Abstract: A method and apparatus for selectively reading radio frequency identification device (RFID) tags by an RFID reader includes the RFID reader transmitting an interrogation signal at each of a plurality of power levels beginning with a lowest power level and sequentially increasing power of the transmitted interrogation signal to a highest power level. The RFID reader receives, in response to transmitting the interrogation for at least one of the power levels, at least one data signal from each RFID tag within a read zone of the RFID reader, wherein each of the data signals contains stored data corresponding to the RFID tag responding to the transmission of the interrogation signal. The RFID reader selectively reads the stored data contained in the data signals received from the responding RFID tags.

Abstract: Data carriers for inventorying by means of a communication station, whereby the communication station and each data carrier are brought into communicative connection, and each data carrier brought into communicative connection with the communication station is configured to generate a response signal that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal with the use of a transmission start moment that can be selected from a plurality of transmission start moments, each data carrier tests whether another data carrier is already giving its response signal. Each data carrier is configured to discontinue the generation or delivery of its response signal if another data carrier is already providing its response signal.

Abstract: A Radio Frequency Identification (RFID) system uses read difficulty factors (RDFs) to improve tag-parameter estimation. During inventory, a reader can obtain a tag's item identifier (II), determine a read metric such as a received signal strength indicator (RSSI), retrieve an RDF associated with the II, and adjust the RSSI using the RDF to more accurately estimate a tag parameter such as distance from the reader antenna. The system can then use the estimated distance to categorize the tag.

Abstract: Indoor locationing using radio frequency based tags includes distributing a plurality of radio frequency based tags at mapped locations within the indoor environment. The radio frequency based tags periodically transmit their identity information in a message. A mobile device in proximity to at least one of the radio frequency based tags receives the message. A location of the mobile device is associating to the mapped location of the radio frequency based tag identified in the received message.

Abstract: A system to multiplex antennas for radio-frequency communication uses one or more antenna shorting circuits to selectively enable RF communication via one of a plurality of antenna matching networks. The system is cost-efficient compared to alternatives. The RF communication includes read and/or read/write communication with, e.g., radio-frequency identification (RFID) tags.

Abstract: A wireless communication module includes an antenna on a first conductive wall among the conductive walls enclosing a closed space; a tag reader connected with the antenna to read an RFID tag in the closed space; and a reflective part having a thin film or plate shape between the first and second conductive walls facing each other. The reflective part partitions the closed space into first and second spaces. The antenna radiates a radio wave that is reflected by the reflective part to become a first reflected wave in the first space. The radio wave also transmits through the reflective part, reflected by the second conductive wall, and transmits through the reflective part to become a second reflected wave in the first space. The position of the reflective part is determined so that the first and second reflected waves are canceled by each other.

Abstract: The present invention relates to the use of RFID technology to identify specific cables in a bundle, and in particular to a cable identification device in which RFID devices are connected to the far end of a plurality of cables and splitters, and an RF measurement device is used to identify each cable from the central location. The RF measurement device provides the AC RF electrical signal power required to pass through the at least one AC couple splitter to operate the plurality of RFID devices, and includes means to identify the unique identification numbers associated with the plurality of coaxial cables from the plurality of identification signals received simultaneously.

Abstract: A method of identifying a plurality of transponders, the method comprising receiving at an interrogator one or more data transmission blocks from each transponder, wherein the first data block contains a uniquely detectable transponder identity and zero or more further data blocks defining a set of data blocks making up a transponder transmission. The first data transmission block also contains in transmission block number; one or more further data transmission blocks containing additional block data and a respective transmission block number; the block number being changed, by decrement or increment, automatically as each data block is transmitted.

Abstract: An intermediary between a remote control device and a remotely controllable device implements identification and/or authentication. The intermediary is, e.g., a node or set of nodes within a head end of a cable network service provider. A remote control device at a customer premise sends a command intended to control a remotely controllably device which is also located at the same customer premise. The customer premise includes a network interface, e.g., a cable modem, which has associated identification information. The command and the associated network interface identification information are communicated to the intermediary, e.g., via a cable modem. The intermediary accesses a subscriber record corresponding to the location based on the network interface identification information. The intermediary identifies the device to be controlled, e.g., a particular set top box and/or authenticates the remote control device. A command is sent via the network to the device to be controlled.

