Terminal, network node, and communication method

Abstract

A terminal comprising a control unit that acquires terminal pending data information for the host device and a transmission unit that transmits notification information including the terminal pending data information to a network node, wherein the notification information includes, as the terminal pending data information for the host device, at least one among: the amount of pending data or the amount of said data buffered; the amount of pending data for a bearer or the amount of said data buffered; the proportion of a part of the pending data to the pending data; the amount of pending data for a designated bearer to the total amount of pending data; the proportion of the pending data to the buffer size; the free capacity of the buffer; the size of the buffer; and information regarding whether or not new data can be received.

Description

Terminal, Network Node, and Communication Method

[0001] The present invention relates to a terminal, a network node, and a communication method in a communication system.

[0002] In 3GPP (registered trademark) (3rd Generation Partnership Project), in order to achieve further increase in system capacity, further increase in data transmission speed, further reduction in latency in the radio section, etc., a radio communication method called 5G or NR (New Radio) (hereinafter, this radio communication method is referred to as "5G" or "NR") is being studied. In 5G, various radio technologies are being studied in order to meet the requirement of achieving a throughput of 10 Gbps or more while reducing the latency in the radio section to 1 ms or less.

[0003] In NR, a network architecture including a 5GC (5G Core Network) or 5GS (5G System) corresponding to the EPC (Evolved Packet Core), which is the core network in the network architecture of LTE (Long Term Evolution), and an NG-RAN (Next Generation - Radio Access Network) corresponding to the E-UTRAN (Evolved Universal Terrestrial Radio Access Network), which is the RAN (Radio Access Network) in the network architecture of LTE, is being studied (for example, Non-Patent Document 1).

[0004] In 6G, which is the next generation of 5G, it is assumed that a terminal is simultaneously connected to multiple RATs (Radio Access Technologies). Also, following 5G, in 6G, a scenario in which a control plane (CP) and a user plane (UP) are separated at a base station and a plurality of UP nodes are connected is being studied.

[0005] 3GPP TS 23.501 V18.7.0 (2024-09) 3GPP TS 38.401 V18.3.0 (2024-09) 3GPP TS 36.321 V18.3.0 (2024-09) 3GPP TS 38.321 V18.3.0 (2024-09) 3GPP TS 38.425 V18.1.0 (2024-06) 3GPP TS 38.323 V18.3.0 (2024-09)

[0006] In PDCP (Packet Data Control Protocol) / RLC (Radio Link Control) processing, terminals have a Layer 2 buffer, and it is necessary to control the data communication to prevent this buffer from overflowing. When a terminal connects to multiple RATs simultaneously, or to multiple UP nodes at a base station, the terminal communicates with multiple network nodes, and the amount of communication data is controlled at each network node.

[0007] However, under the existing specifications, each node cannot determine the amount of data accumulating in the terminal's buffer, which could lead to buffer overflow.

[0008] This invention has been made in view of the above points, and aims to prevent buffer overflow at terminals in wireless communication networks.

[0009] According to the disclosed technology, a terminal is provided having a control unit that acquires terminal data information in its own device, and a transmission unit that transmits notification information including the terminal data information to a network node, wherein the notification information includes, as terminal data information, at least one of the following: the amount of data that is stuck or the remaining buffer amount in the device, the amount of data that is stuck for a bearer or the remaining buffer amount, the proportion of the data that is stuck that is part of the total data that is stuck, the amount of data that is stuck for a designated bearer in the total amount of data that is stuck, the proportion of the data that is stuck that is stuck in the buffer size, the free capacity of the buffer, the size of the buffer, and information regarding whether or not new data can be received.

[0010] According to the disclosed technology, it is possible to prevent buffer overflows at terminals in wireless communication networks.

