Communication processing method, program, communication system, communication control device, and centralized base station

Abstract

To appropriately assign communication flows to distributed base stations while considering a quality request to prevent deterioration in communication quality in a communication network in which various types of communication traffic ae rmixed.SOLUTION: In a communication system 1000, an aggregate base station sets directivity of communication flows to be handled by distributed base stations. A communication controller determines, from a header of a communication packet, a QoS request performed by an application to be provided by a server to set a QoS flow identifier corresponding to the request and, on the basis of the set QoS flow identifier, performs role sharing (decision of directivity) of the distributed base stations. The aggregate base station, on the basis of directivity of the distributed base stations, transmits communication packets of communication flows shared by the respective distributed base stations to a corresponding distributed base station as many as possible. Accordingly, a communication flow with high priority is preferred and a communication flow with low priority is sacrificed, which makes it possible to appropriately prevent deterioration in communication quality.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to communication technologies, and particularly to a technology for allocating communication flows to distributed base stations while considering quality requirements.

Background Art

[0002] In 5G (the fifth-generation mobile communication system), since various devices such as smartphones, IoT devices, robots, and smart cars are connected to the network, it is required to accommodate the traffic of applications with various QoS requirements (QoS: Quality of Service).

[0003] In the 5G standard architecture, a mechanism is provided to identify individual communication flows (a set of communication packets that can be regarded as having the same QoS requirement) from the entire traffic with various mixed QoS requirements, and allocate radio resources corresponding to the QoS requirements of each communication flow for each communication flow. As major types of QoS requirements in 5G, there are eMBB (Enhanced Mobile Broadband, high-speed large-capacity communication) and URLLC (Ultra Reliable Low Latency Communication, highly reliable low-latency communication).

[0004] In a communication system compliant with 5G specifications (5G communication system), it is important to efficiently process different types of traffic. For example, Patent Document 1 discloses a technique for multiplexing different types of traffic in the physical layer (PHY layer) in a 5G communication system. By using the technique of Patent Document 1, it becomes possible to multiplex each traffic on radio resources, for example, in a base station that accommodates traffic in which eMBB communication flows and URLLC communication flows are mixed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the technology of Patent Document 1, since different types of traffic are only multiplexed at the physical layer, the following problems occur.

[0007] When attempting to accommodate both the eMBB communication flow and the URLLC communication flow on the radio resources of a single base station, since low latency is required for the URLLC communication flow, it is necessary to allocate radio resources preferentially over the eMBB communication flow. On the other hand, if the URLLC communication flow is prioritized, the amount of radio resources available for allocation to the eMBB communication flow becomes insufficient, resulting in a problem that the effective quality of the eMBB communication flow deteriorates. Since the technology of Patent Document 1 only multiplexes different types of traffic at the physical layer, such problems occur.

[0008] Therefore, in view of the above problems, an object of the present invention is to realize a communication system, a communication processing method, and a program that can appropriately allocate communication flows to distributed base stations while considering quality requirements even in a situation where various communication traffics coexist in a communication network, and can reduce as much as possible the possibility of an eMBB communication flow being sacrificed by prioritizing the URLLC communication flow.

Means for Solving the Problems

[0009] To solve the above problems, a first invention is a communication processing method used in a communication system including a server that provides a predetermined application, a communication control device, an aggregation base station, and a plurality of distributed base stations. The communication processing method includes a directivity setting step, a QoS flow identifier determination step, a distribution processing step, and a data transmission step.

[0010] In the directivity setting step, the centralized base station sets the directivity of the communication flow handled by the distributed base stations managed by the centralized base station.

[0011] In the QoS flow identifier determination step, the communication control device analyzes the header of the communication packet transmitted from the server, identifies the QoS requirements necessary for the server to provide the application, and determines a QoS flow identifier for setting a communication flow that meets the identified QoS requirements.

[0012] In the distribution processing step, the centralized base station analyzes the communication packets of each communication flow transmitted from the communication control device to obtain the QoS flow identifier of the communication flow of the communication packet, identifies the QoS characteristics corresponding to the obtained QoS flow identifier, and based on the identified QoS characteristics, executes a distribution process to determine the distributed base station to which the communication packet received from the communication control device is to be transmitted.

[0013] In the data transmission step, the centralized base station transmits the communication packet received from the communication control device to the distributed base station determined as the transmission destination by the distribution process.

[0014] In this communication processing method, the centralized base station sets the directivity of the communication flows handled by the distributed base stations managed by the centralized base station, and the communication control device determines from the header of the communication packet (for example, the header including the ToS value) what QoS requirements the application that the server is about to provide has, and sets the corresponding QoS flow identifier. Then, in this communication processing method, based on the QoS flow identifier set by the communication control device, for example, the role sharing (determination of directivity (for example, eMBB directivity, URLLC directivity)) of the distributed base stations in the RAN can be performed. And, in this communication processing method, the centralized base station can transmit the communication packets of the communication flows (the communication flows that each distributed base station handles as many as possible) that each distributed base station is responsible for to the distributed base stations that can handle as many of them as possible based on the directivity of the distributed base stations. Therefore, it is possible to appropriately prevent a situation where high-priority communication flows (for example, URLLC communication flows) are prioritized and low-priority communication flows (for example, eMBB communication flows) are sacrificed, resulting in degradation of communication quality.

[0015] The second invention is the first invention, wherein the directivity of the communication flow set in the directivity setting step is (1) the eMBB directivity, which is a directivity that handles many eMBB communication flows, which are communication flows that satisfy the QoS requirements for realizing high-speed and large-capacity communication, and (2) the URLLC directivity, which is a directivity that handles many URLLC communication flows, which are communication flows that satisfy the QoS requirements for realizing high-reliability and low-latency communication. It includes.

[0016] Then, the centralized base station controls the distributed base stations set with the eMBB directivity to process many eMBB communication flows, and controls the distributed base stations set with the URLLC directivity to process many URLLC communication flows.

[0017] As a result, in this communication processing method, it is possible to set an eMBB-oriented distributed base station and a URLLC-oriented distributed base station, and it is possible to transmit as many eMBB communication flows as possible to the eMBB-oriented distributed base station and as many URLLC communication flows as possible to the URLLC-oriented distributed base station. Therefore, it is possible to appropriately prevent the URLLC communication flow, which is a communication flow with high priority, from being prioritized and the eMBB communication flow, which is a communication flow with low priority, from being sacrificed and the communication quality from deteriorating.

[0018] A third invention is the first or second invention, further comprising a QoS flow identifier-QoS profile correspondence information transmission step in which a communication control device transmits data including correspondence information between a QoS flow identifier and a QoS profile capable of specifying QoS characteristics corresponding to the QoS flow identifier to an aggregated base station.

[0019] As a result, in this communication processing method, it is possible to transmit the correspondence information between the QoS flow identifier and the QoS profile from the communication control device to the aggregated base station, and the aggregated base station can store and hold the correspondence information between the QoS flow identifier and the QoS profile. Then, the aggregated base station refers to the correspondence information between the QoS flow identifier and the QoS profile, and by examining the QoS flow identifier set in the communication packet transmitted from the communication control device, it is possible to specify what kind of QoS requirement communication flow the communication packet is. As a result, the aggregated base station can appropriately determine to which directional distributed base station the communication packet received from the communication control device should be transmitted (relayed).

[0020] A fourth invention is any one of the first to third inventions, and in the directivity setting step, the aggregated base station acquires communication log information of a terminal device that is a communication partner of the distributed base station from the distributed base station, detects a pair of distributed base stations with a high probability of communicating with one terminal device based on the communication log, and sets the directivity of the communication flow handled by the distributed base station based on the detection result.

[0021] Accordingly, in this communication processing method, it is possible to appropriately prevent the directivity of distributed base stations with the same directivity from being biased. That is, in this communication processing method, even when there is a large amount of communication of different types of communication flows, it is possible to appropriately determine the directivity of the distributed base stations, and by performing communication using the distributed base stations that are role - shared according to the directivity, it is possible to effectively prevent the deterioration of communication quality.

[0022] The fifth invention is a program for causing a computer to execute the communication processing method according to any one of the first to fourth inventions.

[0023] Accordingly, it is possible to realize a program for causing a computer to execute a communication processing method that exhibits the same effects as any one of the first to fourth inventions.

[0024] The sixth invention is a communication system including a server that provides a predetermined application, a communication control device, an aggregation base station, and a plurality of distributed base stations.

[0025] The aggregation base station executes a directivity setting step of setting the directivity of the communication flows handled by the distributed base stations managed by the aggregation base station.

[0026] The communication control device executes a QoS flow identifier determination step of analyzing the header of a communication packet transmitted from the server, identifying the QoS requirements necessary for the server to provide the application, and determining a QoS flow identifier for setting a communication flow that satisfies the identified QoS requirements.

[0027] The centralized base station analyzes the communication packets of each communication flow transmitted from the communication control device, obtains the QoS flow identifier of the communication flow of the communication packet, identifies the QoS characteristics corresponding to the obtained QoS flow identifier, and based on the identified QoS characteristics, executes a distribution process step of determining a distributed base station to which the communication packet received from the communication control device is to be transmitted, and a data transmission step of transmitting the communication packet received from the communication control device to the distributed base station determined by the distribution process.

