Fujitsu Corporation

Takuji Furusawa

Katsumi Kobayashi

Hiroaki Kawasumi

Takahiro Koharagi

Masaharu Nozawa

Masashi Kuwahara

Shinichi Hirata

Jun Hasegawa

Manabu Kai

Teruhisa Ninomiya

Joji Maruyama

Katsunori Hayashi

A node apparatus for forming a wireless ad-hoc network, including: a recognition possibility determination unit that determines whether or not a gateway apparatus connecting the wireless ad-hoc network to other network can be recognized; an adjoining node detection unit that detects other node apparatus which is the source of a received packet as an adjoining node; a channel switching unit that switches, when the recognition possibility determination unit determines that the gateway apparatus cannot be recognized, the channel used for reception of packets transmitted in the wireless ad-hoc network successively to each of a plurality of channels; and a channel selection unit that selects a channel to be used for communication in the wireless ad-hoc network based on the number of adjoining nodes detected by the adjoining node detection unit in each of the plurality of channels.

Node apparatus, communication system, and channel selection method

In a planar inverted F antenna, a second radiation element is provided parallel to the GND surface and extending partially with respect to a first radiation element in a longitudinal direction, so as to substantially increase a width of the first radiation element in the vicinity of a power supply section.

Planar inverted F antenna

A gateway apparatus including: a route control packet generating unit that generates a route control packet for constructing routes between node apparatuses forming an ad hoc network and the gateway apparatus; a channel designation signal generating unit that generates channel designation signal for designating a second channel different from a first channel on which the ad hoc network transmits and receives packets; a time designation signal generating unit that generates time designation signal for designating switching time to the node apparatus for switching the channel used for transmission and reception of packets to the second channel; a radio communication unit that transmits the route control packet, the channel designation signal and the time designation signal on the first channel; and a channel switching unit that switches, when it is time to switch, the channel on which the radio communication unit transmits and receives a signal to the second channel.

Gateway apparatus, node apparatus, communication system, and channel switching method

A distribution method is performed in a distribution system including a distribution source device for distributing data and a plurality of distribution destination devices. The distribution method includes searching, by the distribution source device, for the distribution destination devices by expanding a search range by plural stages; executing in each stage, by the distribution source device, an allowance process of allowing distribution of the data to the distribution destination devices found by searching in each stage; detecting in a predetermined range, by the distribution destination device, another distribution destination device that has acquired the data before the distribution destination device performing the detecting; and executing, by the distribution destination device, an acquiring process of acquiring the data from the other distribution destination device, according to allowance of distribution.

Distribution method and distribution system

Growing community of inventors

Tokyo, Japan

Takuji Furusawa