WO2005020497A2 - Improved real time location system - Google Patents

Improved real time location system Download PDF

Info

Publication number
WO2005020497A2
WO2005020497A2 PCT/US2004/028058 US2004028058W WO2005020497A2 WO 2005020497 A2 WO2005020497 A2 WO 2005020497A2 US 2004028058 W US2004028058 W US 2004028058W WO 2005020497 A2 WO2005020497 A2 WO 2005020497A2
Authority
WO
WIPO (PCT)
Prior art keywords
data
location
portable device
computer
radio signal
Prior art date
Application number
PCT/US2004/028058
Other languages
French (fr)
Other versions
WO2005020497A3 (en
Inventor
Chris Zegelin
Original Assignee
Symbol Technologies, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Symbol Technologies, Inc. filed Critical Symbol Technologies, Inc.
Priority to EP04782520A priority Critical patent/EP1658741A2/en
Publication of WO2005020497A2 publication Critical patent/WO2005020497A2/en
Publication of WO2005020497A3 publication Critical patent/WO2005020497A3/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/0009—Transmission of position information to remote stations
    • G01S5/0045—Transmission from base station to mobile station
    • G01S5/0063—Transmission from base station to mobile station of measured values, i.e. measurement on base station and position calculation on mobile
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0252—Radio frequency fingerprinting
    • G01S5/02521—Radio frequency fingerprinting using a radio-map
    • G01S5/02524—Creating or updating the radio-map

