WO2000019235A1 - Rfid detection system - Google Patents

Rfid detection system Download PDF

Info

Publication number
WO2000019235A1
WO2000019235A1 PCT/GB1999/003213 GB9903213W WO0019235A1 WO 2000019235 A1 WO2000019235 A1 WO 2000019235A1 GB 9903213 W GB9903213 W GB 9903213W WO 0019235 A1 WO0019235 A1 WO 0019235A1
Authority
WO
WIPO (PCT)
Prior art keywords
tag
energy
detector
rfid
includes circuitry
Prior art date
Application number
PCT/GB1999/003213
Other languages
French (fr)
Inventor
Howard William Whitesmith
Timothy John Palmer
Alan Edward Ball
Original Assignee
Tagtec Limited
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 Tagtec Limited filed Critical Tagtec Limited
Priority to AT99947682T priority Critical patent/ATE243326T1/en
Priority to DE69908957T priority patent/DE69908957T2/en
Priority to EP99947682A priority patent/EP1112512B1/en
Priority to JP2000572687A priority patent/JP2002525640A/en
Priority to AU61060/99A priority patent/AU6106099A/en
Priority to US09/786,425 priority patent/US6577238B1/en
Publication of WO2000019235A1 publication Critical patent/WO2000019235A1/en

Links

Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/22Electrical actuation
    • G08B13/24Electrical actuation by interference with electromagnetic field distribution
    • G08B13/2402Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
    • G08B13/2451Specific applications combined with EAS
    • G08B13/2462Asset location systems combined with EAS
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S13/00Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/87Combinations of radar systems, e.g. primary radar and secondary radar
    • G01S13/878Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/0008General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10019Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
    • G06K7/10029Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot
    • G06K7/10039Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot interrogator driven, i.e. synchronous

Definitions

  • the present invention relates to radio frequency identification (RFID) tagging and, more specifically, to the use of RFID transponders or "tags" in position monitoring and location.
  • RFID radio frequency identification
  • RFID transponders such as the SupertagTM transponders developed by CSIR
  • & BTG are known for providing automatic data capture and dissemination of ID codes from tagged objects and provide advantages over conventional tagging systems such as bar codes, magnetic stripes and the like, particularly as they utilise so-called anti- collision technology which enables identification of individual tags among groups of tags without requiring singulation of the tags.
  • Such tags may comprise a single, integrated circuit chip bonded to an antenna which may be a flat, printed antenna, and can be incorporated in labels and the like and attached to objects to provide identification of the objects.
  • the SupertagTM technology employs a reflection tag principle in which radio waves incident on the tag are modulated with the data content of the tag and re-broadcast for a given period of time to the interrogator. Following reading of the tag data, the tag is muted for another predetermined period of time to allow other tags in the range of the interrogator to be identified or counted.
  • Such tags receive their operating energy by means of radiated electromagnetic energy and are known as so-called “passive radio tags” and therefore require no attached power source such as battery.
  • the energy required to operate from RF energy is provided from a suitable "interrogator” or reader, referred to hereafter as a "detector".
  • the present invention recognises that RFID tags can be utilised to provide location information and hence may be used to provide a simple security system for objects.
  • a system for monitoring the position of one or more RFID tags comprising: one or more detectors incorporating means for detecting changes in the range of an RFID tag from the detector or detectors; and means for triggering an alarm if a detected change in range of an RFID tag exceeds a predetermined threshold or if the RFID tag cannot be detected by the detector or detectors
  • the detector or detectors preferably measure the time of a returned radio signal from a tag to determine the range of the tag, but, alternatively, the strength of a returned radio signal or its waveform shape may be determined by the detector(s) to determine the range of a tag
  • the system may also have means for recording the time of a change in range of a tag and may include plural detectors may also have means for calculating the location of one or more radio tags having individual codes
  • the system may include tags which have circuitry arranged to emit short bursts of RF energy at periodic intervals, and the or each detector including circuitry for detecting changes in the periodic interval at which energy is transmitted by the or each tag
  • the or each detector preferably includes circuitry for predicting the time of receipt of a burst of energy from a tag and for triggering an alarm if the time of actual receipt varies from the predicted time of receipt by more than a predetermined interval and/or if the rate of change in the periodic interval at which energy is transmitted by a tag is outside a predetermined range
  • the detector(s) may include circuitry for analysing changes in the rate of receipt of bursts of energy from a tag and for triggering an alarm if the rate of change is more than a predetermined level
  • a system according to the invention may be utilised, for example in the home, for ensuring the security of components such as valuable equipment such as televisions personal computers and the like, or other valuable items such as paintings, furniture and the like which may be relatively easily stolen by removal from their normal location, movement out of range of a detector being recognised by the central controller and an appropriate alarm signal given
  • One example of such a system comprises one or more transmitter-receivers (or detectors) and one or more RFID tags, the transmitter-receiver transmitting radio frequencies coded so that the RFID tag can recognise a point in time at which to respond
  • the time delay between the transmission of the time code and reception by the transmitter-receiver of the signal from the RFID tag is a function of both the time delays in the equipment and the propagation time of the signals travelling to and from the RFID tag
  • the total time is measured and stored within the transmitter-receiver It is not necessary to know the value of any of the components of the total time This process is repeated and successive times are compared
  • the difference in times can be due to either changes in the time delay in the equipment or changes in the propagation time of the radio frequency signal As the time delay in the equipment will change only slowly, time differences will be due to change in the propagation delay, which in turn will be due to changes in distance
  • the equipment can thus sense a change in distance between the transmitter- receiver and the RFID tag which can be used to initiate an alarm or for some other purpose
  • the transmitter-receiver transmits and each RFID tag responds in the way previously described
  • the signal received by the transmitter-receiver from the RFID tags will have time and amplitude characteristics which are a function of the relative positions of the transmitter-receiver and the RFID tags
  • the transmitter-receiver captures the time-amplitude 'picture' of the returned signal
  • the process is repeated and successive time-amplitude 'pictures' are compared
  • the equipment can thus sense a change in distance between the transmitter- receiver and two or more RFID tags which can be used to initiate an alarm or for some other purpose
  • an RFID tag could be moved in an arc without changing the distance between the transmitter-receiver and the RFID tag and without changing the time or time-amplitude 'picture' captured by the transmitter-receiver
  • transmitter-receivers each operating as previously described with one or more RFID tags, but displaced in such a way that movement of an RFID tag in two or three dimensions can be sensed
  • the transmitter-receivers operate in a synchronised manner so that changes in relative distance between each transmitter-receiver and the RFID tags can be separately compared
  • the tag is arranged to transmit a short burst, or "chirp", of RF energy at periodic intervals
  • a short burst or "chirp”
  • the tag is arranged to transmit a short burst, or "chirp", of RF energy at periodic intervals
  • the tag with, for example, an on-board capacitor arranged to store electromagnetic energy received by the tag's antenna from an RF transmitter forming part of a detector in the system
  • the repetition rate (chirp rate) of the individual tag is determined by the intensity of the electromagnetic field incident upon the tag and the tag s orientation
  • the chirps may be detected by a base station which is capable of analysing the chirp rate The base station is then be able to predict the time of the next chirp for each tag If the exact frequency of RF energy within a chirp is determined by the tag components, the repetition rate (chirp rate) of the individual tag is determined by the intensity of the electromagnetic field incident upon the tag and the tag s orientation
  • the chirps may be detected by
  • the detector incorporates a transmitter which is relatively simple It is only required that the transmitter send a continuous RF signal
  • the international standards specify the maximum field that is allowed (often given as a measured value at 10m)
  • the time for the next chirp can then be predicted and, if it does not appear within its expected time window then the alarm can be triggered It would not matter if two or more individual chirps arrived at the same time, as the FFT (Fast Fourier Transform) could decode this as long as each tag has a different chirp rate
  • the rate at which the tag receives energy will be dependent upon the orientation of the tag as well as the distance from the transm ⁇ tter(s)
  • changing either of these will alter the chirp rate Therefore, if two tags should happen to be chirping at the same rate, this can be easily corrected by adjusting the orientation of one of the tags during set-up While
  • the tag chirp rate has a strong dependence upon distance and orientation, it should be possible to set up many more clearly identifiable tags over a much wider range than is achievable with a single transmitter
  • the chirp rate of the tag depends upon the amount of the electromagnetic field which is coupled into the coil, this being determined not only by the field strength, which is distance dependent, but also by the angular orientation of the tag with respect to the field, the system is therefore sensitive to rotational movement of the tag about its own axis
  • An example of the implication of this is illustrated by considering a tag that has been placed on a door close to the hinge The rotation of the door when opening would change the orientation of the tag to the field and hence would dramatically alter the chirp rate An intruder alarm could then be triggered by this change Rather than transmitting, the tag could send its chirp back by using the reflection technique already used in many existing tags It is the detection of the chirp rate that is essential to this technique not how the chirp is sent
  • Portable alarms/personal security a small portable system could easily be attached to hotel room doors and windows, and indeed to any valuable items it is desired to protect within a room
  • Figure 1 is a diagram of a first system comprising plural tags and transmitter- receivers
  • Figure 2 illustrates the operative components of a passive radio tag for such a system
  • Figure 3 illustrates, in block diagram form, the components of a transmitter- receiver and a connected central control in such a system
  • Figure 4 is a diagram of a second system comprising plural tags and a single transmitter-receiver
  • Figure 5 is a block-diagram of the internal components of a tag for use with the second system
  • figure 1 there are shown a number of articles 1 on which passive radio tags 2 are located and three transceiver detectors 3 which are arranged to provide a field of coverage for the articles Movement of an article and hence its tag out of the field of cover is detected and an alarm issued
  • Figure 2 illustrates the operative components of a passive radio tag for use in a system according to the present invention
  • a signal from a transceiver (not shown in figure 2) is passed from an antenna 4 to a receiver 5 and the signal decoded in a decoder 6
  • the signal is decoded to extract timing information which is subsequently used by a microprocessor control mechanism 7 to determine the interval after which the passive radio tag transmission commences from a transmitter 9 via a further antenna
  • the transmission may be encoded with data stored in the passive radio tag including such data as the identity of the passive radio tag and is received by the transceivers 3
  • FIG. 3 shows one a number of transceivers 3 employed in the system, connected to a central control 11 which in turn may be connected to an alarm 12
  • the transceivers each have a control 13 which periodically initiates a transmission to the passive radio tags 2 in the system
  • the return transmissions from the passive radio tags are synchronised by coding the transmissions from the transceivers or by starting, stopping or interrupting the transmission from the transceivers
  • the transmission from a passive radio tag is compared with an RF oscillator 14 or another clock to determine the time elapsed since the initiation of the transmission from the transceiver
  • the elapsed time and the decoded data if any from the passive radio tag are stored in the transceiver control 13 and compared with equivalent data from successive cycles to determine whether or not the passive radio tag has moved If movement is detected which is judged by the central control 11 to be indicative of unallowable movement, then the central controller initiates an alarm
  • the second system illustrated in Figures 4 and 5 utilises tags with an on-board capacitor to provide a short burst or "chirp" of RF energy which can be detected by a detector
  • the system 100 is illustrated generally in Figure 4
  • the system includes a transmitter 101 which has a power source (not shown), an oscillator 102 and an amplifier 103 which directs a signal at radio frequencies (RF) to an antenna 104 From the antenna, the RF energy is radiated into the area covered by the system and energy is picked up by tags 201
  • the tags 200 store the energy and emit short bursts ("chirps") of RF energy (at a different frequency to that of the transmitter 101) to one or more detectors 301 which include an antenna 302, a receiver 303 and a controller 304 which is connected to an alarm 401
  • the main function of the controller 304 is to analyse the frequencies that are present in the received signal or pulse train in such a way as to be able to predict the arrival time of the next chirp from any particular tag If the chirp from that tag does not arrive within a given time window, then the controller can take the appropriate action, such as sounding the alarm
  • the controller of the preferred example uses a Digital Signal Processor (DSP) connected to an Analogue to Digital Converter (ADC).
  • ADC Analogue to Digital Converter
  • the DSP could also be connected to some form of user interface such as an LCD display and keyboard if desired.
  • the ADC converts the received analogue signal to a digital pulse train and the DSP then performs a Fast Fourier Transform (FFT) upon that pulse train and then uses the results from the FFT to predict the time of the next chirp from each tag.
  • the controller 304 may also perform a number of other functions, these may include adaptive algorithms to compensate for thermal/environmental changes, as well as general system control, i.e. monitoring any input from the user and the display of information on, say, an attached computer system monitor.
  • the incident RF energy is received by an input coil or antenna, 202.
  • This energy is stored, preferably by rectification and/or voltage multiplication in a rectifier 203 and the subsequent charging of a capacitor 204.
  • a switch 205 is triggered and the energy is fed into a transmit coil or antenna 206.
  • This periodically generates an RF pulse whose frequency is determined by the self-resonance of the coil 206 and the storage capacitor 204.
  • the tags 201 continue to chirp with the same periods (dependant on location within the electromagnetic field of the transmitter 101) thus providing an indication of non-movement.
  • the addition of a filter 207 may enable closer control of the frequency which may desirable to ensure that the appropriate standards are met with assurance.
  • any movement of a tag is detected by the detector
  • the chirp rate will change when the radiant energy impinging on the tag changes as a result of its movement, and this can be arranged to trigger the alarm 401.
  • the switch unit 205 or the filter 207 could be replaced with an intelligent switch which would be able to modulate the signal being generated by the transmit coil.
  • Individual tags may be capable of being programmed by the controller if the intelligent switch mentioned above is given the capability to detect a modulation of the incoming signal; this may be used to place digital information in the switch module and hence program the tag. This programmed information would then control the behaviour of the tag and the messages that it transmitted. This gives an 'adaptive' tag that can be modified by the controller. This has a number of applications, including ID as stated above and chirp frequency modification to allow for a greater tag density.

