US3809818A
Expired / Lapsed
US
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Means and method for telephone line disconnection in frequency division multiplexing
Assignee: Bell Canada Inc
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Filing: 1972-06-05
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Granted: 1974-05-07
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Expires: 1992-06-05
Abstract
Abstract Transmission failure in frequency division multiplexing connected to telephone systems results in the generation of a disconnect tones, one for each carrier, which are simultaneously superimposed on the multiplex link to achieve disconnection of telephone lines and trunks.
Inventors
- 👤 W Johnston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:11
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14; H04; H04J; H04J1/00; H04J1/02; H04J1/14; H04Q; H04Q11/00; H04Q11/02
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
259 words
In a frequency division multiplex system for transmission of information as part of a telephone system; wherein a plurality of channels are provided through said multiplex system, each channel including the frequency range of an information signal; each channel being designed to carry a signal received from a telephone system; the multiplex system being designed so that the such signal in each channel therein is modulated on a carrier, for transmission; saId multiplex system being further designed so that a plurality of carriers are combined on a common path for frequency division multiplex transmission, the plurality of carriers after transmission by the said multiplexing system being respectively reconverted to a plurality of signals for transmission over a telephone system, where the telephone system is of the type designed, on receipt of a signal resulting from a signal of predetermined frequency on a multiplex channel, to effect, in the telephone system, the switching associated with the termination of a call; said multiplexing system being combined with means for detecting a transmission failure in the multiplex transmission system associated with said plurality of carriers; the method comprising: generating a spectrum of disconnect tones in one-to-one correspondence to said first-mentioned plurality of carriers, each of said disconnect tones having the frequency of the multiplex carrier of the pluraltiy to which it corresponds, when such carrier is modulated by a signal of said predetermined frequency, means responsive to the detection of failure of the multiplexing system for simultaneously supplying to said common path for said plurality of modulated carriers said spectrum of tones;
Claim 2
Dependent Claim
259 words
In a frequency division multiplex system for transmission of information as part of a telephone system; wherein a plurality of channels are provided through said multiplex system, each channel including the frequency range of an information signal; each channel being designed to carry a signal received from a telephone system; the multiplex system being designed so that the such signal in each channel therein is modulated on a carrier, for transmission; saId multiplex system being further designed so that a plurality of carriers are combined on a common path for frequency division multiplex transmission, the plurality of carriers after transmission by the said multiplexing system being respectively reconverted to a plurality of signals for transmission over a telephone system, where the telephone system is of the type designed, on receipt of a signal resulting from a signal of predetermined frequency on a multiplex channel, to effect, in the telephone system, the switching associated with the termination of a call; said multiplexing system being combined with means for detecting a transmission failure in the multiplex transmission system associated with said plurality of carriers; the method comprising: generating a spectrum of disconnect tones in one-to-one correspondence to said first-mentioned plurality of carriers, each of said disconnect tones having the frequency of the multiplex carrier of the pluraltiy to which it corresponds, when such carrier is modulated by a signal of said predetermined frequency, means responsive to the detection of failure of the multiplexing system for simultaneously supplying to said common path for said plurality of modulated carriers said spectrum of tones;
Claim 3
Dependent Claim
173 words
In a multiplex system for use with a telephone system, wherein information received from the telephone system is carried in signals within a predetermined frequency range, wherein each of said signals is modulated on a carrier for frequency division multiplexing, and is demodulated from the carrier for use by the telephone system connected thereto, said telephone system including switching means operable by a signal of preselected frequency within said frequency range, to perform switching consequent upon the termination of a call, and wherein said multiplex system includes means for transmitting a plurality of such modulated carriers over a common path, and means for detecting a failure in the transmission over said multiplex system; the improvement comprising: means for generating a spectrum of disconnect tones, each such disconnect tone corresponding to the frequency of a carrier of said plurality carried on such common path when modulated by a signal ofaid preselected frequency, and means responsive to the detection of a failure in transmission for simultaneously applying said spectrum of tones to said common path.
