A networking method based on LoRa

Abstract

The invention discloses a LoRa-based networking method, comprising: a central node starts to send a first round of networking beacons; if a common subnode receives the first round of networking beacons, the central node organizes its own beacon to be sent out once; if the first beacon received by the common subnode is a beacon sent by other common subnodes, the level of the common subnode is judged according to the beacons of other common subnodes, and if the level does not exceed the allowed level, the central node organizes its own beacon to be sent out once; if the common subnode that has completed the first round of networking does not receive a beacon of the next layer, the common subnode is determined to be an end common subnode, and all end common subnodes other than the first layer start to send a second round of beacons; when the central node receives the beacon of the common subnode, a route is formulated according to the field strength information and routing information of each common subnode; the central node selects a working channel group; and the selected working channel group and primary and backup routes are set according to the formulated route.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and more particularly to a LoRa-based networking method. Background Art

[0002] LoRaWAN is a low-power wide-area network specification launched by the LoRa Alliance. The LoRaWAN network architecture is a typical star topology, in which the LoRa gateway acts as a transparent relay, connecting end devices and servers. Currently, LoRa communications generally only provide point-to-point communication and cannot form a network or automatically form a network. Furthermore, limitations such as LoRaWAN frame length make it unsuitable for data collection in the overseas electricity meter industry, necessitating network solutions such as NB-IoT. However, NB-IoT relies on the operator's network, requiring significant investment and providing limited, timely service. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a LoRa-based networking method that can realize self-organizing networking.

[0004] To solve the above technical problems, the present invention provides a LoRa-based networking method, comprising:

[0005] The central node manages the list of local child nodes and initiates the issuance of the first round of networking beacons through the central node's public channel;

[0006] If a common child node receives the first round of networking beacons from the central node, it organizes its own beacon to be sent out once. This common child node acts as a first-layer common child node and sends beacons to the central node and the common child nodes in the next layer respectively. If the first beacon received by a common child node is a beacon sent by another common child node, the node determines its level based on the beacons of the other common child nodes. If the level does not exceed the allowed level, it organizes its own beacon to be sent out once. This common child node becomes an N-layer common child node. If it is already at the maximum level or has already sent its first round of beacons, it does not respond. The beacon includes field strength information, routing information, subnode size, level, and round number.

[0007] For ordinary sub-nodes that have completed the first round of networking, based on the sub-node scale and Lora communication parameters of the network unit, if they do not receive the beacon from the next layer after waiting for a certain period of time, they are determined to be terminal ordinary sub-nodes. All ordinary sub-nodes other than the terminal ordinary sub-nodes of the first layer start sending the second round of beacons. If an ordinary sub-node receives the second round of beacons sent by the ordinary sub-nodes of the next layer, it will directly forward the second round of beacons to the upper layer for reception, and then relay them through each layer until it is sent to the central node.

[0008] When the central node receives the beacon from the common sub-node, it collects the field strength information and routing information of the common sub-node, selects the path from the central node to each common sub-node based on the field strength information and routing information of each common sub-node, and thus formulates the route between the central node and each common sub-node;

[0009] Determine whether the central node has received network information from other central nodes. If so, obtain the working channel groups of other central nodes to select the working channel group.

[0010] Traverse the common child nodes managed by the central node and set the selected working channel group and primary and backup routes according to the established routes.

[0011] Its further technical solution is: the LoRa-based networking method also includes:

[0012] When the sleeping child node wakes up, it checks whether a route is established with the central node. If not, it sends a network access beacon through the public channel;

[0013] If the central node receives a network entry beacon from a sleeping child node, it determines whether the sleeping child node is a legitimate sleeping child node; if a common child node that has already formed a network receives a network entry beacon from a sleeping child node, it processes it and sends it to the central node. The central node receives the network entry beacon of the sleeping child node sent by the common child node and determines whether the sleeping child node is a legitimate sleeping child node.

[0014] If it is a legitimate sleeping sub-node, the central node obtains the field strength information and routing information of the sleeping sub-node, and selects the path from the central node to the sleeping sub-node based on the field strength information and routing information, formulates the route between the central node and the sleeping sub-node, and wakes up the sleeping sub-node to set its routing information, thereby enabling the sleeping sub-node to enter the network.

