Communication control method

Abstract

A communication control method according to one aspect is a communication control method in a mobile communication system. The communication control method includes transmitting, at a user equipment, XR assistance information related to augmented reality (XR) to a base station. The XR includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment obtained by fusing the real world and virtual space.

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 the 3rd Generation Partnership Project (3GPP) (registered trademark, the same below), which is a standardization project for mobile communication systems, Extended Reality (XR) of Release 18 has been approved. XR is a broad term that includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment obtained by fusing the real world and virtual space. XR represents a mixed environment of the real space and the virtual space generated by computer technology and wearable devices, and expresses the interaction between humans and machines. Reference List Non-patent literature

[0003] Non-Patent Document 1: RP-213587, 3GPP TSG RAN Meeting #94e, “Study on XR Enhancementsfor NR”, Nokia, December 6-17, 2021. Non-patent document 2: 3GPP TR 38.838 V17.0.0 (2021-12) 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 the following steps: at a user equipment, sending XR auxiliary information related to extended reality (XR) to a base station. The XR includes virtual reality (VR), augmented reality (AR) and mixed reality (MR), and represents an environment obtained by fusing the real world and the virtual space.

[0005] A communication control method according to one aspect is a communication control method in a mobile communication system. The communication control method includes the following steps: at an access mobility management device, sending XR auxiliary information related to XR to a base station. XR includes virtual reality, augmented reality, and mixed reality, and represents an environment obtained by fusing the real world and the virtual space. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a diagram showing a configuration example of a mobile communication system according to the first embodiment. Figure 2 is a diagram showing a configuration example of a user equipment (UE) according to the first embodiment. Figure 3 : is a diagram showing a configuration example of a gNB (base station) according to the first embodiment. Figure 4 FIG. 1 is a diagram showing a configuration example of a protocol stack of a user plane according to the first embodiment. Figure 5 : is a diagram showing a configuration example of a protocol stack of a control plane according to the first embodiment. Figure 6 is a diagram showing an operation example according to the first embodiment. Figure 7 1 is a diagram showing an operation example according to Modification 1 of the first embodiment. Figure 8 2 is a diagram showing an operation example according to Modification 2 of the first embodiment. Fig. 9 1 is a diagram showing an operation example according to Modification 3 of the first embodiment. Fig.10 is a diagram showing an operation example according to the second embodiment. Fig.11 is a diagram showing an operation example according to the third embodiment. DETAILED DESCRIPTION

[0007] An aspect of the present disclosure provides a communication control method capable of appropriately performing communication using XR.

[0008] A mobile communication system according to an embodiment is described with reference to the accompanying 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 Figure 1 1 is a configuration diagram showing a mobile communication system according to a first embodiment. The mobile communication system 1 complies with the fifth generation system (5GS) of the 3GPP standard. The following description takes 5GS as an example, but the long term evolution (LTE) system may be at least partially applied to the mobile communication system. Alternatively, the sixth 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 (next generation 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. The 5GC 20 may be simply referred to as the core network (CN) 20.

[0011] UE 100 is a mobile wireless communication device. UE 100 may be any device as long as UE 100 is used by a user. Examples of UE 100 include a mobile phone terminal (including a smart phone) or a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided on a sensor, a vehicle or a device provided on a vehicle (vehicle-mounted UE), and an aircraft or a device provided on an aircraft (airborne UE).

[0012] UE 100 includes an XR device. The XR device is, for example, a device capable of processing XR. More specifically, the XR device includes a head-mounted display (HMD) that can be mounted on a person's head, glasses-type AR glasses (or smart glasses), a mobile handheld device that can be held by a hand, a watch-type device (smart watch), and a smart phone. These XR devices may be referred to as wearable devices. The HMD includes a display, a lens, a tracking sensor, a camera, a control unit (e.g., a central processing unit (CPU) or a graphics processing unit (GPU)) that performs XR-related processing, and a communication function. AR glasses have a function that allows video to be sent through them. The mobile handheld device may include various sensors such as a tracking sensor. The HMD, AR glasses, watch-type devices, and mobile handheld devices have communication functions that support 5G systems, etc. In the following, UE 100 will be described assuming that UE 100 includes such an XR device.

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

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

[0015] The 5GC 20 includes an access and mobility management function (AMF) and a user plane function (UPF) 300. The AMF performs various types of mobility control, etc. for the UE 100. The AMF manages the mobility of the UE 100 by communicating with the UE 100 using non-access stratum (NAS) signaling. The UPF controls data transmission. The AMF and the UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0016] Figure 2 1 is a diagram showing a configuration of a user equipment (UE) 100 according to the first embodiment. The UE 100 includes a receiver 110, a transmitter 120, and a controller 130. The receiver 110 and the transmitter 120 constitute a wireless communicator that performs wireless communication with the gNB 200.

[0017] The receiver 110 performs various types of reception under the control of the controller 130. The receiver 110 includes an antenna and a receiving device. The receiving device converts a radio signal received through the antenna into a baseband signal (received signal) and outputs the resulting signal to the controller 130.

[0018] The transmitter 120 performs various types of transmission under the control of the controller 130. The transmitter 120 includes an antenna and a transmission device. The transmission device converts a baseband signal (transmission signal) output by the controller 130 into a radio signal and transmits the resultant signal through the antenna.

[0019] The controller 130 performs various types of control and processing in the UE 100. Such processing includes processing of various layers to be described later. The controller 130 includes at least one processor and at least one memory. The memory stores programs to be executed by the processor and information to be used by the processor for processing. The processor may include a baseband processor and a central processing unit (CPU). The baseband processor performs modulation and demodulation, encoding and decoding of baseband signals, etc. The CPU executes the program stored in the memory, thereby performing various types of processing. Note that in each embodiment to be described below, the controller 130 can perform each processing and each operation in the UE 100.

