40results about How to "Reduce routing overhead" patented technology

The invention provides a method and a system for the fusion of multi-source monitoring data based on a heterogeneous clustering wireless sensor network. The system comprises a plurality of monitoring nodes, a plurality of cluster head nodes, a plurality of trunk nodes, a gateway node and an upper computer. The method comprises the following steps: after the gateway node switches on the upper computer, a PAN network in conformity with the ZigBee protocol is established; after the cluster head nodes and the trunk nodes are electrified, the cluster head nodes and the trunk nodes search for and join in the PAN network to form a wireless meshed network; the cluster head nodes receive broadcast packets of the monitoring nodes to carry out correlation calculation, and provide the calculation result to the upper computer through the wireless meshed network to carry out clustering processing; and then, the monitoring nodes in the cluster acquire environmental data according to the clustering result and send the data to the cluster head nodes in the cluster, and the cluster head nodes send the acquired environmental data to the upper computer through the wireless meshed network to be subjected to corresponding processing based on different sources of the environmental data. Thus, the heterogeneous clustering wireless sensor network and the wireless meshed network are combined, and the advantages of the both can be fully used for data acquisition.

The invention discloses a satellite network based on distributed-type SDN and a construction method thereof, wherein the satellite network adopts a GEO/MEO/LEO three-layer satellite network model. The invention proposes a distributed-type software defined satellite network DSDSN network for the GEO/MEO/LEO three-layer satellite network and proposes a controller system configuration strategy for the same-layer satellite cluster based on the controller clustering technology. The strategy is based on the ideas of an ant colony clustering algorithm and through the selection of appropriate control nodes, the position and number of the controllers can be properly configured; the communication nodes can be deployed according to the formed controller cluster so as to reduce the total delay from the communication nodes to the neighboring controller node. The centralized management of the invention has a global view of all the nodes in the entire network, can grasp the status of satellite nodes and improve the survivability of the network. The invention reduces the routing cost by optimizing three parameters of the link connection duration, the total delay and the satellite resources.

The method comprises: a) after receiving the routing maintenances packet, the node maintains and updates its own routing neighbor list, and selects the neighbor nodes whose gradient value are less than its own gradient value and which have link symmetry from the updated routing neighbor list; the node compares the out-going degrees of the selected neighbor nodes, and takes the neighbor node with maximal out-going degree as the optimal next jump node; c) the node establishes the route between itself and the optimal next jump node.

The invention discloses a centralized routing algorithm in a wireless Mesh network. The centralized routing algorithm comprises the four stages of initial root route setting-up, link state information uploading, path selecting and grouping forwarding, and route self-healing. A mode of calculating routes in a centralized mode through a root node is adopted for finishing finding paths, nodes upload the link state information to the root node, the root node masters whole-network topology, and a route between a source node and a target node which are to communicate is calculated; after the initial link state is uploaded, all the nodes upload the link state information only when the link state changes and exceeds a certain threshold value or the neighbor nodes change, and the link state information is prevented from being uploaded frequently; after the root node calculates to obtain the optimal path, a backup path which does not intersect with the optimal path can be obtained only by deleting the nodes on the path in the original network topology and recalculating the optimal path. According to the centralized routing algorithm, flooding in the path finding process is avoided, the routing overhead is small, and reliability is high.

The invention discloses a dynamic multipath routing algorithm based on mobility prediction, being applied to a high-speed mobile wireless Mesh network. The algorithm comprises the following steps: firstly predicting the route lifetime by utilizing the mobile information of nodes and introducing the ideal of route lifetime into the route discovery process of the DSR protocol; routing multiple paths from the source node to the destination node by utilizing the comprehensive evaluation value generated by non-relevance between the route lifetime and multipath routes and improving the route maintenance, selection and cache mechanism by utilizing the route lifetime. The invention can search for relatively stable routes for the nodes in the high-speed mobile wireless Mesh network, and the searched multiple paths have higher non-relevance, thus reducing the frequency of route discovery, effectively lowering the routing overhead, improving the performances of the original DSR protocols and ensuring the algorithm to be adaptive to the high-speed mobile network environment.

The invention belongs to the technical field of air-ground integrated Internet of Vehicles communication. The invention discloses an air-ground integrated Internet of Vehicles information transmissionmethod based on fog computing and intelligent traffic. The information transmission method based on fog computing is adopted for the problems existing in the prior art. An information transmission problem is formalized into a multi-objective optimization problem related to a link transmission rate, a link switching frequency and a network copy number; the number of times of link switching and thelink transmission rate are optimized in a combined manner; the number of network copies is optimized on the premise of ensuring the link reliability; transmission is carried out in a storage-carrying-forwarding opportunity transmission mode, and the unmanned aerial vehicle and the parking vehicle group are used as fog nodes to assist network communication, so that the network transmission successrate can be effectively improved, and the routing overhead, the transmission time delay and the link switching frequency are reduced. Compared with an existing mechanism, the information transmissionsuccess rate can be effectively improved, and the transmission delay, the routing overhead and the link switching frequency are reduced.

