A communication method and system based on wireless ad hoc network and wireless ad hoc network

Abstract

The present invention relates to the field of wireless communication technology, and discloses a communication method, system and wireless ad hoc network based on wireless ad hoc network, including obtaining neighbor nodes of a sending node and various relay base stations connected to each other; judging whether there is a relay base station among the neighbor nodes, and in response to the absence of a relay base station, clustering each neighbor node to obtain several neighbor node sets, selecting a target relay base station according to preset rules, and selecting a candidate node set; selecting a next hop node from the candidate node set according to constraints and business attributes of data to be sent. The present invention reduces the possibility of network interruption and increases the transmission efficiency of the network by considering the position change of the node, and ensures the stability and reliability of network transmission by setting corresponding node selection constraints for different business data. The present invention meets the network communication requirements under various working environments and improves the safety and efficiency of maintenance work.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a communication method and system based on a wireless ad hoc network and a wireless ad hoc network. Background Art

[0002] A wireless ad hoc network is a wireless communication network composed of nodes with their own wireless transceiver devices, which has the characteristics of self-organization, self-configuration, self-discovery and self-healing. A wireless ad hoc network can realize information sharing and forwarding of wireless nodes without relying on fixed equipment (such as base stations).

[0003] In the power system, with the in-depth development of basin maintenance, maintenance operations exist in a variety of complex environments, including enclosed shielded spaces such as the unit volute and the inside of the main transformer; high-altitude shaft spaces such as the GIL large cavern group and long vertical shaft inclined shaft, unit long flow channel, and hoist gate chamber; as well as outdoor spaces such as the protection tank of the discharge structure, water cushion pond, and energy dissipation pool. Maintenance operations in these complex environments have put forward diverse requirements for digital support equipment, and due to the temporary, local and sudden nature of maintenance work, in addition to requiring the safe deployment of digital support equipment to be simple and fast to reduce safety risks, it is also necessary to ensure the stability and timeliness of the communication network. Therefore, there is an urgent need for a stable and efficient wireless ad hoc network communication method that is suitable for the environmental requirements and operation requirements of the basin maintenance of the power system. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a communication method, system and wireless ad hoc network based on wireless ad hoc network, so as to achieve the technical effect of meeting the stable and efficient data communication requirements in the watershed maintenance scenario of the power system.

[0005] In a first aspect, the present invention provides a communication method based on a wireless ad hoc network, the method comprising:

[0006] Obtain the neighbor nodes of the sending node at the current moment, and each relay base station connected to the sending node;

[0007] Determine whether the relay base station exists among the neighboring nodes, and in response to the absence of the relay base station, cluster each of the neighboring nodes to obtain a plurality of neighboring node sets, select a target relay base station from each of the relay base stations according to a preset rule, and select a candidate node set from the plurality of neighboring node sets;

[0008] Acquire the data to be sent, select a next hop node from a set of candidate nodes according to the constraint conditions and the service attributes of the data to be sent, and send the data to be sent to the next hop node;

[0009] The next hop node is used as a sending node for iterative updating until the data to be sent is sent to the target relay base station.

[0010] Furthermore, the step of selecting a target relay base station from each of the relay base stations according to a preset rule, and selecting a candidate node set from a plurality of neighbor node sets includes:

[0011] Acquire a first distance between the sending node and each of the relay base stations, and use the relay base station corresponding to the minimum value of the first distance as a target relay base station;

[0012] Acquire a first direction vector between the sending node and the cluster center points of each of the neighbor node sets, and a second direction vector between the sending node and the target relay base station;

[0013] Acquire the activity state of the sending node, and if the sending node is in a stationary state, calculate the first angle between the second direction vector and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle as the candidate node set;

[0014] If the sending node is in a moving state, determining the moving direction of the sending node according to the position of the sending node at a previous moment and the position at a current moment;

[0015] A candidate node set is selected from each neighbor node set according to a second angle between the moving direction and the second direction vector.

[0016] Furthermore, the step of selecting a candidate node set from each neighbor node set according to the second angle between the moving direction and the second direction vector includes:

[0017] Determine whether the second angle between the moving direction and the second direction vector is less than 90°, and if so, calculate the third angle between the moving direction and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the third angle as the candidate node set;

[0018] If not, calculate the first angle between the second direction vector and each of the first direction vectors, and the third angle between the moving direction and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle and the neighbor node set corresponding to the minimum value of the third angle as the first candidate node set;

[0019] A second distance between the sending node and the cluster center of the first candidate node set is calculated, and the first candidate node set corresponding to the minimum value of the second distance is used as the candidate node set.

