Central station system including secondary communication path established through commercial telephone network
First Claim
1. In a central station system including a central station, at least one remotely located bridging point having a plurality of output ports and serving a plurality of remote stations, each of which is connected to a respective one of the output ports, and normal telecommunication means for transmitting signals between the central station and the bridging point, apparatus for connecting the central station to selected remote stations comprising:
- means associated with the central station for generating address signals applied to the normal telecommunication means;
means associated with the bridging point for connecting the normal telecommunication means to the output port identified by the address signals and for isolating all other output ports form the normal telecommunication means; and
means for establishing an alternative telecommunication path between the central station and the bridging point through the commercial telephone network to which the address signals are applied and the identified output port is connected in the event of failure of the normal telecommunication means.
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Accused Products
Abstract
A central station system in which the central station is normally connected to one or more remotely located bridging points by a dedicated communication path, each bridging point having a plurality of output ports to which one or more remote station devices are connected. In response to address signals generated by the central station, abridging point connects an identified output port to the dedicated communication path to allow communication between the associated remote stations and the central station. All other output ports are electrically isolated from the dedicated communication path. In the event of failure of the dedicated communication path, apparatus is provided for establishing an alternate communication path through the commercial telephone network. The system is highly immune to tampering and other forms of failure because of automatic decision-making capabilities of the bridging point and other features of the apparatus.
35 Citations
18 Claims
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1. In a central station system including a central station, at least one remotely located bridging point having a plurality of output ports and serving a plurality of remote stations, each of which is connected to a respective one of the output ports, and normal telecommunication means for transmitting signals between the central station and the bridging point, apparatus for connecting the central station to selected remote stations comprising:
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means associated with the central station for generating address signals applied to the normal telecommunication means; means associated with the bridging point for connecting the normal telecommunication means to the output port identified by the address signals and for isolating all other output ports form the normal telecommunication means; and means for establishing an alternative telecommunication path between the central station and the bridging point through the commercial telephone network to which the address signals are applied and the identified output port is connected in the event of failure of the normal telecommunication means. - View Dependent Claims (2, 4, 5, 6, 7, 8)
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3. The apparatus defined in claim 3 wherein the means for establishing an alternative telecommunication path further comprises means associated with the central station for disconnecting the central station from the normal telecommunication means when the central station is connected to the alternative telecommunication path.
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9. A central station system comprising:
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a central station including means for generating address signals; at least one remotely located bridging point having an input port and a plurality of output ports; a plurality of remote stations, each of which is connected to a respective one of the output ports; normal telecommunication means for transmitting signals between the central station and the bridging point and having first and second terminations respectively associated with the central station and the bridging point; alternate telecommunication means for transmitting signals between the central station and the bridging point through the commercial telephone network and having third and fourth terminations respectively associated with the central station and the bridging point; first switching means associated with the central station for normally connecting the means for generating address signals to the first termination; second switching means associated with the bridging point for normally connecting the input port to the second termination; means associated with the bridging point for connecting the input port to the output port identified by the address signals applied to the input port; means associated with the central station for selectively activating the alternative telecommunication means by modulating the signal applied to the third termination to dial the fourth termination; means associated with the bridging point for operating the second switching means to connect the fourth termination to the input port in response to the application of a ringing signal to the fourth termination; and means associated with the central station for operating the first switching means to connect the means for generating address signals to the third termination. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. In a central station system including a central station, at least one remotely located bridging point having an input port and a plurality of output ports, a plurality of remote stations, each of which is connected to a respective one of the output ports, and telecommunication means for transmitting signals between the central station and the input port, apparatus for connecting the central station to selected remote stations comprising:
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means associated with the central station for selectively generating command signals and output port identifying signals applied to the telecommunication means; first and second bridge means associated with the bridging point, each of said bridge means including an input terminal, a plurality of output terminals each associated with a respective one of the output ports, and means for connecting the input terminal to the output terminal associated with the output port identified by the output port identifying signals applied to the input terminal; and means associated with the bridging point for connecting the input port to the input terminal of the one of the first and second bridge means identified by the command signals applied to the input port and for connecting the output terminals of the identified bridge means to the associated output ports.
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Specification