Patent application number | Description | Published |
20090058612 | METHOD AND APPARATUS FOR AVOIDING COLLISION BETWEEN EACH OF RADIO FREQUENCY IDENTIFICATION READERS - 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. | 03-05-2009 |
20090058613 | METHOD AND APPARATUS FOR COMMUNICATION BETWEEN READERS HAVING DUAL SENSITIVITY MODES - 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. | 03-05-2009 |
20090103437 | Method of transmitting/receiving data in sensor network for reducing overhearing of sensor nodes - 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. The receiver node determines a duration time of a deactivated state of the receiver node based on the received first preamble, thereby reducing overhearing in the sensor network. | 04-23-2009 |
20090103564 | Method and apparatus for controlling media access in sensor network - Provided are a method and apparatus for controlling media access in a sensor network and a method of managing traffic information. Since traffic information is exchanged between nodes and data is transmitted by using a dynamic long preamble according to receiver nodes, data transmission efficiency can be improved, energy consumed to transmit the long preamble can be reduced, and data transmission delay can be reduced as well. | 04-23-2009 |
20090154407 | Method of performing routing and allocating resources in wireless sensor network - Provided is a method of performing a routing and allocating a resource in a wireless sensor network. The method includes electing one or more cluster heads, each representing each of one or more clusters comprised of a plurality of sensor nodes, selecting a routing path between the cluster heads and the plurality of sensor nodes, selecting a frame length based on elements and distribution methods of the wireless sensor network and the routing path, forming a time slot resource allocation table for communication between the cluster heads, and exchanging the time slot resource allocation table between the cluster heads separated by one hop. The present invention can enhance the reliability of the wireless sensor network and QoS by effectively performing routing and allocating resources in such a manner that various data requirements can be satisfied. | 06-18-2009 |
20090154485 | Apparatus and method for controlling multi-channel access - 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. | 06-18-2009 |
20090156158 | SUPER REGENERATIVE RECEIVER AND METHOD OF SAVING POWER OF THE SAME - A low power super regenerative receiver and a method of reducing the power consumption of the low power super regenerative receiver are provided. The super regenerative receiver includes: an oscillator having a start-up time period starting oscillation that varies according to an existence of an input signal; and a power controller supplying power within the start-up time period of the oscillator. | 06-18-2009 |
20090161553 | APPARATUS FOR ANALYZING UBIQUITOUS SENSOR NETWORK PROTOCOL - An apparatus for analyzing a USN protocol includes a packet analyzer and a protocol analyzer. The packet analyzer collects packets communicated between USN sensor nodes through at least one or more channels. The protocol analyzer processes/displays the collected packets using an XML schema defined according to the USN protocol. Thus, the USN protocol analyzing apparatus can decode/encode packets collected through a plurality of channels. | 06-25-2009 |
20090262689 | METHOD AND APPARATUS FOR ALLOCATING RESOURCES TO A NODE IN AD-HOC NETWORK - A method of allocating resources to a node in an ad-hoc network includes storing a basic frame structure including a predetermined number of time slots, in which time slots to be used by the node in the ad-hoc network are arranged at predetermined positions, determining a start time slot among the predetermined number of time slots included in the basic frame structure based on a path sequence number that is a number related to a position of the node on a routing path, and determining a frame structure including the predetermined number of time slots from the start time slot in the basic frame structure that circulates as a communications frame structure for communications of the node. | 10-22-2009 |
20100017511 | METHOD OF CONSTRUCTING TREE NETWORK - Provided is a method of constructing a tree network which includes a first node. The method comprises: (a) the first node determining if there is a child node and requesting a parent node to allow the first node to withdraw if there is no child node; (b) selecting a child node based on remaining amounts of battery power of each child node if there are child nodes of the first node; (c) exchanging positions of the first node and the selected child node and requesting the parent node to allow the first node to withdraw if the child node selected in operation (b) does not have child nodes; and (d) repeating operations (b) and (c) if the child node selected in operation (b) has child nodes. The present invention solves the problem of decreasing lifetimes of upper nodes that consume more battery power than lower nodes due to more traffic transmission and reception. | 01-21-2010 |
