Communication control based on service quality determination

Abstract

A communication control device 3 comprises: a service request detection unit 31 for detecting a service request from a communication machine 2; a service quality determination unit 32 for determining whether or not a service quality required in a service is to be achieved by a communication satellite 131 being connected to the communication machine 2; a service request transmission unit 33 for, when the service quality is determined not to be achieved by the communication satellite 131, transmitting a service request to ground base stations 111, 121 capable of achieving the service quality; a response reception unit 34 for receiving a response to the service request from the ground base stations 111, 121; and a connection control unit 35 for changing the connection destination of the communication machine 2 from the communication satellite 131 to the ground base stations 111, 121, on the basis of the response indicating that the service quality can be achieved by the ground base stations 111, 121.

Description

Technical Field

[0001] The present disclosure relates to communication control based on service quality determination in a communication system.

Background Art

[0002] The number, types, and applications of wireless communication devices typified by smartphones and IoT (Internet of Things) devices are on the rise, and the expansion and improvement of wireless communication standards have continued. For example, commercial services of the fifth-generation mobile communication system known as "5G" started in 2018, but standardization is still underway at 3GPP (Third Generation Partnership Project). In addition, efforts have also begun towards standardization of "6G" or the sixth-generation mobile communication system as the next-generation wireless communication standard following 5G.

[0003] A mobile communication (hereinafter also referred to as mobile communication) network for mobile or portable communication devices such as smartphones and mobile phones (hereinafter collectively referred to as communication devices) is generally constructed by communication cells (hereinafter also referred to as terrestrial communication cells) provided on the ground by base stations (hereinafter also referred to as terrestrial base stations) installed on the ground. Patent Document 1 discloses a technique for detecting deterioration in communication quality between a communication device and a terrestrial base station and handing over another communication device that caused the deterioration to another terrestrial base station.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In wireless communication standards since 5G, terrestrial communication cells of a wide range of sizes are used, from femtocells with a radius of less than ten meters to macrocells with a radius exceeding several hundred meters. Also, in some regions, it may be difficult to install a sufficient number of terrestrial base stations for various reasons, and communication satellites or unmanned aerial vehicles flying in the atmosphere such as space and the stratosphere serve as base stations (hereinafter also referred to as non-terrestrial base stations, and in particular, communication satellites are also referred to as satellite base stations), and a non-terrestrial network (NTN: Non-Terrestrial Network) that provides terrestrial communication cells (hereinafter also referred to as non-terrestrial communication cells, and in particular, communication cells provided by communication satellites are also referred to as satellite communication cells) is being considered for introduction in addition to or instead of a terrestrial network (TN: Terrestrial Network) by terrestrial base stations.

[0006] In a mobile communication network where such a variety of base stations and communication cells can exist, handover control based only on the communication quality of each base station as in Patent Document 1 may not be appropriate. Also, even if the communication quality of a base station is sufficient for an average communication device, it is assumed that the communication quality of the base station may be insufficient for a communication device that performs high-quality communication classified as ultra-reliable and low-latency communications (URLLC) in 5G.

[0007] The present disclosure has been made in view of such a situation, and an object thereof is to provide a communication control device or the like that can provide services from an appropriate base station to a communication device.

Means for Solving the Problem

[0008] To solve the above problems, a communication control device according to an aspect of the present invention includes a service request detection unit that detects a service request from a communication device, a service quality determination unit that determines whether the service quality required by the service is achieved by a first base station to which the communication device is connected, and a service request transmission unit that, when it is determined that the service quality is not achieved by the first base station, transmits a service request to a second base station capable of achieving the service quality.

[0009] According to this aspect, when the service quality required by the communication device is not achieved by the first base station to which the communication device is connected, a service request can be transmitted to an appropriate second base station capable of achieving the service quality.

[0010] Another aspect of the present invention is a communication control method. This method includes detecting a service request from a communication device, determining whether the service quality required by the service is achieved by a first base station to which the communication device is connected, and when it is determined that the service quality is not achieved by the first base station, transmitting a service request to a second base station capable of achieving the service quality.

[0011] Still another aspect of the present invention is a storage medium. This storage medium stores a communication control program that causes a computer to detect a service request from a communication device, determine whether the service quality required by the service is achieved by a first base station to which the communication device is connected, and when it is determined that the service quality is not achieved by the first base station, transmit a service request to a second base station capable of achieving the service quality.

[0012] In addition, any combination of the above components, as well as those obtained by converting the expressions of the present disclosure among methods, devices, systems, recording media, computer programs, etc., are also effective as aspects of the present disclosure.

Advantages of the Invention

[0013] According to the present disclosure, services can be provided from an appropriate base station to a communication device.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0015] The communication control device according to the present disclosure can be applied to a terrestrial network (TN: Terrestrial Network) constructed by terrestrial communication cells provided by terrestrial base stations installed on the ground, a non-terrestrial network (NTN: Non-Terrestrial Network) constructed by non-terrestrial communication cells provided by flying non-terrestrial base stations on the ground, and a network in which TN and NTN coexist. These base stations and communication cells may belong to the same mobile communication network, public land mobile network (PLMN: Public Land Mobile Network), mobile network operator (MNO: Mobile Network Operator), mobile virtual network operator (MVNO: Mobile Virtual Network Operator), or may belong to different mobile communication networks, PLMNs, MNOs, MVNOs. Hereinafter, mobile communication networks, PLMNs, MNOs, and MVNOs are collectively referred to as PLMNs.

