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.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to electrical communications systems and, more particularly, to such systems with particular safety functions. 
     BACKGROUND OF THE INVENTION 
     As society has moved into the 21 st  Century, some of its disaffected members have resorted to acts of extreme violence and terror as a way of being heard. Some of these acts have taken the lives of thousands of people and have injured thousands more. Unfortunately, no one foresees an end to such acts. It is, of course, desirable to warn targeted groups well in advance of such a terrorist act so that precautions can be taken to avoid or minimize the expected harm. 
     To a certain extent, mass media—radio and television in particular—is effective in rapidly alerting the public of impending, ongoing and completed acts of terrorism. One drawback of relying solely upon radio and television to provide alerts of terrorist activities is that detailed instructions from governmental leaders cannot be provided to those directly involved in providing for the health, safety and welfare of a group of people such as doctors, firemen, and police. The problem of communicating is compounded by our system of government where federal, state and local responsibilities overlap. Thus, it can be difficult to provide a coordinated response to a terrorist threat, natural disaster or similar event. 
     SUMMARY OF THE INVENTION 
     In light of the drawbacks associated with using broadcast media to rapidly and accurately disseminate information important to public health, safety and welfare, it is a principal object of the invention to provide an emergency warning network that could be used only by authorized personnel to notify specified people of impending dangers. These dangers might include: terrorist alerts and advisories, fires, explosions, chemical spills, hostage takings, radiation leaks, and the spread of biological agents or gasses to name a few. Apart from news regarding dangers, real time-critical information related to weather and earth movements can be delivered to interested parties by the network. 
     It is a further object of the invention to provide an emergency warning network of the type described that can be employed to provide time-critical information to users associated with federal, state and local governmental entities in a manner that permits an orderly chain of command to be maintained at all times. Users positioned “on the ground” are able to obtain the information wherever they may be located: at home, in the field, in a vehicle, etc. 
     It is another object of the invention to provide an emergency warning network of the type described that alerts users of its activation with an audible and visual alarm. Once the alarm has sounded, detailed information may be obtained audibly or visually. 
     It is an object of the invention to provide improved elements and arrangements thereof in an emergency warning network for the purposes described that is rugged in construction, inexpensive to manufacture, easy to use, and dependable in operation. 
     Briefly, the emergency warning network in accordance with this invention achieves the intended objects by featuring a base station for broadcasting a warning signal via a first, earth-orbiting satellite to a pair of substations. After receiving warning signal, one substation broadcasts a forwarding signal carrying the message from the base station, perhaps in a modified form, to at least one portable receiver. The other substation broadcasts a similar signal via a second, earth-orbiting satellite to a pair of branch stations. In turn, the branch stations broadcast forwarding signals to one or more portable receivers. 
     The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The present invention is more readily described with reference to the accompanying drawing that is a schematic diagram of an emergency warning network in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing, an emergency warning network in accordance with the present invention is shown at  10 . Network  10  includes a base station  12  for broadcasting a warning signal  14  via a first, earth-orbiting satellite  16  to a first substation  18  and a second substation  20 . After receiving warning signal  14 , first substation  18  broadcasts a forwarding signal  25  carrying the message from base station  12 , perhaps in a modified form, to portable receivers  22  and  24 . Second substation  20 , however, broadcasts a similar signal  26  via a second, earth-orbiting satellite  28  to a first branch station  30  and a second branch station  32 . Branch stations  30  and  32  broadcast forwarding signals  34  and  36  to portable receivers  22  and  24 . Thus, network  10 , by its very form, establishes a hierarchy for distributing information. 
     Base station  12  includes a central processing unit (CPU)  38  to which is operatively connected: a keyboard  40  for entering data into CPU  38 , a monitor  42  for scrutinizing the entered data and a printer  44  for generating a copy of the entered data on paper. Data entered into CPU  38  may involve any sort of event that may affect the health, safety and welfare of people inhabiting a given geographic area. CPU  38  continuously assimilates, edits and stores the data and encodes such. The encoded data is relayed by CPU  38  in the form of digital data stream to a terminal node controller (TNC)  46  where it is converted to a form that can be broadcast by radio frequency (RF) transmitter  48  to satellite  16  for relay to substations  18  and  20 . A microphone  50  is operatively connected to transmitter  48  so that real-time, live broadcasts of audible information like human speech can be made from base station  12  as part of signal  12  too. 
     Substation  18  has a CPU  38  with a keyboard  40 , a monitor  42  and a printer  44  operating in a conventional fashion so that data can be entered, examined, manipulated and recorded. CPU  38  is connected through a TNC  52  to a receiver  54  so that signal  14  collected by receiver  54  is decoded and fed into CPU  38 . Receipt of signal  14  by CPU  38  energizes an audible or visible alarm  56  associated therewith so as to alert a user of the arrival of signal  14 . Through keyboard  40 , additional data can be entered into CPU  38  that continuously gathers, assimilates, edits and stores the data in encoded form. The encoded data is relayed by CPU  38  to a TNC  46  where it is converted to a form for broadcast by RF transmitter  48  to a desktop radio receiver  22  or a handheld pager  24 . A microphone  50  is connected to transmitter  48  so that live speech broadcasts can be made from substation  18  as part of signal  25 . 
