Ad hoc network construction method and system based on double radio frequencies and Beacon custom broadcast

Abstract

The ad hoc network construction method based on double radio frequencies and Beacon custom broadcast is based on networking communication equipment, the equipment is provided with two sets of independent radio frequency modules, and one set of radio frequency module is configured to be in an STA mode; the other set of radio frequency module is configured as an AP; in the ad hoc network construction process, a plurality of networking devices diverge working channels of respective AP mode radio frequency modules through a negotiation mechanism, and after the working channels are determined, channel information to be used by the networking devices is packaged in a detection request frame to be sent; after the other AP equipment receives the channel selection information, the channel selection process is executed as well; and Beacon custom broadcasting and networking: the AP mode radio frequency module broadcasts the AP information connected with the current equipment in the STA mode through the custom information part in the sent Beacon frame, and the AP mode radio frequency module in the networking equipment broadcasts the AP information connected with the current equipment in the STA mode through the custom information part in the sent Beacon frame.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication networks, in particular to a self-organizing network construction method and system based on dual radio frequency and Beacon self-defined broadcast, and is especially suitable for emergency communication, industrial Internet of Things, mobile ad hoc network and the like. BACKGROUND

[0002] In the existing wireless self-organizing network technology, a device usually only has a single wireless communication mode, that is, either as an access point (AP) to provide network access services for other devices or as a station (STA) to access other APs. This single mode limits the networking flexibility and adaptability of the device in a complex network environment. At the same time, the traditional self-organizing network mostly adopts single-channel communication, while the use of multiple channels can fully utilize frequency resources and improve network concurrency capability, but in actual application, it faces serious challenges in relay transmission. When multiple devices use different channels for relay transmission, signals are prone to interference between them, resulting in serious bandwidth loss and greatly reducing network communication quality and transmission efficiency.

[0003] In the networking process, the connection selection between devices is mainly based on conventional factors such as signal strength, and lacks comprehensive consideration of key information such as device connection state. In addition, the existing technology rarely includes the positioning information of the device itself in the network topology optimization, making it difficult to achieve efficient and stable construction of the network topology and unable to fully meet the network demand in complex and variable scenarios. Therefore, a new self-organizing network construction technology is urgently needed to improve the flexibility, stability and communication efficiency of the network. In order to solve the many problems existing in the current wireless self-organizing network technology, the present application innovates from the aspects of device hardware architecture, communication mechanism and network topology optimization, and proposes a self-organizing network construction method and system based on dual radio frequency and Beacon self-defined broadcast.

[0004] Single-channel self-organizing network has a non-centralized architecture, all nodes are equal, have terminal and routing functions, and do not need infrastructure support, and directly communicate through a single shared channel. Advantages: flexible deployment, suitable for emergency communication or dynamic environment (such as vehicle-mounted network). Disadvantages: intense competition for channel resources, easy to cause data conflict and delay; comparison between STA and AP modes: STA mode (Station mode), definition: the device acts as a wireless terminal client, connects the wireless network created by the existing AP, for example, a mobile phone connects a router WiFi36.

[0005] Functional characteristics: dependent on AP to provide network access, without independent networking capability; supports automatic reconnection of saved AP nodes, suitable for mobile scenarios.

[0006] AP mode (Access Point mode): the device acts as a wireless access point, creates an independent network and manages connected STA devices, such as a router opening a WiFi hotspot.

[0007] Functional characteristics: broadcast SSID and assign IP address, support multi-STA access (default upper limit about 20-30 nodes); have wired network expansion capability (such as connecting to the Internet through Ethernet). SUMMARY

[0008] The purpose of the present application is to provide a self-organizing network construction method and system based on dual radio frequency and Beacon custom broadcast, which realizes reasonable allocation of channels between multiple devices, optimizes device connection selection, constructs efficient and stable self-organizing network topology, and improves the adaptability and communication performance of the network in complex environments through the dual radio frequency function of the device, Beacon frame custom broadcast and the combination of positioning information.

