Location management for radio frequency identification readers

Abstract

A Radio Frequency Identification (RFID) system for managing and identifying locations for an RFID reader is disclosed. An expected location of a fixed radio frequency identification (RFID) reader is determined. A first signal is transmitted from the reader to a first RFID tag to determine whether the reader is at the expected location. The first tag is a fiducial RFID tag fixed at a first location. In one aspect, the reader receives a first response to the first signal from the first tag. The first response identifies the first location of the first tag. The first location is compared to the expected location. If the first location and the expected location are different, an alarm is triggered.

1 .- 20 . (canceled) 
     
     
         21 . A method comprising:
 determining an expected location of a fixed radio frequency identification (RFID) reader; and   transmitting a first signal from the reader to a first RFID tag associated with the reader to determine whether the reader is at the expected location, wherein the first RFID tag is a fiducial RFID tag, including an antenna, fixed at a first location.   
     
     
         22 . The method of  claim 21 , further comprising receiving at the reader a first response to the first signal from the first tag, wherein the first response identifies the first location of the fiducial RFID tag. 
     
     
         23 . The method of  claim 22 , further comprising:
 determining a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the first tag; and   comparing the current location of the reader with the expected location of the reader.   
     
     
         24 . The method of  claim 23 , further comprising triggering an alarm if the current location of the reader and the expected location of the reader are different. 
     
     
         25 . The method of  claim 24 , wherein the reader comprises the alarm. 
     
     
         26 . The method of  claim 23 , further comprising if the current location of the reader and the expected location are the same, transmitting a second signal from the reader to a network to indicate that the reader is proximate to the first location. 
     
     
         27 . The method of  claim 23 , further comprising:
 associating the reader with the current location of the reader if the current location of the reader and the expected location of the reader are the same;   receiving a second response at the reader from a second RFID tag, wherein the second tag is to track an object; and   associating the object with the current location of the reader.   
     
     
         28 . The method of  claim 21 , further comprising triggering an alarm if no response is received from the first RFID tag. 
     
     
         29 . The method of  claim 21 , further comprising triggering an alarm if a response is intermittently received from the first RFID tag. 
     
     
         30 . The method of  claim 21 , wherein the first location is a portal. 
     
     
         31 . The method of  claim 22 , wherein the first response from the first tag is authenticated. 
     
     
         32 . The method of  claim 22 , further comprising:
 receiving at the reader a second response to the first signal from a second RFID tag, wherein the second RFID tag is a fiducial RFID tag fixed at a second fixed location, and   wherein the second response identifies the second location.   
     
     
         33 . A machine-readable medium having instructions to cause a machine to perform a machine-implemented method comprising:
 determining an expected location of a fixed radio frequency identification (RFID) reader; and   transmitting a first signal from the reader to a first RFID tag associated with the reader to determine whether the reader is at the expected location, wherein the first RFID tag is a fiducial RFID tag, including an antenna, fixed at a first location.   
     
     
         34 . The machine-readable medium of  claim 33 , wherein the method further comprises:
 receiving at the reader a first response to the first signal from the first tag, wherein the first response identifies the first location of the fiducial RFID tag.   
     
     
         35 . The machine-readable medium of  claim 34 , wherein the method further comprises:
 determining a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the first tag; and   comparing the first location the current location of the reader with the expected location of the reader.   
     
     
         36 . The machine-readable medium of  claim 35 , wherein the method further comprises;
 triggering an alarm if the current location of the reader and the expected location are different.   
     
     
         37 . The machine-readable medium of  claim 36 , wherein the reader comprises the alarm. 
     
     
         38 . The machine-readable medium of  claim 35 , wherein the method further comprises:
 if the current location of the reader and the expected location are the same, transmitting a second signal from the reader to a network to indicate that the reader is proximate to the first location.   
     
     
         39 . The machine-readable medium of  claim 35 , wherein the method further comprises;
 associating the reader with the current location of the reader if the current location of the reader and the expected location are the same;   receiving a second response at the reader from a second RFID tag, wherein the second tag is to track an object; and   associating the object with the current location of the reader.   
     
     
         40 . The machine-readable medium of  claim 33 , wherein the method further comprises triggering an alarm if no response is received from the first RFID tag. 
     
     
         41 . The machine-readable medium of  claim 33 , wherein the method further comprises triggering an alarm if a response is intermittently received from the first RFID tag. 
     
     
         42 . The machine-readable medium of  claim 33 , wherein the first location is a portal. 
     
     
         43 . The machine-readable medium of  claim 34 , wherein the first response from the first tag is authenticated. 
     
