Abstract: A global positioning system using Bluetooth technology, including: a first Bluetooth master that receives satellite orbit information; a Bluetooth slave that communicates with the first Bluetooth master in a Bluetooth protocol; and a second Bluetooth master that transmits an inquiry code for communication with the Bluetooth slave in the Bluetooth protocol. The second Bluetooth master provides positioning information by requesting the satellite orbit information from the first Bluetooth master through the Bluetooth slave and transmitting the satellite orbit information to the second Bluetooth master through the Bluetooth slave.

Abstract: A method of resource allocation among mobile stations in distributed communication network enables a mobile station to perceive existence of another mobile station through a time slot for resource allocation without having to communicate with a sensor node. If perceiving another mobile station, the mobile station allocates time slot resources not to overlap with the time slot resources of another mobile station, and performs location measurement or media access and reception of service from the sensor node through the allocated time slot resources. Because the mobile stations of the network can perceive each other by communicating with each other, and accordingly allocate their own resources without overlapping with the resource of the others, frequent collision of the signal for location measurement can be prevented.

Abstract: Provided is a method for refining node position information in a wireless sensor network having an ultra wideband communication network and a wireless personal area network where the initial positions of respective nodes are set, by utilizing nodes at a 2-hop distance, or more than a 2-hop distance when the number of neighboring nodes at a 1-hop distance is not sufficient to perform triangulation, and to refine the position of nodes based on a distance measured between the respective nodes. Because the initial position is refined and confirmed in a wireless sensor network, a user node operates as a pseudo anchor node for the nodes which have no anchor node nearby. Furthermore, as a node has the refined position, it can act as a pseudo anchor node and be used to compute the position of the other nodes. Additionally, positions of nodes of the wireless sensor network can be estimated with more accuracy.

Abstract: A time synchronization method in a wireless sensor network, has an upper node that provides back-off scheduling to lower nodes in the wireless sensor network of a hierarchical structure. Each of the lower nodes synchronizes time according to the back-off scheduling based on its local clock. The time synchronous method also allows the number of packets required for synchronization in the wireless sensor network to sharply decrease, and the life time of the network to increase. Additionally, the time synchronous method provides a response packet from a lower node in response to a synchronization packet from an upper node, which is used as a synchronization start packet for secondary lower nodes, so that synchronization in the entire network is rapidly processed.

Abstract: A coordinator's data transmission method, a device's data reception method, a coordinator using the coordinator's data transmission method and a device using the device's data reception method are provided. In a Zigbee system including at least one device and a coordinator for coordinating the device, in a case where a frame pending bit in a beacon frame is determined to be a value representing a direct transmission method, a beacon frame containing an address of a device to receive data and a data transmission time is generated and data is transmitted from the coordinator at the data transmission time. Data transmission time and power consumption can be reduced.

Abstract: A global positioning system using Bluetooth technology, including: a first Bluetooth master that receives satellite orbit information; a Bluetooth slave that communicates with the first Bluetooth master in a Bluetooth protocol; and a second Bluetooth master that transmits an inquiry code for communication with the Bluetooth slave in the Bluetooth protocol. The second Bluetooth master provides positioning information by requesting the satellite orbit information from the first Bluetooth master through the Bluetooth slave and transmitting the satellite orbit information to the second Bluetooth master through the Bluetooth slave.

Abstract: A method for flooding a route request packet that is received at a node in a communication system constructed of at least three nodes including a source node that requests to establish a route and a destination node that receives the route request. One of a plurality of levels having different transmission periods is determined using a strength of a received signal of a measured packet. A transmission start point is selected at the determined level, and it is determined whether a route request packet is re-received before the selected transmission start point. The received packet is broadcast at the selected transmission start point when the packet is not re-received. The transmission start point is randomly selected within the transmission period or at the level in consideration of the number of the connected nodes.

Abstract: An azimuth measurement apparatus including: a positioning signal receiver receiving a first impulse positioning signal and a second impulse positioning signal from a first fixed position and a second fixed position, respectively; a phase difference detector detecting a phase difference between the first impulse positioning signal and the second impulse positioning signal; and an azimuth calculator measuring an azimuth of an object of positioning, based on the detected phase difference of the two positioning signals.

Abstract: A beacon scheduling method and system in a network system. The beacon scheduling method of a router in a network system that includes at least one router, includes receiving a beacon signal from a parent node; calculating a difference between an address of the parent node and an address of the router; and setting the calculated difference to a beacon transmission offset of the router. Accordingly, all devices from the top to the bottom of the network can transmit their beacons without collisions, and thus the multi-hop tree structure can be established.

