Base station device, terminal device, and communication method

Abstract

A base station device (130) includes a wireless communication unit (131) and a control unit (134). The wireless communication unit (131) transmits video data to a terminal device (110) at a predetermined cycle. When a predetermined condition is satisfied by a difference between a receiving timing when the terminal device (110) periodically receives the video data and a display timing when the terminal device (110) displays the video data at a predetermined frame rate, the control unit (134) changes a setting about the receiving timing.

Description

[Technical field]

[0001] The present disclosure relates to a base station device, a terminal device, and a communication method. [Background technology]

[0002] A radio access method and a radio network for cellular mobile communication (hereinafter also referred to as "Long Term Evolution (LTE)", "LTE-Advanced (LTE-A)", "LTE-Advanced Pro (LTE-A Pro)", "New Radio (NR)", "New Radio Access Technology (NRAT)", "Evolved Universal Terrestrial Radio Access (EUTRA)", or "Further EUTRA (FEUTRA)") are being considered in the 3rd Generation Partnership Project (3GPP). In the following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, and NR includes NRAT and FEUTRA. In LTE, a base station device (base station, communication device) is also referred to as eNodeB (evolved NodeB), in NR, a base station device (base station, communication device) is also referred to as gNodeB, and in LTE and NR, a terminal device (mobile station, mobile station device, terminal, communication device) is also referred to as UE (User Equipment). LTE and NR are cellular communication systems in which a plurality of areas covered by a base station device are arranged in a cell shape. A single base station device may manage multiple cells.

[0003] NR has the characteristics of ultra-high speed, low latency, high reliability, and multiple simultaneous connections. As one of the use cases of NR that utilizes such characteristics, for example, utilization in services using Augmented Reality (AR) and Virtual Reality (VR) is being considered. For example, AR technology makes it possible to superimpose various forms of virtual content such as text, icons, or animations on real objects captured in an image of the real space and present them to the user. Non-Patent Documents 1 and 2 disclose use cases and (potential) requirements for services using Augmented Reality (AR) and Virtual Reality (VR) (e.g., AR / VR games). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TR 22.842, V17.1.0 (2019-09) 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on Network Controlled Interactive Services (Release 17) [Non-Patent Document 2] 3GPP TS 22.261 v17.0.1 (2019-10) 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Service requirements for next generation new services and markets (Release 17) Summary of the Invention [Problem to be solved by the invention]

[0005] NR is expected to transmit 4K and 8K video due to its characteristics of ultra-high speed, low latency, high reliability, and multiple simultaneous connections. In addition, wearable devices are expected to become widespread as a post-smartphone. Some use cases for wearable devices require consideration of not only ultra-high speed, but also low latency and high reliability. For example, in cases where VR content is displayed on a head mounted display (HMD) via wireless, it is important to keep the motion-to-photon latency within a certain value to prevent VR sickness. In this way, it is necessary to deliver video content that requires real-time performance so that it can be displayed stably.

[0006] Therefore, the present disclosure proposes a technique that contributes to realizing distribution of video content that can be displayed stably.

[0007] It should be noted that the above problem or objective is merely one of several problems or objectives that can be solved or achieved by several embodiments disclosed in this specification. [Means for solving the problem]

[0008] According to the present disclosure, there is provided a base station device. The base station device includes a wireless communication unit and a control unit. The wireless communication unit transmits video data to a terminal device at a predetermined cycle. The control unit changes a setting related to the reception timing when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a content delivery system according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram illustrating a configuration example of an information processing device according to an embodiment of the present disclosure. [Diagram 3]FIG. 2 is a diagram illustrating a configuration example of a base station device according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a diagram illustrating a configuration example of a terminal device according to an embodiment of the present disclosure. [Diagram 5] A diagram showing an example of 5G architecture. [Figure 6] FIG. 11 is a sequence diagram illustrating an example of a content delivery process according to an embodiment of the present disclosure. [Figure 7] FIG. 11 is a diagram for explaining an example of a rendering process according to an embodiment of the present disclosure. [Figure 8] FIG. 11 is a diagram for explaining another example of the rendering process according to an embodiment of the present disclosure. [Figure 9] FIG. 11 is a sequence diagram illustrating an example of a registration process according to an embodiment of the present disclosure. [Figure 10] A sequence diagram showing an example of a PDU session establishment process relating to an embodiment of the present disclosure. [Figure 11] 1 is a sequence diagram illustrating an example of an RRC_CONNECTED transition process according to an embodiment of the present disclosure. [Figure 12] FIG. 1 is a diagram for explaining an example of video data distribution by a content distribution system. [Figure 13] A diagram for explaining SPS reconfiguration by a base station device according to an embodiment of the present disclosure. [Figure 14] 11 is a flowchart showing the flow of an SPS reconfiguration process according to an embodiment of the present disclosure. [Figure 15] A diagram for explaining an example of SPS setting by a base station device according to an embodiment of the present disclosure. [Figure 16] A diagram for explaining an example of SPS setting by a base station device according to an embodiment of the present disclosure. [Figure 17] A diagram for explaining an example of SPS setting by a base station device according to an embodiment of the present disclosure. [Figure 18] 11 is a diagram for explaining a CG reconfiguration by a base station device according to an embodiment of the present disclosure. FIG. [Figure 19]11 is a diagram for explaining a CG reconfiguration by a base station device according to an embodiment of the present disclosure. FIG. [Figure 20] 11 is a diagram for explaining an example of a display process by a terminal device according to an embodiment of the present disclosure. FIG. [Figure 21] 11A and 11B are diagrams for explaining another example of the display process by the terminal device according to an embodiment of the present disclosure. [Figure 22] 11 is a diagram for explaining an example of a video data allocation process performed by a base station device according to an embodiment of the present disclosure. FIG. [Figure 23] 11 is a diagram for explaining an example of a video data allocation process performed by a base station device according to an embodiment of the present disclosure. FIG. [Figure 24] 11 is a diagram for explaining an example of a video data allocation process performed by a base station device according to an embodiment of the present disclosure. FIG. [Diagram 25] 11 is a diagram for explaining an example of a video data allocation process performed by a base station device according to an embodiment of the present disclosure. FIG. [Figure 26] This is an image of the rendering server and AR / VR client involved in rendering. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted.

[0011] In addition, in this specification and drawings, similar components of the embodiments may be distinguished by adding different alphabets after the same reference numerals. However, when there is no need to particularly distinguish between the similar components, only the same reference numerals are used.

[0012] One or more embodiments (including examples and modified examples) described below can be implemented independently. Meanwhile, at least a part of the embodiments described below may be implemented in appropriate combination with at least a part of another embodiment. These embodiments may include novel features different from each other. Thus, these embodiments may contribute to solving different purposes or problems and may provide different effects.

[0013] The explanation will be given in the following order. 1. Content distribution system configuration example 1.1. Example of the overall configuration of a content distribution system 1.2. Example of information processing device configuration 1.3. Example of base station equipment configuration 1.4. Example of terminal device configuration 1.5. Network architecture configuration example 2. Example of information processing in a content distribution system 2.1. Content distribution processing example 2.2. Rendering process example 2.3. Communication processing example 3.Technical challenges 4. Technical features 4.1.Resetting SPS 4.2.Multiple SPS Configuration 4.3.Resetting the CG 4.4. Timewarp Changes 4.5. Setting Priorities 5. Other embodiments 6. Application Examples 7. Conclusion

[0014] <<1. Example of a content distribution system configuration>> <1.1. Example of overall configuration of content distribution system> 1 is a diagram illustrating a configuration example of a content delivery system 100 according to an embodiment of the present disclosure. The content delivery system 100 is a system that delivers video content to a terminal device 110 via a wireless access network. Here, the wireless access network may be an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) or an NG-RAN (Next Generation Radio Access Network).

[0015] The content delivery system 100 includes a terminal device 110, a base station device 130, and an information processing device 150. In the content delivery system 100, video content is delivered from the information processing device 150 to the terminal device 110 via the base station device 130.

[0016] The terminal device 110 and the base station device 130 are connected via the above-mentioned wireless access network. The base station device 130 and the information processing device 150 may be connected via a wireless or wired access network.

[0017] The devices in the figure may be considered as devices in a logical sense, that is, some of the devices in the figure may be realized by a virtual machine (VM), a container, a Docker, etc., and these may be implemented on the same physical hardware.

[0018] Note that an LTE base station may be referred to as an eNodeB (Evolved Node B) or eNB. Also, an NR base station may be referred to as an NGRAN Node (Next Generation RAN node), gNodeB or gNB. Also, in LTE and NR, a terminal device (also referred to as a mobile station, mobile station device, or terminal) may be referred to as UE (User Equipment). Note that a terminal device is a type of communication device, and may also be referred to as a mobile station, mobile station device, or terminal.

[0019] In this embodiment, the concept of a communication device includes not only portable mobile devices (terminal devices) such as mobile terminals, but also devices installed in structures or mobile bodies. The structures and mobile bodies themselves may be considered as communication devices. The concept of a communication device also includes not only terminal devices, but also base station devices. A communication device is a type of processing device and information processing device. A communication device can also be referred to as a transmitting device or a receiving device.

[0020] [Information processing device] The information processing device 150 is a content management device that manages video content in the terminal device 110. The information processing device 150 is, for example, a personal computer, a workstation, or a game device. The information processing device 150 may also be a device collectively called a cloud server or an edge server.

[0021] [Base station equipment] The base station device 130 is a wireless communication device that wirelessly communicates with the terminal device 110. The base station device 130 is a type of communication device. The base station device 130 is also a type of information processing device.

[0022] The base station device 130 may be configured with a set of multiple physical or logical devices. For example, in the embodiment of the present disclosure, the base station device 130 may be divided into multiple devices, a BBU (Baseband Unit) and a RU (Radio Unit), and may be interpreted as a set of these multiple devices. Additionally or alternatively, in the embodiment of the present disclosure, the base station device 130 may be either or both of a BBU and a RU. The BBU and the RU may be connected by a predetermined interface (e.g., eCPRI). Additionally or alternatively, the RU may be called a Remote Radio Unit (RRU) or a Radio DoT (RD). Additionally or alternatively, the RU may be compatible with gNB-DU, which will be described later. Additionally or alternatively, the BBU may be compatible with gNB-CU, which will be described later. Additionally or alternatively, the RU may be a device formed integrally with an antenna. The antenna of the base station device 130 (e.g., an antenna formed integrally with the RU) may adopt an Advanced Antenna System and support MIMO (e.g., FD-MIMO) and beamforming. In the Advanced Antenna System, the antenna of the base station device 130 (e.g., an antenna formed integrally with the RU) may include, for example, 64 transmitting antenna ports and 64 receiving antenna ports. Furthermore, the antenna mounted on the RU may be an antenna panel composed of one or more antenna elements, and the RU may be equipped with one or more antenna panels. For example, the RU may be equipped with two types of antenna panels, a horizontally polarized antenna panel and a vertically polarized antenna panel, or two types of antenna panels, a right-handed circularly polarized antenna panel and a left-handed circularly polarized antenna panel. Furthermore, the RU may form and control an independent beam for each antenna panel.

[0023] Also, a plurality of base station devices 130 may be connected to each other. One or more base station devices 130 may be included in a radio access network (RAN). That is, the base station device 130 may simply be referred to as a RAN, a RAN node, an AN (Access Network), or an AN node. The RAN in LTE is called EUTRAN (Enhanced Universal Terrestrial RAN). The RAN in NR is called NGRAN. The RAN in W-CDMA (UMTS) is called UTRAN. The LTE base station device 130 is called eNodeB (Evolved Node B) or eNB. That is, the EUTRAN includes one or more eNodeBs (eNBs). Also, the NR base station device 130 is called gNodeB or gNB. That is, the NGRAN includes one or more gNBs. Furthermore, the EUTRAN may include a gNB (en-gNB) connected to a core network (EPC) in an LTE communication system (EPS). Similarly, the NGRAN may include an ng-eNB connected to a core network 5GC in a 5G communication system (5GS). Additionally or alternatively, when the base station device 130 is an eNB, gNB, or the like, it may be referred to as 3GPP Access. Additionally or alternatively, when the base station device 130 is a wireless access point (Access Point), it may be referred to as Non-3GPP Access. Additionally or alternatively, the base station device 130 may be a radio extension device called an RRH (Remote Radio Head). Additionally or alternatively, when the base station device 130 is a gNB, the base station device 130 may be referred to as a combination of the above-mentioned gNB CU (Central Unit) and gNB DU (Distributed Unit), or any of them. The gNB CU (Central Unit) hosts multiple upper layers (e.g., RRC, SDAP, PDCP) of the Access Stratum for communication with the UE. On the other hand, the gNB-DU hosts multiple lower layers (e.g., RLC, MAC, PHY) of the Access Stratum.That is, among the message information described later, RRC signaling (e.g., MIB, various SIBs including SIB1, RRCSetup message, RRCReconfiguration message) may be generated by the gNB CU, while DCI and various physical channels (e.g., PDCCH, PBCH) described later may be generated by the gNB-DU. Alternatively, among the RRC signaling, some configurations such as IE:cellGroupConfig may be generated by the gNB-DU, and the remaining configurations may be generated by the gNB-CU. These configurations may be transmitted and received via the F1 interface described later. The base station device 130 may be configured to be able to communicate with other base station devices 130. For example, when multiple base station devices 130 are eNBs or a combination of an eNB and an en-gNB, the base station devices 130 may be connected to each other via an X2 interface. Additionally or alternatively, when multiple base station devices 130 are gNBs or a combination of a gn-eNB and a gNB, the devices may be connected to each other via an Xn interface. Additionally or alternatively, when multiple base station devices 130 are a combination of a gNB CU (Central Unit) and a gNB DU (Distributed Unit), the devices may be connected to each other via the above-mentioned F1 interface. Message information (RRC signaling or information included in DCI) described below may be communicated between multiple base station devices 130 (e.g., via X2, Xn, or F1 interfaces).