[0028] Thereby, a communication system having the same effect as that of the first invention can be realized.

[0029] The seventh invention is a communication control device used in the communication system which is the sixth invention, and executes a QoS flow identifier determination step and a QoS flow identifier - QoS profile correspondence information transmission step.

[0030] In the QoS flow identifier determination step, the communication control device analyzes the header of the communication packet transmitted from the server, identifies the QoS requirements necessary for the server to provide an application, and determines a QoS flow identifier for setting a communication flow that satisfies the identified QoS requirements.

[0031] In the QoS flow identifier - QoS profile correspondence information transmission step, the communication control device transmits data including correspondence information between the QoS flow identifier and a QoS profile capable of identifying the QoS characteristics corresponding to the QoS flow identifier to the centralized base station.

[0032] Thereby, a communication control device having the same effect as that of the third invention can be realized.

[0033] The eighth invention is a centralized base station used in the communication system which is the sixth invention, and executes a directivity setting step, a distribution process step, and a data transmission step.

[0034] In the directivity setting step, the centralized base station sets the directivity of the communication flow handled by the distributed base stations managed by the centralized base station.

[0035] In the distribution processing step, the centralized base station analyzes the communication packets of each communication flow transmitted from the communication control device, obtains the QoS flow identifier of the communication flow of the communication packet, identifies the QoS characteristics corresponding to the obtained QoS flow identifier, and based on the identified QoS characteristics, executes a distribution process of determining the distributed base station to which the communication packet received from the communication control device is to be transmitted.

[0036] In the data transmission step, the centralized base station transmits the communication packet received from the communication control device to the distributed base station determined as the transmission destination by the distribution process.

[0037] Thereby, a centralized base station having the same effect as the first invention can be realized.

Effect of the Invention

[0038] According to the present invention, in a communication network, even in a situation where various communication traffics are mixed, while considering quality requirements, communication flows are appropriately assigned to distributed base stations, and by prioritizing the communication flows of URLLC, the possibility of generating communication flows of eMBB that are sacrificed can be reduced as much as possible. A communication system, a communication processing method, and a program can be realized.

Brief Description of the Drawings

[0039]

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Embodiments for Carrying Out the Invention

[0040] [First Embodiment] The first embodiment will be described below with reference to the drawings.

[0041] <1.1: Configuration of Communication System> FIG. 1 is a schematic configuration diagram of a communication system 1000 according to the first embodiment.

[0042] FIG. 2 is a schematic configuration diagram of a communication control device 1 according to the first embodiment.

[0043] FIG. 3 is a schematic configuration diagram of an aggregated base station CU1 according to the first embodiment.

[0044] FIG. 4 is a diagram for explaining a dual connectivity function realized using an aggregated base station, a distributed base station, and a terminal device according to the first embodiment.

[0045] As shown in FIG. 1, the communication system 1000 includes M (M: natural number) first servers Svr1 to Mth servers SvrM, a communication control device 1 installed in, for example, an exchange center Cntr1, a RAN (Radio Access Network), and a plurality of terminal devices (in FIG. 1, n (n: natural number) terminal devices UE1 to UEn). The first servers Svr1 to Mth servers SvrM and the communication control device 1 are connected to a network NW1 (for example, the Internet) and can communicate with each other's servers and / or devices.

[0046] Also, as shown in FIG. 1, the RAN is composed of an aggregated base station CU1 and distributed base stations DU1 to DUm (m: natural number) connected to the aggregated base station CU1. Note that, in FIG. 1, the RAN includes one aggregated base station CU1, but is not limited thereto, and may include a plurality of aggregated base stations and one or a plurality of distributed base stations connected to each of the plurality of aggregated base stations.

[0047] Further, the communication control device 1 and the centralized base station CU1 of the RAN may be connected via a network (not shown) (for example, a mobile phone communication network (for example, a 4G / LTE communication network or a 5G communication network (5G: fifth-generation mobile communication system))).

[0048] The first server Svr1 to the Mth server SvrM are each servers that provide a predetermined application and are connected to the network NW1. The first server Svr1 to the Mth server SvrM are each servers (application servers) that establish a communication connection with a terminal device (for example, in FIG. 1, terminal devices UE1 to UEn) and provide an application corresponding to a request from the terminal device. The first server Svr1 to the Mth server SvrM can each communicate with the terminal device via the network NW1, the communication control device 1, and the RAN.

[0049] (1.1.1: Configuration of Communication Control Device) The communication control device 1 is, for example, a device (for example, a 5G core device) installed in an exchange center Cntr1 (for example, an exchange center that connects the transmission network of 5G (fifth-generation mobile communication system) and an external network (for example, the Internet) and conducts communication), and is communicably connected to the network NW1 and the RAN. And the communication control device 1 has a function of controlling communication among the network NW1, the RAN, the server, and / or the terminal device.

[0050] As shown in Fig. 2, the communication control device 1 includes a first communication interface IF11, a data communication processing unit 11, a C-plane signal processing unit 12, a U-plane signal processing unit 13, a storage unit 14, a second communication interface IF12, and a bus Bus1. As shown in Fig. 2, the data communication processing unit 11, the C-plane signal processing unit 12, the U-plane signal processing unit 13, and the storage unit 14 are connected to the bus Bus1 and can transmit and receive data and / or signals (such as control signals) via the bus Bus1. Note that part or all of the data communication processing unit 11, the C-plane signal processing unit 12, the U-plane signal processing unit 13, and the storage unit 14 may be directly connected without using a bus to transmit and receive data, control signals, etc.

[0051] The first communication interface IF11 is a communication interface for performing data transmission and reception with an external device (external servers (the first server Svr1 to the Mth server SvrM)) via the network NW1. Also, as shown in Fig. 2, the first communication interface IF11 is connected to the data communication processing unit 11.

[0052] The first communication interface IF11 is a communication interface for performing data communication with a server, a communication device, etc. connected to the network NW1. The first communication interface IF11 converts the data received from the external (network NW1) into data in a format that can be processed by the data communication processing unit 11 and outputs the converted data to the data communication processing unit 11. Also, the first communication interface IF11 converts the data (data output from the data communication processing unit 11) to be transmitted from the communication control device 1 to the external (network NW1) into data (signals) in a format that can be transmitted to the external (network NW1) and transmits the converted data (signals) to the external (network NW1).

[0053] The data communication processing unit 11 inputs the data output from the first communication interface IF11, and executes predetermined data communication processing (for example, IP packet header analysis processing, processing to obtain predetermined data from received data, etc.) on the data. The data communication processing unit 11 outputs, via the bus Bus1, the data necessary for C-plane signal processing among the data obtained by the data communication processing to the C-plane signal processing unit 12, and also outputs, via the bus Bus1, the data necessary for U-plane signal processing among the data obtained by the data communication processing to the U-plane signal processing unit 13. Further, the data communication processing unit 11 outputs, via the bus Bus1, the data that needs to be stored and held in the communication control device 1 among the data obtained by the data communication processing to the storage unit 14, and stores the data in the storage unit 14.

[0054] Note that "C-plane" refers to the Control plane, which represents data, signals, procedures, or mechanisms for controlling communication in a communication system (for example, a wireless communication system). Also, "U-plane" refers to the User plane, which represents data, procedures, or mechanisms for a user to transmit and receive in a communication system (for example, a wireless communication system).

[0055] In addition, the data communication processing unit 11 inputs, via the bus Bus1, the data output from each functional unit of the communication control device 1. The data communication processing unit 11 executes predetermined data communication processing (for example, IP header addition processing or processing to convert the data into a format that can be transmitted to the network NW1) on the input data. Then, the data communication processing unit 11 outputs the data obtained by the above data communication processing to the first communication interface IF11.

[0056] Note that the data communication processing executed by the data communication processing unit 11 includes processing for analyzing the header of a communication packet (for example, an IP header) received from an external application server and obtaining the ToS value (ToS: Type of Service) of the communication packet (the ToS value defined by RFC2474 (RFC: Request for Comments)).

[0057] The C-plane signal processing unit 12 performs processing (C-plane signal processing) for transmitting and receiving C-plane data with the RAN via the second communication interface IF12.

[0058] In addition, the C-plane signal processing unit 12 inputs data necessary for performing C-plane control from the data communication processing unit 11. Also, the C-plane signal processing unit 12 outputs data obtained by C-plane signal processing and necessary for the data communication processing by the data communication processing unit 11 to the data communication processing unit 11.

[0059] Also, among the data obtained by the C-plane signal processing, the C-plane signal processing unit 12 outputs data that needs to be stored and held in the communication control device 1 to the storage unit 14 via the bus Bus1, and stores the data in the storage unit 14.

[0060] The U-plane signal processing unit 13 performs processing (U-plane signal processing) for transmitting and receiving U-plane data with the RAN via the second communication interface IF12.

