摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Provided is a method for transmitting sensing information in a wireless sensor network including a pair node. The method for transmitting sensing information in a wireless sensor network including a sink node, parent nodes, and sensor nodes set as pair nodes among sensor nodes connected to the parent nodes, includes the steps of: a) setting up predetermined sensor nodes in the same target area as pair nodes for transmitting and receiving sensing information to/from corresponding sensor nodes; b) at the pair nodes, transmitting first sensing information sensed by oneself to corresponding sensor nodes; c) at the sensor nodes, transmitting first sensing information sensed by oneself and second sensing information transmitted from corresponding pair nodes to the parent node; and d) at the parent node, transmitting the received first and second sensing information to the sink node at the same time.
摘要:
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.
摘要:
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.
摘要:
Provided is a method for determining superframe to efficiently perform beacon scheduling by allocating superframe lengths which are different according to a routing depth of sensor nodes in a ZigBee based wireless sensor network. The method for determining a superframe for beacon scheduling, includes the steps of: receiving a beacon from a neighboring node and grasping information on a superframe used by the neighboring nodes; and determining a transmission time and a length of own superframe based on superframe information of the grasped neighboring node.
摘要:
A cable to waveguide transition apparatus having a signal accumulation form of a backshort is disclosed. The cable to waveguide transition apparatus having a signal accumulation form of a backshort, includes: a waveguide; a RF probe for transferring a radio frequency (RF) signal to the waveguide; and a backshort having the signal accumulation form for reflecting the RF signal excited from the RF probe, wherein the backshort reflects a first fundamental frequency signal excited from the RF probe to have a phase identical to a phase of a second fundamental frequency signal excited from the RF probe to an aperture of the waveguide, and reflects a first 2-order harmonic frequency signal excited from the RF probe to have a phase reverse to a phase of a second 2-order harmonic frequency signal excited to an aperture of the waveguide in order to eliminate the 2-order harmonic frequency signal.
摘要:
Provided is a routing method capable of expanding a conventional tree routing to perform the efficient and safe key management in a sensor network environment that requires the symmetric key based key management. Each sensor node transmits a Route Reverse message to a sink node to set a reverse tree routing path. Therefore, it is possible to provide efficient and safe key management mechanism and communication environment by providing a bidirectional communication between a sink node and sensor nodes through an expanded tree routing such that a user is provided with a safe sensor network.
摘要:
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.