Communication control method

Abstract

One aspect relates to a communication control method in a mobile communication system. The communication control method comprises a step for extending PDSCH monitoring or PDCCH monitoring by a predetermined period if a user device does not receive, from a base station, a PDSCH or a PDCCH respectively at a periodic timing of Semi-Persistent Scheduling (SPS) or a periodic timing of Discontinuous Reception (DRX).

Description

Communication Control Method

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

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

[0003] RP-213587, 3GPP TSG RAN Meeting #94e, “Study on XR Enhancements for NR”, Nokia, Dec. 6-17,20213GPP TR 38.838 V17.0.0 (2021-12)

[0004] A communication control method according to one aspect is a communication control method in a mobile communication system, the communication control method including, when a user equipment does not receive a PDSCH or a PDCCH from a base station at a periodic timing of semi-persistent scheduling (SPS) or a periodic timing of discontinuous reception (DRX), respectively, extending monitoring of the PDSCH or monitoring of the PDCCH for a predetermined period.

[0005] According to one aspect, there is provided a communication control method in a mobile communication system, the communication control method including, when a user equipment does not transmit a PUSCH to a base station at a periodic timing of a configured grant (CG), extending transmission of the PUSCH for a predetermined period.

[0006] FIG. 1 is a diagram illustrating an example of the configuration of a mobile communication system according to the first embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a UE (user equipment) according to the first embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a gNB (base station) according to the first embodiment. FIG. 4 is a diagram illustrating an example of the configuration of a protocol stack related to a user plane according to the first embodiment. FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack related to a control plane according to the first embodiment. FIG. 6 is a diagram illustrating an example of an operation according to the first embodiment. FIG. 7 is a diagram illustrating an example of an operation according to the second embodiment. FIG. 8 is a diagram illustrating an example of an operation according to the third embodiment.

[0007] An object of one aspect of the present disclosure is 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 conforms to the 5th Generation System (5GS) of the 3GPP standard. Although the following description will be given using 5GS as an example, the mobile communication system may also be at least partially based on an LTE (Long Term Evolution) system. Alternatively, the mobile communication system may also be at least partially based on a 6th Generation (6G) system.

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

[0011] The UE 100 is a mobile wireless communication device. The UE 100 may be any device that is used by a user. For example, the UE 100 may be a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE).

[0012] The UE 100 includes an XR device. The XR device is, for example, a device capable of XR processing. Specific examples of XR devices include a head-mounted display (HMD) that can be worn on a human head, eyeglass-type AR glasses (or smart glasses), a handheld mobile handset, a wristwatch-type device (smart watch), and a smartphone. These XR devices may also be referred to as wearable devices. The HMD includes a display, lenses, 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. The AR glasses have a function for 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, etc. In the following, the UE 100 will be described as including such an XR device.

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

[0014] In addition, gNBs can also be connected to the Evolved Packet Core (EPC), which is the core network of LTE. LTE base stations can also be connected to 5GC. LTE base stations and gNBs can also be connected via an inter-base station interface.

[0015] The 5GC20 includes an Access and Mobility Management Function (AMF) and a User Plane Function (UPF) 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 controls data forwarding. 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] 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 types of reception under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal 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 a 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 processes of each layer described below. 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 in the processes by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation, encoding / decoding, etc. of baseband signals. The CPU executes programs stored in the memory to perform various processes. Note that the control unit 130 may perform each process or operation in the UE 100 in each of the embodiments described below.

[0020] 3 is a diagram showing the 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 communication unit 240. The transmitter 210 and the receiver 220 constitute a wireless communication unit that performs wireless 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 a 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 types of reception under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 230.

[0023] The control unit 230 performs various controls and processes in the gNB 200. Such processes include processes for each layer described below. 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 in the processes by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation, encoding / decoding, etc. of baseband signals. The CPU executes programs stored in the memory to perform various processes. Note that the control unit 230 may perform each process or operation in the gNB 200 in each of the embodiments described below.

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

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

[0026] The user plane radio interface protocol 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 / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of UE100 and the PHY layer of gNB200 via a physical channel. The PHY layer of UE100 receives downlink control information (DCI) transmitted from gNB200 on a physical downlink control channel (PDCCH). Specifically, UE100 performs blind decoding of the PDCCH using a radio network temporary identifier (RNTI) and acquires the successfully decoded DCI as DCI addressed to the UE. The DCI transmitted from gNB200 has a CRC parity bit scrambled by the RNTI added.