[0020] Furthermore, the step of selecting a next hop node from a candidate node set according to the constraint condition and the service attribute of the data to be sent, and sending the data to be sent to the next hop node includes:

[0021] Acquire the service attributes of the data to be sent and the node attributes of the candidate nodes in the candidate node set, wherein the service attributes include service type, priority, data volume and transmission frequency, and the node attributes include activity, connectivity and load;

[0022] In response to the service type being a periodic service, a candidate node is selected from the candidate node set according to the transmission frequency and the activity, and a next hop node is selected from the candidate node according to a first constraint condition, wherein the first constraint condition includes that the load is not greater than the data volume, the connectivity is greater than a connectivity threshold, the communication distance with the sending node is minimum, and the number of times the data to be sent is transmitted in one communication is unique;

[0023] In response to the service type being a burst service, determining whether the data volume is less than a data volume threshold, and if so, selecting a next hop node from the candidate node set according to a second constraint condition, wherein the second constraint condition includes that the load volume is less than the data volume, and the communication distance between the next hop node and the sending node is the maximum;

[0024] If not, selecting a next hop node from the candidate node set according to a third constraint, wherein the third constraint includes a minimum load, a communication distance with the sending node greater than a communication threshold, a unique number of times the data to be sent is transmitted in one communication, and a neighbor node that is not a previous hop node;

[0025] The next hop node is added to the communication route, and the data to be sent and the communication route are sent to the next hop node according to the priority.

[0026] Furthermore, the step of selecting a candidate node from the candidate node set according to the transmission frequency and the activity includes:

[0027] The difference obtained by subtracting the transmission frequency from the frequency upper limit is calculated, the activity corresponding to the difference is taken as the maximum activity, and a candidate node whose activity is not greater than the maximum activity is selected from the candidate node set, where the activity is determined by the node movement range.

[0028] Further, after the step of selecting a candidate node whose activity is not greater than the maximum activity from the candidate node set, the method further comprises:

[0029] The neighbor nodes of the sending node at the last moment are obtained, and the candidate nodes are updated according to the intersection between the neighbor nodes at the last moment and the candidate nodes.

[0030] Furthermore, the activity determination step includes:

[0031] Obtaining a moving range of a node, and comparing the moving range with a range threshold;

[0032] If the movement range of the node in the current duration exceeds a number of range thresholds, the corresponding activity is increased according to the exceeded range thresholds;

[0033] If the movement range of the node in the current duration is reduced by several range thresholds compared to the movement range in the previous duration, the corresponding activity is reduced according to the reduced range threshold.

[0034] Furthermore, after the step of obtaining the data to be sent, the method further includes:

[0035] Obtain the service attributes of the data to be sent, and in response to the service attributes being periodic services, determine whether a corresponding communication route is stored; if so, perform data transmission according to the stored communication route; if not, select a next hop node from a set of candidate nodes according to the service attributes of the data to be sent, and add the next hop node to the communication route.

[0036] In a second aspect, the present invention provides a communication system based on a wireless ad hoc network, the system comprising:

[0037] A data acquisition module is used to acquire neighbor nodes of the sending node at the current moment, and each relay base station connected to the sending node;

[0038] A candidate node selection module, used to determine whether the relay base station exists among the neighboring nodes, and in response to the absence of the relay base station, cluster the neighboring nodes to obtain a plurality of neighboring node sets, select a target relay base station from the relay base stations according to a preset rule, and select a candidate node set from the plurality of neighboring node sets;

[0039] A next hop node selection module is used to obtain the data to be sent, select a next hop node from a candidate node set according to the constraint conditions and the service attributes of the data to be sent, and send the data to be sent to the next hop node;

[0040] The iterative update module is used to iteratively update the next hop node as a sending node until the data to be sent is sent to the target relay base station.

[0041] In a third aspect, an embodiment of the present invention further provides a wireless ad hoc network, comprising a plurality of communication nodes and a plurality of relay base stations, wherein the communication node comprises a handheld wireless wifi device, the relay base station comprises a wireless ad hoc network radio station, and the communication node adopts the method described above to achieve communication with the relay base station.

[0042] The present invention provides a communication method, system and wireless ad hoc network based on wireless ad hoc network. Through the method, the present invention can reduce the possibility of network interruption and increase the transmission efficiency of the network by considering the position change of the node, and can ensure the stability and reliability of network transmission by setting corresponding node selection constraints for different business data. The present invention can meet the network communication requirements under various working environments, thereby improving the safety and efficiency of maintenance work. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flow chart of a communication method based on a wireless ad hoc network in an embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of the structure of a communication system based on a wireless ad hoc network in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] See also Figure 1 The first embodiment of the present invention proposes a communication method based on a wireless ad hoc network, which includes steps S10 to S40:

[0047] Step S10, obtaining neighbor nodes of the sending node at the current moment, and each relay base station connected to the sending node;

[0048] Step S20, determining whether the relay base station exists among the neighboring nodes, and in response to the absence of the relay base station, clustering each of the neighboring nodes to obtain a plurality of neighboring node sets, selecting a target relay base station from each of the relay base stations according to a preset rule, and selecting a candidate node set from the plurality of neighboring node sets;

[0049] Step S30, obtaining the data to be sent, selecting a next hop node from a candidate node set according to the constraint conditions and the service attributes of the data to be sent, and sending the data to be sent to the next hop node;

[0050] Step S40: Iteratively update the next hop node as a sending node until the data to be sent is sent to the target relay base station.

