KR20230163928A - Aircraft communication apparatus and method for handover thereof, apparatus for supporting mobile communication and method for supporting handover thereof - Google Patents

Abstract

A handover support method performed by a wireless communication support device that supports wireless communication for an aircraft according to an embodiment includes the steps of acquiring preset navigation route information for the aircraft, and providing wireless communication for the aircraft. It includes determining a handover order with serving cells among wireless cells based on the navigation route information, and transmitting information about conditional handover to the aircraft according to the determined handover order.

Description

Communication apparatus for aircraft and its handover method, wireless communication support apparatus and method for supporting handover thereof {Aircraft communication apparatus and method for handover thereof, apparatus for supporting mobile communication and method for supporting handover thereof}

The present invention relates to a communication device for an aircraft, a handover method using a communication device for an aircraft, a device supporting wireless communication for an aircraft, and a method for supporting handover using a device supporting wireless communication.

Recently, interest in urban air mobility (UAM) has been increasing, especially in developed countries, and Korea has also conducted a comprehensive demonstration of Korean-style urban air mobility and is on the verge of commercialization.

According to the Korean urban air traffic technology roadmap, the operating altitude of the UAM aircraft is expected to be approximately 300 to 600 meters, the maximum operating speed is expected to be approximately 320 km/h, and it is expected to be operated along a designated operating route.

Mobile communication base stations will be installed on the UAM aircraft's flight route to support data transmission and reception services for the UAM aircraft, and each base station is responsible for a certain range of communications. Cell coverage, which represents the communication range of a base station, varies depending on the base station's installation environment (e.g., city center, outskirts, countryside), and for communication performance analysis, the 3GPP standard defines base station spacing differently depending on the installation environment. In general, base station spacing is narrow in urban areas with many users, and widens in rural areas with few users. The operation of UAM aircraft basically considers the high-density environment of urban areas, and even if the base station spacing is widened assuming fewer users than a ground network, the fast aircraft operation speed allows handover to cross the cell boundary and move to another cell. It is bound to occur frequently.

When applying a general handover procedure in a mobile communication environment, the UAM aircraft can deliver a measurement report on the strength of the wireless channel to the source cell, and the base station of the source cell can determine the signal strength of the source cell. A handover procedure can be prepared when the signal strength of the source cell is lower than a certain threshold or the signal strength of the target cell is lower than that of the target cell. When the preparation is completed, a handover command can be sent to the UAM aircraft. The UAM aircraft can disconnect the uplink/downlink with the source cell and perform the connection procedure to the target cell, and after the connection procedure is performed smoothly, it can transmit and receive data through the uplink/downlink newly connected to the target cell.

However, as mentioned earlier, the maximum operating speed of a UAM aircraft is about 320 km/h, which can lead to rapid changes in the wireless channel environment for both the source cell and target cell. When a UAM aircraft passes the source cell and approaches the target cell, the signal strength of the source cell may suddenly deteriorate, and in this case, handover with the target cell must be performed quickly.

However, the delay that occurs between the UAM vehicle's measurement report operation, the source cell's handover procedure preparation and handover command transmission, and the UAM vehicle's handover command reception before starting the connection procedure to the target cell is due to the source cell and the upward linkage where the radio channel condition has already deteriorated. /Causes the problem of having to continue sending and receiving data through the downlink. This means that it may be difficult to obtain reliable UAM service communication quality in UAM operation scenarios where handovers frequently occur, and in particular, problems with transmission and reception of C2 (command & control) information related to UAM operation safety are highly likely to occur.

Republic of Korea Patent Publication No. 10-2232183, registration date: March 19, 2021.

According to an embodiment, a handover support method that supports smooth handover in supporting wireless communication for an aircraft such as UAM and a wireless communication support device that performs the same are provided.

In addition, a communication device for an aircraft, such as a UAM, can smoothly perform handover under the support of a wireless communication support device, and a handover method thereof is provided.

The problems to be solved by the present invention are not limited to those mentioned above, and other problems to be solved that are not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description.

A handover support method performed by a wireless communication support device that supports wireless communication for an aircraft according to the first aspect includes obtaining preset navigation route information for the aircraft, and providing wireless communication for the aircraft. Determining a combination of a source cell candidate and a target cell candidate for handover among wireless cells based on the navigation path information; conditional handover (CHO) according to the determined combination of the source cell candidate and the target cell candidate; ) and transmitting information about the aircraft to the aircraft.

A computer-readable recording medium storing a computer program according to a second aspect includes instructions for causing the computer program to cause a processor to perform the handover support method.

A wireless communication support device that supports wireless communication for an aircraft according to a third aspect includes an information acquisition unit that acquires preset navigation route information for the aircraft, a memory unit including a command, and executing the command, It includes a processor unit that processes the navigation route information, and a communication unit that communicates with the aircraft under the control of the processor unit, wherein the processor unit is configured to operate the aircraft among wireless cells that provide wireless communication for the aircraft. Based on the path information, the communication unit determines a combination of a source cell candidate and a target cell candidate for handover, and transmits information about conditional handover to the aircraft according to the determined combination of the source cell candidate and the target cell candidate. Control.