Claim 4
Dependent Claim
173 words
In a multiplex system for use with a telephone system, wherein information received from the telephone system is carried in signals within a predetermined frequency range, wherein each of said signals is modulated on a carrier for frequency division multiplexing, and is demodulated from the carrier for use by the telephone system connected thereto, said telephone system including switching means operable by a signal of preselected frequency within said frequency range, to perform switching consequent upon the termination of a call, and wherein said multiplex system includes means for transmitting a plurality of such modulated carriers over a common path, and means for detecting a failure in the transmission over said multiplex system; the improvement comprising: means for generating a spectrum of disconnect tones, each such disconnect tone corresponding to the frequency of a carrier of said plurality carried on such common path when modulated by a signal ofaid preselected frequency, and means responsive to the detection of a failure in transmission for simultaneously applying said spectrum of tones to said common path.
Claim 5
Dependent Claim
158 words
In a frequency division multiplex system for use with a telephone system, which includes a common path for a plurality of carriers, said multiplex system being so designed that each carrier is modulated in accord with an information signal received from a telephone system, and said multiplexing system is so designed that each carrier may carry a signal of predetermined frequency modulated thereon to cause, in a telephone system receiving said signal, the switching consequent upon termination of a call, said multiplex system including means for detection of a failure of transmission associated with said plurality of carriers; the improvement comprising: means providing a spectrum of disconnect tones, each tone in said group of disconnect tones having the frequency of a carrier on said common path when modulated by a signal of said predetermined frequency, and means responsive to the detection of a failure in transmission to simultaneously apply said spectrum of disconnect tones to said common path.
Claim 6
Dependent Claim
158 words
In a frequency division multiplex system for use with a telephone system, which includes a common path for a plurality of carriers, said multiplex system being so designed that each carrier is modulated in accord with an information signal received from a telephone system, and said multiplexing system is so designed that each carrier may carry a signal of predetermined frequency modulated thereon to cause, in a telephone system receiving said signal, the switching consequent upon termination of a call, said multiplex system including means for detection of a failure of transmission associated with said plurality of carriers; the improvement comprising: means providing a spectrum of disconnect tones, each tone in said group of disconnect tones having the frequency of a carrier on said common path when modulated by a signal of said predetermined frequency, and means responsive to the detection of a failure in transmission to simultaneously apply said spectrum of disconnect tones to said common path.
Claim 7
Dependent Claim
188 words
In a frequency division multiplex system for use with a telephone system, including means for modulating information signals received from the telephone system on carriers and demodulating information signals from carriers for use on a telephone system, and means for combining a plurality of carriers for transmission together on a common path over said multiplexing system and separating such plurality of carriers, wherein said information signals so modulated on carriers are provided with predetermined channels through said multiplexing system, wherein a predetermined frequency siGnal modulated on one of said carriers, results in a signal in a telephone trunk or line connected to receive the information on said channel, which causes switching incidental to disconnection of said trunk or line, means for providing for connection at a predetermined portion of said common path, but normally disconnected therefrom, of means for generating a spectrum of disconnect tones of the respective frequencies of individual carriers at that portion when modulated by said predetermined frequency signal, means responsive to the detection of a failure of transmission, in said multiplex system, to cause connection of said spectrum of disconnect tones to said path.
Claim 8
Dependent Claim
188 words
In a frequency division multiplex system for use with a telephone system, including means for modulating information signals received from the telephone system on carriers and demodulating information signals from carriers for use on a telephone system, and means for combining a plurality of carriers for transmission together on a common path over said multiplexing system and separating such plurality of carriers, wherein said information signals so modulated on carriers are provided with predetermined channels through said multiplexing system, wherein a predetermined frequency siGnal modulated on one of said carriers, results in a signal in a telephone trunk or line connected to receive the information on said channel, which causes switching incidental to disconnection of said trunk or line, means for providing for connection at a predetermined portion of said common path, but normally disconnected therefrom, of means for generating a spectrum of disconnect tones of the respective frequencies of individual carriers at that portion when modulated by said predetermined frequency signal, means responsive to the detection of a failure of transmission, in said multiplex system, to cause connection of said spectrum of disconnect tones to said path.
