A method for fast access of an ultra-long distance wireless ad hoc network node

Abstract

The application provides a kind of super long distance wireless ad hoc network node fast access method, comprising the following steps: S1, if the number of network nodes is less than the planned number of nodes, the master node of network enters S2, and the new network node enters S3;S2, the master node sends initial acquisition information, initial synchronization information in each beam direction, enters S5;S3, if the network node receives initial acquisition information in a certain beam direction, initial synchronization information is received directionally, as a preliminary slave node, synchronizes with the master node, and establishes a fixed beam with the master node in the beam direction, enters S4;S4, the preliminary slave node sends RTT acquisition information, RTT request message based on fixed beam, enters S6;S5, the master node attempts to receive RTT acquisition information in each beam direction, if received, immediately attempts to receive RTT request message, enters S6;S6, the master node directionally sends RTT response message, corresponding preliminary node and master node are precisely synchronized, and network access is completed.

Description

Technical Field

[0001] This invention relates to the field of wireless ad hoc network communication technology, and in particular to a method for rapid access of nodes in ultra-long-distance wireless ad hoc networks. Background Technology

[0002] Distributed wireless ad hoc networks have been applied in various fields, and the design of node access protocols has always been a research focus. Traditional signal broadcast transmission models based on omnidirectional antennas are well-established. However, directional networks using directional antennas for signal transmission and reception will undergo significant changes in their signal transmission models. Existing node access schemes based on wireless signal broadcast models will no longer be suitable for directional networks, necessitating the research of new access methods for rapid node access in ultra-long-distance wireless ad hoc networks within directional networks. Summary of the Invention

[0003] The purpose of this invention is to provide a method for rapid access of nodes in ultra-long-distance wireless self-organizing networks. This method enables beam alignment through the acquisition of spreading codes, allowing wireless data communication between nodes to adopt directional transmission, thereby increasing the transmission distance while shortening the transmission time.

[0004] To achieve the above objectives, this invention provides a method for rapid access of nodes in an ultra-long-range wireless ad hoc network, wherein nodes in the wireless ad hoc network communicate with each other using spreading codes, and the method includes the following steps:

[0005] S1. If the number of nodes in the network is less than the planned number of nodes, the main node in the network proceeds to step S2, and the newly joined node proceeds to step S3.

[0006] S2. The master node sends initial acquisition information in each beam direction during the initial acquisition time slot; after the initial acquisition time slot ends, the master node enters the initial synchronization time slot and sends initial synchronization information in each beam direction; proceed to step S5;

[0007] S3. After the network access node is powered on, it attempts to receive the initial acquisition information in each beam direction. If the initial acquisition information is received in a certain beam direction, the network access node enters the initial synchronization time slot and attempts to receive the initial synchronization information in that beam direction. If the initial synchronization information is received, the network access node synchronizes with the master node as a preparatory slave node and establishes a fixed beam in that beam direction. Proceed to step S4.

[0008] S4. The preparatory slave node enters the RTT (Round Trip Time) acquisition time slot and sends RTT acquisition information based on the fixed beam; after the RTT acquisition time slot ends, the preparatory slave node enters the RTT request time slot and sends an RTT request message; after the RTT request time slot ends, proceed to step S6.

[0009] S5. After the initial synchronization time slot ends, the master node enters the RTT time slot. In the multiple RTT acquisition time slots of its RTT time slot, the master node attempts to receive the RTT acquisition information in each beam direction. When the master node receives the RTT acquisition information, it immediately switches to the RTT request time slot and attempts to receive the RTT request message. After the RTT request time slot ends, it proceeds to step S6.

[0010] S6. The master node enters the RTT response time slot and sends an RTT response message in a targeted manner; the corresponding prepared slave node performs fine synchronization with the master node based on the received RTT response message; the prepared slave node becomes a slave node and completes network access.

[0011] Optionally, the method for rapid access of ultra-long-range wireless self-organizing network nodes further includes: step S7, where the master node and the slave node enter the service time slot, and the master node sends the location information and MAC address of other slave nodes stored in the master node to the slave node.

[0012] Optionally, the master node, slave node, and prospective slave node can all transmit and receive information using a narrow beam.

[0013] Optionally, the synchronization with the master node in step S3 includes: when the network entry node receives the initial synchronization information from the master node, the network entry node synchronizes its own time to the end of the current initial synchronization time slot.

