COMMUNICATION CONTROL DEVICE, COMMUNICATION CONTROL METHOD, AND COMMUNICATION CONTROL PROGRAM

Abstract

This communication control device 3 comprises: a movement information acquiring unit 31 that acquires movement information related to the movement of a relay station RN that can communicate with a terrestrial base station 111 or a non-terrestrial base station 131 to extend a terrestrial communication cell 112 or a non-terrestrial communication cell 132 provided by the base station 111, 131; an extended cell selecting unit 33 that selects, on the basis of the movement information, the communication cell 112, 132 that is to be extended by the currently moving relay station RN; and a connection control unit 35 that connects the relay station RN to the base station 111, 131 providing the selected communication cell 112, 132. The relay station RN is mounted on a movable vehicle V.

Description

[Technical field]

[0001] The present invention relates to a communication control technique in a wireless communication system. [Background technology]

[0002] The number, types, and uses of wireless communication devices, such as smartphones and Internet of Things (IoT) devices, are constantly increasing, and wireless communication standards are continually being expanded and improved. For example, commercial services for the fifth generation mobile communication system, known as "5G," began in 2018, and standardization is still underway at the Third Generation Partnership Project (3GPP). In addition, efforts have begun to develop standards for the sixth generation mobile communication system, or "6G," as the next-generation wireless communication standard following 5G.

[0003] Mobile communication (hereinafter also referred to as mobile communication) networks for mobile communication devices (hereinafter collectively referred to as communication devices) such as smartphones and mobile phones have generally been constructed using communication cells (hereinafter also referred to as terrestrial communication cells) provided by base stations (hereinafter also referred to as terrestrial base stations) installed on the ground. However, there was a problem in that mobile communication was not possible outside the terrestrial communication cells, and even within the terrestrial communication cells, the quality of mobile communication could deteriorate depending on the time and location.

[0004] To solve this problem, relay stations that can expand terrestrial communication cells by communicating with terrestrial base stations are used. Even if a communication device near a relay station cannot directly communicate with the terrestrial base station, it can indirectly communicate with the terrestrial base station via the relay station. In other words, the relay station relays communication radio waves between the terrestrial base station and the communication device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-352894 A Summary of the Invention [Problem to be solved by the invention]

[0006] Since most of the conventional relay stations are fixedly installed at a predetermined position on the ground, it is difficult to flexibly change the configuration of the wireless communication system. Therefore, it is possible to make the relay stations movable, but since a moving relay station passes through many communication cells arranged on the ground, there is a possibility that communication cells that need to be expanded will not be expanded, and communication cells that need to be expanded less will be expanded.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a communication control device and the like that enables a moving relay station to appropriately expand a communication cell. [Means for solving the problem]

[0008] In order to solve the above problem, a communication control device of one embodiment of the present invention includes a mobility information acquisition unit that communicates with a base station to acquire mobility information regarding the movement of a relay station that can expand a communication cell provided by the base station, an expansion cell selection unit that selects a communication cell to be expanded by the moving relay station based on the mobility information, and a connection control unit that connects the relay station to the base station that provides the selected communication cell.

[0009] In this aspect, since the communication cell to be expanded is selected based on the movement information of the relay station, the relay station can expand an appropriate communication cell while moving.

[0010] Another aspect of the present invention is a communication control method, which includes a mobile information acquisition step of acquiring mobile information related to the movement of a relay station capable of expanding a communication cell provided by the base station by communicating with the base station, an expansion cell selection step of selecting a communication cell to be expanded by the moving relay station based on the mobile information, and a connection control step of connecting the relay station to the base station providing the selected communication cell.

[0011] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also effective as aspects of the present invention. Effect of the Invention

[0012] According to the present invention, a moving relay station can expand a suitable communication cell. [Brief description of the drawings]

[0013] [Figure 1] 1 illustrates a schematic overview of a wireless communication system to which a communication control device is applied. [Diagram 2] 1 illustrates a schematic overview of relay station control. [Diagram 3] FIG. 2 is a functional block diagram of a communication control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1 is a schematic diagram showing an outline of a wireless communication system 1 to which a communication control device according to an embodiment of the present invention is applied. The wireless communication system 1 includes a 5G wireless communication system 11 conforming to a fifth generation mobile communication system (5G) using NR (New Radio) or 5G NR (Fifth Generation New Radio) as a radio access technology (RAT) and 5GC (Fifth Generation Core) as a core network (CN), a 4G wireless communication system 12 conforming to a fourth generation mobile communication system (4G) using LTE (Long Term Evolution) or LTE-Advanced as a radio access technology and EPC (Evolved Packet Core) as a core network, and a satellite communication system 13 for satellite communication via a communication satellite 131. Although not shown, the wireless communication system 1 may include a wireless communication system of a generation earlier than 4G, may include a wireless communication system of a generation later than 5G (6G, etc.), or may include any wireless communication system not related to a generation such as Wi-Fi (registered trademark).

