Handover support device and method

Abstract

A handover support method performed by a handover support apparatus according to an embodiment comprises the steps of: acquiring information on a moving direction of an aircraft flying along a preset flight path in a service area on an air network including a plurality of wireless cells; determining one of a first mode or a second mode in which switching conditions among the plurality of wireless cells are different based on the information on the movement direction; and determining a handover of the aircraft or a communication device for the air network installed on the aircraft based on a handover condition corresponding to the determined one mode.

Description

Technical Field

[0001] The present invention relates to a device for determining a handover between radio cells in an onboard network and a method for the device to support a handover. Background Art

[0002] Recently, interest in urban air mobility (UAM) has been increasing, especially in developed countries, and South Korea has also conducted a comprehensive demonstration of Korean-style UAM and is now approaching the commercialization stage.

[0003] According to the technology roadmap of Korean urban air mobility, the flight altitude of the UAM aircraft is expected to vary from about 300 meters to 600 meters, with a maximum flight speed of about 320km / h. The UAM aircraft is expected to operate along a designated flight route.

[0004] In the flight route of the UAM aircraft, it is planned to operate the airborne network to support the data transmission and reception services of the UAM aircraft. The base station for the airborne network will be responsible for the communication for the defined service cell range, so that the UAM aircraft can perform communication within the service coverage of the airborne network provided by the base station for the airborne network. These base stations for the airborne network communicate wirelessly with the communication devices of the airborne network where the corresponding aircraft is located to provide wireless communication services to multiple aircraft operating in the wireless cell.

[0005] In addition, in 3GPP 4G / 5G, the cell coverage, which represents the communication range of a base station, varies according to the installation environment (e.g., urban, suburban, rural). For the purpose of communication performance analysis, the 3GPP standard defines different base station spacings for each installation environment. Generally, the distance between base stations is narrower in urban areas with a large number of users and wider in rural areas with fewer users.

[0006] In the UAM operating system, the flight operation of the UAM aircraft is basically considered in the high-density urban environment. Although the base stations are farther apart, it is assumed that there are fewer users compared to the ground network. Due to the high flight speed of the aircraft, frequent switching of the aircraft across the cell boundary to other cells is inevitable.

[0007] When applying a general switching process in a ground network environment, the UAM aircraft can transmit a measurement report on the strength of the wireless channel to the serving cell. When the signal strength of the serving cell is lower than a certain threshold or when the signal strength of the serving cell is lower than the signal strength of the target cell, the base station of the serving cell can prepare for the switching process. Once the corresponding preparations are completed, the base station of the serving cell can send a switching command to the UAM aircraft. The UAM aircraft can disconnect the uplink / downlink connection with the serving cell and perform an access process for the target cell. After successfully performing the access process, the UAM aircraft can send and receive data through the uplink / downlink newly connected to the target cell. Summary of the invention

[0008] Technical issues

[0009] As mentioned above, as previously mentioned, the maximum flight speed of the UAM aircraft is about 320km / h, which is expected to cause rapid changes in the wireless channel environment of both the serving cell and the target cell. When the UAM aircraft passes through the serving cell and approaches the target cell, the signal strength of the serving cell may suddenly deteriorate. In this case, it is necessary to quickly perform a handover to the target cell. In this UAM flight scenario, unlike the handover in the ground network, a handover process suitable for the airborne network environment is required.

[0010] According to an embodiment, an apparatus and method are provided for determining a handover for applying different handover conditions according to a moving direction of an aircraft flying within a service area of ​​an airborne network.

[0011] However, problems to be solved by the present disclosure are not limited to the above-mentioned problems, and other problems to be solved that are not mentioned can be clearly understood from the following description by those having ordinary skill in the art to which the present disclosure pertains.

[0012] Technical Solution

[0013] According to a first aspect, there is provided a method for determining handover, the method being performed by a device for determining handover. The method may include the following steps: obtaining information about a moving direction of an aircraft operating a flight along a preset flight route within a service area of ​​an airborne network including a plurality of wireless cells, determining a mode among a first mode and a second mode each having a different handover condition between the plurality of wireless cells based on the information about the moving direction, and determining whether to perform handover of the aircraft or a communication device for the airborne network installed at the aircraft according to the handover condition corresponding to the determined mode.

[0014] According to a second aspect, a device for determining handover is provided. The device may include: a communication unit configured to communicate with an aircraft operating a flight along a preset flight route in a service area of ​​an airborne network including a plurality of wireless cells, and a processor unit configured to control the communication unit, wherein after obtaining information about a moving direction of the aircraft, the processor unit may determine a mode among a first mode and a second mode each having a different handover condition between a plurality of wireless cells based on the information about the moving direction, and determine whether to perform handover of the aircraft or a communication device for the airborne network installed at the aircraft according to the handover condition corresponding to the determined mode.

