Patent application number | Description | Published |
20090073043 | Apparatus for determining the location of a mobile node in a wireless system - A wireless system has a set of frequency channels that can be used for communication between a mobile node and a set of anchor nodes. The position of the mobile node is estimated by measuring the power with which wireless signals transmitted by the mobile node are received at the anchor nodes. Each anchor node cyclically scans the frequency channels, and can therefore measure the received power of wireless signals transmitted on any one of the frequency channels. When the mobile node is engaged in a call, if the measured received power drops by at least a certain amount, a quantity is added to the measured value to compensate for effects such as signal blockage by the user's hand. | 03-19-2009 |
20100195560 | Packet relay system and wireless node - A packet relay system in which each node calculates a link cost of each adjacent node based on an arrival rate of a packet from each adjacent node, acquires an accumulated value of a link cost calculated by each node in a range of nodes from a sink node for each adjacent node, calculates, for each adjacent node, a path cost of the one adjacent node by adding the link cost calculated to the accumulated value, and relays a data packet to one adjacent node selected from among nodes adjacent to the node based on a path cost of each adjacent node. This enables establishment of an upstream path to a sink node without increasing the amount of communication in a network. | 08-05-2010 |
20110051652 | Wireless communication apparatus - A packet is transmitted from a source node to a destination node via a relay path in a multi-hop network. The packet is transmitted by cache routing or source routing, depending on the presence or absence of information identifying the destination node in a history table maintained at the source node. In source routing, relay path information is included in the packet. In cache routing, relay nodes obtain routing information from entries in their own cache routing tables. Each entry indicates only the destination node and the next relay node, and each cache routing table has a limited size. When a series of packets are transmitted to the second node, cache routing can be used for all but the first packet, thereby reducing packet overhead. | 03-03-2011 |
20110235504 | Wireless communication system and nodes - A wireless communication system includes a first node, multiple second nodes, and multiple third nodes that communicate with the first node through the second nodes. The second and third nodes transmit control information to their neighboring third nodes, which calculate link costs from the reception status of the control information. The control information transmitted by each node includes a path cost indicating the cost of a path between the transmitting node and the first node. From the path costs in received control information, each third node selects a second node through which to communicate with the first node, and selects a parent node as the destination of the first hop on the path through the selected second node to the first node. Routing is thereby accomplished autonomously without having the second nodes flood the system with routing requests. | 09-29-2011 |
20110249612 | Wireless communication system preventing traffic from being relayed concentratively onto a specific node - In a wireless communication network system performing multi-hop wireless communications, a network node has a calculator for exchanging control packets with its neighboring nodes to calculate link cost values, another calculator for calculating path costs incurred on the way to a network node of interest, a manager for managing the number of downstream nodes subsidiary to each daughter node, and a downstream node adjuster for adjusting the number of the downstream nodes subsidiary to each daughter node. The adjuster produces control information, into which link cost and/or path cost information is inserted. The adjuster adjusts the contents of the link cost or path cost information, to be inserted into the produced control information, according to the numbers of the downstream nodes subsidiary to the daughter nodes. | 10-13-2011 |
20120082065 | WIRELESS NETWORK AND TERMINAL, AND NETWORK CONFIGURATION METHOD AND DEVICE - A tree topology in a multi-hop wireless network is configured by having each node other than the root node select a parent node within direct communication range, thereby becoming a child node of the selected parent node. Neighboring nodes provide selection values such as routing costs and local structural information indicating the existing topology in their vicinities, including parent-child relationships. The selection of the parent node is based on the received selection values, but the local structural information is used to bias the selection in favor of neighboring nodes with at least one other child node. This selection strategy reduces the number of parent nodes in the network and enables more nodes to operate as end nodes, which can then conserve power by carrying out sleep control. | 04-05-2012 |
20120108286 | Wireless Communication Apparatus, Wireless Communication System and Transmitting Power Control Method - A wireless communication apparatus having a plurality of neighboring wireless communication apparatuses may includes a wireless transmitter, an information control storage member, and a transmitting power calculator. A wireless transmitter may transmit a wireless signal with a transmitting power to a destination wireless communication apparatus. An information control storage member may maintain first information of links between the wireless communication apparatus and the plurality of neighboring wireless communication apparatuses, and second information of a communication route between the wireless communication apparatus and the destination wireless communication apparatus. A transmitting power calculator may calculate the transmitting power based on the first and second information, so as to ensure reception of the wireless signal. | 05-03-2012 |
20130070648 | COMMUNICATIONS APPARATUS TRANSMITTING DATA ON CHANNELS ADAPTIVELY SWITCHABLE - In a communications apparatus, a communication controller transmits and receives signals on any of plural channels. A channel switching controller is responsive to channel switching information selectively defining plural reception-waiting periods using the channels to alter a channel to be used by the communication controller. A neighboring node channel controller exchanges channel switching information with other nodes to manage the channel switching information received from the other nodes. When transmitting transmission signals, a transmission controller refers to the channel switching information of the other nodes, and controls repetitive transmission of the transmission signals on the channel thus searched for. | 03-21-2013 |