Abstract: An archive apparatus is provided for storing and archiving laboratory samples including radio frequency identification means. The apparatus comprises a support structure or cabinet (4), a drawer (6) translatable in a translation direction (12) into and out of the support structure (4), and sample support means comprising ribs (8) associated with the drawer (6) for supporting an array (10) of samples or slides (20) spaced along the translation direction (12) for movement with the drawer (6). A radio frequency reader antenna (14) is connected to the support structure (4) adjacent to the drawer (6) and recording means (34, 38) are adapted to operatively communicate with the reader antenna (14) to store information obtained from the radio frequency identification means of laboratory samples or slides (20) supported by the drawer (6).

Abstract: A method for controlling RF power within an RFID system according to one embodiment includes returning a first set of RFID tags that were successfully accessed at a first reader forward mode power level to a hibernate state; initiating a timer operation in each of the RFID tags within the first set of RFID tags, the timer operation defining a period of time; and preventing the first set of RFID tags from responding to an activation command at a second reader forward power level during the period of time, the second reader forward power level being higher than the first reader forward power level; and wherein a flag state stored in each of the RFID tags within the first set of RFID tags indicates whether the timer operation is active to prevent undesired activation at the second reader forward power level.

Abstract: A radio frequency identification (RFID) system employs multiple band transmission to prevent signal collision. The system includes a plurality of RFID tag groups and at least one RFID reader. Each RFID tag group includes at least one RFID tag. The RFID tags of the same RFID tag group are operated for radio frequency transmission in the same transmission frequency band, and those of different RFID tag groups are operated for radio frequency transmission in different transmission frequency bands. When the RFID reader simultaneously receives radio frequency signals issued from RFID tags of different RFID tag groups, since they are transmitted in different transmission frequency bands, signal collision among the RFID tags of the RFID tag groups can be avoided.

Abstract: An IC tag searching apparatus capable of changing the shape of its searching board in a simple manner in accordance with the situations of a location to be searched, said location includes wide to narrow areas and areas in the corners, at the time of searching the positions of wireless IC tags those which are embedded in a concrete construction and the like, efficiently detecting the positions of the embedded wireless IC tags and performing reading and writing of information from/to the wireless IC tags is provided. The IC tag searching apparatus 10 according to the present invention comprises a plurality of plate members 2, 3 each having an antenna built-in, said plate members may be joined with each other in a direction of those flat surfaces, respectively, a joining means provided to the plate members having an antenna built-in and information transmission/reception section 11 for performing data transmission/reception between the plate member having an antenna built-in and the R/W main body 9.

Abstract: Disclosed is a near field radio frequency communication system. The near field radio frequency communication system comprising: a master RFID/USN device which comprises a plurality of antennas to sequentially shower an energy signal through the antennas; and a slave RFID/USN device which generates a first power using the energy signal, detects a power level of the first power, and transmits information created based on the power level to the master RFID/USN device, wherein the master RFID/USN device creates a first position information of the slave RFID/USN device related to a direction by determining an antenna used to communicate with the slave RFID/USN device, and a second position information of the slave RFID/USN device related to a distance using the information created based on the power level.

Abstract: An authentication method includes RFID readers authenticating RFID tags using public-key cryptography. A tag manufacturer or other legitimate authority produces a tag private-public key pair and stores the tag private key in externally unreadable tag memory and the tag public key in externally readable tag memory. The authority produces a master private-public key pair and distributes the master public key to readers in the field. The authority generates a tag-specific electronic signature based on at least the tag public key and the master private key and stores this signature in externally readable tag memory. A reader authenticates the tag by retrieving the tag public key and electronic signature from the tag, verifying the authenticity of the tag public key using the master public key and the electronic signature, challenging the tag, receiving a response from the tag to the challenge, and verifying the response using the tag public key.

Abstract: A radiofrequency identification (RFID) multiplexer, which may be in a network, interprets an RF signal from an RFED reader as RFE) tag interrogation data. A single cable directs an RF signal from the RFID reader and RF control signals and/or RF power through the multiplexer. An RF sampler may be coupled to the cable; and an RF detector detects the RF signal from the cable via the RF sampler. A data decoder decodes and interprets the RF signal as the RFID tag interrogation data and forwards the RFID tag interrogation data to a control logic circuit as a MUX channel-change command. The logic circuit and decoder may be combined in a microcontroller, and an RF backscatter modulator coupled to the cable enables reverse communication with the RFID reader to determine whether another RFID multiplexer is coupled to the RFID multiplexer.