[0061] In addition, the U-plane signal processing unit 13 inputs data necessary for performing U-plane signal processing via the first communication interface IF11, the data communication processing unit 11, and the bus Bus1. Then, the U-plane signal processing unit 13 executes predetermined U-plane signal processing on the input data.

[0062] Also, the U-plane signal processing unit 13 outputs, to the data communication processing unit 11, the data obtained by U-plane signal processing and necessary for the data communication processing by the data communication processing unit 11.

[0063] Also, among the data obtained by U-plane signal processing, the U-plane signal processing unit 13 outputs, via the bus Bus1, the data that needs to be stored and held in the communication control device 1 to the storage unit 14, and stores the data in the storage unit 14.

[0064] Note that the U-plane signal processing includes the following processing. (1) A process of notifying the RAN (aggregated base station CU1) of information regarding the correspondence between the QFI (QoS Flow Identifier) and the QoS Profile (this process is executed at the time of establishment of the PDU session). (2) A process of transmitting to the RAN (aggregated base station CU1) a communication packet to which a QFI corresponding to the ToS value obtained by the data communication processing unit 11 is assigned (communication processing is performed by a communication flow to which a QFI is assigned).

[0065] The storage unit 14 is a functional unit that stores data. The storage unit 14 is connected to the bus Bus1, and performs a data writing process and / or a data reading process based on commands from each functional unit of the communication control device 1.

[0066] The second communication interface IF12 is a communication interface for performing data transmission and reception with the RAN (devices within the RAN). Also, as shown in FIG. 2, the second communication interface IF12 is connected to the C-plane signal processing unit 12 and the U-plane signal processing unit 13.

[0067] The second communication interface IF12 outputs the C-plane data received from the external (RAN) to the C-plane signal processing unit 12, and also inputs the C-plane data output from the C-plane signal processing unit 12, and transmits the U-plane data to the external (RAN).

[0068] In addition, the second communication interface IF12 outputs the U-plane data received from the external (RAN) to the U-plane signal processing unit 13, and also inputs the U-plane data output from the U-plane signal processing unit 13, and transmits the U-plane data to the external (RAN).

[0069] (1.1.2: Configuration of the Centralized Base Station) The centralized base station CU1 is a base station (centralized base station CU (Central Unit)) that aggregates (supervises) one or more distributed base stations (DU: Distributed Unit) (in FIG. 1, from distributed base station DU1 to DUm), and is a base station (centralized base station) for realizing a communication network with CU-DU function separation. In the communication network with CU-DU function separation, for example, the protocol stack between the terminal device and the base station is arranged in order from the upper layer to the lower layer, (1) SDAP layer (SDAP: Service Data Adaptation Protocol), (2) PDCP layer (PDCP: Packet Data Convergence Protocol), (3) RLC layer (RLC: Radio Link Control), (4) MAC layer (MAC: Medium Access Control), (5) PHY layer (physical layer), when defined as such, (A) the centralized base station (CU) shares (executes) the functions of (1) the SDAP layer and (2) the PDCP layer, and (B) the distributed base station (DC) shares (executes) the functions of (3) the RLC layer, (4) the MAC layer, and (5) the PHY layer.

[0070] As shown in FIG. 1, the centralized base station CU1 is communicably connected to each of the communication control device 1 and the distributed base stations DU1 to DUm. The centralized base station CU1 assigns a radio bearer (service line by radio communication) to each of the distributed base stations DU1 to DUm. That is, the centralized base station CU1 performs mapping processing between the distributed base stations DU1 to DUm and the radio bearers. Note that a single radio bearer can include a plurality of traffic flows (communication data (communication packet groups) that require the same QoS). The centralized base station CU1 establishes a PDU session (PDU: Protocol Data Unit) (a session between the communication control device 1, the centralized base station CU1, the distributed base stations DU1 to DUm, and the terminal device) based on the communication data (C-plane data, U-plane data) received from the communication control device 1, and assigns a radio bearer (service line by radio communication) to each of the distributed base stations DU1 to DUm. In the communication system 1000, since different radio bearers are prepared and operated for different qualities, for example, it is assumed that a radio bearer for eMBB and a radio bearer for URLLC can be assigned to each distributed base station (both a radio bearer for eMBB and a radio bearer for URLLC can be assigned).

[0071] Then, the centralized base station CU1 communicates with each of the distributed base stations DU1 to DUm in units of radio bearers.

[0072] As shown in FIG. 3, the centralized base station CU1 includes a CN-side communication interface IF21 (CN: Core Network), a CU C-plane signal processing unit 21, a CU U-plane signal processing unit 22, a storage unit 23, a DU-side communication interface IF22, and a bus Bus2. As shown in FIG. 3, the CU C-plane signal processing unit 21, the CU U-plane signal processing unit 22, and the storage unit 23 are connected to the bus Bus2 and can transmit and receive data and / or signals (such as control signals) via the bus Bus2. Note that part or all of the CU C-plane signal processing unit 21, the CU U-plane signal processing unit 22, and the storage unit 23 may be directly connected without passing through a bus to transmit and receive data, control signals, etc.

[0073] The CN-side communication interface IF21 is a communication interface for performing data transmission and reception with the communication control device 1 (a device of the core network (e.g., a 5G core device)). Also, as shown in FIG. 3, the CN-side communication interface IF21 is connected to the CU C-plane signal processing unit 21 and the CU U-plane signal processing unit 22.

[0074] The CN-side communication interface IF21 outputs the C-plane data received from the communication control device 1 to the CU C-plane signal processing unit 21, inputs the C-plane data output from the CU C-plane signal processing unit 21, and transmits the U-plane data to the outside (communication control device 1).

[0075] Also, the CN-side communication interface IF21 outputs the U-plane data received from the communication control device 1 to the CU U-plane signal processing unit 22, inputs the U-plane data output from the CU U-plane signal processing unit 22, and transmits the U-plane data to the outside (communication control device 1).

[0076] The C-plane signal processing unit 21 for the CU performs processing (C-plane signal processing for the CU) for transmitting and receiving C-plane data with the communication control device 1 via the CN-side communication interface IF21. Also, the C-plane signal processing unit 21 for the CU performs processing (C-plane signal processing for the CU) for transmitting and receiving C-plane data with the distributed base stations DU1 to DUm via the DU-side communication interface IF22.

[0077] Also, among the data acquired by the C-plane signal processing for the CU, the C-plane signal processing unit 21 for the CU outputs data that needs to be stored and held in the aggregated base station CU1 to the storage unit 23 via the bus Bus2, and stores the data in the storage unit 23.

[0078] The U-plane signal processing unit 22 for the CU performs processing for transmitting and receiving U-plane data with the communication control device 1 via the CN-side communication interface IF21 and processing using the U-plane data (U-plane signal processing for the CU). Also, the U-plane signal processing unit 22 for the CU performs processing for transmitting and receiving U-plane data with the distributed base stations DU1 to DUm via the DU-side communication interface IF22 and processing using the U-plane data (U-plane signal processing for the CU).

[0079] Also, among the data acquired by the U-plane signal processing for the CU, the U-plane signal processing unit 22 for the CU outputs data that needs to be stored and held in the aggregated base station CU1 to the storage unit 23 via the bus Bus2, and stores the data in the storage unit 23.

[0080] Note that the U-plane signal processing for the CU includes the following processing. (1) Assignment processing for the distributed base stations (processing for determining the directivity of the distributed base stations) (2) Processing for receiving notification of information regarding the correspondence between the QFI (QoS Flow Identifier) and the QoS Profile from the communication control device 1 (this processing is executed at the time of establishing a PDU session). (3) The process of receiving communication packets of a predetermined communication flow from the communication control device 1. (4) The analysis process of the communication data received from the communication control device 1 (such as the process of obtaining the QFI set in the communication packets of a predetermined communication flow) (5) The process of determining the destination distributed base station based on the QFI of the communication data (communication flow) received from the communication control device 1 and transmitting the data to the determined distributed base station.

[0081] The storage unit 23 is a functional unit for storing data. The storage unit 23 is connected to the bus Bus2 and performs data writing processing and / or data reading processing based on commands from each functional unit of the centralized base station CU1.

[0082] The DU-side communication interface IF22 is a communication interface for performing data transmission and reception with the distributed base stations DU1 to DUm. Also, as shown in FIG. 3, the DU-side communication interface IF22 is connected to the CU C-plane signal processing unit 21 and the CU U-plane signal processing unit 22.

[0083] The DU-side communication interface IF22 outputs the C-plane data received from the distributed base station DUi (i: natural number, 1 ≤ i ≤ m) to the CU C-plane signal processing unit 21, inputs the C-plane data output from the CU C-plane signal processing unit 21, and transmits the U-plane data to the outside (distributed base station DUi).

[0084] Also, the DU-side communication interface IF22 outputs the U-plane data received from the distributed base station DUi to the CU U-plane signal processing unit 22, inputs the U-plane data output from the CU U-plane signal processing unit 22, and transmits the U-plane data to the outside (distributed base station DUi).

