KR20220061902A - Method and apparatus for controlling beam in wireless communication system - Google Patents

Abstract

The present invention relates to a method and apparatus for controlling a beam in a wireless communication system to effectively perform a beam alignment operation for communication between communication nodes. According to one embodiment of the present invention, a beam alignment method performed by a first communication node in a communication system comprises the following steps of: determining the location of a first antenna of the first communication node; setting a first coordinate system on the basis of the location information of the first antenna; checking the location of a second antenna of a second communication node of the communication system; converting location information of the second antenna into coordinate information on the basis of the first coordinate system; calculating a direction change value of the first antenna on the basis of the location information of the second antenna transformed on the basis of the first coordinate system; changing a direction of the first antenna on the basis of the direction change value of the first antenna; and updating a beam alignment state between the first and second antennas.

Description

Beam control method and apparatus in a wireless communication system

The present invention relates to a beam control technology in a wireless communication system, and more particularly, to a communication node mounted on an aerial mobile such as a drone, and beam alignment ( alignment) relates to a beam control technique for effectively controlling an operation.

With the development of information and communication technology, various wireless communication technologies are being developed1. Representative wireless communication technologies include long term evolution (LTE) and new radio (NR) defined in 3rd generation partnership project (3GPP) standards. LTE may be one of 4G (4th Generation) wireless communication technologies, and NR may be one of 5G (5th Generation) wireless communication technologies. Recently, research on 6G (6th Generation) wireless communication technologies, which is a technology after 5G wireless communication, is also being conducted.

Recently, the use of an aerial vehicle (AV) such as a drone or an unmanned aerial vehicle (UAV) has been widely spread around the world. In 5G or later wireless communication technology, research is being conducted to construct a radio access network using a base station (hereinafter, referred to as a public base station) mounted on a public mobile body. Aerial base station (ABS) is mounted on aerial moving objects such as drones, airships, and air balloons to form cell coverage in places where existing communication infrastructure is not established, such as disaster situations or rescue sites, to provide users or terminals with It may have the advantage of being able to provide a service. The public base station may communicate with the ground in a wired or tethered manner. Alternatively, the public base station may communicate with communication nodes on the ground or in the air using a radio link. A public base station may have an advantage that it is less likely to experience a communication failure due to an obstacle on a wireless communication path, compared to a base station located on the ground.

Meanwhile, a public base station may perform wireless communication using a beam in a relatively high frequency band in order to improve communication quality of a wireless link. Beam alignment between the public base station and other communication nodes may greatly affect the communication quality between the public base station and other communication nodes. Unlike a base station located on the ground, an aerial base station may cause an error in beam alignment due to an aerial stop error or a positioning error. In order for a public base station to achieve a required communication quality, a technique capable of effectively performing beam alignment control according to initial beam alignment and subsequent stopping and movement of the aerial base station may be required.

Matters described in this background section are prepared to enhance understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

An object of the present invention to achieve the above needs is to improve communication quality of a public base station by effectively controlling a beam alignment operation in which a public base station aligns beams for communicating with other communication nodes on the ground or in the air. To provide a method and apparatus for controlling a public base station.

A beam alignment method performed by a first communication node in a communication system according to an embodiment of the present invention for achieving the above object, the step of determining a position of a first antenna of the first communication node, the first setting a first coordinate system based on the physical location and direction of the first antenna based on the information on the location of the antenna; confirming the location of a second antenna of a second communication node of the communication system; converting information on the position of a second antenna into coordinate information based on the first coordinate system; based on the position information of the second antenna transformed based on the first coordinate system, the direction change value of the first antenna , changing the direction of the first antenna based on the direction change value of the first antenna, and updating a beam alignment state between the first and second antennas.

The first coordinate system may be a VWU coordinate system in which the physical location of the first antenna is the origin and the direction of the first antenna is the V-axis.

The updating may include reconfirming the position information of the first antenna when a predetermined timer event occurs, updating the first coordinate system based on the information on the position of the first antenna, and the updating Re-converting the location information of the second antenna based on the first coordinate system, and based on the re-transformed location information of the second antenna, comprising the steps of recalculating the direction change value of the first antenna can do.

The recalculating the direction change value of the first antenna may include comparing the recalculated direction change value of the first antenna with a preset change margin, and the recalculated direction change value of the first antenna When the set change margin is exceeded, the method may include changing the direction of the first antenna again based on the re-calculated change value of the direction of the first antenna.

The beam alignment method includes: receiving a first signal transmitted from the second communication node; and adjusting the beam alignment state between the first and second antennas based on information included in the first signal may further include.

The first signal includes information on a transmission (TX) power and a beam width of a beam transmitted from the second communication node, and the adjusting includes, based on the information included in the first signal, the second Calculating an expected range of a received power (RP) when a beam transmitted from a communication node is received by the first antenna, receiving a beam transmitted from the second communication node, the second communication Calculating the RP of the beam transmitted from the node, and when the RP of the beam transmitted from the second communication node is within the expected range of the RP, determining that the beam alignment state is normal.

The first signal includes information on a transmission (TX) power and a beam width of a beam transmitted from the second communication node, and the adjusting includes, based on the information included in the first signal, the second Calculating an expected range of a received power (RP) when a beam transmitted from a communication node is received by the first antenna, receiving a first beam transmitted from the second communication node, the first Calculating the RP of one beam, when the RP of the first beam is outside the expected range of the RP, estimating an optimal reception point through physical control of the first antenna, and the estimated optimal It may include controlling the first antenna based on the reception point of.

The estimating of the optimal reception point includes receiving beams transmitted from the second communication node through the first antenna at each of the three predetermined points, and measuring the beams measured at the three predetermined points. based on the RP values, estimating a specific point between the three predetermined points as the optimal reception point, wherein the three predetermined points are the beams transmitted from the second communication node. It may be determined based on any one of a projected area projected from the position of the first communication node, or a maximum rotation angle supported by the direction control device in which the antenna of the first communication node is installed.

The estimating of the optimal reception point includes receiving beams transmitted from the second communication node through the first antenna at each of the three predetermined points, and measuring the beams measured at the three predetermined points. based on the RP values, estimating a specific point between the three predetermined points as the optimal reception point, wherein the three predetermined points are located in the air mobile unit equipped with the first communication node. It may be determined based on a predetermined movement interval criterion set for the .

In the adjusting, the beam alignment state is determined based on at least one of information on the position of the second antenna included in the first signal or position information of the first antenna recognized by the second communication node. determining whether the beam alignment state is normal, and when it is determined that the beam alignment state is not normal, adjusting the beam alignment state by physically controlling the first antenna based on information included in the first signal may include

In the adjusting, the beam alignment state is determined based on at least one of information on the position of the second antenna included in the first signal or position information of the first antenna recognized by the second communication node. determining whether or not the beam alignment is normal; and when it is determined that the beam alignment state is not normal, the beam by physically controlling the aerial mobile on which the first communication node is mounted based on the information included in the first signal You can adjust the sorting state.

The beam alignment method includes the steps of: confirming movement path information of the second communication node; The method may further include transmitting to the first communication node, and changing the direction of the first antenna based on information indicated by the second signal.

The beam alignment method includes: identifying replacement information indicating that a third communication node of the communication system will replace the second communication node; based on the replacement information, the second antenna and the third communication node transmitting a third signal instructing not to change the direction of the third antenna for a predetermined time to the second and third communication nodes, and based on the information indicated by the second signal, the first antenna It may further include the step of changing the direction of.

A first communication node for performing beam alignment in a communication system according to another embodiment of the present invention for achieving the above object includes a processor, a memory in electronic communication with the processor, and instructions stored in the memory, wherein when the instructions are executed by the processor, the instructions cause the first communication node to determine a location of a first antenna of the first communication node; Based on the information on the position of the first antenna, a first coordinate system is set based on the physical position and direction of the first antenna, and the position of the second antenna of the second communication node of the communication system is confirmed, The information on the position of the second antenna is converted into coordinate information based on the first coordinate system, and the direction change value of the first antenna is based on the position information of the second antenna converted based on the first coordinate system. , change the direction of the first antenna based on the direction change value of the first antenna, and update the beam alignment state between the first and second antennas.

The first coordinate system may be a VWU coordinate system in which the physical location of the first antenna is the origin and the direction of the first antenna is the V-axis.

The instructions allow the first communication node to reconfirm the information on the position of the first antenna when a predetermined timer event occurs, and update the first coordinate system based on the information on the position of the first antenna; further transforming the position information of the second antenna based on the updated first coordinate system, and re-calculating the direction change value of the first antenna based on the transformed position information of the second antenna again can act to cause

The instructions allow the first communication node to receive a first signal transmitted from the second communication node, and determine the beam alignment state between the first and second antennas based on information included in the first signal. may act to cause further adjustment.

The commands are a second signal instructing the first communication node to check the movement path information of the second communication node and change the direction of the second antenna based on the movement path information of the second communication node to the first communication node, and based on information indicated in the second signal, to change the direction of the first antenna.

The instructions determine, by the first communication node, replacement information indicating that a third communication node of the communication system will replace the second communication node, and based on the replacement information, the second antenna and the second communication node. A third signal instructing not to change the direction of the third antenna of the third communication node for a predetermined time is transmitted to the second and third communication nodes, and based on the information indicated by the second signal, the second 1 may be operable to further cause changing the direction of the antenna.

According to an embodiment of the present invention, a beam alignment operation for communication between a communication node mounted on a public mobile object such as a public base station and another communication node can be effectively performed. To this end, each communication node may process coordinate information based on a plurality of coordinate systems such as a GPS coordinate system, a geocentric coordinate system (GCS), an RVCS coordinate system, and a PAH coordinate system. According to an embodiment of the present invention, a public base station performing communication in the air can effectively maintain a wireless connection with other communication nodes on the ground or in the air, such as a wireless backhaul link for communication with a core network.

1 is a conceptual diagram illustrating an embodiment of a communication system.
2 is a block diagram illustrating an embodiment of a communication node constituting a communication system.
3A and 3B are block diagrams for explaining an embodiment of an apparatus for controlling a public base station in a communication system.
4A to 4C are conceptual diagrams for explaining a first embodiment of a beam control method in a communication system.
5A and 5B are conceptual diagrams for explaining a first embodiment of a method for expressing coordinate information in a communication system.
6A and 6B are conceptual diagrams for explaining embodiments of a method for expressing direction information in a communication system.
7 is a conceptual diagram for explaining a second embodiment of a beam control method in a communication system.
8 is a conceptual diagram for explaining a second embodiment of a method for expressing coordinate information in a communication system.
9 is a conceptual diagram for explaining a third embodiment of a method for expressing coordinate information in a communication system.
10 is a conceptual diagram for explaining a fourth embodiment of a method for expressing coordinate information in a communication system.
11 is a flowchart for explaining a third embodiment of a beam control method in a communication system.
12 is a flowchart for explaining a fourth embodiment of a beam control method in a communication system.
13A and 13B are exemplary views for explaining a fifth embodiment of a beam control method in a communication system.
14A to 14D are exemplary views for explaining a sixth embodiment of a beam control method in a communication system.
15A to 15C are exemplary views for explaining a seventh embodiment of a method for controlling a beam in a communication system.
16A to 16C are exemplary views for explaining an eighth embodiment of a beam control method in a communication system.
17 is a flowchart for explaining a ninth embodiment of a beam control method in a communication system.
18A to 18C are exemplary views for explaining a tenth embodiment of a beam control method in a communication system.
19A and 19B are conceptual diagrams for explaining an eleventh embodiment of a beam control method in a communication system.
20A and 20B are conceptual diagrams for explaining a twelfth embodiment of a beam control method in a communication system.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

A communication system to which embodiments according to the present invention are applied will be described. The communication system to which the embodiments according to the present invention are applied is not limited to the content described below, and the embodiments according to the present invention can be applied to various communication systems. Here, a communication system may be used in the same sense as a communication network (network).

Throughout the specification, a network is, for example, a wireless Internet such as WiFi (wireless fidelity), a wireless broadband internet (WiBro) or a mobile Internet such as a world interoperability for microwave access (WiMax), a global system for mobile communication (GSM). ) or 2G mobile communication network such as CDMA (code division multiple access), WCDMA (wideband code division multiple access) or 3G mobile communication network such as CDMA2000, high speed downlink packet access (HSDPA) or high speed uplink packet access (HSUPA) such as It may include a 3.5G mobile communication network, a 4G mobile communication network such as a long term evolution (LTE) network or an LTE-Advanced network, and a 5G mobile communication network.

Throughout the specification, a terminal refers to a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, and an access terminal. and the like, and may include all or some functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, and the like.

Here, a desktop computer that can communicate with a terminal, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch (smart watch), smart glass, e-book reader, PMP (portable multimedia player), portable game console, navigation device, digital camera, DMB (digital multimedia broadcasting) player, digital voice Digital audio recorder, digital audio player, digital picture recorder, digital picture player, digital video recorder, digital video player ) can be used.

Throughout the specification, a base station is an access point, a radio access station, a Node B, an advanced nodeB, a base transceiver station, MMR ( It may refer to mobile multihop relay)-BS, etc., and may include all or some functions of a base station, an access point, a radio access station, a Node B, an eNodeB, a transceiver base station, and an MMR-BS.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate the overall understanding, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

1 is a conceptual diagram illustrating an embodiment of a communication system.

Referring to FIG. 1 , the communication system 100 may include one or more communication nodes 111 , 112 , 113 , 121 , 123 , 131 , 132 , 133 , 140 , 150 , and 180 . At least some of the one or more communication nodes (111, 112, 113, 121, 123, 131, 132, 133, 140, 150, 180) 4G communication defined in the 3rd generation partnership project (3GPP) standard (eg, It may support long term evolution (LTE), advanced LTE (LTE-A), 5G communication (eg, new radio (NR)), or wireless communication after 5G (eg, 6G communication, etc.). 4G communication may be performed in a frequency band of 6 GHz or less. 5G communication or wireless communication after 5G may be performed not only in a frequency band of 6 GHz or less, but also in a frequency band of 6 GHz or more. Meanwhile, at least some of the one or more communication nodes 111 , 113 , 121 , 123 , 131 , 132 , 133 , 140 , 150 , 180 may perform mutual communication according to an independent method or an independent standard. For example, an embodiment of the communication system 100 may include a first base station 111 , a second base station 121 , and/or a core network 150 . The first base station 111 and the second base station 121 may support an orthogonal frequency division multiplexing (OFDM)-based 4G communication protocol, a 5G communication protocol, and/or an evolved communication protocol after 5G. Here, when the communication system 100 supports 4G communication, the core network 150 is a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), and a mobility management entity (MME). and the like. When the communication system 100 supports 5G communication, the core network may include a user plane function (UPF), a session management function (SMF), an access and mobility management function (AMF), and the like. Meanwhile, each of the one or more communication nodes 111 , 112 , 113 , 121 , 123 , 131 , 132 , 133 , 140 , 150 , 180 constituting the communication system 100 may have the following structure.

2 is a block diagram illustrating an embodiment of a communication node constituting a communication system.

Referring to FIG. 2 , the communication node 200 may include at least one processor 210 , a memory 220 , and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240 , an output interface device 250 , a storage device 260 , and the like. Each of the components included in the communication node 200 may be connected by a bus 270 to communicate with each other.

However, each of the components included in the communication node 200 may not be connected to the common bus 270 but to the processor 210 through an individual interface or an individual bus. For example, the processor 210 may be connected to at least one of the memory 220 , the transceiver 230 , the input interface device 240 , the output interface device 250 , and the storage device 260 through a dedicated interface. .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260 . The processor 210 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be configured as at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1, an embodiment of a communication system 100 including a public base station includes one or more base stations 111, 121, one or more users or terminals 131, 132, 133, and the like. may include A network formed through one or more base stations 111 , 121 , one or more users or terminals 131 , 132 , 133 , etc. may be referred to as an “access network” or the like. One or more base stations 111, 121 and one or more users or terminals 131, 132, 133 that are interconnected by wireless communication may be viewed as forming a “radio access network”. Meanwhile, one or more users or terminals 131 , 132 , and 133 are user equipment (UE), terminals, access terminals, mobile terminals, stations, and subscriber stations. ), mobile station, portable subscriber station, node, device, Internet of Things (IoT) device, mounted module/device/terminal or on board device /terminal, etc.) and the like.

Each of the one or more base stations 111 and 121 may operate in a different frequency band, or may operate in the same frequency band. Each of the one or more base stations 111 and 121 may be connected to each other through an ideal backhaul link or a non-ideal backhaul link. Each of the one or more base stations 111 and 121 may exchange information with each other through an ideal backhaul link or a non-ideal backhaul link. Each of the one or more base stations 111 and 121 may be directly or indirectly connected to the core network 150 through an ideal backhaul link or a non-ideal backhaul link. Each of the one or more base stations 111 and 121 may transmit a signal received from the core network 150 to one or more users or terminals 131, 132, 133, and from one or more users or terminals 131, 132, 133 The received signal may be transmitted to the core network 150 .

