Abstract: A tag apparatus communicating with a reader acquires a command from a signal that is received from the reader, converts data corresponding to the acquired command to a plurality of multi-level parallel data, and generates a plurality of tag load impedances based on bias voltages that are mapped to correspond to each level of the plurality of parallel data. Therefore, a signal having electrical energy corresponding to the plurality of tag load impedances is transmitted to the reader.

Abstract: A time synchronization method in a wireless sensor network, a low power routing method using a reservation scheme, and an apparatus for performing the method are provided. The time synchronization method in the wireless sensor network may include: receiving a first synchronization request command packet from a parent node that manages time synchronization for a predetermined synchronization region; receiving, from the parent node, a second synchronization request command packet that has a transmission timestamp value of the first synchronization request command packet; and performing time synchronization for a child node based on a reception time of the first synchronization request command packet, a reception time of the second synchronization request command packet, and the transmission timestamp value of the first synchronization request command packet.

Abstract: A wireless communication method using a control channel between wireless communication devices including: exchanging profile information between a node and intermediate relay nodes therearound so as to allow the node to transmit/receive data to/from a destination node; determining, by the node, a first intermediate relay node using the profile information and determining a wireless communication mode with the first intermediate relay node; and transmitting/receiving data between the node and the first intermediate relay node by the determined wireless communication mode is provided.

Abstract: Provided are a wake-up apparatus and wake-up method for a low power sensor node, and more particularly, to a wake-up apparatus and wake-up method for a low power sensor node, which can extend the battery life of the sensor node and minimize the amount of power consumed by an entire sensor network power by minimizing unnecessary power consumption of the sensor node. The wake-up apparatus for a low power sensor node includes: a wake-up signal detector receiving and detecting a wake-up signal of a sensor node; a wake-up radio frequency (RF) circuit unit filtering and amplifying the wake-up signal; and a wake-up baseband transducer detecting a wake-up address from the wake-up signal and comparing and verifying the wake-up address with a wake-up address that is provided from a server managing the sensor node.

Abstract: To track the location of a terminal in an indoor space by using a pseudo GPS signal transmitter, a GPS signal sent from an artificial satellite is received, and a clock signal of the artificial satellite is extracted from the received GPS signal to perform synchronization with the artificial satellite. Once synchronization with the artificial satellite is performed, a pseudo GPS signal is generated, and the transmission time of the pseudo GPS signal is controlled. The GPS signal is sent to the terminal located in the indoor space by a plurality of transmitting antennas based on the controlled transmission time, thereby enabling the terminal located in the indoor space to track its location.

Abstract: Provided is a high frequency (HF)/ultra high frequency (UHF) radio frequency identification (RFID) multiband tag antenna that may form a circular HF tag pattern on one surface of a single printed circuit board (PCB) and may form a UHF tag pattern having a diameter greater than a diameter of the HF tag pattern on another surface of the single PCB.

Abstract: A method and apparatus for encoding a constant amplitude that is applied to a code division multiplexing communication system are provided. By dividing a data bit into a block unit, the receiving side can easily determine an error, and by reducing power consumption in outdoor wide area communication using a bit string of a small length in a basic unit of an input frame, efficiency can be improved, and thus a physical layer of a ubiquitous sensor network can be optimized.

Abstract: A method and apparatus for allocating a management resource of a channel of a node that is included in a wireless personal area network (WPAN) are provided. A resource of a channel performs communication with a specific node using a multi-superframe including a plurality of superframes, limits a position area of a time slot including a channel that is allocated to communication with a specific node to a predetermined superframe of the plurality of superframes, gives a logical connection ID to the time slot, and is allocated by matching the logical connection ID and a management resource that manages the time slot.

Abstract: Provided is an apparatus and method for tracking a position of a fixed node. The position tracking apparatus of the fixed node may include: an interface to extract, from a database in response to the occurrence of an event about tracking the position of the fixed node, packet data corresponding to a mobile node associated with the event; and a processor to analyze a received signal strength of the packet data and a position of the mobile node from the packet data, and to track the position of the fixed node using the analysis result.

Abstract: Disclosed is a wireless communication system. The wireless communication system includes an embedded-type antenna embedded in a base, and a wireless communication unit including a communication unit that is connected to the embedded-type antenna and exchanges information with an external device, and a housing that is arranged to surround the communication unit, wherein at least one of the communication unit and the housing performs transmission and reception of electric waves as a substitute of the embedded-type antenna.

