Abstract: The method of predicting tag detection probability for RFID framed slotted ALOHA anti-collision protocols is uses recursive calculations to accurately estimate the probability of discovering RFID tags in a multiple rounds discovery system. First, the method estimates the probability of detecting a given number of tags in a single round. Then, using a probability map, the method estimates the probability of detecting the given number of tags in multiple rounds. The probabilities are used to adjust the number of slots in a frame and the number of interrogation rounds used by the RFID tag reader to minimize collisions and optimize tag reading time.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: An RFID reader control system and method is provided. A protocol for controlling an RFID reader and an RFID reader control unit of a mobile phone is defined. Messages, information, commands, responses, and notification are constructed and transmitted between the RPM reader and the RFID reader control unit.

Abstract: Aspects disclosed herein relate to improving NFC-A device collision resolution in an environment with different NFCID sizes. In one example, a communications device is equipped determine a colliding bit in a first NFCID that has a byte length corresponding to a first cascade level value, set a cascade level collision value based on the first cascade level value, generate a second NFCID by selecting a value for the colliding bit, determine that a byte length associated with the second NFCID results in an incomplete NFCID for a first remote NFC device, obtain a further part of the second NFCID using a second cascade level value that corresponds to a longer byte length NFCID than the first cascade level value, determine that at least one other remote NFC device is not yet identified based on the set cascade level collision value, and obtain a third NFCID that corresponds to a second remote NFC device.

Abstract: It is described a RFID device (231a, 231b, 231c, 331) comprising a data memory (236) and an electronic circuit arrangement (237, 238, 239, 247) coupled thereto. The electronic circuit arrangement has a first and a second operational configuration, wherein by receiving a control command (250a) the electronic circuit arrangement can be switched irreversibly from the first to the second configuration. The RFID device further comprises a communication interface (245) being coupled to the electronic circuit arrangement. In the first configuration the RFID device is adapted to communicate with a standard RFID reader (110) via the communication interface. In the second configuration the communication with the standard RFID reader is disabled and the RFID device is adapted to communicate with a readout-RFID device (370). The RFID device may be equipped with a secondary communication interface that can be used to communicate with the RFID device in a privacy-preserving manner.

Abstract: A radio frequency identification (RFID) monitoring system (12) for monitoring a plurality of RFID tags, and in particular for monitoring a plurality of vials incorporating such tags and stored at a low temperature, (eg.?80° C.) within a storage unit (10), for example a freezer. The RFID system (12) comprises an RFID reader (28) and at least one antenna (34a-34i) for transmitting and receiving RF signals to communicate with the RFID tags. The system (12) further includes an electronic switch (38), preferably a FET switch, interposed between the RFID reader and the at least one antenna (34a-34i) to connect a particular antenna (34a-34i) to the RFID reader (28) and transmit RF signals from the antenna (34a-34i) to the RFID tags. The switch (38) is controlled to intermittently connect the antenna (34a-34i) to the RFID reader (28) to regulate the power of the RF signal transmitted from the antenna (34a-34i). The system enables an RFID tag to operate at low temperatures.

Abstract: The data carrier has a communication protocol storage unit storing a communication protocol for communicating with an external communication device, an RF analogue receiver receiving an interrogation signal from the external communication device as an RF signal, a contact communication end terminal unit performing contact communication with the external communication device, a communication command controller controlling a command used in an RF communication protocol performed via said RF analogue receiver or a contact-type serial communication protocol performed via said contact communication end terminal unit, and a connection selector selectively connecting one of said RF analogue receiver and said contact communication end terminal unit with said communication command controller.

Abstract: Turning now to the drawings, systems and methods for reading RFID transponders utilizing readers in which the Q-factor of the resonant antenna of the reader shifts over the course of the reader's interrogation cycle in response to the detection of data from FDX and HDX RFID transponders in accordance with embodiments of the invention are illustrated. One embodiment having a dynamically adjustable Q-factor, wherein the reader transmits an activation signal configured to activate half duplex and full duplex transponders includes a signal source configured to drive a resonant antenna and a dynamic switching circuit configured to set the Q-factor of the resonant antenna to a first value during the transmission of the activation signal.

