KR20240022851A - base station for aerial network and communication method thereof - Google Patents

Abstract

A communication method of a base station for an airspace network according to an embodiment includes determining the amount of interference caused to the ground network by an uplink signal of an aircraft performing communication using an airspace network, and based on the determined amount of interference, It includes transmitting a signal for controlling transmission power of the uplink signal of the aircraft.

Description

Base station for aerial network and communication method thereof {base station for aerial network and communication method thereof}

The present invention relates to a base station that supports airspace network communication for an aircraft and a communication method of the base station.

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 communication, so that the UAM aircraft can achieve cell coverage of the airspace network provided by the base stations. Communication can be carried out within.

However, one of the most important problems in building a 3GPP 5G/LTE airspace network for UAM services is interference between the ground network and the airspace network, and this interference between the ground network and the airspace network can be broadly divided into two types. One is the ground network uplink interference caused by the uplink transmission of the UAM aircraft, and the other is the downlink interference of the ground network terminal caused by the airborne network downlink transmission.

Among these interferences, terrestrial network uplink interference caused by the uplink signal of UAM aircraft is a problem that must be minimized in terms of providing 3GPP 5G/LTE commercial services. Uplink problems of terrestrial network base stations due to the interference may ultimately appear in the form of problems in the use of terrestrial network terminals, such as downlink/uplink speed problems and delays. In other words, there is a problem that terrestrial network uplink interference can significantly reduce the usability of terrestrial network users.

Republic of Korea Patent Publication No. 10-2011-0014239, published on February 10, 2011.

According to an embodiment, a base station for an airspace network that controls transmission power for an uplink signal based on the amount of interference that the uplink signal of the airspace network causes to a terrestrial network and a communication method thereof are 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.

The communication method of the base station for the airspace network according to the first aspect includes determining the amount of interference caused to the ground network by the uplink signal of the aircraft performing communication using the airspace network, and based on the determined amount of interference, It includes transmitting a signal for controlling transmission power of the uplink signal of the aircraft.

A base station for an airspace network according to a second aspect includes a communication unit that performs communication with an aircraft through an airspace network, and a processor unit that controls the communication unit, and the processor unit determines the level of interference caused by the uplink signal of the aircraft to the ground network. The amount is determined, and the communication unit is controlled to transmit a signal for controlling the transmission power of the uplink signal of the aircraft based on the determined amount of interference.

A computer-readable recording medium storing a computer program according to the third aspect includes instructions for causing the computer program to cause a processor to perform a communication method of the base station for the commercial and commercial network.

According to an embodiment, the transmission power for the uplink signal is controlled based on the amount of interference that the uplink signal of the airspace network causes to the terrestrial network. In this way, the transmission power for the uplink signal, which causes terrestrial network uplink interference, is directly reduced, thereby effectively reducing the terrestrial network uplink interference problem.

Figure 1 is a conceptual diagram showing an interference signal between an airspace network and a ground network of a UAM operation system including a base station for an airspace network according to an embodiment of the present invention.
Figure 2 is a configuration diagram of a base station for an airspace network according to an embodiment of the present invention.
Figure 3 is a flowchart illustrating a communication method performed by a base station for an airspace network according to an embodiment of the present invention.

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 conceptual diagram showing an interference signal between an airspace network and a ground network of a UAM operation system including a base station for an airspace network according to an embodiment of the present invention.

Referring to FIG. 1, the UAM operation system 100 includes a plurality of UAM vehicles 111 and 112 and a base station 110 for an airspace network. In addition, although not shown in FIG. 1, a server and UATM (unmanned aircraft system traffic management) that support the operation of the airspace network may be further included. Figure 1 shows two UAM vehicles 111 and 112, but this is an example and the number can be changed. In addition, although one base station 110 for the airspace network is shown in FIG. 1 as an example, the airspace network may be formed by a set of cell coverage provided by a plurality of base stations 110 for the airspace network.

A plurality of UAM aircraft 111 and 112 are operated along a navigation route according to navigation route information preset in the PSU (provider of service for UAM) within the UATM, and are operated by the airspace network base station 110 and a server (not shown). In an environment where wireless communication is supported, the airspace network can be used within the cell coverage provided by the airspace network base station 110.