[0015] A further technical solution is: obtaining the working channel groups of other central nodes and selecting the working channel group specifically includes:

[0016] The central node obtains the working channel groups of other central nodes based on the network information received from other central nodes, and determines whether there are any unoccupied working channel groups. If so, it selects the working channel group that is not occupied by other central nodes. If not, it obtains the signal strength information of other central nodes and selects the working channel group where the central node with weaker signal strength is located.

[0017] A further technical solution is: the step of judging whether the central node has received network information from other central nodes further includes: if not, the central node randomly selects a working channel group.

[0018] Its further technical solution is: the working channel group includes a first channel and a second channel, and the first channel is configured as a communication channel in which the central node actively communicates and the ordinary sub-nodes respond, and the second channel is configured as a communication channel in which the ordinary sub-nodes actively communicate and the central node responds.

[0019] Compared with the prior art, the LoRa-based networking method of the present invention triggers direct reporting or relay reporting of beacons of ordinary sub-nodes through the networking beacon of the central node, and then collects the beacons of ordinary sub-nodes through the central node, and selects the path from the central node to each ordinary sub-node according to the field strength information and routing information of each ordinary sub-node, thereby formulating the route between the central node and each ordinary sub-node, and the central node can select an unoccupied working channel, and set the selected working channel group and main and backup routes according to the formulated route to realize automatic networking of ordinary sub-nodes and central nodes, breaking through the distance limitation of point-to-point communication, and the working channels selected by each central node are staggered and do not interfere with each other, and the network stability is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of the LoRa-based networking method of the present invention.

[0021] Figure 2 This is a schematic diagram of a specific application process of the LoRa-based networking method of the present invention.

[0022] Figure 3 It is a schematic diagram of the process of a sleeping sub-node joining the network in the LoRa-based networking method of the present invention. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0024] Reference Figure 1 , Figure 1 1 is a flow chart of a specific embodiment of a LoRa-based networking method of the present invention. In the embodiment shown in the accompanying drawings, the LoRa-based networking method includes:

[0025] S101: The central node manages a list of local child nodes and initiates the issuance of a first round of networking beacons through the central node's public channel.

[0026] As we all know, the unit where the concentrator is located is called the central node, the communication unit where the collector or metering point (electricity meter) is located is a common sub-node, and the communication unit of the battery-powered water meter is a sleeping sub-node.

[0027] In the present invention, initially, the central node works in a fixed public channel, and the application layer can send child node list information to the central node according to the application layer service protocol so that the central node knows all the legal child nodes of the network cell unit.

[0028] In this step, when the application layer sends down the startup networking signal, the central node sends out the first round of networking beacons using the public channel frequency and enters the state of waiting to receive the beacon networking signal from the child node.

[0029] S102. If an ordinary sub-node receives the first round of networking beacons from the central node, it organizes its own beacon to be sent out once. The ordinary sub-node acts as a first-layer ordinary sub-node and sends beacons to the central node and the ordinary sub-nodes of the next layer respectively. If the first beacon received by the ordinary sub-node is a beacon sent by other ordinary sub-nodes, the level of the ordinary sub-node is determined based on the beacons of the other ordinary sub-nodes. If the level does not exceed the allowed level, the ordinary sub-node organizes its own beacon to be sent out once. The ordinary sub-node becomes an ordinary sub-node of the Nth layer. If it is already at the maximum level or has already sent its first round of beacons, it does not respond.

[0030] In the present invention, beacons initiated from the central node to ordinary subnodes are used to identify topological locations by layer. Understandably, a multi-layer topological network structure can be formed, and ordinary subnodes only communicate with their upper-layer nodes or lower-layer ordinary subnodes, and terminal ordinary subnodes only communicate with upper-layer ordinary subnodes. For example, if an ordinary subnode is a first-layer ordinary subnode, its upper-layer node is the central node, and its lower-layer ordinary subnode is a second-layer ordinary subnode. That is, the ordinary subnode only communicates with the central node and second-layer ordinary subnodes. If the ordinary subnode is a second-layer ordinary subnode, it only communicates with first-layer ordinary subnodes and third-layer ordinary subnodes. If the third-layer ordinary subnode wants to access the first-layer ordinary subnode, it must use the second-layer ordinary subnode as a relay.

