摘要:
Provided are an antenna apparatus for linearly polarized diversity antennas in a radio frequency identification (RFID) reader, and a method of controlling the antenna apparatus. The antenna apparatus includes: a plurality of linearly polarized diversity antennas disposed to have different directions to one another; a switching unit connecting the linearly polarized diversity antennas to the RFID reader; and a controller controlling the switching unit to selectively activate the linearly polarized diversity antennas.
摘要:
A control apparatus for use in wireless communications includes an antenna unit having antennas, the number of the antennas being equal to a maximum allowable number of connections in a specific frequency band; and a controller for receiving a connection request signal from each terminal attempting to connect to the control apparatus via the antenna unit, and transmitting and receiving a data signal to and from each terminal connected to the control apparatus by using a multiple-input-multiple-output scheme. The controller transmit and receive the data signal to and from each terminal connected to the control apparatus by obtaining a signal value of each antenna based on a predicted channel matrix and the number and types of terminals connected to the control apparatus via the antenna and separating the data signal for each terminal from the signal value according to the multiple-input-multiple-output scheme.
摘要:
Provided are a method and an apparatus for avoiding a collision between each of radio frequency identification (RFID) readers. The method and the apparatus divide the RFID readers into first RFID readers and second RFID readers according to a maximum output level, and set first frequency channels for the first RFID readers and second frequency channels for the second RFID readers, set frequency channel disposition information for each of the first RFID readers, generate a channel holding signal in each of the first frequency channels, and if a frequency channel usage request or a frequency channel return request is received from one of the first RFID readers, stop generating or generate the channel holding signal in a frequency channel related to the frequency channel usage or return request. In this manner, the collision between each of the RFID readers is avoided by preventing the second RFID readers from using the first frequency channels for the first RFID readers. Also, the method and the apparatus can efficiently manage frequency channels by controlling a ratio of the number of the first frequency channels to be used by the first RFID readers and the number of the second frequency channels to be used by the second RFID readers, according to usage frequency.
摘要:
Provided is a general-purpose interface port that may interface with a sensor board including multiple types of sensor device drivers and download a sensor device driver from the sensor board, and a sensor node that may recognize a type of sensor included in the sensor board using the downloaded sensor device driver, the sensor node including a micro control unit that may process sensing data received from the sensor board, thereby providing a plug and play function between a micro control unit of a sensor node and a sensing unit including a sensor board in a Ubiquitous Sensor Network (USN) or a Wireless Sensor Network (WSN).
摘要:
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.
摘要:
An antenna providing a plurality of radiation patterns by adjusting a vertical beamwidth and a construction method for the antenna are provided. The antenna may include an integrated circuit (IC) element unit to provide a plurality of radiation patterns, and a switching unit to selectively provide any one of the plurality of radiation patterns based on control data.
摘要:
Provided is a method for communication with between readers having dual sensitivity modes for avoiding conflict between readers arising from interference each other when simultaneously used in a limited space. The method for communication between a tag and a reader using dual sensitivity modes for avoiding conflict between the reader and the tag includes: initializing the reader to a normal sensitivity mode; temporarily selecting a frequency channel by the reader; checking whether or not a different reader uses the selected frequency channel; repeatedly selecting another frequency channel if the other readers occupy the selected frequency channel; switching to a reduced sensitivity mode if the other readers do not occupy the selected frequency channel; and communicating with the tag by the reader in the reduced sensitivity mode.
摘要:
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.
摘要:
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.
摘要:
Disclosed is a method of preventing overlap of multiple PANs in a ZigBee network. According to the method of preventing overlap of multiple personal area networks (PANs) in the ZigBee network, a first node included in a first PAN of the ZigBee network verifies whether overlap of the multiple PANs occurs by verifying packets received from neighbor nodes, identifies beacon information of a neighbor node that causes the overlap of the multiple PANs by gradually adjusting radio frequency (RF) transmission wave, and adjusts a communication range based on the beacon information.