Cell switching method and device for networked unmanned aerial vehicle, and communication system

Abstract

The invention discloses a cell switching method and device for a networked unmanned aerial vehicle, and a communication system. Comprising the following steps: acquiring a measurement report of the networked unmanned aerial vehicle in a target time period; determining a target extended PCI of the networked unmanned aerial vehicle to be switched to the target cell according to the measurement report; matching the target extended PCI with a preset base station mapping table, determining a target base station corresponding to the target extended PCI, and determining a target path for switching to the target base station according to a preset target path table; and switching the networked unmanned aerial vehicle to a target cell covered by the target base station according to the target path. According to the invention, the technical problem that the existing network base station does not support the network-connected unmanned aerial vehicle to switch in the cell without configuring the adjacent cell relationship is solved.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and more specifically, to a cell switching method and device, and a communication system for a networked drone. Background Art

[0002] Currently, 5G networks mainly cover the ground, and the cost of building a new airspace network is high. Therefore, when using existing website addresses, how to ensure the quality of high-altitude and large-scale 5G networks at the same time is the biggest difficulty in airspace networking.

[0003] Usually, the neighboring cell configuration of the ground network is generally determined by the switching relationship of the ground users. After testing and analysis, the airspace usually receives more than 10 signals, which mainly come from the signal reflection of the ground large network. However, due to the long coverage range of the base station in the airspace, the terminal in the current service cell may receive signals transmitted by multiple neighboring cells with the same PCI (Physical Cell Identity) in the surrounding area, and the neighboring cell of the ground network configured according to the switching relationship of the ground users is generally one. Therefore, applying the traditional switching and PCI multiplexing rules based on the neighboring cell relationship of the ground network in the low-altitude network will cause the terminal in the current service cell to switch to the wrong neighboring cell according to the neighboring cell relationship, resulting in terminal access failure.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present application provide a cell switching method and device, and a communication system for a networked drone, so as to at least solve the technical problem that the existing base station does not support the switching of the networked drone in a cell that is not configured with a neighboring cell relationship.

[0006] According to one aspect of an embodiment of the present application, a cell switching method for a networked drone is provided, including: obtaining a measurement report of the networked drone within a target time period; determining a target extended physical cell identifier PCI of a target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI is composed of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; matching the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determining a target path for switching to the target base station using a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within a low-altitude network coverage area, and the target path table includes: paths in which the delay of switching of multiple base stations within the low-altitude network coverage area within a target time period is less than a preset threshold; switching the networked drone to the target cell covered by the target base station according to the target path.

[0007] Optionally, before obtaining the measurement report of the connected UAV within the target time period, the method also includes: receiving a registration request message from the connected UAV, wherein the registration request message includes at least: a registration type, an identity, a last visited tracking area identifier, and requested network slice selection auxiliary information; and allocating an exclusive network slice for the connected UAV based on the registration request message.

[0008] Optionally, the process of constructing the base station mapping table includes: obtaining the base station identifiers of all base stations in the low-altitude network coverage area and the PCI of each cell covered by each base station; for each base station, determining the first number of subcarriers of the first orthogonal frequency division multiplexing signal of the physical broadcast channel of the base station and the second number of subcarriers used for transmitting signals within the first number of subcarriers, wherein the first orthogonal frequency division multiplexing signal is used to carry the main synchronization signal; determining the third number of subcarriers not used for transmitting signals based on the first number and the second number; grouping the third number of subcarriers according to a preset number of carriers to obtain multiple groups of subcarrier groups, and determining the group number of each group of subcarrier groups; forming an extended PCI of each cell covered by the base station by the PCI of each cell covered by the base station and the group number of the subcarrier group where at least one subcarrier corresponding to each cell is located; summarizing the mapping relationship between the base station identifier of each base station and the extended PCI of each cell covered by the base station to obtain a base station mapping table.

[0009] Optionally, the PCI of each cell covered by all base stations in the low-altitude network coverage area is obtained, including: determining all base stations in the low-altitude network coverage area; traversing each base station, taking the current base station as the origin and a preset distance or a preset site level as the radius, and using the Delaunay triangulation algorithm to construct a Delaunay triangulation network to obtain the PCI of each cell in the Delaunay triangulation network.