In one embodiment of the communication system 100, at least some of the one or more base stations 111 and 121 correspond to an aerial base station (ABS) mounted on an aerial vehicle (AV) 112 and 122. can do. Here, a system configured through at least one aerial base station and at least one aerial vehicle may be referred to as an “aerial vehicle system (AVS)” 110 and 120 . Each of the public mobile systems 110 and 120 includes one or more mobile backhaul terminals (MBT) 113 and 123 so that the public base stations 111 and 121 can be connected to other base stations, hubs, or core networks. can do. One or more mobile backhaul terminals 113 and 123 may be mounted on one or more aerial mobile bodies 112 and 122 . One or more mobile backhaul terminals 113 and 123 may be connected to a terrestrial base station, a hub, or a core network. For example, the one or more mobile backhaul terminals 113 and 123 may be connected to one or more mobile backhaul hubs (MBH) connected to the core network 150 on the ground through a wired or wireless communication method. One or more mobile backhaul terminals 113 and 123 may be connected to one or more mobile backhaul hubs in a wired or wireless communication manner. A link between one or more mobile backhaul terminals 113 and 123 and one or more mobile backhaul hubs may be referred to as a 'backhaul link'. An embodiment of the communication system 100 may include a first hub 140 corresponding to a mobile backhaul hub. One or more mobile backhaul terminals 113 and 123 may be connected to the first hub 140 by being connected to the core network 150 connected to the first hub 140 .

In each aerial vehicle system, the aerial vehicle on which the aerial base station is mounted may refer to a device capable of moving or flying using a predetermined power in the air. For example, the aerial moving object may correspond to a drone, an aerial airship, an air balloon, and the like. Aerial base stations are mounted on airborne vehicles and can move to specific locations in the air. The public base station may be mounted on a public mobile body to form cell coverage at a specific location in the air, and may communicate with a user or terminal within the cell coverage. The aerial mobile system may perform a flight function through the aerial vehicle and perform a communication function through the aerial base station. Hereinafter, an embodiment of a communication system will be described by taking as an example a situation in which two public base stations are included in the communication system as shown in FIG. 1 . However, embodiments of the present invention are not limited thereto and may include various embodiments. For example, a communication system may be configured to include one public base station, or three or more public base stations.

The communication system 100 may include a public base station such as a first base station 111 and a second base station 121 . Each of the first base station 111 and the second base station 121 may be mounted on an aerial mobile such as the first mobile body 112 and the second mobile body 122 . The first mobile body 112 and the second mobile body 122 are equipped with the first base station 111 and the second base station 121, respectively, and can be moved in the air or fixed in a specific position in the air to fly. The first base station 111 and the second base station 121 form cell coverage in the air to perform wireless communication with one or more users or terminals within the formed cell coverage. For example, the first base station 111 may be mounted on the first mobile body 112 to form the first cell 115 at a specific location in the air. The first base station 111 may communicate with one or more users or terminals 131 , 132 , 133 located within the coverage of the first cell 115 .

The first base station 111 and the first mobile body 112 may constitute the first public mobile system 110 . The first aerial mobile system 110 may be referred to as the first mobile system 110 . The second base station 121 and the second mobile body 122 may constitute the second aerial mobile system 120 . The second aerial mobile system 120 may be referred to as the second mobile system 120 .

Each of the first mobile system 110 and the second mobile system 120 includes one or more mobile backhaul terminals to connect the first base station 111 and the second base station 121 to a terrestrial base station, hub, or core network. may include For example, the first moving body system 110 may include the first moving backhaul terminal 113 mounted on the first moving body 112 . The second moving body system 120 may include a second moving backhaul terminal 123 mounted on the second moving body 122 .

The first base station 111 and the second base station 121 may be connected to the first hub 140 on the ground through the first mobile backhaul terminal 113 and the second mobile backhaul terminal 123 . The first base station 111 and the second base station 121 may be connected to the core network 150 and the like through the first mobile backhaul terminal 113 and the second mobile backhaul terminal 123 and the first hub 140 . For example, the first base station 111 and the second base station 121 connect the first mobile backhaul terminal 113 and the second mobile backhaul terminal 123 and the first hub 140 to the terrestrial core network 150 . ) can be associated with The first mobile backhaul terminal 113 and the second mobile backhaul terminal 123 may be connected to the first hub 140 connected to the core network 150 on the ground through a wired or wireless communication method. The first hub 140 may correspond to, for example, a mobile backhaul hub. The communication links between the first mobile backhaul terminal 113 and the second mobile backhaul terminal 123 and the first hub 140 may be referred to as a first backhaul link 114 and a second backhaul link 124 , respectively. Each of the first base station 111 and the second base station 121 may be connected to the first hub 140 through the first mobile backhaul terminal 113 and the second mobile backhaul terminal 123 . Each of the first base station 111 and the second base station 121 may be connected to the core network 150 through the first hub 140 . Each of the first base station 111 and the second base station 121 may be connected to the data network 160 and/or one or more application servers 170 through the core network 150 .

Meanwhile, the communication system 100 includes a first base station 111 , a first mobile body 112 , a first mobile backhaul terminal 113 , a second base station 121 , a second mobile body 122 , and a second mobile backhaul terminal. 123 , a first control device 180 for controlling the first hub 140 and/or the core network 150 may be included. The first control device 180 may be connected to components of the first movable body system 110 and/or the second movable body system 120 through the first hub 140 . For example, the first control device 180 may control the first base station 111 , the first mobile body 112 , the first mobile backhaul terminal 113 , the second base station 121 , and the second base station 111 through the first hub 140 . It may be connected to the movable body 122 and/or the second movable backhaul terminal 123 . The first control device 180 includes a first base station 111 , a first mobile body 112 , a first mobile backhaul terminal 113 , a second base station 121 , and a second mobile body connected through the first hub 140 . 122 and/or control the operation of the second mobile backhaul terminal 123 . Alternatively, the first control device 180 may be connected to the first movable body system 110 and the second movable body system 120 through the first hub 140 to control respective components.

The first control device 180 may control the operation of the first and second movable body systems 110 and 120 connected through the first hub 140 and components thereof. For example, the first control device 180 may control wireless communication parameters such as wireless transmission power of the first base station 111 and the second base station 121 . Alternatively, the first control device 180 may adjust the antenna directions of the first base station 111 and the second base station 121 . Meanwhile, the first control device 180 may physically control the first movable body 112 and the second movable body 122 . For example, the first control device 180 may perform an operation such as moving the positions of the first movable body 112 and the second movable body 122 or rotating the directions. The first control device 180 may adjust the antenna directions of the first base station 111 and the second base station 121 , and the positions and/or directions of the first mobile body 112 and the second mobile body 122 . In other words, the first control device 180 may physically control the components of the first and second mobile systems 110 and 120 . The first control device 180 physically controls the components of the first mobile system 110 and the second mobile system 120 to control the orientation of the first cell 115 and the second cell, and You can adjust the position, etc.

Public base stations such as the first base station 111 and the second base station 121 are mounted on a public mobile body to form cell coverage in a disaster situation or a place where the existing communication infrastructure is not built to provide services to users or terminals. may have the advantage of being able to In addition, since the public base station transmits and receives radio signals in the air, it may have an advantage that it is less likely to experience a communication failure due to an obstacle on a communication path compared to a base station installed on the ground.

Meanwhile, a public base station may perform wireless communication using a beam in a relatively high frequency band in order to improve communication quality of a wireless link. Beam alignment between the public base station and other communication nodes may greatly affect the communication quality between the public base station and other communication nodes. Unlike a base station located on the ground, an aerial base station may cause an error in beam alignment due to an aerial stop error or a positioning error. In order for the public base station to achieve the required communication quality, a technique capable of effectively performing beam alignment control according to initial beam alignment and subsequent stopping and movement of the public base station may be required.

In the above, an embodiment of the communication system has been described with reference to an embodiment in which the public mobile system included in the communication system 100 includes a public base station mounted on the public mobile device as an example. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. In another embodiment of the communication system, the aerial mobile system may include a terminal mounted on the aerial mobile. For example, the aerial vehicle system may be configured to include a predetermined terminal mounted on the aerial vehicle to photograph an image and transmit the photographed image. As described above, the terminal mounted on the aerial mobile may perform wireless communication with another communication node of the communication system 100 through a beam. Here, the terminal may perform beam alignment control for wireless communication with another communication node of the communication system 100 .

3A and 3B are block diagrams for explaining an embodiment of an apparatus for controlling a public base station in a communication system.

3A and 3B , the communication system 300 may include a public base station control device 380 . The air base station control device 380 includes one or more aerial vehicle systems (AVS) 310 included in the communication system 300 , a mobile backhaul hub (MBH) 340 , and a core network (core). The network, CN) 350 and the like may be connected in a wired or wireless communication manner. The public base station control apparatus 380 may perform a public base station control operation through a control operation on at least some of the connected AVS 310 , MBH 340 , and CN 350 . Here, the communication system 300 may be configured the same as or similar to the communication system 100 described with reference to FIG. 1 . In other words, the communication system 100 described with reference to FIG. 1 may be configured the same as or similar to the communication system 300 described with reference to FIGS. 3A and 3B . The AVS 310 may be configured the same as or similar to the first and/or second moving body systems 110 and 120 described with reference to FIG. 1 . For example, the AVS 310 may include an aerial base station (ABS) 311 , an aerial vehicle (AV) 312 , and a mobile backhaul terminal (MBT) 313 . The MBH 340 may be configured the same as or similar to the first hub 140 described with reference to Fig. 1. The CN 350 may be configured the same or similar to the core network 150 described with reference to Fig. 1 . The public base station control device 380 may be configured the same as or similarly to the first control device 180 described with reference to FIG.

The public base station control device 380 may be referred to as “AVS Operation Device”, “AVS Operation Server”, or “AVS Operation” on the system. The public base station control apparatus 380 may include one or more application functions (AF) for controlling the public base station or AVS. Aerial base station control device 380 is AVS operation AF (380-1), MBH AF (S) (380-2), MBT AF (S) (380-3), AV AF (S) (380-4), ABS AF(S) 380-5, Core AF(S) 380-6, etc. may be included. Here, the AVS operation AF 380-1 is connected to each of the one or more AFs 380-2, 380-3, 380-4, 380-5, 380-6 included in the public base station control device 380 ( 391-2, 391-3, 391-4, 391-5, 391-6) can be formed. The AVS operation AF 380-1 may control one or more connected AFs 380-2, 380-3, 380-4, 380-5, and 380-6. Alternatively, the AVS operation AF 380-1 is a communication system ( 300) may be connected to AFs of other entities to perform control of other entities. Primitives, messages, information, etc. transmitted for control between the public base station control device 380 and each entity are system information (eg, MIB (Master Information Block), SIB (System Information Block)), RRC ( One or two of Radio Resource Control messages, Medium Access Control (MAC) Control Element (CE), and control information (eg, Downlink Control Information (DCI), Uplink Control Information (UCI), Sidelink Control Information (SCI)) It can be transmitted by a combination of the above.

AVS operation AF (380-1) is performed with MBH AF(S) (380-2) corresponding to server-side AF, MBH AF(C) (340-1) corresponding to client-side AF of MBH (340) and can be connected AVS operation AF (380-1) is through MBT AF(S) (380-3) corresponding to server-side AF, MBT AF(C) (313-1) corresponding to client-side AF of MBT (313) and can be connected The AVS operation AF 380-1 is connected to the AV AF(C) 312-1, which corresponds to the client-end AF of the AV 312, through the AV AF(S) 380-4 corresponding to the server-end AF. can be connected AVS operation AF 380-1 is through ABS AF(S) 380-5 corresponding to server-side AF, and ABS AF(C) 311-1 corresponding to client-side AF of ABS 311 and can be connected AVS operation AF (380-1) is through Core AF (S) (380-6) corresponding to server-side AF, Core AF (C) (350-1) corresponding to client-side AF of CN (350) and can be connected Each of the one or more server-side AFs 380-2, 380-3, 380-4, 380-5, 380-6 included in the public base station control device 380 is one or more client-ends included in each of the other entities. Connections 392 , 393 , 394 , 395 , and 396 may be formed with each of the AFs 340-1, 313-1, 312-1, 311-1, and 350-1. AVS operation AF 380-1 includes one or more server-side AFs 380-2, 380-3, 380-4, 380-5, 380-6 and one or more client-side AFs 340-1, 313- 1, 312-1, 311-1, 350-1) through the connections 392, 393, 394, 395, and 396, communication with other entities or control of other entities may be performed.

Referring to FIG. 3A , a wireless backhaul link may be formed between the MBH 340 and the AVS 310 or the MBT 313 . The wireless backhaul link formed between the MBH 340 and the MBT 313 may be divided into two or more according to an operation or a task to be performed by the AVS 310 . For example, the wireless backhaul link formed between the MBH 340 and the MBT 313 is divided into a backhaul control plane protocol data unit session (BH CP PDU Session) and a backhaul user plane protocol data unit session (BH UP PDU Session). can be The BH UP PDU session may process ABS control plane (CP) traffic and user plane (UP) traffic as a BH ABS CP PDU session and a BH ABS UP PDU session, respectively. The public base station control device 380 may process data for controlling each entity for an operation or task to be performed by the AVS through the BH CP PDU session.

Referring to FIG. 3B , the AVS operation AF 380-1 is one or more AFs 380-2, 380-3, 380-4, 380-5, 380-6 included in the air base station control device 380. Connections 391-2, 391-3, 391-4, 391-5, 391-6 may be formed with each. Each of the one or more server-side AFs 380-2, 380-3, 380-4, 380-5, 380-6 included in the public base station control device 380 is one or more client-ends included in each of the other entities. Connections 392 , 393 , 394 , 395 , and 396 may be formed with each of the AFs 340-1, 313-1, 312-1, 311-1, and 350-1. Here, primitive groups are provided between the respective connections 311-1, 312-1, 313-1, 340-1, 350-1, 392, 393, 394, 395, and 396 formed between the respective AFs. can be defined.

For example, a primitive group defined in the MBH AF(S) 380-2 direction between the AVS Operation AF 380-1 and the MBH AF(S) 380-2 may be referred to as AVSMBH_Primitives. A primitive group defined between the AVS Operation AF 380-1 and the MBH AF(S) 380-2 in the AVS Operation AF 380-1 direction may be referred to as MBHAVS_Primitives. A group of primitives defined in the MBT AF(S) 380-3 direction between the AVS Operation AF 380-1 and the MBT AF(S) 380-3 may be referred to as AVSMBT_Primitives. A group of primitives defined in the AVS Operation AF 380-1 direction between the AVS Operation AF 380-1 and the MBT AF(S) 380-3 may be referred to as MBTAVS_Primitives. A group of primitives defined in the AV AF(S) 380-4 direction between the AVS Operation AF 380-1 and the AV AF(S) 380-4 may be referred to as AVSAV_Primitives. A group of primitives defined between the AVS Operation AF 380-1 and the AV AF(S) 380-4 in the AVS Operation AF 380-1 direction may be referred to as AVAVS_Primitives. A group of primitives defined in the ABS AF(S) 380-5 direction between the AVS Operation AF 380-1 and the ABS AF(S) 380-5 may be referred to as AVSABS_Primitives. A group of primitives defined in the AVS Operation AF 380-1 direction between the AVS Operation AF 380-1 and the ABS AF(S) 380-5 may be referred to as ABSAVS_Primitives. A group of primitives defined in the direction of the Core AF(S) 380-6 between the AVS Operation AF 380-1 and the Core AF(S) 380-6 may be referred to as AVSCore_Primitives. A group of primitives defined in the AVS Operation AF 380-1 direction between the AVS Operation AF 380-1 and the Core AF(S) 380-6 may be referred to as CoreAVS_Primitives.

Meanwhile, a primitive group defined between the MBH AF(S) 380-2 and the MBH AF(C) 340-1 in the direction of the MBH AF(C) 340-1 may be referred to as MBH_SC_Primitives. A primitive group defined between the MBH AF(S) 380-2 and the MBH AF(C) 340-1 in the direction of the MBH AF(S) 380-2 may be referred to as MBH_CS_Primitives. A primitive group defined in the MBT AF(C) 313-1 direction between the MBT AF(S) 380-3 and the MBT AF(C) 313-1 may be referred to as MBT_SC_Primitives. A primitive group defined in the MBT AF(S) 380-3 direction between the MBT AF(S) 380-3 and the MBT AF(C) 313-1 may be referred to as MBT_CS_Primitives. A primitive group defined between the AV AF(S) 380-4 and the AV AF(C) 312-1 in the AV AF(C) 312-1 direction may be referred to as AV_SC_Primitives. A group of primitives defined in the AV AF(S) 380-4 direction between the AV AF(S) 380-4 and the AV AF(C) 312-1 may be referred to as AV_CS_Primitives. A primitive group defined in the ABS AF(C) 311-1 direction between the ABS AF(S) 380-5 and the ABS AF(C) 311-1 may be referred to as ABS_SC_Primitives. A primitive group defined in the ABS AF(S) 380-5 direction between the ABS AF(S) 380-5 and the ABS AF(C) 311-1 may be referred to as ABS_CS_Primitives. A group of primitives defined in the direction of the Core AF(C) 350-1 between the Core AF(S) 380-6 and the Core AF(C) 350-1 may be referred to as Core_SC_Primitives. A group of primitives defined in the direction of the Core AF(S) 380-6 between the Core AF(S) 380-6 and the Core AF(C) 350-1 may be referred to as Core_CS_Primitives.

The air base station control apparatus 380 may perform a control operation for each entity through detail primitives defined in a primitive group defined between AFs. For example, it can be seen that Table 1 shows each of the primitive groups and detailed primitives defined and used for MBH control, MBT control, AV control, ABS control, and the like shown in FIG. 10B .

4A to 4C are conceptual diagrams for explaining a first embodiment of a beam control method in a communication system.

4A to 4C , the communication system 400 may include a plurality of communication nodes that communicate with each other through a beam. 4A to 4C, an embodiment including one mobile backhaul terminal (MBT) 410 and one mobile backhaul hub (MBH) 420 in which the communication system 400 performs mutual communication through a beam is shown. can see. Here, the MBT 410 may be the same as or similar to the first mobile system 110 described with reference to FIG. 1 or the first mobile backhaul terminal 113 constituting the first mobile system 110 . The MBH 420 may be the same as or similar to the first hub 140 described with reference to FIG. 1 . Hereinafter, in the description of the first embodiment of the beam control method in the communication system with reference to FIGS. 4A to 4C , content overlapping with those described with reference to FIGS. 1 to 3B may be omitted.

