Tree network communication method and system based on frequency hopping

Abstract

The invention relates to the technical field of wireless data transmission, in particular to a tree network communication method and system based on frequency hopping, mainly comprising a concentrator, routing nodes and leaf nodes, establishing a network through the concentrator, setting a frequency hopping sequence, and establishing a tree network through the routing nodes. The frequency hopping sequence comprises a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator communicates with nodes of the network according to the frequency hopping sequence. According to the method, each node in the network has the random frequency hopping sequence, and under the condition of multi-node networking communication, the anti-interference capability is high, and the communication stability is high. And meanwhile, a simple and efficient routing mechanism is provided and named as root-to-leaf routing, the communication delay is small, and the communication efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless data transmission, and in particular to a tree network communication method and system based on frequency hopping. Background Art

[0002] Sub-1G (or Sub-1GHz) is a radio communication technology that operates at a frequency band below 1 GHz, usually in the frequency range of 769 -935 MHz, 315 MHz, and 468 MHz. Unlike 2.4G wireless communication technologies such as Wi-Fi and Bluetooth, the actual frequency bands used by Sub-1GHz communication technology vary from region to region. North America and Australia use the 915 MHz band, while Europe uses the 868 MHz band. The 433 MHz band can be used worldwide. The 433, 470, 779 and other bands can be used domestically. Compared with the 2.4GHz band, Sub-1G performs better than Wi-Fi and Bluetooth in terms of communication distance in wireless IoT applications.

[0003] Frequency hopping technology, the full name of which is "Frequency-Hopping Spread Spectrum", abbreviated as FHSS, is one of the most commonly used spread spectrum methods in wireless communication. Frequency hopping technology is a communication method in which the carrier frequency of the wireless transmission signal between the sending and receiving devices is discretely changed according to a predetermined algorithm or rule. In other words, the carrier frequency used in wireless communication is randomly changed under the control of a pseudo-random change code. Based on this frequency hopping technology, in a wireless networking system, wireless communication between nodes is not fixed on a channel, but the channel is switched in a random sequence.

[0004] In current wireless applications, most applications require communication between the central node and each node of the network, but the stability and anti-interference ability of communication need to be improved. Summary of the invention

[0005] The purpose of the present invention is to provide a tree network communication method and system based on frequency hopping to solve the problems existing in the prior art.

[0006] The present invention is achieved through the following technical solutions: A tree network communication method based on frequency hopping, comprising a concentrator, a routing node and a leaf node; A network is established through a concentrator, and a frequency hopping sequence is set, wherein the frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator and the nodes of the network communicate according to the frequency hopping sequence; Before the routing nodes and leaf nodes are powered on and connected to the network, they periodically broadcast network access requests on broadcast channel 0; When the concentrator switches to broadcast channel 0 by frequency hopping and receives a network access request from a routing node or a leaf node, the concentrator allocates a unicast frequency hopping sequence to the node to be networked, performs time synchronization at the same time, and the node to be networked starts broadcasting and unicast frequency hopping; The concentrator sends the unicast frequency hopping sequence and the unicast frequency hopping sequence of the node that has already joined the network to the node to be joined, and exchanges network parameters at the same time to complete the network joining; All network nodes that have joined the network perform frequency hopping according to a unified time axis. When receiving the routing path broadcast packet sent by the concentrator, the node performs time calibration and frequency hopping synchronization; When the concentrator and the target node in the network perform unicast communication, the concentrator queries the unicast frequency hopping sequence of the target node before sending data, switches the channel to the unicast channel that the target node is listening to, and after sending the data, switches the concentrator to the concentrator's frequency hopping sequence to receive data.

[0007] Preferably, the concentrator establishing a network includes: Establish a fixed channel network or a frequency hopping channel network; When establishing a fixed channel network, scan the current environment and select the best channel to establish the network; When a frequency hopping channel network is established, the concentrator randomly generates a frequency hopping sequence and assigns it to the node, and the node communicates according to the frequency hopping sequence.

