Link Monitoring Method and Device Based on Adaptive Hello Slots

Abstract

The present application proposes a link monitoring method and device based on adaptive Hello slots, including the following steps: constructing a link, setting a Hello message timer for each node in the link, and broadcasting Hello messages based on a preset Hello slot of the Hello message timer; determining the communication range of each node based on the Hello messages broadcast by each node, taking other nodes within the communication range of the current node as neighbor nodes, and performing neighbor liveness detection; after each neighbor liveness detection, performing an overtime self-check on the Hello message timer of the current node. If the Hello message timer times out and the current node has no broadcast record, then update the preset Hello slot of the current node. This solution adjusts the Hello slot based on the relative communication distance and predicted moving speed, thereby improving the communication reliability of the edge network.

Description

Technical Field

[0001] This application relates to the field of computer communication, and particularly to a link monitoring method and device based on adaptive Hello slots. Background Art

[0002] With the rapid development of global information technology, the strategic pattern is undergoing profound changes. The modern task execution mode is gradually evolving from a centralized operation mainly based on traditional mechanical equipment to a new collaborative mode dominated by intelligent autonomous systems. Under this background, the diversity and complexity of task execution units have increased significantly, and their structure and organization mode also show the characteristics of small scale and distribution. Real-time and accurate environmental situation perception has become the key foundation for realizing the collaboration of distributed task units, and information advantage plays a decisive role in decision-making and efficient task execution. However, the traditional centralized communication network architecture can no longer meet the needs of this intelligent collaboration, especially in the edge environment far from the control center and with weak communication infrastructure.

[0003] The edge environment is usually called the "first operational mile", where the communication scenario is complex and changeable and resources are limited. In this environment, it is difficult for task units to rely on fixed communication infrastructure to achieve information interaction, and the network connection needs to rely on a dynamic network formed by node self-organization. In response to the growing information interaction requirements in complex environments, edge networks have emerged and become an important research direction in the current field of communication technology. Edge networks deeply integrate the technical characteristics of Mobile Ad Hoc Networks (MANET), with high dynamicity, self-organization, and the ability to support large-scale heterogeneous nodes, and can provide stable and reliable communication guarantees under relatively extreme conditions.

[0004] In recent years, the research and application scope of edge networks have been continuously expanding, and their importance has become increasingly prominent. For example, new operation theories such as multi-field collaborative operation, distributed operation, modular operation, and autonomous system cluster operation have been proposed. These theories emphasize flexible grouping, distributed deployment, and intelligent collaborative operation capabilities, which have greatly promoted the profound changes in the operation system and equipment system. As the key supporting technology for these new operation concepts, edge networks can build small, flexible, and efficient collaborative operation networks in complex environments.

[0005] Although the edge network has broad application prospects in complex environments, it still faces many severe challenges in special operating environments with high adversariality and high dynamics. On the one hand, the high adversariality of complex environments leads to frequent problems such as electronic interference, malicious attacks, and even physical damage to nodes, making communication links extremely vulnerable to interruption. On the other hand, the high dynamics of nodes also cause frequent changes in the network topology, significantly affecting the stability of the link. At the same time, traditional ad hoc routing protocols are difficult to meet the requirements of the edge network for efficient communication in dynamic environments, which further exacerbates the uncertainty and instability of the network, directly affecting the task execution efficiency and communication reliability. Summary of the Invention

[0006] The embodiments of the present application provide a link monitoring method and device based on an adaptive Hello slot. By constructing the relative communication distance of the current node, predicting the moving speed, evaluating the link quality metric, etc., the Hello slot is adjusted. Compared with the traditional fixed-cycle method, it can perceive the network state more real-time, and has significant advantages in core performance indicators such as packet delivery ratio, throughput, and average end-to-end delay, which can improve the communication reliability, stability, adaptability, and anti-destruction ability of the edge network.

[0007] In a first aspect, the embodiments of the present application provide a link monitoring method based on an adaptive Hello slot, and the method includes:

[0008] Construct a link, and the link includes multiple movable nodes. Set a Hello message timer for each node, and each node broadcasts a Hello message based on a preset Hello slot of the Hello message timer.