[0024] Furthermore, as described above, the base station device 130 may be configured to manage multiple cells. A cell provided by the base station device 130 is called a serving cell. The serving cell includes a PCell (Primary Cell) and an SCell (Secondary Cell). When dual connectivity (e.g., EUTRA-EUTRA Dual Connectivity, EUTRA-NR Dual Connectivity (ENDC), EUTRA-NR Dual Connectivity with 5GC, NR-EUTRA Dual Connectivity (NEDC), NR-NR Dual Connectivity) is provided to a UE (e.g., a terminal device 110), a PCell and zero or more SCell(s) provided by a MN (Master Node) are called a Master Cell Group. Furthermore, the serving cell may include a PSCell (Primary Secondary Cell or Primary SCG Cell). That is, when dual connectivity is provided to a UE, a PSCell and zero or more SCell(s) provided by a SN (Secondary Node) are called a Secondary Cell Group (SCG). Unless a special configuration (e.g., PUCCH on SCell) is made, the physical uplink control channel (PUCCH) is transmitted on the PCell and PSCell, but not on the SCell. Radio Link Failure is also detected on the PCell and PSCell, but not on the SCell (does not need to be detected). As such, the PCell and PSCell have a special role among the Serving Cell(s), and are therefore also called Special Cells (SpCells). One cell may be associated with one Downlink Component Carrier and one Uplink Component Carrier. Furthermore, the system bandwidth corresponding to one cell may be divided into multiple bandwidth parts.In this case, one or more Bandwidth Parts (BWPs) may be configured for the UE, and one Bandwidth Part may be used by the UE as an Active BWP. In addition, the radio resources (e.g., frequency band, numerology (subcarrier spacing), slot format (Slot configuration)) that the terminal device 110 can use may differ for each cell, each component carrier, or each BWP.

[0025] [Terminal Device] The terminal device 110 is a wireless communication device that wirelessly communicates with the base station device 130. The terminal device 110 is, for example, a mobile phone, a smart device (a smartphone or a tablet), a PDA (Personal Digital Assistant), or a personal computer. The terminal device 110 may be a head mounted display or VR goggles that has a function of wirelessly transmitting and receiving data.

[0026] Furthermore, the terminal device 110 may be capable of sidelink communication with other terminal devices 110. When performing sidelink communication, the terminal device 110 may be able to use an automatic retransmission technique such as HARQ (Hybrid Automatic Repeat reQuest). The terminal device 110 may be capable of NOMA (Non Orthogonal Multiple Access) communication with the base station device 130. Note that the terminal device 110 may also be capable of NOMA communication in communication (sidelink) with other terminal devices 110. Also, the terminal device 110 may be capable of LPWA (Low Power Wide Area) communication with other communication devices (for example, the base station device 130 and other terminal devices 110). In addition, the wireless communication used by the terminal device 110 may be wireless communication using millimeter waves. Note that the wireless communication used by the terminal device 110 (including sidelink communication) may be wireless communication using radio waves, or may be wireless communication using infrared rays or visible light (optical wireless).

[0027] The terminal device 110 may simultaneously connect to multiple base station devices or multiple cells to perform communication. For example, when one base station device can provide multiple cells, the terminal device 110 can perform carrier aggregation by using a certain cell as a pCell and using another cell as an sCell. Also, when multiple base station devices 130 can provide one or multiple cells, the terminal device 110 can realize DC (Dual Connectivity) by using one or multiple cells managed by one base station device (MN (e.g., MeNB or MgNB)) as a pCell, or a pCell and sCell(s), and using one or multiple cells managed by the other base station device (SN (e.g., SeNB or SgNB)) as a pCell (PSCell), or a pCell (PSCell) and sCell(s). DC may be referred to as MC (Multi Connectivity).

[0028] When a communication area is supported via cells of different base station devices 130 (multiple cells having different cell identifiers or the same cell identifier), the multiple cells can be bundled together and communication can be performed between the base station device 130 and the terminal device 110 by using Carrier Aggregation (CA) technology, Dual Connectivity (DC) technology, or Multi-Connectivity (MC) technology. Alternatively, the terminal device 110 can communicate with the multiple base station devices 130 via the cells of the different base station devices 130 by using Coordinated Multi-Point Transmission and Reception (CoMP) technology.

[0029] The following is a specific description of the configuration of each device that constitutes the content distribution system 100. Note that the configuration of each device shown below is merely an example. The configuration of each device may be different from the configuration shown below.

[0030] <1.2. Example of configuration of information processing device> FIG. 2 is a diagram illustrating a configuration example of an information processing device 150 according to an embodiment of the present disclosure. The information processing device 150 is, for example, a device that manages or generates video content. The information processing device 150 includes a communication unit 151, a storage unit 152, and a control unit 153. Note that the configuration illustrated in FIG. 2 is a functional configuration, and the hardware configuration may be different from this. In addition, the functions of the information processing device 150 may be distributed and implemented in multiple physically separated configurations. For example, the information processing device 150 may be configured by multiple server devices.

[0031] The communication unit 151 is a communication interface for communicating with other devices. The communication unit 151 may be a network interface or a device connection interface. For example, the communication unit 151 may be a LAN (Local Area Network) interface such as a NIC (Network Interface Card), or a USB (Universal Serial Bus) interface configured with a USB host controller, a USB port, and the like. The communication unit 151 may be a wired interface or a wireless interface. The communication unit 151 functions as a communication means of the information processing device 150. The communication unit 151 communicates with the base station device 130 under the control of the control unit 153.

[0032] The storage unit 152 is a data readable / writable storage device such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, a hard disk, etc. The storage unit 152 functions as a storage unit of the information processing device 150. The storage unit 152 stores, for example, video content.

[0033] The control unit 153 is a controller that controls each unit of the information processing device 150. The control unit 153 is realized by a processor such as a central processing unit (CPU), a micro processing unit (MPU), or a graphics processing unit (GPU). For example, the control unit 153 is realized by the processor executing various programs stored in a storage device inside the information processing device 150 using a random access memory (RAM) or the like as a working area. The control unit 153 may be realized by an integrated circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The CPU, MPU, GPU, ASIC, and FPGA can all be considered as controllers.

[0034] The control unit 153 includes an inertial measurement information acquisition unit 1531, a video data generation unit 1532, and a radio resource allocation request unit 1533. Each block (the inertial measurement information acquisition unit 1531 to the radio resource allocation request unit 1533) constituting the control unit 153 is a functional block indicating a function of the control unit 153. These functional blocks may be software blocks or hardware blocks. For example, each of the above-mentioned functional blocks may be one software module realized by software (including a microprogram), or may be one circuit block on a semiconductor chip (die). Of course, each functional block may be one processor or one integrated circuit. The functional blocks may be configured in any manner. The control unit 153 may be configured in functional units different from the above-mentioned functional blocks.

[0035] The inertial measurement information acquisition unit 1531 acquires the inertial measurement information from the terminal device 110 via the base station device 130. The inertial measurement information is information related to inertia, and is, for example, acceleration information, angular velocity information, etc. of the terminal device 110, and information on a detection result (for example, the direction of the user's line of sight) detected by a sensor mounted on the terminal device 110. The inertial measurement information is, for example, information indicating a state of a user using the terminal device 110 (for example, the direction of the head or line of sight, etc.). As a more specific example, the information related to inertia may be the amount of change in each component in the yaw direction, pitch direction, and roll direction as the movement of the user's head. These components may be detected by a sensor mounted on the terminal device 110 (an acceleration sensor or an angular velocity sensor (gyro sensor)).

[0036] The video data generation unit 1532 determines a video area based on the acquired inertial measurement information, and generates video data to be distributed to the terminal device 110. The video data generation unit 1532 determines a video area to distribute video in the direction the user is looking based on the inertial measurement information, and generates video data.

[0037] The wireless resource allocation request unit 1533 requests the base station device 130 to allocate wireless resources to be used for transmitting video data.

[0038] The control unit 153 may acquire information related to an operation input by the user from the terminal device 110 via the base station device 130, determine an area of ​​a video based on the information related to the operation, and generate video data to be distributed to the terminal device 110. Here, the operation input by the user may be, for example, an operation in a game, an operation for remotely controlling or driving a device, or the like.

[0039] <1.3. Example of base station device configuration> Next, a description will be given of a configuration of the base station device 130. Fig. 3 is a diagram illustrating an example of a configuration of the base station device 130 according to an embodiment of the present disclosure.

[0040] The base station device 130 includes a communication unit 131, a storage unit 132, a network communication unit 133, and a control unit 134. Note that the configuration shown in Fig. 3 is a functional configuration, and the hardware configuration may be different from this. Also, the functions of the base station device 130 may be distributed and implemented in multiple physically separated components.

[0041] The communication unit 131 is a signal processing unit for wireless communication with other wireless communication devices (for example, the terminal device 110 and other base station devices 130). The communication unit 131 operates under the control of the control unit 134. When the other wireless communication device is the terminal device 110, the communication unit 131 may be a wireless transceiver compatible with one or more wireless access methods. For example, the communication unit 131 supports both NR and LTE. The communication unit 131 may support W-CDMA and cdma2000 in addition to NR and LTE. The communication unit 131 may also support communication using NOMA. When the other wireless communication device is another base station device 130, the communication unit 131 may be an X2 interface, an Xn interface, or an F1 interface.

[0042] The communication unit 131 includes a reception processing unit 1311, a transmission processing unit 1312, and an antenna 1314. The communication unit 131 may include a plurality of reception processing units 1311, a plurality of transmission processing units 1312, and a plurality of antennas 1314. When the communication unit 131 supports a plurality of radio access methods, each unit of the communication unit 131 may be configured separately for each radio access method. For example, the reception processing unit 1311 and the transmission processing unit 1312 may be configured separately for LTE and NR.

[0043] The reception processing unit 1311 processes an uplink signal received via an antenna 1314. The reception processing unit 1311 operates as a receiving unit that receives a received signal. The reception processing unit 1311 includes a radio receiving unit 1311a, a demultiplexing unit 1311b, a demodulating unit 1311c, and a decoding unit 1311d.

[0044] The radio receiving unit 1311a performs down-conversion, removal of unnecessary frequency components, control of amplification level, orthogonal demodulation, conversion to a digital signal, removal of a guard interval (cyclic prefix), extraction of a frequency domain signal by fast Fourier transform, etc. on the uplink signal. The demultiplexing unit 1311b separates uplink channels such as a PUSCH (Physical Uplink Shared Channel) and a PUCCH (Physical Uplink Control Channel) and an uplink reference signal from the signal output from the radio receiving unit 1311a.

[0045] The demodulator 1311c demodulates the received signal using a modulation method such as BPSK (Binary Phase Shift Keying) or QPSK (Quadrature Phase Shift Keying) for the modulation symbols of the uplink channel. The modulation method used by the demodulator 1311c may be 16QAM (Quadrature Amplitude Modulation), 64QAM, or 256QAM. In this case, the signal points on the constellation do not necessarily have to be equidistant. The constellation may be a non-uniform constellation (NUC).

[0046] The decoder 1311d performs a decoding process on the coded bits of the demodulated uplink channel. The decoded uplink data and uplink control information are output to the controller 134.

[0047] The transmission processing unit 1312 performs a transmission process of the downlink control information and the downlink data. In this manner, the transmission processing unit 1312 is an acquisition unit that acquires, for example, a bit sequence of the downlink control information, the downlink data, and the like from the control unit 134. The transmission processing unit 1312 includes an encoding unit 1312a, a modulation unit 1312b, a multiplexing unit 1312c, and a radio transmission unit 1312d.

[0048] The encoder 1312a encodes the downlink control information and downlink data input from the controller 134 using a coding method such as block coding, convolution coding, turbo coding, etc. The encoder 1312a may also encode the downlink control information and downlink data using a polar code or a low density parity check code (LDPC code).

[0049] The modulation unit 1312b modulates the coded bits output from the coding unit 1312a using a predetermined modulation method such as BPSK, QPSK, 16QAM, 64QAM, or 256QAM. In this case, the signal points on the constellation do not necessarily have to be equidistant. The constellation may be a non-uniform constellation.

[0050] The multiplexing unit 1312c multiplexes the modulation symbols of each channel and the downlink reference signal, and places the multiplexed symbols in a predetermined resource element. The radio transmitting unit 1312d performs various signal processing on the signal from the multiplexing unit 1312c. For example, the radio transmitting unit 1312d performs processing such as conversion from the time domain to the frequency domain by fast Fourier transform, addition of a guard interval (cyclic prefix), generation of a baseband digital signal, conversion to an analog signal, quadrature modulation, up-conversion, removal of unnecessary frequency components, and power amplification. The signal generated by the transmission processing unit 1312 is transmitted from an antenna 1314.

[0051] The storage unit 132 is a data readable / writable storage device such as a DRAM, an SRAM, a flash memory, a hard disk, etc. The storage unit 132 functions as a storage unit of the base station device .

[0052] The network communication unit 133 is a communication interface for communicating with a node (e.g., the information processing device 150) located at a higher level on the network. For example, the network communication unit 133 may be a LAN interface such as a NIC. Additionally or alternatively, the network communication unit 133 may be an S1 interface or an NG interface for connecting to a core network node. The network communication unit 133 may be a wired interface or a wireless interface. The network communication unit 133 functions as a network communication means of the base station device 130.

[0053] The control unit 134 is a controller that controls each unit of the base station device 130. The control unit 134 is realized by a processor (hardware processor) such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). For example, the control unit 134 is realized by the processor executing various programs stored in a storage device inside the base station device 130 using a RAM (Random Access Memory) or the like as a working area. The control unit 134 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The CPU, MPU, ASIC, and FPGA can all be considered as controllers.

[0054] The control unit 134 includes a radio resource allocation setting unit 1341. The blocks constituting the control unit 134 (the radio resource allocation setting unit 1341) are functional blocks indicating the functions of the control unit 134. The functional blocks may be software blocks or hardware blocks. For example, the above-mentioned functional blocks may be one software module realized by software (including a microprogram), or one circuit block on a semiconductor chip (die). Of course, the functional blocks may be one processor or one integrated circuit. The method of configuring the functional blocks is arbitrary. The control unit 134 may be configured in functional units different from the above-mentioned functional blocks.

[0055] The wireless resource allocation setting unit 1341 executes wireless resource allocation in response to, for example, a request from the information processing device 150. The wireless resource allocation setting unit 1341 may be, for example, a function called a scheduler.

[0056] <1.4. Example of terminal device configuration> Next, a description will be given of the configuration of the terminal device 110. Fig. 4 is a diagram illustrating an example of the configuration of the terminal device 110 according to an embodiment of the present disclosure.

[0057] The terminal device 110 includes a communication unit 111, a storage unit 112, an inertial measurement unit 114, a control unit 115, and a display unit 116. Note that the configuration shown in Fig. 4 is a functional configuration, and the hardware configuration may be different from this. Furthermore, the functions of the terminal device 110 may be distributed and implemented in multiple physically separated configurations.