[0028] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat reQuest (HARQ), random access procedures, 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 uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to the UE 100.

[0029] The RLC layer transmits data to the receiving RLC layer using the functions of the MAC layer and 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, and the like.

[0031] The SDAP layer maps IP flows, which are units for Quality of Service (QoS) control by the core network, to radio bearers, which are units for QoS control by the Access Stratum (AS). Note that if the RAN is connected to the EPC, SDAP may not be required.

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

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

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

[0035] The NAS, which is located above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS of the UE 100 and the NAS of the AMF 300. Note that the UE 100 has an application layer and the like in addition to the radio interface protocol. Also, the layer below the NAS is called an Access Stratum (AS).

[0036] (About XR) As described above, XR is a broad term that includes, for example, virtual reality (VR), augmented reality (AR), and mixed reality (MR), and describes an environment that combines the real world and a virtual space. XR is also, for example, a general term for such various types of realities. XR is also, for example, a general term for technology that combines the real world and a virtual space to enable perception of things that do not exist in reality.

[0037] In XR, human-to-machine and human-to-human communication is performed with the aid of a portable or wearable end-user device, the UE 100. Such communication enables XR to be applied in various application areas such as entertainment, healthcare, or education.

[0038] Along with XR, cloud gaming (CG) is one of the use cases in future mobile systems. Cloud gaming is a general term for use cases in which, for example, most of the calculations related to a game are offloaded to an edge server or a remote server. In cloud gaming, the UE 100 transmits information related to pose and / or control. The cloud performs calculations related to video data and the like based on this information and provides the UE 100 with video and other game-related data.

[0039] Virtual reality (VR) refers to the creation of an environment that is not the original (or real world) but is essentially functionally the same as the original by stimulating the user's senses. In virtual reality (VR), the user typically wears an HMD, the user's field of vision is replaced with simulated visual elements, and accompanying audio is provided to the user through headphones. Virtual spaces are designed to mimic sensory stimuli such as sight and hearing in the real world as naturally as possible. Virtual reality (VR) can also include the metaverse, a virtual space (or service) built on a computer or computer network that is different from the real world.

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

[0041] Furthermore, mixed reality (MR) is a technology that combines and / or blends the real world and a virtual space to create a space in which they interact with each other in real time. Mixed reality (MR) is an advanced form of augmented reality (AR) and is constructed with the intention of inserting virtual elements into a physical scene to give the illusion that they are part of the actual scene.

[0042] Typical forms of XR include virtual reality (VR), augmented reality (AR), and mixed reality (MR), but areas that interpolate between these may also be included in XR.

[0043] Many XR and cloud gaming (CG) use cases are characterized by video stream traffic in the DL direction and a combination of pose and / or control traffic and video stream traffic in the UL direction. The video stream has a higher data rate than other use cases, and data related to pose and / or control is updated frequently. Furthermore, XR and cloud gaming (CG) are characterized by the fact that DL traffic and UL traffic are more sensitive to delays than other use cases.

[0044] (XR Traffic Model) The following describes the XR traffic model. XR traffic models include (1) a general traffic model and (2) a specific traffic model. First, (1) the general traffic model will be described. The (1) 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 DL Direction There are two types of traffic models in the DL direction: 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 Sequence of Video Frames

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

[0049] (1.1.2.1) Option #1: Two streams, the first stream being an I (Intra-coded) stream and the second stream being 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 coded by intra-frame prediction. A P slice is, for example, a slice in which all macroblocks included in the P slice are coded by intra-frame prediction or inter-frame prediction. When a video frame is sliced ​​into N slices, one slice can be an I slice, and the remaining (N-1) slices 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 using a video frame without using other video frames. A P-frame is a frame encoded using a video frame preceding it in time. If the GOP size is K frames, an I-frame is transmitted every K frames. A GOP includes one 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: A traffic model in which the first stream is a field of view (FOV) and the second stream is an omnidirectional view. For example, the FOV is video data from the user's line of sight, and the omnidirectional view is omnidirectional video data centered on the user, including video data from the user's line of sight.

[0054] (1.2) Traffic Model in UL Direction The traffic model in the UL direction includes an attitude and / or control stream traffic model, in which the UE 100 transmits data related to attitude and / or control.

[0055] (2) Specific Traffic Models Specific traffic models include (2.1) virtual reality (VR), (2.2) augmented reality (AR), and (2.3) cloud gaming (CG) traffic models.