[0015] According to a third aspect, a non-transitory computer-readable storage medium storing a computer program is provided. The computer program may include instructions for allowing the processor to execute a method for determining handover, the method including the following steps: obtaining information about a moving direction of an aircraft operating a flight along a preset flight route within a service area of ​​an airborne network including a plurality of wireless cells, determining a mode among a first mode and a second mode each having a different handover condition between the plurality of wireless cells based on the information about the moving direction, and determining whether to perform handover of the aircraft or a communication device for the airborne network installed at the aircraft according to the handover condition corresponding to the determined mode.

[0016] Beneficial Effects

[0017] According to an embodiment, when determining the switching between wireless cells of an onboard network of an aircraft (such as a UAM), different switching conditions may be applied according to the direction of movement, thereby achieving a switching process optimized for the onboard network environment. For example, when the aircraft moves in a direction in which the strength of the signal beam of the serving cell increases as the aircraft moves, a switching error may occur due to the characteristics of the onboard network environment, in which a strong signal beam of the serving cell at the boundary area of ​​the serving cell and the target cell is suddenly cut off when a normal switching process in a ground network environment is applied. However, there is an effect of supporting smooth switching by a switching process optimized for the characteristics of the onboard network environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a configuration diagram of a UAM operating system according to one embodiment of the present invention.

[0019] Figure 2 is a diagram showing a configuration of a device for determining handover according to an embodiment of the present invention.

[0020] Figure 3is a flowchart for describing a method for determining handover according to one embodiment of the present invention.

[0021] Figure 4 is a flowchart for describing a method for determining handover according to another embodiment of the present invention.

[0022] Figure 5 is a flowchart for describing a method for determining switching according to still another embodiment of the present invention.

[0023] Figure 6 It is a conceptual diagram for describing the correlation between the direction of the base station signal beam and the moving direction of the UAM aircraft in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The advantages and features of the embodiments and the methods for implementing the embodiments will be clearly understood through the following description in conjunction with the accompanying drawings. However, because the embodiments can be implemented in various forms, the embodiments are not limited to those described. It should be noted that these embodiments are provided to make a complete disclosure and also allow those skilled in the art to know the full scope of the embodiments. Therefore, the embodiments are limited only by the scope of the attached claims.

[0025] Terms used in the specification will be briefly described, and the present disclosure will be described in detail.

[0026] Among the terms used in the present disclosure, general terms that are currently used as widely as possible while considering the functions in the present disclosure are used. However, these terms may change according to the intention of those skilled in the art or precedents, the emergence of new technologies, etc. In addition, in some cases, there are terms arbitrarily selected by the applicant, and in this case, the meanings of these terms will be described in detail in the description of the corresponding invention. Therefore, the terms used in the present disclosure should be defined based on the meaning of the terms and the overall content of the present disclosure, rather than just the names of the terms.

[0027] When it is described that a part of the overall specification "includes" a certain component, unless specifically described to the contrary, it means that other components may also be included rather than excluding other components.

[0028] In addition, the terms such as "unit" or "part" used in the specification refer to software components or hardware components such as FPGA or ASIC, and the "unit" or "part" plays a role. However, the "unit" or "part" is not limited to software or hardware. The "part" or "unit" can be configured in an addressable storage medium, or can be configured to reproduce one or more processors. Therefore, as an example, a "unit" or "part" includes components (such as software components, object-oriented software components, class components, and task components), processes, functions, attributes, programs, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and "units" can be combined into a smaller number of components and "units", or can be further divided into additional components and "units".

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. In the accompanying drawings, parts irrelevant to the description are omitted in order to clearly describe the present disclosure.

[0030] Figure 1 is a configuration diagram of a UAM operating system according to one embodiment of the present invention, and Figure 2 is a configuration diagram of a device for determining switching according to an embodiment of the present invention.

[0031] The UAM operating system 100 may include a plurality of UAM aircraft 111 , 112 , and 113 , a base station 120 , a server 130 , and an unmanned aircraft system traffic management (UATM) 140 . Figure 1 Three UAM aircraft 111, 112, and 113 are illustrated, but this is only an example, and various modifications and changes may be made to the number of UAM aircraft. In addition, although a single base station 120 is exemplarily illustrated, the airborne network 101 may be formed by a collection of wireless cells, each of which is provided by a plurality of base stations 120. For example, the plurality of base stations 120 may provide at least one of a plurality of airborne network wireless cells arranged in the forward direction along the flight routes of the UAM aircraft 111, 112, and 113 as a service coverage.