[0009] Determine the communication range of each node based on the Hello message broadcast by each node, take other nodes within the communication range of the current node as the neighbor nodes of the current node, and perform neighbor liveness detection on each neighbor node. The steps of the neighbor liveness detection include: set a neighbor liveness detection time window for the current node, update the corresponding routing table based on the Hello messages received by the current node within the neighbor liveness detection time window. The routing table records the node information of all neighbor nodes corresponding to the current node. Take the corresponding neighbor node that has not received a Hello message within the neighbor liveness detection time window as a lost neighbor node. If the lost neighbor node is a communication node, the current node constructs an RERR message and returns it to the source node. If the lost neighbor node is not a communication node, delete the node information of the lost neighbor node from the routing table.

[0010] After each neighbor activity detection, perform a timeout self-check on the Hello message timer of the current node. If the Hello message timer times out and the current node has no broadcast record, update the preset Hello time slot of the current node, where the dynamic Hello time slot is calculated based on the relative communication distance and predicted moving speed of the current node, and the dynamic Hello time slot is used as the new preset Hello time slot.

[0011] In a second aspect, an embodiment of the present application provides a link monitoring device based on an adaptive Hello time slot, including:

[0012] A construction module for constructing a link, where the link includes multiple movable nodes, setting a Hello message timer for each node, and each node broadcasts a Hello message based on the preset Hello time slot of the Hello message timer;

[0013] An activity detection module for determining the communication range of each node based on the Hello message broadcast by each node, taking other nodes within the communication range of the current node as neighbor nodes of the current node, and performing neighbor activity detection on each neighbor node. The steps of the neighbor activity detection include: setting a neighbor activity detection time window for the current node, updating the corresponding routing table based on the Hello messages received by the current node within the neighbor activity detection time window, where the routing table records the node information of all neighbor nodes corresponding to the current node, taking the corresponding neighbor nodes that do not receive Hello messages within the neighbor activity detection time window as lost neighbor nodes. If the lost neighbor node is a communication node, the current node constructs a RERR message and returns it to the source node. If the lost neighbor node is not a communication node, delete the node information of the lost neighbor node from the routing table;

[0014] A self-check module for performing a timeout self-check on the Hello message timer of the current node after each neighbor activity detection. If the Hello message timer times out and the current node has no broadcast record, update the preset Hello time slot of the current node, where the dynamic Hello time slot is calculated based on the relative communication distance and predicted moving speed of the current node, and the dynamic Hello time slot is used as the new preset Hello time slot.

[0015] In a third aspect, an embodiment of the present application provides an electronic device, including a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute a link monitoring method based on an adaptive Hello time slot.

[0016] The main contributions and innovations of the present invention are as follows:

[0017] In the embodiments of the present application, neighbor nodes are determined by constructing a link, setting a Hello message timer to broadcast messages, and neighbor liveness detection is performed. Once it is found that a lost neighbor node is a communication node, an RERR message is promptly constructed to trigger route repair; if it is a non-communication node, its information is deleted to ensure a smooth data transmission path. At the same time, the dynamic Hello time slot is calculated based on the relative communication distance and the predicted moving speed, and the Hello time slot is adjusted in real time. Compared with the traditional fixed-cycle method, the network state can be perceived more real-time, and significant advantages are shown in core performance indicators such as packet delivery ratio, throughput, and average end-to-end delay. Furthermore, the communication reliability, stability, adaptability, and anti-destruction ability of the edge network are improved, providing strong support for task execution in complex environments.

[0018] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The illustrative embodiments and descriptions thereof are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0020] Figure 1 is a flowchart of a link monitoring method based on an adaptive Hello time slot according to an embodiment of the present application;

[0021] Figure 2 is an overall framework diagram for calculating a dynamic Hello time slot to replace a preset Hello time slot according to an embodiment of the present application;

[0022] Figure 3 is a motion schematic diagram of a dynamic node according to an embodiment of the present application;

[0023] Figure 4 is a structural block diagram of a link monitoring device based on an adaptive Hello time slot according to an embodiment of the present application;

[0024] Figure 5 is a hardware structure schematic diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. On the contrary, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0026] It should be noted that: In other embodiments, the steps of the corresponding method are not necessarily executed in the order shown and described in this specification. In some other embodiments, the steps included in the method may be more or less than those described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may also be combined into a single step for description in other embodiments.