20100027449 | Transmitting apparatus, transmitting method, receiving apparatus, receiving method and channel status information updating method of sensor node based on multiple channels - 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. The transmitting apparatus and method transmit a wake-up signal for switching neighbor nodes in a power-saving mode in a transmission range of the sensor node to a wake-up mode in which the neighbor nodes wait to receive a message from the sensor node through the control channel, transmit a preamble message including a list of unused available channels from among the data channels to a receiving node to which data is transmitted from among the neighbor nodes through the control channel, receive an acknowledgement message including information that indicates a channel selected from the available channels from the receiving node through the control channel, transmit a connection confirmation message for switching neighbor nodes other than the receiving node to the power-saving mode through the control channel, and transmit data to the receiving node through the selected channel. | 02-04-2010 |
20100042788 | METHOD AND APPARATUS FOR CONTROLLING SHARED MEMORY AND METHOD OF ACCESSING SHARED MEMORY - Provided are a method and apparatus for controlling a shared memory, and a method of accessing the shared memory. The apparatus includes a processing unit configured to process an application program, a user program unit configured to execute a program written by a user based on the application program of the processing unit, a shared memory unit connected to each of the processing unit and the user program unit through a system bus and configured to store data interchanged between the processing unit and the user program unit, and a control unit configured to relay a control signal indicating whether the system bus, by which the data is interchanged between the processing unit and the user program unit, is occupied, and control connection of each of the processing unit and the user program unit with the system bus in response to the control signal. In the apparatus, the processing unit and the user program unit can easily interchange a large amount of messages through the shared memory unit having an abundant memory space. | 02-18-2010 |
20100118737 | METHOD AND APPARATUS FOR CONSTRUCTING SYNCHRONOUS SENSOR NETWORK - 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. | 05-13-2010 |
20100128706 | APPARATUS AND METHOD FOR INCREASING OPERATION TIME IN IEEE802.15.4-2006 BEACON BASED WIRELESS SENSOR NETWORK - Provided are an apparatus and method for increasing operation time in an IEEE802.15.4-2006 beacon based wireless sensor network (WSN) with respect to the same amount of power consumption used by coordinators included in a WSN, by reducing unnecessary standby power consumption required during an active period of a super frame in a beacon-enabled mode. | 05-27-2010 |
20100146157 | MULTI-RADIO INTERFACING AND DIRECT MEMORY ACCESS BASED DATA TRANSFERRING METHODS AND SINK NODE FOR PERFORMING THE SAME IN WIRELESS SENSOR NETWORK - Provided are a method of mediating a plurality of radio frequency (RF) transceivers, which is performed in a sink node in order to perform multi-radio interfacing between the sink node and a plurality of sensor nodes in a wireless sensor network (WSN), and a direct memory access (DMA) based data transfer method. | 06-10-2010 |
20100150042 | APPARATUS AND METHOD OF TRANSMITTING AND RECEIVING WAKE-UP SIGNAL - Provided are an apparatus and method of transmitting and receiving a wake-up signal. The method of receiving a wake-up signal includes the following: operating a radio frequency (RF) receiving unit that receives a wireless signal through an antenna during an SFD detecting time, wherein the SFD detecting time is shorter than a predetermined SFD detecting time period, according to the predetermined SFD detecting time period and detecting a start of frame delimiter (SFD) to indicate that the received wireless signal is a wake-up signal to wake-up a node in a sleep mode; and detecting the wake-up signal by continuously operating the RF receiving unit when the SFD is detected. Power consumption that is used to receive the wake-up signal can be reduced. | 06-17-2010 |
20110006824 | WAKE-UP RECEIVER AND WAKE-UP METHOD USING DUTY CYCLING AND POWER OFF TECHNIQUE - Provided is a low-power wake-up receiver that is sensitive to electric waves, by which power consumed by a radio frequency (RF) transceiver of a sensor node in a ubiquitous sensor network (USN) is minimized. A wake-up receiver waking up a main transceiver includes a duty cycle signal generation unit controlling a duty cycle of a duty cycle signal; a burst signal detection unit receiving an input signal including a burst signal and a data signal based on the duty cycle signal, amplifying the input signal, and, if the amplified input signal is the burst signal, outputting a control signal; and a data signal detection unit re-amplifying the amplified input signal based on the control signal, and, if the re-amplified input signal is the data signal, outputting a wake-up signal. Power supplied to the duty cycle signal generation unit is interrupted based on the control signal and power is re-supplied to the duty cycle signal generation unit based on the wake-up signal. | 01-13-2011 |
20110194471 | WAKE-UP APPARATUS AND WAKE-UP METHOD FOR LOW POWER SENSOR NODE - 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. The wake-up apparatus outputs an interrupt signal for transmitting a sensing event of the sensor node or outputs a wake-up address of another sensor node in an area where the interrupt signal is to be sensed if errors are not detected when the wake-up address is verified. | 08-11-2011 |