3735results about "Memory record carrier reading problems" patented technology

System for tracking mobile tags. Cell controllers with multiple antenna modules generate a carrier signal which is received by the tags. Tags shift the frequency of the carrier signal, modulate an identification code onto it, and transmit the resulting tag signal at randomized intervals. The antennas receive and process the response, and determine the presence of the tags by proximity and triangulation. The recursive-least squares (RLS) technique is used in filtering received signals. Distance of a tag from an antenna is calculated by measuring the round trip signal time. The cell controllers send data from the antenna to a host computer. The host computer collects the data and resolves them into positional estimates. Data are archived in a data warehouse, such as an SQL Server. Also disclosed is an article tracking system that supports both active and passive tags with a cell controller able to read both passive and active tag signals.

A system and method of scheduling RFID tag interrogations by a plurality of RFID readers so as to mitigate the effects of interference within an RFID environment in which the readers are deployed, and to enhance the efficiency and reliability of the overall RFID system. The system includes a plurality of RFID receivers for receiving RFID tag data, a plurality of RFID tag interrogators for transmitting RF interrogation signals for interrogating RFID tags, and a controller for providing to at least one interrogator, at least one receiver, and at least one tag, a parameter associated with operational characteristics of the interrogator, the receiver, and the tag, respectively. The interrogator, the receiver, and the tag are operative, in response to receipt of the respective parameter, to modify its operational characteristics in accordance with the respective parameter, thereby avoiding interference at the receivers and the tags.

An inventory control system and method that tracks inventories of items with RFID tags, includes a reader unit and an intelligent station that tracks RFID tags to determine item information of items to be inventoried. The reader unit transmits and receives RF signals. The intelligent station includes a first RF antenna connected to the reader unit by a first transmission cable through a first switch, and one or more additional RF antennae connected to the reader unit by the same first transmission cable through additional switches. An inventory control processing unit receives item information from the intelligent stations to update inventory information regarding the items to be inventoried.

In one embodiment, the present invention is a method and apparatus for wireless network security. In one embodiment, a method for securing a wireless computing network includes receiving a communication from an unidentified transmitter, identifying the transmitter in accordance with a fingerprint generated from one or more radio frequency signal characteristics extracted from the communication, and taking action in response to an identity of the transmitter.

Apparatus for remote interaction with an object of interest includes a remote station for obtaining information from the object of interest, a base station for transmitting energy in space to and communicating with the remote station and the remote station having a conversion device for energizing the remote station responsive to receipt of the transmitted energy. The energy may be of any suitable type including RF power, light, acoustic, magnetic energy or other form of space transmitted or "radiant" energy. The remote station does not have to contain a source of stored energy or a wired connection to a source of energy. The remote station receives the energy transmission and data transmission from the base station and transmits data to the base station. Microprocessor controllers may be provided for the base station and the remote station. The remote station may receive information from sensors and through one or more transponders sequentially communicate information to the base station. An associated method is provided.

An RFID system includes a hybrid backscatter-based RFID tag protocol-compatible with existing 802.11x/Bluetooth Standards as well as RFID standards. The tag is linked to a multi-protocol Interrogator via a generated RF Continuous Wave (CW) field. The tag includes an antenna coupled to an RFID and a Bluetooth/802.11x transceiver section. A Protocol Processor services RFID and transceiver sections and is coupled to the antenna via a backscatter switch. The Interrogator can switch the tag to an RFID backscatter radiation mode where the processor switches the antenna impedance to reflect the CW signal. For transceiver operation the processor switches antenna impedance in synchronization with a frame organized bit stream. For reception, the RFID section utilizes demodulation techniques, typically Amplitude Shift Keying (ASK), and provides a wake up mode within a predetermined distance of the Interrogator. The transceiver may operate in a backscatter or regular mode as directed by an Access Point.

