Patent US5896560A successfully refreshed from Google Patents.
US5896560A
Expired / Lapsed
US
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Transmit control system using in-band tone signalling
Assignee: EF Johnson Co
•
Filing: 1996-04-12
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Granted: 1999-04-20
•
Expires: 2016-04-12
Abstract
Abstract A transmit control system using in-band tones for activating and deactivating one or more remote sites. The transmit control system detecting energy in two or more spectral regions to determine if the signal received is a harmonic signal or a signalling tone to prevent accidental deactivation of the transmitter system. In one application, a modified Goertzel algorithm is employed by a digital signal processor to provide tone detection and a two stage detection provides controlled switching in noisy environments.
Inventors
- 👤 Steve Pfiefer
- 👤 Donald R. Bauman
- 👤 James K. Lyon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:30
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/65; H04H20/67; H04B; H04B1/00; H04B1/60; H04L; H04L12/00; H04L12/02; H04L12/12; H04W; H04W84/00; H04W84/02; H04W84/04; H04W84/08
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
128 words
A method for transmit control in a repeater system, comprising the steps of: transmitting an in-band tone of frequency F when a central site has no information to transmit over one or more remote sites, and inhibiting the in-band tone when the central site has information to transmit over the one or more remote sites; and at each of the one or more remote sites, controlling a transmitter, by the steps including: analog to digital converting the in-band tone to create a digitized in-band tone; detecting the digitized in-band tone using a processor; if the in-band tone is detected and if measured signals from a different spectral region are substantially absent, disabling a transmitter at the remote site; and if no in-band tone is detected, activating the transmitter.
Claim 2
Independent Claim
128 words
A method for transmit control in a repeater system, comprising the steps of: transmitting an in-band tone of frequency F when a central site has no information to transmit over one or more remote sites, and inhibiting the in-band tone when the central site has information to transmit over the one or more remote sites; and at each of the one or more remote sites, controlling a transmitter, by the steps including: analog to digital converting the in-band tone to create a digitized in-band tone; detecting the digitized in-band tone using a processor; if the in-band tone is detected and if measured signals from a different spectral region are substantially absent, disabling a transmitter at the remote site; and if no in-band tone is detected, activating the transmitter.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the different spectral region is a data spectral region.
Claim 4
Dependent Claim
15 words
The method of claim 1, wherein the different spectral region is a voice spectral region.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein the step of detecting comprises the step of using a modified Goertzel measurement system to detect the in-band tone.
Claim 6
Dependent Claim
21 words
The method of claim 1, wherein the step of transmitting further comprises the step of transmitting a 2600 Hz in-band tone.
Claim 7
Independent Claim
118 words
A method for transmit control in a repeater system, comprising the steps of: analog to digital converting an in-band tone to create a digitized in-band tone; detecting the digitized in-band tone using a processor, the in-band tone transmitted by a central site when the central site has no information to transmit over one or more remote sites and the in-band tone inhibited when the central site has information to transmit over the one or more remote sites; if the in-band tone is detected, measuring signals from a different spectral region, if signals from the different spectral region are substantially absent, then disabling a transmitter at a remote site; and if no in-band tone is detected, activating the transmitter.
Claim 8
Independent Claim
118 words
A method for transmit control in a repeater system, comprising the steps of: analog to digital converting an in-band tone to create a digitized in-band tone; detecting the digitized in-band tone using a processor, the in-band tone transmitted by a central site when the central site has no information to transmit over one or more remote sites and the in-band tone inhibited when the central site has information to transmit over the one or more remote sites; if the in-band tone is detected, measuring signals from a different spectral region, if signals from the different spectral region are substantially absent, then disabling a transmitter at a remote site; and if no in-band tone is detected, activating the transmitter.
Claim 9
Dependent Claim
15 words
The method of claim 6, wherein the different spectral region is a data spectral region.
Claim 10
Dependent Claim
15 words
The method of claim 6, wherein the different spectral region is a voice spectral region.
Claim 11
Dependent Claim
25 words
The method of claim 6, wherein the step of detecting comprises the step of using a modified Goertzel measurement system to detect the in-band tone.