[0008] Preferably, it also includes: After the concentrator establishes the network, it broadcasts broadcast frames at a certain period. After receiving the broadcast frames, the nodes obtain the best communication path of the concentrator. If a routing node in the network switches, all nodes in the network will dynamically switch to the best path of the concentrator after receiving the broadcast frame sent by the concentrator; The broadcast frame includes a timestamp. After receiving the broadcast frame, all nodes in the network calibrate and synchronize the clock of the current node through the timestamp.

[0009] Preferably, it also includes: The concentrator broadcasts a routing path broadcast packet to the network. The routing nodes in the network receive the routing path broadcast packet at the same time and start forwarding it in order. The orderly forwarding includes setting a delay interval delay to obtain a forwarding time for each routing node:

[0010] In the formula, For the The forwarding time of a routing node, It is determined by the order in which the routes enter the network.

[0011] Preferably, it also includes: After receiving the routing path broadcast packet forwarded by other routing nodes, the concentrator and routing node store the forwarded routing node information in the neighbor table; When all routing nodes have forwarded the routing path broadcast packets sent by the concentrator, all nodes obtain their own routing depth.

[0012] Preferably, it also includes: The concentrator broadcasts the routing path broadcast frame, and the routing nodes forward the broadcast in ascending order according to the order in which they join the network. After forwarding is completed, the routing node obtains several paths to the concentrator and saves them in the routing table of each routing node. During communication, a path with the best link quality indicator is selected from the routing table.

[0013] In a second aspect, the present invention provides a tree network communication system based on frequency hopping, comprising: The network establishment module is configured to include a concentrator, a routing node and a leaf node: a network is established through the concentrator, a frequency hopping sequence is set, and the frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator and the node communication of the network are performed according to the frequency hopping sequence; before the routing node and the leaf node are powered on and connected to the network, the network access request is periodically broadcast on the broadcast channel 0; The network access module is configured such that when the concentrator switches to broadcast channel 0 by frequency hopping and receives a network access request from a routing node or a leaf node, the concentrator allocates a unicast frequency hopping sequence to the node to be networked and performs time synchronization at the same time; the node to be networked starts broadcasting and unicast frequency hopping, obtains the unicast frequency hopping sequence of the concentrator and the unicast frequency hopping sequence of the node that has already been networked, and exchanges network parameters at the same time to complete network access; all network nodes after network access perform frequency hopping according to a unified time axis, and perform time calibration and synchronization when receiving a routing path broadcast packet; when the concentrator and the target node in the network perform unicast communication, the unicast frequency hopping sequence of the target node is queried before the concentrator sends data, the channel is switched to the unicast channel that the target node is monitoring, and after sending the data, the concentrator is switched to the frequency hopping sequence of the concentrator to receive data monitoring; A main control module, the main control module is connected to the network establishment module and the network access module, and is used to execute the above-mentioned tree network communication method based on frequency hopping.

[0014] In a third aspect, the present invention further provides an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned frequency hopping-based tree network communication method when executing the computer program.

[0015] In a fourth aspect, the present invention further provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the above-mentioned tree network communication method based on frequency hopping.

[0016] The technical solution of the present invention has at least the following advantages and beneficial effects: The method provided by the present invention mainly includes a concentrator, a routing node and a leaf node. A network is established through the concentrator, and a frequency hopping sequence is set. The frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence. The concentrator and the node communication of the network are carried out according to the frequency hopping sequence. Through the above method, each node in the network has a random frequency hopping sequence. In the case of multi-node networking communication, the anti-interference ability is strong and the communication stability is high. At the same time, it has a concise and efficient routing mechanism, named root-to-leaf routing, with small communication delay and high communication efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of the network topology of the present invention; Figure 2 It is a schematic diagram of the frequency hopping process of the present invention; Figure 3 A schematic diagram of the process of establishing a frequency hopping communication network for the present invention; Figure 4 This is a schematic diagram of the tree-path broadcast process of the present invention; Figure 5 Schematic diagram of the process flow of route discovery of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] The terms "first, second" and the like in the specification and claims of this application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. The naming or numbering of steps in this application does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The named or numbered process steps can be changed in the execution order according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0021] Please refer to Figure 1-Figure 5 ,The present invention provides a tree network communication method based on frequency hopping, including a concentrator, a routing node and a leaf node; Among them, the concentrator is referred to as CT, the router node is referred to as RN, and the leaf node is referred to as LN. For the specific network topology, see the attached Figure 1 . CT is the center of the network, responsible for establishing and managing the network, assigning random frequency hopping sequences to each node in the network, and periodically broadcasting root-to-leaf tree routing path broadcast packets (Root toleaf tree routing path), referred to as tree-path. RN has a relay function, forwarding network data and application data, and extending the communication distance of the network. It is a full-function device that also supports reporting collected data or sending control data. LN is the terminal of the network, reporting collected data or sending control data, and supports low power consumption. The two major characteristics of this network communication system are a simple and efficient root-to-leaf routing mechanism, and all nodes in the network have their own frequency hopping sequence with strong anti-interference ability.