[0010] Optionally, the process of constructing the target path table includes: obtaining the delay between each base station in the low-altitude network coverage area within the target time period; using each base station as a graph node, the switching relationship between each base station as an edge, and the delay between each base station as the weight of the edge to construct a weighted graph of the low-altitude network coverage area; using the Dijkstra algorithm to analyze the weighted graph, and obtain the path in which the switching delay between each base station is less than a preset threshold, to form the target path table.

[0011] Optionally, the networked drone is switched to a target cell covered by a target base station according to a target path, including: determining all intermediate base stations in the target path and the access sequence numbers of each intermediate base station; connecting the networked drone to each intermediate base station in turn according to the access sequence numbers of each intermediate base station until it is switched to the target cell covered by the target base station.

[0012] Optionally, after switching the connected drone to the target cell covered by the target base station according to the target path, the method also includes: releasing wireless resources corresponding to the network slice allocated to the connected drone.

[0013] According to another aspect of an embodiment of the present application, a cell switching device for a networked drone is also provided, including: an acquisition module, used to obtain a measurement report of the networked drone within a target time period; a first determination module, used to determine the target extended PCI of the target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI consists of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; a second determination module, used to match the target extended PCI with a preset base station mapping table, determine the target base station corresponding to the target extended PCI, and determine the target path to switch to the target base station according to a preset target path table, wherein the base station mapping table includes a mapping relationship between multiple groups of extended PCIs and base stations within the coverage range of a low-altitude network, and the target path table includes: a path in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; a switching module, used to switch the networked drone to the target cell covered by the target base station according to the target path.

[0014] According to another aspect of an embodiment of the present application, a communication system is also provided, which includes: a networked drone, a network device, wherein the network device includes: a source base station and a target base station, wherein the networked drone is used to report a measurement report within a target time period to the source base station; the source base station is used to obtain a measurement report of the networked drone within the target time period; the target extended physical cell identifier PCI of the target cell to be switched to by the networked drone is determined based on the measurement report, wherein the target extended PCI consists of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; the target extended PCI is matched with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and the preset target path table determines the target path for switching to the target base station, wherein the base station mapping table includes a mapping relationship between multiple groups of extended PCIs and base stations within the coverage range of the low-altitude network, and the target path table includes: a path in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; the networked drone is switched to the target cell covered by the target base station according to the target path.

[0015] According to another aspect of an embodiment of the present application, a network device is also provided, which includes: a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to execute the above-mentioned cell switching method of the networked drone through the computer program.

[0016] In an embodiment of the present application, a measurement report of a networked UAV within a target time period is obtained; a target extended physical cell identifier PCI of a target cell to be switched to by the networked UAV is determined based on the measurement report, wherein the target extended PCI is composed of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; the target extended PCI is matched with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and a preset target path table is used to determine the target path for switching to the target base station, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage range of a low-altitude network, and the target path table includes: paths in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; the networked UAV is switched to the target cell covered by the target base station according to the target path, thereby solving the technical problem that existing base stations do not support the switching of networked UAVs in cells that are not configured with neighboring cell relationships. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 is a schematic diagram of an optional architecture of a communication system according to an embodiment of the present application;

[0019] Figure 2 It is a hardware structure block diagram of a computer terminal (or mobile device) for implementing a cell switching method of a networked drone according to an embodiment of the present application;

[0020] Figure 3 It is a flowchart of an optional cell switching method for a networked drone according to an embodiment of the present application;

[0021] Figure 4 is a schematic diagram of an optional subcarrier division according to an embodiment of the present application;

[0022] Figure 5 is a schematic diagram of an optional authorized diagram according to an embodiment of the present application;

[0023] Figure 6 is a schematic structural diagram of an optional cell switching device for a networked drone according to an embodiment of the present application;

[0024] Figure 7 It is a schematic diagram of the structure of an optional network device according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] In addition, the relevant information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for display, data for analysis, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. For example, an interface is set up between this system and the relevant user or organization. Before obtaining relevant information, it is necessary to send an acquisition request to the aforementioned user or organization through the interface, and obtain relevant information after receiving the consent information fed back by the aforementioned user or organization.