[0058] The communication unit 111 is a signal processing unit for wireless communication with other wireless communication devices (e.g., base station device 130 and other terminal devices 110). The communication unit 111 operates under the control of a control unit 115. The communication unit 111 may be a wireless transceiver compatible with one or more wireless access methods. For example, the communication unit 41 is compatible with both NR and LTE. The communication unit 111 may be compatible with W-CDMA and cdma2000 in addition to NR and LTE. The communication unit 111 may also be compatible with communication using NOMA.

[0059] The communication unit 111 includes a reception processing unit 1111, a transmission processing unit 1112, a network communication unit 113, and an antenna 1114. The communication unit 111 may include a plurality of reception processing units 1111, a transmission processing unit 1112, and an antenna 1114. The configurations of the communication unit 111, the reception processing unit 1111, the transmission processing unit 1112, and the antenna 1114 are similar to those of the communication unit 131, the reception processing unit 1311, the transmission processing unit 1312, and the antenna 1314 of the base station device 130.

[0060] The storage unit 112 is a data readable / writable storage device such as a DRAM, an SRAM, a flash memory, a hard disk, etc. The storage unit 112 functions as a storage unit of the terminal device 110.

[0061] The network communication unit 113 is a communication interface for communicating with other devices connected via a network. For example, the network communication unit 113 is a LAN interface such as a NIC. The network communication unit 113 may be a wired interface or a wireless interface. The network communication unit 113 functions as a network communication means of the terminal device 110. The network communication unit 113 communicates with other devices under the control of the control unit 115. The other devices are, for example, a controller into which a user inputs information related to an operation.

[0062] The inertial measurement unit 114 is called an IMU (Inertial Measurement Unit) and is a device that detects three-axis angular velocity and acceleration. The inertial measurement unit 114 includes, for example, an acceleration sensor and a gyro sensor. In order to improve reliability, the inertial measurement unit 114 may be equipped with a magnetic field sensor, an air pressure sensor, a temperature sensor, and the like.

[0063] The acceleration information and angular velocity information detected by the inertial measurement device 114 are transmitted to the information processing device 150 as information related to inertia (inertial measurement information, an example of information related to the user).

[0064] Alternatively, the control unit 115 may calculate the state of the user (for example, the direction of the head or line of sight, etc.) based on the acceleration information and angular velocity information detected by the inertial measurement unit 114, and transmit the state of the user to the information processing device 150. The state of the user is, for example, information collectively called pose information.

[0065] The control unit 115 is a controller that controls each unit of the terminal device 110. The control unit 115 is realized by a processor such as a CPU, an MPU, or a GPU. For example, the control unit 115 is realized by the processor executing various programs stored in a storage device inside the terminal device 110 using a RAM or the like as a working area. The control unit 115 may be realized by an integrated circuit such as an ASIC or an FPGA. The CPU, the MPU, the GPU, the ASIC, and the FPGA can all be considered as controllers.

[0066] The control unit 115 includes a video application control unit 1151, a display area specification unit 1152, and a rendering unit 1153. Each block (video application control unit 1151 to rendering unit 1153) constituting the control unit 115 is a functional block indicating a function of the control unit 115. These functional blocks may be software blocks or hardware blocks. For example, each of the above-mentioned functional blocks may be one software module realized by software (including a microprogram), or may be one circuit block on a semiconductor chip (die). Of course, each functional block may be one processor or one integrated circuit. The functional blocks may be configured in any manner. The control unit 45 may be configured in functional units different from the above-mentioned functional blocks.

[0067] The video application control unit 1151 is a control unit that controls a video application that performs the playback of video content, etc. The video application control unit 1151 starts up the video application in response to, for example, an instruction from a user.

[0068] The display area specifying unit 1152 estimates the user's viewpoint using the information about inertia, and specifies the display area to be displayed on the display unit 116 from the acquired video data.

[0069] The rendering unit 1153 generates images to be displayed in each frame based on the video data acquired from the information processing device 150 and in accordance with the display area specified by the display area specification unit 1152, and edits the video.

[0070] The display unit 116 is a display device such as a display, and displays various information such as images generated by the rendering unit 1153. The display unit 116 is, for example, a non-transmissive type, a video see-through type, or an optical see-through type display. The display unit 116 plays back the video edited by the rendering unit 1153 by displaying images at a predetermined frame rate.

[0071] <1.5. Network architecture configuration example> Here, the architecture of a fifth generation mobile communication system (5G) will be described as an example of a communication system applied to the content delivery system 100 according to an embodiment of the present disclosure. FIG. 5 is a diagram showing an example of the 5G architecture. The 5G architecture includes a UE (User Equipment) 10, a RAN (Radio Access Network) / AN (Access Network) 230, a NGC (Next Generation Core) / 5GC (5G Core) 20, and a DN (Data Network) 240.

[0072] The 5GC / NGC20 is also called the 5G core network. The 5GC / NGC20 is connected to the UE10 via the RAN / AN230.

[0073] The RAN 230 is a base station device that provides a wireless interface, and the AN 230 is, for example, an access point or a router that provides a wired interface. The RAN / AN 230 includes a base station device called a gNB or an ng-eNB.

[0074] The 5GC / NGC 20 is configured to include a control plane function group 21 and a UPF (User Plane Function) 220 .

[0075] The control plane function group 21 includes an AUSF (Authentication Server Function) 201, a NEF (Network Exposure Function) 202, a NRF (Network Repository Function) 203, a NSSF (Network Slice Selection Function) 204, a PCF (Policy Control Function) 205, a SMF (Session Management Function) 206, a UDM (Unified Data Management) 207, an AF (Application Function) 208, and an AMF (Access Management Function) 209.

[0076] The UDM 207 has a function of generating 3GPP AKA authentication information and processing a user ID. The UDM 207 includes a UDR (Unified Data Repository) that holds and manages subscriber information, and an FE (Front End) unit that processes the subscriber information.

[0077] In addition, the AMF 209 has functions such as registration processing, connection management, and mobility management for the UE 10.

[0078] The SMF 206 has functions such as session management, IP allocation and management of the UE 10, etc. The AUSF 201 has an authentication function. The NSSF 204 has a function related to network slice selection. The NEF 202 has a function of providing network function capabilities and events to third parties, the AF 208, and edge computing functions.

[0079] The NRF 203 has a function of discovering network functions and maintaining a profile of the network functions. The PCF 205 has a function of policy control. The AF 208 has a function of interacting with the core network to provide services.

[0080] Also, UPF (User Plane Function) 220 has a function of processing the user plane. DN 240 is, for example, an entity that provides a connection to an operator's own service such as an MNO (Mobile Network Operator), an entity that provides an Internet connection, or an entity that provides a connection to a third-party service.

[0081] Here, Namf is a service-based interface provided by the AMF 209, and Nsmf is a service-based interface provided by the SMF 206. Furthermore, Nnef is a service-based interface provided by the NEF 202, and Npcf is a service-based interface provided by the PCF 205. Nudm is a service-based interface provided by the UDM 207, and Naf is a service-based interface provided by the AF 208. Nnrf is a service-based interface provided by the NRF 203, and Nnssf is a service-based interface provided by the NSSF 204. Nausf is a service-based interface provided by the AUSF 201. Each of these NFs (Network Functions) exchanges information with other NFs via each service-based interface.

[0082] Furthermore, N1 is a reference point between the UE 10 and the AMF 209, and N2 is a reference point between the RAN / AN 230 and the AMF 209. N4 is a reference point between the SMF 206 and the UPF 220, and information is exchanged between these network functions (NFs).

[0083] An example of the UE 10 is the terminal device 110 of this embodiment. An example of the RAN / AN 230 is the base station device 130 of this embodiment.

[0084] Furthermore, the information processing device 150 may be an edge server installed within 5GC / NGC20 (or installed in the vicinity of 5GC / NGC20), or a cloud server (not shown), or it may be a cloud server installed on the Internet.

[0085] Alternatively, the information processing device 150 may be composed of a plurality of devices including, for example, a 5GC. In this case, the inertial measurement information acquisition unit 1531 may be implemented in the AF 208, and the radio resource allocation request unit 1533 may be implemented as one function of the AMF 209 or the SMF 206. The video data generation unit 1532 corresponds to an edge server installed in the 5GC / NGC 20, or a cloud server (not shown), or a cloud server (not shown) installed in the Internet. Also, the video data generation unit 1532 may be implemented in the AF 208.

[0086] <<2. Example of information processing in content distribution system>> Next, an example of information processing executed by the content distribution system 100 will be described. <2.1. Content distribution processing example> FIG. 6 is a sequence diagram illustrating an example of a content distribution process according to an embodiment of the present disclosure.

[0087] First, the terminal device 110 starts a video application in response to, for example, a user instruction (step S101), and requests the information processing device 150 to deliver video content specified by the video application via the base station device 130 (step S102).

[0088] The terminal device 110 measures information related to inertia (step S103), and transmits the measured information related to inertia to the information processing device 150 via the base station device 130 (step S104). Note that the processes of steps S103 and S104 are executed in a fixed or variable cycle, or in response to an event.

[0089] The information processing device 150 determines an area of ​​the moving image to be transmitted to the terminal device 110 based on the acquired information related to the inertia (step S105), and generates moving image data of the determined area (step S106).

[0090] The information processing device 150 transmits the generated video data to the terminal device 110 via the base station device 130 (step S107).

[0091] The terminal device 110 determines a display area for the acquired video data based on the latest measured inertia-related information (step S108). The terminal device 110 generates images to be displayed in each frame from the acquired video data according to the determined display area, edits the video, and displays the video on the display unit 116 (step S109).

[0092] <2.2. Rendering process example> Next, an example of a rendering process executed by the terminal device 110 will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining an example of the rendering process according to an embodiment of the present disclosure. The rendering process described here is executed, for example, in step S109 in Fig. 6.

[0093] FIG. 7 shows the display timing of an image (hereinafter also referred to as a frame image) generated by terminal device 110, in other words, the timing of displaying a frame image.

[0094] The terminal device 110 displays moving images on the display unit 116 by updating (generating) frame images, which are still images, at a period corresponding to the frame rate.

[0095] For example, when the frame rate is K [fps], K frame images #n (n is an integer equal to or greater than 1 and equal to or less than (K+1)) are generated per second and displayed on the display unit 116. In this case, the update period of the frame images is 1 / K seconds.

[0096] Next, another example of the rendering process executed by the terminal device 110 will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining another example of the rendering process according to an embodiment of the present disclosure. The rendering process described here is executed, for example, in step S109 in Fig. 6.

[0097] When rendering a frame image, a technique called time warp may be used to draw the frame image. Time warp is a technique for generating an image of a predicted display area based on acquired video data and the latest inertia-related information in order to keep the motion-to-photon latency within a certain value. As one application example of this time warp, the rendering unit 1153 sets the frame rate displayed on the display unit 116 to m times (m>1) the frame rate of the video data acquired from the information processing device 150.

[0098] In addition, the rendering unit 1153 may apply time warping to the drawing of each frame image in order to keep the motion-to-photon latency within a certain value in a delay environment caused by wireless communication between the information processing device 150 and the terminal device 110.

[0099] Here, in VR, it is known that a phenomenon called VR sickness occurs due to a "gap" between the screen seen in front of the user on a head-mounted display (HMD) and the user's physical senses. For example, when a user turns around and the scenery on the screen changes, the scenery actually displayed on the HMD in front of the user may be displayed with a slight delay from the scenery that the user thinks it should be like. Such a delay is called motion-to-photon latency. Alternatively, when a user moves while recognizing the depth (space), the scenery actually displayed on the HMD in front of the user may be shifted from the scenery that the user thinks he or she will see after the movement. When such a delay or gap occurs, VR sickness is likely to occur.

[0100] A known method for improving this VR sickness is to increase the frame rate of the frame images displayed on the display unit. By increasing the frame rate, the difference between the scenery that the user expects and the scenery that is actually displayed on the display unit becomes smaller, and the occurrence of VR sickness can be suppressed.

[0101] Furthermore, by applying the above-mentioned time warping, VR sickness can be improved by reducing the motion-to-photon latency.

[0102] In the rendering process described with reference to Fig. 7, the frame rate is K [fps], and frame images are updated every 1 / K seconds. More specifically, terminal device 110 generates frame images #1, #2, ... every 1 / K seconds from video data acquired from information processing device 150. At this time, terminal device 110 generates frame images #1, #2, ... using the video data acquired each time.

[0103] Therefore, when the terminal device 110 attempts to increase the frame rate in order to suppress the occurrence of VR sickness, for example, it is necessary to shorten the period for acquiring video data, which increases the load on wireless communication.

[0104] Therefore, the terminal device 110 uses a time warp technique to increase the frame rate of the frame images displayed on the display unit 116 without changing the cycle for acquiring video data from the information processing device 150.

[0105] As shown in FIG. 8, the terminal device 110 generates a frame image #1 using the acquired video data D1 and displays it on the display unit 116. The terminal device 110 also generates a frame image #1-1 using the acquired video data D1 and displays it on the display unit 116. At this time, the terminal device 110 uses the latest information related to inertia to perform a time warp process on the video data D1 to generate the frame image #1-1. The terminal device 110 uses the latest information related to inertia to determine the user's viewpoint or a field of view including the viewpoint, and determines a display area based on the determined line of sight direction. This display area is also called a viewport. The terminal device 110 extracts the determined display area from the video data D1 to generate a frame image #1-1. In this case, the information related to inertia can be measured, for example, at a period shorter than the display period of the frame image displayed on the display unit 116.

[0106] In this way, the terminal device 110 generates multiple frame images from one video data using the latest inertia-related information measured at different times, thereby increasing the frame rate without shortening the acquisition period of the video data. For example, in FIG. 8, the terminal device 110 generates two frame images #1 and #1-1 from one video data D1. This allows the terminal device 110 to shorten the period (hereinafter also referred to as the frame period) of display on the display unit 116 to 1 / 2 compared to the case where one frame image #1 is generated from one video data D1.

[0107] The terminal device 110 can reduce the motion-to-photon latency and suppress VR sickness by reflecting the change in the information related to inertia in the same video data and shortening the frame period. The method of reflecting the change in the information related to inertia in the same video data in this way is called the above-mentioned time warp or asynchronous time warp (ATW). By applying this time warp or asynchronous time warp, it is possible to reduce the motion-to-photon latency and shorten the frame period.

[0108] <2.3. Communication processing example> Next, an example of communication processing executed in the content delivery system 100 will be described with reference to Figures 9 to 11. As described above with reference to Figure 5, the content delivery system 100 employs the NR network architecture.