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

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

[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: same as (2.1.1) above

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

[0062] (2.3) Cloud Gaming (CG) Traffic Model The traffic model for cloud gaming (CG) can be summarized as follows:

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

[0064] (2.3.2) UL stream: Same as (1.2) "Traffic model in UL direction" above

[0065] (SPS and CG) In a 5G system, a scheduling method called SPS (Semi-Persistent Scheduling) may be used in the DL direction. SPS is a scheduling method in which, for example, when radio resources in the DL direction are allocated by DCI (Downlink Control Information) transmitted using a PDCCH (Physical Downlink Control Channel), the UE 100 can then periodically communicate using the radio resources without using the DCI. Unlike dynamic scheduling, which performs scheduling using DCI for each PDSCH (Physical Downlink Shared Channel), SPS enables semi-fixed scheduling, which makes it possible to reduce the processing effort in the UE 100. The period is notified from the gNB 200 to the UE 100 by the SPS setting (SPS-Config) included in an RRC message (for example, an RRC setup message or an RRC reconfiguration message). The gNB 200 can also set multiple SPS settings with different periods.

[0066] In addition, in 5G systems, a scheduling method called CG (Configured Grant) may be used in the UL direction. CG is a scheduling method in which, for example, once radio resources in the UL direction are allocated by DCI transmitted using the PDCCH, the UE 100 can then periodically communicate in the UL direction using the radio resources without using DCI. The period is notified from the gNB 200 to the UE 100 by a CG setting (ConfiguredGrantConfig) included in an RRC message (for example, an RRC setup message or an RRC reconfiguration message). Note that there are two types of CG: Type 1, which allows UL transmission without using DCI, and Type 2, which performs UL transmission using DCI. In the case of Type 1, the radio resources are directly included in the CG setting. gNB200 is also capable of setting multiple CG settings with different periods.

[0067] (Communication Control Method According to First Embodiment) In XR traffic, jitter has been attracting attention.

[0068] For example, the average packet arrival time of a video stream is determined by the frame rate (e.g., 60 frames per second (fps)). However, packet arrival times actually vary due to encoding delays and transmission delays. Such variations can affect packet arrival times as jitter. Jitter thus refers to fluctuations in packet arrival times. In XR traffic, jitter is modeled as a random variable added on top of periodic packet arrival times.

[0069] Here, it is assumed that gNB200 transmits such jittered XR traffic using SPS. If a packet for XR traffic arrives from CN20 to gNB200 earlier than the SPS timing, gNB200 stores the packet in a buffer or the like and transmits it at the SPS timing. This does not pose a major problem.

[0070] However, if the packet arrives at the gNB 200 at a timing later than the SPS timing, the gNB 200 will wait until the next SPS timing to transmit the packet. In this case, a transmission delay of one SPS period will occur. On the other hand, the UE 100 will not be able to receive the packet at the SPS timing, and will have to wait until the next SPS period to receive the packet.

[0071] As described above, in XR traffic, jitter may cause transmission delay. The transmission delay may affect the user experience (UX) in use cases such as augmented reality (AR) or cloud gaming (CG). Therefore, in the mobile communication system 1, communication using XR traffic may not be performed appropriately.

[0072] The first embodiment aims to appropriately perform communication using XR traffic.

[0073] Therefore, in the first embodiment, an example will be described in which, when UE 100 is unable to receive a packet using PDSCH at SPS timing, the waiting period for PDSCH is extended.

[0074] Specifically, if a user device (e.g., UE100) does not receive a PDSCH from a base station (e.g., gNB200) at the SPS periodic timing, it extends monitoring of the PDSCH for a predetermined period of time.

[0075] As a result, for example, the PDSCH monitoring period at the SPS timing is extended, so that the UE 100 can receive packets during the extended period without waiting for one SPS cycle. Therefore, transmission delay can be suppressed. Therefore, in the mobile communication system 1, it is possible to appropriately perform communication using XR traffic.

[0076] The SPS timing refers to, for example, periodic timing in the SPS. The periodic timing in the SPS refers to, for example, timing of a period indicated in the SPS setting. The UE 100 monitors the PDSCH at the SPS timing. Then, the UE 100 receives a packet transmitted by the PDSCH.

