Communication control method, user equipment, network node, communication system, program, and chipset

Abstract

To provide an XR (eXtended Reality) traffic communication control method, user equipment, a network B node, a program, and a chipset in a mobile communication system.SOLUTION: A communication control method in a mobile communication system includes: a base station 200 transmitting, to user equipment, setting information including a QoS (Quality of Service) follow identifier corresponding to XR (eXtended Reality) traffic and a session ID linked to the QoS follow identifier; and the user equipment transmitting XR assist information to the base station based on the setting information.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a communication control method in a mobile communication system.

Background Art

[0002] In the specifications of 3GPP (The Third Generation Partnership Project) (registered trademark; the same applies hereinafter), which is a standardization project for mobile communication systems, XR (Extended Reality) has been approved for Release 18. XR includes virtual reality (VR: Virtual Reality), augmented reality (AR: Augmented Reality), and mixed reality (MR: Mixed Reality), and is a broad term representing an environment that fuses the real world and virtual space. XR represents a composite environment of the real space and the virtual space generated by computer technology and wearable devices, and represents the interaction between humans and machines.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

[0004] A communication control method according to one aspect is a communication control method in a mobile communication system. The communication control method includes a step in which a user device transmits XR assist information related to XR (Extended Reality) to a base station. Here, the XR includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment in which the real world and the virtual space are fused.

[0005] Also, a communication control method according to one aspect is a communication control method in a mobile communication system. The communication control method includes a step in which an access mobility management device transmits XR assist information related to XR to a base station. Here, the XR includes virtual reality, augmented reality, and mixed reality, and represents an environment in which the real world and the virtual space are fused.

Brief Description of the Drawings

[0006]

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[0007] One aspect of the present disclosure aims to provide a communication control method that enables appropriate communication using XR.

[0008] A mobile communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0009] [First Embodiment] (Configuration of Mobile Communication System) FIG. 1 is a diagram showing the configuration of a mobile communication system according to the first embodiment. The mobile communication system 1 complies with the 5th generation system (5GS) of the 3GPP standard. Hereinafter, the 5GS will be described as an example, but the LTE (Long Term Evolution) system may be at least partially applied to the mobile communication system. Alternatively, the 6th generation (6G) system may be at least partially applied to the mobile communication system.

[0010] The mobile communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN) 10, and a 5G core network (5GC) 20. Hereinafter, the NG-RAN 10 may be simply referred to as the RAN 10. Also, the 5GC 20 may be simply referred to as the core network (CN) 20.

[0011] UE100 is a mobile wireless communication device. UE100 can be any device that can be used by a user. For example, UE100 can be a mobile phone terminal (including smartphones), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided for a sensor, a vehicle or a device provided for a vehicle (Vehicle UE), an aircraft or a device provided for an aircraft (Aerial UE).

[0012] UE100 includes an XR device. The XR device is, for example, a device capable of XR processing. Specifically, as XR devices, there are a head-mounted display (HMD) that can be worn on a human head, glasses-type AR glasses (or smart glasses), a mobile handset that can be held in the hand, a wristwatch-type device (smartwatch), or a smartphone, etc. These XR devices may be called wearable devices. The HMD includes a display, a lens, a tracking sensor, a camera, a control unit (such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit)) that performs XR-related processing, and a communication function. The AR glasses have a function of transmitting images. The mobile handset may include various sensors such as a tracking sensor. The HMD, AR glasses, wristwatch-type device, and mobile handset have a communication function that supports a 5G system or the like. Hereinafter, UE100 will be described as including such an XR device.

[0013] NG-RAN 10 includes base stations (referred to as "gNB" in the 5G system) 200. The gNBs 200 are interconnected via the Xn interface, which is an interface between base stations. The gNB 200 manages one or more cells. The gNB 200 performs wireless communication with the UE 100 that has established a connection with its cell. The gNB 200 has functions such as a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as "data"), and a measurement control function for mobility control and scheduling. A "cell" is used as a term indicating the smallest unit of a wireless communication area. A "cell" is also used as a term indicating a function or resource for performing wireless communication with the UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0014] Note that the gNB can also be connected to the EPC (Evolved Packet Core), which is the core network of LTE. The base station of LTE can also be connected to the 5GC. The base station of LTE and the gNB can also be connected via an interface between base stations.

[0015] The 5GC 20 includes an AMF (Access and Mobility Management Function) and a UPF (User Plane Function) 300. The AMF performs various mobility controls for the UE 100. The AMF manages the mobility of the UE 100 by communicating with the UE 100 using NAS (Non-Access Stratum) signaling. The UPF performs data transfer control. The AMF and the UPF are connected to the gNB 200 via the NG interface, which is an interface between the base station and the core network.

[0016] FIG. 2 is a diagram showing the configuration of the UE 100 (user equipment) according to the first embodiment. The UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit 130. The receiving unit 110 and the transmitting unit 120 constitute a wireless communication unit that performs wireless communication with the gNB 200.

[0017] The receiving unit 110 performs various receptions under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts the radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130.

[0018] The transmitting unit 120 performs various transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0019] The control unit 130 performs various controls and processes in the UE 100. Such processes include the processes of each layer described later. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for the processing by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals, etc. The CPU executes programs stored in the memory to perform various processes. Note that the control unit 130 may perform each process or each operation in the UE 100 in each of the embodiments shown below.

[0020] FIG. 3 is a diagram showing the configuration of the gNB 200 (base station) according to the first embodiment. The gNB 200 includes a transmitting unit 210, a receiving unit 220, a control unit 230, and a backhaul communication unit 240. The transmitting unit 210 and the receiving unit 220 constitute a radio communication unit that performs radio communication with the UE 100. The backhaul communication unit 240 constitutes a network communication unit that communicates with the CN 20.

[0021] The transmitting unit 210 performs various transmissions under the control of the control unit 230. The transmitting unit 210 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.

