Terminal device, terminal device method, and base station device

Abstract

A terminal device (10) transmits: a first buffer status reporting (BSR) medium access control control element (MAC CE) based on a first table; and a second BSR MAC CE based on either the first table or a second table. The terminal device transmits the second BSR MAC CE if: information for permitting the use of the second table is set; the amount of available data is within a buffer size defined in the second table; and the number of padding bits is equal to or greater than a prescribed size.

Description

Terminal device, terminal device method, and base station device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims the benefit of priority from Japanese Patent Application No. 2023-188709, filed November 2, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a terminal device, a terminal device method, and a base station device.

[0003] In recent years, technological development related to extended reality (XR) has progressed. XR is a concept that includes multimedia integration technologies such as virtual reality (VR), augmented reality (AR), mixed reality (MR), and substitutional reality (SR). In XR, three-dimensional time-series image data in real space and / or virtual space, audio data of multiple channels (stereo, 5.1ch, etc.), other data presented to the user, control data, etc. are transmitted and received in parallel. XR requires low latency and high reliability to maintain and improve the quality of the user's experience.

[0004] In Non-Patent Document 1, implementation of XR in 5G NR (Fifth Generation New Radio), which is a wireless specification defined by the Third Generation Partnership Project (3GPP (registered trademark)), is being considered.

[0005] 3GPP TR 38.838 V17.0.0 (2021-12)3GPP TS 38.321 V17.2.0 (2022-09)3GPP TS 38.331 V17.2.0 (2022-09)

[0006] Non-Patent Document 2 describes a procedure for buffer status reporting (BSR). Furthermore, Non-Patent Document 3 describes parameters for BSR, which are transmitted from a base station device. The BSR indicates the buffer size of uplink data for predetermined data. The predetermined data corresponds to one logical channel group (LCG). The terminal device calculates the buffer size for each LCG and transmits a BSR including the calculated buffer size to the base station device. The base station device allocates radio resources to the terminal device based on the BSR.

[0007] BSRs include three types: Regular BSR, Padding BSR, and Periodic BSR. Regular BSR, Padding BSR, and Periodic BSR are triggered based on different conditions. BSRs have multiple formats. When a BSR is triggered, a terminal device selects a format according to the conditions that are met. The inventors discovered a problem: for example, if a Padding BSR is triggered in XR, the terminal device may not be able to transmit a BSR in a specific format depending on the number of padding bits. Note that this problem also occurs in ordinary terminal devices and base station devices other than those implementing XR.

[0008] The present disclosure provides a technique that enables a terminal device to appropriately select a BSR format.

[0009] A terminal device in the present disclosure includes: a transmitter that transmits, to a base station device, a first Buffer Status Reporting (BSR) Medium Access Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes; and a receiver that receives, from the base station device, a Radio Resource Control (RRC) message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical Channel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes. When the information for permitting use of the second table is set, the amount of available data is within a buffer size defined in the second table, and the number of padding bits is equal to or greater than a predetermined size, the transmitter transmits to the base station device a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data, based on either the first table or the second table.

[0010] A method for a terminal device in the present disclosure includes transmitting a first Buffer Status Reporting (BSR) Medium Access Control Element (MAC CE) to a base station device, the first Buffer Status Reporting (BSR) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes, and receiving a Radio Resource Control (RRC) message from the base station device, the RRC message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical Channel (LCH) belongs, and information for authorizing the LCG to use a second table related to buffer sizes. The method further includes, when the information for permitting use of the second table is set, and the amount of available data is within a buffer size defined in the second table, and a number of padding bits is equal to or greater than a predetermined size, transmitting to the base station device a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data based on either the first table or the second table.

[0011] A base station device in the present disclosure includes: a receiving unit that receives, from a terminal device, a first Buffer Status Reporting (BSR) Medium Access Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes; and a transmitting unit that transmits, to the terminal device, a Radio Resource Control (RRC) message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical Channel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes. When the information for permitting use of the second table is set, the amount of available data is within a buffer size defined in the second table, and a number of padding bits is equal to or greater than a predetermined size, the receiving unit receives from the terminal device a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data based on either the first table or the second table.

[0012] According to the above configuration, the terminal device can appropriately select either the first BSR or the second BSR as the BSR format. Note that the above configuration may achieve other effects instead of or in addition to the above effect.

[0013] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a diagram illustrating a communication system S, Fig. 2 is a diagram illustrating a U-plane protocol stack, Fig. 3 is a diagram illustrating a C-plane protocol stack, Fig. 4 is a block diagram illustrating a schematic hardware configuration of a terminal device 10, Fig. 5 is a block diagram illustrating a schematic functional configuration of the terminal device 10, Fig. 6 is a block diagram illustrating a schematic hardware configuration of a base station device 20, Fig. 7 is a block diagram illustrating a schematic functional configuration of the base station device 20, Fig. 8 is a diagram illustrating a radio frame configuration, Fig. 9 is a diagram illustrating a configuration of a short BSR, Fig. 10 is a diagram illustrating a configuration of a long BSR, and Fig. 11 is a diagram illustrating a radio frame configuration. FIG. 12 is a diagram showing an example of a BSR table (i.e., a first table), FIG. 13 is a sequence diagram showing the processing flow of the terminal device 10 and the base station device 20, FIG. 14 is a diagram showing an example of an additional BSR table (i.e., a second table), FIG. 15 is a diagram showing the configuration of the additional BSR (i.e., a second BSR), FIG. 16 is a diagram showing an example of the configuration of a delay information report, FIG. 17 is a diagram showing another example of the configuration of a delay information report, and FIG. 18 is a sequence diagram showing the processing flow of the terminal device 10 and the base station device 20.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and drawings, elements that can be similarly described will be designated by the same reference numerals, and redundant description may be omitted.

[0015] The embodiments described below are merely examples of configurations that can realize the present disclosure. Each of the following embodiments can be modified or changed as appropriate depending on the configuration of the device to which the present disclosure is applied and various conditions. Not all of the combinations of elements included in each of the following embodiments are necessarily essential for realizing the present disclosure, and some of the elements can be omitted as appropriate. Therefore, the scope of the present disclosure is not limited to the configurations described in each of the following embodiments. As long as there are no mutual contradictions, configurations that combine multiple configurations described in the following embodiments can also be adopted.

[0016] 1. First Embodiment 1.1. Communication System As shown in Fig. 1, a communication system S includes one or more terminal apparatuses (Terminal Apparatus) 10, one or more base station apparatuses (Base Station Apparatus) 20, and a core network 30. The communication system S is configured according to predetermined technical specifications. For example, the communication system S may comply with technical specifications (e.g., 5G, 5G Advanced, 6G, etc.) defined by 3GPP.

[0017] In the communication system S, a user plane where user data is transmitted and received and a control plane where control data is transmitted and received are configured separately. That is, the communication system S supports C / U separation. The user plane is abbreviated as U-plane, and the control plane is abbreviated as C-plane.

[0018] The terminal device 10 is a device that wirelessly communicates with the base station device 20 and may be, for example, user equipment (UE) that operates in accordance with the 3GPP 5G NR technical specifications. The terminal device 10 may also be a device that complies with other older or newer 3GPP technical specifications.

[0019] The terminal device 10 may be, for example, a mobile phone terminal such as a smartphone, a tablet terminal, a laptop PC, a communication module, a communication card, or an IoT device such as a surveillance camera or a robot. The terminal device 10 may be a vehicle (e.g., a car, a train, etc.) or a device provided therein. The terminal device 10 may be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device provided therein. The terminal device 10 may be a sensor or a device provided therein. Note that the terminal device 10 may be called by other names such as a terminal, a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal, a remote device, or a remote unit. The terminal device 10 may be a device adapted to one or more of enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC).

[0020] The base station device 20 manages at least one cell. A cell constitutes the smallest unit of a communication area. For example, one cell belongs to one frequency (e.g., carrier frequency) and is composed of one component carrier. The term "cell" can refer to wireless communication resources and can also refer to a communication target of the terminal device 10. The base station device 20 wirelessly communicates with the terminal device 10 located in its own cell in the U-plane and C-plane. In other words, the base station device 20 terminates the U-plane protocol and C-plane protocol for the terminal device 10.

[0021] The base station device 20 communicates with the core network 30 in the U-plane and the C-plane. More specifically, the core network 30 includes multiple logical nodes including an Access and Mobility Management Function (AMF) and a User Plane Function (UPF). The base station device 20 connects to the AMF in the C-plane and connects to the UPF in the U-plane.

[0022] The base station device 20 may be, for example, a gNB that provides the terminal device 10 with a U-plane and a C-plane conforming to the 3GPP 5G NR technical specifications and connects to the 3GPP 5GC (5G Core Network). The base station device 20 may also be a device conforming to other older or newer 3GPP technical specifications.

[0023] The base station device 20 may be configured by a plurality of unit devices. For example, the base station device 20 may be configured by a central unit (CU), a distributed unit (DU), and a radio unit (RU).

[0024] A radio access network (RAN) is formed by interconnecting multiple base station devices 20. The radio access network formed by the base station devices 20 that are gNBs may be referred to as an NG-RAN. The base station devices 20 that are gNBs may be referred to as NG-RAN nodes.

[0025] The plurality of base station devices 20 are connected to each other via a predetermined interface (for example, an Xn interface). More specifically, for example, the plurality of base station devices 20 are connected to each other via an Xn-U interface in the U-plane and via an Xn-C interface in the C-plane. Note that the plurality of base station devices 20 may also be connected to each other via other interfaces with different functions or names.

[0026] Each base station device 20 is connected to the core network 30 via a predetermined interface (for example, an NG interface). More specifically, for example, each base station device 20 is connected to the UPF of the core network 30 via an NG-U interface in the U-plane, and is connected to the AMF of the core network 30 via an NG-C interface in the C-plane. Note that each base station device 20 may be connected to the core network 30 via another interface with a different function or name.

[0027] The radio protocol architecture between the terminal device 10 and the base station device 20 will be described with reference to Fig. 2. The radio protocol architecture between the terminal device 10 and the base station device 20 and between the terminal device 10 and the core network 30 will be described with reference to Fig. 3.

[0028] As shown in Fig. 2, the U-plane protocol stack includes, from the bottom up, a physical (PHY) layer, a media 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. Each of the above layers is terminated at the base station device 20 on the network side. The MAC layer is also referred to as a "medium access control layer."

[0029] As shown in FIG. 3 , the C-plane protocol stack includes, from the bottom up, a physical (PHY) layer, a media access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a non-access stratum (NAS). The above-mentioned layers except for the non-access stratum are terminated at the base station device 20 on the network side. The non-access stratum is terminated at the AMF of the core network 30 on the network side. The MAC layer is also referred to as a "medium access control layer."

[0030] 4, the terminal device 10 has, as hardware elements, a processor 101, a memory 102, an input / output interface 103, a wireless interface 104, and an antenna 105. The above elements provided in the terminal device 10 are connected to each other by an internal bus. Note that the terminal device 10 may have hardware elements other than the elements shown in FIG. 4.

[0031] The processor 101 is a computing element that realizes various functions of the terminal device 10. The processor 101 may be a system-on-a-chip (SoC) that includes elements such as a central processing unit (CPU), a graphics processing unit (GPU), and a memory controller.

[0032] The memory 102 is composed of at least one storage medium such as a RAM (Random Access Memory) or an eMMC (embedded Multi Media Card). The memory 102 is an element that temporarily or permanently stores programs and data used to execute various processes in the terminal device 10. The programs include one or more instructions for operating the terminal device 10. The processor 101 implements the functions of the terminal device 10 by expanding and executing the programs stored in the memory 102 in the memory 102 and / or a system memory (not shown).

[0033] The input / output interface 103 is an interface that receives operations on the terminal device 10 and supplies the operations to the processor 101, and presents various information to the user. The input / output interface 103 is, for example, a touch panel.

[0034] The wireless interface 104 is a circuit that performs various signal processing to realize wireless communication, and includes a baseband processor and an RF circuit. The wireless interface 104 transmits and receives wireless signals to and from the base station device 20 via an antenna 105.

[0035] 5, the terminal device 10 has, as functional blocks, a control unit 110 and a communication unit 120. The communication unit 120 has at least one transmission unit 121 and at least one reception unit 122.

[0036] The control unit 110 may include at least one processor 101 and at least one memory 102. In other words, the control unit 110 may be realized by the processor 101 and the memory 102. The control unit 110 executes various control processes in the terminal device 10. For example, the control unit 110 controls wireless communication with the base station device 20 via the communication unit 120. That is, the control unit 110 transmits and receives data / information / messages via the communication unit 120.

[0037] The communication unit 120 includes the wireless interface 104 and the antenna 105. In other words, the communication unit 120 is realized by the wireless interface 104 and the antenna 105. The communication unit 120 wirelessly communicates with the base station device 20 by transmitting and receiving wireless signals to and from the base station device 20. Two or more wireless interfaces 104 and two or more antennas 105 may be included in the communication unit 120.

