Fujitsu Corporation

Yasuaki Kamimura

Yukio Hayashi

Yoshihiko Shirokura

Takao Ito

Shigemasa Matsubara

Hiroaki Tamai

Naoto Miyauchi

Yosuke Nishikata

Masahiro Machida

Takafumi Kawakami

Kazuya Takeuchi

Katsumi Kobayashi

Taiji Kondo

Akira Okubo

Koichi Ishibashi

Hiroaki Kawasumi

Takahiro Koharagi

Shinichi Hirata

Masashi Kuwahara

Joji Maruyama

Mitsuaki Yasuoka

Kobun Nakajima

Katsumi Okuda

Katsunori Hayashi

Hajimu Hirai

Tetsuhiro Murata

A communication device is provided in a wireless multi-hop network. The communication device receives a sequence number, a divided time acquired by dividing a time width allocated for transmitting detected usage data by a division number, and the division number. The communication device calculates a remainder by dividing the received sequence number by the division number and calculates a transmission offset time based on the remainder and the divided time. The communication device transmits the usage data based on the calculated transmission offset time.

Communication device and communication method

A data communication apparatus forms a mesh network together with at least one gateway includes a frame generating unit and a frame transferring unit. The frame generating unit generates a meter data frame to transmit to a gateway. The meter data frame is a frame including meter data. The frame transferring unit transfers the meter data frame received from another data communication apparatus. The meter data frame is addressed to the gateway. The frame generating unit transmits the meter data frame to which number of alternate routing that indicates number of allowable transmission attempts from a data communication apparatus adjacent to a destination gateway of the meter data frame to the gateway is added. The frame transferring unit changes the number of alternate routing added thereto to a value smaller by 1 than a value that has been set and transits the meter data frame to another data communication apparatus.

Data communication apparatus, data communication system, and data communication method

The present invention increases accommodation efficiency in a wireless master station for wireless slave stations, and efficiently uses wireless resources while controlling traffic. In a communication system in which a plurality of wireless slave stations---, . . . , perform wireless communication with wireless master stations-and-directly or through another wireless slave station and which performs communication from the wireless master stations with a collection control deviceby means of wired communication or the like. The collection control devicestores first through fourth threshold values a, b, c, and d in memory, and makes efficient use while suppressing traffic by performing a 'connection suppression notification', a 'specific high-frequency communication stop notification', and an &#x201c;accommodation refusal notification&#x201d;, and performs functionality control through stages according to the number of accommodated wireless slave stations.

Communication system, congestion avoidance method thereof, and meter reading system using communication system

A software update system includes an administration server, a wireless communication terminal, and a wireless-communication key station. The wireless communication terminal is configured to be connected to the administration server through a communication network. The a wireless-communication key station is configured to be positioned between the administration server and the wireless communication terminal, and to perform processing of distributing software of an update object transmitted from the administration server to the wireless communication terminal.

Wireless communication terminal, software update system, and software update method

Growing community of inventors

Tokyo, Japan

Yasuaki Kamimura