[0022] The receiving unit 220 performs various receptions under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts the radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 230.

[0023] The control unit 230 performs various controls and processes in the gNB 200. Such processes include the processes of each layer described later. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for the processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of the baseband signal, etc. The CPU executes the programs stored in the memory to perform various processes. Note that the control unit 230 may perform each process or each operation in the gNB 200 in each of the embodiments shown below.

[0024] The backhaul communication unit 240 is connected to an adjacent base station via the Xn interface which is a base station-to-base station interface. The backhaul communication unit 240 is connected to the AMF / UPF 300 via the NG interface which is a base station-core network interface. Note that the gNB 200 is composed of a CU (Central Unit) and a DU (Distributed Unit) (that is, functionally split), and the two units may be connected by the F1 interface which is a fronthaul interface.

[0025] Figure 4 is a diagram showing the configuration of the protocol stack of the radio interface of the user plane that handles data.

[0026] The wireless interface protocol of the user plane has a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an SDAP (Service Data Adaptation Protocol) layer.

[0027] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Between the PHY layer of UE100 and the PHY layer of gNB200, data and control information are transmitted via a physical channel. Note that the PHY layer of UE100 receives downlink control information (DCI) transmitted on the physical downlink control channel (PDCCH) from gNB200. Specifically, UE100 performs blind decoding of the PDCCH using a radio network temporary identifier (RNTI) and obtains the DCI that has been successfully decoded as the DCI addressed to itself. The DCI transmitted from gNB200 has CRC parity bits scrambled by the RNTI added thereto.

[0028] The MAC layer performs priority control of data, retransmission processing by hybrid automatic repeat request (HARQ), and random access procedures, etc. Between the MAC layer of UE100 and the MAC layer of gNB200, data and control information are transmitted via a transport channel. The MAC layer of gNB200 includes a scheduler. The scheduler determines the uplink and downlink transport formats (transport block size, modulation and coding scheme (MCS)) and the resource blocks allocated to UE100.

[0029] The RLC layer transmits data to the RLC layer on the receiving side by utilizing the functions of the MAC layer and the PHY layer. Between the RLC layer of UE100 and the RLC layer of gNB200, data and control information are transmitted via logical channels.

[0030] The PDCP layer performs functions such as header compression / expansion and encryption / decryption.

[0031] The SDAP layer performs the mapping between the IP flow, which is the unit for the core network to perform QoS (Quality of Service) control, and the radio bearer, which is the unit for the AS (Access Stratum) to perform QoS control. Note that when the RAN is connected to the EPC, the SDAP may not be necessary.

[0032] Figure 5 is a diagram showing the configuration of the protocol stack of the radio interface of the control plane that handles signaling (control signals).

[0033] The protocol stack of the radio interface of the control plane has an RRC (Radio Resource Control) layer and a NAS (Non-Access Stratum) instead of the SDAP layer shown in Figure 4.

[0034] Between the RRC layer of UE100 and the RRC layer of gNB200, RRC signaling for various settings is transmitted. The RRC layer controls the logical channel, transport channel, and physical channel in response to the establishment, re-establishment, and release of the radio bearer. When there is a connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in the RRC connected state. When there is no connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in the RRC idle state. When the connection between the RRC of UE100 and the RRC of gNB200 is suspended, UE100 is in the RRC inactive state.

[0035] The NAS, which is positioned above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS of the UE100 and the NAS of the AMF300. Note that the UE100 has an application layer etc. in addition to the protocol of the radio interface. Also, the layer below the NAS is called the AS (Access Stratum).

[0036] (Regarding XR) As described above, XR is a broad term that includes, for example, virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment that fuses the real world and the virtual space. XR is also, for example, a general term for various types of realities such as these. Also, XR is, for example, a general term for technologies that enable the perception of things that do not exist in reality by fusing the real world and the virtual space.

[0037] In XR, human - to - machine and human - to - human communications are executed with the assistance of the UE100, which is a portable or wearable end - user device. Through such communications, it becomes possible to apply XR to various application areas such as entertainment, healthcare, or education.

[0038] Together with XR, cloud gaming (CG) is one of the use cases in future mobile systems. Cloud gaming is, for example, a general term for use cases in which most of the calculations related to games are offloaded to an edge server or a remote server. In cloud gaming, the UE100 transmits information related to pose and / or control. On the cloud side, based on this information, calculations related to video data etc. are performed, and video etc. related to the game are provided to the UE100.

[0039] Note that virtual reality (VR) refers to creating an environment that, while not the original (or real world), has the same essence as the original in terms of functionality by stimulating the user's senses. In virtual reality (VR), usually, the user wears an HMD, the user's field of vision is replaced by simulated visual elements, and the accompanying audio is provided to the user through headphones. In the virtual space, it is designed to mimic the sensory stimuli such as vision or hearing in the real world as naturally as possible. Also, the metaverse, which is a virtual space (or service) constructed in a computer or computer network and different from the real world, can also be included in virtual reality (VR).

[0040] Also, augmented reality (AR) is, for example, a technology that overlays a virtual space on the real world for display. In augmented reality (AR), it is also about providing additional information (artificially generated items or content) overlaid on the user's real environment. The additional information can be directly perceived without accompaniments such as sensors, or can also be indirectly perceived through sensors or the like.

[0041] Furthermore, mixed reality (MR) is, for example, a technology that combines and / or fuses the real world and the virtual space to construct a space where they affect each other in real time. Mixed reality (MR) is an evolved form of augmented reality (AR) and is constructed with the intention of inserting virtual elements into a physical scene to give the illusion of being part of the actual scene.

[0042] Typical forms of XR include virtual reality (VR), augmented reality (AR), and mixed reality (MR), but the area interpolating between them can also be included in XR.