[0020] Figure 3 2 is a diagram showing a configuration of a gNB 200 (base station) according to the first embodiment. The gNB 200 includes a transmitter 210, a receiver 220, a controller 230, and a backhaul communicator 240. The transmitter 210 and the receiver 220 constitute a wireless communicator that performs wireless communication with the UE 100. The backhaul communicator 240 constitutes a network communicator that performs communication with the CN 20.

[0021] The transmitter 210 performs various types of transmission under the control of the controller 230. The transmitter 210 includes an antenna and a transmission device. The transmission device converts a baseband signal (transmission signal) output by the controller 230 into a radio signal and transmits the resultant signal through the antenna.

[0022] The receiver 220 performs various types of reception under the control of the controller 230. The receiver 220 includes an antenna and a receiving device. The receiving device converts a radio signal received through the antenna into a baseband signal (received signal) and outputs the resulting signal to the controller 230.

[0023] The controller 230 performs various types of control and processing in the gNB 200. Such processing includes processing of various layers to be described later. The controller 230 includes at least one processor and at least one memory. The memory stores programs to be executed by the processor and information to be used by the processor for processing. The processor may include a baseband processor and a CPU. The baseband processor performs modulation and demodulation, encoding and decoding, etc. of baseband signals. The CPU executes the program stored in the memory, thereby performing various types of processing. Note that the controller 230 can perform all processing and operations in the gNB 200 in each embodiment to be described below.

[0024] The backhaul communicator 240 is connected to the neighboring base station via the Xn interface which is an interface between base stations. The backhaul communicator 240 is connected to the AMF / UPF 300 via the NG interface between the base station and the core network. Note that the gNB 200 may include a central unit (CU) and a distributed unit (DU) (ie, the functions are divided), and the two units may be connected via the F1 interface which is a fronthaul interface.

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

[0026] The radio interface protocol of the user plane includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.

[0027] The PHY layer performs encoding and decoding, modulation and demodulation, antenna mapping and demapping, and resource mapping and demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the gNB 200 via a physical channel. Note that the PHY layer of the UE 100 receives downlink control information (DCI) transmitted from the gNB 200 through the physical downlink control channel (PDCCH). Specifically, the UE 100 blindly decodes the PDCCH using the radio network temporary identifier (RNTI) and acquires the successfully decoded DCI as the DCI addressed to the UE 100. The DCI transmitted from the gNB 200 is attached with CRC parity bits scrambled by the RNTI.

[0028] The MAC layer performs priority control of data, retransmission processing by hybrid ARQ (HARQ: Hybrid Automatic Repeat Request), a random access procedure, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the gNB 200 via a transport channel. The MAC layer of the gNB 200 includes a scheduler. The scheduler determines the transport format (transport block size, modulation and coding scheme (MCS)) in uplink and downlink and resource blocks to be allocated to the UE 100.

[0029] The RLC layer transmits data to the RLC layer on the receiving side by using the functions of the MAC layer and the PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via a logical channel.

[0030] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

[0031] The SDAP layer performs mapping between IP flows (as the unit of QoS (Quality of Service) control performed by the core network) and radio bearers (as the unit of QoS control performed by the access stratum (AS)). Note that when the RAN is connected to the EPC, SDAP does not need to be provided.

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

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

[0034] RRC signaling for various configurations is transmitted between the RRC layer of the UE 100 and the RRC layer of the gNB 200. The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, reestablishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in the RRC connected state. When there is no connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in the RRC idle state. When the connection between the RRC of the UE 100 and the RRC of the gNB 200 is suspended, the UE 100 is in the RRC inactive state.

[0035] NAS located above the RRC layer performs session management, mobility management, etc. NAS signaling is sent between the NAS of the UE 100 and the NAS of the AMF 300. Note that the UE 100 includes an application layer in addition to the protocol of the radio interface. A layer lower than the NAS is called an access stratum (AS).

[0036] 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 obtained by fusing the real world and virtual space. XR is also a general term for these various types of reality. XR is also a general term for technologies that enable perception of things that do not exist in reality by, for example, fusing the real world and virtual space.

[0037] According to XR, the UE 100, which is a portable or wearable end-user device, assists in performing human-machine communication or human-human communication. Such communication enables XR to be applied to various application fields such as entertainment, healthcare, or education.

[0038] In addition to XR, cloud gaming (CG) is one of the use cases in future mobile systems. Cloud gaming is a general term for use cases that offload most of the computations related to the game to an edge server or a remote server. According to cloud gaming, UE100 sends information related to gestures and / or controls. The cloud side performs computations related to video data, etc. based on this information, and provides UE 100 with videos related to the game, etc.

[0039] Note that virtual reality (VR) refers to creating an environment that is not the original environment (or the real world) but whose functional essence is the same as the original environment by stimulating the user's senses. According to virtual reality (VR), the user usually wears an HMD, the user's field of view is replaced with simulated visual elements, and accompanying audio is provided to the user through headphones. The virtual space is designed to imitate the visual, auditory and other sensory stimulations of the real world as naturally as possible. The metaverse can also be included in virtual reality (VR), which is a virtual space (or service) built in a computer or computer network and different from the real world.

[0040] Augmented reality (AR) is a technology that displays a virtual space over the real world, for example. Augmented reality (AR) also provides additional information by overlaying additional information (artificially generated items or content) on the user's real environment. The additional information can also be perceived directly without sensors or the like, or indirectly via sensors or the like.

