Samsung Electronics Co., Ltd.

The City University of New York

Jong-hun Park

Myung-Jong Lee

Yong Liu

Daeyoung Kim

Seung-Hwan Oh

Kyung-hun Jang

Min-Seop Jeong

Woo-jong Park

Xu-hui Hu

Min-Q Kim

Tae-jin Lee

Hyun-sook Kang

Hyunhak Kim

Xuhui Hu

Chun-hui Zhu

Soon-jin Choi

Won-soo Kim

Tae-kyung Kwon

Min-scop Jeong

Jian Liang Zheng

Min-seop Jeong

Seongeun Yoo

An address assigning method in a ZigBee network environment formed of a plurality of devices (or nodes), includes: linking the plurality of nodes in a cluster-tree structure; requesting desirable address blocks from a lowest level to a second highest level of the tree ancestor nodes desirable address blocks, respectively; and assigning the desired address blocks to descendents using a top-down procedure.

Zigbee network device for assigning addresses to child nodes after constructing cluster-tree structure, address assigning method and routing method

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.

Method of refining node position information in wireless sensor network

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.

Time synchronization method in wireless sensor network

A routing requesting method to transmit data to a device of a different piconets in a scatternet including at least two piconets which have a master device and at least one slave device controlled by the master device. A source device generates as a single packet an information inquiring a first radio resource used in each device of the piconet and an information requesting the routing. The source device broadcasts the packet to adjacent devices. The adjacent device, which receives the generated packet, sends the packet to a destination device by repeating the above process. The destination device assigns itself the master device, generates a RREP message including a clock information, and sends the generated RREP message to an adjacent device. The source device becomes aware of devices along the route using the information contained in the RREP message.

Routing system and method in scatternet

A beacon scheduling method is provided which can efficiently avoid beacon collisions and prevent power consumption of the router due to the unnecessary beacon transmissions. The beacon scheduling method of a router in a network system including at least one coordinator which sends beacons in a cycle and at least one router, includes sending a message to the router; receiving a reply message from the router; and determining a beacon transmission time of the router to an inactive period when the inactive period is secured in a beacon cycle of the coordinator.

Beacon scheduling method in wireless sensor network system

A route recovery method in a wireless network of a tree topology, in which a second node, which is a lower node of a first node and is disconnected from the first node, recovers the route in the network. The route recovery method includes the second node broadcasting a local repair request (LREQ) packet, each node receiving the LREQ packet sending a local repair reply (LREP) packet to the second node to act as a relay node for the route recovery, the second node selecting the relay node from among the nodes sending the LREP packet, and sending a local repair confirm (LCON) packet from the second node to the relay node, and establishing the route between the second node and the first node by the relay node sending a local repair inform (LINF) packet to the first node.

Method for route recovery in wireless network of tree topology

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.

Beacon scheduling method and system in a network system

A routing method comprising receiving a first packet, the first packet being broadcast for discovery of a route. A first backoff of the first packet is calculated based on a route cost of the first packet. The first packet is rebroadcast if a second packet is not received within the first backoff, the second packet being a duplicate of the first packet. A second backoff of the second packet is calculated based on a route cost of the second packet if the second packet is received within the first backoff. One of the first and the second packets is rebroadcast as a result of comparing the first backoff and the second backoff.

Cost-based routing using backoff scheme

A system and method for selecting a starting point to transmit a beacon (BTSP) from a coordinator and a first node in a communication system. The communication system includes the coordinator, a first node group with at least one node having the first node which receives the beacon from the coordinator, and a second node group with at least one node having a second node which receives the beacon from the first node. The coordinator determines a beacon window size for the beacon transmission, selects the BTSP within the beacon window size, and transmits at the BTSP, the beacon containing information on the beacon window size and the BTSP. The first node selects its BTSP within the beacon window size so as not to overlap with the BTSP of the received beacon.

System and method for selecting beacon transmission starting point in communication system

The present invention is a wireless media access method on a wireless network synchronized by a synchronizing signal broadcasted from a coordinator. In the method, priority is assigned to a plurality of devices interconnected over the wireless network for securing wireless resources in accordance with application characteristics of a packet to be transmitted, and if the devices request communication, dividing at least one slot within a superframe into a plurality of minislots. Minislots are then allocated to the devices, respectively, according to the priority, and information about the allocated minislots is inserted into the synchronizing signal. The information is then broadcast, thereby allowing each of the devices with the allocated minislots to exclusively use the allocated minislot for data communication.

Wireless media access method

A broadcast method in a wireless network and a communication apparatus using the same. The broadcast method determines whether the broadcast packet is first received upon receiving a broadcast packet. If a determination reveals that the packet is first received, the broadcast packet is stored and rebroadcast to neighbor nodes. Subsequently, a node, among the neighbor nodes, from which the broadcast packet is received, is marked as 'relayed'. The broadcast packet is rebroadcast when all of the neighbor nodes from which the broadcast packet is received are not marked as 'relayed'. When all of the neighbor nodes from which the broadcast packet is received are marked as &#x2018;relayed&#x2019;, the broadcast packet is destroyed. Accordingly, an efficient link-based broadcast method is provided.

Broadcast method in wireless network and communication apparatus using the same

A wireless communication apparatus, a wireless communication system employing the same and a control method thereof. When the wireless communication apparatus is operated as a master device, the wireless communication apparatus includes a transceiving unit for receiving and transmitting data externally, and a controller for analyzing a destination of a packet received for a certain period of time, detecting an amount of slot usage according to the destination, selecting a temporary master device according to the amount of slot usage, and transferring role of a master to the selected temporary master device. Accordingly, wireless sources can be efficiently used, and at the same time, peer-to-peer communication can be carried out among devices acting as slaves.

Wireless communication apparatus, wireless communication system employing the same and control method thereof

A wireless communication apparatus, a wireless communication method thereof, and a wireless communication system employing the same. A master device of the wireless communication system requests one slave device of a network to perform a function of a master device for a predetermined time, and sends Piconet information about other slave devices of the network, while the one slave device receives the Piconet information from the master device and communicates with the other slave devices of the network for a predetermined time as a temporary master device. Accordingly, the one slave device becomes a dynamic master device and communicates with the other slave devices by using a frequency hopping sequence and a clock of a previous master device as they are, there is no need to transmit the frequency hopping sequence and the clock of the new master device to the slave devices, and accordingly, much time can be saved.

Growing community of inventors

Suwon-si, South Korea

Jong-hun Park