[0043] Many use cases of XR and cloud gaming (CG) are characterized by traffic in the DL direction being video stream traffic and traffic in the UL direction being a combination of pose and / or control and video stream traffic. The video stream also has the characteristics of being at a high data rate compared to others, and the data regarding pose and / or control being updated frequently. Also, XR and cloud gaming (CG) have the characteristic that traffic in the DL direction and traffic in the UL direction are traffic that is strict with respect to latency compared to other use cases.

[0044] (Traffic Model of XR) Hereinafter, the traffic model of XR will be described. As the traffic model of XR, there are (1) a general traffic model and (2) a specific traffic model. First, (1) the general traffic model will be described. (1) The general traffic model includes (1.1) a traffic model in the DL direction and (1.2) a traffic model in the UL direction.

[0045] (1) General Traffic Model

[0046] (1.1) Traffic Model in the DL Direction The traffic model in the DL direction includes a single-stream DL traffic model and a multi-stream DL traffic model. The two traffic models can be summarized as follows.

[0047] (1.1.1) Single-Stream DL Traffic Model: A series of video frames

[0048] (1.1.2) Multi-Stream DL Traffic Model:

[0049] (1.1.2.1) Option #1: Two streams where the first stream is an I (Intra-coded) stream and the second stream is a P (Predicted) stream. Option #1 includes a slice-based traffic model (Option #1A) and a GOP (Group-Of-Picture)-based traffic model (Option #1B).

[0050] (1.1.2.1A) Option #1A (slice-based): The first stream is an I slice (I stream) and the second stream is a P slice (P stream). Here, an I slice is, for example, a slice in which all macroblocks included in the I slice are encoded by intra-frame prediction. A P slice is, for example, a slice in which all macroblocks included in the P slice are encoded by intra-frame prediction or inter-frame prediction. When a video frame is sliced into N pieces, 1 piece can be an I slice and the remaining (N - 1) pieces can be P slices.

[0051] (1.1.2.1B) Option #1B (GOP-based): The first stream is an I frame (I stream) and the second stream is a P slice (P stream). Here, an I frame is a frame encoded with the video frame without using other video frames. A P frame is a frame encoded using a temporally forward video frame. When the size of a GOP is K frames, an I frame is transmitted every K frames. A GOP includes 1 I frame and (K - 1) P frames.

[0052] (1.1.2.2) Option #2: A traffic model with two streams where the first stream is video and the second stream is audio and / or data.

[0053] (1.1.2.3) Option #3: The first stream is a traffic model with FOV (Field Of View), and the second stream is an omnidirectional view. For example, the FOV is video data of the user's line of sight, and the omnidirectional view is omnidirectional video data centered on the user, including the video data of the user's line of sight.

[0054] (1.2) Traffic model in the UL direction As a traffic model in the UL direction, there is a posture and / or control stream traffic model. It is a traffic model in which the UE100 transmits data related to posture and / or control.

[0055] (2) Specific traffic models As specific traffic models, there are traffic models for (2.1) virtual reality (VR), (2.2) augmented reality (AR), and (2.3) computer gaming (CG).

[0056] (2.1) Traffic model of virtual reality (VR) The traffic model of virtual reality (VR) can be summarized as follows.

[0057] (2.1.1) DL stream: Single stream model: The same as the above (1.1.1) "Single stream DL traffic model" (a series of video frames) Multi-stream model: The same as the above (1.1.2.2) "Option #2" (the first stream is video, and the second stream is audio and / or data)

[0058] (2.1.2) UL stream: The same as the above (1.2) "Traffic model in the UL direction"

[0059] (2.2) Traffic model of augmented reality (AR) The traffic model of augmented reality (AR) can be summarized as follows.

[0060] (2.2.1) DL Stream: The same as the above (2.1.1)

[0061] (2.2.2) UL Stream: Model #1: 1-stream model Model #2: 2-stream model: The first stream combines posture and / or control, and the second stream combines scene (e.g., continuous video), video, data, and audio. Model #3A: 3-stream model A: The first stream combines posture and / or control, the second stream combines a stream of scene and a stream of video into one stream, and the third stream combines a stream of audio and data into one stream. Model #3B: 3-stream model B: The first stream combines posture and / or control, the second stream is the I stream of video, and the third stream is the P stream of video.

[0062] (2.3) Traffic model for computer gaming (CG) The traffic model for computer gaming (CG) can be summarized as follows.

[0063] (2.3.1) DL Stream Single-stream model: The same as the above (1.1.1) "Single-stream DL traffic model" (a series of video frames) Multi-stream model: The same as the above (1.1.2) "Multi-stream DL traffic model"

[0064] (2.3.2) UL Stream: The same as the above (1.2) "Traffic model in the UL direction"

[0065] (Communication control method according to the first embodiment) In the first embodiment, with the aim of appropriately performing communication using XR in the mobile communication system 1 in consideration of the characteristics regarding such XR traffic.

[0066] Therefore, the user equipment (e.g., UE100) transmits XR assist information related to XR to the base station (e.g., gNB200). Here, XR includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment that fuses the real world and the virtual space.

[0067] Since the XR assist information is transmitted to the gNB200, the gNB200 can perform appropriate settings for communication using XR for the UE100 based on the XR assist information. Therefore, in the mobile communication system 1, through such settings, it is possible to appropriately perform communication using XR.

[0068] Here, the XR assist information includes traffic information related to the traffic characteristics of XR traffic. In the first embodiment, an example in which the XR assist information includes traffic information will be described.

[0069] (Operation example according to the first embodiment) FIG. 6 is a diagram showing an operation example according to the first embodiment.

[0070] As shown in FIG. 6, in step S10, the AS of the UE100 receives traffic information from the upper layer (e.g., the application layer or the NAS layer).

[0071] In step S11, the UE100 transmits XR assist information including the traffic information to the gNB200. The XR assist information is assist information related to XR. The XR assist information may be information that the UE100 expects the gNB200 to perform optimal settings for communication related to XR by transmitting the information to the gNB200. Note that the gNB200 may request the UE100 to notify the gNB200 of the XR assist information prior to step S11. The request may be included and transmitted in, for example, an RRC message or a MAC CE.