[0022] The routing node in the network plays a role similar to the trunk branch in the tree network. It is a full-function device that does not support low power consumption and has the ability to forward data, but can also collect and report data or send control data to CT. After joining the network, RN will obtain its own unicast frequency hopping sequence, network PANID, network communication address and other information from CT. The network communication address of RN also represents the order of access to the network, named RN-addr, ranging from 0x01-0x80.

[0023] The leaf node in the network is similar to the leaf role in the tree network. It supports low power consumption and mainly collects and reports data or sends control data to the CT. After joining the network, the LN will obtain information such as the unicast frequency hopping sequence, network communication address, and network PANID from the CT. The network communication address of the LN is defined as a 16-bit range of 0x0081-0xfffe.

[0024] The network communication address of all nodes in the network is described as follows: 0x00- represents the network communication address of CT, which is always 0. 0x01-0x80 represents the network communication address of RN and also represents the order of RN access to the network. 0x0081-0xfffe represents the network communication address of LN and also represents the order of LN access to the network. The first LN to join the network has an address of 0x81, the second to join the network has an address of 0x82, and so on. For details, see the attached Figure 3 The network access process.

[0025] S101: Establishing a network through a concentrator, setting a frequency hopping sequence, wherein the frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator and the nodes of the network communicate according to the frequency hopping sequence; The main function of CT is to establish and manage the network. In a tree network, it is equivalent to the role of the tree root. The network established can be a fixed channel network or a frequency hopping channel network. If a fixed channel network is established, the current environment will be scanned before the network is established to select an optimal channel (interference-free channel) to establish the network. If a frequency hopping channel network is established, when a node joins the network, CT will randomly generate a frequency hopping sequence and assign it to the node. When communicating with this node in the future, the communication will be carried out according to this frequency hopping sequence. After CT establishes the network, it broadcasts and sends tree-paths at a certain period to maintain the communication path from CT to each node, and also maintains the heartbeat function of the network. The node detects whether CT is online in the network to realize self-organizing and network self-healing functions.

[0026] S102: before the routing node and the leaf node are powered on and connected to the network, they periodically broadcast a network access request on broadcast channel 0 (CH0); S103: When the concentrator switches frequency hopping to broadcast channel 0 (CH0) and receives a network access request from a routing node or a leaf node, the concentrator allocates a unicast frequency hopping sequence to the node to be networked, performs time synchronization at the same time, and the node to be networked starts broadcast and unicast frequency hopping; CT and nodes in the network communicate according to the specified frequency hopping sequence. Before joining the network, the channel list parameters of all nodes of CT, RN, and LN need to be completely consistent. The channel list specifies the starting channel, channel interval, and end channel, so that the frequency hopping communication remains at the same frequency. Of course, the channel list parameters can be configured, but after configuration, the channel list parameters of all nodes must be consistent.

[0027] The frequency hopping sequence includes broadcast frequency hopping sequence and unicast frequency hopping sequence. The broadcast frequency hopping sequence is configured in the order of the channel list (CH0, CH1, CH2, CH3, CH4...........). For unicast frequency hopping sequence, each node in the network has its own frequency hopping sequence. After CT establishes the network, it will randomly generate a unicast frequency hopping sequence for itself. When a node joins the network, CT will randomly generate a unicast frequency hopping sequence (CH8, CH4, CH12, CH5, CH1...........) for the node and send it to the node. At the same time, it will also send the unicast sequence of the node that has joined the network and CT to the node that is joining the network. Therefore, each node in the network will know the unicast frequency hopping sequence of other nodes in the network.