[0016] FIG. 1 schematically shows an overview of a wireless communication system 1 to which a communication control device according to the present embodiment is applied. The wireless communication system 1 complies with a 5G wireless communication system 11 that uses NR (New Radio) or 5G NR (Fifth Generation New Radio) as a radio access technology (RAT) and uses 5GC (Fifth Generation Core) as a core network (CN), a 4G wireless communication system 12 that uses LTE (Long Term Evolution) or LTE-Advanced as a radio access technology and uses EPC (Evolved Packet Core) as a core network, and a satellite communication system 13 that is responsible 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 prior to 4G, may include a wireless communication system of a generation after 5G (such as 6G), or may include any wireless communication system not associated with a generation such as Wi-Fi (registered trademark). Further, the wireless communication system 1 may not include some or all of the 5G wireless communication system 11, the 4G wireless communication system 12, and the satellite communication system 13.

[0017] The 5G wireless communication system 11 includes a plurality of 5G base stations 111A, 111B, 111C (hereinafter sometimes collectively referred to as 5G base stations 111) that are installed on the ground and can communicate with communication devices 2A, 2B, 2C, 2D (hereinafter sometimes collectively referred to as communication devices 2), such as smartphones, also called user equipment (UE), via 5G NR. The base station 111 in 5G is also called a gNodeB (gNB). The communicable range or support range of each of the 5G base stations 111A, 111B, 111C is called a cell, and is illustrated as 112A, 112B, 112C (hereinafter sometimes collectively referred to as 5G cells 112), respectively.

[0018] The size of each 5G cell 112 of each 5G base station 111 is arbitrary, but typically ranges from several meters to several tens of kilometers in radius. Although there is no established definition, cells with a radius of several meters to ten meters are called femtocells, cells with a radius of ten meters to several tens of meters are called picocells, cells with a radius of several tens of meters to several hundreds of meters are called microcells, and cells with a radius exceeding several hundreds of meters may be called macrocells. In 5G, high-frequency radio waves such as millimeter waves are often used. Due to the high directivity, the radio waves are blocked by obstacles and the communication range becomes short. For this reason, in 5G, smaller cells tend to be used more frequently than in generations before 4G.

[0019] If the communication device 2 is inside at least one of the plurality of 5G cells 112A, 112B, 112C, it can perform 5G communication. In the illustrated example, the communication devices 2B inside the 5G cells 112A and 112B can communicate with both of the 5G base stations 111A and 111B via 5G NR. Also, the communication device 2C inside the 5G cell 112C can communicate with the 5G base station 111C via 5G NR. Since the communication devices 2A and 2D are outside all of the 5G cells 112A, 112B, 112C, they are in a state where they cannot communicate via 5G NR. The 5G communication via 5G NR between each communication device 2 and each 5G base station 111 is managed by the 5GC which is the core network. For example, the 5GC performs data transfer with each 5G base station 111, data transfer with external networks such as the EPC, the satellite communication system 13, and the Internet, and mobility management of the communication device 2.

[0020] The 4G wireless communication system 12 includes a plurality of 4G base stations 121 (only one is shown in FIG. 1) installed on the ground and capable of communicating with the communication device 2 via LTE or LTE-Advanced. The base station 121 in 4G is also called an eNodeB (eNB). Similar to 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.

[0021] 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 via LTE or LTE-Advanced. Since the communication devices 2C and 2D are outside the 4G cell 122, they are in a state where they cannot communicate via LTE or LTE-Advanced. The 4G communication via LTE or LTE-Advanced between each communication device 2 and each 4G base station 121 is managed by the EPC, which is the core network. For example, the EPC conducts data transfer with each 4G base station 121, data transfer with external networks such as the 5GC, the satellite communication system 13, and the Internet, and mobility management of the communication device 2.

[0022] Focusing on each of the communication devices 2A, 2B, 2C, and 2D, in the illustrated example, the communication device 2A is in a state where it can perform 4G communication with the 4G base station 121, the communication device 2B is in a state where it can perform 5G communication with the 5G base stations 111A and 111B and 4G communication with the 4G base station 121, and the communication device 2C is in a state where it can perform 5G communication with the 5G base station 111C. When there are multiple communicable base stations (111A, 111B, 121) like the communication device 2B, one base station determined to be optimal from the perspective of communication quality and the like is selected under the management of the 5GC and / or the EPC, which is the core network, to communicate with the communication device 2B. Also, since the communication device 2D is not in a state where it can communicate with any of the 5G base stations 111 and the 4G base station 121, it communicates via the satellite communication system 13 described below.

[0023] The satellite communication system 13 is a wireless communication system that uses a communication satellite 131 as a non-terrestrial base station flying in a low-earth orbit space at an altitude of about 500 km to 700 km from the earth's surface. Similar to 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 a satellite communication cell 132 as a non-terrestrial communication cell to the ground. If the communication device 2 on the ground is inside the satellite communication cell 132, satellite communication can be performed. Similar to 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 perform wireless communication directly with the communication device 2 in the satellite communication cell 132 or indirectly via an aircraft or the like. The radio access technology used by the communication satellite 131 for wireless communication with the communication device 2 in the satellite communication cell 132 may be the same 5G NR as the 5G base station 111, or the same LTE or LTE-Advanced as the 4G base station 121, or any other radio access technology that the communication device 2 can use. Therefore, the communication device 2 does not need to be provided with special functions or components for satellite communication.

