Patent application number | Description | Published |
20080224870 | APPARATUS AND METHOD FOR MANAGING POWER OF RFID TAG - An apparatus and method for managing power of a radio frequency identification (RFID) tag are provided. It is possible for the apparatus for managing the power of the RFID tag to effectively reduce power consumption of the RFID tag by measuring the power strength of a radio frequency (RF) signal received from an RFID reader and adjusting a level of transmission power based on the measured power strength of the signal. | 09-18-2008 |
20080224873 | APPARATUS AND METHOD FOR DETECTING WAKE-UP BURST OF ACTIVE RFID TAG - An apparatus and method for detecting a wake-up burst of an active RFID tag are provided. The apparatus and method, for detecting the wake-up burst of the active RFID tag, are capable of reducing power consumption of the RFID tag by enabling the RFID tag when a RFID reader starts to communicate. | 09-18-2008 |
20080267121 | NODE DEVICE AND METHOD FOR BEACON SCHEDULING IN AD-HOC NETWORK AND DATA TRANSMITTING METHOD THEREOF - Provided are a device of a node and method for beacon scheduling in an ad-hoc network and a data transmitting method thereof, which reduce power consumptions of nodes in an ad-hoc network when data communications between the nodes occur frequently. A beacon transmitting node checks its residual power. If the residual power is lower than a predetermined level, the beacon transmitting node notifies a plan to change its beacon cycle to other nodes. Thereafter, the beacon transmitting node increases the beacon cycle and transmits a beacon at the increased beacon cycles. Consequently, the beacon transmitting node can change its beacon cycle dynamically according to its power condition. Thus, the life span of the node can be increased. Therefore, it is possible to reduce an overhead of reconstructing a sensor network. | 10-30-2008 |
20090109929 | MEDIA ACCESS METHOD PERFORMED BY READER IN DENSE READER ENVIRONMENT - Provided are a media access method and a reader for performing the media access method in a dense reader environment. The media access method divides an air time between the reader and a tag into a plurality of time slots, and operates in each of the plurality of time slots by using a listen before talking (LBT) technique. The plurality of time slots form a frame. Thus, the media access method can control the reader by performing channel scheduling between each of a plurality of readers and can efficiently recognize tags. | 04-30-2009 |
20090122733 | Coordinator in wireless sensor network and method of operating the coordinator - Provided are a coordinator in a wireless sensor network (WSN) which can improve transmission performance and prevent data loss, and a method of operating the coordinator. The method includes: scanning a transmitted beacon and storing information on a channel included in the beacon; when it is determined that a home channel communicating with a parent node is in an inactive mode on the basis of the information on the channel, in synchronization with the activation of another channel of the same hierarchical level as that of the home channel, activating a home channel communicating with a child node and communicating with the child node; and communicating with the child node through an auxiliary channel that has a frequency band different from those of the home channel communicating with the child node and home channels of other nodes and is always in an active mode. | 05-14-2009 |
20090141667 | METHOD FOR ROUTING MESSAGE IN WIRELESS NETWORK BASED ON RELAY PROBABILITY - Provided is a method for routing a message in a wireless network based on relay probability. The method allows dynamic delivery of a message by calculating the relay probability of each node for message transmission, measuring the strength of a beacon signal received from a destination node, and determining a node that will relay a message based on the relay probability and the strength of beacon signal. | 06-04-2009 |
20090141741 | METHOD AND APPARATUS FOR CONNECTING SENSOR NETWORK TO HETEROGENEOUS NETWORK - Provided are a method and apparatus for connecting a sensor network to a heterogeneous network, in which an external network connected to the sensor network functions as a virtual personal area network (PAN) so that the same PAN address system is used between the sensor network and the external network by using a concept of a ‘virtual PAN’. According to the method and apparatus for connecting the sensor network to the heterogeneous network, a node of the sensor network can efficiently communicate with a node of the external network including the heterogeneous network by assigning the virtual PAN address to the node of the external network including the heterogeneous network without inserting any additional layer into the node of the sensor network. | 06-04-2009 |
20090146833 | Coordinator, gateway, and transmission method for IPv6 in wireless sensor network - Provided are a coordinator, a gateway, and a transmission method for applying IPv6 in a wireless sensor network (WSN). Dual addressing of a link local address using a short address used in the WSN and a global unicast address using an extended unique identifier (EUI) of a node makes it possible to support mobility of the WSN and communicate data with an external network. | 06-11-2009 |