[0014] Optionally, the RTT time slot includes multiple time slot units, which sequentially include: an RTT capture time slot, an RTT request time slot, and an RTT response time slot; the slave node sends RTT capture information in its RTT capture time slot, and the master node receives the RTT capture information sent by the slave node in its RTT capture time slot; the slave node sends an RTT request message in its RTT request time slot, and the master node receives the RTT request message sent by the slave node in its RTT request time slot; the master node sends an RTT response message in its RTT response time slot, and the slave node receives the RTT response message sent by the master node in its RTT response time slot.

[0015] Optionally, let t1 be the duration of the RTT acquisition time slot of the master node, t1 = t2 + t3; where t2 is the duration of the initial synchronization time slot, and t3 is the total duration of all beams used by the master node to receive RTT acquisition information.

[0016] Optionally, in step S4, the slave node randomly selects two time slot units in its RTT time slot and sends RTT capture information and RTT request messages in the RTT capture time slot and RTT request time slot of the two time slot units, respectively.

[0017] Optionally, the RTT request message includes: the MAC address and location information of the prospective slave node; the RTT response message includes: the MAC address of the master node, the MAC address of the prospective slave node parsed from the prospective slave node's RTT request message, the location information of the master node, the node number assigned to the prospective slave node, and the arrival time TOAI of the prospective slave node's RTT request message; the arrival time TOAI is: the duration from the start time of the master node's RTT capture time slot to the time when the master node receives the RTT request message.

[0018] Optionally, in step S6, performing fine synchronization includes:

[0019] S61. Prepare to calculate the arrival time TOAR of the RTT response message from the node; the arrival time TOAR is: the duration from the start time of the RTT capture time slot of the node to the time when the node receives the RTT response message.

[0020] S62. Based on the arrival time TOAR, the synchronization time error t with the master node is calculated using the arrival time TOAI.

[0021] t = (Td + TOAI - TOAR) / 2, where Td is the duration from the start of the RTT capture time slot to the start of the RTT response time slot;

[0022] S63. If t is greater than 0, the slave node will advance the clock by the time offset t; if t is less than 0, the slave node will slow down the clock by the time offset |t|; if t equals 0, the slave node's clock does not need to be adjusted.

[0023] Optionally, after receiving the initial acquisition information, the candidate slave node updates the direction of its fixed beam in real time according to its own attitude information, so that the fixed beam always points to the master node; after receiving the position information of the candidate slave node, the master node updates the direction of the beam it sends to the candidate slave node in real time according to its own attitude information, so that the sent beam always points to the corresponding candidate slave node.

[0024] Compared with existing technologies, the beneficial effects of the ultra-long-range wireless ad hoc network node fast access method of the present invention are as follows:

[0025] To reduce the time required for directional narrow-beam communication, the wireless ad hoc network of this invention uses information-free spreading codes for communication between nodes. This invention performs beam alignment based on spreading code acquisition, enabling communication connections to be established even without knowing the locations of the communicating parties. This invention allows nodes to quickly and autonomously access the wireless ad hoc network while ensuring robust wireless communication relationships between nodes. Furthermore, this invention enables directional transmission of wireless data communication between nodes, increasing transmission distance while shortening transmission time. Attached Figure Description

[0026] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings in the following description are one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0027] Figure 1 In an embodiment of the present invention, when the number of network nodes is less than the planned number of nodes, the time slot partitioning diagram within the working cycle of the master node is shown.

[0028] Figure 2 This is a flowchart of the method for rapid access of ultra-long-distance wireless self-organizing network nodes according to the present invention;

[0029] Figure 3 This is a flowchart illustrating how a network access node connects to a wireless ad hoc network, as described in this embodiment of the invention.

