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.

Abstract: In general, embodiments of the present invention provide approaches for providing power to RFID transponders. In one embodiment, the RFID transponder is powered using a magnetic field generated by power lines. In another embodiment, the RFID transponder is powered using a field generated by a wireless network. In the case of the latter, the RFID transponder acts as a member of the wireless network. In so doing, the RFID transponder is granted user rights and controls, and can control devices that are available on the network.

Abstract: An autonomous battery-free microwave frequency communication device which includes a capacitance, at least one antenna, a microwave energy harvesting system, a microwave frequency transceiver, and a control system. The energy harvesting system is configured to harvest and store microwave energy received via the antenna onto the capacitance. The transceiver is empowered by energy stored on the capacitance, and is configured to autonomously generate a microwave frequency carrier and to autonomously transmit information using the microwave frequency carrier according to a predetermined communications protocol via the antenna. The control system is empowered by energy stored on the capacitance, and is configured to provide information for transmission. Energy may be harvested from various communication forms, such as wireless network protocols or cellular communications. The frequency band from which energy is harvested may differ from the frequency band used for communications.

Abstract: A detection unit positioned on a package includes a magnet, a first magnetic switch, a second magnetic switch, a processor, and a clock. The first magnetic switch outputs a first control signal or a second control signal according to magnetic flux density of the magnet. The second magnetic switch outputs a third control signal or a fourth control signal according to the magnetic flux density of the magnet. The first control signal is the same as the third control signal; the second control signal is the same as the fourth control signal. When the processor receives the first control signal and the third control signal at the same time, the processor reads a first real-time clock (RTC) signal from the clock. When the processor receives the second control signal and the fourth control signal at the same time, the processor reads a second RTC signal from the clock.

Abstract: Methods and devices for enabling a user to obtain item information relating to an item (10), the item having associated therewith an item identification means (12) and an RFID response means (14) arranged to provide a predetermined response on being subjected to a currently applicable trigger signal; the method comprising steps of: establishing from the item identification means (12) item identification information; using the item identification information to determine from an item information source (30) a currently applicable trigger signal for the RFID response means (14); subjecting the RFID response means (14) to the currently applicable trigger signal; receiving a predetermined response from the RFID response means (14); and using the predetermined response to obtain item information from the item information source (30); wherein the RFID response means (14) is arranged to generate a new currently applicable trigger signal and a new predetermined response associated therewith following subjecting of th

Abstract: According to one embodiment, a near field radio communication apparatus, as described in embodiments, comprises a signal receiving unit configured to convert a radio signal into an electric signal an information obtaining unit configured to obtain information from a signal output from the signal receiving unit and an operating power supplying unit configured to supply an operating power to the information obtaining unit if a voltage level of the electric signal output from the signal receiving unit varies to he equal to or higher than a preset threshold value.

Abstract: A field device for automation technology, which has a metal housing for accommodating a field device electronics. On the field device at least one opening is provided, which is closable via a lid composed at least partially of a non-metallic material, wherein an RFID chip and an RF antenna are arranged in the housing in such a manner that communication and energy exchange with an RFID reading device arranged outside of the field device can transpire, and wherein the reading device is so embodied that it provides sufficient energy to the RFID chip when the energy supply to the field device is interrupted, in order to read out via the RFID antenna the data stored on the RFID chip.

Abstract: The present invention introduces a location determining system. The location determining system includes a reader array and a location determining engine server. The reader array includes three readers, where each reader includes a plurality of reader groups that receives a tag information signal transmitted from the tag, generates a PN code generated from inside, correlation and standard deviation of the correlation, and bypasses the tag information signal, in a case a ratio of correlation and standard deviation of the correlation is greater than a predetermined critical value. The location determining engine server determines a final location value relative to the tag, using the tag information signal having a time difference of tag information signals received from the three readers forming each reader group among the tag information signals bypassed by the plurality of reader groups smaller than a predetermined marginal time difference.

