Ntt Docomo, Inc.

Hidenori Aoki

Kengo Yagyu

Shinji Takeda

Yoichi Matsumoto

Atsushi Fujiwara

Narumi Umeda

Koji Omae

Junichiro Hagiwara

A wireless communication apparatus is provided. The wireless communication apparatus includes: detection means that detects that there is another wireless communication apparatus around the wireless communication apparatus; comparison means that compares a first reference value managed in the wireless communication apparatus with a second reference value managed in the another wireless communication apparatus; means that corrects the first reference value based on the comparison result; and means that announces the first reference value to the another wireless communication apparatus. Frequencies are set such that a frequency of the wireless communication apparatus becomes same as a frequency of still another wireless communication apparatus to which a radio wave of the wireless communication apparatus does not reach but a radio wave of the another wireless communication apparatus reaches.

Wireless communication apparatus and wireless communication method

A fault-tolerant packet transmission system is disclosed that can avoid localized load concentration on a specific portion of a network, while autonomously keeping route optimization, without adding a route control function to non-mesh devices. In a packet transmission system including multiple wireless base stations and one or more terminal devices belonging to one of the wireless base stations, each of the wireless base stations has a location table describing each of the terminal devices associated with a corresponding wireless base station to which the terminal device currently belongs. The wireless base stations exchange the information in the location table with each other to update the location tables and forward a received packet to the next hop along a transmission route toward a destination terminal device.

Packet transfer system, radio base station, and packet transfer route optimization method

A channel allocation method for dynamically allocating channels of a plurality of radio interfaces at each access point included in a mesh network is provided. The method includes the steps of (a) acquiring, at each access point, in-node information about the access point itself, and (b) grouping high-traffic access points in a cluster using a same channel set based on the acquired information.

Channel allocation for access point in mesh network

A wireless communication apparatus for performing communication via a plurality of wireless interfaces in a wireless ad hoc network is disclosed. When the wireless communication apparatus receives a request frame via one of the plurality of wireless interfaces, the wireless communication apparatus sends the request frame from at least two wireless interfaces in the plurality of wireless interfaces. In addition, the wireless communication apparatus selects a wireless interface to be used for communication from among the plurality of wireless interfaces based on the request frame.

Wireless communication apparatus, communication routing control apparatus, communication routing control method and communication system

In a wireless packet transmission system that includes multiple wireless basestations and one or more wireless terminals belonging to one of the wireless basestations, transmission trees extending from two or more wireless basestations as root stations are used. Each of the wireless basestations has a tree table configured to record the root stations in association with the ID information about the transmission trees. When receiving a packet, each of the wireless basestations determines the transmission tree to be used for the packet transmission, and transmits the packet to a next node along the determined transmission tree.

Packet transmission system, wireless basestation, and route optimization for packet transmission

A communication apparatus is disclosed, which includes an information collection unit, a storage unit, a selection unit, and a route control unit. The information collection unit is configured to collect route information and condition information. The storage unit is configured to store the route information and the connection information. The selection unit is configured to select a connection apparatuses for a terminal apparatus based on the route information and the connection information. The route control unit is configured to control routes from the communication apparatus to the connection apparatus.

Communication system capable of selecting optimum gateway for terminals

A mobile node () capable of establishing an ad hoc network routing is disclosed. The mobile node comprises a transmitting/receiving unit () for communicating with other communication unit and a routing request generator () for generating a routing request message for requiring an ad hoc network routing. The mobile node further comprises: an address storage () for storing an address of the mobile node () and an address of a receiving node; a random number generator () for generating a random number; a certificate issuing unit () for issuing a certificate of the mobile node (); a digital signature creator () for creating a digital signature of the mobile node (); and a controller () for transmitting/receiving the routing request message accompanied by the address of the mobile node, the address of the receiving node, the random number, the certificate and the digital signature via the transmitting/receiving unit, according to an ad hoc network protocol.

Growing community of inventors

Yokohama, Japan

Hidenori Aoki