[0015] The 5G wireless communication system 11 includes communication devices 2A, 2B, 2C, and 2D (hereinafter collectively referred to as communication devices 2) such as smartphones that are installed on the ground and are also called UE (User Equipment), and a plurality of 5G base stations 111A, 111B, and 111C (hereinafter collectively referred to as 5G base stations 111) that can communicate by 5G NR. The base station 111 in 5G is also called gNodeB (gNB). The communication range or support range of each of the 5G base stations 111A, 111B, and 111C is called a cell, and is illustrated as 112A, 112B, and 112C (hereinafter collectively referred to as 5G cell 112).

[0016] The size of the 5G cell 112 of each 5G base station 111 is arbitrary, but typically has a radius of several meters to tens of kilometers. Although there is no established definition, a cell with a radius of several meters to tens of meters is called a femtocell, a cell with a radius of tens to tens of meters is called a picocell, a cell with a radius of tens to hundreds of meters is called a microcell, and a cell with a radius of more than several hundred meters is called a macrocell. 5G often uses high-frequency radio waves such as millimeter waves, and because of their high linearity, the radio waves are blocked by obstacles and the communication distance is shortened. For this reason, 5G tends to use smaller cells than 4G and earlier generations.

[0017] The communication device 2 can perform 5G communication if it is in at least one of the multiple 5G cells 112A, 112B, and 112C. In the illustrated example, the communication device 2B in the 5G cells 112A and 112B can communicate with both the 5G base stations 111A and 111B by 5G NR. Also, the communication device 2C in the 5G cell 112C can communicate with the 5G base station 111C by 5G NR. The communication devices 2A and 2D are outside all of the 5G cells 112A, 112B, and 112C, and therefore cannot communicate by 5G NR. The 5G communication by 5G NR between each communication device 2 and each 5G base station 111 is managed by the 5GC, which is a core network. For example, the 5GC performs data exchange with each 5G base station 111, data exchange with external networks such as EPC, satellite communication system 13, and the Internet, and mobility management of the communication device 2.

[0018] The 4G wireless communication system 12 includes a plurality of 4G base stations 121 (only one of which is shown in FIG. 1) that are installed on the ground and can communicate with the communication device 2 by LTE or LTE-Advanced. The base station 121 in 4G is also called an eNodeB (eNB). As with each 5G base station 111, the communication range or support range of each 4G base station 121 is also called a cell and is illustrated as 122.

[0019] If the communication device 2 is inside the 4G cell 122, it can perform 4G communication. In the illustrated example, the communication devices 2A and 2B inside the 4G cell 122 can communicate with the 4G base station 121 by LTE or LTE-Advanced. The communication devices 2C and 2D are outside the 4G cell 122 and therefore cannot communicate by LTE or LTE-Advanced. The 4G communication by LTE or LTE-Advanced between each communication device 2 and each 4G base station 121 is managed by the EPC, which is a core network. For example, the EPC performs data exchange with each 4G base station 121, data exchange with external networks such as 5GC, satellite communication system 13, and the Internet, and mobility management of the communication device 2.

[0020] Focusing on each of the communicators 2A, 2B, 2C, and 2D, in the illustrated example, the communicator 2A is in a state where 4G communication with the 4G base station 121 is possible, the communicator 2B is in a state where 5G communication with the 5G base stations 111A and 111B and 4G communication with the 4G base station 121 are possible, and the communicator 2C is in a state where 5G communication with the 5G base station 111C is possible. When there are multiple base stations (111A, 111B, 121) that can communicate like the communicator 2B, one base station that is determined to be optimal in terms of communication quality and the like is selected under the management of the 5GC and / or EPC, which are the core networks, and communicates with the communicator 2B. In addition, the communicator 2D is not in a state where it can communicate with any of the 5G base stations 111 and the 4G base station 121, so it communicates through the satellite communication system 13 described below.