Abstract: RFID tags are used for many purpose including tracking. RFID interrogators are used to retrieve information from tags. In many applications, a plurality of RFID interrogators are required. Synchronization between interrogators in the same theatre of operation is critical to ensure that their broadcasts do not interfere with each other. In fixed RFID interrogator applications, RFID interrogators can be wired together allowing a channel to synchronize the transmissions of the RFID interrogators. Methods described herein can ensure that synchronization is maintained in the event of the failure of a synchronizing master. Furthermore, additional methods for synchronizing RFID interrogators in wireless applications are described allowing synchronization in the absence of wired connections between interrogators.

Abstract: A wireless communication device according to embodiments includes a position detection unit configured to detect the position of the wireless communication medium in a moving path, and a control unit configured to control communication based on the detection signal from the position detection unit.

Abstract: An RFID system has an active tag with one antenna inside, and one outside, an RF-blocking enclosure having a port with a selected shortest dimension. The RFID reader is located outside the enclosure and uses a selected RF read frequency range. The RFID tag simultaneously transmits on a plurality of frequencies corresponding to respective wavelengths smaller than the selected shortest dimension, so that a respective beat frequency is defined between two of the frequencies. The beat frequency is within the selected RF uplink frequency range. The tag transmits a first signal at a first one of the plurality of frequencies using the interior antenna and a second signal at a second, different one of the plurality of frequencies using the exterior antenna.

Abstract: According to one embodiment, an IC card includes a communication module, a first command processing module, a determining module, a second command processing module, a response processing module. The first command processing module performs a process corresponding to a first command received from the external device. The determining module determines whether a second command is contained in a data portion of the first command. The second command processing module performs a process corresponding to the second command if the determining module determines that the second command is contained in the data portion of the first command. The response processing module sets a processing result of the second command executed by the second command processing module in the data portion of the response indicating a processing result of the first command executed by the first command processing module and transmit the same to the external device.

Abstract: A method for interleaving time slots in a multi-antenna system for communication with RFID tags is disclosed. An example is shown for an eight antenna system. A first four antennas arranged side-by-side are sequentially energized to interrogate RFID transponders. A second set of four antennas arranged side-by-side, the first of which is adjacent to the last of the first set of antennas. A four-antenna sequence is performed for the first four antennas and a second four antenna sequence is performed for the second set of antennas. The first and second four antenna sequences are offset by only a marginal amount, sufficient to ensure that a transponder signal received four antennas away from an active antenna is not acknowledged because the receive window for the non-active antenna is delayed.

Abstract: The invention describes an arbitration management method and system for use in identifying RFID transponders or tags which each transmit a response signal to a reader within a respective waiting period the maximum duration of which can be adjusted. The maximum duration is determined by a random number transmitted to a counter along a number of data lines, at least one of the data lines being provided with logic gates which block or permit data line signals reaching the binary inputs of the counter to control the maximum length of the waiting period.

Abstract: Systems and methods are provided for enhancing a signal for load modulation from reading a smartcard. According to such methods, an antenna signal is generated by transceiver circuitry. An antenna signal field associated with the antenna signal can be transmitted. A reference signal that is substantially constant in amplitude and phase and substantially in phase with a carrier frequency of the antenna signal can be generated. A modulated antenna signal can be received. The modulated antenna signal can include the antenna signal that has been modulated as a result of the presence of a smartcard within the antenna signal field. The reference signal can be subtracted from the modulated antenna signal to produce a resultant signal. The resultant signal may be provided to receiving circuitry of the transceiver circuitry.

Abstract: An apparatus is disclosed including one or more security structures. The one or more security structures includes: a weldable frame; a plurality of composite panels, each panel securable to the weldable frame, each composite panel configured to form at least one joint with at least one adjoining composite panel; and a respective security element embedded within each of the composite panels. The security element is configured to detect a breach in the composite panel.