[0030] Figure 4 This is a schematic diagram of the RTT capture time slots of the master node and the prospective slave node in an embodiment of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0033] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0034] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0035] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrases "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0036] Furthermore, in the description of this application, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] In ad hoc wireless networks, directional communication access protocols are required for ultra-long-distance node access to meet network access sensitivity and access time requirements. Currently, the main methods for node access in ad hoc wireless networks are as follows:

[0038] 1) A method for determining the beam through handshake during beam scanning. However, this method requires network-wide time synchronization and the transmitted frames carry data information, increasing the time required to confirm the beam. 2) A method for long-distance communication networking consisting of a linear network composed of several communication nodes connected in series. However, this networking method requires linear transmission between nodes, resulting in low data transmission efficiency. 3) A method for multiple access in distributed aircraft networks under directional antenna conditions. However, the access of a new node in this method requires the ground station to inject information into the network nodes for scanning, increasing node redundancy. 4) A node access method based on narrow beam directional antennas. Narrow beam directional antennas offer advantages such as long transmission distance and high spatial reuse. However, when a node joins the network, the master node broadcasts data frames in each beam direction; the longer the distance, the longer the broadcast data frame, thus increasing the network access time. 5) A swarm networking neighbor discovery method based on directional antennas, which improves neighbor discovery efficiency by utilizing common neighbors based on the planning algorithm of the basic scanning method. However, this method requires network-wide external clock synchronization and is not applicable to networks without an external clock.

[0039] This invention provides a method for rapid node access in an ultra-long-range wireless ad hoc network, wherein nodes in the wireless ad hoc network communicate with each other using spreading codes. The wireless ad hoc network in this embodiment is a time-division multiple access network, where the node's working cycle includes multiple time slots, and the node performs corresponding operations in different time slots.

[0040] If the number of network nodes is less than the planned number of nodes, such as Figure 1 As shown, each working cycle of the master node in the network is divided into the following time sequence: initial capture time slot, initial synchronization time slot, RTT time slot, and service time slot.

[0041] If a network node discovers that the number of network-connected nodes has reached the planned number of nodes, the initial capture time slot and the initial synchronization time slot will no longer occupy the master node's working cycle. If a network-connected node experiences a network drop (the number of network-connected nodes has not reached the planned number of nodes), the initial capture time slot and the initial synchronization time slot will be included in the master node's working cycle again. The RTT time slot comprises multiple time slot units, which sequentially include: an RTT capture time slot, an RTT request time slot, and an RTT response time slot.

[0042] Initially, the new node only has an initial capture time slot and an initial synchronization time slot.

[0043] like Figure 2 As shown, the method for rapid access of ultra-long-distance wireless self-organizing network nodes according to the present invention includes the following steps:

[0044] S1. If the number of nodes in the network is less than the planned number of nodes, the main node in the network proceeds to step S2, and the newly joined node proceeds to step S3.

[0045] S2. The master node transmits initial acquisition information in each beam direction through a narrow beam during its initial acquisition time slot; after the initial acquisition time slot ends, the master node enters the initial synchronization time slot and transmits initial synchronization information (spreading code) in each beam direction through a narrow beam; proceed to step S5.

[0046] S3, such as Figure 3 As shown, after the network access node is powered on, it uses a narrow beam to attempt to receive the initial acquisition information in each beam direction. If the initial acquisition information is received in a certain beam direction, the network access node switches to the initial synchronization time slot and attempts to receive the initial synchronization information in that beam direction. If the network access node still does not receive the initial synchronization information by the end of the initial synchronization time slot, the network access node switches to the initial acquisition time slot and repeats step S3. If the network access node receives the initial synchronization information in the initial synchronization time slot, the network access node synchronizes with the master node, uses the network access node as a pre-slave node, and establishes a fixed beam with the master node in that beam direction (the direction in which the initial acquisition information and the initial synchronization information are received), and proceeds to step S4.

[0047] In this embodiment, the network access node attempts to capture initial acquisition information in a certain beam direction. If it fails to capture the information within a set time, it switches to the next beam direction until the initial acquisition information is captured.

[0048] Neither the initial acquisition information nor the initial synchronization information sent by the master node carries any data. The new node acquires the beam direction for wireless communication with the master node by capturing the master node's initial acquisition information (spreading code), enabling directional communication with the master node even without knowing its location.

[0049] In this embodiment, the synchronization between the network-entering node and the master node includes: when the network-entering node receives the initial synchronization information from the master node, the network-entering node synchronizes its current time to the end of the current initial synchronization time slot. For example, if the network-entering node is in the initial synchronization time slot, and the actual time at which the network-entering node received the initial synchronization information is T, and it will take another Δt to end the initial synchronization time slot, then the network-entering node will use T+Δt as its current time. In this invention, the preparing slave node also has such... Figure 1 The RTT time slot is shown in the diagram. The purpose of synchronizing the incoming node with the master node is to enable the incoming node to become a ready slave node and enter the RTT time slot as soon as possible. Therefore, the maximum time difference between the ready slave node and the master node is the duration of one initial synchronization time slot.