Definitions

  • This invention relates to real time location systems and in particular to systems wherein portable devices, which are equipped with data communications radios are located using RF signals transmitted between the portable device and fixed devices having known locations.
  • Systems of tins type are known, which use data communications protocols, such as IEEE standard 802.11 for wireless data communications.
  • the signal strength at the receiver for transmissions between the mobile unit and the fixed devices is measured, either at the portable device or at the fixed devices.
  • Location may be estimated using a database that correlates signal strength within an area to location within the area. Alternately, location can be estimated based on signal strength. The location estimation can be made either by signal strength as received at the fixed devices or the signal strength as received at the mobile device.
  • items can be located by scanning the identity of an item, such as by scanning a bar code or reading an RFID tag, and knowing the location of the portable device that includes the scanner or RFID tag reader. In such systems location information may take several seconds to be calculated, since it is frequently done at a central computer. Where the location of an object is to be correlated with the location of the portable device, the portable device may have moved between the last update of it's location and the location of the object. Accordingly there can be a latency in the determining location of the item. It is an objection of the present invention to provide a method and apparatus that determines when a portable device has changed location.
  • a portable device arranged for wireless data communications with a computer, is located using radio signals between the portable device and fixed devices.
  • the computer has a database relating radio signal characteristics to location within an area.
  • the computer communicates location data to the portable device using wireless data communication, i accordance with the improvement of the invention, the computer further communicates characteristic data representing radio signal environment in a sub area corresponding to the location data to the portable device.
  • the portable device momtors received radio signals corresponding to the data representing radio signal environment to detect changes in location of the device.
  • a processor on the portable device can use the characteristic data and the radio signals corresponding to radio signal environment to update the location data.
  • a portable device arrange to communicate with a computer using wireless data communications.
  • the device includes at least one radio receiver for receiving signals including data communications signals.
  • the device also includes a processor arranged to receive from the radio and store location data and characteristic data representing radio signal environment in a sub area corresponding to the location data.
  • the processor is further arranged to cause the receiver to monitor signals corresponding to the radio signal environment and provide the processor with radio signal data corresponding to the radio signal environment.
  • the processor is arranged to use the radio signal data and the characteristic data representing radio signal environment in a sub area corresponding to the location data to determine if the device has changed location.
  • the device may also use radio signal data and the characteristic data representing radio signal environment to update the location data.
  • the device transmits the updated location data in association with the other data.
  • the portable device processor may be arranged to cause the transmitter to send a data message to the computer to cause the computer to update the location data if the device has changed location. Alternately, the processor may cause the transmitter to send a data message to the computer to cause the computer to provide an increased rate of updated location data if the device has changed location.
  • a portable device arranged for wireless data communications with a computer, is located using radio signals between the portable device and fixed devices.
  • the computer uses a database relating radio signal characteristics to location to compute location of the device and communicate location data to the portable device using wireless data communications.
  • the portable device monitors received radio signals corresponding to the radio signal characteristics to detect a change in location of the device. When a change in location is detected, the portable device may signal the computer to provide updated location data. Alternately, the portable device may signal the computer to provide an increase rate of updated location data.
  • a portable device arranged to communicate with a computer using wireless data communications.
  • the device includes at least one radio for sending and receiving signals including data communications signals.
  • the device further includes a processor arranged to cause the receiver to monitor signals corresponding to radio signal environment, and to provide the processor with radio signal data corresponding to the radio signals.
  • the processor is arranged to used the radio signal data to determine if the device has changed location. When it is determined that the device has changed location; the device processor may be arranged to cause the transmitter to send a data message to the computer to cause the computer to provide updated location data. Alternately, the processor may cause the transmitter of the unit to send a data message to cause the computer to provide an increased rate of updated location data.
  • Figure 1 is a drawing illustrating a system in which the improvement of the present invention may be practiced.
  • Figure 2 is a flow diagram illustrating a first method in accordance with a first embodiment of the present invention.