[0109] Here, in the NR network architecture, for example, registration with the 5GC / NGC 20 is performed so that the UE 10 can receive services via the 5GC / NGC 20. The UE 10 selects, for example, a PLMN (Public Land Mobile Network) corresponding to the 5GC / NGC 20, and executes a registration procedure.

[0110] Hereinafter, an example of communication processing, including the registration processing, performed for the UE 10 to receive a service provided via the 5GC / NGC 20 will be described with reference to Figs.

[0111] (Registration process) First, a registration process performed by the UE 10 will be described with reference to Fig. 9. Fig. 9 is a sequence diagram showing an example of the registration process according to the embodiment of the present disclosure.

[0112] 9, UE 10 in RM-DEREGISTERED state, i.e., unregistered state in 5GC / NGC 20, transmits a registration request message to RAN / AN 230 to perform initial registration (step S301). At this time, UE 10 transmits the registration request message including UE identity.

[0113] If the UE has a valid EPS GUTI, the UE identity is the 5G-GUTI mapped from the EPS GUTI. Here, EPS (Evolved Packet System) refers to the 4G system equivalent to LTE (Long Term Evolution) and consists of EUTRAN and EPC. From the viewpoint of security, the EPS GUTI (Globally Unique Temporary Identifier) ​​is a temporary ID used to identify the UE within the EPS, instead of an ID uniquely assigned to each UE, such as an IMSI (International Mobile Subscriber Identity) or an IMEI (International Mobile Equipment Identity).

[0114] Alternatively, the UE identity is a PLMN-specific 5G-GUTI assigned by the PLMN to which the UE 10 is attempting to register, if available.

[0115] Alternatively, the UE identity is a PLMN-specific 5G-GUTI, if available, assigned by the PLMM which is treated as an equivalent PLMN to the PLMN (Public Land Mobile Network) to which the UE 10 is attempting to register.

[0116] Alternatively, the UE identity is a PLMN-specific 5G-GUTI assigned by any PLMN, if available.

[0117] Otherwise, the UE 10 includes a Subscription Concealed Identifier (SUCI) in the registration request message, where the SUCI is an encrypted version of a Subscription Permanent Identifier (SUPI), which is an ID uniquely assigned to each UE 10.

[0118] The UE 10 includes in the registration request message a mapping of each S-NSSAI (Single NSSAI) of the Requested NSSAI with the S-NSSAIs of the Home PLMN (HPLMN). This allows the UE 10 to check whether the S-NSSAI(s) of the Requested NSSAI (Network Slice Selection Assistance Information) are allowed based on the Subscribed S-NSSAIs.

[0119] In addition, if the UE 10 uses the Default Configured NSSAI, the UE 10 includes a Default Configured NSSAI Indication in the registration request message.

[0120] Here, the S-NSSAI consists of a mandatory SST (Slice / Service Type) that identifies the slice type, and an optional SD (Slice Differentiator) that distinguishes different slices in the same SST. Note that the mandatory SST is 8 bits, and the optional SD is 24 bits.

[0121] In addition, all or each of the services for AR, VR, MR (Mixed Reality), SR (Substitutional Reality), and XR (X Reality or extended reality) applications may be defined as a slice identified by this S-NSSAI. In other words, the services for AR, VR, MR, SR, and XR applications may be realized by one or more network slices. That is, the services for AR, VR, MR, SR, and XR applications may be associated with one or more S-NSSAI.

[0122] Here, AR is also called augmented reality, and is a technology that extends a virtual world, such as 3D images and characters created with CG (Computer Graphics), by overlaying it onto the real world.

[0123] VR, also known as virtual reality, is a technology that allows you to experience a virtual world using 360° images captured with CG and cameras.

[0124] MR, also known as mixed reality, is a technology that closely blends the real world with the virtual world to make the virtual world appear more realistic.

[0125] SR, also known as alternate reality, is a technology that allows users to perceive a virtual world as replacing the real world.

[0126] XR is a general term for technologies that create experiences that add some kind of change to the real world, including AR, VR, MR, and SR.

[0127] When the RAN / AN 230 receives a registration request message from the UE 10, it executes AMF Selection (step S302). If the registration request message does not include a 5G-S-TMSI (5G S-Temporary Mobile Subscription Identifier) ​​or a GUAMI (Globally Unique AMF Identifier), the RAN / AN 230 selects the AMF 209 based on the (R)AT (Radio Access Technology) and, if available, the Requested NSSAI. Alternatively, if the registration request message does not include a 5G-S-TMSI or a GUAMI, the RAN / AN 230 selects the AMF 209 based on the (R)AT (Radio Access Technology) and, if available, the Requested NSSAI.

[0128] If the RAN / AN 230 is an NG-RAN, the RAN / AN 230 transfers a registration request including the selected PLMN ID or a combination of a PLMN ID and a Network Identifier (NID) that identifies a Standalone Nonpublic Network (SNPN) to the AMF 209 (step S303).

[0129] If UE 10 has not provided SUCI to AMF 209, AMF 209 initiates an Identity Request process and sends an Identity Request message to UE 10 to request SUCI (step S304).

[0130] When the UE 10 receives the Identity Request message in step S304, the UE 10 responds with an Identity Response message including the SUCI (step S305). Here, the UE 10 can obtain the SUCI by using the public key of the HPLMN.

[0131] The AMF 209 executes AUSF Selection based on the SUPI or SUCI (step S306) and initiates authentication of the UE 10.

[0132] When the AUSF 201 receives an authentication request from the AMF 209, it must perform authentication of the UE 10.

[0133] The AUSF 201 selects the UDM 207 for authentication processing, and obtains authentication data from the UDM 207 .

[0134] When the UE 10 is authenticated, the AUSF 201 provides information regarding security to the AMF 209 .

[0135] If authentication is successful in the AMF 209, the AMF 209 initiates an NG Application Protocol (NGAP) process to provide a security context to the RAN / AN 230.

[0136] The RAN / AN 230 maintains the security context and returns a response to the AMF 209.

[0137] The RAN / AN 230 then uses this security context to protect messages exchanged with the UE 10.

[0138] The AMF 209 executes UDM Selection based on the SUPI and selects the UDM 207 (step S307).

[0139] The AMF 209 is registered with the UDM 207 using Nudm_UECM_Registration (step S308).

[0140] If the AMF 209 does not have subscriber information (Subscription Data) of the UE 10, it uses Nudm_SDM_Get (step S309) to acquire Subscription Data such as Access and Mobility Subscription data and SMF Selection Subscription data (step S310).

[0141] The AMF 209 generates a UE context after acquiring the Access and Mobility Subscription data from the UDM 207. The Access and Mobility Subscription data includes information indicating whether or not the NSSAI may be included in plaintext in the RRC Connection Establishment in 3GPP Access.

[0142] The AMF 209 transmits a registration accept to the UE 10 (step S311). The registration accept message includes a 5G-GUTI and a registration area. The N2 message including the registration accept message includes an allowed NSSAI.

[0143] Allowed NSSAIs include only S-NSSAIs that do not require Network Slice-Specific Authentication and Authorization based on subscriber information, or S-NSSAIs that have successfully completed Network Slice-Specific Authentication and Authorization based on the UE context of AMF209.

[0144] In addition, the AMF 209 may provide a list of equivalent PLMNs to the UE 10 registered in a PLMN, but the AMF 209 must not provide a list of equivalent PLMNs to the UE 10 registered in an SNPN.

[0145] UE10 sends a Registration Complete message to AMF209 to notify that a new 5G-GUTI has been allocated (step S312).

[0146] According to the above registration process, the UE 10 becomes registered with the 5GC / NGC 20, that is, becomes the RM-REGISTERED state.

[0147] (PDU session establishment process) Next, a PDU session establishment process performed by the UE 10 will be described with reference to Fig. 10. Fig. 10 is a sequence diagram showing an example of a PDU session establishment process according to an embodiment of the present disclosure.

[0148] As shown in Fig. 10, the UE 10 registered in the AMF 209 transmits a PDU Session Establishment Request message to the AMF 209 (step S401). Here, the PDU Session Establishment Request message includes an S-NSSAI corresponding to the requested service among the Allowed NSSAI, and a UE Requested DNN (Data Network Name). The UE Requested DNN is, for example, a DNN that enables connection to AR, VR, MR, SR, and XR services.

[0149] Upon receiving the PDU session establishment request message, AMF 209 executes SMF Selection (step S402). Here, if the PDU session establishment request message includes an S-NSSAI but does not include a DNN, the default DNN for this S-NSSAI is selected as the DNN. For example, assume that all or each of the services for AR, VR, MR, SR, and XR applications is defined as a slice identified by a specific S-NSSAI. In this case, the default DNN for a specific S-NSSAI is a DNN that enables connection to the AR, VR, MR, SR, and XR services.

[0150] The AMF 209 transmits an Nsmf_PDUSession_CreateSMContext Request including an S-NSSAI of the Allowed NSSAI to the selected SMF 206 (Step S403). Here, the Nsmf_PDUSession_CreateSMContext Request includes a SUPI, an S-NSSAI, and a UE Requested DNN or a DNN.

[0151] If the Session Management Subscription data corresponding to SUPI, DNN, and S-NSSAI is not available, the SMF 206 uses Nudm_SDM_Get to obtain the Session Management Subscription data from the UDM 207. The SMF 206 also uses Nudm_SDM_Subscribe to register to be notified when the Session Management Subscription data is updated.

[0152] Upon receiving the Nsmf_PDUSession_CreateSMContext Request, the SMF 206 creates an SM context if it can process the PDU session establishment request. Then, the SMF 206 responds with an Nsmf_PDUSession_CreateSMContext Response to the AMF 209, providing the SM Context ID (Step S404).

[0153] If it is necessary to perform a second authentication and authorization process by the DN-AAA server during the establishment of the PDU session, the SMF206 initiates a PDU Session establishment authentication / authorization process (step S405).

[0154] If dynamic Policy and Charging Control (PCC) is applied to the PDU session to be established, the SMF 206 performs PCF Selection (step S406). Otherwise, the SMF 206 may apply a local policy.

[0155] In addition, the SMF 206 may execute an SM Policy Association Establishment procedure to establish an SM Policy Association with the PCF 205 and obtain default PCC rules for the PDU session (step S407). This makes it possible to obtain the PCC rules before selecting the UPF 220.

[0156] The SMF 206 executes UPF Selection to select one or more UPFs 220 (step S408).

[0157] The SMF 206 transmits an N4 Session Establishment Request message to the selected UPF 220 (step S409).

[0158] The UPF 220 responds to the SMF 206 by returning an N4 Session Establishment Response message (step S410).

[0159] If multiple UPFs 220 are selected for the PDU session, this N4 session establishment process is initiated for each UPF 220.

[0160] The SMF 206 transmits a Namf_Communication_N1N2MessageTransfer message to the AMF 209 (step S411). Here, the Namf_Communication_N1N2MessageTransfer message includes a PDU Session ID, N2 SM information, CN Tunnel Info, an S-NSSAI of an Allowed NSSAI, and an N1 SM container. Here, the N2 SM information includes a PDU Session ID, QFI(s), QoS Profile(s), etc. Also, when multiple UPFs 220 are used for a PDU session, the CN Tunnel Info includes tunneling information related to the multiple UPFs 220 that terminate N3.

[0161] The N1 SM container includes a PDU Session Establishment Accept that the AMF 209 must provide to the UE 10. The PDU Session Establishment Accept also includes an S-NSSAI that is an Allowed NSSAI.

[0162] The Namf_Communication_N1N2MessageTransfer message includes a PDU Session ID so that the AMF 209 knows which access to use for the UE 10.

[0163] The AMF 209 transmits an N2 PDU Session Request message to the RAN / AN 230 (step S412). Here, the AMF 209 transmits a NAS (Non-Access-Stratum) message including a PDU Session ID and a PDU Session Establishment Accept with the UE 10 as the destination, and the N2 SM information received from the SMF 206 to the RAN / AN 230 via the N2 PDU Session Request message.

[0164] The RAN / AN 230 transfers a NAS message including the PDU Session ID and the N1 SM container to the UE 10 (step S413). Here, the N1 SM container includes a PDU Session Establishment Accept.

[0165] The RAN / AN 230 responds with an N2 PDU Session Response message to the AMF 209 (step S414).

[0166] The AMF 209 transfers the N2 SM information received from the RAN / AN 230 to the SMF 206 via a Nsmf_PDUSession_UpdateSMContext Request message including the SM Context ID and the N2 SM information (step S415).

[0167] The SMF 206 initiates an N4 Session Modification procedure between the SMF 206 and the UPF 220, and transmits an N4 Session Modification Request message to the UPF 220 (step S416). The SMF 206 provides the UPF 220 with AN tunneling information (AN Tunnel Info) in addition to the forwarding rule.

[0168] The UPF 220 returns an N4 Session Modification Response message to the SMF 206 (step S417). When multiple UPFs 220 are used in the PDU session, the above-mentioned N4 session modification procedure is performed on all UPFs 220 that terminate N3.

[0169] The PDU session is established according to the above process.

[0170] For each QoS flow, the QoS Profile must include QoS parameters, such as 5QI (5G QoS Identifier) ​​and ARP (Allocation and Retention Priority).

[0171] A QoS flow may be either "GBR (Guaranteed Bit Rate)" or "Non-GBR" depending on the QoS Profile.

[0172] For a Non-GBR QoS flow, the QoS Profile may include a QoS parameter called a Reflective QoS Attribute (RQA).

[0173] For GBR QoS flows, the QoS parameters must include the uplink and downlink Guaranteed Flow Bit Rate (GFBR) and Maximum Flow Bit Rate (MFBR).

[0174] 5QI is a set of parameters for access nodes to control the forwarding process of QoS flows, such as scheduling weights, admission thresholds, queue management thresholds, link layer settings, etc.

[0175] The ARP contains information about priority level, pre-emption capability, and pre-emption vulnerability.

[0176] The ARP priority level defines the relative importance of a QoS flow and can range from 1 to 15, with 1 being the highest importance.

[0177] The ARP pre-emption capability is a metric that defines whether a QoS flow can use resources that have already been allocated to another QoS flow with a lower priority level.

[0178] ARP pre-emption vulnerability is a metric that defines whether or not a QoS flow will give up resources allocated to it in order to allow other QoS flows with a higher priority level.

[0179] ARP pre-emption capability and ARP pre-emption vulnerability must be set to either "enabled" or "disabled".