The MBT 410 mounted on an aerial mobile such as a drone and the MBH 420 on the ground may form a wireless backhaul link (BH link). The wireless backhaul link may be configured based on a beam having a high frequency, such as a millimeter wave. In an embodiment of the communication system 400 , the MBT 410 may transmit a beam through an antenna of a horn antenna type. MBH 420 may transmit a beam through a Cassegrain antenna type antenna. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

In order to reduce path loss in the wireless backhaul link, the MBT 410 and/or the MBH 420 may increase the frequency of the beam or sharpen the beam for transmission. The beam width of each beam may be calculated based on a horizontal or vertical angle. Alternatively, the beam width of each beam may be calculated based on a horizontal or vertical length at a specific point. The beam width of the beam may not be easy to flexibly adjust during communication. As the beam width of the beam is sharper, the path loss of the beam may be reduced, and the maximum working distance of the wireless backhaul link based on the beam may be increased. For example, in an embodiment of the communication system 400 , when the beam width of the beam is 10 degrees, the maximum working distance of the wireless backhaul link is 2 km, and when the beam width is 5 degrees, the maximum working distance of the wireless backhaul link may be 10 km. When the MBT 410 and/or the MBH 420 narrows the beam width of the beam to increase the operating distance of the wireless backhaul link, the importance of the beam alignment operation between the MBT 410 and the MBH 420 may increase. there is. If the aerial vehicle is operated on its own fuel or its own battery without a separate wired connection, there may be restrictions on flight time. Accordingly, the time required for the beam alignment operation and the amount of power consumed by the beam alignment operation may need to be minimized.

Referring to FIG. 4A , the antenna of the MBT 410 and the antenna of the MBH 420 may be aligned toward each other. A state in which the antenna of the MBT 410 and the antenna of the MBH 420 are aligned toward each other may be referred to as a 'perfect mutual beam alignment' state.

The MBT 410 may transmit a beam having a predetermined beam width. A beam (hereinafter, MBT beam) transmitted by the MBT 410 may have a circular or circular-like cross-section 415 . Due to the characteristics of the antenna of the MBT 410 , a uniform expected power may be guaranteed only in a partial area 417 of the cross-section 415 of the MBT beam. The MBH 420 may transmit a beam having a predetermined beam width. The beam (hereinafter, MBH beam) transmitted by the MBH 420 may have a circular or circular-like cross-section 425 . Due to the characteristics of the antenna of the MBH 420 , a uniform expected power may be guaranteed only in a partial region 427 of the cross section 425 of the MBH beam.

In the alignment state as shown in Figure 4a, the beam transmission and reception (TRX) between the MBT (410) and the MBH (420) can be easy. That is, the beam transmitted (TX) from the antenna of the MBH 420 may be easily received (RX) from the antenna of the MBT 410 . Conversely, a beam transmitted (TX) from the antenna of the MBT 410 may be easily received (RX) from the antenna of the MBH 420 . If the MBT 410 and the MBH 420 operate the transmit antenna and the receive antenna separately, the alignment of the transmit antenna of the MBH 420 (TX align) and the alignment of the receive antenna of the MBT 410 (RX align) are may have to be aligned with each other. Conversely, the alignment of the transmit antenna of the MBT 410 (TX align) and the alignment of the receive antenna of the MBH 420 (RX align) may have to be aligned with each other.

Referring to FIG. 4B , the antenna of the MBT 410 may be aligned in the MBH 420 direction, and the antenna of the MBH 420 may not be aligned in the MBT 410 direction. A state in which the antenna of the MBH 420 is not aligned in the MBT 410 direction may be referred to as a 'MBH misalignment' state.

In the MBH misalignment state, when the angle between the direction in which the MBH beam is aligned and the direction of the MBT 410 (hereinafter referred to as the MBH misalignment angle) is larger than the angle of the beam width of the MBH beam, between the MBT 410 and the MBH 420 Wireless communication may not be easy. For example, if the antennas responsible for both radio signal transmission and reception (TRX) in the MBH 420 are misaligned, the MBH 420 cannot transmit (TX) a signal to the MBT 410 and receive a signal from the MBT 410 . It may not even be able to receive (RX). On the other hand, when the transmitting antenna of the MBH 420 is aligned in the MBT 410 direction and the receiving antenna is misaligned, the MBH 420 may transmit (TX) a radio signal to the MBT 410, but the MBT 410 ) may not receive (RX) a radio signal from. On the other hand, when the reception antenna of the MBH 420 is aligned in the MBT 410 direction and the transmission antenna is misaligned, the MBH 420 may receive (RX) a radio signal from the MBT 410, but the MBT 420 ) may not be able to transmit (TX) a wireless signal.

Referring to FIG. 4C , the antenna of the MBH 420 may be aligned in the direction of the MBT 410 , and the antenna of the MBT 410 may not be aligned in the direction of the MBH 420 . A state in which the antenna of the MBT 410 is not aligned in the MBH 420 direction may be referred to as a 'MBT misalignment' state.

In the MBT misalignment state, when the angle between the direction in which the MBT beam is aligned and the MBH 420 direction (hereinafter referred to as the MBT misalignment angle) is larger than the angle of the beam width of the MBT beam, the MBT 410 and the MBH 420 between the Wireless communication may not be easy. For example, if the antennas responsible for all of the wireless signal transmission and reception (TRX) in the MBT 410 are misaligned, the MBT 410 cannot transmit (TX) a signal to the MBH 420 and receive a signal from the MBH 420 . It may not even be able to receive (RX). On the other hand, when the transmit antenna of the MBT 410 is aligned in the MBH 420 direction and the receive antenna is misaligned, the MBT 410 may transmit (TX) a radio signal to the MBH 420, but the MBH 420 ) may not receive (RX) a radio signal from. On the other hand, when the reception antenna of the MBT 410 is aligned in the MBH 420 direction and the transmission antenna is misaligned, the MBT 410 may receive (RX) a radio signal from the MBH 420, but the MBT 420 ) may not be able to transmit (TX) a wireless signal.

The MBT misalignment state and/or the MBH misalignment state shown in FIGS. 4B and 4C may occur due to a positioning error with respect to the MBT 410 and/or the MBH 420 . Here, the positioning error may mean an error generated by a device or a sensor used for positioning. For example, when a Global Positioning System (GPS) is used for positioning, a positioning error may occur due to an error of the GPS itself or an error of the GPS module. When a level is used for positioning, a positioning error may occur due to an error of the level sensor. When a barometer is used for positioning, a positioning error may occur due to an error of the barometer sensor. When a Real North (True North) sensor is used for positioning, a positioning error may occur due to an error of the True North sensor. When a magnetometer is used for positioning, a positioning error may occur due to an error of the magnetometer sensor. When an inertial sensor such as an accelerometer or an accelerometer is used for positioning, a positioning error may occur due to an error of the inertial sensor.

A positioning error generated by a device or a sensor used for positioning may be classified into a static error component and a drift error component. The static error component may mean an error component that does not change at a plurality of measurement time points. The drift error component may mean an error component that varies with time. For example, when positioning is performed at a plurality of viewpoints through GPS, an average of positioning errors included in the positioning results at the plurality of viewpoints may be defined as a static error component. Meanwhile, dispersion of positioning errors included in positioning results at a plurality of viewpoints may be defined as a drift error component. Alternatively, a remainder obtained by subtracting a static error component from a positioning error included in positioning results at a plurality of viewpoints may be defined as a drift error component.

Meanwhile, the MBT misalignment state and/or the MBH misalignment state may occur due to an air stop error of the aerial vehicle. For example, even if the aerial moving object is to be stopped at a predetermined position in the air, it may not be able to maintain a complete stop state due to wind, air flow, operation error of the power unit, etc. and may move little by little around the predetermined position. The drift error component of the positioning error and the air stop error can be summed up and referred to as a 'dynamic error'.

The higher the performance of the positioning device, the smaller the positioning error may be. The higher the performance of the flight control device (or flight control software) of the aerial vehicle, the smaller the size of the air stop error may be. However, high performance positioning devices and/or high performance flight control devices may be expensive or heavy in weight. When expensive positioning devices and/or flight control devices are used, the cost of configuring the system may increase. When a heavy positioning device and/or flight control device is used, the flight time of the aerial vehicle may be shortened.

In configuring the communication system 400, a positioning device and/or a flight control device having relatively low performance may be used. In this case, positioning errors and/or hovering errors may occur. Therefore, MBT misalignment and/or MBH misalignment problems may occur. The MBT misalignment and/or MBH misalignment problem may occur during initial beam alignment, or may occur during communication after initial beam alignment. MBT misalignment and MBH misalignment may occur simultaneously, or either one of MBT misalignment and MBH misalignment may occur. When an MBT misalignment and/or MBH misalignment problem occurs, a beam alignment operation may be performed to overcome the generated misalignment and achieve a perfect mutual beam alignment state. For example, misalignment may occur due to one or more errors. If the total error angle, which is the sum of one or more errors, is within the beam width angle (eg, 5 degrees), a separate beam alignment operation is not required to overcome the misalignment, or a relatively simple beam alignment operation is performed. The misalignment can be easily overcome. Even if the total error angle, which is the sum of one or more errors, exceeds the angle of the beam width of the beam, if the dynamic error occurs within the angle of the beam width of the beam, the beam alignment operation may be relatively easy. On the other hand, if the total error angle, which is the sum of one or more errors, exceeds the angle of the beam width of the beam, and the dynamic error exceeds the angle of the beam width of the beam by 1 or 2 times or more, beam alignment to overcome misalignment The operation may not be easy. A control method and apparatus for effectively performing a beam alignment operation to overcome misalignment may be required.

4A to 4C, in a communication system 400 using a beam having a high frequency such as millimeter wave as a communication medium, a beam control operation between a communication node mounted on an aerial mobile and a communication node performing communication at a predetermined location on the ground. One embodiment can be seen as shown. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. For example, the embodiment of the beam control method in the communication system 400 may be equally or similarly applied to a beam control operation between a plurality of communication nodes mounted on an aerial mobile body. The embodiment of the beam control method in the communication system 400 may be equally or similarly applied to a beam control operation in free space optic (FSO) communication or a communication system using a laser beam. The embodiment of the beam control method in the communication system 400 may be equally or similarly applied to a beam control operation between high-spec communication equipments with a maximum communication distance exceeding 10 km. For example, the embodiment of the beam control method in the communication system 400 may be equally or similarly applied to a beam control operation of a military beam having a maximum communication distance exceeding 100 km.

5A and 5B are conceptual diagrams for explaining a first embodiment of a method for expressing coordinate information in a communication system.

It can be seen that FIG. 5A illustrates an embodiment of a method for expressing coordinate information based on a Geocentric Coordinate System (GCS). It can be seen that FIG. 5B shows an embodiment of a method for expressing coordinate information based on GCS and a topocentric coordinate system. In an embodiment of the communication system, coordinate information of communication nodes such as MBT(A), MBH(B) may be expressed based on a coordinate system such as GCS and/or topocentric coordinate system. Here, MBT(A) and MBH(B) may be the same as or similar to the MBT 410 and MBH 420 described with reference to FIGS. 4A to 4C . Hereinafter, in describing embodiments of a method for expressing coordinate information in a communication system with reference to FIGS. 5A and 5B , content overlapping with those described with reference to FIGS. 1 to 4C may be omitted.

MBT(A) and MBH(B) may acquire coordinate information by performing a position measurement (location) operation. The MBT(A) and the MBH(B) may acquire the other's coordinate information by mutually transmitting and receiving coordinate information. MBT(A) and MBH(B) may perform a beam alignment operation based on the obtained coordinate information. MBT(A) and MBH(B) may use one or more sensors for positioning operation and beam alignment operation. For example, the MBT(A) and/or MBH(B) may use a GPS, a horizontal sensor, a compass sensor (or a true north sensor), etc. for a positioning operation and a beam alignment operation. MBT(A) and MBH(B), which perform a positioning operation light beam alignment operation using a GPS, a horizontal sensor, a compass sensor, etc., may be configured with relatively low cost and low complexity. On the other hand, MBT(A) and/or MBH(B) may further use an inertial sensor (angular accelerometer, accelerometer, etc.), barometric pressure sensor, magnetometer, etc. to improve the accuracy of the positioning operation and beam alignment operation. there is. In order to improve the accuracy of beam alignment between MBT(A) and MBH(B), MBT(A) and MBH(B) may be configured to use the same kind of sensors for positioning operation and beam alignment operation.

'와 같이 표시될 수 있다. 위도는 적도(equator), 북극, 및 남극에서 각각 0°, 북위 90°(90°N), 및 남위 90°(90°S)의 값을 가질 수 있다. 경도는 '°'의 단위를 가질 수 있으며, '

' 또는 '

'와 같이 표시될 수 있다. 경도는 그리니치 자오선(Greenwich Meridian)에서 0°의 값을 가질 수 있다. 경도는 그리니치 자오선을 중심으로, 동쪽으로 동경 180°(180°E)까지, 서쪽으로 서경 180°(180°W)까지의 값을 가질 수 있다. 고도는 높이 값으로 정의될 수 있다. 고도는 어떤 위치와 지구 중심 간의 거리를 나타내는 값일 수 있다. 또는, 고도는 어떤 위치의 높이가 소정의 기준면의 높이와 얼마나 차이나는지를 나타내는 값일 수 있다. 고도의 기준이 되는 소정의 기준면은, 지구 타원체(Earth Ellipsoid, EE)일 수도 있고, 중력에 의하여 정의되는 가상의 표면인 지오이드(Geoid)일 수도 있고, 또는 해수면(sea level)일 수도 있다. 도 5a에는 EE 또는 해수면을 기준으로 고도를 표현하는 실시예가 도시된 것으로 볼 수 있다. 해수면이 기준면이 될 경우, 고도는 '해발 고도'와 같이 칭할 수도 있다.Referring to FIGS. 5A and 5B , the GCS may be a coordinate system in which each position is indicated with the center of the earth as the origin. In an embodiment of the communication system, the GCS may be expressed based on three axes, such as an X-axis, a Y-axis, and a Z-axis. In another embodiment of the communication system, the GCS may be expressed based on latitude, longitude, and altitude. Latitude and longitude can be defined as angular values. Latitude can have units of '°' (degree, degree), and '

' can be displayed as Latitude can have values of 0°, 90° north (90°N), and 90° south (90°S) latitude at the equator, north pole, and south pole, respectively. Longitude can have units of '°', '

' or '

' can be displayed as Longitude may have a value of 0° at the Greenwich Meridian. Longitude can range from the Greenwich meridian to 180° east longitude (180°E) and west to 180° west longitude (180°W). Altitude can be defined as a height value. The altitude may be a value indicating a distance between a certain location and the center of the earth. Alternatively, the altitude may be a value indicating how much the height of a certain location differs from the height of a predetermined reference plane. A predetermined reference plane as a reference for altitude may be an Earth Ellipsoid (EE), a geoid that is a virtual surface defined by gravity, or a sea level. It can be seen that FIG. 5A shows an embodiment in which an altitude is expressed based on EE or sea level. When the sea level is the reference plane, the altitude may be referred to as 'altitude above sea level'.

Referring to FIG. 5A , in an embodiment of the communication system, a positioning operation may be performed using GCS and GPS. GPS can represent each location as latitude, longitude, and altitude values. MBT(A) and MBH(B) may each acquire information about their location through GPS. The information on the location obtained through the GPS may include information on an altitude value that is a height value calculated based on a predetermined reference plane.

), 경도(

) 및 고도(

)로 계산될 수 있다. 여기서, GCS에서의 위도 및 경도 값은 GPS에서의 위도 및 경도 값과 동일 또는 근사할 수 있다. GCS에서의 고도 값은, 앞서 계산된 MBT(A) 및 MBH(B)의 총 높이 값에 해당할 수 있다. 또는, GCS에서의 MBT(A) 및 MBH(B)의 좌표값은, X축, Y축, Z축 등 3개의 축을 기준으로 계산될 수도 있다. X축, Y축, Z축을 기준으로 계산된 GCS에서의 MBT(A)의 좌표값은 '(XA, YA, ZA)' 와 같이 표현될 수 있다. X축, Y축, Z축을 기준으로 계산된 GCS에서의 MBH(B)의 좌표값은 '(XB, YB, ZB)' 와 같이 표현될 수 있다. MBT(A) 및 MBH(B)의 좌표값에 기초하여, MBT(A) 및 MBH(B) 사이의 무선 통신 경로에 대응되는 A-B 라인(A-B line)의 정보가 계산될 수 있다.To convert information about a location identified through GPS into GCS, you may need the 'total height value', which is the distance from the center of the earth, not the altitude value. The total height value of the MBT(A) location is the MBT GPS altitude value corresponding to the altitude of the MBT(A) location, and the distance between the center of the earth and a predetermined reference plane that is the basis of altitude information at the location of the MBT (MBT reference height) ) can be calculated as the sum of In other words, 'MBT total height value' = 'MBT GPS altitude' + 'MBT reference height'. The total height value of the MBH(B) position is the MBH GPS altitude value corresponding to the altitude of the MBH(B) position, and the distance between the center of the earth and a predetermined reference plane that is the basis of altitude information at the MBH position (MBH reference height) ) can be calculated as the sum of In other words, 'MBH total height value' = 'MBH GPS altitude' + 'MBH reference height'. The values of the MBT reference height and the MBH reference height may be the same or different. Based on the calculated total height values of MBT(A) and MBH(B), coordinate values of MBT(A) and MBH(B) in the GCS may be calculated. The coordinate values of MBT(A) and MBH(B) in GCS are

), Hardness(

) and altitude (

) can be calculated as Here, the latitude and longitude values in the GCS may be the same as or approximate to the latitude and longitude values in the GPS. The altitude value in the GCS may correspond to the total height value of the previously calculated MBT(A) and MBH(B). Alternatively, the coordinate values of MBT(A) and MBH(B) in the GCS may be calculated based on three axes, such as the X-axis, the Y-axis, and the Z-axis. The coordinate values of MBT(A) in the GCS calculated based on the X-axis, Y-axis, and Z-axis may be expressed as '(XA, YA, ZA)'. The coordinate value of MBH(B) in the GCS calculated based on the X-axis, Y-axis, and Z-axis may be expressed as '(XB, YB, ZB)'. Based on the coordinate values of the MBT(A) and MBH(B), information on the AB line corresponding to the wireless communication path between the MBT(A) and the MBH(B) may be calculated.