[0032] A plurality of UAM aircraft 111, 112, and 113 may operate along a flight route. Here, the flight route may be a route corresponding to flight route information preset by a service provider for UAM (PSU) in UATM 140. In addition, a plurality of UAM aircraft 111, 112, and 113 may use the airborne network 101 within the wireless cell coverage of the base station 120 in an environment supporting wireless communication. In addition, the UAM aircraft 111, 112, and 113 may perform inter-aircraft communication with other UAM aircraft. For example, inter-aircraft communication may include or may be one or more of all communication methods supporting direct communication between aircraft, rather than a communication link connection method (e.g., 3GPP 4G / 5G) of the airborne network 101. In addition, the UAM aircraft 111, 112, and 113 may be equipped with a communication device (not illustrated) for the aircraft for wireless communication with the base station 120. In addition, the UAM aircraft 111, 112, and 113 may be communicatively connected to the UATM 140 through the base station 120 and the server 130 of the onboard network 101, or may be communicatively connected to the UATM 140 through satellite communication. The communication device for the aircraft (not illustrated) that may be equipped on the UAM aircraft 111, 112, and 113 may correspond to a mobile communication terminal in a general land mobile communication network such as 3GPP 4G / 5G.

[0033] In addition, a plurality of UAM aircraft 111, 112, and 113 may operate and fly within the airborne network 101 along a flight route defined by preset flight route information, and may perform switching between a plurality of wireless cells in response to a switching command from the base station 120. To this end, the UAM aircraft 111, 112, or 113 or a communication device for the aircraft (not illustrated) may transmit at least one of current position information, flight speed information, signal strength of a serving cell, or signal strength of a target cell to the base station 120 or the UATM 140 on the preset flight route.

[0034] The base station 120 provides mobile communication services to UAM aircraft located within its wireless cell among the plurality of UAM aircraft 111 , 112 , and 113 through the onboard network 101 .

[0035] In addition, the base station 120 can obtain information about the moving directions of the UAM aircraft 111, 112, and 113 operating in the service area of ​​the airborne network 101, and determine a mode among multiple switching modes based on the information about the moving directions. In this case, each of the multiple switching modes can be a mode in which the switching conditions between the multiple wireless cells are set differently. For example, the multiple switching modes may include a first mode and a second mode. The base station 120 according to one embodiment of the present disclosure is preferably configured to support switching between the wireless cells of the UAM aircraft 111, 112, and 113. For example, the base station 120 may include or be combined with Figure 2 The process of determining handover by the device 200 for determining handover or the base station 120 will be further described below.

[0036] The server 130 may transmit information about wireless cells of the airborne network 101 to the UAM aircraft 111, 112, and 113 through the base station 120 based on flight route information about the UAM aircraft 111, 112, and 113. For example, when the airborne network 101 is implemented as 3GPP 4G / 5G, the server 130 may be a mobility management entity (MME) or another entity constituting a core network.

[0037] The PSU in UATM 140 may determine the flight routes of UAM aircraft 111 , 112 , and 113 based on relevant information such as the origin, destination, flight time, and weather environment of UAM aircraft 111 , 112 , and 113 , and may provide the set flight routes to server 130 .

[0038] In addition, similar to the above-mentioned base station 120, the UATM 140 can obtain information about the movement direction of the UAM aircraft 111, 112, and 113 operating in the service area of ​​the airborne network 101, and determine a mode among a plurality of switching modes based on the information about the movement direction. For example, the plurality of switching modes may include a first mode and a second mode. The UATM 140 according to one embodiment of the present disclosure is preferably configured to support switching between wireless cells of the UAM aircraft 111, 112, and 113. For example, the UATM 140 may include or be combined with Figure 2 The process of determining the switching by the device 200 or the UATM 140 for determining the switching will be further described below.

[0039] like Figure 2 As shown, the device 200 for determining switching may include a communication unit 210 and a processor unit 220 , and may further include a storage unit 230 .

[0040] The communication unit 210 may perform communication with a UAM aircraft operating in flight within a service area of ​​the onboard network.

[0041] The processor unit 220 can control the communication unit 210, and after obtaining information about the moving direction of the UAM aircraft, determine a mode among multiple switching modes based on the information obtained about the moving direction. For example, the processor unit 220 can determine a mode among the first mode and the second mode.

[0042] The storage unit 230 may store various processing results of the processor unit 220 according to the control of the processor unit 220. The storage unit 230 may store a computer program including instructions that allow the processor unit 220 to perform each step according to the method of determining switching based on the embodiment of the present invention.

[0043] First, an embodiment in which the apparatus 200 for determining handover is included in or combined with the UATM 140 will be described, followed by an embodiment in which the apparatus 200 for determining handover is included in or combined with the base station 120.

[0044] According to an embodiment in which the device 200 for determining switching is included in the UATM 140 or combined with the UATM 140, the processor unit 220 may determine a mode among a plurality of switching modes based on the current position information and the moving direction information about the UAM aircraft. In addition, the processor unit 220 may determine a mode among a plurality of switching modes by further reflecting the flight speed information about the UAM aircraft and the current position information and the moving direction information about the UAM aircraft.

[0045] According to an embodiment in which the device 200 for determining switching is included in the base station 120 or combined with the base station 120, the processor unit 220 can determine the switching of the UAM aircraft or a communication device for an onboard network (not illustrated) installed at the UAM aircraft according to the switching conditions of the determined switching mode.

