111 results about "Neighbour discovery" patented technology

Methods and apparatus for using end nodes, e.g., wireless terminals, to discover base stations and communicate information about discovered access nodes, e.g., base stations, to other access nodes in a system are described. As the wireless terminal roams in the system and new access nodes are encountered, one or more physically adjacent access nodes will be informed of the presence of the new access node as a result of communications with the wireless terminal. A message indicating an access node's inability to route a message to another access node which is known to a wireless terminal may trigger the wireless terminal to begin the process of updating access node routing and neighbor information.

The present invention discloses a method to prevent spoofed packet attacks, wherein, a DHCPv6 relay agent device forwards address assignment packets between a DHCPv6 client and a DHCPv6 server in stateful configuration mode, establishes and maintains a client information table according to the client information in the address assignment packets, and filters neighbour discovery (ND) packets sent from clients according to the client information table. The present invention also discloses a DHCPv6 relay agent device. The technical proposal of the invention can protect the DHCPv6 relay agent device against spoofed ND packet attacks.

Methods and systems for reliable neighbor discovery in wireless ad hoc networks are provided herein. In one aspect, embodiments of the present invention provide methods and systems for analyzing the quality of a communication link. In embodiments, several factors affecting link quality may be incorporated in the analysis, and basic and/or complex statistical and/or probabilistic analysis may be used. In another aspect, embodiments of the present invention provide methods and systems for neighbor node discovery that adapt to network and/or node operating conditions and that dynamically maintain a neighbor node set at a given node according to these conditions. In a further aspect, embodiments of the present invention extend the utility of neighbor node discovery beyond the customary role of data routing support into the problem of deploying an ad hoc network by providing a display module for displaying node connectivity information.

The invention provides an access control method and equipment. The method comprises that an ED is used as a neighbor discovery server ENDS, receives the registration which is sent out by the ED which is used as a neighbor discovery client EDNC, and informs any other ENDCs which are registered to the ENDS to the ENDCs which initiate the registration; and the ED is used as the ENDC, initiates the registration to the ED which is used as the ENDS, and acquires any other ENDCs which are registered in the ENDS from the ENDS, the ENDC which is alternately accessed to the ENDC from all the acquired ENDCs to establish a virtual forwarding passage according to the visit control strategy of the ENDC, so the established virtual forwarding passage is used to alternately accessed the selected ENDC.

The invention relates to a routing method for unmanned aerial vehicle network communication. The method comprises the following steps: 1, randomly deploying unmanned aerial vehicle network nodes; 2, interacting link information and node information between the nodes to perform link perception and neighbor discovery; 3, electing a cluster head node according to the link information and the node information; 4, the non-cluster head node sending a join request to the cluster head node, and the cluster head node establishing topological structure information in the cluster after receiving the joinrequest; 5, each cluster head node informing the non-cluster head nodes in the cluster of the topological structure information in the cluster, so that the non-cluster head nodes in the cluster establish a topological structure in the cluster; each cluster head node sending information indicating that the cluster head node is a cluster head to other cluster head nodes, and establishing a clusterhead network topology structure between the cluster head nodes; and 6, establishing a routing table according to the link information, the node information and the in-cluster topological structure. The method is good in expandability, high in network stability and real-time performance, low in energy consumption and particularly suitable for large-scale unmanned aerial vehicle network communication.

The invention relates to an intra-group member phase selection method and system based on a group neighbor discovery mechanism. The intra-group member phase selection method comprises the steps that when only a master node exists in a node group, an initial group sequence is the same as the sequence of the current master node, wherein the group sequence includes N phases; when the situation that a new node is added to the node group is discovered, the new node serves as a slave node of the master node, the slave node corresponds to a sequence, with N phase positions, in a group, and an or operation is carried out on the slave nodes and the current group sequence to obtain N combined sequences; the time delay between each combined sequence and the group sequence to obtain N sets of time delay, and the N sets of time delay are sorted by size; the minimum set of time delay is obtained, and the phase position corresponding to the minimum set of time delay serves as an optimum phase; the master node distributes the optimum phase to the slave node, and the group sequence is updated as a sequence obtained after the or operation is carried out on the current group sequence and the slave node. According to the intra-group member phase selection method, the optimal combination of phase differences is selected, and the discovery time delay of other existing neighbor discovery strategies is shortened.

Transmitting a probe signal. A method includes transmitting a signal, having a predetermined total power, during a transmit cycle. The signal has a traffic channel transmitting user data and a probe channel to locate new nodes to add to the network. The transmit channel uses a first portion of the total power and the probe channel uses a second portion of the total power. The method further includes performing a probe cycle by lowering the power in the first portion of the total power and raising the power in the second portion of the total power, but maintaining the total power at the same level as the total power during the transmit cycle. The method further includes, after the probe cycle, raising the power in the first portion of the total power and lowering the power in the second portion of the total power.