Abstract: Provided is a communication apparatus having a human body contact sensing function and method. The apparatus includes: an electrode that comes in contact with the human body; a contact sensor coupled to the electrode that instructs the CPU to perform an initial operation if contact with the human body is sensed; and a data processing unit that receives a control signal from the CPU to select whether to transmit or receive data, and performs a transmitting or receiving operation according to the control signal. To reduce power consumption in a stand-by state before body contact is made when using a human body as a communication medium, a human body contact sensor is included to minimize power consumption of a micro processing unit and a transmitter/receiver circuit until contact occurs. Minimizing power consumption when in a stand-by mode by using a contact sensor with low power consumption extends stand-by time.

Abstract: A method for managing drilling rods, drilling tools, well—tubing and the like for ground drilling, particularly for exploring deposits of fossil fuels or geothermal reservoirs. An electronic data processing system stores information regarding the inventory and the present storage location of parts to be inserted into the well, such as drilling rods, drilling pipes, lining tubing, intermediate parts, drill bits, and the like, with additional information being saved in the computing system regarding the installation position and/or installation sequence of all parts inserted into the well so that the computing system can indicate to a user when and from where which part shall be fed to the well hole—supply system and/or to what location which part shall be returned to for storage when it must be removed from the well, and/or the computing system controls an automatic storage, supply, and restorage device.

Abstract: A transponder and method for operating a transponder, which has a capacitor (Cbuf) for storing power transmitted via an air interface and an arithmetic logic unit (10) that can be supplied with the stored power, in which a capacitor voltage (VC) of the capacitor (Cbuf) is compared with a first threshold (V1), in which the capacitor voltage (VC) is compared with a second threshold (V2), whereby the first threshold (V1) and the second threshold (V2) are different, in which in a first operating mode (M1), when the capacitor voltage (VC) is above the first threshold (V1), the arithmetic logic unit (10) performs a number of routines with a different priority, in which in a second operating mode (M2), when the capacitor voltage (VC) is between the first threshold (V1) and the second threshold (V2), a number of low-priority routines are stopped and a number of high-priority routines are continued.

Abstract: Disclosed herein is an electronic shelf label system. The electronic shelf label system includes a plurality of electronic tags that are installed on a product display stand and confirms the residual amount of a battery to turn-on a battery warning light when the residual amount is smaller than a reference voltage and transmits replacement request signals to inform the replacement time of the battery; and a wired/wireless communication converter that relays information between the electronic tags and a server and transmits the replacement request signals received from the electronic tags to be relayed thereby to the server. The electronic shelf label system of the present invention can intuitively and easily confirm the timing when the battery of the electronic is replaced, thereby making it possible to improve the efficiency in the working of replacing the battery.

Abstract: A mobile terminal has a contactless function module that is used to perform a contactless transaction and also used to perform battery recharging. The mobile terminal has a power source operatively connected with the contactless function module and adapted to be recharged by induced current created by electromagnetic fields detected by the contactless function module.

Abstract: A method for card-reading anti-collision with automatic frequency hopping is provided, which is used for a system in which a card reader simultaneously reads a plurality of cards in radio frequency identification technologies. The method comprises: both the card reader and the cards to be read are configured to have an automatic frequency-sweep function and a function of hopping from a current channel to another channel, and to store access addresses and transaction addresses; when the card reader is in a frequency-hopping card-seeking state, it is in an n-channel frequency-hopping working state, in which, the access address of each channel is the same, and the card reader reads the cards by means of hopping frequencies in a sequence iteratively through n channels. When the card reader detects that two or more cards collide, the card reader sends a command of random frequency hopping, making all the conflicting cards to hop to other channels randomly and to wait to access those channels.

Abstract: Objects of the invention are to provide a semiconductor device including an RFID, which can transmit and receive individual information without a check of remaining capacity of the battery and a change of the battery in accordance with deterioration over time of the battery for a driving power supply; and which maintains a favorable communication state even when electric power, as a power supply for driving, from an external radio wave or electromagnetic wave (carrier wave) is not sufficient. A battery is provided as a power supply for supplying electric power in the RFID, and electric power obtained by a power generation element is charged in the battery.

Abstract: Provided are a terminal having a radio frequency identification (RFID) function and a method of processing information of the terminal for allowing intuitive interaction between a screen manipulation and an RFID manipulation with respect to using an RFID related service. The method of processing the information of the terminal including a screen and an RFID recognition unit, includes detecting a screen area corresponding to a position of the RFID recognition unit disposed at a predetermined position of the screen; displaying an RFID icon at a position of the detected screen area; recording information in an RFID tag based on the RFID tag contacting the RFID icon, and recognizing the information from the RFID tag the RFID tag contacting the RFID icon.