[0050] In this embodiment, the slave node also updates the direction of its fixed beam in real time based on its own attitude information, so that the fixed beam always points to the master node, ensuring the robustness of communication.

[0051] S4, such as Figure 3 As shown, the preparatory slave node enters the RTT acquisition time slot and sends RTT acquisition information (spreading code) based on the fixed beam (narrow beam); after the RTT acquisition time slot ends, the preparatory slave node enters the RTT request time slot and sends an RTT request message; after the RTT request time slot ends, proceed to step S6.

[0052] In this invention, the master node obtains the beam direction for wireless communication with the prospective slave node based on the RTT capture information received from the prospective slave node, and performs directional communication with the prospective slave node without knowing its location.

[0053] In this embodiment, the prospective slave node randomly selects two time slot units within its RTT time slot and sends RTT capture information and RTT request messages in the RTT capture time slot and RTT request time slot of the two time slot units, respectively. This is to prevent two prospective slave nodes from simultaneously sending their respective RTT capture information in the same RTT capture time slot or simultaneously sending their respective RTT request messages in the same RTT request time slot.

[0054] The RTT request message in this embodiment includes: the MAC address and location information of the intended slave node.

[0055] S5. After the initial synchronization time slot ends, the master node enters the RTT time slot. In the multiple RTT acquisition time slots of its RTT time slot, the master node attempts to receive the RTT acquisition information in each beam direction. When the master node receives the RTT acquisition information, it immediately switches to the RTT request time slot and attempts to receive the RTT request message. After the master node's RTT request time slot ends, it proceeds to step S6.

[0056] The new node acquires the master node's beam during the initial acquisition time slot and synchronizes with the master node during the initial synchronization time slot. However, the master node has not yet acquired the beam of the new node (the prospective slave node). Therefore, the master node attempts to acquire RTT acquisition information on various beams using directional radiation during the RTT acquisition time slot. If RTT acquisition information is acquired, the master node obtains the corresponding prospective slave node's beam (but at this time, the master node cannot determine the time difference with the prospective slave node). The master node waits to receive RTT request messages on the acquired beam. After the master node obtains the prospective slave node's location information based on the received RTT request message, the master node updates the direction of the beam it sends to the prospective slave node in real time according to its own attitude information, ensuring that the sent beam always points to the corresponding prospective slave node, thus guaranteeing communication robustness.

[0057] It should be noted that, since the network-entering node synchronized with the master node in step S3, as follows: Figure 4 As shown, when a slave node prepares to enter its RTT acquisition time slot, the master node may still be in its initial synchronization time slot. To ensure that the master node can receive the RTT acquisition information (sent by the slave node) in its RTT acquisition time slot, let t1 be the duration of the master node's RTT acquisition time slot, t1 = t2 + t3; where t2 is the duration of the initial synchronization time slot, and t3 is the total duration of all beams used by the master node to receive the RTT acquisition information.

[0058] S6. The master node enters the RTT response time slot and sends an RTT response message; the corresponding slave node performs fine synchronization with the master node based on the received RTT response message; such as Figure 3 As shown, the node to be prepared becomes a slave node and completes network access.

[0059] The master node sends an RTT response message in its RTT response time slot. The prospective slave node receives the RTT response message sent by the master node in its RTT response time slot. The RTT response message includes: the master node's MAC address (source address), the prospective slave node's MAC address (destination address) parsed from the prospective slave node's RTT request message, the master node's location information, the node number assigned to the prospective slave node, and the arrival time (TOAI) of the prospective slave node's RTT request message to the master node. The arrival time (TOAI) is the duration from the start time of the master node's RTT capture time slot to the time the master node receives the RTT request message.

[0060] If the destination address in the RTT response message received by the prepared slave node (only the master node sends RTT response messages) is the MAC address of the prepared slave node, then the prepared slave node acts as a slave node and caches the master node's location information, the assigned node number, calculates the arrival time (TOAR) of the RTT response message, and the master node's MAC address.