[0072] UE100 may send the XR assist information to gNB200 by including it in the RRC message. In this case, UE100 may send the XR assist information as UE assistance information. Alternatively, UE100 may send the XR assist information as a new message (e.g., XR Assistance Information). Also, UE100 may send the XR assist information by including it in the MAC CE instead of the RRC message, or may include the XR assist information in the PDCP Control PDU (Protocol Data Unit). Furthermore, if there is a Control PDU dedicated to the XR layer, UE100 may include the XR assist information in the PDU and send it.

[0073] The traffic information included in the XR assist information includes, for example, the following.

[0074] First, the traffic information may be a logical channel ID (LCID: Logical Channel Identifier) used to transmit XR traffic. The traffic information may also be a bearer ID of a bearer used to transmit XR traffic. Alternatively, the traffic information may be an RLC channel ID of an RLC channel used to transmit XR traffic. The traffic information may be represented by an RNTI (Radio Network Temporary Identifier). For example, a CS-RNTI (Configured Scheduling Radio Network Temporary Identifier) used when transmitting XR traffic using CS (Configured Scheduling) may be the traffic information. Note that CS (Configured Scheduling) is a scheduling method that enables transmission in the UL direction using the radio resources periodically after radio resources for the UL direction are allocated. Also, for example, if there is an RNTI dedicated to XR, the RNTI may be the traffic information. If there is an XR session ID, the traffic information may be the XR session ID. That is, the traffic information may be identification information regarding the transmission path for transmitting XR traffic.

[0075] Second, the traffic information may be the throughput of XR traffic. The traffic information may be the number of transmission bits per burst. In this case, the number of transmission bits may be the transport block size. The traffic information may be the throughput per burst. The traffic information may be the average throughput.

[0076] Third, the traffic information may be a packet delay budget (PDB). Note that PDB is, for example, a QoS (Quality of Service) parameter representing the upper limit of packet delay between the UE 100 and the UPF.

[0077] Fourthly, the traffic information may be a traffic pattern. Specifically, the traffic pattern may be a transmission period and / or a reception period. The transmission period and / or the reception period may represent the duration of one burst or the interval between bursts. The traffic pattern may be represented by the generation rate (fps (frames per second) or Hz) of video frames.

[0078] Fifthly, the traffic information may be an identifier indicating the transmission direction (UL direction or DL direction) of XR traffic. This is considered in view of the fact that the traffic pattern of XR traffic may be different between the UL direction and the DL direction. The UE100 may transmit traffic information in the UL direction and traffic information in the DL direction. For example, the throughput in the UL direction is XX, the delay tolerance is YY, etc., and the throughput in the DL direction is ZZ, the delay tolerance is UU, etc.

[0079] Sixthly, the traffic information may be represented by a QoS value. The QoS value may represent the base characteristics of XR traffic. The base characteristics may be represented by 5QI. For example, when the QoS value of the traffic information is represented by "5" of 5QI, the QoS represented by "5" of 5QI may be the base characteristics of XR traffic. The QoS value can also be combined with the above-described delay tolerance. For example, when the QoS value is represented by "5" of 5QI and the delay tolerance is represented by 2 ms, it can be expressed as XR traffic with the base characteristics of "5" of 5QI and a delay tolerance of 2 ms.

[0080] Seventhly, the traffic information may be the time difference between the assigned CG (Configured Grant) setting and the actual arrival time of the packet. Specifically, the difference between the transmission start timing in the CG set by the CG setting (or the start timing of the DRX active time representing the time when the UE 100 monitors the PDCCH) and the timing when the UE 100 actually receives the packet from the upper layer in the AS may be the traffic information. The difference between the transmission start timing in the CG and the timing when the packet from the upper layer has been waiting for transmission (for example, the PDCP processing completion timing) may be the traffic information. In the UE 100, the smaller such a difference is, the more possible it is to perform transmission with low latency.

[0081] Eighthly, when multi-stream transmission is performed in XR traffic, the XR assist information may include traffic information for each stream. In the traffic model of XR traffic described above, as multi-streams, there is two-stream transmission (the above (1.1.2.1)) using an I stream and a P stream, etc. The XR assist information may include traffic information of the I stream, traffic information of the P stream, etc. In this case, in the XR assist information, the traffic information of each stream may be represented in a list form. The number of streams may be implicitly represented by the number of entries in the list. Information representing the association between streams may be included in the XR assist information. For example, when two streams are used as an XR session, it may be information indicating that the two streams are associated with one XR session. When each stream in the multi-stream is associated with each QoS flow ID, each bearer ID, or each LCID, information representing the association between each QoS flow ID, each bearer ID, or each LCID may be included in the XR assist information.

[0082] In step S12, gNB200 performs settings for UE100 based on the XR assist information. For example, in the DL direction, gNB200 sets C-DRX (Connected mode-Discontinuous Reception) settings (or SPS (Semi-Persistent Scheduling) settings), and in the UL direction, gNB200 sets CG settings, etc. Note that C-DRX is a technology in which UE100 performs intermittent operations while maintaining the RRC connected state. Also, SPS is a scheduling method that enables transmission in the DL direction using the radio resource periodically after the radio resource in the DL direction is allocated. Here, gNB200 may perform scheduling based on the XR assist information. The scheduling may be dynamic scheduling (e.g., allocation of radio resources for each PDSCH) in addition to SPS or CG.

[0083] In step S13, gNB200 transmits the setting information to UE100. gNB200 may include the setting information in an RRC message such as an RRC setup (RRCSetup) message and transmit it. Alternatively, gNB200 may include the setting information in a dedicated RRC message and transmit it. gNB200 may include the setting information in MAC CE or DCI and transmit it. Note that if gNB200 was unable to perform the settings for UE100 in step S12, in step S13, gNB200 may transmit an error notification to UE100. Similar to the setting information, gNB200 may transmit an RRC message, MAC CE, or DCI that includes the error notification. The error notification may include time information when the setting information can be used (or the setting information can be transmitted). The time information may be represented by the elapsed time from the current time (e.g., 3 hours later). Alternatively, the time information may be represented by time information (e.g., 24:00, etc.).