[0041] Mixed reality (MR) is a technology that mixes and / or fuses, for example, the real world and virtual space to construct a space that affects each other in real time. Mixed reality (MR) is a development of augmented reality (AR), and its construction purpose is to insert virtual elements into the physical scene and present the illusion that the virtual elements are part of the actual scene.

[0042] Representative forms of XR are virtual reality (VR), augmented reality (AR) and mixed reality (MR), and XR also includes areas of intersection between these VR, AR and MR.

[0043] In many use cases of XR and cloud gaming (CG), the DL direction is characterized by video streaming services, and the UL direction is characterized by services that are a combination of gestures and / or control with video streaming. The video stream also has the following characteristics: the video stream has a relatively high data rate, and the data related to gestures and / or control is frequently updated. XR and cloud gaming (CG) also have the following characteristics: compared with other use cases, the services in the DL direction and the services in the UL direction are services with strictly limited latency.

[0044] XR Business Model In the following, the XR business model will be described. The XR business model includes (1) a general business model and (2) a specific business model. First, the (1) general business model will be described. The (1) general business model includes (1.1) a business model for the DL direction and (1.2) a business model for the UL direction.

[0045] (1) General business model

[0046] (1.1) DL business model The service models in the DL direction include a single-stream DL service model and a multi-stream DL service model. These two service models can be summarized as follows.

[0047] (1.1.1) Single-stream DL service model: video frame series

[0048] (1.1.2) Multi-stream DL service model:

[0049] (1.1.2.1) Option #1: Two streams, a first stream and a second stream, where the first stream is an intra-coded (I) stream and the second stream is a predicted (P) stream. Option #1 includes a slice-based service model (Option #1A) and a group of pictures (GOP)-based service 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). An I slice is, for example, a slice obtained by encoding all macroblocks included in an I slice by intra prediction. A P slice is, for example, a slice obtained by encoding all macroblocks included in a P slice by intra prediction or inter prediction. When a video frame is sliced ​​into N frames, one frame may be an I slice, and the remaining (N-1) frames may be P slices.

[0051] (1.1.2.1B) Option #1B (GOP-based): The first stream is I frames (I stream) and the second stream is P slices (P stream). An I frame is a frame that is encoded from the corresponding video frame without using another video frame. A P frame is a frame that is encoded forward in time using a video frame. When the GOP size is K frames, one I frame is sent every K frames. A GOP consists of one I frame and (K-1) P frames.

[0052] (1.1.2.2) Option #2: The service model includes two streams: a first stream and a second stream, wherein the first stream is video and the second stream is audio and / or data.

[0053] (1.1.2.3) Option #3: The service model includes a first stream as field of view (FOV) and a second stream as omnidirectional view. For example, FOV is the video data of the user's line of sight, and omnidirectional view is the omnidirectional video data (it includes the video data of the user's line of sight and its center is the user).

[0054] (1.2) UL business model The traffic model in the UL direction includes a gesture and / or control flow traffic model. This traffic model is a traffic model in which the UE 100 sends data related to gesture and / or control.

[0055] (2) Specific business model The specific business models include (2.1) a virtual reality (VR) business model, (2.2) an augmented reality (AR) business model, and (2.3) a computer game (CG) business model.

[0056] (2.1) Virtual Reality (VR) Business Model The virtual reality (VR) business model can be summarized as follows.

[0057] (2.1.1) DL flow: Single stream model: Same as the above (1.1.1) "Single stream DL service model" (video frame series) Multi-stream model: Same as above (1.1.2.2) "Option #2" (first stream is video and second stream is audio and / or data)

[0058] (2.1.2) UL flow: Same as the above (1.2) “service model in UL direction”.

[0059] (2.2) Augmented Reality (AR) Business Model The augmented reality (AR) business model can be summarized as follows.

[0060] (2.2.1) DL flow: Same as above (2.1.1)

[0061] (2.2.2) UL flow: Model #1: 1-stream model Model #2: 2-stream model: The first stream is gesture and / or control, and the second stream is a collection of scene (eg, continuous video), video, data, and audio. Model #3A: 3-stream Model A: The first stream is gesture and / or control, the second stream is a collective stream of scene stream and video stream, and the third stream is a collective stream of audio and data. Model #3B: 3-stream Model B: The first stream is gesture 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) Computer Game (CG) Business Model The computer game (CG) business model can be summarized as follows.

[0063] (2.3.1) DL Flow Single stream model: Same as the above (1.1.1) "Single stream DL service model" (video frame series) Multi-stream model: Same as the above (1.1.2) "Multi-stream DL service model"

[0064] (2.3.2) UL flow: Same as the above (1.2) “service model in UL direction”.

[0065] Communication Control Method According to the First Embodiment An object of the first embodiment is that the mobile communication system 1 appropriately performs communication using XR in consideration of characteristics associated with such XR services.

[0066] A user equipment (eg, UE 100) transmits XR auxiliary information related to XR to a base station (eg, gNB 200). XR includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment obtained by fusing the real world and a virtual space.

[0067] The XR assistance information is transmitted to the gNB 200 so that the gNB 200 can perform appropriate configuration related to communication using XR on the UE 100 based on the XR assistance information. Therefore, the mobile communication system 1 can appropriately perform communication using XR through such configuration.

[0068] The XR auxiliary information includes service information related to service characteristics of the XR service. The first embodiment will describe an example in which the XR auxiliary information includes the service information.

[0069] Operation Example According to the First Embodiment Figure 6 is a diagram showing an operation example according to the first embodiment.

[0070] like Figure 6 As shown, in step S10, the AS of the UE 100 receives service information from an upper layer (eg, an application layer or a NAS layer).