Abstract: Systems, methods and computer program products for detecting and re-personalizing are provided herein. In an embodiment, the invention operates by obtaining an ID (i.e., an identification, such as a Dynamic Unique Identifier) from a RFID tag, generating a new ID, and writing the new ID to the RFID tag. The ID read from the tag is used to lookup a subject's record in a database. If the write of the new ID to the tag is verified, then database changes are committed to link the new ID to the subject. In an alternative embodiment, the invention operates by obtaining data from a memory of a RFID tag, wherein the memory has a first partition and a second partition, generating a new ID, and writing the new ID to either of the first partition or the second partition of the RFID tag. If such write is verified, then the new ID is written to the other partition of the RFID tag. The data from the tag is used to lookup a subject's record in a database.

Abstract: An autonomous and controllable system of sensors and methods for using such a system of sensors are described.

Abstract: When multiple readers for RF transponders have to be placed in close proximity, such as in adjacent lanes of a highway toll barrier, they can be set to operate at different frequencies. When signals from two adjacent ones of the readers interfere, the resulting signal includes interference terms whose frequencies equal the sum of the reader frequencies and the difference between the reader frequencies. To remove such interference terms while passing the desired terms, a tag includes a low-pass or other frequency-selective filter.

Abstract: A wide area radio frequency identification (RFID) system includes: a first RFID cell and a second RFID cell. The first RFID cell and the second RFID cell each include a reader and tags. The readers access the tags using ultra-wide band signaling. The RFID cells each include: a communications interface operable to communicate with a network operations center, and a communications gateway which supports direct communications between RFID cells. The method includes accessing the second RFID cell from the first RFID cell, and the accessing is performed using the communications gateway that can cover a range of at least five hundred meters.

Abstract: In some embodiments, a technique for logging an item encountered by a mobile device comprises automatically detecting an item in an uncontrolled environment, extracting an identity associated with the item, logging an encounter, wherein the encounter includes the identity, and deleting the encounter after a predetermined period of time has elapsed, wherein the encounter is not marked as relevant.

Abstract: A dosing system and a method for dosing a medium, having a dosing control unit (4), at least one exchangeable container (2) containing a medium to be dosed, and a dosing valve (3, 3?) that can be connected to the container (2), wherein at least one part of the dosing valve (3, 3?) that comes into contact with the medium is designed as an exchangeable system component (7, 10) and has a machine-readable code for identification purposes, wherein at least one container (2), as an exchangeable system component (2), has a machine-readable code for identification purposes, wherein the exchangeable parts (2, 7, 10, 19) that come into contact with the medium are designed as disposable parts, and wherein the dosing control unit (4) is connected with a communication unit (5) to read the codes, and wherein the communication unit (5) has a unique read connection (22) to each exchangeable system component (2, 7, 10, 19) or its code.

Abstract: The method includes: a reader begins to count the tags, and waits for feedback of the tags; the tags are split into two subsets if the tags feedback the collision, the tags of one of the subsets feedback, the tags of the other subset begin to feedback when the tags of one of the subsets complete the count; when the collision occurs in the course of feedback, then the split continues until all the tags are completed the count; the tags of many branches are at least once split simultaneously when the tags of the subsets are split.

Abstract: Mobile devices may minimize the radiation exposure to users by controlling the distance between the user, specifically the groin area, and the mobile device to a minimum distance. The reduction in exposure is realized due to the operation of the Inverse Square Rule on electromagnetic signal from the mobile device recognizing there is a steep fall off of signal strength resultant from increased distance between the head of the user and the source of the signal. Embodiments alert the user to a mobile device in the users pocket is in a transmission mode and thus should be removed from the users pocket to maintain operational distance between the user and the device to reduce signal absorption of the users reproductive organs. Enabled mobile devices detect the transmission mode and the acceleration of the device in determining whether to alert the user. Embodiments influence the user to maintain a minimum distance via alerts, interruptions and warnings.

Abstract: The present invention provides an inter-communication system with security functionality capable of reporting incidents such as abnormalities occurring in a security system. In an inter-communication system (100), if a communication sound control device (11) receives an alarm from a security system via a main shop processing device (17), the communication sound control device (11) notifies a predetermined order reception communication device, such as a manager communication device (14), of the reception of the alarm, and the main shop processing device (17) reports to a preset destination over a communication network (35).