[0027] Embodiment 1

[0028] The embodiment of the present application provides a link monitoring method based on adaptive Hello slots. By constructing the communication relative distance of the current node, predicting the moving speed, and evaluating the link quality metrics, etc., the Hello slots are adjusted. Compared with the traditional fixed-period method, it can perceive the network state more real-time, and has significant advantages in core performance indicators such as packet delivery ratio, throughput, and average end-to-end delay. It can improve the communication reliability, stability, adaptability, and anti-destruction ability of the edge network. Specifically, referring to Figure 1 , the method includes:

[0029] Construct a link, and the link includes multiple movable nodes. Set a Hello message timer for each node, and each node broadcasts a Hello message based on the preset Hello slots of the Hello message timer;

[0030] Determine the communication range of each node based on the Hello message broadcast by each node, take the other nodes within the communication range of the current node as the neighbor nodes of the current node, and perform neighbor liveness detection on each neighbor node. The steps of the neighbor liveness detection include: set a neighbor liveness detection time window for the current node, update the corresponding routing table based on the Hello messages received by the current node within the neighbor liveness detection time window. The routing table records the node information of all neighbor nodes corresponding to the current node. Take the corresponding neighbor node that has not received a Hello message within the neighbor liveness detection time window as a lost neighbor node. If the lost neighbor node is a communication node, the current node constructs an RERR message and returns it to the source node. If the lost neighbor node is not a communication node, delete the node information of the lost neighbor node from the routing table;

[0031] After each neighbor activity detection, perform a timeout self-check on the Hello message timer of the current node. If the Hello message timer times out and the current node has no broadcast record, update the preset Hello time slot of the current node, where the dynamic Hello time slot is calculated based on the relative communication distance and predicted moving speed of the current node, and the dynamic Hello time slot is used as the new preset Hello time slot.

[0032] In some specific embodiments, the Hello message timer is used to control the nodes in the link to periodically send Hello messages to discover and maintain neighbor relationships in the link. The Hello message includes the node identifier, link status, node load, neighbor information, etc. of the current node. The nodes in the link confirm the neighbor information with each other through Hello, and data can be transmitted in the link through the neighbor relationship.

[0033] In some specific embodiments, set a lost message threshold, and use the product of the lost message threshold and the preset Hello time slot of the Hello message timer as the neighbor activity detection time window.

[0034] Specifically, first initialize the parameters of the Hello message timer for each node, set the preset Hello time slot of the Hello message timer to 1 s, that is , and set the lost message threshold to 2, that is , where the preset Hello time slot is the initial value of the Hello message timer when the node just joins the link or rejoins the link after being lost, that is, the node broadcasts a Hello message every 1 s. The lost message threshold is used to confirm whether the current node is lost. The lost message threshold is used to control the number of times the node does not broadcast a Hello message. That is, when the node does not broadcast a Hello message twice in a row, it is considered that the node is lost.

[0035] Specifically, due to some possible network fluctuations, it may cause the Hello information of the node to be sent unsuccessfully or sent with a delay. In order to avoid directly discarding the node when this situation is found, the lost message threshold in this solution is set to 2, and the node will be discarded only when the node does not broadcast a Hello message twice in a row.

[0036] Therefore, the neighbor activity detection time window of the current node is , since the preset Hello time slots of each node in the link are the same, even though the preset Hello time slots in this solution are dynamically updated, the time slot differences between neighboring nodes are not significant. Therefore, the current node in this solution uses the product of the lost message threshold and the preset Hello time slot of the Hello message timer as the neighbor activity detection time window, ensuring that each node can send at least two Hello messages within the time of the neighbor activity detection time window, thereby maintaining the neighbor relationship between nodes for data transmission.

[0037] In some embodiments, each node stores a corresponding routing table, which records the node information of all neighbor nodes corresponding to the current node. Since the nodes in the link are constantly moving, such as an unmanned aerial vehicle queue, and the neighbor nodes will change due to the change of the communication range during the movement of these nodes, the neighbor nodes are recorded through the Hello messages continuously sent by each node and the routing table of each node.

[0038] Therefore, in the step of "updating the corresponding routing table based on the Hello messages received by the current node within the neighbor activity detection time window", when there is a corresponding entry in the routing table for the received Hello message, the corresponding entry in the routing table is updated based on the received Hello message. When there is no corresponding entry in the routing entry for the received Hello message, the content of the Hello message is added to the routing table as a new entry, and the node corresponding to the Hello message is a new neighbor node.

