Panasonic Corporation

National Institute of Information and Communications Technology, Incorporated

Matsushita Electric Industrial Co., Ltd.

Nissan Motor Company Limited

Tetsuya Kawakami

Yoshihiro Suzuki

Masayuki Fujise

Genadi Velev

Atsushi Nakamura

Jon Schuringa

Michiru Yokobori

Kazuhiko Miyamoto

Satoshi Kitajima

A technique is disclosed, by which it is possible to achieve the reduction of power consumption of each wireless node and to perform efficient access control in wireless communication system. According to this technique, a given period with a beacon transmitted from a gateway (GW)at the foremost position is divided to an active period where each wireless node (P2P tag) transmits and receives a frame and a sleep period where transmitting and receiving of the frames are stopped. Further, the active period is divided to a plurality of timeslots each with a fixed length, and the period is partitioned to sub-periods where each type of a GW, a fixed node (P2P-S tag), and a mobile node (P2P-M tag) can transmit frames respectively. Each of the P2P tags selects a timeslot at random from the period for each type, and after waiting for a waiting period at random at the selected timeslot, it transmits a frame including information to identify the selected timeslot or the waiting period in addition to its own ID.

Wireless communication system, communication control method and communication node

A technology is disclosed in which, when a normal mobile node (that does not newly provide a dedicated function) is used, signaling for reconfiguring a tunnel during a mobile node movement is reduced and, furthermore, packet loss is reduced. In the technology, when an MN moves from under the control of an ARthat is a movement origin to be under the control of an ARthat is a movement destination, the ARreceives an NS transmitted from the MN to the AR. The ARthat receives the NS destined to the ARtransmits a 'Location Update' to the AR. The ARthat receives the 'Location Update' uses an MN management table of the relevant MN and creates &#x201c;Prefix Information&#x201d; and returns the &#x201c;Prefix Information&#x201d; to the AR. A tunnel is established between access routers of the ARand ARthrough use of the &#x201c;Prefix Information&#x201d;, and a packet destined to the MN is transferred to the MN via the tunnel.

Mobile communication method and access router

The present invention provides a radio node apparatus, a multi-hop radio system and a multi-hop radio system constructing method, capable of constructing a tree type multi-hop radio system in which mutual radio nodes determine a radio node which becomes a root node of a tree in an autonomous manner and the root node is set as a root in an autonomous manner. The radio node apparatus includes a storage unit for storing state information, used for constructing a multi-hop radio system, including information for specifying a root radio node apparatus positioned at a summit of the multi-hop radio system, with the radio node apparatus has a connection, and the number of hops from the root ratio node apparatus, a collection unit for collecting state information transmitted from surrounding radio node apparatus, and a selection unit for selecting a host connection-accepting radio node apparatus on the basis of the information for specifying the root radio node apparatus and the number of hops included in the collected state information.

Radio node apparatus, multi-hop radio system, and multi-hop radio system constructing method

A wireless node apparatus in a multihop wireless LAN with a tree structure having a plurality of wireless node apparatuses, at least some of which become relay apparatuses to provide multihop communication, transfers packets among wireless nodes as done in a tree type LAN, without intervening a root node, to communicate among the wireless nodes.

Wireless node apparatus, and multihop wireless LAN system

In a dynamic damper including: a torque transmissible tube member; a mass member housed within an inside of the tube member concentrically to the tube member; and a pair of elastic members, both ends of the mass member in a center axis direction of the tube member are coupled to the tube member via the pair of elastic members, the mass member includes a large mass section interposed between the pair of elastic members, a length of the mass member in the center axis direction of the tube member is longer than a diameter of the large mass section, and, from among two different bending resonance vibration modes of the tube member, a node of a higher order bending resonance vibration mode is placed at a position between the pair of elastic members.

Dynamic damper with multiple degree of freedom

In flow control apparatus formed of a network of switching hubs in a hierarchy configuration for performing data packet transfer within each of a plurality of respectively separate groups of terminals, based on use of group identifiers contained in the data packets, occurrence of congestion of the output section of a port of a switching hub is judged respectively separately for each of the terminal groups, and one or more congestion notification packets for effecting a pause in data packet transmission are generated and transmitted from that switching hub, directed only to one or more terminals of a group relating to the congestion. As a result, the effects of port congestion and of congestion control operations are limited to the terminal group concerned. Congestion can be judged for a terminal group based on a level of utilization of a port output buffer that is used only by that group, or based on a rate of flow of data from that group into a port output buffer which is used in common for all terminal groups, and congestion notification packets may be transmitted from a single port or from a plurality of ports of a switching hub, in accordance with the detected degree of congestion.

Growing community of inventors

Kanagawa, Japan

Tetsuya Kawakami