A handover method for wireless communication performed by a communication device for an aircraft according to the fourth aspect includes receiving information about a conditional handover from the wireless communication support device for wireless communication, and preset navigation route information of the aircraft. determining whether handover performance conditions are satisfied with respect to a target cell candidate for the conditional handover among wireless cells that include at least a portion of the navigation route according to the service area, and if the handover performance conditions are satisfied, in the source cell It includes performing a handover to the target cell candidate.

A computer program stored in a computer-readable recording medium according to the fifth aspect includes instructions for causing a processor to perform the handover method.

A communication device for an aircraft that performs handover for wireless cells providing wireless communication according to the sixth aspect includes a communication unit that performs wireless communication with the wireless communication support device for wireless communication, a memory unit including instructions, and , and a processor unit that controls performance of handover by the communication unit by executing the command, wherein the processor unit receives information about conditional handover from the wireless communication support device through the communication unit, and It is determined whether the handover performance condition is satisfied for "N" after the target cell of the conditional handover among the wireless cells that include at least a portion of the navigation route according to the set navigation route information as a service area, and if the handover performance condition is satisfied, , the communication unit is controlled to perform handover from the source cell to the target cell candidate.

According to the embodiment, in supporting wireless communication for aircraft such as UAM, smooth handover is supported. For this purpose, the combination of the source cell candidate and the target cell candidate is determined based on the flight route information of the aircraft, and then information on conditional handover is transmitted to the aircraft according to the determined combination of source cell candidate and target cell candidate, thereby performing a measurement report operation. Delays during handover are prevented through omission of the handover command transmission procedure and rapid handover processing according to the handover order on the navigation route.

Figure 1 is a configuration diagram of a UAM operation system including a communication device for an aircraft and a wireless communication support device according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of a wireless communication support device capable of configuring the UAM operation system of FIG. 1.
Figure 3 is a configuration diagram of a communication device for an aircraft that can configure the UAM operation system of Figure 1.
FIG. 4 is a flowchart illustrating an example of a signal processing and information transmission process of an aircraft communication device and a wireless communication support device that can configure the UAM operation system of FIG. 1.
FIG. 5 is a diagram illustrating the navigation routes of a plurality of UAM aircraft and wireless cells including at least a portion of the navigation routes as a service area.
Figures 6 and 7 show an example in which the handover procedure may vary depending on morphological differences in serving cells located on the navigation path of a UAM aircraft equipped with a communication device for the aircraft.
FIG. 8 is a flowchart illustrating another example of a signal processing and information transmission process of an aircraft communication device and a wireless communication support device that can configure the UAM operation system of FIG. 1.
FIG. 9 is a flowchart illustrating the process of selecting handover performance conditions when the signal processing and information transfer process of FIG. 8 is applied to the UAM operating system of FIG. 1.

The advantages and features of the present invention and methods for achieving them will become clear with reference to the embodiments described below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to be understood by those skilled in the art. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The terms used in this specification will be briefly explained, and the present invention will be described in detail.

The terms used in the present invention are general terms that are currently widely used as much as possible while considering the function in the present invention, but this may vary depending on the intention or precedent of a person working in the art, the emergence of new technology, etc. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the relevant invention. Therefore, the terms used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, rather than simply the name of the term.

When it is said that a part 'includes' a certain element throughout the specification, this does not mean excluding other elements, but may further include other elements, unless specifically stated to the contrary.

Additionally, the term 'unit' used in the specification refers to software or hardware components such as FPGA or ASIC, and the 'unit' performs certain roles. However, 'wealth' is not limited to software or hardware. The 'part' may be configured to reside on an addressable storage medium and may be configured to run on one or more processors. Therefore, as an example, 'part' refers to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, procedures, Includes subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. In order to clearly explain the present invention in the drawings, parts unrelated to the description are omitted.

Figure 1 is a configuration diagram of a UAM operation system including a communication device for an aircraft and a wireless communication support device according to an embodiment of the present invention.

Referring to FIG. 1, the UAM operation system 100 may include an aircraft communication device 110, a base station 120, a wireless communication support device 130, and UTM 140 (unmanned aircraft system traffic management). .

The communication device 110 for an aircraft can be mounted on a UAM aircraft and can use the mobile communication network 101 through the base station 120 under an environment in which wireless communication is supported by the wireless communication support device 130. This communication device 110 for an aircraft may be operated along an operation route according to operation route information preset in the PSU (provider of service for UAM) within the UTM 140, and includes at least a portion of the operation route as a service area. Handover can be sequentially performed on wireless cells of the mobile communication network 101. Let's take a look at this communication device 110 for an aircraft again with reference to FIG. 3.

The wireless communication support device 130 is a source cell candidate and a target cell candidate based on navigation route information preset in the UTM 140 among wireless cells that provide wireless communication for a UAM aircraft on which the aircraft communication device 110 is mounted. The combination and handover order are determined, and information about conditional handover is sent to the air vehicle communication device 110 through the base station 120 (e.g., the base station of the source cell) according to the determined combination of the source cell candidate and the target cell candidate. It can be delivered to . For example, when the mobile communication network 101 is implemented in 3GPP 4G/5G, the wireless communication support device 130 may be a mobility management entity (MME) or another entity constituting the core network. This wireless communication support device 130 will be looked at again with reference to FIG. 2.