  • Figure 3 is a block diagram illustrating a method in accordance with a second embodiment of the present invention.
  • Figure 4 is a block diagram illustrating a method in accordance with third embodiment of the present invention.
  • Figure 5 is a block diagram illustrating a portable device for practicing the method of the present invention.
  • a computer 22 acts as a server for mobile units 12 which communicate with the server through access point 16, 18, and 20.
  • the mobile unit 12 includes a bar code scanner 30, shown in Figure 5 for scanning a bar code label 26 on a package 24 to be located.
  • the processor 34 on the mobile unit 12 caused radio 38, having antenna 14 to transmit the identification read from label 26 along with the location of mobile unit 12 to server 22 using one of access points 16, 18, or 20.
  • the location of a package or other item 24 can be determined by determining the location of the mobile unit 12 at the time the label 26 was read by the scanner in mobile unit 12.
  • the location of mobile unit 12 may advantageously be determined by measuring the signal strength at which the mobile unit 12 receives from transmissions from access points 16, 18, and 20.
  • mobile unit 12 may measure the signal strength, such as by using the RSSI function provided by IEEE Standard 802.11.
  • Data representing the received signal strength from, for example, 3 or 4 access points is transmitted by mobile unit 12 to server 22.
  • Server 22 compares the signal strength data received from the mobile unit to a database which correlates signal strength with location within an area to be monitored, such as a medical facility, a warehouse, a factory or an office. Accordingly, server 22 can record the time, location and identification of item 24. This type of system can be used to track the location of articles as they move through a facility.
  • the access point 16, 18, and 20 may measure the signal strength of signals received from mobile unit 12 and provide such signal strength measurement data to server 22 for determining the location of mobile unit 12.
  • the present invention is intended to provide a method for improving the latency experienced by the mobile unit 12 when it is moving within a facility.
  • FIG 2 there is shown a flow diagram of a first embodiment of the method of the present invention, hi accordance with the first embodiment, the computer servr 22 determines and downloads location data to the portable device 12 which receives and store data representing its location.
  • the computer server 22 downloads RF characteristic data which is a portion of the database used by the computer server 22 for determining location of mobile units.
  • the downloaded characteristic data consist of a sub area of the database that corresponds to the region surrounding the location computed for the mobile unit.
  • the RF characteristic data is received and stored at the portable device, for example in memory 36 associated with processor 34, shown in Figure 6.
  • portable device 12 uses a bar code scanner, or alternately an RFID reader 32 to read a tag associated with an item 24.
  • the identification read from a tag or label is correlated with the location data that has been downloaded to the portable device, and may be communicated to computer server 22 using wireless data communication.
  • the processor 34 of portable device 12 causes radio 38 having antenna 14 to monitored the RF environment, for example by measuring the received signal strength of beacon signals sent by access point 16, 18, and 20.
  • the RF environment data measured by processor 34 and radio 38 is compared to the sub area RF characteristic data which has been downloaded. Using this comparison the processor 34 can determine if the portable device 12 has moved from the location corresponding to the location data previously downloaded. If a motion has been detected the location data may be updated by processor 34 and thereafter the updated location data is associated with identification data read from labels or tags thereafter.
  • FIG 3 there is shown a second embodiment of the method of the present invention, hi the embodiment of Figure 3, location data is downloaded by the server 22 to portable device 12. The location data is associated with data read from tags or labels on item 24.
  • processor 24 causes radio 38 to monitored the RF environment, again such as the beacon signals received from access point 16, 18, and 20.
  • the RF signal strength determined by processor 34 are compared to prior measurements of RF signal strength, either the immediate prior measurement or an average of two or more prior measurements, to determine whether the portable device 12 has moved.
  • processor 34 causes radio 38 to signal the server 22 and request updated location data. If it is determined that portable device 12 has not moved, the device continues the process of using the same location data. As an alternate to requesting updated location data, the processor 34 may signal the server 22 to provide location updates at a higher rate, since it is evident from the changed location that the portable device 12 is moving.
  • FIG. 4 there is shown a third embodiment of the method of the present invention, h the embodiment of Figure 4 the determination that the portable device has moved is made using downloaded RF characteristic data.
  • the processor 34 may signal the server 22 to request an updated location data and may also calculate the movement and update the location data itself pending the receipt of new location data from the server 22. Alternately, the processor 34 may signal the server 22 to provide more frequent location data. While there have been described what are believe to be the preferred embodiments of the invention, those skilled in the art will recognize that other changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the true scope of the invention.