[0061] Because the master node immediately switches to the RTT request slot after receiving the RTT capture information, the boundary between the master node's RTT capture slot and RTT request slot becomes blurred. Therefore, the slave node starts sending the master node's RTT capture slot at the start time of calculating the Time of Arrival (TOAR), rather than at the start time of sending the master node's RTT request slot.

[0062] In this embodiment, preparing for fine synchronization (clock adjustment) between the slave node and the master node includes:

[0063] S61. Prepare to calculate the arrival time (TOAR) of the RTT response message from the slave node; the arrival time (TOAR) is the duration from the start time of the slave node's RTT capture time slot to the time when the slave node receives the RTT response message.

[0064] S62. Calculate the synchronization time error t with the master node based on arrival time TOAR and arrival time TOAI;

[0065] t = (Td + TOAI - TOAR) / 2, where Td is the duration from the start of the RTT capture time slot to the start of the RTT response time slot;

[0066] S63. If t is greater than 0, the slave node will advance the clock by the time offset t; if t is less than 0, the slave node will slow down the clock by the time offset |t|; if t equals 0, the slave node's clock does not need to be adjusted.

[0067] S7. On-network nodes (including master nodes and slave nodes) send service data in service time slots. The service data includes the location information of the on-network node itself, as well as the location information and MAC addresses of all slave nodes stored by the on-network node.

[0068] Slave nodes passing through the RTT (Round-Trip Time) slot can only obtain the location information of the master node and cannot communicate with other networked slave nodes. The master node, however, can obtain the location information of all networked slave nodes through the RTT slot. In one embodiment, to enable communication between networked nodes, the master node sends service data in the service slot carrying the location information of all its cached slave nodes. Simultaneously, when a networked slave node sends service data in the service slot, it also sends its own location information, as well as the location information of all its cached slave nodes.

[0069] Whether an existing slave node only needs a service time slot can be analyzed based on specific circumstances. In one embodiment, if the location update rate requirement is not high, the slave node can also enter the initial capture time slot. In another embodiment, if the location update rate requirement is high, the slave node may not need to enter the initial capture time slot.

[0070] The purpose of RTT time slots is time synchronization, specifically aligning the clocks of the master and slave nodes. As time progresses, the time between the master and slave nodes drifts, necessitating constant time synchronization; therefore, RTT time slots for slave nodes remain essential. The purpose of RTT capture time slots is to allow the master node to obtain the beam pointing of the slave nodes. Once the master node obtains the slave node's location, it can calculate the beam pointing from that location, eliminating the need for RTT capture time slots. Therefore, RTT capture time slots corresponding to existing slave nodes can be reused. In the reused RTT capture time slots, the master node transmits all cached slave node location information to each slave node.

[0071] The ultra-long-range wireless ad hoc network node rapid access method of this invention is based on beam alignment through spreading code acquisition, enabling the establishment of communication links even without knowing the locations of the communicating parties. This invention allows nodes to quickly and autonomously access the wireless ad hoc network while ensuring robust wireless communication relationships between nodes. Furthermore, this invention enables directional transmission of wireless data communication between nodes, increasing transmission distance while shortening transmission time.

[0072] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0073] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for rapid access of nodes in an ultra-long-range wireless ad hoc network, wherein nodes in the wireless ad hoc network communicate using spreading codes, characterized in that... The method includes the following steps: S1. If the number of nodes in the network is less than the planned number of nodes, the main node in the network proceeds to step S2, and the newly joined node proceeds to step S3. S2. The master node sends initial acquisition information in each beam direction during the initial acquisition time slot; after the initial acquisition time slot ends, the master node enters the initial synchronization time slot and sends initial synchronization information in each beam direction. Proceed to step S5; S3. After the network node is powered on, it attempts to receive the initial acquisition information in each beam direction; If initial acquisition information is received in a certain beam direction, the network access node enters the initial synchronization time slot and attempts to receive the initial synchronization information in that beam direction; if the initial synchronization information is received, the network access node synchronizes with the master node as a preparatory slave node and establishes a fixed beam in that beam direction. Proceed to step S4; S4. The preparatory slave node enters the RTT acquisition time slot and sends RTT acquisition information based on the fixed beam; after the RTT acquisition time slot ends, the preparatory slave node enters the RTT request time slot and sends an RTT request message; after the RTT request time slot ends, proceed to step S6. S5. After the initial synchronization time slot ends, the master node enters the RTT time slot. In the multiple RTT acquisition time slots of its RTT time slot, the master node attempts to receive the RTT acquisition information in each beam direction. When the master node receives the RTT acquisition information, it immediately switches to the RTT request time slot and attempts to receive the RTT request message. After the RTT request time slot ends, it proceeds to step S6. S6. The master node enters the RTT response time slot and sends an RTT response message in a targeted manner; the corresponding slave node performs fine synchronization with the master node based on the received RTT response message; Prepare to become a slave node and complete network access.