20090147699 | METHOD OF SUPPORTING NODE PORTABILITY IN SENSOR NETWORK - Provided is a method of supporting node portability in a sensor network, wherein data transmission to a portable node can be guaranteed since even when the portable node is assigned with a different address by being associated with another network, the newly assigned address is transmitted to a parent node or a sink node that was previously associated with the portable node. | 06-11-2009 |
20090147715 | ENERGY SAVING METHOD IN WIRELESS NETWORK - Provided is a method of minimizing power consumed by each node in a wireless network when communicating with neighboring nodes. | 06-11-2009 |
20090147725 | CROSS-LAYER ROUTING METHOD IN WIRELESS SENSOR NETWORK - Provided is a cross-layer routing method in a wireless sensor network including: locating a destination node which is a final destination of data by a source node which generates the data; and determining an optimal relay node among one or more neighboring nodes using their position information for each hop and forwarding the data from the source node to the destination node through the determined relay nodes. Therefore, an effective and stable routing which reduces overheads of additional control messages used for stable data forwarding and reduces collisions in a shared channel by using wireless link layer characteristics can be implemented. | 06-11-2009 |
20090147760 | Method and apparatus for routing in wireless sensor network - Provided are a method and apparatus for efficiently performing routing in a wireless sensor network having a tree-hierarchical structure, the method and apparatus reducing the number of hops required for transmitting data. According to the method and apparatus, a node is determined as a proximal node from among nodes within range of a wireless signal of a transmission node, wherein the node is a node having the smallest difference from among differences between each of address values of the nodes within the range and an address value of a target node, and data is directly transmitted from the transmission node to the proximal node. | 06-11-2009 |
20090150699 | SLEEP SCHEDULING METHOD BASED ON MOVING DIRECTIONS OF TARGET IN SENSOR NETWORK - Provided is a sleep scheduling method based on directions of a target in a sensor network. A track subregion is set as an oval shape that is in proportion to a probability of the target moving in certain directions so as to track the target, and sleep patterns of sensor nodes in the tracking subregion are scheduled in consideration of a probability of the target moving in certain directions. As such, the energy efficiency of each sensor node in the sensor network can be improved. | 06-11-2009 |
20090161637 | COMMUNICATION APPARATUS AND METHOD IN WIRELESS SENSOR NETWORK - Provided are a communication method and apparatus of a wireless sensor network which uses at least one channel and has a tree structure. The method includes: generating windows, where a beacon interval is divided, according to each channel; selecting a window, which is not assigned to nodes that exist within a predetermined range from a certain node, from among the generated windows; and the certain node communicating with a child node of the certain node by using a channel to which the selected window belongs during a time corresponding to the selected window. | 06-25-2009 |
20100014460 | SENSOR NETWORK MAC SYSTEM FOR MULTIHOP COMMUNICATION - Provided is a method of synchronizing time for a multihop sensor network. According to the method, receiving nodes accurately synchronize time by adding a delay transmission time value to a beacon frame in a beacon mode, or by using a time synchronization frame and time synchronization acknowledgement frame containing time information and superframe structure information in a non-beacon mode. Accordingly, a mesh topology is supported, and a media access control (MAC) structure having high reliability and low delay time is provided. | 01-21-2010 |
20100034159 | SENSOR NETWORK MEDIUM ACCESS CONTROL (MAC) SYSTEM FOR MULTIHOP COMMUNICATION - A medium access control (MAC) technique of a multihop sensor network. In the multihop sensor network, the MAC technique may contribute to significantly reducing transmission delay, and allow real-time services to be provided to all nodes by extending a guaranteed time slot (GTS) restricted to one hop in a personal area network (PAN) coordinator (PNC) to all nodes. Furthermore, the MAC technique may allow the number of available GTSs to be significantly increased, by using all 16 frequency band channels instead of using only a single frequency band and setting a multi-superframe. | 02-11-2010 |
20100085930 | SUPER FRAME STRUCTURE AND BEACON SCHEDULING METHOD FOR MESH NETWORKING - A super frame structure supporting a mesh network, and a beacon scheduling method. The super frame structure and the beacon scheduling method may support a mesh topology in a beacon enabled mode, may have an algorithm that is simple and easily realized via beacon scheduling using a distribution method, and may easily adapt to changes in a network environment. | 04-08-2010 |