[0009] The technical solution of the present application is a self-organizing network construction method based on dual radio frequency and Beacon custom broadcast, based on the following network communication device, the device is equipped with two independent radio frequency modules, one of which is configured as STA mode for connecting external AP to obtain network resources; the other radio frequency module is configured as AP mode for providing network access service for other devices, so that the device has the dual role of access and service provider;

[0010] Channel allocation method: in the process of self-organizing network construction, multiple network devices diverge the working channels of their AP mode radio frequency modules through negotiation mechanism, the process is as follows: scan the AP of the surrounding autonomous network, if an AP is detected, get the list of surrounding AP working channels, and judge whether there is an idle channel; if no AP is detected, randomly select a channel as the working channel; in the initialization stage, the device determines the working channel through the above process, and encapsulates the channel information to be used in the probe request frame and sends it; after receiving, other AP devices also execute the above channel selection process, so as to avoid same frequency interference and improve network communication quality;

[0011] Beacon custom broadcast and network organization: the AP mode radio frequency module in the network organization device broadcasts the AP information connected by the STA mode of the current device in the Beacon frame through the custom information part, including the identification and signal strength of the AP; the STA mode of other network organization devices evaluates the distance according to the connection information in the received Beacon frame combined with the signal strength, the specific process is as follows:

[0012] Judging whether the Beacon frame signal strength is higher than the threshold value, and judging whether there are multiple APs meeting the conditions: if yes, selecting an AP connection according to the self-defined strategy such as load balancing, if not, directly selecting an AP connection, completing the ad hoc network networking connection, and constructing the network topology.

[0013] When other devices comprehensively evaluate and select a suitable AP for connection, the signal strength threshold value is set, and the AP with signal strength higher than the threshold value and stable connection quality is preferentially selected. If multiple APs meet the conditions, the selection is made according to the self-defined connection strategy (such as load balancing strategy), so as to realize the networking connection of the ad hoc network and construct the network topology. After the networking device calculates and evaluates the distance, it will preliminarily screen out potential connection objects according to the evaluation results, and further comprehensively sort the screening results considering the load condition and connection capacity of the device itself, so as to provide more accurate basis for subsequent connection selection. After completing the preliminary screening and sorting, the device will also dynamically adjust the connection strategy according to the overall load condition of the network.

[0014] For the AP with excessive load, other devices will reduce the priority of connection therewith, and guide the flow to be transferred to the AP with lighter load, so as to further guarantee the balanced operation and efficient transmission of the network.

[0015] Topology optimization based on positioning information: when the device has positioning function, the positioning information (such as latitude and longitude coordinates, altitude, etc.) of the device is added to the self-defined information part of the Beacon frame for broadcasting. After other devices receive the Beacon frame containing the positioning information, the topology optimization algorithm is executed according to the following steps:

[0016] 1. Distance calculation: the distance between terminals is calculated through the latitude and longitude information of the device

[0017] 2. Path analysis: traverse the current network topology to obtain the connection path established between devices, and count the hop number and bandwidth utilization of each path.

[0018] 3. Optimization judgment: according to the path distance and communication hop number of the network topology, it is calculated whether there is an optimization update

[0019] Connection

[0020] 4. Connection request: for the device meeting the optimization condition, a new connection is initiated to connect a new AP

[0021] 5. Stability verification: after the new connection is established, the network delay, packet loss rate and other indicators are continuously monitored, and if the performance decreases, the connection is rolled back.

[0022] Beneficial effects: the radio unit 1 (STA mode) accesses the external wireless network as a client, and the radio unit 2 (AP mode) creates a local wireless network as a hotspot for other devices to access; an "external network Two-way data channel for local devices; dynamic switching and parallel processing of network roles are achieved;

[0023] 1. Wireless relay extension

[0024] STA radio connects to the main router to obtain network signals, and AP radio rebroadcasts the signals, solving the problem of insufficient coverage of a single router (such as large-scale residential buildings and factory buildings). At this time, the module essentially plays the role of a signal amplifier.

