275 results about "Topology control" patented technology

A method includes connecting to a client at a Virtual Private Network (VPN) device in a cloud system; forwarding requests from the client for the Internet or public clouds accordingly; and, for requests for an enterprise associated with the client, contacting a topology controller to fetch a topology of the enterprise, causing a tunnel to be established from the enterprise to the VPN device, and forwarding the requests for the enterprise through the tunnel. A cloud system and VPN system are also described. Advantageously, connections between the cloud and on-premises proxy are dynamic, on-demand and orchestrated by the cloud. Security is provided at the edge—there is no need to punch any holes in the existing on-premises firewalls.

The bridgeless boost topology reduces the power dissipation, cost, and size of prior PFC systems by eliminating the intrinsic loss of the input rectifier bridge. Sensing of the input line voltage by the controller is unnecessary. The use of One Cycle Control (also known as Single Cycle Control) allows the Power Factor Correction function to be performed without complex rectification networks to obtain the AC line voltage reference. The use of bi-directional switches makes it possible to control inrush current (the startup over-current due to the charging of the output bulk capacitor), which allows elimination of over-current limiting devices and reduction of the diode surge capability requirements. Moving the boost inductor to the system input adds an additional filtering function, reducing the cost of input EMI filtering.

The invention relates to one efficient wireless sensor network topological control method, which combines topological control cluster division method and power control method and comprises the following steps: a, dividing the network clusters and selecting cluster head point; b, forming cluster inner network; c, processing power control on cluster point to form final network topological structure; after failure, re-establishing network topological structure.

The invention relates to a topology control method for wireless sensor network based on uneven cluster, belong to sensor technical field, comprising: during the topology generating stage, introducing an uneven minimum mean square subtraction clustering mechanism on a finished cluster in order to reduce energy consumption of in-cluster node; using a strategy based on cluster head energy consumption for setting cluster head changing time, in order to equalize energy consumption on each cluster head node in the network; establishing a cluster head-cluster head energy sensing route, in order to avoid remote wireless transmission; during topology maintenance stage, using a cluster head selection scheme based on node surplus energy and in-cluster node distribution, and using the same strategy to set cluster changing time. With the realization of the method, it can reduce total network energy consumption and equalize energy consumption on each node, in order to prolong cooperative working time of most nodes in the network.

The invention discloses a ground-air wireless sensor network communication device compatible with a UAV. The device comprises a sensing monitoring system, a mobile platform system, an integrated Wi-Fi network communication system and a dispatching control platform. The sensing monitoring system indicates that in a sensor network, sensor nodes randomly scattered in a monitored region monitor specific variable objects in a target region in real time. The mobile platform system comprises UAVs for mounting Wi-Fi network communication modules, wherein the controllability of the flying speeds and the paths of the UAVs is realized by using rotor vertical lifting platforms. The integrated Wi-Fi network communication system indicates a structure which takes a Wi-Fi communication mode as the main and refers to a cellular mobile communication network. The dispatching control platform is a set of software platform which is used for controlling flying paths of the unmanned aerial vehicles and collecting wireless network topology control information and environment variable information. According to the device, grid network development demands can be satisfied; and through establishment of the UAV communication network taking the network as the center, sufficient stability and reliability and high interconnection and interoperability can be realized.

The invention relates to a distributed topology control realization method for wireless sensor network based on double clustering, which comprises a physical clustering step and a virtual clustering step, wherein, the physical clustering step is determining the cluster head or cluster member status of each node, so as to form a physical cluster; the virtual clustering step adopts distributed competitive mode; the cluster head of the physical cluster can generate own cycle dispatch table or follow the cycle dispatch table which is generated by the adjacent cluster head, so that the cluster heads of the adjacent physical clusters can form a virtual clustering which is run periodically and slept synchronously, and the communication between the cluster heads can be realized through an adaptivecommunication mechanism. The invention aims at the characteristics of the wireless sensor network on energy limitation, application specificity, and random dense distribution of nodes; on the basis of meeting the specific QoS requirement, the network load balancing can be realized effectively; the network energy consumption efficiency can be enhanced and the life time of network system can be extended.

