Oki Electric Industry Co., Ltd.

Yuki Kubo

Masanori Nozaki

Hiroshi Nishimura

Kentarou Yanagihara

Kosuke Sekiyama

Masaaki Date

Toshihiko Matsunaga

Yasutaka Kawamoto

Kentaro Yanagihara

Provided is a communication device including: a response request determination unit that determines whether a response request is included, from content of a transmission frame; a transmission unit that carries out processing to transmit a frame; a timer that starts to measure a time period after transmission processing is completed; a reception state determination unit that determines whether a response frame is being received when a first time period is measured; a communication processing deciding unit that decides that the time period to be measured by the timer is to be extended by a second time period in when it has been determined that the response frame is being received, and decides that predetermined processing is to be carried out when it has been determined that the response frame is not being received; and a response reception check unit that checks whether the response frame is being received correctly.

Communication device, communication method, and communication system

In a wireless communication system managing wireless communication channels, a wireless communication device includes a radio unit communicable by switching to select any one of wireless communication channels, a channel list storage storing therein a list of the channels, a channel transmission controller controlling the radio unit to transmit a packet while switching a channel on the basis of the list, a channel search transmission controller controlling the radio unit to transmit the packet while switching the channel on the basis of the list until the packet is successfully transmitted, and a transmission control selector selecting either the channel transmission controller or the channel search transmission controller on the basis of a content of the packet of a transmission target for transmission control.

Device, method and system for wireless communication on a channel selected from an available-channel list

There is provided a wireless transmission device in which a lower layer processing unit inserts first random delay before frame transmission in response to a frame transmission request made by an upper layer processing unit, the wireless transmission device including a frame transmitting unit configured to transmit a frame when the frame transmission request is made by the upper layer processing unit, and a frame group transmitting unit configured to transmit a frame group including one or two or more types of frame in accordance with a listening state of a facing wireless reception device when the frame transmission request is made by the upper layer processing unit.

Wireless transmission device, wireless reception device, wireless transmission program, wireless reception program, and wireless communication system

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.

Packet relay system and wireless node

The communication apparatus intermittently carries out receiving operation during a predetermined reception period. The apparatus includes a wireless communication section for carrying out wireless communication, which includes a carrier sensor for sensing a carrier at the beginning of the communication, and a carrier sense switching section for using carrier sense levels different between packet transmission and reception to switch the carrier sense level of the carrier sensor according to the packet. Thus, the apparatus can use and flexibly adjust the optimum carrier sense level for the intermittent receiving operation within the reception period.

Intermittently operable communication apparatus with different carrier sense levels switched between transmission and reception and method therefor

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.

Communications apparatus transmitting data on channels adaptively switchable

An information communication apparatus may include a request buffer, a request sorting device, a sending device, a frame generating device, and a frame transmitting device. A request buffer may store transmission requests corresponding to frames. A request sorting device may sort the transmission requests. A sending device may send the sorted transmission requests in accordance with a transmission timing that is determined based on destinations of the frames and in which a receiving node can receive the frames. A frame generating device may generate frames based on the received transmission requests. A frame transmitting device configured to transmit the generated frames.

Information communication apparatus and program storage medium

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.

Wireless communication apparatus, wireless communication system and transmitting power control method

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.

Wireless network and terminal, and network configuration method and device

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.

Wireless communication system and nodes

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.

Wireless communication apparatus

An intermittent operation communication device periodically repeats beacon transmission, data reception or data reception wait, and sleep to transmit data to any of reception side communication devices. The intermittent operation communication device includes a data transmitter for performing transmission when receiving a beacon from any of the reception side communication devices and having data traffic generated meant for a reception side communication device, a transmission announcer for intermittently transmitting a transmission announcement beacon while waiting for reception when having the data traffic generated, and an adjuster for monitoring a transmission announcement beacon from any other of the intermittent operation communication devices to adjust the transmission of the data traffic.

Intermittent operation communication device and communication system using beacon and sleep mode

An intermittent operative communication apparatus can send data, received from a source communication device, to any receiver communication device at a predetermined interval and wait for receiving data at the predetermined interval. The communication apparatus has a selector for selecting one or multiple receiver communication devices as a reference communication device that gives a reference timing at which the communication apparatus waits for receiving data, and a timing controller for setting a timing, at which the communication apparatus waits for receiving data, to a timing according to operation of any reference communication device.

Intermittent operative communication apparatus adaptively controlling the timing of waiting data reception and a method therefor

A transmission timing control apparatus included in a network node constituting a telecommunications system is configured to use the reception timing of a timing signal from another node to determine the transmission timing of a timing signal of the own node and determine a time slot for transmission of a data signal in accordance with the transmission timing and the reception timing of a timing signal from the other node. A response timing signal transmitter transmits a response timing signal when received the timing signal from the other node. A transmission timing control circuit uses the reception timing of the timing signal and that of the response timing signal to determine the timing at which the own node transmits the timing signal.

Communication timing control for allotting a time slot by a distributed coordination through interaction with neighboring nodes

A telecommunications control apparatus is included in each of a plurality of nodes constituting a telecommunications system and includes a reception power decider for determining the reception power value of a control signal received from another node. A control signal decider decides, in accordance with the reception power value of the control signal thus determined, whether or not the own node should communicate with the other node in relation to interference at the own node. A communication controller controls communication between the own node and the other node in accordance with the result of decision made by the control signal decider.

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Osaka, Japan

Yuki Kubo