[0028] In order to better understand the embodiments of the present application, the technical terms involved in the embodiments of the present application are explained as follows:

[0029] Network Slice Selection Assistance Information (NSSI) is a parameter used to identify network slices in 5G networks. It includes the SST (Slice / Service Type) field and the SD (Slice Differentiator) field. The SST field indicates the slice / service type, and the SD field is used to further distinguish different slice instances under the same SST value. Therefore, NSSI is used to transmit slice-related information in signaling messages between user equipment and the network, assisting the network in selecting appropriate network slices based on UE requirements and network policies.

[0030] Example 1

[0031] Under the current group site address, the neighboring cell configuration of the ground network is usually set according to the switching needs of ground users. The common practice is to configure multiple layers of base stations (generally no more than three layers of sites) for the site service range to ensure that there is an overlapping coverage relationship between them.

[0032] However, in airspace networking, due to the wide coverage of the airspace (which can cover multiple base stations), the networked drones in the airspace will receive signals reflected from multiple large ground networks. However, since the ground stations that are far apart have a long coverage range and strong transmission signals (this is because there is less obstruction in the airspace), and some of the signals received by the networked drones have no neighboring relationship with the service cells covered by the current source base station, the networked drones cannot directly switch cells according to the signals, which seriously affects the perception of airspace users.

[0033] In addition, since the low-altitude network has a long coverage range, and the existing physical cell identifier PCI rules configured for cells within the range of each base station are the same, the low-altitude network cannot directly use the PCI rules planned for the ground network. For example, the networked drone receives signals from three cells with a PCI of 4 in the current service cell, and the base station where the current service cell is located is only configured with one neighboring cell with a PCI of 4. Based on the neighboring cell relationship, the networked drone may be switched to the wrong cell, resulting in service discontinuity.

[0034] In order to solve the problems existing in the above-mentioned technologies, relevant solutions are provided in the embodiments of the present application, which are described in detail below.

[0035] According to an embodiment of the present application, a method embodiment of a cell switching method for a networked drone is provided. The technical solution of the embodiment of the present application can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system or 5G system, etc.

[0036] For example, the architecture of the communication system 100 used in the embodiment of the present application is as follows: Figure 1 The communication system 100 may include a network device 110, and the network device 110 includes: a source base station and a target base station, both of which may communicate with a terminal device 120 (or referred to as a communication terminal or terminal).

[0037] Specifically, the network device 110 can provide communication coverage for a specific geographical area, and can communicate with terminal devices located in the coverage area. Optionally, the network device 110 can be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, or a base station (NodeB, NB) in a WCDMA system, or an evolutionary base station (Evolutional Node B, eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (Cloud Radio Access Network, CRAN), or the network device can be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network side device in a 5G network, or a network device in a future evolved public land mobile network (Public Land Mobile Network, PLMN), etc.

[0038] The communication system 100 also includes at least one terminal device 120 located within the coverage of the network device 110. The "terminal device" used herein may be a networked drone. Optionally, the terminal devices 120 may perform device-to-device (D2D) communication.

[0039] In addition, it should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0040] The method embodiments provided in the embodiments of the present application may be executed in a mobile terminal, a computer terminal or a similar computing device in a source base station. Figure 2 The hardware structure block diagram of a computer terminal (or mobile device) for implementing a cell switching method for a networked drone is shown. Figure 2 As shown, the computer terminal 20 (or mobile device 20) may include one or more (202a, 202b, ..., 202n are used to illustrate) processors 202 (the processor 202 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 204 for storing data, and a transmission device 206 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 2The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 2 More or fewer components as shown, or with Figure 2 Different configurations are shown.

[0041] It should be noted that the one or more processors 202 and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computer terminal 20 (or mobile device). As described in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0042] The memory 204 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the cell switching method of the networked drone in the embodiment of the present application. The processor 202 executes various functional applications and data processing by running the software programs and modules stored in the memory 204, that is, the cell switching method of the networked drone of the above-mentioned application is realized. The memory 204 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 204 may further include a memory remotely arranged relative to the processor 202, and these remote memories may be connected to the computer terminal 20 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0043] The transmission device 206 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the computer terminal 20. In one example, the transmission device 206 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 206 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0044] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 20 (or mobile device).