The base station 110 for the airspace network provides mobile communication services through the airspace network to the UAM aircraft located within its cell coverage among the plurality of UAM aircraft 111 and 112. In addition, the base station 110 for the airspace network determines the amount of interference that the uplink signal of the UAM aircraft (111, 112) that performs communication using the airspace network causes to the ground network, and based on the identified amount of interference, the UAM aircraft A signal for controlling the transmission power of the uplink signal of (111, 112) is transmitted. This airspace network base station 110 may provide cell coverage to at least one cell among a plurality of mobile communication cells arranged in the direction of travel along the navigation path of the UAM aircraft 111 and 112. Let's look at the base station 110 for this airspace network again with reference to FIG. 2.

The server (not shown) is connected to mobile communication cells that provide mobile communication for a plurality of UAM vehicles 111 and 112 based on navigation route information of the UAM vehicles 111 and 112 preset in UATM (not shown). Information can be transmitted to the UAM aircraft (111, 112) through the airspace network base station (110). For example, if the commercial network is implemented with 3GPP 4G/5G, the server may be a mobility management entity (MME) or another entity that constitutes the core network.

The PSU in UATM (not shown) can determine and set the operation route of the UAM vehicles 111 and 112 based on related information such as the departure point, destination, operation time, and weather environment of the UAM vehicles 111 and 112. , the navigation route information of the UAM aircraft 111 and 112 set in this way can be provided to a server (not shown).

Looking at the communication link and interference signal in the UAM operation system 100 constructed including the base station 110 for the airspace network as illustrated in FIG. 1, communication between the base station 10 for the land network and the terminals 11 and 12 Links 21, 22, communication links 121, 112 between the base station 110 for the airborne network and the UAM aircraft 111, 112, interference signals 131, 132 for the ground network of the airborne network, and the airborne network of the ground network It can be seen that interference signals 141 and 142 may exist.

Figure 2 is a configuration diagram of a base station 110 for an airspace network according to an embodiment of the present invention.

Referring to FIG. 2, the base station 110 for the airspace network includes a communication unit 201 and a processor unit 202, and may further include a storage unit 203.

The communication unit 201 performs communication with a plurality of UAM aircraft 111 and 112 through an airspace network under the control of the processor unit 202.

The processor unit 202 controls the communication unit 201. This processor unit 202 determines the amount of interference that the uplink signal of the UAM vehicle (111, 112) causes to the ground network, and based on the identified amount of interference, it determines the amount of interference to the uplink signal of the UAM vehicle (111, 112). The communication unit 201 is controlled to transmit a signal for controlling the transmission power. When determining the amount of interference caused by the uplink signal of the UAM vehicle 111, 112 to the ground network, the processor unit 202 determines the amount of interference depending on the distance between the UAM vehicle 111, 112 and the base station 10 for the ground network. You can decide the amount. Alternatively, when the processor unit 202 determines the amount of interference that the uplink signal of the UAM vehicle (111, 112) causes to the ground network, the processor unit 202 determines the interference according to the operating altitude or antenna gain of the UAM vehicle (111, 112). The amount can be determined. Alternatively, when determining the amount of interference caused by the uplink signal of the UAM aircraft 111 and 112 to the terrestrial network, the processor unit 202 detects the interference according to the antenna tilt angle or beam pattern of the terrestrial network base station 10. The amount can be determined. Meanwhile, the processor unit 202 may control the communication unit 210 to transmit a signal for controlling transmission power when allocating uplink data transmission resources to the UAM aircraft 111 and 112.

In addition, when the processor unit 202 transmits a signal for controlling the transmission power of the uplink signal of the UAM vehicles 111 and 112, the UAM vehicles 111 and 112 are classified into a plurality of groups according to the operating altitude. Afterwards, signals for controlling the transmission power of the uplink signals of the UAM vehicles 111 and 112 may be transmitted according to different standards for a plurality of groups. Here, the plurality of groups includes a first group in a first operating altitude range and a second group in a second operating altitude range that is higher than the first operating altitude range, and the first group lowers the transmission power according to the amount of interference. A signal for controlling the transmission power may be transmitted to increase or decrease the transmission power, and the second group may transmit a signal for controlling the transmission power to increase the transmission power under a set condition.