     
         44 . The machine-readable medium of  claim 34 , wherein the method further comprises:
 receiving at the reader a second response to the first signal from a second RFID tag, wherein the second RFID tag is a fiducial RFID tag fixed at a second location, and   wherein the second response identifies the second location.   
     
     
         45 . An apparatus comprising:
 means for determining an expected location of a fixed radio frequency identification (RFID) reader; and   means for transmitting a first signal from the reader to a first RFID tag associated with the reader to determine whether the reader is at the expected location, wherein the first RFID tag is a fiducial RFID tag, including an antenna, fixed at a first location.   
     
     
         46 . The apparatus of  claim 45 , further comprising means for receiving at the reader a first response to the first signal from the first tag, wherein the first response identifies the first location of the fiducial RFID tag. 
     
     
         47 . The apparatus of  claim 46 , further comprising:
 means for determining a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the first RFID tag; and   means for comparing the current location of the reader with the expected location of the reader.   
     
     
         48 . The apparatus of  claim 47 , further comprising means for triggering an alarm if the current location of the reader and the expected location are different. 
     
     
         49 . The apparatus of  claim 48 , wherein the reader comprises the alarm. 
     
     
         50 . The apparatus of  claim 47 , further comprising:
 if the current location of the reader and the expected location are the same, means for transmitting a second signal from the reader to a network to indicate that the reader is proximate to the first location.   
     
     
         51 . The apparatus of  claim 47 , further comprising:
 means for associating the reader with the current location of the reader if the current location of the reader and the expected location of the reader are the same;   means for receiving a second response at the reader from a second RFID tag, wherein the second tag is to track an object; and   means for associating the object with the current location of the reader.   
     
     
         52 . The apparatus of  claim 45 , further comprising means for triggering an alarm if no response is received from the first RFID tag. 
     
     
         53 . The apparatus of  claim 45 , further comprising means for triggering an alarm if a response is intermittently received from the first RFID tag. 
     
     
         54 . The apparatus of  claim 45 , wherein the first location is a portal. 
     
     
         55 . The apparatus of  claim 46 , wherein the first response from the first tag is authenticated. 
     
     
         56 . The apparatus of  claim 46 , further comprising means for receiving at the reader a second response to the first signal from a second RFID tag, wherein the second RFID tag is a fiducial RFID tag fixed at a second fixed location, and wherein the second response identifies the second location. 
     
     
         57 . An apparatus comprising:
 a processor coupled to a memory through a bus, the processor configured to:
 determine an expected location of a fixed radio frequency identification (RFID) reader; and 
 transmit a first signal from the reader to a first RFID tag associated with the reader to determine whether the reader is at the expected location, wherein the first RFID tag is a fiducial RFID tag, including an antenna, fixed at a first location. 
   
     
     
         58 . The apparatus of  claim 57 , wherein the processor is further configured to receive at the reader a first response to the first signal from the first tag, wherein the first response identifies the first location of the fiducial RFID tag. 
     
     
         59 . The apparatus of  claim 58 , wherein the processor is further configured to perform the following:
 determine a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the first tag; and   compare the current location of the reader with the expected location of the reader.   
     
     
         60 . The apparatus of  claim 59 , wherein the processor is further configured to trigger an alarm if the current location of the reader and the expected location of the reader are different. 
     
     
         61 . The apparatus of  claim 60 , wherein the reader comprises the alarm. 
     
     
         62 . The apparatus of  claim 59 , wherein if the current location of the reader and the expected location of the reader are the same, the processor is further configured to transmit a second signal from the reader to a network to indicate that the reader is proximate to the first location. 
     
     
         63 . The apparatus of  claim 59 , wherein the processor is further configured to perform the following:
 associate the reader with the current location of the reader if the current location of the reader and the expected location of the reader are the same;   receive a second response at the reader from a second RFID tag, wherein the second tag is to track an object; and   associate the object with the current location of the reader.   
     
     
         64 . The apparatus of  claim 57 , wherein the processor is further configured to trigger an alarm if no response is received from the first RFID tag. 
     
     
         65 . The apparatus of  claim 57 , wherein the processor is further configured to trigger an alarm if a response is intermittently received from the first RFID tag. 
     
     
         66 . The apparatus of  claim 57 , wherein the first location is a portal. 
     
     
         67 . The apparatus of  claim 59 , wherein the first response from the first tag is authenticated. 
     