[0045] In the above operating environment, Figure 3is a flow chart of an optional cell switching method for a networked drone according to an embodiment of the present application, such as Figure 3 As shown, the method at least includes steps S302-S306, wherein:

[0046] Step S302, obtaining a measurement report of the networked UAV within a target time period.

[0047] In the technical solution provided in step S302, the measurement report (MR) is important information about signal quality reported by the user equipment to the network, such as RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), neighboring cell measurement, etc. Among them, the above measurement report can be reported to the source base station periodically (the periodic interval is equal to the target time period) by the networked drone, or it can be triggered by a specific event (the time interval from the last report to this report is equal to the target time period).

[0048] Step S304: determine the target extended physical cell identifier PCI of the target cell to which the networked drone is to switch based on the measurement report.

[0049] In the technical solution provided in step S304, after the source base station receives the measurement report reported by the networked drone, it will determine the best switching target cell based on the information in the report, such as the signal quality of the cell, the signal quality of the current service cell, and other factors that may affect the decision, such as cell load, switching protocol between cells, etc. Since the low-altitude network cannot directly use the PCI rules planned for the ground network, for this reason, the target extended PCI composed of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell is adopted in the embodiment of the present application. This is because the number of subcarriers allocated to each base station is different, the subcarriers defined for transmitting energy are different, and the number of subcarriers configured for each cell under the coverage of the base station is also different. Therefore, the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell can be used as the physical identification of the cell.

[0050] Step S306, matching the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determining the target path to switch to the target base station using the preset target path table.

[0051] In the technical solution provided in step S306, the above-mentioned base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage range of the low-altitude network. Therefore, the source base station can match the target extended PCI determined in the above-mentioned step S406 with the base station mapping table, determine the target base station corresponding to the target extended PCI, and then determine the target path for switching from the source base station to the target base station according to a pre-established target path table, wherein the target path table includes: the path in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold (i.e., the shortest delay). Therefore, the determined target path can ensure the switching delay of low-altitude services in application scenarios with high real-time requirements.

[0052] Step S308: switch the networked drone to the target cell covered by the target base station according to the target path.

[0053] The above method of this embodiment is further introduced below.

[0054] As an optional implementation, before obtaining the measurement report of the networked UAV within the target time period, the source base station may also perform an online detection on the networked UAV according to the following method, including:

[0055] Step 1: The source base station receives the registration request message (Registration Request) of the networked drone, where the registration request message includes at least: registration type (Registration Type), identity (such as subscriber permanent identity SUCI, global unique temporary identity GUTI, permanent equipment identity PEI, etc.), the last visited tracking area identity TAI (Tracking Area Identity, used to identify the tracking area where the mobile device is located), and the requested network slice selection auxiliary information NSSI (used to help the network understand the type of network slice it wants to access, and select the appropriate access and mobility management function AMF network and related network slice instances accordingly);

[0056] Step 2: Allocate exclusive network slices for connected drones based on the registration request message.

[0057] Among them, the source base station allocates exclusive network slices for the connected drone to provide the connected drone with wireless resources that can meet its needs.

[0058] As an optional implementation, in the technical solution provided in the above step S406, the process of constructing the base station mapping table of the low-altitude network may include the following steps:

[0059] Step 1: Obtain the base station identification of all base stations in the low-altitude network coverage area and the PCI of each cell covered by each base station.

[0060] Specifically, the base station identifier of the above base station and the PCI of each cell covered by the base station are pre-configured when the network is deployed. Therefore, since the low-altitude network coverage is large, in order to accurately obtain the PCI of all cells covered by the base station, the embodiment of the present application proposes the following method:

[0061] First, identify all base stations within the low-altitude network coverage area.

[0062] Then, traverse each base station in turn, take the current base station as the origin, and use the preset distance (such as 10 km from the current site) or the preset site level (such as the 5-layer site around the current site) as the radius, and use the Delaunay triangulation algorithm to construct a Delaunay triangulation network to obtain the PCI of each cell in the Delaunay triangulation network.

