Directional finding system implementing a rolling code

Abstract

A method and system for finding an object, e.g., person, automobile. A monitoring device may be configured to monitor one or more units “monitored units” which are attached to various objects, e.g., person, automobile. The monitoring device may poll each monitored unit. Based on the signal strength of the responses, the monitoring device may determine the approximate distance each monitored unit is located from the monitoring device. Both the monitoring device and each monitored unit may be configured to store an algorithm to allow for a rolling identification code to be transmitted between the two devices. By transmitting a rolling identification code between the two devices, a third party would be less likely to associate the identification code with the object, e.g., person, attached to the monitored unit.

1 . A method for finding an object comprising the steps of: 
 receiving input to monitor a unit by a monitoring device, wherein said monitored unit is assigned a first code;    receiving input to establish a maximum distance said monitored unit can be located from said monitoring device;    polling said monitored unit with a second code;    receiving an acknowledgement from said monitored unit with a third code; and    determining an approximate distance said monitored unit is located from said monitoring device.    
     
     
         2 . The method as recited in  claim 1  further comprising the step of: 
 activating said monitoring device.  
 
     
     
         3 . The method as recited in  claim 2 , wherein the step of activating said monitoring device comprises plugging an activation unit in said monitoring device.  
     
     
         4 . The method as recited in  claim 3 , wherein said activation unit activates said monitoring device for a limited duration.  
     
     
         5 . The method as recited in  claim 1  further comprising the step of: 
 determining if said approximate distance said monitored unit is located from said monitoring device is beyond a pre-selected percentage of said maximum distance said monitored unit can be located from said monitoring device.  
 
     
     
         6 . The method as recited in  claim 5 , wherein if said monitored unit is located beyond said pre-selected percentage of said maximum distance said monitored unit can be located from said monitoring device then the method further comprises the step of: 
 determining if said monitored unit is located beyond said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         7 . The method as recited in  claim 6 , wherein if said monitored unit is not located beyond said maximum distance said monitored unit can be located from said monitoring device, then the method further comprises the step of: 
 outputting an indication that said monitored unit is located beyond said pre-selected percentage of said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         8 . The method as recited in  claim 6 , wherein if said monitored unit is located beyond said maximum distance said monitored unit can be located from said monitoring device, then the method further comprises the step of: 
 outputting an indication that said monitored unit is located beyond said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         9 . The method as recited in  claim 8  further comprising the step of: 
 transmitting queries to said monitored unit in a substantially continuous manner.  
 
     
     
         10 . The method as recited in  claim 9  further comprising the step of: 
 receiving acknowledgments from said monitored unit.  
 
     
     
         11 . The method as recited in  claim 10  further comprising the step of: 
 determining a direction of said monitored unit from a signal strength and a direction of said acknowledgments.  
 
     
     
         12 . The method as recited in  claim 8  further comprising the step of: 
 resetting a maximum distance said monitored unit can be located from said monitoring device.  
 
     
     
         13 . The method as recited in  claim 1 , wherein said step of receiving input to monitor said monitored unit comprises the step of: 
 reading said first code from said monitored unit.    
     
     
         14 . The method as recited in  claim 13 , wherein said step of receiving input to monitor said monitored unit comprises the step of: 
 storing said received first code.    
     
     
         15 . The method as recited in  claim 13 , wherein said step of receiving input to monitor said monitored unit comprises the step of: 
 assigning said monitored unit to a light emitting diode on said monitoring device.    
     
     
         16 . The method as recited in  claim 1  further comprising the step of: 
 receiving an indication that said monitored unit has been tampered with.  
 
     
     
         17 . The method as recited in  claim 16  further comprising the step of: 
 transmitting queries to said monitored unit in a substantially continuous manner.  
 
     
     
         18 . The method as recited in  claim 17  further comprising the step of: 
 receiving acknowledgments from said monitored unit.  
 
     
     
         19 . The method as recited in  claim 18  further comprising the step of: 
 determining a direction of said monitored unit from a signal strength and a direction of said acknowledgments.  
 
     
     
         20 . The method as recited in  claim 1  further comprising the step of: 
 determining if said third code is recognized.  
 
     
     
         21 . The method as recited in  claim 20 , wherein if said third code is recognized, then the method further comprises the step of: 
 transmitting a fourth code to said monitored unit.    
     
     
         22 . A system, comprising: 
 a monitoring device configured to monitor a position of a monitored unit attached to an object, wherein said monitoring device comprises: 
 circuitry operable for receiving input to monitor said monitored unit, wherein said monitored unit is assigned a first code;  
 circuitry operable for receiving input to establish a maximum distance said monitored unit can be located from said monitoring device;  
 circuitry operable for polling said monitored unit with a second code;  
 circuitry operable for receiving an acknowledgement from said monitored unit with a third code; and  
 circuitry operable for determining an approximate distance said monitored unit is located from said monitoring device.  
   
     
     
         23 . The system as recited in  claim 22 , wherein said monitoring device is activated upon plugging in an activation unit.  
     
     
         24 . The system as recited in  claim 23 , wherein said activation unit activates said monitoring device for a limited duration.  
     