The invention discloses a fast routing convergence optimization method for an LEO/MEO (Low Earth Orbit/Medium Earth Orbit) satellite network. The method comprises a step of carrying out dynamic bidirectional forwarding detection; a step of carrying out coverage clustering on the LEO/MEO satellite network; and a step of judging a fault type of the satellite network. During a fault detection stage, the fault detection speed is increased through the dynamic bidirectional forwarding detection; during an LSA (Link State Advertisement) diffusion stage, the routing overhead and the queuing delay are reduced through a coverage network clustering algorithm; and during a routing table updating stage, the updating delay of a routing table is reduced through an SFTJM (Satellite Network Fault Type Judging Method) algorithm, and the fast convergence of the whole network is finally realized.

In this invention we disclose methods for incorporating a security gateway within a wireless mesh network. In one embodiment, the wireless mesh network is a heterogeneous mesh network. In one embodiment, a gateway node, which is part of the wireless mesh network, requests a connection to the core network through a security gateway. The security gateway responds by creating an IPSec tunnel and a GRE tunnel within the IPSec tunnel from itself to the gateway node. Once the gateway node is communicatively coupled to the security gateway via secure tunneling, the gateway node sends a mesh routing protocol to the security gateway.

Disclosed is an ad hoc multi-path route method based on the bidirectional route reestablishment; the method relates to a source node, an intermediate node and a destination node: (1) the source node processes the route detection and establishes a plurality of routes from the source node to the destination node through an intermediate node (optional). (2) under the required situation, both the source node and the destination node can initiate the route reestablishing and establish a plurality of route paths from the source node to the destination node; when all the shortest paths from the source node to the destination node are interrupted, the source node uses the residual paths to send the data and informs the destination node to initiate the route reestablishing; when all the available paths are interrupted, the source node initiates the route reestablishing. The ad hoc multi-path route method based on the bidirectional route reestablishment can reduce the message loss caused by the frequent route interruption, improve the performance of the route discovering frequency, the route overhead and the average network delay effectively.

The invention discloses an efficient routing method for an orthogonal circular orbit configuration satellite constellation. According to the invention, the method comprises the steps: proposing a principle of proximity, a principle of approach and an equatorial orbit satellite active periodic updating mechanism according to a constellation link model to ensure the rationality and the cheapness ofa network link; proposing a link priority algorithm based on hop count prediction on the basis of the link model; enabling a satellite to send out a data packet according to the priority of each linkthrough sequential decisions of a link actual on-off state, a link pseudo-off state caused by a non-backhaul strategy, a destination node direction, a link congestion degree and a link propagation delay factor; carrying out discussion in four situations according to the categories of the source satellite node and the destination satellite node, and providing a hop count prediction method for sending data packets from different links for each situation according to satellite numbers and state information.

The invention belongs to the technical field of unmanned aerial vehicle ad hoc network communication, and discloses a relay selection method based on a track relationship in an unmanned aerial vehiclead hoc network, and an unmanned aerial vehicle, and the method comprises the steps: constructing an unmanned aerial vehicle ad hoc network model which comprises a source node, G ground base station nodes and N unmanned aerial vehicle nodes; constructing an information transmission scheme between communication nodes based on the unmanned aerial vehicle ad hoc network model, and defining track information; calculating a track direction and a transmission probability between the communication nodes based on an information transmission scheme between the communication nodes and the track information; establishing a relay selection method based on the track relationship based on the position relationship and the transmission probability between the communication nodes; and simulating the relayselection method based on the track relationship and the existing mechanism based on the same network parameters, and verifying the superiority of the method. Compared with an existing mechanism, themethod has better performance in the aspects of improving the information transmission success rate and reducing the transmission delay and the routing overhead.

The invention relates to a wireless ad hoc network reactive route method based on probability, belonging to the field of wireless networking protocols. A wireless ad hoc network has the following conditions: each node is configured with a wireless antenna with isotropy and has mobility; the two nodes are communicated directly when in mutual wireless communication range; and the node does not know the position information per se. The route method comprises a finding method and a route maintaining method. The route method is characterized in that a route re-finding method comprises the steps of: participating in path recovery by only an intermediate node being apart a certain distance (within K hop) from an old path, wherein the node on the old path participates in by the probability of 1; and participating in forwarding a route request message by other nodes in the range by the probability of p*. For communication conversation with longer durability time, the method can effectively lower the communication cost.