[0046] As another example, the processor unit 220 may determine a mode among a plurality of switching modes based on directionality information about a signal beam transmitted by a base station and movement direction information about the UAM aircraft.

[0047] For example, the processor unit 220 may compare the information about the moving direction of the UAM aircraft with the directional information about the signal beam, and determine the mode among the first mode and the second mode according to the difference between the moving direction of the UAM aircraft and the direction of the signal beam and the comparison result of the preset threshold. For example, the processor unit 220 may determine the switching mode as the first mode when the two directions (that is, the moving direction of the UAM aircraft and the direction of the signal beam) are the same, and determine the switching mode as the second mode when the two directions are opposite to each other. In addition, when the UAM aircraft moves in the direction in which the intensity of the signal beam of the serving cell is weakened, the processor unit 220 may determine the switching mode as the first mode, and when the UAM aircraft moves in the direction in which the intensity of the signal beam of the serving cell is enhanced, the processor unit 220 may determine the switching mode as the second mode. For example, the first mode may include at least one of the following items as a switching condition: when the signal strength of the serving cell is less than the preset first threshold, when the signal strength of the target cell is greater than the signal strength of the serving cell, and when the signal strength of the serving cell is less than the preset second threshold and the signal strength of the target cell is greater than the preset third threshold. In addition, the second mode may include at least one of the following items as a switching condition: when the signal strength of the serving cell is greater than a preset fourth threshold and when the signal strength of the target cell is greater than a preset fifth threshold. In addition, the processor unit 220 may set a smaller hysteresis value for the second mode than for the first mode, and may set a larger filter value for the second mode than for the first mode, the filter value determining the number of times the reference signal received power (RSRP) and the reference signal received quality (RSRQ) are averaged.

[0048] In the embodiment of the present disclosure, considering the upward tilt angle of the antenna set in the base station 120, the installation position of the base station 120, the moving route of the UAM aircraft, etc., it is illustrated that the processor unit 220 uses the information about whether the UAM aircraft moves in the direction in which the intensity of the signal beam of the serving cell is weakened or in the direction in which the intensity of the signal beam of the serving cell is enhanced, but the present disclosure is not limited thereto. Since the upward tilt angle of the antenna set in the base station 120, the installation position of the base station 120, the moving route of the UAM aircraft, etc. can be changed, various modifications can be applied by reflecting the upward tilt angle of the antenna set in the base station 120, the installation position of the base station 120, the moving route of the UAM aircraft, etc. As an example, according to the upward tilt angle of the antenna set in the base station 120 or the installation position of the base station 120, the UAM aircraft can move in the direction in which the intensity of the signal beam of the serving cell is gradually enhanced until a specific position, and after reaching the specific position, the UAM aircraft can move in the direction in which the intensity of the signal beam of the serving cell is gradually weakened and move to the switching area where the signal of the target cell is received. In such an environment, the processor unit 220 may identify directivity information about a signal beam based on an upward tilt angle of an antenna provided in the base station 120 or an installation position of the base station 120 and may determine a pattern by reflecting the identified directivity information about the signal beam.

[0049] In addition, the upward tilt angle of the antenna set in the base station 120, the installation position of the base station 120, etc. can be preset so that information related thereto can be preset and provided. In addition, since the UAM aircraft moves along the preset route, the remaining distance from the current position of the UAM aircraft to the boundary between the serving cell and the target cell can be calculated. In addition, since the UAM aircraft moves along the preset route, the remaining distance from the current position of the UAM aircraft to the boundary between the serving cell and the target cell can be calculated. Therefore, the processor unit 220 can determine the timing of requesting switching based on the remaining distance from the current position of the UAM aircraft to the boundary between the serving cell and the target cell. As an example, the processor unit 220 can request switching when the first remaining distance is reached in the first mode, and can request switching when the second remaining distance is reached in the second mode. Since the switching mode is determined to be the first mode when the UAM aircraft moves in a direction in which the strength of the signal beam of the serving cell is weakened, and the switching mode is determined to be the second mode when the UAM aircraft moves in a direction in which the strength of the signal beam of the serving cell is enhanced, the signal beam of the serving cell can reach a relatively long distance in the first mode, but only a relatively short distance in the second mode. In view of this, the first remaining distance can be set to be relatively larger than the second remaining distance.

[0050] Figure 3 is a flowchart for describing a method for determining switching according to an embodiment of the present invention, Figure 4 is a flowchart for describing a method for determining switching according to another embodiment of the present invention, and Figure 5 is a flowchart for describing a method for determining switching according to another embodiment of the present invention. Here, Figure 3 Illustrated in Figure 4 and Figure 5 The steps commonly performed in the implementation methods are as follows. Figure 6 It is a conceptual diagram for describing the correlation between the direction of the base station signal beam and the moving direction of the UAM aircraft in an embodiment of the present invention.