[0038] The control unit 110 operates to execute various processes of the terminal device 10 .

[0039] 6, the base station device 20 has, as hardware elements, a processor 201, a memory 202, a network interface 203, a wireless interface 204, and an antenna 205. The above elements provided in the base station device 20 are connected to each other by an internal bus. Note that the base station device 20 may have hardware elements other than the elements shown in FIG. 6.

[0040] The processor 201 is a computing element that realizes various functions of the base station device 20. The processor 201 may be a CPU, and may further include other processors such as a GPU.

[0041] The memory 202 is configured by at least one storage medium such as a read-only memory (ROM), a RAM, a hard disk drive (HDD), or a solid state drive (SSD). The memory 202 is an element that temporarily or permanently stores programs and data used to execute various processes in the base station device 20. The programs include one or more instructions for operating the base station device 20. The processor 201 implements the functions of the base station device 20 by expanding and executing the programs stored in the memory 202 in the memory 202 and / or a system memory (not shown).

[0042] The network interface 203 is an interface used to transmit and receive signals to and from other base station devices 20 and the core network 30 .

[0043] The wireless interface 204 is a circuit that performs various signal processing to realize wireless communication, and includes a baseband processor and an RF circuit. The wireless interface 204 transmits and receives wireless signals to and from the terminal device 10 via an antenna 205.

[0044] 7, the base station device 20 has, as functional blocks, a control unit 210, a communication unit 220, and a network communication unit 230. The communication unit 220 has at least one transmission unit 221 and at least one reception unit 222.

[0045] The control unit 210 may include at least one processor 201 and at least one memory 202. In other words, the control unit 210 may be realized by the processor 201 and the memory 202. The control unit 210 executes various control processes in the base station device 20. For example, the control unit 210 controls wireless communication with the terminal device 10 via the communication unit 220. That is, the control unit 210 transmits and receives data / information / messages via the communication unit 220. Furthermore, for example, the control unit 210 controls communication with other nodes (e.g., other base station devices 20, nodes of the core network 30) via the network communication unit 230.

[0046] The communication unit 220 includes a wireless interface 204 and an antenna 205. In other words, the communication unit 220 is realized by the wireless interface 204 and the antenna 205. The communication unit 220 wirelessly communicates with the terminal device 10 by transmitting and receiving wireless signals to and from the terminal device 10. Two or more wireless interfaces 204 and two or more antennas 205 may be included in the communication unit 220.

[0047] The network communication unit 230 includes the network interface 203. In other words, the network communication unit 230 is realized by the network interface 203. The network interface 203 transmits and receives signals to and from the network (and thus to the other nodes described above).

[0048] The control unit 210 operates to execute various processes in the base station device 20 .

[0049] 1.2 Radio Resources The terminal device 10 and the base station device 20 communicate with each other wirelessly using radio resources in the frequency domain and the time domain. Radio resources will be described below.

[0050] The transmission method for downlink communication from the base station device 20 to the terminal device 10 is, for example, Orthogonal Frequency Division Multiplexing (OFDM) using a cyclic prefix (CP), i.e., CP-OFDM. The transmission method for uplink communication from the terminal device 10 to the base station device 20 is, for example, the above-mentioned CP-OFDM or DFTS-OFDM in which CP-OFDM is applied after transform precoding that performs discrete Fourier transform (DFT) spreading.

[0051] A cyclic prefix is ​​a redundant signal that functions as a guard period (GP) to prevent inter-symbol interference and inter-carrier interference, and is inserted at the beginning of an OFDM symbol. There are two types of cyclic prefixes: a normal cyclic prefix and an extended cyclic prefix.

[0052] As radio resources in the frequency domain of OFDM, multiple subcarriers that are orthogonal to each other are used. The multiple subcarriers are arranged in the frequency domain at a predetermined subcarrier spacing (sub-carrier spacing, SCS) Δf. Multiple subcarrier spacings Δf can be applied in a communication system S. The subcarrier spacing Δf can be expressed, for example, by the following equation: Δf=2 μ ・15 [kHz]

[0053] Here, μ is an integer equal to or greater than 0 and can take on at least one of the values ​​0, 1, 2, 3, 4, 5, and 6. Therefore, the subcarrier spacing Δf [kHz] can take on at least one of the values ​​15, 30, 60, 120, 240, 480, and 960. Note that μ may also take on a value of 7 or greater.

[0054] In the time domain of OFDM, a layered radio frame structure is used as shown in Figure 8. One radio frame includes 10 subframes. Subframes are assigned subframe numbers that count up by one from 0 to 9. One radio frame is divided into two half frames. The time length of a radio frame is 10 ms, the time length of a half frame is 5 ms, and the time length of a subframe is 1 ms. These time lengths do not depend on the subcarrier spacing Δf.

[0055] One subframe includes one or more slots (slot(s)). The number Ns of slots included in one subframe depends on the value of μ described above, and further depends on the subcarrier spacing Δf. The number Ns of slots is expressed by the following formula, for example: Ns=2 μ

[0056] One slot contains multiple symbols. The number of symbols in one slot depends on the type of cyclic prefix. For example, if a normal cyclic prefix is ​​used, one slot contains 14 symbols. For example, if an extended cyclic prefix is ​​used, one slot contains 12 symbols.

[0057] As described above, the number of slots and the number of symbols included in each of a radio frame, half frame, and subframe, each of which has a fixed time length, are variable. Therefore, the time length of a slot and the time length of a symbol are also variable.

[0058] A resource element (RE) is a radio resource unit in the time-frequency domain consisting of one subcarrier and one symbol, and a resource block (RB) is a radio resource unit in the time-frequency domain consisting of 12 subcarriers and multiple symbols.

[0059] Each radio frame is assigned a system frame number (SFN), which counts up by one from 0 to 1023. SFN "0" corresponds to the initial value of the SFN, and SFN "1023" corresponds to the maximum value of the SFN. Therefore, the radio frame following a radio frame assigned SFN 1023 is assigned SFN 0. Since the time length of a radio frame is 10 ms, the time length of one cycle of the system frame number is 10,240 ms (= 10.24 seconds).

[0060] Here, the base station device 20 may configure one or more serving cells for the terminal device 10. The serving cell may correspond to a component carrier in the downlink and / or a component carrier in the uplink. The technology in which one or more serving cells are configured and the base station device 20 and the terminal device 10 perform wireless communication may also be referred to as carrier aggregation.

[0061] Furthermore, the base station device 20 may configure one or more bandwidth parts (Bandwidth Parts, BWPs) for the terminal device 10 with respect to each of one or more serving cells. For example, a Downlink Bandwidth Part (DL-BWP) may be configured in the downlink of one serving cell. Furthermore, an Uplink Bandwidth Part (UL-BWP) may be configured in the uplink of one serving cell. Herein, the DL-BWP may include an initial DL-BWP and / or a dedicated DL-BWP. Furthermore, the UL-BWP may include an initial UL-BWP and / or a dedicated UL-BWP. Hereinafter, the BWP may include a DL-BWP and / or a UL-BWP.

[0062] 1.3 Channels and Control Information The terminal device 10 and the base station device 20 transmit and receive user data and control information to and from each other. The transmission and reception of control information in the downlink and uplink will be exemplified below.

[0063] The terminal device 10 and the base station device 20 transmit and receive user data and control information using a plurality of hierarchical channels. The physical channel is a channel used for physical communication between the terminal device 10 and the base station device 20. Examples of the physical channel include a physical downlink control channel (PDCCH), a physical broadcast channel (PBCH), and a physical uplink control channel (PUCCH).

[0064] A transport channel is a channel located above a physical channel and is mapped to a physical channel in the PHY layer. Multiple transport channels may be mapped to one physical channel. Examples of transport channels include a Downlink Shared Channel (DL-SCH) and an Uplink Shared Channel (UL-SCH). For example, data in the downlink may also be referred to as DL-SCH data. Furthermore, for example, data in the uplink may also be referred to as UL-SCH data. Here, DL-SCH data includes user data in the downlink. Furthermore, UL-SCH data includes user data in the uplink.

[0065] A logical channel is a channel located above a transport channel and is mapped to the transport channel in the MAC layer. Multiple logical channels may be mapped to one transport channel, and one logical channel may be mapped to multiple transport channels. Logical channels are classified according to the characteristics of the information they transmit. Examples of logical channels include a Broadcast Control Channel (BCCH), a Common Control Channel (CCCH), and a Dedicated Control Channel (DCCH).

[0066] The base station device 20 transmits downlink control information (DCI) to the terminal device 10 using the PDCCH, which is a physical channel. The DCI includes information on downlink and uplink resource allocation for the terminal device 10, and control information for the terminal device 10. The DCI is mapped to the PDCCH and corresponds to Layer 1 signaling.

[0067] Here, one or more formats may be defined for transmission of DCI in the PDCCH. The format defined for transmission of DCI in the PDCCH may be referred to as a DCI format. For example, the DCI format may include a DCI format used for scheduling a Physical Downlink Shared Channel (PDSCH) (e.g., a format referred to as DCI format 1_0, DCI format 1_1, and / or DCI format 1_2). Furthermore, for example, the DCI format may include a DCI format used for scheduling a Physical Uplink Shared Channel (PUSCH) (e.g., a format referred to as DCI format 0_0, DCI format 0_1, and / or DCI format 0_2). Furthermore, the DCI format may include a DCI format not used for scheduling a PDSCH and / or a PUSCH. The DCI format used for scheduling a PDSCH and / or a PUSCH may be referred to as a scheduling DCI format. A DCI format that is not used for scheduling the PDSCH and / or PUSCH may be referred to as a non-scheduling DCI format. Hereinafter, for ease of explanation, a "DCI format" may be simply referred to as a "PDCCH." Furthermore, a "DCI generated according to a DCI format" may be simply referred to as a "DCI format."

[0068] For example, the base station device 20 may configure frequency domain resources and / or time domain resources that the terminal device 10 monitors (i.e., monitors) a PDCCH candidate set. For example, the frequency domain resources that the terminal device 10 monitors the PDCCH candidate set may be referred to as a control resource set (CORESET). Furthermore, the time domain resources that the terminal device 10 monitors the PDCCH candidate set may be referred to as a search space set (SSS). The terminal device 10 may monitor the PDCCH candidate set in one or more CORESETs in the DL-BWP of a serving cell for which PDCCH monitoring is configured, according to the corresponding search space set. Here, monitoring may imply attempting to decode each PDCCH candidate according to the monitored DCI format. The above configuration may be referred to as blind decoding.

[0069] Here, a Cyclic Redundancy Check (CRC) scrambled with a Radio Network Temporary Identifier (RNTI) may be added to the DCI (or DCI format) transmitted on the PDCCH. The CRC may also be referred to as a CRC parity bit. Multiple types of RNTI are defined. For example, the base station device 20 may set each RNTI by transmitting an RRC message including at least one of information indicating a C-RNTI (Cell-RNTI), information indicating a Modulation and Coding Scheme Cell-RNTI (MCS-C-RNTI), and information indicating a Configured Scheduling-RNTI (CS-RNTI). That is, a CRC scrambled with at least one of the C-RNTI, MCS-C-RNTI, and CS-RNTI may be added to the DCI (or DCI format) transmitted on the PDCCH.

[0070] The terminal device 10 may monitor (and / or receive) the PDCCH and detect (and / or receive) the DCI format.

[0071] The terminal device 10 transmits uplink control information (UCI) to the base station device 20 using the PUCCH, which is a physical channel. The UCI includes control information such as a scheduling request (SR), a hybrid automatic repeat reQuest (HARQ) ACK / NACK, and channel state information (CSI). The UCI is mapped to the PUCCH or PUSCH and corresponds to layer 1 signaling.

[0072] The base station device 20 uses the DL-SCH, which is a transport channel, to transmit a control element (CE) of the MAC layer to the terminal device 10. The downlink MAC CE is mapped to the PDSCH via the DL-SCH and corresponds to Layer 2 signaling.

[0073] The terminal device 10 transmits a control element (CE) of the MAC layer to the base station device 20 using the UL-SCH, which is a transport channel. The uplink MAC CE includes control information such as a buffer status report (BSR). The uplink MAC CE is mapped to a PUSCH via the UL-SCH and corresponds to Layer 2 signaling.

[0074] The base station device 20 transmits (or broadcasts) system information (SI) to the terminal device 10 using the BCCH, which is a logical channel. The SI includes minimum system information (MSI) and other system information (OSI). The MSI includes a master information block (MIB) and system information block 1 (SIB1). SIB1 may be referred to as remaining minimum system information (RMSI). The OSI includes system information blocks (SIB2 onward) other than SIB1. Of the BCCH, the MIB is mapped to the PBCH via the BCH (Broadcast CHannel), and the SIB is mapped to the PDSCH via the DL-SCH.