[0051] The communication method provided by the present invention is applied to a wireless ad hoc network, which includes multiple communication nodes and multiple relay base stations, wherein the communication node adopts a handheld wireless wifi device, and the relay base station adopts a wireless ad hoc network radio. Due to the complexity of the power maintenance environment and the mobility of the maintenance personnel, the data collected by the terminal equipment used by the maintenance personnel can be transmitted to the on-site command center at any time through the handheld wireless wifi device. However, problems such as network interruption due to the large range of movement will occur. At the same time, the wireless ad hoc network radio supports multiple transmission powers and can form a decentralized wireless broadband network efficiently and quickly without relying on base stations. As a relay base station of the wireless ad hoc network, it can establish a high-bandwidth and high-speed wireless network and support a multi-hop relay number. The wireless ad hoc network of this embodiment preferably adopts Mesh technology to realize the ad hoc network.

[0052] Based on the above network architecture, the present invention provides a communication method between a sending node and a relay base station. Specifically, first, all neighbor nodes within the communication radius of the sending node and all relay base stations connected to the sending node are obtained. It should be noted that the nodes and base stations are determined through periodic detection. The neighbor nodes and relay base stations detected in each period within a period of time will be saved for subsequent node selection. The neighbor nodes of the sending node are determined based on the maximum transmission power of the sending node. Then, it is determined whether there is a relay base station among these neighbor nodes. If so, the data to be sent is directly sent to the relay base station. If not, it is necessary to select the next hop node from the neighbor nodes as the communication node on the communication route between the relay base station.

[0053] In this embodiment, the neighbor nodes are first clustered and grouped. Specifically, a clustering method such as K-means is used to achieve clustering and grouping by using the signal strength, angle information or other positioning technology between the nodes. The purpose of clustering and grouping is to divide the neighbor nodes into several different groups. The nodes in each group have similar directional characteristics. Then, a candidate node set is selected from the clustered groups, and a target relay base station for transmission is determined. The specific steps include:

[0054] Acquire a first distance between the sending node and each of the relay base stations, and use the relay base station corresponding to the minimum value of the first distance as a target relay base station;

[0055] Acquire a first direction vector between the sending node and the cluster center points of each of the neighbor node sets, and a second direction vector between the sending node and the target relay base station;

[0056] Acquire the activity state of the sending node, and if the sending node is in a stationary state, calculate the first angle between the second direction vector and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle as the candidate node set;

[0057] If the sending node is in a moving state, determining the moving direction of the sending node according to the position of the sending node at a previous moment and the position at a current moment;

[0058] A candidate node set is selected from each neighbor node set according to a second angle between the moving direction and the second direction vector.

[0059] In this embodiment, the target relay base station is determined based on the distance from the sending node, that is, the relay base station closest to the sending node is selected as the target relay base station, and the selection of the candidate node set is based on the direction. In fact, when conducting watershed maintenance, the maintenance personnel cannot be fixed. Therefore, when business transmission is required, the sending node has two activity states, one is a stationary state and the other is a mobile state.

[0060] When the sending node is temporarily fixed within a position range or does not move significantly, it is considered to be in a stationary state. At this time, the first direction vector between the sending node and the cluster center point of each cluster grouping, and the second direction vector between the sending node and the target relay base station are obtained, and then the angle between each first direction vector and the second direction vector is calculated, and the cluster grouping with the smallest angle is selected as the candidate node set. The candidate node set selected in this way is actually the communication nodes with the highest consistency in direction with the target relay base station. The advantage of this node selection is that the nodes consistent with the direction of the relay base station may have better signal quality and higher transmission efficiency. By selecting such a node as the candidate node of the next hop, the throughput and performance of the network can be improved. Of course, this method is more suitable for node selection when the sending node is in a stationary state. For the sending node in a mobile state, its data communication in the mobile state will be more easily affected by the moving direction and distance, resulting in the problem of network link abnormality in data transmission. Therefore, for the sending node in a mobile state, the following another node selection method is adopted.