Abstract

Portable devices are provided with location data determined at a server computer by comparing radio signal characteristics to a database of characteristics. In one arrangement the server additionally downloads a portion of the database of radio signal characteristics to the portable device and the portable device uses the downloaded portion of the data base to determine if its location has changed. The portable device may either update the location data that it has previously downloaded from the server or alternately may signal the server to provide either updated location data or an increased rate of location data update.

Description

IMPROVED REAL TIME LOCATION SYSTEM SPECIFICATION
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Serial No. 10/648,712 filed August 26, 2003 entitled "Real Time Location System".
BACKGROUND OF THE INVENTION
This invention relates to real time location systems and in particular to systems wherein portable devices, which are equipped with data communications radios are located using RF signals transmitted between the portable device and fixed devices having known locations. Systems of tins type are known, which use data communications protocols, such as IEEE standard 802.11 for wireless data communications. In some systems of this type, the signal strength at the receiver for transmissions between the mobile unit and the fixed devices is measured, either at the portable device or at the fixed devices. Location may be estimated using a database that correlates signal strength within an area to location within the area. Alternately, location can be estimated based on signal strength. The location estimation can be made either by signal strength as received at the fixed devices or the signal strength as received at the mobile device. hi systems wherein such communications protocols are used, items can be located by scanning the identity of an item, such as by scanning a bar code or reading an RFID tag, and knowing the location of the portable device that includes the scanner or RFID tag reader. In such systems location information may take several seconds to be calculated, since it is frequently done at a central computer. Where the location of an object is to be correlated with the location of the portable device, the portable device may have moved between the last update of it's location and the location of the object. Accordingly there can be a latency in the determining location of the item. It is an objection of the present invention to provide a method and apparatus that determines when a portable device has changed location.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided an improvement in a system wherein a portable device, arranged for wireless data communications with a computer, is located using radio signals between the portable device and fixed devices. The computer has a database relating radio signal characteristics to location within an area. The computer communicates location data to the portable device using wireless data communication, i accordance with the improvement of the invention, the computer further communicates characteristic data representing radio signal environment in a sub area corresponding to the location data to the portable device. The portable device momtors received radio signals corresponding to the data representing radio signal environment to detect changes in location of the device. Once it has been determined that the location of a device has moved, a processor on the portable device can use the characteristic data and the radio signals corresponding to radio signal environment to update the location data. Where the device is arranged to transmit location data to a computer in association with other data, the device transmits the updated location data in association with the other data. When is determined that the device has moved the portable device may signal the computer to provide updated location data. Alternately the portable device can signal the computer to provide an increase rate of updated location data. In accordance with the invention there is provided a portable device arrange to communicate with a computer using wireless data communications. The device includes at least one radio receiver for receiving signals including data communications signals. The device also includes a processor arranged to receive from the radio and store location data and characteristic data representing radio signal environment in a sub area corresponding to the location data. The processor is further arranged to cause the receiver to monitor signals corresponding to the radio signal environment and provide the processor with radio signal data corresponding to the radio signal environment. The processor is arranged to use the radio signal data and the characteristic data representing radio signal environment in a sub area corresponding to the location data to determine if the device has changed location. The device may also use radio signal data and the characteristic data representing radio signal environment to update the location data. Where the device is arrange to transmit the location data to a computer in association with other data, the device transmits the updated location data in association with the other data. The portable device processor may be arranged to cause the transmitter to send a data message to the computer to cause the computer to update the location data if the device has changed location. Alternately, the processor may cause the transmitter to send a data message to the computer to cause the computer to provide an increased rate of updated location data if the device has changed location. In accordance with the invention there is provided a system wherein a portable device, arranged for wireless data communications with a computer, is located using radio signals between the portable device and fixed devices. The computer uses a database relating radio signal characteristics to location to compute location of the device and communicate location data to the portable device using wireless data communications. According to the improvement of the invention the portable device monitors received radio signals corresponding to the radio signal characteristics to detect a change in location of the device. When a change in location is detected, the portable device may signal the computer to provide updated location data. Alternately, the portable device may signal the computer to provide an increase rate of updated location data. In accordance with the invention there is provided a portable device arranged to communicate with a computer using wireless data communications. The device includes at least one radio for sending and receiving signals including data communications signals. The device further includes a processor arranged to cause the receiver to monitor signals corresponding to radio signal environment, and to provide the processor with radio signal data corresponding to the radio signals. The processor is arranged to used the radio signal data to determine if the device has changed location. When it is determined