[0031] Specifically, in this step, N is a natural number greater than 1, and the beacon sent by each node includes field strength information, routing information, sub-node scale, level and round information, and the central node and ordinary sub-nodes send beacons to each other through the CAMA-CA mechanism at the MAC layer. That is, when networking, if the beacons are concurrent, the carrier sense multiple access with collision avoidance (CSMA-CA) control mechanism is adopted.

[0032] S103. For ordinary sub-nodes that have completed the first round of networking, based on the sub-node scale and Lora communication parameters of the network unit in which they are located, if they have not received the beacon from the next layer after waiting for a certain period of time, they are determined to be the terminal ordinary sub-nodes. All ordinary sub-nodes other than the terminal of the first layer start sending the second round of beacons. If an ordinary sub-node receives the second round of beacons sent by the ordinary sub-node of the next layer, the second round of beacons will be directly forwarded to the upper layer for reception, and relayed through each layer until it is sent to the central node.

[0033] In this step, the Lora communication parameters include the frequency division factor, bandwidth, preamble, load length, i.e. the length of the content of the beacon sent, and the coding rate. Based on the Lora communication parameters, the code element period, preamble communication time and load communication time can be calculated according to the relevant standard formula, and the waiting time (ms) = (preamble communication time + load communication time) * (network unit sub-node size).

[0034] In the present invention, during the first round of networking, the central node can receive beacons from ordinary sub-nodes of the first layer. During the second round of networking, the central node can receive beacons from ordinary sub-nodes of the second layer or higher layers through ordinary sub-nodes of the first layer to form a network.

[0035] S104. When the central node receives the beacon of the ordinary sub-node, it collects the field strength information and routing information of the ordinary sub-node, selects the path from the central node to each ordinary sub-node according to the field strength information and routing information of each ordinary sub-node, and thus formulates the route between the central node and each ordinary sub-node.

[0036] In this step, when the central node receives a beacon from a common child node, it collects the field strength information and routing information of the common child nodes in the managed child node list. Based on the field strength information and routing information of each common child node's beacon, it selects a path from the central node to each common child node. Routes between the central node and each common child node are determined based on conditions such as suitable field strength information, shortest path, and large coverage area, forming a network topology structure for the communication network unit. Field strength information can be prioritized to determine a primary route between the central node and each common child node to maximize network coverage. Alternatively, the shortest route can be prioritized to minimize communication time, with the remaining routes serving as backup routes. It is understood that a beacon from a common child node may be transmitted to the central node via different paths. Each relay common child node has field strength information. Field strength information or path length can be used as a selection criterion for selecting the primary and backup routes. This allows the network to automatically select a backup route when the primary route becomes inoperable due to changes in the external environment, resulting in application layer data transmission.

[0037] S105: Determine whether the central node has received network information from other central nodes. If so, obtain the working channel groups of other central nodes, and select a working channel group.

[0038] This step specifically includes: if the central node receives network information from other central nodes, then based on the received network information, it obtains the working channel groups of the other central nodes, and determines whether there are any unoccupied working channel groups. If so, it selects the working channel group that is not occupied by other central nodes; if not, it obtains the signal strength information of other central nodes, and selects the working channel group where the central node with weaker signal strength is located.

[0039] Furthermore, after determining whether the central node has received network information from other central nodes, the method further includes: if not, the central node randomly selects a working channel group.

[0040] Preferably, in the present invention, the working channel group includes a first channel and a second channel, and the first channel is configured as a communication channel in which the central node actively communicates and the ordinary sub-nodes respond, and the second channel is configured as a communication channel in which the ordinary sub-nodes actively communicate and the central node responds.

[0041] S106: traverse the common sub-nodes managed by the central node, and set the selected working channel group and primary and backup routes according to the established routes.

[0042] In this step, all common sub-nodes managed by the central node are traversed, and the working channel group parameters, main route and backup route are set according to the route established in the above step S104. After the setting is completed, the networking of the central node and the common sub-nodes is completed.

