Abstract: In a wireless communication system that includes a plurality of wireless terminals each of which has a first device type and transmits data to a destination, and a plurality of wireless relay apparatuses each of which has a second device type and relays the data that is received in wireless communication with each wireless terminal to the destination, each of the plurality of wireless terminals detects a wireless frame, receives data contained in the wireless frame when the detected wireless frame contains information that represents the first device type, and avoids receiving data contained in the wireless frame when the detected wireless frame contains information that represents the second device type.

Abstract: A transfer destination selecting method conducted by a communication device includes selecting, when the communication device stores, according to a destination, pieces of information indicating a plurality of other communication devices that are candidates for a transfer destination of data, one of the other communication devices to be the transfer destination from among the candidates on the basis of a number of destinations in a routing table used for controlling a data transfer and stored in each of the plurality of other communication devices.

Abstract: A method executed by a wireless communication device used in a wireless ad hoc network includes: designating a bit in a loop detection array added to a received frame in accordance with identification information of the wireless communication device; deciding that a route in which the received frame has been transmitted is not a loop when the bit designated in the loop detection array is not used; deciding that the route is a loop when the bit designated in the loop detection array is used; updating the bit designated in the loop detection array to a state of being used and transmitting the received frame toward a destination node when it is decided that the route is not a loop; and returning the received frame to an adjacent node that is a local transmission source of the received frame when it is decided that the route is a loop.

Abstract: A selection device is selected from a first group in a first cluster. The node devices of the first group can communicate with a node device in a second cluster adjacent to the first cluster. The selection device performs transmission and reception of a report frame that reports an identifier of a node device included in the first group. The selection device selects from the first group a first relay device that relays a relay frame used for a communication between a node device in the first cluster and a node device in the second cluster. The first relay device determines anode device adjacent to the first relay device to be a second relay device that relays the relay frame to a node device in the second cluster.

Abstract: A communication device includes a memory and a processor coupled to the memory and configured to, when a first vibration is detected in the communication device, set a certain state that protects information stored in the memory, and cancel the certain state based on receiving from another communication device a notification indicating that the other communication device detected a second vibration.

Abstract: A communication method for causing a communication apparatus included in a network to perform a process. The method includes: specifying an arrangement of the communication apparatus in the network, using the number of adjacent apparatuses, which are apparatuses adjacent to the communication apparatus, and the number of adjacent apparatuses of each of the adjacent apparatuses; determining the number of times of broadcast of a broadcast frame, using number-of-times-information in which candidates for an arrangement of the communication apparatus in the network and the number of times at which the communication apparatus broadcasts a frame are associated; and broadcasting the broadcast frame the determined number of times.

Abstract: A transfer destination selecting method conducted by a communication device includes selecting, when the communication device stores, according to a destination, pieces of information indicating a plurality of other communication devices that are candidates for a transfer destination of data, one of the other communication devices to be the transfer destination from among the candidates on the basis of a number of destinations in a routing table used for controlling a data transfer and stored in each of the plurality of other communication devices.

Abstract: A communication system includes a first communication apparatus that transmits a transmission notice of data and thereafter transmits the data, and a second communication apparatus that transmits a negative acknowledgement signal to the first communication apparatus when receiving the transmission notice and thereafter failing to detect data transmission corresponding to the transmission notice, wherein the first communication apparatus performs a retransmission process of the data when receiving the negative acknowledgement signal.

Abstract: A node apparatus includes a TTL memory configured to store a TTL value for a first node apparatus in the cluster; a receiving unit configured to receive a first Hello packet including a first sequence number and a second Hello packet including a second sequence number that is incremented when the node apparatus transmits a Hello packet; a sequence number judging unit configured to judge whether a first sequence number and a second sequence number match each other; a TTL decrementing unit configured to perform a process to decrement the TTL value stored in the TTL memory, when the first sequence number and the second sequence number are identical according to a judgment; and a cluster information updating unit configured to separate the first node apparatus from the cluster, when the TTL value for the first node apparatus becomes equal to or smaller than a prescribed value.

Abstract: A node apparatus in a network including a plurality of node apparatuses includes: a cluster information memory configured to store apparatus identification information of node apparatus included in a first cluster including the node apparatus; a merge cluster node number determination unit configured to obtain the number of node apparatuses included in the second cluster based on information included in the hello packet upon receipt of a hello packet from one of adjacent node apparatuses included in a second cluster, and to determine whether a sum of the number of node apparatuses included in the first cluster and that of node apparatuses included in the second cluster is equal to or smaller than a maximum number of cluster nodes; and a cluster merge processing unit configured to merge the second cluster with the first cluster based on a result of the determination.

Abstract: A node device includes a transmitter, processor, and a receiver. The receiver receives a packet from an adjacent node device. The processor generates a cluster list and a first hello packet. The cluster list records device identification information of a node device included in a cluster. The cluster is a group of node devices for which route information is stored. The first hello packet reports the route information with cluster identification information of the cluster. The transmitter broadcasts the first hello packet. Upon receipt of, from a free-node device that does not belong to a cluster, a second hello packet that includes information that associates the cluster identification information with device identification information of the free-node device, the processor adds the device identification information of the free-node device to the cluster list until a number of node devices recorded in the cluster list reaches a threshold.