[0085] (1.1.3: Configuration of the Distributed Base Station) The distributed base stations DU1 to DUm are each communicably connected to the centralized base station CU1. Also, each of the distributed base stations DU1 to DUm can be communicably connected to one or more terminal devices. The distributed base stations DU1 to DUm each transmit the communication data received from the centralized base station CU1 to the terminal device that is the destination of the communication data (for example, the destination described in the header). Also, each of the distributed base stations DU1 to DUm transmits the communication data received from the terminal device to the centralized base station CU1. Note that each of the distributed base stations DU1 to DUm has a dual connectivity function and can communicate with one terminal device from a plurality of distributed base stations simultaneously using different communication flows. With the dual connectivity function, for example, as shown in FIG. 4, communication with the terminal device UE3 from the centralized base station CU1 can be performed by two different communication flows using two distributed base stations DU1 and DU2. In the case of FIG. 4, with the dual connectivity function, (1) communication by the first communication flow Flow1 is realized among the centralized base station CU1, the distributed base station DU1, and the terminal device UE3, and (2) communication by the second communication flow Flow2 is realized among the centralized base station CU1, the distributed base station DU2, and the terminal device UE3. Note that the number of simultaneously connected communication flows may be "3" or more with the dual connectivity function.

[0086] (1.1.4: Terminal Device) A plurality of terminal devices (in FIG. 1, n terminal devices UE1 to UEn (n: natural number)) are each communicably connected (for example, wirelessly communicably connected) to a distributed base station assigned to the own terminal device among the distributed base stations DU1 to DUm of the RAN. Each of the plurality of terminal devices can establish a PDU session between the communication control device 1, the centralized base station CU1, and the distributed base station. And each of the plurality of terminal devices can communicate in units of communication flows (QoS flow units, which are units of communication packet groups that require the same QoS) between the communication control device 1, the centralized base station CU1, and the distributed base station. Also, each of the plurality of terminal devices (in FIG. 1, n terminal devices UE1 to UEn (n: natural number)) may be able to communicate by means of communication flows connected simultaneously by means of a multi-connection function (Dual connectivity function).

[0087] <1.2: Operation of the communication system> The operation of the communication system 1000 configured as described above will be described below.

[0088] FIG. 5 is a diagram for explaining the operation of the communication system 1000.

[0089] FIGS. 6 to 8 are sequence diagrams of processes executed in the communication system 1000.

[0090] FIG. 9 is a flowchart of the distribution process executed in the communication system 1000.

[0091] For the sake of convenience of explanation, as shown in FIG. 5, it is assumed that the communication system 1000 includes two servers, a first server Svr1 and a second server Svr2, and six terminal devices UE1 to UE6. And it is assumed that each of the terminal devices UE1 to UE6 can communicate by means of communication flows connected simultaneously by means of a multi-connection function (Dual connectivity function).

[0092] Also, assume that the first server Svr1 is a server that provides applications that require high-speed and large-capacity communication, and the second server Svr2 is a server that provides applications that require highly reliable and low-latency communication. And assume that the first server Svr1 provides applications to the terminal devices UE1 to UE6, and the second server Svr2 also provides applications to the terminal devices UE1 to UE6.

[0093] Also, assume that the communication system 1000 is a communication system (5G communication system) compliant with the 5G standard.

[0094] For the above case, the operation of the communication system 1000 will be described.

[0095] Hereinafter, the operation of the communication system 1000 will be described with reference to the sequence diagrams and flowcharts of FIGS. 6 to 9.

[0096] (Step S1): In step S1, the centralized base station CU1 executes the allocation process for the distributed base stations. Specifically, the process is performed as follows.

[0097] The centralized base station CU1 determines the directivity (eMBB-directed, URLLC-directed) of the distributed base stations that are communicably connected to the centralized base station CU1 (in the case of FIG. 5, the distributed base stations DU1 to DU3). That is, the centralized base station CU1 determines which of the distributed base stations that are communicably connected to the centralized base station CU1 (in the case of FIG. 5, the distributed base stations DU1 to DU3) will be the eMBB-directed distributed base station and which will be the URLLC-directed distributed base station. This determination of the directivity of the distributed base stations may be determined (assigned) randomly, for example, or may be determined (assigned) considering the installation positions of the respective distributed base stations, the positions of the terminal devices (in the case of FIG. 5, the terminal devices UE1 to UE6) that can communicate with each distributed base station, etc.

[0098] Here, for the sake of convenience of explanation, as shown in FIG. 5, the centralized base station CU1 is described below on the assumption that (1) the distributed base stations 1 and DU3 are set as eMBB-oriented distributed base stations, and (2) the distributed base station DU2 is set as a URLLC-oriented distributed base station.

[0099] (Step S2): In step S2, the first server Svr1 and the second server Svr2 determine the ToS value based on the application to be provided. As shown in FIG. 10, the ToS value can be determined, for example, by the value of the ToS field in the IP header defined in RFC791.

[0100] (1) Since the first server Svr1 provides an application that requires high-speed and large-capacity communication, it is necessary to make a QoS request to achieve high-speed and large-capacity communication. In this case, the first server Svr1 sets the DSCP value (DSCP: Differentiated Services codepoint) (defined in RFC2474) included in the ToS field to the DSCP value of the service class corresponding to the service that realizes high-speed and large-capacity communication (for example, the DSCP value of "001010" when the service class is "High Throughput Data") (see FIGS. 10 and 11). That is, the first server Svr1 sets the ToS value to 001010 (service class: "High Throughput Data") generates an IP packet with the ToS value, and generates a communication packet (a communication packet for transmission to the communication control device 1) including the IP packet.

[0101] (2) Since the second server Svr2 provides applications that require highly reliable and low-latency communication, it is necessary to make QoS requests to achieve highly reliable and low-latency communication. In this case, the second server Svr2 sets the DSCP value (DSCP: Differentiated Services codepoint) (specified in RFC2474) included in the ToS field to the DSCP value of the service class corresponding to the service that realizes high-speed and large-capacity communication (for example, the DSCP value of "010010" when the service class is "Low-Latency Data") (see FIGS. 10 and 11). That is, the second server Svr2 ToS value = 010010 (service class: "Low-Latency Data") sets it, generates an IP packet with the ToS value, and generates a communication packet (a communication packet for transmitting to the communication control device 1) including the IP packet.

[0102] (Step S3): In step S3, the first server Svr1 and the second server Svr2 transmit communication packets having the ToS value set in step S1 to the communication control device 1.

[0103] The communication control device 1 receives the communication packets transmitted from the first server Svr1 and the second server Svr2, and executes analysis processing (received data analysis processing) of the received communication packets (for example, the analysis processing is executed by the data communication processing unit 11 of the communication control device 1).

[0104] Then, from the ToS value obtained by the analysis processing of the received communication packets, the communication control device 1 grasps that (1) the first server Svr1 makes a QoS request to realize high-speed and large-capacity communication, and (2) the second server Svr2 makes a QoS request to realize highly reliable and low-latency communication.

[0105] (Steps S4, S41, S42): In step S4, a PDU session establishment process (PDU: Protocol Data Unit) is executed. That is, in order for the first server Svr1 and the second server Svr2 to realize communication that requires QoS, the communication control device 1, the centralized base station CU1, the distributed base station, and the terminal device perform the setting of a communication flow (a set of communication packets with the same QoS requirement) and a radio bearer (a communication path set for each distributed base station and capable of including a plurality of communication flows), and perform a process of establishing a PDU session. Note that the PDU session establishment process is a process for realizing the U-plane function, and predetermined processing is executed by the U-plane signal processing unit 13 of the communication control device 1 and the CU U-plane signal processing unit 22 of the centralized base station CU1, and the PDU session establishment process is executed by executing predetermined U-plane signal processing in the distributed base station and the terminal device.

[0106] In addition, the communication control device 1 performs a process of generating correspondence information between a QFI and a QoS Profile (hereinafter referred to as "QoS profile") (step S41). This will be described with reference to FIG. 12.

[0107] In the 5G communication system, a QFI is assigned to each communication flow, and a QoS profile corresponding to one QFI is determined. That is, the QFI and the QoS profile correspond one-to-one. The QoS profile includes a 5QI, and the QoS characteristics are determined by this 5QI (specified in 3GPP TS 23.501). The right diagram in FIG. 12 is a diagram showing a table indicating the QoS characteristics corresponding to the standard 5QI values.

[0108] That is, if the 5QI value of the QoS profile is determined, the QoS characteristics can be determined, and if the association between the QFI and the QoS profile is determined, the QoS characteristics are determined by the QFI.

[0109] Therefore, the communication control device 1 determines the association between the QFI and the QoS profile, and generates data including the correspondence information between the determined QFI and the QoS profile (step S41). Further, the communication control device 1 determines the QoS characteristics that satisfy the QoS requirements of the first server Svr1 and the second server Svr2 from the ToS values obtained from the communication data transmitted from the first server Svr1 and the second server Svr2, determines the 5QI value of the QoS characteristics, and further determines the value of the QFI. For example, as shown in FIG. 12, (1) When high-speed large-capacity communication (eMBB) is required (when the ToS value is "001010"), the communication control device 1 sets the 5QI and the QFI to 5QI = 6, QFI = 6 respectively. (2) When ultra-reliable and low-latency communication (URLLC) is required (when the ToS value is "010010"), the communication control device 1 sets the 5QI and the QFI to 5QI = 82, QFI = 10 respectively.