[0075] The base station device 20 transmits control information in the RRC layer to the terminal device 10 using a signaling radio bearer (SRB) established between the terminal device 10 and the base station device 20 in the RRC layer. Hereinafter, messages exchanged between the base station device 20 and the terminal device 10 in the RRC layer may be referred to as RRC messages. There are multiple types of SRBs (e.g., SRB0, SRB1, SRB2, SRB3, SRB4). The SRBs are used to transmit and receive RRC messages as well as NAS messages containing control information in the NAS layer. The CCCH or DCCH is used to transmit RRC messages from the base station device 20 to the terminal device 10. The CCCH and DCCH are each mapped to the PDSCH via the DL-SCH. The RRC message corresponds to Layer 3 signaling.

[0076] As an example of a downlink RRC message, an RRC reconfiguration message will be described. The RRC reconfiguration message is an RRC message transmitted from the base station device 20 to the terminal device 10 using SRB1 or SRB3. The DCCH is used to transmit the RRC reconfiguration message. The RRC reconfiguration message is used to reconfigure or modify the connection between the base station device 20 and the terminal device 10.

[0077] The terminal device 10 transmits an RRC message to the base station device 20 using the above-mentioned SRB. The CCCH or DCCH is used to transmit the RRC message from the terminal device 10 to the base station device 20. The CCCH and DCCH are each mapped to the PUSCH via the UL-SCH. The RRC message corresponds to Layer 3 signaling.

[0078] As an example of an uplink RRC message, a user equipment capability information (UECapabilityInformation) message will be described. The user equipment capability information message is an RRC message transmitted from the terminal device 10 to the base station device 20 using SRB1. The DCCH is used to transmit the user equipment capability information message. The user equipment capability information message is used to notify the base station device 20 of information related to the radio access capability of the terminal device 10.

[0079] As an example of an uplink RRC message, a user equipment assistance information (UE Assistance Information, UAI) message will be described. The UAI message is an RRC message transmitted from the terminal device 10 to the base station device 20 using SRB1 or SRB3. The DCCH is used to transmit the UAI message. The UAI message is used to notify the base station device 20 of various information related to the terminal device 10 (e.g., UE assistance information).

[0080] 1.4. Uplink Scheduling 1.4.1. Scheduling Request (SR) The SR is used by the terminal device 10 to request PUSCH radio resource allocation from the base station device 20. The SR may also be used to request UL-SCH resources for initial transmission. The base station device 20 allocates PUCCH resources for transmitting the SR to the terminal device 10. The base station device 20 transmits an RRC message including SR parameters to the terminal device 10. The SR parameters are included in a SchedulingRequestResourceConfig IE, which is an example of an RRC information element (IE).

[0081] The terminal device 10 transmits UCI including SR to the base station device 20 using the configured PUCCH resource. The terminal device 10 may transmit UCI on demand. The terminal device 10 may transmit UCI at a configured periodicity. For example, the terminal device 10 may transmit an SR set to "0" (negative SR) and / or an SR set to "1" (positive SR). The base station device 20 allocates PUSCH radio resources to the terminal device 10 according to the SR.

[0082] 1.4.2 Dynamic Grant (DG) DG is a scheduling method for allocating PUSCH radio resources in accordance with an uplink grant procedure. The base station device 20 transmits an uplink grant to the terminal device 10 via the PDCCH. The terminal device 10 transmits the PUSCH in accordance with the uplink grant. For example, the base station device 20 may allocate PUSCH radio resources using a DCI format with a CRC scrambled by the C-RNTI and / or MCS-C-RNTI (i.e., a DCI format used for PUSCH scheduling), and the terminal device 10 may perform uplink transmission using the allocated PUSCH radio resources. Here, a new data indicator (New Data Indicator) included in the DCI format to which the CRC scrambled by the C-RNTI and / or MCS-C-RNTI is added may be set to 0 or 1. Furthermore, the base station device 20 may allocate radio resources for the PUSCH using a DCI format with a CRC scrambled by the CS-RNTI (i.e., a DCI format used for scheduling the PUSCH), and the terminal device 10 may perform uplink transmission using the allocated radio resources for the PUSCH. Here, a new data indicator included in the DCI format with a CRC scrambled by the CS-RNTI may be set to 1.

[0083] 1.4.3. Configured Grant (CG) CG is a scheduling method for allocating radio resources for the PUSCH without the above-described dynamic uplink grant procedure. CG includes two types: Type 1 and Type 2. The base station device 20 transmits an RRC message including CG parameters to the terminal device 10. The CG parameters are included in a ConfiguredGrantConfig IE, which is an example of an RRC information element (IE). The ConfiguredGrantConfig IE includes a parameter periodicity related to the periodicity of transmission using the PUSCH. Note that the parameter periodicity is set in units of the number of slots or the number of symbols. Alternatively, the parameter periodicity may be set in units of frames per second (FPS). In Type 1, the terminal device 10 starts transmitting signals at the set periodicity without being triggered by DCI. On the other hand, in Type 2, the base station device 20 transmits DCI scrambled with CS-RNTI to the terminal device 10. The CS-RNTI is used to activate periodic transmission. In response to activation by DCI scrambled with the CS-RNTI, the terminal device 10 starts transmission using the PUSCH at a set period.

[0084] 1.5 Buffer Status Report (BSR) The terminal device 10 transmits a BSR by MAC signaling using the allocated PUSCH radio resources. The BSR is composed of a MAC CE included in a MAC PDU (Medium Access Control Protocol Data Unit). The BSR is used to indicate information about the buffer status of uplink data in the MAC entity. The base station device 20 allocates uplink radio resources to the terminal device 10 based on the BSR.

[0085] In the BSR, logical channels (LCHs) are assigned to logical channel groups (LCGs). Each LCG includes one or more LCHs. The terminal device 10 calculates the buffer size of uplink data for each LCG. The terminal device 10 transmits the buffer size corresponding to each LCG as a BSR to the base station device 20.

[0086] The base station device 20 transmits an RRC message including BSR parameters to the terminal device 10. The BSR parameters are included in a BSR-Config IE, which is an example of an RRC information element (IE). For example, the BSR-Config IE includes three timers: a periodicBSR-Timer, a retxBSR-Timer, and a logicalChannelSR-DelayTimer.

[0087] Furthermore, parameters related to the LCG are included in the LogicalChannelConfig IE, which is an example of an RRC information element (IE). That is, the base station device 20 may transmit an RRC message including the LogicalChannelConfig IE. Furthermore, the terminal device 10 may identify the configuration related to the LCH and / or LCG based on the LogicalChannelConfig IE included in the RRC message. For example, the LogicalChannelConfig IE includes a logicalChannelGroup IE. The logicalChannelGroup IE assigns an LCH to an LCG. For example, an LCG index (ID) may be set for each of one or more LCHs, and the LCG to which the one or more LCHs belong may be set. Note that the LogicalChannelConfig IE may include a logicalChannelGroupIAB-Ext IE. The logicalChannelGroupIAB-Ext IE is applied only to IAB-MT (Integrated Access Backhaul-Mobile Termination). If the logicalChannelGroupIAB-Ext IE is set, the LogicalChannelConfig IE is ignored.

[0088] The terminal device 10 may trigger a BSR according to a predetermined condition. For example, the terminal device 10 may trigger a BSR when any of the following conditions (a1) to (a4) is satisfied for an activated cell group. Note that the following conditions may be referred to as "events." (a1) For an LCH belonging to a certain LCG, uplink data becomes available in the MAC entity, and one of the following two conditions is satisfied: - The uplink data belongs to an LCH with a higher priority than an LCH belonging to any LCG that contains available uplink data. - There is no LCH belonging to any LCG that contains available uplink data. (a2) Uplink resources are allocated, and the number of padding bits is equal to or greater than the size of the BSR MAC CE plus its subheader. (a3) ​​The retxBSR-Timer expires, and at least one LCH belonging to the LCG contains uplink data. (a4) The periodic BSR-Timer expires.

[0089] The BSR includes at least a Regular BSR, a Padding BSR, and a Periodic BSR. The Regular BSR, the Padding BSR, and the Periodic BSR may be triggered based on different conditions. For example, the terminal device 10 triggers a Regular BSR when any of the above conditions (a1) and (a3) ​​is satisfied. The terminal device 10 triggers a Padding BSR when the above condition (a2) is satisfied. The terminal device 10 triggers a Periodic BSR when the above condition (a4) is satisfied.

[0090] The BSR includes multiple formats, including at least a short BSR and a long BSR. A MAC PDU including a BSR includes a MAC subheader. The MAC subheader includes a Logical Channel Identifier (LCID) or an extended Logical Channel Identifier (eLCID). The value of the LCID or eLCID may be referred to as a codepoint. The codepoint value identifies the format of the BSR.

[0091] The short BSR is a format for reporting the buffer status (i.e., buffer size) of one LCG. As shown in Figure 9, the short BSR includes one field 900 with a fixed size of 8 bits. The field 900 includes a first part 910 and a second part 920.

[0092] The first part 910 is made up of three bits. The first part 910 is information for identifying the LCG for which the buffer status is reported. The first part 910 is sometimes referred to as an "LCG ID field."

[0093] The second part 920 consists of 5 bits. The second part 920 is information for identifying the total amount of data available in all LCHs included in the LCG indicated by the first part 910. The second part 920 may also be simply referred to as the "buffer size." The second part 920 indicates an index indicating the number of bytes. The terminal device 10 references a predetermined BSR table and sets the second part 920 to an index corresponding to the buffer size. The BSR table has 32 index values ​​(e.g., also referred to as "code points"). For example, the second part 920 indicates one of values ​​0 to 31. Each index value corresponds to a range of buffer sizes. In other words, the above BSR table defines the correspondence between the index and the range of buffer sizes. The smaller the index value, the smaller the buffer size corresponding to that index value. The larger the index value, the larger the buffer size corresponding to that index value.

[0094] The short BSR may include a Truncated format, which is a format for an LCH with a high priority (i.e., LCH priority), and an Extended format, which is a format capable of transmitting a larger amount of information.

[0095] The Long BSR is a format for reporting the buffer status (i.e., buffer size) of multiple LCGs. As shown in Figure 10, the Long BSR has a variable size. The Long BSR includes an LCG field 1010 and a buffer size field 1020.

[0096] The LCG field 1010 is composed of 8 bits. In the LCG field 1010, the 8 bits correspond to 8 LCGi, respectively. Here, i is an integer from 0 to 7. The definition of i will remain the same in the following description. The LCG field 1010 may indicate whether a buffer size field for LCGi exists. For example, if the value of LCGi in the LCG field 1010 is 1, this indicates that a buffer size field corresponding to LCGi exists. If the value of LCGi is 0, this indicates that a buffer size field corresponding to LCGi does not exist.

[0097] The number of fields included in the buffer size field 1020 varies depending on the value of the LCG field 1010. It is assumed that the bit corresponding to LCG1 is 1 and the bit corresponding to LCG2 is 1 in the LCG field 1010. Therefore, the buffer size field 1020 includes a field 1021 corresponding to LCG1 and a field 1022 corresponding to LCG2. Note that, since it is assumed that the bit corresponding to LCG0 in FIG. 10 is 0, the buffer size field 1020 does not include a field corresponding to LCG0.

[0098] Each field included in the buffer size field 1020 consists of 8 bits. Each field indicates the buffer size to be reported (e.g., the size of data available for transmission). Each field indicates an index indicating the number of bytes.

[0099] The terminal device 10 refers to the BSR table 1100 shown in FIG. 11 and sets the buffer size field 1020 to an index corresponding to the buffer size.

[0100] The BSR table 1100 has 255 index values ​​(e.g., also referred to as "code points"). The index values ​​range from 0 to 254. Each index value corresponds to a range of buffer sizes. That is, the BSR table 1100 defines the correspondence between the index and the buffer size range. The smaller the index value, the smaller the buffer size corresponding to that index value. The larger the index value, the larger the buffer size corresponding to that index value. Furthermore, each buffer size range corresponding to the 255 index values ​​is defined according to a predetermined exponential function. Therefore, the larger the index value, the larger the buffer size range corresponding to that index value.

[0101] Hereinafter, the BSR table used for the second part 920 of the short BSR and the BSR table 1100 used for the buffer size field 1020 of the long BSR may be collectively referred to as the "first table." Note that the buffer size field set by referring to the first table may be referred to as the "first buffer size field."

[0102] Like the short BSR, the long BSR may include a truncated format and an extended format.

[0103] The BSR may also include a Pre-emptive BSR format and an Extended Pre-emptive BSR format, which are used in the IAB-MT.

