In some implementations, a system may receive, from a motion sensor, an inactivity indication that indicates a period of inactivity within a physical environment. The system may store, in a data structure, identifiers of a plurality of RFID tags that a tag reader read during the period of inactivity. The system may receive, from the motion sensor, a motion notification that indicates a period of activity within the physical environment. The system may cause the tag reader to collect an identifier of an RFID tag in the physical environment during the period of activity. The system may determine, based on the identifier and the identifiers of the plurality of RFID tags, a movement status associated with the RFID tag during the period of activity and perform an action associated with the movement status of the RFID tag.

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; EGOTM RFID backscatter transponders, SEGOTM 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.

An RFID system comprises an array of antennas each configured to emit a plurality of beams in different directions. The beams of each pair of adjacent antennas are directed towards one another and overlap. A pair of adjacent antennas transmits simultaneously and the overlapping beams interfere to create an interference pattern. An RFID reader controls the relative phase and/or frequency of the beams to move the interference pattern to read an RFID tag within the moving pattern. As the chance of a RFID tag responding to an emitted beam generally increases with signal strength of the reader beam an area of constructive interference means that RFID tags in that region are more likely to respond to the signal. The system can cover a large proportion of the area below ceiling-mounted antennas, where cover generally means that RFID tags in that area will be successfully read.

The invention relates to local positioning and more particularly to methods of searching and registering tags in a local positioning system. A method of registering tags in a local positioning system is provided. Registering is performed in near-field mode. Tag stores identifying data of the local positioning system. Positioning unit stores identifying data of the tag. Furthermore, a method of searching a tag registered in a local positioning system is provided. Positioning units send address search packets into the space of the local positioning system. Desired tag responds with a positioning pulse. There is also provided a method of searching identifying data of a tag not registered in a local positioning system. Positioning units send broadcast search packets into the space of the local positioning system. Bisection method is used to detect identifying data of the tag. The invention can reduce power consumption by the tag and the positioning unit, and eliminate overlapping the signals received from a plurality of tags.

A stock management system includes a theoretical-stock acquiring unit configured to acquire information concerning theoretical stocks of commodities individually managed by wireless tags, a reading processing unit configured to read information received by an antenna, a comparison processing unit configured to compare the information acquired by the theoretical-stock acquiring unit and the information read by the reading processing unit to associate theoretical stock numbers and measured stock numbers of the commodities, a details presenting unit configured to show, among serial numbers of commodities, the measured stock numbers of which exceed the theoretical stock numbers thereof, at least serial numbers not included in the theoretical stocks, and a search processing unit configured to search for a wireless tag matching the serial number selected from the serial numbers shown by the details presenting unit.

Various embodiments illustrated herein disclose a method. The method includes receiving, by a first radio-frequency identification (RFID) tag in an RFID reader, a first interrogation command from another RFID reader. The method includes transmitting, by the first RFID tag in the RFID reader, a first response signal to the other RFID reader in response to the reception of the first interrogation command. The method further includes transmitting, by a processor in the RFID reader, a second interrogation command to one or more second RFID tags, where the transmission of the second interrogation command is concurrent to the reception of the first interrogation command or the transmission of the first response signal.

Response parameters for a population of RFID tags present in an inventory space are determined by (a) continuously scanning the inventory space to interrogate the population of RFID tags and receiving responses from RFID tags within the population; (b) after multiple responses have been received from a specific RFID tag, determining response times for the specific RFID tag corresponding to time periods between sequential ones of the multiple responses from the specific RFID tag, (c) calculating a maximum acceptable response time based at least in part on the response times determined in step (b); and (c) recording a response interval data set including one or more of the response times determined in step (b) and the maximum acceptable response time calculated in step (c).

A noncontact communication medium includes a coil and a processor mounted on a magnetic tape cartridge. The processor communicates with a communicatee by coupling between the coil and the communicatee by electromagnetic induction through an external magnetic field applied from the communicatee. The communicatee merges a command into the external magnetic field. The processor executes processing corresponding to the command merged into the external magnetic field. The processor changes a response time of the processor in response to the command, according to a characteristic of at least one of the magnetic tape cartridge, the noncontact communication medium, or the communicatee.

A reading system includes an evaluation value acquirer and a determining processor. The evaluation value acquirer is configured to acquire, with regard to a reading device configured to perform wireless communication with an electronic tag attached to each of one or more items by using a radio wave as a medium to read item information on each of one or more items, an evaluation value about at least one of: the number of times; a time interval; or a frequency, of reading the item information for each of at the one or more items. The determining processor is configured to determine, for each of the one or more items, whether or not each of the one or more items is an object to be read based on a change in the evaluation value over time.

Response parameters for a population of RFID tags present in an inventory space are determined by (a) continuously scanning the inventory space to interrogate the population of RFID tags in the inventory space and receiving responses from multiple RFID tags within the population, (b) after multiple responses have been received from a specific RFID tag within the population, determining response times for the specific RFID tag corresponding to time periods between sequential ones of the multiple responses from the specific RFID tag, (c) calculating a maximum acceptable response time based at least in part on the response times determined in step (b), and (d) recording a response interval data set including one or more of the response times determined in step (b) and the maximum acceptable response time calculated in step (c).