20100090809 | METHOD AND APPARATUS FOR TRANSMITTING SENSOR STATUS OF RADIO FREQUENCY IDENTIFICATION TAG - Provided are a method and apparatus for transmitting a sensor status of a radio frequency identification (RFID) tag. The method and apparatus transmit an RFID tag identifier (ID) together with sensor data or sensor status information to an RFID reader, thereby enabling the RFID reader to receive the sensor status information about the RFID tag without additionally communicating with the RFID tag. | 04-15-2010 |
20100110888 | METHOD OF PREVENTING DATA COLLOSIONS IN BEACON-ENABLED ZIGBEE SYSTEM HAVING TREE ROUTING SCHEME - Provided is a method of preventing a data collision that occurs when two or more child nodes simultaneously transmit data to a parent node in a ZigBee network having a tree routing scheme and operating in a beacon mode. In the ZigBee system having the tree routing scheme and operating in the beacon mode, data communication to the parent node is performed in a beacon frame of the parent node. Here, when several child nodes exist under a single parent node, the child nodes transmit data to the parent node at the moment of receiving the beacon of the parent node, so that the data collision may occur when the child nodes simultaneously transmit the data to the parent node in the beacon frame of the parent node. In the method of preventing a data collision, each of the two or more child nodes is set to wait for its guard time (delay time) when transmitting data to the parent node to induce a normal slotted carrier sense multiple access with collision avoidance (CSMA-CA) operation. Therefore, the data collision can be prevented. | 05-06-2010 |
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 |
20100207736 | MOBILE RFID READER AND RFID COMMUNICATION METHOD USING SHARED SYSTEM CLOCK - The present invention relates to a mobile radio frequency identification (RFID) reader and a RFID communication method using a shared system clock. According to the present invention, clock for synchronizing the mobile RFID readers can be shared without changing hardware of a conventional RHD device. Also, since the shared clock is used, a technology for preventing a collision with the readers can be easily realized in a mobile multi-reader environment. | 08-19-2010 |
20100207737 | TDMA CONTROL METHOD USED BY RFID READER VIA MOBILE PHONE BASE STATION AND MOBILE RFID READER - A time division multiple access (TDMA) control method used by a mobile radio frequency identifier (RFID) reader through a mobile phone base station and a mobile RFID reader are provided. Each mobile RFID reader occupies a frequency channel during a time slot allocated through a mobile communication base station, thereby avoiding interference between readers. | 08-19-2010 |
20100220653 | MULTI-PATH ROUTING METHOD IN WIRELESS SENSOR NETWORK - A multi-path routing method is provided a multi-path routing method for selecting appropriate multiple paths when information sensed from a source node is transmitted to a sink node in wireless sensor networks. The source node for transmitting the sensed information first transmits a Hello message to the sink node to identify the existence and position of the sink node. The sink node receives the Hello message and then re-transmits the Hello message with respect to all the received Hello messages. Respective middle nodes accumulate distances between the middle nodes while the Hello message is transmitted to the source node through a reverse path of the Hello message, and all the middle nodes maintain a real distance from the sink node. The source node receiving all the Hello messages can rout a plurality of appropriate paths through Hop-by-hop to the sink node by providing respective weights to an energy remaining amount, an appropriate transmission radius and a real distance from the sink node. Accordingly, priorities can be provided to lifetime of the source node, average energy consumption and the shortest path by adjusting the respective weights when routing the plurality of paths. In addition, appropriate paths can be routed considering the transmission success rate of a path, and a load balancing effect can be obtained using path cost. | 09-02-2010 |
20100241655 | APPARATUS FOR AND METHOD OF TRANSMITTING SENSING DATA OF SENSOR NODE FOR PROACTIVE DATA FILTERING IN WIRELESS SENSOR NETWORK - An apparatus for and a method of transmitting sensing data of a sensor node for proactive data filtering in a wireless sensor network are provided. In the apparatus and method, a request query of sensing data and timer parameters are received, local sensing data sensed in the sensor node in response to the received request query are detected, a driving time of a timer applying the timer parameters based on the request query is set, and the local sensing data are transmitted when the local sensing data do not overlap sensing data of a neighboring sensor node within a wireless reception range of the sensor node by overhearing the sensing data of the neighboring sensor node during the set driving time of the timer. Thus, since a data transferring path is selected considering the remaining energy of the node, the energy exhaustion of the node is distributed, thereby improve the lifespan of the network. | 09-23-2010 |