[0021] The satellite communication system 13 is a wireless communication system that uses a communication satellite 131 as a low-orbit satellite flying in space at a low orbit at an altitude of about 500 km to 700 km above the earth's surface as a non-terrestrial base station. As with the 5G base station 111 and the 4G base station 121, the communication range or support range of the communication satellite 131 is also called a cell and is illustrated as 132. In this way, the communication satellite 131 as a non-terrestrial base station provides the satellite communication cell 132 as a non-terrestrial communication cell to the ground. If the terrestrial communication device 2 is inside the satellite communication cell 132, it can perform satellite communication. As with the 5G base station 111 in the 5G wireless communication system 11 and the 4G base station 121 in the 4G wireless communication system 12, the communication satellite 131 as a base station in the satellite communication system 13 can wirelessly communicate with the communication device 2 in the satellite communication cell 132 directly or indirectly via an aircraft or the like. The wireless access technology that the communication satellite 131 uses for wireless communication with the communication device 2 in the satellite communication cell 132 may be 5G NR, the same as the 5G base station 111, LTE or LTE-Advanced, the same as the 4G base station 121, or any other wireless access technology that can be used by the communication device 2. For this reason, the communication device 2 does not need to be provided with special functions or components for satellite communication.

[0022] The satellite communication system 13 includes a gateway 133 as a ground station installed on the ground and capable of communicating with a communication satellite 131. The gateway 133 includes a satellite antenna for communicating with the communication satellite 131, and is connected to a 5G base station 111 and a 4G base station 121 as terrestrial base stations constituting a terrestrial network (TN). In this way, the gateway 133 connects a non-terrestrial network (NTN) constituted by the communication satellite 131 as a non-terrestrial base station or satellite base station and a TN constituted by the terrestrial base stations 111 and 121 so that they can communicate with each other. When the communication satellite 131 performs 5G communication with the communication device 2 in the satellite communication cell 132 by 5G NR, the 5GC connected via the gateway 133 and the 5G base station 111 (or a 5G radio access network) in the TN is used as a core network, and when the communication satellite 131 performs 4G communication with the communication device 2 in the satellite communication cell 132 by LTE or LTE-Advanced, the EPC connected via the gateway 133 and the 4G base station 121 (or a 4G radio access network) in the TN is used as a core network. In this way, appropriate cooperation is achieved between different wireless communication systems such as 5G communication, 4G communication, and satellite communication via the gateway 133.

[0023] Satellite communication by the communication satellite 131 is mainly used to cover areas where no or few terrestrial base stations such as the 5G base station 111 and the 4G base station 121 are installed. In the illustrated example, the communication device 2D located outside the communication cells of all terrestrial base stations communicates with the communication satellite 131. On the other hand, the communication devices 2A, 2B, and 2C that can communicate well with any of the terrestrial base stations are also able to communicate with the communication satellite 131 because they are located within the satellite communication cell 132. However, by communicating with the terrestrial base station instead of the communication satellite 131 as a satellite base station in principle, the limited communication resources (including power) of the communication satellite 131 are saved for the communication device 2D and the like. The communication satellite 131 improves the quality of communication with the communication device 2D by directing communication radio waves to the communication device 2D within the satellite communication cell 132 by beamforming.

[0024] The size of the satellite communication cell 132 of the communication satellite 131 as a satellite base station can be set arbitrarily according to the number of beams emitted by the communication satellite 131. For example, a maximum of 2,800 beams can be combined to form a satellite communication cell 132 with a diameter of about 24 km. As shown in the figure, the satellite communication cell 132 is typically larger than a terrestrial communication cell such as the 5G cell 112 or the 4G cell 122, and may include one or more 5G cells 112 and / or 4G cells 122 therein. Note that, although the communication satellite 131 flying in a low orbit space at an altitude of about 500 km to 700 km above the earth's surface has been exemplified above as a flying non-terrestrial base station, a communication satellite flying in a high orbit space such as a geostationary orbit or an unmanned or manned aircraft flying in the atmosphere such as the stratosphere at a lower altitude (for example, about 20 km above the earth's surface) may be used as a non-terrestrial base station in addition to or instead of the communication satellite 131.

[0025] As described above, the wireless communication system 1 according to this embodiment includes terrestrial networks (TN) 11, 12 capable of communicating with the communication device 2 in the terrestrial communication cells 112, 122 provided on the ground by terrestrial base stations 111, 121 installed on the ground, and a non-terrestrial network (NTN) 13 capable of communicating with the communication device 2 in the non-terrestrial communication cell 132 provided on the ground by an airborne non-terrestrial base station 131. The communication control device according to this embodiment controls a mobile relay station that expands any terrestrial communication cell and / or non-terrestrial communication cell in the wireless communication system 1 in which the TN and NTN coexist.

[0026] FIG. 2 shows a schematic overview of relay station control according to this embodiment. In this example, a relay station RN (Relay Node or Relay Station) is attached to an automobile V as a movable moving body. Other examples of the moving body include any other vehicle such as a train, a motorcycle, a bicycle, an airplane, a ship, etc., and a moving person or object, and the relay station RN may be attached to these moving bodies. Furthermore, these moving bodies may move along a predetermined moving route, or may move along an arbitrary moving route. In the example of FIG. 2, an automobile V to which a relay station RN is attached moves on the ground along an arbitrary moving route RT. On the ground, there are five terrestrial communication cells 112, 122 (shown as "TN Cell TN1" to "TN Cell TN5" in FIG. 2) provided by terrestrial base stations 111, 121, and one non-terrestrial communication cell 132 (shown as "NTN Cell NTN1" in FIG. 2) provided by a non-terrestrial base station 131.