The invention provides a routing method for an internet of vehicles based on a user activity area model. The routing method for the internet of vehicles based on the user activity area model is provided to overcome the problem in the current internet of vehicles that user motion has community character, thus a message packet is difficult to transmit to a destination mode to result in a low delivery rate. The method comprises the following steps: (1) exploring the most possible activity area of a user according to the community character of node activity in a social network (SNs:Social Networks); (2) forwarding a message packet to the most possible occurrence area of the destination node by adopting the principle of proximity; and (3) waiting for the meeting the destination node and a hotspot carrying the message packet to deliver the message packet. The purpose is to change the traditional mode that the message packet is forwarded to a signal node into a mode that the message packet is forwarded to the user activity area, so as to greatly improve the delivery rate of the message packet.

The invention discloses an Ad hoc network route discovery method based on Brownian motion, and the Ad hoc network route discovery method based on Brownian motion aims to reduce the routing overhead of a network with the help of the thought of combining history record orientation and probability forwarding. According to the method, a mobile network model based on Brownian motion is built, and the distribution rule of intermediate nodes which have met a targeted node is found and summarized; a calculation formula of probability of intermediate node forwarding is designed according to the distribution rule and the network environment; whether the intermediate nodes participate in forwarding or not is determined according to the forwarding probability, and routing between a source node and the targeted node is built. Based on the directional broadcasting, the routing algorithm reduces the density of the intermediate nodes which participate in forwarding, and is simple and low in consumption.

A method for data path provisioning in a reconfigurable data network is disclosed. A data path between a source IP router and a destination IP router is determined taking into account the IP-subnets of the network interfaces of the IP routers included in the path. In one embodiment, the requirement that two IP routers can send packets via their connected interface if and only if the two interfaces are on the same subnet (i.e., the subnet constraint) is completely honored during the data path determination. In another embodiment, the data path is determined while allowing some number of violations of the subnet constraint. A transform network graph is computed and is used to determine the data path taking into account the IP-subnets.

The invention provides a mobile communication system based on a wireless Ad hoc network. The basic thought is that each communication device in the mobile communication system periodically transmits a route data frame including a link state message; a local communication device updates a calculated link state value to the link state message, and broadcasts the link state message conforming to a certain condition, so that a link state between the local communication device and a destination communication device can be represented by the link state value of the link state message transmitted by the local communication device after an adjacent-hop communication device receives the link state message transmitted by the local communication device; and each communication device maintains routing information according to the received route data frame, and determines an optimal next-hop communication device of each communication device in order to ensure an optimal communication path between each communication device and the destination communication device, so that the wireless Ad hoc network which is free from a fixed center, is high in robustness, is not limited by a network center node on the aspect of network communication range, and is high in network communication performance is built.

The invention discloses a DSR routing protocol implementation method based on an unmanned aerial vehicle ad hoc network. The method comprises the following steps: 1) state information of all nodes isexpanded; 2) a source node routing request option is extended, and a measurement factor flag bit is added on the basis of the original request option; 3) a routing request is initiated after the source node initializes the routing request packet expanded in the step 2); 4) an intermediate node receives the routing request broadcasted in the step 3), decides whether to receive the routing request or not according to the state of the intermediate node and the numerical value of the measurement factor flag bit of the read request option, calculates the measurement factor of the intermediate node,inserts the measurement factor flag bit of the request option and rebroadcasts the request; and 5) a destination node receives the routing request and replies a routing response to the requested source node. The method reduces the transmission delay, reduces the cost of the network control message, and improves the stability of service data reception.

The invention introduces a software defined network (SDN) technology into a low-power-consumption wide-area multi-hop network, and completes dynamic networking and flexible transmission of the networkthrough design and implementation of links such as topology discovery and maintenance, flow table generation and issuing and the like. Through control and data transmission decoupling of the network,software definition, flexibility and controllability of the network transmission process are realized, and meanwhile, the routing overhead of common sensing nodes is effectively reduced by adopting acentralized control algorithm, so that the routing success rate and the network stability are improved. The networking and transmission method provided by the invention is essentially different fromthe traditional routing-based networking method. According to the software defined network idea based on centralized control and numerical control separation, the advantages of a traditional softwaredefined network and the requirements of a wireless multi-hop network can be well met, and convenience is brought to the network management, centralized network configuration and the like of the wireless multi-hop network.