[0011] This is a diagram illustrating an example of a communication system. This is a diagram illustrating an example of a communication system in a roaming environment. This is a diagram illustrating an example of an option to connect to two RATs in 6G. This is a diagram illustrating an example of an option to connect to three RATs in 6G. This is a diagram illustrating an example of an option to connect to three RATs in 6G. This is a diagram illustrating Dual stack in 6G. This is a diagram illustrating transmission control considering terminal lag data. This is a diagram illustrating DL lag data in DC. This is a diagram illustrating DL lag data in C / U plane separation. This is a diagram illustrating DL lag data in CN aggregation. This is a diagram illustrating UL lag data in DC. This is a diagram illustrating UL lag data in C / U plane separation. This is a diagram illustrating UL lag data in CN aggregation. This is a diagram illustrating a method for reporting the amount of terminal lag data in an embodiment of the present invention. This is a diagram illustrating an example of the functional configuration of a base station 10 and a network node 30 in an embodiment of the present invention. This is a diagram illustrating an example of the functional configuration of a terminal 20 in an embodiment of the present invention. This is a diagram illustrating an example of the hardware configuration of a base station 10 and a terminal 20 in an embodiment of the present invention. This figure shows an example of the configuration of a vehicle 2001 in an embodiment of the present invention.

[0012] Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiments described below are examples, and the embodiments to which the present invention is applied are not limited to those described below.

[0013] In the operation of the wireless communication system according to the embodiments of the present invention, existing technologies may be used as appropriate. However, such existing technologies include, for example, existing LTE, but are not limited to existing LTE. Furthermore, the term "LTE" as used herein has a broad meaning that includes LTE-Advanced, LTE-Advanced and later technologies (e.g., NR), or wireless LAN (Local Area Network), unless otherwise specified.

[0014] Furthermore, in the embodiments of the present invention, "configuring" wireless parameters means that predetermined values ​​are pre-configured, or that wireless parameters notified from the network node 30 or terminal 20 are configured.

[0015] Figure 1 is a diagram illustrating an example of a communication system. As shown in Figure 1, the communication system consists of a terminal 20 (UE) and multiple network nodes 30. Hereafter, one network node 30 will be assumed to correspond to each function, however, one network node 30 may implement multiple functions, or multiple network nodes 30 may implement one function. Furthermore, the "connection" described below may be a logical connection or a physical connection. In the following description, " / " means "and / or" unless otherwise specified, or unless it is clear from the context that it has a different meaning.

[0016] The RAN (Radio Access Network) is a network node 30 having wireless access functionality, which may include a base station 10, and is connected to a UE, AMF (Access and Mobility Management Function), and UPF (User plane function). The AMF is a network node 30 having functions such as terminating the RAN interface, terminating the NAS (Non-Access Stratum), registration management, connection management, reachability management, and mobility management. The UPF is a network node 30 interconnected with the DN (Data Network) and having functions such as a PDU (Protocol Data Unit) session point to the outside, packet routing and forwarding, and user plane QoS (Quality of Service) handling. The UPF and DN constitute a network slice. In the wireless communication network in the embodiment of the present invention, multiple network slices are constructed.

[0017] AMF is connected to UE, RAN, SMF (Session Management function), NSSF (Network Slice Selection Function), NEF (Network Exposure Function), NRF (Network Repository Function), UDM (Unified Data Management), AUSF (Authentication Server Function), PCF (Policy Control Function), and AF (Application Function). AMF, SMF, NSSF, NEF, NRF, UDM, AUSF, PCF, and AF are network nodes 30 that are interconnected via interfaces based on their respective services: Namf, Nsmf, Nnssf, Nnef, Nnrf, Nudm, Nausf, Npcf, and Naf.

[0018] The SMF is a network node 30 that has functions such as session management, IP (Internet Protocol) address allocation and management for UEs, DHCP (Dynamic Host Configuration Protocol) functionality, ARP (Address Resolution Protocol) proxy, and roaming functionality. The NEF is a network node 30 that has the function of notifying other NFs (Network Functions) of capabilities and events. The NSSF is a network node 30 that has functions such as selecting the network slice to which the UE connects, determining the allowed NSSAI (Network Slice Selection Assistance Information), determining the NSSAI to be set, and determining the AMF set to which the UE connects. The PCF is a network node 30 that has the function of controlling network policies. The AF is a network node 30 that has the function of controlling application servers. The NRF is a network node 30 that has the function of discovering NF instances that provide services. The UDM is a network node 30 that manages subscriber data and authentication data. The UDM is connected to the UDR (User Data Repository) that holds the said data.

[0019] Figure 2 is a diagram illustrating an example of a communication system in a roaming environment. As shown in Figure 2, the network consists of a terminal 20 (UE) and multiple network nodes 30. Hereafter, one network node 30 will be assigned to each function, but one network node 30 may implement multiple functions, or multiple network nodes 30 may implement one function. Also, the "connection" described below may be a logical connection or a physical connection.