[0024] 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 is equipped with a satellite antenna for communicating with the communication satellite 131, and is connected to a 5G base station 111 or a 4G base station 121 as a ground base station constituting a terrestrial network, and 5G NR, LTE, or other wired or wireless access technologies or interfaces, which are respective radio access technologies. In this way, the gateway 133 connects the NTN constituted by the communication satellite 131 and the TN constituted by the ground 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 using 5G NR, the 5GC connected via the gateway 133 and the 5G base station 111 (or 5G radio access network) in the TN is used as the core network. When the communication satellite 131 performs 4G communication with the communication device 2 in the satellite communication cell 132 using LTE or LTE-Advanced, the EPC connected via the gateway 133 and the 4G base station 121 (or 4G radio access network) in the TN is used as the core network. In this way, appropriate cooperation is achieved among different radio communication systems such as 5G communication, 4G communication, and satellite communication via the gateway 133.

[0025] Satellite communication by the communication satellite 131 is mainly used to cover areas where ground base stations such as the 5G base station 111 and the 4G base station 121 are not provided or are few. In the illustrated example, the communication device 2D outside the communication cells of all the ground base stations communicates with the communication satellite 131. On the other hand, the communication devices 2A, 2B, and 2C, which are in a state where they can communicate well with any of the ground base stations, can also communicate with the communication satellite 131 because they are within the satellite communication cell 132. However, in principle, instead of communicating with the communication satellite 131 as a satellite base station, they communicate with the ground base station, so that 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 communication quality with the communication device 2D by directing communication radio waves toward the communication device 2D in the satellite communication cell 132 through beamforming.

[0026] The size of the satellite communication cell 132 of the communication satellite 131 as a satellite base station can be arbitrarily set according to the number of beams emitted by the communication satellite 131. For example, by combining up to 2,800 beams, a satellite communication cell 132 with a diameter of about 24 km can be formed. As shown in the figure, the satellite communication cell 132 is typically larger than terrestrial communication cells such as 5G cells 112 and 4G cells 122, and may include one or more 5G cells 112 and / or 4G cells 122 inside. In addition, as a non-terrestrial base station in flight, the communication satellite 131 flying in the low Earth orbit (LEO) space at a height of about 500 km to 700 km from the Earth's surface has been exemplified above. However, a communication satellite flying in a high orbit such as a geosynchronous equatorial orbit (GEO), or an unmanned or manned aircraft flying in the atmosphere such as the stratosphere at a lower altitude (e.g., about 20 km from the Earth's surface) may be used as a non-terrestrial base station in addition to or instead of the communication satellite 131.

[0027] As described above, the wireless communication system 1 according to the present embodiment includes terrestrial networks (TN) 11 and 12 that can communicate with the communication devices 2 in the terrestrial communication cells 112 and 122 provided on the ground by the terrestrial base stations 111 and 121 installed on the ground, and a non-terrestrial network (NTN) 13 that can communicate with the communication devices 2 in the non-terrestrial communication cell 132 provided on the ground by the flying non-terrestrial base station 131. And the communication control device according to the present embodiment controls the TN and the NTN.

[0028] FIG. 2 is a functional block diagram schematically showing a communication control device 3 according to the present embodiment. The communication control device 3 includes a service request detection unit 31, a service quality determination unit 32, a service request transmission unit 33, a response reception 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, a memory, an input device, an output device, and peripheral devices connected to a computer, and software executed using these resources. Regardless of the type and installation location of the computer, each of the above functional blocks may be realized by the hardware resources of a single computer, or may be realized by combining the hardware resources distributed among a plurality of computers. For example, part or all of the functional blocks of the communication control device 3 may be realized distributively or centrally by a computer or a processor provided in a communication device 2, a terrestrial base station 111, 121, a non-terrestrial base station 131, a gateway 133, a terrestrial base station 111, 121, and / or a core network (not shown in FIG. 2) to which the non-terrestrial base station 131 is connected.

[0029] In the example of FIG. 2, a TN composed of terrestrial base stations 111 and 121 and terrestrial communication cells 112 and 122 (shown as "TN Cell" in FIG. 2) coexists with an NTN composed of communication satellite 131 and satellite communication cell 132 (shown as "NTN Cell" in FIG. 2). The TN and the NTN belong to different PLMNs (public land mobile networks). Hereinafter, the PLMN to which the NTN in FIG. 2 belongs is also referred to as the first PLMN (shown as "PLMN1" in FIG. 2), the communication satellite 131 belonging to the first PLMN is also referred to as the first base station, and the satellite communication cell 132 belonging to the first PLMN is also referred to as the first communication cell. Similarly, the PLMN to which the TN in FIG. 2 belongs is also referred to as the second PLMN (shown as "PLMN2" in FIG. 2), the terrestrial base stations 111 and 121 belonging to the second PLMN are also referred to as the second base stations, and the terrestrial communication cells 112 and 122 belonging to the second PLMN are also referred to as the second communication cells. For example, the first PLMN is a home network with which the user of communication device 2 has subscribed to a communication service, and the second PLMN is a roaming network in which communication device 2 can roam through cooperation between communication service providers. Therefore, the communication device 2 located within the overlapping area of the first PLMN and the second PLMN is generally connected to the communication satellite 131 belonging to the first PLMN, which is the home network.

[0030] Hereinafter, the present embodiment will be described centering around this example, but the present disclosure is not intended to be limited to this example. For example, the first base station and the first communication cell may be the terrestrial base stations 111 and 121 and the terrestrial communication cells 112 and 122 constituting the TN, and the second base station and the second communication cell may be the communication satellite 131 and the satellite communication cell 132 constituting the NTN. Specifically, both the first PLMN and the second PLMN may be TN, both the first PLMN and the second PLMN may be NTN, or the first PLMN may be TN and the second PLMN may be NTN. Also, the second PLMN may be the home network of the communication device 2, or the first PLMN may be the roaming network. Furthermore, the first base station (first communication cell) and the second base station (second communication cell) may belong to the same PLMN (mobile communication network). For example, the first base station and the second base station may belong to the same home network, or the first base station and the second base station may belong to the same roaming network.