[0071] In step S11, UE 100 transmits XR assistance information including service information to gNB 200. XR assistance information is assistance information related to XR. XR assistance information may be information indicating that UE 100 expects gNB 200 to perform optimal configuration for XR-related communication by transmitting the information to gNB 200. Note that before step S11, gNB 200 may request UE 100 to notify gNB 200 of XR assistance information. The request may be included in, for example, an RRC message, a MAC CE, etc. and transmitted.

[0072] The UE 100 may include the XR assistance information in an RRC message to be sent to the gNB 200. In this case, the UE 100 may send the XR assistance information as UE assistance information. Alternatively, the UE 100 may send the XR assistance information as a new message (e.g., XR assistance information). The UE 100 may include the XR assistance information in a MAC CE instead of an RRC message to be sent, or may include the XR assistance information in a PDCP control protocol data unit (PDU) to be sent. If there is a control PDU dedicated to the XR layer, the UE 100 may include the XR assistance information in the PDU to be sent.

[0073] The service information included in the XR auxiliary information is as follows, for example.

[0074] First, the service information may be a logical channel identifier (LCID: Logical Channel ID) for sending the XR service. The service information may be a bearer ID of a bearer for sending the XR service. Alternatively, the service information may be an RLC channel ID of an RLC channel for sending the XR service. The service information may be represented by a radio network temporary identifier (RNTI). For example, a configuration scheduling radio network temporary identifier (CS-RNTI) used when using configuration scheduling (CS) to send XR services may be service information. Note that configuration scheduling (CS) is a scheduling scheme that, when radio resources are allocated in the UL direction, radio resources can then be used to periodically send in the UL direction. For example, when there is an RNTI dedicated to XR, the RNTI may be service information. When there is an XR session ID, the service information may be an XR session ID. That is, the service information may be identification information related to the channel for sending the XR service.

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

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

[0077] Fourth, the service information may be a service mode. The service mode may be more specifically a transmission cycle and / or a reception cycle. The transmission cycle and / or the reception cycle may indicate a duration of a burst or a burst interval. The service mode may be represented by a video frame generation rate (fps (frames per second) or Hz).

[0078] Fifth, the service information may be an identifier indicating the transmission direction (UL direction or DL ​​direction) of the XR service. It is also considered that the service mode of the XR service is different between the UL direction and the DL direction. The UE 100 may send service information in the UL direction and service information in the DL direction. For example, the throughput in the UL direction is XX and the packet delay budget is YY, and the throughput in the DL direction is ZZ and the packet delay budget is UU.

[0079] Sixth, the service information can be represented by a QoS value. The QoS value can indicate the basic characteristics of the XR service. The basic characteristics can be represented by 5QI. For example, when the QoS value of the service information is indicated as "5" of 5QI, the QoS indicated as "5" of 5QI can be the basic characteristic of the XR service. The QoS value can also be combined with the above-mentioned packet delay budget. For example, when the QoS value is indicated as "5" of 5QI and the packet delay budget is indicated as 2ms, the XR service can be indicated as an XR service whose basic characteristic is "5" of 5QI and whose packet delay budget is 2ms.

[0080] Seventh, the service information may be the time difference between the allocated configuration grant (CG) configuration and the actual packet arrival time. More specifically, the difference between the transmission start timing in the CG configured by the CG configuration (or the start timing of the DRX active time indicating the time when the UE 100 monitors the PDCCH) and the timing at which the AS of the UE 100 actually receives the packet from the upper layer may be the service information. The difference between the transmission start timing in the CG and the timing at which the packet from the upper layer is in the transmission standby state (for example, the PDCP processing completion timing) may be the service information. As this difference is smaller, the UE 100 can perform transmission with lower delay.

[0081] Eighth, when multi-stream transmission is performed for the XR service, the XR auxiliary information may include service information for each stream. The service model of the above-mentioned XR service includes the transmission of two streams (above-mentioned (1.1.2.1)), which are an I stream and a P stream as multi-streams. The XR auxiliary information may include service information for the I stream, service information for the P stream, and the like. In this case, the XR auxiliary information may indicate the service information for each stream in a list form. The number of streams may be implicitly indicated by the number of entries in the list. The XR auxiliary information may include information indicating the association between streams. For example, when two streams are used as an XR session, information indicating that the two streams are associated with one XR session may be used. When each stream of a multi-stream service is associated with each QoS stream ID, each bearer ID, or each LCID, the XR auxiliary information may include information indicating the association between each QoS stream ID, each bearer ID, or each LCID.

[0082] In step S12, the gNB 200 performs configuration on the UE 100 based on the XR auxiliary information. For example, the gNB 200 configures a connected mode-discontinuous reception (C-DRX) configuration (or an SPS (semi-persistent scheduling) configuration) in the DL direction, a CG configuration in the UL direction, and the like. Note that C-DRX is a technology in which the UE 100 performs intermittent operations while maintaining an RRC connected state. SPS is a scheduling scheme in which, when radio resources in the DL direction are allocated, these radio resources can then be used for transmission in the DL direction. Here, the gNB 200 may perform scheduling based on the XR auxiliary information. In addition to SPS or CG, the scheduling may also be dynamic scheduling (for example, allocating radio resources for each PDSCH).

[0083] In step S13, the gNB 200 transmits configuration information to the UE 100. The gNB 200 may include the configuration information in an RRC message (e.g., an RRC Setup message) for transmission. Alternatively, the gNB 200 may include the configuration information in a dedicated RRC message for transmission. The gNB 200 may include the configuration information in a MAC CE, a DCI, etc. for transmission. Note that when the gNB 200 cannot perform configuration on the UE 100 in step S12, the gNB 200 may transmit an error notification to the UE 100 in step S13. The gNB 200 may transmit an RRC message, a MAC CE, or a DCI including an error notification similar to the configuration information. The error notification may include time information at which the configuration information can be used (or at which the configuration information can be transmitted). The time information may be represented by a time (e.g., three hours later) elapsed from the current time. Alternatively, the time information may be represented by time information (e.g., 24:00).