Abstract: There is provided a sensor tag device capable of detecting event data by a sensor tag all the time even when no radio wave is received, saving power supply for a microprocessor, and enlarging the radio communication distance. The sensor tag device includes generation means 6 and 7 using one or more environmental changes, power supply voltage rise control means 8, and power supply synthesis means 9, and power is supplied to a microprocessor 12 and event data is stored in the microprocessor 12 when an event, i.e., an environmental change has occurred. A power receiving circuit having a transmission/reception antenna, a built-in power receiving circuit, and the microprocessor and capable of bi-directional communication by radio waves is combined with a stab resonance RF boost circuit and a ladder boost rectification circuit.

Abstract: The reader/writer repeatedly reads data, which is stored in an IC tag existing in an area where communication with the reader/writer can be established, from the IC tag in a noncontact method. The reader/writer transmits the read data to the administrative device. The administrative device generates read data which shows the result of reading in chronologic order and generates feature data indicative of the feature of the result of reading on the basis of the generated time series data. An IC tag is sorted as a target tag or an unnecessary tag by sorting the read data as necessary data or unnecessary data on the basis of the generated feature data.

Abstract: A system having a first motion sensor configured to sense movement of an object on a first side of a portal, the object including an RFID tag, a first RFID reader being activated by the first motion sensor when the first motion sensor senses movement of the object, the first RFID reader reading the RFID tag, a second motion sensor configured to sense movement of the object on a second side of the portal and a second RFID reader being activated by the second motion sensor when the second motion sensor senses movement of the object, the second RFID reader reading the RFID tag, wherein, when one of the first and second motion sensors sense movement of the object, the other one of the first and second motion sensors is deactivated for a predetermined period of time.

Abstract: In certain embodiments, a method may include receiving, at one of a plurality of remote units, a command from a control unit. The method may also include determining a random number specifying a time slot of a first series of time slots for transmitting a second data sequence to the control unit, and, in response to a determination that the random number specifies the first time slot in the first series of time slots, determining a new random number. The method may further include transmitting, in the first time slot in the first series of time slots, a first data sequence to the control unit. The method may further include receiving a control signal. The control signal having been transmitted by the control unit upon detection of an at least partially simultaneous transmission of first data sequences by more than one of the remote units.

Abstract: A system and method is disclosed for using an input data signal as a clock signal in a state machine of a radio frequency identification (RFID) tag. An output of a demodulator in the RFID tag is directly coupled to a clock input of the command state machine in the RFID state machine. The command state machine receives an edge detect signal directly from the input data signal and then immediately generates backscatter signals to begin a backscatter process. The edge detect signal may comprise a rising edge of a data symbol of the RFID protocol. The immediate initiation of the backscatter process reduces latency of the backscatter process in the RFID state machine.

Abstract: The RFID system includes an RFID reader for sending information selected from among collision type information, idle type information, and readable type information, to all of the RFID tags depending on the number of signals in the corresponding time slot, and RFID tags for performing functions, in which, when information, indicating that a current time slot is a collision type, is fed back from the RFID reader, each of RFID tags selects one arbitrary value of either 0 or 1 and is assigned a time slot, in which a corresponding RFID tag will send a signal to the RFID reader, based on the selected value, a single tag group that caused a collision is divided into two sub-groups depending on the assigned time slots, and tags of the sub-groups send signals, including IDs thereof, to the RFID reader in different time slots for the respective sub-groups.

Abstract: A transportation and storage unit includes a transponder identification unit for distinguishing and identifying goods or other objects, a multiplicity of which may be disposed, transported and/or stored and/or handled on palettes or similar transport aids in so-called groups, bunches, units or bundles. A plurality of mutually-separated transponders are embedded in the transponder identification unit. The transponder identification unit surrounds the periphery of the transportation and storage unit. A reading unit for sensing a multiplicity of transportation and storage units is also provided.

Abstract: RFID readers transmit a Quiet Technology (QT) command to RFID tags causing at least one of the tags to transition between a private profile and a public profile. When a tag is inventoried in the private profile, it replies to the reader with contents from its private memory. When a tag is inventoried in the public profile, it replies to the reader with contents from its public memory, where the contents of the public memory may be a subset and/or modified version of the private memory contents, or entirely different altogether. The tag's profile can be switched again by another QT command from the reader, or following a loss of power at the tag. An access password and/or a short-range mechanism may be employed to allow only authorized readers to transition tag profiles or interrogate the private memory contents of tags in the public profile.