Abstract: A transmission apparatus includes a transmission unit that transmits, to a reception apparatus performing intermittent reception, a frame in which a subframe is repeated at intervals each being shorter than an interval for the intermittent reception, the subframe containing at least a preamble, a synchronization word, and data for the reception apparatus.

Abstract: In a wireless communication system that includes a plurality of wireless terminals each of which has a first device type and transmits data to a destination, and a plurality of wireless relay apparatuses each of which has a second device type and relays the data that is received in wireless communication with each wireless terminal to the destination, each of the plurality of wireless terminals detects a wireless frame, receives data contained in the wireless frame when the detected wireless frame contains information that represents the first device type, and avoids receiving data contained in the wireless frame when the detected wireless frame contains information that represents the second device type.

Abstract: A method executed by a wireless communication device used in a wireless ad hoc network includes: designating a bit in a loop detection array added to a received frame in accordance with identification information of the wireless communication device; deciding that a route in which the received frame has been transmitted is not a loop when the bit designated in the loop detection array is not used; deciding that the route is a loop when the bit designated in the loop detection array is used; updating the bit designated in the loop detection array to a state of being used and transmitting the received frame toward a destination node when it is decided that the route is not a loop; and returning the received frame to an adjacent node that is a local transmission source of the received frame when it is decided that the route is a loop.

Abstract: A node receives, from a neighboring node that is a node in the neighborhood, neighboring node information indicating a node that neighbors the neighboring node and determines whether a common neighboring node is present, the common neighboring node being common amongst a neighboring node and a node indicated by the received neighboring node information. When it is determined that the common neighboring node is present, the node registers, in a storage unit, information that a link on a simplex path is to be formed with the common neighboring node or the neighboring node that is the source of the neighboring node information. Alternatively, when it is determined that the common neighboring node is not present, the node registers, in the storage unit, information that a link on a duplex path is to be formed with the neighboring node that is the source of the neighboring node information.

Abstract: Anode apparatus includes: a receiver configured to receive data from a first node apparatus adjacent to the node apparatus, a transmission source of the data being a second node apparatus; a data generator configured to generate transmission data in which the second node apparatus is specified as a final destination; a transmitter configured to transmit the transmission data to an adjacent node apparatus of the node apparatus other than the first node apparatus; and a decision unit configured to decide that an alternative path for transmitting data via an adjacent node apparatus of the node apparatus other than the first node apparatus does not exist between the node apparatus and the second node apparatus, when the node apparatus receives the transmission data transmitted by the transmitter to all adjacent node apparatuses of the node apparatus other than the first node apparatus.

Abstract: A selection device is selected from a first group in a first cluster. The node devices of the first group can communicate with a node device in a second cluster adjacent to the first cluster. The selection device performs transmission and reception of a report frame that reports an identifier of a node device included in the first group. The selection device selects from the first group a first relay device that relays a relay frame used for a communication between a node device in the first cluster and a node device in the second cluster. The first relay device determines anode device adjacent to the first relay device to be a second relay device that relays the relay frame to a node device in the second cluster.

Abstract: A node transmits a route search demand, which is a demand to search for a route from the node to a predetermined device among adjacent communication devices, to an adjacent communication device that is not selected as a transmission destination of the route search demand. The node transmits the route search demand when the number of adjacent communication devices serving as confirmed routes is smaller than a predetermined number and when there is an adjacent communication device that has not been selected. The node stops transmission of the route search demand when the number of the adjacent communication devices serving as the confirmed routes reaches the predetermined number. The node transmits a warning to the predetermined device when the number of the adjacent communication devices serving as the confirmed routes is smaller than the predetermined number and when there is no adjacent communication device that has not been selected.

Abstract: A communication method for causing a communication apparatus included in a network to perform a process. The method includes: specifying an arrangement of the communication apparatus in the network, using the number of adjacent apparatuses, which are apparatuses adjacent to the communication apparatus, and the number of adjacent apparatuses of each of the adjacent apparatuses; determining the number of times of broadcast of a broadcast frame, using number-of-times-information in which candidates for an arrangement of the communication apparatus in the network and the number of times at which the communication apparatus broadcasts a frame are associated; and broadcasting the broadcast frame the determined number of times.

Abstract: A node apparatus in a network including a plurality of node apparatuses includes: a cluster information memory configured to store apparatus identification information of node apparatus included in a first cluster including the node apparatus; a merge cluster node number determination unit configured to obtain the number of node apparatuses included in the second cluster based on information included in the hello packet upon receipt of a hello packet from one of adjacent node apparatuses included in a second cluster, and to determine whether a sum of the number of node apparatuses included in the first cluster and that of node apparatuses included in the second cluster is equal to or smaller than a maximum number of cluster nodes; and a cluster merge processing unit configured to merge the second cluster with the first cluster based on a result of the determination.