[0061] When the sending node is in a moving state, the moving direction of the node is first determined according to the position at the previous moment and the current moment, and then the candidate node set is determined according to the relationship between the moving direction and the second direction vector. The specific steps include:

[0062] Determine whether the second angle between the moving direction and the second direction vector is less than 90°, and if so, calculate the third angle between the moving direction and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the third angle as the candidate node set;

[0063] If not, calculate the first angle between the second direction vector and each of the first direction vectors, and the third angle between the moving direction and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle and the neighbor node set corresponding to the minimum value of the third angle as the first candidate node set;

[0064] A second distance between the sending node and the cluster center of the first candidate node set is calculated, and the first candidate node set corresponding to the minimum value of the second distance is used as the candidate node set.

[0065] In this embodiment, the angle between the moving direction and the second direction vector is first determined. If it is less than 90 degrees, it means that the trend of the moving direction is close to the target relay base station. At this time, the angle between the moving direction and each first direction vector is calculated, and the neighbor node set with the smallest angle is used as the candidate node set. That is to say, in this case, the neighbor node set closest to the moving direction is selected as the candidate node set. Since the node selected is consistent with the moving direction of the sending node, and the node is also consistent with the direction of the target relay base station, the length of the signal propagation path can be reduced, the transmission delay can be reduced, and the transmission efficiency can be improved. This is very beneficial for application scenarios where mobile nodes communicate frequently or require low-latency transmission. At the same time, the node consistent with the moving direction of the sending node may mean better link quality. Because directional consistency usually means that there is no interference from obstacles or interference sources on the signal propagation path, thus providing better signal quality and lower packet loss rate.

[0066] If the angle is greater than 90 degrees, it means that the trend of the moving direction is opposite to the direction of the target relay base station. At this time, it is necessary to select the neighbor node set with the highest consistency with the target relay base station direction through the angle between the first direction vector and the second direction vector, and then select the neighbor node set with the highest consistency with the moving direction through the angle between the moving direction and the first direction vector, and then judge the distance between the cluster center point of the two subsets and the sending node, and select the subset with the closest distance as the candidate node set. In this case, if the moving direction is opposite to the target relay base station direction, but the distance to the node in the direction consistent with the base station is closer, the node in the direction of the base station is still selected as the candidate node. Even in the move, since the direction is consistent with the relay base station and the distance is closer, it can still guarantee good link quality and low transmission delay. When the distance of the node inconsistent with the base station direction is closer, the node in the moving direction will be selected to prevent the network topology change caused by the mobility of the node. By considering the moving direction of the sending node, it can better adapt to the position change of the node, reduce the possibility of network interruption, and increase the stability of the network.

[0067] What is selected through the above steps is actually just a set of candidate nodes, and the next-hop node needs to be further selected from the candidate node set based on the service attributes of the data to be sent. The specific selection steps include:

[0068] Acquire the service attributes of the data to be sent and the node attributes of the candidate nodes in the candidate node set, wherein the service attributes include service type, priority, data volume and transmission frequency, and the node attributes include activity, connectivity and load;

[0069] In response to the service type being a periodic service, a candidate node is selected from the candidate node set according to the transmission frequency and the activity, and a next hop node is selected from the candidate node according to a first constraint condition, wherein the first constraint condition includes that the load is not greater than the data volume, the connectivity is greater than a connectivity threshold, the communication distance with the sending node is minimum, and the number of times the data to be sent is transmitted in one communication is unique;

[0070] In response to the service type being a burst service, determining whether the data volume is less than a data volume threshold, and if so, selecting a next hop node from the candidate node set according to a second constraint condition, wherein the second constraint condition includes that the load volume is less than the data volume, and the communication distance between the next hop node and the sending node is the maximum;

[0071] If not, selecting a next hop node from the candidate node set according to a third constraint, wherein the third constraint includes a minimum load, a communication distance with the sending node greater than a communication threshold, a unique number of times the data to be sent is transmitted in one communication, and a neighbor node that is not a previous hop node;

[0072] The next hop node is added to the communication route, and the data to be sent and the communication route are sent to the next hop node according to the priority.

[0073] In this embodiment, the specific next hop node is determined by the matching relationship between the service attributes of the data to be sent and the node attributes of the candidate node. In the actual working scenario, the service data to be sent can be divided into two types. One is periodic service. Periodic service includes small traffic data interaction including some signaling. The amount of data transmitted is not large, but it is frequent and regular. The other is burst service. The data transmission volume of burst service is generally large, not too frequent, but sudden. The priority of burst service is higher than that of periodic service. For these two different service types, the way of selecting the next hop is also different.