[0110] Note that the value of the 5QI and the value of the QFI do not necessarily have to match (they do not have to be the same value).

[0111] Therefore, when set as described above, for the communication data from the first server Svr1 (communication data with the ToS value set to "001010"), the communication control device 1 sets a communication flow with QFI = 6 (5QI = 6) (determines to communicate by the communication flow with QFI = 6 (eMBB communication flow)).

[0112] Also, when set as described above, for the communication data from the second server Svr2 (communication data with the ToS value set to "010010"), the communication control device 1 sets a communication flow with QFI = 10 (5QI = 82) (determines to communicate by the communication flow with QFI = 10 (URLLC communication flow)).

[0113] The communication control device 1 stores and holds the above setting information in the storage unit 14.

[0114] The communication control device 1 transmits data including the correspondence information between the QFI and the QoS profile generated as described above to the centralized base station CU1 (step S42).

[0115] The centralized base station CU1 receives data including the correspondence information between the QFI and the QoS profile transmitted from the communication control device 1, and stores and holds the received correspondence information between the QFI and the QoS profile (stores it in the storage unit 23) (step S42).

[0116] Note that the processes of steps S41 and S42 may be executed during the execution of the PDU session establishment process of step S4. Also, in the communication system 1000, the process of step S4 (PDU session establishment process) and the processes of steps S41 and S42 may be executed before the process of step S2. In the communication system 1000, since the communication control device 1 can execute the process of associating the QFI with the QoS profile without knowing in advance what ToS value is set for the communication data of each application and transmitted, as described above, in the communication system 1000, the process of step S4 (PDU session establishment process) and the processes of steps S41 and S42 may be executed before the process of step S2.

[0117] (Step S51): In step S51, the first server Svr1 generates communication data having a ToS value (=001010) set based on the application (high-speed large-capacity application) to be provided, and transmits the generated communication data to the communication control device 1.

[0118] The communication control device 1 receives the communication data transmitted from the first server Svr1.

[0119] (Step S52): In step S52, the communication control device 1 executes communication data analysis processing on the communication data received from the first server Svr1. That is, the communication control device 1 executes the analysis processing of the communication packet received from the first server Svr1 (for example, the data communication processing unit 11 of the communication control device 1 executes the analysis processing), and recognizes that the ToS value set by the first server Svr1 is "001010".

[0120] (Steps S53, S54): In step S53, the communication control device 1 determines the QFI corresponding to the ToS value (=001010) obtained by the communication data analysis processing, and performs a process (QFI addition process) of adding the determined QFI to the transmission packet to be transmitted to the centralized base station CU1 (setting the QFI). Since the ToS value obtained by the communication data analysis processing is "001010", the communication control device 1 refers to the correspondence data between the ToS value and the QFI value stored in the storage unit 14, and determines the value of the QFI corresponding to the ToS value to be "6" (determines QFI = 6, 5QI = 6). Then, the communication control device 1 enables communication to be executed by the communication flow with the determined QFI value (QFI = 6), that is, the eMBB communication flow. That is, the communication control device 1 generates a communication packet (communication packet for 5G communication in the eMBB communication flow) with a header having a QFI value set to "6" added to the data received from the first server Svr1, and transmits the generated communication packet to the centralized base station CU1 (step S54).

[0121] Then, the centralized base station CU1 receives the communication packet (communication packet for 5G communication in the eMBB communication flow) transmitted from the communication control device 1 (step S54).

[0122] (Step S55): In step S55, the centralized base station CU1 executes the distribution process. The specific process will be described with reference to the flowchart of the distribution process in FIG. 9 (steps SA1 to SA8).

[0123] (Step SA1): In step SA1, the aggregated base station CU1 executes analysis processing of communication data (5G communication packets) received from the communication control device 1. That is, the aggregated base station CU1 recognizes from the header of the communication data (5G communication packets) received from the communication control device 1 that the value of the QFI of the communication data is "6". Then, the aggregated base station CU1 refers to the correspondence information between the QFI and the QoS profile stored and held in the storage unit 23, and recognizes that the QoS profile of the communication data with QFI = 6 has a 5QI value of "6", and from the corresponding QoS characteristics, the communication data with QFI = 6 is the communication data of a communication flow (eMBB communication flow) that requires high-speed large-capacity communication.

[0124] (Step SA2): In step SA2, the aggregated base station CU1 determines whether the terminal device of the destination of the communication data received from the communication control device 1 can communicate with a plurality of distributed base stations. The aggregated base station CU1 judges the transmission and reception status of U-plane signals and C-plane signals between the terminal device of the destination and each of the distributed base stations (each of the distributed base stations DU1 to DU3), and determines whether the terminal device of the destination of the communication data received from the communication control device 1 can communicate with a plurality of distributed base stations.

[0125] If it is determined that the terminal device of the destination of the communication data received from the communication control device 1 can communicate with a plurality of distributed base stations, the process proceeds to step SA4. On the other hand, if it is determined that the terminal device of the destination of the communication data received from the communication control device 1 cannot communicate with a plurality of distributed base stations, the process proceeds to step SA3.

[0126] (Step SA3): In step SA3, the centralized base station CU1 identifies a distributed base station capable of communicating with the terminal device that is the destination of the communication data received from the communication control device 1, and causes the identified distributed base station to transmit data to the destination terminal device. That is, the centralized base station CU1 transmits the communication data received from the communication control device 1 to the distributed base station identified above, and further controls (instructs) the distributed base station so that the communication data received by the distributed base station is transmitted to the destination terminal device.

[0127] (Step SA4): In step SA4, the centralized base station CU1 determines whether the QFI value of the communication data received from the communication control device 1 is a value corresponding to the eMBB communication flow (eMBB-directed value).

[0128] If it is determined that the QFI value of the communication data received from the communication control device 1 is a value corresponding to the eMBB communication flow (eMBB-directed value), the process proceeds to step SA5. On the other hand, if it is determined that the QFI value of the communication data received from the communication control device 1 is not a value corresponding to the eMBB communication flow (eMBB-directed value), the process proceeds to step SA6.

[0129] (Step SA5): In step SA5, the centralized base station CU1 identifies a distributed base station that is set in the distributed base station directed to eMBB and is capable of communicating with the terminal device that is the destination of the communication data received from the communication control device 1, and causes the identified distributed base station to transmit data to the destination terminal device. That is, the centralized base station CU1 transmits the communication data received from the communication control device 1 to the distributed base station (eMBB-directed distributed base station) identified above, and further controls (instructs) the distributed base station so that the communication data received by the distributed base station is transmitted to the destination terminal device.

[0130] (Step SA6): In step SA6, the centralized base station CU1 determines whether the QFI value of the communication data received from the communication control device 1 is a value corresponding to the URLLC communication flow (a URLLC-directed value).

[0131] If it is determined that the QFI value of the communication data received from the communication control device 1 is a value corresponding to the URLLC communication flow (a URLLC-directed value), the process proceeds to step SA7. On the other hand, if it is determined that the QFI value of the communication data received from the communication control device 1 is not a value corresponding to the URLLC communication flow (a URLLC-directed value), the process proceeds to step SA8.

[0132] (Step SA7): In step SA7, the centralized base station CU1 identifies a distributed base station that is set in the URLLC-directed distributed base stations and is capable of communicating with the terminal device that is the destination of the communication data received from the communication control device 1, and causes the identified distributed base station to transmit data to the destination terminal device. That is, the centralized base station CU1 transmits the communication data received from the communication control device 1 to the above-identified distributed base station (URLLC-directed distributed base station), and further controls (instructs) the distributed base station so that the communication data received by the distributed base station is transmitted to the destination terminal device.

[0133] (Step SA8): In step SA8, the centralized base station CU1 identifies a distributed base station that is capable of communicating with the terminal device that is the destination of the communication data received from the communication control device 1, and causes the identified distributed base station to transmit data to the destination terminal device. That is, the centralized base station CU1 transmits the communication data received from the communication control device 1 to the above-identified distributed base station, and further controls (instructs) the distributed base station so that the communication data received by the distributed base station is transmitted to the destination terminal device.

[0134] As described above, the centralized base station CU1 executes the distribution process.

[0135] In the case of step S55, since the value of QFI is "6" (it is determined that the communication packet received from the communication control device 1 is a communication packet of the eMBB communication flow), the process of step SA5 is executed. The centralized base station CU1 transmits the communication data received from the communication control device 1 to the identified distributed base station (the distributed base station directed to eMBB), and further controls (instructs) the distributed base station to transmit the communication data received by the distributed base station to the destination terminal device.