The storage unit 203 may store various processing results by the processor unit 202 under the control of the processor unit 202. In this storage unit 203, a computer program including instructions that cause the processor unit 202 to perform each step according to the communication method of the base station for the air and air network according to an embodiment of the present invention may be stored.

Figure 3 is a flowchart illustrating a communication method performed by the base station 110 for the airspace network according to an embodiment of the present invention.

Hereinafter, with reference to FIGS. 1 to 3, we will look at the communication method performed by the airspace network base station 110 in the UAM operation system 100 with the UAM aircraft 111 and 112.

First, the processor unit 202 of the airborne network base station 110 determines the amount of interference that the uplink signals of the UAM aircraft 111 and 112 cause to the ground network.

Here, in order for the processor unit 202 to accurately determine the amount of interference that the uplink signals of the UAM vehicles 111 and 112 cause to the ground network, it is necessary to check various conditions affecting interference. Various conditions include the distance between the UAM vehicles 111 and 112 and the base station 10 for the ground network, the operating altitude or antenna gain of the UAM vehicles 111 and 112, and the antenna tilt angle of the base station 10 for the ground network. Or there is a beam pattern, etc. The processor unit 202 may reflect all of these various conditions to determine the amount of interference that the uplink signals of the UAM vehicles 111 and 112 cause to the ground network, and determine the condition that has the greatest impact on interference among the various conditions. You can also select to determine the amount of interference that the uplink signal of the UAM vehicle (111, 112) causes to the ground network.

It can be said that the strength of the uplink signal of the UAM vehicles 111 and 112 is most affected by distance conditions. According to the 3GPP standard document (TR 38.901), the pathloss (PL) amount, which indicates the degree to which an air network signal is attenuated according to distance, is expressed as Equation 1 below. In the equation below, d is the distance (unit: m) between the ground network base station 10 and the UAM aircraft (111, 112), and f is the frequency (unit: GHz) used for communication.

39.25+22·log10(d)으로 바뀌고, 운항 고도인 300~600m를 대입하면 93.75~100.37dB 정도의 값이 계산된다. 즉, UAM 비행체(111, 112)의 안테나 성능과 전송 전력 등의 조건은 동일하다고 가정할 경우, 고도 300m에서 운행하는 UAM 비행체(111, 112)는 고도 600m에서 운행하는 UAM 비행체(111, 112)에 비해 대략 7dB 정도 더 높은 간섭의 영향을 일으킨다고 볼 수 있다. 이를 반영하여, UAM 비행체(111, 112)의 운항 고도에 따라 전송 전력 조절을 다르게 운용할 수가 있다.For example, when the base station 110 for the airspace network uses the 5G frequency band of 3.6 ~ 3.7 GHz, the above formula is PL

It changes to 39.25+22·log10(d), and by substituting the operating altitude of 300~600m, a value of about 93.75~100.37dB is calculated. That is, assuming that the conditions such as antenna performance and transmission power of the UAM vehicles 111 and 112 are the same, the UAM vehicles 111 and 112 operating at an altitude of 300 m are equivalent to the UAM vehicles 111 and 112 operating at an altitude of 600 m. It can be seen that the effect of interference is approximately 7dB higher than that of . Reflecting this, transmission power control can be operated differently depending on the operating altitude of the UAM vehicles 111 and 112.

The antenna performance of the UAM vehicles 111 and 112 is expressed as antenna gain, and the greater the gain, the greater the amount of interference transmitted to the terrestrial network. For example, if UAM vehicle #1 with an antenna gain of 10dB and UAM vehicle #2 with an antenna gain of 20dB use the same transmission power at the same altitude, the impact of interference from UAM vehicle #2 may be 10dB greater. On the other hand, the impact of interference according to the tilt angle of the terrestrial network becomes smaller because the interference signal from the UAM aircraft 111 and 112 enters the back of the antenna of the terrestrial network base station 10 as the tilt angle becomes smaller. This is expressed as 90 degrees when the front of the antenna of the terrestrial network base station 10 is parallel to the ground surface, and as it tilts down to the ground, the angle is expressed as 80 degrees, 70 degrees, 60 degrees, ??, The higher you head into the sky, the more it is expressed as 100 degrees, 110 degrees, 124 degrees, and ??. The beam pattern determines the effect of interference by how much the beam angle is formed in the sky, which is also closely related to the amount of tilt angle. For example, if the beam used in the ground network can cover about 10 degrees up and down based on the antenna boresight, if it is not tilted, the beam pattern about 10 degrees above is the interference signal of the UAM aircraft (111, 112). However, if it is tilted down by 10 degrees, interference signals from that beam are not received.