[0020] The RAN is a network node 30 having wireless access functionality and is connected to the UE, AMF, and UPF. The AMF is a network node 30 having functions such as RAN interface termination, NAS termination, registration management, connection management, reachability management, and mobility management. The UPF is a network node 30 interconnected with the DN, having functions such as external PDU session point, packet routing and forwarding, and user plane QoS handling. The UPF and DN constitute a network slice. In the wireless communication network according to the embodiment of the present invention, multiple network slices are constructed.

[0021] AMF is connected to UE, RAN, SMF, NSSF, NEF, NRF, UDM, AUSF, PCF, AF, and SEPP (Security Edge Protection Proxy). AMF, SMF, NSSF, NEF, NRF, UDM, AUSF, PCF, and AF are network nodes 30 that are interconnected via interfaces based on their respective services: Namf, Nsmf, Nnssf, Nnef, Nnrf, Nudm, Nausf, Npcf, and Naf.

[0022] SMF is a network node 30 that has functions such as session management, IP address allocation and management for UEs, DHCP functionality, ARP proxy, and roaming functionality. NEF is a network node 30 that has the function of notifying other NFs of capabilities and events. NSSF is a network node 30 that has functions such as selecting the network slice to which the UE connects, determining which NSSAIs are allowed, determining which NSSAIs are configured, and determining which AMF set the UE connects to. PCF is a network node 30 that has the function of controlling network policies. AF is a network node 30 that has the function of controlling application servers. NRF is a network node 30 that has the function of discovering NF instances that provide services. SEPP is an opaque proxy that filters control plane messages between PLMNs (Public Land Mobile Networks). In Figure 2, vSEPP is the SEPP in the visited network, and hSEPP is the SEPP in the home network.

[0023] As shown in Figure 2, the UE is in a roaming environment connected to the RAN and AMF in the Visited PLMN. The Visited PLMN and Home PLMN are connected via vSEPP and hSEPP. The UE can communicate with the UDM of the Home PLMN, for example, via the AMF of the Visited PLMN.

[0024] (Buffered data in UE) UE is equipped with an L2 buffer to perform PDCP (Packet Data Control Protocol) / RLC (Radio Link Control) processing at Layer 2 (L2), and buffers UL data and DL data.

[0025] UL data includes, for example, UL data before PDCP transmission processing, UL data during PDCP transmission processing, and UL data after PDCP transmission processing where the PDCP Sequence Number has not been confirmed to have been delivered in-sequence by RLC ACK.

[0026] DL data includes, for example, DL data received from the MAC layer before RLC reception processing, DL data received from the MAC layer during RLC reception processing, DL data received from the MAC layer after RLC reception processing but before PDCP reception processing, and DL data received from the MAC layer after RLC reception processing but during PDCP reception processing (including reordering).

[0027] (UE L2 Buffer Overflow) If the amount of data buffered by the UE increases and the L2 buffer overflows, the following packet discards are expected to occur: - All packets in the L2 buffer are discarded. - Packets are discarded in an amount that resolves the L2 buffer overflow. - UL data is stored in the buffer before being stored in the L2 buffer (it is not forwarded to the L2 buffer).

[0028] Furthermore, the following problems are expected to occur when packet dropping occurs: • Degradation of communication quality due to packet loss in UDP communications • Increased delay due to TCP retransmission in TCP communications • Reduced throughput due to a shrinking congestion window in TCP communications • (If only some packets are dropped) Reordering is not resolved, causing delays until t-Reordering expires • Functionality is interrupted as an error in the application.

[0029] (C / U split architecture) Following 5G, a scenario in which CU-CP / CU-UP nodes are separated and multiple UP nodes are connected is also being considered for 6G. For the specifications in 5G, please refer to section 6.2 of Non-Patent Document 2, etc.

[0030] (Multiple RAT connection technology in 6G) In 6G, it is assumed that a terminal will connect to multiple RATs (Radio Access Technology) simultaneously. In this assumption, terminal 20 may register with one or more core networks. Terminal 20 may also connect to two or more RAN nodes (base stations 10) simultaneously. For example, terminal 20 may connect to 5G and 6G networks simultaneously, or to 4G, 5G, and 6G networks simultaneously.