[0025] 2. Industrial Internet of Things gateway

[0026] o STA radio accesses enterprise intranet / cloud platform to transmit data;

[0027] o AP radio establishes a local group device subnet (such as connecting sensors and PLC controllers) to achieve centralized management and control of devices.

[0028] Remote upload after local aggregation of data reduces network complexity.

[0029] 3. Multimedia collaboration system

[0030] Technical advantages

[0031] Zero switching delay: two radios work independently, STA connection maintenance and AP service provision do not interfere with each other;

[0032] Load balancing: external network access traffic is handled through the STA channel, and intranet data exchange is handled by the AP channel, optimizing throughput efficiency;

[0033] Flexible topology: single / dual mode can be configured through software to adapt to different deployment needs.

[0034] Expansion explanation: under the AP+STA hybrid architecture, the module needs to have dual-frequency concurrent capability (such as 2.4GHz+5GHz) to avoid same-frequency interference and improve concurrent capacity. Typical representatives include industrial Internet of Things gateway ESP8266 dual-frequency module

[0035] Beacon custom broadcast function allows devices to send specific format data packets through BLE protocol, supporting multi-device intelligent filtering (by MAC / RSSI, etc.); typical application scenarios include indoor positioning (error 1-3 meters), retail push, and WeChat check-in; can be used in low-power applications, etc.

[0036] (Three) beneficial effects

[0037] 1. Improve network flexibility: the dual-radio design of the device enables it to assume both STA and AP roles, allowing flexible switching in different network environments, enhancing the device's adaptability in ad hoc networks, and meeting diverse network needs.

[0038] 2. Reduce channel interference: through the channel negotiation mechanism between devices, the working channels of AP mode are diverged, effectively avoiding co-channel interference, improving the spectrum utilization and communication stability of the network, and reducing the data transmission error rate.

[0039] 3. Optimize connection selection: based on the device connection information and signal strength broadcasted by the Beacon frame, the device can more comprehensively and accurately evaluate the connectable APs, select the optimal connection object, and improve the network connection quality and data transmission efficiency.

[0040] 4. Implement intelligent topology optimization: combine device positioning information to optimize network topology, make network connection more consistent with physical reality, reduce invalid connections and redundant paths, improve the overall performance and reliability of the network, especially suitable for complex scenarios that require dynamic adjustment of topology structure. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The specific process of the present application in the self-organizing network construction process, multiple devices diverge the working channels of their AP mode radio frequency modules through negotiation mechanism;

[0042] Figure 2 The specific process of the present application in the self-organizing network construction process, multiple devices diverge the working channels of their AP mode radio frequency modules through negotiation mechanism;

[0043] Figure 3 The specific process of the present application in the self-organizing network construction process, multiple devices diverge the working channels of their AP mode radio frequency modules through negotiation mechanism; DETAILED DESCRIPTION

[0044] Hardware architecture: the device involved in the present application is equipped with two independent radio frequency modules, one of which is configured as STA mode, used to connect external AP to obtain network resources; the other radio frequency module is configured as AP mode, used to provide network access service for other devices, so that the device has the dual role of access and service provider. The two independent radio frequency modules of the present application are completely independent and have the same function, and can work in different channels of the same frequency band at the same time, so when the AP of the device works in a certain frequency band, the STA can select other frequency bands or other channels of the same frequency band, fully utilizing the channel resources

[0045] Channel allocation method: in the self-organizing network construction process, multiple devices diverge the working channels of their AP mode radio frequency modules through negotiation mechanism, the specific process is as follows Figure 1 :

[0046] The device encapsulates the channel information to be used in the detection request frame and sends it after determining the working channel through the above process in the initialization stage. Other devices receive it and also execute the above channel selection process, thereby avoiding co-frequency interference and improving network communication quality.