[0077] Furthermore, in 3GPP, an inactivity timer (drx-InactivityTimer) is specified in a DRX (Discontinuous Reception) setting. The inactivity timer is a timer for continuing monitoring of the PDCCH when the UE 100 receives the PDCCH during a DRX on duration (On duration), taking into consideration that the UE 100 will subsequently receive the PDCCH. That is, the inactivity timer is a timer that is activated when the UE 100 receives the PDCCH. On the other hand, in the first embodiment, the inactivity timer is different from the inactivity timer in that it is activated when the UE 100 does not receive the PDSCH.

[0078] In the following, "receiving a PDSCH" and "receiving a packet using a PDSCH" may be used without distinction. Also, in the following, "transmitting a PDSCH" and "transmitting a packet using a PDSCH" may be used without distinction. Furthermore, in the following, "transmitting a PUSCH" and "transmitting a packet using a PUSCH" may be used without distinction.

[0079] (Operation Example of First Embodiment) FIG. 6 is a diagram showing an operation example of the first embodiment.

[0080] As shown in FIG. 6, in step S10, the gNB 200 performs SPS configuration for the UE 100. The SPS configuration may include configuration information indicating whether to extend PDSCH monitoring. The UE 100 can determine, based on the configuration information, whether to extend PDSCH monitoring or monitor PDSCH without extension. The configuration information may include information indicating an extension period for PDSCH monitoring. The information indicating the extension period may be expressed as a timer value. Note that the gNB 200 may include the SPS configuration including the configuration information in an RRC message, MAC CE, or the like, and transmit it to the UE 100.

[0081] In step S11, the gNB 200 transmits the PDSCH at the SPS timing. In this case, the UE 100 receives the PDSCH at the SPS timing and ends monitoring of the PDSCH.

[0082] In step S12, the gNB 200 does not transmit the PDSCH at the SPS timing. In this case, in step S13, the UE 100 does not receive the PDSCH at the SPS timing.

[0083] In step S14, UE 100 extends the monitoring of the PDSCH for a predetermined period after the SPS timing. That is, if UE 100 does not receive the PDSCH from gNB 200 at the SPS periodic timing (step S13), UE 100 extends the monitoring of the PDSCH for a predetermined period. Here, UE 100 determines to extend the monitoring of the PDSCH for a predetermined period based on the configuration information (step S10), and extends the monitoring. The predetermined period is, for example, a period indicated by information indicating the extension period included in the configuration information. UE 100 may count the period by starting a PDSCH standby extension timer. The PDSCH standby extension timer may be started at the end of the SPS timing. Alternatively, the PDSCH standby extension timer may be started at the start of the SPS timing. UE 100 may continue monitoring the PDSCH while the PDSCH standby extension timer is operating, and may stop monitoring the PDSCH when the PDSCH extension timer expires. Alternatively, UE 100 may continue monitoring the PDSCH while the PDSCH standby extension timer is operating, and may stop the operation of the PDSCH standby extension timer when receiving the PDSCH. The information indicating the extension period included in the configuration information may indicate a period during which the PDSCH standby extension timer is activated.

[0084] In step S15, the UE 100 monitors the PDSCH for a predetermined period after the SPS timing and receives the PDSCH. Note that, if the UE 100 does not receive the PDSCH at the SPS timing, the UE 100 extends the period for monitoring the PDSCH at the SPS timing.

[0085] (Modification 1 of First Embodiment) In the first embodiment, an example of SPS has been described, but the present invention is not limited to this. For example, the present invention can also be applied to CG.

[0086] That is, the gNB 200 performs CG configuration for the UE 100, including configuration information indicating whether to extend the PUSCH transmission (or the radio resource of the PUSCH) for a predetermined period (step S10). The configuration information may include information (e.g., a timer value) indicating the extension period of the PUSCH transmission (or the radio resource of the PUSCH).

[0087] Then, if the UE 100 is unable to transmit the PUSCH at the CG timing (or does not transmit the PUSCH at the CG timing), the UE 100 extends the PUSCH transmission (or the radio resources of the PUSCH) for a predetermined period (step S14). The UE 100 determines to extend the PUSCH transmission (or the radio resources of the PUSCH) for a predetermined period based on the configuration information. The predetermined period may be counted by starting a PUSCH extension timer in the UE 100. The PUSCH extension timer may be started at the start of the CG timing. Alternatively, the PUSCH extension timer may be started at the end of the CG timing. The UE 100 may continue the PUSCH transmission (or the radio resources of the PUSCH) while the PUSCH extension timer is operating, and may stop the PUSCH transmission (or the radio resources of the PUSCH) when the PUSCH extension timer expires. Alternatively, UE 100 may continue PUSCH transmission (or radio resources for PUSCH) while the PUSCH extension timer is operating, and stop the counting operation of the PUSCH extension timer when transmitting PUSCH.

