Method for Routing in a Mobile Ad Hoc Network

A method of sending a message from a source node to be sent from that source node to a selected destination node through a mobile ad hoc network,

• the ad hoc network comprising nodes including neighbour nodes that correspond to those nodes within range for direct communication with the source node,
• the method comprising:
• referring to routing data, the routing data comprising for each neighbor node, a lowest cost for sending messages to available destination nodes based upon a cost function;
• identifying the best neighbour node for routing the message by searching the routing data for the selected destination node of the message, determining which neighbour node has the lowest cost for the selected destination node;
• and
• attempting to forward the message to the best neighbour node.

A method of maintaining data links to and from a source node in an ad hoc mobile network,

• wherein the network further comprises nodes including neighbour nodes corresponding to nodes within range for direct communication with the source node, the neighbour nodes comprising active neighbour nodes and inactive neighbour nodes, the active neighbour nodes being connected to the source node via respective active data links and the inactive neighbour nodes having respective inactive data links to the source node, the active and inactive data links forming an existing configuration of data links,
• the method comprising:
• (1) identifying one or more lost neighbour nodes corresponding to neighbour nodes of the existing configuration that have moved out of range for direct communication with the source node and/or are about to move out of range for direct communication;
• (2) determining revised configurations of data links in which any active links to lost neighbour nodes are considered inactive and, for at least one revised configuration, an inactive link is considered active and/or a further active link is considered inactive;
• (3) determining an overall configuration value for each revised configuration based at least partly on the best costs of sending messages from the source node using the revised configuration of data links, wherein the best costs of sending messages are determined with reference to routing data, the routing data comprising for each neighbor node, a lowest cost for sending messages to available destination nodes based upon a cost function;
• (4) selecting a new configuration of data links from the revised configurations according to the overall configuration values determined;
• and
• (5) forming the new configuration of data links by breaking data links with neighbour nodes that are active on the existing configuration list but inactive on the new configuration list, and forming data links with any neighbour nodes that are inactive on the existing configuration list and active on the new configuration list.