Abstract

A system (100) is disclosed for monitoring the position of one or more RFID tags (201). The system has a detector (301) incorporating circuitry (304) for detecting changes in the range of an RFID tag (201) from the detector and for triggering an alarm (401) if a detected change in range of an RFDI tag (201) exceeds a predetermined threshold or if the RFDI radio tag cannot be detected by the detector (301). Range may be detected, for example, by measuring the time of a returned radio signal from a tag (201), by measuring the strength of a returned radio signal from a tag, or by detecting changes in a periodic interval at which energy is transmitted by a tag.

Description

RFID DETECTION SYSTEM
The present invention relates to radio frequency identification (RFID) tagging and, more specifically, to the use of RFID transponders or "tags" in position monitoring and location.
Current tag systems detect the movement or presence of a tag as it comes into range of a detector and have been used for access control (eg in the form of personal access cards) or for security control (eg being attached to articles for sale in retail outlets). However, such systems provide only a relatively crude or simple measure of security and rely on passage of the tag past a related detector to monitor movement.
RFID transponders, such as the Supertag™ transponders developed by CSIR
& BTG are known for providing automatic data capture and dissemination of ID codes from tagged objects and provide advantages over conventional tagging systems such as bar codes, magnetic stripes and the like, particularly as they utilise so-called anti- collision technology which enables identification of individual tags among groups of tags without requiring singulation of the tags.
Such tags may comprise a single, integrated circuit chip bonded to an antenna which may be a flat, printed antenna, and can be incorporated in labels and the like and attached to objects to provide identification of the objects. The Supertag™ technology employs a reflection tag principle in which radio waves incident on the tag are modulated with the data content of the tag and re-broadcast for a given period of time to the interrogator. Following reading of the tag data, the tag is muted for another predetermined period of time to allow other tags in the range of the interrogator to be identified or counted. Such tags receive their operating energy by means of radiated electromagnetic energy and are known as so-called "passive radio tags" and therefore require no attached power source such as battery. The energy required to operate from RF energy is provided from a suitable "interrogator" or reader, referred to hereafter as a "detector".
The present invention recognises that RFID tags can be utilised to provide location information and hence may be used to provide a simple security system for objects.
According to the present invention therefore, there is provided a system for monitoring the position of one or more RFID tags, the system comprising: one or more detectors incorporating means for detecting changes in the range of an RFID tag from the detector or detectors; and means for triggering an alarm if a detected change in range of an RFID tag exceeds a predetermined threshold or if the RFID tag cannot be detected by the detector or detectors
The detector or detectors preferably measure the time of a returned radio signal from a tag to determine the range of the tag, but, alternatively, the strength of a returned radio signal or its waveform shape may be determined by the detector(s) to determine the range of a tag
The system may also have means for recording the time of a change in range of a tag and may include plural detectors may also have means for calculating the location of one or more radio tags having individual codes
The system may include tags which have circuitry arranged to emit short bursts of RF energy at periodic intervals, and the or each detector including circuitry for detecting changes in the periodic interval at which energy is transmitted by the or each tag The or each detector preferably includes circuitry for predicting the time of receipt of a burst of energy from a tag and for triggering an alarm if the time of actual receipt varies from the predicted time of receipt by more than a predetermined interval and/or if the rate of change in the periodic interval at which energy is transmitted by a tag is outside a predetermined range Alternatively, or additionally, the detector(s) may include circuitry for analysing changes in the rate of receipt of bursts of energy from a tag and for triggering an alarm if the rate of change is more than a predetermined level
A system according to the invention may be utilised, for example in the home, for ensuring the security of components such as valuable equipment such as televisions personal computers and the like, or other valuable items such as paintings, furniture and the like which may be relatively easily stolen by removal from their normal location, movement out of range of a detector being recognised by the central controller and an appropriate alarm signal given
One example of such a system comprises one or more transmitter-receivers (or detectors) and one or more RFID tags, the transmitter-receiver transmitting radio frequencies coded so that the RFID tag can recognise a point in time at which to respond In the case of a single transmitter-receiver and a single RFID tag, the time delay between the transmission of the time code and reception by the transmitter-receiver of the signal from the RFID tag is a function of both the time delays in the equipment and the propagation time of the signals travelling to and from the RFID tag The total time is measured and stored within the transmitter-receiver It is not necessary to know the value of any of the components of the total time This process is repeated and successive times are compared The difference in times can be due to either changes in the time delay in the equipment or changes in the propagation time of the radio frequency signal As the time delay in the equipment will change only slowly, time differences will be due to change in the propagation delay, which in turn will be due to changes in distance
The equipment can thus sense a change in distance between the transmitter- receiver and the RFID tag which can be used to initiate an alarm or for some other purpose
In the case of a single transmitter-receiver and two or more RFID tags the transmitter-receiver transmits and each RFID tag responds in the way previously described The signal received by the transmitter-receiver from the RFID tags will have time and amplitude characteristics which are a function of the relative positions of the transmitter-receiver and the RFID tags The transmitter-receiver captures the time-amplitude 'picture' of the returned signal The process is repeated and successive time-amplitude 'pictures' are compared As previously described the variations will be due to changes in the relative positions of the transmitter-receiver and RFID tags The equipment can thus sense a change in distance between the transmitter- receiver and two or more RFID tags which can be used to initiate an alarm or for some other purpose However, it is possible that an RFID tag could be moved in an arc without changing the distance between the transmitter-receiver and the RFID tag and without changing the time or time-amplitude 'picture' captured by the transmitter-receiver
This can be circumvented by using two or more transmitter-receivers each operating as previously described with one or more RFID tags, but displaced in such a way that movement of an RFID tag in two or three dimensions can be sensed The transmitter-receivers operate in a synchronised manner so that changes in relative distance between each transmitter-receiver and the RFID tags can be separately compared
While the example described above may be operable with relatively small numbers of tags operating in a confined area, it may be advantageous to utilise other methods of range monitoring with larger numbers of tags and areas of operation in a further example of a system according to the invention, the tag is arranged to transmit a short burst, or "chirp", of RF energy at periodic intervals This is achieved by providing the tag with, for example, an on-board capacitor arranged to store electromagnetic energy received by the tag's antenna from an RF transmitter forming part of a detector in the system Although the exact frequency of RF energy within a chirp is determined by the tag components, the repetition rate (chirp rate) of the individual tag is determined by the intensity of the electromagnetic field incident upon the tag and the tag s orientation As the tag is moved within the field, the power received by the tag varies causing the chirp rate to alter The chirps may be detected by a base station which is capable of analysing the chirp rate The base station is then be able to predict the time of the next chirp for each tag If the chirp is not received within the correct time window, then the tag can be deemed to have moved and an alarm can be sounded
As in the first example system the detector incorporates a transmitter which is relatively simple It is only required that the transmitter send a continuous RF signal
No modulation is required for basic functionality, although, as an enhancement, it might be used to vary the average power received by a tag, this would alter its chirp rate and could possibly give a more accurate position location by analysing the variation of the chirp rate with modulation depth The transmitter and antenna design are such that the maximum permissible field can be obtained if required, thereby giving maximum range
The international standards specify the maximum field that is allowed (often given as a measured value at 10m)
The use of a separate transmit coil (antenna) within the tag allows the tag to transmit on a frequency that is well spaced from the incident RF field This can make the base-station receiver design more straightforward However, it is possible to use only one coil for both transmit and receive
As the chirp rate of each tag in a system will be dependent upon the incident field at the tag, tags at different distances chirp at different rates and they can therefore be differentiated from one another One technique therefore is to perform a Fourier transform on the pulse train received at the detector This yields frequency peaks for each of the tags which enables the chirps from each tag to be identified The time for the next chirp can then be predicted and, if it does not appear within its expected time window then the alarm can be triggered It would not matter if two or more individual chirps arrived at the same time, as the FFT (Fast Fourier Transform) could decode this as long as each tag has a different chirp rate As the rate at which the tag receives energy will be dependent upon the orientation of the tag as well as the distance from the transmιtter(s), changing either of these will alter the chirp rate Therefore, if two tags should happen to be chirping at the same rate, this can be easily corrected by adjusting the orientation of one of the tags during set-up While it has been proposed, above, that the tags are powered by the incident RF energy, increased range might be obtained by providing a battery within the tag A potential enhancement to the basic system would be to analyse the RF frequency of a chirp and possibly its decay envelope This would enable the individual tags to be specifically identified For instance, it might be possible to say that tag #fιve is the furthest away and is twice as distant as tag #two It might also be possible for the user to customise the tags and give them particular characteristics that the system controller could identify, e g the decay envelope could be controlled by cutting or removing parts of the tag which would change a resistor or capacitor in the transmit coil circuit Some of the current commercial RFID tags have 'intelligent' capabilities This enables them to accept, store, and retransmit digital data The individual tags can then be uniquely identified This capability could thus be added to "chirping" tags if desired
Thermal changes will have an effect upon the chirping characteristics, however, these would be relatively long term and would tend to affect all of the tags Such effects could be compensated for in software without compromising the integrity of the system Of course if a tag is attached to a piece of equipment which heats up in use, such as a television, then only the characteristics of that tag would change This could be dealt with in several ways, the alarm threshold for each tag could be different or, as the rate of change would still be much longer than that occurring if the tag is moved rapidly, it could again be filtered out The system could also be given the ability to 'learn' the typical long term behaviour of each tag and could compensate for it, this could possibly be implemented by the use of a neural network False alarms could also be dealt with by such a method This would tend to decrease the number of false alarms and lead to greater user confidence in the system
It would be possible to increase the coverage by having several transmit coils and but maybe only one receiver As the tag chirp rate has a strong dependence upon distance and orientation, it should be possible to set up many more clearly identifiable tags over a much wider range than is achievable with a single transmitter As the chirp rate of the tag depends upon the amount of the electromagnetic field which is coupled into the coil, this being determined not only by the field strength, which is distance dependent, but also by the angular orientation of the tag with respect to the field, the system is therefore sensitive to rotational movement of the tag about its own axis An example of the implication of this is illustrated by considering a tag that has been placed on a door close to the hinge The rotation of the door when opening would change the orientation of the tag to the field and hence would dramatically alter the chirp rate An intruder alarm could then be triggered by this change Rather than transmitting, the tag could send its chirp back by using the reflection technique already used in many existing tags It is the detection of the chirp rate that is essential to this technique not how the chirp is sent
Example applications of the system, the key functional features here being orientation detection, ease of installation and portability are as follows
Car security, placing a controller and antenna within a vehicle and then fitting tags to each door would give a very effective alarm system Opening any door could set off the alarm Installation would be simple with none of the additional wiring that can be a major cost for car manufacturers
Portable alarms/personal security, a small portable system could easily be attached to hotel room doors and windows, and indeed to any valuable items it is desired to protect within a room
It may also be appreciated that since it is the change in range of a tag from a detector which triggers an alarm, movement of a detector while a tag is stationary may also trigger an alarm This may be used to advantage to protect equipment or articles capable of housing a detector, alarm and power supply as an alternative to fitting them with tags For example, a briefcase or laptop computer may be capable of being fitted with a detector and alarm so that if it is removed from the vicinity of a tag located with its owner, an alarm may sound This is particularly useful for protecting equipment and articles which are frequently carried by a person as it is in most cases, impractical for a person to carry the detector, power supply and alarm Two examples of systems according to the invention will now be described with reference to the accompanying drawings, in which
Figure 1 is a diagram of a first system comprising plural tags and transmitter- receivers,
Figure 2 illustrates the operative components of a passive radio tag for such a system,
Figure 3 illustrates, in block diagram form, the components of a transmitter- receiver and a connected central control in such a system,
Figure 4 is a diagram of a second system comprising plural tags and a single transmitter-receiver, and Figure 5 is a block-diagram of the internal components of a tag for use with the second system
In figure 1 there are shown a number of articles 1 on which passive radio tags 2 are located and three transceiver detectors 3 which are arranged to provide a field of coverage for the articles Movement of an article and hence its tag out of the field of cover is detected and an alarm issued
Figure 2 illustrates the operative components of a passive radio tag for use in a system according to the present invention A signal from a transceiver (not shown in figure 2) is passed from an antenna 4 to a receiver 5 and the signal decoded in a decoder 6 The signal is decoded to extract timing information which is subsequently used by a microprocessor control mechanism 7 to determine the interval after which the passive radio tag transmission commences from a transmitter 9 via a further antenna
10 The transmission may be encoded with data stored in the passive radio tag including such data as the identity of the passive radio tag and is received by the transceivers 3
Figure 3 shows one a number of transceivers 3 employed in the system, connected to a central control 11 which in turn may be connected to an alarm 12 The transceivers each have a control 13 which periodically initiates a transmission to the passive radio tags 2 in the system The return transmissions from the passive radio tags are synchronised by coding the transmissions from the transceivers or by starting, stopping or interrupting the transmission from the transceivers The transmission from a passive radio tag is compared with an RF oscillator 14 or another clock to determine the time elapsed since the initiation of the transmission from the transceiver The elapsed time and the decoded data if any from the passive radio tag are stored in the transceiver control 13 and compared with equivalent data from successive cycles to determine whether or not the passive radio tag has moved If movement is detected which is judged by the central control 11 to be indicative of unallowable movement, then the central controller initiates an alarm
The second system, illustrated in Figures 4 and 5 utilises tags with an on-board capacitor to provide a short burst or "chirp" of RF energy which can be detected by a detector The system 100 is illustrated generally in Figure 4 The system includes a transmitter 101 which has a power source (not shown), an oscillator 102 and an amplifier 103 which directs a signal at radio frequencies (RF) to an antenna 104 From the antenna, the RF energy is radiated into the area covered by the system and energy is picked up by tags 201 As described below, the tags 200 store the energy and emit short bursts ("chirps") of RF energy (at a different frequency to that of the transmitter 101) to one or more detectors 301 which include an antenna 302, a receiver 303 and a controller 304 which is connected to an alarm 401
The main function of the controller 304 is to analyse the frequencies that are present in the received signal or pulse train in such a way as to be able to predict the arrival time of the next chirp from any particular tag If the chirp from that tag does not arrive within a given time window, then the controller can take the appropriate action, such as sounding the alarm Although a purely analogue system could be created, the controller of the preferred example uses a Digital Signal Processor (DSP) connected to an Analogue to Digital Converter (ADC). In addition, the DSP could also be connected to some form of user interface such as an LCD display and keyboard if desired. The ADC converts the received analogue signal to a digital pulse train and the DSP then performs a Fast Fourier Transform (FFT) upon that pulse train and then uses the results from the FFT to predict the time of the next chirp from each tag. The controller 304 may also perform a number of other functions, these may include adaptive algorithms to compensate for thermal/environmental changes, as well as general system control, i.e. monitoring any input from the user and the display of information on, say, an attached computer system monitor.
At each tag 201 , the incident RF energy is received by an input coil or antenna, 202. This energy is stored, preferably by rectification and/or voltage multiplication in a rectifier 203 and the subsequent charging of a capacitor 204. When a predetermined amount of energy has been received, a switch 205 is triggered and the energy is fed into a transmit coil or antenna 206. This periodically generates an RF pulse whose frequency is determined by the self-resonance of the coil 206 and the storage capacitor 204. The tags 201 continue to chirp with the same periods (dependant on location within the electromagnetic field of the transmitter 101) thus providing an indication of non-movement. The addition of a filter 207 may enable closer control of the frequency which may desirable to ensure that the appropriate standards are met with assurance.
This may also help to extend the operable range by putting the same amount of energy into a narrower band, thereby allowing a receiver with a tighter bandwidth to be used.
As with the first example, any movement of a tag is detected by the detector
301 , in this case because the chirp rate will change when the radiant energy impinging on the tag changes as a result of its movement, and this can be arranged to trigger the alarm 401.
Referring to Figure 5, to convey tag specific information to the controller, the switch unit 205 or the filter 207 could be replaced with an intelligent switch which would be able to modulate the signal being generated by the transmit coil. Individual tags may be capable of being programmed by the controller if the intelligent switch mentioned above is given the capability to detect a modulation of the incoming signal; this may be used to place digital information in the switch module and hence program the tag. This programmed information would then control the behaviour of the tag and the messages that it transmitted. This gives an 'adaptive' tag that can be modified by the controller. This has a number of applications, including ID as stated above and chirp frequency modification to allow for a greater tag density.