Claim 9
Dependent Claim
166 words
In a frequency division multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to carry information, wherein said multiplexing system is combined with means for detecting transmission failure therein, where a carrier in said path when modulated by a signal of predetermined frequency will produce in the telephone system circuitry receiving said signal, a signal to effect disconnection of telephone switching equipment: the improvement comprising means for generating a spectrum of disconnect tones including a tone corresponding in frequency to that of each of the carriers on said path when such carrier is modulated to carry said predetermined frequency, said spectrum of disconnect tones being normally disconnected from said path, but connectible in response to the detection of transmission failure in the multiplex system to simultaneously supply said spectrum of tones to said common transmission path.
Claim 10
Dependent Claim
166 words
In a frequency division multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to carry information, wherein said multiplexing system is combined with means for detecting transmission failure therein, where a carrier in said path when modulated by a signal of predetermined frequency will produce in the telephone system circuitry receiving said signal, a signal to effect disconnection of telephone switching equipment: the improvement comprising means for generating a spectrum of disconnect tones including a tone corresponding in frequency to that of each of the carriers on said path when such carrier is modulated to carry said predetermined frequency, said spectrum of disconnect tones being normally disconnected from said path, but connectible in response to the detection of transmission failure in the multiplex system to simultaneously supply said spectrum of tones to said common transmission path.
Claim 11
Dependent Claim
169 words
In a multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to provide an information channel; wherein said multiplexing system is combined with means for detecting transmission failure therein, wherein a carrier of said plurality, when modulated by a signal of predetermined frequency, will produce in a telephone system connected to receive the information modulated on said channel, a signal to indicate an idle channel to telephone switching equipment; the improvement comprising: providing a source for generating a spectrum of disconnect tones, including disconnect tones respectively corresponding to the frequency of individual ones of said carriers when modulated by said predetermined frequency, said source being normally disconnected from said path, and means for connecting said source to said path in response to the detection of transmission failure, to supply said spectrum of disconnect tones to said common transmission path.
Claim 12
Dependent Claim
169 words
In a multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to provide an information channel; wherein said multiplexing system is combined with means for detecting transmission failure therein, wherein a carrier of said plurality, when modulated by a signal of predetermined frequency, will produce in a telephone system connected to receive the information modulated on said channel, a signal to indicate an idle channel to telephone switching equipment; the improvement comprising: providing a source for generating a spectrum of disconnect tones, including disconnect tones respectively corresponding to the frequency of individual ones of said carriers when modulated by said predetermined frequency, said source being normally disconnected from said path, and means for connecting said source to said path in response to the detection of transmission failure, to supply said spectrum of disconnect tones to said common transmission path.
Claim 13
Dependent Claim
141 words
In a multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals where each of said carriers may be modulated to provide an information channel, wherein said multiplexing system includes means for detecting transmission failure therein, wherein a carrier of said plurality, modulated by a signal of predetermined frequency, will produce in the telephone system receiving said signal, a signal to effect disconnection of telephone switching equipment, the method of: generating a spectrum of disconnect tones, where each of the tones corresponds to the frequency of a carrier in said common transmission path when modulated by a signal of said pre-determined frequency, responsive to the detection of transmission in the multiplex system, providing to said common transmission path said spectrum of disconnect tones.
Claim 14
Dependent Claim
141 words
In a multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals where each of said carriers may be modulated to provide an information channel, wherein said multiplexing system includes means for detecting transmission failure therein, wherein a carrier of said plurality, modulated by a signal of predetermined frequency, will produce in the telephone system receiving said signal, a signal to effect disconnection of telephone switching equipment, the method of: generating a spectrum of disconnect tones, where each of the tones corresponds to the frequency of a carrier in said common transmission path when modulated by a signal of said pre-determined frequency, responsive to the detection of transmission in the multiplex system, providing to said common transmission path said spectrum of disconnect tones.
Claim 15
Dependent Claim
189 words
In a frequency division multiplex system for use with a telephone system, including means for modulating information signals received from the telephone system on carriers and demodulating information signals from carriers for use on a telephone system, and means for combining a plurality of carriers for transmission together over a common transmission path in said multplexing system and separating such plurality of carriers, wherein said information signals so modulated on carriers are provided with predetermined channels on said common transmission path, wherein a predetermined frequency signal modulated on a carrier in said common transmission path, results in a signal in a telephone trunk or line connected to receive the information on the corresponding channel, which causes switching incidental to disconnection of said trunk or line, the method comprising: generating a spectrum of disconnect tones having frequencies respectively corresponding to the respective frequencies of individual carriers on said common transmission path in said multiplex system when said individual carriers are respectively modulated by said predetermined frequency signal, and responsive to the detection of a failure of transmission in said multiplex system, supplying said spectrum of disconnect tones to said path.