Referring to FIG. 5B , in an embodiment of the communication system, a positioning operation may be performed using a topocentric coordinate system. The topocentric coordinate system may be referred to as an 'observation-centric coordinate system' or an 'observer-centric coordinate system'. The topocentric coordinate system uses the tangent plane set based on the coordinate information of a specific point of the GCS as the horizontal plane, and is one coordinate system defined based on the set tangent plane and the direction of the true north (Real North, True North). can In the topocentric coordinate system of MBT(A), the position of MBT(A) may be the origin. In the topocentric coordinate system of MBH(B), the position of MBH(B) may be the origin. In the topocentric coordinate system, coordinates or directions may be expressed based on three axes, such as the V-axis, the W-axis, and the U-axis. A coordinate system expressing coordinates or directions based on three axes, such as the V-axis, the W-axis, and the U-axis, may be referred to as the VWU coordinate system. The topocentric coordinate system set based on the true north direction may be referred to as 'RNH (Real North Head) VWU (RNH VWU Coordinate System, RVCS)'. The RVCS may express direction information or angle information based on the V-axis, the W-axis, and the U-axis. In an embodiment of the communication system, the RVCS may be set so that the V-axis faces the true north direction. The RVCS may be set so that the UW plane formed by the U and W axes coincides with a predetermined tangent plane set based on coordinate information of the GCS. When the V-axis and UW planes of the RVCS are set to coincide with the true north direction and the tangent plane checked through the horizontal sensor, respectively, confirmed by the compass sensor, the positioning operation based on the RVCS can be performed only through the 2-axis sensor instead of the 3-axis sensor. can be performed. RVCS may optionally further express size information or scalar information. A method of expressing direction information based on values such as roll, pitch, and yaw in a coordinate system such as a VWU coordinate system and an RVCS coordinate system will be described in more detail below with reference to FIGS. 6A and 6B .

6A and 6B are conceptual diagrams for explaining embodiments of a method for expressing direction information in a communication system.

Referring to FIGS. 6A and 6B , in an embodiment of a communication system, direction information may be expressed around three axes, such as a V-axis, a W-axis, and a U-axis. Here, the communication system may be the same as or similar to the communication system described with reference to FIGS. 5A and 5B . In the communication system, direction information may be expressed based on a coordinate system such as the VWU coordinate system described with reference to FIG. 5B or an RVCS defined based on the VWU coordinate system.

Specifically, in the VWU coordinate system, values such as Roll, Pitch, and Yaw may be expressed based on the V axis, the W axis, and the U axis. Here, each of roll, pitch, and yaw may mean an angle value rotating around any one of the V axis, the W axis, and the U axis. For example, the roll may mean an angle value that rotates about the W axis. The pitch may mean an angle value that rotates about the U-axis. The yaw may mean an angle value rotated about the V-axis. The roll, pitch, and yaw rotation values may refer to angle values rotated in a left hand or clockwise direction about a W axis, a U axis, and a V axis. Alternatively, roll, pitch, and yaw may mean an angle value rotated in a right-hand direction or a counter-clockwise (CCW) direction about the W-axis, the U-axis, and the V-axis. 6A and 6B , it can be seen that an embodiment in which rotation values of roll, pitch, and yaw are calculated based on a left hand direction or a clockwise direction (CW) is illustrated. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. In another embodiment of the communication system, the rotation values of roll, pitch, and yaw may be calculated based on a right hand direction or a counterclockwise direction (CCW).

In the embodiments of the method for expressing direction information shown in FIGS. 6A and 6B , when roll, pitch, and yaw information for a specific object is provided, it may be considered that direction information for the corresponding object is provided. In other words, in the embodiments of the method for expressing direction information shown in FIGS. 6A and 6B , direction information for a specific object may be expressed through roll, pitch, and yaw information for the corresponding object. For example, information on a direction in which the first object is currently facing may be expressed through information on roll, pitch, and yaw of the first object. Alternatively, the information on the target direction in which the first object is to face forward may be expressed through roll, pitch, and yaw information in the target direction in which the first object is to face forward.

Referring to FIG. 6A , in an embodiment of the method for expressing direction information based on the VWU coordinate system, rotation values of roll, pitch, and yaw may be calculated based on a left-handed direction or a clockwise direction. Here, the roll may have a value of up to +180° in a clockwise direction and up to -180° in a counterclockwise direction with respect to the W axis. The pitch may have a value of up to +180° in a clockwise direction and up to -180° in a counterclockwise direction about the U-axis. The yaw may have a value of up to +180° in a clockwise direction and up to -180° in a counterclockwise direction with respect to the V axis.

Referring to FIG. 6B , in another embodiment of the method for expressing direction information based on the VWU coordinate system, rotation values of roll, pitch, and yaw may be calculated based on a left-handed direction or a clockwise direction. Here, the roll may have a value of up to +360° clockwise around the W axis. The pitch may have a value up to +360° clockwise around the U-axis. The yaw may have a value up to +360° clockwise around the V-axis.

7 is a conceptual diagram for explaining a second embodiment of a beam control method in a communication system.

Referring to FIG. 7 , a communication system may include a plurality of communication nodes that communicate with each other through a beam. 7 can be seen as showing an embodiment in which the communication system includes one MBT (A) and one MBH (B) for performing mutual communication through a beam. Here, MBT(A) and MBH(B) may be the same as or similar to the MBT 410 and MBH 420 described with reference to FIGS. 4A to 4C . MBT(A) and MBH(B) are based on coordinate information and/or direction information expressed in the same or similar manner to the method for expressing coordinate information described with reference to FIGS. 5A and 5B and the method for expressing direction information described with reference to FIG. 6 . to control the antenna or the antenna head. Hereinafter, in the description of the second embodiment of the beam control method in the communication system with reference to FIG. 7 , content overlapping with those described with reference to FIGS. 1 to 6B may be omitted.

MBT(A) and MBH(B) may communicate with each other through a beam. For accurate control of beam directions of MBT(A) and MBH(B), antennas for transmitting beams of MBT(A) and MBH(B) may be installed in a predetermined direction control device. For example, an antenna for transmitting beams of MBT(A) and MBH(B) may be installed on a gimbal. In an embodiment of the communication system, the MBT(A) and MBH(B) may control the direction of the antenna and the beam by controlling the gimbal on which the antenna is installed. Unless otherwise stated, the configurations described with respect to the 'gymball' in the present application may be equally applied to other direction control devices other than the gimbal.

In one embodiment of the communication system, MBT (A) and MBH (B) performing mutual communication through a beam, to control the antenna to face in the direction of the other party, check its own coordinate information and the other party's coordinate information action can be performed. An operation of converting coordinate information expressed based on a specific coordinate system into coordinate information based on another coordinate system may be performed. For example, the MBT (A) and the MBH (B) may acquire their location information through GPS. The location information obtained through GPS may be expressed based on the GPS coordinate system. Coordinate information of MBT(A) and MBH(B) based on the GPS coordinate system may be converted into coordinate information based on the earth-centered coordinate system (GCS). Coordinate information based on the GPS coordinate system or GCS may be converted into coordinate information based on RVCS. In Table 1, it can be seen that an embodiment in which coordinate information for each of MBT(A) and MBH(B) is expressed as coordinate information based on each of the GPS coordinate system, GCS, and RVCS is expressed.

,

) 정보 및 경도(

) 정보는, GPS A 및 GPS B에 포함되는 위도(

,

) 정보 및 경도(

) 정보와 동일 또는 근사한 값으로 결정될 수 있다. 한편, GCS A 및 GCS B에 포함되는 고도(

,

) 정보는 GPS A 및 GPS B에 포함되는 고도(

,

) 정보와 상이한 값으로 결정될 수 있다. 이를테면, 도 5a를 참조하여 설명한 바와 같이, GCS A 및 GCS B에 포함되는 고도(

,

)의 값은 GPS A 및 GPS B에 포함되는 고도(

,

)의 값에 소정의 기준 높이의 값을 더한 값으로 결정될 수 있다. 위도, 경도 및 고도 정보 기반으로 표현된 GCS A(

,

,

) 및 GCS B(

,

,

)는, X축, Y축 및 Z축에 기초한 좌표 정보로 변환되어 GCS A(

,

,

) 및 GCS B(

,

,

)와 같이 표현될 수 있다.where the latitudes included in GCS A and GCS B (

,

) information and hardness (

) information is the latitude (

,

) information and hardness (

) can be determined as the same or approximate value as the information. On the other hand, the altitudes included in GCS A and GCS B (

,

) information is included in the altitude (

,

) can be determined as a different value from the information. For example, as described with reference to FIG. 5A, the altitudes included in GCS A and GCS B (

,

) is the altitude that is included in GPS A and GPS B (

,

) may be determined as a value obtained by adding a value of a predetermined reference height to a value of . GCS A expressed based on latitude, longitude and altitude information (

,

,

) and GCS B(

,

,

) is converted into coordinate information based on the X-axis, Y-axis and Z-axis, and GCS A (

,

,

) and GCS B(

,

,

) can be expressed as

The coordinate information based on the RVCS may indicate information of the A-B line corresponding to the wireless communication path between the MBT(A) and the MBH(B). For example, the MBT(A) may provide the coordinate information (GPS A) of the MBT(A) based on the GPS coordinate system or the coordinate information (GCS A) of the MBT(A) based on the GCS to the MBH(B). The MBH(B) may provide the coordinate information (GPS B) of the MBH(B) based on the GPS coordinate system or the coordinate information (GCS B) of the MBH(B) based on the GCS to the MBT(A). MBT(A) and MBH(B) may calculate coordinate information based on RVCS based on the mutually transmitted and received coordinate information.

Specifically, the MBH(B) may check the coordinate information of the MBT(A) provided from the MBT(A). MBH(B) calculates the direction information of MBT(A) based on the location of MHT(B) based on the coordinate information of MBH(B) and the coordinate information of MBT(A) provided from MBT(A). can The calculated direction information may be the same as RVCS A of Table 1. MBH(B) may control its antenna to face the direction of MBT(A) based on the calculated RVCS A information. Alternatively, the MBT(A) is based on the coordinate information of the MBT(A) and the coordinate information of the MBH(B) provided from the MBH(B), the direction information of the MBT(A) based on the position of the MBH(B) can also be calculated like RVCS A. MBT(A) may provide information of calculated RVCS A to MBH(B). MBH(B) may control its antenna to face the direction of MBT(A) based on the information of RVCS A provided from MBT(A).

Meanwhile, the MBT(A) may check the coordinate information of the MBH(B) provided from the MBH(B). MBT(A) calculates direction information of MBH(B) based on the location of MHT(B) based on the coordinate information of MBT(A) and the coordinate information of MBH(B) provided from MBH(B). can The calculated direction information may be the same as RVCS B of Table 1. The MBT(A) may control its antenna to face the direction of the MBH(B) based on the calculated RVCS A information. Or, MBH(B) is direction information of MBH(B) based on the location of MHT(A) based on the coordinate information of MBH(B) and the coordinate information of MBT(A) provided from MBT(A). may be calculated as in RVCS B. MBH(B) may provide the calculated RVCS B information to MBT(A). The MBT(A) may control its antenna to face the direction of the MBH(B) based on the information of the RVCS B provided from the MBH(B).

RVCS A and RVCS B may include direction information such as roll, pitch, and yaw. RVCS A and RVCS B may optionally further include scalar value information (Scalar A, Scalar B). Specifically, in an embodiment of the communication system, RVCS A and RVCS B may not include scalar value information. In this case, RVCS A and RVCS B may indicate only direction information and not accurate location information. In another embodiment of the communication system, in one embodiment of the communication system, RVCS A and RVCS B may include information of a scalar value. Here, information on scalar values (Scalar A, Scalar B) included in RVCS A and RVCS B may correspond to a distance between MBT(A) and MBH(B). In this case, RVCS A and RVCS B may indicate accurate location information by including both direction information and distance information.

Meanwhile, information on scalar values (Scalar A, Scalar B) included in RVCS A and RVCS B may indicate transmit power of an antenna. For example, MBH(B) may calculate the direction information of MBT(A) based on the position of MBH(B) as Roll A°, Pitch A°, and Yaw A°. MBH(B) may be expressed as Scalar A by determining the transmit power of the antenna for MBT(A). MBH(B) may control the direction and transmit power of the antenna based on RVCS A including information of Roll A°, Pitch A°, Yaw A° and Scalar A. Conversely, the MBT(A) can calculate the direction information of the MBH(B) based on the position of the MBT(A), such as Roll B°, Pitch B°, and Yaw B°. MBT(A) may be expressed as Scalar B by determining the transmit power of the antenna for MBH(B). MBT(A) may control the direction and transmit power of the antenna based on RVCS B including information of Roll B°, Pitch B°, Yaw B° and Scalar B.

In one embodiment of the communication system, MBT(A) and MBH(B) may express information about the current antenna direction in the same or similar form as RVCS A and RVCS B. Alternatively, the MBT(A) and MBH(B) may express information on a direction that the antenna intends to face in the future in the same or similar form as that of RVCS A and RVCS B. MBT(A) and MBH(B) may control the direction of an antenna by controlling a gimbal based on direction information expressed in the same or similar form as RVCS A and RVCS B.

As described with reference to FIGS. 6A and 6B , in an embodiment of the method for expressing direction information based on roll, pitch, and yaw, the roll, pitch, and yaw may have a total rotation value of 360°. In an embodiment of the communication system, communication nodes such as MBT(A), MBH(B), etc. may control the direction of the antenna based on direction information based on roll, pitch and yaw having a total rotation value of 360°. there is.

Meanwhile, in another embodiment of the communication system, the gimbal in which the antenna of the communication node such as MBT(A), MBH(B) is installed may not have a rotation value of 360° in all directions due to a limitation on the hardware structure. For example, the gimbal on which the antenna is installed may have a rotatable angle of up to 120° with respect to any one or more axes of roll, pitch, and yaw. If the target direction of the antenna is out of the range of the rotatable angle of the gimbal on which the antenna is installed, it may not be easy to control the direction of the antenna by controlling only the gimbal. In this case, a method of adjusting the direction of the antenna through additional physical control of the body of the communication node itself may be used.

8 is a conceptual diagram for explaining a second embodiment of a method for expressing coordinate information in a communication system.

Referring to FIG. 8 , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. MBT included in the communication system may be the same as or similar to the MBT (A) described with reference to FIG. The MBH included in the communication system may be the same as or similar to the MBH(B) described with reference to FIG. 7 . Hereinafter, in describing the second embodiment of the method for expressing coordinate information in a communication system with reference to FIG. 8 , the content overlapping with those described with reference to FIGS. 1 to 7 may be omitted.

MBT and MBH may express coordinate information based on a coordinate system such as a GPS coordinate system, GCS, and RVCS described with reference to FIG. 7 . The MBT and MBH may perform a beam control operation based on coordinate information expressed based on a coordinate system such as a GPS coordinate system, GCS, or RVCS described with reference to FIG. 7 .

On the other hand, MBT and MBH may set a coordinate system based on the position and direction of a 'physical antenna head (Physical Antenna Head, PAH)' corresponding to the physical head of each antenna. Here, the position and direction of the PAH of the antenna may refer to the position and direction of a radiator emitting a beam from the antenna. Alternatively, the position and direction of the PAH of the antenna may refer to the position of the axis or origin of the gimbal that controls the direction of the antenna, and the direction to which the antenna is determined by the gimball.

In the MBT and MBH, the position of the PAH as the reference position or origin, the direction of the PAH as the V-axis, and the V-axis, the W-axis, and the U-axis can set a coordinate system expressing the direction in three axes. As described above, the VWU coordinate system set based on the position and direction of the PAH may be referred to as a 'PAH VWU coordinate system'. The VWU coordinate system set based on the position and direction of the PAH of the MBT may be referred to as 'MBT PAH VWU coordinate system'. The VWU coordinate system set based on the position and direction of the MBH PAH may be referred to as 'MBH PAH VWU coordinate system'.

9 is a conceptual diagram for explaining a third embodiment of a method for expressing coordinate information in a communication system.

Referring to FIG. 9 , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. MBT included in the communication system may be the same as or similar to the MBT (A) described with reference to FIG. The MBT included in the communication system may be mounted on a kind of aerial flight. The aerial vehicle on which the MBT is mounted may be the same as or similar to the first and second movable objects 112 and 122 described with reference to FIG. 1 . In the description of the third embodiment of the method for expressing coordinate information in a communication system with reference to FIG. 9 , content overlapping with those described with reference to FIGS. 1 to 8 may be omitted.