[0084] In step S14, the UE 100 applies the configuration information. The AS of the UE 100 may output the transmission timing and / or reception timing information of XR-related communications to the upper layer (eg, application layer) based on the configuration information. The upper layer may appropriately adjust the resolution, bit rate, etc. of the XR application according to the configuration information.

[0085] Modification 1 of the first embodiment As described in the first embodiment, the XR service model includes various types. For example, the UL stream of augmented reality (AR) includes a first stream, a second stream, and a third stream, wherein the first stream is a gesture and / or control, the second stream is a collection stream of a scene stream and a video stream, and the third stream is a collection stream of audio and data (model #3A). As described in non-patent document 2, each type has different required performance.

[0086] Modification 1 of the first embodiment will describe an example in which the information included in the XR auxiliary information includes information related to the XR service type. More specifically, the information related to the XR service type includes the number of streams and transmission information of each stream.

[0087] Therefore, for example, the gNB 200 can recognize what type of stream the UE 100 transmits to the gNB 200 or what type of stream the UE 100 can receive from the gNB 200, and can perform configuration on the UE 100 according to this type. Therefore, the mobile communication system 1 can appropriately perform communication using XR.

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

[0089] like Figure 7 As shown, in step S20, UE 100 sends XR auxiliary information including information related to the service type. Note that, similar to the first embodiment, before step S20, gNB 200 may request UE 100 to notify gNB 200 of the XR auxiliary information.

[0090] The information related to the business type is shown below, for example.

[0091] First, the information may be identification information of a channel for transmitting the XR service. The identification information of the channel may be LCID or the like similar to the first embodiment.

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

[0093] Third, the information may be transmission information for each stream. The transmission information may be information indicating at least one item selected from the group consisting of: posture, control, scene, video, audio, data, intra-coded (I) video stream, and predicted (P) video stream. The transmission information may be QoS information for each stream. The transmission information may be identification information for distinguishing each XR business model described in the first embodiment from other XR business models. For example, the identification information of the single-stream model in the DL stream of the above-mentioned (2.2.1) virtual reality (VR) is "XXX", and the identification information of model #3A in the UL stream of the above-mentioned (2.2.2) augmented reality (AR) is "YYY", etc. The identification information of such a business model or type may be determined by the specification.

[0094] Fourth, the XR auxiliary information may include information indicating resources of a desired XR service.

[0095] Step S12 and subsequent steps are the same as those in the first embodiment.

[0096] Modification 2 of the first embodiment The first embodiment has described an example in which the XR auxiliary information includes service information, and the modification 1 has described an example in which the XR auxiliary information includes information related to the XR service type. However, the present disclosure is not limited thereto. For example, the XR auxiliary information may include upper layer information related to the upper layer.

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

[0098] like Figure 8 As shown, in step S30, UE 100 sends XR auxiliary information including upper layer information to gNB 200. The AS of UE 100 may include the upper layer information received from the upper layer (e.g., application layer) in the XR auxiliary information to send to gNB 200. Note that, similar to the first embodiment, before step S30, gNB 200 may request UE 100 to notify gNB 200 of the XR auxiliary information.

[0099] The upper layer information is as follows, for example.

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

[0101] Secondly, the upper layer information may be the type of the device (i.e., UE 100) that performs XR and / or the product name (or model) of the corresponding device. Specifically, according to augmented reality (AR), the performance or content of communication is considered to vary depending on the device. The gNB 200 that has received the upper layer information may identify the service characteristics based on the model information of the device, etc., and may also perform configuration matching the service characteristics on the UE 100. The gNB 200 may also identify the QoS information requested for each device from the model information of the device, etc., and may configure the UE 100 to match the QoS characteristics.

[0102] Third, the upper layer information may be a service model type (or encoding type). For example, the service model type may be identification information indicating I frames and P frames based on GOP. Alternatively, the service model type may be identification information indicating I slices and P slices based on slices. Alternatively, the service model type may be identification information for identifying each XR service model described in the first embodiment.

[0103] Step S12 and subsequent steps are the same as those in the first embodiment.

[0104] Modification 3 of the first embodiment The first embodiment has described that the UE 100 sends the XR auxiliary information to the gNB 200. However, the present disclosure is not limited thereto. For example, the CN 20 may send the XR auxiliary information to the gNB 200.

[0105] More specifically, the access mobility management device (e.g., AMF 300) transmits XR assistance information related to XR to the base station (e.g., gNB 200). The XR assistance information may be transmitted from the session management device (e.g., session management function (SMF)) to the AMF 300 or the gNB 200. XR includes virtual reality, augmented reality, and mixed reality, and represents an environment obtained by fusing the real world and the virtual space.

[0106] Also in modification 3, gNB 200 may perform configuration related to XR communication on UE 100 based on XR auxiliary information. Therefore, similar to the first embodiment, mobile communication system 1 may appropriately perform XR-related communication. In this regard, since XR auxiliary information is transmitted from CN 20 to gNB 200, UE 100 may not transmit XR auxiliary information. Therefore, radio resources used to transmit XR auxiliary information may be used for other wireless communications.

[0107] Fig. 9 1 is a diagram showing an operation example according to Modification 3 of the first embodiment.

[0108] like Fig. 9 As shown, in step S40, CN 20 may receive service information from XR application server 400. XR application server 400 performs XR-related communication with UE 100 via CN 20 and gNB 200 of mobile communication system 1. Therefore, XR application server 400 may maintain service information related to XR services. The service information according to variant example 3 may include the same information as the service information described in the first embodiment.

