Abstract: A method and apparatus for optimizing communication of data within a disruption tolerant network. The method comprises of receiving a data packet, said data packet including a context and a state related to said context, storing the data packet to a buffer and disseminating the data packet to neighboring vehicles and RSU, and passing said state to an application, said application associated with said application context. In one embodiment, the method functions as a software protocol within a dashboard computer. The apparatus comprises a processor and a memory operable to receive a data packet, said data packet including a context and a state related to said context, store the data packet to a buffer when the context matches an application context, disseminating the data packet to neighboring vehicles and RSU, and pass said state to an application when the context matches an application context, said application associated with said application context.

Abstract: A method and system for determining a size of a local peer group (LPG) network in a dynamic roadway (mobile) environment is provided. In one embodiment, the method comprises measuring a roundtrip time between a first node and a second node, and utilizing the measured roundtrip time to select the size of the local peer group network from a lookup table. In another embodiment, the method comprises determining when the roundtrip time exceeds a time interval of the heartbeat signal, and when the roundtrip time exceeds the time interval of the heartbeat signal adjusting the size of the local peer group network.

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 method for maintaining a local peer group (LPG) for supporting communications among vehicles. The LPG is formed from a plurality of vehicles. Each vehicle is equipped with a wireless communications device. One of the vehicles is selected as a group header node (GH). The method comprises receiving periodically a heartbeat packet from the GH, the heartbeat packet including a maximum hop count, and a heartbeat cycle, forwarding the heartbeat packet until the maximum hop count is reached after waiting for a first random relay delay, which is less than a maximum allowable adjustable value, replying to the heartbeat packet with a membership report packet, forwarding a membership report packet towards the GH, and adding a vehicle that submitted the membership report packet to a LPG membership as a member node of the LPG if the membership report packet is new or updating information for a member node.

Abstract: A method of controlling a wireless communication device that is installed in a moving vehicle. The method comprises receiving roadway topology information and vehicle traffic pattern information, receiving vehicle and wireless communication device performance information from a plurality of other moving vehicles, determining current position information for the moving vehicle; determining a first set of metrics for a performance of the wireless communication device installed in the moving vehicle, estimating at least one second metric related to the performance of the wireless communication device or an ad-hoc network which includes each wireless communication device and changing an operation or routing parameter for the wireless communication device based upon the estimation. The second metric is based upon at least a sub-set of the first set of metrics, the received information and the determined current position information for the moving vehicle.

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 transmitting data in vehicular network comprising determining a communication window between at least two nodes, grouping a plurality of fragments of content together into an aggregate fragment block, forwarding the aggregate fragment block to a target node and assembling the plurality of fragments into the content. The content is divided into the plurality of fragments. A fragment signature is generated for the fragments that contain fragment index information regarding each fragment. Each fragment is unambiguously identified by its signature. A number of fragments grouped into the aggregate fragment block is dependent on the communication window.

Abstract: The present invention offers systems and methods for effective multiple-hop routing, multicasting and media access control for vehicle group communications that employ directional wireless radio technology. Multi-beam optic-wireless media and streamlined operations provide low-overhead communications among vehicles. Systems and methods are provided to maintain a quasi-stationary group of neighboring vehicles, enable high-throughput on-demand switching among multiple vehicles, enable group coding in the vehicle group to achieve higher throughput, and enable dynamic adjustment of link to maintain desirable vehicle group. The proposed solution builds upon the conception of a MAC-free wireless operation and quasi-stationary vehicular switched network to achieve ultra-low-overhead and high-throughput vehicle communications.

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: 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: A method for routing a multicast message comprising the steps of receiving a multicast message including at least a message, a source identifier, a sequence number, a time-to-live value and a multicast group destination, determining if the multicast group destination is in a multicast forwarding table, determining if the message has been previously received, adding the multicast message to the multicast forwarding table if it is determined that the multicast message has not been previously received, determining if a node that received the multicast message is a forwarding node; randomly setting a wait time for forwarding the multicast message; and forwarding the multicast message at the expiration of the wait time.

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: 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 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.