Abstract:
Real-time location tracking apparatus and method using a global positioning system (GPS) signal relay tag is provided. Here, a tag may receive a GPS signal and transmit the received GPS signal to a reader, and the reader may calculate a location of the tag, and thereby a real-time location tracking service may be provided.
Abstract:
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.
Abstract:
A passive tag including a volatile memory is provided. The passive tag includes: a sensing unit which senses or measures information about environmental surroundings of the tag; a volatile memory; a non-volatile memory; and a control unit which firstly stores resultant data sensed or measured by the sensing unit in the volatile memory and then moves the data stored in the volatile memory to the non-volatile memory according to pre-set conditions. Therefore, the life of the tag is prolonged and stability of important data can be secured.
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. 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.
Abstract:
Provided is an antenna system with high isolation. The high-isolation antenna has transmission ports of a transmission antenna and reception ports of a reception antenna highly isolated from each other by using quadrature hybrid couplers. The antenna system includes: a transmission antenna having two feed points for transmitting signals; a reception antenna having two feed points for receiving signals; a transmission hybrid coupler which is connected to the two feed points of the transmission antenna and transmits transmission signals which have a phase difference of 90° with each other; and a reception hybrid coupler which is connected to the two feed points of the reception antenna and receives reception signals which have a phase difference of 90° with each other. The signals leaking from the two feed points of the transmission antenna to the two feed points of the reception antenna are offset.
Abstract:
A regional positioning method and apparatus in a wireless sensor network (WSN) is provided. The regional positioning method in a WSN, the regional positioning method including: setting a locating premise in the WSN based on a signal strength of an anchor node; sensing an event where a sensor node, installed in a target and called a target node, joins the WSN; detecting a locating premise where the target node is located based on the sensing of the event; and recognizing a location of the target based on the detected locating premise.
Abstract:
Provided is an apparatus and method for computing the location of a radio beacon by using received signal strength (RSS) and multiple frequencies. The apparatus and method of the present invention computes the location of a radio beacon without limitation in distance by using multiple frequencies and received signal strength to resolve the problem of phase ambiguity. A radio beacon location computing system includes a plurality of base stations configured to receive signals of multiple frequencies transmitted from the radio beacon, and detect and output phase differences and received signal strength; and a location computing server configured to receive the phase differences and the received signal strength outputted from the respective base stations, acquire calculation distances based on the phase differences, remove phase ambiguity from the calculation distances based on the received signal strength, and compute the location of the radio beacon.
Abstract:
Provided is a power control device and a control method thereof for reducing power consumption. A standby power control devices includes a plurality of electronic devices each of which is operated in a standby mode and a normal mode, and a central control unit configured to monitor load power consumed by one of the electronic devices, and perform a control operation for electrically connecting or isolating the one of the electronic devices to or from a power line by referring to a result of the monitoring and each profile information of the electronic devices, wherein the central control unit controls the one of the electronic devices to be isolated or keep a connection from or to the power line when the load power consumed by the one of the electronic devices is kept as the standby mode over a reference time.
Abstract:
Provided is a programming method of network nodes in sensor network. The programming method receives a code to be programmed in the network nodes. The programming method determines the kind of the received code. The programming method selects a programming scheme according to the determined kind of the code. The programming method programs the received code in the network nodes based on the selected programming scheme.
Abstract:
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.