[0180] (RRC_CONNECTED transition processing) Signaling between the UE 10 and the core network (e.g., AMF 209) is performed by NAS signaling. A NAS signaling connection is used to enable this NAS signaling.

[0181] The NAS signaling connection is composed of an AN signaling connection between the UE 10 and an Access Network (AN), and an N2 connection between the AN and the AMF 209. Here, the AN signaling connection is, for example, a Radio Resource Control (RRC) connection.

[0182] An RRC_CONNECTED transition process for transitioning the RRC state of the UE 10 from RRC_IDLE to RRC_CONNECTED will be described with reference to Fig. 11. Fig. 11 is a sequence diagram showing an example of the RRC_CONNECTED transition process according to an embodiment of the present disclosure. The RRC_CONNECTED transition process is activated by the UE 10 (an example of the terminal device 110) when transitioning from RRC_IDLE to RRC_CONNECTED.

[0183] First, it is assumed that the UE 10 is in an RRC_IDLE and CM-IDLE state (step S500). Here, the RRC_IDLE state is a state in which an RRC connection is not established with the base station device 130. The CM-IDLE state is a state in which an NAS signaling connection is not established with the AMF 209 via N1.

[0184] The UE 10 transmits an RRC Setup Request message via a Signaling Radio Bearer (SRB) 0 to establish a new connection with the base station device 130 (step S501).

[0185] When the UE 10 receives an RRC setup (RRC Setup) message from the base station apparatus 130 (step S502), the UE 10 transitions the RRC state from RRC_IDLE to RRC_CONNECTED, and maintains the CM-IDLE state as it is (step S503).

[0186] When the base station device 130 receives an RRC setup complete (RRCSetupComplete) message from the UE 10 (step S504), the base station device 130 completes the RRC setup process, and the UE 10 transitions to CM-CONNECTED (step S505).

[0187] The initial NAS message (INITIAL UE MESSAGE) from the UE 10 transmitted in the RRC setup complete (RRCSetupComplete) message is transmitted to the AMF 209 (step S506).

[0188] Here, the first NAS message is, for example, a Registration Request message (see step S301 in FIG. 9) or a PDU Session Establishment Request message (step S401 in FIG. 10). In addition, several NAS messages are exchanged between the UE 10 and the AMF 209.

[0189] The AMF 209 prepares UE context data and transmits the UE context data to the base station device 130 via an INITIAL CONTEXT SETUP REQUEST message (step S507). Here, the UE context data includes a PDU session context, a Security Key, UE Radio Capability, and UE Security Capabilities.

[0190] Base station device 130 transmits a SecurityModeCommand message to UE 10 (step S508), and when UE 10 transmits a SecurityModeComplete message to base station device 130 via SRB1 (step S509), base station device 130 activates AS (Access-Stratum) security.

[0191] In order to set up SRB2 and DRBs (Data Radio Bearers), base station device 130 transmits an RRC Reconfiguration message to UE 10 (step S510), and when UE 10 transmits an RRC Reconfiguration Complete message to base station device 130 via SRB1 (step S511), the RRC reconfiguration process is completed.

[0192] The base station device 130 transmits an initial context setup response message to the AMF 209 (step S512) to notify that the setup process has been completed.

[0193] (SPS-Config and ConfiguredGrantConfig settings) When the AMF 209 receives a PDU session establishment request message (see step S401 in FIG. 10) including an S-NSSAI (e.g., S-NSSAI1) corresponding to a specific service from the terminal device 110, the AMF 209 selects an SMF 206 for providing a service corresponding to this S-NSSAI 1. Here, the specific service is, for example, a service for an AR, VR, MR, SR, or XR application.

[0194] In addition, the SMF 206 selected to provide services corresponding to the S-NSSAI1 selects, for example, the PCF 205 and UPF 220 required to provide services for AR, VR, MR, SR, and XR applications.

[0195] Furthermore, for example, the base station device 130 may determine the SPS-Config and ConfiguredGrantConfig to be set for the downlink and uplink with the terminal device 110, respectively, in response to an instruction from the AMF 209.

[0196] The base station device 130 can configure the SPS-Config and the ConfiguredGrantConfig in the terminal device 110 via RRC. For example, the base station device 130 configures the SPS-Config and the ConfiguredGrantConfig in the terminal device 110 by transmitting an RRC reconfiguration message (see step S508 in FIG. 11) including the SPS-Config and the ConfiguredGrantConfig.

[0197] SPS-Config is used to configure downlink semi-persistent transmission. Multiple SPSs (Semi-Persistent Schedulings) can be configured for one BWP (Bandwidth Part) of a serving cell. Multiple SPSs are configured in SPS-ConfigList.

[0198] In addition to the above-mentioned method called Type 1 via RRC, the base station device 130 can also set the ConfiguredGrantConfig using a method called Type 2 via a PDCCH in which a CS-RNTI (Radio Network Temporary Identifier) ​​is specified.

[0199] The SPS-Config information element included in the RRC message includes fields called periodicity, periodicityExt, and SPS-ConfigIndex.

[0200] Here, if periodicityExt is not included in the SPS-Config information element, the periodicity is referenced, and if periodicityExt is included, the periodicity is ignored.

[0201] TS38.331 defines the following values ​​for the periodicity of SPS-Config: 10 ms, 20 ms, 32 ms, 40 ms, 64 ms, 80 ms, 128 ms, 160 ms, 320 ms, and 640 ms.

[0202] Also, regarding periodicityExt of SPS-Config, when SCS (Subcarrier Spacing) is 15 kHz, it is defined that any number of slots between 1 slot and 640 slots can be set as periodicityExt. When SCS is 30 kHz, it is defined that any number of slots between 1 slot and 1280 slots can be set as periodicityExt. When SCS is 60 kHz, it is defined that any number of slots between 1 slot and 2560 slots can be set as periodicityExt. When SCS is 120 kHz, it is defined that any number of slots between 1 slot and 5120 slots can be set as periodicityExt.

[0203] When SPS is configured, the MAC entity must determine that the Nth downlink allocation occurs in a slot (Slot#_N) in a System Frame Number (SFN) that satisfies the following equation (1).

[0204] (numberOfSlotsPerFrame×SFN+Slot#_N)= [(numberOfSlotsPerFrame×SFNinit+slotinit) + N × periodicity × numberOfSlotsPerFrame / 10] modulo(1024×numberOfSlotsPerFrame)...(1)

[0205] Here, numberOfSlotsPerFrame is the number of slots in a radio frame (e.g., 10 if the SCS is 15 kHz), and SFNinit and slotinit are the SFN and slot# at which the SPS was configured and the first PDSCH (Physical Downlink Shared Channel) transmission was performed, respectively.

[0206] In addition, a parameter numberOfSlotsPerSPS may be introduced to allocate multiple consecutive slots on the time axis as SPS resources. The MAC entity determines that the Nth downlink allocation occurs in numberOfSlotsPerSps consecutive slots starting from the slot (Slot#_N) in the SFN that satisfies the above formula (1).

[0207] The ConfiguredGrantConfig information element includes fields called periodicity, periodicityExt, and ConfiguredGrantConfigIndex.

[0208] Here, if periodicityExt is not included in the ConfiguredGrantConfig information element, the periodicity is referenced, and if periodicityExt is included, the periodicity is ignored.

[0209] In TS38.331, for example, when the SCS is 15 kHz, 2, 7, and n*14 symbols are defined as the periodicity of ConfiguredGrantConfig, where n is one of the following values: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, and 640.

[0210] Furthermore, regarding periodicityExt in ConfiguredGrantConfig, when the SCS is 15 kHz, for example, it is defined that any number of symbols between 1 symbol and 640 symbols can be set as periodicityExt, and a period of periodicityExt*14 symbols can be set.

[0211] When a CG (Configured Grant) is set, the MAC entity must determine that the Nth uplink allocation occurs at a symbol (Symbol#_N) in a Slot# of a System Frame Number (SFN) that satisfies the following equation (2).

[0212] [(SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot) +(Slot#×numberOfSymbolsPerSlot)+Symbol#_N]= (timeDomainOffset×numberOfSymbolsPerSlot+S+N×periodicity) modulo(1024×numberOfSlotsPerFrame×numberOfSymbolsPerSlot)...(2)

[0213] Here, numberOfSlotsPerFrame is the number of slots in a radio frame (for example, 10 when SCS is 15 kHz), and numberOfSymbolsPerSlot is the number of symbols in a slot (14 when Normal CP). In addition, timeDomainOffset and S are parameters obtained from SLIV (Start and length indicator value). timeDomainOffset is the offset value on the time axis of resources at SFN=0, and S is the symbol (Symbol#) to which PUSCH (Physical Uplink Shared Channel) is initially assigned.

[0214] In addition, a parameter numberOfSymbolsPerCg may be introduced to allocate multiple consecutive symbols on the time axis as CG resources. The MAC entity determines that the Nth uplink allocation occurs in the consecutive numberOfSymbolsPerCg symbols starting from the symbol (Symbol#_N) in Slot# in SFN that satisfies the above formula (2).

[0215] <<3.Technical issues>> Next, technical issues of the content delivery system 100 according to the embodiment of the present disclosure will be described, particularly focusing on the case where video data is transmitted by semi-persistent transmission.

[0216] Fig. 12 is a diagram for explaining an example of video data distribution by a content distribution system. In Fig. 12, video data is communicated between a base station device 130 and a terminal device 110 via an SPS. The terminal device 110 is also assumed to display video by doubling the frame rate using the above-mentioned time warp.

[0217] For example, in order to use an XR service, the terminal device 110, which is an HMD, sends a PDU session establishment request message including an S-NSSAI1 (see step S401 in FIG. 10) to the AMF 209. The AMF 209 that receives the PDU session establishment request message instructs the base station device 130 to set SPS-Config and ConfiguredGrantConfig in the downlink and uplink with the terminal device 110, respectively.

[0218] The terminal device 110 receives video data at a frame rate of, for example, 45 fps by downlink SPS (Semi-Persistent Scheduling) via the base station device 130. Hereinafter, the frame rate of the video data transmitted by the information processing device 150 is also referred to as a first frame rate.

[0219] Furthermore, the terminal device 110 transmits information relating to inertia measured by the inertial measurement device 114 via the base station device 130 by using a configured grant (CG) of the uplink.

[0220] Terminal device 110 utilizes time warping on the received video data of the first frame rate (45 fps) to display it as a video with a frame rate of, for example, 90 fps. Hereinafter, the frame rate of the video that terminal device 110 displays on display unit 116 is also referred to as a second frame rate.

[0221] Video data at the second frame rate (90 fps) is displayed on the display of the terminal device 110 at a cycle of 11.11 ms. Video data at the first frame rate (45 fps) is ideally received at a cycle of 22.22 ms. However, since the cycle of the SPS is set in slot units (1 ms when the SCS is 15 kHz), the cycle is set to the closest cycle, for example, 22 ms.

[0222] Here, a method for setting the SPS cycle will be described. Information related to the format including the frame rate of the video handled by the service corresponding to S-NSSAI1 is stored in, for example, a UDR (Unified Data Repository).

[0223] When establishment of a PDU session is requested to provide a service corresponding to S-NSSAI1, SMF206 obtains information regarding the format, including the frame rate, of the video handled by the service corresponding to S-NSSAI1 from the UDR and provides it to AMF209 via a NAS message.

[0224] The AMF 209 determines the cycle of the SPS from the acquired information related to the format of the video, and instructs the base station device 130 to set the SPS with the determined cycle.

[0225] Furthermore, the SMF 206 may determine the SPS period based on information related to the format including the frame rate of the video handled by the service corresponding to the S-NSSAI1 acquired from the UDR, and provide the SPS period to the base station device 130 via the AMF 209. For example, the SPS period may be included in the QoS Profile or QoS parameters included in the N2 SM information that the SMF 206 provides to the base station device 130 via the AMF 209.

[0226] Furthermore, the QoS Profile or the QoS parameters may include information for explicitly instructing the setting of the SPS, for example, by setting "sps-enabled".

[0227] In addition, the SMF 206 may include the SPS period and further information for explicitly instructing the SPS setting, such as “sps-enabled”, in the Alternative QoS Profile provided to the base station apparatus 130.

[0228] Alternatively, information regarding the format, including the frame rate, of the video handled by the service corresponding to S-NSSAI1 may be included in the PCC Rules provided from PCF205 to SMF206.

[0229] In addition, a QFI (QoS Flow Identifier) ​​and a 5QI (5G QoS Identifier) ​​corresponding to the video format handled by the service corresponding to S-NSSAI1 or the SPS period may be defined, and the SMF 206 may notify the base station device 130 of this QFI and 5QI.

[0230] At the NAS level, the QoS flow is characterized by the QoS profile provided from the 5GC to the base station device 130 and the QoS rule(s) provided from the 5GC to the terminal device 110. The QoS profile is used by the base station device 130 to determine how to process the wireless interface.

[0231] The QoS Profile includes QoS parameters, such as 5QI and ARP.

[0232] QoS rule(s) are used to dictate the correspondence between uplink user plane data and QoS flows. For example, CG configuration is included in the QoS rule.

[0233] Here, the CG setting is the CG period, and further, information for explicitly instructing the CG setting, for example, "cg-enabled".

[0234] At the AS level, the DRB determines how to process packets on the radio interface. The base station device 130 maps QoS flows to DRBs based on the QoS Profile associated with the QFI.

[0235] As described above, terminal device 110 receives video data at a cycle of 22 ms, and displays video (frame images) on display unit 116 at a cycle of 11.11 ms.

[0236] 12, the terminal device 110 receives video data D1 in a predetermined reception period from point A. The terminal device 110 displays a first video generated from the received video data D1 at the next display timing (point B1). The terminal device 110 also displays a second video generated from the video data D1 at point B2 as a time warp of the first video displayed at point B1 (hereinafter also referred to as time warp display).

[0237] Terminal device 110 receives video data at a cycle of 22 ms and displays the video at a display cycle of 11.11 ms. More specifically, terminal device 110 displays a first video at a cycle of 22.22 ms and time-warp displays a second video at a cycle of 22.22 ms.

[0238] In this way, the cycle in which the terminal device 110 receives video data (the SPS cycle) is different from the cycle in which the terminal device 110 displays the first video (the first frame rate). Therefore, even if the timing of receiving video data and the timing of displaying a video at the first frame rate (45 fps) are aligned at a certain point in time, as in point A in Fig. 12, a gradual deviation occurs between the reception timing and the display timing. Although this deviation is slight, as the deviation gradually accumulates, the amount of delay until display becomes too large to be ignored from the viewpoint of motion-to-photon latency, or conversely, a problem occurs in that the display is not in time.