     
         68 . The apparatus of  claim 59 , wherein the processor is further configured to perform the following:
 receive at the reader a second response to the first signal from a second RFID tag, wherein the second RFID tag is a fiducial RFID tag fixed at a second fixed location, and   wherein the second response identifies the second location.   
     
     
         69 . A system comprising:
 a fiducial radio frequency identification (RFID) tag, including an antenna, fixed at a first location; and   a fixed RFID reader within reading range of the fiducial RFID tag, the reader to elicit a response from the fiducial RFID tag, the response received by the reader to communicate the first location of the fiducial RFID tag to the reader.   
     
     
         70 . The system of  claim 69 , wherein the reader is to perform the following:
 determine a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the first tag; and   compare an expected location of the reader with the current location of the reader.   
     
     
         71 . The system of  claim 69 , further comprising an alarm coupled to the RFID reader, wherein the alarm is triggered if the expected location of the reader is different from the current location of the reader. 
     
     
         72 . The system of  claim 69 , wherein the first location comprises a portal for tracking RFID tagged objects. 
     
     
         73 . The system of  claim 72 , wherein the fiducial tag is embedded within a structural member of the portal. 
     
     
         74 . The system of  claim 72 , wherein the fiducial tag is concealed at the first location. 
     
     
         75 . An apparatus comprising a fiducial Radio Frequency Identification (RFID) tag fixed at a first location, the fiducial tag including a memory, the memory storing data identifying the fixed location of the fiducial tag, wherein the data in the fiducial tag is sufficient for a RFID reader to self-determine a current location of the RFID reader. 
     
     
         76 . The apparatus of  claim 75 , wherein the first location is a portal for tracking RFID tagged objects. 
     
     
         77 . The apparatus of  claim 75 , wherein the fiducial tag is embedded within a structural element of the portal. 
     
     
         78 . The apparatus of  claim 75 , wherein the data identifying the fixed location of the fiducial tag includes latitude and longitude coordinate data. 
     
     
         79 . The apparatus of  claim 78 , wherein the data identifying the fixed location of the fiducial tag further includes elevation data. 
     
     
         80 . A radio frequency identification (RFID) reader for use in reading RFID tags, the reader comprising:
 a transmitter to transmit a first signal from the reader to an RFID tag including an antenna; and   a receiver to receive a first response from the RFID tag, the first response identifying a first location of the RFID tag,   wherein the reader is operable to:
 determine a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the RFID tag; and 
 compare the current location of the reader to an expected location of the reader to verify whether there is a match. 
   
     
     
         81 . The RFID reader of  claim 80 , wherein the RFID tag is a fiducial RFID tag fixed at the first location. 
     
     
         82 . The RFID reader of  claim 80 , wherein the reader is communicatively coupled to a computing device on a network, the computing device to compare the current location of the reader with the expected location of the reader. 
     
     
         83 . The RFID reader of  claim 82 , further comprising an alarm to be triggered if the current location of the reader and the expected location are determined to be different. 
     
     
         84 . The RFID reader of  claim 82 , further comprising an alarm to be triggered if no response is received from the first RFID tag. 
     
     
         85 . The RFID reader of  claim 80 , further comprising a decoder to decode the first response so that the current location of the reader and the expected location of the reader can be compared. 
     
     
         86 . A machine-readable storage medium having instructions, which when executed by a machine, cause the machine to perform a machine-implemented method, the method comprising:
 transmitting a first signal from a radio frequency identification (RFID) reader;   receiving a first response to the first signal from a first RFID tag, wherein the first RFID tag is a fiducial RFID tag, including an antenna, fixed at a first location;   identifying the first location of the first RFID tag based on the received response;   determining a current location of the reader based on calculating the reader's location with respect to the first location based on the first response to the first signal received from the first tag; and   comparing the current location of the reader to an expected location of the reader to verify the reader is at the expected location.   
     
     
         87 . The machine-readable storage medium of  claim 86 , wherein the method further comprises triggering an alarm if the current location of the reader and the expected location are different. 
     
     
         88 . The machine-readable storage medium of  claim 86 , wherein the method further comprises, if the current location of the reader and the expected location of the reader are the same, transmitting a signal from the reader to a network to indicate that the reader is proximate to the first location. 
     
     
         89 . The machine-readable storage medium of  claim 86 , wherein the method further comprises:
 associating the reader with the current location of the reader if the current location of the reader and the expected location of the reader are the same;   transmitting a second signal from the reader;   receiving a second response to the second signal from a second RFID tag, wherein the second RFID tag is to track an object; and   associating the object with the current location of the reader.   
     