[0063] The criterion adopted by the above-mentioned Delaunay triangulation algorithm may be any one of the following: the maximum criterion of the minimum internal angle, the maximum criterion of the opening angle, the empty circumscribed circle criterion, and the minimum criterion of the maximum circumscribed circle.

[0064] Step 2: The first OFDM symbol of the base station's physical broadcast channel (PBCH) is used to carry PSS (Primary Synchronization Signal). The corresponding number of subcarriers can be set according to the system bandwidth and subcarrier spacing (such as 15kHz, 30kHz, 60kHz, 120kHz and 240kHz, etc.), and different cells covered by the base station can use different bandwidth parts (Bandwidth Part, BWP), and each BMP can have different subcarrier spacing and bandwidth configuration. Therefore, the number of subcarriers used by each cell covered by the base station is also different.

[0065] Therefore, for each base station, the following steps may be performed cyclically to determine the extended PCI of each cell covered by the base station:

[0066] First, determining a first number of subcarriers of a first orthogonal frequency division multiplexing signal of a physical broadcast channel of a base station and a second number of subcarriers used for transmitting signals within the first number of subcarriers, wherein the first orthogonal frequency division multiplexing signal is used to carry a primary synchronization signal;

[0067] Then, determining a third number of subcarriers not used for transmitting signals according to the first number and the second number; grouping the third number of subcarriers according to a preset number of carriers to obtain multiple groups of subcarriers, and determining a group number of each subcarrier group;

[0068] Finally, the extended PCI of each cell covered by the base station is composed of the PCI of each cell covered by the base station and the group number of the subcarrier group to which at least one subcarrier corresponding to each cell belongs.

[0069] For example, the first number of subcarriers corresponding to the first OFDM symbol of the physical broadcast channel configured by base station A is 240, and the serial numbers of each subcarrier are 0-239. If PSS uses the 120 (i.e., the second number) subcarriers in the middle of the first OFDM symbol (i.e., the subcarriers with serial numbers 60-179), then the remaining subcarriers not used for energy transmission are 120 (i.e., the third number), i.e., the subcarriers with serial numbers 0-59, 180-239; the remaining 120 subcarriers are grouped according to 15 subcarriers per group (the preset number of carriers) to obtain 8 groups, such as Figure 4 As shown, the group number of each subcarrier group is determined in sequence, such as the group number of the subcarrier group where the subcarriers with sequence numbers 0-14 are located is 1, the group number of the subcarrier group where the subcarriers with sequence numbers 15-29 are located is 2, and so on. Since the subcarriers allocated to each cell covered by the base station are usually one or more, and in the case of multiple subcarriers, the subcarriers are usually continuous, the group number of the corresponding subcarrier group can be determined according to the subcarrier group where the sequence number of at least one subcarrier corresponding to each cell is located, and then the extended PCI of each cell covered by the base station is composed of the PCI of each cell covered by the base station and the group number of the subcarrier group where at least one subcarrier corresponding to each cell is located.

[0070] Step 3: Summarize the mapping relationship between the base station identifier of each base station and the extended PCI of each cell covered by the base station to obtain a base station mapping table.

[0071] It should be noted that after obtaining the above base station mapping table, the base station mapping table may be stored locally in the source base station.

[0072] As an optional implementation, in the technical solution provided in the above step S406, since the delays corresponding to the paths switched between base stations in the low-altitude network coverage area are different in different time periods, the process of constructing the target path table of the low-altitude network coverage area in the target time period may include:

[0073] Step 1: Obtain the delay between each base station in the low-altitude network coverage area during the target time period.

[0074] Among them, the source base station can first obtain the delay between each base station in the low-altitude network coverage area within the target time period through the PING packet between base stations.

[0075] Step 2: Use each base station as a graph node, the switching relationship between base stations as an edge, and the time delay between base stations as the weight of the edge to construct a weighted graph of the low-altitude network coverage area.