[0239] -Outline of proposed technology Therefore, this disclosure proposes a technique for stably displaying video in terminal device 110, which periodically receives video data and periodically displays the video. As the proposed technique, base station device 130 changes a setting related to the reception timing when the difference between the periodic reception timing of video data in terminal device 110 and the display timing of the video satisfies a predetermined condition.

[0240] <<4. Technical Features>> <4.1.Resetting SPS> FIG. 13 is a diagram for explaining reconfiguration of the SPS by the base station device 130 according to an embodiment of the present disclosure.

[0241] As described above, terminal device 110 receives video data at a cycle of 22 ms, and displays the first video at a cycle of 22.22 ms.

[0242] In this way, if the cycle in which the terminal device 110 receives video data (the cycle of the SPS) differs from the cycle in which the terminal device 110 displays the first video, a shift (difference) occurs between the reception timing and the display timing.

[0243] When the absolute value of the difference between the reception timing at which the terminal device 110 receives the video data and the display timing of the first video becomes equal to or greater than a predetermined threshold, the base station device 130 resets the current SPS setting and sets the SPS again. The base station device 130 resets the SPS-Config so that the reception timing at which the terminal device 110 receives the video data and the display timing of the first video are aligned.

[0244] When the absolute value of the difference between the reception timing of the video data and the display timing of the first video becomes equal to or greater than a predetermined threshold, the terminal device 110 receives the video data at the changed reception timing based on the reconfigured SPS-Config.

[0245] 14 is a flowchart showing the flow of the SPS reconfiguration process according to an embodiment of the present disclosure. In FIG. 14, the SPS reconfiguration process is performed by the terminal device 110.

[0246] The terminal device 110 sets an SPS based on a notification (for example, an RRC message including SPS-Config) from the base station device 130 (step S601). The terminal device 110 receives video data from the base station device 130 at the period of the set SPS (step S602).

[0247] The terminal device 110 measures the accumulated time of the difference between the SPS period (e.g., 22 ms) and the frame rate of the video data (e.g., the first frame rate, 22.22 ms) (step S603). More specifically, the terminal device 110 accumulates the difference (0.22 ms) between the SPS period and the first frame rate each time it receives video data, and calculates the difference from the display timing at the reception timing of the video data.

[0248] Terminal device 110 may calculate the difference between the reception timing and the display timing by calculating the difference between the time when the video data is received and the time when the video data is displayed.

[0249] The terminal device 110 determines whether the measured cumulative time is equal to or greater than a predetermined threshold value (step S604). If the cumulative time is less than the threshold value (step S604; No), the process returns to step S602, and the terminal device 110 receives video data at the SPS cycle.

[0250] On the other hand, if the accumulated time is equal to or greater than the threshold (step S604; Yes), the terminal device 110 starts a process of requesting the base station device 130 to reset the SPS (step S605), and returns to step S601.

[0251] In step S605, the terminal device 110 may report the accumulated time to be corrected or the number of slots equivalent to this accumulated time to be corrected as an offset value in the request for SPS reconfiguration (reconfiguration of SPS-Config).

[0252] When the base station device 130 receives a request for reconfiguring the SPS-Config from the terminal device 110, the base station device 130 reconfigures the SPS based on the reported information related to the cumulative time to be corrected. Note that the request for reconfiguring the SPS-Config is made via an RRC message.

[0253] The terminal device 110 executes the above-mentioned SPS reconfiguration process while receiving video data.

[0254] Here, the terminal device 110 requests SPS reconfiguration, but this is not limiting (i.e., the request for SPS reconfiguration by the terminal device 110 may not be a required component). For example, the base station device 130 may calculate the difference between the display timing at the reception timing of the video data and the display timing, and determine whether to reconfigure the SPS. In this case, the base station device 130 acquires information on the frame rate of the video data from, for example, the information processing device 150. In addition or instead, the base station device 130 may acquire information on the frame rate of the video data from the UDR or NF of 5GC / NGC20. In addition or instead, the base station device 130 may acquire information on an upper layer that is not originally terminated (i.e., information on the frame rate of the video data) by reading it using DPI (Deep Packet Inspection) or the like.

[0255] Alternatively, the base station device 130 may be made to reset the SPS based on the difference between the display timing and the reception timing at which the NF of 5GC / NGC 20 receives the video data. Here, a case will be described in which the SMF 206 instructs the base station device 130 on the timing to reset the SPS.

[0256] In this case, in addition to S-NSSAI1, terminal device 110 includes in the PDU session establishment request message (see step S401 in Figure 10) that it sends to receive the service corresponding to S-NSSAI1, the absolute value of the cumulative time difference between the SPS period and the video frame rate period that terminal device 110 can tolerate.

[0257] The SMF 206 obtains the S-NSSAI 1 and the cumulative time allowable by the terminal device 110 from the AMF 209 via an Nsmf_PDUSession_CreateSMContext Request (see step S401 in Figure 10).

[0258] In this embodiment, the terminal device 110 notifies the allowable cumulative time, but the present invention is not limited to this. For example, the SMF 206 may set a predetermined value based on the motion-to-photon latency or the like as the allowable cumulative time.

[0259] The SMF 206 obtains information related to the format, including the frame rate, of the video handled by the service corresponding to S-NSSAI1 from the UDR.

[0260] The SMF 206 determines the period of the SPS based on the frame rate of the video, and determines the period for setting the SPS based on the allowable cumulative time. Here, the period for setting the SPS is the period from when the SPS is set until when the SPS needs to be reset.

[0261] AMF209 obtains the SPS period and the period for setting the SPS from SMF206 via N2 SM information of Namf_Communication_N1N2MessageTransfer (see step S411 in Figure 10).

[0262] The AMF 209 notifies the base station device 130 of the SPS period and period for setting the SPS acquired from the SMF 206, and the number of slots equivalent to the accumulated time to be corrected as an offset value, via an N2 PDU session request message (see step S412 in FIG. 10).

[0263] The base station device 130 sets an SPS period for the downlink with the terminal device 110 based on the SPS period and the period for setting the SPS obtained from the AMF 209, and starts a timer that sets the period for setting the SPS.

[0264] When the timer expires, the base station device 130 resets the SPS by offsetting the slot at which the SPS starts by the number of slots corresponding to the offset value, and resets the timer.

[0265] Thereafter, this SPS reconfiguration process is repeated until the terminal device 110 terminates the service corresponding to S-NSSAI1.

[0266] <4.2. Multiple SPS Settings> In the above example, the base station device 130 sets one SPS, but the base station device 130 may set multiple SPSs. This allows the base station device 130 to increase resources allocated to the SPSs.

[0267] 15 and 16 are diagrams for explaining an example of SPS setting by the base station device 130 according to an embodiment of the present disclosure.

[0268] As shown in Fig. 15, the base station device 130 may set multiple SPSs in multiple consecutive slots within an SPS period (e.g., 22 ms). Alternatively, the base station device 130 may set multiple SPSs in multiple distributed slots as shown in Fig. 16.

[0269] The base station device 130 allocates video data to a plurality of slots in which the SPS is set, for example, and transmits the data.

[0270] Furthermore, the base station device 130 may reconfigure the SPS by switching between each of a plurality of SPSs.

[0271] In addition, in Fig. 15 and Fig. 16, the base station device 130 sets the SPS in multiple slots from the beginning of the SPS cycle, but this is not limited to this. The base station device 130 may set the SPS in multiple slots from the end of the SPS cycle, or may set the SPS in multiple slots located in the center of the SPS cycle. In addition, in Fig. 15 and Fig. 16, the number of resource allocations in which the base station device 130 sets the SPS is three, but this is not limited to this, and the number may be two or four or more.

[0272] Furthermore, the base station apparatus 130 sets the terminal apparatus 110 to discontinuous reception (DRX) in order to periodically monitor the PDCCH. One of the processes performed by the terminal apparatus 110 in idle mode is to monitor the PDCCH that notifies paging from the base station apparatus 130. Therefore, in the idle mode, in order to reduce power consumption during standby, DRX is set for periodically monitoring the PDCCH.

[0273] Also, it is important to reduce power consumption in the terminal device 110 in connected mode. Therefore, the base station device 130 can set C-DRX (Connected mode DRX) by using RRC Connection Setup or RRC Connection Reconfiguration. The value of longDRX-Cycle is set according to the monitoring period of the PDCCH, and the values ​​of drxStartOffset and onDurationTimer are set based on the slot position to which the PDCCH is allocated. Furthermore, the base station device 130 receives scheduling information via the PDCCH and sets drx-InactivityTimer as a period for receiving data indicated by the scheduling information. Furthermore, the base station device 130 can set Short DRX in addition to this Long DRX.

[0274] Short DRX is set by drxShortCycleTimer and shortDRX-Cycle. The terminal device 110 in connected mode monitors the PDCCH according to the setting of Long DRX. When demodulation of the PDCCH including the scheduling information is successful over the period in which the onDurationTimer is valid, the drx-InactivityTimer is started, and data indicated by the scheduling information can be received over the period in which the drx-InactivityTimer is valid. When the validity period of the drx-InactivityTimer expires, the terminal device 110 starts the drxShortCycleTimer, and monitors the PDCCH at a cycle of the shortDRX-Cycle, which is more frequent than the longDRX-Cycle, over the period in which the drxShortCycleTimer is valid. By monitoring the PDCCH with this shortDRX-Cycle, for example, it is possible to ensure the QoS of packets transmitted in a short period. When the validity period of the drxShortCycleTimer expires, the terminal device 110 resumes periodic monitoring of the PDCCH according to the setting of Long DRX.

[0275] The base station device 130 sets the C-DRX in the terminal device 110 based on the PDCCH monitoring cycle and the SPS cycle. For example, when the PDCCH is notified in a slot in which the SPS is set, one Long DRX is set. The value of longDRX-Cycle is set according to the SPS cycle, and the values ​​of drxStartOffset and onDurationTimer are set based on the slot position in which the SPS is set. Here, when the SPS is set in a plurality of consecutive slots (FIG. 15), the value of onDurationTimer is set according to the number of consecutive slots. Alternatively, the values ​​of drxStartOffset and onDurationTimer of Long DRX are set according to the position of the first slot in which the SPS is set, and the value of drx-InactivityTimer is set according to the position of the second or subsequent slots. When the SPS is set in a plurality of distributed slots (FIG. 16), the value of onDurationTimer is set so that all of the distributed slots are included. Alternatively, when SPS is set in multiple distributed slots, the values ​​of drxStartOffset and onDurationTimer of Long DRX are set according to the position of the first slot in which SPS is set, and the drxShortCycleTimer and shortDRX-Cycle of Short DRX are set according to the positions of the second and subsequent slots.The value of drxShortCycleTimer is set based on the period of the slots set in a distributed manner within the SPS period, and the shortDRX-Cycle is set based on the period that includes the multiple slots set in a distributed manner.

[0276] Also, when the PDCCH is notified in a slot adjacent to the slot in which SPS is set, the value of longDRX-Cycle is set to one according to the SPS period, and the values ​​of drxStartOffset and onDurationTimer are set based on the positions of the adjacent slot and the slot in which SPS is set. In other words, the PDCCH is monitored and data sent using the slot in which SPS is set is received over the period of onDurationTimer.

[0277] Note that this single Long DRX setting is reset when the SPS is reset. When the SPS is reset by switching each SPS among multiple SPS, the Long DRX is reset every time the SPS is switched. The values ​​of drxStartOffset and onDurationTimer or drx-InactivityTimer are reset based on the slot position of the switched SPS. In order to update each DRX parameter in this DRX reset, each parameter may be notified via DCI.

[0278] Also, the PDCCH monitoring period and the SPS period may be set flexibly, that is, two independent Long DRXs may be set to set different periods. A first Long DRX is set for monitoring the PDCCH, and a second Long DRX is set for receiving data via the SPS. The value of the first longDRX-Cycle is set according to the PDCCH monitoring period, and the values ​​of the first drxStartOffset and the first onDurationTimer are set according to the slot for notifying the PDCCH. The value of the second longDRX-Cycle is set according to the SPS period, and the values ​​of the second drxStartOffset and the second onDurationTimer are set based on the slot position in which the SPS is set. The second Long DRX can be set using the method shown in the case of setting one Long DRX described above. Here, if the period of the first onDurationTimer and the period of the second onDurationTimer overlap in part or in whole, the terminal device 110 determines the period that is the logical sum (OR) of the periods of the first onDurationTimer and the second onDurationTimer as the period of the onDurationTimer. Also, if the period between the end timing of the first onDurationTimer and the start timing of the second onDurationTimer, or the period between the end timing of the second onDurationTimer and the start timing of the first onDurationTimer, is equal to or less than a certain threshold, it may be difficult to control the on-off of the reception system of the terminal device 110. In such a case, the terminal device 110 can avoid the problem of controlling the on-off of the reception system by setting a continuous period including the periods of the first onDurationTimer and the second onDurationTimer as the period of the third onDurationTimer. Furthermore, the threshold value for this determination (e.g., 5 slots, etc.) may be notified to the terminal device 110 as one of the parameters of Long DRX (e.g., DurationThreshold) when configuring the second Long DRX. Note that the above-mentioned concept of slot in the configuration of SPS or DRX may include minislot.

[0279] FIG. 17 is a diagram for explaining an example of setting an SPS by a base station device 130 according to an embodiment of the present disclosure.

[0280] In FIG. 17, the base station device 130 sets a plurality of SPSs having the same period within an SPS period (for example, 22 ms).

[0281] The base station device 130 sets resource allocations 701 to 704 corresponding to four SPSs having arbitrary slot intervals, for example, in the downlink with the terminal device 110. In Fig. 17, there is a gap of six slots between resource allocations 701 and 702, between resource allocations 702 and 703, and between resource allocations 703 and 704. There is also a gap of four slots between resource allocation 704 and resource allocation 701 of the next cycle.

[0282] The base station device 130 may individually activate each of the configured resource allocations using Downlink Control Information (DCI). Here, for example, the base station device 130 first activates only the SPS corresponding to the resource allocation 701.

[0283] Assume that the cumulative time difference between the period of the SPS and the period of the first frame rate of the moving image is equal to or greater than the time difference between resource allocation 701 and resource allocation 702, that is, 6 slots in the example of Fig. 17. In this case, the base station device 130 deactivates the SPS corresponding to resource allocation 701 using DCI, and activates the SPS corresponding to resource allocation 702.