Abstract: A method of providing a service at a remote terminal including receiving information broadcast by a commercial radio station in a broadcast radio channel; discriminating an identifier of an application within the received broadcast information; initiating an authentication process for authenticating broadcast information received via the broadcast channel; and in response to a positive authentication, enabling use of information received via the broadcast radio channel by the identified application.

Abstract: A method, apparatus and system for radio frequency identification provides a modulated illumination signal containing a sequence of bits configured to illuminate a radio frequency identification (RFID) tag, The illumination signal is received at the RFID tag, rectified to generate a wake signal for waking a processor which is subsequently powered by a battery. The received illumination signal is sampled and subjected to a thresholding process. Mobile telephone band interference is countered by correlating the sampled illumination signal to determine its bit sequence and then correlating the bit sequence against a predetermined key. An identification signal from the RFID tag is sent in response to a match.

Abstract: A dual mode interrogation is carried out by sending narrow band radio frequency interrogation (RFID) signal for narrow band RFID communication units, the narrow band signal comprising substantially continuous periods, and by sending a high data rate RFID interrogation signal during the substantially continuous periods of the narrow band RFID signal so that two different types of RFID communication units are interrogated substantially simultaneously.

Abstract: A reader and method for adjusting the transmission time of a continuous wave (CW), wherein the method comprises setting an initial value for a response waiting time, sending the CW to a tag after sending a command to the tag and waiting for a response from the tag, judging whether the response from the tag is received within the response waiting time. If the response from the tag is received within the response waiting time, then sending of the CW is stopped and the response waiting time is adjusted. If the response from the tag is still not received beyond the response waiting time, then sending of the CW is stopped. The time for the reader to wait for a response from the tag is far less than 20 ms. Consequently, a command failure can be found early, so as to improve the processing efficiency of an RFID system.

Abstract: RFID tags, ICs for RFID tags, and methods are provided. In some embodiments, an RFID tag includes a memory with multiple sections, and a processing block. The processing block may map one of these sections, or another of these sections, for purposes of responding to a first command from an RFID reader. As such, an RFID tag can operate according to the data stored in the section mapped at the time. In some embodiments, a tag can even transition from mapping one of the sections to mapping another of the sections. This can amount to the tag exhibiting alternative behaviors, and permits hiding data on the tag.

Abstract: Provided are a Radio Frequency IDentification (RFID) tag with a signal reception method. The RFID tag includes a demodulator that receives a read signal containing read data. The demodulator includes; a voltage generating circuit that provides a first voltage signal and a second voltage signal derived from the received read signal, an inverter that provides a data pulse signal indicative of the read data by inverting the second voltage signal using an inverting voltage defined in relation to the first voltage signal, and a buffer that recovers the read data by buffering the data pulse signal.

Abstract: A contactless device having an energy antenna configured to transmit/receive an energy signal; and a data antenna configured to transmit a data signal. Also, a method for transmitting a contactless signal including transmitting/receiving an energy signal from an energy antenna of a contactless device; and transmitting a data signal from a data antenna of the contactless device.

Abstract: A pn junction type solar cell is formed in a predetermined region on a substrate made of glass. Light emitted from a light emitting unit reaches an n-type semiconductor layer after it passed through substrate. The solar cell generates electromotive force corresponding to a quantity of the emitted light. A control circuit, a mask ROM, a transmitting circuit and an antenna are formed on an upper side of the solar cell. A surface of a semiconductor storage device is entirely covered with an insulating film to block entry of outside air. The insulating film is typically formed of physicochemically stable glass or silicon dioxide.

Abstract: An interrogator (Interrog) is additionally provided with a logic circuit (ActCommProt-ImplLCI) for implementing an active communication protocol and with a receiving second antenna (AI2) provided for an active communication. Said antenna is connected through an active receiver (AMActRecI) for receiving amplitude-modulated signals to said logic circuit (ActCommProtlmplLCI). A transmitting and receiving first antenna (AT1) in each transponder (Transp) is connected through an active receiver (AM-ActRecT) for receiving amplitude-modulated signals to a logic circuit (ActCommProt-ImplLCT) for implementing the active communication protocol, an output signal of which logic circuit is conducted through an active transmitter (AMActTransmT) for transmitting amplitude-modulated signals to a transmitting second antenna (AT2) for active communication. The transponder (Transp) is provided with a power supply circuit (SupplC).