[0084] In step S14, UE100 applies the configuration information. The AS of UE100 may output transmission timing and / or reception timing information regarding XR communication to an upper layer (e.g., the application layer) based on the configuration information. The upper layer may appropriately adjust the resolution or bit rate of the XR application according to the configuration information.

[0085] (Modification Example 1 of the First Embodiment) As described in the first embodiment, there are various types of XR traffic models. For example, in the UL stream of augmented reality (AR), the first stream is for posture and / or control, the second stream is a single stream that combines the scene stream and the video stream, and the third stream is a single stream that combines audio and data (model #3A). And as described in Non-Patent Document 2, different required performances exist according to each type.

[0086] Modification Example 1 of the first embodiment will describe an example in which information regarding the type of XR traffic is included as information included in the XR assist information. Specifically, the information regarding the type of XR traffic includes the number of streams and the transmission information for each stream.

[0087] Thereby, for example, gNB200 can grasp what types of streams UE100 transmits to gNB200 or what types of streams UE100 can receive from gNB200, and perform settings corresponding to such types for UE100. Therefore, in the mobile communication system 1, it is possible to appropriately perform communication using XR.

[0088] FIG. 7 is a diagram showing an operation example according to Modification Example 1 of the first embodiment.

[0089] As shown in FIG. 7, in step S20, UE 100 transmits XR assist information including information regarding the type of traffic. Note that, similar to the first embodiment, gNB 200 may request UE 100 to notify gNB 200 of XR assist information prior to step S20.

[0090] Examples of the information regarding the type of traffic include the following.

[0091] First, the information may be identification information of a transmission path used to transmit XR traffic. Similar to the first embodiment, the identification information of the transmission path may be an LCID or the like.

[0092] Second, the information may be information indicating the number of streams.

[0093] Third, the information may be transmission information for each stream. The transmission information may be information indicating at least any one of posture, control, scene, video, audio, data, an I (Intra-coded) stream of video, and a P (Predicted) stream of video. The transmission information may be QoS information for each stream. The transmission information may be identification information for distinguishing each XR traffic model described in the first embodiment from others. For example, the identification information of the single-stream model in the DL stream of virtual reality (VR) in the above (2.2.1) is "XXX", and the identification information of model #3A in the UL stream of augmented reality (AR) in the above (2.2.2) is "YYY", etc. Such traffic model or type identification information may be determined in the specification.

[0094] Fourth, the XR assist information may include information indicating a request for resources for XR traffic.

[0095] After step S12, it is the same as the first embodiment.

[0096] (Modification Example 2 of the First Embodiment) In the first embodiment, an example in which traffic information is included in the XR assist information was described, and in Modification 1, an example in which information regarding the type of XR traffic is included in the XR assist information was described, but the present invention is not limited thereto. For example, the XR assist information may include upper layer information regarding the upper layer.

[0097] FIG. 8 is a diagram showing an operation example according to Modification 2 of the first embodiment.

[0098] As shown in FIG. 8, in step S30, the UE 100 transmits XR assist information including upper layer information to the gNB 200. The AS of the UE 100 may transmit the upper layer information received from the upper layer (for example, the application layer) to the gNB 200 by including it in the XR assist information. Note that, similar to the first embodiment, the gNB 200 may request the UE 100 to notify the gNB 200 of the XR assist information prior to step S30.

[0099] Examples of the upper layer information include the following.

[0100] First, the upper layer information may be information indicating any one of virtual reality (VR), augmented reality (AR), and cloud gaming (CG). Further, the upper layer information may be information indicating any one of virtual reality (VR), augmented reality (AR), cloud gaming (CG), and mixed reality (MR).

[0101] Second, the upper layer information may be the type of device that executes XR (that is, the UE 100) and / or the product name (or model number) of the device. In particular, for augmented reality (AR), it is conceivable that the performance or communication content differs depending on the device. The gNB 200 that has received the upper layer information can grasp the traffic characteristics from the model number information of the device or the like, and can also perform settings for the UE 100 according to the traffic characteristics. Further, the gNB 200 can also grasp the QoS information required for each device from the model number information of the device or the like, and can also perform settings for the UE 100 according to the QoS characteristics.

[0102] Thirdly, the upper layer information may be the type of traffic model (or the type of encoding). For example, as the type of traffic model, it may be identification information indicating GOP-based I-frames and P-frames. Alternatively, as the type of traffic model, it may be identification information indicating slice-based I-slices and P-slices. Or, as the type of traffic model, it may be identification information for identifying each of the XR traffic models described in the first embodiment.

[0103] Steps S12 and later are the same as those in the first embodiment.

[0104] (Modification Example 3 of the First Embodiment) In the first embodiment, it has been described that UE100 transmits XR assist information to gNB200, but it is not limited to this. For example, CN20 may transmit XR assist information to gNB200.

[0105] Specifically, an access mobility management device (for example, AMF300) transmits XR assist information related to XR to a base station (for example, gNB200). The XR assist information may be transmitted from a session management device (for example, SMF (Session Management Function)) to AMF300 or gNB200. Here, XR includes virtual reality, augmented reality, and mixed reality, and represents an environment that fuses the real world and the virtual space.

[0106] In modification example 3 as well, gNB200 can perform settings related to XR communication for UE100 based on the XR assist information. Therefore, similar to the first embodiment, the mobile communication system 1 can appropriately perform communication related to XR. However, since the XR assist information is transmitted from CN20 to gNB200, UE100 does not have to transmit the XR assist information. Therefore, the radio resources used for transmitting the XR assist information can be utilized for other wireless communications.