[0284] Next, assume that the cumulative time difference between the period of the SPS and the period of the first frame rate of the moving image becomes equal to or greater than 6 slots, which is the time difference between resource allocation 702 and resource allocation 703. In this case, the base station device 130 deactivates the SPS corresponding to resource allocation 702 using DCI, and activates the SPS corresponding to resource allocation 703.

[0285] Next, assume that the cumulative time difference between the period of the SPS and the period of the first frame rate of the video becomes equal to or greater than 6 slots, which is the time difference between resource allocation 703 and resource allocation 704. In this case, base station device 130 deactivates the SPS corresponding to resource allocation 703 using DCI, and base station device 130 activates the SPS corresponding to resource allocation 704.

[0286] Similarly, assume that the cumulative time difference between the period of the SPS and the period of the first frame rate of the moving image is equal to or greater than four slots, which is the time difference between resource allocation 704 and the next period of resource allocation 701. In this case, the base station device 130 deactivates the SPS corresponding to resource allocation 704 using DCI, and activates the SPS corresponding to resource allocation 701.

[0287] Thereafter, the activation / deactivation process of each SPS of the set multiple SPSs continues until the terminal device 110 terminates the service corresponding to S-NSSAI1.

[0288] As described above, when switching the SPS used for transmitting video data, the base station device 130 may notify the terminal device 110 of the offset of the SPS before and after the switching, for example, by using DCI.

[0289] Here, information regarding the SPS period, the number of SPSs to be set within the SPS period, the resource allocation arrangement corresponding to each SPS within the SPS period, and the period from activation to deactivation of each SPS is notified from SMF 206 to base station device 130 during the PDU session establishment process.

[0290] <4.3. Resetting the CG> In applications such as AR, VR, MR, SR, and XR, where free viewpoint video and real-time video are viewed on an HMD, it is important to suppress the motion-to-photon latency within a certain value as described above. Therefore, in order to reflect head movement, viewpoint, or changes in the field of view including the viewpoint in each frame image of the video, a periodic uplink occurs in which the terminal device 110 transmits information related to the latest inertia detected. Therefore, when the terminal device 110 sends a PDU session establishment request to the AMF 209 to receive a service corresponding to the S-NSSAI1, the 5GC sets a CG (Configured Grant) in addition to the above-mentioned SPS. Here, the CG can be set in the same manner as the SPS setting method described so far.

[0291] Also, in the PDU session establishment process for the service corresponding to S-NSSAI1, the selected SMF 206 may use the AF 208 to provide the service corresponding to S-NSSAI1.

[0292] For example, the AF 208 determines the setting of the SPS when the application used by the terminal device 110 requires periodic downlink reception. Furthermore, when the application involves receiving a moving image, the AF 208 identifies the format of the moving image and determines the setting of the SPS required according to the identified format of the moving image.

[0293] Furthermore, the AF 208 may determine the CG setting when the application used by the terminal device 110 requires periodic uplink transmission. For example, in order to reflect information related to inertia detected by the terminal device 110 in a video received by the application, the CG setting is determined taking into account the frame rate of the video. That is, the AF 208 provides information to assist the setting required for receiving video data and the setting required for transmitting information used to generate video data (for example, information related to inertia) to another NF or the base station device 130 based on the format of the video handled by the application.

[0294] The SPS settings and CG settings determined by the AF 208 are provided to the base station device 130 via the SMF 206 and the AMF 209.

[0295] In the above example, the base station device 130 resets the SPS, but the base station device 130 may reset the ConfiguredGrantConfig (CGConfig). This will be described with reference to Figs. 18 and 19.

[0296] 18 and 19 are diagrams for explaining the CG reconfiguration by the base station device 130 according to an embodiment of the present disclosure.

[0297] 18, during the inertial measurement information reception period, the information processing device 150 periodically receives the inertial measurement information via the base station device 130. The period at this time is determined by the period of uplink communication in which the base station device 130 receives the inertial measurement information from the terminal device 110, and coincides with the CG period set in ConfiguredGrantConfig, for example.

[0298] The information processing device 150 executes a moving image data generation process based on the received inertial measurement information to generate moving image data, and transmits the moving image data to the terminal device 110 via the base station device 130. The moving image data is transmitted at an SPS period by data transmission using the SPS.

[0299] When the SPS period and the CG period are the same, the information processing device 150 can generate video data based on the most recently received inertial measurement information.

[0300] In this case, when the accumulated time of the difference between the SPS period and the first frame rate becomes equal to or greater than a threshold, the base station device 130 performs SPS resetting, which causes a delay in data transmission using the SPS.

[0301] In the example of Fig. 18, the SPS is reset so that the transmission timing of data transmission using the SPS is advanced. Therefore, even if the information processing device 150 generates moving image data based on the most recently received inertial measurement information, the moving image data cannot be transmitted because it will not be in time for the reset transmission timing. Alternatively, in order to transmit the moving image data, the information processing device 150 must generate the moving image data using the inertial measurement information received most recently or previously.

[0302] Therefore, as shown in Fig. 19, the base station device 130 according to this embodiment resets the ConfiguredGrant (CG) when resetting the SPS. At this time, it is preferable that the base station device 130 resets the CG before the timing of resetting the SPS. This allows the information processing device 150 to generate video data based on the latest inertial measurement information most recently received, even if the SPS is reset.

[0303] <4.4. Changing the Time Warp> In the above example, the base station device 130 reconfigures the SPS or CG to reduce the difference between the communication timing and the display timing that occurs in the terminal device 110, but the method for reducing the difference is not limited to this. For example, the terminal device 110 may reduce the difference by adjusting the number of time warp images that are displayed using time warp.

[0304] FIG. 20 is a diagram for explaining an example of a display process by the terminal device 110 according to an embodiment of the present disclosure.

[0305] As shown in Fig. 20, terminal device 110 generates and displays a frame image (hereinafter also referred to as a first image) using the latest inertia-related information from video data received during the reception period of the SPS cycle. Terminal device 110 also performs time warp display of a frame image (time warp image) generated in a similar manner. Terminal device 110 displays the first image or the time warp image as a frame image at a second frame rate.

[0306] In this case, due to the accumulation of slight discrepancies between the SPS cycle and the first frame rate (45 fps), a state occurs in which the reception of video data is not in time for the display timing of the first image. In Figure 20, at point B, a state occurs in which the reception of video data is not in time for the display timing of the first image.

[0307] Assume that the accumulated time difference between the SPS period and the first frame rate period exceeds a certain threshold, and the display timing of the first image cannot be made in time. As shown in the lower diagram of Fig. 20, at the timing when the first image is originally to be displayed, the terminal device 110 displays a time warped image obtained by applying time warping to the video data received at the previous reception timing. This enables the terminal device 110 to delay the display timing of the first image by a half cycle, and to display the first image generated using the most recently received video data.

[0308] In the above example, a case has been described in which the timing of receiving the moving image data is delayed and the first image is not displayed in time. A case will now be described in which the timing of receiving the moving image data is advanced.

[0309] FIG. 21 is a diagram for explaining another example of the display process by the terminal device 110 according to an embodiment of the present disclosure.

[0310] The accumulation of slight discrepancies between the SPS cycle and the first frame rate (45 fps) cycle can cause a situation in which the delay between receiving video data and the timing at which the first image generated based on the video data is displayed becomes large. In Fig. 21, at point D, the delay between receiving video data and the timing at which the first image is displayed becomes so large that, for example, the motion-to-photon latency cannot be ignored.

[0311] In this way, suppose that the cumulative time difference between the SPS period and the first frame rate period exceeds a certain threshold, and the delay between receiving video data and the display timing of the first image becomes so large that the motion-to-photon latency cannot be ignored.

[0312] As shown in the lower diagram of Fig. 21, the terminal device 110 displays a first image generated from the most recently received video data at the timing (point C) for displaying a time warped image obtained by applying time warp to the video data received at the previous reception timing. This enables the terminal device 110 to advance the display timing of the first image by half a cycle, thereby reducing the effect of motion-to-photon latency.

[0313] <4.5. Setting Priority> In the above-mentioned examples, the case where one video data is assigned to one SPS has been described, but the present invention is not limited to this. For example, the base station device 130 may assign video data divided into multiple regions to multiple SPSs according to the priority of each region. Here, each divided video data is, for example, data called a segment.

[0314] 22 to 25 are diagrams for explaining an example of a video data allocation process by the base station device 130 according to an embodiment of the present disclosure.

[0315] The information processing device 150 sets the user's viewpoint or a field of view including the viewpoint, based on the latest inertia-related information acquired from the terminal device 110. Furthermore, the information processing device 150 determines an area so that the set viewpoint or field of view point is at the center, and generates video data of the determined area.

[0316] At this time, the information processing device 150 divides the generated video data into a plurality of regions as shown in Fig. 22. Then, the information processing device 150 changes the resolution of the divided regions according to the distance between the set user's viewpoint and the divided regions.

[0317] For example, as shown in FIG. 22, the information processing device 150 generates moving image data assuming that the user's viewpoint is located at the center of the moving image data, and divides the generated moving image data into nine 3×3 regions.

[0318] In this case, as shown in Fig. 23, the information processing device 150 sets the resolution of the divided regions, the region 801 located in the center and closest to the viewpoint, to the highest (high resolution). Also, the information processing device 150 sets the resolution of the divided regions, the regions 806 to 809 located in the corners of the video data and farthest from the viewpoint, to the lowest (low resolution). The information processing device 150 sets the resolution of the remaining regions 802 to 805 to a resolution between high resolution and low resolution (medium resolution). The regions 802 to 805 are regions that border the region 801, which is closest to the viewpoint, on their sides, and the regions 806 to 809 are regions that border the regions 802 to 805 on their sides.

[0319] Here, the case where the video data is divided into nine parts has been described, but the number of divisions of the image data is not limited to nine. The number of divisions may be between two and eight, or may be ten or more. Here, the case where the resolution of the regions is divided into three, low, medium, and high, has been described, but the number of resolutions is not limited to three. The number of resolutions may be two, or may be four or more. Here, the case where the size of each divided region is the same has been described, but the example is not limited to the case where the size of each region is the same. For example, the region may be divided into regions of different sizes.

[0320] Here, multiple formats with different resolutions may be predefined as video data applicable to each region. That is, the information processing device 150 generates video data by selecting a video format with different resolutions according to the distance from the viewpoint.

[0321] The information processing device 150 may select a video format with a different resolution based on the communication quality between the terminal device 110 and the base station device 130 in addition to the distance from the viewpoint. For example, the AF 208 includes a wireless communication quality acquisition unit (not shown) and acquires the communication quality between the terminal device 110 and the base station device 130 from the base station device 130. The wireless communication quality acquisition unit provides the communication quality between the terminal device 110 and the base station device 130 acquired from the base station device 130 to the information processing device 150.

[0322] As shown in Fig. 24, the AF 208 assigns a priority according to the resolution of each area of ​​a video. A high priority is assigned to a high-resolution area 801, a medium priority is assigned to medium-resolution areas 802 to 805, and a low priority is assigned to low-resolution areas 806 to 809. Here, the priority is, for example, a QFI (QoS Flow identifier) ​​and a 5QI (5G QoS Identifier).

[0323] Here, the QoS flow is the concept of the finest granularity for differentiating QoS within a PDU session, and in 5GS, the QoS flow is identified by the QFI. In the N3 between the UPF 220 and the RAN / AN 230 corresponding to the base station device 130, each data flow is sent with the encapsulated QFI added to the header. Note that the QFI may be equivalent to the 5QI.

[0324] The AMF 209 determines the SPS settings, including the SPS period, based on the frame rate of the video in each priority area. Here, the AMF 209 may set the frame rate of the video in each priority area to the same, or may lower the frame rate of the video in a low priority area.

[0325] Furthermore, the SPS setting for each priority level is determined taking into consideration that a video in an area with a higher priority level is received by the terminal device 110 earlier than a video in an area with a lower priority level.

[0326] The SPS settings for each priority determined by the AMF 209 are provided to the base station device 130 via the SMF 206 and the AMF 209.

[0327] The base station device 130 performs SPS resource allocation based on the SPS settings for each priority level acquired from the AMF 209.

[0328] In the example shown in FIG. 25, the base station device 130 sets periodic resource allocation 810 of an SPS for high priority, periodic resource allocation 811 of an SPS for medium priority, and periodic resource allocation 812 of an SPS for low priority.

[0329] The base station device 130 identifies the priority based on the QFI added to the data flow received from the UPF 220, and transmits data of each region of the video data using resource allocation according to the priority. For example, the base station device 130 transmits a high priority region 801 to the terminal device 110 using resource allocation 810. Similarly, the base station device 130 transmits medium priority regions 802 to 805 to the terminal device 110 using resource allocation 811, and transmits low priority regions 806 to 809 to the terminal device 110 using resource allocation 812.

[0330] Furthermore, information including mapping and the format of each region required for the rendering unit 1153 of the terminal device 110 to restore the divided videos to one video is transmitted using periodic resource allocation 810 for sending high priority data. Here, the information including mapping and the format of each region required for restoring the divided videos to one video may be, for example, a Media Presentation Description (MPD) or a file for a similar purpose.

[0331] Based on this mapping and information including the format of each region, the rendering unit 1153 can apply a decoding method suitable for the format of each divided region to restore it as video data of a single region.

[0332] The rendering unit 1153 sets the timing of the video frame to be displayed (e.g., see point B1 in FIG. 12) based on the timing set by the SPS that first received data via the periodic resource allocation 810 (e.g., see point A in FIG. 12). The timing of this video frame is subject to an offset period that takes into account, for example, the period required for decoding, the period required for rendering processing, and a margin. This offset period is controlled by the video application control unit 1151.

[0333] Here, an example has been shown in which the resolution of the divided regions is changed according to the distance between the user's viewpoint and the divided regions, but only the priority may be changed without changing the resolution of each divided region. The information processing device 150 sets the priority of the region 801 located in the center and closest to the viewpoint to the highest priority (high priority). Furthermore, the information processing device 150 sets the priority of the regions 806 to 809 located in the corners of the video data and farthest from the viewpoint to the lowest priority (low priority). The information processing device 150 sets the priority of the remaining regions 802 to 805 to a priority between high and low priority (medium priority). Here, the priority is, for example, QFI and 5QI.

