Wireless network coverage method

Abstract

The invention relates to a wireless network coverage method. The technologies of AP fixed point directional coverage, a dual-polarization intelligent antenna, MESH networking and the like are creatively fused. The method comprises the following steps: 1) deploying a plurality of fixed AP sites in a mining area, and configuring a directional antenna to cover the whole operation area; 2) installing a dual-polarization intelligent antenna system on a mobile device, transmitting and receiving data through dual polarization, and obtaining the position and orientation of the device by using a GPS and an attitude sensor; (3) the controller operates an algorithm, adjusts the antenna beam direction in real time, and keeps an optimal signal with the nearest AP site; 4) adopting WLAN MESH networking, selecting a nearest node with the strongest signal as a father node by a mobile node to establish a link, and realizing wireless full coverage through multi-hop forwarding; and 5) the AP station evaluates the service quality of the mobile node, optimizes the MESH link, and ensures the network reliability and time delay. According to the method, global dynamic coverage of the mining area is realized on the basis of limited fixed stations, and the high-standard requirement of key services of the mining area on a network is met.

Description

Technical Field

[0001] The invention belongs to the technical field of mining engineering and wireless communication, and in particular relates to a wireless network coverage method. Background Art

[0002] For environments with complex and changeable terrain and harsh working environments, such as open-pit mines, the planning and deployment of wireless communication networks pose great challenges. At present, the wireless communication solutions commonly used in open-pit mines are mainly the following: 1) Public network 4G / 5G cellular solution. This solution rents the operator's public network cellular base stations to cover the mining area, which is flexible to deploy, but the battery life is expensive. At the same time, public network base stations are mainly deployed outside the mining area, making it difficult to achieve reliable coverage inside the mine. 2) Self-built 4G / 5G private network solution. The mining area builds its own 4G / 5G base stations and core networks, which can be flexibly deployed, dedicated networks, and enhanced coverage and capacity. However, the application and approval process for private network frequency resources is complicated, the number of base stations is large, and the network construction and operation and maintenance costs are high.

[0003] 3) Wi-Fi bridge solution. Root APs are deployed at the edge of the mining area to introduce signals into the mining area and expand coverage through Wi-Fi bridges. This solution uses unlicensed frequency bands, has flexible networking, and low construction costs, but is limited by the coverage radius of Wi-Fi and requires the deployment of a large number of bridge nodes, which limits reliability and capacity. 4) Wireless MESH self-organizing network solution. The network coverage is dynamically expanded between mobile device nodes through a multi-hop forwarding MESH networking method. This solution has the advantages of self-healing and self-configuration, and has high networking flexibility, but the multi-hop forwarding delay is large and the throughput is limited.

[0004] In summary, traditional wireless communication solutions are difficult to take into account the requirements of coverage, capacity, and reliability in complex environments such as open-pit mines with large areas, deep scenes, and high dynamics. There is an urgent need for a new economical and efficient wireless network solution. In response to the pain points of wireless coverage in the above-mentioned mining areas, the present invention innovatively proposes a wireless network coverage method. This method cleverly combines technologies such as AP fixed-point directional coverage, dual-polarization smart antennas, and MESH networking. On the basis of limited fixed sites, it achieves full-area dynamic coverage of complex environments, and can meet the high standards of network coverage continuity, mobility, and reliability for key businesses such as production scheduling, video surveillance, and unmanned driving. Summary of the invention

[0005] 1. A wireless network coverage method of the present invention is characterized by comprising the following steps:

[0006] Step 1: Deploy multiple fixed AP sites around and on commanding heights and platforms inside the open-pit mine. Each AP site is equipped with one or more directional antennas to enable directional beams to cover the entire mining area.

[0007] Step 2: Install a dual-polarization smart antenna system on the mobile operating equipment inside the mine area. The system includes a dual-polarization smart antenna array, a GPS positioning module, a posture sensor, a beamforming circuit, and a controller. The dual-polarization antenna simultaneously sends and receives data through two channels, vertical polarization and horizontal polarization, to improve spectrum utilization. The GPS module and posture sensor obtain the three-dimensional position coordinates and orientation angle of the mobile device in real time.