Abstract: An encoding module and related systems and components are provided. The encoding module includes a plurality of encoding elements arranged in an array of columns and rows and one or more switching elements configured to selectively connect the encoding elements to a reader. The connection of the encoding elements may be based on the location of a targeted transponder disposed among multiple adjacent transponders to ensure the selective communication with the targeted transponder only. The module is configured for various types and locations transponders to be used within a system, such as a printer-encoder. Each encoding element may include a loaded conductive strip comprising a loop shape portion and a shield that corresponds to the loop shape portion. In another embodiment, an access control system having an encoding module with the plurality of couplers and an access card having a plurality of transponders corresponding to the couplers is provided.

Abstract: A method and an identification system used for communicating between a reader and a plurality of transponders are disclosed. The reader has a transmitter for transmitting a signal and each transponder includes a receiver for receiving the reader signal and a transmitter for generating a transponder signal. When the reader recognizes a transponder signal from one of the transponders it immediately issues a mute instruction, muting all other active transponders and passing control to the said transponder, without the need for a specifically timed acknowledgement to the said controlling transponder. The reader may issue a single disable/wakeup instruction which disables the controlling transponder returning control to the reader and reactivated all muted (but not disabled) transponders.

Abstract: A method for communicating with a plurality of radio frequency (RF) devices includes transmitting a first signal at a first power level, interrogating RF devices responding to the first signal, instructing the responding RF devices to change state, and transmitting a second signal at a second power level higher than the first power level. The RF devices responding to the first signal do not respond to the second signal upon changing state.

Abstract: The performance of a radio frequency identification (RFID) system is improved by a protocol that eliminates collisions between signals generated by a) RFID tags that the RFID reader has already identified as being in its interrogation zone and b) RFID tags that are newly arrived and thus that the reader has not yet identified. This is illustratively accomplished by the use of separate identification and access frames. It is during the identification frame that newly arrived tags become identified by the reader. Although there may be collisions during the identification frame, those collisions are only among newly arrived tags. The already-identified tags communicate with the reader during respective time slots of the access frame, so that they neither collide with each other nor with the newly arrived tags.

Abstract: A fueling environment is equipped with leak detection probes and liquid level probes. Each of the probes is associated with a wireless transceiver. The wireless transceivers send probe data to a site communicator wireless transceiver. To ensure that the site communicator receives the probe data, repeaters are used within the fueling environment. The repeaters receive the probe data, and some period of time after the sensor transceivers stop transmitting, the repeaters retransmit the probe data to the site communicator. The site communicator discards duplicative information and processes the probe data as needed.

Abstract: A method and system for challenge-response authentication are provided. Challenge data are transferred within an anti-collision loop from a reading device to a transponder by means of one or more commands of an anti-collision method, with the one or more commands serving to determine transponder identification data. In the one or more commands respective challenge data are contained in a data field that is used for specifying transponder identification data, wherein it is indicated to the transponder by a parameter value in the at least one of the one or more commands that the data field of the one or more commands contains challenge data instead of transponder date. The transponder recognizes with the help of the parameter value that in the received one or more commands challenge data are contained. The transponder processes the transferred challenge data based on the challenge response authentication.

Abstract: The present invention relates to a strap device for a curtain or a flexible door, said straps having embedded RFID reader antenna modules and different MEMS and MOEMS sensors that make it possible to detect the direction of the objects passing through the gate and also detect the size of the objects so as to modulate the switching of the radiating elements of antennas on the basis of the position of the objects being read. The device also has embedded biosensors that measure in parallel the presence of toxic substances or materials. The device according to the invention has an LED or OLED and PHOLED display means embedded in the strap, more specifically, in a flexible material of the strap. The invention is particularly intended for the qualitative and quantitative traceability of materials passing through a logistical check gate. The device is intended for all places already having curtains with flexible straps, into which it is easily embedded. The device is suitable for all existing RFID readers.

Abstract: Included are network devices, systems, methods, and computer readable medium. These may employ a microcontroller with access to computer readable memory and computer readable storage wherein the microcontroller operates at a first network component of a local area network. The microcontroller may be configured to spatially locate one or more fiducial network components of a local area network in which the microcontroller is a member. The spatial location may be determined by receiving a unique identifier for a first fiducial network component, receiving a wireless signal from the first fiducial network component, determining a physical distance between the first network component and the first fiducial network component, and updating a registry with the determined physical distance. In certain embodiments, the network component may be an RFID reader and the unique identifier may be an IP or MAC address.