[0334] Furthermore, when transmitting data for each region, the order of transmission may be determined based on pixels. For example, the information processing device 150 transmits information on pixels at a specific location of a frame image with priority so that a low-resolution image can be displayed even if the terminal device 110 cannot receive information on all pixels within a predetermined period. Then, the information processing device 150 controls to transmit information on pixels of the remaining portion. The base station device 130 transmits data for each region to the terminal device 110 according to the priority based on the pixels. The rendering unit 1153 synthesizes the received multiple low-resolution frame images to generate a high-resolution frame image.

[0335] <<5. Other embodiments>> The above-described embodiment is merely an example, and various modifications and applications are possible.

[0336] In the above embodiment, an example is shown in which a video with a frame rate of 45 fps is displayed as a video with a frame rate of 90 fps using time warp, but the frame rate is not limited to this example. The technology of the present disclosure may be applied to the display of videos with various frame rates.

[0337] In the above embodiment, the information processing device 150 generates video data based on information related to inertia and transmits it to the terminal device 110. That is, the information processing device 150 generates video data according to the user's viewpoint from 360-degree video information and transmits it to the terminal device 110, but this is not limited to the above. For example, the information processing device 150 may transmit the 360-degree video data as it is to the terminal device 110. In this case, the information processing device 150 may reduce the amount of data to be transmitted by transmitting, for example, 360-degree video data with a low resolution. In addition, the information processing device 150 may transmit both the video data according to the user's viewpoint and the 360-degree video data with a reduced resolution to the terminal device 110.

[0338] In the above embodiment, the NF of the base station device 130 or 5GC / NGC 20 acquires the frame rate, but this is not limited to this. That is, the information on the frame rate acquired by the NF of the base station device 130 or 5GC / NGC 20 may be not only the value of the frame rate itself (e.g., 45 fps or 90 fps) but also an index corresponding to the frame rate (e.g., QFI or 5QI).

[0339] In addition, although an example in which the information for restoring the divided moving images to one moving image includes mapping and the format of each region has been shown, the information for restoring the divided moving images to one moving image may include information on the frame rate. The base station device 130 and the NF of the 5GC / NGC 20 may acquire the frame rate via the information for restoring the divided moving images to one moving image.

[0340] In the above embodiment, the terminal device 110 receives video data on the downlink and transmits information related to inertia on the uplink, but the present invention is not limited to this. For example, the data received by the terminal device 110 may be data that is received periodically in real time, and may be other than video data. The data transmitted by the terminal device 110 may be data that is transmitted periodically in real time, and may be other than information related to inertia. In this way, the technology of the present disclosure may be applied to various types of data communication that is performed periodically in real time.

[0341] <<6. Application Examples>> In addition, in some embodiments, the settings of the SPS or CG described above may take into account the requirements of services (e.g., cloud gaming) using Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) / Substitutional Reality (SR).

[0342] Several services are being considered as use cases for 5G NR (New Radio). Among these, AR / VR services are expected to be the killer content of 5G NR. 3GPP TR 22.842 v17.1.0 and TS 22.261 v17.0.1 specify requirements for rendering game images for cloud gaming using AR / VR. More specifically, these technical specifications and reports describe motion-to-photon delay and motion-to-sound delay as the allowable delay in rendering game images that does not cause AR / VR users to feel uncomfortable with the movement of the images, as follows:

[0343] Motion-to-photon latency: While maintaining the required data rate (1Gbps), the motion-to-photon latency is in the range of 7-15ms. Motion-to-sound latency: less than 20ms.

[0344] The motion-to-photon delay is defined as the delay between the physical movement of the user's head and an updated image in an AR / VR headset (e.g., a Head Mount Display). The motion-to-sound delay is defined as the delay between the physical movement of the user's head and an updated sound wave from a head mounted speaker reaching the user's ear. The AR / VR headset and the head mounted speaker here may be the terminal device 110 in this disclosure.

[0345] In order to meet these latency requirements, the above-mentioned technical specifications and reports stipulate that the 5G system must meet the following two rendering requirements:

[0346] Max Allowed End-to-end latency: 5 ms (i.e., the total allowable latency of the uplink and downlink between a terminal (e.g., the terminal device 110) and an interface to a data network (e.g., a network in which an Application Function (AF) is located) is 5 ms), Service bit rate: user-experienced data rate: 0.1Gbps (100Mbps) (i.e., throughput capable of supporting AR / VR content).

[0347] The rendering here includes cloud rendering, edge rendering, and split rendering. Cloud rendering is rendering of AR / VR data on the cloud of a network (on a certain entity based on the arrangement of a core network (including UPF) and a data network (including application servers and AFs) that does not consider the user's location). Edge rendering is rendering of AR / VR data on the edge of a network (on a certain entity (e.g., an Edge Computing Server (an application server in a data network in a network arrangement for Edge Computing)) based on the arrangement of a core network (including UPF) and a data network (including application servers and AFs) close to the user's location). Split rendering means that a part of the rendering is performed on the cloud and the other part is performed on the edge.

[0348] FIG. 26 is an image diagram of a rendering server and an AR / VR client related to rendering. FIG. 26 is described in the above-mentioned technical report. Here, the AR / VR client may correspond to the terminal device 110 in the present disclosure. Also, the Cloud Render Server may correspond to the information processing device 150 in the present disclosure. Also, the Cloud Render Server may be an application server (for example, an Edge Computing Server) for edge computing in a Local Area Data Network (LADN) with a Local UPF connected to the base station device 130 in the present disclosure as an interface. Also, the Cloud Render Server may be named an Edge Render Server or a Split Render Server.

[0349] In this application example, for example, in the case of data communication (e.g., session (PDU session), bearer (Radio Bearer), packet flow (QoS flow)) requiring motion-to-photon delay (7-15 ms) or motion-to-sound delay (less than 20 ms), the above-mentioned SPS or CG reconfiguration may be performed.

[0350] In another aspect, the above-mentioned SPS or CG reconfiguration may be performed in the case of data communication (e.g., session (PDU session), bearer (Radio Bearer), packet flow (QoS flow)) that requires the rendering requirement Max Allowed End-to-end latency (5 ms).

[0351] <<7. Conclusion>> Although the preferred embodiment of the present disclosure has been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field of the present disclosure can conceive of various modified or amended examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0352] Among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically by a known method. In addition, the information including the processing procedures, specific names, various data and parameters shown in the above documents and drawings can be changed arbitrarily unless otherwise specified. For example, the various information shown in each drawing is not limited to the illustrated information.

[0353] In addition, each component of each device shown in the figure is a functional concept, and does not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc.

[0354] Furthermore, the above-described embodiments can be appropriately combined as long as the processing contents are not contradictory.

[0355] In addition, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above effects.

[0356] Note that the following configurations also fall within the technical scope of the present disclosure. (1) a wireless communication unit that transmits video data to a terminal device at a predetermined period; a control unit that changes a setting related to the reception timing when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition; and A base station device comprising: (2) The base station device according to (1), wherein the setting regarding the reception timing is a Semi-Persistent Scheduling (SPS) setting. (3) The base station device according to (1) or (2), wherein the control unit changes the setting related to the reception timing by resetting the reception timing so that the reception timing and the display timing are aligned. (4) The base station device according to any one of (1) to (3), wherein the control unit changes the setting related to the reception timing by notifying the terminal device of an offset indicating the reception timing after the change. (5) The base station device according to any one of (1) to (4), wherein, when the settings related to a plurality of the reception timings are set in the terminal device, the control unit changes the settings related to the reception timings by notifying the terminal device of the settings to be deactivated and the settings to be newly activated among the settings related to the plurality of the reception timings. (6) The base station device according to any one of (1) to (5), wherein the predetermined condition is that the difference is equal to or greater than a threshold, or that the accumulated difference is equal to or greater than a threshold. (7) The base station device according to any one of (1) to (6), wherein the control unit changes the setting related to the reception timing in response to a request from the terminal device. (8) The base station device according to any one of (1) to (7), wherein the control unit changes the setting related to the reception timing in response to an instruction from a network function belonging to a connected network. (9) The base station device according to any one of (1) to (8), wherein the control unit acquires information regarding the frame rate from a content server that acquires the video data. (10) The base station device according to any one of (1) to (9), wherein the terminal device generates images from the video data based on information about a user's viewpoint, and adjusts the number of images generated in accordance with the difference when displaying the video data at a second frame rate greater than the frame rate. (11) the control unit transmits each of the plurality of divided areas of the video data at the setting of the reception timing according to a priority of the area; The priority of the region is set based on information about a user's viewpoint. The base station device according to any one of (1) to (10). (12) the priority of the region is set according to a resolution of the region that is set based on information about the user's viewpoint; A base station device as described in (11). (13) a wireless communication unit that receives video data from a base station device at a predetermined period; A control unit for displaying the video data at a predetermined frame rate; Equipped with when a difference between a periodic reception timing for receiving the video data and a display timing for displaying the video data at the predetermined frame rate satisfies a predetermined condition, the wireless communication unit receives the video data based on the changed setting of the reception timing. Terminal device. (14) Transmitting video data to a terminal device at a predetermined period; changing a setting related to the reception timing when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition; A communication method including: (15) receiving video data from a base station device at a predetermined period; displaying the video data at a predetermined frame rate; when receiving the moving image data, if a difference between a periodic reception timing for receiving the moving image data and a display timing for displaying the moving image data at the predetermined frame rate satisfies a predetermined condition, receiving the moving image data based on the changed setting of the reception timing; A communication method including: (16) a wireless communication unit that receives information about a user from a terminal device at a first period and transmits video data generated based on the information about the user at a second period; a control unit that changes a setting related to a transmission timing at which the terminal device periodically transmits information about the user when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition; A base station device comprising: (17) The base station device according to (1), wherein the control unit further sets a period of intermittent reception and an on period based on settings related to the reception timing. (18) The base station device according to (17), wherein the control unit sets one discontinuous reception as the discontinuous reception setting and assigns a downlink control channel to an on period in the one discontinuous reception setting. (19) The control unit sets, as the discontinuous reception setting, a second discontinuous reception setting different from a first discontinuous reception setting for monitoring a downlink control channel, The base station device according to (17), wherein a cycle and an on period of the second intermittent reception are set based on a setting related to the reception timing. (20) The base station device according to (19), wherein the control unit sets a threshold value related to an interval between a first on-period of the first discontinuous reception and a second on-period of the second discontinuous reception as the second discontinuous reception setting. (twenty one) The terminal device according to (13), wherein the wireless communication unit sets a period and an on period of intermittent reception based on the setting of the reception timing. (twenty two) the wireless communication unit sets, as the discontinuous reception setting, a second discontinuous reception setting different from a first discontinuous reception setting for monitoring a downlink control channel; Here, the cycle and on period of the second intermittent reception are set based on the setting of the reception timing. (twenty three) The terminal device described in (22), wherein the wireless communication unit sets a third on period including the first on period and the second on period when a first on period of the first intermittent reception overlaps with part or all of a second on period of the second intermittent reception. (twenty four) The terminal device described in (22), wherein the wireless communication unit sets a threshold value related to the interval between the first on period of the first intermittent reception and the second on period of the second intermittent reception as the second intermittent reception setting, and when the interval between the first on period of the first intermittent reception and the second on period of the second intermittent reception is equal to or less than the threshold value, sets a third on period including the first on period and the second on period. [Explanation of symbols]

[0357] 100 Content Delivery System 110 Terminal Equipment 130 Base station equipment 131 Communications Department 134 Control Unit 150 Information processing equipment

Claims

1. a wireless communication unit that transmits video data to a terminal device at a predetermined period; a control unit that changes a setting related to the reception timing when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition; and A base station device comprising:

2. The base station apparatus according to claim 1 , wherein the setting related to the reception timing is a Semi-Persistent Scheduling (SPS) setting.

3. The base station device according to claim 1 , wherein the control unit changes the setting related to the reception timing by resetting the reception timing so that the reception timing and the display timing are aligned.

4. The base station device according to claim 1 , wherein the control unit changes the setting related to the reception timing by notifying the terminal device of an offset indicating the reception timing after the change.

5. The base station device according to claim 1, wherein when the settings regarding a plurality of the reception timings are set in the terminal device, the control unit changes the settings regarding the reception timings by notifying the terminal device of the settings to be deactivated and the settings to be newly activated among the settings regarding the plurality of the reception timings.

6. The base station device according to claim 1 , wherein the predetermined condition is that the difference is equal to or greater than a threshold, or that a cumulative sum of the differences is equal to or greater than a threshold.

7. The base station device according to claim 1 , wherein the control unit changes the setting related to the reception timing in response to a request from the terminal device.

8. The base station device according to claim 1 , wherein the control unit changes the setting related to the reception timing in response to an instruction from a network function belonging to a connected network.

9. The base station device according to claim 1 , wherein the control unit acquires information about the frame rate from a content server that acquires the video data.

10. The base station device of claim 1, wherein the terminal device generates images from the video data based on information about a user's viewpoint, and adjusts the number of images generated according to the difference when displaying the video data at a second frame rate greater than the frame rate.

11. the control unit transmits each of the plurality of divided areas of the video data at the setting of the reception timing according to a priority of the area; The priority of the region is set based on information about a user's viewpoint. The base station device according to claim 1 .

12. the priority of the region is set according to a resolution of the region that is set based on information about the user's viewpoint; The base station device according to claim 11.

13. a wireless communication unit that receives video data from a base station device at a predetermined period; A control unit for displaying the video data at a predetermined frame rate; Equipped with when a difference between a periodic reception timing for receiving the video data and a display timing for displaying the video data at the predetermined frame rate satisfies a predetermined condition, the wireless communication unit receives the video data based on the changed setting of the reception timing. Terminal device.

14. Transmitting video data to a terminal device at a predetermined period; changing a setting related to the reception timing when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition; A communication method including:

15. receiving video data from a base station device at a predetermined period; displaying the video data at a predetermined frame rate; when receiving the moving image data, if a difference between a periodic reception timing for receiving the moving image data and a display timing for displaying the moving image data at the predetermined frame rate satisfies a predetermined condition, receiving the moving image data based on the changed setting of the reception timing; A communication method including:

16. a wireless communication unit that receives information about a user from a terminal device at a first period and transmits video data generated based on the information about the user at a second period; a control unit that changes a setting related to a transmission timing at which the terminal device periodically transmits information about the user when a difference between a periodic reception timing at which the terminal device receives the video data and a display timing at which the video data is displayed on the terminal device at a predetermined frame rate satisfies a predetermined condition; A base station device comprising:

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