[0008] Step 3: The controller runs an adaptive coverage adjustment algorithm to calculate the distance and angle difference between the mobile device and each fixed AP site in real time, selects the nearest AP site as the service AP, and drives the beamforming circuit to adjust the horizontal and vertical pointing angles of the antenna beam according to the direction of the line pointing from the mobile device to the service AP, so that the antenna beam is continuously aimed at the service AP, thereby maintaining the best signal strength between the mobile device and the service AP when the position and orientation of the mobile device continue to change;

[0009] Step 4: Using WLAN MESH networking technology, after receiving the existence broadcast of other nodes, the mobile device node calculates the distance between nodes, selects the node with the closest distance and the strongest signal as the parent node, and establishes a MESH link with it; when a mobile node cannot directly communicate with any fixed AP site due to occlusion or other reasons, the data is forwarded to the neighboring node through the established MESH link in multiple hops until it reaches the fixed AP site, thereby achieving wireless coverage of the entire operating area of ​​the mine;

[0010] Step 5: The fixed AP site evaluates the signal quality and service quality of each mobile node based on the RSSI value and latency of the uplink data sent by the mobile device nodes, optimizes and adjusts the MESH link, avoids relay nodes with poor quality, and ensures the overall reliability and latency performance of the network.

[0011] The specific design steps of the dual-polarization smart antenna in step 2 are:

[0012] 1) The antenna is mainly composed of a horizontally polarized smart antenna, a vertically polarized smart antenna, a feeding circuit and a control circuit; the horizontally polarized smart antenna and the vertically polarized smart antenna are respectively composed of n units, which are placed on a flat bottom plate and arranged in a circular array to achieve 360° omnidirectional coverage; each horizontally polarized smart antenna and vertically polarized smart antenna unit is a group, which transmits a signal beam to a specific direction with a coverage angle of 360° / n; by switching the switch control circuit, different groups of directional antennas are controlled to carry out network communication.

[0013] 2) n open slot antenna elements perpendicular to the bottom plate are evenly arranged in a ring shape, fixed to the bottom plate through n square openings on the bottom plate; another n open slot antenna elements are evenly arranged in a ring shape, placed above the vertically polarized antenna, parallel to the bottom plate, and fixed above the n vertical open slot antenna elements.

[0014] 3) The feeding control circuit of the horizontally polarized antenna is embedded in the horizontally polarized antenna. The input signal is divided from the center 1 to n and fed to each antenna element through a power divider. The end of the power divider excites the corresponding antenna element through a coupling branch. The feeding circuit of the vertically polarized antenna is made on the back of the base plate. The input signal is divided from the center 1 to n and fed to each antenna element through a power divider. The end of the power divider passes through the metallized hole through the opening on the front of the base plate and is connected to the opening gap of the vertically polarized antenna element.

[0015] 4) The beams in the same direction of the horizontally polarized antenna and the vertically polarized antenna are simultaneously controlled by the switch control circuit. The n groups of antennas are independently controlled. Only one group of antennas works at each moment, and the control circuit controls the feed disconnection of the remaining groups of antennas.

[0016] The specific steps of the adaptive coverage adjustment algorithm in step 3 are:

[0017] 1) The dual-polarized smart antenna system obtains the current three-dimensional position coordinates (x, y, z) and orientation (roll angle, pitch angle, yaw angle) of the mobile device in real time;

[0018] 2) traverse and calculate the three-dimensional distance d[i] and azimuth angle difference φ[i] between the mobile device and each fixed AP site, where i is the AP site number;

[0019] 3) Compare each d[i] and select the AP site with the smallest distance as the serving AP site;

[0020] 4) Taking the line from the mobile device to the service AP site as the target direction of antenna beamforming, calculate the adjustment angles of the antenna beam in the horizontal and vertical planes as follows:

[0021] Δaz[i]=φaz[i]-yaw

[0022] Δel[i]=φel[i]-pitch

[0023] Where φaz[i] and φel[i] are the azimuth and elevation angles of the mobile device pointing to the serving AP site, respectively;

[0024] 5) Drive the antenna beamforming circuit to adjust the pointing angles of the horizontal and vertical beams to align them with the service AP site;

[0025] 6) The above algorithm is repeatedly executed periodically to achieve real-time adaptive adjustment of the antenna beam.