[0088] In this way, if the UE 100 does not transmit a PUSCH to the gNB 200 at the CG periodic timing, the PUSCH transmission (or the radio resource of the PUSCH) is extended for a predetermined period. Therefore, even in the first modification, even if the UE 100 is unable to transmit a PUSCH at the CG timing, the PUSCH can be transmitted in the extension period of the PUSCH transmission (or the radio resource of the PUSCH) without waiting until the next CG timing. Therefore, even in the first modification, transmission delay can be suppressed. Therefore, in the mobile communication system 1, it is possible to appropriately perform communication using XR traffic.

[0089] (Second Modification of First Embodiment) The first embodiment can also be applied to DRX.

[0090] That is, the gNB 200 performs DRX configuration for the UE 100, including configuration information indicating whether to extend the PDCCH monitoring for a predetermined period during the DRX on period (On duration) (step S10). The configuration information may include information (e.g., a timer value) indicating the extension period for monitoring the PDCCH.

[0091] Then, when the UE 100 is unable to receive the PDCCH during the DRX on duration (On duration) (step S13), the UE 100 extends the monitoring of the PDCCH for a predetermined period (step S14). The UE 100 determines to extend the monitoring of the PDCCH for a predetermined period based on the setting information. The predetermined period may be counted using a PDCCH standby extension timer, as in the first embodiment. The operation of the PDCCH standby extension timer may be the same as in the first embodiment.

[0092] In this way, if UE100 does not receive a PDCCH from gNB200 at the DRX period timing (i.e., on duration), it extends the monitoring of the PDCCH for a predetermined period. Therefore, even in variant 1, even if it is not possible to receive a PDCCH during the DRX on duration, it is possible to receive the PDCCH during the extended period of PDCCH monitoring without waiting until the next on duration. Therefore, in variant 2, transmission delay can also be suppressed. Therefore, in mobile communication system 1, it is possible to appropriately perform communication using XR traffic.

[0093] Second Embodiment Next, a second embodiment will be described.

[0094] In the first embodiment, an example was described in which gNB200 transmits configuration information to UE100, and UE100 extends monitoring of PDSCH when PDSCH is not received at SPS timing.

[0095] In the second embodiment, an example is described in which gNB200 instructs UE100 to extend monitoring of PDSCH.

[0096] Specifically, first, the base station (e.g., gNB 200) transmits a first standby extension notification indicating that the monitoring of the PDSCH will be extended for a predetermined period to the user equipment (e.g., UE 100). Second, in response to receiving the first standby extension notification, the user equipment extends the monitoring of the PDSCH for a predetermined period.

[0097] This allows gNB200 to take the lead in controlling the extension of PDSCH monitoring for UE100, for example, by notifying (or instructing) UE100 of the extension of PDSCH monitoring at SPS timing.

[0098] 7 is a diagram illustrating an example of operation according to the second embodiment. The following mainly describes the differences from the first embodiment.

[0099] As shown in Figure 7, in step S12, gNB200 does not transmit PDSCH at SPS timing.

[0100] Then, in step S20, the gNB 200 transmits a first standby extension notification indicating that the monitoring of the PDSCH will be extended for a predetermined period to the UE 100. The gNB 200 may transmit a MAC CE or DCI including the first standby extension notification to the UE 100.

[0101] In step S14, in response to receiving the first standby extension notification, UE 100 extends the monitoring of the PDSCH at the SPS timing for a predetermined period of time.

[0102] The first standby extension notification may be a notification indicating that PUSCH transmission (or radio resources for PUSCH) at CG timing is to be extended for a predetermined period, similar to the first modification of the first embodiment.

[0103] Furthermore, the first standby extension notification may be a notification indicating that monitoring of the PDCCH in the DRX on duration (On duration) is to be extended for a predetermined period, similar to the second modification of the first embodiment.

[0104] Third Embodiment Next, a third embodiment will be described.

[0105] In the second embodiment, an example has been described in which the gNB 200 transmits the first standby extension notification to the UE 100. In the third embodiment, an example will be described in which the UE 100 transmits a standby extension notification (referred to as a "second extended standby notification") to the gNB 200.

