Abstract: An emergency warning network including a base station for broadcasting warning signals at a plurality of frequencies and an earth-orbiting satellite for receiving the warning signals and rebroadcasting such to extend the range of communications of the base station. The network also includes a number of receivers for receiving the warning signals from the earth-orbiting satellite. Each of the receivers is tuned to recognize a respective one of the number of radio frequencies.

Abstract: An emergency warning network including a base station for broadcasting a warning signal and a first, earth-orbiting satellite for receiving the warning signal and rebroadcasting such to extend the range of communications of the base station. A first substation receives the warning signal and broadcasts a first forwarding signal in response thereto to a first portable receiver. A second substation also receives the warning signal and broadcasts a second forwarding signal in response thereto via a second, earth-orbiting satellite to a first branch station. The first branch station broadcasts a third forwarding signal in response to the second forwarding signal to a second portable receiver. A second branch station also receives the second forwarding signal via the second, earth-orbiting satellite and broadcasts a fourth forwarding signal to a third portable receiver.

Abstract: An emergency warning network including a base station for broadcasting a warning signal and a first, earth-orbiting satellite for receiving the warning signal and rebroadcasting such to extend the range of communications of the base station. A first substation receives the warning signal and broadcasts a first forwarding signal in response thereto to a first portable receiver. A second substation also receives the warning signal and broadcasts a second forwarding signal in response thereto via a second, earth-orbiting satellite to a first branch station. The first branch station broadcasts a third forwarding signal in response to the second forwarding signal to a second portable receiver. A second branch station also receives the second forwarding signal via the second, earth-orbiting satellite and broadcasts a fourth forwarding signal to a third portable receiver.

Abstract: An emergency warning system including a sensor for detecting an environmental condition. A first transmitter is connected to the sensor for broadcasting a communication signal carrying information describing the environmental condition. A first receiver receives the communication signal from the first transmitter. A second transmitter is connected to the first receiver for broadcasting an alert signal carrying information describing the environmental condition. A second receiver receives the alert signal from the second transmitter and has an indicator for exhibiting the information indicative of the environmental condition.

Abstract: An emergency warning system including a sensor for detecting an environmental condition. A first transmitter is connected to the sensor for broadcasting a communication signal carrying information describing the environmental condition. A first receiver receives the communication signal from the first transmitter. A second transmitter is connected to the first receiver for broadcasting an alert signal carrying information describing the environmental condition. A second receiver receives the alert signal from the second transmitter and has an indicator for exhibiting the information indicative of the environmental condition.