[0027] The relay station RN can communicate with the terrestrial base stations 111, 121 and / or the non-terrestrial base station 131 to expand the terrestrial communication cells 112, 122 and / or the non-terrestrial communication cells 132 provided by the base stations. Here, "expansion of the communication cell" includes not only expanding the area covered by the existing communication cell but also improving the communication quality of at least a part of the existing communication cell. Furthermore, "expansion of the area covered by the communication cell" includes not only expanding the area of ​​the existing communication cell in the horizontal plane but also expanding the existing communication cell in the vertical direction, for example, to the basement or to the upper and / or lower floors of a building. In addition, a technology called IAB (Integrated Access and Backhaul) is known that uses a backhaul between base stations to make one base station function as a relay station for other base stations, and in this case, one base station may be used as the relay station RN of this embodiment. The relay station RN may be a communication device 2 that can function as a relay station, for example, a communication device 2 equipped with a so-called tethering function or personal hotspot function. When such a communication device 2, which generally functions as a wireless LAN access point, is used as a relay station RN, the RAT (e.g., 5G NR) used by the base station from which the expansion is initiated (e.g., 5G base station 111) is different from the RAT used by the relay station RN to which the expansion is initiated.

[0028] When an automobile V equipped with a relay station RN moves on the ground where a large number of communication cells (TN1 to TN5, NTN1, etc.) exist, it is necessary to appropriately select one or more communication cells to be extended by the relay station RN during the movement. In the example of Fig. 2, the relay station RN moving along the moving route RT together with the automobile V first selects the first terrestrial communication cell TN1 as the extension target cell to provide the first terrestrial extension cell TN1+, then selects the third terrestrial communication cell TN3 as the extension target cell to provide the third terrestrial extension cell TN3+, and finally selects the first non-terrestrial communication cell NTN1 as the extension target cell to provide the first non-terrestrial extension cell NTN1+.

[0029] A communication device 2 in the first terrestrial extended cell TN1+ (outside the first terrestrial communication cell TN1) can indirectly communicate with the terrestrial base station 111, 121 that provides the first terrestrial communication cell TN1 via a relay station RN, a communication device 2 in the third terrestrial extended cell TN3+ (outside the third terrestrial communication cell TN3) can indirectly communicate with the terrestrial base station 111, 121 that provides the third terrestrial communication cell TN3 via a relay station RN, and a communication device 2 in the first non-terrestrial extended cell NTN1+ (outside the first non-terrestrial communication cell NTN1) can indirectly communicate with the non-terrestrial base station 131 that provides the first non-terrestrial communication cell NTN1 via a relay station RN.

[0030] In the example of Fig. 2, the second terrestrial communication cell TN2 and the fifth terrestrial communication cell TN5, which are far from the moving route RT of the automobile V to which the relay station RN is attached, are not selected as cells to be expanded by the relay station RN. In addition, although the fourth terrestrial communication cell TN4 is close to the moving route RT, expanding the first non-terrestrial communication cell NTN1 can provide a wider communication area (NTN1+) than expanding the fourth terrestrial communication cell TN4, so the first non-terrestrial communication cell NTN1 is preferentially selected as a cell to be expanded by the relay station RN, and the fourth terrestrial communication cell TN4 is not selected as a cell to be expanded by the relay station RN.

[0031] As described above, the communication cell to be extended to the relay station RN attached to the vehicle V while it is moving is selected according to the movement information of the vehicle V, such as the movement route RT, and cell information, such as the arrangement of multiple communication cells relative to the movement route RT.

[0032] FIG. 3 is a functional block diagram of the communication control device 3 according to this embodiment. The communication control device 3 includes a movement information acquisition unit 31, an activity history information collection unit 32, an extended cell selection unit 33, a cell information acquisition unit 34, and a connection control unit 35. These functional blocks are realized by the cooperation of hardware resources such as a central processing unit of a computer, a memory, an input device, an output device, and peripheral devices connected to the computer, and software executed using them. Regardless of the type of computer or the installation location, each of the above-mentioned functional blocks may be realized by the hardware resources of a single computer, or may be realized by combining hardware resources distributed among multiple computers. In particular, in this embodiment, some or all of the functional blocks of the communication control device 3 may be realized in a distributed or centralized manner by computers and processors provided in the relay station RN, the automobile V, the communication device 2, the terrestrial base stations 111 and 121, the non-terrestrial base station 131, the gateway 133, and the core network CN (for convenience, all of these are shown as separate entities in FIG. 3).