[0047] Beacon custom broadcast and networking: the Beacon frame belongs to the management frame and is used for broadcasting network information (such as SSID, encryption mode, etc.). In a dual-radio environment: the radio of the AP is responsible for sending the Beacon frame by default. In the present application, the AP mode radio module of the device includes the information of the AP connected by the STA mode of the current device in the Beacon frame, in addition to the general information, and also broadcasts the custom information part, including the identification and signal strength of the AP. The STA mode of other devices can construct the topology of the ad hoc network according to the connection information in the received Beacon frame, and the specific process is as follows Figure 2 :

[0048] Other devices comprehensively evaluate and select the appropriate AP for connection, set a signal strength threshold, and preferentially select the AP with a signal strength higher than the threshold and stable connection quality. If multiple APs meet the conditions, the selection is made according to the custom connection strategy (such as the load balancing strategy), thereby realizing the networking connection of the ad hoc network and constructing the network topology. When there are multiple selectable APs, different selection strategies can be developed, and the AP selection strategy is as follows:

[0049] 1. First, create the topology data of the current network according to the STA connection AP information in the Beacon frame of each AP;

[0050] 2. According to the topology data, select the AP that can guarantee the reduction of the number of networks after connection. If all the selections cannot reduce the number of networks, all the APs that meet the conditions are added to the candidate;

[0051] 3. Sort the signals of the selectable APs. The stronger the signal, the higher the score;

[0052] 4. If the load balancing strategy is enabled, sort the number of connected STAs of the selected APs. The more the connected STAs, the lower the score, otherwise the scores are the same;

[0053] 5. According to the proportion strategy of signal and load balancing, calculate the various scores in proportion and add them up;

[0054] 6. Select the AP with the highest final calculation score for connection;

[0055] After the initial screening and sorting, the device will also dynamically adjust the connection strategy according to the overall load of the network. For APs with excessive load, other devices will reduce the priority of connecting to them, guiding the flow to APs with lighter load, further ensuring the balanced operation and efficient transmission of the network.

[0056] Topology optimization based on positioning information: When the device has positioning function, add its positioning information (such as latitude and longitude coordinates, altitude, etc.) to the custom information part of the Beacon frame for broadcast. After receiving the Beacon frame containing positioning information, other devices execute the topology optimization algorithm according to the following steps: Figure 3 ):

[0057] 1. Distance calculation: Calculate the spherical distance between the receiving device and the broadcasting device by Haversine formula, public

[0058] formula:

[0059]

[0060] Where lat1,lon1 is the latitude and longitude of device 1, lat2,lon2 is the latitude and longitude of device 2, and R is the average radius of the earth;

[0061] 2. Path analysis: Traverse the current network topology to obtain the established connection paths between devices, and count the number of hops and bandwidth utilization of each path.

[0062] 3. Optimization judgment: Select the device pair with a distance less than the threshold (such as 50 meters) and not directly connected, simulate the network topology after one of the terminal STAs connects to another AP:

[0063] Calculate the number of hops of the new path, if the number of hops is reduced by more than 1 hop, mark it as a potential optimization path;

[0064] Calculate the bandwidth utilization of the new path according to the distance, if the utilization rate is improved by more than 10%, it will be included in the optimization candidate.

[0065] The relationship between distance and bandwidth utilization can be calculated using the following table, M1-M9 in the table can be measured by actual transmission in engineering, when d<=M1, bandwidth utilization is 100%, when M1<d<=M2, bandwidth utilization is 90%, and so on

[0066] Distance Bandwidth utilization M1 100％ M2 90％ …… M9 10％

[0067] 4. Connection request: For devices that meet the optimization conditions, initiate a new connection, and update the network topology after connection

[0068] 5. Stability verification: after the establishment of a new connection, continuously monitor network delay, packet loss rate and other indicators, and if performance decreases, roll back the connection.

[0069] Through the above-mentioned channel allocation, Beacon self-defined broadcast networking and topology optimization based on positioning information and a series of technical means, the application forms a complete ad hoc network construction scheme, each link closely cooperates, and comprehensively improves the network performance.