[0136] (Step S56): In step S56, the centralized base station CU1 transmits the communication data received from the communication control device 1 to the distributed base station determined by the distribution process. In the case of FIG. 7, since the communication data received by the centralized base station CU1 from the communication control device 1 is communication data of the eMBB communication flow, the communication data is transmitted from the centralized base station CU1 to the distributed base station directed to eMBB. Then, the distributed base station directed to eMBB that has received the communication data transmits (forwards) the communication data to the destination communication terminal. That is, the communication data of the eMBB communication flow is transmitted to as many distributed base stations directed to eMBB as possible, and is transmitted (forwarded) from the distributed base stations directed to eMBB to the destination terminal device.

[0137] In addition, when the base station directed to eMBB is in a situation where it cannot communicate with the destination terminal device, the communication data received by the centralized base station CU1 from the communication control device 1 is transmitted to a distributed base station not set to be directed to eMBB (in the case of FIG. 7, the distributed base station directed to URLLC). Then, the distributed base station that has received the communication data transmits (forwards) the communication data to the destination communication terminal.

[0138] By repeatedly executing the processes of S51 to S56, communication data for realizing an application that requires high-speed large-capacity communication is sent from the first server Svr1 to the destination terminal device (the terminal device that receives the service), and the application is provided to the destination terminal device.

[0139] (Step S61): In step S61, the second server Svr2 generates communication data having a ToS value (= 010010) set based on the application to be provided (high-reliability low-latency application), and transmits the generated communication data to the communication control device 1.

[0140] The communication control device 1 receives the communication data transmitted from the second server Svr2.

[0141] (Step S62): In step S62, the communication control device 1 executes communication data analysis processing on the communication data received from the second server Svr2. That is, the communication control device 1 executes analysis processing of the communication packet received from the second server Svr2 (for example, the data communication processing unit 11 of the communication control device 1 executes the analysis processing), and recognizes that the ToS value set by the second server Svr2 is "010010".

[0142] (Steps S63, S64): In step S63, the communication control device 1 determines a QFI corresponding to the ToS value (= 010010) obtained by the communication data analysis processing, and performs processing (QFI assignment processing) of assigning the determined QFI to the transmission packet to be transmitted to the centralized base station CU1 (setting the QFI). Since the ToS value obtained by the communication data analysis processing is "010010", the communication control device 1 refers to the correspondence data between the ToS value and the QFI value stored and held in the storage unit 14, and determines the value of the QFI corresponding to the ToS value to be "10" (determines QFI = 10, 5QI = 82). Then, the communication control device 1 causes communication to be executed by the communication flow with the determined QFI value (QFI = 10), that is, the URLLC communication flow. That is, the communication control device 1 generates a communication packet (a communication packet for eMBB communication flow (a packet for 5G communication)) in which a header (5G header) with the QFI value set to "10" is added to the data received from the second server Svr2, and transmits the generated communication packet to the centralized base station CU1 (step S54).

[0143] Then, the centralized base station CU1 receives communication packets (communication packets of the URLLC communication flow (5G communication packets)) transmitted from the communication control device 1 (step S64).

[0144] (Step S65): In step S65, the centralized base station CU1 performs a distribution process.

[0145] (Step SA1): In step SA1, the centralized base station CU1 performs an analysis process on the communication data (5G communication packets) received from the communication control device 1. That is, the centralized base station CU1 recognizes from the header of the communication data (5G communication packets) received from the communication control device 1 that the value of the QFI of the communication data is "6". Then, the centralized base station CU1 refers to the correspondence information between the QFI and the QoS profile stored in the storage unit 23, and recognizes that the QoS profile of the communication data with QFI = 10 has a 5QI value of "82", and from the corresponding QoS characteristics, the communication data with QFI = 10 is the communication data of a communication flow (URLLC communication flow) that requires high-reliability and low-latency communication.

[0146] The processing of steps SA2 to SA8 is the same as the processing described in the explanation of step S55.

[0147] The centralized base station CU1 performs a distribution process by executing the processing of steps SA1 to SA8.

[0148] In the case of step S65, since the value of the QFI is "10" (it is determined that the communication packet received from the communication control device 1 is a communication packet of the URLLC communication flow), the processing of step SA7 is executed, and the centralized base station CU1 transmits the communication data received from the communication control device 1 to a specific distributed base station (URLLC-oriented distributed base station), and further controls (instructs) the distributed base station so that the communication data received by the distributed base station is transmitted to the destination terminal device.

[0149] (Step S66): In step S66, the centralized base station CU1 transmits the communication data received from the communication control device 1 to the distributed base stations determined by the distribution process. In the case of FIG. 8, since the communication data received by the centralized base station CU1 from the communication control device 1 is the communication data of the URLLC communication flow, the communication data is transmitted from the centralized base station CU1 to the distributed base stations directed to URLLC. Then, the distributed base stations directed to URLLC that have received the communication data transmit (transfer) the communication data to the communication terminals of the destinations. That is, the communication data of the URLLC communication flow is transmitted to as many distributed base stations directed to URLLC as possible, and is transmitted (transferred) from the distributed base stations directed to URLLC to the terminal devices of the destinations.

[0150] In the case where the base station directed to URLLC is in a situation where it cannot communicate with the terminal device of the destination, the communication data received by the centralized base station CU1 from the communication control device 1 is transmitted to the distributed base stations not set to be directed to URLLC (in the case of FIG. 8, the distributed base stations directed to eMBB). Then, the distributed base station that has received the communication data transmits (transfers) the communication data to the communication terminal of the destination.

[0151] By repeatedly executing the processes of S61 to S66, communication data for realizing an application that requires high-reliability and low-latency communication is sent from the second server Svr2 to the terminal device (the terminal device that receives the service) of the destination, and the application is provided to the terminal device of the destination.

[0152] In the communication system 1000, by processing as described above, even in a situation where various communication traffics are mixed in the communication network, while considering the quality requirements, the communication flows are appropriately allocated to the distributed base stations, and by prioritizing the URLLC communication flow, the possibility of generating the eMBB communication flow that becomes a sacrifice can be reduced as much as possible.

[0153] Here, an example will be given to explain that in the communication system 1000, it is possible to reduce as much as possible the possibility that the eMBB communication flow that is sacrificed by prioritizing the URLLC communication flow occurs. The case shown in FIG. 5 will be described. For the case of FIG. 5, it is assumed that the radio bearers and communication flows are set as follows. (1) A radio bearer Wbr1e (radio bearer for eMBB) and a radio bearer Wbr1u (radio bearer for URLLC) are set from the centralized base station CU1 to the distributed base station DU1 (eMBB-oriented distributed base station). The URLLC radio bearer Wbr1u includes one URLLC communication flow (denoted as "Wbr1u.URLLC_flow(1)"), and the eMBB radio bearer Wbr1e includes three eMBB communication flows (denoted as "Wbr1e.eMBB_flow(1)", "Wbr1e.eMBB_flow(2)", "Wbr1e.eMBB_flow(3)"). (2) A radio bearer Wbr2u (radio bearer for URLLC) is set from the centralized base station CU1 to the distributed base station DU2 (URLLC-oriented distributed base station). The URLLC radio bearer Wbr2u includes four URLLC communication flows (denoted as "Wbr2u.URLLC_flow(1)", "Wbr2u.URLLC_flow(2)", "Wbr2u.URLLC_flow(3)", "Wbr2u.URLLC_flow(4)"). (3) A radio bearer Wbr3e (radio bearer for eMBB) and a radio bearer Wbr3u (radio bearer for URLLC) are set from the centralized base station CU1 to the distributed base station DU3 (eMBB-oriented distributed base station). The URLLC radio bearer Wbr3u includes one URLLC communication flow (denoted as "Wbr3u.URLLC_flow(1)"), and the eMBB radio bearer Wbr3e includes three eMBB communication flows (denoted as "Wbr1e.eMBB_flow(1)", "Wbr1e.eMBB_flow(2)", "Wbr1e.eMBB_flow(3)"). (U1) The terminal device UE1 performs eMBB communication (receives eMBB communication packets) through the eMBB communication flow Wbr1e.eMBB_flow(1) from the distributed base station DU1 (eMBB-oriented distributed base station). Also, the terminal device UE1 performs URLLC communication (receives URLLC communication packets) through the URLLC communication flow Wbr1u.URLLC_flow(1) from the distributed base station DU1 (eMBB-oriented distributed base station). (U2) The terminal device UE2 performs eMBB communication (receives eMBB communication packets) through the eMBB communication flow Wbr1e.eMBB_flow(2) from the distributed base station DU1 (eMBB-oriented distributed base station). Also, the terminal device UE1 performs URLLC communication (receives URLLC communication packets) through the URLLC communication flow Wbr2u.URLLC_flow(1) from the distributed base station DU2 (URLLC-oriented distributed base station). (U3) The terminal device UE3 performs eMBB communication (receives eMBB communication packets) through the eMBB communication flow Wbr1e.eMBB_flow(3) from the distributed base station DU1 (eMBB-oriented distributed base station). Also, the terminal device UE1 performs URLLC communication (receives URLLC communication packets) through the URLLC communication flow Wbr2u.URLLC_flow(2) from the distributed base station DU2 (URLLC-oriented distributed base station). (U4) The terminal device UE4 performs URLLC communication (receives URLLC communication packets) through the URLLC communication flow Wbr2u.URLLC_flow(3) from the distributed base station DU2 (URLLC-oriented distributed base station). Also, the terminal device UE4 performs eMBB communication (receives eMBB communication packets) through the eMBB communication flow Wbr3e.eMBB_flow(1) from the distributed base station DU3 (eMBB-oriented distributed base station). (U5) The terminal device UE5 performs URLLC communication (receives URLLC communication packets) from the distributed base station DU2 (URLLC-oriented distributed base station) through the URLLC communication flow Wbr2u.URLLC_flow(4). Also, the terminal device UE5 performs eMBB communication (receives eMBB communication packets) from the distributed base station DU3 (eMBB-oriented distributed base station) through the eMBB communication flow Wbr3e.eMBB_flow(2). (U6) The terminal device UE6 performs URLLC communication (receives URLLC communication packets) from the distributed base station DU2 (eMBB-oriented distributed base station) through the URLLC communication flow Wbr3u.URLLC_flow(1). Also, the terminal device UE6 performs eMBB communication (receives eMBB communication packets) from the distributed base station DU3 (eMBB-oriented distributed base station) through the eMBB communication flow Wbr3e.eMBB_flow(3).