[0031] The terrestrial communication cells 112 and 122 of the TN (second PLMN) and the satellite communication cell 132 of the NTN (first PLMN) overlap, and the communication device 2 as the control target of the communication control device 3 is in this overlapping area. In the example of FIG. 2, since the entire terrestrial communication cells 112 and 122 are included in the satellite communication cell 132, the entire terrestrial communication cells 112 and 122 are the overlapping area of the terrestrial communication cells 112 and 122 and the satellite communication cell 132. The communication device 2 in the overlapping area of such a first communication cell (satellite communication cell 132) and a second communication cell (terrestrial communication cells 112 and 122) is connected to the communication satellite 131 belonging to the first PLMN (NTN) which is the home network in principle.

[0032] The service request detection unit 31 detects a service request from the communication device 2 connected to the communication satellite 131. The service request includes information on the service requested by the communication device 2 and the quality of service (QoS) required for the service. Information on QoS in 5G includes various QoS parameters specified by a 5G QoS Identifier (5QI) or the like. Examples of QoS parameters include whether bitrate guarantee is required, priority level, packet delay budget, packet error rate, allocation and retention priority (ARP), guaranteed flow bit rate (GFBR), maximum flow bit rate (MFBR), aggregate maximum bit rate (AMBR), and maximum packet loss rate.

[0033] For typical use cases, the 5QI defines a recommended combination of the above various QoS parameters. Use cases are broadly classified into three resource types: non-guaranteed bitrate (Non-GBR), guaranteed bitrate (GBR), and delay-critical GBR. Each resource type is further divided into multiple different QoS levels, and for each QoS level, a recommended combination of QoS parameters is defined, and a unique 5QI for specifying the combination is set. Generally, in the above three resource types, the required QoS level increases in the order of Non-GBR, GBR, and delay-critical GBR.

[0034] In the following embodiments, the case where the communication device 2 requests a "high-quality" service from the first PLMN will be described. However, it may be classified as "high-quality" or not according to the resource type in 5QI. For example, a service request with a resource type specified by 5QI being "delay-critical GBR" may be treated as a "high-quality" service request, or a service request with a resource type specified by 5QI being "delay-critical GBR" or "GBR" may be treated as a "high-quality" service request. Also, it may be classified as "high-quality" or not according to the value of each QoS parameter specified by 5QI. For example, a service request with a priority level specified by 5QI being below a predetermined value may be treated as a "high-quality" service request, or a service request with a packet delay budget or packet error rate specified by 5QI being below a predetermined value may be treated as a "high-quality" service request.

[0035] The service request detection unit 31 is implemented in at least one of the communication device 2, the communication satellite 131 as the first base station, the gateway 133, and the core network (not shown in FIG. 2) of the first PLMN to which the communication satellite 131 is connected via the gateway 133. The communication device 2 itself that generates a service request for the first PLMN can always function as the service request detection unit 31. Also, the communication satellite 131 that directly receives the service request transmitted by the communication device 2, the gateway 133 that indirectly receives the service request received by the communication satellite 131, and the core network of the first PLMN can also function as the service request detection unit 31.

[0036] The service quality determination unit 32 determines whether the service quality (various QoS parameters) required for the service detected by the service request detection unit 31 can be achieved by the first PLMN to which the communication satellite 131 to which the communication device 2 is connected belongs. In the example of FIG. 2 where the first PLMN is an NTN, a large propagation delay occurs between the communication device 2 and the communication satellite 131, and between the communication satellite 131 and the gateway 133. For this reason, in services that particularly require low latency, it is highly likely that the service quality determination unit 32 determines that the first PLMN cannot achieve the required service quality.

[0037] The service quality determination unit 32 is implemented in at least one of the communication device 2, the communication satellite 131, the gateway 133, and the core network of the first PLMN. It is preferable that the service quality determination unit 32 is implemented in the same or a nearby location on the network or in hardware as the service request detection unit 31. For example, when the service request detection unit 31 is implemented in the communication device 2, the service quality determination unit 32 can also be implemented in the communication device 2, so that the detection of the service request and the determination of the service quality can be executed together in the communication device 2. Also, when the service request detection unit 31 is implemented on the network side such as the communication satellite 131, the gateway 133, or the core network of the first PLMN, the service quality determination unit 32 can also be implemented on the network side, so that the detection of the service request and the determination of the service quality can be executed together on the network side. Furthermore, the service quality determination unit 32 may be implemented in the application layer that provides an application to the communication device 2 through the first PLMN to which the communication satellite 131 belongs, or may be implemented in a lower layer than the application layer, such as the physical (PHY) layer, the media access control (MAC) layer, the radio link control (RLC) layer, or the packet domain convergence protocol (PDCP) layer. These specific examples will be described later.

