A fast onboarding method for mesh network node dynamic cut-in

Abstract

The application relates to a fast network entry method when a mesh network node is dynamically cut in, and belongs to the field of Internet of Things. The method comprises the following steps: detecting whether a network signal exists when a new node enters the network, broadcasting RREQ if the network signal is detected, and waiting for RREP in the network; all in-network nodes in the network calculate self state scores according to self state information, construct RREP and reply after receiving the RREQ broadcasted by the new node; the new node calculates the state scores of the response nodes again after receiving the RREP, selects multiple relay nodes to build a route; after the route is built, the new node constructs a network entry application frame and forwards the network entry application frame to a center node through the relay nodes, and the center node judges whether to agree to the network entry of the new node. The application considers the residual power of the node as the selection basis of the relay node, simultaneously uses a greedy algorithm to quickly select the relay node, reduces the route discovery time, and improves the network entry speed of the new node.

Description

Technical Field

[0001] The invention belongs to the field of Internet of Things and relates to a method for quickly accessing a Mesh network node when the node is dynamically switched in. Background Art

[0002] A wireless sensor network is a self-organizing network consisting of a large number of dispersed sensor nodes that collect and exchange information about the monitored area through wireless communication technology.

[0003] Compared with other network topologies, wireless Mesh network topology has the following advantages: 1. Easy deployment and installation: It is very simple to install Mesh network nodes, allowing users to easily add new Mesh network nodes to increase the network capacity and coverage of the Mesh network; 2. Stability: In a Mesh network, each node has one or several transmission paths. If a node fails or is interfered with, the data packet can still transmit the data to the destination through other paths; 3. Flexible structure: Devices can access the network through different nodes without causing a decrease in system performance. During the transmission process, each device has multiple transmission paths available. The network can dynamically allocate communication routes based on the communication load of each node, effectively avoiding node congestion.

[0004] Due to the complex structure of mesh networks, the onboarding of new nodes is slow, impacting the network's real-time performance and scalability. Furthermore, due to the lack of a fast route discovery mechanism, new nodes may take a long time to find the optimal path to their destination. Furthermore, some wireless sensor networks deploy passive nodes that rely on internal batteries. Battery life is a key factor limiting their performance. This not only affects the continued operation of individual nodes, but also the stability of the entire network. Nodes with depleted batteries can create network coverage gaps, impacting data collection and transmission. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for fast network access when a Mesh network node is dynamically connected. By comprehensively considering the remaining power of the node as the basis for selecting relay nodes, and using a greedy algorithm to quickly select relay nodes, the route discovery time is reduced and the speed of new node access to the network is improved.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for quickly joining a mesh network node when it is dynamically connected. The mesh network to which this method applies adopts a centralized structure, which includes a central node (CN) and several child nodes. The central node plays a core role in network management and control, responsible for maintaining global network information, including routing tables, node status, etc. The child nodes are divided into relay nodes (RN) and ordinary nodes (Node). Relay nodes have data forwarding and routing functions. They are usually located in the center or key positions of the network to ensure that data can flow efficiently in the network. Ordinary nodes are mainly responsible for collecting and sending data, but do not have the responsibility of data forwarding. When a new node requests to join the network, it will send a network access request to the central node. The central node quickly performs authentication and allocates the necessary network parameters based on the current network conditions.

[0008] The method provided by the present invention comprises the following steps:

[0009] S1. In a Mesh network, when a new node joins the network, it first detects whether there is a network signal. If a network signal is detected, it broadcasts a route request frame (RREQ) and waits for a route response frame (RREP) from the network.

[0010] S2. All nodes in the network calculate their own status scores based on their own status information. After receiving the RREQ broadcast by the new node, they construct an RREP and reply.

[0011] Among them, the network node regularly obtains its own status information such as remaining power and hop count, and calculates the status score based on this status information;

[0012] S3. After receiving the RREP, the new node recalculates the status score of each responding node, and then uses a greedy algorithm to select multiple relay nodes based on the status score of each responding node, and uses the selected relay nodes to build a route;

[0013] S4. After the route is built, the new node constructs a network access application frame and forwards it to the central node through the relay node. The central node determines whether to approve the new node's network access.

[0014] S5. After the new node successfully joins the network, the fast relay network access process ends.

[0015] Furthermore, the new node determines whether there is a network signal by detecting the received signal strength (RSSI); if the RSSI value is higher than a set threshold, it is considered that the new node has entered the network coverage range and there is a network signal; otherwise, the channel is switched to continue detection.

[0016] Furthermore, the status score is calculated by the following formula:

[0017]

[0018] node score =ω1×Hop score +ω2×battery score +ω3×rssi score

[0019] In the formula, node score Represents the state score of the node; ω1, ω2, ω3 are weight coefficients; Hop score Indicates the node hop score, Hop count Indicates the number of hops from the response node to the central node; battery score Indicates the node power status score, voltage full Indicates the voltage value when the battery is fully charged. empty Indicates the voltage value when the battery is exhausted, current voltage Indicates the current voltage value of the battery; rssi score Indicates the node signal strength score, rssi value Indicates the actual current signal strength value between two nodes, rssi threshold Indicates ideal signal strength, rssi range Indicates the signal strength variation range.