The invention provides a fuzzy decision-based low-power dissipation self-adaption clustering multihop wireless sensor network topology control method, which is aimed at solving the problem of uncertainty of node energy dissipation and communication path in a self-organization wireless sensor network (WSN). A round is a cycle. Each round comprises an establishment stage and a stabilization stage, wherein the establishment stage comprises three steps of cluster head election, clustering, and route selection among clusters, and the stabilization stage comprises the step of data transmission. The method introduces a concept of fuzzy set, and selects excellent communication relay nodes by using a theory of fuzzy decision, so that a dynamic network route structure is formed. The method provided by the invention can adapt to more network conditions more effectively, balance energy and prolong life cycle of the network.

The invention relates to a routing method suitable for the static ad hoc formation. Aiming at the special organization structure of the static Ad hoc formation, a centralized topologic control is carried out inside the ad hoc formation; the formations are clustered according to the results of the topologic control; and a new double-frequency multi-stage routing method is adopted so as to ensure the reliable and quick routing establishment and the data transmission inside the formation and among the members inside the formation. The method is characterized in that the method includes the following steps: the topologic control in the formation, the establishment of the formation network structure, the maintenance of the formation network structure, the search of a transmission router, the maintenance of the transmission router, the routing error control and the re-establishment of the router. By adopting the method, the reliable and quick routing establishment and the data transmission in the formation and among the members inside the formation can be realized, the interference in the wireless transmission can be reduced, the network capacity can be further improved, the node service life is prolonged, and the network survival time is increased.

The invention discloses a wireless sensor network topological control method based on potential games. A network model is determined, and a sensor network is expressed by a planar topological graph, and a connected network is determined, and then a TCBPG is established. According to the TCBPG, a payoff function of the game is determined to guarantee a Nash equilibrium solution existing in the game, and the TCBPG is defined as an ordinal potential game. After the TCBPG is determined according to the above mentioned steps, a distributed energy consumption equalization topological control algorithm is realized, and is divided into a neighbor discovering phase, a game executing phase, and a topology maintaining phase, and then a stable wireless sensor network topological structure is acquired. From a power control and energy consumption equalization angle, residual energy of nodes and transmitted power of nodes are comprehensively considered to design a new utility function, and a distributed topological control algorithm based on the potential games is provided. According to theoretical analysis and simulation results, the topology constructed by the algorithm is capable of realizing the Nash equilibrium, and is capable of guaranteeing the good characteristics of the network such as connectivity and energy consumption equalization, and therefore the life cycle of the network is prolonged.

A content distribution system in which content is distributed from a broadcasting station via a plurality of nodes connected in a hierarchical tree structure, including: a base tree obtained by connecting the plurality of nodes in a hierarchical tree structure using the broadcasting station as an apex; an extension tree obtained by connecting the plurality of other nodes in a hierarchical tree structure using, as an apex, a first root node as any of the nodes included in the base tree; and a topology controller for controlling a topology of each of the nodes belonging to the base tree.The first root node controls the topology of each of the nodes belonging to the extension tree using the first root node as an apex.

The invention discloses a clustering topology control method based on asymmetric energy distribution and mobile nodes. A distributed idea is introduced into a clustering type two-stage topology control process; and the mobile nodes with asymmetric energy distribution play a key role in prolonging the service life of a wireless sensor network. The method comprises the following steps of: 1, initializing the network, selecting a cluster head for the first time and forming a cluster structure; 2, maintaining the cluster, namely after the cluster structure is formed, the network starts to transmit information according to a relevant route protocol; and 3, reconstructing the cluster. In conclusion, after the nodes are gathered to guide the network to be initialized, the network starts to run completely in a self-organized mode, so that the mobile nodes and the cluster head with asymmetric energy are selected.