[0039] Specifically, since the Hello message includes key information such as node identification, link status, node load, neighbor information, etc., the received Hello messages can be traversed in the routing table to confirm whether there is a corresponding item. If it exists, it means that the node and the current node are still maintaining a neighbor relationship, and the content of the Hello message is used to update the corresponding item in the routing table. If there is no corresponding item, it means that the node is a newly added neighbor node, and the content of the Hello message is added to the routing table as a new item for convenient data information transmission at any time.

[0040] On the contrary, the corresponding neighbor nodes that do not receive Hello messages within the neighbor activity detection time window are regarded as lost neighbor nodes.

[0041] In some embodiments, the role of the link is to connect through different nodes to complete the transmission of data information. For example, in an area, there are 3 nodes A, B, and C. If you want to transmit data information from A to C, since the distance between A and C is relatively far, it cannot be directly transmitted. However, the data information can be transmitted to B, and then the message can be transmitted from A to B and then to C. At this time, B is the communication node. If there is also a node D in this area, but D is not used for the transmission of data information, then D is a non-communication node.

[0042] That is to say, the communication node in this solution is the node for transmitting data information, and the RERR message constructed by the current node returns to the source node along the original path.

[0043] In some embodiments, if the lost neighbor node is a communication node, it means that the transmission of data information is interrupted. At this time, the current node constructs an RERR message and returns it to the source node. Among them, the RERR message is used to indicate that the link is disconnected due to node loss. After receiving the RERR message, the source node triggers route repair and sets a new path in the link to transmit data information.

[0044] Specifically, when a link failure occurs in this solution, it quickly senses the location of the failure and notifies the network in a timely manner, re-plans the optimal communication path, realizes efficient repair of the link, improves the reliability and stability of network communication, and further enhances the adaptability and survivability of the edge network, providing solid support for task execution in complex environments.

[0045] In some embodiments, if the lost neighbor node is a non-communication node, it means that the lost neighbor node is not used for communication in the current node. Therefore, the corresponding entry is directly deleted from the routing table, that is, the node information corresponding to the lost neighbor node is deleted to avoid affecting the construction of the data information path transmission in the future.

[0046] In some embodiments, in the step of "performing timeout self-check on the Hello message timer of the current node", if the current node does not broadcast the Hello message within the preset Hello time slot, it is considered that the Hello message timer of the current node has timed out. If the current node broadcasts the Hello message within the preset Hello time slot, it is considered that the Hello message timer of the current node has not timed out.

[0047] Further, if the Hello message timer has not timed out, neighbor liveness detection is performed again; if the Hello message timer times out and a broadcast is performed within the previous preset Hello time slot, the node continues to wait to determine whether the Hello message timer times out until the consecutive timeout count of the Hello message timer is greater than the timeout threshold. When the consecutive timeout count of the Hello message timer is greater than the timeout threshold, it is determined that the corresponding node is disconnected.

[0048] Specifically, if a node has sent a Hello message within the previous Hello time slot, even if the Hello message timer times out, the node will continue to wait for the next cycle, thus ensuring that the update of the Hello time slot only occurs when actually needed, rather than being forced to update every time it times out, thereby improving network stability.

[0049] In the step of "calculating the dynamic Hello time slot based on the relative communication distance and predicted moving speed of the current node", the relative communication distance is the product of the dynamic ratio parameter and the communication radius, and the formula is expressed as follows:

[0050]

[0051]

[0052] where d is the relative communication distance, is the dynamic ratio parameter, r is the communication radius, is the arctangent function compression mapping of the link change degree parameter, is the maximum-minimum normalization result of the node load capacity parameter, is the maximum-minimum normalization result of the node stability parameter, is a fixed value, The size of is set according to the subsequent experimental results.

