Nec Corporation

Masato Kudou

Masakazu Ono

Shingo Watanabe

Shigeru Asai

Kenji Wakafuji

Hideto Shibohta

Hideto Shibouta

Yoshinori Yamada

Junichi Funada

Tsuneo Nakata

Hisashi Mizumoto

A processor () in a wireless terminal () executes a communication service application to thereby perform an operation as a client for using a communication service. Further, in an abnormal situation where the wireless terminal () cannot access a server system () of an operator of the communication service, the processor () executes a predetermined activation procedure in the wireless terminal () without passing through the server system () to thereby activate a special account in the wireless terminal (). This makes it possible, for example, to perform communication by the special account using an online service application installed in the wireless terminal during an abnormal situation where the wireless terminal cannot access the online service server.

Wireless terminal and method for messaging

A node in a DTN includes: a memory; and a processor coupled to the memory and configured to execute data transfer processing for the DTN, wherein the data transfer processing including: receiving a plurality of bundles to be transferred to a same destination node on the DTN, each of the plurality of bundles including any one of a plurality of data segments acquired by dividing data of a content; deleting a part of the bundles from among the plurality of bundles without transferring to any other node or compressing a data size of a payload of the part of the bundles in accordance with a communication status of the DTN; and transmitting either a rest of the bundles excluding the deleted part of the bundles or the plurality of bundles including the part of the bundles having the compressed payloads to the DTN for transmitting to the destination node.

Apparatus and method for data delivery in delay-tolerant network (DTN)

A wireless terminal device () for use in a store-and-forward type wireless network includes a wireless communication unit (), a memory (), and a control unit (). The memory () is coupled to the wireless communication unit () and is configured to store messages transferred via the wireless network. The control unit () is configured to adjust, based on first information, at least one of a maximum number and maximum retention time of messages stored in the memory (). The first information relates to a degree of contribution of the wireless terminal device () to success in sending messages from a source node to a destination node via the wireless network. It is thus possible to provide, for example, an efficient memory control method suitable for a store-and-forward type wireless network.

Wireless terminal device and control method thereof

A wireless communication device of the present invention has a device information storage part that stores device information identifying another wireless communication device that can establish wireless communication. When transmitting data, the wireless communication device attaches transmission source neighboring device information stored in the device information storage part of the device to the data, and transmits the data to another wireless communication device. When receiving data, the wireless communication device stores transmission source device information identifying another wireless communication device having transmitted the data into the device information storage part of the device. The wireless communication device determines whether to relay and transmit the received data to another wireless communication device on the basis of the result of comparison between the transmission source neighboring device information attached to the received data and receiver neighboring device information stored in the device information storage part of the device.

Wireless communication device

A processor () implemented in a wireless terminal () is configured to perform gateway processing by executing a first application program () stored in a memory (). The gateway processing includes: (a) receiving transmission data of other application programs (-); (b) selecting, from a plurality of communication interfaces (-), at least one communication interface to which the transmission data is to be transmitted; and (c) sending the transmission data to the selected at least one communication interface. This contributes, for example, to allowing an application program to easily communicate via a communication interface (i.e., communication path) conforming to a communication protocol that is additionally installed on a wireless terminal (e.g., smartphone).

Wireless terminal, computer readable medium storing application program, and method

The present invention is provided to implement an automated setting change of network setting items on an ad hoc network which does not have a specific base station. A method of changing network setting for changing setting of a network where a plurality of terminals are connected, the method including the steps of: a request source terminal transmitting a request for setting change to a selected representative terminal; the selected representative terminal, upon receiving the request for setting change, transmitting a request for permission to at least a majority of representative terminals; the selected representative terminal transmitting a success notification to the request source terminal upon receiving a notification of permission from the majority of representative terminals in response to the request for permission; the request source terminal transmitting, to the plurality of terminals, an execution instruction including at least a content of setting change, upon receiving the success notification; and the terminal which has received the execution instruction changing the setting according to the content of setting change.

Network setting change method and system thereof, and terminals which are used with said system

A radio wave jamming system () comprises a plurality of radio transmitters () that are adapted to transmit respective jamming signals () including substantially the same frequency. The plurality of radio transmitters () are further adapted to temporally change at least one of the transmission phases of the jamming signals (), which are to be transmitted from the plurality of radio transmitters (), so as to temporally change the phase differences among the jamming signals () when the jamming signals () transmitted from the plurality of radio transmitters () arrive at a particular site (). Thus, for example, a radio wave jamming system that can be constituted by small-output radio devices can be provided.

Radio wave jamming system, radio wave jamming apparatus, and radio wave jamming method

A server () receives a first message indicating that a final destination is a first mobile node. Next, the server () determines, from among a plurality of gateways (to) that provide connectivity with a network infrastructure () to a plurality of wireless ad-hoc networks (to), a first gateway to which the first message is to be transferred, based on a movement history of the first mobile node. Then, the server () attempts to transmit the first message to the first mobile node through the determined first gateway. It is thus possible to contribute, for example, to an improvement of probability of delivering messages addressed to mobile nodes within a wireless ad-hoc network.

Server and communication method thereof

A node device (A) receives a second ACK list in communication with an adjacent node (B) and updates a first ACK list and a first summary vector on the basis of the second ACK list. The first summary vector, which indicates messages stored in a message buffer of the node device (A), is transmitted to the adjacent node (B) prior to transmission of the messages in the communication with the adjacent node (B). The first ACK list indicates ACK messages recognized by the node device (A). The second ACK list indicates ACK messages recognized by the adjacent node (B). Each ACK message represents a message of arrival at an ultimate destination node via a DTN (). In this way, for example, a copy having the same content as a message having arrived at an ultimate destination node can be prevented from being scattered in the Disruption Tolerant Network (DTN).

Node device used in disruption/delay/disconnect tolerant network and communication method

A wireless communication device includes two wireless communication units, each switching one of a VHF band and a UHF band to another to conduct wireless communication; a determination unit which determines whether or not it is necessary to change a frequency band when one of the wireless communication units uses the VHF band to conduct the wireless communication, and further determines whether or not there is a wireless communication device that becomes unable to conduct wireless communication due to using the UHF band when the change is necessary; and a communication control unit which performs control to switch the band to the UHF band when it is determined that there is no wireless communication device which becomes unable to conduct wireless communication, and to leave the band as the VHF band when it is determined that there is a wireless communication device which becomes unable to conduct wireless communication.

Growing community of inventors

Tokyo, Japan

Masato Kudou