Abstract: A location recognition system and method using stereophonic sound, the system having a transmitter and a receiver. The transmitter uses the stereophonic sound and transmits location tracking information of an object. The transmitter includes a sound detector which detects a sound of the object and converts the detected sound to an electrical signal; a data converter which converts the electrical signal converted by the sound detector, to acoustic data; and a first communication interface which transmits the acoustic data converted by the data converter and the location tracking information to the receiver. A user can immediately recognize the location of the transmitter which transmits the location tracking information and is the target of the location tracking. Therefore, the mutual communications between the transmitter and the receiver which receives the location tracking information can be smoothly carried out.

Abstract: There is provided a node position measurement apparatus and method including sequentially transmitting measurement impulses corresponding to a plurality of base stations, respectively, to at least one node; receiving time offset information that is a difference in time of receiving the measurement impulses, from the node receiving the measurement impulses; and measuring a position of the node based on the time offset information.

Abstract: An azimuth measurement apparatus including: a positioning signal receiver receiving a first impulse positioning signal and a second impulse positioning signal from a first fixed position and a second fixed position, respectively; a phase difference detector detecting a phase difference between the first impulse positioning signal and the second impulse positioning signal; and an azimuth calculator measuring an azimuth of an object of positioning, based on the detected phase difference of the two positioning signals.

Abstract: A position recognition method and system include transmitting a first transmit signal and a second transmit signal via a first transmit antenna and a second transmit antenna of a transmitter at intervals; receiving the first transmit signal and the second transmit signal via an receive antenna of a receiver; and calculating a position of the receiver using transmission times of the first transmit signal and the second transmit signal. Accordingly, the mobile object can recognize its position efficiently.

Abstract: A time synchronization method in a wireless sensor network, has an upper node that provides back-off scheduling to lower nodes in the wireless sensor network of a hierarchical structure. Each of the lower nodes synchronizes time according to the back-off scheduling based on its local clock. The time synchronous method also allows the number of packets required for synchronization in the wireless sensor network to sharply decrease, and the life time of the network to increase. Additionally, the time synchronous method provides a response packet from a lower node in response to a synchronization packet from an upper node, which is used as a synchronization start packet for secondary lower nodes, so that synchronization in the entire network is rapidly processed.

Abstract: Provided is a method for refining node position information in a wireless sensor network having an ultra wideband communication network and a wireless personal area network where the initial positions of respective nodes are set, by utilizing nodes at a 2-hop distance, or more than a 2-hop distance when the number of neighboring nodes at a 1-hop distance is not sufficient to perform triangulation, and to refine the position of nodes based on a distance measured between the respective nodes. Because the initial position is refined and confirmed in a wireless sensor network, a user node operates as a pseudo anchor node for the nodes which have no anchor node nearby. Furthermore, as a node has the refined position, it can act as a pseudo anchor node and be used to compute the position of the other nodes. Additionally, positions of nodes of the wireless sensor network can be estimated with more accuracy.

Abstract: A method of resource allocation among mobile stations in distributed communication network enables a mobile station to perceive existence of another mobile station through a time slot for resource allocation without having to communicate with a sensor node. If perceiving another mobile station, the mobile station allocates time slot resources not to overlap with the time slot resources of another mobile station, and performs location measurement or media access and reception of service from the sensor node through the allocated time slot resources. Because the mobile stations of the network can perceive each other by communicating with each other, and accordingly allocate their own resources without overlapping with the resource of the others, frequent collision of the signal for location measurement can be prevented.

Abstract: An impulse signal acquisition method and apparatus are provided. The impulse signal acquisition apparatus includes: an impulse generator which varies a pulse width of an impulse signal used for transmitting data according to a predetermined control signal to generate the impulse signal; and a controller which applies a pulse width control signal used to vary the pulse width of the impulse signal to the impulse generator.

Abstract: A system for accessing a node of a private network includes an assigning portion for assigning external port values to respective network nodes based on information collected from the network nodes of the private network, and storing the assigned external port values; an exchanging portion for exchanging the external port values of the respective network nodes of private networks; and an address converting portion for converting the external port values into corresponding private IP addresses and internal port values when a network node of one private network accesses another network node of another private network by using the external port values of another network node of another private network. Accordingly, a network node of a private network without a global IP address becomes accessible.

Abstract: A control packet management device of a packet forwarding system has a packet queue having a plurality of queues to store a control packet as transmitted, a first processor to transmit said control packet stored in one queue of said plurality of queues to a host a by one-to-one interrupt, a second processor to divide said control packets stored in said one queue into groups of a predetermined size and transmit said control packets to said host in the group unit and by direct memory access (DMA), a third processor to discard a most common type of said control packets stored in said one queue, and a controller to control said first, second and third processors to selectively operate in accordance with an accumulation state of said control packets stored in said plurality of queues.

Abstract: A shooting game method and an apparatus for a mobile terminal device using local positioning communication to run a shooting game by local positioning communication based on positions of the mobile terminal device and a neighboring mobile terminal device. Accordingly, improving the user convenience implementing an intelligent shooting game using a position recognizing function of the mobile terminal device, and also, instead of a stand-alone game, twosome or more games can be implemented.