[0074] For periodic services, the first node selection is performed based on its transmission frequency. The transmission frequency represents the frequency of service transmission. The higher the transmission frequency, the more stable the nodes on the communication route should be. In this case, the success rate of each transmission should be guaranteed as much as possible, while the transmission efficiency is required to be lower. Based on this situation, the activity of the communication node is set in this embodiment to represent the stability of the node, wherein the activity of the node is determined by the moving range of the node. The specific steps include:

[0075] Obtaining a moving range of a node, and comparing the moving range with a range threshold;

[0076] If the movement range of the node in the current duration exceeds a number of range thresholds, the corresponding activity is increased according to the exceeded range thresholds;

[0077] If the movement range of the node in the current duration is reduced by several range thresholds compared to the movement range in the previous duration, the corresponding activity is reduced according to the reduced range threshold.

[0078] In this embodiment, multiple range thresholds are set, each range threshold corresponds to an activity. When the movement range of the node within a certain time length is greater than a threshold, an activity is increased. Conversely, when the movement range within the current time length is reduced compared to the previous time length and is reduced to within a certain threshold, the corresponding activity is reduced according to the degree of reduction. In other words, the activity of the node is essentially the mobility of the node. The larger the movement range and the higher the activity, the lower the stability of the node, because the movement of the node may cause the interruption of the communication link and cause the transmission failure. The higher the transmission frequency of the service, the more stable the node is required. The higher the qualitative value, the inversely proportional relationship between the transmission frequency of the service and the activity of the node. Therefore, in this embodiment, the transmission frequency and the activity are set equivalently, that is, an upper limit value of the transmission frequency is set, and the upper limit value is actually the lower limit value of the activity. Therefore, when the transmission frequency is subtracted from the upper limit of the frequency, the result is the maximum activity of the corresponding node. For example, when the upper limit is 10 and the transmission frequency is 7, the maximum activity of the selected node is 3. Of course, if there is no node within the maximum activity in actual situation, the maximum activity can be increased successively until the node with the lowest activity is found, that is, the node with the highest stability.

[0079] This embodiment determines the activity of the node according to the node's mobile range and transmission frequency, which can better adapt to the changes in node mobility and data transmission mode. The activity can reflect the stability of the node, so as to better select the next hop node suitable for the current environment and needs.

[0080] When there are at least two nodes selected by transmission frequency and activity, the next hop node needs to be selected by the first constraint condition. The first constraint condition includes load constraint, connectivity constraint, communication distance constraint and communication number constraint. Among them, the load constraint includes that the load of the next hop node should not be greater than the data volume of the transmission service. This is to ensure load balancing and avoid excessive load on a certain node, thereby improving the performance and stability of the overall network; the connectivity constraint includes that the connectivity of the next hop node should be greater than the connectivity threshold, for example, at least greater than 2. Connectivity can ensure the link stability of the node and prevent network interruption due to abnormal joint points. Occurs; the communication distance constraint includes that the next hop node should be the node with the shortest communication distance with the sending node among the candidate nodes. This is because periodic services have a certain transmission frequency. If the maximum power transmission is always used, energy consumption will increase. The requirements of periodic services for transmission timeliness are lower than the requirements for transmission stability. Therefore, selecting the node with the shortest communication distance can effectively reduce the communication energy consumption of the node, improve endurance, and maintain transmission stability; the number of communications constraint includes that the next hop node can only exist once in the communication route. This constraint is mainly to ensure that the communication route will not have triangular links or dead loops, and to ensure transmission efficiency. It should be noted that when the first constraint condition cannot be fully met, the node that meets the most constraints is selected as the next hop node. If there is a situation where the number of constraints met is the same, the next hop node is randomly selected. The same applies when selecting according to other constraints. I will not go into details later.

[0081] For burst services, the activity of the node is not the primary consideration, but the load of the node should be considered. This is because burst services usually have a large amount of data and may only need to be transmitted once in a long period of time. Therefore, burst services should be transmitted efficiently and timely. In this embodiment, the data volume of the burst service is first determined. If the data volume is less than the data volume threshold, it means that the data volume of this burst service is not that large. At this time, it is only necessary to select the node according to the fastest transmission efficiency. The second constraint condition for node selection includes load constraint and communication distance constraint. Among them, the load constraint means that the load of the next hop node should be less than the data volume. This is to avoid excessive node load and maintain network balance, thereby helping to prevent certain nodes from experiencing performance degradation or failure due to excessive load; the communication distance constraint means that the next hop node should be the node with the largest communication distance between the candidate node and the sending node. Since the transmission frequency of burst services is very low, a larger transmission frequency can be used for burst services with small data volume. By increasing the transmission distance, network resources can be utilized to the greatest extent and the speed of data transmission can be increased.