[0033] The movement information acquisition unit 31 acquires movement information regarding the movement of the relay station RN attached to the automobile V. The movement information includes at least one of the movement route RT of the automobile V or the relay station RN, the arrival time of the automobile V or the relay station RN at each position on the movement route RT, the traffic congestion situation on the movement route RT, the movement speed of the automobile V or the relay station RN, the movement direction of the automobile V or the relay station RN, and the current position of the automobile V or the relay station RN. A part or all of the movement information can be acquired from the automobile V or the relay station RN itself, the communication device 2 used by the person riding in the automobile V, a movement instruction device (not shown) that remotely gives movement instructions to the automobile V, and the like. For example, the movement route RT, the arrival time at each position on the movement route RT, and the traffic congestion situation on the movement route RT can be acquired from a map application or a navigation application installed in the automobile V, the relay station RN, the communication device 2, the movement instruction device, and the like. In addition, the movement speed, the movement direction, and the current position can be acquired from a positioning module such as a GPS module mounted on the automobile V, the relay station RN, the communication device 2, and the like.

[0034] The movement information acquisition unit 31 may estimate a part or all of the movement information of the relay station RN attached to the automobile V based on the activity history information collected by the activity history information collection unit 32. The activity history information collection unit 32 collects activity history information of at least one of one or more specific or unspecified communication devices 2 capable of communicating with the terrestrial base stations 111, 121 and / or the non-terrestrial base station 131 directly without the relay station RN and / or indirectly via the relay station RN, the relay station RN or automobile V that is the target of the estimation of the movement information, and another relay station RN or automobile V. The activity history information collected by the activity history information collection unit 32 is also used by the enhanced cell selection unit 33 described later.

[0035] For example, the NWDAF (Network Data Analytics Function) and LMF (Location Management Function) introduced in 5GC as the core network CN of 5G can be used as the activity history information collector 32. The NWDAF is responsible for collecting and analyzing data on a network including 5G. Specifically, the NWDAF collects and accumulates activity history information (including history information on the base stations to which the communication device 2, relay station RN, and automobile V are connected, and the positions of the communication device 2, relay station RN, and automobile V) related to various activities performed on the network by a large number of communication devices 2, relay stations RN, and automobiles V connected to the network, and utilizes the analysis results for example for traffic control on the network. The LMF manages the physical positions of a large number of communication devices 2, relay stations RN, and automobiles V on a network including 5G. It is assumed that functions similar to the NWDAF and / or LMF are provided under different names in other wireless communication systems including wireless communication systems of generations after 5G, but in this embodiment, such similar functions may be used instead of or in addition to the NWDAF and / or LMF.

[0036] Furthermore, a server used by a service provider that provides map services, navigation services, location tracking services, and the like to a large number of communication devices 2, relay stations RN, and automobiles V connected to the network can also be used as the activity history information collection unit 32. These servers can also collect activity history information (including history information related to the positions of the communication devices 2, relay stations RN, and automobiles V) related to various activities performed by a large number of communication devices 2, relay stations RN, and automobiles V connected to the network in relation to the services provided.

[0037] From the NWDAF, LMF, and service provider's server as the activity history information collection unit 32, statistical information on the activities on the network of an unspecified number of communication devices 2, relay stations RN, and automobiles V connected to the network (including statistical information on the base stations of the connection destinations) and / or history information on the physical locations can be acquired. In the example of Fig. 3, the movement information acquisition unit 31 and / or the extended cell selection unit 33 acquire activity history information such as the congestion situation and communication traffic in each time period in the area between the fourth terrestrial communication cell TN4 and the first non-terrestrial communication cell NTN1 where the automobile V is passing at the current time, and in the area where the automobile V will arrive or pass at a future time on the movement route RT.

[0038] Based on the activity history information (including network and / or physical congestion information and traffic jam information) of these unspecified number of communication devices 2, relay stations RN, and automobiles V for each time period, the movement information acquisition unit 31 can estimate with high accuracy the position and movement state at the current or future time of the relay station RN or automobile V, which are the targets of communication control by the communication control device 3, and the extended cell selection unit 33 can identify areas where there is a high demand for communication but a shortage of communication resources, and select a communication cell (e.g., the first non-terrestrial communication cell NTN1) that can provide an extended cell (e.g., the first non-terrestrial extended cell NTN1+) that can effectively cover the area as a cell to be expanded by the relay station RN.