     
         90 . The machine-readable storage medium of  claim 86 , wherein the method further comprises triggering an alarm if a response is intermittently received from the first RFID tag. 
     
     
         91 . The machine-readable storage medium of  claim 86 , wherein the first location is a portal. 
     
     
         92 . A method comprising:
 transmitting a signal from a radio frequency identification (RFID) reader, the signal to elicit responses from RFID tags;   receiving at the reader a first response to the signal from at least one fiducial RFID tag including an antenna, the fiducial RFID tag being fixed at a known location within a space and having a unique code programmed within the at least one fiducial RFID tag to associate the fiducial RFID tag with the known location within the space;   receiving at the reader a second response to the signal from a different RFID tag, wherein the different RFID tag is attached to a moveable object; and   estimating a location of the object within the space based on the responses received from the at least one fiducial RFID tag and the different RFID tag.   
     
     
         93 . The method of  claim 92 , further comprising estimating a location of the reader within the space based on the response received from the at least one fiducial RFID tag. 
     
     
         94 . The method of  claim 92 , further comprising:
 receiving at the reader a plurality of responses from a plurality of fiducial RFID tags, the plurality of fiducial RFID tags being fixed at known locations within the space; and   wherein estimating the location of the moveable object is based on the responses received from the plurality of fiducial RFID tags.   
     
     
         95 . The method of  claim 92 , further comprising generating a map of the space, the map indicating an estimated location of the moveable objects within the space. 
     
     
         96 . A method comprising:
 transmitting a signal from a radio frequency identification (RFID) reader, the signal to elicit responses from RFID tags;   receiving at the reader a first response to the signal from at least one fiducial RFID tag including an antenna, the fiducial RFID tag being fixed at a known location within a space and having a unique code programmed within the fiducial RFID tag to associate the fiducial RFID tag with the known location within the space;   receiving sensor data at the reader; and   associating the sensor data with the known location within the space based on the response received from the fiducial RFID tag.   
     
     
         97 . The method of  claim 96 , wherein the response to the signal from the fiducial RFID tag includes the sensor data. 
     
     
         98 . The method of  claim 97 , wherein the sensor data is generated by a sensor coupled to the fiducial RFID tag. 
     
     
         99 . The method of  claim 96 , wherein the sensor data is generated by a sensor coupled to the RFID reader. 
     
     
         100 . The method of  claim 96 , wherein the sensor data is selected from the group consisting of temperature data, humidity data, smoke data, acoustic noise data, light data, motion data, security data, and chemical presence data. 
     
     
         101 . The method of  claim 96 , wherein the sensor data includes a time, the time indicating when the sensor data was generated. 
     
     
         102 . The method of  claim 96 , further comprising generating a map of the space, the map indicating the sensor data associated with the known location within the space. 
     
     
         103 . A system comprising:
 a plurality of fixed radio frequency identification (RFID) tags positioned about a space, each of the plurality of fixed RFID tags including an antenna, fixed at a known location within the space and having a unique code programmed within to associate with the known location within the space;   a first RFID tag attached to a moveable object, the first RFID tag to track the object; and   a mobile RFID reader to transmit a signal to elicit a response from the plurality of fixed RFID tags and the first RFID tag, wherein a location of the object is capable of being estimated based on responses received from the fixed RFID tags and the first RFID tag as the reader is moved about the space.   
     
     
         104 . The system of  claim 103 , wherein the plurality of fixed RFID tags are substantially linearly positioned within the space, the fixed RFID tags spaced apart at substantially equal intervals. 
     
     
         105 . The system of  claim 103 , wherein the plurality of fixed RFID tags are substantially positioned in a grid pattern within the space. 
     
     
         106 . The system of  claim 103 , wherein a location of the mobile RFID reader is capable of being estimated based on responses received from the fixed RFID tags. 
     
     
         107 . The system of  claim 103 , wherein the mobile RFID reader is capable of randomly moving about the space. 
     
     
         108 . The system of  claim 103 , wherein the mobile RFID reader is capable of moving about the space along a predetermined course. 
     
     
         109 . The system of  claim 103 , wherein the mobile reader is capable of providing feedback to indicate an estimated location of the object to a user. 
     
     
         110 . The system of  claim 109 , wherein the feedback indicates the estimated location of the object by reference to a logical identifier. 
     
     
         111 . The system of  claim 109 , wherein the feedback is selected from the group consisting of audio feedback and visual feedback. 
     
     
         112 . The system of  claim 103 , wherein the fixed RFID tags are capable of responding to the mobile RFID reader only after the fixed RFID tags have authenticated the mobile RFID reader.