[0104] The terminal device 10 may select either a short BSR or a long BSR according to a predetermined method. For example, in the case of regular BSR and periodic BSR, a MAC entity in which the logicalChannelGroup-IABExt IE is not configured by a higher layer may select either a short BSR or a long BSR as follows: (b1) If two or more LCGs have available data for transmission when a MAC PDU including a BSR is built: The terminal device 10 transmits (or reports) long BSRs for all LCGs that have available data. (b1) Otherwise: The terminal device 10 transmits (or reports) short BSRs.

[0105] In the case of regular BSR and periodic BSR, a MAC entity for which the logicalChannelGroup-IABExt IE is set by a higher layer may select one of a long BSR, an extended long BSR, and an extended short BSR as follows: (c1) If two or more LCGs have available data for transmission when a MAC PDU containing a BSR is constructed: (c2) If the maximum value of LCG IDs among the configured LCGs is 7 or less, the terminal device 10 transmits (or reports) a long BSR for all LCGs that have available data. (c2) Otherwise: The terminal device 10 transmits (or reports) an extended long BSR for all LCGs that have available data. (c1) Otherwise: The terminal device 10 transmits (or reports) an extended short BSR.

[0106] In addition, in the case of a padding BSR, the terminal device 10 may transmit one of the following BSR formats according to the conditions that are met: Short BSR Long BSR Short Truncated BSR Long Truncated BSR Extended Short BSR Extended Long BSR Extended Short Truncated BSR Extended Long Truncated BSR

[0107] For example, in the case of a padding BSR, a MAC entity in which the logicalChannelGroup-IABExt IE is not set by a higher layer may select a BSR format as follows: (d1) If the number of padding bits is equal to or greater than the size of the short BSR plus its subheader and smaller than the size of the long BSR plus its subheader: (d2) If two or more LCGs have available data for transmission when the BSR is constructed: (d3) If the number of padding bits is equal to the size of the short BSR plus its subheader: The terminal device 10 transmits (or reports) a short truncated BSR for the LCG containing the LCH with the highest priority among the LCHs with available data for transmission. (d3) Otherwise: The terminal device 10 transmits (or reports) Long Truncated BSRs for LCGs including LCHs with available data for transmission, in descending order of the LCHs with the highest priority, regardless of whether they have available data for transmission or not, in each LCG. Note that if the priorities are the same, the terminal device 10 transmits (or reports) Long Truncated BSRs in ascending order of LCG ID. (d2) Otherwise: The terminal device 10 transmits (or reports) Short BSRs. (d1) Otherwise, if the number of padding bits is equal to or greater than the size of the long BSR plus its subheader: The terminal device 10 transmits (or reports) Long BSRs for all LCGs with available data for transmission.

[0108] For example, in the case of a padding BSR, a MAC entity in which the logicalChannelGroup-IABExt IE is set by a higher layer may select a BSR format as follows: (e1) If the number of padding bits is equal to or greater than the size of an Extended Short BSR plus its subheader and smaller than the size of an Extended Long BSR plus its subheader: (e2) If two or more LCGs have available data for transmission when the BSR is constructed: (e3) If the number of padding bits is smaller than the size of an Extended Long Truncated BSR with a buffer size field set to zero plus its subheader: The terminal device 10 transmits (or reports) an Extended Short Truncated BSR for an LCG that includes an LCH with the highest priority among the LCHs that have available data for transmission. (e3) Otherwise: The terminal device 10 transmits (or reports) Extended Long Truncated BSRs for LCGs including LCHs with available data for transmission, in descending order of the LCHs with the highest priority, regardless of whether they have available data for transmission or not, in each LCG. Note that if the priorities are the same, the terminal device 10 transmits (or reports) Extended Long Truncated BSRs in ascending order of LCG ID. (e2) Otherwise: The terminal device 10 transmits (or reports) Extended Short BSRs. (e1) Otherwise, if the number of padding bits is equal to or greater than the size of the Extended Long BSR plus its subheader: The terminal device 10 transmits (or reports) Extended Long BSRs for all LCGs with available data for transmission.

[0109] As described above, the terminal device 10 may select a BSR format based on the number of padding bits and the priority of the LCH. The priority of the LCH may be included in the LogicalChannelConfig IE, which is an example of an RRC information element. For example, the priority of the LCH is the priority included in the LogicalChannelConfig IE. The priority is expressed as a positive integer. The larger the value of the priority included in the LogicalChannelConfig IE, the higher the priority of the LCH. The base station device 20 transmits an RRC message including the priority of the LCH. The terminal device 10 identifies the priority of the LCH based on the RRC message.

[0110] Next, examples of transmission of a short truncated BSR and a long truncated BSR will be described.

[0111] As shown in the example of Figure 12, it is assumed that two LCGs are configured. Specifically, LCG1 and LCG2 are configured. LCG1 includes two LCHs, LCH1 and LCH2. The priority of LCH1 is 1. LCH1 has available data. The priority of LCH2 is 8. LCH2 does not have available data. LCG2 includes two LCHs, LCH3 and LCH4. The priority of LCH3 is 2. LCH3 has available data. The priority of LCH4 is 4. LCH4 does not have available data. Note that the priority in Figure 12 is the priority included in the LogicalChannelConfig IE. Therefore, the larger the integer value, the higher the priority of the LCH.

[0112] Assume that the conditions (d1), (d2), and (d3) are satisfied. In this case, the terminal device 10 transmits a short truncated BSR as follows: The LCH with the highest priority among the LCHs with available data is LCH3. Therefore, the terminal device 10 transmits a short truncated BSR for LCG2, which includes LCH3. Note that the configuration of the short truncated BSR is the same as the configuration of the short BSR shown in FIG. 9.

[0113] Assume that the condition (d1) is satisfied, the condition (d2) is satisfied, and the condition (d3) is not satisfied. In this case, the terminal device 10 transmits a Long Truncated BSR as follows: The LCH with the highest priority, regardless of whether it has available data for transmission or not, is LCH2. The priority of LCG1, which includes LCH2, is higher than that of LCG2. The terminal device 10 reports the buffer sizes in the order of LCG1 and LCG2.

[0114] For example, the buffer size field 1020 may include multiple fields in order of priority: a field for the buffer size of LCG1, and a field for the buffer size of LCG2, in that order.

[0115] In the case of a long truncated BSR, the number of fields included in the buffer size field 1020 may be variable according to the number of padding bits. For example, if three LCGs are configured but the number of padding bits is small, the buffer size field 1020 may include only two fields. In this case, the terminal device 10 may include two fields in the buffer size field 1020 in order of priority.

[0116] The configuration of the Long Truncated BSR is basically the same as the configuration of the Long BSR shown in Fig. 10, but differs in the following respects. The LCG field 1010 indicates whether the LCGi has available data. For example, if the value of LCGi in the LCG field 1010 is 1, this indicates that the LCGi has available data. If the value of LCGi is 0, this indicates that the LCGi does not have available data.

[0117] The procedure by which the terminal device 10 transmits a BSR to the base station device 20 will be described below.

[0118] As shown in Fig. 13, the communication unit 220 of the base station device 20 transmits an RRC message to the terminal device 10 (S1301). The RRC message includes parameters related to the BSR and parameters related to the LCG. The RRC message may be an RRC reconfiguration message. The control unit 110 of the terminal device 10 generates a BSR based on the parameters included in the RRC message. The communication unit 120 of the terminal device 10 transmits the BSR (S1302).

[0119] Specifically, after receiving the RRC message, the terminal device 10 determines whether any of the above conditions (a1) to (a4) is satisfied, and may trigger any of a regular BSR, a padding BSR, and a periodic BSR according to the satisfied condition, as described above.

[0120] If the triggered BSR is a regular BSR or a periodic BSR, the terminal device 10 may select a BSR format in accordance with the above condition (b1). Also, if the triggered BSR is a regular BSR or a periodic BSR, the terminal device 10 may select a BSR format in accordance with the above conditions (c1) to (c2).

[0121] If the triggered BSR is a padding BSR, the terminal device 10 may select a BSR format according to the above conditions (d1) to (d3). Also, if the triggered BSR is a padding BSR, the terminal device 10 may select a BSR format according to the above conditions (e1) to (e3).

[0122] 1.6. Extended Reality (XR) This section describes the characteristics of traffic generated in XR. In XR, multiple types of data (video data, audio data, user data, control data, etc.) are transmitted and received in parallel. The multiple data streams corresponding to the above data each have different traffic characteristics and QoS requirements.

[0123] The timing of sending and receiving the above data can sometimes experience time shifts, which can be expressed as jitter, variability, or fluctuation, due to factors such as video and audio encoding and network delays.

[0124] Reference 1 states that the following definitions may be introduced for transmission and reception in XR: [Reference 1] 3GPP TR 23.700-60 V1.1.0 (2022-09)

[0125] PDU Set: A set of PDUs consisting of one or more PDUs that carry the payload of one unit of information generated at the application level. The application level corresponds, for example, to a frame or a video slice in an XR service. Data Burst: A set of data multiple PDUs generated and transmitted by an application in a short period of time. A PDU in a PDU set may correspond to a PDCP Service Data Unit (SDU).

[0126] Furthermore, in XR, the packet delay budget (PDB) requirement is considered as one of the above QoS requirements. PDB is the upper bound of the allowable packet delay time between the terminal device 10 and the UPF. Reference 1 also describes that the following new QoS parameters may be introduced: PDU-Set Delay Budget (PSDB): This is the upper bound of the allowable PDU set delay time between the terminal device 10 and the UPF. PDU-Set Error Rate (PSER): This is the upper bound of the error rate calculated between a PDU set processed by the sender and all PDUs in the PDU set that are not successfully delivered to the upper layer of the corresponding receiver.

[0127] 1.7. Buffer Status Report (BSR) Enhancement In BSR, an index corresponding to a predefined buffer size range is indicated in a BSR table (e.g., BSR table 1100), resulting in quantization error. As described above, the larger the index value defined in the BSR table, the larger the buffer size range corresponding to that index value. Therefore, in the case of large-volume traffic such as XR, when the terminal device 10 reports the buffer size using BSR, the quantization error may also be large. The base station device 20 may not be able to appropriately allocate radio resources to the terminal device 10 based on the BSR.

[0128] In response to this, a new BSR table 1400 shown in Fig. 14 may be defined. Hereinafter, the BSR table 1400 will be referred to as a "second table." The second table may also be referred to as an "enhanced BSR table," an "additional BSR table," or an "XR BSR table." The buffer size field set by referring to the second table may also be referred to as a "second buffer size field."

[0129] The second table, like the BSR table 1100, is a table for an 8-bit buffer status field. Therefore, the second table may have 256 index values. The index may be a value from 0 to 255. Each index value may correspond to a range of buffer sizes. That is, the second table may define a correspondence between an index and a range of buffer sizes. Note that, although a character string is inserted in the BS Value in FIG. 14 for the purpose of explanation, a numerical value is actually set. For example, the smaller the index value, the smaller the buffer size corresponding to that index value. The larger the index value, the larger the buffer size corresponding to that index value. Furthermore, the range of buffer sizes corresponding to each of the 256 index values ​​may be defined according to a predetermined exponential function.

[0130] Furthermore, the range and / or granularity of the second table may differ from those defined in the first table (e.g., BSR table 1100). Here, the range of the second table may refer to the range between the minimum and maximum buffer sizes in the second table. Furthermore, the granularity of the second table may refer to the degree of fineness or coarseness of the division width when the range of the second table is divided by the number of indexes (e.g., 256). Note that if the ranges of buffer sizes corresponding to the index values ​​are defined according to a predetermined exponential function, the larger the index value, the larger the division width (i.e., the buffer size range) corresponding to the index value. The range and / or granularity of the second table may be defined to correspond to, for example, XR traffic. For example, the range of the second table may be narrower than the range of the first table (i.e., the range between the minimum and maximum buffer sizes in the first table). For example, the range of the second table may be narrower than the range of the BSR table 1100. That is, a range narrower than that of the first table (e.g., BSR table 1100) may be divided into 256 ranges, and an index value may be assigned to each divided range. Therefore, the granularity of the second table may be finer than that of the first table (e.g., BSR table 1100).

[0131] The base station device 20 may transmit an RRC message including configuration information for the second table to the terminal device 10. Hereinafter, this configuration information is referred to as "first configuration information." The first configuration information may be included in a MAC-CellGroupConfig IE, which is an example of an RRC information element (IE). The first configuration information may be additionalBSR-TableAllowed included in the MAC-CellGroupConfig IE.

[0132] The first setting information may be "information indicating whether the terminal device 10 is permitted to use the second table." The first setting information may be a flag indicating "permission to use the second table" or "not permission to use the second table."