[0053] Specifically, in a conventional relative distance model, to calculate the specific value of the relative distance, it is necessary to subtract the distance after the two nodes move from the distance before the movement. However, in the case of a link disconnection, whether it is because a node leaves the communication range of its neighbor node or the neighbor node has been damaged, the two nodes cannot know each other's positions, that is, the position information of the two nodes cannot be obtained, and thus the Euclidean distance between the two nodes cannot be known. However, since nodes with a longer communication range can maintain connection stability within a longer hello interval, so in this solution, the relative distance is defined as proportional to the communication radius of the node, that is 。

[0054] In some embodiments, the link change degree is calculated from the link number change rate within the previous preset Hello time slot and the formula is expressed as follows:

[0055]

[0056]

[0057] in, is the link variation degree, The last preset Hello time slot The rate of change of the number of links within is the weight coefficient, , Respectively represent the last preset Hello time slot The number of newly added and reduced links in The last preset Hello time slot The total number of link changes within, specifically, the weight coefficient is 0.8.

[0058] Furthermore, as the link dynamics increases, the predicted value of the communication distance needs to be shortened, and considering the link change degree parameter The unbounded feature of may lead to numerical instability, so the link change degree parameter is compressed and mapped using the inverse tangent function, that is:

[0059]

[0060] In some embodiments, the node load capacity parameter is the number of data packets on the node at the current moment, and the formula is as follows:

[0061]

[0062] in, is the number of data packets on the node at the current moment.

[0063] Furthermore, since the communication distance needs to be reduced when the node load increases, the node load capacity parameter is normalized to the maximum-minimum using the known node queue capacity boundary, and the formula is as follows:

[0064]

[0065] in, is the known node queue capacity boundary.

[0066] In some embodiments, the node stability is obtained based on the average moving speed and instantaneous moving speed of the node, and the average speed is based on the displacement of the node in the last Hello time slot. And preset Hello time slot Calculation, the formula is as follows:

[0067]

[0068] Among them, is the magnitude of the average moving speed.

[0069] The magnitude of the instantaneous moving speed is obtained in real time by the node itself, and the formula is as follows:

[0070]

[0071] Among them, is the instantaneous moving speed of the node at the current time t.

[0072] Then the formula for the node stability parameter is as follows:

[0073]

[0074] Among them, is the magnitude of the instantaneous moving speed, is the magnitude of the average moving speed, is the weight coefficient, and the weight coefficient is set to 0.8 according to subsequent specific experiments.

[0075] Furthermore, when the node motion becomes unstable, the communication distance prediction should also be shortened. At the same time, based on the magnitude of the node moving speed, fixed maximum and minimum values can be set according to subsequent experiments. Therefore, the maximum-minimum normalization of the node stability parameter is performed, and the formula is as follows:

[0076]

[0077] Among them, is the maximum moving speed of the node, is the minimum moving speed of the node.

[0078] In some embodiments, in the step of "calculating the dynamic Hello slot based on the communication relative distance and predicted speed of the current node", the formula for the predicted moving speed is:

[0079]

[0080] Among them, is the smoothing factor, is the moving speed of the node at the current time t, is the predicted value of the moving speed of the node at the previous time, is the observed value of the node speed at the current time t, that is, the instantaneous speed of the node at the current time, obtained by the node itself.

[0081] Specifically, the smoothing factor The calculation formula is as follows:

[0082]

[0083] Among them, is a fixed value, which is set to 0.8 according to subsequent experiments, is the Hello time slot.

[0084] In some specific embodiments, the calculation formula of the dynamic Hello time slot is expressed as:

[0085]

[0086] Among them, is the dynamic Hello time slot, d is the relative communication distance, is the predicted moving speed.

[0087] Specifically, considering that the Hello time slot should not be too short or too long, so is set.

[0088] In some specific embodiments, the overall framework diagram for calculating the dynamic Hello time slot to replace the preset Hello time slot is as Figure 2 shown. In this solution, a mathematical relationship between parameters is established through theoretical derivation, and normalization processing and parameter weighting methods are used to ensure the robustness of the model. The experimental parameter settings are based on the calibration of subsequent simulation scenarios and have a certain adaptability. Compared with the traditional fixed-period method, this solution dynamically adjusts the Hello interval by real-time sensing of the network state to ensure the real-time performance of topology discovery.

[0089] In some specific embodiments, Figure 3 is a schematic diagram of the movement of a dynamic node according to an embodiment of the present application. In Figure 3 , the communication range of the node is represented by a circle. As the node moves, the communication range of the node also moves accordingly. Therefore, the communication ranges of different nodes will change with the movement of the nodes.