The PSU in the UTM 140 can determine and set the operation route of the UAM aircraft based on relevant information such as departure point, destination, operation time, weather environment, etc. of the UAM aircraft equipped with the aircraft communication device 110. Navigation route information of the set UAM aircraft can be provided to the wireless communication support device 130.

FIG. 2 is a configuration diagram of a wireless communication support device 130 that can configure the UAM operation system 100 of FIG. 1.

Referring to FIG. 2, the wireless communication support device 130 includes an information acquisition unit 131, a processor unit 132, and a communication unit 133, and may further include a memory unit 134.

The information acquisition unit 131 can obtain preset navigation route information for a UAM aircraft equipped with the aircraft communication device 110 from the UTM 140, and provides the obtained navigation route information to the processor unit 132. can do. Here, the preset navigation route information for the UAM aircraft may be acquired in advance and stored in the memory unit 134, and in this case, the information acquisition unit 131 extracts the navigation route information from the memory unit 134 and processes it. It can be provided to unit 132.

The communication unit 133 performs communication with the aircraft communication device 110 mounted on the UAM aircraft under the control of the processor unit 132.

The memory unit 134 may store a computer program including at least one instruction that allows the processor unit 132 to perform a handover support method according to an embodiment of the present invention. Additionally, as mentioned above, navigation route information may be stored in the memory unit 134.

The processor unit 132 processes the navigation route information provided from the information acquisition unit 131. The processor unit 132 loads and executes the computer program stored in the memory unit 134, based on navigation route information among the wireless cells that provide wireless communication to the aircraft communication device 110 mounted on the UAM aircraft. Determine the combination of source cell candidate and target cell candidate. Here, the processor unit 132 may determine the handover order for multiple combinations. In addition, the processor unit 132 controls the communication unit 133 to transmit information about conditional handover to the communication device 110 for a UAM vehicle mounted on the UAM vehicle according to the determined combination of the source cell candidate and the target cell candidate. Here, the processor unit 132 may select serving cells among wireless cells that include at least a portion of the navigation route according to navigation route information as a service area. For example, the navigation route information may include latitude and longitude information for a plurality of locations on the navigation route, and the processor unit 132 may compare the information on the service areas of wireless cells with the latitude and longitude information. It can be determined whether at least part of the navigation route is included in the service area.

In addition, the processor unit 132 is capable of acquiring real-time flight route information for a UAM aircraft equipped with the aircraft communication device 110, and based on the result of comparing the preset flight route information and real-time flight route information, the UAM If the flight route of the aircraft is changed, the combination of source cell candidate and target cell candidate can be updated, and information on conditional handover updated according to the updated combination of source cell candidate and target cell candidate can be sent to the aircraft mounted on the UAM aircraft. It can be transmitted to the communication device 110.

In addition, when the communication device 110 for an aircraft or a UAM aircraft transmits a report related to location information and time information and the wireless communication support device 130 obtains it, the processor unit 132 provides information about the conditional handover. Information on the handover method selected according to the report of the corresponding UAM vehicle may be further included in the included handover performance conditions. For example, the handover performance conditions may include selecting one of the handovers based on the location information of the UAM vehicle, the handover based on the time information of the UAM vehicle, and the handover based on the RSRP value of the target cell candidate. .

Additionally, when the processor unit 132 updates the combination of the source cell candidate and the target cell candidate, the handover order may be updated together. In addition, the processor unit 132 operates when the UAM aircraft does not wirelessly connect to the source cell candidate or the target cell candidate included in the information about the conditional handover, or when the UAM aircraft wirelessly connects to a cell other than the source cell candidate and the target cell candidate. It can be determined that the operation route of the UAM aircraft has changed.

For example, information about conditional handover may include information about one or more target cell candidates adjacent to the UAM vehicle and handover performance conditions, and the handover performance condition may include the received signal reference power (RSRP) of one or more target cell candidates. ) A handover instruction to the target cell candidate with the maximum value may be included. Alternatively, information about conditional handover may include information about fallback to the source cell when handover from the source cell to the target cell is delayed or fails. Alternatively, the information about the conditional handover may include information about a plurality of target cell candidates and handover performance conditions corresponding to multiple handovers according to the consecutive handover order, and the handover performance conditions may include a plurality of target cell candidates. A handover instruction to the target cell candidate with the maximum RSRP value of may be included.

FIG. 3 is a configuration diagram of a communication device 110 for an aircraft that can configure the UAM operation system 100 of FIG. 1.

Referring to FIG. 3, the communication device 110 for an aircraft includes a communication unit 111 and a processor unit 112, and may further include a memory unit 113. This communication device 110 for an aircraft can be mounted on a UAM aircraft.

The communication unit 111 may perform wireless communication with the wireless communication support device 130 through the base station 120 and may perform handover to serving cells during wireless communication.

The memory unit 113 may store a computer program including at least one instruction that allows the processor unit 112 to perform a handover method for wireless communication according to an embodiment of the present invention.

The processor unit 112 can control the performance of handover by the communication unit 111 by loading and executing a computer program stored in the memory unit 113, and the memory unit 113 can control the performance of the handover by the processor unit 112. Various processing results can be stored.