[0020] Furthermore, when each node on the network constructs a RREP, if there are multiple routes, the state score of the neighboring nodes on each route needs to be calculated separately.

[0021] Furthermore, when the new node calculates the status score of each responding node again after receiving the RREP, it needs to first obtain the actual signal strength value rssi between the new node and each responding node. value Then, the status score of each response node is calculated based on the number of hops and power information in the response node routing response frame. score .

[0022] After the status score is recalculated, the new node will calculate each response node according to the status score node score Sorting is performed to generate a sorting table, and then a greedy algorithm is used to select three response nodes with the highest scores from the sorting table as relay nodes.

[0023] Furthermore, after receiving the network access application frame of the new node, the central node evaluates the current network capacity. If the current network has sufficient resources to accommodate the new node, it agrees to allow the new node to join the network, fills the result in the network access application response frame, and sends the network access application response frame to the new node.

[0024] Furthermore, after a new node successfully joins the network, if there is a subsequent new node that selects the new node that has joined the network as a relay node, the new node that has joined the network will be changed from a common node to a relay node.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention uses a greedy algorithm to quickly select relay nodes, reduce routing discovery time, improve network efficiency and the speed of new node access, and enhance the real-time performance and scalability of the network.

[0027] (2) The present invention realizes load balancing by comprehensively considering the remaining power of the node as the basis for relay selection, which can extend the battery life of the node and further improve the stability of data transmission and the overall performance of the network.

[0028] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0030] Figure 1 Schematic diagram of the process of the present invention;

[0031] Figure 2 This is the Mesh network structure diagram;

[0032] Figure 3 Schematic diagram of the new node broadcast process. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] This embodiment builds a Mesh network, such as Figure 2As shown in Figure 1, the network adopts a centralized structure consisting of a central node and several sub-nodes. The central node plays a core role in network management and control, responsible for maintaining global network information, including routing tables and node status. Sub-nodes are divided into relay nodes and ordinary nodes. Relay nodes have data forwarding and routing functions and are usually located in the center or key locations of the network to ensure efficient data flow within the network. Ordinary nodes are mainly responsible for collecting and sending data but do not have data forwarding responsibilities.

[0035] In this network, when a new node requests to join the network, it sends a network access request to the central node. The central node quickly authenticates and allocates necessary network parameters based on the current network status. In this embodiment, the network access method for a new node is as follows: Figure 1 As shown, the specific process is as follows:

[0036] Step 1: The new node detects the presence of a network signal. Specifically, it checks the RSSI. If the RSSI value is above a set threshold, the new node is considered to have entered the network coverage area. If the new node does not detect the corresponding RSSI, it switches channels and continues to detect the presence of a network. The set threshold is -70dBm.

[0037] Step 2: After detecting the network signal, the new node broadcasts REEQ and waits for REEP from the network to collect relevant status information of surrounding nodes. The REEQ format and REEP format are shown in Table 1 and Table 2 respectively.

[0038] Table 1

[0039] Field describe Message Type Distinguishing different message types RREQ ID Distinguishing different routing requests life cycle The maximum time that a RREQ can exist in the network Destination IP address Destination node address Source IP address Source node address

[0040] Table 2

[0041]

[0042]

[0043] In the REEP structure shown in Table 2, the accumulated node score The value refers to the sum of the comprehensive scores of all relay nodes on the path from the current response node to the central node. Whenever a data packet arrives at a new relay node, the node will update the accumulated node score, that is, add its own score to the current accumulated value.

[0044] In step 2, specifically, the new node's REEQ broadcast process is as follows: Figure 3As shown in the figure, the new node first prepares to send a broadcast message and initializes the broadcast sequence. Then, the new node constructs the broadcast message according to the REEQ format. Before sending the broadcast, the new node needs to use the CSMA / CA mechanism to detect whether the channel is idle to reduce conflicts. When the channel is idle, the new node sends the broadcast message and sets a continuous receiving time window after broadcasting the REEQ. In this embodiment, this time window lasts for 200ms to receive the REEP of surrounding nodes.

[0045] Step 3: All nodes in the network periodically obtain their own status information such as remaining power and hop count, and calculate their own status score based on the status information. After receiving the REEQ from the new node, they construct and reply REEP.

[0046] The calculation process of the own status score is as follows:

[0047]

[0048] node score =ω1×Hop score +ω2×battery score +ω3×rssi score (4)

[0049] Among them, Hop score Hop is the node hop score. count is the number of hops from the node to the central node, battery score is the node power status score, voltage full is the voltage value when the battery is fully charged. empty is the voltage value when the battery is exhausted, current voltage is the current voltage of the battery, rssi score is the node signal strength score, rssi value is the actual signal strength value between the two nodes, rssi threshold is the ideal signal strength, rssi range Is the signal strength variation range, its value is rssi max -rssi min , node score is the node comprehensive status score, ω1, ω2, ω3 are constants, and ω1+ω2+ω3=1. In particular, the rssi between nodes value It is detected by the receiving node through scanning the wireless channel during the communication process.