The invention discloses a static clustering algorithm for a wireless sensor network, which belongs to the technical field of wireless sensor networks. The algorithm is applied to topology control of the wireless sensor network, and is different from the conventional network clustering algorithm. In the algorithm, clusters are partitioned firstly through convergent nodes, and a current turn of cluster head is used for electing a next turn of cluster head. The executing process of the algorithm is periodical, and is partitioned into a cluster partitioning stage, a cluster head selecting stage and a stable data communication stage when a network is established or a large quantity of nodes are added or leave the network, and only the last two stages are performed in the rest of periods. Compared with the conventional hierarchy topology, the algorithm has the advantages that: energy consumption in a network deployment process can be lowered, hierarchical division is more reasonable, and the service life of the network can be effectively prolonged.

The invention belongs to the technical field of wireless network protocols, in particular relates to an opportunistic routing method based on grid clustering in a wireless sensor network. The invention adopts a grid-type clustering method and the opportunistic routing algorithm to fully take advantages of the energy effectiveness of a clustering topology control method and the advantage of an opportunistic routing in the aspect of end-to-end throughput, thereby ensuring that the sensor network achieves effective optimization in the aspects of data throughput, transmission reliability, and the like on the premise of energy saving.

The invention discloses a topology control method of a wireless sensor network used for monitoring the water quality of an inland river. The topology control method comprises a network initialization stage, a clustering stage, a cluster head election stage, an in-cluster communication stage and an inter-cluster communication stage. Aimed at the wireless sensor network which is used for monitoring the water quality of the inland river and characterized by multiple aggregation nodes and long-distance bilinear distribution, the topology control method divides the wireless sensor network into virtual grids same in size, and all active sensor nodes in each virtual grid constitute a cluster. In each turn, nodes with low communication cost and high residual energy are selected to serve as clusters, other nodes transmit monitoring data to the clusters in a single-hop data transmission mode, data fusion is conducted on the clusters, the data are transmitted to the near aggregation nodes in an inter-cluster multi-hop data transmission mode, and if a path is blocked, the data are reversely transmitted to the far aggregation nodes. The topology control method effectively prolongs the life cycle of the network, balances the load of the network, and optimizes the performance of the network.

The invention provides a wireless sensor network topology control method based on an artificial neural network (ANN). The method is characterized in that the aim of saving energy is achieved by simulating an information processing system of a biological neutral network; when the total vector of the signals input by senor nodes is more than the threshold of a neurone, the neurone is activated and gives out pulses, thus outputting the signals; the nodes are selected to become the cluster heads according to the output signals and the dump energy to primarily form a network topology map; other nodes select the nearest cluster heads and join in the clusters and transfer own information to the cluster heads; the network topology map is optimized in combination with power control; and the transmitting power of the cluster heads is controlled so as to balance the number of the sensor nodes covered by the network, thus reducing collision during communication and improving the communication efficiency. The method has the following beneficial effects: under the condition of ensuring the network connectivity and coverage, the network energy is reasonably and efficiently used as far as possible, the life time of the whole network is lengthened and the nodes in each cluster are balanced to reduce communication interference among the nodes and improve the network communication efficiency.

The invention discloses an Internet of Things sensing layer topology control method. According to the method, an Internet of Things sensing layer wireless sensor network topology structure is established, data transmission is conducted based on the Internet of Things sensing layer wireless sensor network topology structure, and the Internet of Things sensing layer wireless sensor network topology structure is maintained. Due to the fact that cluster head nodes are selected layer by layer by means of positioning nodes during cluster head election, the selected cluster heads are distributed more evenly and reasonably. A aggregation node does not need to know the global information of a network, only small-range broadcast is needed, the increase of the number of nodes has few impacts on the method, data are forwarded through replay nodes and the cluster head nodes together during data transmission, the optimal path for forwarding is already determined during election of the cluster head nodes and the relay nodes, seeking of the optimal path is not needed, and energy consumption of the cluster head nodes is saved.