[0038] When the service quality (various QoS parameters) required by the service detected by the service request detection unit 31 cannot be achieved by the first PLMN to which the communication satellite 131 to which the communication device 2 is connected belongs (that is, the required service quality is too high for the first PLMN), as determined by the service quality determination unit 32, the service request transmission unit 33 transmits the service request from the communication device 2 detected by the service request detection unit 31 to the terrestrial base stations 111 and 121 as the second base stations that can achieve the service quality. The service request transmission unit 33 is implemented by at least one of the communication device 2, the communication satellite 131, the gateway 133, and the core network of the first PLMN. The service request transmission unit 33 is preferably implemented at the same or a nearby location on the network or in hardware as the service request detection unit 31 and the service quality determination unit 32. For example, when the service request detection unit 31 and the service quality determination unit 32 are implemented in the communication device 2, the service request transmission unit 33 can also be implemented in the communication device 2, so that the detection of the service request, the determination of the service quality, and the transmission of the service request can be collectively executed by the communication device 2. Also, when the service request detection unit 31 and the service quality determination unit 32 are implemented on the network side such as the communication satellite 131, the gateway 133, and the core network of the first PLMN, the service request transmission unit 33 can also be implemented on the network side, so that the detection of the service request, the determination of the service quality, and the transmission of the service request (transfer from the communication satellite 131 in the first PLMN to the terrestrial base stations 111 and 121 in the second PLMN) can be collectively executed on the network side.

[0039] The response receiving unit 34 receives responses from the terrestrial base stations 111 and 121 to the service request transmitted by the service request transmitting unit 33 to the second PLMN. The response receiving unit 34 is implemented by at least one of the communication device 2, the communication satellite 131, the gateway 133, and the core network of the first PLMN. The response receiving unit 34 is preferably implemented in the same or a nearby location on the network or in hardware as the service request detecting unit 31, the service quality determining unit 32, and the service request transmitting unit 33. For example, when the service request detecting unit 31, the service quality determining unit 32, and the service request transmitting unit 33 are implemented by the communication device 2, the response receiving unit 34 can also be implemented by the communication device 2, so that the detection of the service request, the determination of the service quality, the transmission of the service request, and the reception of the response from the second PLMN can be collectively executed by the communication device 2. Also, when the service request detecting unit 31, the service quality determining unit 32, and the service request transmitting unit 33 are implemented on the network side such as the communication satellite 131, the gateway 133, and the core network of the first PLMN, the response receiving unit 34 can also be implemented on the network side, so that the detection of the service request, the determination of the service quality, the transmission of the service request, and the reception of the response from the second PLMN can be collectively executed on the network (first PLMN) side.

[0040] When the connection control unit 35 receives from the second PLMN a response indicating that a high service quality (various QoS parameters) required by the service detected by the service request detection unit 31, which cannot be achieved in the first PLMN, can be achieved in the second PLMN to which the terrestrial base stations 111 and 121 belong, the connection control unit 35 changes the connection destination of the communication device 2 from the first PLMN to which the communication satellite 131 belongs to the second PLMN to which the terrestrial base stations 111 and 121 belong. When the connection control unit 35 is implemented on the network (first PLMN) side, known connection destination change methods such as Redirection, Idle Mode Load Balancing, and Service-Based Handover can be used. In the example of FIG. 2, where the first PLMN (NTN) is the home network with which the user of the communication device 2 has subscribed to a communication service, and the second PLMN (TN) is a roaming network in which the communication device 2 can roam through cooperation between communication service providers, with the change of the connection destination of the communication device 2 by the connection control unit 35, the communication device 2 starts roaming communication in the second PLMN (TN). In the roaming destination second PLMN (TN), since the high service quality (various QoS parameters) required by the service detected by the service request detection unit 31 is achieved, the communication device 2 can receive the intended high-quality service.

[0041] FIGS. 3 to 5 show three examples of communication control based on QoS determination executed by the communication control device 3. FIG. 3 shows an example in which the communication control based on QoS determination is led by the network side (the communication satellite 131 as the first base station, the gateway 133, the core network of the first PLMN, the terrestrial base stations 111 and 121 as the second base stations, the core network of the second PLMN, etc.). FIG. 4 shows an example in which the communication control based on QoS determination is led by the communication device 2. FIG. 5 shows an example in which the communication control based on QoS determination is led by the application layer. "S" in these figures means step or process.

[0042] In FIG. 3, the communication device 2 (UE) is connected to a first PLMN (PLMN#1) which is a home network (S1). In this state, the communication device 2 transmits a high-quality service request to the communication satellite 131 of the first PLMN (S2). Here, the so-called "high quality" means higher than the communication quality (various QoS parameters) that the first PLMN can provide to the communication device 2. Since "high quality" is a relative concept with respect to the communication quality of the first PLMN in this way, it is not possible to generally specify "high-quality services", but typical examples of "high-quality services" are remote control classified into resource types such as "delay-critical GBR" and "GPR", ITS (Intelligent Transport System), conversational voice, conversational video, real-time games, V2X messages, power distribution, process automation, discrete automation, emergency calls, emergency communications, autonomous driving of automobiles, etc., VR (Virtual Reality) communications such as 4K and 8K, and other ultra-reliable and low-latency communications (URLLC), etc.

[0043] The service request detection unit 31 implemented in the first PLMN detects the high-quality service request transmitted by the communication device 2 to the communication satellite 131 (S2). Then, the service quality determination unit 32 implemented in the first PLMN compares the communication quality and available communication resources that the first PLMN itself can provide with the required high service quality (various QoS parameters), and determines that the first PLMN cannot achieve the required high service quality (S3). Following this determination, the service request transmission unit 33 implemented in the first PLMN transfers the service request from the communication device 2 received by the communication satellite 131 as the first base station to the terrestrial base stations 111 and 121 as the second base stations through a base station-to-base station interface IF such as the Xn interface or the X2 interface (FIG. 2), etc. (S4).

