Alarm monitoring telecommunications line condition detection and automatic calibration
AssigneeTyco Safety Products Canada Ltd.
InventorsStephane Foisy, Pavel Raikhlin
Life of this patent
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Abstract
A method at an alarm monitoring station and security system arrangement for detecting alarm signals originating at security systems on incoming calls carried by a telecommunications line includes, for each call, measuring a noise level on the line in the absence of signals originated by the security systems. Based on the measuring, at least one signal detection threshold above the noise level is set, wherein a level of a signal must exceed the signal detection threshold in order to be detected as a data signal. Alarm data signals in the call are detected using the signal detection threshold.
Claims24
A method of detecting alarm data signals originating at security systems on incoming calls received by way of a telecommunications line at an alarm monitoring station, said method comprising:
- for each call,
- measuring a noise level in at least one frequency band on said telecommunications line in the absence of signals originated by said security systems in said at least one frequency band;
- based on said measuring, setting at least one signal detection threshold above said noise level, wherein a level of a signal must exceed said signal detection threshold in order to be detected as a data signal;
- and
- detecting said alarm data signals in said call using said signal detection threshold.
An alarm monitoring apparatus for receiving incoming alarm data signals on calls carried by a telecommunications line, said apparatus comprising:
- a noise detector for measuring a noise level on said telecommunications line in the absence of a signal in said at least one frequency band originated by said alarm transmitter;
- a signal detector for detecting signals on said telecommunications line, said signal detector having at least one adjustable signal detection threshold wherein a level of a signal must exceed said signal detection threshold in order to be detected as a data signal;
- and
- a controller in communication with said noise detector and said signal detector, said controller operable to, for each of said calls:
- receive an indication from said noise detector of a noise level in said at least one frequency band on said telecommunications line;
- based on said indication, set at least one signal detection threshold of said signal detector to exceed the noise level on said telecommunications line;
- and
- detect said alarm data signals in each said incoming calls using said signal detection threshold.
A security system arrangement comprising:
- at least one telecommunications line;
- an alarm transmitter at a monitored premise for sending an alarm signal;
- an alarm monitoring station comprising an alarm monitoring apparatus, said apparatus comprising:
- a noise detector for measuring a noise level on said telecommunications line in the absence of a signal in at least one frequency band originated by said alarm transmitter;
- a signal detector for detecting signals on said telecommunications line, said signal detector having at least one adjustable signal detection threshold wherein a level of a signal must exceed said signal detection threshold in order to be detected as a data signal;
- and
- a controller in communication with said noise detector and said signal detector, said controller operable to, for each incoming call:
- receive an indication from said noise detector of a noise level in said at least one frequency band on said telecommunications line;
- based on said indication, set at least one signal detection threshold of said signal detector to exceed the noise level on said telecommunications line;
- and
- detect said alarm data signals in each said incoming call using said signal detection threshold.
Dependencies are inferred from the claim text.