Abstract: A communications path is established among an ordered sequence of moving nodes, representing vehicles. Available channels may differ from one node to the next node and a node cannot use the same channel for both receiving and transmitting information. Three methods are described that provide an optimal sequence of channel assignments between the nodes. A sequence of channel assignments is called optimal if it establishes a communications path from the first node in the sequence to the last node in the sequence, or, if such a path does not exist, from the first node to the farthest node possible in the sequence. The first method uses a depth-first search starting from the first node in the sequence. The second method uses a “look ahead” scheme in the depth-first search method. The third method requires only a single pass through the sequence of nodes by identifying optimal channel assignments in subsequences of nodes without a need for backtracking.

Abstract: A method for distributing a packet to a plurality of moving nodes comprising receiving a packet containing at least a message, a sender identifier, a location of a sender, an identifier for a relay node and distance from the sender and the relay node, determining if a node receiving the packet is the relay node and immediately distributing the packet to a plurality of moving nodes if the receiving node is the relay node. If the receiving node is not the relay node, the method further comprises steps of waiting a set period of time, determining if a packet is received from a different sender containing the same message, within the period of time and distributing the packet to a plurality of moving nodes if a packet containing the same message is not received within the period of time. The distributed packet includes an identifier for a successive relay node.

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.

Abstract: A method for organizing and maintaining an ad-hoc network for communication between a plurality of moving devices is disclosed. The method comprises the steps of grouping the plurality of moving devices into at least one local peer group (LPG), ordering the plurality of devices within each LPG based upon a relative position of each of the plurality of devices within each LPG and assigning a unique identifier for each of the plurality of moving devices, where the unique identifier is based, in part on the LPG that the corresponding moving device is located.

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 for determining a transmission channel for multi-hop transmission of a data packet from a plurality of data channels in an ad-hoc network. The network includes at least one local peer group. Each local peer group has a plurality of moving vehicles as nodes. The method comprises steps of determining available channels for data packet transmission at each node, transmitting a first list of available channels to at least one other node, receiving, from the at least one other node, a second list of available channel for the at least one other node, creating an available channel table including the first and second lists of available channels, selecting a transmitting channel for a data packet based upon information in the available channel table, and advertising the selected channel to the at least one other node.

Abstract: A method for distributing a packet to a plurality of moving nodes comprising receiving a packet containing at least a message, a sender identifier, a location of a sender, an identifier for a relay node and distance from the sender and the relay node, determining if a node receiving the packet is the relay node and immediately distributing the packet to a plurality of moving nodes if the receiving node is the relay node. If the receiving node is not the relay node, the method further comprises steps of waiting a set period of time, determining if a packet is received from a different sender containing the same message, within the period of time and distributing the packet to a plurality of moving nodes if a packet containing the same message is not received within the period of time. The distributed packet includes an identifier for a successive relay node.

Abstract: A communications path is established among an ordered sequence of moving nodes, representing vehicles. Available channels may differ from one node to the next node and a node cannot use the same channel for both receiving and transmitting information. Three methods are described that provide an optimal sequence of channel assignments between the nodes. A sequence of channel assignments is called optimal if it establishes a communications path from the first node in the sequence to the last node in the sequence, or, if such a path does not exist, from the first node to the farthest node possible in the sequence. The first method uses a depth-first search starting from the first node in the sequence. The second method uses a “look ahead” scheme in the depth-first search method. The third method requires only a single pass through the sequence of nodes by identifying optimal channel assignments in subsequences of nodes without a need for backtracking.

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.

Abstract: A method for establishing and maintaining the network and a corresponding ad-hoc moving-device to moving-device network having a plurality of moving-devices grouped into a Local Peer Group (LPG) is disclosed. A group header node (GH) is selected from the plurality of moving wireless devices in the LPG. The GH controls and manages the LPG by broadcasting a plurality of control messages, including a heartbeat message at a fixed interval. The LPG also includes at least one group node (GN). The at least one GN can communicate with the GH via a network link created between the at least one GN and the GH. The GNs join the LPG via the GH. If there is more then one GH in an LPG, header resolution occurs to select only one GH.

Abstract: Establishing and maintaining a moving ad-hoc network is provided. The ad-hoc network includes a plurality of equivalent cells communicationally linked together to form a linked equivalent cell network. An equivalent cell header manages each equivalent cell. Additionally, regular nodes, scattered throughout the equivalent cell network, may be provided. Regular nodes have restricted communication privileges compared to the equivalent cell headers. However, equivalent cell headers can be demoted to regular nodes and regular nodes can be promoted to equivalent cell headers as required by equivalent cell network.

Abstract: A method for organizing and maintaining an ad-hoc network for communication between a plurality of moving devices is disclosed. The method comprises the steps of grouping the plurality of moving devices into at least one local peer group (LPG), ordering the plurality of devices within each LPG based upon a relative position of each of the plurality of devices within each LPG and assigning a unique identifier for each of the plurality of moving devices, where the unique identifier is based, in part on the LPG that the corresponding moving device is located.