[0090] Specifically, this solution shows significant advantages in the core performance indicators when calculating the dynamic Hello interval. By constructing a dynamic Hello period model based on relative distance-speed double constraints, the packet delivery rate is significant in two scenarios. At the same time, the designed multi-dimensional link state evaluation system can effectively guarantee the throughput, and the dynamic time slot adjustment mechanism realizes the optimization of the average end-to-end delay, meeting the needs of continuous communication.

[0091] Embodiment 2

[0092] Based on the same concept, referring to Figure 4 , the present application also proposes a link monitoring device based on an adaptive Hello time slot, including:

[0093] A building module is used to build a link, and the link includes multiple movable nodes. A Hello message timer is set for each node, and each node broadcasts a Hello message based on a preset Hello time slot of the Hello message timer.

[0094] An activity detection module determines the communication range of each node based on the Hello message broadcast by each node, takes other nodes within the communication range of the current node as neighbor nodes of the current node, and performs neighbor activity detection on each neighbor node. The steps of the neighbor activity detection include: setting a neighbor activity detection time window for the current node, updating the corresponding routing table based on the Hello messages received by the current node within the neighbor activity detection time window. The routing table records the node information of all neighbor nodes corresponding to the current node. The corresponding neighbor node that does not receive a Hello message within the neighbor activity detection time window is regarded as a lost neighbor node. If the lost neighbor node is a communication node, the current node constructs an RERR message and returns it to the source node. If the lost neighbor node is not a communication node, the node information of the lost neighbor node is deleted from the routing table.

[0095] A self-check module is used to perform an overtime self-check on the Hello message timer of the current node after each neighbor activity detection. If the Hello message timer times out and the current node has no broadcast record, the preset Hello time slot of the current node is updated. Specifically, a dynamic Hello time slot is calculated based on the relative communication distance and predicted moving speed of the current node, and the dynamic Hello time slot is used as the new preset Hello time slot.

[0096] Embodiment III

[0097] This embodiment also provides an electronic device. Refer to Figure 5 , which includes a memory 404 and a processor 402. A computer program is stored in the memory 404, and the processor 402 is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0098] Specifically, the above processor 402 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC for short), or one or more integrated circuits configured to implement the embodiments of the present application.

[0099] Among them, the memory 404 may include a mass memory 404 for data or instructions. By way of example and not limitation, the memory 404 may include a hard disk drive (HDD), a floppy disk drive, a solid state drive (SSD), a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. In appropriate cases, the memory 404 may include removable or non-removable (or fixed) media. In appropriate cases, the memory 404 may be internal or external to the data processing device. In a particular embodiment, the memory 404 is non-volatile memory. In a particular embodiment, the memory 404 includes a read-only memory (ROM) and a random access memory (RAM). In appropriate cases, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically alterable ROM (EAROM), or a flash memory, or a combination of two or more of these. In appropriate cases, the RAM may be a static random access memory (SRAM) or a dynamic random access memory (DRAM), where the DRAM may be a fast page mode dynamic random access memory (FPMDRAM), an extended date out dynamic random access memory (EDODRAM), a synchronous dynamic random access memory (SDRAM), etc.

[0100] The memory 404 can be used to store or cache various data files required for processing and / or communication, as well as possible computer program instructions executed by the processor 402.

[0101] The processor 402 reads and executes the computer program instructions stored in the memory 404 to implement any one of the above-described link monitoring methods based on adaptive Hello time slots.

[0102] Optionally, the above-described electronic device may further include a transmission device 406 and an input / output device 408. Among them, the transmission device 406 is connected to the above-described processor 402, and the input / output device 408 is connected to the above-described processor 402.

[0103] The transmission device 406 can be used to receive or send data via a network. Specific examples of the above network may include a wired or wireless network provided by a communication provider of the electronic device. In one example, the transmission device includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices through a base station and thus communicate with the Internet. In one example, the transmission device 406 can be a radio frequency (Radio Frequency, abbreviated as RF) module, which is used to communicate with the Internet wirelessly.

[0104] The input / output device 408 is used to input or output information. In this embodiment, the input information can be the Hello time slot of each node, the movement distance, etc., and the output information can be the dynamic Hello time slot, etc.