Claims

1. A system (100) for monitoring the position of one or more RFID tags (201 ), the system comprising: at least one RFID tag (2,201 ); one or more detectors (3,301) incorporating means (6,304) for detecting changes in the range of an RFID tag (2,201) from the detector or detectors; and control means (7,304) for triggering an alarm (401 ) if a detected change in range of an RFID tag (2,201 ) exceeds a predetermined threshold or if the RFID radio tag cannot be detected by the detector or detectors (3,301).
2. A system (100) according to claiml , wherein the detector or detectors (301) are arranged to measure the time of a returned radio signal from a tag (201) to determine the range of the tag.
3. A system (100) according to claiml , wherein the detector or detectors (301 ) are arranged to determine the strength or waveform shape of a returned radio signal from a tag (201) to determine the range of the tag.
4. A system (100) according to claim 1 , wherein the or each tag (201) includes circuitry (204,205,206) arranged to emit short bursts of RF energy at periodic intervals.
5. A system (100) according to claim 4, further including an RF transmitter (101) arranged to transmit RF energy to the or each tag (201 ), and wherein the or each tag includes circuitry (202,203,204) arranged to store energy received from the transmitter and to provide energy for transmitting the short bursts of RF energy.
6. A system (100) according to claim 4 or claim 5, wherein the or each detector (301) includes circuitry (304) for detecting changes in the periodic interval at which energy is transmitted by the or each tag (201).
7. A system (100) according to claim 6, wherein the or each detector (301 ) includes circuitry (304) for predicting the time of receipt of a burst of energy from a tag (201 ) and for triggering an alarm (401 ) if the time of actual receipt varies from the predicted time of receipt by more than a predetermined interval. 8 A system (100) according to claim 6, wherein the or each detector (301 ) includes circuitry for analysing changes in the rate of receipt of bursts of energy from a tag (201 ) and for triggering an alarm (401) if the rate of change is more than a predetermined level
9 A system (100) according to claim 6, wherein the or each detector (301 ) includes circuitry for triggering an alarm (401) if the rate of change in the periodic interval at which energy is transmitted by a tag (201) is outside a predetermined range
10 A system (100) according to claim 6, wherein the transmitter (101) includes circuitry arranged to vary the average power transmitted and hence received by the or each tag (201) to alter the periodic interval at which the or each tag emits bursts of energy
11 A system (100) according to any of claims 4 to 10 wherein the or each tag (201) includes a receiving antenna (202) and a transmitting antenna (206)
12 An RFID tag (201) for use in a system (100) for monitoring the position of one or more RFID tags, the RFID tag including circuitry (204,205,206) arranged to emit short bursts of RF energy at periodic intervals
13 An RFID tag (201) according to claim 12, wherein the tag includes circuitry (202,203,204) arranged to store energy received from the transmitter (101) and to provide energy for transmitting the short bursts of RF energy
14 An RFID tag (201) according to claim 12 or claim 13, wherein the tag includes a receiving antenna (202) and a transmitting antenna (206)
15 An RFID tag (201) according to claim 12, wherein the tag includes a battery AMENDED CLAIMS
[received by the International Bureau on 13 March 2000 ( 13.03.00) ; original claim 1 amended; new claim 12 added ; original claims 2-15 renumbered as claims 13-16 , other claims unchanged (2 pages ) ]
1. A system (100) for monitoring the position of one or more RFID tags (201 ), the system comprising: at least one RFID tag (2,201); one or more detectors (3,301) incorporating means (6,304) for detecting changes in the range of an RFID tag (2,201 ) from the detector or detectors; and control means (7,304) for triggering an alarm (401 ) if a detected change in range of an RFID tag (2,201) exceeds a predetermined threshold.
2. A system (100) according to claiml , wherein the detector or detectors (301 ) are arranged to measure the time of a returned radio signal from a tag (201) to determine the range of the tag.
3. A system (100) according to claiml , wherein the detector or detectors (301 ) are arranged to determine the strength or waveform shape of a returned radio signal from a tag (201) to determine the range of the tag.
4. A system (100) according to claim 1 , wherein the or each tag (201) includes circuitry (204,205,206) arranged to emit short bursts of RF energy at periodic intervals.
5. A system (100) according to claim 4, further including an RF transmitter (101) arranged to transmit RF energy to the or each tag (201), and wherein the or each tag includes circuitry (202,203,204) arranged to store energy received from the transmitter and to provide energy for transmitting the short bursts of RF energy.
6. A system (100) according to claim 4 or claim 5, wherein the or each detector (301) includes circuitry (304) for detecting changes in the periodic interval at which energy is transmitted by the or each tag (201).
7. A system (100) according to claim 6, wherein the or each detector (301 ) includes circuitry (304) for predicting the time of receipt of a burst of energy from a tag (201 ) and for triggering an alarm (401) if the time of actual receipt varies from the predicted time of receipt by more than a predetermined interval.
A system (100) according to claim 6, wherein the or each detector (301 ) includes circuitry for analysing changes in the rate of receipt of bursts of energy from a tag (201 ) and for triggering an alarm (401 ) if the rate of change is more than a predetermined level.
9. A system (100) according to claim 6, wherein the or each detector (301 ) includes circuitry for triggering an alarm (401) if the rate of change in the periodic interval at which energy is transmitted by a tag (201 ) is outside a predetermined range.
10. A system (100) according to claim 6, wherein the transmitter (101) includes circuitry arranged to vary the average power transmitted and hence received by the or each tag (201) to alter the periodic interval at which the or each tag emits bursts of energy.
11. A system (100) according to any of claims 4 to 10, wherein the or each tag (201 ) includes a receiving antenna (202) and a transmitting antenna (206).
12. A system (100) according to any of claims 4 to 11 , wherein the control means (7,304) is additionally arranged to trigger the alarm if the RFID radio tag cannot be detected by the detector or detectors (3,301).
13. An RFID tag (201 ) for use in a system (100) for monitoring the position of one or more RFID tags, the RFID tag including circuitry (204,205,206) arranged to emit short bursts of RF energy at periodic intervals.
14. An RFID tag (201 ) according to claim 13, wherein the tag includes circuitry
(202,203,204) arranged to store energy received from the transmitter (101) and to provide energy for transmitting the short bursts of RF energy.
15. An RFID tag (201) according to claim 13 or claim 14, wherein the tag includes a receiving antenna (202) and a transmitting antenna (206).
16. An RFID tag (201 ) according to claim 13, wherein the tag includes a battery.
PCT/GB1999/003213 1998-09-28 1999-09-28 Rfid detection system WO2000019235A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
AT99947682T ATE243326T1 (en) 1998-09-28 1999-09-28 DETECTION AND RF IDENTIFICATION SYSTEM
DE69908957T DE69908957T2 (en) 1998-09-28 1999-09-28 SYSTEM FOR DETECTION AND RF IDENTIFICATION
EP99947682A EP1112512B1 (en) 1998-09-28 1999-09-28 Rfid detection system
JP2000572687A JP2002525640A (en) 1998-09-28 1999-09-28 RFID detection system
AU61060/99A AU6106099A (en) 1998-09-28 1999-09-28 Rfid detection system
US09/786,425 US6577238B1 (en) 1998-09-28 1999-09-28 RFID detection system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB9821046.1A GB9821046D0 (en) 1998-09-28 1998-09-28 Detection system
GB9821046.1 1998-09-28