The invention provides a method and equipment for detecting asymmetric static aggregation. A neighbour discovery protocol is enabled by a static aggregation group member port, a neighbour relation is built between the static aggregation group member port and opposite end equipment, a neighbour discovery protocol message carrying neighbour summary information is received, whether the neighbour discovery protocol message is consistent with relevant information of a static aggregation group reference port or not is judged according to relevant content in the neighbour summary information, and if not, a port where a neighbour is located is not selected in a static aggregation group, and is blocked. According to the scheme, the method and equipment are simple, universal and high in compatibility.

The invention provides an underwater acoustic network penetration routing method, which comprises the following steps that: after nodes in an underwater acoustic network initiate neighbor discovery, a source node starts a timer, calculates to obtain the packet loss rate of a data packet, sets the flag position of a relay data packet of the source node as zero, updates the source node and sends the data packet until a destination node receives the data packet from the source node; and a route is established, successful relaying of data is completed, the connectivity probability of a link is calculated, and a permeation route process is ended and permeated to a destination in a grid, wherein a relay path in a data packet received by a destination node is a finally established route path. Reliable transmission of the route is effectively guaranteed by improving the redundancy of link communication, huge overhead caused by route flooding is greatly reduced by adopting the limiting condition that each data packet is only transmitted once on each link, and the method is simple, effective and easy to operate and implement and has feasibility. Rapid transmission of data packets from a source to a destination is realized, and reliable and timely communication service tasks are provided.

The invention discloses a fast neighbor discovery method for a double-area-array radar ad hoc network. The method comprises the following steps: firstly, obtaining a coarse position of a neighbor nodeby using an inherent scanning function of the radar; then, allocating a neighbor discovery scanning area according to the bidirectional transmission characteristics of a double-area-array phased array radar; and finally, fully utilizing the advantages of the double-area-array phased array radar to reasonably schedule two area-arrays to cooperatively work, performing deep scanning in a scanning interval, and achieving neighbor discovery in the whole network in a secondary handshake manner. By adoption of the method disclosed by the invention, neighbor discovery can be achieved efficiently andquickly in the background of the double-area-array radar ad hoc network.

The invention discloses a directional ad hoc network neighbor discovery method based on cooperation, and belongs to the technical field of wireless communication. According to the invention, the method comprises the steps: when a node observes a conflict, determining that a plurality of neighbors exist in a beam range selected by a current time slot, and giving a rewards to the node; utilizing the information of discovered neighbors in the neighbor discovery process to calculate the number of beams where potential neighbors are located, so cooperation among the nodes is realized; enabling each time slot node to randomly select a receiving and transmitting mode, selecting one beam for communication according to beam probability distribution, and updating the probability distribution of the beams according to conflict occurrence conditions and stored potential neighbor information, thereby improving the probability that the beams with conflicts or potential neighbors are selected in the next time slot. The problem that the neighbor discovery efficiency is low due to the fact that information obtained in the neighbor discovery process is not fully utilized although the influence brought by conflicts is considered in an existing method is solved. The method can be applied to military and other fields.

The invention discloses a cooperative neighbor discovery and access control protocol based on a power broadband carrier. The protocol comprises the following steps that waking time of the station in the high-speed carrier communication network is set as the multiple of the prime number, the prime number is automatically selected by a global calculator of the neighbor discovery protocol, and an expected station work period or discovery delay is matched when each multiple of the prime number is selected; the station selects a work period or discovery delay, and obtains the minimum discovery delay of the work period; the station acquires communication neighbor information, and executes an access control protocol after completing verification of all communication neighbors; a real neighbor isidentified based on the positioned routing distributed protocol, and a relay station is selected to forward data through multi-point relay routing; the neighbor discovery protocol is realized in the broadband power line carrier communication network, and data packet forwarding efficiency can be improved; the protocol has good discovery performance, minimum discovery delay and maximum work period;the security is relatively high, and the site discovery delay can be effectively controlled.

The invention discloses a directional antenna ad hoc network neighbor discovery method based on an SARSA (lambda) algorithm, and the method comprises the following steps: 1, enabling each node to initialize an own Q matrix at the beginning of a neighbor discovery process, and randomly selecting an initial state and an initial action; 2, enabling the node to enter a transmission mode and a receiving mode to carry out corresponding steps, and adopting different steps; 3, employing a greedy strategy to select the action of the next time slot; 4, calculating a one-step prediction error; 5, for all states and actions, updating a Q matrix according to a one-step prediction error; 6, entering the next time slot, returning to the step 2, and stopping until the neighbor discovery process is finished. Compared with a complete random algorithm, the ad hoc network neighbor discovery method disclosed by the invention can accumulate experience in scanning and adaptively find sectors with undiscovered neighbors, so the neighbor discovery speed is accelerated.