Abstract: An improved RFID Tag, Interrogator, and system wherein at least one tag modulates a radio frequency signal by modulated backscatter operations.

Abstract: An RFID read/write station includes read/write equipment with a transmitter, a receiver, a processor unit, and at least one read/write antenna. A first passive electronic tag is coupled via a first coupling element to an output from the transmitter and an input to the receiver with a pre-set coefficient of coupling, while a second passive electronic tag is coupled to a read/write antenna through a second coupling element with a pre-set coefficient of coupling. For the purpose of periodically or aperiodically monitoring the RFID read/write station, an identification of the first and second tags can be made and/or the data content of which can be read.

Abstract: A radio frequency identification (RFID) reader outputs an interrogation signal, and hops/varies the phase of the interrogation signal sent by the RFID reader over time. Varying the phase of the interrogation signal enables the RFID reader to provide, for each zone of an RF field of the RFID reader, a particular phase that reduces of the effects of interference RF signal(s) present in that zone of the RF field. Reducing the interference in each zone of the RF field increases the throughput of RFID tags that can be successfully read by the RFID reader.

Abstract: Systems and methods for efficiently querying and identifying multiple items on a communication channel are disclosed. The invention is well suited to use with radio frequency identification with interrogation devices and systems that identify radio frequency identification transponders. A depth-first tree traversal protocol algorithm, including commands and symbols, is used to more efficiently interrogate a plurality of transponders in a short amount of time.

Abstract: A multi-document read-write station provides the ability to read/write to a stack of Radio Frequency Identification (RFID) tags within a small area. Specifically, the station provides the ability to read from and write to a tall stack of RFID tagged sheets with the RFID tags stacked one on top of the other. The station and capability described herein is the result of and comprises several components including a closed chamber comprising a document slot, an antenna system, and a power management system.

Abstract: Provided is a communication control method for a radio-frequency identification (RFID) reader, which communicates with a plurality of RFID tags, the communication control method including: (a) setting a session in which the RFID tags are initialized after a persistence time; (b) communicating with the RFID tags during the persistence time of the RFID tags; and (c) terminating communications during a set delay time after the persistence time of the RFID tags is over.

Abstract: A group proving method includes the following steps. First, a query command is broadcasted to radio frequency identification (RFID) tags, each of which responds the query command with tag identification data. Next, a first round parameter is generated and broadcasted according to the tag identification data, and each RFID tag responds the first round parameter with a first response parameter. Then, a second round parameter is generated and broadcasted according to the first response parameter, and each RFID tag determines whether the second round parameter is received in a predetermined period after the first round parameter was received and whether the first and second round parameters correspond to each other. If so, each RFID tag updates its tag key according to a random number parameter and outputs a second response parameter. Thereafter, group proving data are generated according to the above-mentioned data.

Abstract: Apparatus and methods are described which are useful for determining a location characteristic between an RFID tag and an RFID tag reader or a second RFID tag. In various embodiments, signals backscattered from a singulated tag over a range of frequencies are evaluated for in-phase I and in-quadrature Q signal components. The I-Q data is processed to determine phase delay angles associated with each signal frequency. The phase delay data can be processed by a sum of squared errors method or Fourier transform method to determine a distance to the singulated tag. The methods can also be used to determine any of a location, a radial velocity, a directional velocity of the singulated tag, and proximity of the singulated tag to a second tag.

Abstract: Methods and systems for coordinating transmission of data from wireless identification tags are disclosed. According to an aspect, a wireless identification tag includes a communication module configured to wirelessly transmit data in response to receipt of an instruction. The wireless identification tag also includes a timer configured to communicate the instruction to the communication module for transmission of the data within a timeslot based on a stored first identifier of the wireless identification tag. Further, the timer module is configured to receive second identifier. The timer module is also configured to change the first identifier based on the second identifier.