[0105] Optionally, in this embodiment, the above-described processor 402 can be set to execute the following steps through a computer program:

[0106] Construct a link, and the link includes multiple movable nodes. Set a Hello message timer for each node, and each node broadcasts a Hello message based on a preset Hello time slot of the Hello message timer;

[0107] Determine the communication range of each node based on the Hello messages broadcast by each node, take the other nodes within the communication range of the current node as the neighbor nodes of the current node, and perform neighbor liveness detection on each neighbor node. The steps of the neighbor liveness detection include: setting a neighbor liveness detection time window for the current node, updating the corresponding routing table based on the Hello messages received by the current node within the neighbor liveness detection time window. The routing table records the node information of all neighbor nodes corresponding to the current node. Take the corresponding neighbor nodes that do not receive Hello messages within the neighbor liveness detection time window as lost neighbor nodes. If the lost neighbor node is a communication node, the current node constructs a RERR message and returns it to the source node. If the lost neighbor node is not a communication node, delete the node information of the lost neighbor node from the routing table;

[0108] After each neighbor liveness detection is completed, perform a timeout self-check on the Hello message timer of the current node. If the Hello message timer times out and the current node has no broadcast record, update the preset Hello time slot of the current node. Among them, calculate the dynamic Hello time slot based on the relative communication distance and predicted moving speed of the current node, and use the dynamic Hello time slot as the new preset Hello time slot.

[0109] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation manners, and will not be elaborated here.

[0110] Generally, various embodiments can be implemented in hardware or special circuits, software, logic, or any combination thereof. Some aspects of the present invention can be implemented in hardware, while other aspects can be implemented by firmware or software executed by a controller, microprocessor, or other computing device. However, the present invention is not limited thereto. Although various aspects of the present invention can be shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as a non-limiting example, the blocks, devices, systems, technologies, or methods described herein can be implemented in hardware, software, firmware, special circuits or logic, general hardware or a controller, or other computing devices, or some combination thereof.

[0111] Embodiments of the present invention can be implemented by computer software, which can be executed by a data processor of a mobile device, such as in a processor entity, or by hardware, or by a combination of software and hardware. A computer software or program (also referred to as a program product), including software routines, applets, and / or macros, can be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. The computer program product can include one or more computer-executable components configured to execute the embodiments when the program runs. One or more computer-executable components can be at least one software code or a part thereof. Additionally, at this point, it should be noted that any box in the logical flow, as Figure 5 shown in [reference], can represent a program step, or interconnected logic circuits, boxes, and functions, or a combination of program steps and logic circuits, boxes, and functions. The software can be stored on physical media such as memory chips or storage blocks implemented within the processor, magnetic media such as hard disks or floppy disks, and optical media such as, for example, DVDs and their data variants, CDs. The physical media are non-transitory media.

[0112] Those skilled in the art should understand that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0113] The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A link monitoring method based on adaptive Hello time slot, characterized in that: The following steps are involved: A link is established, wherein the link includes a plurality of movable nodes, a Hello message timer is set for each node, and each node broadcasts a Hello message based on a preset Hello time slot of the Hello message timer; Determine the communication range of each node based on the Hello message broadcast by each node, take other nodes within the communication range of the current node as neighbor nodes of the current node, and perform neighbor activity detection on each neighbor node, the step of neighbor activity detection includes: setting a neighbor activity detection time window for the current node, updating the corresponding routing table based on the Hello message received by the current node within the neighbor activity detection time window, the routing table records the node information of all neighbor nodes corresponding to the current node, and takes the corresponding neighbor node that has not received the Hello message within the neighbor activity detection time window as the lost neighbor node, if the lost neighbor node is a communication node, the current node constructs a RERR message to return to the source node, if the lost neighbor node is a non-communication node, then delete the node information of the lost neighbor node in the routing table; After each neighbor activity detection is completed, the Hello message timer of the current node is self-checked for timeout. If the Hello message timer times out and the current node has no broadcast record, the preset Hello time slot of the current node is updated, wherein the dynamic Hello time slot is calculated based on the communication relative distance and the predicted moving speed of the current node, and the dynamic Hello time slot is used as the new preset Hello time slot, wherein the communication relative distance is the product of the dynamic ratio parameter and the communication radius, and the formula is expressed as follows: Where d is the relative communication distance, is the dynamic scale parameter, r is the communication radius, is the inverse tangent function compression mapping of the link variation parameter, is the maximum-minimum normalized result of the node load capacity parameter, is the maximum-minimum normalized result of the node stability parameter, is a fixed value; The formula for predicting the moving speed is expressed as: in, is the smoothing factor, is the node moving speed at the current time t, is the predicted value of the node's moving speed at the previous moment, is the observed value of the node velocity at the current moment; The calculation formula of the dynamic Hello time slot is expressed as: in, is the dynamic Hello time slot, d is the relative communication distance, To predict the movement speed.