     Substations  18  and  20  are substantially identical to one another in terms of function and structure and, in the drawing, their functional features are shown to be identically numbered. It is believed, therefore, that a full understanding of the functional features of substation  20  can be obtained by reading the previous paragraph of this specification. It is of note, however, that transmitter  48  of substation  20  preferably broadcasts an RF signal  26  to satellite  28 . Satellite  28 , in turn, relays signal  26  to branch stations  30  and  32 . 
     As shown in the drawing, branch stations  30  and  32  are equipped like substations  18  and  20  detailed above. The discussion of the functional features of branch stations  30  and  32 , then, will not be belabored. Noteworthy, however, is the fact that transmitters  48  of branch stations  30  and  32  broadcast to portable receivers  22  and  24 . 
     All portable receivers  22  and  24  include alarms  58  to indicate to a user that a signal has been received. Each alarm  58  may be a tone generator capable of emitting audible sound. On the other hand, each alarm  58  may include an array of six, light emitting diodes (LEDs) with the colors: white, green, blue, yellow, orange and red to convey an impression of the immediate likelihood of an act of terror as proposed by the Office of Homeland Security. The color white would be employed with all messages not involving terrorist threats. It is anticipated that each of the LEDs in the array would be represented by a unique sequence of numbers or code that, when input into CPUs  38  through keyboards  40  and broadcast by transmitters  48  would cause corresponding one of the LEDs to be illuminated. Alarms  56  may be constructed and configured like alarms  58 . 
     Each portable receiver  22  and  24  may also include an LCD display  60  for producing any written message associated with signals  14 ,  25 ,  34 , or  36 . The written messages will generally correspond to the different levels of threats issued by the Office of Homeland Security. Display  60  may exhibit the word “low” for a green alert, “guarded” for blue, “elevated” for yellow, “high” for orange, and “severe” for red to correspond with each level of threat. Of course, the exact content of the written message will be determined by inputs made with keyboards  40 . A reset button (not shown) on receivers  22  and  24  permit a user to deenergize alarm  58 , clear LCD display  60 , and place receiver  22  or  24  in a “stand-by” mode waiting for the next signal  14 ,  25 ,  34 , or  36 . 
     Receivers  22  and  24  may be adjusted using conventional switches or other means (not shown). For example, receivers  22  and  24  can, and will be, made to receive only signals  14 ,  25 ,  34  and  36  at a specified frequency. These adjustments are preferably made at the time that receivers  22  and  24  is manufactured or distributed, but could be accomplished by a user. Of course, receivers  22  and  24  may be made to receive RF weather bulletins directly from NOAA or to receive signals from an alternative source. 
     It is expected that network  10  would be used principally by governmental agencies to distribute information from federal to local governmental entities in times of crisis. Base station  12 , then, would be placed in the possession of an authority responsible for emergency preparedness on a national basis. Substations  18  and  20  that receive signal  14  from base station  12  would be placed, respectively, in the possession of a federal entity having a regional presence such as a military base and in the possession of a state agency, say, the state police force. In turn, branch stations  30  and  32  that receive signal  26  from substation  20  would be operated by local entities, fire and sheriffs departments and the like. 
     It is likely that base station  10  would be operated by the new Office of Homeland Security or a similar agency to broadcast messages regarding events that pose a threat to the health, safety and welfare of the public. A typical message carried by signal  14  possesses: a writing capable of visualization on monitor  42  of substation  18 , a code to energize alarm  56  of substation  18 , as well as a voice transmission capable of being transduced by a speaker perhaps positioned within monitor  42  of substation  18 . Signal  14  would preferably be encoded before broadcast and decoded using conventional means by CPU  38  of substation  18 . 
     When substation  18  receives signal  14  relayed by satellite  16 , CPU  38  causes alarm  56  to be energized. Then, the voice transmission is emitted from monitor  42 . Should the operator of substation  18 , say, the army, desire additional information, it may be gleaned from monitor  42  that will have produced the writing carried by signal  14 . Now, the operator of substation  18  employing his keyboard  40  and microphone  50  may generate a new signal  25  carrying a new message for broadcast to receivers  22  and  24  located in the field where users, like army troops, can act on the message that will be seen on LCD display  60  and produced audibly through an internal speaker (not shown). 
     In some instances, it may be preferable for the operator of base station  12  to bypass substation  18  and send a message directly from satellite  16  to portable receivers  22  and  24  in the field. This is easily accomplished by tuning receivers  22  and  24  so that they are capable of detecting and decoding signals  14  from satellite  16  as shown schematically in the drawing. Thus, if substation  18  became inoperative for any reason, then a message, even an incomplete one, can be delivered to a few users in the field. 
     Substation  20  would normally be operated by a state&#39;s emergency management director. After receiving signal  14  and reviewing the contents of a message carried thereby, a new message is entered into CPU  38  of substation  20  using keyboard  40  for broadcast via transmitter  48  to branch stations  30  and  32 . Branch stations  30  and  32  are free to act upon the message carried by signal  26  and to generate new messages with their own equipment for broadcast as RF signals  34  and  36  to portable receivers  22  and  24  in the possession of field agents where they may be seen on displays  60  and heard through internal speakers. Thus, any threats or other dangerous events described by the operator of base station  12  are passed through network  10  in a secure an efficient manner with those in a supervisory position staying informed and being able to deliver messages to those under their command. 
     While the invention has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications may be made thereto. For example, network  10  may be provided with any number of substations, branch stations, and portable receivers. Therefore, it is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.