Abstract: The present invention provides methods for efficient control message distribution in a VANET. Efficient flooding mechanisms are provided to fulfill the objective of flooding (delivering a message to every connected node) with a limited number of re-broadcasting by selected key nodes. A suppression-based efficient flooding mechanism utilizes a Light Suppression (LS) technique to reduce the number of flooding relays by giving up the broadcasting of a flooding message when a node observes downstream relay of the same flooding message. Additionally, a relay-node based efficient flooding mechanism selects Relay Nodes (RN) to form an efficient flooding tree for control message delivery. RNs are nodes that relay at least one control message, for instance a Membership Report (MR) to the upstream node in “k” previous control message cycles The upstream node may be the group header (GH) for the LPG.

Abstract: An on-demand method of routing data between a plurality of local peer groups (LPG). Each LPG includes a plurality of moving nodes. The method comprises transmitting a route request message from a source node, relaying the route request message to a native boundary node; forwarding the route request message to a foreign boundary node, determining if the destination node is within an LPG for the foreign boundary node; relaying the route request message to another boundary node if the destination node is not within the LPG, relaying the route request message to the destination node if the destination node is within the LPG, receiving the routing request message at the destination node, transmitting a routing response to the source node, relaying the routing response to the source node through a path discovered by the route request, receiving the routing response at the source node, and transmitting the data, upon receipt of the routing response.

Abstract: A method and communication device for routing unicast and multicast messages. The method for routing a unicast message includes receiving a first control packet including routing parameters from a group header node, updating a routing table based upon the routing parameters, receiving a second control packet including additional routing parameters from a group node, updating the routing table based upon the additional routing parameters and generating a forwarding table from the routing table when both of the updated steps are completed. The unicast message is routed based upon the forwarding table. A method for routing a multicast message comprises receiving the multicast message, determining if a multicast group destination for the multicast message is in a multicast forwarding table (MFT), determining if the multicast message has been previously forwarded and forwarding the multicast message if the message was not previously forwarded and the multicast group destination is in the MFT.

Abstract: An ad-hoc wireless network with a roadside network unit (RSU) and a local peer group (LPG). The LPG is formed from a plurality of moving vehicles. The LPG includes a group header node (GH) for managing the LPG. The GH is elected from one of the moving vehicles. The LPG further includes group nodes (GN) designated from the remaining moving vehicles in a given area. Each of the moving vehicles, whether the GH or the GN, communicates with other using routing paths created based upon a first control packet broadcast from the GH and a second control packet broadcast from each of the GN. Each moving vehicle communicates with the RSU using a routing paths created based upon a beacon broadcast by the RSU and a reply signal from each of the moving vehicles. The RSU can also be a member of the LPG and act as GN or GH.