As described above, since the interference caused by the uplink signal of the UAM vehicle (111, 112) to the ground network is affected by various conditions, the processor unit 202 provides the uplink signal of the UAM vehicle (111, 112) to the ground network. When determining the amount of interference caused, the distance between the UAM vehicles 111 and 112 and the ground network base station 10, the operating altitude or antenna gain of the UAM vehicles 111 and 112, the antenna tilt angle of the ground network base station 10, or The amount of interference can be determined according to the beam pattern (S310).

And, the processor unit 202 controls the communication unit 201 to transmit a signal for controlling the transmission power of the uplink signal of the UAM aircraft 111 and 112 based on the amount of interference identified in step S310, The communication unit 201 transmits a signal for controlling the transmission power of the uplink signal to the UAM aircraft 111 and 112 under the control of the processor unit 202. Here, the processor unit 202 may control the communication unit 210 to transmit a signal for controlling transmission power when allocating uplink data transmission resources to the UAM aircraft 111 and 112, but is not limited to this period. (S330)

In this way, controlling and changing the transmission power of the UAM vehicles 111 and 112 through step S330 can be performed in various forms. For example, the maximum transmission power of all UAM aircraft 111 and 112 connected to the airspace network base station 110 can be limited. For example, a signal for controlling transmission power can be transmitted by including it in broadcast information periodically transmitted from the airspace network base station 110, and the UAM aircraft 111 and 112 that receive this can use the maximum available The transmission power can be limited to the smaller of the transmission power and the maximum transmission power of the air network cell. In this case, the amount of interference of the UAM aircraft (111, 112) operating within the airspace network cell coverage can be lowered below a certain level, but it cannot be set differently depending on the operating altitude of the UAM aircraft (111, 112).

When the airspace network base station 110 allocates time and/or frequency as uplink data transmission resources to the UAM vehicles 111 and 112, a signal for controlling transmission power is transmitted to the UAM vehicles 111 and 112. Transmission power can be adjusted only for interfering UAM vehicles. However, only for data transmission among uplink signals, transmission power can be changed directly through DCI (Downlink Control Information) control information, and control signals (e.g., ACK/NACK transmission for downlink data reception, channel status information (channel status information) Changes in transmission power of status information (feedback transmission, etc.) and reference signals (e.g., sounding reference signal (SRS), etc.) must be changed through an RRC message, so it may be difficult to apply them immediately.

In addition, when transmitting a signal for controlling the transmission power, if it is desired to change the transmission power by a value that exceeds the predetermined power control range, the signal for controlling the transmission power is transmitted multiple times as necessary to change the transmission power. can be controlled. For example, when you want to lower the transmission power by 5dB, you can control the transmission power by transmitting a signal for controlling the transmission power 5 times at 1dB increments.

Meanwhile, the airspace network base station 110 may group the UAM vehicles 111 and 112 (S320) and control and change the transmission power of the UAM vehicles 111 and 112 for each group (S330). For example, the processor unit 202 classifies the UAM vehicles 111 and 112 into a plurality of groups according to operating altitude, and then performs the uplink of the UAM vehicles 111 and 112 according to different standards for the plurality of groups. A signal for control of transmission power for the signal can be transmitted. Here, the plurality of groups includes a first group in a first operating altitude range and a second group in a second operating altitude range that is higher than the first operating altitude range, and the first group lowers the transmission power according to the amount of interference. A signal for controlling the transmission power may be transmitted to increase or decrease the transmission power, and the second group may transmit a signal for controlling the transmission power to increase the transmission power under a set condition. Through this, the processor unit 202 can increase the uplink data transmission power of the UAM vehicles 111 and 1112 and lower the transmission power of the control signal and reference signal even within the same group depending on the situation. For example, UAM aircraft operating at low altitudes can be grouped to lower transmission power when the impact of interference is large and increase transmission power when the impact of interference is low. On the other hand, UAM aircraft operating at high operating altitudes can be grouped together to perform operations to increase power when necessary.

