摘要:
An open communication method between at least two sub-networks of different routable network addressing schemes comprises receiving a packet for a specific application, the packet including an application identifier, determining if the packet is to be relayed to another of the at least two sub-network based upon the application identifier; determining if a node receiving the packet is a broker node, relaying the packet to a broker node if not a broker node, forwarding, by the broker node, the packet to at least one node in another of the at least two sub-networks, broadcasting a status packet from a broker node to each sub-network that the broker node is configured to communicate, receiving the status packet from the broker node, and updating a broker table using information from the status packet, wherein only a broker node updates the broker table.
摘要:
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.
摘要:
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.
摘要:
A method and system for providing location-aware and location-based content services. The system preferably comprises an overlay service network that includes a plurality of information gateway servers. A mobile client uses the servers in the overlay service network to request and receive information. The particular server used by the mobile client is selected based on the geo-location of the mobile client. The method comprises partitioning a geographic area into a plurality of sub-areas and associating resources to the sub-areas based on the location of mobile units within a sub-area.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.