Abstract: Methods and apparatuses are disclosed that allow an electronic device to autonomously adapt one or more user alerts of the electronic device. For example, some embodiments may include a method for operating a haptic device including driving a haptic device using a control signal, measuring a frequency related to the operation of the haptic device and comparing the measured frequency with a target frequency. A control signal is adjusted based on the comparison to drive the haptic device to the target frequency.

Abstract: Systems and methods to detect cross reads in RFID tags are disclosed. Existing RFID reading mechanisms do not have the provision of detecting cross reads and eliminating the cross reads while performing inventory of an area. As a result, the user will have to manually determine the cross reads from the data and eliminate them. The disclosed method employs a RFID reader that is equipped with a plurality of engines for performing scan on the inventories. The scanned data is processed by a processing unit. In the processing unit, normalization is performed on the scanned data, neighboring assets and spatial location maps are created. The data from the above processes is employed for detecting cross reads during the scan. The identified cross reads are eliminated based on various other parameters obtained by analyzing scanned data.

Abstract: Systems and methods for providing an estimate of a population of passive Radio Frequency Identification (RFID) sensors in a coverage area of an RFID reader system are disclosed. In accordance with embodiments of this invention, the contention resolutions or results of each slot in an interrogation receive frame are determined. The contention resolutions are then used to determine the probabilities of different population estimates. A population estimate is then selected as the population based on the probability of the estimate meeting predetermined criteria.

Abstract: Radio Frequency Identification (RFID) readers may transmit one or more run commands specifying one or more programs for tag execution prior to tag singulation. A run command may encapsulate the program(s), in which case a tag may store or store and execute the program(s). A run command may alternatively specify programs stored on a tag. The reader may instruct a tag to execute the program(s) upon receipt, upon a trigger event, serially or in parallel, and/or may cause the tag to modify the program(s) by adjusting parameters. The reader may instruct tags to execute the program(s) via the run command or another command, which may be sent prior to tag singulation. A reader may cause a tag to determine whether to participate in a subsequent inventory round, modify a behavior during a subsequent inventory round, or store a result in a tag memory, based on the executed program(s).

Abstract: Radio Frequency Identification (RFID) tags may receive one or more run commands, prior to being singulated, that specify one or more programs for the tag to execute. A run command may encapsulate the programs, in which case the tag may execute or store and execute the program(s). A run command may alternatively specify programs stored on the tag. The tag may execute the program(s) upon receipt, upon a trigger event, serially or in parallel, and/or may modify the instructions or program(s) by adjusting parameters. A reader may tell the tag to execute the instructions or program(s) via the run command or another command which, in some cases, may be sent prior to tag singulation. A tag may, based on a result of the executed program(s), determine whether to participate in a subsequent inventory round, modify a behavior during a subsequent inventory round, or store the result in tag memory.

Abstract: A method and a data carrier for contactless communication of a reading device with at least two communication-ready applications located on a portable data carrier. A first communication-readiness signal is generated for a first application and sent to the reading device, the signal having a first identification number that is assigned to the first application and indicates to the reading device the communication readiness of said first application, and a second communication-readiness signal is generated and sent for a second application, the second signal having a second identification number different from the first identification number, which is assigned to said second application and indicates to the reading device the communication readiness of the second application. The identification numbers simulate for the reading device the communication readiness of a data carrier in each case. The reading device thus has the impression of communicating with applications of two separate data carriers.

Abstract: A method and device of power management for a networked radio frequency identification (“RFID”) system are disclosed. The described power management methods reduce the power consumption of battery-operated RFD) readers and REED tags. These power conservation methods increase the RFID system's hours of operation and decrease the cost by allowing the RFID readers and tags to function for a longer period of time before requiring charging or replacement of their batteries.

Abstract: A collision avoidance method for transmitting data from multiple wireless tire condition sensors on a vehicle is executed by each wireless tire condition sensor having a unique ID and multiple different wake-up times. After the sensor is operated to sense data, the method has steps of reading the ID and computing a determination value with the ID and a variable, selecting one of the wake-up times according to the determination result, and after the selected wake-up time expires, transmitting the sensed data. As the selected wake-up times of the sensors differ from one another, data collision at the receiving end arising from data transmission from the sensors can be avoided. Additionally, besides the wake-up time, a time gap between data transmitted twice consecutively from each sensor can be employed to achieve data collision avoidance.

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.