[0051] In the following, reference is made to Figures 1 to 6 , the process of switching of a communication device for an onboard network or a UAM aircraft installed at a UAM aircraft in a UAM operating system supported by a device for determining switching will be described in more detail for each embodiment. In the description of the following embodiments, one of the first mode and the second mode is determined as a plurality of switching modes with different switching conditions will be exemplarily described, but the number of the plurality of switching modes is not limited to two. That is, the number of the plurality of switching modes may be three or more.

[0052] <First Embodiment> Refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 6 .

[0053] The UAM aircraft 111, 112, and 113 operate flights within the service area of ​​the airborne network 101 along a preset flight route, and transmit information about the movement directions of the UAM aircraft 111, 112, and 113 to the device 200 included in or combined with the UATM 140 for determining switching.

[0054] Then, the communication unit 210 of the apparatus 200 for determining switching receives information about the moving directions of the UAM aircraft 111 , 112 , and 113 and transmits it to the processor unit 220 ( S310 ).

[0055] Next, the processor unit 220 determines a mode among the first mode and the second mode each having a different switching condition between the plurality of radio cells based on the information about the moving directions of the UAM aircraft 111 , 112 , and 113 ( S320 ).

[0056] In addition, the processor unit 220 may control the communication unit 210 to transmit the information about the switching mode determined in step S320 to the base station 120. The base station 120, which has received the information about the switching mode determined from the apparatus 200 for determining switching, may determine the switching of the UAM aircraft 111, 112, and 113 according to the corresponding mode.

[0057] Reference Figure 6 , the difference between the first mode and the second mode having different switching conditions will be described.

[0058] Since the ground network provides communication services to the entire area on the map, while the airborne network provides communication services only within a specific width and a specific altitude range (e.g., from an altitude of 300 meters to an altitude of 600 meters) on a predetermined flight route, in a UAM operating system according to an embodiment of the present disclosure, Figure 6 As shown, multiple base stations 120 can be installed in a row along the route of UAM aircraft 111, 112 and 113. In addition, due to the characteristic that the antenna is tilted upward at a specific angle in a specific direction (e.g., 20 degrees to 60 degrees), multiple base stations 120 can be installed in a row from D offset distance (rather than directly above the location of base station 120) extending to D s The distance of the cell coverage operation.

[0059] exist Figure 6 In the environment of the UAM operating system shown, when operating the flight in the first direction 601, the UAM aircraft 111, 112, and 113 move in a direction in which the strength of the signal beam in the service cell weakens as the UAM aircraft 111, 112, and 113 moves within the service cell. In addition, when operating the flight in the second direction 602, the UAM aircraft 111, 112, and 113 move in a direction in which the strength of the signal beam in the service cell strengthens as the UAM aircraft 111, 112, and 113 moves within the service cell.

[0060] As described above, in the environment of the UAM operating system, when the UAM aircraft 111, 112 and 113 operate and fly in the first direction 601 within the service cell, the signal of the service cell gradually weakens as the UAM aircraft moves, but when the UAM aircraft is near the coverage range of the target cell, the signal of the target cell gradually increases, and the UAM aircraft can compare the signal strengths of the corresponding cells and perform a switch to the cell with greater signal strength.

[0061] In contrast, in the environment of the UAM operating system, when the UAM aircraft 111, 112 and 113 operate and fly in the second direction 602 within the service cell, as the UAM aircraft moves, the distance to the service cell gradually becomes closer. Therefore, even if the switching opportunity gradually approaches, the signal strength of the service cell gradually increases. Once the cell coverage is exceeded, the signal quality suddenly deteriorates, which may cause problems when the normal switching operation of the ground network is operated based on the criterion that the signal strength of the service cell is a predetermined level or lower. Since the signal strength of the service cell is relatively higher than the signal strength of the target cell, even at the location where the switching should be performed due to the cell coverage, the switching will not be triggered by the normal switching operation of the ground network. Then, once the cell coverage is exceeded, the signal strength of the service cell drops sharply, and the service cell may have difficulty sending or receiving data when the switching process is performed, resulting in switching failure or quality degradation in the wireless link.

[0062] The device 200 for determining switching can determine a mode among the first mode and the second mode having different switching conditions as a switching mode according to the moving direction of the UAM aircraft 111, 112, and 113, thereby preventing switching failure or quality degradation in the wireless link in advance. Here, when the UAM aircraft 111, 112, and 113 move in a direction in which the strength of the signal beam of the serving cell is weakened, the device 200 for determining switching can determine the switching mode as the first mode, and when the UAM aircraft 111, 112, and 113 move in a direction in which the strength of the signal beam of the serving cell is enhanced, the device 200 for determining switching can determine the switching mode as the second mode. Here, since the UAM aircraft 111, 112 and 113 fly according to a preset flight route and a preset flight plan, the device 200 for determining switching can identify information about the moving direction of the UAM aircraft 111, 112 and 113, and can determine whether the UAM aircraft 111, 112 and 113 are moving in a direction in which the strength of the signal beam of the service cell is increased or in a direction in which the strength of the signal beam of the service cell is decreased, and can determine a mode between the first mode and the second mode.