[0107] FIG. 9 is a diagram showing an operation example according to Modification Example 3 of the first embodiment.

[0108] As shown in FIG. 9, in step S40, the CN 20 may receive traffic information from the XR application server 400. The XR application server 400 communicates with the UE 100 via the CN 20 and the gNB 200 of the mobile communication system 1 regarding XR. Therefore, the XR application server 400 can hold traffic information regarding XR traffic. The traffic information of Modification Example 3 may include the same information as the traffic information described in the first embodiment.

[0109] In step S41, the CN 20 (for example, the AMF 300) transmits XR assist information to the gNB 200. The XR assist information includes traffic information. The traffic information may be the traffic information received from the XR application server 400. Similar to the traffic information of the first embodiment, the traffic information includes identification information regarding the transmission path for transmitting XR traffic. The identification information may be represented by any one of a QoS flow ID, a PDU session ID, an MBS session ID, and an XR session ID. Note that the XR assist information may include information regarding the type of traffic described in Modification Example 1. Alternatively, the XR assist information may include upper layer information regarding the upper layer described in Modification Example 2. Note that the gNB 200 may request the CN 20 to transmit XR assist information to the gNB 200 prior to step S41. The request may be transmitted, for example, included in an NG message.

[0110] In step S42, the gNB 200 performs settings regarding XR communication for the UE 100 based on the XR assist information. Similar to the first embodiment, the settings for the DL may be C-DRX (or SPS) settings, and the settings for the UL may be CG settings, etc.

[0111] In the third modification example, an example in which XR assist information is transmitted from CN20 to gNB200 was described. Further, the XR assist information may be transferred from the source gNB200-1 (or source cell) of the handover to the target gNB200-2 (or target cell) at the time of handover. Specifically, the XR assist information is transmitted to the target gNB200-2 (or target cell) together with a message requesting a handover from the source gNB200-1 (or source cell) or AMF300 of the handover.

[0112] [Second Embodiment] In the third modification example of the first embodiment, an example in which CN20 transmits XR assist information to gNB200 was described. In this case, gNB200 can set a bearer (DRB: Data Radio Bearer) with UE100 based on the XR assist information.

[0113] In the second embodiment, an example in which gNB200 transmits setting information including information related to the setting to UE100 when performing bearer setting, for example, will be described.

[0114] Specifically, first, a base station (for example, gNB200) sets a transmission path for transmitting XR traffic. Second, the base station transmits setting information related to the set transmission path to a user device (for example, UE100). Third, the user device transmits XR assist information including identification information related to the transmission path to the base station based on the setting information. Here, the setting information includes association information between the identification information and the XR session ID.

[0115] Thereby, for example, as described in the first embodiment, UE100 can also transmit XR assist information including a bearer ID (for example, identification information related to a transmission path) to gNB200. Therefore, in the mobile communication system 1, it is possible to appropriately perform communication related to XR.

[0116] The operations performed in the second embodiment may be performed before the operations performed in the first embodiment. However, the second embodiment does not necessarily assume the operations of the first embodiment and may be implemented independently.

[0117] FIG. 10 is a diagram showing an operation example according to the second embodiment.

[0118] As shown in FIG. 10, in step S50, the gNB 200 performs a transmission path setting for XR transmission for the UE. The transmission path setting includes, for example, the following.

[0119] First, the transmission path setting may include association information between a bearer ID and an XR session ID. For example, when the gNB 200 associates a bearer set between the gNB 200 and the UE 100 with an XR session set between the UPF 300 and the UE 100, the association information between the XR session ID of the XR session and the bearer ID of the bearer may be included in the transmission path setting. Instead of the bearer ID, an LCID, an RLC channel ID, or an RNTI may be used. Also, instead of the bearer ID, a QoS flow ID may be used. The XR session ID may be a stream ID of each stream in the XR traffic. Alternatively, the XR session ID may be a traffic type (I stream, P stream, or type such as pose and / or control) assigned to each stream. Alternatively, the XR session ID may be an identifier only indicating that it is used for the XR session. Or, set information of a plurality of bearers (or association information of a plurality of bearers) may be included in the transmission path setting. For example, association information for associating two bearers for use in one XR transmission, etc. For example, association information for associating a bearer for an I stream and a bearer for a P stream, etc.

[0120] Second, the transmission path setting may include the association information between the TMGI (Temporary Mobile Group Identity) and the XR session ID. However, when the UE100 uses MBS (Multicast and Broadcast Services), the gNB200 may set the association information. Therefore, for example, the gNB200 may set the association information after the UE100 transmits MBS-related interest information to the gNB200. In the DL direction, when increasing the capacity using MBS, the association between the TMGI and the XR session ID may be effective. Note that instead of the TMGI, an MRB ID (MBS Radio Bearer ID), an LCID, or an RLC channel ID may be used. Also, instead of the TMGI, an RNTI such as a G-RNTI (Group-RNTI) or a G-CS-RNTI (Group Configured Scheduling RNTI) may be used.

[0121] Third, the transmission path setting may include the association information between the DRX setting and the XR session ID. Also in this case, when the gNB200 performs a DRX setting in the DL direction for XR transmission, the association information may be included in the transmission path setting. Further, the transmission path setting may include the association information between the SPS setting and the XR session ID. Also in this case, when the gNB200 performs an SPS setting in the DL direction for XR transmission, the association information may be included in the transmission path setting.

[0122] Fourth, the transmission path setting may include the association information between the CG (Configured Grant) setting and the XR session ID. During the CG setting period, only data transmission of the XR session may be permitted. Also in this case, when the gNB200 performs a CG setting in the UL direction for XR transmission, the association information may be included in the transmission path setting.

[0123] Fifthly, the transmission path setting may include association information between identification information of the transmission path such as a bearer ID and the type of XR traffic. For example, it may be association information between bearer #1 and an I stream (or an I frame), or association information between bearer #2 and a P stream (or a P frame). Similar to Modification Example 1 of the First Embodiment, the gNB 200 can transmit the type of traffic used in the transmission path to the UE 100.