In addition, the processor unit 112 may receive information about conditional handover from the wireless communication support device 130 through the communication unit 111, and at least part of the navigation route according to the preset navigation route information of the UAM aircraft. It can be determined whether handover performance conditions are satisfied for the target cell candidate for conditional handover among the wireless cells included in the service area, and if the handover performance conditions are satisfied, handover from the source cell to the target cell candidate can be performed. The communication unit 111 can be controlled.

For example, information about conditional handover may include information about fallback to the source cell in case of handover delay or failure from the source cell to the target cell, and the processor unit 112 may provide information about the fallback to the source cell when performing handover. If handover delay or handover failure occurs, it can fall back to the source cell.

Additionally, the information about the conditional handover may include information about a plurality of target cell candidates adjacent to the UAM vehicle, and when performing handover, the processor unit 112 sets the maximum RSRP value among the plurality of target cell candidates. Handover can be performed to a target cell candidate having .

In addition, information about conditional handover includes a plurality of targets corresponding to multiple consecutive handovers according to a handover order determined based on navigation route information among wireless cells that provide wireless communication for the aircraft communication device 110. Information about cell candidates may be included, and when performing handover, the processor unit 112 may perform handover to the target cell candidate having the maximum RSRP value among the plurality of target cell candidates. Alternatively, when a handover delay or handover failure occurs for a high-priority target cell candidate according to the handover order, the processor unit 112 selects a low-priority target cell based on information about a plurality of target sets corresponding to multiple handovers. Handover to the candidate can be performed.

FIG. 4 is a flowchart for explaining the signal processing and information transmission process of the aircraft communication device 110 and the wireless communication support device 130 that can configure the UAM operation system 100 of FIG. 1. Referring to FIG. 4, a handover method using the aircraft communication device 110 and a handover support method using the wireless communication support device 130 can be viewed.

FIG. 5 is a diagram illustrating the navigation routes of a plurality of UAM aircraft and wireless cells including at least a portion of the navigation routes as a service area.

Figures 6 and 7 show an example in which the handover procedure may vary depending on morphological differences in serving cells located on the navigation path of a UAM aircraft equipped with the aircraft communication device 110.

Hereinafter, with reference to FIGS. 1 to 7, a handover procedure for serving cells is performed during operation of the UAM aircraft by the UAM operation system 100 including the aircraft communication device 110 and the wireless communication support device 130. Let me explain an example of what happens.

First, the information acquisition unit 131 of the wireless communication support device 130 acquires preset navigation route information of UAM aircraft from the UTM 140, and transfers the obtained navigation route information to the processor unit of the wireless communication support unit 130. Provided in (132). Alternatively, the information acquisition unit 131 may extract navigation route information of UAM aircraft obtained in advance from the UTM 140 and stored in the memory unit 134 of the wireless communication support device 130, and extract the extracted navigation route information. Path information may be provided to the processor unit 132 (S501).

Then, the processor unit 132 determines a combination of the source cell candidate and the target cell candidate based on the navigation route information among the wireless cells that provide wireless communication for the vehicle communication device 110 mounted on the UAM vehicle. At this time, the handover order may be determined for multiple combinations.

The handover order that can be determined by the processor unit 132 can be viewed with reference to FIG. 5. As illustrated in FIG. 5, the first UAM vehicle 1 may be operated as a second navigation route 12 starting from a wireless cell (Cell #1), and the second UAM vehicle 2 may operate using a wireless cell (Cell #1). It can be operated as the first navigation route 11 with (Cell #1) as the starting point. In this case, the processor unit 132 performs a handover procedure from the source cell (Cell #1) to the target cell (Cell #4) and the source cell communication device (110) mounted on the first UAM vehicle (1). It may be decided to sequentially perform the handover procedure from (Cell #4) to the target cell (Cell #7). In addition, the processor unit 132 performs a handover procedure from the source cell (Cell #1) to the target cell (Cell #10) and the source cell (Cell #10). It may be decided to sequentially perform the handover procedure from #10) to the target cell (Cell #20) (S503).

Next, the processor unit 132 operates the communication unit 133 to transmit information about the conditional handover to the communication device 110 for a UAM vehicle mounted on the UAM vehicle according to the combination of the source cell candidate and the target cell candidate determined in step S503. The communication unit 133 transmits information about the conditional handover to the aircraft communication device 110 mounted on the UAM aircraft under the control of the processor unit 132 (S505).

Information about the conditional handover transmitted from the wireless communication support device 130 to the aircraft communication device 110 through step S505 may include information about target cell candidates for handover and handover performance conditions, and handover Performance conditions may include a case where the RSRP value of the source cell is smaller than the RSRP of the target cell candidate. In addition, the information about the conditional handover may include information about a plurality of target cell candidates adjacent to the UAM aircraft and handover performance conditions, and the handover performance condition is the target having the maximum value among the RSRP values of the plurality of target cell candidates. A handover instruction to a cell candidate may be included. Additionally, information about conditional handover may include information about fallback to the source cell in case of handover delay or failure from the source cell to the target cell. Additionally, information about conditional handover may include information about a plurality of target cell candidates corresponding to multiple consecutive handovers according to the handover order. For example, the vehicle communication device 110 mounted on the first UAM vehicle 1 is provided with information for handover from the source cell (Cell #1) to the target cell (Cell #4) as well as the target cell (Cell # 7) Information for handover and handover performance conditions can be provided in advance, and the handover performance conditions are the target with the larger RSRP value between the target cell (Cell #4) and the target cell (Cell #7). A handover instruction to the cell may be included.