[0050] It should be noted that in the process of constructing REEP, there may be multiple routes for the responding node, and the neighbor nodes on each route need to be calculated separately.score Among them, neighbor nodes refer to nodes that can communicate directly within the wireless coverage area.

[0051] Step 4: After receiving the REEP of the node on the network, the new node recalculates the status score of each responding node based on its own RSSI measurement value relative to the neighboring node. Specifically, the new node obtains the RSSI of itself and the responding node. value , and according to the hop count, power and other information in the response frame of the response node, calculate and update the node again through formula (1) to formula (4) score , all the response nodes are sorted by their node score Sort.

[0052] Step 5: Based on the ranking table generated in Step 4, a greedy algorithm is used to select the node with the highest priority as a relay node. The three nodes with the highest scores in the ranking table are selected as relay nodes. Multiple routes to the network center or other destination nodes are then constructed using the selected relay nodes.

[0053] Among them, the greedy algorithm is a method that selects the best option in the current state in each step. This can quickly determine the local optimal relay node without waiting for the calculation of the global optimal solution, thereby speeding up the speed of new nodes entering the network.

[0054] Step 6: After the route is established, the new node constructs a network application frame and forwards it to the central node via a relay node. After receiving the network application frame, the central node evaluates the current network capacity to determine whether there are sufficient resources to accommodate the new node. It then determines whether to approve the new node's joining the network and enters the result in the network application response frame. The formats of the network application frame and network application response frame are shown in Tables 3 and 4.

[0055] Table 3

[0056] Field describe Message Type Identify the frame as a network access application frame Source Address New node address Destination Address Central node address Serial number Used to match network access applications Node Status Including battery level, etc. Routing ID Uniquely identifies each route <![CDATA[累加node score ]]> <![CDATA[每条路由的累加node score ]]> Hop Count Number of hops from the new node to the central node Relay node list The relay node address that the new node passes through

[0057] Table 4

[0058]

[0059]

[0060] Step 7: When the new node successfully joins the network, the fast relay network joining process ends. If a routing request frame from another newly joined node is subsequently received, step 3 and subsequent steps are executed.

[0061] Finally, it is to be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the purpose and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A method for quickly accessing a Mesh network node during dynamic network access, characterized by: The method includes: when a new node joins the network, it first detects whether there is a network signal. If a network signal is detected, it broadcasts a route request frame and waits for a route response frame from the network; the networked nodes in the network calculate their own status scores based on their own status information, and after receiving the route request frame broadcast by the new node, they construct and reply with a route response frame; after receiving the route response frame, the new node again calculates the status score of each response node, and then uses a greedy algorithm to select multiple relay nodes based on the status score of each response node, and constructs a route using the selected relay nodes; after the route is constructed, the new node constructs a network access application frame and forwards it to the central node through the relay node, and the central node determines whether to approve the new node's network access; The status score is calculated by the following formula: node score =ω1×Hop score +ω2×battery score +ω3×rssi score In the formula, node score Represents the state score of the node; ω1, ω2, ω3 are weight coefficients; Hop score Indicates the node hop score, Hop count Indicates the number of hops from the response node to the central node; battery score Indicates the node power status score, voltage full Indicates the voltage value when the battery is fully charged. empty Indicates the voltage value when the battery is exhausted, current voltage Indicates the current voltage value of the battery; rssi score Indicates the node signal strength score, rssi value Indicates the actual current signal strength value between two nodes, rssi threshold Indicates ideal signal strength, rssi range Indicates the signal strength variation range.

2. The fast network access method according to claim 1, characterized in that: The new node determines whether there is a network signal by detecting the received signal strength; if the received signal strength is higher than a set threshold, it is considered that the new node has entered the network coverage and there is a network signal; otherwise, the channel is switched to continue detection.

3. The fast network access method according to claim 1, characterized in that: When each node on the network constructs a routing response frame, if there are multiple routes, the status score of the neighboring nodes on each route needs to be calculated separately.

4. The fast network access method according to claim 1, wherein: When the new node calculates the status score of each responding node again after receiving the routing response frame, it needs to first obtain the actual signal strength value rssi between the new node and each responding node. value Then, the status score of each response node is calculated based on the number of hops and power information in the response node routing response frame. score .

5. The fast network access method according to claim 4, characterized in that: The new node scores each response node according to its status score Sorting is performed to generate a sorting table, and then a greedy algorithm is used to select three response nodes with the highest scores from the sorting table as relay nodes.

6. The fast network access method according to claim 1, characterized in that: After receiving the network access application frame of the new node, the central node evaluates the current network capacity. If the current network has sufficient resources to accommodate the new node, it agrees to allow the new node to join the network, fills the result in the network access application response frame, and sends the network access application response frame to the new node.

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