[0043] Reference Figure 2 , Figure 2 The figure is a schematic diagram of a specific application flow of the LoRa-based networking method of the present invention. Figure 2It can be seen that in this specific application scenario, the central node and the ordinary sub-nodes form a two-layer topology network structure, and the networking principle is described with a maximum allowable 2 layers, that is, it includes a central node, a first-layer sub-node and a second-layer sub-node. When networking, the application layer first sends a list of local sub-nodes to the central node according to the application layer service protocol. In the first round, the central node sends a "0-layer" networking beacon through its public channel frequency. If an ordinary sub-node receives the "0-layer" beacon from the central node, the ordinary sub-node is a first-layer sub-node (that is, the first-layer ordinary sub-node in the networking method based on LoRa of the present invention), and forwards the "1-layer" beacon through the CSMA-CA mechanism of the MAC layer; if the ordinary sub-node does not receive the "0-layer" beacon from the central node, but receives the "1-layer" beacon from other ordinary sub-nodes (may receive multiple), then the ordinary sub-node acts as a second-layer sub-node (that is, the second-layer ordinary sub-node in the networking method based on LoRa of the present invention), and the second-layer sub-node is the end sub-node and no longer directly responds to the first round of beacons. After an appropriate delay, the second round of beacon transmission is started. The terminal child node (the second-layer child node) forwards the "2-layer" beacon to the first-layer child node through the CSMA-CA mechanism of the MAC layer. If the ordinary child node (i.e., the first-layer child node) that has received the "0-layer" beacon receives a "2-layer" beacon, it will forward it to the central node through the CSMA-CA mechanism of the MAC layer. After receiving the "1-layer" beacon and / or the "2-layer" beacon, the central node formulates the main route and backup route for each child node based on the collected field strength information and routing information of the ordinary child nodes, and selects a different working channel group from other central nodes based on the working channel groups received from other central nodes. Then, all ordinary child nodes managed by the central node are traversed, and the working channel group and main and backup routes are set according to the main route and backup routes obtained above. In this way, the networking of a single network unit is completed.

[0044] Preferably, in addition to ordinary sub-nodes in working state, the sub-nodes may also include sleeping sub-nodes in sleeping state. The LoRa-based networking method of the present invention may also include: when the sleeping sub-node wakes up, it checks whether a route is established with the central node. If not, a network access beacon is sent through a public channel; if the central node receives a network access beacon from the sleeping sub-node, it determines whether the sleeping sub-node is a legal sleeping sub-node, that is, it determines whether the sleeping sub-node is a sub-node in the sub-node list managed by the central node; and if an ordinary sub-node that has been networked receives a network access beacon from the sleeping sub-node, it processes it and sends it to the central node, the central node receives the sleeping sub-node network access beacon sent from the ordinary sub-node, and determines whether the sleeping sub-node is a legal sleeping sub-node; if it is a legal sleeping sub-node, the central node obtains the field strength information and routing information of the sleeping sub-node, and selects a path from the central node to the sleeping sub-node according to the field strength information and routing information, formulates a route between the central node and the sleeping sub-node, and wakes up the sleeping sub-node to set its routing information, thereby realizing the network access of the sleeping sub-node.

[0045] Understandably, in the present invention, the beacon sent by the sleeper node to the central node can be used to identify the topological location at the "level". The following example describes the process of a sleeper node joining the network in detail:

[0046] Reference Figure 3 The network access principle is explained using a two-layer network. When a sleeping child node wakes up, it checks whether a route has been established with the central node. If not, it sends a "Level 0" network access beacon through a public channel to apply for network access. If a first-layer ordinary child node receives a "Level 0" network access beacon, it sends a "Level 1" beacon to the central node through the MAC's CSMA-CA mechanism. If the central node receives a "Level 0" network access beacon or a "Level 1" beacon, it determines whether the sleeping child node is a legitimate sleeping child node. If it is a legitimate sleeping child node, the central node obtains the field strength information and routing information of the sleeping child node, and selects a path from the central node to the sleeping child node based on the field strength information and routing information, formulates a route between the central node and the sleeping child node, and wakes up the sleeping child node to set its routing information, thereby realizing the network access of the sleeping child node. It is understandable that if the second-layer ordinary sub-node receives a "level 0" network access beacon, it sends a "level 2" beacon to the first-layer ordinary sub-node, and the first-layer ordinary sub-node then sends a "level 1" beacon to the central node, and the central node determines whether it is a legitimate sleeping sub-node.