The invention discloses a maritime search and rescue wireless sensor network topology structure which comprises a plurality of common sensor nodes and aggregation nodes. The common sensor nodes are connected with one another in a wireless mode to form the network topology structure and used for monitoring search and rescue information in real time. The aggregation nodes are used for collecting the monitored information of all the common sensor nodes in a wireless sensor network. The aggregation nodes and the common sensor nodes are connected through two-way symmetrical links. When the space between any two nodes in the aggregation nodes and the common sensor nodes is smaller than the communication radius of each node, the two nodes are in direct communication, and if the space between any two nodes is larger than the communication radius, communication is achieved through other nodes in a multi-hop mode. According to the maritime search and rescue wireless sensor network topology structure, the influence of node displacement is added into the edge weight calculating process in a network model, the advantage of low topology redundancy of minimum spanning tree structures is fully utilized, and the mean distance of the minimum spanning tree structures is decreased by edge deleting and long-range edge adding through the small-world characteristic of a complex network.

The invention relates to a wireless sensor network clustering method based on particle swarm optimization and belongs to the field of topology control of wireless sensor networks. The wireless sensor network clustering method is characterized in that the number of optimal clusters is dynamically decided according to the current state of a farmland environment monitoring network, factors affecting energy consumption are taken into full consideration, a fitness function is constructed, and optimal cluster heads are selected by using a particle swarm optimization algorithm, so that the cluster heads are uniformly distributed in a network, and the load of the network is equalized; during clustering, the factors affecting the energy consumption are taken into full consideration, and the optimization is carried out by using the particle swarm optimization algorithm, so that the utilization ratio of energy is increased, and the life cycle of the farmland environment monitoring network is prolonged; and the residual energy of nodes is taken into consideration during cluster head selection, so that cluster head nodes have enough energy to execute tasks, such as collection and aggregation, and the security of data is guaranteed.

A wireless network (1) comprises a base station (2) and sensor nodes (3). The base station (2) comprises a network interface (10), an application interface (11), topology control functions (12) a timer (13), and a buffer (14). Each sensor node (3) comprises a network interface (20), route control functions (21), processing functions (22), sensors (23), flood mechanism programs (24), tree mechanism programs (25), and data forwarding programs (26). The network operates by establishing a conventional routing tree from the sink node that is used when the network is stable. But when a sending node detects a node or link failure it dynamically switches to sending its data packets using a flooding mechanism, rather than waiting for the routing tree to be reestablished. This reduces the latency for data delivery. Also, when flooding the data packets, it allows the packets to be flooded to nodes that are an equal number of hops from the sink node as the send node is from the sink node. This approach is suitable in situations where an obstacle causes the path between the sending node and the sink to be blocked, thus requiring a strategy in which packets are routed by less direct means. It increases the probability of delivery.

The invention relates to a method for clustering a wireless sensor network and an in-cluster topology control algorithm based on backup nodes. The method for clustering the wireless sensor network and the in-cluster topology control algorithm based on the backup nodes comprise the steps that the position of each cluster head and the range of each cluster are determined, wherein the clusters are divided into ring zones with the same ring radius and are segmented into multiple sectors at the same angle amplitude, and then the transmission range of nodes in the clusters is determined; a topological structure is established in the mode that the backup nodes and an implicit link are added to the nodes in the clusters on the basis of traditional tree topology; the generated backup nodes have the self-curing characteristic, the network can conduct automatic repair locally according to information of the nodes in the inner ring zone and the outer ring zone when a node failure occurs, and then connectivity is ensured; a standby cluster head is selected from each cluster, energy consumed for forwarding data is used as a weight, the shortest path algorithm is used for communication with the nodes of the outer cluster, and the information is forwarded to the aggregation node finally. The method for clustering the wireless sensor network and the in-cluster topology control algorithm based on the backup nodes have the advantages that network connectivity can be achieved through the backup nodes, and energy consumption balance is realized finally by means of controlling the hop counts of the nodes and the regional range of the clusters, setting the priority and the like.

The invention discloses a distributed topology control method for a cognitive Ad Hoc network, and mainly solves the problems of mutual interference of secondary users and failure in guarantee of connectivity of networks of the secondary users in the prior art. An implementation process of the distributed topology control method for the cognitive Ad Hoc network includes: enabling each node in the network to sequentially broadcast a HELLO packet twice, and receiving the HELLO packet of initial neighbor nodes to set up a local two-hop topology subgraph; constructing a shortest path tree according to energy consumption link cost weight on the basis of the local two-hop topology subgraph, and on the basis of the shortest path tree, constructing a local generation subgraph capable of guaranteeing user communication; adjusting transmission power according to one-hop neighbor nodes in the local generation subgraph; enabling all nodes in the network and links between the nodes and the logical neighbor nodes thereof to form a whole network topology; after topology construction is finished, performing independent channel selection for the nodes in the network. The distributed topology control method for the cognitive Ad Hoc network has the advantages of low complexity and realization of guaranteeing communication of user networks and eliminating user interference, and is applicable to the cognitive Ad Hoc network.