[0031] Figure 3 shows an example of an option for connecting to two RATs in 6G. As shown in Figure 3, the options for connecting to two RATs in 6G are Option 1, Option 2, and Option 3, which are Dual Connectivity between 5G and 6G RANs, and Option 2, which is Core Network Aggregation (CN) between 5G and 6G CNs.

[0032] Figures 4 and 5 illustrate an example of the options for connecting to three RATs in 6G. As shown in Figures 4 and 5, the options for connecting to three RATs in 6G are Option 5, Option 7, Option 8, and Option 9, which are multi-connectivity between 4G, 5G, and 6G RANs, and Option 6, which is core network aggregation between 4G, 5G, and 6G CNs.

[0033] Figure 6 is a diagram illustrating Dual stack in 6G. As shown in Figure 6, terminal 20, which supports Dual stack, is capable of handling protocol stacks (PHY, MAC, RLC, PDCP, RRC, NAS) in both 5G and 6G. Furthermore, terminal 20 may be capable of Dual registration, registering with both 5GC and 6GC simultaneously, or it may be capable of registering with only one of 5GC or 6GC.

[0034] In this core network aggregation configuration, coordination between 5G and 6G RAN nodes is unnecessary, and user plane data is distributed to either 5G or 6G within the core network.

[0035] (Transmission control considering UE data volume) At RAN nodes (base stations), there is a method to monitor the amount of UE data volume and stop data transmission if buffer overflow is suspected. In this method, DL data that has been transmitted but for which delivery confirmation has not been obtained in-sequence is considered to be volume in the reordering layer. In addition, the amount of UL data reported from the UE in the Buffer Status Report is considered to be volume in the volume (see Non-Patent Document 3, Section 5.4.5 and Non-Patent Document 4, Section 5.4.5).

[0036] Figure 7 illustrates transmission control that takes into account terminal data hoarding. As shown in Figure 7(a), the network-side RLC estimates the amount of data hoarding in the UE's L2 buffer. If DL data hoards in the UE's RLC due to reordering and there is a risk of exceeding the UE's L2 buffer hoarding limit, the network-side RLC stops transmitting new DL data, as shown in Figure 7(b). Note that Figure 7 only describes the operation of DL, but if the amount of UL data hoarding is also considered, new data transmission will be stopped if the amount of DL / UL data hoarding exceeds the UE's L2 buffer hoarding limit.

[0037] (Understanding the Amount of Backlogged Data) When a network consisting of multiple CU-UP nodes communicates with a UE, each node needs to accurately understand the amount of backlogged data at the UE. Furthermore, when dual connectivity (multi-connectivity) is implemented, multiple nodes communicate with the UE, but under existing specifications, each node cannot accurately understand the amount of backlogged data at the UE. In addition, when CN aggregation is implemented, the aforementioned transmission control method cannot be used, so CN nodes cannot accurately understand the amount of backlogged data at the UE. Consequently, each node cannot perform transmission control that takes into account the amount of backlogged data at the UE, which may lead to L2 buffer overflow at the UE.

[0038] (Issues related to DL lag data in DC (Dual Connectivity)) When using a DC, if the PDCP termination node has two different bearers, there is a possibility that the two bearers will be configured simultaneously. Figure 8 is a diagram illustrating DL lag data in a DC. As shown in Figure 8, the Master Node (MN) terminated bearer (first bearer) is a C-plane bearer (SRB) or a bearer where stability is required (for example, for voice). The Secondary Node (SN) terminated bearer (second bearer) is a bearer where high bandwidth is required (for packets).

[0039] Existing methods estimate the amount of data backed up in the reordering layer (i.e., the PDCP layer). However, since a node cannot know the amount of DL backed up by the other bearer, it cannot consider the amount of DL backed up by the other bearer. Consequently, existing methods underestimate the amount of data backed up, raising concerns about UE L2 buffer overflow.

[0040] (Issues regarding DL backlog data in C / U split) In a C / U plane separation configuration, if the PDCP termination node has two different bearers, there is a possibility that these two bearers will be configured simultaneously. Figure 9 is a diagram illustrating DL backlog data in C / U plane separation. As shown in Figure 9, bearers are configured across multiple CU-UP nodes to distribute the load of U-plane processing. Here, since the processing of one bearer cannot take into account the amount of DL backlog data from the other bearer, existing methods tend to underestimate the amount of backlog data, raising concerns about UE L2 buffer overflow.