[0026] The specific steps of the WLAN MESH networking algorithm in step 4 are:

[0027] 1) Each mobile device node publishes its own ID, location coordinates, neighbor list and other information to the surrounding by periodically broadcasting Hello frames;

[0028] 2) After receiving the Hello frame from other nodes, the mobile node extracts the node's ID, coordinates and other information, calculates the three-dimensional distance dist between the two nodes, and adds the nodes whose dist is lower than a certain threshold value to the neighbor list;

[0029] 3) The mobile node selects the node with the closest distance and strongest signal as the parent node based on the neighbor list and establishes a MESH link with it;

[0030] 4) If the mobile node cannot communicate directly with any fixed AP site, it sends the data packet to the parent node through the established MESH link, and the parent node continues to forward it to the upper-level neighbor node until a node can directly connect to the fixed AP;

[0031] 5) When the location of the mobile node changes, the signal of the parent node deteriorates, or other reasons cause the need to switch the parent node, repeat the above step 3) to select a new parent node;

[0032] 6) Fixed AP sites periodically send heartbeat frames. Mobile nodes evaluate the current network status and dynamically optimize local MESH routing based on the reception quality of the heartbeat frames from each AP site.

[0033] Advantages of the invention

[0034] A wireless network coverage method of the present invention uses a combination of advanced wireless communication technologies to achieve wireless network coverage; based on high-gain antennas, radio frequency and baseband technologies, it achieves efficient data transmission of mobile devices and solves the high cost problem of 5G base station construction; based on reconfigurable antennas and adaptive coverage adjustment algorithms, it adapts to the requirements of changing open-pit mine excavation depth and mobile device operating position, and solves the problems of unstable communication, high latency and weak roaming capability; based on WLAN MESH technology, it coordinates between mobile devices and conducts self-organizing networks, and neighboring devices provide network relay backhaul for mobile devices in coverage blind spots, solving the problem of base station blind spots. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a schematic diagram of a wireless network coverage system of the present invention. DETAILED DESCRIPTION

[0036] like Figure 1As shown, a schematic diagram of a wireless network coverage system of the present invention is mainly composed of three parts: fixed AP sites, mobile device nodes and wireless backhaul network.

[0037] Fixed AP sites are located at commanding heights and platforms around and inside the mine area, and are connected to the core network of the mine area through optical fiber or microwave links. Each site is equipped with 1-6 directional antennas, working in the 5GHz frequency band, using MIMO technology to improve beamforming gain and directional coverage of a sector area of ​​the mine working surface. The site deployment location, antenna type and configuration parameters have been carefully designed to minimize the total number of sites and reduce investment costs while meeting full coverage requirements. High-speed wireless bridges are used to interconnect sites to build a wireless ring network to achieve backhaul transmission of service traffic and control signaling.

[0038] Mobile equipment nodes include various types of equipment operating inside the mine area, such as electric shovels, drilling rigs, etc. Each device is equipped with an intelligent dual-polarization antenna system, including a dual-polarization intelligent antenna array, beamforming circuits, inertial navigation modules such as accelerometers / gyroscopes, GPS positioning modules, and controllers. When working, the inertial navigation and GPS modules obtain the three-dimensional position and attitude information of the device in real time, call the adaptive coverage algorithm through the controller, calculate the antenna beamforming angle of the device pointing to the nearest fixed AP in real time, drive the beamforming circuit to adjust the direction of the antenna beam, and realize continuous alignment of the beam with the service AP site. It avoids the signal dropout and energy loss caused by the back-and-forth fluctuations of the antenna of traditional equipment, and significantly improves the receiving sensitivity and system capacity of mobile devices.

[0039] In order to solve the problem of blind spots in the mining area that cannot be directly covered by fixed APs, WLAN MESH networking technology is used. When a mobile device cannot communicate directly with any fixed AP site because the current location is in a non-line-of-sight area or there are obstacles blocking it, the data is transmitted to the fixed AP site in multiple hops by establishing a MESH link with other mobile devices, thus achieving seamless wireless coverage of the entire mining area.

[0040] MESH networking is a fully distributed collaborative technology that does not require human intervention and has very good scalability and self-healing capabilities. The algorithm process is as follows: each mobile node publishes its own ID, location coordinates and other information through periodic broadcasting; neighboring nodes collect information about all single-hop reachable nodes, calculate the Euclidean distance to them, and maintain a neighbor table. When data needs to be sent, the neighbor node with the closest distance and the best signal quality is selected as the next-hop forwarding node according to the neighbor table. If the next hop can reach the fixed AP site, it is sent directly; otherwise, multi-hop forwarding continues until the data is continuously delivered to the fixed AP site. At the same time, when the node position changes or the neighbor link condition deteriorates, the algorithm can automatically switch to the new neighbor node to achieve self-repair of the link.