[0109] In step S41, CN 20 (e.g., AMF 300) sends XR auxiliary information to gNB 200. The XR auxiliary information includes service information. The service information may be service information received from the XR application server 400. Similar to the service information according to the first embodiment, the service information includes identification information related to the channel through which the XR service is transmitted. The identification information may be represented by one of a QoS flow ID, a PDU session ID, an MBS session ID, or an XR session ID. Note that the XR auxiliary information may include information related to the service type described in variant 1. Alternatively, the XR auxiliary information may include the above-mentioned layer information related to the upper layer described in variant 2. Note that before step S41, gNB 200 may request CN 200 to send XR auxiliary information to gNB 200. For example, the request may be included in an NG message and transmitted.

[0110] In step S42, the gNB 200 performs configuration related to XR communication on the UE 100 based on the XR auxiliary information. Similar to the first embodiment, the configuration may also be a C-DRX (or SPS) configuration in DL and a CG configuration in UL.

[0111] Modification 3 has described an example in which XR assistance information is transmitted from CN 20 to gNB 200. XR assistance information may be transmitted from the handover source gNB 200-1 (or source cell) to the handover destination gNB 200-2 (or target cell) at the time of handover. More specifically, the XR assistance information is transmitted from the handover source gNB 200-1 (or source cell) or AMF 300 to the handover destination gNB 200-2 (or target cell) together with a message for requesting handover.

[0112] Second embodiment Modification 3 of the first embodiment has described an example in which CN 20 transmits XR assistance information to gNB 200. In this case, gNB 200 can configure a bearer (DRB: Data Radio Bearer) for UE 100 based on the XR assistance information.

[0113] The second embodiment will describe the following example: When gNB 200 performs, for example, bearer configuration, gNB 200 sends configuration information including information related to the configuration to UE 100.

[0114] More specifically, first, the base station (e.g., gNB 200) configures a channel for sending XR services. Second, the base station sends configuration information related to the configured channel to the user equipment (e.g., UE 100). Third, the user equipment sends XR auxiliary information including identification information related to the channel to the base station based on the configuration information. Here, the configuration information includes association information between the identification information and the XR session ID.

[0115] Therefore, for example, as described in the first embodiment, the UE 100 can also send XR auxiliary information including a bearer ID (eg, identification information related to a channel) to the gNB 200. Therefore, the mobile communication system 1 can appropriately perform XR-related communications.

[0116] The operations performed in the second embodiment may be performed before the operations performed in the first embodiment. However, the second embodiment is not necessarily premised on the operations of the first embodiment, but may be performed independently.

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

[0118] like Fig.10 As shown, in step S50, gNB 200 configures a channel for XR transmission for UE. The channel configuration includes, for example, the following contents.

[0119] First, the channel configuration may include association information between the bearer ID and the XR session ID. For example, when the gNB 200 associates the bearer configured between the gNB 200 and the UE 100 with the XR session configured 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 and the configuration. The bearer ID may be replaced with an LCID, an RLC channel ID, or an RNTI. The bearer ID may be replaced with a Qos stream ID. The XR session ID may be a stream ID for each stream in the XR service. Alternatively, the XR session ID may be a service type (I stream, P stream, or a type such as gesture and / or control) assigned to each stream. Alternatively, the XR session ID may be an identifier that indicates only that the XR session ID is used for the XR session. Alternatively, the channel configuration may include setting information for multiple bearers (or association information for multiple bearers). For example, the setting information is association information for associating two bearers for one XR transmission, etc. For example, the setting information is association information for associating a bearer for an I stream with a bearer for a P stream.

[0120] Secondly, the channel configuration may include association information between a temporary mobile group identity (TMGI) and an XR session ID. In this regard, when the UE 100 uses a multicast and broadcast service (MBS), the gNB 200 may configure the association information. Thus, for example, after the UE 100 sends interest information for the MSB to the gNB 200, the gNB 200 may configure the association information. When MBS in the DL direction is used to increase capacity, the association between the TMGI and the XR session ID may be valid. Note that an MRBID (MBS Radio Bearer ID), LCID, or RLC Channel ID may be used instead of the TMGI. An RNTI such as a Group RNTI (G-RNTI) or a Group Configuration Scheduling RNTI (G-CS-RNTI) may be used instead of the TMGI.

[0121] Third, the channel configuration may include association information between the DRX information and the XR session ID. In this case, when the gNB 200 performs DRX configuration in the DL direction for the XR transmission, the channel configuration may also include the association information. The channel configuration may include association information between the SPS configuration and the XR session ID. In this case, when the gNB 200 performs SPS configuration in the DL direction for the XR transmission, the channel configuration may also include the association information.

[0122] Fourth, the channel configuration may include association information between a configuration grant (CG) configuration and an XR session ID. During CG configuration, only data transmission of an XR session may be allowed. In this case, when the gNB 200 performs CG configuration in the UL direction for XR transmission, the channel configuration may also include the association information.

[0123] Fifth, the channel configuration may include association information between identification information of the channel (e.g., bearer ID) and the XR service type. For example, the association information may be association information between bearer #1 and I stream (or I frame) or association information between bearer #2 and P stream (or P frame). Similar to variation 1 of the first embodiment, the gNB 200 may send the service type for the channel to the UE 100.

[0124] In step S51, gNB 200 sends the configuration information to UE 100. gNB 200 may send an RRC message (e.g., an RRCSetup message) including the configuration information. Alternatively, gNB 200 may send a MAC CE including the configuration information.

[0125] In step S52, UE 100 applies the channel configuration configured by gNB 200 by applying the received configuration information.