Publications (1)

Publication Number Publication Date
WO2000019235A1 true WO2000019235A1 (en) 2000-04-06

Family

ID=10839570

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1999/003213 WO2000019235A1 (en) 1998-09-28 1999-09-28 Rfid detection system

Country Status (8)

Country Link
US (1) US6577238B1 (en)
EP (1) EP1112512B1 (en)
JP (1) JP2002525640A (en)
AT (1) ATE243326T1 (en)
AU (1) AU6106099A (en)
DE (1) DE69908957T2 (en)
GB (1) GB9821046D0 (en)
WO (1) WO2000019235A1 (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001357073A (en) * 2000-06-13 2001-12-26 Kyowa Engineering Consultants Co Ltd Dynamic marketing information collecting and analyzing system
WO2002019252A1 (en) * 2000-08-25 2002-03-07 Rf Code, Inc. Zone based radio frequency identification
EP1288878A2 (en) * 2001-08-17 2003-03-05 Paul Dalton A security apparatus and a method of operating the security apparatus
WO2003023690A1 (en) * 2001-09-13 2003-03-20 Tagtec Limited Wireless communications system
EP1447681A3 (en) * 2003-02-14 2004-08-25 AMB -IT Holding B.V. System for determining a position of a moving transponder
EP1811426A2 (en) * 2006-01-18 2007-07-25 Hitachi, Ltd. Wireless signal receiver
WO2008009023A2 (en) * 2006-07-14 2008-01-17 Emerson Electric Co. Rfid detection system for enhanced marketing
WO2008016461A2 (en) * 2006-07-31 2008-02-07 Caterpillar Inc. System and method to identify and track rfid tags
US7482934B2 (en) 2005-01-17 2009-01-27 Fujitsu Limited Communication device and communication method
US8310379B2 (en) 2007-03-22 2012-11-13 Deutsche Post Ag Monitoring device for a tracking system
EP2239374B2 (en) 2009-04-03 2017-03-15 Joseph Vögele AG Paver
US10454706B2 (en) 2014-07-28 2019-10-22 Mylaps B.V. Transponder module and access module for activating and configuring such transponder module over a CAN bus
US11373008B2 (en) 2014-07-28 2022-06-28 Mylaps B.V. Transponder module and access module for activating and configuring such transponder module