Abstract: A security method that includes defining rules specifying permitted movements of passengers in a transportation terminal. Passengers entering the terminal may be issued a boarding pass having a Radio Frequency Identification (RFID) tag attached thereto. The location of the RFID tag may be measured and responsive to the measured location of the RFID tag, a violation of at least one of the rules by the passenger may be detected. An action with respect to the detected violation may be taken. The rules may define a region that is forbidden for access, a region in which the passengers are expected to be in motion, a region in which the passengers are expected not to be stationary for more than a given time period, etc.

Abstract: In a data carrier (1) for contactless communication with a base station (2) across an electromagnetic field (HF) generated by the base station (2), coil voltage control means (16) are arranged for controlling the unmodulated coil voltage (US) of the received signal (ES), the coil voltage control means (16) being arranged for control in response to an essentially decreasing coil voltage (US) when the field strength of the electromagnetic field (HF) increases.

Abstract: An RFID transponder is provided which includes an automatic gain control (AGC) stage for amplifying a radio frequency (RF) signal and for providing an amplified RF signal. The AGC stage has a control signal indicating an increase of the amplitude of the RF signal. A demodulator is coupled to receive the amplified RF signal for demodulating the amplified RF signal. The demodulator provides a data signal. A burst detector is coupled to receive the control signal of the AGC stage and adapted to provide a start signal in response to a change of the control signal. A wake pattern detector is coupled to receive the data signal and the start signal. The wake pattern detector is adapted to detect a predefined wake pattern in the data signal after having received the start signal and to issue a wake signal if the predefined wake pattern is detected for switching the RFID transponder from a first operating mode into a second operating mode having higher power consumption than the first operating mode.

Abstract: The present invention relates to a method for determining an optimal frame size for tag collision prevention in an Aloha-based RFID system in which frame sizes limited to a certain unit are used to identify tags, the method including the steps of using an RFID for: (a) calculating an estimated optimal frame value for the RFID reader identifying the tags; (b) calculating expected time delays per tag of a left-hand frame size and a right-hand frame size, which show the smallest differences with respect to the estimated optimal frame value, among the frame sizes; (c) comparing, the expected time delay per tag of the left-hand frame size with that of the right-hand frame size; and (d) determining a frame size which has a smaller expected time delay per tag, between the left-hand frame size and the right-hand frame size, to be an optimal frame size.

Abstract: A memory tag comprises an array of non-volatile memory, means for inductively obtaining power to enable receipt of data from and transmission of data to a reader device, a processor operable to process received data and to generate data to be transmitted; and a hash co-processor configured to apply a hash function to data applied to it. The array of non-volatile memory includes an area of write only memory. Reader devices for use with such memory tags and methods of using such memory tags are also described.

Abstract: An encrypted ID takes as its initial value a tag ID that constitutes an original ID of a wireless tag, and is encrypted using an encryption key each time an ID inquiry is received from a reader/writer. Another encrypted ID also takes the tag ID as its initial value, and is encrypted using an encryption key each time an ID inquiry is received. The wireless tag gives confidential variability to the ID by transmitting a combination of the encrypted ID and the another encrypted ID in reply. The reader/writer can obtain the original ID merely by decoding the two encrypted values until they match, and the decoding load does not increase even if the number of wireless tags that are reading targets increases.

Abstract: The wireless information and safety system for mines of the present invention enables continuously tracking and monitoring underground miners and moveable equipment in underground mines using ZigBee-enabled active RFID devices forming a wireless network among them and other static and mobile ZigBee devices placed at strategic locations. The present invention provides a wireless information and safety system for mines comprises in combination of ZigBee-compliant devices (programmable to operate as end devices, routers and coordinators by hardware specific embedded software) and wireless sensor network (WSN) software having various application modules both for underground and opencast mines. Use of the system of the present invention would help in identifying the miners entering in underground mine to keep the track of the miners and maintain computerized attendance. This would help in monitoring equipment locations and their operation to improve productivity and reduce fatal collision accident.