that the device has changed location; the device processor may be arranged to cause the transmitter to send a data message to the computer to cause the computer to provide updated location data. Alternately, the processor may cause the transmitter of the unit to send a data message to cause the computer to provide an increased rate of updated location data. For a better understanding of the present invention, together with other and further objects, reference is made to the following description, taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a drawing illustrating a system in which the improvement of the present invention may be practiced. Figure 2 is a flow diagram illustrating a first method in accordance with a first embodiment of the present invention. Figure 3 is a block diagram illustrating a method in accordance with a second embodiment of the present invention. Figure 4 is a block diagram illustrating a method in accordance with third embodiment of the present invention. Figure 5 is a block diagram illustrating a portable device for practicing the method of the present invention.
DESCRIPTION OF THE INVENTION
Referring to Figures 1 and 6, there is shown a representative system 10 in which the method of the present invention may be practiced. A computer 22 acts as a server for mobile units 12 which communicate with the server through access point 16, 18, and 20. In one arrangement the mobile unit 12 includes a bar code scanner 30, shown in Figure 5 for scanning a bar code label 26 on a package 24 to be located. Using a built-in radio 38, the processor 34 on the mobile unit 12 caused radio 38, having antenna 14 to transmit the identification read from label 26 along with the location of mobile unit 12 to server 22 using one of access points 16, 18, or 20. Once this data has been received by the server the location of a package or other item 24 can be determined by determining the location of the mobile unit 12 at the time the label 26 was read by the scanner in mobile unit 12. The location of mobile unit 12 may advantageously be determined by measuring the signal strength at which the mobile unit 12 receives from transmissions from access points 16, 18, and 20. In one arrangement, mobile unit 12 may measure the signal strength, such as by using the RSSI function provided by IEEE Standard 802.11. Data representing the received signal strength from, for example, 3 or 4 access points is transmitted by mobile unit 12 to server 22. Server 22 compares the signal strength data received from the mobile unit to a database which correlates signal strength with location within an area to be monitored, such as a medical facility, a warehouse, a factory or an office. Accordingly, server 22 can record the time, location and identification of item 24. This type of system can be used to track the location of articles as they move through a facility. Alternately the access point 16, 18, and 20 may measure the signal strength of signals received from mobile unit 12 and provide such signal strength measurement data to server 22 for determining the location of mobile unit 12. The present invention is intended to provide a method for improving the latency experienced by the mobile unit 12 when it is moving within a facility. Referring to Figure 2, there is shown a flow diagram of a first embodiment of the method of the present invention, hi accordance with the first embodiment, the computer servr 22 determines and downloads location data to the portable device 12 which receives and store data representing its location. In addition, the computer server 22 downloads RF characteristic data which is a portion of the database used by the computer server 22 for determining location of mobile units. The downloaded characteristic data consist of a sub area of the database that corresponds to the region surrounding the location computed for the mobile unit. The RF characteristic data is received and stored at the portable device, for example in memory 36 associated with processor 34, shown in Figure 6. Thereafter, portable device 12 uses a bar code scanner, or alternately an RFID reader 32 to read a tag associated with an item 24. The identification read from a tag or label is correlated with the location data that has been downloaded to the portable device, and may be communicated to computer server 22 using wireless data communication. In addition, the processor 34 of portable device 12 causes radio 38 having antenna 14 to monitored the RF environment, for example by measuring the received signal strength of beacon signals sent by access point 16, 18, and 20. The RF environment data measured by processor 34 and radio 38 is compared to the sub area RF characteristic data which has been downloaded. Using this comparison the processor 34 can determine if the portable device 12 has moved from the location corresponding to the location data previously downloaded. If a motion has been detected the location data may be updated by processor 34 and thereafter the updated location data is associated with identification data read from labels or tags thereafter. Referring to Figure 3 there is shown a second embodiment of the method of the present invention, hi the embodiment of Figure 3, location data is downloaded by the server 22 to portable device 12. The location data is associated with data read from tags or labels on item 24. In addition, processor 24 causes radio 38 to monitored the RF environment, again such as the beacon signals received from access point 16, 18, and 20. In the embodiment of Figure 3, the RF signal strength determined by processor 34 are compared to prior measurements of RF signal strength, either the immediate prior measurement or an average of two or more prior measurements, to determine whether the portable device 12 has moved. When it is determined by processor 34 that the portable device has moved, processor 34 causes radio 38 to signal the server 22 and request updated location data. If it is determined that portable device 12 has not moved, the device continues the process of using the same location data. As an alternate to requesting updated location data, the processor 34 may signal the server 22 to provide location updates at a higher rate, since it is evident from the changed location that the portable device 12 is moving. Referring to Figure 4 there is shown a third embodiment of the method of the present invention, h the embodiment of Figure 4 the determination that the portable device has moved is made using downloaded RF characteristic data. When movement is detected the processor 34 may signal the server 22 to request an updated location data and may also calculate the movement and update the location data itself pending the receipt of new location data from the server 22. Alternately, the processor 34 may signal the server 22 to provide more frequent location data. While there have been described what are believe to be the preferred embodiments of the invention, those skilled in the art will recognize that other changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the true scope of the invention.

