via said switching network to said trunk port connected to said central office for serving said call connection.
Claim 11
Dependent Claim
47 words
The method of claim 8 wherein the step of establishing a first path includes the steps of: 1) seizing concurrently said trunk port and said dial tone detection circuit; and 2) assigning a network time slot to interconnect said trunk port to said dial tone detection circuit.
Claim 12
Dependent Claim
60 words
The method of claim 8 wherein the step of establishing a first path is in combination with the steps of: 1) activating a decremental timer to begin decrementing from a specified allotted time period within which to detect said central office dial tone [from said central office]; and 2) abandoning said call connection request when said decremental timer fully decrements.
Claim 13
Dependent Claim
59 words
The method of claim 8 wherein the step of establishing a second path is in combination with the steps of: 1) disengaging an interconnection between said dial tone detection and said switching network to remove a portion of said first established path; and 2) utilizing said assigned network time slot to interconnect said calling station to said trunk port.
Claim 14
Dependent Claim
32 words
The method of claim 8 wherein the step of transmitting includes the step of: activating an indicator at said calling station to provide an indication of said central office dial tone detection.
Claim 15
Dependent Claim
30 words
The method of claim 12 wherein the step of activating includes the step of: providing an audible indication at said calling station to indicate said central office dial tone detection.
Claim 16
Dependent Claim
27 words
The method of claim 2 wherein the step of activating includes: providing a visual indication at said calling station to indicate said central office dial tone detection.
Claim 17
Dependent Claim
102 words
In a PBX where a calling station requests a call connection to a called station served by a central office; a method for providing central office dial tone notification to said calling station, to said method comprising the steps of: 1) operating said PBX to detect a dial tone from said central office; 2) responding to a presence of said central office dial tone to generate an indication to said calling station indicative of said central office availability; and 3) establishing a path from said calling station via a switching network of said PBX to said central office for serving said call.
Claim 18
Dependent Claim
102 words
In a PBX where a calling station requests a call connection to a called station served by a central office; a method for providing central office dial tone notification to said calling station, to said method comprising the steps of: 1) operating said PBX to detect a dial tone from said central office; 2) responding to a presence of said central office dial tone to generate an indication to said calling station indicative of said central office availability; and 3) establishing a path from said calling station via a switching network of said PBX to said central office for serving said call.
Claim 19
Dependent Claim
63 words
The method of claim 15 wherein the step of operating includes the steps of: 1) seizing concurrently a trunk port connected to said central office and a dial tone detection circuit to establish a path between said trunk port and said dial tone detection circuit; and 2) assigning a network time slot to interconnect said trunk port and said dial tone detection circuit.
Claim 20
Dependent Claim
53 words
The method of claim 15 wherein the step of operating is in combination with the steps of: 1) activating a decremental timer to begin decrementing from a specified allotted time period within which to detect said central office dial tone; and 2) abandoning said call connection request when said decremental timer fully decrements.
Claim 21
Dependent Claim
68 words
The method of claim 15 wherein the step of operating is in combination with the steps of: 1) scanning an excessive dial tone delay history table to identify when a predefined threshold value is exceeded to indicate that excessive central office dial tone delays exist; and 2) entering said calling station into a trunk queue when excessive dial tone delays exist indicated by exceeding said predefined threshold value.
Claim 22
Dependent Claim
57 words
The method of claim 15 wherein the step of generating is in combination with the steps of: removing said calling station from said trunk queue; activating a ring and tone generator to provide a ringing indication at said calling station; and establishing a path between said calling station and said called station served by said central office.
References Cited (Backward Citations)
No citation records indexed.
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