[0039] For example, in the current or future time period when the movement information acquisition unit 31 estimates the movement information of the relay station RN or the automobile V, if the past communication traffic volume or the number of the communication device 2, the relay station RN, and the automobile V in a specific area among a plurality of areas where the relay station RN or the automobile V may be present is significantly large, it can be estimated that there is a high possibility that the relay station RN or the automobile V to be estimated is in that area. Similarly, in the current or future time period when the extension cell selection unit 33 selects an extension target cell by the relay station RN, if the past communication traffic volume or the number of the communication device 2, the relay station RN, and the automobile V in a specific communication cell are significantly large among a plurality of communication cells (for example, the fourth terrestrial communication cell TN4 and the first non-terrestrial communication cell NTN1) in which the relay station RN can provide an extension cell, the communication cell can be selected as the extension target cell.

[0040] From the NWDAF, LMF, and service provider's server as the activity history information collection unit 32, it is possible to acquire not only an unspecified number of communication devices 2, relay stations RN, and automobiles V, but also statistical information (including statistical information on the base station to which the relay station RN or automobile V itself is connected) on the network activity of the estimation target or communication control target, and / or history information on the physical location. Based on the activity history information of the relay station RN or automobile V itself for each time period, the movement information acquisition unit 31 can estimate with high accuracy the location and movement state of the relay station RN or automobile V at the current or future time, and the expansion cell selection unit 33 can select an appropriate expansion target cell by referring to the history of communication cells that the relay station RN has expanded in the past.

[0041] For example, if the frequency with which the relay station RN or the automobile V was in a specific area is high in the current or future time period when the movement information acquisition unit 31 estimates the movement information of the relay station RN or the automobile V, it can be estimated that there is an extremely high possibility that the relay station RN or the automobile V to be estimated is in that area. Similarly, if the frequency with which the relay station RN expanded a specific communication cell is high in the current or future time period when the expansion cell selection unit 33 selects an expansion target cell by the relay station RN, it can preferentially select that communication cell as the expansion target cell.

[0042] In addition to or instead of the activity history information of the past on another day as described above, the movement information acquisition unit 31 and / or the extension cell selection unit 33 may use the activity history information of the relay station RN or the automobile V itself immediately before (for example, within one hour) estimating the movement information of the relay station RN or the automobile V and / or immediately before (for example, within one hour) selecting the expansion target cell. For example, if the relay station RN or the automobile V was moving in a specific direction in a specific area 30 minutes before the movement information acquisition unit 31 estimates the movement information of the relay station RN or the automobile V, it can be estimated that there is a very high possibility that the relay station RN or the automobile V to be estimated is in that area or in a nearby area that can be moved from there in that direction in 30 minutes. Similarly, if the relay station RN has expanded a specific communication cell 30 minutes before the extension cell selection unit 33 selects an expansion target cell by the relay station RN, the communication cell can be preferentially selected as the expansion target cell as long as the relay station RN remains in an area where the communication cell can be expanded.

[0043] The expansion cell selection unit 33 selects a communication cell to be expanded to the relay station RN moving together with the automobile V, based on the movement information acquired by the movement information acquisition unit 31, the activity history information collected by the activity history information collection unit 32, and various cell information (cell placement information, cell communication quality information, cell expansion restriction information) acquired by the cell information acquisition unit 34. The cell information acquisition unit 34 includes a cell placement information acquisition unit 341, a cell communication quality information acquisition unit 342, and a cell expansion restriction information acquisition unit 343.

[0044] The cell placement information acquisition unit 341 acquires cell placement information regarding the placement of one or more communication cells to be selected by the extended cell selection unit 33. The cell placement information acquisition unit 341 acquires the placement on the ground of the terrestrial communication cells TN1 to TN5 and the non-terrestrial communication cell NTN1 as shown in FIG. 2, for example, from each base station itself that provides each communication cell, or from a core network CN that collectively manages information on each communication cell. This cell placement information not only allows the center position and shape and size of the coverage area (communication possible range) of each communication cell to be recognized, but also allows the presence or absence of a communication cell in each area on the ground, the type of the communication cell (terrestrial communication cell or non-terrestrial communication cell), the density of the communication cells, the continuity and overlap of the communication cells, the distance from the center position and edge of the communication cell, and the like. The extended cell selection unit 33 selects a communication cell to be extended to the relay station RN moving with the automobile V, while referring to this cell placement information together with other information (such as the movement information acquired by the movement information acquisition unit 31).

[0045] In the example of Fig. 2, in the upper area where the automobile V passes first, a group of dense and continuous communication cells is arranged by the first terrestrial communication cell TN1 and the third terrestrial communication cell TN3. Therefore, when the relay station RN passes through the area together with the automobile V, the extension cell selection unit 33 causes the relay station RN to provide the first terrestrial extension cell TN1+, which is an extension target cell, in the vicinity of the first terrestrial communication cell TN1, and causes the relay station RN to provide the third terrestrial extension cell TN3+, which is an extension target cell, in the vicinity of the third terrestrial communication cell TN3.