The invention provides a hierarchical and regular mesh network routing method in the technical field of communications, which comprises the steps as follows: routing on a mesh network is realized by building a hierarchical and regular network topology structure; the hierarchical and regular network topology structure consists of the actual network nodes of a pyramid topology; a mesh network of a plane structure is firstly formed by the actual network nodes; then regular virtual plot topologies are formed by a valid topology control strategy; the virtual plot consists of actual network entities; under the hierarchical and regular network topology structure, a comprehensive link quality assessment index is adopted to describe the quality of a link between the virtual plots in the network as well as between the actual nodes; and the mesh network routing realizes the adaptation of the QoS (quality of service) demands and protocol and path quality by adopting a routing protocol based on geographical positions and link states. The hierarchical and regular mesh network routing method has the obvious effects of improving the adaptation capacity of the mesh network routing for channels and services, the fault-tolerance and load balancing of the mesh network and the QoS performance of the services.

The invention discloses a topology control method for a wireless optical sensor network based on clustering, in order to mainly solve the problems of un-uniform energy consumption of network nodes andunstable network topology in the prior art. The topology control method has the implementation scheme characterized by comprising the steps of: 1. initializing the wireless optical sensor network toenable nodes to generate random numbers; 2. calculating the cluster radius of each node and partial average residual energy in the wireless optical sensor network according to a radio energy consumption model; 3. setting a cluster head election threshold according to a present cluster head election threshold by taking residual energy of the node and the distance from the node to a base station asan important standard; and 4. comparing the random numbers generated by the nodes with the cluster head election threshold, electing cluster heads and cluster members and performing clustering. The topology control method of the invention has the beneficial effects of prolonging service life of the nodes, effectively improving stability of the network, and uniforming the energy consumption of thenodes, and the topology control method can be applied to topology control of an optical communication network with static nodes.

The invention discloses a distributed fault-tolerant topology control method based on dump energy sensing. The distributed fault-tolerant topology control method based on the dump energy sensing mainly solves the problem that balance of dump energy between nodes and network topology fault-tolerant capability can not be guaranteed at the same time in the prior art. The distributed fault-tolerant topology control method based on the dump energy sensing comprises the steps of broadcasting a HELLO package of each node in a network and receiving the HELLO package of an initial neighbor node, and establishing a local topology subgraph; construing a shortest path tree based on the local topology subgraph and according to link cost weight and constructing a local k communication generation subgraph by traversing all directed edges according to distance weight from small to large; adjusting emission power according to a one-hop neighbor node in the local k communication generation subgraph, and connecting non-logic neighbor nodes within the emission power range; and finally construing a whole network topology according to all the nodes in the network and links between the nodes and the logic neighbor nodes. The process can be repeatedly executed according to the updating cycle T of the topology. The distributed fault-tolerant topology control method based on the dump energy sensing has the advantages that life cycle of the network is prolonged, and fault-tolerant capability of the network is enhanced. The distributed fault-tolerant topology control method based on the dump energy sensing can be applied to a wireless self-organizing network.

The invention discloses a software defined networking (SDN) network topology flow visual monitoring method comprising the steps of 1, sending a network topology request via a front end, calling a northbound interface, receiving the request of the front end and forwarding the request to an SDN controller; 2, processing the request, responding to link connection information of a switch, a router and a host via a southbound interface, de-weighting and combining connection relations of ports of devices, and generating logic relations between the devices by using the SDN controller; 3, dynamically rendering a TOPO association relation graph according to the logic relations between the devices; and 4, acquiring network flow, collected by S-flow data collection technology, of a device or overall devices according to the TOPO association relation graph, and returning the network flow to the front end, thus being convenient to achieve overall distribution of network resources. The invention also discloses an SDN network topology controller control terminal which can count, analyze and display the overall network flow and the abnormal network flow.