[0063] The control of switching of the UAM aircraft 111, 112 and 113 to the first mode or the second mode is performed by the base station 120. The first mode may include at least one of the following items as a switching condition: when the signal strength of the serving cell is less than a preset first threshold, when the signal strength of the target cell is greater than the signal strength of the serving cell, and when the signal strength of the serving cell is less than a preset second threshold and the signal strength of the target cell is greater than a preset third threshold. The second mode may include at least one of the following items as a switching condition: when the signal strength of the serving cell is greater than a preset fourth threshold and when the signal strength of the target cell is greater than a preset fifth threshold.

[0064] In addition, the filter values ​​for determining the number of times the reference signal received power (RSRP) and the reference signal received quality (RSRQ) are averaged in the first mode and the second mode can be set differently. In addition, in order to prevent ping-pong, the hysteresis value can be set differently in the first mode and the second mode. For example, the hysteresis value can be set to be smaller in the second mode than in the first mode, and the filter value can be set to be larger in the second mode than in the first mode. When the hysteresis value is set to be smaller in the second mode than in the first mode and the filter value is set to be larger in the second mode than in the first mode, the measurement report sent by the UAM aircraft 111, 112 and 113 to the base station 120 can reflect more recent values, thereby triggering switching faster in the second mode than in the first mode. With these settings, even if the switching is performed a little earlier in the second mode than in the first mode, the signal of the target cell will gradually become better as the UAM aircraft moves. Therefore, a relatively more stable wireless communication environment can be established.

[0065] In addition, if Figure 4 As shown, the device 200 for determining switching can also obtain information about the moving directions of the UAM aircraft 111, 112 and 113 (S410) and current position information about the UAM aircraft 111, 112 and 113 (S420), or also obtain flight speed information about the UAM aircraft 111, 112 and 113 (S430), and as the number of types of information obtained increases, the switching mode is determined more accurately based on the information obtained (S440).

[0066] In step S420, when the current position information about the UAM aircraft 111, 112 and 113 is obtained, it can be determined whether the UAM aircraft 111, 112 and 113 are moving in a direction in which the strength of the signal beam of the service cell is weakened or in a direction in which the strength of the signal beam of the service cell is increased without referring to the preset flight routes and flight plans of the UAM aircraft 111, 112 and 113.

[0067] In addition, the determination of whether the UAM aircraft 111, 112, and 113 are moving in a direction in which the strength of the signal beam of the serving cell is weakened or in a direction in which the strength of the signal beam of the serving cell is enhanced can be performed in various forms. For example, the measurement reports of the UAM aircraft 111, 112, and 113 can be input into a pre-learned artificial neural network model to determine the direction using the output of the artificial neural network model, or to determine a mode among the first mode and the second mode each having a different switching condition.

[0068] In addition, in step S430, the device 200 for determining switching may obtain flight speed information about the UAM aircraft 111, 112, and 113, and determine the timing of switching by reflecting the flight speed information about the UAM aircraft 111, 112, and 113. For example, the device 200 for determining switching may determine the timing of requesting switching earlier when the flight speed of the UAM aircraft 111, 112, and 113 exceeds a predetermined value.

[0069] <Second Embodiment> Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6 .

[0070] The UAM aircraft 111, 112 and 113 operate flights along preset flight routes within the service area of ​​the airborne network 101, and send information about the movement directions of the UAM aircraft 111, 112 and 113 to a device 200 included in or combined with the base station 120 for determining switching.

[0071] Then, the communication unit 210 of the apparatus 200 for determining switching receives information about the moving directions of the UAM aircraft 111 , 112 , and 113 and transmits it to the processor unit 220 ( S310 ).

[0072] Next, the processor unit 220 determines a mode among the first mode and the second mode each having a different switching condition between the plurality of radio cells based on the information about the moving directions of the UAM aircraft 111 , 112 , and 113 ( S320 ).

[0073] In addition, the processor unit 220 may control the communication unit 210 to transmit the information about the switching mode determined at step S320 to the base station 120. The base station 120, which has received the information about the switching mode determined at step S320 from the apparatus 200 for determining switching, may determine the switching of the UAM aircraft 111, 112, and 113 according to the corresponding mode.

[0074] Reference Figure 6 , the difference between the first mode and the second mode having different switching conditions has been described above in the description of the first embodiment.