[0028] During network communication, the source node queries the frequency hopping sequence of the target node before sending data to the target node, switches the PHY channel to the channel that the target node is monitoring to send data, and the target node can successfully receive the data. Figure 2 .like Figure 3 As shown, the broadcast frequency hopping sequence is fixed, and the unicast frequency hopping sequence is allocated during the network access process.

[0029] S104: Obtain the unicast frequency hopping sequence of the concentrator and the unicast frequency hopping sequence of the node that has already joined the network, and send them to the node to be joined, while exchanging network parameters to complete the network joining; S105: All network nodes that have joined the network perform frequency hopping according to a unified time axis, and perform time calibration and synchronization when receiving a routing path broadcast packet; S106: When the concentrator and the target node in the network perform unicast communication, the concentrator queries the unicast frequency hopping sequence of the target node before sending data, switches the channel to the unicast channel that the target node is monitoring, and after sending the data, switches the concentrator to the frequency hopping sequence of the concentrator to monitor the received data.

[0030] When a node unicasts data to other nodes or a node unicasts data to a CT, it follows the method in the previous step and first switches to the frequency hopping channel of the target node, and then switches to its own frequency hopping sequence after sending the data.

[0031] In an exemplary embodiment of the present invention, the concentrator establishes a network including: Establish a fixed channel network or a frequency hopping channel network; when establishing a fixed channel network, scan the current environment and select the best channel to establish the network; when establishing a frequency hopping channel network, the concentrator randomly generates a frequency hopping sequence and assigns it to the node, and the node communicates according to the frequency hopping sequence.

[0032] An exemplary embodiment of the present invention further includes: After the concentrator establishes the network, it broadcasts broadcast frames at a certain period. After receiving the broadcast frames, the nodes obtain the best communication path of the concentrator. If the routing nodes in the network switch, all nodes in the network will dynamically switch to the best path of the concentrator after receiving the broadcast frames sent by the concentrator. The broadcast frames include timestamps. After receiving the broadcast frames, all nodes in the network will calibrate and synchronize the clocks of the current nodes through the timestamps.

[0033] An exemplary embodiment of the present invention further includes: The concentrator broadcasts a frame of routing path broadcast packet to the network. The routing nodes in the network receive the routing path broadcast packet and start to forward it in order. Orderly forwarding includes setting the delay interval delay to obtain the forwarding time for each routing node:

[0034] In the formula, For the The forwarding time of a routing node, Determined by the order in which routing nodes join the network.

[0035] In root-to-leaf routing, the concentrator module CT broadcasts a frame of tree-path to the network. The RNs in the network will receive the tree-path at the same time. The RNs start to forward in order. RN-1 (RN-addr is 1, indicating the first RN to enter the network) forwards immediately without delay. RN-2 forwards with a delay of 1*delay, RN-3 forwards with a delay of 2*delay, and finally RN-m forwards with a delay of (m-1)*delay. The baseline delay of RN forwarding is related to the air speed of wireless communication. The higher the air speed, the smaller the delay.

[0036] An exemplary embodiment of the present invention further includes: After the concentrator and routing node receive the routing path broadcast packet forwarded by other routing nodes, they are stored in the neighbor table; when all routing nodes have forwarded the routing path broadcast packet, all routing nodes also obtain their own routing depth.

[0037] CT will receive the tree-path forwarded by RN and store the forwarded RN in the neighbor table. Similarly, RN will also receive the tree-path forwarded by other RNs and store the forwarded RN in the neighbor table. At this point, all RNs and CTs in the network have their own neighbor tables.

[0038] After the tree-path frame is broadcasted from CT to all RNs, all nodes will get their own routing depth (depth for short). The depth of CT is 0. If RN can successfully receive the tree-path broadcasted by CT, the depth of RN in this range is 1, named RN-depth1. The RN that receives the tree-path forwarded by RN-depth1 is RN-depth2, and so on. All nodes in the network receive the tree-path frame and broadcast it only once, refer to Figure 4 If a broadcast frame with this sequence number has already been broadcast, it will not be broadcast again after receiving it again.