[0082] For burst services with large data volumes, in addition to considering transmission efficiency, the node load also needs to be considered. At this time, the constraint condition used to select the next hop node is the third constraint condition, which includes load constraint, communication distance constraint, communication number constraint and neighbor node constraint. Among them, the load constraint includes that the load of the next hop node should be the minimum load value among the candidate nodes. By selecting a node with a smaller load as the next hop node, the load of each node in the network can be balanced to avoid overloading a single node; the communication distance constraint includes that the communication distance between the next hop node and the sending node should be greater than the communication threshold, such as greater than the communication half-time. The maximum transmission power is one-half of the path. This is because the amount of business data is large, and the maximum transmission power will increase the node energy consumption and is not conducive to ensuring the stable transmission of the network link; the communication number constraint is also that the next hop node can only exist once in the communication route. This constraint is mainly to ensure that the communication route will not have triangular links or dead loops, and to ensure the transmission efficiency; and the neighbor node constraint includes that the next hop node should not be a neighbor node of the previous hop node. The advantage of doing so is that it can increase the fault tolerance and redundancy of the network. When a node or link fails, there are backup paths to choose from. At the same time, it can reduce the number of communication routing nodes and improve transmission efficiency.

[0083] After selecting the next-hop node for different types of business data through the above steps, the business data can be sent to the next-hop node according to the priority of the business. At the same time, the route of this time can also be sent to the next-hop node. By setting the priority, it is ensured that the urgent data can be transmitted to the target node as soon as possible, thereby meeting the emergency needs of sudden business. For periodic business, when a business is successfully sent, the communication route it sends can be stored. Periodic business within a certain period of time can select the stored communication route for data transmission according to its business ID. This is due to the relative stability of its communication route, which can reduce the time of route selection and thus improve data transmission efficiency.

[0084] In a preferred embodiment, in order to further ensure the stability of the next-hop node of the periodic service, the present invention also provides another candidate node selection method, that is, after selecting the candidate node within the maximum activity, the neighbor node of the sending node at the previous moment can also be obtained to determine whether there are nodes in the candidate node that do not belong to the neighbor node at the previous moment. These nodes are obviously newly added unstable nodes. At this time, these nodes can be deleted from the candidate nodes, thereby further ensuring the stability of the candidate nodes. By selecting a stable node as the next-hop node, the frequency of dynamic routing changes can be reduced, the control overhead in the network and the complexity of routing calculation can be reduced, thereby improving the stability and performance of the network.

[0085] This embodiment provides a communication method based on a wireless ad hoc network. The present invention better adapts to the location changes of nodes by considering the moving direction of the sending node and the direction of the relay base station, thereby reducing the possibility of network interruption. At the same time, the present invention also takes into account the different needs of different types of business data. By setting node selection constraints for periodic services, the changes in dynamic routing are reduced, and the stability and transmission efficiency of network transmission are effectively improved. By setting node selection constraints for burst services, the timeliness and reliability of data transmission are ensured, and the emergency needs of burst services are met. The communication method provided by the present invention can be applied to various complex working environments of river basin maintenance, meets the network communication needs in various working environments, ensures the stability and timeliness of network transmission, and further improves the safety and efficiency of maintenance work implementation.

[0086] See also Figure 2 Based on the same inventive concept, a communication system based on a wireless ad hoc network is proposed in a second embodiment of the present invention, comprising:

[0087] The data acquisition module 10 is used to acquire the neighbor nodes of the sending node at the current moment, and each relay base station connected to the sending node;

[0088] A candidate node selection module 20 is used to determine whether the relay base station exists among the neighboring nodes, and in response to the absence of the relay base station, cluster the neighboring nodes to obtain a plurality of neighboring node sets, select a target relay base station from the relay base stations according to a preset rule, and select a candidate node set from the plurality of neighboring node sets;

[0089] A next hop node selection module 30 is used to obtain the data to be sent, select a next hop node from a candidate node set according to the constraint conditions and the service attributes of the data to be sent, and send the data to be sent to the next hop node;

[0090] The iterative updating module 40 is used to iteratively update the next hop node as a sending node until the data to be sent is sent to the target relay base station.

[0091] The technical features and technical effects of the communication system based on wireless ad hoc network proposed in the embodiment of the present invention are the same as those of the method proposed in the embodiment of the present invention, and are not described in detail here. Each module in the above-mentioned communication system based on wireless ad hoc network can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0092] In addition, an embodiment of the present invention also proposes a wireless ad hoc network, including several communication nodes and several relay base stations, the communication node includes a handheld wireless wifi device, the relay base station includes a wireless ad hoc network radio, and the communication node adopts the method as described above to achieve communication with the relay base station.