Abstract: A constant amplitude decoding apparatus and method for multiplexed direct-sequence spread spectrum communication system are provided. The constant amplitude decoding apparatus includes: a despreading and demultiplexing module receiving a data stream of a constant amplitude and despreading and demultiplexing the received data stream to restore it to a 2D signal; a decoding module first performing a vertical decoding on the 2D signal and then performing horizontal decoding thereon; a control module determining whether to repeatedly perform vertical decoding and horizontal decoding; and a bit stream information output module outputting the decoding results from the decoding module as a bit stream.

Abstract: Provided is a tag integrated circuit (IC) module apparatus and a method of fabricating tag IC module apparatus. The tag IC module apparatus may include an n-turn loop coil, n denoting a natural number, connected in series with a tag IC, and a printed circuit board (PCB) disposed below the tag IC and patterned with the n-turn loop coil.

Abstract: A tag of an apparatus for simultaneously identifying massive tags according to the present invention may include an analog circuit unit to communicate with a reader through an analog signal and to receive energy via magnetic coupling with the reader. Further, the tag may include a digital circuit unit to be supplied with power from the analog circuit unit. The digital circuit unit may support a sleep mode for the tag to stand by in a low power state after transmitting an identifier (ID) to the reader and a wait mode for controlling random access to the reader.

Abstract: A loop antenna includes first and second loops that are formed with respective conductive wires. In this case, the second loop is formed with a double loop having current paths of opposite directions.

Abstract: Provided is a Radio Frequency Identification (RFID) reader that can minimize collision among RFID readers in an environment where there are a plurality of RFID readers within a limited operating environment by making each RFID reader select a channel at different delay time based on a random value, and a method for controlling operation of the RFID reader. The RFID reader includes a random value generating unit; a reader control unit for adaptively deciding a counter value for generating the random value; an anti-collision unit for preventing collision among a plurality of tags; a reader transmitting unit for generating a reader command message determined by the anti-collision unit, encoding the reader command message, and modulating the reader command message; a reader receiving unit for demodulating and decoding a tag signal; and a channel operation control unit for selecting a channel to be used for the communication with the tag.

Abstract: A virtual sensor generation apparatus of a sensor network sets a communication connection to a sensor node at a periphery of a smart device, generates a logical sensor corresponding to a physical sensor that is connected to the sensor node, generates a virtual sensor with the logical sensor, and provides an application service to a user using the virtual sensor.

Abstract: Disclosed are a radio frequency identification (RFID) security apparatus and a method thereof. According to the RFID security method, a secure tag reader performs determining an AES key using security information received from a secure tag and generating an output key using the determined AES key, decrypting AES data received from the secure tag using the output key, and encrypting data to be transmitted to the secure tag using the output key and transmitting the data, and a secure tag performs generating an output key using an AES key and security information, and transmitting the security information to a secure tag reader, encrypting data to be transmitted to the secure tag reader using the output key, and transmitting the encrypted data to the secure tag reader, and decrypting data received from the secure tag reader using the output key.

Abstract: When RF signals of a plurality of RFID tags installed in a plurality of casino chips are received through a plurality of reader antennas, a system for managing casino chips using RFID (radio frequency identification) estimates an angle of arrival of the received RF signals, calculates the number and positions of the plurality of casino chips by using the received RF signals and each estimated angle of arrival, and manages the plurality of casino chips by using the number and the positions of the plurality of casino chips.

Abstract: Provided are a node device of a beacon-enabled Wireless Personal Area Network (WPAN) managing a channel resource and a method thereof. The node device may generate a pseudo random binary sequence (PRBS) and generate a hopping sequence based on a number of available channels using the PRBS, thereby generating a hopping sequence having a characteristic of pseudo randomness and selecting a channel to be hopped, using the hopping sequence.

Abstract: In integrated circuit chips that are used for RFID, a method of calibrating an operation frequency that is generated in an operation frequency generator and a semiconductor wafer including a calibration circuit are provided. The method of calibrating an operation frequency of integrated circuit chips includes: supplying DC power to the integrated circuit chips; selecting an integrated circuit chip to perform calibration of an operation frequency; receiving an operation frequency that is generated in the selected integrated circuit chip; generating a frequency calibration value by comparing the operation frequency with a calibration target frequency; transmitting a control signal including the frequency calibration value to the integrated circuit chip; and releasing a selection of the integrated circuit chip in which calibration of the operation frequency is complete.