[0126] Third embodiment XR transmission may also include transmission of video data (or video stream) as described in the first embodiment. Therefore, a large amount of data can be sent compared to other technologies. In this case, the wireless transmission of XR may require a large amount of radio resources. On the other hand, when the XR transmission is ended, it is preferred to release the radio resources used for the XR transmission as quickly as possible.

[0127] The third embodiment will describe an example in which, when the transmission of the XR service is ended or when the transmission of the XR service is temporarily interrupted, the UE 100 notifies the gNB 200 of the end or temporary interruption of the transmission. More specifically, the user equipment (e.g., UE 100) transmits one of end information indicating the end of the transmission of the XR service or interruption information indicating the interruption of the transmission of the XR service to the base station (e.g., gNB 200). Note that the third embodiment may be performed after the XR auxiliary information described in the first embodiment is transmitted from the UE 100 to the gNB 200 and the configuration related to XR is performed. In this regard, the third embodiment may be performed without the first embodiment.

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

[0129] like Fig.11 As shown, in step S60, the configuration of the XR session is performed on the UE 100. Examples of the configuration of the XR session include DRX (or SPS) configuration of XR transmission in the DL direction, CG (configuration grant) configuration of XR transmission in the UL direction, etc. As the configuration of the XR session, the channel configuration of the XR transmission described in the second embodiment can be performed.

[0130] In step S61, the AS of the UE 100 receives a notification from an upper layer (e.g., an application layer) to end the XR application. The AS of the UE 100 may receive a notification from the upper layer to end the XR session. Alternatively, the AS of the UE 100 may receive a notification from the upper layer to end the XR transmission. Alternatively, the AS of the UE 100 may receive a notification from the upper layer to temporarily stop the XR transmission (or XR session or XR application).

[0131] In step S62, UE 100 sends end information indicating that the XR session has ended to gNB 200. UE 100 may send request information for requesting cancellation of the configuration of the XR session to gNB 200. Alternatively, UE 100 may send pause information indicating temporary cessation of XR service transmission to gNB 200. The end information, request information, or pause information may include identification information of a channel associated with the XR session. Similar to the first embodiment, the identification information may be one of an LCID, a bearer ID, an RLC channel ID, an RNTI, or an XR session ID. UE 100 may send an RRC message including the end information, request information, or pause information to gNB 200. UE 100 may send a MAC CE including the end information, request information, or pause information to gNB 200. UE 100 may send a DCI including the end information, request information, or pause information to gNB 200.

[0132] In step S63, gNB 200 cancels the configuration of the XR session in response to receiving the end information. gNB 200 may temporarily stop the configuration of the XR session in response to receiving the pause information.

[0133] Note that before starting (or resuming) communication using XR, UE 100 may send information indicating the start (or resumption) of communication using XR to gNB 200. That is, when starting (or resuming) communication using XR, UE 100 may notify gNB 200 of information indicating that an XR session has been started (or information indicating that the XR session has been resumed, or information indicating that the XR session is started and / or resumed in the near future). The notification may be a configuration request for an XR session. The notification may include information of a channel associated with the XR session. In the case where the notification indicates that the XR session is started and / or resumed in the near future, the notification may include time information indicating the start and / or resumption of the XR session (e.g., the start time or the time until the start). The notification may be included in an RRC message, a MAC CE, or the like, and sent from UE 100 to gN 200.

[0134] Other embodiments A program that causes a computer to execute each process performed by UE 100 or gNB 200 may be provided. The program may be recorded in a computer-readable medium. The program can be installed on a computer using a computer-readable medium. 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 specifically limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0135] Circuits for performing processing performed by UE 100 or gNB 200 may be integrated, and at least a portion of UE 100 or gNB 200 may be implemented as a semiconductor integrated circuit (chip set, system on chip (SoC)).

[0136] The embodiments have been described in detail above with reference to the accompanying drawings, but the specific configuration is not limited to the above configuration, and various design changes can be made without departing from the gist of the present disclosure. All or some of the embodiments, operations, processes, and steps can be combined without contradiction.

[0137] Unless otherwise expressly stated, the phrases "based on" and "depending on" used in this disclosure do not mean "based only on" and "depending only on". The phrase "based on" means both "based only on" and "based at least in part on". The phrase "depending on" means "depending only on" and "depending at least in part on". The terms "include", "include" and their variations do not mean "only including the items", but mean "may only include the items" or "may include not only the items but also other items". The term "or" used in this disclosure is not intended to be an "exclusive or". Any reference to elements using names such as "first" and "second" in this disclosure does not generally limit the number or order of these elements. These names can be used as a convenient method to distinguish two or more elements in this article. Therefore, the reference to the first element and the second element does not mean that only two elements can be used there or that the first element needs to be in some way before the second element. For example, when English articles such as "one", "an" and "the" are added in this disclosure by translation, these articles include plural unless otherwise clearly indicated in the context.

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

[0139] Additional Notes (Supplementary Note 1) According to one embodiment, a communication control method in a mobile communication system includes the following steps: at a user equipment, sending XR auxiliary information related to extended reality (XR) to a base station. The XR includes virtual reality (VR), augmented reality (AR), and mixed reality (MR), and represents an environment obtained by fusing the real world and the virtual space.

[0140] (Supplementary Note 2) According to the communication control method described in (Supplementary Note 1) above, the XR auxiliary information may include service information related to service characteristics of the XR service.

[0141] (Supplementary Note 3) According to the communication control method described in (Supplementary Note 1) or (Supplementary Note 2) above, the service information may indicate at least one item selected from the group consisting of: identification information related to the channel for sending the XR service, the throughput of the XR service, the packet delay budget of the XR service, the service mode of the XR service, an identifier of the sending direction of the XR service, a quality of service (QoS) value, and a difference between a configuration authorization (CG) configuration and the timing of receiving a packet from an upper layer.