2. The method for rapid access of ultra-long-range wireless self-organizing network nodes as described in claim 1, characterized in that, It also includes: step S7, where the master node and the slave node enter the service time slot, and the master node sends the location information and MAC address of other slave nodes stored in the master node to the slave node.

3. The method for rapid access of ultra-long-distance wireless self-organizing network nodes as described in claim 1, characterized in that, The master node, slave node, and prospective slave node all transmit and receive information via a narrow beam.

4. The method for rapid access of ultra-long-distance wireless self-organizing network nodes as described in claim 1, characterized in that, The synchronization with the master node in step S3 includes: when the network entry node receives the initial synchronization information from the master node, the network entry node synchronizes its own time to the end of the current initial synchronization time slot.

5. The method for rapid access of ultra-long-distance wireless self-organizing network nodes as described in claim 1, characterized in that, The RTT time slot contains multiple time slot units, which sequentially include: RTT capture time slot, RTT request time slot, and RTT response time slot; the slave node prepares to send RTT capture information in its RTT capture time slot, and the master node receives the RTT capture information sent by the slave node in its RTT capture time slot; The slave node prepares to send an RTT request message in its RTT request time slot, and the master node receives the RTT request message sent by the slave node in its RTT request time slot; the master node sends an RTT response message in its RTT response time slot, and the slave node prepares to receive the RTT response message sent by the master node in its RTT response time slot.

6. The method for rapid access of ultra-long-range wireless self-organizing network nodes as described in claim 1, characterized in that, Let t1 be the duration of the RTT acquisition time slot of the master node, t1 = t2 + t3; where t2 is the duration of the initial synchronization time slot, and t3 is the total duration of all beams used by the master node to receive RTT acquisition information.

7. The method for rapid access of ultra-long-range wireless self-organizing network nodes as described in claim 5, characterized in that, In step S4, the slave node randomly selects two time slot units in its RTT time slot and sends RTT capture information and RTT request messages in the RTT capture time slot and RTT request time slot of the two time slot units respectively.

8. The method for rapid access of ultra-long-range wireless self-organizing network nodes as described in claim 1, characterized in that, The RTT request message includes: the MAC address and location information of the prospective slave node; the RTT response message includes: the MAC address of the master node, the MAC address of the prospective slave node parsed from the prospective slave node's RTT request message, the location information of the master node, the node number assigned to the prospective slave node, and the arrival time TOAI of the prospective slave node's RTT request message; the arrival time TOAI is: the duration from the start time of the master node's RTT capture time slot to the time when the master node receives the RTT request message.

9. The method for rapid access of ultra-long-range wireless self-organizing network nodes as described in claim 8, characterized in that, In step S6, the precise synchronization includes: S61. Prepare to calculate the arrival time TOAR of the RTT response message from the node; the arrival time TOAR is: the duration from the start time of the RTT capture time slot of the node to the time when the node receives the RTT response message. S62. Based on the arrival time TOAR, the synchronization time error t with the master node is calculated using the arrival time TOAI. t=(Td+TOAI-TOAR) / 2, where Td is the duration from the start of the RTT capture time slot to the start of the RTT response time slot; S63. If t is greater than 0, then advance the clock by the offset t from the node. If t is less than 0, the slave node will slow down its clock by the time offset by |t|; if t is equal to 0, the slave node's clock does not need to be adjusted.

10. The method for rapid access of ultra-long-range wireless self-organizing network nodes as described in claim 8, characterized in that, Upon receiving the initial acquisition information, the candidate slave node updates the direction of its fixed beam in real time based on its own attitude information, ensuring that the fixed beam always points to the master node; upon receiving the position information of the candidate slave node, the master node updates the direction of the beam it sends to the candidate slave node in real time based on its own attitude information, ensuring that the sent beam always points to the corresponding candidate slave node.

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