Coordinate information such as the location and direction of the MBT may be expressed based on a coordinate system such as the GPS coordinate system described with reference to FIG. 7, GCS, RVCS, or the PAH VWU coordinate system described with reference to FIG. 8 . Coordinate information such as the position and direction of the aerial vehicle may be expressed based on the coordinate system such as the GPS coordinate system, GCS, and RVCS described with reference to FIG. 7 .

On the other hand, as described with reference to FIG. 7, in an embodiment of the communication system, a gimball in which an antenna of a communication node such as an MBT is installed may not have a rotation value of 360° in all directions due to a limitation on a hardware structure. If the target direction of the antenna is out of the range of the rotatable angle of the gimbal on which the antenna is installed, it may not be easy to control the direction of the antenna by controlling only the gimbal. In this case, a method of adjusting the direction of the antenna through additional physical control of the body of the communication node itself may be used.

For example, when it is not easy to control the direction of the antenna of the MBT by controlling only the gimbal on which the antenna of the MBT is installed, the operation of adjusting the direction of the antenna by controlling the direction of the aerial vehicle equipped with the MBT may be performed. To this end, it is possible to set a coordinate system based on the position and direction of an 'Aerial Flight Head (AFH)' corresponding to the head of the aerial vehicle. Here, the position and direction of the AFH may be set based on the reference position and direction of the aerial vehicle set in the aerial vehicle attitude control program.

In the aerial vehicle, the position of the AFH as the reference position or origin, the direction of the AFH as the V-axis, and the V-axis, the W-axis, and the U-axis can set a coordinate system that expresses the direction. As described above, the VWU coordinate system set based on the position and direction of the AFH may be referred to as an 'AFH VWU coordinate system'.

Coordinate information expressed based on a coordinate system such as RVCS, may be converted into coordinate information based on the PAH VWU coordinate system based on the PAH of the MBT, or the AFH VWU coordinate system based on the AFH. Coordinate information based on the PAH VWU coordinate system may be converted into coordinate information based on the AFH VWU coordinate system. Conversely, coordinate information based on the AFH VWU coordinate system may be converted into coordinate information based on the PAH VWU coordinate system. The coordinate information conversion operation between the PAH VWU coordinate system and the AFH VWU coordinate system may be performed based on relative position information between the MBT and the antenna of the MBT and the aerial vehicle.

10 is a conceptual diagram for explaining a fourth embodiment of a method for expressing coordinate information in a communication system.

Referring to FIG. 10 , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIG. The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIG. 8 . Hereinafter, in describing the fourth embodiment of the method for expressing coordinate information in a communication system with reference to FIG. 8 , the content overlapping with those described with reference to FIGS. 1 to 9 may be omitted.

Coordinate information such as the location and direction of the MBT and MBH may be expressed based on a coordinate system such as the GPS coordinate system described with reference to FIG. 7, GCS, RVCS, or the PAH VWU coordinate system described with reference to FIG. 8 . In the PAH VWU coordinate system, current MBT PAH reference position information and current MBH PAH reference position information may be expressed based on the current positions and current directions of the MBT and MBH.

On the other hand, for smooth wireless communication between the MBT and the MBH, the PAH of the MBT may have to be aligned in the MBH direction or the PAH direction of the MBH. To this end, the MBT may receive the coordinate information of the MBH or the PAH of the MBH from the MBH. The MBT may convert the coordinate information received from the MBH into coordinate information based on the MBT PAH VWU coordinate system. The transformed coordinate information may correspond to information on the direction of MBH PAH or "?? It can be used to ensure that the direction of the PAH is matched normally The transformed coordinate information may be referred to as 'Target A-B line-MBT PAH Match Reference Position'.

Conversely, for smooth wireless communication between the MBT and the MBH, the PAH of the MBH may have to be aligned in the MBT direction or the PAH direction of the MBT. To this end, the MBH may receive the coordinate information of the MBT or the PAH of the MBT from the MBT. The MBH may convert the coordinate information received from the MBT into coordinate information based on the MBH PAH VWU coordinate system. The transformed coordinate information may correspond to information on the direction of the MBT or the PAH direction of the MBT viewed from the MBH standpoint. The transformed coordinate information may be used so that the wireless communication path (line A-B) between the MBT and the MBH and the direction of the PAH of the MBH match normally. The transformed coordinate information may be referred to as 'Target A-B line-MBH PAH Match Reference Position'.

[Initial beam alignment procedure]

11 is a flowchart for explaining a third embodiment of a beam control method in a communication system.

Referring to FIG. 11 , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIG. The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIG. 8 . The MBT and the MBH may perform an initial beam alignment procedure for mutual communication through the operations according to the third embodiment of the beam control method in the communication system shown in FIG. 11 . Hereinafter, in the description of the third embodiment of the beam control method in the communication system with reference to FIG. 11 , content overlapping with those described with reference to FIGS. 1 to 10 may be omitted.

In order for the MBH to perform initial beam alignment in the MBT direction, first, coordinate information such as the position and direction of the MBH PAH (hereinafter, MBH PAH) may be confirmed. For example, the MBH may check the coordinates of the center position (B) of the gimbal controlling the direction of the MBH antenna ( S1110 ). MBH may determine the coordinates of location B based on GPS or the like. The MBH may determine the identified location B as the location of the MBH PAH. MBH may transmit coordinate information of location B. Here, the coordinate information of the location B may be transmitted in a broadcast method, a multicast method, a unicast method, and the like.

The MBH may check the coordinates of the MBT or the aerial position (A) of the MBT-mounted aerial vehicle (S1120). For example, the MBT may transmit a signal including the coordinate information of the location A corresponding to the aerial location of the MBT. Here, the coordinate information of the location A may be transmitted in a broadcast method or may be transmitted toward the MBH in a unicast method. Here, the aerial location of the MBT may mean the aerial location of the MBT PAH. Location A may be the current public location of the MBT. Alternatively, location A may correspond to a location where the MBT is to move and perform wireless communication with the MBH. In this case, the MBT may transmit a signal including information on the coordinates of the location A corresponding to the location where the MBT is to move and perform wireless communication with the MBH and move to the location A. The MBH may receive a signal transmitted from the MBT, and check information about the coordinates of the location A.

The MBH may set the MBH PAH VWU coordinate system based on the coordinate information of the location B (S1130). MBH may convert coordinate information of location B into coordinate information based on a coordinate system such as a topocentric coordinate system or RVCS. The MBH may set the MBH PAH VWU coordinate system based on the transformed coordinate information. This may be the same as or similar to the operations in the second embodiment of the method for expressing coordinate information in the communication system described with reference to FIG. 8 . The MBH may convert the current coordinate information of the location B and the coordinate information of the location A into coordinate information based on the MBH PAH VWU coordinate system (S1130). That is, the MBH may acquire information on the line A-B expressed based on the MBH PAH VWU coordinate system. The MBH may acquire information on the 'target A-B line-MBH PAH match reference position' described with reference to FIG. 10 .

The MBH may calculate a direction change value of the MBH PAH for making the direction of the MBT PAH coincide with the line A-B based on the information on the A-B line obtained for the direction of the MBH PAH (S1140). For example, the MBH may compare the direction information of the current MBH PAH based on the MBH PAH VWU coordinate system with the direction information of the A-B line. The MBH may calculate a direction change value such as roll, pitch, and yaw of the MBH PAH based on a result of comparing the current direction information of the MBH PAH with the direction information of the A-B line. In an embodiment of the communication system, the MBH may additionally calculate a scalar value in addition to the direction change value of the MBH PAH based on the coordinate information of the location A. For example, the MBH may calculate a scalar value corresponding to the distance between the MBT at the A location and the MBH at the B location. Alternatively, the MBH may calculate the distance between the MBT at the A location and the MBH at the B location, and calculate a scalar value corresponding to the strength of the beam to be transmitted to the MBT based on the distance between the MBT and the MBH.

The MBH may control the direction of the MBH PAH based on the direction change value calculated in step S1140 (S1150). In other words, the MBH may align the antennas of the MBH based on the direction change value obtained in step S1140. If a scalar value such as beam intensity is additionally calculated in step S1140, the MBH may additionally perform an operation based on information on the additionally calculated scalar value.

11 , it can be seen that embodiments of operations for performing an initial beam alignment procedure from the MBH standpoint are illustrated. The MBT may also perform the initial beam alignment procedure through the same or similar operations as the MBH. For example, the MBT may check and transmit coordinate information for the aerial location (A) of the MBT. The aerial location of the MBT may refer to the aerial location of the MBT PAH. A location may mean the current aerial location of the MBT. Alternatively, location A may correspond to a location where the MBT is moved to perform wireless communication with the MBH. In this case, the MBT may move to the A position after transmitting the coordinate information of the A position.

The MBT may receive coordinate information for the location (B) of the MBH transmitted from the MBH. The MBT may convert the coordinate information of the A position and the B position into coordinate information based on the MBT PAH VWU coordinate system. The MBT may acquire information on the 'target A-B line-MBT PAH match reference position' described with reference to FIG. 10 . MBT can calculate the direction change value of roll, pitch, yaw, etc. to control the direction of the MBT PAH. In an embodiment of the communication system, the MBT may additionally calculate a scalar value corresponding to the distance between the MBT and the MBH, or the strength of a beam to be transmitted to the MBH. The MBT may perform a beam alignment operation such as controlling the direction of the MBH PAH based on information such as the calculated direction change value.

[Adaptive beam alignment procedure]

12 is a flowchart for explaining a fourth embodiment of a beam control method in a communication system.

Referring to FIG. 12 , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIG. 11 . The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIG. 11 . The MBT and the MBH may perform an initial beam alignment procedure for mutual communication through the operations according to the third embodiment of the beam control method in the communication system shown in FIG. 11 . When the MBH misalignment and/or the MBT misalignment described with reference to FIGS. 4B and 4C occurs after the MBT and the MBH perform the initial beam alignment, an adaptive beam alignment procedure may be required for smooth communication. For example, if the beam alignment is misaligned over time after the MBT and MBH perform the initial beam alignment, it may be necessary to adjust the beam alignment. Alternatively, when the initial beam alignment procedure is not accurately performed due to a positioning error or the like, additional adjustment of the beam alignment may be required. In this case, the MBT and the MBH may perform an adaptive beam alignment procedure for beam alignment adjustment through the operations according to the fourth embodiment of the beam control method in the communication system shown in FIG. 12 . Hereinafter, in the description of the fourth embodiment of the beam control method in the communication system with reference to FIG. 12 , content overlapping with those described with reference to FIGS. 1 to 11 may be omitted.

). 주기적 타이머 시간의 초기값은 단위 시간 간격의 초기값과 동일하게 설정될 수 있다(

). 관찰 횟수의 초기값은 100회로 설정될 수 있다(

). After performing the initial beam alignment in the MBH direction, the MBT may set initial settings for the adaptive beam alignment procedure. For example, MBT can initially set variables such as unit time interval, periodic event timer time, number of observations, observation time margin, observation time variable, gimball change count variable, gimball change count margin, offset margin (OM), etc. there is. The initial value of the unit time interval may be set to 1 second (

). The initial value of the periodic timer time may be set to be the same as the initial value of the unit time interval (

). The initial value of the number of observations may be set to 100 (

).

). 관찰 시간 변수는 0으로 설정될 수 있다(

). 짐볼 변경 카운트 변수의 초기값은 0으로 설정될 수 있다(

). 짐볼 변경 카운트 마진의 초기값은 10회로 설정될 수 있다(

). 방향 변경 마진 중 롤, 피치, 요의 변경 마진은 각각 5°, 2°, 2°로 설정될 수 있다(

,

,

). 그러나 이는 설명의 편의를 위한 예시일 뿐이며, 본 발명의 실시예는 이에 국한되지 않는다.The initial value of the observation time margin may be set as the product of the periodic timer time and the initial value of the number of observations (

). The observation time variable can be set to zero (

). The initial value of the gimball change count variable may be set to 0 (

). The initial value of the gimbal change count margin may be set to 10 (

). Among the direction change margins, the roll, pitch, and yaw change margins may be set to 5°, 2°, and 2°, respectively (

,

,

). However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

).Whenever the periodic timer time set in step S1210 elapses, a timer event may occur periodically (S1220). When a timer event occurs, the MBT may update the value of the observation time variable to a value obtained by adding the value of the periodic timer time to the value of the existing observation time variable (

).

MBT can check the coordinate information of the position (A') of the MBT PAH. For example, the MBT may check the coordinates of the center position of the gimbal controlling the direction of the MBT antenna (S1230). The MBT may determine the identified A' position as the position of the MBT PAH. Here, the position A' may be the same as or different from the position A described with reference to FIG. 11 . For example, when the MBT-mounted aerial vehicle is fixedly flying at the existing position after the initial beam alignment procedure, the A' position may be the same as the A position. On the other hand, when the MBT-mounted aerial moving object moves from the existing position after the initial beam alignment procedure or an aerial stop error occurs, the A' position may be different from the A position. On the other hand, since the MBH is not a mobile communication node, the B position may remain the same even after the initial beam alignment. Alternatively, if a measurement error occurs during the initial measurement of location B, the location B at the time may not be the same as information on location B initially identified. The MBT may check the coordinate information of the location of the MBH based on the signal transmitted from the MBH.

The MBT may convert the current coordinate information of the B position and the coordinate information of the A' position into coordinate information based on the MBT PAH VWU coordinate system (S1240). That is, the MBHT may acquire information of the line A-B expressed based on the MBT PAH VWU coordinate system. The MBT may calculate a direction change value of roll, pitch, yaw, etc. for controlling the direction of the MBT PAH in the A-B line direction (S1250). In an embodiment of the communication system, the MBT may additionally calculate a scalar value corresponding to the distance between the MBT and the MBH, or the strength of a beam to be transmitted to the MBH.

The MBT may compare the direction change value calculated in step S1250 with the direction change margin set in step S1210 (S1260). Even if the beam alignment between the MBT and the MBH is shifted, if the communication quality is shifted within a level that is not abnormal, it may not be necessary to actually perform direction change control. The direction change margin set in step S1210 may be considered to be set to prevent wastage of resources such as time or power required for beam alignment control by not performing unnecessary direction change control. For example, when one or more of the change values of roll, pitch, and yaw exceeds the direction change margin set in step S1210, the MBT may determine that direction change control is required. The MBT may perform a beam alignment operation such as controlling the direction of the antenna (ie, the direction of the MBT PAH) by controlling the gimbal on which the antenna of the MBT is installed based on the calculated direction change value (S1270). After performing the beam alignment operation in step S1270, the MBT may perform a reset operation for the periodic timer (S1280). On the other hand, when the calculated roll, pitch, and yaw change values are all below the roll, pitch, and yaw change margin set in step S1210, the MBT determines that a separate direction change control is not required and terminates the beam alignment operation. can Thereafter, whenever a timer event occurs periodically (S1220), the MBT may perform operations according to steps S1230 to S1280.

). 만약 관찰 시간 변수가 관찰 시간 마진을 초과하고(

) 짐볼 변경 카운트 변수가 짐볼 변경 카운트 마진 이하일 경우(

), MBT는 주기적 타이머 시간의 값을, 기존의 주기적 타이머 시간의 값에 단위 시간 간격의 값을 더한 값으로 갱신할 수 있다(

). MBT는 변경 카운트 변수 및 관찰 시간 변수를 0으로 설정할 수 있다. 이후, 타이머 이벤트가 주기적으로 발생할 때마다(S1220), MBT는 S1230 내지 S1280 단계에 따른 동작들을 수행할 수 있다.In the periodic timer reset operation in step S1280, first, the MBT may increase the value of the gimball change count variable by 1 (

). If the observation time variable exceeds the observation time margin (

) If the gimball change count variable is below the gimball change count margin (

), the MBT may update the value of the periodic timer time to a value obtained by adding the value of the unit time interval to the value of the existing periodic timer time (

). The MBT may set the change count variable and observation time variable to zero. Thereafter, whenever a timer event occurs periodically (S1220), the MBT may perform operations according to steps S1230 to S1280.

) 짐볼 변경 카운트 변수가 짐볼 변경 카운트 마진을 초과할 경우(

), MBT는 주기적 타이머 시간의 값을, 기존의 주기적 타이머 시간의 값에서 단위 시간 간격의 값을 뺀 값으로 갱신할 수 있다(

). MBT는 변경 카운트 변수 및 관찰 시간 변수를 0으로 설정할 수 있다. 이후, 타이머 이벤트가 주기적으로 발생할 때마다(S1220), MBT는 S1230 내지 S1280 단계에 따른 동작들을 수행할 수 있다.If the observation time variable exceeds the observation time margin (

) when the gimball change count variable exceeds the gimball change count margin (

), the MBT may update the value of the periodic timer time to a value obtained by subtracting the value of the unit time interval from the value of the existing periodic timer time (

). The MBT may set the change count variable and observation time variable to zero. Thereafter, whenever a timer event occurs periodically (S1220), the MBT may perform operations according to steps S1230 to S1280.

) 짐볼 변경 카운트 변수가 짐볼 변경 카운트 마진 이하일 경우(

), MBT는 주기적 타이머 시간의 값을, 기존의 주기적 타이머 시간의 값에서 단위 시간 간격의 값을 뺀 값으로 갱신할 수 있다(

). MBT는 변경 카운트 변수 및 관찰 시간 변수를 0으로 설정할 수 있다. 이후, 타이머 이벤트가 주기적으로 발생할 때마다(S1220), MBT는 S1230 내지 S1280 단계에 따른 동작들을 수행할 수 있다.If the observation time variable is below the observation time margin (

) If the gimball change count variable is below the gimball change count margin (

), the MBT may update the value of the periodic timer time to a value obtained by subtracting the value of the unit time interval from the value of the existing periodic timer time (

). The MBT may set the change count variable and observation time variable to zero. Thereafter, whenever a timer event occurs periodically (S1220), the MBT may perform operations according to steps S1230 to S1280.