[0076] The source base station can use all base stations in the service area of ​​the low-altitude network coverage as graph nodes, the Xn interfaces between base stations as the path start and end points, and the transmission delay between base stations as the path length to construct a weighted graph. Figure 5 An optional weighted graph is shown, where the numbers in the circles are the numbers of the base stations, and the numbers on the lines between the base stations are the delays.

[0077] Step 3: Use the Dijkstra algorithm to analyze the weighted graph, obtain the paths whose switching delay between base stations is less than the preset threshold, and form the target path table.

[0078] Specifically, for any two graph nodes in a weighted graph, one of the graph nodes is used as the starting point and the other as the ending point, and the Dijkstra algorithm is used to determine the path from the starting point to the ending point with a delay less than a preset threshold in multiple paths. The Dijkstra algorithm starts from the starting point and uses a greedy algorithm strategy to traverse the adjacent nodes of the vertex closest to the starting point and not visited each time until it reaches the end point.

[0079] As an optional implementation, in the technical solution provided in the above step S306, the source base station can perform cell switching for the networked drone in accordance with the following method, including: determining the access numbers of all intermediate base stations and each intermediate base station in the target path; connecting the networked drone to each intermediate base station in turn according to the access number of each intermediate base station until switching to the target cell covered by the target base station.

[0080] In this embodiment, connecting the networked drone to each intermediate base station in sequence according to the access sequence number of each intermediate base station means that the cell switching request message initiated by the source base station is first sent to the first intermediate base station, and then the first intermediate base station responds to the request successfully, and then feeds back an access success response message to the source base station, and forwards the cell switching request message to the second intermediate base station at the same time, and so on, until the target base station feeds back an access success response message to the previous intermediate base station, at which time the networked drone switches to the target cell covered by the target base station.

[0081] Furthermore, after the source base station switches the connected drone to the target cell covered by the target base station according to the target path, the source base station can release the wireless resources corresponding to the network slice allocated to the connected drone before the switching.

[0082] In addition, the source base station may forward the unsent data to the target base station and update the node relationship between the user plane and the control plane.

[0083] Based on the scheme defined in the above steps S302 to S306, it can be known that in an embodiment, the source base station determines the target extended PCI of the target cell to be switched to by the networked drone according to the measurement report of the networked drone in the target time period, wherein in order to avoid the PCI multiplexing problem of the traditional ground network, the blank subcarriers of the PSS signal in the PBCH can be used to group them, and the PCI of each cell can be marked by different carrier groups to construct an extended PCI, so as to greatly improve the accuracy of identifying the target cell; in addition, in order to improve the service transmission delay during the switching process, the target path with the lowest delay can be selected from the multiple paths between the source base station and the target base station, so as to switch the networked drone to the target cell covered by the target base station according to the target path. This solves the technical problem that the existing network base station does not support the switching of networked drones in cells that are not configured with neighboring cell relations.

[0084] Example 2

[0085] Based on Embodiment 1 of the present application, an embodiment of a cell switching device for a networked drone is also provided, and the cell switching method for a networked drone of the above embodiment is executed when the device is running. Figure 6 is a schematic structural diagram of an optional cell switching device for a networked drone according to an embodiment of the present application, such as Figure 6 As shown, the cell switching device of the networked drone includes at least an acquisition module 62, a first determination module 64, a second determination module 66 and a switching module 68, wherein:

[0086] An acquisition module 62 is used to obtain a measurement report of the networked UAV within a target time period;

[0087] A first determination module 64 is used to determine the target extended PCI of the target cell to be switched to by the networked drone according to the measurement report, wherein the target extended PCI is composed of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell;

[0088] The second determination module 66 is used to match the target extended PCI with a preset base station mapping table, determine the target base station corresponding to the target extended PCI, and determine the target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage range of the low-altitude network, and the target path table includes: paths in which the delay of switching of multiple base stations within the coverage range of the low-altitude network within the target time period is less than a preset threshold;

[0089] The switching module 68 is used to switch the networked drone to the target cell covered by the target base station according to the target path.