2. A link monitoring method based on adaptive Hello timeslot according to claim 1, characterized in that: Set the message loss threshold and use the product of the message loss threshold and the preset Hello time slot of the Hello message timer as the neighbor activity detection time window.

3. A link monitoring method based on adaptive Hello timeslot according to claim 1, characterized in that: When the received Hello message has a corresponding entry in the routing table, the corresponding entry in the routing table is updated based on the received Hello message. When the received Hello message does not have a corresponding entry in the routing entry, the content of the Hello message is added to the routing table as a new entry, and the node corresponding to the Hello message is the new neighbor node.

4. The link monitoring method based on adaptive Hello timeslot according to claim 1, characterized in that: The timeout self-check includes: if the current node does not broadcast a Hello message within a preset Hello time slot, it is considered that the Hello message timer of the current node has timed out; if the current node broadcasts a Hello message within the preset Hello time slot, it is considered that the Hello message timer of the current node has not timed out.

5. A link monitoring method based on adaptive Hello timeslot according to claim 4, characterized in that: If the Hello message timer has not timed out, the neighbor activity detection is performed again; if the Hello message timer has timed out and the broadcast is performed in the previous preset Hello time slot, the node continues to wait to determine whether the Hello message timer has timed out and re-performs the neighbor activity detection.

6. A link monitoring device based on adaptive Hello timeslot, characterized in that: include: A construction module, used for constructing a link, wherein the link includes a plurality of movable nodes, setting a Hello message timer for each node, and each node broadcasting a Hello message based on a preset Hello time slot of the Hello message timer; An activity detection module determines the communication range of each node based on the Hello message broadcast by each node, takes other nodes within the communication range of the current node as neighbor nodes of the current node, and performs neighbor activity detection on each neighbor node. The step of neighbor activity detection includes: setting a neighbor activity detection time window for the current node, updating the corresponding routing table based on the Hello message received by the current node within the neighbor activity detection time window, wherein the routing table records the node information of all neighbor nodes corresponding to the current node, and takes the corresponding neighbor node that has not received the Hello message within the neighbor activity detection time window as a lost neighbor node. If the lost neighbor node is a communication node, the current node constructs a RERR message and returns it to the source node. If the lost neighbor node is a non-communication node, the node information of the lost neighbor node is deleted from the routing table. The self-check module is used to perform a timeout self-check on the Hello message timer of the current node after completing a neighbor activity detection. If the Hello message timer times out and the current node has no broadcast record, the preset Hello time slot of the current node is updated, wherein the dynamic Hello time slot is calculated based on the communication relative distance and the predicted moving speed of the current node, and the dynamic Hello time slot is used as the new preset Hello time slot, wherein the communication relative distance is the product of the dynamic ratio parameter and the communication radius, and the formula is expressed as follows: Where d is the relative communication distance, is the dynamic scale parameter, r is the communication radius, is the inverse tangent function compression mapping of the link variation parameter, is the maximum-minimum normalized result of the node load capacity parameter, is the maximum-minimum normalized result of the node stability parameter, is a fixed value; The formula for predicting the moving speed is expressed as: in, is the smoothing factor, is the node moving speed at the current time t, is the predicted value of the node's moving speed at the previous moment, is the observed value of the node velocity at the current moment; The calculation formula of the dynamic Hello time slot is expressed as: in, is the dynamic Hello time slot, d is the relative communication distance, To predict the movement speed.

7. An electronic device comprising a memory and a processor, characterized in that: The memory stores a computer program, and the processor is configured to run the computer program to execute the link monitoring method based on adaptive Hello timeslots according to any one of claims 1-5.

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