Families Citing this family (201)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050192727A1 (en) * 1994-05-09 2005-09-01 Automotive Technologies International Inc. Sensor Assemblies
US7786864B1 (en) * 2000-09-08 2010-08-31 Automotive Technologies International, Inc. Vehicular RFID and sensor assemblies
US9443358B2 (en) 1995-06-07 2016-09-13 Automotive Vehicular Sciences LLC Vehicle software upgrade techniques
US8464359B2 (en) * 1997-11-03 2013-06-11 Intellectual Ventures Fund 30, Llc System and method for obtaining a status of an authorization device over a network
US7499527B2 (en) * 1997-11-03 2009-03-03 Light Elliott D System and method for determining the status of a telephone in a packet switched network
US7460859B2 (en) * 1997-11-03 2008-12-02 Light Elliott D System and method for obtaining a status of an authorization device over a network for administration of theatrical performances
US7088802B2 (en) * 1997-11-03 2006-08-08 Light Elliott D Method and apparatus for obtaining telephone status over a network
US7280642B2 (en) * 1997-11-03 2007-10-09 Intellectual Ventures Fund 30, Llc Status monitoring system utilizing an RFID monitoring system
US10240935B2 (en) 1998-10-22 2019-03-26 American Vehicular Sciences Llc Vehicle software upgrade techniques
US7064669B2 (en) * 2000-06-09 2006-06-20 Light Elliott D Electronic tether for portable objects
US7042360B2 (en) * 2000-06-09 2006-05-09 Light Elliott D Electronic tether for portable objects
US7937042B2 (en) * 2000-06-09 2011-05-03 Dot Holdings, Llc Animal training and tracking system using RF identification tags
US7375638B2 (en) * 2000-06-09 2008-05-20 Robelight, Llc Electronic tether for portable objects
US6951305B2 (en) * 2001-11-21 2005-10-04 Goliath Solutions, Llc. Advertising compliance monitoring system
US7374096B2 (en) 2001-11-21 2008-05-20 Goliath Solutions, Llc Advertising compliance monitoring system
US6837427B2 (en) 2001-11-21 2005-01-04 Goliath Solutions, Llc. Advertising compliance monitoring system
US20030160693A1 (en) * 2002-02-25 2003-08-28 Omron Corporation Status monitoring system employing a movement history and a self-organizing network
US20030160695A1 (en) * 2002-02-25 2003-08-28 Omron Corporation Identification and surveillance systems for freight container, and method for the same
US6879257B2 (en) * 2002-02-25 2005-04-12 Omron Corporation State surveillance system and method for an object and the adjacent space, and a surveillance system for freight containers
US6744366B2 (en) * 2002-04-04 2004-06-01 Hoton How Method and apparatus of obtaining security tag operation using local magnetic marker
US6933849B2 (en) 2002-07-09 2005-08-23 Fred Sawyer Method and apparatus for tracking objects and people
US6736316B2 (en) * 2002-08-23 2004-05-18 Yoram Neumark Inventory control and indentification method
JP4055514B2 (en) * 2002-08-27 2008-03-05 豊丸産業株式会社 Gaming machine and fraud monitoring system using the gaming machine
US20040049733A1 (en) * 2002-09-09 2004-03-11 Eastman Kodak Company Virtual annotation of a recording on an archival media
US7474210B2 (en) * 2003-01-10 2009-01-06 Monismart Systems Llc Method and system for monitoring room activity
US8264329B2 (en) * 2003-01-10 2012-09-11 Monismart Systems, Llc Method and system for room activity communication
EP1593217A4 (en) 2003-02-10 2009-04-01 Nielsen Media Res Inc Methods and apparatus to adaptively gather audience information data
JP4092692B2 (en) 2003-06-06 2008-05-28 ソニー株式会社 COMMUNICATION SYSTEM, COMMUNICATION DEVICE, COMMUNICATION METHOD, AND PROGRAM
JP4005542B2 (en) * 2003-07-25 2007-11-07 豊丸産業株式会社 Gaming machine and fraud monitoring system using the gaming machine
JP4496392B2 (en) * 2003-07-31 2010-07-07 豊丸産業株式会社 Surveillance system and game machine
DE602004013448T2 (en) * 2003-08-25 2009-06-04 Koninklijke Philips Electronics N.V. Personal proximity network
US7046147B2 (en) * 2003-08-29 2006-05-16 Rf Monolithics, Inc. Integrated security system and method
US7109986B2 (en) * 2003-11-19 2006-09-19 Eastman Kodak Company Illumination apparatus
ES2280888T3 (en) * 2003-11-24 2007-09-16 Black & Decker Inc. WIRELESS SYSTEM FOR MONITORING AND SECURITY OF PROPERTY.
US7002473B2 (en) * 2003-12-17 2006-02-21 Glick Larry D Loss prevention system
US20050149350A1 (en) * 2003-12-24 2005-07-07 Kerr Roger S. Patient information management system and method
US7285958B2 (en) * 2004-01-15 2007-10-23 Metrotech Corporation, Inc. Method and apparatus for digital detection of electronic markers using frequency adaptation
WO2005071596A2 (en) * 2004-01-16 2005-08-04 Koninklijke Philips Electronics, N.V. System and method for using rf tags as action triggers
US8406341B2 (en) 2004-01-23 2013-03-26 The Nielsen Company (Us), Llc Variable encoding and detection apparatus and methods
US7119738B2 (en) * 2004-03-01 2006-10-10 Symbol Technologies, Inc. Object location system and method using RFID
WO2005086802A2 (en) 2004-03-08 2005-09-22 Proxense, Llc Linked account system using personal digital key (pdk-las)
SE0400720D0 (en) * 2004-03-22 2004-03-22 Torbjoern Hallberg Safety Position
US7907732B2 (en) * 2004-03-29 2011-03-15 Intel Corporation Radio frequency identification tag lock and key
US20050237159A1 (en) * 2004-04-13 2005-10-27 Impinj, Inc. RFID tag systems, RFID tags and RFID processes with reverse link burst mode
US20070023520A1 (en) * 2004-04-22 2007-02-01 Matsushita Electric Industrial Co., Ltd. Contactless reader/writer
WO2005106782A1 (en) * 2004-04-28 2005-11-10 Ic Brains Co., Ltd. Ic tag and dishonest taking prevention device using ic tag
US7030736B2 (en) * 2004-06-03 2006-04-18 Brunswick Bowling & Billiards Corporation Radio frequency identification (RFID) pin detection system
US8475289B2 (en) 2004-06-07 2013-07-02 Acushnet Company Launch monitor
US8622845B2 (en) 2004-06-07 2014-01-07 Acushnet Company Launch monitor
US8556267B2 (en) * 2004-06-07 2013-10-15 Acushnet Company Launch monitor
US8500568B2 (en) * 2004-06-07 2013-08-06 Acushnet Company Launch monitor
US7837572B2 (en) 2004-06-07 2010-11-23 Acushnet Company Launch monitor
JP2006023963A (en) 2004-07-07 2006-01-26 Fujitsu Ltd Wireless ic tag reader/writer, wireless ic tag system and wireless ic tag data writing method
US7089099B2 (en) 2004-07-30 2006-08-08 Automotive Technologies International, Inc. Sensor assemblies
US6980100B1 (en) * 2004-08-11 2005-12-27 Hammond Dorothy L Security device and alarm system
US7959517B2 (en) 2004-08-31 2011-06-14 Acushnet Company Infrared sensing launch monitor
US7372365B2 (en) * 2004-09-15 2008-05-13 Radarfind Corporation Methods, systems and computer program products for automated location and monitoring of mobile device
US7525432B2 (en) * 2004-09-15 2009-04-28 Radarfind Corporation Methods, identification tags and computer program products for automated location and monitoring of mobile devices
US20060061481A1 (en) * 2004-09-23 2006-03-23 Kurple William M Receptacle locator
WO2006037014A2 (en) * 2004-09-27 2006-04-06 Nielsen Media Research, Inc. Methods and apparatus for using location information to manage spillover in an audience monitoring system
US7574732B2 (en) * 2004-09-29 2009-08-11 Symbol Technologies Inc Object location based security using RFID
JPWO2006041031A1 (en) * 2004-10-08 2008-05-15 松下電器産業株式会社 Authentication system
US20060092040A1 (en) * 2004-11-02 2006-05-04 Fishkin Kenneth P Detecting activity of RFID objects via multiple tags/readers
RU2007127725A (en) 2004-12-20 2009-01-27 ПРОКСЕНС, ЭлЭлСи (US) PERSONAL DATA (PDK) AUTHENTICATION BY BIOMETRIC KEY
US7209042B2 (en) * 2004-12-20 2007-04-24 Temptime Corporation RFID tag with visual environmental condition monitor
JP4607905B2 (en) * 2004-12-28 2011-01-05 富士通株式会社 Tag extraction device, tag extraction method, and tag extraction program
US20060176152A1 (en) * 2005-02-10 2006-08-10 Psc Scanning, Inc. RFID power ramping for tag singulation
US7676380B2 (en) * 2005-02-11 2010-03-09 Nortel Networks Limited Use of location awareness to establish and suspend communications sessions in a healthcare environment
US8929528B2 (en) * 2005-02-11 2015-01-06 Rockstar Consortium Us Lp Method and system for enhancing collaboration
US20060181243A1 (en) * 2005-02-11 2006-08-17 Nortel Networks Limited Use of location awareness to facilitate clinician-charger interaction in a healthcare environment
US8050939B2 (en) 2005-02-11 2011-11-01 Avaya Inc. Methods and systems for use in the provision of services in an institutional setting such as a healthcare facility
US7707044B2 (en) * 2005-02-11 2010-04-27 Avaya Inc. Use of location awareness to transfer communications sessions between terminals in a healthcare environment