[0090] It should be noted that the various modules in the cell switching device of the above-mentioned networked drone can be program modules (for example, a set of program instructions to implement a certain specific function) or hardware modules. For the latter, it can be expressed in the following forms, but is not limited to this: the expression form of each of the above-mentioned modules is a processor, or the functions of each of the above-mentioned modules are implemented by a processor.

[0091] Example 3

[0092] According to an embodiment of the present application, a non-volatile storage medium is also provided, in which a program is stored, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute the cell switching method of the networked drone in Example 1.

[0093] Optionally, the device where the non-volatile storage medium is located implements the following steps by running the program: obtaining a measurement report of the networked drone within a target time period; determining a target extended physical cell identifier PCI of the target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI consists of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; matching the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determining the target path to switch to the target base station with a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage area of ​​the low-altitude network, and the target path table includes: a path in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; switching the networked drone to the target cell covered by the target base station according to the target path.

[0094] According to an embodiment of the present application, a computer program product is also provided, which includes a stored computer program, wherein when the computer program is executed by a processor, the cell switching method of the networked drone in Example 1 is implemented.

[0095] Optionally, the computer program executes the following steps: obtaining a measurement report of the networked drone within a target time period; determining a target extended physical cell identifier PCI of the target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI consists of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; matching the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determining a target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage area of ​​the low-altitude network, and the target path table includes: paths in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; switching the networked drone to the target cell covered by the target base station according to the target path.

[0096] According to an embodiment of the present application, a processor is also provided, which is used to run a program, wherein the cell switching method of the networked drone in Example 1 is executed when the program is running.

[0097] Optionally, when the program is running, the following steps are executed: obtaining a measurement report of the networked drone within a target time period; determining a target extended physical cell identifier PCI of the target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI consists of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; matching the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determining the target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage area of ​​the low-altitude network, and the target path table includes: paths in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; switching the networked drone to the target cell covered by the target base station according to the target path.

[0098] According to an embodiment of the present application, a network device is also provided, wherein: Figure 7 is a schematic diagram of the structure of an optional network device according to an embodiment of the present application, such as Figure 7 As shown, the network device includes one or more processors; a memory for storing one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors are implemented to run the programs, wherein the programs are configured to execute the cell switching method of the networked drone in the above-mentioned embodiment 1 when running.

[0099] Optionally, the processor is configured to execute the following steps through a computer program: obtaining a measurement report of the networked drone within a target time period; determining a target extended physical cell identifier PCI of the target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI consists of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; matching the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determining the target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage area of ​​the low-altitude network, and the target path table includes: a path in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; switching the networked drone to the target cell covered by the target base station according to the target path.

[0100] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0101] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0102] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0103] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0104] In addition, each functional unit in each embodiment of the present application 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.

[0105] 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. Based on this understanding, the technical solution of the present application, or the part that contributes to the relevant technology or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc. Various media that can store program codes.

[0106] The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A cell switching method for a networked drone, characterized in that: include: Obtain measurement reports of networked drones within a target time period; Determine, according to the measurement report, a target extended physical cell identifier PCI of a target cell to which the networked drone is to be switched, wherein the target extended PCI is composed of a PCI of the target cell and a group number of an idle subcarrier group corresponding to the target cell; Match the target extended PCI with a preset base station mapping table, determine the target base station corresponding to the target extended PCI, and determine the target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes mapping relationships between multiple groups of extended PCIs and base stations within the coverage range of the low-altitude network, and the target path table includes: paths in which the delay of switching of multiple base stations within the coverage range of the low-altitude network within a target time period is less than a preset threshold; The networked drone is switched to the target cell covered by the target base station according to the target path.

2. The method according to claim 1, characterized in that Before obtaining the measurement report of the networked UAV within the target time period, the method further includes: Receive a registration request message from the networked drone, wherein the registration request message includes at least: a registration type, an identity, a tracking area identifier last visited, and requested network slice selection auxiliary information; Allocate an exclusive network slice for the networked drone based on the registration request message.