[0106] Specifically, the user equipment (e.g., UE100) transmits a second standby extension notification to the base station (e.g., gNB200) indicating that monitoring of the PDSCH will be extended for a predetermined period of time.

[0107] This allows, for example, gNB200 to transmit PDSCH when triggered by receiving the second standby extension notification.

[0108] 8 is a diagram illustrating an example of operation according to the third embodiment. The following mainly describes the differences from the second embodiment.

[0109] 8, in step S10, the gNB 200 may configure the UE 100 to transmit a second standby extension notification. The gNB 200 may transmit configuration information to the UE 100, the configuration information including information indicating the second standby extension notification.

[0110] In step S12, the gNB 200 does not transmit the PDSCH at the SPS timing. In step S13, the UE 100 does not receive the PDSCH at the SPS timing.

[0111] Then, in step S30, the UE 100 transmits a second standby extension notification indicating that the monitoring of the PDSCH will be extended for a predetermined period to the gNB 200. The UE 100 may transmit a MAC CE or DCI including the second standby extension notification to the gNB 200.

[0112] In step S14, UE 100 extends the monitoring of the PDSCH at the SPS timing for a predetermined period of time.

[0113] The second standby extension notification may be a notification indicating that PUSCH transmission (or radio resources for PUSCH) at CG timing is to be extended for a predetermined period, similar to the first modification of the first embodiment.

[0114] Furthermore, the second standby extension notification may be a notification indicating that monitoring of the PDCCH in the DRX on duration (On duration) is to be extended for a predetermined period, similar to the second modification of the first embodiment.

[0115] [Other embodiments] A program may be provided that causes a computer to execute each process performed by the UE 100 or the gNB 200. The program may be recorded on a computer-readable medium. 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 and / or a DVD-ROM.

[0116] In addition, circuits that perform each process performed by UE100 or gNB200 may be integrated, and at least a portion of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).

[0117] Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes can be made within the scope of the gist. Furthermore, it is also possible to combine all or part of each embodiment, each operation, each process, and each step within the scope of consistent combinations.

[0118] As used in this disclosure, the terms "based on" and "depending on" do not mean "based only on" or "depending only on," unless expressly stated otherwise. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "depending on" means both "based only on" and "at least in part on." Furthermore, "obtain" may mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating the information. The terms "include," "comprise," and variations thereof do not mean including only the listed items, but may also mean including only the listed items or including additional items in addition to the listed items. Furthermore, as used in this disclosure, the term "or" is not intended to mean an exclusive or. Furthermore, any reference to an element using a designation such as "first," "second," etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient method of distinguishing between two or more elements. Thus, reference to a first and a second element does not imply that only two elements may be employed therein, or that the first element must precede the second element in some way. In this disclosure, when articles are added by translation, such as a, an, and the in English, these articles are intended to include the plural unless the context clearly dictates otherwise.

[0119] This application claims priority from Japanese Patent Application No. 2022-073807 (filed April 27, 2022), the entire contents of which are incorporated herein by reference.

[0120] (Supplementary Note) In one embodiment, (Supplementary Note 1) a communication control method in a mobile communication system may include a step of extending monitoring of the PDSCH or monitoring of the PDCCH for a predetermined period when a user equipment does not receive a PDSCH or a PDCCH from a base station at a periodic timing of SPS (Semi-Persistent Scheduling) or a periodic timing of DRX (Discontinuous Reception), respectively.

[0121] (Supplementary Note 2) The communication control method of (Supplementary Note 1) above may further include a step in which the base station transmits to the user equipment configuration information indicating whether or not to extend the monitoring of the PDSCH or the monitoring of the PDCCH for the predetermined period, and the extending step may include a step in which the user equipment extends the monitoring of the PDSCH or the monitoring of the PDCCH for the predetermined period based on the configuration information.

[0122] (Supplementary Note 3) In the communication control method of (Supplementary Note 1) or (Supplementary Note 2) above, the base station may further include a step of transmitting a first standby extension notification to the user equipment indicating that the monitoring of the PDSCH or the monitoring of the PDCCH will be extended for the predetermined period, and the extending step may include a step of the user equipment extending the monitoring of the PDSCH or the monitoring of the PDCCH for the predetermined period in response to receiving the first standby extension notification.