[0154] Also, as shown in FIG. 13, a wireless resource (e.g., the wireless resource of a distributed base station) is represented by a rectangle taking the unit of the frequency domain vertically and the unit of the time domain horizontally. As shown in FIG. 13, the unit of the frequency domain is set to the resource block (RB) unit, and it is assumed that 1 resource block is equivalent to 12 sub-carriers. Also, as shown in FIG. 13, the unit of the time domain is set to the time slot unit, and it is assumed that 1 time slot is equivalent to 7 mini-slots (equivalent to 14 symbols). Note that this setting is an example, and the wireless resource may be represented in other formats.

[0155] When adopting the representation format of the wireless resource as shown in FIG. 13, the resource allocation unit of the eMBB communication flow is set to 1RB×1 time slot (=1RB×7 mini-slots) as shown in FIG. 14 (an example).

[0156] Also, when adopting the representation format of the wireless resource as shown in FIG. 13, the resource allocation unit of the URLLC communication flow is set to 1RB×1 mini-slot as shown in FIG. 14 (an example).

[0157] FIG. 16 is a diagram schematically showing the status of radio resources of each distributed base station in the prior art (when the distributed base station is not set to a directional distributed base station). In FIG. 16, terminal devices UE1 to UE6 are each shown in a state of receiving (1) data for one resource allocation unit of the eMBB communication flow (communication data of the eMBB communication flow) and (2) data for four resource allocation units of the URLLC communication flow (URLLC communication flow communication data) from the distributed base station.

[0158] In this case, as shown in FIG. 16, distributed base stations DU1 to DU3 each use radio resources corresponding to (1) data for two resource allocation units of the eMBB communication flow (communication data of the eMBB communication flow) and (2) data for eight resource allocation units of the URLLC communication flow (URLLC communication flow communication data). In FIG. 16, the rectangular diagram showing the usage state of the upper radio resources is displayed with an aspect ratio different from that of the diagrams representing the radio resources in FIGS. 13 to 15 for convenience of explanation.

[0159] The portion indicated by the dotted circle in FIG. 16 is the portion where the resources allocated for the eMBB communication flow are overwritten for allocation to the URLLC communication flow. As can be seen from FIG. 16, in the case of FIG. 16, among the resources allocated for the eMBB communication flow, resources for 12 RBs × 1 mini-slot are overwritten for allocation to the URLLC communication flow.

[0160] In the communication flow of URLLC, since low latency is required, radio resources can be allocated preferentially over the communication flow of eMBB. Therefore, by preferentially allocating resources for the URLLC communication flow as described above, the communication of the URLLC communication flow can be guaranteed. On the other hand, communication packets of the eMBB communication flow corresponding to the parts overwritten for allocation to the URLLC communication flow are likely to have errors. Then, the symbol sequence (or the entire packet) of the part where the error occurred is retransmitted, but this retransmission consumes additional radio resources. Also, since the radio resources used during retransmission are allocated with a particularly high priority, they cannot be allocated as resources for the URLLC communication flow. Therefore, if there are many parts of the resources allocated for the eMBB communication flow that are overwritten for allocation to the URLLC communication flow, the communication quality deteriorates.

[0161] Next, the case shown in FIG. 17 (when an eMBB-oriented distributed base station and a URLLC distributed base station are set) will be described. In the case shown in FIG. 17, the distributed base station DU1 and the distributed base station DU3 are set as eMBB-oriented distributed base stations, and the distributed base station DU2 is set as a URLLC-oriented distributed base station. Therefore, in this case, as much communication of the URLLC communication flow as possible is allocated to the URLLC-oriented distributed base station DU2. And as much communication of the eMBB communication flow as possible is allocated to the eMBB-oriented distributed base stations DU1 and DU3. Therefore, different from the prior art, the eMBB communication flow is less likely to be sacrificed by prioritizing the URLLC communication flow.

[0162] In Fig. 17, the part indicated by the dotted circle is the part where the resources allocated for the eMBB communication flow are overwritten for allocation to the URLLC communication flow. As can be seen from Fig. 17, in the case of Fig. 17, among the resources allocated for the eMBB communication flow, resources for 6 RBs × 1 mini-slot are overwritten for allocation to the URLLC communication flow. Compared with the case using the prior art (Fig. 16), the part of the resources allocated for the eMBB communication flow that is overwritten for allocation to the URLLC communication flow is considerably less.

[0163] In the communication system 1000, since the eMBB-oriented distributed base stations and URLLC distributed base stations are set, deterioration of communication quality can be appropriately prevented. That is, in the communication system 1000, each distributed base station performs role sharing so as to become a "distributed base station that accommodates as many eMBB communication flows as possible" or a "distributed base station that accommodates as many URLLC communication flows as possible". Therefore, the possibility of generating eMBB communication flows that are sacrificed by prioritizing URLLC communication flows can be dramatically reduced. As a result, deterioration of communication quality can be appropriately prevented.

[0164] As described above, in the communication system 1000, the server determines from the ToS value what QoS requirements the application it is trying to provide has, sets the corresponding QFI, and based on the set QFI, performs role sharing (determination of directivity (eMBB-oriented, URLLC-oriented)) of the distributed base stations in the RAN. Then, in the communication system 1000, the centralized base station CU1 transmits communication packets of the communication flows (communication flows that each distributed base station handles as many as possible) that each distributed base station is in charge of to the distributed base station that can handle as many as possible based on the directivity of the distributed base stations. Therefore, a communication flow with a high priority (for example, a URLLC communication flow) is prioritized, and a communication flow with a low priority (for example, an eMBB communication flow) is sacrificed, and it is possible to appropriately prevent the communication quality from deteriorating.

[0165] <<Modification Example>> Next, a modification of the first embodiment will be described. Note that the same parts as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0166] In the above embodiment, when the centralized base station CU1 determines the directivity (eMBB directivity, URLLC directivity) of the distributed base stations (in the case of FIG. 5, distributed base stations DU1 to DU3) that are communicably connected to the centralized base station CU1, the case of randomly determining and the case of assuming manual setting in advance were described. In the communication system of this modification, based on the operation log of the communication between the distributed base station and the terminal device, the directivity (eMBB directivity, URLLC directivity) of each distributed base station is determined. Otherwise, the communication system of this modification is the same as the communication system 1000 of the first embodiment.

[0167] For example, the case shown in FIG. 18 will be described.

[0168] FIG. 18 is a diagram for explaining a method of determining the directivity (eMBB directivity, URLLC directivity) of each distributed base station based on the operation log of the communication between the distributed base station and the terminal device, and schematically shows three distributed base stations A, B, and C and six terminal devices UE1 to UE6 included in the communication system of this modification.

[0169] In FIG. 18, it is assumed that UE1 to UE3 are often connected (the connection probability is high) in pairs of the distributed base stations A and B, and UE4 to UE6 are often connected (the connection probability is high) in pairs of the distributed base stations B and C.

[0170] In such a case, the centralized base station CU1 of the communication system of this modification (assuming that the centralized base station CU1 is a centralized base station that generalizes (controls) the distributed base stations A to C) can collect log information from the distributed base stations A to C on which terminal device each distributed base station is communicating with. Therefore, by referring to the log information, the centralized base station CU1 can know which pair of the distributed base stations a specific terminal device is highly likely to be connected to.

[0171] The centralized base station CU1 of the communication system of this modification example sets the distributed base stations that are likely to be connected in pairs to have different directivities based on the log information indicating which terminal devices each distributed base station is communicating with.