[0124] In step S51, the gNB 200 transmits the setting information to the UE 100. The gNB 200 may transmit an RRC message (for example, an RRC Setup message, etc.) including the setting information. Alternatively, the gNB 200 may transmit a MAC CE including the setting information.

[0125] In step S52, the UE 100 applies the received setting information to apply the transmission path setting set by the gNB 200.

[0126] [Third Embodiment] As described in the First Embodiment, XR transmission may include the transmission of video data (or a video stream). Therefore, in some cases, a large amount of data transmission may occur compared to others. In this case, a large amount of radio resources may be required for XR wireless transmission. On the other hand, when XR transmission ends, it may be better to release the radio resources used for XR transmission as soon as possible in some cases.

[0127] Therefore, in the third embodiment, an example will be described in which the UE 100 notifies the gNB 200 to that effect when the transmission of XR traffic ends or when the transmission of XR traffic is temporarily interrupted. Specifically, the user equipment (for example, UE 100) transmits either end information indicating the end of the transmission of XR traffic or interruption information indicating the interruption of the transmission of XR traffic to the base station (for example, gNB 200). Note that the third embodiment may be implemented after the XR assist information described in the first embodiment is transmitted from the UE 100 to the gNB 200 and the settings related to XR are made. However, the third embodiment may be implemented without assuming the first embodiment.

[0128] FIG. 11 is a diagram showing an operation example according to the third embodiment.

[0129] As shown in FIG. 11, in step S60, settings for the XR session are made for the UE 100. Examples of the settings for the XR session include, for example, DRX (or SPS) settings for XR transmission in the DL direction and CG (Configured Grant) settings for XR transmission in the UL direction. As the settings for the XR session, the transmission path settings for XR transmission described in the second embodiment may be made.

[0130] In step S61, the AS of the UE 100 receives a notification of the end of the XR application from the upper layer (for example, the application layer). The AS of the UE 100 may receive a notification of the end of the XR session from the upper layer. Alternatively, the AS of the UE 100 may receive a notification of the end of the XR transmission from the upper layer. Or, the AS of the UE 100 may receive a notification of the suspension of the XR transmission (or XR session, or XR application) from the upper layer.

[0131] In step S62, the UE 100 transmits end information indicating that the XR session has ended to the gNB 200. The UE 100 may transmit request information requesting de - configuration of the settings for the XR session to the gNB 200. Alternatively, the UE 100 may transmit suspend information indicating that the transmission of XR traffic is to be paused to the gNB 200. The end information, request information, or suspend information may include identification information of the transmission path associated with the XR session. Similar to the first embodiment, the identification information may be any one of LCID, bearer ID, RLC channel ID, RNTI, and XR session ID. The UE 100 may transmit an RRC message including the end information, request information, or suspend information to the gNB 200. Also, the UE 100 may transmit a MAC CE including the end information, request information, or suspend information to the gNB 200. Further, the UE 100 may transmit a DCI including the end information, request information, or suspend information to the gNB 200.

[0132] In step S63, upon receiving the end information, the gNB 200 de - configures the settings for the XR session. Upon receiving the suspend information, the gNB 200 may pause the settings for the XR session.

[0133] Note that before starting (or resuming) communication by XR, UE100 may send a message indicating the start (or resumption) of communication by XR to gNB200. That is, when communication by XR is started (or resumed), information indicating the start of the XR session (or information indicating the resumption, or information indicating that the start and / or resumption will be performed in the near future) may be notified from UE100 to gNB200. The notification may be a setting request for the XR session. The notification may include information on the transmission path associated with the XR session. When the notification indicates that the start and / or resumption will be performed in the near future, the notification may include information indicating the time of the start and / or resumption (e.g., the start time or the time until the start). The notification may be included in an RRC message or a MAC CE and transmitted from UE100 to gNB200.

[0134] [Other Embodiments] A program for causing a computer to execute each process performed by UE100 or gNB200 may be provided. The program may be recorded on a computer-readable medium. By using a computer-readable medium, it is possible to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0135] Also, circuits for executing each process performed by UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chipset, SoC: System on a chip).

[0136] As described above, one embodiment has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the gist. Also, within a non-contradictory range, all or part of each embodiment, each operation, each process, and each step can be combined.

[0137] As used in this disclosure, the terms "based on" and "depending on" do not mean "only based on" or "only depending on" unless otherwise specified. The term "based on" means both "only based on" and "at least partially based on". Similarly, the term "depending on" means both "only depending on" and "at least partially depending on". Also, the terms "include", "comprise", and their variants do not mean to include only the listed items, but may include only the listed items or may further include additional items in addition to the listed items. Further, the term "or" used in this disclosure is not intended to be an exclusive disjunction. Additionally, any reference to an element using designations such as "first", "second", etc. in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this specification as a convenient way to distinguish between two or more elements. Thus, a reference to the first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in any form. In this disclosure, for example, when articles are added by translation such as a, an, and the in English, these articles shall be construed to include plural ones unless the context clearly indicates otherwise.

[0138] This application claims the priority of Japanese Patent Application No. 2022-070308 (filed on April 21, 2022), and all of its contents are incorporated herein by reference.

[0139] (Appendix) In one embodiment, (Appendix 1) A communication control method in a mobile communication system, comprising a step in which a user device transmits XR assist information related to XR (Extended Reality) to a base station, where the XR includes virtual reality (VR: Virtual Reality), augmented reality (AR: Augmented Reality), and mixed reality (MR: Mixed Reality), and represents an environment in which the real world and the virtual space are fused.

[0140] (Appendix 2) In the communication control method of (Appendix 1) above, the XR assist information may include traffic information related to the traffic characteristics of XR traffic.