[0041] In summary, the wireless network coverage method proposed in the present invention integrates multiple advanced technologies such as directional coverage, dual-polarization smart antennas, MESH networking, etc., which can maximize the seamless coverage and mobility continuity of any location on the mining work surface, significantly improve the reliability and capacity of the mining area wireless network, and provide a network foundation for the deployment of high-bandwidth and low-latency applications such as video surveillance and unmanned driving.

Claims

1. A wireless network coverage method of the present invention is characterized in that: The steps include: Step 1: Deploy multiple fixed AP sites around and on commanding heights and platforms inside the open-pit mine. Each AP site is equipped with one or more directional antennas to enable directional beams to cover the entire mining area. Step 2: Install a dual-polarization smart antenna system on the mobile operating equipment inside the mine area. The system includes a dual-polarization antenna array, a GPS positioning module, a posture sensor, a beamforming circuit, and a controller. The dual-polarization antenna simultaneously sends and receives data through two channels, vertical polarization and horizontal polarization, to improve spectrum utilization. The GPS module and posture sensor obtain the three-dimensional position coordinates and orientation angle of the mobile device in real time. Step 3: The controller runs an adaptive coverage adjustment algorithm to calculate the distance and angle difference between the mobile device and each fixed AP site in real time, selects the nearest AP site as the service AP, and drives the beamforming circuit to adjust the horizontal and vertical pointing angles of the antenna beam according to the direction of the line pointing from the mobile device to the service AP, so that the antenna beam is continuously aimed at the service AP, thereby maintaining the best signal strength between the mobile device and the service AP when the position and orientation of the mobile device continue to change; Step 4: Using WLAN MESH networking technology, after receiving the existence broadcast of other nodes, the mobile device node calculates the distance between nodes, selects the node with the closest distance and the strongest signal as the parent node, and establishes a MESH link with it; when a mobile node cannot directly communicate with any fixed AP site due to occlusion or other reasons, the data is forwarded to the neighboring node through the established MESH link in multiple hops until it reaches the fixed AP site, thereby achieving wireless coverage of the entire operating area of ​​the mine; Step 5: The fixed AP site evaluates the signal quality and service quality of each mobile node based on the RSSI value and latency of the uplink data sent by the mobile device nodes, optimizes and adjusts the MESH link, avoids relay nodes with poor quality, and ensures the overall reliability and latency performance of the network.

2. The method according to claim 1, characterized in that The specific steps of the adaptive coverage adjustment algorithm in step 3 are: 1) The dual-polarized smart antenna system obtains the current three-dimensional position coordinates (x, y, z) and orientation (roll angle, pitch angle, yaw angle) of the mobile device in real time; 2) Traverse and calculate the three-dimensional distance d[i] and azimuth angle difference between the mobile device and each fixed AP site Where i is the AP site number; 3) Compare each d[i] and select the AP site with the smallest distance as the serving AP site; 4) Taking the line from the mobile device to the service AP site as the target direction of antenna beamforming, calculate the adjustment angles of the antenna beam in the horizontal and vertical planes as follows: in and are the azimuth and elevation angles of the mobile device pointing to the serving AP site, respectively; 5) Drive the antenna beamforming circuit to adjust the pointing angles of the horizontal and vertical beams to align them with the service AP site; 6) The above algorithm is repeatedly executed periodically to achieve real-time adaptive adjustment of the antenna beam.

3. The method according to claim 1, characterized in that In step 4, the specific steps of the WLAN MESH networking algorithm are: 1) Each mobile device node publishes its own ID, location coordinates, neighbor list and other information to the surrounding by periodically broadcasting Hello frames; 2) After receiving the Hello frame from other nodes, the mobile node extracts the node's ID, coordinates and other information, calculates the three-dimensional distance dist between the two nodes, and adds the nodes whose dist is lower than a certain threshold value to the neighbor list; 3) The mobile node selects the node with the closest distance and strongest signal as the parent node based on the neighbor list and establishes a MESH link with it; 4) If the mobile node cannot communicate directly with any fixed AP site, it sends the data packet to the parent node through the established MESH link, and the parent node continues to forward it to the upper-level neighbor node until a node can directly connect to the fixed AP; 5) When the location of the mobile node changes, the signal of the parent node deteriorates, or other reasons cause the need to switch the parent node, repeat the above step 3) to select a new parent node; 6) Fixed AP sites periodically send heartbeat frames. Mobile nodes evaluate the current network status and dynamically optimize local MESH routing based on the reception quality of the heartbeat frames from each AP site.

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