Claim 12
Dependent Claim
15 words
The method of claim 6, wherein the in-band tone is a 2600 Hz in-band tone.
Claim 13
Independent Claim
96 words
A method for transmit control in a repeater system, comprising the steps of: transmitting an in-band tone of frequency F when a central site has no information to transmit over one or more remote sites, and inhibiting the in-band tone when the central site has information to transmit over the one or more remote sites, wherein the in-band tone is for analog to digital conversion and detection at a remote site, and if the in-band tone is detected and if signals from a different spectral region are substantially absent, disabling a transmitter at the remote site.
Claim 14
Independent Claim
96 words
A method for transmit control in a repeater system, comprising the steps of: transmitting an in-band tone of frequency F when a central site has no information to transmit over one or more remote sites, and inhibiting the in-band tone when the central site has information to transmit over the one or more remote sites, wherein the in-band tone is for analog to digital conversion and detection at a remote site, and if the in-band tone is detected and if signals from a different spectral region are substantially absent, disabling a transmitter at the remote site.
Claim 15
Dependent Claim
15 words
The method of claim 11, wherein the different spectral region is a data spectral region.
Claim 16
Dependent Claim
15 words
The method of claim 11, wherein the different spectral region is a voice spectral region.
Claim 17
Dependent Claim
18 words
The method of claim 11, wherein a modified Goertzel measurement system is used to detect the in-band tone.
Claim 18
Dependent Claim
21 words
The method of claim 11, wherein the step of transmitting further comprises the step of transmitting a 2600 Hz in-band tone.
Claim 19
Dependent Claim
80 words
A transmit control system, comprising: an in-band tone generator for generating an in-band tone when a central site has no information to transmit; an analog to digital convertor for converting signals in a spectral vicinity of the in-band tone; a processor, located at a remote site, for detecting an in-band tone from samples generated by the analog to digital convertor; and a comparator for comparing signals generated by the analog to digital convertor and signals from a different spectral area.
Claim 20
Dependent Claim
80 words
A transmit control system, comprising: an in-band tone generator for generating an in-band tone when a central site has no information to transmit; an analog to digital convertor for converting signals in a spectral vicinity of the in-band tone; a processor, located at a remote site, for detecting an in-band tone from samples generated by the analog to digital convertor; and a comparator for comparing signals generated by the analog to digital convertor and signals from a different spectral area.
Claim 21
Dependent Claim
34 words
The system of claim 16, further comprising a transmission inhibitor for disabling a transmitter at the remote site if an in-band tone is detected and energy in a different spectral region is not detected.
Claim 22
Dependent Claim
19 words
The system of claim 16, wherein the processor executes a modified Goertzel algorithm for detecting an in-band tone signal.
Claim 23
Dependent Claim
15 words
The system of claim 16, wherein the in-band tone generator generates a 2600 Hz tone.
Claim 24
Dependent Claim
21 words
The system of claim 16, wherein the signals from a different spectral area comprise data signals transmitted by the central site.
Claim 25
Independent Claim
79 words
A method of link detection, comprising: monitoring signals from a central site, including monitoring a predetermined spectral region for presence of an in-band tone; if an in-band tone is detected, signalling an active link; and if the in-band tone is not detected and if wideband spectral energy is substantially absent over an interval of time, signalling an inactive link; wherein the interval of time is selected to avoid errors in detection during fluctuation of signals from the central site.
Claim 26
Independent Claim
79 words
A method of link detection, comprising: monitoring signals from a central site, including monitoring a predetermined spectral region for presence of an in-band tone; if an in-band tone is detected, signalling an active link; and if the in-band tone is not detected and if wideband spectral energy is substantially absent over an interval of time, signalling an inactive link; wherein the interval of time is selected to avoid errors in detection during fluctuation of signals from the central site.
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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) | 2002-04-19 | 2002-10-19 | 2003-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-04-19 | 2006-10-19 | 2007-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-04-19 | 2010-10-19 | 2011-04-20 | $7700.00 | Window Closed / Lapsed |