Next, the communication unit 111 of the vehicle communication device 110 mounted on the UAM vehicle receives information about the conditional handover transmitted from the wireless communication support device 130 through the base station 120, and receives the received conditional handover information. Information about the handover is provided to the processor unit 112 of the aircraft communication device 110 (S507).

Then, the processor unit 112 determines whether handover performance conditions are satisfied for the target cell candidate included in the information about the conditional handover provided from the wireless communication support device 130 in step S505 (S509), and determines whether the handover performance condition is satisfied in step S505, and If the candidate satisfies the handover performance conditions, the communication unit 111 is controlled to perform handover from the source cell to the target cell candidate.

Here, as discussed above, the handover performance condition including the information about the conditional handover transmitted from the wireless communication support device 130 to the aircraft communication device 110 through step S505 is that the RSRP value of the source cell is a target cell candidate. Cases smaller than the RSRP of may be included. For example, the processor unit 112 of the vehicle communication device 110 mounted on the first UAM vehicle 1 determines that the RSRP value of the source cell (Cell #1) is smaller than the RSRP of the target cell (Cell #4). In this case, the communication unit 111 can be controlled to perform handover from the source cell (Cell #1) to the target cell (Cell #4).

Alternatively, the information about the conditional handover transmitted from the wireless communication support device 130 to the vehicle communication device 110 through step S505 includes information about a plurality of target cell candidates adjacent to the UAM vehicle and handover performance conditions. The handover performance condition may include an instruction for handover to the target cell candidate with the maximum RSRP value among the plurality of target cell candidates. For example, in the information about conditional handover transmitted to the vehicle communication device 110 mounted on the first UAM vehicle 1, the target cell (Cell #7) and the target cell (Cell #20) are target cell candidates. It may be included as, and the processor unit 112 of the aircraft communication device 110 is configured to operate on the source cell (Cell #4) when the RSRP of the target cell (Cell #7) is greater than the RSRP value of the source cell (Cell #20). ) can control the communication unit 111 to perform a handover from ) to the target cell (Cell #7).

Alternatively, the information about the conditional handover transmitted from the wireless communication support device 130 to the air vehicle communication device 110 through step S505 includes information about a fallback to the source cell in case of delay or failure of handover from the source cell to the target cell. may be included. For example, the processor unit 112 of the vehicle communication device 110 mounted on the first UAM vehicle 1 has a handover delay or failure from the source cell (Cell #1) to the target cell (Cell #4). If this occurs, the communication unit 111 can be controlled to perform a fallback to the source cell (Cell #1).

Alternatively, the information about the conditional handover transmitted from the wireless communication support device 130 to the aircraft communication device 110 through step S505 includes a plurality of target cell candidates corresponding to a plurality of consecutive handovers according to the handover order. Information about may be included. For example, the processor unit 112 of the vehicle communication device 110 mounted on the first UAM vehicle 1 has a handover delay or failure from the source cell (Cell #1) to the target cell (Cell #4). If this occurs, the communication unit 111 can be controlled to perform a handover from the source cell (Cell #1) directly to the target cell (Cell #7) without going through the source cell (Cell #4). As illustrated in FIG. 6, when the service area 601 of the serving cell located first on the navigation route 603 is much narrower than the service area 603 of the serving cell located behind it, the service area 601 is Handover failure to the target cell candidate may occur, and in this case, handover to the target cell candidate having the service area 602 can be performed. Alternatively, as illustrated in FIG. 7, when the navigation route 703 does not pass through the center of the service area 701, handover failure to a target cell candidate having the service area 701 may occur, in this case Handover to a target cell candidate having a service area 702 can be performed (S511).

Meanwhile, the flight route of a UAM aircraft equipped with the aircraft communication device 110 may suddenly change during operation. For example, if there is a risk of collision with an unnecessary object on the preset navigation route of the UAM aircraft, the navigation route may be changed. In preparation for this case, the processor unit 132 of the wireless communication support device 130 receives real-time navigation route information from the aircraft communication device 110 mounted on the UAM aircraft through the communication unit 131 or the information acquisition unit 131. It can be obtained through (S513), and when the navigation route of the UAM aircraft is changed based on the result of comparing the preset navigation route information and real-time navigation route information, the combination of the source cell candidate and the target cell candidate can be updated. For example, the processor unit 132 may determine if the UAM aircraft does not wirelessly connect to the source cell candidate or the target cell candidate included in the information about the conditional handover, or if the UAM aircraft does not wirelessly connect to a cell other than the source cell candidate and the target cell candidate. When connected, it can be determined that the navigation route of the UAM aircraft has changed (S515).