[0075] In the environment of the UAM operating system according to an embodiment of the present disclosure, when operating the flight in the first direction 601, the UAM aircraft 111, 112, and 113 moves in a direction in which the strength of the signal beam in the service cell weakens as the UAM aircraft 111, 112, and 113 moves within the service cell. In addition, when operating the flight in the second direction 602, the UAM aircraft 111, 112, and 113 moves in a direction in which the strength of the signal beam in the service cell strengthens as the UAM aircraft 111, 112, and 113 moves within the service cell.

[0076] As described above, the device 200 for determining switching can determine a mode among the first mode and the second mode, each of which has different switching conditions, as a switching mode according to the moving directions of the UAM aircraft 111, 112, and 113, thereby preventing in advance the switching failure or quality degradation in the wireless link that may occur when relying on the normal switching operation of the ground network. Here, the processor unit 220 of the device 200 for determining switching can compare the difference between the moving directions of the UAM aircraft 111, 112, and 113 and the direction of the signal beam of the base station 120 with a preset threshold value based on the information about the moving directions of the UAM aircraft 111, 112, and 113 and the direction of the signal beam of the base station 120 obtained in step S510, and when the difference between the two directions is equal to or less than the preset threshold value, the switching mode is determined to be the first mode, and when the difference between the two directions exceeds the preset threshold value, the switching mode is determined to be the second mode. Alternatively, instead of comparing the difference between the two directions with a threshold value, when the UAM aircraft 111, 112 and 113 move in a direction in which the strength of the signal beam of the serving cell weakens, the processor unit 220 of the device 200 for determining switching may determine the switching mode as a first mode, and when the UAM aircraft 111, 112 and 113 move in a direction in which the strength of the signal beam of the serving cell increases as they move, the processor unit 220 of the device 200 for determining switching may determine the switching mode as a second mode (S520).

[0077] Then, step S530 performed by the base station 120 can be inferred from the description given above by the first embodiment. The control of the switching of the UAM aircraft 111, 112 and 113 to the first mode or the second mode is performed by the base station 120. The first mode may include at least one of the following items as a switching condition: when the signal strength of the serving cell is less than a preset first threshold, when the signal strength of the target cell is greater than the signal strength of the serving cell, and when the signal strength of the serving cell is less than a preset second threshold and the signal strength of the target cell is greater than a preset third threshold. The second mode may include at least one of the following items as a switching condition: when the signal strength of the serving cell is greater than a preset fourth threshold and when the signal strength of the target cell is greater than a preset fifth threshold.

[0078] In addition, the filter value that determines the number of times RSRP and RSRQ are averaged in the first mode and the second mode can be set differently. In addition, in order to prevent jumping, the hysteresis value can be set differently in the first mode and the second mode. For example, the hysteresis value can be set to be smaller in the second mode than in the first mode, and the filter value can be set to be larger in the second mode than in the first mode. When the hysteresis value is set to be smaller in the second mode than in the first mode and the filter value is set to be larger in the second mode than in the first mode, the measurement report sent by the UAM aircraft 111, 112 and 113 to the base station 120 can reflect more recent values, thereby triggering switching faster in the second mode than in the first mode. With these settings, even if the switching is performed a little earlier in the second mode than in the first mode, the signal of the target cell will gradually become better as the UAM aircraft moves. Therefore, a relatively more stable wireless communication environment can be established.

[0079] Furthermore, each step included in the method of determining switching according to the above-described embodiment may be implemented as a computer program including instructions for allowing a processor to execute the steps.

[0080] In addition, a computer program including instructions for allowing a processor to execute each step included in the method of determining switching according to the above-described embodiment may be recorded on a computer-readable storage medium.

[0081] As described above, according to an embodiment of the present invention, when determining the switching between wireless cells of an onboard network of an aircraft (such as a UAM), different switching conditions can be applied according to the moving direction, thereby realizing a switching process optimized for the onboard network environment. For example, when the UAM aircraft moves in a direction in which the strength of the signal beam of the serving cell increases as the UAM aircraft moves, a switching error may occur due to the characteristics of the onboard network environment. In the onboard network environment, when the normal switching process in the ground network environment is applied, the strong signal beam of the serving cell at the boundary area of ​​the serving cell and the target cell is suddenly cut off. However, smooth switching is supported by a switching process optimized for the characteristics of the onboard network environment.

[0082] The combination of steps in each flowchart attached to the present disclosure can be performed by computer program instructions. Since computer program instructions can be installed on a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device, the instructions executed by the processor of the computer or other programmable data processing device create a device for performing the function described in each step of the flowchart. Computer program instructions can also be stored on a computer-available or computer-readable storage medium, which can be used for a computer or other programmable data processing device to implement functions in a specific manner. Therefore, instructions stored on a computer-available or computer-readable recording medium can also produce a product containing an instruction device for performing the function described in each step of the flowchart. Computer program instructions can also be installed on a computer or other programmable data processing device. Therefore, it is also possible to perform a series of operation steps on a computer or other programmable data processing device to create a computer executable process, and it is also possible to instruct the execution of a computer or other programmable data processing device to provide steps for performing the function described in each step of the flowchart.