US7801743B2 (en) * 2005-02-11 2010-09-21 Avaya Inc. Use of location awareness of establish communications with a target clinician in a healthcare environment
US8180650B2 (en) * 2005-02-11 2012-05-15 Avaya Inc. Use of location awareness to request assistance for a medical event occurring in a healthcare environment
US7966008B2 (en) * 2005-02-11 2011-06-21 Avaya Inc. Use of location awareness to control radio frequency interference in a healthcare environment
US20060184376A1 (en) * 2005-02-11 2006-08-17 Nortel Networks Limited Use of location awareness to detect potentially supsicious motion or presence of equipment in a healthcare environment
US7239240B1 (en) * 2005-02-16 2007-07-03 Hoton How Method and apparatus for implementing security protection over RFID
US20060208893A1 (en) * 2005-02-28 2006-09-21 Anson Gary S Weight audit methods and systems utilizing data reader
TW200644509A (en) * 2005-03-02 2006-12-16 Koninkl Philips Electronics Nv Ranging based association for UWB wireless PAN devices
DE102005013102A1 (en) * 2005-03-18 2006-09-21 K.A. Schmersal Holding Kg Non-contact switch
US20060267733A1 (en) * 2005-05-27 2006-11-30 Psc Scanning, Inc. Apparatus and methods for saving power in RFID readers
US20060284727A1 (en) * 2005-06-16 2006-12-21 Psc Scanning, Inc. Method and system with functionality for finding range between an electronic tag reader and tag
US7405662B2 (en) * 2005-06-14 2008-07-29 Datalogic Mobile, Inc. Wireless tag ranging
US7538682B2 (en) * 2005-06-15 2009-05-26 Steven Michael Trost Method and device for identification
US7323996B2 (en) * 2005-08-02 2008-01-29 International Business Machines Corporation RFID reader having antenna with directional attenuation panels for determining RFID tag location
US20070030609A1 (en) * 2005-08-03 2007-02-08 Thingmagic, Inc. Methods, devices and systems for protecting RFID reader front ends
DE102005036847A1 (en) * 2005-08-04 2006-10-26 Siemens Ag Object e.g. eyeglass, protecting method for use by person, involves evaluating received response signals by control device, and triggering alarm by device, if predetermined response signals are missing or incorrectly received
US20070046470A1 (en) * 2005-08-29 2007-03-01 Mark Pempsell Hybrid Acousto-Magnetic Radio Frequency Transceiver Device
US20070046438A1 (en) * 2005-08-29 2007-03-01 Mark Pempsell Electronic Radio Frequency Identification Transceiver Device Activated by Radiant Means
JP2007064765A (en) * 2005-08-30 2007-03-15 Fujitsu Ltd Rfid tag device, rfid reader writer device and distance measuring system
US8107446B2 (en) 2005-11-07 2012-01-31 Radiofy Llc Wireless RFID networking systems and methods
US8193935B2 (en) * 2005-11-22 2012-06-05 Gates Tell A RFID perimeter alarm monitoring system
US8433919B2 (en) 2005-11-30 2013-04-30 Proxense, Llc Two-level authentication for secure transactions
JP2007163249A (en) * 2005-12-13 2007-06-28 National Institute Of Advanced Industrial & Technology Method and system for sensing mobile object
US11206664B2 (en) 2006-01-06 2021-12-21 Proxense, Llc Wireless network synchronization of cells and client devices on a network
US9113464B2 (en) 2006-01-06 2015-08-18 Proxense, Llc Dynamic cell size variation via wireless link parameter adjustment
US20070159337A1 (en) * 2006-01-12 2007-07-12 Sdgi Holdings, Inc. Modular RFID tag
GB2434239A (en) * 2006-01-12 2007-07-18 Motorola Inc Security system with RFID tag reader
US7605685B2 (en) * 2006-01-27 2009-10-20 Orbiter, Llc Portable lap counter and system
MX2007015979A (en) 2006-03-31 2009-04-07 Nielsen Media Res Inc Methods, systems, and apparatus for multi-purpose metering.
GB0610558D0 (en) * 2006-05-30 2006-07-05 Tagtec Ltd Security monitoring system
US20070290791A1 (en) * 2006-06-09 2007-12-20 Intelleflex Corporation Rfid-based security systems and methods
AU2007202771B9 (en) * 2006-06-15 2009-06-18 James Nott (Red Alert) Portable Electronic Security Device
US7561050B2 (en) * 2006-06-28 2009-07-14 International Business Machines Corporation System and method to automate placement of RFID repeaters
US7446661B2 (en) * 2006-06-28 2008-11-04 International Business Machines Corporation System and method for measuring RFID signal strength within shielded locations
US7310070B1 (en) 2006-08-23 2007-12-18 Goliath Solutions, Llc Radio frequency identification shelf antenna with a distributed pattern for localized tag detection
DE102006042547A1 (en) * 2006-09-11 2008-03-27 Bartec Gmbh System for monitoring a danger zone, in particular a vehicle
US7821400B2 (en) * 2006-09-29 2010-10-26 Datalogic Scanning, Inc. System and method for verifying number of wireless tagged items in a transaction
KR100779215B1 (en) * 2006-09-29 2007-11-26 한국전자통신연구원 Method and apparatus for automatically migrating user's working data
KR101033200B1 (en) * 2006-10-20 2011-05-06 주식회사 케이티 RFID and system and method for the mobile station location identication service using communication network
WO2008048059A1 (en) * 2006-10-20 2008-04-24 Kt Corporation Real-time rfid positioning system and method, repeater installation method therefor, position confirmation service system using the same
US20080114684A1 (en) * 2006-10-31 2008-05-15 Chuck Foster Termination of transactions
US8060437B2 (en) * 2006-10-31 2011-11-15 International Funding Partners Llc Automatic termination of electronic transactions
US20080114691A1 (en) * 2006-10-31 2008-05-15 Chuck Foster Processing transactions
US9269221B2 (en) 2006-11-13 2016-02-23 John J. Gobbi Configuration of interfaces for a location detection system and application
US20080136642A1 (en) * 2006-12-07 2008-06-12 Charles Michael Wise Personal security system
US20080147461A1 (en) * 2006-12-14 2008-06-19 Morris Lee Methods and apparatus to monitor consumer activity
US8344949B2 (en) 2008-03-31 2013-01-01 Golba Llc Wireless positioning approach using time-delay of signals with a known transmission pattern
US8314736B2 (en) * 2008-03-31 2012-11-20 Golba Llc Determining the position of a mobile device using the characteristics of received signals and a reference database
US8294554B2 (en) * 2006-12-18 2012-10-23 Radiofy Llc RFID location systems and methods
US10885543B1 (en) 2006-12-29 2021-01-05 The Nielsen Company (Us), Llc Systems and methods to pre-scale media content to facilitate audience measurement
US20110288938A1 (en) * 2007-03-02 2011-11-24 Store Kraft Interactive display system
US20080243088A1 (en) * 2007-03-28 2008-10-02 Docusys, Inc. Radio frequency identification drug delivery device and monitoring system
US8195189B2 (en) * 2007-04-17 2012-06-05 Hewlett-Packard Developmet Company, L.P. Managing of items distributed in a global supply chain
US20080272896A1 (en) * 2007-05-01 2008-11-06 Maria Adamczyk Object tracking method and apparatus
US8260201B2 (en) * 2007-07-30 2012-09-04 Bae Systems Information And Electronic Systems Integration Inc. Dispersive antenna for RFID tags
US8659427B2 (en) 2007-11-09 2014-02-25 Proxense, Llc Proximity-sensor supporting multiple application services
US8727216B2 (en) * 2007-12-03 2014-05-20 Apple Inc. Portable memory module with wireless emitter to facilitate the provision of location-dependent services
US7999741B2 (en) * 2007-12-04 2011-08-16 Avaya Inc. Systems and methods for facilitating a first response mission at an incident scene using precision location
US8589176B2 (en) * 2007-12-05 2013-11-19 Avaya, Inc. Methods and systems for managing communication requests in an institutional setting such as a healthcare facility
US8171528B1 (en) 2007-12-06 2012-05-01 Proxense, Llc Hybrid device having a personal digital key and receiver-decoder circuit and methods of use
WO2009079666A1 (en) 2007-12-19 2009-06-25 Proxense, Llc Security system and method for controlling access to computing resources
DE102008006044B4 (en) * 2008-01-25 2019-06-19 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Monitoring system and method for loss detection with regard to at least one object to be monitored
US8508336B2 (en) 2008-02-14 2013-08-13 Proxense, Llc Proximity-based healthcare management system with automatic access to private information
US9262912B2 (en) * 2008-02-25 2016-02-16 Checkpoint Systems, Inc. Localizing tagged assets using modulated backscatter
US9829560B2 (en) 2008-03-31 2017-11-28 Golba Llc Determining the position of a mobile device using the characteristics of received signals and a reference database
US7800541B2 (en) * 2008-03-31 2010-09-21 Golba Llc Methods and systems for determining the location of an electronic device