[0133] For example, the first configuration information may be information indicating whether or not use of the second table is permitted for each LCG. The first configuration information may be a bit string (i.e., a bitmap) including multiple bits. For example, the leftmost bit may be a bit corresponding to LCG ID "0". The second bit from the left may be a bit corresponding to LCG ID "1". When the value of a bit is 1, this may indicate that use of the second table in addition to the first table is permitted when reporting the buffer size of the LCG corresponding to the bit. When the value of a bit is 0, this may indicate that use of the second table is not permitted when reporting the buffer size of the LCG corresponding to the bit. In other words, when the value of a bit is 0, this may indicate that only the first table is used when reporting the buffer size of the LCG corresponding to the bit.

[0134] The base station device 20 may transmit system information (SI, for example, SIB1 and / or an SIB other than SIB1) including the first setting information to the terminal device 10. The base station device 20 may transmit DCI including the first setting information to the terminal device 10.

[0135] To use the second table, an additional BSR MAC CE may be defined, which may be referred to as an "Enhanced BSR MAC CE," a "refined BSR MAC CE," or an "XR BSR MAC CE."

[0136] Hereinafter, BSRs in which the buffer size is set using only the first table will be collectively referred to as "first BSR" or "first BSR format." That is, the existing BSRs described below will be referred to as "first BSR" or "first BSR format." Short BSR Long BSR Short Truncated BSR Long Truncated BSR Extended Short BSR Extended Long BSR Extended Short Truncated BSR Extended Long Truncated BSR

[0137] The BSR in FIG. 15 corresponds to the additional BSR MAC CE described above, and is referred to as the "second BSR" or "second BSR format" to distinguish it from the first BSR.

[0138] As shown in FIG. 15, the long BSR as the second BSR includes an LCG field 1510, a buffer size table (BT) field 1520, and a buffer size field 1530.

[0139] The LCG field 1510 is configured with 8 bits. The LCG field 1510 has the same configuration as the LCG field 1010 in Fig. 10. The LCG field 1510 may indicate whether a buffer size field for LCGi exists.

[0140] The BT field 1520 consists of 8 bits. The 8 bits correspond to 8 LCGi, respectively. For example, the BT field 1520 indicates whether the first table (e.g., BSR table 1100) or the second table was used to indicate the buffer size of the LCGi. If the value of BTi is 0, this may indicate that the first table was used to indicate the buffer size of the LCGi. If the value of BTi is 1, this may indicate that the second table was used to indicate the buffer size of the LCGi.

[0141] The number of fields included in buffer size field 1530 varies depending on the value of LCG field 1510. It is assumed that in LCG field 1510, the bit corresponding to LCG1 is 1 and the bit corresponding to LCG2 is 1. Therefore, buffer size field 1530 includes field 1531 corresponding to LCG1 and field 1532 corresponding to LCG2. Note that, since it is assumed that the bit corresponding to LCG0 in FIG. 15 is 0, buffer size field 1530 does not include a field corresponding to LCG0.

[0142] Further, assume that in the BT field 1520, the bit of BT1 corresponding to LCG1 is 0 and the bit of BT2 corresponding to LCG2 is 1. Therefore, the field 1531 corresponding to LCG1 is set by referring to a first table (e.g., the BSR table 1100). That is, the field 1531 corresponding to LCG1 corresponds to the first buffer size field. Furthermore, the field 1532 corresponding to LCG2 is set by referring to a second table. That is, the field 1532 corresponding to LCG2 corresponds to the second buffer size field.

[0143] 15 may be applied to a Long Truncated BSR as the second BSR. In this configuration, the LCG field 1510 may indicate whether the LCGi has available data. For example, if the value of LCGi in the LCG field 1510 is 1, this may indicate that the LCGi has available data. If the value of LCGi is 0, this may indicate that the LCGi does not have available data.

[0144] The MAC PDU may include identification information for identifying whether the BSR is a secondary BSR. For example, the MAC subheader includes an LCID or eLCID value (i.e., a code point). LCID or eLCID values ​​indicating that the BSR is a secondary BSR may be defined. For example, the following LCID or eLCID values ​​may be defined: - The MAC CE includes a secondary BSR, and the secondary BSR is a long BSR. - The MAC CE includes a secondary BSR, and the secondary BSR is a long truncated BSR.

[0145] The terminal device 10 may select either the first BSR or the second BSR according to the procedure of Fig. 13 and transmit the selected BSR to the base station device 20. For example, the RRC message of step S1301 may include the first setting information. The control unit 110 triggers any of the regular BSR, padding BSR, and periodic BSR according to the above conditions (a1) to (a4). Below, aspect 1 and aspect 2 will be described as the operation of the terminal device 10 when a BSR is triggered.

[0146] 1.7.1 Aspect 1 The control unit 110 may select either the first BSR or the second BSR based on at least one of a parameter included in the RRC message (e.g., first configuration information) and a buffer size to be reported (i.e., the size of data available for transmission). For example, the control unit 110 may operate according to the following aspects 1-1 to 1-3.

[0147] (Aspect 1-1) If the first configuration information indicates that use of the second table is permitted for at least one LCG, the control unit 110 may select the second BSR. In this case, the control unit 110 may select the second BSR regardless of the number of LCGs that have available data for transmission. For example, if there is one LCG that has available data for transmission, the control unit 110 may select the second BSR instead of the first BSR that includes a short BSR.

[0148] On the other hand, if the first setting information indicates that there is no LCG that is permitted to use the second table, the control unit 110 may select the first BSR.

[0149] In another example, if the first configuration information indicates that no LCG is permitted to use the second table and the triggered BSR is a regular BSR or a periodic BSR, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above condition (b1). The control unit 110 may select a BSR format according to the above conditions (c1) to (c2).

[0150] In another example, when the first configuration information indicates that no LCG is permitted to use the second table and the triggered BSR is a padding BSR, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0151] (Aspect 1-2) When a MAC PDU including a BSR is constructed, if the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, the control unit 110 may select the second BSR.

[0152] On the other hand, if only the LCG that is not permitted to use the second table has available data for transmission, the control unit 110 may select the first BSR.

[0153] In another example, if the triggered BSR is a regular BSR or a periodic BSR and only an LCG that is not permitted to use the second table has available data for transmission, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above condition (b1). The control unit 110 may select a BSR format according to the above conditions (c1) to (c2).

[0154] In another example, if the triggered BSR is a padding BSR and only LCGs that are not permitted to use the second table have available data for transmission, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0155] (Aspect 1-3) When a MAC PDU including a BSR is constructed, if the first configuration information indicates that the second table is permitted to be used for at least one LCG having available data for transmission, and if the total amount of available data for transmission (i.e., buffer size to be reported) of all LCHs belonging to the at least one LCG is within the range of the second table, the control unit 110 may select the second BSR.

[0156] The total amount of data available for transmission may be within the range of the second table if the total amount of data is greater than or equal to a minimum buffer size defined in the second table and less than or equal to a maximum buffer size defined in the second table. The minimum buffer size may be a value corresponding to index "0" in the second table. The maximum buffer size may be a value corresponding to index "255" in the second table.

[0157] On the other hand, even if the first setting information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, if the total amount of available data for transmission held by all LCHs belonging to that LCG is not within the range of the second table, the control unit 110 may select the first BSR.

[0158] In another example, if the triggered BSR is a regular BSR or a periodic BSR, and the first configuration information indicates that the second table is permitted to be used for at least one LCG having available data for transmission, and the total amount of available data for transmission of all LCHs belonging to the LCG is not within the range of the second table, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above condition (b1). The control unit 110 may select a BSR format according to the above conditions (c1) to (c2).

[0159] In another example, if the triggered BSR is a padding BSR, and the first configuration information indicates that the second table is permitted to be used for at least one LCG having available data for transmission, and the total amount of available data for transmission of all LCHs belonging to the LCG is not within the range of the second table, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0160] 1.7.2 Aspect 2 The second BSR further includes a BT field 1520 compared to the first BSR, so the size of the second BSR is larger than that of the first BSR. If the triggered BSR is a padding BSR, the terminal device 10 may not be able to transmit the second BSR depending on the number of padding bits. In consideration of this, the control unit 110 may operate according to the following aspects 2-1 to 2-3.

[0161] (Aspect 2-1) If the triggered BSR is a padding BSR, the control unit 110 does not select the second BSR. That is, if the triggered BSR is a padding BSR, the control unit 110 may select the first BSR. In another example, if the triggered BSR is a padding BSR, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format in accordance with the above conditions (d1) to (d3). The control unit 110 may select a BSR format in accordance with the above conditions (e1) to (e3).

[0162] If the triggered BSR is a regular BSR or a periodic BSR, the control unit 110 may select a second BSR. For example, the control unit 110 may select either the first BSR or the second BSR according to any of the above aspects 1-1 to 1-3.

[0163] (Aspect 2-2) When the triggered BSR is a padding BSR, the control unit 110 may select either the first BSR or the second BSR based on at least one of the first configuration information, the number of padding bits, and the buffer size to be reported (e.g., the buffer size of an LCG having available data).

[0164] For example, if the triggered BSR is a padding BSR, the control unit 110 may select either the first BSR or the second BSR according to any of the above-mentioned aspects 1-1 to 1-3. In this case, the control unit 110 may select either the first BSR or the second BSR by further taking into consideration the number of padding bits.

[0165] For example, if the triggered BSR is a padding BSR, the control unit 110 may operate as follows based on a combination of the above-mentioned aspect 1-1 and the condition of the number of padding bits: If the first configuration information indicates that the use of the second table is permitted for at least one LCG, and the number of padding bits is equal to or greater than the size of the second BSR plus its subheader (i.e., the number of padding bits is equal to or greater than the number of bits required to transmit the second BSR), the control unit 110 may select the second BSR.

[0166] If the first configuration information indicates that the second table is permitted to be used for at least one LCG, and the number of padding bits is less than the size of the second BSR plus its subheader, the control unit 110 may select the first BSR.

[0167] If the first configuration information indicates that the second table is permitted to be used for at least one LCG, and the number of padding bits is less than the size of the second BSR plus its subheader, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0168] For example, if the triggered BSR is a padding BSR, the control unit 110 may operate as follows based on a combination of the above-mentioned aspect 1-2 and the condition of the number of padding bits: If the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the number of padding bits is equal to or greater than the size of the second BSR plus its subheader, the control unit 110 may select the second BSR.

[0169] If the first configuration information indicates that the second table is allowed to be used for at least one LCG that has available data for transmission, and the number of padding bits is less than the size of the second BSR plus its subheader, the control unit 110 may select the first BSR.

[0170] If the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the number of padding bits is less than the size of the second BSR plus its subheader, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0171] For example, if the triggered BSR is a padding BSR, the control unit 110 may operate as follows based on a combination of the above-mentioned aspects 1-3 and the condition of the number of padding bits: If the first configuration information indicates that the second table is permitted to be used for at least one LCG having available data for transmission, and the total amount of available data for transmission of all LCHs belonging to the at least one LCG is within the range of the second table, and the number of padding bits is equal to or greater than the size of the second BSR plus its subheader, the control unit 110 may select the second BSR.

[0172] If the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the total amount of available data for transmission held by all LCHs belonging to the at least one LCG is within the range of the second table, and the number of padding bits is less than the size of the second BSR plus its subheader, the control unit 110 may select the first BSR.

[0173] In another example, if the first configuration information indicates that the second table is permitted to be used for at least one LCG having available data for transmission, and the total amount of available data for transmission held by all LCHs belonging to the at least one LCG is within the range of the second table, and the number of padding bits is less than the combined size of the second BSR and its subheader, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0174] If the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the number of padding bits is equal to or greater than the size of the second BSR plus its subheader, and the total amount of available data for transmission held by all LCHs belonging to that one LCG is not within the range of the second table, the control unit 110 may select the first BSR.

[0175] If the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the number of padding bits is equal to or greater than the size of the second BSR plus its subheader, and the total amount of available data for transmission held by all LCHs belonging to the LCG is not within the range of the second table, the control unit 110 may select a BSR format as follows: The control unit 110 may select a BSR format according to the above conditions (d1) to (d3). The control unit 110 may select a BSR format according to the above conditions (e1) to (e3).

[0176] (Aspect 2-3) When the triggered BSR is a padding BSR, the control unit 110 may select a long truncated BSR configured as the second BSR. That is, when the triggered BSR is a padding BSR, the control unit 110 may select one of the first BSR, the long BSR as the second BSR, and the long truncated BSR as the second BSR based on at least one of the first configuration information, the number of padding bits, the buffer size of the report target (e.g., the buffer size of the LCG having available data), and the priority of the report target (e.g., the priority of the LCH belonging to the LCG having available data). For example, the control unit 110 may select a long truncated BSR having the configuration shown in FIG. 15.

[0177] For example, when the first configuration information indicates that the second table is permitted to be used for at least one LCG and the number of padding bits is a predetermined size, the control unit 110 may select a long truncated BSR having the configuration shown in Fig. 15. The predetermined size of the number of padding bits may mean, for example, that the number of padding bits is equal to or greater than the sum of the size of the long truncated BSR as the second BSR and its subheader (e.g., 5 bytes or more) and / or less than the size of the long BSR as the second BSR and its subheader.