[0044] In response to the service request transferred from the first PLMN (PLMN#1), the second PLMN (PLMN#2) compares the communication quality that the second PLMN itself can provide and the available communication resources with the high service quality (various QoS parameters) required, and determines that the second PLMN can achieve the required high service quality. This determination result is transmitted from the second PLMN to the first PLMN through the base station interface IF or the like, and is received by the response receiving unit 34 implemented in the first PLMN (S5). Based on this determination result, the connection control unit 35 implemented in the first PLMN changes the connection destination of the communication device 2 from the first PLMN that cannot provide high-quality services to the second PLMN that can provide high-quality services (S6).

[0045] In FIG. 4, the communication device 2 (UE) is connected to the first PLMN (PLMN#1) which is the home network (S1). In this state, the communication device 2 generates a high-quality service request (S2). At this time, the communication device 2 functioning as the service request detection unit 31 immediately detects the service request it has generated. Then, the service quality determination unit 32 implemented in the communication device 2 compares the communication quality that the first PLMN can provide and the available communication resources with the high service quality (various QoS parameters) required by the communication device 2 itself, and determines that the first PLMN cannot achieve the required high service quality (S3).

[0046] Here, the communication device 2 (service quality determination unit 32) can measure or estimate the communication quality that the first PLMN can provide in various ways. For example, by measuring a reference signal such as CSI-RS (Channel State Information Reference Signal) periodically transmitted from the communication satellite 131 as the first base station, the communication device 2 can directly measure the communication quality of the first PLMN or the communication satellite 131. Also, by referring to the communication history of the communication device 2 on the first PLMN (channel state, throughput of the communication device 2, etc. in past communications), the communication quality and QoS that the first PLMN can provide can be estimated with high accuracy. Further, when the communication device 2 transmits a service request to the first PLMN as in S2 in FIG. 3 and the composition of the QoS flow or radio bearer for the service request is rejected, etc., the communication device 2 can obtain from the network side a suggestion that the first PLMN cannot provide the service.

[0047] Subsequent to the determination in S3, the service request transmission unit 33 implemented in the communication device 2 transmits the service request (S2) generated by the communication device 2 to the terrestrial base stations 111 and 121 as the second base stations (S4). The second PLMN (PLMN#2) compares the communication quality and available communication resources that the second PLMN itself can provide with the required high service quality (various QoS parameters) in response to the service request received from the communication device 2, and determines that the second PLMN can achieve the required high service quality. This determination result is transmitted from the terrestrial base stations 111 and 121 to the communication device 2, and is received by the response reception unit 34 implemented in the communication device 2 (S5). Based on this determination result, the connection control unit 35 implemented in the communication device 2 changes the connection destination of the communication device 2 from the first PLMN that cannot provide a high-quality service to the second PLMN that can provide a high-quality service (S6).

[0048] In FIG. 5, the communication device 2 (UE) is connected to a first PLMN (PLMN#1) which is a home network (S1). In this state, the communication device 2 generates a high-quality service request (S2). At this time, the communication device 2 functioning as the service request detection unit 31 immediately detects the service request it has generated. Alternatively, the service request detection unit 31 realized in the first PLMN detects the high-quality service request transmitted by the communication device 2 to the communication satellite 131 (S2).

[0049] The service quality determination unit 32 realized in the application layer of the communication device 2 and / or the first PLMN determines whether the required service quality can be realized by the first PLMN to which the communication satellite 131 belongs according to the situation of the application executed in the application layer (S3). For example, based on the processing speed and throughput of the application being executed in the application layer, and various data indicating the communication quality of the first PLMN obtained during the execution of the application, the service quality determination unit 32 on the application layer measures or estimates the communication quality that can be provided by the first PLMN. Also, based on the history of the applications executed in the application layer so far, the service quality determination unit 32 can accurately estimate the communication quality that can be provided by the first PLMN. Furthermore, when the composition of the QoS flow or radio bearer for the service request (S2) transmitted by the communication device 2 to the first PLMN is rejected, etc., the application layer can obtain from the network side a suggestion that the first PLMN cannot provide the service.

[0050] In the example of FIG. 5, a service quality determination unit 32 implemented in the application layer compares the communication quality and available communication resources that can be measured or estimated based on the execution status of the current or past application with the high service quality (various QoS parameters) required in S2, and determines that the high service quality required cannot be achieved in the first PLMN (S3). Following the determination in S3, a service request transmission unit 33 implemented in the communication device 2 or the first PLMN transmits the service request (S2) generated by the communication device 2 to the terrestrial base stations 111 and 121 or the second PLMN as the second base station (S4). The second PLMN (PLMN#2) compares the communication quality and available communication resources that the second PLMN itself can provide with the high service quality (various QoS parameters) required in response to the service request received in S4, and determines that the high service quality required can be achieved if it is the second PLMN. This determination result is transmitted from the terrestrial base stations 111 and 121 to the communication device 2 (response receiving unit 34), or is transmitted from the terrestrial base stations 111 and 121 to the communication satellite 131 or the gateway 133 (response receiving unit 34) through the inter-base station interface IF or the like (S5). Based on this determination result, a connection control unit 35 implemented in the application layer of the communication device 2 and / or the first PLMN changes the connection destination of the communication device 2 from the first PLMN that cannot provide a high-quality service to the second PLMN that can provide a high-quality service (S6).

[0051] FIG. 6 shows a modified example of FIG. 2. In FIG. 6, a first PLMN (PLMN1) as a 4G network composed of a 4G base station 121 and a 4G cell 122 (shown as "4G Cell" in FIG. 6) coexists with a second PLMN (PLMN2) as a 5G network composed of a 5G base station 111 and a 5G cell 112 (shown as "5G Cell" in FIG. 6).