20100265889 | METHOD FOR RECOGNIZING POSITIONS OF A PLURALITY OF NODES WHICH CONSIST WIRELESS SENSOR NETWORK - A method for recognizing positions of a plurality of nodes which constitute a wireless sensor network is provided, the method comprises generating sub-maps which represent the relative position to neighbor nodes by taking each of the plurality of nodes as a reference; selecting a sub-map which takes a node with the highest connectivity as a reference from among the plurality of nodes; selecting a sub-map which takes a node with the highest connectivity as a reference, except for the node which becomes a reference of the selected sub-map among the nodes which are included in the selected sub-map; integrating the selected sub-maps into one map by matching the same nodes among the nodes which are commonly included in the selected sub-maps; and thereafter correcting positions of nodes which are included in the integrated map to real positions, whereby integrating order of the sub-map is adjusted using an information of the connectivity of the nodes, and the positions of the nodes which constitute the wireless sensor network is constituted are correctly recognized by correcting the position of the nodes. | 10-21-2010 |
20100272092 | APPARATUS AND METHOD FOR BROADCASTING DATA, AND APPARATUS AND METHOD FOR BROADCASTING RESPONSE DATA, OF SENSOR NODE IN WIRELESS SENSOR NETWORK SYSTEM - Provided are an apparatus and method for broadcasting data, and an apparatus and method for broadcasting response data, of a sensor node in a beacon mode in a wireless sensor network system including a plurality of nodes. According to the apparatus and method for broadcasting data, an admission application message requesting an admission of a sensor node is transmitted to the wireless sensor network system, in which time-division time slots are assigned to each of the nodes of the wireless sensor network system, wherein, in the time-division time slot, the reception function of the node is activated and sensing data is transmitted; a beacon frame is received, which includes information that indicates a broadcasting time slot among the time-division time slots, wherein, in the broadcasting time slot, the reception function of each of the nodes of the wireless sensor network system having received the admission application message, is activated at the same time; and broadcasting data is transmitted during the broadcasting time slot. Accordingly, broadcasting data can be efficiently transmitted in a beacon mode of the wireless sensor network system. | 10-28-2010 |
20100278163 | METHOD OF DELIVERING DATA IN WIRELESS PRESONAL AREA NETWORK - Provided is a method of delivering data in a wireless personal area network. One of nodes forming the wireless personal area network broadcasts data including the address and the sequence number of one node to a plurality of other nodes, and broadcasts one of the data and other data to the other nodes depending on whether the data is received from the other nodes within a predetermined time. Accordingly, all the nodes on the network can receive data reliably and simultaneously power consumption is reduced, and thus the life of the network is extended. | 11-04-2010 |
20100296493 | DISTRIBUTED CHANNEL HOPPING METHOD IN WIRELESS AD-HOC NETWORK - A distributed channel hopping communication method in a low power wireless ad-hoc network. A beacon transmission and reception scheduling method using a distributed channel hopping method in a wireless ad-hoc network, the method includes: transmitting beacons using channel hopping, before establishing the wireless ad-hoc network including a plurality of nodes having a BP including at least one time slot, and receiving beacons of a plurality of neighboring nodes of each of the plurality of nodes; collecting information about the wireless ad-hoc network and information about the plurality of neighboring nodes from the received beacons; scheduling the receiving of the beacons that are transmitted from the plurality of neighboring nodes in the BP, using TDMA in each of the at least one time slot based on the information about the plurality of neighboring nodes; and scheduling transmitting of a beacon in each of the at least one time slot. | 11-25-2010 |
20100306351 | METHOD AND APPARATUS FOR DOMAIN NAME AUTOCONFIGURATION IN IP-BASED WIRELESS SENSOR NETWORK - A method and apparatus for domain name autoconfiguration in an IP-based wireless sensor network is provided. The method includes: receiving sensor node information including position information for representing an installed position of a sensor node, a type of data to be provided by the sensor node, and an internet address of the sensor node; searching for area information including an administrative address corresponding to the position information of the sensor node; generating a domain name of the sensor node based on a type of the sensed data and the found area information; and binding the generated domain name with an internet address of the sensor node and registering the bound result in a domain name server. | 12-02-2010 |
20100308972 | COMMUNICATION METHOD FOR RADIO FREQUENCY IDENTIFICATION - Provided is a communication method for radio frequency identification (RFID). In order to transmit a command message with respect to an RFID tag, an RFID reader generates a command message comprising a command code indicating a type of command to be delivered to the RFID tag, a response format having one or more bits for indicating a type of additional data to be added to a response message to be received from the RFID tag, and an identifier identifying the RFID tag; and transmits the command message to the RFID tag, thereby allowing the RFID tag to immediately transmit the additional data via the response message in response to the command message. | 12-09-2010 |