Abstract: Transponders are disclosed that are configurable to operate in an HDX mode and/or an FDX-B mode and that use a switchable load impedance across the transponders' resonant antenna circuit to induce amplitude and/or frequency modulation. An RF level detection circuit determines when the instantaneous activation signal strength is sufficient to support monoplex, multiplex, and diplex operation. A non-volatile memory stores identification data coded in HDX and FDX-B formats. One embodiment of the invention includes an inductive antenna including two terminals connected to tag circuitry, where the inductive antenna forms a resonant antenna circuit tuned to resonate at the frequency of the activation signal.

Abstract: Systems for identifying and categorizing distributed devices, e.g., lighting fixtures and thermostats, is disclosed. In an embodiment, a user (200) sends a low power discovery message to devices (201) using a portable programming tool (100). The devices (201) within range respond with identification information. The portable programming tool (100) organizes the responses by proximity and sends a “flash” message to the device with the closest perceived proximity. That device responds with a visual or audible signal (202), allowing the user (200) to determine whether that device is the one intended for selection. If so, the user initiates a store routine in which identification information, including category information, is stored in one or more locations, such as, the selected device (201), the portable programming tool (100), and/or a central or local controller (1100). The identification and categorization can, for example, be used to automate load shedding and to reduce energy consumption.

Abstract: In a method of operating an electronic system (1) a first device (3) of the electronic system (1) sends a message to a second device (6) of the electronic system (1). The second device (6) receives the message, generates a first value utilizing a first function based on at least parts of the history of at least parts of messages previously received at the second device (6), and stores the first value in a memory (8) of the second device (6). The first value is compared 5 with a second value generated at the first device (3), wherein the second value utilizes a second function based on at least parts of the history of at least parts of messages previously sent from the first device (3) to the second device (6). The first and second values are evaluated, and a signal is generated if the evaluating of the first and second values indicates that the history—of the messages previously received at the second device (6) differs from the 10 history of messages previously sent from the first device (3).

Abstract: A power supply control apparatus is applied to a communication apparatus that is applied to a mobile apparatus. The power supply control apparatus includes a switch, coupled between the communication apparatus and a power supply; and a signal detecting unit, for detecting a wireless signal via an electromagnetic introduction approach to correspondingly generate a detection signal. It is determined whether to provide power to the communication apparatus via the switch according to the detection signal.

Abstract: Radio frequency identification (RFID) tag assemblies and methods having an RFID semiconductor chip, a conductor and an antenna, the RFID semiconductor chip has an antenna interface mounted on a mounting surface of a mounting substrate and a predetermined operating frequency, the conductor is electrically coupled to the antenna interface of the RFID semiconductor chip, and the antenna is electrically coupled to the conductor and includes a first radiating element lying in a first plane and a second radiating element lying in a second plane that is at an angle relative to the first plane.

Abstract: The present invention relates to an RF tag reader and writer including: a communication unit which communicates with an RF tag as a target from which information is obtained and obtains the information held in the RF tag; and a communication stability determination unit which determines that stable communication with a specific RF tag is being established when the same information is obtained over a predetermined plural number of times from the RF tag communicating with the communication unit.

Abstract: A control system is provided for controlling an electronic device. The control system includes a control apparatus and a processing device. The control apparatus includes a transponder and a coupling unit. The transponder of the control apparatus may be configured to receive an activation signal and transmit a control signal to the processing device. The coupling unit may be configured to enable and disable transmission of the control signal to the processing device. The processing device may be configured to receive the control signal and communicate the control signal to an electronic device or utilize the control signal to control the electronic device.

Abstract: A process for monitoring containers including use of a severable security lock with an radio frequency identification (RFID) antenna adapted sever upon dislocation of the lock. The process utilizes an electronic identification number to ensure security lock integrity. The process includes detecting the security lock in transit by the use of mobile and fixed transmission units at regional boundaries. Updates are provided to an event log associated with the security lock.

