US4528423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Remote subscriber terminal unit
Assignee: BASE TEN TELECOM Inc A CORP OF NEW JERSEY
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Filing: 1984-01-18
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Granted: 1985-07-09
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Expires: 2004-01-18
Abstract
Abstract A central control unit (scanner) is connected across a set of subscriber loops. At each subscriber's premises, an individual subscriber terminal unit (STU) is connected across that particular subscriber's loop. To each STU are connected the various instrumentalities which are to be monitored by the system, e.g. fire alarms, burglar alarms, etc. FSK modulated signals in the upper part of the audible range are transmitted from the scanner to the STUs at appropriate times. The STUs reply by means of similar signals to indicate the status (e.g. alarm, or non-alarm) of the instrumentalities at the respective subscriber premises. This transmission and retransmission is interrupted when the subscriber's telephone is off-hook. In addition, a signal below the audible range (low tone) is produced at the STU, and transmitted to the scanner over the telephone loop if, but only if, all the instrumentalities at the particular subscriber premises are in a given state (e.g. non-alarm). If not, low tone is stopped. Such stoppage is sensed by the scanner, and causes immediate transmission of the FSK signals from the scanner to the corresponding STU, even though the associated telephone is off-hook at the time. The reply to such transmission provides information about the reason for the stoppage, i.e. what is the source of the alarm.
Inventors
- 👤 Rolland T. James
- 👤 Ronald J. Chebra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:33
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/04; H04M11/002
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
120 words
A subscriber terminal unit for use in a system for providing communication between a central location and an instrumentality other than a conventional telephone located at the premises of a telephone network subscriber, said subscriber terminal unit comprising: means connected to a telephone and responsive to a signal transmitted from the central location for retransmitting to the central location a signal in the audible telephone frequency range and of characteristics indicative of the state of the instrumentality; means for transmitting to the central location a signal at a frequency below the audible range when the instrumentality is in a predetermined state; and means responsive to the instrumentality changing to another predetermined state to interrupt the transmission of said below-audible-range signal.
Claim 2
Dependent Claim
120 words
A subscriber terminal unit for use in a system for providing communication between a central location and an instrumentality other than a conventional telephone located at the premises of a telephone network subscriber, said subscriber terminal unit comprising: means connected to a telephone and responsive to a signal transmitted from the central location for retransmitting to the central location a signal in the audible telephone frequency range and of characteristics indicative of the state of the instrumentality; means for transmitting to the central location a signal at a frequency below the audible range when the instrumentality is in a predetermined state; and means responsive to the instrumentality changing to another predetermined state to interrupt the transmission of said below-audible-range signal.
Claim 3
Dependent Claim
22 words
A subscriber terminal unit according to claim 1 wherein the below-audible-range signal is transmitted at least during off-hook conditions of the telephone.
Claim 4
Dependent Claim
23 words
A subscriber terminal unit according to claim 1 wherein the below-audible-range signal is transmitted both during on-hook and off-hook conditions of the telephone.
Claim 5
Dependent Claim
29 words
A subscriber terminal unit according to claim 1 conditioned to respond to a FSK modulated signal in the upper portion of the audible range transmitted from the central location.
Claim 6
Dependent Claim
30 words
A subscriber terminal unit according to claim 4 wherein the signal retransmitted to the central location is also a FSK modulated signal in the upper portion of the audible range.
Claim 7
Dependent Claim
22 words
A subscriber terminal unit according to claim 5 wherein the FSK carrier frequencies are in the vicinity of 2700 and 2900 Hz.
Claim 8
Dependent Claim
20 words
A subscriber terminal unit according to claim 1 wherein the below-audible-range signal is at a frequency of approximately 25 Hz.