[0178] For example, if the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the number of padding bits is a predetermined size, the control unit 110 may select a long truncated BSR having the configuration of FIG. 15 .

[0179] For example, if the first configuration information indicates that the second table is permitted to be used for at least one LCG that has available data for transmission, and the total amount of available data for transmission held by all LCHs that belong to that one LCG is within the range of the second table, and the number of padding bits is a predetermined size, the control unit 110 may select a long truncated BSR having the configuration of FIG. 15 .

[0180] For example, if the first configuration information indicates that the second table is permitted to be used for an LCG to which an LCH with the highest priority belongs among LCGs having available data for transmission, and the number of padding bits is a predetermined size, the control unit 110 may select a long truncated BSR having the configuration of Fig. 15. That is, if the triggered BSR is a padding BSR, the control unit 110 may select a long truncated BSR having the configuration of Fig. 15 based on the LCG to which an LCH with the highest priority belongs among LCGs having available data for transmission. The LCH with the highest priority may be determined regardless of whether the LCH has available data.

[0181] For example, if the first configuration information indicates that the second table is permitted to be used for the LCG to which the LCH with the highest priority belongs among the LCGs having data available for transmission, and the total amount of data available for transmission held by all LCHs belonging to the LCG is within the range of the second table, and the number of padding bits is a predetermined size, the control unit 110 may select a long truncated BSR having the configuration of FIG. 15 .

[0182] More specifically, in case of a padding BSR, a MAC entity in which the logicalChannelGroup-IABExt IE is not set by higher layers may select a BSR format as follows: (f1) If the first configuration information indicates that the second table is permitted to be used for at least one LCG, and the total amount of data available for transmission of all LCHs belonging to the at least one LCG is within the range of the second table: (f2) If the number of padding bits is equal to or greater than the size of the short BSR plus its subheader, and is smaller than the size of the long BSR (i.e., the long BSR having the configuration of Figure 15) as the second BSR plus its subheader: (f3) If two or more LCGs have data available for transmission when the BSR is constructed: (f4) If the number of padding bits is equal to the size of the short BSR plus its subheader: The terminal device 10 transmits (or reports) a Short Truncated BSR of the LCG that includes the LCH with the highest priority among the LCHs that have data available for transmission. (f4) Otherwise: The terminal device 10 reports a Long Truncated BSR (i.e., a Long Truncated BSR having the configuration of FIG. 15) configured as a second BSR for an LCG including an LCH that has available data for transmission, in descending order of the LCH with the highest priority, regardless of whether it has available data for transmission or not, in each LCG. Note that if the priorities are the same, the terminal device 10 transmits (or reports) a Long Truncated BSR configured as a second BSR in ascending order of LCG ID. (f3) Otherwise: The terminal device 10 transmits (or reports) a Short BSR.(f2) Otherwise, if the number of padding bits is equal to or greater than the size of the long BSR as the second BSR (i.e., the long BSR having the configuration of FIG. 15) plus its subheader: The terminal device 10 transmits (or reports) the long BSR configured as the second BSR (i.e., the long BSR having the configuration of FIG. 15) for all LCGs that have available data for transmission.

[0183] 1.8. Delay Information Report XR is expected to be operated under various requirements, including a requirement for low latency. Accordingly, for uplink communication from the terminal device 10, the base station device 20 allocates radio resources taking into consideration the above requirements. To allocate such radio resources, the terminal device 10 transmits a delay information report including delay information for predetermined data to the base station device 20. The delay information report may also be referred to as a "Delay Status Report (DSR)."

[0184] The above-mentioned predetermined data means a unit of data to be reported in a delay information report. Hereinafter, the above-mentioned predetermined data may be referred to as "data to be reported" or "unit of data to be reported." According to this configuration, the terminal device 10 can transmit delay information about the data to be reported to the base station device 20.

[0185] The unit of data to be reported may be data corresponding to one LCH. Alternatively, the unit of data to be reported may be data corresponding to one LCG. The one LCG may include one or more LCHs (i.e., data corresponding to one or more LCHs). In this configuration, the unit of data to be reported may be a portion or all of the data available for one LCG. That is, in this configuration, the unit of data to be reported may be a portion or all of the data available for all LCHs belonging to one LCG.

[0186] The unit of data to be reported may be data corresponding to one PDU. In this configuration, the unit of data to be reported may be a part or all of the data available for one PDU. Also, the unit of data to be reported may be data corresponding to one PDU set. In this configuration, the unit of data to be reported may be a part or all of the data available for one PDU set. Furthermore, the unit of data to be reported may be data corresponding to multiple PDU sets. For example, the unit of data to be reported may be data (or a part of data) available for one, several, or all PDUs (or PDU sets) belonging to one PDU set.

[0187] The unit of data to be reported may be data corresponding to one data burst. In this configuration, the unit of data to be reported may be a portion or all of the data available for one data burst. Note that the unit of data to be reported may be data corresponding to multiple data bursts. For example, the unit of data to be reported may be data (or a portion of data) available for one, multiple, or all of the data (or data bursts) belonging to one data burst.

[0188] The delay information may include one or both of information that explicitly indicates a delay and information that implicitly indicates a delay.

[0189] - Information explicitly indicating a delay For example, the delay information may be a delay time or an index representing a delay time. The delay information may be the remaining time until a predetermined first deadline is reached. The remaining time may be calculated based on a PDCP discard timer. The PDCP discard timer is set for a Data Radio Bearer (DRB). The terminal device 10 may calculate the remaining time based on the PDCP discard timer, taking the time of the initial (or first) transmission of the delay information report as a reference. For example, the terminal device 10 may calculate the remaining time of a PDU in a certain PDU set based on the PDCP discard timer associated with the first-arrived PDU in the PDU set. The delay information may include information about multiple remaining times. In another example, the delay information may be information about the shortest remaining time among multiple remaining times.

[0190] - Information implicitly indicating a delay For example, the delay information may include information about data to which a time constraint or requirement is imposed among the data to be reported. Hereinafter, the entire data to be reported will be referred to as "first data", and the data to which a time constraint or requirement is imposed among the data to be reported will be referred to as "second data".

[0191] The second data is data that should be transmitted with priority. The second data may be referred to as urgent data. The second data may be data that satisfies a delay condition. For example, the second data may be data associated with the remaining time. For example, a predetermined first threshold Th1 may be applied to the remaining time of the PDCP discard timer. The second data may be data whose remaining time is less than the first threshold Th1.

[0192] The delay information may be information about the size of the second data. The delay information may be an index indicating the number of bytes of the second data. For example, the delay information may be an index value set by referring to the first table. The delay information may be an index value set by referring to the second table.

[0193] The terminal device 10 may receive parameters related to the delay information report from the base station device 20. The base station device 20 may transmit an RRC message including parameters related to the delay information report to the terminal device 10. The parameters related to the delay information report may be included in a MAC-CellGroupConfig IE, which is an example of an RRC information element (IE). The parameters related to the delay information report may be included in an IE (e.g., an LCG-DSR-Config IE) related to the delay information report included in the MAC-CellGroupConfig IE. The parameters related to the delay information report may include first indication information.

[0194] The first instruction information may be "information that explicitly or implicitly indicates whether to trigger (or send) a delay information report." The first instruction information may indicate "to trigger (or send) a delay information report" or "not to trigger (or send) a delay information report." The first instruction information may be a flag that indicates "to trigger (or send) a delay information report" or "not to trigger (or send) a delay information report." Note that the first instruction information may be "information that indicates whether to send delay information (e.g., the remaining time described above)." Furthermore, the first instruction information may be "information that indicates whether to send information regarding the size of the second data."

[0195] For example, the terminal device 10 may trigger (or transmit) a delay information report when the RRC message includes first instruction information. Furthermore, the terminal device 10 may not trigger (or transmit) a delay information report when the RRC message does not include first instruction information.

[0196] The first instruction information may be set for an LCG. The first instruction information may be information identifying an LCG (e.g., an LCG ID). The terminal device 10 may determine whether to include delay information related to the LCG in a delay information report based on the first instruction information set for an LCG. For example, if the first instruction information indicates that a delay information report is to be transmitted for a certain LCG, the terminal device 10 may include delay information related to the LCG in the delay information report. The first instruction information may be set for an LCH. The first instruction information may be information identifying an LCH. For example, the first instruction information may be set as a new element of the LogicalChannelConfig IE. The terminal device 10 may determine whether to include delay information related to the LCH in a delay information report based on the first instruction information set for an LCH. For example, if the first instruction information indicates that delay information is to be transmitted for a certain LCH, the terminal device 10 may include delay information related to the LCH in the delay information report. The first instruction information may be set for a PDU or a PDU set. The first indication information may be information identifying a PDU or a PDU set. The terminal device 10 may determine whether to include delay information for a PDU or a PDU set in a delay information report based on the first indication information set for the PDU or the PDU set. For example, if the first indication information indicates that delay information is to be transmitted for a certain PDU or a PDU set, the terminal device 10 may include the delay information for the certain PDU or the PDU set in a delay information report. The first indication information may be set in an IE associated with a PDU or a PDU set included in the RRC message. The first indication information may be set for a data burst. The first indication information may be information identifying a data burst. The terminal device 10 may determine whether to include delay information for the certain data burst in a delay information report based on the first indication information set for the data burst. For example, if the first indication information indicates that delay information is to be transmitted for a certain data burst, the terminal device 10 may include delay information for the certain data burst in a delay information report.The first indication information may be set in an IE associated with a data burst included in the RRC message.

[0197] The base station device 20 may transmit system information (SI, for example, SIB1 and / or an SIB other than SIB1) including the first instruction information to the terminal device 10. The base station device 20 may transmit DCI including the first instruction information to the terminal device 10.

[0198] The base station device 20 may transmit information indicating the first threshold value Th1 as a parameter related to the delay information report to the terminal device 10. The base station device 20 may transmit an RRC message including information indicating the first threshold value Th1 to the terminal device 10. For example, the first threshold value Th1 may be included in a MAC-CellGroupConfig IE, which is an example of an RRC information element (IE). The first threshold value Th1 may be included in an IE related to the delay information report (e.g., an LCG-DSR-Config IE) included in the MAC-CellGroupConfig IE.

[0199] The first threshold Th1 may be set for an LCG. For example, the first threshold Th1 may be set in association with the first indication information (e.g., LCG ID) in the IE related to the delay information report. Alternatively, the first threshold Th1 may be set as a new element of a logicalChannelGroup IE. The first threshold Th1 may be set for an LCH. For example, the first threshold Th1 may be set as a new element of a LogicalChannelConfig IE. The first threshold Th1 may be set for a PDU or a PDU set. The first threshold Th1 may be set for an IE related to a PDU or a PDU set included in an RRC message. The first threshold Th1 may be set for a data burst. The first threshold Th1 may be set for an IE related to a data burst included in an RRC message. The first threshold Th1 may be set for the terminal device 10.

[0200] The base station device 20 may transmit system information (SI, for example, SIB1 and / or an SIB other than SIB1) including information indicating the first threshold value Th1 to the terminal device 10. The base station device 20 may transmit DCI including information indicating the first threshold value Th1 to the terminal device 10.

[0201] The first threshold Th1 may be used as a threshold for triggering a delay information report. That is, the terminal device 10 may trigger (and / or transmit) a delay information report based on the first threshold Th1. When the remaining time falls below the first threshold Th1, the terminal device 10 may trigger (and / or transmit) a delay information report.

[0202] For example, if the remaining time for a certain PDU or PDU set falls below a first threshold Th1 set for the LCG, the terminal device 10 may trigger (and / or transmit) a delay information report.

[0203] For example, when the smallest value of multiple PDCP discard timers among all PDUs in the LCG falls below a first threshold Th1, the terminal device 10 may trigger (and / or transmit) a delay information report.

[0204] The base station device 20 may set multiple first thresholds Th1 for each LCG. In this configuration, the multiple first thresholds Th1 may be different from each other. Similarly, the base station device 20 may set multiple first thresholds Th1 for each PDU, PDU set, or data burst.

[0205] The base station device 20 may use the first threshold value Th1 to indicate to the terminal device 10 whether to trigger (or transmit) a delay information report. For example, the terminal device 10 may control to trigger (and / or transmit) a delay information report when the RRC message includes information indicating the first threshold value Th1. Furthermore, the terminal device 10 may control not to trigger (and / or transmit) a delay information report when the RRC message does not include information indicating the first threshold value Th1.

[0206] The terminal device 10 may receive second instruction information as a parameter related to the delay information report from the base station device 20. The base station device 20 may transmit an RRC message including the second instruction information to the terminal device 10.