[0123] (Supplementary Note 4) In any of the communication control methods described above in (Supplementary Note 1) to (Supplementary Note 3), the method may further include a step in which the user equipment transmits to the base station a second standby extension notification indicating that monitoring of the PDSCH or monitoring of the PDCCH will be extended for the predetermined period.

[0124] In one embodiment, (Supplementary Note 5) is a communication control method in a mobile communication system, which may include a step of extending transmission of a PUSH for a predetermined period when a user equipment does not transmit a PUSH to a base station at a periodic timing of a CG (Configured Grant).

[0125] (Supplementary Note 6) In the communication control method of (Supplementary Note 5) above, the base station may further have a step of transmitting configuration information to the user equipment indicating whether or not to extend the transmission of the PUSH for the predetermined period, and the extending step may include a step in which the user equipment extends the transmission of the PUSH for the predetermined period based on the configuration information.

[0126] (Supplementary Note 7) In the communication control method of (Supplementary Note 5) or (Supplementary Note 6) above, the base station may further have a step of transmitting a first standby extension notification to the user equipment indicating that the transmission of the PUSH will be extended for the predetermined period, and the extending step may include a step in which the user equipment extends the transmission of the PUSH for the predetermined period in accordance with the first standby extension notification.

[0127] (Supplementary Note 8) In the communication control methods of (Supplementary Note 5) to (Supplementary Note 7) above, the user equipment may further include a step of transmitting a second standby extension notification to the base station, indicating that transmission of the PUSCH will be extended for the predetermined period.

[0128] 1: Mobile communication system 20: CN 100: UE 110: Receiving unit 120: Transmitting unit 130: Control unit 200: gNB 210: Transmitting unit 220: Receiving unit 230: Control unit 300: AMF

Claims

1. A communication control method in a mobile communication system, comprising: When the user equipment does not receive a PDSCH or a PDCCH from a network node at a periodic timing of SPS (Semi-Persistent Scheduling) or a periodic timing of DRX (Discontinuous Reception), the user equipment extends monitoring of the PDSCH or monitoring of the PDCCH for a predetermined period. Communications control method.

2. The network node transmits configuration information to the user equipment, the configuration information indicating whether to extend the monitoring of the PDSCH or the monitoring of the PDCCH for the predetermined period, The extending includes extending the monitoring of the PDSCH or the monitoring of the PDCCH by the user equipment based on the configuration information, The communication control method according to claim 1.

3. The network node further comprises transmitting a first standby extension notification to the user equipment, the first standby extension notification indicating that monitoring of the PDSCH or monitoring of the PDCCH is extended for the predetermined period; The extending includes extending the monitoring of the PDSCH or the monitoring of the PDCCH for the predetermined period in response to receiving the first standby extension notification by the user equipment. The communication control method according to claim 1.

4. The user equipment further includes transmitting a second standby extension notification to the network node, the second standby extension notification indicating that monitoring of the PDSCH or monitoring of the PDCCH is extended for the predetermined period. The communication control method according to claim 1.

5. A communication control method in a mobile communication system, comprising: When the user equipment does not transmit a PUSCH to a network node at a periodic timing of a configured grant (CG), the transmission of the PUSCH is extended for a predetermined period. Communications control method.

6. The network node further includes transmitting configuration information indicating whether to extend the transmission of the PUSCH for the predetermined period to the user equipment, The extending includes extending the transmission of the PUSCH for the predetermined period based on the setting information by the user equipment. The communication control method according to claim 5.

7. The network node further includes transmitting a first standby extension notification to the user equipment, the first standby extension notification indicating that the transmission of the PUSCH is extended for the predetermined period; The extending includes extending the transmission of the PUSCH for the predetermined period according to the first standby extension notification by the user equipment. The communication control method according to claim 5.

8. The user equipment further includes transmitting a second standby extension notification to the network node, the second standby extension notification indicating that the transmission of the PUSCH is extended for the predetermined period. The communication control method according to claim 5.

9. A user device, When the user equipment does not receive a PDSCH or a PDCCH from a network node at a periodic timing of SPS (Semi-Persistent Scheduling) or a periodic timing of DRX (Discontinuous Reception), the user equipment has a control unit that extends monitoring of the PDSCH or monitoring of the PDCCH for a predetermined period. User equipment.

10. A user device, comprising: A control unit that extends transmission of a PUSCH for a predetermined period of time when the PUSCH is not transmitted to a network node at a periodic timing of a CG (Configured Grant) is provided. User equipment.