) 짐볼 변경 카운트 변수가 짐볼 변경 카운트 마진을 초과할 경우(

), MBT는 타이머 재설정을 위한 별도의 동작을 수행하지 않고 빔 정렬 동작을 종료할 수 있다. 이후, 타이머 이벤트가 주기적으로 발생할 때마다(S1220), MBT는 S1230 내지 S1280 단계에 따른 동작들을 수행할 수 있다.If the observation time variable is below the observation time margin (

) when the gimball change count variable exceeds the gimball change count margin (

), the MBT may end the beam alignment operation without performing a separate operation for resetting the timer. Thereafter, whenever a timer event occurs periodically (S1220), the MBT may perform operations according to steps S1230 to S1280.

12, it can be seen that embodiments of the operation for performing the adaptive beam alignment procedure from the MBT standpoint is shown. MBH may also perform an adaptive beam alignment procedure through the same or similar operations as MBT. For example, the MBH may set an initial set value for a periodic timer and the like, and may adaptively perform beam alignment operations whenever a periodic timer event occurs. MBH based on the signal transmitted from the MBT, it is possible to determine the coordinate information for the current aerial location (A') of the MBT. The aerial location of the MBT may refer to the aerial location of the MBT PAH. A' location may mean the current aerial location of the MBT. Meanwhile, the MBH may reconfirm coordinate information about the current location of the MBH or the location of the MBH PAH by performing a positioning operation.

The MBH may calculate direction change values such as roll, pitch, and yaw for controlling the direction of the MBH PAH. When the calculated direction change value exceeds the direction change margin set in the initial setting, the MBH may perform a direction adjustment operation and a timer reset operation of the MBH PAH. Meanwhile, when the calculated direction change value is equal to or less than the direction change margin set in the initial setting, the MBH may determine that a separate direction change control is not required and end the beam alignment operation.

[Open-loop beam alignment procedure]

13A and 13B are exemplary views for explaining a fifth embodiment of a beam control method in a communication system.

13A and 13B , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT(A) and one MBH(B) for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. MBT (A) included in the communication system may be the same as or similar to the MBT (A) described with reference to FIG. MBH(B) included in the communication system may be the same as or similar to MBH(B) described with reference to FIG. 7 . The MBT(A) and MBH(B) may perform an open-loop beam alignment procedure through the operations according to the fifth embodiment of the beam control method in the communication system shown in FIGS. 13A and 13B . Here, the open-loop beam alignment procedure may be performed together with the initial beam alignment procedure and the adaptive beam alignment procedure described with reference to FIGS. 11 and 12, or may be performed independently of the initial beam alignment procedure and the adaptive beam alignment procedure. there is. Hereinafter, in the description of the fifth embodiment of the beam control method in the communication system with reference to FIGS. 13A and 13B , the content overlapping with those described with reference to FIGS. 1 to 12 may be omitted.

Even if a beam alignment operation between transmission/reception antennas of communication nodes performing mutual communication through beams in a communication environment is normally performed, the best communication quality may not be guaranteed. Accordingly, a procedure for achieving an optimal beam alignment state may be performed based on a value of a signal strength (SS) of a beam transmitted by the MBH(B) to the MBT(A). Such a procedure may be referred to as an 'open loop SS-based beam alignment' procedure.

Referring to FIG. 13A , the MBH(B) may provide information on the transmission (TX) power of a beam transmitted to the MBT(A) to the MBT(A). Here, information on the transmit power of the beam may be provided through a paging control channel (PCCH). The MBT(A) may obtain information of the TX power of the beam from the MBH(B). MBT(A) is based on the information of the TX power of the beam obtained from MBH(B), MBT that is the received power when the MBT(A) receives the beam transmitted from MBH(B) (received power, RP) You can calculate the expected range of RP. The expected range of MBT RP may include an RP expected maximum value (estimated RP maximum value, RPest.-max) and RP expected minimum value (estimated RP minimum value, RPest.-min). The expected range of the MBT RP may be calculated based on the distance (A-B distance) information between the MBT (A) and the MBH (B), information on the TX power of the beam transmitted from the MBH (B), and the like. The expected range of the MBT RP may be calculated under the assumption that the wireless communication path between the MBT (A) and the MBH (B) is a line-of-sight (LOS) condition. The expected range of the MBT RP may be calculated based on a predetermined system performance target set within the maximum communication distance between the MBT (A) and the MBH (B) (ex. 400 MHZ used downlink 1.25 Gbps or more).

If the MBT RP is within the expected range of the RP, it can be expected that wireless communication between the MBT (A) and the MBH (B) is normally performed. On the other hand, if the MBT RP is outside the RP expected range, it may be necessary to adjust the beam alignment state between the MBT (A) and the MBH (B).

Referring to Figure 13b, the MBT (A) based on a predetermined paging message transmitted through the PCCH from the MBH (B), may calculate the RP expected range for the MBT RP. Here, the paging message may include MBH antenna information (MBH Antenna info) (S1310). The paging message may include a list of location information of the MBT antenna (MBT Antenna's Position Info List) (S1320). The paging message may be configured to include some or all of the MBH antenna information (MBH Antenna info) and the MBT antenna location information list (MBT Antenna's Position Info List).

The MBH antenna information (MBH Antenna info) (S1310) may include information on the type of location information of the MBH antenna (MBH Antenna's Position Type) and the location information of the MBH antenna (MBH Antenna's Position Info). Here, the location information of the MBH antenna may have a type such as GPS coordinate information, GCS coordinate information based on latitude, longitude, and altitude information, or GCS coordinate information based on X, Y, and Z axes. The MBH antenna information may include information on TX power of a beam transmitted from the MBH antenna. The MBH antenna information may include information on a beam width of a beam transmitted from the MBH antenna. Here, the information on the beam width may include information on a vertical angle (Vertical°) and/or information on a horizontal angle (Horizontal°) of the beam.

)가 도시된 것으로 볼 수 있다. MBH 안테나에 대한 각각의 위치 정보 엔트리는, MBT 안테나의 위치 정보의 타입의 정보(MBT Antenna's Position Type), 및 MBT 안테나의 위치 정보(MBT Antenna's Position Info)를 포함할 수 있다. 여기서, MBT 안테나의 위치 정보는 GPS 좌표 정보, 위도, 경도, 고도 정보에 기초한 GCS 좌표 정보, 또는 X, Y, Z 축에 기초한 GCS 좌표 정보 등의 타입을 가질 수 있다. MBT antenna's position information list (MBT Antenna's Position Info List) (S1320), may include the position information of the MBT antenna grasped or estimated in MBH. When the MBH is performing communication with a plurality of MBTs, the location information list of the MBT antenna may include a location information entry for each of the antennas of the plurality of MBTs. When the MBT includes a plurality of antennas, the location information list of the MBT antenna may include a location information entry for each of the plurality of MBT antennas. Even if there is one MBT antenna, if it is estimated that the MBT antenna is located in any one of a plurality of locations in MBH, the location information list of the MBT antenna may include a location information entry for each of a plurality of locations. In Figure 13b, there is one MBT antenna communicating with the MBH, and the MBH grasps or estimates the location of the MBT antenna as a specific location, so the location information list of the MBT antenna is one location information entry ( Example ([0]) including only

) can be seen as shown. Each location information entry for the MBH antenna may include information on the type of location information of the MBT antenna (MBT Antenna's Position Type), and the location information of the MBT antenna (MBT Antenna's Position Info). Here, the location information of the MBT antenna may have a type such as GPS coordinate information, latitude, longitude, GCS coordinate information based on altitude information, or GCS coordinate information based on the X, Y, Z axes.

The MBT may check information included in the paging message transmitted from the MBH. In an embodiment of the communication system, the MBT may compare the location information of the MBH antenna included in the paging message transmitted from the MBH and the location information of the MBH or the location information of the MBH antenna recognized by the MBT. When there is an error exceeding a predetermined criterion between the location information of the MBH or the location information of the MBH antenna identified in the MBT and the location information of the MBH antenna included in the paging message, the MBT determines the location of the MBH antenna included in the paging message. By adjusting the direction of the MBT PAH based on the information, it is possible to improve the communication quality.

In one embodiment of the communication system, the MBT may compare the location information of the actual MBT antenna with the location information of the MBT antenna identified in the MBH, included in the paging message transmitted from the MBH. If there is an error exceeding a predetermined standard in the location information of the MBT antenna grasped by the MBH, the MBT performs the actual movement of the MBT antenna through the movement of the location of the aerial mobile body equipped with the MBT and/or physical control of the MBT antenna. It is possible to match the location with the location information of the MBT antenna identified in the MBH. Alternatively, if there is an error exceeding a predetermined criterion in the location information of the MBT antenna identified in the MBH, the MBT may transmit a signal including the location information of the actual MBT antenna to the MBH. In this case, the MBH can improve the communication quality by adjusting the direction of the MBH PAH based on the location information of the MBT antenna provided from the MBT.

In an embodiment of the communication system, the MBT may calculate the RP expected range for the MBT RP, based on the information included in the paging message transmitted from the MBH. The MBT may calculate the RP value or the RP estimate value (RPest) based on the reception result of the beam transmitted from the MBH. When the RP value or the RP estimate value calculated according to the beam reception result is outside the RP expected range, the MBT according to the sixth to eighth embodiments of the beam control method in the communication system to be described with reference to FIGS. 14A to 16C below. By performing the operations, it is possible to improve the communication quality.

[Triangular moving beam alignment procedure]

14A to 14D are exemplary views for explaining a sixth embodiment of a method for controlling a beam in a communication system.

14A to 14D , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIGS. 13A and 13B. The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIGS. 13A and 13B . Hereinafter, in the description of the sixth embodiment of the beam control method in a communication system with reference to FIGS. 14A to 14D , content overlapping with those described with reference to FIGS. 1 to 13B may be omitted.

In Figure 14a, the initial physical beam alignment for the MBT in the MBH (Initial Physical Beam Alignment), based on the information of the A-B line corresponding to the wireless communication path between the MBT and MBH can be seen as shown in a state that is normally performed. When the initial physical beam alignment between the MBT and the MBH is normally performed, an additional beam alignment operation between the MBT and the MBH may not be required. On the other hand, it can be seen that Figure 14b shows a state in which the initial physical beam alignment for the MBT in the MBH is not normally performed. For example, when information on the A-B line identified by the MBT and/or MBH is not accurate, an error may occur in beam alignment. Alternatively, when the communication path and/or communication environment including the existing A-B line is not an optimal condition for wireless communication between the MBT and the MBH, the beam alignment result based on the information of the A-B line may be evaluated as not normal. In this case, the MBT and/or MBH may require an additional beam alignment operation for adjusting the beam alignment state. The MBT and/or MBH may modify or update the information of the A-B line, and may perform an SS-based beam alignment operation based on the information of the new A-B line.

14c, it can be seen that an embodiment in which the MBT performs a triangular moving beam alignment procedure based on information included in a paging message transmitted from the MBH is shown. Here, the paging message transmitted in the MBH may be the same as or similar to the paging message described with reference to FIGS. 13A and 13B . The paging message transmitted in the MBH may include location information of the MBH antenna, information on the beam width of a beam transmitted in the MBH, location information of the MBT antenna, and the like.

The MBT may calculate a distance (A-B distance) between the MBT and the MBH based on information included in the paging message transmitted from the MBH. Based on the information included in the paging message transmitted from the MBH and the value of the A-B distance, the projected distance or the projected area at which the beam transmitted from the MBH is projected at the MBT location may be estimated. Here, the projected area may correspond to the entire area 425 in the cross-section of the MBH beam described with reference to FIG. 4A , or may correspond to a partial area 427 in the cross-section of the MBH beam in which uniform expected power is guaranteed.

The MBT may select a plurality of points within the estimated projected area. For example, in one embodiment of the communication system, the MBT may select three points (α, β, γ) within the calculated projected area. In one embodiment of the communication system, the three points α, β, γ may be selected to form a triangle inscribed in the projected area. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

MBT can adjust the MBT PAH based on three selected points (α, β, γ). By slightly adjusting the angle of the PAH through the gimbal of the antenna, the MBT can match the three points (α, β, γ) with the position and direction of the MBT PAH once. MBT may receive a beam transmitted from MBH at each of three points (α, β, γ).

Referring to Figure 14d, the MBT can calculate the RP value of the beam received at each of the three points (α, β, γ). The MBT may estimate the optimal reception point for the optimal MBH beam based on the RP value calculated at each of the three points (α, β, γ). MBT can estimate the optimal reception point through the proportional calculation of the RP value for each point. The MBT may set information of a new A-B line based on the estimated optimal reception point.

Specifically, when the RP at the α point is 80 dB, the RP at the β point is 60 dB, and the RP at the γ point is 50 dB, the MBT determines the optimal reception point based on the following calculation process. can be found First, on the α-β line connecting the α point and the β point, a point (point a) in which the distance from the α point and the β point is 60:80 can be found. Also, on the α-γ line connecting the α point and the γ point, a point (point b) where the distance from the α point and the γ point is 50:80 can be found. Also, on the β-γ line connecting the β point and the γ point, a point (point c) in which the distance from the β point and the γ point is 50:60 can be found. The MBT may estimate an optimal reception point based on point a, point b, and point c. For example, the MBT optimizes a point where a normal line a passing through the α-β line at point a, a normal line b passing through the α-γ line at point b, and a normal line c passing through the β-γ line at point c meet meet. It can be estimated as the receiving point. The MBT may update information on the A-B line based on the estimated optimal reception point. The MBT may receive the beam transmitted from the MBH at the estimated optimal reception point by controlling the MBT PAH based on the information of the new A-B line. Through this, the communication quality between the MBT and MBH can be improved.

[Extended Triangular Moving Beam Alignment Procedure]

15A to 15C are exemplary views for explaining a seventh embodiment of a method for controlling a beam in a communication system.

15A to 15C , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIGS. 13A and 13B. The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIGS. 13A and 13B . Hereinafter, in the description of the seventh embodiment of the beam control method in a communication system with reference to FIGS. 15A to 15C , the content overlapping with those described with reference to FIGS. 1 to 14D may be omitted.

In the seventh embodiment of the beam control method in the communication system, similar to the sixth embodiment of the beam control method in the communication system, the MBT receives the beam transmitted in the MBH at a plurality of different points, each It is possible to obtain a reception strength (RP) value at the point. For example, the MBT may receive a beam transmitted from the MBH at three predetermined points and check three RP values, and estimate an optimal reception point based on the obtained three RP values. In the seventh embodiment of the beam control method in the communication system, unlike the sixth embodiment of the beam control method in the communication system, three of the virtual points according to the maximum rotation angle supported by the gimbal in which the MBT PAH is installed It is possible to calculate the RP value at each of the points. Three points at which the MBT receives the beam transmitted from the MBH in the seventh embodiment of the beam control method in the communication system, the MBT receives the beam transmitted from the MBH in the sixth embodiment of the beam control method in the communication system It can be selected from a wider area than three points. The alignment procedure according to the seventh embodiment of the beam control method in a communication system may be referred to as an 'extended triangular moving beam alignment procedure'.

15a can be seen as showing a state in which the initial physical beam alignment for the MBT in the MBH is normally performed. On the other hand, it can be seen that Figure 15b shows a state in which the initial physical beam alignment for the MBT in the MBH is not normally performed. In this case, the MBT may select three points (α, β, γ) from among the virtual points according to the maximum rotation angle supported by the gimbal in which the MBT PAH is installed. Referring to Figure 15c, the MBT can receive the beam transmitted from the MBH at each of the three selected points (α, β, γ), based on the reception result at each of the three points (α, β, γ) You can calculate the RP value. MBT can estimate the optimal reception point based on the RP value at each of the three selected points (α, β, γ) MBT is based on the RP value at each of the three points (α, β, γ) Thus, the operation of estimating the optimal reception point may be performed identically or similarly to the operation of estimating the optimal reception point described with reference to FIG. 14D.

[Aerial vehicle triangular moving beam alignment procedure]

16A to 16C are exemplary views for explaining an eighth embodiment of a beam control method in a communication system.

16A to 16C , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIGS. 13A and 13B. The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIGS. 13A and 13B . Hereinafter, in the description of the eighth embodiment of the beam control method in a communication system with reference to FIGS. 16A to 16C , the content overlapping with those described with reference to FIGS. 1 to 15C may be omitted.

In the eighth embodiment of the beam control method in the communication system, similarly to the sixth and seventh embodiments of the beam control method in the communication system, the MBT receives the beam transmitted in the MBH at a plurality of different points. , it is possible to obtain a reception strength (RP) value at each point. For example, the MBT may receive a beam transmitted from the MBH at three predetermined points and check three RP values, and estimate an optimal reception point based on the obtained three RP values. In the eighth embodiment of the beam control method in the communication system, unlike the sixth and seventh embodiments of the beam control method in the communication system, not only the movement of the MBT PAH through the gimbal, but also the position of the MBT-mounted aerial mobile body itself. Three points can be selected based on the movement. That is, in the eighth embodiment of the beam control method in the communication system, three points can be selected in a wider area than the area according to the maximum rotation angle supported by the gimbal in which the MBT PAH is installed, and at each of the selected three points You can calculate the RP value of The three points at which the MBT receives the beam transmitted from the MBH in the eighth embodiment of the beam control method in the communication system are: It can be selected in a wider area than three points receiving the beam. The alignment procedure according to the eighth embodiment of the beam control method in the communication system may be referred to as 'aerial moving object triangular moving beam alignment procedure'.