[0172] In the case of FIG. 18, it can be known from the log information that UE1 to UE3 are often connected (with a high connection probability) in pairs with distributed base stations A and B, and UE4 to UE6 are often connected (with a high connection probability) in pairs with distributed base stations B and C. Therefore, based on the log information, the centralized base station CU1 sets the distributed base stations A and B, which are distributed base stations that are likely to be connected in pairs, to have different directivities from each other, and also sets the distributed base stations B and C, which are distributed base stations that are likely to be connected in pairs, to have different directivities from each other.

[0173] For example, in the case of FIG. 18, based on the log information, the centralized base station CU1 (1) sets the distributed base station A as an eMBB-oriented distributed base station, (2) sets the distributed base station B as a URLLC-oriented distributed base station, (3) sets the distributed base station C as an eMBB-oriented distributed base station.

[0174] Thereby, in the communication system of this modification example, even when there is a large amount of communication of different types of communication flows, the directivity of the distributed base stations can be appropriately determined, and by performing communication with the distributed base stations whose roles are shared by directivity, the deterioration of communication quality can be effectively prevented.

[0175] [Other Embodiments] In the communication system 1000, and / or the communication control device 1 and the centralized base station CU1 described in the above embodiments (including the modification example), each block may be individually integrated into one chip by a semiconductor device such as an LSI, or may be integrated into one chip so as to include part or all of them.

[0176] ​Here, an LSI is used as an example, but depending on the degree of integration, it may also be referred to as an IC, a system LSI, a super LSI, or an ultra LSI.

[0177] In addition, the method of integrating circuits is not limited to LSI, and it may also be realized by a dedicated circuit or a general-purpose processor. After manufacturing the LSI, an FPGA (Field Programmable Gate Array) that can be programmed, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used.

[0178] Also, part or all of the processing of each functional block in the above embodiments may be realized by a program. And part or all of the processing of each functional block in the above embodiments is performed by a central processing unit (CPU) in a computer. Also, the program for performing each process is stored in a storage device such as a hard disk or a ROM, and is read out and executed in the ROM or in the RAM.

[0179] Also, each process in the above embodiments may be realized by hardware, or may be realized by software (including the case where it is realized together with an OS (operating system), middleware, or a predetermined library). Furthermore, it may be realized by a mixed process of software and hardware.

[0180] For example, when each functional unit in the above embodiments is realized by software, a hardware configuration shown in FIG. 19 (for example, a hardware configuration in which a CPU (including a GPU), a ROM, a RAM, an input unit, an output unit, etc. are connected by a bus Bus) may be used to realize each functional unit by software processing.

[0181] Also, the execution order of the processing method in the above embodiments is not necessarily limited to the description in the above embodiments, and the execution order can be changed without departing from the gist of the invention.

[0182] A computer program that causes a computer to execute the above-described method and a computer-readable recording medium on which the program is recorded are included in the scope of the present invention. Here, examples of the computer-readable recording medium include a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a large-capacity DVD, a next-generation DVD, and a semiconductor memory.

[0183] The above computer program is not limited to that recorded on the above recording medium, and may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, or the like. Note that the specific configuration of the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the gist of the invention.

Explanation of Reference Numerals

[0184] 1000 Communication system Svr1 First server Svr2 Second server 1 Communication control device CU1 Aggregation base station DU1~DUm Distributed base stations UE1~UEn Terminal devices

Claims

1. A communication processing method used in a communication system including a server that provides a predetermined application, a communication control device, an aggregation base station, and a plurality of distributed base stations, comprising: a directivity setting step in which the aggregation base station sets a communication flow directivity that is a criterion for determining the allocation of communication flows handled by the distributed base stations managed by the aggregation base station and the role sharing of the distributed base stations; a QoS flow identifier determination step in which the communication control device analyzes a header of a communication packet transmitted from the server, specifies a QoS requirement required for the server to provide the application, and determines a QoS flow identifier for setting a communication flow that satisfies the specified QoS requirement; a sorting process step in which the aggregation base station analyzes communication packets of each communication flow transmitted from the communication control device to obtain the QoS flow identifier of the communication flow of the communication packet, specifies QoS characteristics corresponding to the obtained QoS flow identifier, and based on the specified QoS characteristics, executes a sorting process for determining a distributed base station to which the communication packet received from the communication control device is to be transmitted; a data transmission step in which the aggregation base station transmits the communication packet received from the communication control device to the distributed base station determined as the transmission destination by the sorting process; characterized in that: The communication flow directivity set in the directivity setting step is: (1) eMBB directivity which is an index for determining the role sharing of the distributed base stations so as to handle many eMBB communication flows which are communication flows satisfying QoS requirements for realizing high-speed large-capacity communication; and (2) URLLC directivity which is an index for determining the role sharing of the distributed base stations so as to handle many URLLC communication flows which are communication flows satisfying QoS requirements for realizing highly reliable low-latency communication; including: The aggregation base station controls the distributed base stations set with the eMBB directivity to process many eMBB communication flows, and controls the distributed base stations set with the URLLC directivity to process many URLLC communication flows. A communication processing method.

2. A QoS flow identifier-QoS profile correspondence information transmission step in which the communication control device transmits data including correspondence information between the QoS flow identifier and a QoS profile capable of specifying QoS characteristics corresponding to the QoS flow identifier to the aggregated base station The communication processing method according to claim 1, further comprising the above.

3. The directivity setting step is The aggregated base station acquires communication log information of a terminal device that is a communication partner of the distributed base station from the distributed base station, and based on the communication log information, detects a pair of the distributed base stations with a high probability of communicating with one terminal device, and based on the detection result, sets the communication flow directivity handled by the distributed base station. The communication processing method according to claim 1 or 2.

4. A program for causing a computer to execute the communication processing method according to any one of claims 1 to 3.

5. A communication system including a server that provides a predetermined application, a communication control device, an aggregated base station, and a plurality of distributed base stations, The aggregated base station is executing a directivity setting step of setting a communication flow directivity that is a criterion for determining the allocation of communication flows handled by the distributed base stations managed by the aggregated base station and the role sharing of the distributed base stations, The communication control device is executing a QoS flow identifier determination step of analyzing a header of a communication packet transmitted from the server, specifying a QoS requirement required for the server to provide the application, and determining a QoS flow identifier for setting a communication flow that satisfies the specified QoS requirement, The aggregated base station is By analyzing the communication packets of each communication flow transmitted from the communication control device, obtaining the QoS flow identifier of the communication flow of the communication packet, specifying the QoS characteristics corresponding to the obtained QoS flow identifier, and based on the specified QoS characteristics, executing a distribution process step of determining a distributed base station to which the communication packet received from the communication control device is to be transmitted, and a data transmission step of transmitting the communication packet received from the communication control device to the distributed base station determined as the transmission destination by the distribution process, executing, The communication flow directivity set in the directivity setting step is An eMBB directivity, which is an index for determining the role sharing of the distributed base stations so as to handle many eMBB communication flows, which are communication flows satisfying QoS requirements for realizing high-speed large-capacity communication, and a URLLC directivity, which is an index for determining the role sharing of the distributed base stations so as to handle many URLLC communication flows, which are communication flows satisfying QoS requirements for realizing highly reliable low-latency communication, are included, the centralized base station controls the distributed base stations set with the eMBB directivity to process many eMBB communication flows, and controls the distributed base stations set with the URLLC directivity to process many URLLC communication flows. Communication system.

6. A communication control device used in the communication system according to claim 5, a QoS flow identifier determination step of analyzing the header of a communication packet transmitted from the server, specifying QoS requirements required for the server to provide the application, and determining a QoS flow identifier for setting a communication flow satisfying the specified QoS requirements; a QoS flow identifier - QoS profile correspondence information transmission step of transmitting data including correspondence information between the QoS flow identifier and a QoS profile capable of specifying QoS characteristics corresponding to the QoS flow identifier to the centralized base station; A communication control device that executes.

7. A centralized base station used in the communication system according to claim 5, a directivity setting step of setting a communication flow directivity, which is a criterion for determining the allocation of communication flows handled by the distributed base stations managed by the centralized base station and the role sharing of the distributed base stations; a sorting process step of analyzing the communication packets of each communication flow transmitted from the communication control device, obtaining the QoS flow identifier of the communication flow of the communication packet, specifying the QoS characteristics corresponding to the obtained QoS flow identifier, and determining, based on the specified QoS characteristics, the distributed base station to which the communication packet received from the communication control device is to be transmitted, and executing a sorting process; a data transmission step of transmitting the communication packet received from the communication control device to the distributed base station determined as the transmission destination by the sorting process; execute, The communication flow directivity set in the directivity setting step is An eMBB directivity, which is an index for determining the role sharing of the distributed base stations so as to handle many eMBB traffic flows, which are traffic flows satisfying QoS requirements for realizing high-speed large-capacity communication, and a URLLC directivity, which is an index for determining the role sharing of the distributed base stations so as to handle many URLLC traffic flows, which are traffic flows satisfying QoS requirements for realizing high-reliability low-latency communication, and including, executing a step of controlling the distributed base station set with the eMBB directivity so as to process many eMBB traffic flows, and controlling the distributed base station set with the URLLC directivity so as to process many URLLC traffic flows, a centralized base station.

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