Abstract:
A passive tag including a volatile memory is provided. The passive tag includes: a sensing unit which senses or measures information about environmental surroundings of the tag; a volatile memory; a non-volatile memory; and a control unit which firstly stores resultant data sensed or measured by the sensing unit in the volatile memory and then moves the data stored in the volatile memory to the non-volatile memory according to pre-set conditions. Therefore, the life of the tag is prolonged and stability of important data can be secured.
Abstract:
Provided are an impedance matching device of a sensor node and an impedance matching method of a sensor node. The impedance matching device comprises: a variable impedance matching unit disposed between a transmission unit, which is used for modulating a received signal to a radio frequency (RF) signal and outputting the RF signal, and an antenna and including a plurality of impedance matching circuits which have different impedance values from each other; a signal intensity measuring unit which measures the intensity of an output signal that is output through the variable impedance matching unit; and a control unit which controls one of the impedance matching circuits of the variable impedance matching unit to have an impedance value that maximizes the intensity of the output signal. Accordingly, impedance between the transmission unit and the antenna of the sensor node is adjusted when the impedance varies due to the environment in which the sensor node is used, and thus the transmission efficiency of the sensor node is improved. Consequently, a limited power source of the sensor node can be used for a longer duration, the sensor node can be connected to other sensor nodes more successfully, and the communication reliability of the sensor node can be secured.
Abstract:
There is provided a matching system for preventing the loss of data between a low-power network and a non-low-power network, the matching system including: an RF communication schedule management unit, installed in the low-power network side system, for managing a schedule of an RF communication period indicative of a data transmission period of the low-power network; a heterogeneous network communication schedule management unit, disposed in the non-low-power network side system, for creating a schedule to transmit data to the low-power network side system based on the RF communication period provided by the RF communication schedule management unit; and a heterogeneous network communication unit for transmitting the data to the low-power network side system depending on the schedule created by the heterogeneous network communication schedule management unit.
Abstract:
Provided are a radio frequency identification (RFID) tag and a wake-up method thereof. The RFID tag includes: a power source that supplies a driving voltage; a continuous wave detector that receives the driving voltage from the power supply so as to detect a continuous wave in a signal received from an RFID tag reader; a command detector that selectively receives the driving voltage and detects a command in the signal; and a controller that executes the command detected by the command detector by supplying the driving voltage to the command detector if the continuous wave is detected, and stops the driving voltage from being supplied to the command detector if no command is received from the command detector for a predetermined time period.
Abstract:
Provided are an apparatus and method of optimizing a power output of a radio frequency identification reader (RFID) reader. The apparatus includes a loss measurement unit which measures an interface loss between the RFID reader and an antenna by receiving a signal output from the antenna of the RFID reader, a output power compensation amplifier which amplifies a power output to compensate for the measured interface loss, and an output fixation unit which uniformly maintains a power output of the output power compensation amplifier by storing the output compensated power value.
Abstract:
Provided is a method of managing addresses of incommunicable nodes in a ZigBee network, and more particularly, a method of managing address values of a plurality of nodes that form a ZigBee network by efficiently withdrawing address values from nodes which are incommunicable for reasons of abnormality. An address management process can be performed using two methods. According to a first method, a parent node withdraws address values of child nodes that do not transmit a hello message for a predetermined period of time. According to a second method, a parent node transmits a periodic or non-periodic request message to child nodes, and the child nodes, which receive the request message, immediately transmit a hello message to the parent node. Then, the parent node withdraws address values of child nodes that do not respond to the request message sent by the parent node more than a predetermined number of times. An address value assignment process and a process for nodes that have their address values withdrawn are also provided.
Abstract:
Provided is a method for reading a tag in a mobile Radio Frequency Identification (RFID) environment. The tag reading method effectively identifies a tag by repeatedly transmitting a tag identification request in a predetermined time to prevent collision among RFID readers, when a plurality of RFID readers access to a tag. The method for reading a tag in a mobile RFID environment, which includes the steps of: a) transmitting a tag identification request signal to a tag; b) waiting for an acknowledgement signal to be transmitted from the tag; and c) when no acknowledgement signal is transmitted from the tag, retransmitting the tag identification request signal after a predetermined delay time passes.
Abstract:
Provided is a data storing apparatus and method for Radio Frequency Identification (RFID) tags with sensors. The apparatus includes: a first storing block which includes a kill password storage and an access password storage; a second storing block which includes an Electronic Product Code (EPC) storage, a protocol control storage, and an error check storage storing a Cyclic Redundancy Checking (CRC) code for detecting a transmission error; a third storing block which includes a tag identifier storage storing a tag identifier including a manufacture model and a serial number of the tag; and a fourth storing block which includes an initial sensor data storage storing initial information of the sensor, a real-time information storage, a maximum/minimum data storage storing maximum/minimum values, a sensor data storage storing sensing data actually measured through the sensor embedded in the RFID tag.
Abstract:
Provided is a power control method for a mobile Radio Frequency Identification (RFID) reader and an RFID reader using the same. The RFID reader includes: an RFID reader transmission/reception control unit for creating a message to be transmitted to an RFID tag and transmitting RFID tag information to a terminal control unit; a reader transmitting unit for encoding and modulating the created message; a power amplifier for amplifying an output signal; a reader receiving unit for demodulating and decoding the signal and transmitting the signal to the RFID reader transmission/reception control unit; and an RFID reader power control unit for controlling power, wherein when the RFID reader transmission/reception control unit receives a command for acquiring the RFID tag information, the RFID reader power control unit applies power to the power amplifier.
Abstract:
Provided is a distributional alert system using a ubiquitous sensor network (USN). When a disaster occurs, the distributional alert system detects it in a sensor node, informs the area where the disaster occurs of danger through an actuator, such as siren, or informs a management system of the danger through a wired/wireless network. The distributional alert system includes: a first sensor node for generating sense data by sensing surroundings with a sensor therein, determining whether a disaster occurs by analyzing the sense data, and creating and transmitting emergency data based on the determination result, while forming a sensor network; and an alerting node for receiving emergency data from the first sensor node on the sensor network, and outputting disaster circumstantial information to a sensor field of the sensor network upon receipt of the emergency data.