In embodiments of the present invention improved capabilities are described for a passive radio frequency identification (RFID) tag, where the passive RFID tag contains an RF network node and communication facility. The RF network node includes an RF and analog block for receiving and transmitting an RFID reader signal, a data processing and controller block for digital information processing, a memory store, and a power management block for managing power requirements of the RF network node. The communication facility communicates at least in part with an external display facility. The distribution of power to the RF network node functional blocks is controlled using the power management block to select between an extended operational time and an increase in available functionality.

A resonant antenna circuit for a radio frequency identification (RFID) reader generates an electrical signal for activating a passive identification tag. The identification tag in turn generates a coded electrical signal that is detected by the reader. The electrical characteristics of the resonant circuit are dynamically altered so that the antenna performs more optimally as a transmitter and receiver for different types of transponders. The resonant circuit uses only passive components and the instantaneous resonant frequency tuning point is determined by the state of the activation signal transmitter.

A system and method for monitoring and characterizing various sources of RF interference within an RFID environment, and for adjusting the operational characteristics of an array of RFID readers within the system based on these interference characterizations. The system examines the received transmissions from readers in the network by controlling a calibration cycle or while they are operating as interrogators to determine interference parameters, and to verify the operation of the readers in the array. The system also examines outside sources of interference, and signal dependent interference. The interference characterization can also be estimated from a combination of calculations and co-monitoring.

A radio device such as a wireless tag reader communicates with multiple types of wireless identification tags in a monitored region. The radio device includes a network interface to receive messages transmitted over a network. In response to receiving a message indicating to reconfigure the radio device to support an additional wireless tag protocol, the radio is reconfigured to support communications with a corresponding new type of wireless identification tag in a monitored region. Based on this technique of reconfiguring the radio device via network messages, the radio device optionally supports additional, new or latest versions of wireless tag protocols without having to physically reprogram or replace the radio device.

The present invention features an RFID smart shelf reader capable of working with a wide range of antenna types and numbers. The smart shelf reader readily accommodates and accurately reads a diverse range of package shapes, sizes, and contents. Multiple tags in close proximity to one another are accurately read by the smart shelf reader. The reader includes features for optimizing its own interface by periodically recalibrating itself to the current antenna load characteristics caused by varying external conditions, primarily in the type, number, and position of merchandise items on the shelf proximate at least one of the antennas. An external I/O interface is provided for communication with a remote controller.

Techniques are disclosed for providing enhanced privacy in an RFID system comprising a plurality of RFID devices, each having an associated identifier, and at least one reader which communicates with one or more of the devices. A blocker device is operative to receive a communication directed from the reader to one or more of the RFID devices, and to generate, possibly based on information in the received communication, an output transmittable to the reader. The output simulates one or more responses from at least one of the RFID devices in a manner which prevents the reader from determining at least a portion of the identifier of at least one of the RFID devices. The blocker device may itself comprise one of the RFID devices. In an illustrative embodiment, the output generated by the blocker device interferes with the normal operation of a singulation algorithm implemented by the reader.

A data transmission system includes a reader transceiver and one or more tag transceivers. The reader transmits an activation signal to a tag. The tag selectively transmits a response signal to the reader at a specific time determined by a detected level of communications channel activity. The detector operates in a low-power standby state until the time it receives the activation signal, and then operates in an active state. The invention further incorporates a technique to maintain an extremely low power state to the tag during quiescent mode while retaining full sensitivity to reader activation signals. The reader transceivers are of a modular architecture with each module operating independently, yet in concert with the others. The modules are interconnected in a media independent method and can interact remotely with other modules.

An energy harvesting circuit has an active automatic tuning circuit to search for broadcast frequencies in a band of interest and selecting only those broadcast signals received with sufficient RF strength to be used in energy harvesting. This circuit would provide power storage devices with a circuit that has a means to select the ambient RF that can maximize or enhance the performance of an RFID circuit by increasing the amount of energy for harvesting. This automatic tuning would enable a power storage devices charger circuit to move from location to location without manual tuning of the circuit and increase the effective range of an RFID circuit.