Claim 9
Dependent Claim
127 words
A terminal for signalling through a telephone system the condition of an instrumentality, said terminal comprising: means for receiving, from an instrumentality, condition signals representative of the condition of said instrumentality; means for receiving, through a telephone system, interrogation signals from a central location; means responsive to said condition signals and said interrogation signals for transmitting, through said telephone system, response signals in the audible telephone frequency range and representative of the condition of said instrumentality; means for transmitting, through said telephone system, a low-tone signal at a frequency below the audible range when said instrumentality is in a predetermined condition; and means responsive to said condition signals for sensing a change to a second condition of said instrumentality and for interrupting transmission of said low-tone signal.
Claim 10
Dependent Claim
127 words
A terminal for signalling through a telephone system the condition of an instrumentality, said terminal comprising: means for receiving, from an instrumentality, condition signals representative of the condition of said instrumentality; means for receiving, through a telephone system, interrogation signals from a central location; means responsive to said condition signals and said interrogation signals for transmitting, through said telephone system, response signals in the audible telephone frequency range and representative of the condition of said instrumentality; means for transmitting, through said telephone system, a low-tone signal at a frequency below the audible range when said instrumentality is in a predetermined condition; and means responsive to said condition signals for sensing a change to a second condition of said instrumentality and for interrupting transmission of said low-tone signal.
Claim 11
Dependent Claim
23 words
A terminal according to claim 8 wherein the low-tone signal is transmitted at least during off-hook conditions of the telephone at said terminal.
Claim 12
Dependent Claim
24 words
A terminal according to claim 8 wherein the low-tone signal is transmitted both during on-hook and off-hook conditions of the telephone at said terminal.
Claim 13
Dependent Claim
22 words
A terminal according to claim 8 wherein the interrogation signals are FSK modulated signals in the upper portion of the audible range.
Claim 14
Dependent Claim
23 words
A terminal according to claim 11 wherein the response signals are also FSK modulated signals in the upper portion of the audible range.
Claim 15
Dependent Claim
20 words
A terminal according to claim 12 wherein the FSK carrier frequencies are in the vicinity of 2700 and 2900 Hz.
Claim 16
Dependent Claim
20 words
A terminal according to claim 8 wherein the low-tone signal is at a frequency substantially below the audible frequency range.
Claim 17
Dependent Claim
18 words
A terminal according to claim 14 wherein the low-tone signal is at a frequency of approximately 25 Hz.
Claim 18
Dependent Claim
138 words
A terminal for signalling through a telephone system the condition of a plurality of instrumentalities, said terminal comprising: means for receiving, from a plurality of instrumentalities, a plurality of condition signals representative of the conditions of said instrumentalities; means for receiving, through a telephone system, interrogation signals from a central location; means responsive to said condition signals and said interrogation signals for transmitting, through said telephone system, response signals in the audible telephone frequency range and representative of the conditions of said instrumentalities; means for transmitting, through said telephone system, a low-tone signal at a frequency below the audible range when said instrumentalities are in a predetermined condition; and means responsive to said condition signals for sensing a change to a second condition of at least one of said instrumentalities and for interrupting transmission of said low-tone signal.
Claim 19
Dependent Claim
138 words
A terminal for signalling through a telephone system the condition of a plurality of instrumentalities, said terminal comprising: means for receiving, from a plurality of instrumentalities, a plurality of condition signals representative of the conditions of said instrumentalities; means for receiving, through a telephone system, interrogation signals from a central location; means responsive to said condition signals and said interrogation signals for transmitting, through said telephone system, response signals in the audible telephone frequency range and representative of the conditions of said instrumentalities; means for transmitting, through said telephone system, a low-tone signal at a frequency below the audible range when said instrumentalities are in a predetermined condition; and means responsive to said condition signals for sensing a change to a second condition of at least one of said instrumentalities and for interrupting transmission of said low-tone signal.
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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) | 1988-07-08 | 1989-01-07 | 1989-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-08 | 1993-01-07 | 1993-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-08 | 1997-01-07 | 1997-07-09 | $7700.00 | Window Closed / Lapsed |