[0093] In summary, the embodiments of the present invention propose a communication method, system and wireless self-organizing network based on wireless ad hoc network. The method obtains the neighbor nodes of the sending node at the current moment and the various relay base stations connected to the sending node; determines whether the relay base station exists among the neighbor nodes, and in response to the absence of the relay base station, clusters the neighbor nodes to obtain several neighbor node sets, selects a target relay base station from each of the relay base stations according to preset rules, and selects a candidate node set from the several neighbor node sets; obtains data to be sent, selects a next hop node from the candidate node set according to constraints and business attributes of the data to be sent, and sends the data to be sent to the next hop node; iteratively updates the next hop node as the sending node until the data to be sent is sent to the target relay base station. The present invention better adapts to the location changes of nodes by considering the moving direction of the sending node and the direction of the relay base station, thereby reducing the possibility of network interruption. At the same time, the present invention also takes into account the different needs of different types of business data, and reduces the changes in dynamic routing by setting node selection constraints for periodic services, effectively improving the stability and transmission efficiency of network transmission. By setting node selection constraints for burst services, the timeliness and reliability of data transmission are ensured, and the emergency needs of burst services are met. The communication method provided by the present invention can be applied to various complex working environments of river basin maintenance, meets the network communication needs under various working environments, ensures the stability and timeliness of network transmission, and further improves the safety and efficiency of maintenance work implementation.

[0094] Each embodiment in this specification is described in a progressive manner, and the same or similar parts of each embodiment can be directly referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. It should be noted that the technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-mentioned embodiments only express several preferred implementation modes of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in the technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be based on the protection scope of the claims.

Claims

1. A communication method based on wireless ad hoc network, characterized in that: include: Obtain the neighbor nodes of the sending node at the current moment, and each relay base station connected to the sending node; Determine whether the relay base station exists among the neighboring nodes, and in response to the absence of the relay base station, cluster each of the neighboring nodes to obtain a plurality of neighboring node sets, select a target relay base station from each of the relay base stations according to a preset rule, and select a candidate node set from the plurality of neighboring node sets; Acquire the data to be sent, select a next hop node from a set of candidate nodes according to the constraint conditions and the service attributes of the data to be sent, and send the data to be sent to the next hop node; Iteratively updating the next hop node as a sending node until the data to be sent is sent to the target relay base station; The step of selecting a target relay base station from each of the relay base stations according to a preset rule and selecting a candidate node set from a plurality of neighbor node sets includes: Acquire a first distance between the sending node and each of the relay base stations, and use the relay base station corresponding to the minimum value of the first distance as a target relay base station; Acquire a first direction vector between the sending node and the cluster center points of each of the neighbor node sets, and a second direction vector between the sending node and the target relay base station; Acquire the activity state of the sending node, and if the sending node is in a stationary state, calculate the first angle between the second direction vector and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle as the candidate node set; If the sending node is in a moving state, determining the moving direction of the sending node according to the position of the sending node at a previous moment and the position at a current moment; Selecting a candidate node set from each neighbor node set according to a second angle between the moving direction and the second direction vector; The step of selecting a next hop node from a candidate node set according to the constraint condition and the service attribute of the data to be sent, and sending the data to be sent to the next hop node comprises: Acquire the service attributes of the data to be sent and the node attributes of the candidate nodes in the candidate node set, wherein the service attributes include service type, priority, data volume and transmission frequency, and the node attributes include activity, connectivity and load; In response to the service type being a periodic service, a candidate node is selected from the candidate node set according to the transmission frequency and the activity, and a next hop node is selected from the candidate node according to a first constraint condition, wherein the first constraint condition includes that the load is not greater than the data volume, the connectivity is greater than a connectivity threshold, the communication distance with the sending node is minimum, and the number of times the data to be sent is transmitted in one communication is unique; In response to the service type being a burst service, determining whether the data volume is less than a data volume threshold, and if so, selecting a next hop node from the candidate node set according to a second constraint condition, wherein the second constraint condition includes that the load volume is less than the data volume, and the communication distance between the next hop node and the sending node is the maximum; If not, selecting a next hop node from the candidate node set according to a third constraint, wherein the third constraint includes a minimum load, a communication distance with the sending node greater than a communication threshold, a unique number of times the data to be sent is transmitted in one communication, and a neighbor node that is not a previous hop node; The next hop node is added to the communication route, and the data to be sent and the communication route are sent to the next hop node according to the priority.

2. The communication method based on wireless ad hoc network according to claim 1, characterized in that: The step of selecting a candidate node set from each neighbor node set according to the second angle between the moving direction and the second direction vector comprises: Determine whether the second angle between the moving direction and the second direction vector is less than 90°, and if so, calculate the third angle between the moving direction and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the third angle as the candidate node set; If not, calculate the first angle between the second direction vector and each of the first direction vectors, and the third angle between the moving direction and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle and the neighbor node set corresponding to the minimum value of the third angle as the first candidate node set; A second distance between the sending node and the cluster center of the first candidate node set is calculated, and the first candidate node set corresponding to the minimum value of the second distance is used as the candidate node set.