Abstract: Active RFID technologies are used to tag assets and people within buildings or open areas, such as parking lots or military bases; and to identify, preferably within a few meters, the real-time location (RTL) of the tag, i.e. to create a real-time location system, known as an RTLS. A novel and complex algorithm is provided that combines signal strength computations with factors that incorporate physical realities, such as walls and floors, to determine a tag's real-time location more accurately.

Abstract: Briefly, in accordance with one or more embodiments, a mixer circuit at a receiver of an RFID interrogator may operate at a power supply voltage selected based at least in part on a power level of the self-jammer signal. The mixer circuit may operate at a higher power supply voltage if the expected power level of the self-jammer signal is higher, and may operate at a lower power supply voltage if the expected power level of the self-jammer signal is lower.

Abstract: A multi-protocol RFID interrogating system employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGO™ RFID backscatter transponders, SEGO™ RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame, to eliminate downlink on uplink interference.

Abstract: This disclosure discloses an apparatus for reading radio frequency identification (RFID) tag information configured to perform information transmission and reception with a plurality of RFID tag circuit elements having an IC circuit part storing information and a tag antenna connected to the IC circuit part, comprising: a first movement detecting portion configured to detect a moving state of the apparatus for reading RFID tag information; a transmitting portion configured to generate a reading command to acquire the information stored in the IC circuit part and to transmit the command to the RFID tag circuit element; and a first reading control portion configured to control the number of reading trial times per unit time using the reading command by the transmitting portion according to a detection result of the first movement detecting portion.

Abstract: Provided are an anti-collision system and method which address the mobility of radio frequency identification (RFID) tags. An RFID reader may transmit an identification start command to identify a plurality of RFID tags in an identification area of the RFID reader. The RFID tags compare the number of collisions of each RFID tag receiving the identification start command with a collision threshold Cth and attempt to be identified in a binary tree section of a frame or in a framed slotted ALOHA (FSA) section of the frame based on the comparison.

Abstract: A keyless entry system for an automobile is described. The keyless entry system comprises a radio frequency identification (RFID) tag that has been programmed to selectively unlock an automobile when the RFID tag is within a predetermined distance and, optionally, to lock the automobile when the RFID is outside the predetermined distance. An interrogator housed on or within the automobile comprises an actuatable RF signal generator for transmitting an electromagnetic signal and a time-out circuit. Regardless whether the programmed RFID tag is detected, or not, the RF signal generator transmits a first electromagnetic signal having a first limited total continuous transmit time, followed by an interim period of a defined length where the time-out circuit renders the interrogator incapable of transmitting the electromagnetic signal, followed by the RF signal generator transmitting a second electromagnetic signal having a second limited total continuous transmit time.

Abstract: A timing circuit that can function as an accurate persistent node in an RFID tag includes a power capture circuit for capturing power from a power source, and a counter circuit that provides a count representing a progression of time. The count can then be compared to a reference value representing a time constant of the circuit.

Abstract: A wireless communication tag according to the present invention includes a first antenna 8 previously set with predetermined identification information, and for wirelessly communicating various types of data with a reader/writer 6; a controller (IC chip 14) for controlling the data communicated through the first antenna; a second antenna 10 for receiving an electromotive radio wave 4e for causing electric power by a radio wave; and a charging unit (rectifying circuit 16 and a capacitor 18) for causing electric power by the electromotive radio wave received from the second antenna as well as for storing the caused electric power. With use of the electric power stored in the charging unit, the first antenna supplies data relating to the identification information to the reader/writer. The second antenna also can provide the reader/writer with the identification information.

Abstract: RFID data signals from RFID tags may be recovered by determining the probabilities of transitions between data states between a series of a pairs of signal samples using a set of predetermined probabilities related to data, timing, baud rate and/or phase variables affecting the received signal and processing those determined probabilities to determine the sequence of such transitions that has the highest probability of occurrence. A second set of predetermined probabilities related to transitions in the opposite direction may be used to sequence in a reverse direction. The determination of the sequence representing the RFID tag data may be iterated in both directions until further iterations do not change the determined probabilities.

Abstract: The present invention provides a power supply circuit provided with a battery as a power source for supplying power to an RFID, and the battery of the power supply circuit is charged with a wireless signal. Then, a switching circuit is provided in the power supply circuit that supplies power to a signal control circuit which transmits and receives individual information to and from the outside to intermittently control supply of power to the signal control circuit by a signal from a low-frequency signal generation circuit.