[0141] (Appendix 3) In the communication control method of (Appendix 1) or (Appendix 2) above, the traffic information may represent at least any one of identification information related to the transmission path for transmitting the XR traffic, the throughput of the XR traffic, the delay tolerance of the XR traffic, the traffic pattern of the XR traffic, an identifier indicating the transmission direction of the XR traffic, a QoS (Quality of Service) value, and the difference between the CG (Configured Grant) setting and the timing of receiving a packet from the upper layer.

[0142] (Appendix 4) In the communication control method of any one of (Appendix 1) to (Appendix 3) above, the identification information can be any one of the logical channel ID for transmitting the XR traffic, the bearer ID, the RLC channel ID, the RNTI (Radio Network Temporary Identifier), and the XR session ID.

[0143] (Appendix 5) In the communication control method of any one of (Appendix 1) to (Appendix 4) above, when the XR traffic is multi-stream, the XR assist information may include the traffic information for each stream.

[0144] (Appendix 6) In any of the communication control methods described in the above (Appendix 1) to (Appendix 5), the XR assist information may include information regarding the type of XR traffic.

[0145] (Appendix 7) In any of the communication control methods described in the above (Appendix 1) to (Appendix 6), the information regarding the type of XR traffic may include the number of streams and transmission information for each stream.

[0146] (Appendix 8) In any of the communication control methods described in the above (Appendix 1) to (Appendix 7), the transmission information may be information indicating at least any one of posture, control, scene, video, audio, data, the I (Intra-coded) stream of video, and the P (Predicted) stream of video for each stream.

[0147] (Appendix 9) In any of the communication control methods described in the above (Appendix 1) to (Appendix 8), the XR assist information may include upper layer information regarding the upper layer.

[0148] (Appendix 10) In any of the communication control methods described in the above (Appendix 1) to (Appendix 9), the upper layer information may include at least any one of information representing any one of virtual reality, augmented reality, and cloud gaming, information regarding the type and product name of the user device, and information representing a traffic model.

[0149] (Appendix 11) In any of the communication control methods described in the above (Appendix 1) to (Appendix 10), further, the base station has steps of setting the transmission path for transmitting the XR traffic and transmitting setting information regarding the transmission path to the user device, and the step of transmitting the XR assist information to the base station includes the step of the user device transmitting the XR assist information including the identification information to the base station based on the setting information, and the setting information may include association information between the identification information and the XR session ID.

[0150] (Appendix 12) In any of the communication control methods described in the above (Appendix 1) to (Appendix 11), the user device may further include a step of transmitting to the base station either end information indicating the end of the transmission of XR traffic or suspend information indicating the suspension of the transmission of XR traffic.

[0151] Also, in one embodiment, (Appendix 13) A communication control method in a mobile communication system, wherein an access mobility management device has a step of transmitting XR assist information related to XR to a base station, and the XR includes virtual reality, augmented reality, and mixed reality, and represents an environment in which the real world and the virtual space are fused.

[0152] (Appendix 14) In the communication control method described in the above (Appendix 13), the XR assist information includes identification information related to a transmission path for transmitting XR traffic, and the identification information can be represented by any one of a QoS flow ID, a PDU (Protocol Data Unit) session ID, an MBS (Multicast and Broadcast Services) session ID, and an XR session ID.

Explanation of Reference Numerals

[0153] 1: Mobile communication system 20: CN 100: UE 110: Receiver 120: Transmitter 130: Control unit 200: gNB 210: Transmitter 220: Receiver 230: Control unit 300: AMF

Claims

1. A communication control method in a mobile communication system, comprising: A network node transmits, to a user device, configuration information including an identifier of a Quality of Service (QoS) follow corresponding to an extended reality (XR) traffic and a session ID associated with the identifier of the QoS follow; The user equipment transmits XR assist information to the network node based on the configuration information. Communications control method.

2. The XR assist information includes a period of the XR traffic. The communication control method according to claim 1 .

3. The XR assist information includes a delay tolerance of the XR traffic. The communication control method according to claim 1 .

4. and transmitting, by the user equipment, a logical channel ID for the XR traffic to the network node. The communication control method according to claim 1 .

5. The method further comprises transmitting, to the network node, a difference between a setting from the network node and a timing at which a packet is received from an upper layer. The communication control method according to claim 1 .

6. and further comprising the user equipment including the difference in a MAC CE. The communication control method according to claim 5.

7. and transmitting a delay tolerance of the XR traffic to the network node by the access mobility management device. The communication control method according to claim 1 .

8. A user device, A receiving unit that receives, from a network node, configuration information including an identifier of a Quality of Service (QoS) follow corresponding to an extended reality (XR) traffic and a session ID associated with the identifier of the QoS follow; A transmission unit that transmits XR assist information to the network node based on the setting information. User equipment.

9. A network node for use in a mobile communication system, comprising: A transmission unit that transmits, to a user device, configuration information including an identifier of a Quality of Service (QoS) follow corresponding to an extended reality (XR) traffic and a session ID associated with the identifier of the QoS follow; A receiving unit that receives XR assist information from the user device. Network node.

10. A mobile communication system, comprising: A network node transmits, to a user device, configuration information including an identifier of a Quality of Service (QoS) follow corresponding to an extended reality (XR) traffic and a session ID associated with the identifier of the QoS follow; The user device transmits XR assist information to the network node based on the setting information. Mobile communication system.

111. A user device includes: A process of receiving, from a network node, configuration information including an identifier of a Quality of Service (QoS) follow corresponding to an extended reality (XR) traffic and a session ID associated with the identifier of the QoS follow; and transmitting XR assist information to the network node based on the setting information. program.

12. A chipset for a user device, comprising: Receiving configuration information from a network node, the configuration information including an identifier of a Quality of Service (QoS) follow corresponding to an extended reality (XR) traffic and a session ID associated with the identifier of the QoS follow; and transmitting XR assist information to the network node based on the setting information. Chipset.

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