In this case, the communication unit 133 of the wireless communication support device 130 transmits information about the updated conditional handover under the control of the processor unit 132 to the vehicle communication device 110 mounted on the UAM vehicle, (S517), the communication unit 111 of the aircraft communication device 110 transmits information about the updated conditional handover to the processor unit 112 (S519).

Then, the processor unit 112 of the vehicle communication device 110 mounted on the UAM vehicle performs a handover for the target cell candidate included in the information about the conditional handover provided from the wireless communication support device 130 in step S517. It is determined whether the conditions are satisfied (S521), and if the target cell candidate satisfies the handover performance conditions, the communication unit 111 is controlled to perform handover from the source cell to the target cell candidate (S523). Since this handover procedure is performed similarly to steps S509 and S511, detailed description thereof will be omitted.

FIG. 8 is a flowchart illustrating another example of the signal processing and information transmission process of the aircraft communication device 110 and the wireless communication support device 130 that can configure the UAM operation system 100 of FIG. 1. Comparing the flowchart of FIG. 8 with the flowchart of FIG. 4, during operation of the UAM vehicle, the communication device 110 for the UAM vehicle transmits a report related to the location information and time information of the UAM vehicle, and the wireless communication support device 130 transmits a report related to the location information and time information of the UAM vehicle. It can be seen that a receiving process (S811) has been added.

According to the embodiment of FIG. 8, when the processor unit 132 of the wireless communication support device 130 acquires real-time navigation route information through the communication unit 131 or the information acquisition unit 131 in step S513, through step S811 A report related to the location information and time information of the UAM aircraft provided by the aircraft communication device 110 can be obtained.

In this case, the processor unit 132 may update the combination of the source cell candidate and the target cell candidate by reflecting the report related to the location information and time information of the UAM aircraft (S515), and may update the combination of the source cell candidate and the target cell candidate for the updated conditional handover. Information can be transmitted to the vehicle communication device 110 mounted on the UAM vehicle (S517). Here, according to one embodiment, the report of the UAM aircraft in step S811 is reflected in the information transfer process for conditional handover in steps S515 and S517. If step S811 is performed before step S503, the report of the UAM vehicle in step S811 may be reflected in the information transfer process for conditional handover in steps S503 and S505. This may mean that the wireless communication support device 130 can obtain a report related to the location information and time information of the UAM aircraft separately from the real-time navigation route information, and reflect this in the information about conditional handover. .

According to the embodiment of FIG. 8, the information about the conditional handover provided through step S517 may include information about one or more target cell candidates adjacent to the UAM vehicle and handover performance conditions, and the handover performance conditions included therein In this case, one of the handovers based on the location information of the UAM vehicle, the handover based on the time information of the UAM vehicle, and the handover based on the RSRP value of the target cell candidate may be selected according to the report of the corresponding UAM vehicle. In this way, an embodiment in which the processor unit 132 of the wireless communication support device 130 selects one of a plurality of handover methods is shown in the flowchart of FIG. 9.

Referring to FIG. 9, the processor unit 132 of the wireless communication support device 130 checks a report related to the location information and time information of the UAM aircraft obtained through step S811. For example, the report may provide information on whether the UAM aircraft has properly received a global positioning system (GPS) signal and/or a global navigation satellite system (GNSS) signal, and information on the location and/or location of the received GPS signal and/or GNSS signal. It may include information about whether the time has been synchronized (S901).

Then, the processor unit 132 can check whether the UAM aircraft that transmitted the report is synchronized to the GPS signal or GNSS signal, and can check whether the position accuracy is better than the preset reference accuracy. For example, location accuracy may be provided by the UAM aircraft as included in a report related to location information and time information (S903, S905).

According to the confirmation results of steps S903 and S905, the processor unit 132 performs one of the following: handover based on the location information of the UAM vehicle, handover based on the time information of the UAM vehicle, and handover based on the RSRP value of the target cell candidate. Selection information about the over method can be transmitted by including it in information about the conditional handover.

Here, the processor unit 132 may select handover based on the RSRP value of the target cell candidate before the UAM vehicle is synchronized to the GPS signal or GNSS signal. In this case, the UAM aircraft may not properly receive GPS signals or GNSS signals, and in this case, handover based on location information and/or time information cannot be performed, but handover based on RSRP values can be performed. It may be in a state (S911).

Additionally, after the UAM vehicle is synchronized to the GPS signal or GNSS signal, the processor unit 132 may select handover based on the time information of the UAM vehicle if the location accuracy of the UAM vehicle is not in good condition as it is below a preset level. In this case, it may be in a high-density environment with many other UAM aircraft nearby, where there is difficulty in receiving signals due to the actions of other UAM aircraft, or when the UAM aircraft in question makes a rotational maneuver. At this time, there is a possibility that the location accuracy of the relevant UAM aircraft may be significantly shaken, but time synchronization is likely to be maintained, so handover based on time information can be selected. Alternatively, it may be the case that the location accuracy received from the UAM vehicle differs from the expected value by a certain level, but is not at a level to determine that it has deviated from the flight path. In this case, the location accuracy may be low, so handover based on time information is performed. You can select (S907).