[0207] The second instruction information may indicate a type of data to be reported. For example, the second instruction information may be information indicating any one of an LCH, an LCG, a PDU, a PDU set, and a data burst. In this configuration, the terminal device 10 may select a type of data to be reported based on the second instruction information. The terminal device 10 may transmit a delay information report for the selected data.

[0208] The second indication information may be information implicitly indicated according to an IE to which the first indication information is set. For example, if the first indication information is set for a MAC cell group, it may indicate that the unit of data to be reported is data corresponding to one LCG. For example, the first indication information may be set for an IE related to a MAC cell group included in the RRC message. As another example, if the first indication information is set for an LCG, it may indicate that the unit of data to be reported is data corresponding to one LCG. For example, the first indication information may be set for an IE related to an LCG. An example of such an IE is the logicalChannelGroup IE. If the first indication information is set for an LCH, it may indicate that the unit of data to be reported is data corresponding to one LCH. The first indication information may be set for an IE related to an LCH. An example of such an IE is the LogicalChannelConfig IE.

[0209] If the first indication information is set for a PDU or a PDU set, it may indicate that the data unit to be reported is data corresponding to a PDU or one or more PDU sets, for example, the first indication information may be set in an IE related to a PDU or a PDU set included in the RRC message.

[0210] If the first indication information is set for a data burst, it may indicate that the unit of data to be reported is data corresponding to one or more data bursts. For example, the first indication information may be set in an IE related to a data burst included in the RRC message.

[0211] The base station device 20 may transmit system information (SI, for example, SIB1 and / or an SIB other than SIB1) including the second instruction information to the terminal device 10. The base station device 20 may transmit DCI including the second instruction information to the terminal device 10.

[0212] The terminal device 10 may transmit a MAC CE including delay information as a delay information report. Therefore, the delay information report may be referred to as a "DSR MAC CE."

[0213] For example, the terminal device 10 may transmit a DSR MAC CE shown in Fig. 16. As shown in Fig. 16, the DSR MAC CE includes an LCG field 1610 and a delay information field 1620.

[0214] The LCG field 1610 consists of 8 bits. In the LCG field 1610, the 8 bits correspond to 8 LCGi, respectively. The LCG field 1610 may indicate whether delay information for LCGi (i.e., the remaining time field and buffer size field, which will be described later) is present in the delay information field 1620. For example, if the value of LCGi in the LCG field 1610 is 1, this indicates that the remaining time field and buffer size field for LCGi are present in the delay information field 1620. If the value of LCGi is 0, this indicates that the remaining time field and buffer size field for LCGi are not present in the delay information field 1620.

[0215] The number of fields included in the delay information field 1620 varies depending on the value of the LCG field 1610. Assume that in the LCG field 1610, the bit corresponding to LCG1 is 1 and the bit corresponding to LCG2 is 1. Therefore, the delay information field 1620 includes delay information corresponding to LCG1 (i.e., a remaining time field 1621 and a buffer size field 1622). Furthermore, the delay information field 1620 includes delay information corresponding to LCG2 (i.e., a remaining time field 1623 and a buffer size field 1624). Note that it is assumed that in the LCG field 1610, the bit corresponding to LCG0 is 0. Therefore, the delay information field 1620 does not include delay information corresponding to LCG0.

[0216] The remaining time field 1621 includes a first portion 1621a and a second portion 1621b. The first portion 1621a is composed of 7 bits. The first portion 1621a represents the remaining time for data corresponding to LCG1. The first portion 1621a may be an index representing the remaining time. The first portion 1621a may represent the smallest value of multiple PDCP discard timers among all PDUs in LCG1. The first portion 1621a may represent the smallest value of multiple PDCP discard timers among all PDCP SDUs buffered in LCG1.

[0217] The second portion 1621b is composed of one bit and represents a buffer size table (BT). The second portion 1621b indicates whether the first table (e.g., BSR table 1100) or the second table was used to indicate the buffer size of LCG1. That is, the second portion 1621b indicates whether the buffer size field 1622 was set using the first table or the second table. If the value of the second portion 1621b is 0, this may indicate that the first table was used to set the buffer size field 1622. If the value of the second portion 1621b is 1, this may indicate that the second table was used to set the buffer size field 1622. Furthermore, the second portion 1621b may not be included in the delay information report. In this case, whether the first table or the second table was used to indicate the buffer size of LCG1 may be specified in advance in the specifications. For example, it may be assumed that the first table was used to indicate the buffer size of LCG1. It may be assumed that the second table is used to indicate the buffer size for LCG1.

[0218] The buffer size field 1622 is configured with 8 bits. The buffer size field 1622 may indicate the buffer size of the second data corresponding to LCG1. For example, the buffer size field 1622 may be the size of data having a remaining time below the first threshold Th1. The buffer size field 1622 may represent the sum of the sizes of all PDUs included in the same PDU set as the PDU (i.e., PDCP SDU) that has a remaining time below the first threshold Th1 and triggered a delay information report (i.e., DSR) for the corresponding LCG. The buffer size field 1622 may represent the sum of the sizes of all PDUs included in the same PDU set as the PDU having a remaining time below the first threshold Th1. For example, the buffer size field 1622 may be the size of data having a remaining time indicated in the first portion 1621a (or having a time less than the remaining time indicated in the first portion 1621a). The buffer size field 1622 may represent the sum of the sizes of all PDUs included in the same PDU set as the PDU (i.e., PDCP SDU) that has the remaining time indicated in the first portion 1621 a and that triggered a delay information report (i.e., DSR) for the corresponding LCG. The buffer size field 1622 may represent the sum of the sizes of all PDUs included in the same PDU set as the PDU that has the remaining time indicated in the first portion 1621 a.

[0219] The remaining time field 1623 has the same structure as the remaining time field 1621. The remaining time field 1623 includes a first portion 1623a and a second portion 1623b. The first portion 1623a represents the remaining time for the data corresponding to LCG2. The second portion 1623b indicates whether the buffer size field 1624 is set in the first table or the second table.

[0220] The buffer size field 1624 has the same configuration as the buffer size field 1622. The buffer size field 1624 may indicate the buffer size of the second data corresponding to LCG2.

[0221] The terminal device 10 may transmit a DSR MAC CE shown in Fig. 17. As shown in Fig. 17, the DSR MAC CE includes an LCG field 1710, a buffer size table (BT) field 1720, and a delay information field 1730.

[0222] The LCG field 1710 has the same structure as the LCG field 1610. The LCG field 1710 is composed of 8 bits. Each of the 8 bits corresponds to 8 LCGi. The LCG field 1710 may indicate whether delay information for LCGi (i.e., the remaining time field and buffer size field described below) is present in the delay information field 1730. For example, if the value of LCGi in the LCG field 1710 is 1, this indicates that the remaining time field and buffer size field for LCGi are present in the delay information field 1730. If the value of LCGi is 0, this indicates that the remaining time field and buffer size field for LCGi are not present in the delay information field 1730.

[0223] The BT field 1720 is composed of 8 bits. Each of the 8 bits corresponds to 8 LCGi. For example, the BT field 1720 indicates whether the first table or the second table was used for the buffer size field for LCGi. When the value of BTi is 0, this may indicate that the first table was used to indicate the buffer size of LCGi. When the value of BTi is 1, this may indicate that the second table was used to indicate the buffer size of LCGi. Furthermore, the BT field 1720 may not be included in the delay information report. In this case, whether the first table or the second table was used to indicate the buffer size of LCGi may be specified in advance in the specifications. For example, it may be assumed that the first table was used to indicate the buffer size of LCGi. It may be assumed that the second table was used to indicate the buffer size of LCGi.

[0224] The number of fields included in the delay information field 1730 varies depending on the value of the LCG field 1710. It is assumed that the bit corresponding to LCG1 in the LCG field 1710 is 1. Therefore, the delay information field 1730 includes delay information corresponding to LCG1 (i.e., the remaining time field 1731 and the buffer size field 1732). It is assumed that the bit corresponding to LCG0 in the LCG field 1710 is 0. Therefore, the delay information field 1730 does not include delay information corresponding to LCG0.

[0225] The remaining time field 1731 is configured with 8 bits. The remaining time field 1731 has the same configuration as the first part 1621a of the remaining time field 1621. The remaining time field 1731 indicates the above remaining time for the data corresponding to LCG1.

[0226] The buffer size field 1732 is configured with 8 bits. The buffer size field 1732 has the same configuration as the buffer size field 1622. The buffer size field 1732 may indicate the buffer size of the second data corresponding to LCG1.

[0227] 16 and 17, the DSR MAC CE includes both the remaining time and the buffer size as delay information, but is not limited to this configuration. The DSR MAC CE may be configured to include either the remaining time or the buffer size.

[0228] The MAC PDU may include identification information for identifying whether it is a delay information report. For example, the MAC subheader includes an LCID or eLCID value (i.e., a code point). An LCID or eLCID value indicating a delay information report may be defined.

[0229] Furthermore, the following LCID or eLCID values ​​may be defined based on the type of data to be reported: - The MAC CE includes a delay information report, and the unit of the data to be reported is data corresponding to one LCH. - The MAC CE includes a delay information report, and the unit of the data to be reported is data corresponding to one LCG. - The MAC CE includes a delay information report, and the unit of the data to be reported is data corresponding to one PDU. - The MAC CE includes a delay information report, and the unit of the data to be reported is data corresponding to one or more PDU sets. - The MAC CE includes a delay information report, and the unit of the data to be reported is data corresponding to one or more data bursts.

[0230] The procedure by which the terminal device 10 transmits a delay information report (for example, DSR MAC CE) to the base station device 20 will be described below.

[0231] 18 , the communication unit 220 of the base station device 20 transmits an RRC message to the terminal device 10 (S1801). The RRC message includes parameters related to a delay information report. The parameters related to the delay information report may include at least one of a first threshold Th1, first instruction information, and second instruction information. The RRC message may be an RRCReconfiguration message.

[0232] The control unit 110 of the terminal device 10 triggers a delay information report based on a parameter included in the RRC message. For example, when the remaining time falls below a first threshold Th1, the control unit 110 may trigger the delay information report. The communication unit 120 of the terminal device 10 transmits the delay information report (S1802).

[0233] The control unit 210 of the base station device 20 allocates radio resources to the terminal device 10 based on the delay information report. The control unit 210 may determine the degree of delay based on the delay information included in the delay information report. For example, the control unit 210 may determine the degree of delay based on the remaining time and / or the size of the second data. Furthermore, the control unit 210 may allocate radio resources for uplink communication from the terminal device 10 based on the delay information.

[0234] As described above, for example, the terminal device 10 triggers a BSR according to conditions (a1) to (a4). The terminal device 10 may also trigger a delay information report based on a first threshold Th1. Because the conditions for triggering a BSR and the conditions for triggering a delay information report are different, the BSR and the delay information report may be triggered at substantially the same time. If the buffer of the terminal device 10 contains only data with a small remaining time, information on all buffer sizes is included in the delay information report. Therefore, there is little need to transmit a BSR.

[0235] In consideration of the above, if a BSR and a delay information report are triggered and the terminal device 10 transmits a delay information report, the terminal device 10 may cancel the triggered BSR based on the transmission of the delay information report.

[0236] For example, when a MAC PDU is transmitted and this PDU includes a delay information report (e.g., a DSR MAC CE), and the delay information report includes the buffer status up to the last event that triggered a BSR before MAC PDU assembly, all BSRs triggered before MAC PDU assembly may be canceled. For example, if the buffer status information included in the triggered BSR can all be included in the delay information report, the terminal device 10 may cancel the triggered BSR.

[0237] When the BSR and the delay information report are triggered and the terminal device 10 transmits the BSR, the terminal device 10 does not need to cancel the triggered delay information report. That is, the terminal device 10 may transmit the delay information report after transmitting the BSR. Since the BSR does not include information about the remaining time, transmitting the delay information report has an advantage.

[0238] 2. Modifications Although the present disclosure has been described based on the above embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the equivalent range. Other combinations including one or more elements included in the above embodiment are also within the scope and spirit of the present disclosure.

[0239] The words, phrases, and other expressions used in the above embodiments are merely examples and may be replaced with substantially identical or similar expressions. In particular, since the technology according to the above embodiments relates to technical specifications, the expressions in the above embodiments may be replaced with substantially identical or similar expressions in technical specifications (e.g., technical specifications cited in this specification).

[0240] The information transmitted and received in the above embodiment may be contained in the same or a different message or element already described in the technical specifications, or may be contained in a newly defined message or element. The information transmitted and received in the above embodiment may be transmitted and received using a different layer and / or a different channel than those in the above embodiment.

[0241] The means and / or functions provided by the devices described in the above embodiments can be provided by software recorded in a tangible memory device and a computer that executes the software, software alone, hardware alone, or a combination thereof. For example, if any of the above devices is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including a large number of logic circuits, or an analog circuit.