Abstract: An improved system and method for monitoring objects, people, animals, or places uses a passive Modulating Reflector (MR) tag where a characteristic of an antenna is modified according to a time-varying pattern by a modulating network thereby causing the reflective characteristics of the antenna to vary in accordance with the time-varying pattern. When an interrogator transmits an RF waveform that impinges on the antenna, the return signal reflecting off the antenna is modulated in accordance with the time-varying pattern allowing a remote receiver to demodulate information from the modulated return signal. The antenna is embedded in a dielectric material. The MR tag can be used with a wide variety of tag-interrogator configurations employing monostatic and/or bistatic radar techniques to allow monitoring, locating, and/or tracking of objects, people, animals, or place with which MR tags are associated.

Abstract: The present invention relates to an RFID reader and a method thereof, and an RFID data processing method. The RFID reader generates a specific query message to a plurality of RFIDs, receives a first response message corresponding to the query message from at least one RFID among the RFIDs, and sequentially identifies a tag ID of a collided RFID by using a collision solving message when a collision occurs according to the result of receiving a first response message. The RFID reader can quickly and accurately identify a plurality of RFIDs since it can eliminate an unnecessary time such as excessive no response slot generation or repeated rounds through a sequential identification process for the collided RFIDs.

Abstract: An embodiment of the present invention improves the efficiency of radio frequency identification (RFID) systems and helps to extend the effective read range for certain configurations of closely spaced RFID tags. Specifically, an embodiment helps to minimize energy losses that result when there is excess energy from the excitation source. This excess energy has the potential to damage the circuitry in RFID tags. A shunt regulator is often used to protect the RFID circuitry by clamping the voltage, but has the undesirable effect of converting this excess excitation energy into heat. Various embodiments are directed toward using only as much of the excitation energy as necessary to power the RFID circuitry.

Abstract: In a circuit for a data carrier, which data carrier comprise a sensor that is designed for providing a sensor signal that represents an environment parameter and a communication element that is designed for the contact-less communication with an interrogator station, first connection elements for connecting the circuit to the communication element and second connection elements for establishing an electronic connection of the circuit to the sensor are provided, wherein the second connection elements are realized by the first connection elements and wherein the circuit comprises a sensor signal processing stage designed for receiving said sensor signal via the first connection element and for processing said received sensor signal.

Abstract: An alarm system senses alarm conditions on a premises, reports the occurrence of an alarm condition to a remote monitoring facility and for selected alarm conditions establishes two way voice communications with a person at the monitored premises or elsewhere. Multiple modes of communication are available such as public switched telephone (audio or audio modulated data), GSM (cellular audio), GPRS (cellular packet data), GSM/SMS (cellular text), etc. The programmed processor selects the network and communication protocol to rely on data communications if only data reporting is required. When two way voice communications will be required, the processor can select a network (e.g., GSM) that can be used for both data and audio communications.

Abstract: RFID reader systems, readers, components, software and methods cause RFID tags to backscatter a combination made from at least portions of a first code and a second code, without transmitting any commands in the interim. The first and/or second codes may include a tag response to a reader challenge. In a number of embodiments, a separate command does not have to be sent for reading the second code along with the first code, thereby saving time in inventorying the tags. Plus, the combination can enable reading tag codes during tag manufacturing that are not otherwise readily available to read in the field. In some embodiments, the combination may further include one or more error-checking codes.

Abstract: Systems, methods and computer program products for the centralized control of radio frequency identification (RFID) readers are described herein. An input event control embodiment operates by receiving a signal from a non-RFID input device and commanding an RFID reader associated with the non-RFID input device to begin reading. According to an alternative time coordination embodiment, non-overlapping time slots are assigned to a plurality of RFID readers, and the RFID readers read only during their respective non-overlapping time slots. According to an alternative combined input event control/time coordination embodiment, non-overlapping time slots are assigned to a plurality of RFID readers. A signal from a non-RFID input device is received, and an RFID reader associated with the non-RFID input device is commanded to begin reading. However, such RFID reader only begins to read at the beginning of its next assigned time slot.