Alternatively, after the UAM vehicle is synchronized to the GPS signal or GNSS signal, the processor unit 132 may select handover based on the location information of the UAM vehicle if the location accuracy of the UAM vehicle is in a good condition above a preset level. Handover based on time information may cause changes in navigation speed due to environmental factors such as weather or wind, so when location accuracy is good, select handover based on location information to avoid deterioration in communication quality due to handover. It can be minimized (S909).

Thereafter, the processor unit 112 of the communication device 110 for an aircraft may perform steps S519 to S523 as previously described with reference to FIG. 4 . Here, when performing handover in step S523, information about the conditional handover reflecting the location/time information report in step S811 is transmitted through step S517, so the handover of the communication device 110 for an aircraft is carried out in various forms. It can be done.

The communication device 110 for an aircraft may determine whether the handover performance conditions included in the information about the conditional handover are satisfied differently depending on the situation.

When the aircraft communication device 110 performs handover based on the RSRP value, the criteria for determining whether the handover performance condition is satisfied can be adjusted according to the reference signal transmission period and average number of times for each cell. For example, if RSRP has not yet been measured a sufficient number of times or there are transmission problems with the serving cell other than signal strength, the handover operation to the target cell can be performed more quickly by adjusting the criteria for determining whether the handover performance conditions are satisfied. there is.

If there are multiple cells among target cell candidates that satisfy the handover performance conditions based on information about conditional handover, handover can be performed to the target cell with the highest satisfaction with the handover performance conditions among the plurality of target cell candidates. .

Fallback to the source cell has been previously described when the handover operation to the target cell fails or is delayed. In this case, the communication device 110 for an aircraft may not immediately fall back to the source cell, but may perform a handover to the target cell by checking whether there is a cell that satisfies the handover performance conditions based on information about the conditional handover among other target cell candidates. there is.

Meanwhile, the processor performs each step included in the handover method for wireless communication performed by the aircraft communication device 110 and the handover support method performed by the wireless communication support device 130 according to the above-described embodiment. It can be implemented as a computer program that includes instructions for performing the task.

In addition, the processor performs each step included in the handover method for wireless communication performed by the aircraft communication device 110 and the handover support method performed by the wireless communication support device 130 according to the above-described embodiment. A computer program including instructions for execution may be recorded on a computer-readable recording medium.

As described so far, according to an embodiment of the present invention, smooth handover is supported in supporting wireless communication for aircraft such as UAM. To this end, after determining the handover order of the serving cells based on the navigation route information of the aircraft, information on conditional handover is transmitted to the aircraft according to the determined handover order, thereby omitting measurement report operations and handover command transmission procedures, Delays during handover are prevented through rapid handover processing according to the handover order on the flight route.

Combinations of each step in each flowchart attached to the present invention may be performed by computer program instructions. Since these computer program instructions can be mounted on the processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, the instructions performed through the processor of the computer or other programmable data processing equipment perform the functions described in each step of the flowchart. It creates the means to carry out these tasks. These computer program instructions may also be stored on a computer-usable or computer-readable recording medium that can be directed to a computer or other programmable data processing equipment to implement a function in a particular way, so that the computer program instructions are computer-usable or computer-readable. The instructions stored in the recording medium can also produce manufactured items containing instruction means that perform the functions described in each step of the flowchart. Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in each step of the flowchart.

Additionally, each step may represent a module, segment, or portion of code containing one or more executable instructions for executing specified logical function(s). Additionally, it should be noted that in some alternative embodiments it is possible for the functions mentioned in the steps to occur out of order. For example, two steps shown in succession may in fact be performed substantially simultaneously, or the steps may sometimes be performed in reverse order depending on the corresponding function.

The above description is merely an illustrative explanation of the technical idea of the present invention, and those skilled in the art will be able to make various modifications and variations without departing from the essential quality of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted in accordance with the claims below, and all technical ideas within the scope equivalent thereto shall be construed as being included in the scope of rights of the present invention.

According to an embodiment of the present invention, in supporting wireless communication for aircraft such as UAM, handover is performed through omission of measurement report operations and handover command transmission procedures, and rapid handover processing according to the handover order on the navigation route. It supports smooth handover by preventing delays during processing. This embodiment of the present invention can be used in various systems and related technical fields that support wireless communication in aircraft such as UAM.

100: UAM operation system
110: Communication device for aircraft
130: Wireless communication support device
140:UTM

Claims (20)