[0142] (Supplementary Note 4) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 3) above, the identification information may be one of a logical channel ID, a bearer ID, an RLC channel ID, a radio network temporary identifier (RNTI), or an XR session ID for sending the XR service.

[0143] (Supplementary Note 5) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 4) above, when the XR service is a multi-stream service, the XR auxiliary information may include service information of each stream.

[0144] (Supplementary Note 6) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 5) above, the XR auxiliary information may include information related to the type of the XR service.

[0145] (Supplementary Note 7) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 6) above, the information related to the type of the XR service may include the number of streams and transmission information of each stream.

[0146] (Supplementary Note 8) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 7) above, the transmitted information may be information indicating at least one item selected from the group consisting of: posture, control, scene, video, audio, data, intra-coded (I) video stream, and predicted (P) video stream of each stream.

[0147] (Supplementary Note 9) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 8) above, the XR auxiliary information may include upper layer information related to the upper layer.

[0148] (Supplementary Note 10) According to the communication control method described in any one of (Supplementary Note 1) to (Supplementary Note 9) above, the upper layer information may include at least one item selected from the group consisting of: information indicating one of virtual reality, augmented reality or cloud gaming, information related to the type and product name of the user device, and information indicating a business model.

[0149] (Supplementary Note 11) The communication control method according to any one of (Supplementary Note 1) to (Supplementary Note 10) above may further include the following steps: at the base station, configuring a channel for sending XR services; and at the base station, sending configuration information related to the channel to the user equipment, and the step of sending XR auxiliary information to the base station may include the step of sending XR auxiliary information including the identification information to the base station at the user equipment based on the configuration information, and the configuration information may include association information between the identification information and the XR session ID.

[0150] (Supplementary Note 12) The communication control method according to any one of the above (Supplementary Note 1) to (Supplementary Note 11) may also include the following steps: at the user equipment, sending to the base station one of end information indicating the end of sending the XR service or pause information indicating the temporary stop of sending the XR service.

[0151] (Supplementary Note 13) According to one embodiment, a communication control method in a mobile communication system includes the step of sending XR auxiliary information related to XR to a base station at an access mobility management device, and XR includes virtual reality, augmented reality, and mixed reality and represents an environment obtained by fusing the real world and the virtual space.

[0152] (Supplementary Note 14) According to the communication control method described in (Supplementary Note 13) above, the XR auxiliary information may include identification information related to the channel for sending the XR service, and the identification information is represented by one of a QoS flow ID, a protocol data unit (PDU) session ID, a multicast and broadcast service (MBS) session ID, or an XR session ID. Reference numerals

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

Claims

1. A communication control method in a mobile communication system, the communication control method comprising: At the user equipment, XR auxiliary information related to the extended reality XR is sent to the base station, Among them, the XR includes virtual reality VR, augmented reality AR and mixed reality MR, and represents an environment obtained by integrating the real world and the virtual space.

2. The communication control method according to claim 1, wherein: The XR auxiliary information includes service information related to service characteristics of the XR service.

3. The communication control method according to claim 2, wherein: The service information indicates at least one item selected from the group consisting of: identification information related to the channel for sending the XR service, the throughput of the XR service, the packet delay budget of the XR service, the service mode of the XR service, an identifier indicating the sending direction of the XR service, a quality of service QoS value, and the difference between a configured authorized CG configuration and the timing of packets received from an upper layer.

4. The communication control method according to claim 3, wherein: The identification information is one of a logical channel ID, a bearer ID, an RLC channel ID, a radio network temporary identifier RNTI, or an XR session ID used to send the XR service.

5. The communication control method according to claim 3, wherein: When the XR service is a multi-stream service, the XR auxiliary information includes service information of each stream.

6. The communication control method according to claim 1, wherein: The XR auxiliary information includes information related to the type of XR service.

7. The communication control method according to claim 6, wherein: The information related to the type of the XR service includes the number of streams and transmission information of each stream.

8. The communication control method according to claim 7, wherein: The transmission information is information indicating at least one item selected from the group consisting of posture, control, scene, video, audio, data, intra-coded I video stream, and predicted P video stream of each stream.

9. The communication control method according to claim 1, wherein: The XR auxiliary information includes upper layer information related to an upper layer.

10. The communication control method according to claim 9, wherein: The upper layer information includes at least one item selected from the group consisting of: information indicating one of virtual reality, augmented reality, or cloud gaming, information related to a type and a product name of the user device, and information indicating a business model.

11. The communication control method according to claim 3, further comprising the following steps: At the base station, configuring a channel for sending the XR service; At the base station, sending configuration information related to the channel to the user equipment, The sending of the XR auxiliary information to the base station includes: at the user equipment, sending the XR auxiliary information including the identification information to the base station based on the configuration information, The configuration information includes association information between the identification information and the XR session ID.

12. The communication control method according to claim 1, further comprising: At the user equipment, one of the following information is sent to the base station: end information indicating the end of sending the XR service or pause information indicating the temporary stop of sending the XR service.

13. A communication control method in a mobile communication system, the communication control method comprising: At the access mobility management device, XR auxiliary information related to XR is sent to the base station, Among them, the XR includes virtual reality, augmented reality and mixed reality, and refers to an environment obtained by integrating the real world and the virtual space.

14. The communication control method according to claim 13, wherein: The XR auxiliary information includes identification information related to the channel for sending the XR service, The identification information is represented by one of a QoS flow ID, a protocol data unit PDU session ID, a multicast and broadcast service MBS session ID, or an XR session ID.

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