Abstract: The present disclosure relates generally to wireless detection systems. In one illustrative embodiment, a wireless detection system includes a plurality of surface acoustic wave (SAW) sensors, and an electronic reader for interrogating the plurality of SAW sensors. In some instances, each of the surface acoustic wave based sensors includes an integrated sensor coil. The electronic reader may include a plurality of reader coils and a controller. The controller may be configured to interrogate the plurality of surface acoustic wave based sensors using a time division interrogation. In some cases, each of the plurality of reader coils is inductively coupled to only one of the integrated coils of the SAW sensors at any given time.

Abstract: An electronic device and a method of operating the device. The device receives a first signal having a first frequency and a predetermined signal strength and retransmits a signal after a latency period and during a time period. The device comprises an oscillation circuit operating in a sub-threshold area in a meta-stable, first mode of operation. When the first signal is received, the oscillation circuit is trigged and passes to an active mode in a second mode of operation, wherein the circuit oscillates. Finally, the device is reset to the first mode of operation. The device may have an identity, which is used for the purpose of the system, which may be an RFID system.

Abstract: According to one embodiment, an interrogator apparatus includes a transmitting section configured to generate a transmission signal, a receiving section configured to process a reception signal, an antenna configured to transmit and receive a radio signal, a directional coupler configured to supply the transmission signal from the transmitting section to the antenna and supply the reception signal from the antenna to the receiving section, a switching element, a first terminal of which is connected to the directional coupler and a second terminal of which is grounded, the switching element connecting the first terminal or the second terminal to the antenna according to a control signal, and a control section configured to control, when performing carrier sense and detecting a carrier, the switching element to back-scatter an interrupt signal and stop transmission of a radio signal to another interrogator apparatus having a lower priority degree than the interrogator apparatus.

Abstract: A network of interlocks and input devices and a system for tracking their use and control, in which each interlock and input device is associated with a machine which performs a process. Machines are associated with input devices by reading machine identifications from Data Storage Devices (DSDs) with input devices. To disarm an interlock prior to using a machine, the input device is used to read one or more DSDs containing information required to track the process. The input device sends the DSD data to a CPU which then sends an authorization signal to a machine interface. Upon receiving the signal, the machine interface enables the machine to be turned on. The CPU logs the process and DSD data. Once the operator turns off the machine, it cannot be restarted until the operator reads the DSDs required by the machine.

Abstract: A system for dispensing, receiving, and tracking towels or other items includes a cabinet structure having first and second interior spaces. An access door provides access to the first interior space, and a return door permits items to be returned to the second interior space. An RFID system conducts read operations to determine how many items having RFID tags are disposed in the first and second interior spaces. The system determines what items have been removed from the first interior space, and associates removed items with specific users. The RFID system conducts read operations as items are returned to the second interior space and credits the user.

Abstract: Provided are a reader-tag integrated RFID apparatus and a method for controlling the same. The apparatus includes a tag unit for communicating with an external reader, and transmitting a response signal and data corresponding to a signal transmitted from the external reader to the external reader, a reader unit for selecting a channel between other reader and the reader-tag integrated RFID apparatus with a different delay time, and communicating with an external tag using a random value to minimize collision; and a controller for selectively activating one of the tag unit and the reader unit if it necessary.

Abstract: Embodiments of the present invention include systems and methods for providing Quality of service to RFID. In one embodiment the present invention includes a method of providing quality of service in an RFID network comprising storing RFID priority information corresponding to the RFID network, wherein the RFID network comprises one or more tags and one or more readers mapping the RFID priority information into priority information corresponding to a second network.

Abstract: There is provided a radio interrogator system which reduces the interference with a radio transponder and avoids the decrease in throughput of the entire system in a case in which a plurality of radio interrogators are disposed at positions brought relatively close to each other and are simultaneously placed into operation. The plurality of radio interrogators are classified into two groups and each of the radio interrogators has an operation mode setting unit capable of exclusively setting, for each of the classified groups, a transmission mode for transmitting a radio transmission signal to a radio transponder or a reception mode for receiving a radio response signal transmitted from the radio transponder as a response to a radio transmission signal from the radio interrogator.