Claim 16
Dependent Claim
189 words
In a frequency division multiplex system for use with a telephone system, including means for modulating information signals received from the telephone system on carriers and demodulating information signals from carriers for use on a telephone system, and means for combining a plurality of carriers for transmission together over a common transmission path in said multplexing system and separating such plurality of carriers, wherein said information signals so modulated on carriers are provided with predetermined channels on said common transmission path, wherein a predetermined frequency signal modulated on a carrier in said common transmission path, results in a signal in a telephone trunk or line connected to receive the information on the corresponding channel, which causes switching incidental to disconnection of said trunk or line, the method comprising: generating a spectrum of disconnect tones having frequencies respectively corresponding to the respective frequencies of individual carriers on said common transmission path in said multiplex system when said individual carriers are respectively modulated by said predetermined frequency signal, and responsive to the detection of a failure of transmission in said multiplex system, supplying said spectrum of disconnect tones to said path.
Claim 17
Dependent Claim
154 words
In a frequency division multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to carry information, wherein said multiplexing system is combined with means for detecting transmission failure therein, where a carrier in said path when modulated by a signal of predetermined frequency will produce in the telephone system circuitry receiving said signal, a signal to effect disconnection of telephone switching equipment, the method comprising: generating a spectrum of disconnect tones including a signal corresponding in frequency to that of each of the carriers on such path when modulated to carry said predetermined frequency, maintaining said source normally disconnected from said path, responsive to the detection of a failure of transmission in said multiplex system supplying said spectrum of disconnect tones to said path.
Claim 18
Dependent Claim
154 words
In a frequency division multiplex system for use with a telephone system, wherein, at a stage in the multiplexing heirarchy, a common transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to carry information, wherein said multiplexing system is combined with means for detecting transmission failure therein, where a carrier in said path when modulated by a signal of predetermined frequency will produce in the telephone system circuitry receiving said signal, a signal to effect disconnection of telephone switching equipment, the method comprising: generating a spectrum of disconnect tones including a signal corresponding in frequency to that of each of the carriers on such path when modulated to carry said predetermined frequency, maintaining said source normally disconnected from said path, responsive to the detection of a failure of transmission in said multiplex system supplying said spectrum of disconnect tones to said path.
Claim 19
Dependent Claim
159 words
In a multiplex system for use with a telephone system, wherein, at a stage in the multiplexing hierarchy, a transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to provide an information channel; wherein said multiplexing system is combined with means for detecting transmission failure therein, wherein a carrier of said plurality, when modulated by a signal of predetermined frequency, will produce in a telephone system connected to receive the information modulated on said channel, a signal to indicate an idle channel to telephone switching equipment, the method comprising: generating a spectrum of disconnect tones, including tones respectively corresponding in frequency to the frequency of individual ones of the carriers in said common path when modulated by said predetermined frequency, maintaining said spectrum of tones normally unconnected to said path, and responsive to the detection of transmission failure, supplying said spectrum of disconnect tones to said path.
Claim 20
Dependent Claim
159 words
In a multiplex system for use with a telephone system, wherein, at a stage in the multiplexing hierarchy, a transmission path is provided for a plurality of carrier signals of different frequencies where each of said carriers may be modulated to provide an information channel; wherein said multiplexing system is combined with means for detecting transmission failure therein, wherein a carrier of said plurality, when modulated by a signal of predetermined frequency, will produce in a telephone system connected to receive the information modulated on said channel, a signal to indicate an idle channel to telephone switching equipment, the method comprising: generating a spectrum of disconnect tones, including tones respectively corresponding in frequency to the frequency of individual ones of the carriers in said common path when modulated by said predetermined frequency, maintaining said spectrum of tones normally unconnected to said path, and responsive to the detection of transmission failure, supplying said spectrum of disconnect tones to said path.
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USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |