Cellular alarm backup system
First Claim
1. In a security alarm system comprising alarm detection means for generating an output signal indicative of an alarm condition, means responsive to said output signal for generating a telephone call to a central security station, said means responsive to said output signal being coupled to a line of a land-based telephone system for making a telephone call in response to the input therein of said output signals, and means coupling said means responsive to said output signal to the telephone land-based system, wherein the improvement comprises:
- a backup cellular transmission system for alternatively sending an alarm call from said means responsive to said output signal via a cellular telephone system, said backup cellular system comprising a cellular transceiver, a cellular interface means coupled to said cellular transceiver, and a first switch means coupled between said means responsive to said output signal and said cellular interface and said means coupling said means responsive to said output signal to the telephone land-based system; and
line fault detection means for detecting the inoperativeness of the telephone land-based system, said line fault detection means being coupled to said first switch means for controlling the state thereof to thereby automatically cause said first switch means to switch over from said telephone land-based system to the cellular system in response to said line fault detection mean'"'"'s detection of a line fault on the land line system; and
a telephone set coupled to said first switch means for making a call over said cellular backup system when said means responsive to said output signal is not activated and when said line fault detection means is activated in response to the loss of the telephone land-based system.
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Accused Products
Abstract
A cellular backup system is provided for a standard security alarm network, so that upon the inoperativeness of the telephone land line, automatic switch over to the cellular system is achieved, so that a digital communicator or telephone tape dialer may still transmit its distress call to a central alarm station, via the cellular system. A line fault monitor is provided which automatically detects the outage of the land-based telephone system which, in turn, provides an output signal to a latching relay which causes the activation of a pair of switching relays to automatically switch the connection of the alarm communicator from the DB-8 cord of the land-based system to a cellular interface coupled to a conventional cellular transceiver of a cellular system. The switching relays are latched in the state connecting the alarm communicator to the cellular backup system and held in such a state, regardless of the state of the land-based system, as long as a manual rest switch has not been used. The pair of switching relays are also used for coupling a standard land telephone handset also to the cellular system upon the outage of the land-based lines.
104 Citations
13 Claims
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1. In a security alarm system comprising alarm detection means for generating an output signal indicative of an alarm condition, means responsive to said output signal for generating a telephone call to a central security station, said means responsive to said output signal being coupled to a line of a land-based telephone system for making a telephone call in response to the input therein of said output signals, and means coupling said means responsive to said output signal to the telephone land-based system, wherein the improvement comprises:
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a backup cellular transmission system for alternatively sending an alarm call from said means responsive to said output signal via a cellular telephone system, said backup cellular system comprising a cellular transceiver, a cellular interface means coupled to said cellular transceiver, and a first switch means coupled between said means responsive to said output signal and said cellular interface and said means coupling said means responsive to said output signal to the telephone land-based system; and line fault detection means for detecting the inoperativeness of the telephone land-based system, said line fault detection means being coupled to said first switch means for controlling the state thereof to thereby automatically cause said first switch means to switch over from said telephone land-based system to the cellular system in response to said line fault detection mean'"'"'s detection of a line fault on the land line system; and a telephone set coupled to said first switch means for making a call over said cellular backup system when said means responsive to said output signal is not activated and when said line fault detection means is activated in response to the loss of the telephone land-based system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification