Abstract: A data-storing-terminal counting unit counts the number of communication terminals in which each of a number of data are stored. Based on the results of the counts, a communication terminal count estimation unit estimates the number of communication terminals that will transmit data with the same timing. An adjustment reference value calculation unit computes an adjustment reference value for constraining the number of communication terminals estimated by the communication terminal count estimation unit to be less than or equal to a preset allowable number. On the basis of the adjustment reference value computed by the adjustment reference value calculation unit, a determination unit determines whether or not to permit transmission of data stored by a storing means. If the determination unit permits the transmission of said data, a data transmission unit transmits the data to a communication terminal in which said data is not stored.

Abstract: Provided are a communications state determination device, etc., capable of improving the accuracy of network state specification. This communications state estimation device comprises: a setting means that, in accordance with given communications parameters, applies the communications parameters to a communications device that determines the occurrence of communications errors in communications with a communications destination device; a detection means that sends communications instructions to the communications device that performs communications, in accordance with received communications instructions, and detects the occurrence of communications errors that have been determined in the communications that are in accordance with the instructions; and an estimation means that estimates whether or not the communications device can perform the communications, on the basis of the communications parameters and the existence or otherwise of communications errors.

Abstract: A communication terminal in an ad hoc network has a wireless communication part, a lower layer protocol part operating on a lower layer of the network, and an upper layer protocol part operating on an upper layer of the network. The lower layer protocol part has a routing table holding route information including a destination IP address and a next hop IP address associated with each other. The upper layer protocol part has: an information sharing management part transmitting and receiving a message including an IP address of the local communication terminal to and from a neighbor communication terminal through the wireless communication part by broadcast communication; and a route information registration part registering, into the routing table, the route information including the IP address included in the message received by broadcast communication as the destination IP address and as the next hop IP address.

Abstract: A method to reduce group reformation time and maintain seamless connectivity in a peer-to-peer network at the time of disappearance of the Group Owner (GO). Each of the nodes is provided with an emergency leader list which prioritizes a predetermined number of emergency leader nodes each of which is a client node having intent of acting as an emergency leader, wherein the emergency leader list is prepared right at the time of group formation. The emergency leader nodes broadcast beacons when a leader node disappears from the group without notice. Each of the client nodes barring a first-priority emergency leader node of the emergency leader list connects to a highest priority one of emergency leader nodes detected by the client node.

Abstract: A communication terminal has a wireless communication part and a control part. The control part sequentially switches a plurality of communication channels and discovers another communication terminal existing around the communication terminal itself. In the case of connecting to the other communication terminal found in the discovery, the control part determines which of the communication terminals transmits a connection request. In a case where the communication terminal itself does not transmit a connection request, the control part stops the discovery process and waists for reception of a connection request from the other communication terminal by using a given communication channel.

Abstract: A node device 100 is configured to: allocate a channel for communication to each of radio interfaces; between the radio interface and a radio interface which is included by an adjacent node device and to which the same channel as the channel allocated to the radio interface is allocated, establish a communication link using the channels; and, by using a communication link (a use communication link) set for the destination of received data among established communication links, transfer the data to the adjacent node device. The node device 100 specifies an unused channel that is other than a channel used by a communication link set as the use communication link among already allocated channels (101), and releases allocation of the unused channel (102).

Abstract: A communication terminal, comprises: a wireless communication unit to which a plurality of channels are allocated; a channel status calculation unit that calculates, when one of the plurality of channels is set as a forwarding channel, a capacity that can be used in the one channel by the communication terminal and a capacity that can be used in the one channel by another communication terminal; and a channel selection unit that determines, when one of the plurality of channels is set as a forwarding channel, whether a capacity that can be used in the one channel by the communication terminal satisfies a required bandwidth and determines, when another communication terminal has set the one channel as a forwarding channel, whether a capacity that can be used in the one channel by the another communication terminal satisfies the required bandwidth.

Abstract: Upon sensing an update of any routing information entry held in a routing information storage unit (A104), an information exchange coordination unit (A105) references a node information storage unit (A102), and if a node information entry corresponding to the updated routing information entry does not exist, acquires the corresponding node information entry from another communication terminal (A1b). Alternatively, upon sensing an update of any node information entry held in the node information storage unit (A102), the information exchange coordination unit (A105) references the routing information storage unit (A104), and if a routing information entry corresponding to the updated node information entry does not exist, acquires the corresponding routing information entry from another communication terminal (A1b). This provides a communication terminal for acquiring both the node information entry and the routing information entry relating to a specific communication terminal substantially at the same time.

Abstract: A node device has a delivery predictability management part, a DTN communication part, and a user interface part. The delivery predictability management part stores, for each destination node, delivery predictabilities including a delivery predictability for the destination node calculated by a local node and a delivery predictability for the destination node calculated by a neighboring node. The DTN communication part refers to the delivery predictabilities for each destination node and selects a next hop node in transferring transfer data from the local node to the destination node. The user interface part allows selection of a destination node for DTN communication with the local node as a source node on a basis of the delivery predictabilities for each destination node.