[0046] When the relay station RN passes near the third terrestrial communication cell TN3, the density of the communication cell group decreases and the continuity is also lost. At this time, the communication cells to be selected or selected as candidates by the expansion cell selection unit 33 are the fourth terrestrial communication cell TN4 and the first non-terrestrial communication cell NTN1. In a typical terrestrial communication cell and a non-terrestrial communication cell, the latter is larger, and the area that can be expanded by the relay station RN is also larger. Therefore, in such an area where the communication cell group is low density and discontinuous, the expansion cell selection unit 33 selects the non-terrestrial communication cell (first non-terrestrial communication cell NTN1) that can provide a larger expansion cell (first non-terrestrial expansion cell NTN1+) as the expansion target cell, preferentially over the terrestrial communication cell (fourth terrestrial communication cell TN4).

[0047] The cell communication quality information acquisition unit 342 acquires communication quality information (e.g., signal strength and communication delay) of one or more communication cells to be selected by the extended cell selection unit 33 from each base station itself that provides each communication cell, the communication device 2 in communication with each base station (including the communication device 2 measuring the communication quality of each base station as an adjacent base station), the core network CN that collectively manages information about each communication cell, etc. The extended cell selection unit 33 selects a communication cell to be extended to the relay station RN moving with the automobile V while referring to the cell communication quality information together with other information (such as the movement information acquired by the movement information acquisition unit 31).

[0048] For example, when there are a plurality of communication cells (fourth terrestrial communication cell TN4 and first non-terrestrial communication cell NTN1) as candidates for expansion on or near the relay station RN or the moving route RT of the automobile V as shown in FIG. 3, the expansion cell selection unit 33 selects a communication cell (e.g., the first non-terrestrial communication cell NTN1) having a higher (or lower) communication quality indicated by the cell communication quality information acquired by the cell communication quality information acquisition unit 342 as an expansion target cell, and causes the relay station RN to provide an expansion cell (e.g., the first non-terrestrial expansion cell NTN1+). The expansion cell selection unit 33 may select an expansion target cell based on communication quality normalized by communication demand grasped based on the activity history information collected by the activity history information collection unit 32. For example, the expansion cell selection unit 33 may preferentially select a communication cell having a shortage of communication resources despite a high communication demand, i.e., a communication cell having a low communication quality normalized by communication demand, as an expansion target cell.

[0049] The cell expansion restriction information acquisition unit 343 acquires cell expansion restriction information on the expansion restriction of one or more communication cells to be selected by the expansion cell selection unit 33 from each base station itself that provides each communication cell, a core network CN that collectively manages information on each communication cell, etc. When a relay station RN communicates with a base station to expand a communication cell, the communication resources of the base station are used, so it is possible that some base stations may restrict the expansion of a communication cell by a specific or unspecified relay station RN. Examples of the mode of the expansion restriction of a communication cell include setting an upper limit on the communication amount, communication speed, number of UE connections, etc. via a relay station RN, and prohibiting the expansion of a communication cell. In addition, these expansion restrictions may be always applied to the target communication cell, may be applied depending on the time period or location, or may be applied when the communication amount, communication speed, and number of UE connections of a target communication cell not depending on a relay station RN are equal to or greater than a certain amount and there is no spare communication resource. When selecting an expansion target cell from multiple communication cells as selection candidates, the expansion cell selection unit 33 lowers the priority of a communication cell to which an expansion restriction is applied, and preferentially selects a communication cell to which an expansion restriction is not applied.

[0050] Various pieces of information that the expansion cell selection unit 33 can refer to when selecting an expansion target cell have been described above. In practice, the expansion cell selection unit 33 selects one or more expansion target cells that are deemed optimal under a certain criterion by comprehensively taking into consideration or considering these pieces of information (movement information acquired by the movement information acquisition unit 31, activity history information collected by the activity history information collection unit 32, cell layout information acquired by the cell layout information acquisition unit 341, cell communication quality information acquired by the cell communication quality information acquisition unit 342, and cell expansion restriction information acquired by the cell expansion restriction information acquisition unit 343). For this purpose, the expansion cell selection unit 33 may be configured by artificial intelligence that has been machine-learned using comprehensive training data or learning data.

[0051] The connection control unit 35 connects the relay station RN to the base station providing the communication cell selected by the extended cell selection unit 33. In the example of Fig. 3, the relay station RN is connected to the communication satellite 131 providing the first non-terrestrial communication cell NTN1 selected by the extended cell selection unit 33. The relay station RN connected to the communication satellite 131 provides a first non-terrestrial extended cell NTN1+ extending outside the first non-terrestrial communication cell NTN1.