Meanwhile, a computer program may be implemented to include instructions for causing a processor to perform each step included in the communication method performed by the airspace network base station 110 according to the above-described embodiment.

In addition, a computer program including instructions for causing a processor to perform each step included in the communication method performed by the airspace network base station 110 according to the above-described embodiment may be recorded on a computer-readable recording medium.

As described so far, according to an embodiment of the present invention, the transmission power for the uplink signal is controlled based on the amount of interference that the uplink signal of the airspace network causes to the terrestrial network. In this way, the transmission power for the uplink signal, which causes terrestrial network uplink interference, is directly reduced, thereby effectively reducing the terrestrial network uplink interference problem.

If the amount of interference in the ground network does not fall below a certain level even though the transmission power of the uplink signal of the airspace network is sufficiently lowered, the communication resources of the ground network and the airspace network are operated separately. For example, in the case of time resource separation, the ground network and the airspace network can operate by setting different time slots/symbols, and in the case of frequency resource separation, the ground network and the airspace network can operate in different time slots/symbols. ) can be used separately. The degree of resource utilization can be determined according to the traffic load of the ground network and airspace network.

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, the transmission power for the uplink signal is controlled based on the amount of interference that the uplink signal of the airspace network causes to the terrestrial network. In this way, the transmission power for the uplink signal, which causes terrestrial network uplink interference, is directly reduced, thereby effectively reducing the terrestrial network uplink interference problem. This embodiment of the present invention can be used in various systems and related technical fields that provide mobile communication services to aircraft such as UAM.

100: UAM operation system
110: Base station for airspace network
111, 112: UAM aircraft
10: Base station for terrestrial network
11, 12: Terminal

Claims (8)

As a communication method of a base station for an airspace network,
A step of determining the amount of interference caused to the ground network by the uplink signal of the aircraft performing communication using the airspace network;
Comprising the step of transmitting a signal for controlling transmission power for the uplink signal of the aircraft based on the identified amount of interference.
Communication method of base station for commercial network. According to claim 1,
The step of determining the amount of interference is,
Determining the amount of interference according to the distance between the aircraft and the base station for the ground network
Communication method of base station for commercial network. According to claim 1,
The step of determining the amount of interference is,
Determining the amount of interference according to the operating altitude or antenna gain of the aircraft
Communication method of base station for commercial network. According to claim 1,
The step of determining the amount of interference is,
Determining the amount of interference according to the antenna tilt angle or beam pattern of the terrestrial network base station
Communication method of base station for commercial network. According to claim 1,
Transmitting a signal for controlling the transmission power when allocating uplink data transmission resources to the aircraft
Communication method of base station for commercial network. According to claim 1,
The aircraft is plural,
The step of transmitting a signal for controlling the transmission power includes:
Classifying the plurality of aircraft into a plurality of groups according to operating altitude;
Comprising the step of transmitting a signal for controlling the transmission power according to different standards for the plurality of groups.
Communication method of base station for commercial network. According to claim 6,
The plurality of groups includes a first group in a first operating altitude range and a second group in a second operating altitude range higher than the first operating altitude range,
The first group transmits a signal for controlling the transmission power to lower or increase the transmission power depending on the amount of interference,
The second group transmits a signal for controlling the transmission power to increase the transmission power under a set condition.
Communication method of base station for commercial network. A communications department that carries out communications through aircraft and airspace networks,
It includes a processor unit that controls the communication unit,
The processor unit,
Determine the amount of interference that the uplink signal of the aircraft causes to the ground network, and control the communication unit to transmit a signal for controlling the transmission power of the uplink signal of the aircraft based on the determined amount of interference. doing
Base station for commercial network.

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