Abstract: This invention makes possible small size, long range, reliable, low-power, low-cost RFIDs fulfilling the needs of the industry and the roadmap set for RFID, as by Walmart and the DoD. Tag energization and data communication take place by independent means. The invention employs low-power communication means, such as ultra wideband (UWB), for transfer of data between Tag and Reader, and relatively high power narrowband means to remotely energize the Tag. Said means of powering and communication mechanisms, further, are independent of the underlying process, or technology, of implementation of the Microchip on the Tag, as well as from the transceiver technology aboard the Reader. As such, they provide an ideal method and system by which to power and communicate with RFIDs, through cycles of evolution and changes in physical implementation technology.

Abstract: A passive wireless system for monitoring a protected area. The passive wireless system comprises at least one passive sensor for sensing an event, a reader for receiving signals from the at least one passive sensor, a plurality of exciters disposed within the protected area for transmitting a radio frequency pulse at a variable time interval to the at least one passive sensor, and a controller for controlling each of the plurality of exciters to transmit the radio frequency pulse at the variable time interval. The radio frequency pulse powers the passive sensors.

Abstract: An application specific integrated circuit chip includes capacitors and antennas. The antennas receive energy from an outside source, and charge capacitors on the chip in order to provide power to the chip itself. The chip in turn communicates by antenna to outside receivers for the purposes of identification of the chip and hence a bag or article to which it is attached. The chip is attached to its article by means of glue which is in turn applied by an applicator which shoots the chip and the glue against the article.

Abstract: Systems and methods convey information from a controller to at least one slave unit using a single wire referenced to an alternating current (AC) power supply. A control signal has a high voltage and a low voltage. The high voltage is greater than a voltage midpoint of the AC power supply and the low voltage is less than the voltage midpoint. The control signal is conveyed through the single wire to each of the at least one slave unit. At each slave unit, a comparison voltage, representative of the voltage midpoint, is generated by dividing substantially midway the potentials between the power lines of the AC power supply and the control signal is compared to the comparison voltage to determine low and high states of the control signal; the low and high states represent the information.

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: An apparatus includes an energy store for supplying an actuator, an antenna device for receiving, by contactless communication, energy for charging the energy store and one or more control signals comprising a command for triggering the actuator, and a control unit for controlling the supply of energy to the actuator on the basis of the control signals. After the triggering command has been received, the state of charge of the energy store is determined. When this state is less than a state of charge threshold value that is sufficient for triggering the actuator, a response signal to continue contactless communication is transmitted to the transmitting device via the antenna device. When this state is greater than or equal to the state of charge threshold value, the control unit controls the supply of energy from the energy store to the actuator so that it is possible to trigger the actuator.

Abstract: An apparatus comprises a shipping box containing an access area and a configurable electronic device. The configurable electronic device comprises an electrical connector accessible via the access area on the shipping box. The configurable electronic device also comprises a management module that receives electrical power via the electrical connector when a single external cable is mated to the electrical connector through the access area. The management module receives configuration information via the single external cable while the configurable electronic device is still in the shipping box and without having host logic in the configurable electronic device being powered up. In other embodiments, multiple configurable electronic devices can be reconfigured simultaneously and wirelessly by an external programming unit.

Abstract: An adaptive wakeup methodology may be implemented to allow an radio frequency identification (RFID) tag to stay synchronized with periodic radio frequency (RF) interrogator polling signal while at the same time optimizing power consumption. A receiver (or transceiver) component of a RFID tag may only be operated when an interrogator polling signal is expected, and in a manner that reduces the amount of time between when the receiver or transceiver is turned on and when the interrogator polling signal is received (i.e., the receive buffer time). At other times, the RFID tag may be placed in a low power consumption sleep state. The amount of time that the RFID tag spends in such a low power sleep state before waking and receiving the following interrogator polling signal may also be optionally adjusted, e.g., to fit characteristics of a given situation and/or to re-synchronize a given aRFID tag with first band transmissions from an aRFIDI.

Abstract: A technique of message-passing using shared memory of an RF tag involves storing a message in the shared memory while a security processor of the RF tag is in a sleep mode, the security processor being constructed and arranged to access the shared memory when the security processor is in a wakened mode. The technique further involves transitioning the security processor from the sleep mode to the wakened mode, and processing the message from the shared memory using the security processor after the security processor has transitioned from the sleep mode to the wakened mode. If the security processor is awakened only as needed (rather than remain in the wakened mode), lifetime of a battery which powers the security processor can be maximized.