A handover support method performed by a wireless communication support device that supports wireless communication for an aircraft, comprising:
Obtaining preset navigation route information for the aircraft;
determining a combination of a source cell candidate and a target cell candidate for handover based on the navigation route information among wireless cells that provide wireless communication for the aircraft;
Comprising the step of transmitting information about conditional handover (CHO) to the aircraft according to the determined combination of the source cell candidate and the target cell candidate.
How to support handover. According to claim 1,
The source cell candidate and the target cell candidate are selected from among wireless cells that include at least a portion of the navigation route according to the navigation route information as a service area.
How to support handover. According to claim 2,
The navigation route information includes latitude and longitude information for a plurality of locations on the navigation route,
When determining whether at least a portion of the navigation route is included in the service area, based on a result of comparing information on the service area of the wireless cells and the latitude and longitude information
How to support handover. According to claim 1,
Obtaining real-time flight route information for the aircraft;
updating the combination of the source cell candidate and the target cell candidate when the navigation route of the aircraft is changed based on a result of comparing the preset navigation route information and the real-time navigation route information;
Further comprising transmitting information about conditional handover updated according to the combination of the updated source cell candidate and the target cell candidate to the aircraft.
How to support handover. According to claim 4,
If the aircraft does not wirelessly connect to the source cell candidate or the target cell candidate included in the information about the conditional handover, or if the aircraft wirelessly connects to a cell other than the source cell candidate and the target cell candidate, the aircraft It is determined that the flight route has been changed.
How to support handover. According to claim 1,
Further comprising the step of obtaining a report related to the location information and time information of the aircraft,
The information about the conditional handover includes information about one or more target cell candidates adjacent to the aircraft and handover performance conditions,
The handover performance condition is that one of the handovers based on the location information of the aircraft, the handover based on the time information of the aircraft, and the handover based on the RSRP value of the target cell candidate is selected according to the report.
How to support handover. According to claim 6,
Before the aircraft is synchronized to the GPS signal or GNSS signal, handover based on the RSRP value of the target cell candidate is selected.
How to support handover. According to claim 7,
The information about the conditional handover includes information about one or more target cell candidates adjacent to the aircraft and handover performance conditions,
The handover performance condition includes a handover instruction to the target cell candidate having the maximum value among the received signal reference power (RSRP) values of the one or more target cell candidates.
How to support handover. According to claim 7,
The information about the conditional handover includes information about fallback to the source cell in case of delay or failure in handover from the source cell to the target cell.
How to support handover. According to claim 7,
The information about the conditional handover includes information about a plurality of target cell candidates corresponding to multiple consecutive handovers and handover performance conditions,
The handover performance condition includes a handover instruction to the target cell candidate with the maximum RSRP value of the plurality of target cell candidates.
How to support handover. According to claim 6,
After the aircraft is synchronized to the GPS signal or GNSS signal, either a handover based on the position information of the aircraft or a handover based on the time information of the aircraft is performed depending on whether the position accuracy of the aircraft is higher than a preset level. selected
How to support handover. A computer-readable recording medium storing a computer program,
The computer program is,
A computer-readable recording medium including instructions for causing a processor to perform the handover support method according to any one of claims 1 to 11. A wireless communication support device that supports wireless communication for an aircraft, comprising:
An information acquisition unit that acquires preset navigation route information for the aircraft,
A memory unit containing instructions,
A processor unit that performs processing on the navigation route information by executing the command,
Comprising a communication unit that performs communication with the aircraft under the control of the processor unit,
The processor unit,
Determining a combination of a source cell candidate and a target cell candidate for handover based on the navigation route information among wireless cells that provide wireless communication for the aircraft,
Controlling the communication unit to transmit information about conditional handover to the aircraft according to the determined combination of the source cell candidate and the target cell candidate.
A device that supports wireless communications. As a handover method for wireless communication performed by a communication device for an aircraft,
Receiving information about conditional handover from the wireless communication support device for wireless communication;
determining whether handover performance conditions are satisfied for a target cell candidate for the conditional handover among wireless cells whose service area includes at least a portion of the navigation route according to the preset navigation route information of the aircraft;
If the handover performance condition is satisfied, performing a handover from the source cell to the target cell candidate.
Handover method. According to claim 14,
The information about the conditional handover includes information about one or more target cell candidates adjacent to the aircraft and handover performance conditions,
The step of performing the handover is one of a handover based on the location information of the aircraft, a handover based on the time information of the aircraft, and a handover based on the RSRP value of the target cell candidate according to the handover performance conditions. Choosing a handover
Handover method. According to claim 15,
When handover based on the RSRP value of the target cell candidate is selected, handover is performed to the target cell candidate having the maximum value among the RSRP values of the one or more target cell candidates.
Handover method. According to claim 14,
The information about the conditional handover includes information about a fallback to the source cell when handover from a source cell to a target cell is delayed or fails,
If a handover delay or handover failure to the target cell occurs in the step of performing the handover, it further includes the step of falling back to the source cell.
Handover method. According to claim 14,
The information about the conditional handover includes information about a plurality of target cell candidates corresponding to multiple consecutive handovers,
The step of performing the handover includes performing a handover to the target cell candidate having the maximum value among the RSRP values of the plurality of target cell candidates.
Handover method. A computer program stored on a computer-readable recording medium,
The computer program is,
A computer program comprising instructions for causing a processor to perform the handover method according to any one of claims 14 to 18. A communication device for an aircraft that performs handover to wireless cells providing wireless communication, comprising:
a communication unit that performs wireless communication with a wireless communication support device for the wireless communication;
A memory unit containing instructions,
A processor unit that controls performance of handover by the communication unit by executing the command,
The processor unit,
Receive information about conditional handover from the wireless communication support device through the communication unit,
Determining whether handover performance conditions are satisfied for a target cell candidate for the conditional handover among wireless cells whose service area includes at least a portion of the navigation route according to the preset navigation route information of the aircraft,
If the handover performance condition is satisfied, controlling the communication unit to perform handover from the source cell to the target cell candidate.
Communication device for aircraft.

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