Abstract: Upon receiving a routing control message from another communication terminal (B1), a communication terminal (A1) uses a MANET routing control unit (A133) to update and manage route information when a routing domain described in the routing control message matches the routing domain of the communication terminal (A1) itself. When the communication terminal itself does not belong to the routing domain, the communication terminal uses a DTN routing control unit (A132) to update and manage route information to another routing domain, and uses a route information advertisement unit (A134) to advertise the route information to another routing domain and the routing domain to which the communication terminal (A1) itself belongs, for another communication terminal (B1).

Abstract: A storage part stores the history of a failure in connection to the other communication device. A searching part performs search for the other communication device. A connection availability determination part performs determination whether or not to connect to the other communication device found in the search on the basis of the history. A connection control part causes the searching part to perform the search again in a case where it is determined not to connect. On the other hand, in a case where it is determined to connect, the connection control part executes a connection process of connecting to the other communication device and, when the connection process fails, the connection control part performs update of the history and causes the searching part to perform the search again.

Abstract: An information sharing system is provided with multiple communication devices that wirelessly connect with other communication devices in order to communicate with them without going through an access point. Each communication device has: an internal deduction portion that, using a reception history of notification messages received from the other communication devices, deduces which information is currently being held by each of the other communication devices; a duplication determination portion that determines whether or not the information that is currently being held by another communication device and that was deduced by the internal deduction portion matches information held by its own host device; and an information exchange portion that, when the duplication determination portion determines that the information does not match, transmits a notification message that contains the information held by its own host communication device.

Abstract: A first communication terminal, unconnected with a communication network, searches for a second communication terminal existing around the own communication terminal. In the communication network, one of a plurality of communication terminals functions as a master having a function of an access point, and the rest of the communication terminals function as slaves of the master. Based on the information included in a communication message received from one or more second communication terminals found through the search, the first communication terminal determines a second communication terminal which serves as a connection counterpart from among the second communication terminals, and configures a communication network with the determined connection counterpart.

Abstract: A first communication terminal, unconnected with a communication network, searches for a second communication terminal existing around the own communication terminal. In the communication network, one of communication terminals functions as a master having a function of an access point and the rest of the communication terminals function as slaves of the master. Among the one or more second communication terminals found through the search, the first communication terminal determines a second communication terminal, in which information included in a communication message received from the second communication terminal shows that it is a connected master terminal which is a terminal connected with the communication network and functions as the master, to be a connection counterpart. Then, the first communication terminal configures a network with the determined connection counterpart.

Abstract: Individual communication terminals are connected to a communication network in which one communication terminal functions as a parent that has a relay function, the other communication terminals function as children, and transmitting and receiving of communication messages between child communication terminals are performed via the parent. Each communication terminal transmits a holding list that lists information about data that the own communication terminal holds, to other communication terminals. Further, each communication terminal temporarily stores holding lists received from other communication terminals.

Abstract: Provided is a data sharing system in which data are shared between a plurality of communication terminals capable of wirelessly transmitting and receiving a communication message to and from each other. Each communication terminal determines whether or not the own communication terminal is a specified terminal. Each communication terminal, in case of it is determined that the own communication terminal is a specified terminal, transmits a holding list that lists information about data that the own communication terminal holds, to another communication terminal through use of a communication message. Each communication terminal, when receiving a holding list from another communication terminal, transmits and receives communication messages to and from the other communication terminal that is a source of the holding list that does not match the holding list of the own communication terminal so as to share data with each other.

Abstract: According to one embodiment, a microwave-assisted magnetic recording head includes a SIL formed either in an area outside a FGL in a track width direction or in an area outside a FGL in a depth direction perpendicular to an air bearing surface of the FGL. An area between the SIL and the FGL can be enlarged, and an intermediate layer can be formed therebetween such that an area in which the intermediate layer contacts the FGL can be enlarged as well.

Abstract: The purpose of the present application is to provide a technique for the exchange of path information between different routing domains, which, while reducing the exchange of useless path information in the stage for constructing a hierarchical structure, can maintain robustness of path recognition that tolerates network partition.

Abstract: One problem in a related art is that the total throughput of a network decreases with an increase in the number of radio terminals or an increase in a traffic density of a radio communication. A communication system (1) according to the present invention includes a plurality of terminals and an access point (201) with which the terminals communicate. The communication system (1) includes means for acquiring the number of terminals in a communication network of the access point (201), means for dividing, based on the number of terminals, the plurality of terminals into groups so that each group includes the number of terminals equal to or smaller than the number of terminals permitted to communicate with the access point (201) within a predetermined period, means for allocating the group to the predetermined period, and means for determining, based on the group to which a terminal belongs, whether to permit data transmission within the predetermined period to which the group is allocated.

Abstract: There is provided a communication delay time derivation method for calculating a communication delay time depending on a combination of channels set between communication terminals on a communication path in the MCH/IF environment. When selecting a channel to be used for communication in each section on the communication path per section between communication terminals on the communication path, a calculation target section specification means 82 detects an inter-terminal selected channel repetitive pattern as a pattern of the selected channels cyclically appearing on the communication path, and defines a section corresponding to the inter-terminal selected channel repetitive pattern as a communication delay time calculation target section. A communication delay time derivation means 83 derives a communication delay time in the calculation target section based on the inter-terminal selected channel repetitive pattern.