[0070] Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and modifications to the above-mentioned embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A method for constructing an ad hoc network based on dual radio frequency and Beacon custom broadcast, characterized in that: Based on the following networking communication equipment, the device is equipped with two independent radio frequency modules. One radio frequency module is configured in STA mode to connect to an external AP to obtain network resources; the other radio frequency module is configured in AP mode to provide network access services to other devices, enabling the device to play the dual role of access provider and service provider. The two radio frequency sets are completely independent and can work simultaneously on the same frequency band and different channels; Channel allocation method: During the ad hoc network construction process, multiple networking devices negotiate to choose the operating channels of their AP-mode radio modules. The process is as follows: The device scans for nearby APs in the ad hoc network. If an AP is detected, the device obtains a list of nearby AP operating channels and determines whether there are any idle channels. If no AP is detected, the device randomly selects a channel as the operating channel. During the initialization phase, after determining the working channel through the above process, the device encapsulates the channel information it intends to use in a probe request frame and sends it; After receiving the signal, other AP devices also perform the above channel selection process to avoid co-channel interference and improve network communication quality. Beacon custom broadcast and networking: The AP mode radio module in the networking device broadcasts the AP information of the current device in STA mode, including the AP ID and signal strength, through the custom information part in the Beacon frame sent; STA mode devices on other organizations' networks use the connection information in the received Beacon frames and the signal strength to calculate the distance. The specific process is as follows: Determine whether the Beacon frame signal strength is higher than the threshold and whether there are multiple APs that meet the conditions: If so, complete the network topology construction based on the STA connection information in the Beacon, and select an AP to connect to through custom strategies such as load balancing. Otherwise, directly select an AP to connect to complete the self-organizing network connection and build the network topology.

2. The method for constructing an ad hoc network based on dual radio frequency and Beacon custom broadcast according to claim 1, wherein: When other devices comprehensively evaluate and select the appropriate AP for connection, they set a signal strength threshold and give priority to APs with signal strength higher than the threshold and stable connection quality. If multiple APs meet the conditions, they are selected according to the custom connection strategy, thus achieving self-organizing network connection and building network topology; After calculating the evaluation distance, the networking device will preliminarily screen potential connection targets based on the evaluation results. Taking into account the device's own load and connection capabilities, the device will further comprehensively sort the screening results to provide a more accurate basis for subsequent connection selection. After completing the initial screening and sorting, the device will also dynamically adjust the connection strategy based on the overall network load. For APs that are overloaded, other devices will lower their connection priority and guide traffic to APs with lighter loads, further ensuring balanced operation and efficient transmission of the network.

3. The method for constructing an ad hoc network based on dual radio frequency and Beacon custom broadcast according to claim 1, wherein: Topology optimization based on positioning information: When a device has positioning capabilities, it adds its own positioning information, including latitude and longitude coordinates and altitude, to the custom information section of the Beacon frame for broadcast. After other devices receive the Beacon frame containing positioning information, they execute the topology optimization algorithm according to the following steps: 3-1. Distance Calculation: The spherical distance between the receiving device and the broadcasting device is calculated using the Haversine formula. The Haversine formula is a mathematical model used to calculate the great circle distance between two points on the Earth's surface. It is suitable for scenarios requiring high precision, such as navigation and geographic information systems. The formula is: Where lat1, lon1 are the latitude and longitude of device 1, lat2, lon2 are the latitude and longitude of device 2, and R is the average radius of the earth; 3-2. Path analysis: traverse the current network topology, obtain the established connection paths between devices, and count the number of hops and bandwidth utilization of each path. 3-3. Optimization judgment: Filter out device pairs whose distance is less than the threshold and are not directly connected, and simulate the network topology after connection: Calculate the number of hops on the new path. If the number of hops is reduced by more than 1, mark it as a potential optimized path. Calculate the bandwidth utilization of the new path. If the utilization rate increases by more than 10%, the path is included in the optimization candidate. 3-4. Connection Request: For device pairs that meet the optimization criteria, the device with the stronger signal strength initiates the connection request. After both parties confirm, the network topology is updated. 3-5. Stability verification: After a new connection is established, continuously monitor network latency, packet loss rate, and other indicators. If performance degrades, roll back the connection.

Images