Abstract: In a network registration system including a communicator to be registered on a network and a register registering the communicator on the network, either of the communicator and the register includes a check information generator generating a check information signal according to check information for prompting the user to check that the communicator is treated as an object to be registered in the network registration system; and a check information output section outputting the check information signal in a form sensible to the user. The other of the communicator and the register includes an evaluation criterion supplier supplying evaluation criterion information allowing the user to evaluate the suitability of the check information emitted from the check information output section. Thus, the network registration system can prevent an incorrect registration while easily registering the communicator to the network.

Abstract: A wireless communication node on the multi-hop wireless network has a control message exchanger for exchanging control messages with peripheral nodes to determine neighbor nodes whose information should be registered in a neighbor node information storage; a timing adjuster for adjusting, depending on a connective state of the wireless communication node in the network, a timing at which a first control message is sent back in response to a second control message arriving from other wireless communication nodes; and a registered node determiner for primarily referencing the order of arrival of a first control message from the other wireless communication node to determining neighbor nodes whose information should be registered in the neighbor node information storage.

Abstract: There is provided a wireless communication apparatus capable of using a first MAC protocol and a second MAC protocol including one wireless communication unit. The wireless communication unit includes: a MAC protocol control unit carrying out state transitions and processing in a present state according to the first MAC protocol and the second MAC protocol; and a frame communication unit carrying out communication of frames according to the first MAC protocol and communication of frames according to the second MAC protocol whose frame format is the same as the frames according to the first MAC protocol.

Abstract: A packet relay system in which each node calculates a link cost of each adjacent node based on an arrival rate of a packet from each adjacent node, acquires an accumulated value of a link cost calculated by each node in a range of nodes from a sink node for each adjacent node, calculates, for each adjacent node, a path cost of the one adjacent node by adding the link cost calculated to the accumulated value, and relays a data packet to one adjacent node selected from among nodes adjacent to the node based on a path cost of each adjacent node. This enables establishment of an upstream path to a sink node without increasing the amount of communication in a network.

Abstract: In a communications apparatus, a communication controller transmits and receives signals on any of plural channels. A channel switching controller is responsive to channel switching information selectively defining plural reception-waiting periods using the channels to alter a channel to be used by the communication controller. A neighboring node channel controller exchanges channel switching information with other nodes to manage the channel switching information received from the other nodes. When transmitting transmission signals, a transmission controller refers to the channel switching information of the other nodes, and controls repetitive transmission of the transmission signals on the channel thus searched for.

Abstract: A wireless communication node on the multi-hop wireless network has a control message exchanger for exchanging control messages with peripheral nodes to determine neighbor nodes whose information should be registered in a neighbor node information storage; a timing adjuster for adjusting, depending on a connective state of the wireless communication node in the network, a timing at which a first control message is sent back in response to a second control message arriving from other wireless communication nodes; and a registered node determiner for primarily referencing the order of arrival of a first control message from the other wireless communication node to determining neighbor nodes whose information should be registered in the neighbor node information storage.

Abstract: In a network registration system including a communicator to be registered on a network and a register registering the communicator on the network, either of the communicator and the register includes a check information generator generating a check information signal according to check information for prompting the user to check that the communicator is treated as an object to be registered in the network registration system; and a check information output section outputting the check information signal in a form sensible to the user. The other of the communicator and the register includes an evaluation criterion supplier supplying evaluation criterion information allowing the user to evaluate the suitability of the check information emitted from the check information output section. Thus, the network registration system can prevent an incorrect registration while easily registering the communicator to the network.

Abstract: A wireless communication apparatus having a plurality of neighboring wireless communication apparatuses may includes a wireless transmitter, an information control storage member, and a transmitting power calculator. A wireless transmitter may transmit a wireless signal with a transmitting power to a destination wireless communication apparatus. An information control storage member may maintain first information of links between the wireless communication apparatus and the plurality of neighboring wireless communication apparatuses, and second information of a communication route between the wireless communication apparatus and the destination wireless communication apparatus. A transmitting power calculator may calculate the transmitting power based on the first and second information, so as to ensure reception of the wireless signal.

Abstract: A tree topology in a multi-hop wireless network is configured by having each node other than the root node select a parent node within direct communication range, thereby becoming a child node of the selected parent node. Neighboring nodes provide selection values such as routing costs and local structural information indicating the existing topology in their vicinities, including parent-child relationships. The selection of the parent node is based on the received selection values, but the local structural information is used to bias the selection in favor of neighboring nodes with at least one other child node. This selection strategy reduces the number of parent nodes in the network and enables more nodes to operate as end nodes, which can then conserve power by carrying out sleep control.

Abstract: There is provided a wireless communication apparatus capable of using a first MAC protocol and a second MAC protocol including one wireless communication unit. The wireless communication unit includes: a MAC protocol control unit carrying out state transitions and processing in a present state according to the first MAC protocol and the second MAC protocol; and a frame communication unit carrying out communication of frames according to the first MAC protocol and communication of frames according to the second MAC protocol whose frame format is the same as the frames according to the first MAC protocol.

