A tag measurement environment evaluation device includes a processor and a memory storing a program. The program is configured to, when executed by the processor, cause the processor to determine a moving tag evaluation value of each of a plurality of wireless tags based on a radio wave transmitted from each of the wireless tags and received by a tag reader configured to communicate with each of the wireless tags, and determine whether a measurement environment is suitable for a moving tag detection based on the moving tag evaluation values.

One embodiment of the present invention relates to a method for a reader to transmit and receive a signal to and from a tag, the method comprising: a step in which a first reader transmits a first signal to a tag; and a step in which the first reader receives the first signal reflected on the tag. The timing for the first reader to transmit the first signal is determined by using an offset value based on an ID related to the first reader.

Various embodiments of the teachings herein include a tag identification method. Some embodiments comprise: receiving a tag signal in a time slot; and determining whether a tag collision occurs in the time slot. If a tag collision occurs, the method includes selecting one tag signal from a plurality of received tag signals to identify a corresponding tag and recording a quantity of unidentified tags in the time slot.

Methods, systems and devices for providing an interrogation signal from a handheld deactivation device for identifying a security tag. Identifying the security tag includes initiating an interrogation signal, wherein the interrogation signal includes plurality of transmission bursts and a plurality of random time periods to wait between transmission bursts such that a unique time period elapses between each of the plurality of transmission bursts. The interrogation signal is then transmitted by transmitting each of the plurality of transmission bursts for a portion of a duty cycle and interrupting transmission between each of the plurality of transmission bursts for one of the plurality of random time periods such that a unique and random time period elapses between each of the plurality of transmission bursts. The period transmission of the interrogation signal provides for improved battery life of a handheld scanning and deactivation device.

The present disclosure provides systems and methods implemented using physical property sensors. A physical/property sensor includes a sensor coil configured to wirelessly communicate with an external interrogator, an analog front end communicatively coupled to the sensor coil, a microcontroller communicatively coupled to the analog front end, and a physical property sensing element, wherein the microcontroller is configured to generate a digitally modulated electrical signal based on signals generated by the physical property sensing element, and wherein the analog front end is configured to forward the digitally modulated electrical signal to the sensor coil for transmission to the external interrogator.

According to one embodiment, a wireless tag communication apparatus includes a plurality of communication units configured to communicate with a wireless tag. The communication units are disposed such that communicable ranges of the communication units overlap each other. A control unit controls each of the plurality of communication units to alternate between a communication state and a pause state. When the wireless tag is positioned within communication ranges of both first and second communication units of the plurality of communication units, the control unit controls the first communication unit to be in the communication state and the second communication unit to be in the pause state.

A method for locating a wireless tag includes transmitting a first set of signals by the wireless tag in a first time period, receiving the first set of signals by a base station of at least one base station during the first time period, generating a first set of distance values according to the first set of signals received by the base station, generating a first subset of distance values by removing at least a maximum distance value and a minimum distance value from the first set of distance values, obtaining a first distance between the wireless tag and the base station by averaging the first subset of distance values, and identifying a first location of the wireless tag according to at least one first distance.

An RFID reader includes a transmitter, a receiver, and an evaluator. The receiver receives signals from RFID tags within a given number of slots of a time frame with a given frame size and provides a number of successful slots and a number of collided slots. The evaluator sets a modified frame size based on an estimated number of RFID tags which is determined based on the frame size, the number of successful slots, and the number of collided slots. The invention also refers to a corresponding method.

A method for locating a wireless tag includes transmitting a first set of signals by the wireless tag in a first time period, receiving the first set of signals by a base station of at least one base station during the first time period, generating a first set of distance values according to the first set of signals received by the base station, generating a first subset of distance values by removing at least a maximum distance value and a minimum distance value from the first set of distance values, obtaining a first distance between the wireless tag and the base station by averaging the first subset of distance values, and identifying a first location of the wireless tag according to at least one first distance.

Provided is a method of preventing collision between a plurality of RFID tags by an RFID reader. An anti-collision method by a tag reader apparatus in an RFID system including a plurality of RFID tags, includes changing a length of a collision recovery slot in the collision recovery slot which successfully identifies a plurality of tags even though at least two tags simultaneously replied in one slot to cause collision so that data transmission of at least one identified tag is achieved.