[0039] An exemplary embodiment of the present invention further includes: The concentrator broadcasts a routing path broadcast frame, and the routing nodes forward the broadcast according to the order of joining the network, from small to large, that is, the first to join is forwarded first; after the forwarding is completed, the routing node obtains several paths to the concentrator and saves them in the routing table of each routing node. When communicating, a path with the best link quality indication is selected in the routing table.

[0040] During the process of route discovery for all nodes, CT sends a tree-path broadcast frame. The RN node with a routing depth of 1 starts broadcasting and forwarding, followed by the RN node with a routing depth of 2. This continues until all RN nodes have completed broadcasting and forwarding. Figure 4 As shown in the figure, the RN node will obtain multiple paths to the CT and save them in its own routing table. When communicating, it will select a path with the best LQI in the routing table. The CT obtains the path of each node, as shown in the attached figure. Figure 4 As shown in the figure, when the RN with a routing depth of 2 obtains the best path, it will unicast its own path and its child nodes to the CT (the RN with a routing depth of 1 is a neighbor node of the CT and knows its path). And so on, the RN node with a routing depth of 3 starts to reply. After receiving the reply, the CT knows the path to each node and stores it in its own routing table.

[0041] In combination with the above method provided by the present invention, a specific example is given for further explanation: Step 1: CT establishes a network, RN and LN join the network to establish frequency hopping communication. Figure 3 As shown: When the CT is powered on, a network is established. The broadcast frequency hopping sequence switches on the channel in the order of CH0, CH1, CH2... in the channel list, and a unicast frequency hopping sequence is randomly assigned, such as a sequence like CH8, CH2, CH5, CH9...

[0042] The broadcast frequency hopping sequence and unicast frequency hopping sequence of CT have been established. Figure 2 The frequency hopping is performed as shown below, the steps to achieve it are: For broadcast, set the broadcast dwell time and broadcast interval; for unicast, set the unicast dwell time.

[0043] The time axis starts from the synchronization time 0, and CT first stays on the broadcast channel CH0 to send and receive data, and after the broadcast dwell time, it switches to the unicast channel CH8 for sending and listening. When the next broadcast channel CH1 arrives, it switches to the CH1 broadcast channel for sending and listening, and after the broadcast dwell time, it switches to the unicast channel CH2 for sending and listening, and so on.

[0044] When the RN (or LN) access node is powered on and joins the network, it is fixed on the CH0 channel and periodically broadcasts network access requests, because at this time the access node has not yet obtained the unicast frequency hopping information.

[0045] When CT frequency hopping switches to the broadcast CH0 channel and receives the access request from the RN (or LN) access node, CT assigns the unicast frequency hopping sequence to the access node and also performs time synchronization. Figure 2 Start broadcast and unicast frequency hopping.

[0046] CT sends its own unicast frequency hopping sequence and the unicast frequency hopping sequence of the node that has already joined the network to the node that joins the network, and at the same time exchanges the network PANID, network key, network address and other network parameters to complete the network entry.

[0047] After joining the network, each node in the network will know the unicast frequency hopping sequence and broadcast frequency hopping sequence of all other nodes, hop frequencies according to the same timeline, and perform time calibration and synchronization whenever a broadcast packet is received.

[0048] When CT conducts unicast communication with a node in the network, CT queries the unicast sequence of the target node before sending data, and switches the channel to the unicast channel that the target node is monitoring (if the target node is monitoring the broadcast channel at this moment, CT will wait for the target node to switch to unicast monitoring before switching the channel). After sending the data, CT switches to its own frequency hopping sequence to receive data monitoring.

[0049] Similarly, when a node unicasts data to other nodes or a node unicasts data to a CT, it first switches to the frequency hopping channel of the target node according to the method in step 7, and then switches to its own frequency hopping sequence after sending the data.

[0050] Step 2: After all nodes have completed networking, establish a routing path (routing discovery). The specific implementation steps are as follows: Figure 4 , Figure 5 As shown: During network operation, CT will broadcast tree-path frames at a certain period to dynamically maintain network routing, and the routing path can be automatically repaired.