Abstract: A wireless communication system includes a first node, multiple second nodes, and multiple third nodes that communicate with the first node through the second nodes. The second and third nodes transmit control information to their neighboring third nodes, which calculate link costs from the reception status of the control information. The control information transmitted by each node includes a path cost indicating the cost of a path between the transmitting node and the first node. From the path costs in received control information, each third node selects a second node through which to communicate with the first node, and selects a parent node as the destination of the first hop on the path through the selected second node to the first node. Routing is thereby accomplished autonomously without having the second nodes flood the system with routing requests.

Abstract: A packet is transmitted from a source node to a destination node via a relay path in a multi-hop network. The packet is transmitted by cache routing or source routing, depending on the presence or absence of information identifying the destination node in a history table maintained at the source node. In source routing, relay path information is included in the packet. In cache routing, relay nodes obtain routing information from entries in their own cache routing tables. Each entry indicates only the destination node and the next relay node, and each cache routing table has a limited size. When a series of packets are transmitted to the second node, cache routing can be used for all but the first packet, thereby reducing packet overhead.

Abstract: In a communications apparatus, a communication controller transmits and receives signals on any of plural channels. A channel switching controller is responsive to channel switching information selectively defining plural reception-waiting periods using the channels to alter a channel to be used by the communication controller. A neighboring node channel controller exchanges channel switching information with other nodes to manage the channel switching information received from the other nodes. When transmitting transmission signals, a transmission controller refers to the channel switching information of the other nodes, and controls repetitive transmission of the transmission signals on the channel thus searched for.

Abstract: A wireless communication apparatus having a plurality of neighboring wireless communication apparatuses may includes a wireless transmitter, an information control storage member, and a transmitting power calculator. A wireless transmitter may transmit a wireless signal with a transmitting power to a destination wireless communication apparatus. An information control storage member may maintain first information of links between the wireless communication apparatus and the plurality of neighboring wireless communication apparatuses, and second information of a communication route between the wireless communication apparatus and the destination wireless communication apparatus. A transmitting power calculator may calculate the transmitting power based on the first and second information, so as to ensure reception of the wireless signal.

Abstract: A tree topology in a multi-hop wireless network is configured by having each node other than the root node select a parent node within direct communication range, thereby becoming a child node of the selected parent node. Neighboring nodes provide selection values such as routing costs and local structural information indicating the existing topology in their vicinities, including parent-child relationships. The selection of the parent node is based on the received selection values, but the local structural information is used to bias the selection in favor of neighboring nodes with at least one other child node. This selection strategy reduces the number of parent nodes in the network and enables more nodes to operate as end nodes, which can then conserve power by carrying out sleep control.

Abstract: A source terminal measures characteristics of the path at the source terminal itself, produces a characteristics-measurement packet, and transmits the produced characteristics-measurement packet to a relay terminal. Upon receiving the characteristics-measurement packet, the relay terminal measures characteristics of the path at the relay terminal itself, renews the characteristics of the path included in the characteristics-measurement packet using the measured characteristics of the path, and transmits the characteristics of the wireless communication path to the destination terminal. The source terminal produces an admission-request packet and transmits the packet to the destination terminal. Upon receiving the admission-request packet, the destination terminal allows or rejects the traffic quality maintenance request according to the characteristics of the wireless communication path.

Abstract: In a wireless communication network system performing multi-hop wireless communications, a network node has a calculator for exchanging control packets with its neighboring nodes to calculate link cost values, another calculator for calculating path costs incurred on the way to a network node of interest, a manager for managing the number of downstream nodes subsidiary to each daughter node, and a downstream node adjuster for adjusting the number of the downstream nodes subsidiary to each daughter node. The adjuster produces control information, into which link cost and/or path cost information is inserted. The adjuster adjusts the contents of the link cost or path cost information, to be inserted into the produced control information, according to the numbers of the downstream nodes subsidiary to the daughter nodes.

Abstract: A wireless communication system includes a first node, multiple second nodes, and multiple third nodes that communicate with the first node through the second nodes. The second and third nodes transmit control information to their neighboring third nodes, which calculate link costs from the reception status of the control information. The control information transmitted by each node includes a path cost indicating the cost of a path between the transmitting node and the first node. From the path costs in received control information, each third node selects a second node through which to communicate with the first node, and selects a parent node as the destination of the first hop on the path through the selected second node to the first node. Routing is thereby accomplished autonomously without having the second nodes flood the system with routing requests.

Abstract: A packet is transmitted from a source node to a destination node via a relay path in a multi-hop network. The packet is transmitted by cache routing or source routing, depending on the presence or absence of information identifying the destination node in a history table maintained at the source node. In source routing, relay path information is included in the packet. In cache routing, relay nodes obtain routing information from entries in their own cache routing tables. Each entry indicates only the destination node and the next relay node, and each cache routing table has a limited size. When a series of packets are transmitted to the second node, cache routing can be used for all but the first packet, thereby reducing packet overhead.

Abstract: A packet relay system in which each node calculates a link cost of each adjacent node based on an arrival rate of a packet from each adjacent node, acquires an accumulated value of a link cost calculated by each node in a range of nodes from a sink node for each adjacent node, calculates, for each adjacent node, a path cost of the one adjacent node by adding the link cost calculated to the accumulated value, and relays a data packet to one adjacent node selected from among nodes adjacent to the node based on a path cost of each adjacent node. This enables establishment of an upstream path to a sink node without increasing the amount of communication in a network.