[0242] The device described in the above embodiment executes a program stored in a non-transitory tangible storage medium, and the execution of the program executes a method corresponding to the program.

[0243] 3. Supplementary Notes Some or all of the above embodiments and modified examples may also be described as, but are not limited to, the following supplementary notes. Below, relationships are expressed in which a supplementary note that is subordinate to multiple supplementary notes is subordinate to another supplementary note that is subordinate to multiple supplementary notes. All of the following subordinate relationships of supplementary notes are included in the above embodiments.

[0244] (Supplementary Note A1) A terminal device comprising: a control unit (110) configured to generate, as a buffer status report (BSR), a first BSR including a first buffer size field set by referring to a first table, and a second BSR including the first buffer size field and a second buffer size field set by referring to a second table different from the first table; and a communication unit (120) configured to transmit the BSR to a base station device (20), wherein the control unit is configured to select either the first BSR or the second BSR depending on whether a triggered BSR is a regular BSR, a padding BSR, or a periodic BSR.

[0245] (Supplementary Note A2) The terminal device according to Supplementary Note A1, wherein the control unit is configured to select the first BSR if the triggered BSR is the padding BSR.

[0246] (Supplementary Note A3) The terminal device according to Supplementary Note A2, wherein the communication unit is configured to receive, from the base station device, configuration information indicating whether the terminal device is permitted to use the second table, and the control unit is configured to select the second BSR if the triggered BSR is the regular BSR or the periodic BSR and the configuration information indicates that the terminal device is permitted to use the second table.

[0247] (Supplementary Note A4) The terminal device according to Supplementary Note A1, wherein the communication unit is configured to receive, from the base station device, configuration information indicating whether the terminal device is permitted to use the second table, and the control unit is configured, when the triggered BSR is the padding BSR, to select either the first BSR or the second BSR based on at least one of the configuration information, the number of padding bits, and a buffer size to be reported.

[0248] (Supplementary Note A5) The terminal device according to Supplementary Note A4, wherein the control unit is configured to select the second BSR when the setting information indicates that the terminal device is permitted to use the second table and the number of padding bits is equal to or greater than the number of bits required to transmit the second BSR.

[0249] (Supplementary Note A6) The terminal device according to Supplementary Note A4, wherein the control unit is configured to select the first BSR when the configuration information indicates that the terminal device is permitted to use the second table and the number of padding bits is less than the number of bits required to transmit the second BSR.

[0250] (Supplementary Note A7) The terminal device according to Supplementary Note A4, wherein the control unit is configured to select the second BSR when the setting information indicates that the terminal device is permitted to use the second table, and the number of padding bits is equal to or greater than the number of bits required to transmit the second BSR, and the buffer size of the report target is within the range of the second table.

[0251] (Supplementary Note A8) The terminal device according to Supplementary Note A4, wherein the control unit is configured to select the first BSR when the configuration information indicates that the terminal device is permitted to use the second table, and the number of padding bits is equal to or greater than the number of bits required to transmit the second BSR, and the buffer size of the report target is not within the range of the second table.

[0252] (Supplementary Note A9) The terminal device according to Supplementary Note A5 or A7, wherein the second BSR is a long truncated BSR.

[0253] (Supplementary Note A10) The terminal device according to Supplementary Note A9, wherein the control unit is configured to include one or more of the second buffer size fields in the second BSR according to a priority of a logical channel (LCH).

[0254] (Supplementary Note A11) The terminal device according to Supplementary Note A1, wherein the control unit is configured to generate a delay information report including delay information, and when the BSR and the delay information report are triggered and the communication unit transmits the delay information report, the control unit is configured to cancel the triggered BSR.

[0255] (Supplementary Note A12) The terminal device according to Supplementary Note A1, wherein the control unit is configured to generate a delay information report including delay information, and when the BSR and the delay information report are triggered and the communication unit has transmitted the BSR, the control unit is configured to further transmit the delay information report.

[0256] (Supplementary Note A13) A method for a terminal device, comprising: generating, as a Buffer Status Report (BSR), a first BSR including a first buffer size field set by referring to a first table, and a second BSR including the first buffer size field and a second buffer size field set by referring to a second table different from the first table; and transmitting the BSR to a base station device (20), wherein the generating step comprises selecting either the first BSR or the second BSR according to whether the triggered BSR is a regular BSR, a padding BSR, or a periodic BSR.

[0257] (Supplementary Note A14) A program that causes a processor (101) in a terminal device (10) to execute the following steps: generate, as a Buffer Status Report (BSR), a first BSR including a first buffer size field set by referring to a first table, and a second BSR including the first buffer size field and a second buffer size field set by referring to a second table different from the first table; and transmit the BSR to a base station device (20), wherein the generating step includes selecting either the first BSR or the second BSR depending on whether the triggered BSR is a regular BSR, a padding BSR, or a periodic BSR.

[0258] (Supplementary Note A15) A non-transitive tangible recording medium having recorded thereon a program causing a processor (101) in a terminal device (10) to execute the following steps: generate, as Buffer Status Reports (BSRs), a first BSR including a first buffer size field set by referring to a first table, and a second BSR including the first buffer size field and a second buffer size field set by referring to a second table different from the first table; and transmit the BSRs to a base station device (20), wherein the generating step includes selecting either the first BSR or the second BSR depending on whether a triggered BSR is a regular BSR, a padding BSR, or a periodic BSR.

[0259] (Supplementary Note B1) A terminal device includes: a transmitter (121) that transmits a first Buffer Status Reporting (BSR) Medium Access Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes to a base station device (20); and a receiver (122) that receives, from the base station device, a Radio Resource Control (RRC) message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical Channel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes, wherein the transmitter: the terminal device transmits, to the base station device, a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data, based on either the first table or the second table, when the information for permitting use of the second table is set, and the amount of available data is within a buffer size defined in the second table, and the number of padding bits is equal to or greater than a predetermined size.

[0260] (Supplementary Note B2) The terminal device according to Supplementary Note B1, wherein the transmitter transmits one of the first BSR MAC CE and the BSR MAC CE to the base station device as a padding BSR.

[0261] (Supplementary Note B3) The terminal device according to Supplementary Note B1 or B2, wherein the second BSR MAC CE includes a field indicating whether the first table or the second table is to be used.

[0262] (Supplementary Note B4) The terminal device according to any one of Supplementary Notes B1 to B3, wherein the predetermined size is a size of the second BSR MAC CE plus its subheader.

[0263] (Supplementary Note B5) The terminal device according to any one of Supplementary Notes B1 to B4, further comprising: a control unit (110) that triggers a BSR and a Delay Status Report (DSR), wherein the transmission unit transmits a DSR MAC CE to the base station device, and the control unit cancels the triggered BSR based on information about a buffer size included in the DSR MAC CE.

[0264] (Supplementary Note B6) A method for a terminal device, comprising: transmitting to a base station device (20) a first Buffer Status Report (BSR) Medium Access Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes; and receiving from the base station device a Radio Resource Control (RRC) message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical Channel (LCH) belongs and information for authorizing the LCG to use a second table related to buffer sizes, wherein the method further comprises: transmitting, based on either the first table or the second table, a second BSR having a second format including a buffer size field for indicating the amount of available data, when the information for authorizing use of the second table is set and the amount of available data is within a buffer size defined in the second table and a number of padding bits is equal to or greater than a predetermined size. transmitting a MAC CE to the base station device.

[0265] (Supplementary Note B7) The method according to Supplementary Note B6, further comprising transmitting one of the first BSR MAC CE and the BSR MAC CE to the base station device as a padding BSR.

[0266] (Supplementary Note B8) The method according to Supplementary Note B6 or B7, wherein the second BSR MAC CE includes a field indicating whether the first table or the second table is to be used.

[0267] (Supplementary Note B9) The method according to any one of Supplementary Notes B6 to B8, wherein the predetermined size is a size of the second BSR MAC CE plus its subheader.

[0268] (Supplementary Note B10) The method according to any one of Supplementary Notes B6 to B9, further comprising: triggering a BSR and a Delay Status Report (DSR); transmitting a DSR MAC CE to the base station device; and canceling the triggered BSR based on information about a buffer size included in the DSR MAC CE.

[0269] (Supplementary Note B11) A base station device, comprising: a receiver (222) for receiving, from a terminal device (10), a first Buffer Status Reporting (BSR) Medium Access Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes; and a transmitter (221) for transmitting, to the terminal device, a Radio Resource Control (RRC) message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical Channel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes, wherein the receiver: and when the information for permitting use of the second table is set, and the amount of available data is within a buffer size defined in the second table, and a number of padding bits is equal to or greater than a predetermined size, the base station device receives from the terminal device a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data based on either the first table or the second table.

[0270] (Supplementary Note B12) The base station apparatus according to Supplementary Note B11, wherein the receiving unit receives one of the first BSR MAC CE and the BSR MAC CE from the terminal apparatus as a padding BSR.

[0271] (Supplementary Note B13) The base station apparatus according to Supplementary Note B11 or B12, wherein the second BSR MAC CE includes a field indicating whether the first table or the second table is to be used.

[0272] (Supplementary Note B14) The base station device according to any one of Supplementary Notes B11 to B13, wherein the predetermined size is a size of the second BSR MAC CE plus its subheader.

[0273] The disclosures of the above prior art documents and references are incorporated herein by reference.

Claims

1. A terminal device, comprising: a transmitter (121) for transmitting a first Buffer Status Reporting (BSR) Medium Access Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes to a base station device (20); and a receiver (122) for receiving a Radio Resource Control (RRC) message from the base station device including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical CHannel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes, wherein the transmitter: the terminal device transmits, to the base station device, a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data based on either the first table or the second table, when the information for permitting use of the second table is set, and the amount of available data is within a buffer size defined in the second table, and a number of padding bits is equal to or greater than a predetermined size.

2. The terminal device according to claim 1, wherein the transmission unit transmits one of the first BSR MAC CE and the BSR MAC CE to the base station device as a padding BSR.

3. The terminal device according to claim 1 or 2, wherein the second BSR MAC CE includes a field indicating whether the first table or the second table is to be used.

4. The terminal device according to claim 1, wherein the predetermined size is a size of the second BSR MAC CE plus its subheader.

5. The terminal device according to any one of claims 1 to 4, further comprising a control unit (110) that triggers a BSR and a Delay Status Report (DSR), wherein the transmission unit transmits a DSR MAC CE to the base station device, and the control unit cancels the triggered BSR based on information regarding a buffer size included in the DSR MAC CE.

6. A method for a terminal device, comprising: transmitting a first Buffer Status Reporting (BSR) Medium Access Control Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes to a base station device (20); receiving a Radio Resource Control (RRC) message from the base station device including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical CHannel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes, the method further comprising: transmitting a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data based on either the first table or the second table, when the information for permitting the use of the second table is set, and the amount of available data is within a buffer size defined in the second table, and a number of padding bits is equal to or greater than a predetermined size. transmitting a CE to the base station device.

7. The method according to claim 6, further comprising transmitting one of the first BSR MAC CE and the BSR MAC CE to the base station device as a padding BSR.

8. The method according to claim 6 or 7, wherein the second BSR MAC CE includes a field indicating whether the first table or the second table is to be used.

9. The method according to any one of claims 6 to 8, wherein the predetermined size is a size of the second BSR MAC CE plus its subheader.

10. The method according to any one of claims 6 to 9, further comprising: triggering a BSR and a Delay Status Report (DSR); transmitting a DSR MAC CE to the base station device; and canceling the triggered BSR based on information about a buffer size included in the DSR MAC CE.

11. A base station device, comprising: a receiving unit (222) for receiving from a terminal device (10) a first Buffer Status Reporting (BSR) Medium Access Control Control Element (MAC CE) having a first format including a buffer size field for indicating an amount of available data based on a first table related to buffer sizes; and a transmitting unit (221) for transmitting to the terminal device a Radio Resource Control (RRC) message including information for setting an identifier (ID) of a Logical Channel Group (LCG) to which a Logical CHannel (LCH) belongs, and information for permitting the LCG to use a second table related to buffer sizes, wherein the receiving unit: receiving, from the terminal device, a second BSR MAC CE having a second format including a buffer size field for indicating the amount of available data based on either the first table or the second table, when the information for permitting use of the second table is set, and when the amount of available data is within a buffer size defined in the second table, and when a number of padding bits is equal to or greater than a predetermined size.

12. The base station apparatus according to claim 11, wherein the receiving unit receives, as a padding BSR, either the first BSR MAC CE or the BSR MAC CE from the terminal apparatus.

13. The base station device according to claim 11 or 12, wherein the second BSR MAC CE includes a field indicating whether the first table or the second table is to be used.

14. The base station device according to claim 11, wherein the predetermined size is a size of the second BSR MAC CE plus its subheader.

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