Claims

IfWE CLA : 1. In a system wherein a portable device, arranged for wireless data communications with a computer, is located using radio signals between said portable device and fixed devices, and wherein said computer uses a database relating radio signal characteristics to location to compute location of said device , and communicates location data to said portable device using wireless data communications, the improvement wherein said computer communicates characteristic data representing radio signal environment in a sub-area corresponding to said location data to said portable device, and wherein said portable device monitors received radio signals corresponding to said data representing radio signal environment to detect a change in location of said device. 2. The improvement specified in claim 1 wherein said portable device uses said characteristic data and said radio signals corresponding to said radio signal environment to update said location data. 3. The improvement specified in claim 2 wherein said device is arranged to transmit said location data to a computer in association with other data and wherein said device transmits said updated location data in association with said other data. 4. The improvement specified in claim 1 wherein said portable device signals said computer to provide updated location data if said device determines that it has changed location. 5. The improvement specified in claim 1 wherein said portable device signals said computer to provide an increased rate of updated location data if said device determines that it has moved. 6. A portable device arranged to communicate with a computer using wireless data communications, comprising: at least one radio receiver for receiving signals including data communications signals; and a processor arranged to receive from said radio and store location data and characteristic data representing radio signal environment in a sub-area corresponding to said location data, said processor being arranged to cause said receiver to monitor signals corresponding to said radio signal environment and to provide said processor with radio signal data corresponding to said radio signal environment, and said processor being further arranged to use said radio signal data and said characteristic data representing radio signal environment in a sub-area corresponding to said location data to determine if said device has changed location. 7. A portable device as specified in claim 6 wherein said processor is further arranged to use said radio signal data and said characteristic data representing radio signal environment in a sub-area corresponding to said location data to update said location data. 8. A portable device as specified in claim 7 wherein said device is arranged to transmit said location data to a computer in association with other data. 9. A portable device as specified in claim 6 wherein said portable device further includes a transmitter and wherein said processor is arranged to cause said transmitter to send a data message to said computer to cause said computer to update said location data if said device has changed location. 10. A portable device as specified in claim 6 wherein said portable device further includes a transmitter and wherein said processor is arranged to cause said transmitter to send a data message to said computer to cause said computer to provide an increased rate of location data if said device has changed location. 11. In a system wherein a portable device, arranged for wireless data communications with a computer, is located using radio signals between said portable device and fixed devices, and wherein said computer uses a database relating radio signal characteristics to location to compute location of said device, and communicates location data to said portable device using wireless data communications, the improvement wherein said portable device monitors received radio signals and compares received radio signal characteristics to the characteristics of previously received radio signals to detect a change in location of said device. 12. The improvement specified in claim 11 wherein said portable device signals said computer to provide updated location data if said device determines that it has changed location. 13. The improvement specified in claim 11 wherein said portable device signals said computer to provide an increased rate of updated location data if said device determines that it has changed locations. 14. A portable device arranged to communicate with a computer using wireless data communications, comprising: at least one radio for sending and receiving signals including data communications signals; and a processor arranged to cause said radio to monitor received radio signals and to provide said processor with radio signal data corresponding to characteristics of said radio signals, and said processor being arranged to compare said radio signal data to previously received radio signal data to determine if said device has changed location. 15. A portable device as specified in claim 14 wherein said portable device further includes a transmitter and wherein said processor is arranged to cause said transmitter to send a data message to said computer to cause said computer to update device location data if said device has changed location. 16. A portable device as specified in claim 14 wherein said portable device further includes a transmitter and wherein said processor is arranged to cause said transmitter to send a data message to said computer to cause said computer to provide an increased rate of updated location data if said device has changed location.
PCT/US2004/028058 2003-08-26 2004-08-26 Improved real time location system WO2005020497A2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP04782520A EP1658741A2 (en) 2003-08-26 2004-08-26 Improved real time location system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/648,712 2003-08-26
US10/648,712 US20050054350A1 (en) 2003-08-26 2003-08-26 Real time location system

Publications (2)

Publication Number Publication Date
WO2005020497A2 true WO2005020497A2 (en) 2005-03-03
WO2005020497A3 WO2005020497A3 (en) 2005-08-04

Family

ID=34216789

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2004/028058 WO2005020497A2 (en) 2003-08-26 2004-08-26 Improved real time location system

Country Status (3)

Country Link
US (1) US20050054350A1 (en)
EP (1) EP1658741A2 (en)
WO (1) WO2005020497A2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010051413A1 (en) * 2008-10-31 2010-05-06 Qualcomm Incorporated Method and apparatus to confirm mobile equipment has remained relatively stationary using one or more pilot signal
EP2676498A4 (en) * 2011-02-17 2016-09-14 Ericsson Telefon Ab L M Devices, methods, and computer programs for detecting potential displacement of a wireless transceiver