[0052] The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention.

[0053] The functional configuration of each device described in the embodiment can be realized by hardware resources, software resources, or by the cooperation of hardware resources and software resources. A processor, ROM, RAM, and other LSIs can be used as hardware resources. An operating system, an application, and other programs can be used as software resources. [Industrial Applicability]

[0054] The present invention relates to a communication control technique in a wireless communication system. [Explanation of symbols]

[0055] 1 wireless communication system, 2 communication device, 3 communication control device, 11 5G wireless communication system, 12 4G wireless communication system, 13 satellite communication system, 31 movement information acquisition unit, 32 activity history information collection unit, 33 expansion cell selection unit, 34 cell information acquisition unit, 35 connection control unit, 111 5G base station, 112 5G cell, 121 4G base station, 122 4G cell, 131 communication satellite, 132 satellite communication cell, 133 gateway, 341 cell placement information acquisition unit, 342 cell communication quality information acquisition unit, 343 cell expansion restriction information acquisition unit.

Claims

1. a movement information acquisition unit that acquires movement information related to movement of a relay station that can expand a communication cell provided by the base station by communicating with the base station; an expansion cell selection unit that selects a communication cell to be expanded to the relay station while the relay station is moving based on the movement information; a connection control unit that connects the relay station to a base station that provides the selected communication cell; Equipped with The communication cells include terrestrial communication cells provided on the ground by terrestrial base stations installed on the ground and non-terrestrial communication cells provided on the ground by flying non-terrestrial base stations; When the relay station is located in a position where both the terrestrial communication cell and the non-terrestrial communication cell can be expanded, the expansion cell selection unit selects the non-terrestrial communication cell as a communication cell to be expanded by the relay station while moving. Communications control device.

2. The communication control device according to claim 1 , wherein the relay station is attached to a movable body.

3. 3. The communication control device according to claim 1, wherein the movement information includes at least any one of a movement route of the relay station, an arrival time of the relay station at each position on the movement route, a traffic congestion situation on the movement route, a movement speed of the relay station, a movement direction of the relay station, and a current position of the relay station.

4. An activity history information collection unit that collects activity history information of at least one of a communication device that communicates with the base station, the relay station, and another relay station, The movement information acquisition unit estimates movement information of the relay station based on the activity history information. The communication control device according to claim 1 .

5. Further comprising a cell placement information acquisition unit that acquires cell placement information regarding placement of a plurality of communication cells; The expansion cell selection unit selects a communication cell to be expanded by the moving relay station based on the movement information and the cell placement information. The communication control device according to claim 1 .

6. A cell communication quality information acquisition unit that acquires communication quality information of a communication cell, The expansion cell selection unit selects a communication cell to be expanded by the moving relay station based on the movement information and the communication quality information. The communication control device according to claim 1 .

7. A cell extension restriction information acquisition unit that acquires cell extension restriction information related to an extension restriction of a communication cell, The expansion cell selection unit selects a communication cell to be expanded by the moving relay station based on the movement information and the cell expansion restriction information. The communication control device according to claim 1 .

8. 8. The communication control device according to claim 1, wherein the non-terrestrial base station is a communication satellite flying in outer space.

9. a movement information acquisition step of acquiring movement information regarding movement of a relay station capable of expanding a communication cell provided by the base station by communicating with the base station; an expansion cell selection step of selecting a communication cell to be expanded by the moving relay station based on the movement information; a connection control step of connecting the relay station to a base station that provides the selected communication cell; Equipped with The communication cells include terrestrial communication cells provided on the ground by terrestrial base stations installed on the ground and non-terrestrial communication cells provided on the ground by flying non-terrestrial base stations; When the relay station is located in a position where both the terrestrial communication cell and the non-terrestrial communication cell can be extended, the extension cell selection step selects the non-terrestrial communication cell as a communication cell to be extended by the relay station while moving. Communications control method.

10. a movement information acquisition step of acquiring movement information regarding movement of a relay station capable of expanding a communication cell provided by the base station by communicating with the base station; an expansion cell selection step of selecting a communication cell to be expanded by the moving relay station based on the movement information; a connection control step of connecting the relay station to a base station that provides the selected communication cell; Run the following on your computer: The communication cells include terrestrial communication cells provided on the ground by terrestrial base stations installed on the ground and non-terrestrial communication cells provided on the ground by flying non-terrestrial base stations; When the relay station is located in a position where both the terrestrial communication cell and the non-terrestrial communication cell can be extended, the extension cell selection step selects the non-terrestrial communication cell as a communication cell to be extended by the relay station while moving. Communications control program.

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