It can be seen that FIG. 16a shows a state in which the initial physical beam alignment for the MBT in the MBH is normally performed. Meanwhile, it can be seen that FIG. 16b shows a state in which the initial physical beam alignment for the MBT in the MBH is not normally performed. In this case, the MBT can select three points (α, β, γ) where it can move through the aerial vehicle on which the MBT is mounted. The three points (α, β, γ) may be selected based on a predetermined movement interval criterion, centered on the initial physical beam alignment position based on the information of the A-B line. Here, the predetermined movement interval reference may be set for an aerial mobile body equipped with an MBT. The predetermined movement interval criterion may be determined based on a communication distance between the MBT and the MBH. In an embodiment of the communication system, the predetermined movement interval criterion may be set in units of several m. In another embodiment of the communication system, when the communication distance between the MBT and the MBH is 10 km, the predetermined movement interval criterion may be set to 100 m or more. The distance between the three points (α, β, γ) selected based on the predetermined movement interval criterion may have a value equal to or close to the predetermined movement interval criterion.

Referring to Figure 16c, the MBT can receive the beam transmitted from the MBH at each of the three selected points (α, β, γ), based on the reception result at each of the three points (α, β, γ) You can calculate the RP value. MBT can estimate the optimal reception point based on the RP value at each of the three selected points (α, β, γ) MBT is based on the RP value at each of the three points (α, β, γ) Thus, the operation of estimating the optimal reception point may be performed identically or similarly to the operation of estimating the optimal reception point described with reference to FIG. 14D.

[Beam alignment procedure based on transmit/receive power information]

17 is a flowchart for explaining a ninth embodiment of a beam control method in a communication system.

Referring to FIG. 17 , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT described with reference to FIGS. 13A and 13B. The MBH included in the communication system may be the same as or similar to the MBH described with reference to FIGS. 13A and 13B . The MBT and the MBH may perform a beam alignment procedure based on transmission/reception power information through operations according to the ninth embodiment of the beam control method in the communication system shown in FIG. 17 . Hereinafter, in the description of the ninth embodiment of the beam control method in the communication system with reference to FIG. 17 , the content overlapping with those described with reference to FIGS. 1 to 16C may be omitted.

In an embodiment of the communication system, the MBT and MBH may perform an initial beam alignment procedure in order to perform mutual wireless communication through a beam (S1710). Operations according to step S1710 may be the same as or similar to operations according to the third embodiment of the beam control method in the communication system described with reference to FIG. 11 . After the initial beam alignment procedure is performed, the MBT and MBH may perform an adaptive beam alignment procedure to maintain and/or adjust the beam alignment (S1720). Operations according to step S1720 may be the same as or similar to operations according to the fourth embodiment of the beam control method in the communication system described with reference to FIG. 12 . MBT and MBH, in order to maintain or improve the quality of mutual wireless communication, an open loop signal strength-based beam alignment (open loop SS-based beam alignment) procedure may be performed. In an embodiment of the communication system, the MBH may transmit a first signal including information of the TX power of the beam transmitted in the MBH to the MBT. The MBT may check information on the TX power of the beam transmitted from the MBH, based on the first signal transmitted from the MBH. The MBH may transmit the first signal once or may transmit the first signal multiple times. In an embodiment of the communication system, at least some of the first signals transmitted one or more times may further include location information of the MBH antenna, location information of the MBT antenna identified in the MBH, and the like. At this time, the MBT may update the information of the A-B line based on the location information of the MBH antenna included in the first signal, the location information of the MBT antenna grasped by the MBH, etc., and based on the updated information of the A-B line, the MBH It is possible to receive a beam transmitted from MBT, based on the distance between the MBT and the MBH, and information on the TX power of the beam transmitted from the MBH identified on the basis of the first signal, it is possible to calculate the reference RP range. Here, the reference RP range may be the same as or similar to the MBT RP expected range described with reference to FIG. 13a.

MBT may calculate the MBT RP value based on the reception result for the beam transmitted from the MBH. MBT may determine whether the MBT RP value is within or outside the reference RP range (S1730). If it is determined that the MBT RP value is within the reference RP range in step S1730, the MBT may determine that the current beam alignment state is normal. In this case, the MBT may end the transmission/reception power information-based beam alignment procedure. Alternatively, the MBT may perform the adaptive beam alignment procedure according to step S1720 or the determination operation according to step S1730 again. On the other hand, if it is determined that the MBT RP value is outside the reference RP range in step S1730, the MBT may perform a triangular moving beam alignment procedure (S1740). The operations in step S1740 may be the same as or similar to the operations according to the sixth embodiment of the beam control method in the communication system described with reference to FIGS. 14A to 14D .

After performing the triangular moving beam alignment procedure according to step S1740, the MBT may calculate an MBT RP value based on the reception result for the beam transmitted from the MBH again. MBT may determine whether the MBT RP value is within or outside the reference RP range (S1750). If it is determined that the MBT RP value is within the reference RP range in step S1750, the MBT may determine that the current beam alignment state is normal. In this case, the MBT may end the transmission/reception power information-based beam alignment procedure. Alternatively, the MBT may perform the adaptive beam alignment procedure according to step S1720 or the determination operation according to step S1730 again. On the other hand, if it is determined that the MBT RP value is outside the reference RP range in step S1750, the MBT may perform an extended triangular moving beam alignment procedure (S1760). The operations in step S1760 may be the same as or similar to the operations according to the seventh embodiment of the beam control method in the communication system described with reference to FIGS. 15A to 15C .

After performing the extended triangular moving beam alignment procedure according to step S1760, the MBT may calculate the MBT RP value based on the reception result for the beam transmitted from the MBH again. MBT may determine whether the MBT RP value is within or outside the reference RP range (S1770). If it is determined that the MBT RP value is within the reference RP range in step S1770, the MBT may determine that the current beam alignment state is normal. In this case, the MBT may end the transmission/reception power information-based beam alignment procedure. Alternatively, the MBT may perform the adaptive beam alignment procedure according to step S1720 or the determination operation according to step S1730 again. On the other hand, if it is determined that the MBT RP value is outside the reference RP range in step S1770, the MBT may perform a drone triangular moving beam alignment procedure or an aerial moving body triangular moving beam alignment procedure (S1780). The operations in step S1780 may be the same as or similar to the operations according to the eighth embodiment of the beam control method in the communication system described with reference to FIGS. 16A to 16C .

After performing the aerial mobile triangular moving beam alignment procedure according to step S1780, the MBT may end the transmission/reception power information-based beam alignment procedure. Alternatively, the MBT may perform the adaptive beam alignment procedure according to step S1720, a determination operation according to step S1730, or a determination operation according to step S1770 again.

Based on the operations according to steps S1710 to S1780, the MBT and the MBH may perform a beam alignment procedure based on transmit/receive power information. Accordingly, the MBT and the MBH can be controlled so that wireless communication between the MBT and the MBH configured through the initial beam alignment procedure and the adaptive beam alignment procedure can be continuously performed smoothly.

[Closed-loop beam alignment procedure]

18A to 18C are exemplary views for explaining a tenth embodiment of a beam control method in a communication system.

18A to 18C , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT(A) and one MBH(B) for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. MBT (A) included in the communication system may be the same as or similar to the MBT (A) described with reference to FIG. MBH(B) included in the communication system may be the same as or similar to MBH(B) described with reference to FIG. 7 . The MBT(A) and MBH(B) may perform a closed-loop beam alignment procedure through the operations according to the tenth embodiment of the beam control method in the communication system shown in FIGS. 18A to 18C . Here, the closed-loop beam alignment procedure may be performed together with at least some of the embodiments of the beam alignment procedure described with reference to FIGS. 11 to 17, or the embodiments of the beam alignment procedure described with reference to FIGS. 11 to 17 and It can also be performed independently. Hereinafter, in the description of the tenth embodiment of the beam control method in a communication system with reference to FIGS. 18A to 18C , content overlapping with those described with reference to FIGS. 1 to 17 may be omitted.

Even if a beam alignment operation between transmission/reception antennas of communication nodes performing mutual communication through beams in a communication environment is normally performed, the best communication quality may not be guaranteed. Accordingly, based on the value of the signal strength (SS) of the beam transmitted by the MBH(B) to the MBT(A), and/or the value of the SS of the beam transmitted by the MBT(A) to the MBH(B) Procedures may be performed to achieve optimal beam alignment conditions. Such a procedure may be referred to as a 'closed loop SS-based beam alignment' procedure.

Referring to FIG. 18A , the MBH(B) may provide information on the transmission (TX) power of a beam transmitted to the MBT(A) to the MBT(A). MBH(B) may transmit a first signal including information on TX power of a beam transmitted to MBT(A) to MBT(A). Meanwhile, the MBT(A) may provide information on the TX power of a beam transmitted to the MBH(B) to the MBH(B). The MBT(A) may transmit a second signal including information on TX power of a beam transmitted to the MBH(B) to the MBH(B). Here, in a state in which a wireless connection between the MBT(A) and the MBH(B) is configured, the first and second signals may be transmitted through a predetermined dedicated channel for the MBT(A). For example, the MBH(B) may transmit the first signal to the MBT(A) through a dedicated control channel (DCCH) for the MBT(A). Meanwhile, the MBT(A) may transmit the second signal to the MBH(B) through the DCCH for the MBT(A).

The MBT(A) may obtain information on the TX power of the beam from the MBH(B) through the first signal. MBT(A) is based on the information of the TX power of the beam obtained from MBH(B), it is possible to calculate the expected range of the MBT RP, which is the RP when the MBT(A) receives the beam transmitted from MBH(B). there is. The expected range of the MBT RP may be calculated based on the distance (A-B distance) information between the MBT (A) and the MBH (B), information on the TX power of the beam transmitted from the MBH (B), and the like. The expected range of the MBT RP may be calculated under the assumption that the wireless communication path between the MBT (A) and the MBH (B) is a LOS condition. The expected range of the MFBT RP may be calculated based on a predetermined system performance target set within the maximum communication distance between the MBT (A) and the MBH (B). If the MBT RP is within the expected range of the MBT RP, it can be expected that wireless communication between the MBT (A) and the MBH (B) is normally performed. On the other hand, if the MBT RP is outside the expected range of the MBT RP, it may be necessary to adjust the beam alignment state between the MBT (A) and MBH (B).

The MBH(B) may obtain information on the TX power of the beam from the MBT(A) through the second signal. MBH(B) is based on the information of the TX power of the beam obtained from MBT(A), the expected range of MBH RP, which is the RP when MBH(B) receives the beam transmitted from MBT(A) Can be calculated there is. The expected range of the MBH RP may be calculated based on A-B distance information, information on the TX power of the beam transmitted from the MBT (A), and the like. The expected range of the MBH RP can be calculated under the assumption that the wireless communication path between the MBT (A) and the MBH (B) is a LOS condition. The expected range of the MBT RP may be calculated based on a predetermined system performance target set within the maximum communication distance between the MBT (A) and the MBH (B). It may be calculated based on a given system performance target. If the MBH RP is within the expected range of the MBH RP, it can be expected that wireless communication between the MBT (A) and the MBH (B) is normally performed. On the other hand, if the MBH RP is outside the expected range of the MBH RP, it may be necessary to adjust the beam alignment state between the MBT (A) and the MBH (B).

18A, one MBT (A) and one MBH (B) can be seen as showing an embodiment in which communication is performed through a beam. However, embodiments of the present invention are not limited thereto. For example, in an embodiment of the communication system, one MBH may communicate with a plurality of MBTs through a beam. In this case, the MBH may not be able to maintain an optimal beam alignment state for each of all MBTs. The MBH may select any one of the plurality of MBTs based on the plurality of second signals transmitted from the plurality of MBTs. For example, the MBH may select a first MBT from among a plurality of MBTs and adjust a beam alignment state of the MBH for the first MBT. The MBH may perform an operation for preventing a collision between the MBTs for the remaining MBTs except for the first MBT. For example, the MBH may provide information on the location of the MBH to the remaining MBTs after performing beam alignment based on the first signal transmitted from the first MBT. Alternatively, after the MBH performs beam alignment based on the first signal transmitted from the first MBT, it may provide different virtual information about the location of the MBH for the remaining MBTs.

Referring to Figure 18b, the MBT (A) may calculate the RP expected range for the MBT RP based on the first signal transmitted through the DCCH from the MBH (B). Here, the first signal may correspond to an RRC message. The RRC message may include MBH-driven beam alignment information (S1810). The RRC message may include MBH antenna information (MBH Antenna info) (S1820). The RRC message may include a list of location information of the MBT antenna (MBT Antenna's Position Info List) (S1830).

Here, MBH Antenna info (S1820) may be the same as or similar to MBH Antenna info (S1310) included in the paging message described with reference to FIG. 13B . MBT antenna's position information list (MBT Antenna's Position Info List) (S1830) may be the same as or similar to the MBT antenna's Position Info List (MBT Antenna's Position Info List) (S1320) included in the paging message described with reference to FIG. 13b there is. The MBT may check the information included in the RRC message transmitted from the MBH. In an embodiment of the communication system, the MBT evaluates and adjusts the beam alignment state by comparing the location information of the MBH antenna included in the RRC message transmitted from the MBH with the location information of the MBH or the location information of the MBH antenna identified by the MBT. can In an embodiment of the communication system, the MBT may evaluate and adjust the beam alignment state by comparing the location information of the MBT antenna identified in the MBH and the location information of the actual MBT antenna included in the RRC message transmitted from the MBH. This may be the same as or similar to that described with reference to FIG. 13B.

In an embodiment of the communication system, the MBT may calculate the expected range of the MBT RP, based on the information included in the RRC message transmitted from the MBH. Based on the comparison of the expected range of MBT RP with the actual measured MBT RP value, MBT can perform beam alignment procedures such as triangular moving beam alignment procedure, extended triangular moving beam alignment procedure, and aerial moving object triangular moving beam alignment procedure. there is. This may be the same as or similar to that described with reference to FIGS. 14A to 17 .

MBH-driven beam alignment information (MBH-driven Beam Alignment info) (S1810) included in the RRC message is information indicating whether the MBT maintains the existing beam alignment state or performs an operation of updating the beam alignment may include MBH-driven beam alignment stop flag (MBH-driven beam align. lock flag) can instruct stop beam alignment when it is setup(1), and can indicate release of stop beam alignment when it is release(0), mutual When -movement(2), a beam alignment operation based on movement of both MBH and MBT may be indicated. On the other hand, MBH-driven beam alignment activation time (MBH-driven beam alignment. Activation time) may indicate the timing of applying the command indicated by the MBH-driven beam alignment stop flag. MBH-driven beam alignment information (MBH-driven Beam Alignment info) (S1810) may optionally further include duration (Duration Time) information. The duration information may mean a length of time for which a command indicated by the MBH-led beam alignment stop flag lasts.

In an embodiment of the communication system, when the MBH-led beam alignment information of the RRC message received by the MBT indicates 'setup(1), activation time (X=2), duration time (Y=10)', MBT may stop the beam alignment operation after 2 seconds, and may maintain the existing beam alignment state for 10 seconds thereafter. When 12 seconds have elapsed since the MBT receives the RRC message, the beam alignment stop may be released. On the other hand, when the MBH-led beam alignment information of the RRC message received by the MBT indicates 'setup(1), activation time (X=0), duration time (Y=0)', the MBT receives the RRC message. Immediately after, the beam alignment operation may be stopped. MBT may continue to stop beam alignment until 'release(0)' is indicated through a separate RRC message thereafter.

Referring to Figure 18c, MBH (B) can calculate the RP expected range for the MBH RP based on the second signal transmitted through the DCCH from the MBT (A). Here, the second signal may correspond to an RRC message. The RRC message may include location information of the MBT antenna (MBT Antenna's Position Info) (S1840). The RRC message may include MBH antenna information (MBH Antenna Info) (S1850).

Location information of the MBT antenna (MBT Antenna's Position Info) (S1840), information on the type of location information of the MBT antenna (MBT Antenna's Position Type), and the location information of the MBT antenna (MBT Antenna's Position Info) may include. The location information of the MBT antenna may include information on the TX power of the beam transmitted from the antenna of the MBT. The location information of the MBT antenna may include information on the beam width of the beam transmitted from the antenna of the MBT.

MBH antenna information (MBT Antenna Info) (S1850) may include location information of the MBH antenna grasped or estimated in the MBT. The MBH antenna information may include MBH Antenna's Position Type and MBH Antenna's Position Info.

MBH may check the information included in the RRC message transmitted from the MBT. In an embodiment of the communication system, the MBH may compare the location information of the MBT antenna included in the RRC message transmitted from the MBT, and the location information of the MBT or the location information of the MBT antenna identified in the MBH. When there is an error exceeding a predetermined criterion between the location information of the MBT or the location information of the MBT antenna, which is understood in the MBH, and the location information of the MBT antenna included in the paging message, the MBH is the location of the MBT antenna included in the RRC message. By adjusting the direction of the MBH PAH based on the information, it is possible to improve the communication quality.

In one embodiment of the communication system, the MBH may compare the location information of the actual MBH antenna with the location information of the MBH antenna identified by the MBT, included in the paging message transmitted from the MBT. If there is an error exceeding a predetermined standard in the location information of the MBH antenna grasped by the MBT, the MBH performs physical control of the MBH antenna to determine the actual location of the MBH antenna in the MBT location information of the MBH antenna. can be matched to Alternatively, if there is an error exceeding a predetermined criterion in the location information of the MBH antenna recognized by the MBT, the MBH may transmit a signal including the location information of the actual MBH antenna to the MBT. In this case, the MBT can improve the communication quality by adjusting the direction of the MBT PAH based on the location information of the MBH antenna provided from the MBH.

