Abstract:
A system including a radio frequency identification (RFID) network and a wireless local area network (WLAN). The RFID network transfers ultra-wide band signals between a reader and a tag. In the wireless local area network (WLAN) an access point communicates with a WLAN transceiver using WLAN signals. The reader is operatively attached to either the wireless access point or the WLAN transceiver and the WLAN is a back haul network of the RFID network. Co-existence of the two networks is provided either by time division between the ultra-wide band signals and WLAN signals; and/or receiver isolation of said RFID network from said WLAN signals.
Abstract:
A method for providing security and maintenance of a group of devices using a group of tags. Each of the tags is attached to a device and includes a radio frequency transceiver for intercommunicating using ultra-wide band signals. Using the intercommunication, distance between two of the tags is determined and an alarm is triggered when the distance is greater than a previously defined threshold distance. The distance is preferably determined by measuring a round trip delay time between the transmission of a transmitted signal to the other tag and reception of a response signal in response to the transmitted signal from the other tag. The distance is preferably determined by measuring a time delay between transmitting a unicast ultra-wide band message and receiving a unicast response message. The intercommunication preferably uses ultra-wide band signals which relay information regarding completeness of the group between the tags of the group. A configuration mechanism is typically used for configuring the group. Upon completing the configuration, the configuration mechanism, e.g. reader or monitor, may be removed and the tags maintain the group and provide security by the intercommunication between the tags. The tags are preferably synchronized to transmit and receive solely during a previously determined periodic sequence of time intervals.
Abstract:
A system of radio frequency communication between Readers and Tags, the system comprising at least one tag Reader and a plurality of Tags, each tag is given a unique tag ID, deployed in a region in which at least some of the Tags are in radio communication with the tag Reader and a Media Access Control protocol such that the tag Reader is configured to send and receive radio communication to and from at least some of the plurality of Tags. The plurality of Tags are configured to send and receive radio communication to and from the tag Reader and the Media Access Control protocol is configured to control the radio communication between the tag Reader and the plurality of Tags The Media Access Control protocol includes a multi-dimensional addressing scheme allowing Readers to efficiently address tag communities ranging from small to very large in unicast, multicast and broadcast modes. The multi-dimensional addressing scheme enables division of the plurality of Tags into a number of groups for different stages of Media Access Control protocol processing, based on different portions of the tag ID. A hash function is used to transform the tag ID into a pseudo random ID5 so as to achieve better spreading of tag population and lower statistical dependency between dimensions. The MAC has an inherent flexibility in the sense that it allows readers to communicate with different versions of tags and also to optimize communication parameters to reader's capabilities, without pre-configuration of the tags. Furthermore, the MAC supports means to achieve very high access reliability, such as relay between, tags, and the ability to work with tags that alternate between active and sleep mode) including means for power savings. All of these novel features, coupled with some prior art concepts like collision resolution algorithms, result in a scalable MAC protocol for an active RFID system employing multiple access.
Abstract:
A method for synchronizing on a pulsed waveform sequence including pulsed waveforms. An impulse radio receiver is provided including a radio frequency (RF) front end (30) connected to a demodulator (31), and the demodulator is connected to a processing unit (32). Power is provided to at least a portion of an RF component such as the RF front end and/or the demodulator, during time windows sufficient for testing an hypothesis regarding timing of the pulsed waveforms. The powering is controlled by the processing unit. Preferably, testing the hypothesis includes accumulating a signal of the pulsed waveforms, correlating with the pulsed waveforms, or accumulating the correlation result of the pulsed waveforms. Preferably, others functions of the receiver are powered or enabled subsequent to the testing. Preferably, the impulse radio receiver is an ultra-wide band receiver.
Abstract:
A system of radio frequency communication between Readers and Tags where each tag is given a unique tag ID. The Tags are configured to send and receive radio communication to and from the tag Reader and the Media Access Control protocol is configured to control the radio communication between the tag Reader and the plurality of Tags. The Media Access Control protocol includes a multidimensional addressing scheme allowing Readers to efficiently address tag communities ranging from small to very large in unicast, multicast and broadcast modes.
Abstract:
A method for communicating between elements including a reader and tags of a radio frequency identification system. The method includes addressing a wide-band-message signal by including in the signal an identifier of the first tag. The addressed wide-band-message signal is transmitted by the reader. A first tag waits to receive the addressed wide-band-message signal; and upon receiving the addressed wide-band-message signal and recognizing the identifier, the first tag responds to the addressed wide-band-message signal by transmitting an addressed wide-band response signal either back to the reader or to a relaying tag. The tag relays to another element of the system by transferring at least one datum of the query from the addressed wide-band-message signal to the addressed wide-band response signal, where the elements are readers or tags. The system and method allow for many parallel wide band addressed links, and for position determination using at least two tags with known locations.
Abstract:
A method for synchronizing on a pulsed waveform sequence including pulsed waveforms. An impulse radio receiver is provided including a radio frequency (RF) front end connected to a demodulator, and the demodulator is connected to a processing unit. Power is provided to at least a portion of an RF component such as the RF front end and/or the demodulator, during time windows sufficient for testing an hypothesis regarding timing of the pulsed waveforms. The powering is controlled by the processing unit. Preferably, testing the hypothesis includes accumulating a signal of the pulsed waveforms, correlating with the pulsed waveforms, or accumulating the correlation result of the pulsed waveforms. Preferably, others functions of the receiver are powered or enabled subsequent to the testing. Preferably, the impulse radio receiver is an ultra-wide band receiver.
Abstract:
A system capable of monitoring an area and detecting a disturbance with the area. The system has a plurality of ultra-wide band radio frequency tags, each of the tags including a digital signal processing module configured to monitor changes in radio frequency multipath properties of received packets transmitted by at least one other of the tags. Changes in the radio frequency multipath properties may be caused by a disturbance indicative of an object in the vicinity of the tags. A corresponding method is also disclosed.
Abstract:
The Very Light Readers of the present invention are based on an augmented Tag circuit with a preferred embodiment including at least one VLSI chip integrating a UWB front end, digital transceiver, and possibly an internal controller; a UWB Antenna; a power supply; a controller configured to implement the Media Access Control protocol of the system; a Communication Interface subsystem for connection to the system network and a clock source. Also described is a system capable of reducing collision occurrence in a network for communicating between multiple readers and a plurality of RF Tags. Tags are configured to receive interrogation signals and transmit response signals. Readers are configured to transmit interrogation signals, receive response signals, estimate the quantity of responses received to an interrogation, determine the round trip delay time of each response and estimates whether a collision between responses has occurred. If so, the Reader transmits an additional interrogation signal. The Reader also transmits an acknowledgment packet to responding Tags so responding Tag will not answer again to that broadcast session. Other Readers in the network also receive the acknowledge packet and do not try again to reach the responding Tags, thereby lowering congestion directed toward Tags from multiple Reader transmissions.
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.