[0052] The 4G cell 122 of the 4G network (the first PLMN) and the 5G cell 112 of the 5G network (the second PLMN) overlap, and there is a communication device 2 to be controlled by the communication control device 3 within this overlapping area. In the example of FIG. 6, since the entire 5G cell 112 is included in the 4G cell 122, the entire 5G cell 112 is the overlapping area of the 4G cell 122 and the 5G cell 112. The communication device 2 within the overlapping area of such a first communication cell (4G cell 122) and a second communication cell (5G cell 112) is connected to the 4G base station 121 belonging to the first PLMN (4G network), which is the home network, in principle.

[0053] The service request detection unit 31 detects a service request from the communication device 2 connected to the 4G base station 121. The service request detection unit 31 is realized by at least any one of the communication device 2, the 4G base station 121 as the first base station, and the EPC (not shown in FIG. 6) as the core network to which the 4G base station 121 is connected. The communication device 2 itself that generates a service request for the first PLMN can always function as the service request detection unit 31. Also, the 4G base station 121 that directly receives the service request transmitted by the communication device 2, and the EPC that indirectly receives the service request received by the 4G base station 121 can also function as the service request detection unit 31.

[0054] The service quality determination unit 32 determines whether the service quality (various QoS parameters) required for the service detected by the service request detection unit 31 can be realized by the first PLMN to which the 4G base station 121 to which the communication device 2 is connected belongs. In the example of FIG. 6 where the first PLMN is a 4G network, particularly in services that require high throughput such as those classified as eMBB (Enhanced Mobile Broadband) in 5G, it is highly likely that the service quality determination unit 32 determines that the first PLMN cannot realize the required service quality. The service quality determination unit 32 is realized by at least one of the communication device 2, the 4G base station 121, and the EPC. The service quality determination unit 32 is preferably realized in the same or a nearby location on the network or in hardware as the service request detection unit 31. Further, the service quality determination unit 32 may be realized in the application layer that provides an application to the communication device 2 through the first PLMN to which the 4G base station 121 belongs.

[0055] When the service quality determination unit 32 determines that the service quality (various QoS parameters) required by the service detected by the service request detection unit 31 cannot be realized by the first PLMN to which the 4G base station 121 to which the communication device 2 is connected belongs, the service request transmission unit 33 transmits the service request from the communication device 2 detected by the service request detection unit 31 to the 5G base station 111 as the second base station constituting the second PLMN capable of realizing the service quality. The service request transmission unit 33 is realized by at least one of the communication device 2, the 4G base station 121, and the EPC. The service request transmission unit 33 is preferably realized at the same or a location close on the network or in hardware as the service request detection unit 31 and the service quality determination unit 32. When the service request transmission unit 33 is realized by the communication device 2, the service request is transmitted from the communication device 2 to the 5G base station 111 through 5G NR. When the service request transmission unit 33 is realized on the network side (4G base station 121 or EPC), the service request is transferred from the first PLMN (4G network) to the second PLMN (5G network) through the base station interface IF such as the X2 interface between the 4G base station 121 and the 5G base station 111 or the core network interface (not shown in FIG. 6) between the EPC of the first PLMN and the 5GC of the second PLMN.

[0056] The response receiving unit 34 receives a response from the 5G base station 111 to the service request transmitted by the service request transmitting unit 33 to the second PLMN. The response receiving unit 34 is implemented by at least one of the communication device 2, the 4G base station 121, and the EPC. The response receiving unit 34 is preferably implemented at the same or a nearby location on the network or in hardware as the service request detecting unit 31, the service quality determining unit 32, and the service request transmitting unit 33. When the response receiving unit 34 is implemented by the communication device 2, a response from the second PLMN is transmitted from the 5G base station 111 to the communication device 2 through 5G NR. When the response receiving unit 34 is implemented on the network side (the 4G base station 121 or the EPC), a response from the second PLMN (5G network) is transmitted to the first PLMN (4G network) through the base station interface IF or the core network interface between the EPC and the 5GC.

[0057] When the connection control unit 35 receives from the second PLMN a response indicating that a high service quality (various QoS parameters) required for the service detected by the service request detecting unit 31, which cannot be realized in the first PLMN, can be realized in the second PLMN to which the 5G base station 111 belongs, the connection control unit 35 changes the connection destination of the communication device 2 from the first PLMN to which the 4G base station 121 belongs to the second PLMN to which the 5G base station 111 belongs. In the example of FIG. 6, where the first PLMN (4G network) is the home network with which the user of the communication device 2 has subscribed to a communication service, and the second PLMN (5G network) is a roaming network in which the communication device 2 can roam through cooperation between communication service providers, with the change of the connection destination of the communication device 2 by the connection control unit 35, the communication device 2 starts roaming communication in the second PLMN (5G network). In the roaming destination second PLMN (5G network), since a high service quality (various QoS parameters) required for the service detected by the service request detecting unit 31 is realized, the communication device 2 can receive the expected high-quality service.

[0058] The above has been described based on embodiments. It is understood by those skilled in the art that the embodiments are examples, and various modifications are possible for each component and combination of each processing process, and such modifications are also within the scope of the present disclosure.

[0059] Note that the functional configurations of the respective devices described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. As hardware resources, a processor, ROM, RAM, and other LSIs can be used. As software resources, programs such as an operating system and applications can be used.

[0060] The present disclosure may also be expressed as follows.