3. The method according to claim 1, characterized in that The construction process of the base station mapping table includes: Obtaining base station identifiers of all base stations in the low-altitude network coverage area and PCIs of each cell covered by each base station; For each base station, determine a first number of subcarriers of a first orthogonal frequency division multiplexing signal of a physical broadcast channel of the base station and a second number of subcarriers used for transmitting signals within the first number of subcarriers, wherein the first orthogonal frequency division multiplexing signal is used to carry a primary synchronization signal; determine a third number of subcarriers not used for transmitting signals based on the first number and the second number; group the third number of subcarriers according to a preset number of carriers to obtain multiple groups of subcarrier groups, and determine a group number of each group of the subcarrier groups; form an extended PCI of each cell covered by the base station by the PCI of each cell covered by the base station and the group number of the subcarrier group where at least one subcarrier corresponding to each cell is located; The mapping relationship between the base station identifier of each base station and the extended PCI of each cell covered by the base station is summarized to obtain the base station mapping table.

4. The method according to claim 3, characterized in that Get the PCI of each cell covered by all base stations in the low-altitude network coverage area, including: Determine all base stations within the low-altitude network coverage area; Each of the base stations is traversed, with the current base station as the origin and a preset distance or a preset site level as the radius, a Delaunay triangulation algorithm is used to construct a Delaunay triangulation network, and the PCI of each cell in the Delaunay triangulation network is obtained.

5. The method according to claim 1, characterized in that The process of constructing the target path table includes: Obtaining the time delay between each of the base stations in the low-altitude network coverage area within a target time period; Taking each of the base stations as a graph node, taking the switching relationship between each of the base stations as an edge, and taking the time delay between each of the base stations as the weight of the edge, a weighted graph of the low-altitude network coverage area is constructed; The weighted graph is analyzed by using the Dijkstra algorithm to obtain paths whose switching delays between the base stations are less than a preset threshold, and the target path table is formed.

6. The method according to claim 1, characterized in that Switching the networked drone to a target cell covered by the target base station according to the target path includes: Determine all intermediate base stations and access sequence numbers of each intermediate base station in the target path; The networked drone is connected to each of the intermediate base stations in sequence according to the access sequence number of each of the intermediate base stations, until it is switched to the target cell covered by the target base station.

7. The method according to claim 2, characterized in that After switching the networked drone to a target cell covered by the target base station according to the target path, the method further includes: Release the wireless resources corresponding to the network slice allocated to the connected drone.

8. A cell switching device for a networked drone, characterized in that: include: An acquisition module is used to obtain measurement reports of networked drones within a target time period; A first determination module is used to determine the target extended PCI of the target cell to be switched to by the networked drone according to the measurement report, wherein the target extended PCI is composed of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; The second determination module is used to match the target extended PCI with a preset base station mapping table, determine the target base station corresponding to the target extended PCI, and determine the target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes a mapping relationship between multiple groups of extended PCIs and base stations within the coverage range of the low-altitude network, and the target path table includes: paths in which the delay of switching of multiple base stations within the coverage range of the low-altitude network within a target time period is less than a preset threshold; A switching module is used to switch the networked drone to a target cell covered by the target base station according to the target path.

9. A communication system, characterized in that: The communication system includes: a networked drone and a network device, wherein the network device includes: a source base station and a target base station, wherein: The networked drone is used to report the measurement report within the target time period to the source base station; The source base station is used to obtain a measurement report of the networked drone within a target time period; determine a target extended physical cell identifier PCI of the target cell to be switched to by the networked drone based on the measurement report, wherein the target extended PCI is composed of the PCI of the target cell and the group number of the idle subcarrier group corresponding to the target cell; match the target extended PCI with a preset base station mapping table to determine the target base station corresponding to the target extended PCI, and determine the target path to switch to the target base station using a preset target path table, wherein the base station mapping table includes a mapping relationship between multiple groups of extended PCIs and base stations within the coverage range of the low-altitude network, and the target path table includes: a path in which the delay of switching of multiple base stations within the coverage area of ​​the low-altitude network within the target time period is less than a preset threshold; switch the networked drone to the target cell covered by the target base station according to the target path.

10. A network device, characterized in that: include: A memory and a processor, wherein the processor is used to run a program stored in the memory, wherein the program, when running, executes the cell switching method for a networked drone as described in any one of claims 1 to 7.

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