     
         25 . The system as recited in  claim 22 , wherein said monitoring device further comprises: 
 circuitry operable for determining if said approximate distance said monitored unit is located from said monitoring device is beyond a pre-selected percentage of said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         26 . The system as recited in  claim 25 , wherein if said monitored unit is located beyond said pre-selected percentage of said maximum distance said monitored unit can be located from said monitoring device then said monitoring device further comprises: 
 circuitry operable for determining if said monitored unit is located beyond said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         27 . The system as recited in  claim 26 , wherein if said monitored unit is not located beyond said maximum distance said monitored unit can be located from said monitoring device, then said monitoring device further comprises: 
 circuitry operable for outputting an indication that said monitored unit is located beyond said pre-selected percentage of said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         28 . The system as recited in  claim 26 , wherein if said monitored unit is located beyond said maximum distance said monitored unit can be located from said monitoring device, then said monitoring device further comprises: 
 circuitry operable for outputting an indication that said monitored unit is located beyond said maximum distance said monitored unit can be located from said monitoring device.    
     
     
         29 . The system as recited in  claim 28 , wherein said monitoring device further comprises: 
 circuitry operable for transmitting queries to said monitored unit in a substantially continuous manner.    
     
     
         30 . The system as recited in  claim 29 , wherein said monitoring device further comprises: 
 circuitry operable for receiving acknowledgments from said monitored unit.    
     
     
         31 . The system as recited in  claim 30 , wherein said monitoring device further comprises: 
 circuitry operable for determining a direction of said monitored unit from a signal strength and a direction of said acknowledgments.    
     
     
         32 . The system as recited in  claim 28 , wherein said monitoring device further comprises: 
 circuitry operable for resetting a maximum distance said monitored unit can be located from said monitoring device.    
     
     
         33 . The system as recited in  claim 22 , wherein said circuitry operable for receiving input to monitor said monitored unit comprises: 
 circuitry operable for reading said first code from said monitored unit.    
     
     
         34 . The system as recited in  claim 33 , wherein said circuitry operable for receiving input to monitor said monitored unit comprises: 
 circuitry operable for storing said received first code.    
     
     
         35 . The system as recited in  claim 33 , wherein said circuitry operable for receiving input to monitor said monitored unit comprises: 
 circuitry operable for assigning said monitored unit to a light emitting diode on said monitoring device.    
     
     
         36 . The system as recited in  claim 22 , wherein said monitoring device further comprises: 
 circuitry operable for receiving an indication that said monitored unit has been tampered with.    
     
     
         37 . The system as recited in  claim 36 , wherein said monitoring device further comprises: 
 circuitry operable for transmitting queries to said monitored unit in a substantially continuous manner.    
     
     
         38 . The system as recited in  claim 37 , wherein said monitoring device further comprises: 
 circuitry operable for receiving acknowledgments from said monitored unit.    
     
     
         39 . The system as recited in  claim 38 , wherein said monitoring device further comprises: 
 circuitry operable for determining a direction of said monitored unit from a signal strength and a direction of said acknowledgments.    
     
     
         40 . The system as recited in  claim 22 , wherein said monitoring device further comprises: 
 circuitry operable for determining if said third code is recognized.    
     
     
         41 . The method as recited in  claim 40 , wherein if said third code is recognized, then said monitoring device further comprises: 
 circuitry operable for transmitting a fourth code to said monitored unit.    
     
     
         42 . A system, comprising: 
 a monitored unit attached to an object; and    a monitoring device configured to monitor a position of said monitored unit, wherein said monitoring device comprises: 
 circuitry operable for receiving input to monitor said monitored unit, wherein said monitored unit is assigned a first code;  
 circuitry operable for receiving input to establish a maximum distance said monitored unit can be located from said monitoring device;  
 circuitry operable for polling said monitored unit with a second code;  
 circuitry operable for receiving an acknowledgement from said monitored unit with a third code; and  
 circuitry operable for determining an approximate distance said monitored unit is located from said monitoring device.  
   
     
     
         43 . A system, comprising: 
 a monitored unit attached to an object, wherein said monitored unit comprises: 
 circuitry operable for detecting tampering of said monitored unit;  
 circuitry operable for transmitting an indication that said monitored unit has been tampered with; and  
 circuitry operable for transmitting signals in a substantially continuous manner; and  
   a monitoring device configured to monitor a position of said monitored unit, wherein said monitoring device comprises: 
 circuitry operable for receiving said indication that said monitored unit has been tampered with;  
 circuitry operable for receiving said transmitted signals; and  
 circuitry operable for determining a direction of said monitored unit via a signal strength and a direction of said transmitted signals.  
   
     
     
         44 . A method for finding one or more objects comprising the steps of: 
 receiving input to monitor one or more units by a monitoring device, wherein each of said one or more units is assigned a unique identification code, wherein each of said one or more units is attached to an object; and    polling each of said one or more units with a rolling identification code.    
     
     
         45 . A system, comprising: 
 a monitoring device, wherein said monitoring device comprises: 
 a system on a chip (SoC) configured to monitor a unit attached to an object; and  
 an activation unit coupled to said SoC, wherein said activation unit activates said SoC for a limited duration.