[0047] In summary, the LoRa-based networking method of the present invention triggers direct reporting or relay reporting of beacons of ordinary sub-nodes through the networking beacon of the central node, and then collects the field strength information and routing information of the ordinary sub-nodes through the central node, and selects the path from the central node to each ordinary sub-node according to the field strength information and routing information of each ordinary sub-node, thereby formulating the route between the central node and each ordinary sub-node, and selecting an unoccupied working channel through the central node, and setting the selected working channel group and the main and backup routes according to the formulated route to realize automatic networking of ordinary sub-nodes and central nodes, breaking through the distance limit of point-to-point communication, and the working channels selected by each central node are staggered and do not interfere with each other, and the network stability is good. In addition, the LoRa-based networking method of the present invention can build a network on demand, with low investment cost and flexible maintenance, while meeting the low-power communication problem of remote low-power devices (battery-powered).

[0048] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Those skilled in the art may make various equivalent changes and improvements based on the above embodiment. Any equivalent changes or modifications made within the scope of the claims shall fall within the scope of protection of the present invention.

Claims

1. A LoRa-based networking method, characterized in that: include: The central node manages the list of local child nodes and initiates the issuance of the first round of networking beacons through the central node's public channel; If a common child node receives the first round of networking beacons from the central node, it organizes its own beacon to be sent out once. This common child node acts as a first-layer common child node and sends beacons to the central node and the common child nodes in the next layer respectively. If the first beacon received by a common child node is a beacon sent by another common child node, the node determines its level based on the beacons of the other common child nodes. If the level does not exceed the allowed level, it organizes its own beacon to be sent out once. This common child node becomes an N-layer common child node. If it is already at the maximum level or has already sent its first round of beacons, it does not respond. The beacon includes field strength information, routing information, subnode size, level, and round number. For ordinary sub-nodes that have completed the first round of networking, based on the sub-node scale and Lora communication parameters of the network unit, if they do not receive the beacon from the next layer after waiting for a certain period of time, they are determined to be terminal ordinary sub-nodes. All ordinary sub-nodes other than the terminal ordinary sub-nodes of the first layer start sending the second round of beacons. If an ordinary sub-node receives the second round of beacons sent by the ordinary sub-nodes of the next layer, it will directly forward the second round of beacons to the upper layer for reception, and then relay them through each layer until it is sent to the central node. When the central node receives the beacon from the common sub-node, it collects the field strength information and routing information of the common sub-node, selects the path from the central node to each common sub-node based on the field strength information and routing information of each common sub-node, and thus formulates the route between the central node and each common sub-node; Determine whether the central node has received network information from other central nodes. If so, obtain the working channel groups of other central nodes to select the working channel group. Traverse the common child nodes managed by the central node and set the selected working channel group and primary and backup routes according to the established routes; When the sleeping child node wakes up, it checks whether a route is established with the central node. If not, it sends a network access beacon through the public channel; If the central node receives a network entry beacon from a sleeping child node, it determines whether the sleeping child node is a legitimate sleeping child node; if a common child node that has already formed a network receives a network entry beacon from a sleeping child node, it processes it and sends it to the central node. The central node receives the network entry beacon of the sleeping child node sent by the common child node and determines whether the sleeping child node is a legitimate sleeping child node. If it is a legitimate sleeping sub-node, the central node obtains the field strength information and routing information of the sleeping sub-node, and selects the path from the central node to the sleeping sub-node based on the field strength information and routing information, formulates the route between the central node and the sleeping sub-node, and wakes up the sleeping sub-node to set its routing information, thereby enabling the sleeping sub-node to enter the network.

2. The LoRa-based networking method according to claim 1, wherein: The obtaining of the working channel groups of other central nodes, thereby selecting the working channel group, specifically includes: The central node obtains the working channel groups of other central nodes based on the network information received from other central nodes, and determines whether there are any unoccupied working channel groups. If so, it selects the working channel group that is not occupied by other central nodes. If not, it obtains the signal strength information of other central nodes and selects the working channel group where the central node with weaker signal strength is located.

3. The LoRa-based networking method according to claim 2, wherein: The step of determining whether the central node has received network information from other central nodes further includes: if not, the central node randomly selecting a working channel group.

4. The LoRa-based networking method according to claim 1, wherein: The working channel group includes a first channel and a second channel, and the first channel is configured as a communication channel where the central node actively communicates and the ordinary sub-nodes respond, and the second channel is configured as a communication channel where the ordinary sub-nodes actively communicate and the central node responds.

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