Families Citing this family (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4021372B2 (en) * 2003-05-29 2007-12-12 株式会社東芝 Telephone exchange method and system
US7295114B1 (en) * 2005-01-21 2007-11-13 Alien Technology Corporation Location management for radio frequency identification readers
EP1867094A2 (en) 2005-03-15 2007-12-19 Trapeze Networks, Inc. System and method for distributing keys in a wireless network
US7702370B2 (en) * 2005-03-17 2010-04-20 Qualcomm Incorporated GPS position tracking method with variable updating rate for power conservation
US7551574B1 (en) * 2005-03-31 2009-06-23 Trapeze Networks, Inc. Method and apparatus for controlling wireless network access privileges based on wireless client location
US7738884B2 (en) * 2005-06-28 2010-06-15 Microsoft Corporation Positioning service utilizing existing radio base stations
US20060293069A1 (en) * 2005-06-28 2006-12-28 Patel Jayesh M Method and system for controlling an electronic device
US7724703B2 (en) 2005-10-13 2010-05-25 Belden, Inc. System and method for wireless network monitoring
US8638762B2 (en) 2005-10-13 2014-01-28 Trapeze Networks, Inc. System and method for network integrity
WO2007044986A2 (en) 2005-10-13 2007-04-19 Trapeze Networks, Inc. System and method for remote monitoring in a wireless network
US7573859B2 (en) 2005-10-13 2009-08-11 Trapeze Networks, Inc. System and method for remote monitoring in a wireless network
US7558266B2 (en) 2006-05-03 2009-07-07 Trapeze Networks, Inc. System and method for restricting network access using forwarding databases
US8966018B2 (en) 2006-05-19 2015-02-24 Trapeze Networks, Inc. Automated network device configuration and network deployment
US8818322B2 (en) 2006-06-09 2014-08-26 Trapeze Networks, Inc. Untethered access point mesh system and method
US9191799B2 (en) 2006-06-09 2015-11-17 Juniper Networks, Inc. Sharing data between wireless switches system and method
US9258702B2 (en) 2006-06-09 2016-02-09 Trapeze Networks, Inc. AP-local dynamic switching
US8340110B2 (en) 2006-09-15 2012-12-25 Trapeze Networks, Inc. Quality of service provisioning for wireless networks
US7873061B2 (en) 2006-12-28 2011-01-18 Trapeze Networks, Inc. System and method for aggregation and queuing in a wireless network
US7734299B2 (en) 2007-03-20 2010-06-08 Microsoft Corporation Facilitating use of a device based on short-range wireless technology
US8902904B2 (en) 2007-09-07 2014-12-02 Trapeze Networks, Inc. Network assignment based on priority
US20090085741A1 (en) * 2007-09-27 2009-04-02 Symbol Technologies, Inc. Methods and apparatus for locating an rfid reader using rfid tags
US8238942B2 (en) 2007-11-21 2012-08-07 Trapeze Networks, Inc. Wireless station location detection
US8150357B2 (en) 2008-03-28 2012-04-03 Trapeze Networks, Inc. Smoothing filter for irregular update intervals
US8978105B2 (en) 2008-07-25 2015-03-10 Trapeze Networks, Inc. Affirming network relationships and resource access via related networks
US8238298B2 (en) * 2008-08-29 2012-08-07 Trapeze Networks, Inc. Picking an optimal channel for an access point in a wireless network
US8090616B2 (en) 2008-09-08 2012-01-03 Proctor Jr James Arthur Visual identification information used as confirmation in a wireless communication
US9279878B2 (en) 2012-03-27 2016-03-08 Microsoft Technology Licensing, Llc Locating a mobile device
US8862067B2 (en) * 2012-03-27 2014-10-14 Microsoft Corporation Proximate beacon identification
CN102801781B (en) * 2012-06-29 2016-08-03 宇龙计算机通信科技(深圳)有限公司 Terminal, location-server and localization method
US9612121B2 (en) 2012-12-06 2017-04-04 Microsoft Technology Licensing, Llc Locating position within enclosure
WO2016118609A1 (en) * 2015-01-20 2016-07-28 Red Point Positioning Corporation Method, system, and apparatus for determining and provisioning location information of wireless devices
US9820101B2 (en) * 2015-08-24 2017-11-14 Thinking Source, LLC Device tracking system