WO2009126732A2 (en) 2008-04-08 2009-10-15 Proxense, Llc Automated service-based order processing
US9288268B2 (en) 2008-06-30 2016-03-15 The Nielsen Company (Us), Llc Methods and apparatus to monitor shoppers in a retail environment
JP5442965B2 (en) * 2008-07-01 2014-03-19 日本信号株式会社 Article position detection system
US8410935B2 (en) * 2008-07-10 2013-04-02 Radarfind Corporation Rotatable tags for automated location and monitoring of moveable objects and related systems
US9442192B2 (en) * 2008-07-28 2016-09-13 Thingamagigwerks, Llc Method and apparatus for location determination using reflected interferometry
MX2011001931A (en) * 2008-08-20 2011-07-28 Wherepro Llc Data packet generator for generating passcodes.
US8902073B2 (en) * 2009-02-10 2014-12-02 Cubic Corporation Smartcard protection device
US20120026029A1 (en) * 2009-02-11 2012-02-02 Koninklijke Philips Electronics N.V. Motion detection system and method with null points
US8239277B2 (en) 2009-03-31 2012-08-07 The Nielsen Company (Us), Llc Method, medium, and system to monitor shoppers in a retail or commercial establishment
WO2012100232A2 (en) 2011-01-20 2012-07-26 Innovative Timing Systems, Llc Rfid tag read triggered image and video capture even timing system and method
WO2011109419A2 (en) 2010-03-01 2011-09-09 Innovative Timing Systems, Llc Variably spaced multi-point rfid tag reader systems and methods
US9002979B2 (en) 2010-01-11 2015-04-07 Innovative Timing Systems, Llc Sports timing system (STS) event and participant announcement communication system (EPACS) and method
US8360331B2 (en) * 2010-01-29 2013-01-29 Innovative Timing Systems, Llc Harsh operating environment RFID tag assemblies and methods of manufacturing thereof
EP2529336B1 (en) 2010-01-29 2018-12-12 Innovative Timing Systems Harsh operating environment rfid tag assemblies and methods
US8576051B2 (en) * 2010-01-29 2013-11-05 Innovative Timing Systems, LLC. Spaced apart extended range RFID tag assemblies and methods of operation
US20110244798A1 (en) * 2010-02-24 2011-10-06 Wherepro, Llc Data Packet Generator and Implementations of Same
WO2013112851A1 (en) 2012-01-25 2013-08-01 Innovative Timing Systems, Llc A timing system and method with integrated participant even image capture management services
US9883332B2 (en) 2010-03-01 2018-01-30 Innovative Timing Systems, Llc System and method of an event timing system having integrated geodetic timing points
US8855101B2 (en) 2010-03-09 2014-10-07 The Nielsen Company (Us), Llc Methods, systems, and apparatus to synchronize actions of audio source monitors
US9418205B2 (en) 2010-03-15 2016-08-16 Proxense, Llc Proximity-based system for automatic application or data access and item tracking
US20110285506A1 (en) * 2010-05-19 2011-11-24 Joshua Bradley Hillis System and method for tracking items
EP2398002A1 (en) * 2010-06-16 2011-12-21 Alcatel Lucent Method and related guarding device for guarding at least one object
US8918854B1 (en) 2010-07-15 2014-12-23 Proxense, Llc Proximity-based system for automatic application initialization
EP2599058A4 (en) 2010-07-29 2015-03-11 Innovative Timing Systems Llc Automated timing systems and methods having multiple time event recorders and an integrated user time entry interface
EP2612303A2 (en) 2010-09-03 2013-07-10 Innovative Timing Systems, LLC Integrated detection point passive rfid tag reader and event timing system and method
US8885842B2 (en) 2010-12-14 2014-11-11 The Nielsen Company (Us), Llc Methods and apparatus to determine locations of audience members
TWI420425B (en) * 2010-12-17 2013-12-21 Trade Van Information Services Co RFID patrol surveillance system and its method
US9508036B2 (en) 2011-01-20 2016-11-29 Innovative Timing Systems, Llc Helmet mountable timed event RFID tag assembly and method of use
EP2666125A2 (en) 2011-01-20 2013-11-27 Innovative Timing Systems, LLC Rfid timing system and method with integrated event participant location tracking
US9265450B1 (en) * 2011-02-21 2016-02-23 Proxense, Llc Proximity-based system for object tracking and automatic application initialization
US20120235816A1 (en) * 2011-03-17 2012-09-20 Luis Estrada Item location and theft prevention system
US20130030966A1 (en) 2011-07-28 2013-01-31 American Express Travel Related Services Company, Inc. Systems and methods for generating and using a digital pass
WO2013063507A1 (en) 2011-10-26 2013-05-02 Milwaukee Electric Tool Corporation Wireless tracking of power tools and related devices
EP2774129A4 (en) * 2011-11-02 2015-06-24 Avery Dennison Corp Method, system, and apparatus for an indicator drive by an rfid tag for localization purposes
EP2807612A4 (en) 2012-01-25 2015-03-11 Innovative Timing Systems Llc An integrated timing system and method having a highly portable rfid tag reader with gps location determination
CN103246909A (en) * 2012-02-06 2013-08-14 鸿富锦精密工业(深圳)有限公司 Electronic tag, and article seeking system and method applying same
JP6199540B2 (en) * 2012-03-14 2017-09-20 ソニー株式会社 Authentication device, authentication method, authentication system, storage system, communication device, and medical device
US9187154B2 (en) 2012-08-01 2015-11-17 Innovative Timing Systems, Llc RFID tag reading systems and methods for aquatic timed events
US9282366B2 (en) 2012-08-13 2016-03-08 The Nielsen Company (Us), Llc Methods and apparatus to communicate audience measurement information
GB201214976D0 (en) 2012-08-22 2012-10-03 Connect In Ltd Monitoring system
US10158213B2 (en) 2013-02-22 2018-12-18 Milwaukee Electric Tool Corporation Worksite power distribution box
US9466198B2 (en) 2013-02-22 2016-10-11 Milwaukee Electric Tool Corporation Wireless tracking of power tools and related devices
US9021516B2 (en) 2013-03-01 2015-04-28 The Nielsen Company (Us), Llc Methods and systems for reducing spillover by measuring a crest factor
US9118960B2 (en) 2013-03-08 2015-08-25 The Nielsen Company (Us), Llc Methods and systems for reducing spillover by detecting signal distortion
US9219969B2 (en) 2013-03-13 2015-12-22 The Nielsen Company (Us), Llc Methods and systems for reducing spillover by analyzing sound pressure levels
US9191704B2 (en) 2013-03-14 2015-11-17 The Nielsen Company (Us), Llc Methods and systems for reducing crediting errors due to spillover using audio codes and/or signatures
WO2014183106A2 (en) 2013-05-10 2014-11-13 Proxense, Llc Secure element as a digital pocket
US9219928B2 (en) 2013-06-25 2015-12-22 The Nielsen Company (Us), Llc Methods and apparatus to characterize households with media meter data
US9426525B2 (en) 2013-12-31 2016-08-23 The Nielsen Company (Us), Llc. Methods and apparatus to count people in an audience
US9699499B2 (en) 2014-04-30 2017-07-04 The Nielsen Company (Us), Llc Methods and apparatus to measure exposure to streaming media
EP2963901A1 (en) * 2014-07-03 2016-01-06 Nxp B.V. Communication portable device and communication method
WO2019218050A1 (en) 2018-05-17 2019-11-21 1010210 B.C. Ltd Security alarm system comprising an rfid tag
US11645897B2 (en) 2014-07-25 2023-05-09 1010210 B.C. Ltd. Sensor assembly for use in a security alarm system and method of installing the same
US11341829B2 (en) 2014-07-25 2022-05-24 1010210 B.C. Ltd. Sensor assembly for use in a security alarm system and method of installing the same
US11763652B2 (en) 2014-07-25 2023-09-19 1010210 B.C. Ltd. Method of arranging a security alarm system on a window/door and framing, and combination comprising the window/door, framing and security alarm system thereof
DE102014114811A1 (en) * 2014-10-13 2016-04-14 Sick Ag System for asynchronous serial data transmission and safety switches
KR102356599B1 (en) * 2014-12-05 2022-01-28 삼성전자주식회사 Method for determining region of interest of image and device for determining region of interest of image
US9727763B2 (en) * 2014-12-31 2017-08-08 Intermec Ip Corp. Modulation index (depth) based grouping, addressing, and fingerprinting RFID tags
US9924224B2 (en) 2015-04-03 2018-03-20 The Nielsen Company (Us), Llc Methods and apparatus to determine a state of a media presentation device
US9848222B2 (en) 2015-07-15 2017-12-19 The Nielsen Company (Us), Llc Methods and apparatus to detect spillover
US20170178474A1 (en) * 2015-12-18 2017-06-22 Checkpoint Systems, Inc. Product-monitoring drone
WO2020118421A1 (en) 2018-12-10 2020-06-18 1010210 B.C. Ltd. Method of installing a security alarm system and wireless access point
CN113424238B (en) * 2019-02-22 2022-09-13 本田技研工业株式会社 Antitheft device and generator antitheft system
US11839803B2 (en) 2020-08-04 2023-12-12 Orbiter, Inc. System and process for RFID tag and reader detection in a racing environment

