Method For Controlling Communication Route of Wireless Multi-Hop Network System and Communication Terminal

A communication terminal for use in a wireless multi-hop network which forms a multi-hop network in which control packets are exchanged by wireless signals between a plurality of communication terminals serving as nodes of the network, retains topology information of the multi-hop network, and controls communication routes of the packets exchanged between the communication terminals based on the topology information, said communication terminal comprising:

• means for detecting own movement information including at least a movement speed;
• means for controlling the exchange frequency of the control packet to be exchanged with other communication terminals on the multi-hop network based on the detected movement information so as to reduce a control load in accordance with its movement state;
• means for updating the topology information of the multi-hop network that the communication terminal itself retains based on the control packets from the other communication terminals.
• means for exchanging neighbor detection messages with neighboring communication terminals on the multi-hop network as the control packets;
• means for, when a link with each of the neighboring communication terminals has been established by the exchange of the neighbor detection message, retaining, in addition to terminal identification information of each of the neighboring communication terminals, identification attribute information of the neighboring detection message received from each of the neighboring communication terminals at the time point when the link has been established as link information included in the topology message;
• and
• means for broadcasting, as the control packet, a network topology message including the link information compsoed of the terminal identification information of each of the neighboring communication terminals and identification attribute information of the neighbor detection message on the wireless multi-hop network.

A wireless multi-hop network which includes a plurality of communication terminals, forms a multi-hop network in which control packets are exchanged by wireless signals between the communication terminals serving as nodes of the network, retains topology information of the multi-hop network, and controls communication routes of the packets exchanged between the communication terminals based on the topology information, wherein

• each of the communication terminals comprises:
• means for detecting own movement information including at least a movement speed;
• means for controlling the exchange frequency of the control packet to be exchanged with other communication terminals on the multi-hop network based on the detected movement information so as to reduce a control load in accordance with its movement state;
• means for updating the topology information of the multi-hop network that the communication terminal itself retains based on the control packets from the other communication terminals,
• a step in which each of the communications terminals exchanges neighbor detection messages with neighboring communications terminals on the multi-hop network as the control packets;
• a step in which, when a link with each of the neighboring communication terminals has been established by the exchange of the neighbor detection message, each of the communication terminals retains, in addition to terminal identification information of each of the neighboring communication terminals, identification attribute information of the neighbor detection message received from each of the neighboring communication terminals at the time point when the link has been established as link information included in the topology message;
• and
• a step in which each of the communications terminals broadcasts, as the control packet, a network topology message inlcuding the link information composed of the terminal identification information of each of the neighboring communication terminals and identification attribute information of the neighbor detection message on the multi-hop network

An operation program of a communication terminal for use in a wireless multi-hop network system which forms a multi-hop network in which control packets are exchanged by wireless signals between a plurality of communication terminals serving as nodes of the network, retains topology information of the multi-hop network, and controls communication routes of the packets exchanged between the communication terminals based on the topology information, characterized by allowing a computer to execute the steps of:

• detecting movement information of each of the communication terminals itself, including at least a movement speed;
• controlling the exchange frequency of the control packet to be exchanged with other communication terminals on the multi-hop network based on the detected movement information so as to reduce a control load in accordance with the movement state of each of the communication terminals itself;
• updating the topology information of the multi-hop network that each of the communication terminals itself retains based on the control packets from the other communication terminals,
• means for eschanging neighbor detection messages with neighboring communication terminals on the multi-hop network as the control packets;
• means for, when a link with each of the neighboring communication terminals has been established by the exchange of the neighbor detection message, retaining, in addition to terminal identification information of each of the neighboring communication terminals, identification attribute information of the neighbor detection message received from each of the neighboring communication terminals at the time point when the link has been established as link information included in the topology message;
• and
• means for broadcasting, as the control packet, a network topology message including the link information composed of the terminal identification information of each of the neighboring communication terminals and identification attribute information of the neighbor detection message on the multi-hop network.