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6195550B1 (en) * 1998-12-30 2001-02-27 Nortel Networks Corporation Method for reducing messaging for inter-VLR location updates
US6768719B1 (en) * 1999-06-23 2004-07-27 Nortel Networks Limited Method and apparatus for mobile assisted detection of a transmission fault on the abis interface of a mobile telecommunications network

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7714778B2 (en) * 1997-08-20 2010-05-11 Tracbeam Llc Wireless location gateway and applications therefor
US6799047B1 (en) * 1999-02-25 2004-09-28 Microsoft Corporation Locating and tracking a user in a wireless network through environmentally profiled data
US7133909B2 (en) * 2001-01-12 2006-11-07 Microsoft Corporation Systems and methods for locating mobile computer users in a wireless network
US7013149B2 (en) * 2002-04-11 2006-03-14 Mitsubishi Electric Research Laboratories, Inc. Environment aware services for mobile devices
JP2004229078A (en) * 2003-01-24 2004-08-12 Ntt Docomo Inc Device for managing information of local position and home position, and mobile communication system
US7116987B2 (en) * 2003-07-19 2006-10-03 Polaris Wireless, Inc. Location estimation of wireless terminals through pattern matching of deduced and empirical signal-strength measurements

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6195550B1 (en) * 1998-12-30 2001-02-27 Nortel Networks Corporation Method for reducing messaging for inter-VLR location updates
US6768719B1 (en) * 1999-06-23 2004-07-27 Nortel Networks Limited Method and apparatus for mobile assisted detection of a transmission fault on the abis interface of a mobile telecommunications network

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010051413A1 (en) * 2008-10-31 2010-05-06 Qualcomm Incorporated Method and apparatus to confirm mobile equipment has remained relatively stationary using one or more pilot signal
CN102272620A (en) * 2008-10-31 2011-12-07 高通股份有限公司 Method and apparatus to confirm mobile equipment has remained relatively stationary using one or more pilot signal
US8639262B2 (en) 2008-10-31 2014-01-28 Qualcomm Incorporated Method and apparatus to confirm mobile equipment has remained relatively stationary using one or more pilot signal
EP2676498A4 (en) * 2011-02-17 2016-09-14 Ericsson Telefon Ab L M Devices, methods, and computer programs for detecting potential displacement of a wireless transceiver
US9538405B2 (en) 2011-02-17 2017-01-03 Telefonaktiebolaget Lm Ericsson (Publ) Devices, methods, and computer programs for detecting potential displacement of a wireless transceiver

Also Published As

Publication number Publication date
WO2005020497A3 (en) 2005-08-04
US20050054350A1 (en) 2005-03-10
EP1658741A2 (en) 2006-05-24

Similar Documents

Publication Publication Date Title
US20050054350A1 (en) Real time location system
US6909399B1 (en) Location system with calibration monitoring
CA2599406C (en) System and method for asset location in wireless networks
US6236335B1 (en) System and method of tracking short range transmitters
US6011487A (en) System and method of locating wireless devices
EP2341361B1 (en) Method and system for locating a hand-held terminal
US7982614B2 (en) Method and apparatus for wireless asset tracking using asset tags with motion sensors
EP1923816B1 (en) Method and system for tuning an RFID interrogator
US7772978B1 (en) Intelligent RFID tag for magnetic field mapping
US20060092040A1 (en) Detecting activity of RFID objects via multiple tags/readers
US20080225810A1 (en) Configurable zone-based location detection
EP1585992B1 (en) Method and system for calibrating a location system
US20110260922A1 (en) Mapping locations based on received signal strengths
US20080042803A1 (en) Adjusting signal strength used to detect tags
US8120469B2 (en) Method and system for tuning an RFID interrogator
US20080266097A1 (en) Method and apparatus for detecting position
US7256681B1 (en) Asset tracking using wireless LAN infrastructure
NL2015432B1 (en) Method of transmitting data from a mobile transmitter device to a host unit, and mobile transmitter device.
US7587200B2 (en) Computer system and base transceiver stations
JP2021109750A (en) Article management system and article management method

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2004782520

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2004782520

Country of ref document: EP