In an embodiment of the communication system, the MBH may calculate an expected range of the MBH RP based on the information included in the RRC message transmitted from the MBT. The MBH may perform beam alignment procedures such as a triangular moving beam alignment procedure and an extended triangular moving beam alignment procedure based on a comparison of the expected range of MBH RP with the actual measured MBH RP value. This may be similar to the beam alignment operations of the MBT described with reference to FIGS. 14A to 15C.

[Aerial movement-based beam alignment procedure]

19A and 19B are conceptual diagrams for explaining an eleventh embodiment of a beam control method in a communication system.

19A and 19B , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include one MBT and one MBH for performing communication through a beam. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The MBT included in the communication system may be the same as or similar to the MBT (A) described with reference to FIGS. 18a to 18c. The MBH included in the communication system may be the same as or similar to the MBH(B) described with reference to FIGS. 18A to 18C . Hereinafter, in the description of the eleventh embodiment of the beam control method in a communication system with reference to FIGS. 19A and 19B , content overlapping with those described with reference to FIGS. 1 to 18C may be omitted.

An aerial moving object, such as a drone equipped with an MBT, may perform fixed flight at any one position in the air. Alternatively, the aerial vehicle may move from one location in the air to another location in order to perform a mission. Due to the movement of the aerial vehicle, the position of the MBT may be changed from position A to position A'. When the position of the MBT is changed from the A position to the A' position, the MBT and the MBH may have to update the existing beam alignment based on the A-B line to the beam alignment based on the A'-B line.

In an embodiment of the communication system, the MBT may transmit information on the movement path of the MBT to the MBH. Here, information on the movement path of the MBT may be included in the RRC message transmitted through the DCCH and transmitted from the MBT to the MBH. Information on the moving path of the MBT may include destination information. Information on the movement path of the MBT may further include information on intermediate locations passed before reaching the destination. On the other hand, in another embodiment of the communication system, the MBT may move based on information about the movement path of the MBT indicated from the MBH. In this case, information on the movement path of the MBT may be included in the RRC message through the DCCH and transmitted from the MBH to the MBT.

The MBH may calculate a direction change value for moving the direction of the MBH PAH from the A-B line to the A'-B line based on the information on the movement path of the MBT. MBH may calculate values such as MBH offset roll, MBH offset pitch, and MBH offset yaw through the direction change value calculation operation.

The MBT may calculate a direction change value for moving the direction of the MBT PAH from the A-B line to the A'-B line based on the information on the movement path of the MBT. MBT may calculate values such as MBT offset roll, MBT offset pitch, and MBT offset yaw through the direction change value calculation operation.

The MBH may instruct the MBT to perform beam alignment based on the movement of both the MBH and the MBT. The MBH may transmit the same or similar message to the RRC message described with reference to FIG. 18b to the MBT through the DCCH. Here, the value of the MBH-led beam alignment stop flag may be set to mutual-movement(2). The MBH-led beam alignment activation time may be set based on the time required to prepare the MBT for movement. The duration may be set based on the time it takes for the MBT to move from position A to position A'.

For example, when the MBH-led beam alignment information of the RRC message received by the MBT indicates 'mutual-movement(2), activation time (X=1), duration time (Y=10)', the MBT RRC message After 1 second has elapsed from the time of transmission, it can move from position A to position A' for 10 seconds. MBT and MBH can adjust their respective antenna directions for 10 seconds after 1 second has elapsed from the time when the RRC message is transmitted.

MBT and MBH may each independently adjust the direction of the antenna, or may adjust the direction of the antenna based on a mutually synchronized direction adjustment plan. For a synchronized direction adjustment plan, MBT and MBH may set a unit time. For example, MBH offset roll, MBH offset pitch, and MBH offset yoga are 3°, 4°, and 2° respectively, and MBT offset roll, MBT offset pitch and MBT offset yoga are 0°, 7°, 8° respectively, and MBT and MBH mutual When the preset unit time is 1 second, the MBT and MBH may adjust the direction of the antenna based on the synchronized direction adjustment plan identically or similarly to that shown in Table 2.

When the movement of the MBT and direction adjustment of the antennas of the MBT and the MBH are completed, the MBT may perform communication with the MBH in a beam-aligned state with the MBH at the A' position. On the other hand, as the communication path between the MBT and the MBH is changed from the A-B line to the A'-B line, the communication distance between the MBT and the MBH may also be changed from the A-B distance to the A'-B distance. The MBT and/or MBH may further perform an operation of changing the beam strength according to a change in the communication distance.

[Backup Aerial Vehicle-based Beam Alignment Procedure]

20A and 20B are conceptual diagrams for explaining a twelfth embodiment of a beam control method in a communication system.

20A and 20B , a communication system may include a plurality of communication nodes that perform communication through a beam. For example, the communication system may include first and second MBTs performing communication through a beam, and one MBH. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The first and second MBTs included in the communication system may be the same as or similar to the MBT (A) described with reference to FIGS. 18A to 18C. The MBH included in the communication system may be the same as or similar to the MBH(B) described with reference to FIGS. 18A to 18C . Hereinafter, in the description of the twelfth embodiment of the beam control method in a communication system with reference to FIGS. 20A and 20 , content overlapping with those described with reference to FIGS. 1 to 19B may be omitted.

An aerial moving object such as a drone equipped with an MBT may perform flight in the air. If the aerial vehicle is operated on its own fuel or its own battery without a separate wired connection, there may be restrictions on flight time. Therefore, in order to continuously perform a mission, it may be necessary to replace an aerial vehicle whose fuel or battery is exhausted more than a certain amount by an additional aerial vehicle serving as a backup.

For example, in FIGS. 20A and 20B , it can be seen that the main drone equipped with the first MBT is replaced by the backup drone equipped with the second MBT. When the backup drone replaces the main drone, the MBH that previously communicated with the first MBT may need to communicate with the second MBT. In one embodiment of the communication system, when the main drone deviates from the existing location and the backup drone moves to the existing main drone location, the second MBT communicates with the MBH at the location where the first MBT communicated with the MBH. communication can be performed. Meanwhile, in another embodiment of the communication system, when the backup drone moves to a location adjacent to the main drone, the MBH may perform an operation of changing the direction of the antenna from the first MBT direction to the second MBT direction.

In one embodiment of the communication system, the first MBT and / or the second MBT MBT replacement information including information indicating that the second MBT will replace the first MBT, and information on the location of the second MBT to the MBH can be transmitted For example, the MBT replacement information may be included in the RRC message transmitted through the DCCH and transmitted from the first MBT to the MBH. On the other hand, in another embodiment of the communication system, the first and second MBT based on the MBT replacement information indicated from the MBH, may perform a replacement procedure. In this case, the MBT replacement information may be included in the RRC message through the DCCH and transmitted from the MBH to the first and the second MBT.

The MBH may calculate a direction change value for moving the direction of the MBH PAH from the A1-B line to the A2-B line based on the MBT replacement information. MBH may calculate values such as MBH offset roll, MBH offset pitch, and MBH offset yaw through the direction change value calculation operation.

The MBH may instruct the first and the second MBT to stop the beam alignment operation for a predetermined time. The MBH may transmit the same or similar message to the RRC message described with reference to FIG. 18b to the first and second MBTs through the DCCH. Here, the value of the MBH-led beam alignment stop flag may be set to setup(1). The MBH-led beam alignment activation time may be set based on the time required to prepare the MBH for changing the antenna direction. The duration may be set based on the time taken for the MBH to change the direction of the antenna from the A1 direction to the A2 direction. Alternatively, the duration may be set based on the time it takes for the backup drone to take over the task of the main drone.

For example, when the MBH-led beam alignment information of the RRC message received by the first and second MBTs indicates 'setup(1), activation time (X=1), duration time (Y=10)', the first And the second MBT may stop the beam alignment operation by changing the direction of each antenna for 10 seconds after 1 second has passed from the time when the RRC message is transmitted. The MBH may adjust the antenna direction of the MBH for 10 seconds after 1 second has elapsed from the time the RRC message is transmitted.

In one embodiment of the communication system, the MBH may steer the antenna based on a predetermined steering scheme. For direction adjustment planning, MBH may set a unit time. For example, if MBH offset roll, MBH offset pitch and MBH offset yoga are 3°, 4°, and 2° respectively, and the preset unit time is 1 second, MBH is based on the same or similar set direction adjustment plan as shown in Table 3 The direction of the antenna can be adjusted.

When the direction adjustment of the antenna of the MBH is completed, the second MBT may perform communication with the MBH at the A2 position. Meanwhile, as the communication path of the MBH is changed from the A1-B line to the A2-B line, the communication distance may also be changed from the A1-B distance to the A2-B distance. The MBH may further perform an operation of changing the beam strength according to a change in the communication distance.

At least some of the embodiments of the present invention described with reference to FIGS. 1 to 20B may be applied to a beam alignment operation between a communication node mounted on an aerial mobile and a communication node performing communication at a predetermined location on the ground. At least some of the embodiments of the present invention described with reference to FIGS. 1 to 20B may be equally or similarly applied to a beam alignment operation between a plurality of communication nodes mounted on an aerial mobile device.

At least some of the embodiments of the present invention described with reference to FIGS. 1 to 20B may be applied when the communication medium is a beam having a high frequency or a higher frequency, such as a millimeter wave. At least some of the embodiments of the present invention described with reference to FIGS. 1 to 20B may be equally or similarly applied to a beam alignment operation in free space optic (FSO) communication or communication using a laser beam.

At least some of the embodiments of the present invention described with reference to FIGS. 1 to 20B may be equally or similarly applied to a beam alignment operation between high-spec communication equipments with a maximum communication distance exceeding 10 km. For example, at least some of the embodiments of the present invention described with reference to FIGS. 1 to 20B may be equally or similarly applied to a beam alignment operation of a military beam having a maximum communication distance exceeding 100 km.

According to an embodiment of the present invention, a beam alignment operation for communication between a communication node mounted on a public mobile object such as a public base station and another communication node can be effectively performed. To this end, each communication node may process coordinate information based on a plurality of coordinate systems such as a GPS coordinate system, a geocentric coordinate system (GCS), an RVCS coordinate system, and a PAH coordinate system. According to an embodiment of the present invention, a public base station performing communication in the air can effectively maintain a wireless connection with other communication nodes on the ground or in the air, such as a wireless backhaul link for communication with a core network.

However, effects that can be achieved by the method and apparatus for controlling a public base station in a wireless communication system according to embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned are described in the specification of the present application. From the configurations described in the present invention will be clearly understood by those of ordinary skill in the art.

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.

Examples of computer-readable media include hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a setting computer using an interpreter or the like. The hardware device described above may be configured to operate as at least one software module to perform the operations of the present invention, and vice versa.

Although it has been described with reference to the above embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. will be able

Claims (19)

A beam alignment method performed by a first communication node in a communication system, comprising:
determining a position of a first antenna of the first communication node;
setting a first coordinate system based on the physical location and direction of the first antenna based on the information on the location of the first antenna;
identifying a location of a second antenna of a second communication node of the communication system;
converting the position information of the second antenna into coordinate information based on the first coordinate system;
calculating a direction change value of the first antenna based on the position information of the second antenna transformed based on the first coordinate system;
changing the direction of the first antenna based on the direction change value of the first antenna; and
and updating a beam alignment state between the first and second antennas. The method according to claim 1,
The first coordinate system is a VWU coordinate system with the physical location of the first antenna as the origin and the direction of the first antenna as the V-axis. The method according to claim 1,
The updating step is
reconfirming information on the position of the first antenna when a predetermined timer event occurs;
updating the first coordinate system based on the information on the position of the first antenna;
converting the position information of the second antenna again based on the updated first coordinate system; and
Based on the re-converted position information of the second antenna, comprising the step of re-calculating the direction change value of the first antenna, the beam alignment method. 4. The method according to claim 3,
Recalculating the direction change value of the first antenna comprises:
comparing the recalculated direction change value of the first antenna with a preset change margin; and
When the re-calculated change in the direction of the first antenna exceeds a preset change margin, changing the direction of the first antenna again based on the re-calculated change in the direction of the first antenna , the beam alignment method. The method according to claim 1,
The beam alignment method is
receiving a first signal transmitted from the second communication node; and
Further comprising the step of adjusting the beam alignment state between the first and second antennas based on the information included in the first signal, the beam alignment method. 6. The method of claim 5,
The first signal includes information on transmit (TX) power and beam width of a beam transmitted from the second communication node,
The adjusting step is
calculating an expected range of received power (RP) when the beam transmitted from the second communication node is received by the first antenna, based on the information included in the first signal;
receiving a beam transmitted from the second communication node;
calculating the RP of the beam transmitted from the second communication node; and
When the RP of the beam transmitted from the second communication node is within the expected range of the RP, the beam alignment method comprising the step of determining that the beam alignment state is normal. 6. The method of claim 5,
The first signal includes information on transmit (TX) power and beam width of a beam transmitted from the second communication node,
The adjusting step is
calculating an expected range of received power (RP) when the beam transmitted from the second communication node is received by the first antenna, based on the information included in the first signal;
receiving a first beam transmitted from the second communication node;
calculating the RP of the first beam;
estimating an optimal reception point through physical control of the first antenna when the RP of the first beam is outside the expected range of the RP; and
and controlling the first antenna based on the estimated optimal reception point. 8. The method of claim 7,
The step of estimating the optimal reception point includes:
receiving beams transmitted from the second communication node through the first antenna at each of three predetermined points; and
Based on the RP values measured at the three predetermined points, comprising the step of estimating a specific point between the three predetermined points as the optimal reception point,
The three predetermined points are selected from among a projected area on which beams transmitted from the second communication node are projected from the position of the first communication node, or a maximum rotation angle supported by the direction control device in which the antenna of the first communication node is installed. The beam alignment method is determined based on any one. 8. The method of claim 7,
The step of estimating the optimal reception point includes:
receiving beams transmitted from the second communication node through the first antenna at each of three predetermined points; and
Based on the RP values measured at the three predetermined points, comprising the step of estimating a specific point between the three predetermined points as the optimal reception point,
The three predetermined points are determined based on a predetermined movement interval criterion set with respect to the aerial mobile body on which the first communication node is mounted. 6. The method of claim 5,
The adjusting step is
Determining whether the beam alignment state is normal based on at least one of information on the position of the second antenna included in the first signal or position information of the first antenna recognized by the second communication node step; and
and when it is determined that the beam alignment state is not normal, adjusting the beam alignment state by physically controlling the first antenna based on information included in the first signal. 6. The method of claim 5,
The adjusting step is
Determining whether the beam alignment state is normal based on at least one of information on the position of the second antenna included in the first signal or position information of the first antenna recognized by the second communication node step; and
When it is determined that the beam alignment state is not normal, based on the information included in the first signal, adjusting the beam alignment state by physically controlling the aerial mobile on which the first communication node is mounted , the beam alignment method. The method according to claim 1,
The beam alignment method is
checking movement path information of the second communication node;
transmitting a second signal instructing to change the direction of the second antenna to the first communication node based on movement path information of the second communication node; and
Based on the information indicated by the second signal, the method further comprising the step of changing the direction of the first antenna, beam alignment method. The method according to claim 1,
The beam alignment method is
checking replacement information indicating that a third communication node of the communication system will replace the second communication node;
transmitting, to the second and third communication nodes, a third signal instructing not to change directions of the second antenna and a third antenna of the third communication node for a predetermined time based on the replacement information; and
Based on the information indicated by the second signal, the method further comprising the step of changing the direction of the first antenna, beam alignment method. A first communication node for performing beam alignment in a communication system, comprising:
processor;
a memory in electronic communication with the processor; and
including instructions stored in the memory;
When the instructions are executed by the processor, the instructions cause the first communication node to:
locating a first antenna of the first communication node;
setting a first coordinate system based on the physical location and direction of the first antenna based on the information on the location of the first antenna;
ascertain a location of a second antenna of a second communication node of the communication system;
converting information on the position of the second antenna into coordinate information based on the first coordinate system;
calculating a direction change value of the first antenna based on the position information of the second antenna transformed based on the first coordinate system;
change the direction of the first antenna based on the direction change value of the first antenna; And
and cause updating a beam alignment state between the first and second antennas. 15. The method of claim 14,
The first coordinate system is a VWU coordinate system with the physical location of the first antenna as the origin and the direction of the first antenna as the V-axis, the first communication node. 15. The method of claim 14,
The instructions allow the first communication node to
when a predetermined timer event occurs, reconfirming the information on the position of the first antenna;
updating the first coordinate system based on the information on the position of the first antenna;
transforming the position information of the second antenna again based on the updated first coordinate system; And
and, based on the retransformed position information of the second antenna, further cause recalculating the direction change value of the first antenna. 15. The method of claim 14,
The instructions allow the first communication node to
receive a first signal transmitted from the second communication node; And
and cause adjusting the beam alignment state between the first and second antennas based on information included in the first signal. 15. The method of claim 14,
The instructions allow the first communication node to
check movement path information of the second communication node;
transmit a second signal instructing to change the direction of the second antenna to the first communication node based on the movement path information of the second communication node; And
and further cause to change the direction of the first antenna based on information indicated in the second signal. 15. The method of claim 14,
The instructions allow the first communication node to
check replacement information indicating that a third communication node of the communication system will replace the second communication node;
transmit, to the second and third communication nodes, a third signal instructing not to change directions of the second antenna and a third antenna of the third communication node for a predetermined time based on the replacement information; And
and further cause to change the direction of the first antenna based on information indicated in the second signal.

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