Fujitsu Corporation

Yuichi Inao

Kenji Yamada

Tatsuya Soneda

Syunsuke Koga

Katsuhiko Yamatsu

Yayoi Nomura

Taiji Kondo

Yuuta Nakaya

Norihito Nishimoto

Koki Mie

Takayuki Okamasu

Yasuhiro Kurogi

Yuji Higashihara

Makoto Kawatoko

Hidefumi Takaoka

Kensuke Kubo

Kouki Mie

Masahiro Hayashi

Etsuko Katou

A communication apparatus includes a receiver, a memory, a processor, and a transmitter. The receiver receives a route information frame and a first frame that is not the route information frame. The memory holds a route information table. The route information table records route information included in the route information frame. When the route information table does not include the source address of the first frame, the processor associates the source address with the address of a transfer-source apparatus that has transferred the first frame to the receiver, and registers these addresses in a registration table. In order to transmit a second frame addressed to a destination apparatus that is not recorded in the route information table, the processor obtains the address of a transfer-source apparatus registered in association with the address of the destination apparatus. The transmitter transmits the second frame to the address obtained by the processor.

Communication method and communication apparatus

A wireless communication apparatus stores therein, in an associated manner, each piece of path information on a plurality of destinations and a use frequency of data communication that is performed by using the path information. When the wireless communication apparatus receives data whose send source is a first destination, the wireless communication apparatus specifies, on the basis of the use frequency, path information that is less frequently used from among the pieces of the stored path information. The wireless communication apparatus updates the specified path information to path information whose destination is the first destination.

Wireless communication apparatus, wireless communication method, computer-readable recording medium, and wireless communication system

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

A network includes node devices each storing a table that manages paths to plural gateway devices for connecting to another network. A node device generates a hello frame for specifying a main gateway device of the node device at a predetermined timing, and transmits the hello frame to adjacent node devices. The node device, upon receiving a hello frame from an adjacent node device operating as a first hop destination of a data frame destined for the main gateway device, determines whether quality of a path to the main gateway device is lowest among paths to the plural gateway devices, based on path quality information included in the hello frame. When the quality of a path to the main gateway device is lowest, the node device changes the main gateway device to a gateway device that is registered in the table and specified by information included in the hello frame.

Apparatus and method for determining an optimum gateway node in a communication network

A wireless communication apparatus on the receiving side receives communication data that is a transmitted to the wireless communication apparatus using one of the plurality of channels. Subsequently, the wireless communication apparatus on the receiving side obtains channel information contained in the communication data received by the receiving unit and judges whether the obtained channel information is target information indicating a channel of a processing target. The wireless communication apparatus on the receiving side performs a receiving process on the received communication data, when the judging unit determines that the obtained channel information is the target information, performs a receiving process on the communication data received by the receiving unit and that, when the judging unit determines that the obtained channel information is not the target information, discards the received communication data.

Wireless communication apparatus and non-transitory computer readable storage medium

A wireless communication system is provided. A control device includes: a receiver configured to be able to receive information from radio frequency channels; a processor that judges whether a first channel is congested, and generates switchover instruction information when the first channel is judged to be congested; and a transmitter that transmits the switchover instruction information. Each node device includes: a receiver that receives information through the first channel; a transmitter that transmits information through a transmission channel; and a processor that recognizes whether a hop count from the control device is one, selects a second channel and specifies it as the transmission channel in a first case in which the receiver receives the switchover instruction information from the control device and the hop count is recognized as one, and specifies the first channel as the transmission channel in a second case in which the first case does not hold.

Communication system, control device, and node device

Anode device includes a transmitter and a processor. The transmitter transmits an inspection frame used in inspecting a status of a route from a source node device to a destination node device. The processor generates a first inspection frame and selects a first node device to which the transmitter transmits the first inspection frame from among candidates for a node device to which a frame addressed to the destination node device is to be forwarded. The processor judges whether a transmission of the first inspection frame has been successfully performed. When the transmission of the first inspection frame has failed, the processor generates a second inspection frame which records a failure in a communication with the first node device. The processor selects a second node device to which the transmitter transmits the second inspection frame from among the candidates.

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Fukuoka, Japan

Yuichi Inao