3. The communication method based on wireless ad hoc network according to claim 1, characterized in that: The step of selecting a candidate node from the candidate node set according to the transmission frequency and the activity comprises: The difference obtained by subtracting the transmission frequency from the frequency upper limit is calculated, the activity corresponding to the difference is taken as the maximum activity, and a candidate node whose activity is not greater than the maximum activity is selected from the candidate node set, where the activity is determined by the node movement range.

4. The communication method based on wireless ad hoc network according to claim 3, characterized in that: After the step of selecting a candidate node whose activity is not greater than the maximum activity from the candidate node set, the method further comprises: The neighbor nodes of the sending node at the last moment are obtained, and the candidate nodes are updated according to the intersection between the neighbor nodes at the last moment and the candidate nodes.

5. The communication method based on wireless ad hoc network according to claim 3, characterized in that: The activity determination step includes: Obtaining a moving range of a node, and comparing the moving range with a range threshold; If the movement range of the node in the current duration exceeds a number of range thresholds, the corresponding activity is increased according to the exceeded range thresholds; If the movement range of the node in the current duration is reduced by several range thresholds compared to the movement range in the previous duration, the corresponding activity is reduced according to the reduced range threshold.

6. The communication method based on wireless ad hoc network according to claim 1, characterized in that: After the step of obtaining the data to be sent, the method further includes: Obtain the service attributes of the data to be sent, and in response to the service attributes being periodic services, determine whether a corresponding communication route is stored; if so, perform data transmission according to the stored communication route; if not, select a next hop node from a set of candidate nodes according to the service attributes of the data to be sent, and add the next hop node to the communication route.

7. A communication system based on wireless ad hoc network, characterized in that: include: A data acquisition module is used to acquire neighbor nodes of the sending node at the current moment, and each relay base station connected to the sending node; A candidate node selection module, used to determine whether the relay base station exists among the neighboring nodes, and in response to the absence of the relay base station, cluster the neighboring nodes to obtain a plurality of neighboring node sets, select a target relay base station from the relay base stations according to a preset rule, and select a candidate node set from the plurality of neighboring node sets; The step of selecting a target relay base station from each of the relay base stations according to a preset rule, and selecting a candidate node set from a plurality of neighbor node sets includes: Acquire a first distance between the sending node and each of the relay base stations, and use the relay base station corresponding to the minimum value of the first distance as a target relay base station; Acquire a first direction vector between the sending node and the cluster center points of each of the neighbor node sets, and a second direction vector between the sending node and the target relay base station; Acquire the activity state of the sending node, and if the sending node is in a stationary state, calculate the first angle between the second direction vector and each of the first direction vectors, and use the neighbor node set corresponding to the minimum value of the first angle as the candidate node set; If the sending node is in a moving state, determining the moving direction of the sending node according to the position of the sending node at a previous moment and the position at a current moment; Selecting a candidate node set from each neighbor node set according to a second angle between the moving direction and the second direction vector; A next hop node selection module is used to obtain the data to be sent, select a next hop node from a candidate node set according to the constraint conditions and the service attributes of the data to be sent, and send the data to be sent to the next hop node; The step of selecting a next hop node from a candidate node set according to the constraint condition and the service attribute of the data to be sent, and sending the data to be sent to the next hop node comprises: Acquire the service attributes of the data to be sent and the node attributes of the candidate nodes in the candidate node set, wherein the service attributes include service type, priority, data volume and transmission frequency, and the node attributes include activity, connectivity and load; In response to the service type being a periodic service, a candidate node is selected from the candidate node set according to the transmission frequency and the activity, and a next hop node is selected from the candidate node according to a first constraint condition, wherein the first constraint condition includes that the load is not greater than the data volume, the connectivity is greater than a connectivity threshold, the communication distance with the sending node is minimum, and the number of times the data to be sent is transmitted in one communication is unique; In response to the service type being a burst service, determining whether the data volume is less than a data volume threshold, and if so, selecting a next hop node from the candidate node set according to a second constraint condition, wherein the second constraint condition includes that the load volume is less than the data volume, and the communication distance between the next hop node and the sending node is the maximum; If not, selecting a next hop node from the candidate node set according to a third constraint, wherein the third constraint includes a minimum load, a communication distance with the sending node greater than a communication threshold, a unique number of times the data to be sent is transmitted in one communication, and a neighbor node that is not a previous hop node; Adding a next hop node to the communication route, and sending the data to be sent and the communication route to the next hop node according to the priority; The iterative update module is used to iteratively update the next hop node as a sending node until the data to be sent is sent to the target relay base station.

8. A wireless ad hoc network, characterized in that: The wireless ad hoc network includes several communication nodes and several relay base stations, the communication node includes a handheld wireless wifi device, the relay base station includes a wireless ad hoc network radio station, and the communication node adopts the method described in any one of claims 1 to 6 to achieve communication with the relay base station.

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