The invention provides an efficient and fast convergence neighbor discovery scheme, which is mainly applied to constructing neighbor discovery nodes in an autonomous control plane and adopts two mechanisms of 'constructing an adjacency list using simplified neighbor discovery messages' and 'efficiently and fast accessing a node into a security autonomous domain'. The first mechanism mainly solvesthe problems that neighbor messages are redundant and too long in the neighbor discovery process. The second mechanism mainly solves the problem that when a new node is added into a security autonomous domain, neighbor table convergence is too slow. By using the two new mechanisms, the neighbor discovery method provided by the invention can reduce the control overhead and effectively improve the convergence speed of the adjacency list, thereby reducing the control overhead and improving the neighbor discovery efficiency in the neighbor discovery process.

The invention provides a neighbor discovery method and system. The method comprises the steps: carrying out the scrambling of data through employing a scrambling code, and transmitting the data to a receiving node so as to enable the receiving node to extract the scrambling code from the data, and detect the energy of the scrambling code; establishing a neighbor list according to the energy of thescrambling code. When the method is applied to a receiving node, the method comprises the following steps: receiving data sent from a sending node, the data being scrambled by the sending node in advance by using a scrambling code; extracting scrambling codes from the data, and detecting the energy of the scrambling codes; establishing a neighbor list according to the energy of the scrambling code. According to the method, scrambling codes are used for scrambling sent data, the one-to-one corresponding relation that the scrambling code detection distance is far larger than the data transmission distance and a user corresponds to the scrambling codes is fully utilized, the neighbor detection range of network nodes is expanded, the nodes can detect neighbor nodes outside a two-hop range only through broadcasting of a one-hop HELLO message without extra expenditure, and a multi-hop neighbor information list is established and updated.

The invention provides a neighbor discovery method and device for an unmanned aerial vehicle ad hoc network and an unmanned aerial vehicle, and the method comprises the steps: periodically sending a beacon frame to each member node in each sending sector, so as to establish bidirectional alignment with each member node in the sending sector until bidirectional alignment with all member nodes is established; broadcasting the HELLO packet to the member node, so that the member node responds based on the HELLO packet to generate a REPLY packet; and generating a neighbor list based on the REPLY packet fed back by each member node. According to the neighbor discovery method and device for the unmanned aerial vehicle ad hoc network and the unmanned aerial vehicle provided by the invention, all member nodes can be distributed uniformly by the cluster head node after being aligned to the cluster head node in a scene with a relatively long communication distance and a relatively large network coverage area, and feedback information of the plurality of member nodes is received in sequence, so that compared with the traditional sequential traversal, the neighbor discovery efficiency is improved. The neighbor discovery speed and efficiency can be improved.

The invention discloses an unmanned aerial vehicle ad hoc network directional access protocol optimization design method, and the method comprises the steps: carrying out the modeling of a neighbor discovery process and link maintenance time in an unmanned aerial vehicle ad hoc network, and obtaining the results of the neighbor discovery speed and link duration under different beam widths; establishing the protocol time overhead minimization model, introducing the idea of network link balance innovatively into the optimization model, analyzing the network time overhead by taking the total network link number as an evaluation index, and obtaining the optimal network structure. According to the method, the structure optimization problem of the MAC protocol under the condition that the unmanned aerial vehicle ad hoc network is equipped with the directional antenna is solved, the protocol performance can be improved, and certain reference and guidance are provided for the protocol design and network construction of the actual unmanned aerial vehicle ad hoc network.

The invention provides a wireless network neighbor discovery method with low conflict probability, which adopts a short frame structure and a back-off mechanism to reduce the conflict occurrence probability, and solves the problem of access request node channel competition by combining timeout and the back-off mechanism. Terminating judgment of a round of neighbor discovery is carried out by adopting a multi-timeout mechanism; neighbor discovery adopts a master-slave exploration request confirmation mode and is a scheduling method, nodes do not need a channel idle interception mechanism, the neighbor discovery process has high determinacy, and compared with a random access method, the scheduling method is more reliable; and in the reverse request confirmation mode, the access request nodealso establishes a reliable neighbor list, i.e., the access request node confirms that a reliable communication link exists in the neighbor list of the access request node.