Abstract: A received signal strength indicator is provided. The received signal strength indicator includes a plurality of differential amplifiers forming an amplifier chain for amplifying differential signals and a plurality of rectifiers for rectifying signals output from the plurality of differential amplifiers and the differential signals, and a low pass filter for combining the signals rectified by the plurality of rectifiers to output received signal strength. Each rectifier includes a class AB voltage-current converter for converting a differential voltage into a current, and two triode transistors.

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 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: Provided are an apparatus and method for charging an internal battery in a wireless sensor network. A method for a slave sensor node to charge an internal battery in a sensor network includes estimating an hourly chargeable electric energy rate in a scan phase with a master sensor node, transmitting the estimated hourly chargeable electric energy rate using an association request message requesting association with the master sensor node after recognizing the master sensor node, requesting charging from the master sensor node and performing wireless charging when a power level of an internal battery requires charging, reporting the power level of the internal battery varied by the wireless charging to the master sensor node by predetermined time periods during the wireless charging, and stopping the wireless charging when the power level reported to the master sensor node reaches a predetermined power level.

Abstract: An IP packet forwarding server forwards an IP data packet between a user terminal and a machine-type communications (MTC) device allocated with a private internet protocol (IP). Such an IP packet forwarding server allocates a call identifier for connection between the user terminal and the MTC device, sets up a packet call to the MTC device and the user terminal using the call identifier, obtains packet forwarding information while setting up the packet call to the MTC device and the user terminal, and forwards an IP data packet between the MTC device and the user terminal using the packet forwarding information.

Abstract: A method and apparatus using a synchronous sensor network medium access control (MAC) protocol, such as a ZigBee or IEEE 802.15.4 low-rate wireless personal area network (WPAN), is disclosed. A method and apparatus for constructing a ubiquitous sensor network (USN) of which a life is increased by using power beacons and reducing the number of unnecessary control packets (beacon packets), thereby reducing an initialization time between nodes and preventing beacon collision, is also disclosed. A beacon packet channel having a large output power and a data channel of which a transmission range is restricted by reducing an output power to be less than that of the beacon packet channel, may be simultaneously used.

Abstract: In a wireless sensor network system including at least one sensor network, when a network message received from a sensor node of a sensor network corresponds to a predetermined service, the wireless sensor network system forms a wireless local area network (WLAN) overlay network which is based on a WLAN system within a service area at which the sensor node is located. Data corresponding to the predetermined service is transmitted and received through the WLAN overlay network.

Abstract: A complex communication apparatus transmits/receives voice information with other complex communication apparatuses through a set voice channel. The complex communication apparatus broadcasts a signaling packet expressing a destination identifier representing a desired communication type of one-to-one communication, group communication, and broadcast communication with other complex communication apparatuses and information of the set voice channel and performs voice communication with a complex communication apparatus corresponding to a destination identifier of other complex communication apparatuses, having received the signaling packet.

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: 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 method of transmitting/receiving data in a sensor node for reducing overhearing of sensor nodes, and a sensor network which implements the method. A sender node having transmission data from among a plurality of nodes which perform a low power listening (LPL) operation in an asynchronous manner at predetermined time intervals, generates a long preamble including short preambles, each having information including a destination address of the transmission data, a remainder of the long preamble, and a length of the transmission data, and sequentially transmits the second preamble and the transmission data. A receiver node from among the plurality of nodes determines whether a valid signal is sensed during an active state in the LPL operation. If it is determined that the valid signal is sensed, the receiver node receives the short preamble transmitted from the sender node.

Abstract: 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).

Abstract: Provided is a method for managing dormant nodes in a wireless sensor network. The method includes the steps of: a) acquiring and storing information on distance and location of sensor nodes registered in a corresponding cluster among at least one cluster managed by a managing node; b) selecting a dormant object node among the sensor nodes by the managing node; c) transmitting dormant information that the dormant object node should go into a dormant state for a predetermined period through a beacon message to the dormant object node and creating a dormant node management table; and d) updating a dormant time of the dormant node management table every beacon cycle by the managing node according to setup of a dormant time central managing function and notifying dormancy expiration to the corresponding dormant node.

Abstract: Provided are an apparatus and method for charging an internal battery in a wireless sensor network. A method for a slave sensor node to charge an internal battery in a sensor network includes estimating an hourly chargeable electric energy rate in a scan phase with a master sensor node, transmitting the estimated hourly chargeable electric energy rate using an association request message requesting association with the master sensor node after recognizing the master sensor node, requesting charging from the master sensor node and performing wireless charging when a power level of an internal battery requires charging, reporting the power level of the internal battery varied by the wireless charging to the master sensor node by predetermined time periods during the wireless charging, and stopping the wireless charging when the power level reported to the master sensor node reaches a predetermined power level.

Abstract: Provided is a method for buffering a receive packet in a sensor node including a radio frequency (RF) transceiver, a media access control (MAC) hardware block and a micro controller unit (MCU).

Abstract: Provided is an apparatus and method for controlling multi-channel access in USN-based MAC. The multi-channel access control apparatus includes a channel scanner, a control channel preoccupier, and an available channel exchanger. The channel scanner scans at least one or more available channels among the N data channels in a Tx sensor node. The control channel preoccupier preoccupies, in the Tx sensor node, the control channel through control channel sensing and back-off and broadcasts a preamble on the control channel periodically. The available channel exchanger detects, in an Rx sensor node, the available channels available to the Tx sensor node on the basis of the received preamble, selects a channel available to the Rx sensor node among the detected available channels, and transmits information about the selected channel to the Tx sensor node.

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.

Abstract: Disclosed is an asynchronous MAC based sensor node using a Wake-Up RF. The sensor node includes a main transceiver to transmit/receive data, a Wake-Up transceiver to transit a state of the sensor node; and a micro-control unit, which transmits a Wake-Up frame to at least one receiving node through the Wake-Up transceiver such that the receiving node is activated from an inactive state into an active state and transmits data to the activated receiving node through the main transceiver.

Abstract: Provided are a method and apparatus for using a synchronous sensor network medium access control (MAC) protocol such as a ZigBee or IEEE 802.15.4 low-rate wireless personal area network (WPAN). Also provided are a method and apparatus for constructing a ubiquitous sensor network (USN) of which a life is increased by using power beacons and reducing the number of unnecessary control packets (beacon packets), thereby reducing an initialization time between nodes and preventing beacon collision. According to the present invention, a beacon packet channel having a large output power and a data channel of which a transmission range is restricted by reducing an output power to be less than that of the beacon packet channel, may be simultaneously used.

Abstract: Provided are a transmitting apparatus, a transmitting method, a receiving apparatus, a receiving method and a channel status information updating method of a sensor node based on multiple channels.