The invention discloses an implementation method for a wireless sensing network of railway traffic, which comprises the following steps: firstly, dividing regions along railways needing to transfer train traveling information into a plurality of sections, and establishing a convergent node at each section; further dividing the section into M region blocks the length of which is 1; computing the number ni of wireless nodes needing to be arranged in each region block, thereby computing the distance di between every two wireless node pieces in each region block, wherein di is equal to 1 / ni; uniformly arranging the wireless nodes in the middle of each region block according to the distance di, and sequentially configuring an ID number for each wireless node; enabling the wireless nodes to work and sleep by turns by using the region blocks as units; and enabling all wireless nodes in the sections to communicate with a control center for safe operation of trains through the convergent nodes in the sections. In the invention, the sectioned node arranging method is used for determining the optimal arranging distance between every two wireless nodes in the region blocks. The mechanism of working and sleeping by turns is adopted by the wireless nodes to effectively prolong the life cycle of the network and ensure the traveling safety of trains.

The invention relates to a potential competing topological control method based on power and energy optimization. The potential competing topological control method includes the steps of a topology building phase, where (i)N( / i) order proximal analysis method is employed to calculate optimal network cluster number, guide selection of cluster heads, and guide non-cluster head nodes to join the clusters through network communication cost, the Sink nodes directly or indirectly establish communication relation with the cluster head nodes to build inter-cluster routes after cluster members of each cluster and communication between nodes are determined; a topology maintenance phase, where when node failure triggers local topology maintenance, the topology structure optimization problem during the process is mapped into a potential competing optimization problem, nodes participated in competing execute a topology maintenance algorithm, and each participant carries out power selection to allow the competing to be converged to a Nash equilibrium state. Energy balance and node communication interference are both taken into consideration. Network QoS is ensured, while a network service period is effectively prolonged.

The invention discloses a method and a device for realizing band switching and topology control. The method comprises the following steps: triggering the band switching through a node; detecting whether the node is a key node or not according to the adjacent node information of the collected node if the band switching is switched from an authorized band to an unauthorized band; if so, refusing the switching; otherwise, carrying out the switching; and carrying out the switching if the band switching is switched from the unauthorized band to the authorized band. The device for realizing the band switching comprises a band triggering unit, a detecting unit and a switching unit. The method and the device provide the novel topology control technology for perceiving the radio technology; and inaddition, the method and the device can also reduce the energy consumption of wireless networks effectively, reduce the waste of power and prolong the lifetime of the networks.

The invention relates to the field of topology control and construction of a wireless sensor network and in particular to a layered-structure-based topology control method for a dynamic wireless sensor network. The method comprises a node networking process, a node registration process and a network optimizing process. According the method nodes are enabled to access the network in a self-adaptive manner without changing the whole network topology by dynamic hierarchical regulation and networking algorithm control of the nodes on the condition of maintaining equal network functions of the whole network nodes, and the topology of a local network is minimally changed, thus reducing the additional cost of the network. The novel topology control mechanism provided by the invention integrates the advantages of a plane structure, thus the whole robustness of the network is enhanced, the complexity for network realization is reduced, and the problems existing in the prior art are solved.

The embodiment of the invention relates to the field of communication, and discloses a virtual private topology control method, a virtual private topology control device and a virtual private topology control system. The method comprises the following steps of: receiving a message transmitted by customer edge equipment, wherein the message comprises a source media access control (MAC) address anda destination MAC address of the message; when an out port of the message corresponds to a pseudo wire, determining whether to send the message out according to the source MAC address and the destination MAC address in the message and an operation matching table of the message; and if the message is determined to be sent out, sending the message to operator edge equipment at the destination end of the message. The method, the device and the system are mainly used in a process of the virtual private topology control, and can realize the virtual private topology control and simultaneously avoidsending an unnecessary message into a network, thereby saving network sources.