[0083] In addition, each step may represent a module, segment or part of a code containing one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative embodiments, the functions mentioned in the steps may not occur in order. For example, two steps illustrated in succession may actually be performed substantially simultaneously, or steps may sometimes be performed in reverse order according to the corresponding functions.

[0084] The above description is merely an exemplary description of the technical scope of the present disclosure, and those skilled in the art will understand that various changes and modifications may be made without departing from the original features of the present disclosure. Therefore, the embodiments disclosed in the present disclosure are intended to explain rather than limit the technical scope of the present disclosure, and the technical scope of the present disclosure is not limited by the embodiments. The protection scope of the present disclosure should be interpreted based on the attached claims, and it should be understood that all technical scopes included in the equivalent scope of the present disclosure are included in the protection scope of the present disclosure.

[0085] According to one embodiment of the present invention, when determining the handover between wireless cells of an onboard network of an aircraft such as a UAM, different handover conditions may be applied according to the moving direction, thereby implementing a handover process optimized for the onboard network environment. These embodiments of the present invention may be used in various systems and prior art technologies that support wireless communications to aircraft such as a UAM.

Claims

1. A method for determining a handover to be performed by a device for determining a handover, the method comprising the following steps: obtaining information about a direction of movement of an aircraft operating a flight along a preset flight route within a service area of ​​an airborne network including a plurality of wireless cells; determining a mode among a first mode and a second mode each having a different switching condition between the plurality of wireless cells based on the information about the moving direction; as well as Whether to perform switching of the aircraft or a communication device installed at the aircraft for an onboard network is determined according to a switching condition corresponding to the determined mode.

2. The method according to claim 1, wherein: In the step of determining the mode, the mode is further determined based on current position information about the aircraft on the preset flight route.

3. The method according to claim 1, wherein: In the step of determining the mode, the mode is determined further based on flight speed information about the aircraft.

4. The method according to claim 1, wherein: In the step of determining the pattern, the pattern is determined further based on directionality information of a signal beam transmitted by a base station serving at least one of the plurality of wireless cells.

5. The method according to claim 1, wherein: In the step of determining the mode, one of the first mode and the second mode is determined according to a result of comparing a difference between a moving direction of the aircraft and a direction of a signal beam transmitted by a base station serving at least one of the plurality of wireless cells with a preset threshold.

6. The method according to claim 1, wherein: In the step of determining the mode, when the aircraft moves in a direction in which the strength of the signal beam of the serving cell weakens as the aircraft moves, the switching mode is determined to be the first mode, and when the aircraft moves in a direction in which the strength of the signal beam of the serving cell increases as the aircraft moves, the switching mode is determined to be the second mode.

7. The method according to claim 1, wherein: The first mode includes at least one of the following items as the switching condition: when the signal strength of the serving cell is less than a preset first threshold, when the signal strength of the target cell is greater than the signal strength of the serving cell, and when the signal strength of the serving cell is less than a preset second threshold and the signal strength of the target cell is greater than a preset third threshold, and The second mode includes at least one of the following items as the switching condition: when the signal strength of the serving cell is greater than a preset fourth threshold and when the signal strength of the target cell is greater than a preset fifth threshold.

8. The method according to claim 1, wherein: The hysteresis value is set smaller in the second mode than in the first mode, and the filter value determining the number of times reference signal received power RSRP and reference signal received quality RSRQ are averaged is set larger in the second mode than in the first mode.

9. The method according to claim 1, wherein: In the step of determining the handover, the timing of the handover is determined based on a remaining distance from the current position of the aircraft to a boundary between a serving cell and a target cell, and Wherein, the remaining distance in the second mode is set to be longer than the remaining distance in the first mode.

10. A device for determining a handover, the device comprising: a communication unit configured to communicate with an aircraft operating along a preset flight route within a service area of ​​an onboard network including a plurality of wireless cells; as well as a processor unit configured to control the communication unit, Wherein, after obtaining information about the moving direction of the aircraft, the processor unit determines a mode among a first mode and a second mode, each of which has different switching conditions between multiple wireless cells, based on the information about the moving direction, and determines whether to perform switching of the aircraft or a communication device for an onboard network installed at the aircraft according to the switching condition corresponding to the determined mode.

11. A non-transitory computer-readable storage medium storing a computer program, the computer program comprising instructions when executed by a processor, the instructions being used to allow the processor to perform a method for determining a handover, the method comprising the following steps: obtaining information about a direction of movement of an aircraft operating a flight along a preset flight route within a service area of ​​an airborne network including a plurality of radio cells; determining a mode among a first mode and a second mode each having a different switching condition between the plurality of wireless cells based on the information about the moving direction; as well as Whether to perform switching of the aircraft or a communication device installed at the aircraft for an onboard network is determined according to a switching condition corresponding to the determined mode.

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