[0061] Item 1: A service request detection unit that detects a service request from a communication device, A service quality determination unit that determines whether the service quality required by the service is realized by a first base station to which the communication device is connected, A service request transmission unit that, when it is determined that the service quality is not realized by the first base station, transmits the service request to a second base station capable of realizing the service quality, A communication control device comprising the above. Item 2: The service request detection unit, the service quality determination unit, and the service request transmission unit are provided in at least one of the first base station and a core network to which the first base station is connected, The service request detection unit detects the service request transmitted by the communication device to the first base station, The service quality determination unit determines whether the first base station can realize the service quality, The service request transmission unit transfers the service request from the first base station to the second base station when it is determined that the first base station cannot realize the service quality. The communication control device according to item 1. Item 3: The service request detection unit, the service quality determination unit, and the service request transmission unit are provided in the communication device, and are the communication control device according to item 1 or 2. Item 4: The service quality determination unit is provided in an application layer that provides an application to the communication device through the first base station, and determines whether the service quality is realized by the first base station according to the situation of the application executed in the application layer. The communication control device according to any one of items 1 to 3. Item 5: A response reception unit that receives a response from the second base station to the request for the service; A connection control unit that changes the connection destination of the communication device from the first base station to the second base station based on a response indicating that the second base station can realize the service quality; The communication control device according to any one of items 1 to 4, further comprising: Item 6: The communication device is within an overlapping area of a first communication cell provided on the ground by the first base station and a second communication cell provided on the ground by the second base station. The communication control device according to any one of items 1 to 5. Item 7: The first base station and the second base station belong to different mobile communication networks. The communication control device according to any one of items 1 to 6. Item 8: The first base station and the second base station belong to the same mobile communication network. The communication control device according to any one of items 1 to 6. Item 9: At least one of the first base station and the second base station is a non-ground base station that flies. The communication control device according to any one of items 1 to 8. Item 10: The non-ground base station is a communication satellite flying in outer space. The communication control device according to item 9. Item 11: Detecting a service request from a communication device; Determining whether the quality of service required by the service is achieved by the first base station to which the communication device is connected; When it is determined that the quality of service is not achieved by the first base station, transmitting a request for the service to a second base station capable of achieving the quality of service; A communication control method comprising the steps of: Item 12: Detecting a service request from a communication device; Determining whether the quality of service required by the service is achieved by the first base station to which the communication device is connected; When it is determined that the quality of service is not achieved by the first base station, transmitting a request for the service to a second base station capable of achieving the quality of service; A storage medium storing a communication control program for causing a computer to execute the steps of:

Industrial Applicability

[0062] The present disclosure relates to communication control based on quality of service determination in a communication system.

Explanation of Signs

[0063] 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 Service request detection unit, 32 Quality of service determination unit, 33 Service request transmission unit, 34 Response reception 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.

Claims

1. A service request detection unit that detects a service request from a communication device, A service quality determination unit that determines whether the service quality required by the service is achieved by a first base station to which the communication device is connected, A service request transmission unit that, when it is determined that the service quality is not achieved by the first base station, transmits the service request to a second base station that can achieve the service quality, Comprising, The first base station is a flying non-terrestrial base station belonging to a home network with which the user of the communication device has a communication service contract, and the second base station is a terrestrial base station belonging to a roaming network in which the communication device can roam through cooperation between communication service providers, The service quality is a communication control device related to the propagation delay between the communication device and the non-terrestrial base station.

2. The service request detection unit, the service quality determination unit, and the service request transmission unit are provided in at least one of the first base station and a core network to which the first base station is connected, The service request detection unit detects the service request transmitted by the communication device to the first base station, The service quality determination unit determines whether the first base station can achieve the service quality, The service request transmission unit transfers the service request from the first base station to the second base station when it is determined that the first base station cannot achieve the service quality. The communication control device according to claim 1.

3. The communication control device according to claim 1, wherein the service request detection unit, the service quality determination unit, and the service request transmission unit are provided in the communication device.

4. The service quality determination unit is provided in an application layer that provides an application to the communication device through the first base station, and determines whether the service quality is achieved by the first base station according to the situation of the application executed in the application layer. The communication control device according to claim 1.

5. A response reception unit that receives a response from the second base station to the service request, A connection control unit that changes the connection destination of the communication device from the first base station to the second base station based on a response indicating that the second base station can achieve the service quality. The communication control device according to claim 1, further comprising.

6. The communication device according to claim 1, wherein the communication device is within an overlapping area of a first communication cell provided by the first base station on the ground and a second communication cell provided by the second base station on the ground.

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

8. Detecting a service request from a communication device; Determining whether the quality of service required by the service is achieved by a first base station to which the communication device is connected; When it is determined that the quality of service is not achieved by the first base station, transmitting the service request to a second base station capable of achieving the quality of service; comprising: The first base station is a flying non-ground base station belonging to a home network with which the user of the communication device has subscribed to a communication service, and the second base station is a ground base station belonging to a roaming network in which the communication device can roam through cooperation between communication service providers. The quality of service is a communication control method related to the propagation delay between the communication device and the non-ground base station.

9. Detecting a service request from a communication device; Determining whether the quality of service required by the service is achieved by a first base station to which the communication device is connected; When it is determined that the quality of service is not achieved by the first base station, transmitting the service request to a second base station capable of achieving the quality of service; causing a computer to execute; The first base station is a flying non-ground base station belonging to a home network with which the user of the communication device has subscribed to a communication service, and the second base station is a ground base station belonging to a roaming network in which the communication device can roam through cooperation between communication service providers. The quality of service is a storage medium storing a communication control program related to the propagation delay between the communication device and the non-ground base station.

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