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4675656A (en) * 1984-03-16 1987-06-23 Narcisse Bernadine O Out-of-range personnel monitor and alarm
US5661460A (en) * 1994-12-13 1997-08-26 Secure Technologies, Inc. Distance determination and alarm system
GB2314986A (en) * 1996-07-02 1998-01-14 Alan Michael Cox Electronic child protection system

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5119072A (en) * 1990-12-24 1992-06-02 Hemingway Mark D Apparatus for monitoring child activity
US6097301A (en) * 1996-04-04 2000-08-01 Micron Communications, Inc. RF identification system with restricted range
US5936527A (en) * 1998-02-10 1999-08-10 E-Tag Systems, Inc. Method and apparatus for locating and tracking documents and other objects
US6028518A (en) * 1998-06-04 2000-02-22 Checkpoint Systems, Inc. System for verifying attachment of an EAS marker to an article after tagging

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4675656A (en) * 1984-03-16 1987-06-23 Narcisse Bernadine O Out-of-range personnel monitor and alarm
US5661460A (en) * 1994-12-13 1997-08-26 Secure Technologies, Inc. Distance determination and alarm system
GB2314986A (en) * 1996-07-02 1998-01-14 Alan Michael Cox Electronic child protection system

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001357073A (en) * 2000-06-13 2001-12-26 Kyowa Engineering Consultants Co Ltd Dynamic marketing information collecting and analyzing system
WO2002019252A1 (en) * 2000-08-25 2002-03-07 Rf Code, Inc. Zone based radio frequency identification
EP1288878A2 (en) * 2001-08-17 2003-03-05 Paul Dalton A security apparatus and a method of operating the security apparatus
EP1288878A3 (en) * 2001-08-17 2003-08-27 Paul Dalton A security apparatus and a method of operating the security apparatus
WO2003023690A1 (en) * 2001-09-13 2003-03-20 Tagtec Limited Wireless communications system
EP1447681A3 (en) * 2003-02-14 2004-08-25 AMB -IT Holding B.V. System for determining a position of a moving transponder
US6864829B2 (en) 2003-02-14 2005-03-08 Amb It Holding B.V. System for determining a position of a moving transponder
US7482934B2 (en) 2005-01-17 2009-01-27 Fujitsu Limited Communication device and communication method
EP1811426A2 (en) * 2006-01-18 2007-07-25 Hitachi, Ltd. Wireless signal receiver
EP1811426A3 (en) * 2006-01-18 2010-12-22 Hitachi, Ltd. Wireless signal receiver
WO2008009023A2 (en) * 2006-07-14 2008-01-17 Emerson Electric Co. Rfid detection system for enhanced marketing
WO2008009023A3 (en) * 2006-07-14 2008-04-17 Emerson Electric Co Rfid detection system for enhanced marketing
WO2008016461A2 (en) * 2006-07-31 2008-02-07 Caterpillar Inc. System and method to identify and track rfid tags
WO2008016461A3 (en) * 2006-07-31 2008-04-17 Caterpillar Inc System and method to identify and track rfid tags
US7579952B2 (en) 2006-07-31 2009-08-25 Caterpillar Inc. System and method to identify and track RFID tags
US8310379B2 (en) 2007-03-22 2012-11-13 Deutsche Post Ag Monitoring device for a tracking system
EP2239374B2 (en) 2009-04-03 2017-03-15 Joseph Vögele AG Paver
US10454706B2 (en) 2014-07-28 2019-10-22 Mylaps B.V. Transponder module and access module for activating and configuring such transponder module over a CAN bus
US11373008B2 (en) 2014-07-28 2022-06-28 Mylaps B.V. Transponder module and access module for activating and configuring such transponder module

Also Published As

Publication number Publication date
ATE243326T1 (en) 2003-07-15
DE69908957D1 (en) 2003-07-24
AU6106099A (en) 2000-04-17
JP2002525640A (en) 2002-08-13
US6577238B1 (en) 2003-06-10
EP1112512A1 (en) 2001-07-04
GB9821046D0 (en) 1998-11-18
DE69908957T2 (en) 2004-05-19
EP1112512B1 (en) 2003-06-18

Similar Documents

Publication Publication Date Title
EP1112512B1 (en) Rfid detection system
US7408456B2 (en) Wireless communication system
CA2662175C (en) Radio frequency id doppler motion detector
CA2174886C (en) Proximity alarm system
EP2377076B1 (en) Method and system for item level uhf rfid tag with low frequency power assist
US6476719B2 (en) Ultra-sensitive magnetic field receiver capable of operating in high noise environments
EP2543025B1 (en) Method and system for reducing effect of interference in integrated metal detection/electronic article surveillance systems
EP0556277A1 (en) Dual mode electronic identification system
WO1991016695A1 (en) Proximity sensing security system
CA2601336A1 (en) Multiple frequency detection system
CN1965246A (en) Wireless monitoring device
CA2683095A1 (en) Method and system for power management of electronic article surveillance systems
US7671739B2 (en) System and method for implementing ranging microwave for detector range reduction
US7339464B2 (en) Detection-resistant transponder with “stealth packaging” for high-risk surveillance applications
WO2001086608A3 (en) Eas system with wide exit coverage and reduced over-range
CA2628112A1 (en) Short-distance ranging system
GB2382959A (en) Asset protection system
EP3355236B1 (en) A method of reading a barcode and deactivating an electronic article surveillance tag
WO2001067043A1 (en) Ultra-sensitive magnetic field receiver capable of operating in high noise environments
Williamson et al. A coded radar reflector for remote identification of personnel and vehicles
JP2004318299A (en) Intruder detection system for crime prevention
KR19980025908A (en) Wireless remote universal remote recognition system and its devices
JPH01233581A (en) Automatic identification device for mobile body

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AL AM AT AU AZ BA BB BG BR BY CA CH CN CR CU CZ DE DK DM EE 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 MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

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

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 1999947682

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 09786425

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: IN/PCT/2001/419/KOL

Country of ref document: IN

WWP Wipo information: published in national office

Ref document number: 1999947682

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWG Wipo information: grant in national office

Ref document number: 1999947682

Country of ref document: EP