[0051] CT broadcasts a frame of tree-path.

[0052] RN1, RN2, and RN3 are within the effective communication range of CT, and RN1, RN2, and RN3 can receive the broadcast tree-path of CT.

[0053] RN1 broadcasts tree-path, RN2 delays broadcasting by 1*delay, and RN3 delays broadcasting by 2*delay to avoid broadcast storms caused by simultaneous broadcasts. The electromagnetic wave transmission speed is very fast, so the delay is very small.

[0054] RN4, RN5, and RN6 are within the effective communication distance of RN1, RN2, and RN3, and can receive the broadcast tree-path of RN1, RN2, and RN3.

[0055] RN4 broadcasts tree-path, RN5 delays 4*delay broadcast, and RN6 delays 5*delay broadcast to avoid broadcast storms caused by simultaneous broadcasts. The electromagnetic wave transmission speed is very fast, so the delay is very small.

[0056] When all nodes have completed the tree-path broadcast forwarding, each node stores multiple paths to CT in its routing table, selects the path with the best LQI value as the communication path, and uses other paths as backup paths. In this way, all nodes know the path to CT.

[0057] CT Obtain the path of RN and LN After the RN node with a routing depth exceeding depth1 obtains the best path for the first time, it sends the best path and its child node LN to CT in unicast mode, and the sending order is RN4, RN5, and RN6.

[0058] CT is a periodic broadcast tree-path, and the broadcast period can be set. RN nodes with a routing depth exceeding depth1 will only notify CT by unicast when the best path changes or when their child node LN changes.

[0059] CT is a periodic broadcast tree-path that updates the network routing path at regular intervals. Therefore, when an RN moves or leaves the network, the network routing path can be automatically repaired.

[0060] CT saves the path of each RN node and LN node in the source routing table. There is no need to dynamically find the path of the node each time communication occurs. Data can be sent directly, which improves communication efficiency.

[0061] In a second aspect, the present invention provides a tree network communication system based on frequency hopping, comprising: The network establishment module is configured to include a concentrator, a routing node and a leaf node: a network is established through the concentrator, a frequency hopping sequence is set, and the frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator and the node communication of the network are performed according to the frequency hopping sequence; the routing node and the leaf node periodically broadcast a network access request on the channel before being powered on and accessing the network; The network access module is configured such that when the concentrator switches to the broadcast channel by frequency hopping and receives a network access request from a routing node or a leaf node, the concentrator allocates a unicast frequency hopping sequence to the node to be networked, performs time synchronization at the same time, and the node to be networked starts broadcasting and unicast frequency hopping; obtains the unicast frequency hopping sequence of the concentrator and the unicast frequency hopping sequence of the node that has already been networked, and sends them to the node to be networked, and exchanges network parameters at the same time to complete network access; all network nodes after network access perform frequency hopping according to a unified time axis, and perform time calibration and synchronization when receiving a routing path broadcast packet; when the concentrator and the target node in the network perform unicast communication, the unicast frequency hopping sequence of the target node is queried before the concentrator sends data, and the channel is switched to the unicast channel that the target node is monitoring, and after sending the data, the concentrator is switched to the frequency hopping sequence of the concentrator to receive data monitoring; A main control module, the main control module is connected to the network establishment module and the network access module, and is used to execute the above-mentioned tree network communication method based on frequency hopping.

[0062] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0063] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tree network communication method based on frequency hopping, characterized in that: Includes concentrators, routing nodes, and leaf nodes; A network is established through a concentrator, and a frequency hopping sequence is set, wherein the frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator and the nodes of the network communicate according to the frequency hopping sequence; Before the routing nodes and leaf nodes are powered on and connected to the network, they periodically broadcast network access requests on broadcast channel 0; When the concentrator switches to broadcast channel 0 by frequency hopping and receives a network access request from a routing node or a leaf node, the concentrator allocates a unicast frequency hopping sequence to the node to be networked, performs time synchronization at the same time, and the node to be networked starts broadcasting and unicast frequency hopping; The concentrator sends the unicast frequency hopping sequence and the unicast frequency hopping sequence of the node that has already joined the network to the node to be joined, and exchanges network parameters at the same time to complete the network joining; All network nodes that have joined the network perform frequency hopping according to a unified time axis. When receiving the routing path broadcast packet sent by the concentrator, the node performs time calibration and frequency hopping synchronization; When the concentrator and the target node in the network perform unicast communication, the concentrator queries the unicast frequency hopping sequence of the target node before sending data, switches the channel to the unicast channel that the target node is listening to, and after sending the data, switches the concentrator to the concentrator's frequency hopping sequence to receive data.

