Fujitsu Corporation

Takayuki Okamasu

Yayoi Nomura

Yasuhiro Kurogi

Kenji Yamada

Mitsuharu Amano

Taiji Kondo

Tatsuya Soneda

Syunsuke Koga

Yuichi Inao

Makoto Kawatoko

Kazuaki Sumi

First node stores completion information on second node that is adjacent to the first node, the completion information indicating whether or not a route between a target destination and the second node has been constructed using an address with a specified size; acquire a first address with the specified size that specifies the first node, and transmits to adjacent nodes the completion information on the first node indicating that the route between the target destination and the first node has been constructed using an address with a specified size, when the completion information on the second node has indicated that the route between the target destination and the second node has been constructed using the address with the specified size and when the first address has been acquired; and transmits a data frame by using the first address, when the completion information on the first node is transmitted.

Node apparatus, record medium for storing control program, wireless communication system, and method for data communication

A node apparatus that establishes a wireless communication network through wireless communication with other node apparatuses adjacent to the node apparatus includes a memory configured to store node alive-or-dead information, which represents whether or not a node apparatus is in an abnormal state, a controller configured to perform processes including receiving a data frame, performing determination regarding an alive-or-dead state for a transmission destination node apparatus obtained from the data frame on the basis of the node alive-or-dead information stored in the memory, and determining a destination of the data frame from a transmission destination node apparatus obtained from the data frame and a transmission source node apparatus obtained from the data frame on the basis of a result of the determination, and a transmission unit configured to transmit the data frame in which the determined destination is set.

Node apparatus, recording medium that has stored control program therein, and method of operating node apparatus

A method and a device perform time-synchronization with an ad hoc network configured by a plurality of nodes. The method includes: transmitting a time-synchronization request frame including an address of one of the plurality of nodes which belong to the ad hoc network to one of the plurality of nodes having a function of receiving the time-synchronization request frame and transmitting a time-synchronization reply frame including time-synchronization information; receiving the time-synchronization reply frame including the time-synchronization information from one of the plurality of nodes which receive the time-synchronization request frame; and performing time-synchronization with one of the plurality of nodes using the time-synchronization information included in the time-synchronization reply frame.

Method and device for time-synchronization in ad hoc network

Each of the nodes included in an ad-hoc network determines whether an identifier indicative of high-priority data is included in data received from another node. When the identifier is included in the received data, each of the nodes determines whether the subject node is a device that relays the received data to a destination. When determining that the subject node is a device that relays the received data to the destination, each of the nodes transmits the received data to the destination. When determining that the subject node is not a device that relays the received data to the destination, each of the nodes suppresses data transmission to the nodes included in the ad-hoc network.

Transmission control method and node

In a data communication system which reduces traffic on a wireless network by reducing Ack responses, on a transmitting side, an Ack request provided within a wireless data frame is validated (turned 'ON') to be transmitted; and an Ack request cycle is extended when an Ack in response to the Ack request has been received within a fixed time (timeout period 'To') during a cycle for transmitting the Ack request while if otherwise, the cycle is shortened. On a receiving side, only in case that a frame identifier indicating a sequence of an Ack request is found to be an expected one and the present Ack request receiving interval is found to be longer than the last Ack request receiving interval, a redundant transmission frequency of the Ack in response to the Ack request is decreased while the Ack request receiving interval is updated to the present interval in either case.

Data communication system

A wireless terminal and wireless communication method that can improve data transfer efficiency and reduce traffic. A frame transmitter of a wireless terminal transmits a frame by wireless. A wireless terminal receives the frame transmitted from the frame transmitter and transmits the received frame by wireless to a wireless terminal. A frame receiver receives the frame transmitted from the succeeding wireless terminal to the wireless terminal. When the frame is received by the frame receiver, a frame reception recognizer recognizes that the frame has been received by the succeeding wireless terminal. It is therefore unnecessary for the wireless terminal to receive, from the succeeding wireless terminal, a frame indicative of reception of the frame, so that the data transfer efficiency improves and the traffic reduces.

Growing community of inventors

Fukuoka, Japan

Takayuki Okamasu