20100314452 | APPARATUS AND METHOD OF GENERATING WAKE-UP SIGNAL IN BATTERY-POWERED PASSIVE TAG - An apparatus and method of generating a wake-up signal from a passive tag with a battery is provided. According to the present invention, since a wake-up signal is generated by a signal received from a Radio Frequency Identification (RFID) reader, battery life can be extended. That is, a wake-up signal can be generated for the battery to be operated according to a signal from the RFID reader so that the battery included in the tag can be controlled from the RFID reader, thereby controlling the amount of battery power consumed. Therefore, the battery life and the life of the tag including the battery can be increased. | 12-16-2010 |
20110116414 | APPARATUS AND METHOD FOR COMMUNICATION IN WIRELESS SENSOR NETWORK - Provided are a bridge system, a network management server, and communication methods at the bridge system and the network management server for efficient communication in a wireless sensor network (WSN). The communication method at the network management server includes communicating with bridge systems connected with a plurality of radio frequency (RF) regions within a personal area network (PAN) composed of sensor nodes using the same wireless channel, in which radio signals of the sensor nodes within the PAN reach the bridge systems, searching for a new channel to be used and an alternative bridge system which is to perform a channel change into the new channel based on information about the bridge systems upon receipt of an association failure report message from an error bridge system which is reported of an association failure from the RF region from among the bridge systems, sending a channel change request message to the found alternative bridge system, and adjusting channel information for the found alternative bridge system to the new channel and replacing information about sensor nodes connected to the found alternative bridge system with information about sensor nodes that are newly connected with the found alternative bridge system through the new channel. | 05-19-2011 |
20110125922 | METHOD AND APPARATUS FOR SETTING ROUTING PATH IN WIRELESS SENSOR NETWORK - Provided are a method and apparatus for setting a routing path in a wireless sensor network. The apparatus for setting a routing path includes a neighbor table storing information of a peripheral device within wireless communication distance of a transmitter transmitting data; a searching unit sequentially searching whether at least one of an address of a destination, a parent address or ancestor address of the destination representing an address of a receiver receiving data transmitted by the transmitter exists or not in the neighbor table; and a link quality indicator (LQI) judging unit transmitting the data to the receiver when a LQI value of the address is greater than a value that is previously set in a case in which an address is searched in the searching unit. | 05-26-2011 |
20110131320 | APPARATUS AND METHOD OF DYNAMICALLY MANAGING SENSOR MODULE ON SENSOR NODE IN WIRELESS SENSOR NETWORK - Provided is an apparatus and method of dynamically managing a sensor module on a sensor node in a wireless sensor network. The apparatus includes an update unit, a request unit, and a transmission unit. If a change occurs in sensor data corresponding to each sensor node stored in a sensor information storage server, the update unit receives the sensor data from the sensor information storage server, and transmits the received sensor data to the corresponding sensor node. The request unit requests the sensor data from the sensor information storage server upon receipt of a sensor data request message from the sensor node. The transmission unit receives the requested sensor data from the sensor information storage server and transmits the received sensor data to the sensor node. | 06-02-2011 |
20110164573 | METHOD AND APPARATUS FOR ASSIGNING CHANNEL IN AD-HOC NETWORK - The present invention provides a method and apparatus for assigning a channel in an ad-hoc network, which can minimize beacon collision in the ad-hoc network and prevent channel overlapping or collision, and thus a channel can be efficiently assigned. The method of assigning a channel including: obtaining join order information which is information on the order in which a first node has been joined to a second node, which is a parent node, and level information of the second node in an ad-hoc network; determining a reference value for setting a channel that is to be assigned to the first node based on an address value of the first node, which is determined based on the join order information and the level information, a level value of the first node, a channel value of the second node, which is determined based on the level information, and the join order information; and determining a channel value of the first node by dividing the reference value by the maximum number of usable channels in the ad-hoc network. | 07-07-2011 |