2. A frequency hopping based tree network communication method according to claim 1, characterized in that: The concentrator establishes a network including: Establish a fixed channel network or a frequency hopping channel network; When establishing a fixed channel network, scan the current environment and select the best channel to establish the network; When a frequency hopping channel network is established, the concentrator randomly generates a frequency hopping sequence and assigns it to the node, and the node communicates according to the frequency hopping sequence.

3. A frequency hopping based tree network communication method according to claim 2, characterized in that: Also includes; After the concentrator establishes the network, it broadcasts broadcast frames at a certain period. After receiving the broadcast frames, the nodes obtain the best communication path of the concentrator. If a routing node in the network switches, all nodes in the network will dynamically switch to the best path of the concentrator after receiving the broadcast frame sent by the concentrator; The broadcast frame includes a timestamp. After receiving the broadcast frame, all nodes in the network calibrate and synchronize the clock of the current node through the timestamp.

4. A frequency hopping based tree network communication method according to claim 3, characterized in that: Also includes: The concentrator broadcasts a routing path broadcast packet to the network. The routing nodes in the network receive the routing path broadcast packet at the same time and start forwarding it in order. The orderly forwarding includes setting a delay interval delay to obtain a forwarding time for each routing node: In the formula, For the The forwarding time of a routing node, It is determined by the order in which the routes enter the network.

5. A frequency hopping based tree network communication method according to claim 4, characterized in that: Also includes: After receiving the routing path broadcast packet forwarded by other routing nodes, the concentrator and routing node store the forwarded routing node information in the neighbor table; When all routing nodes have forwarded the routing path broadcast packets sent by the concentrator, all nodes obtain their own routing depth.

6. A frequency hopping based tree network communication method according to claim 5, characterized in that: Also includes: The concentrator broadcasts the routing path broadcast frame, and the routing nodes forward the broadcast in ascending order according to the order in which they join the network. After forwarding is completed, the routing node obtains several paths to the concentrator and saves them in the routing table of each routing node. During communication, a path with the best link quality indicator is selected from the routing table.

7. A tree network communication system based on frequency hopping, characterized in that: include: The network establishment module is configured to include a concentrator, a routing node and a leaf node: a network is established through the concentrator, a frequency hopping sequence is set, and the frequency hopping sequence includes a broadcast frequency hopping sequence and a unicast frequency hopping sequence, and the concentrator and the node communication of the network are performed according to the frequency hopping sequence; before the routing node and the leaf node are powered on and connected to the network, the network access request is periodically broadcast on the broadcast channel 0; Network access module: when the concentrator switches to broadcast channel 0 by frequency hopping and receives a network access request from a routing node or a leaf node, the concentrator allocates a unicast frequency hopping sequence to the node to be networked, performs time synchronization at the same time, and the node to be networked starts broadcasting and unicast frequency hopping; The concentrator sends the unicast frequency hopping sequence of the node that has joined the network to the node to be joined, and exchanges network parameters at the same time to complete the network joining; all network nodes that have joined the network perform frequency hopping according to the unified time axis, and perform time calibration and synchronization when receiving the routing path broadcast packet; when the concentrator and the target node in the network perform unicast communication, the concentrator queries the unicast frequency hopping sequence of the target node before sending data, switches the channel to the unicast channel that the target node is monitoring, and after sending the data, switches the concentrator to the concentrator's frequency hopping sequence to receive data monitoring; A main control module, the main control module is connected to the network establishment module and the network access module, and is used to execute a tree network communication method based on frequency hopping as described in any one of claims 1-6.

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