[0041] (Issues regarding DL backlog data in CN aggregation) In CN aggregation, there is a case where two bearers with different RATs are configured simultaneously. Figure 10 is a diagram illustrating DL backlog data in CN aggregation. As shown in Figure 10, high-speed communication is achieved by using both 5-GRAN and 6-GRAN frequency bands. In existing methods, mechanisms for understanding the amount of DL backlog data, mechanisms for taking ACKs for data, or IP technologies that are confined to the bearer are used in the CN (e.g., MP-TCP, MP-QUIC). Therefore, in the CN, the processing in one bearer cannot take into account the amount of DL backlog data from the other bearer, leading to an underestimation of the amount of backlog data and raising concerns about UE L2 buffer overflow.

[0042] (Issues regarding UL lag data in DC (Dual Connectivity)) When using DC, if the PDCP termination node has two different bearers, there is a possibility that the two bearers will be configured simultaneously. Figure 11 is a diagram illustrating UL lag data in DC. As shown in Figure 11, the MN node cannot grasp the amount of UL lag data in the second bearer that is handled by the SN's RLC. The amount of UL lag data from the first bearer and the amount of UL lag data via the RLC handled by the MN of the second bearer are reported only to the MN. Furthermore, the SN cannot grasp the amount of UL lag data from the first bearer and the amount of UL lag data from the second bearer that is handled by the MN's RLC. The amount of UL lag data via the RLC handled by the SN of the second bearer is reported only to the SN. In other words, it is not possible to grasp the amount of UL lag data from all bearers at a given node. Therefore, since not all nodes can grasp the amount of UL data accumulating in the UE, existing methods tend to underestimate the amount of accumulating data, raising concerns about UE L2 buffer overflow.

[0043] (Issues related to UL retained data in C / U split) In the configuration of C / U plane separation, when a PDCP termination node has two different bearers, a case where the two bearers are set simultaneously can be considered. FIG. 12 is a diagram for explaining UL retained data in C / U plane separation. As shown in FIG. 12, the first CU-UP node cannot grasp the retained data amount of the UL retained data amount of the second bearer. Only the UL retained data amount by the first bearer is reported to the first CU-UP node. Also, the second CU-UP node cannot grasp the retained data amount of the UL retained data amount of the first bearer. Only the UL retained data amount of the second bearer is reported to the second CU-UP node. That is, since all nodes cannot grasp the UL retained data amount of the UE, in the existing method, the retained data amount is underestimated, and there is a concern of UE L2 buffer overflow.

[0044] (Issues related to UL retained data in CN aggregation) In CN aggregation, a case where two bearers with different RATs are set simultaneously can be considered. FIG. 13 is a diagram for explaining DL retained data in CN aggregation. As shown in FIG. 13, by using both the frequency bands of 5G RAN and 6G RAN, high-speed communication is realized. In the existing method, all nodes cannot grasp the UL retained data amount of the UE, and there is no mechanism to grasp the UL retained data amount. Also, since it is not a node that schedules UL data, there is no mechanism to grasp the UL data amount of the UE in advance. Therefore, the retained data amount is underestimated, and there is a concern of UE L2 buffer overflow.

[0045] (Example) A method for preventing buffer overflow in a terminal in a wireless communication network will be described. Here, the base station 10 may be a gNB, gNB-CU (Central Unit), gNB-CU-CP (C-plane), or gNB-CU-UP, which are RAN nodes in 5G, and may also be a RAN node in 6G (corresponding to the 5G gNB, gNB-CU, gNB-CU-CP, and gNB-CU-UP). Also, the network node 30 may be a network node 30 in the 5G core network (e.g., AMF / UPF, etc.) or a network node 30 in the 6G core network. The network node 30 may have a functional configuration similar to that of the base station 10, and as a network-side device for the terminal 20, the base station 10 may be one of the network nodes 30.

[0046] (Method 1) For the terminal 20 connected to multiple RATs, the base station 10, the terminal 20, and the network node 30 may assume that the network node 30 grasps information on the retained data in the terminal (terminal retained data information) for data transmission control considering the terminal retained data information.

[0047] Also, the terminal 20 may transmit a message including the terminal retained data information to the network node 30. The network node 30 may store the received terminal retained data information in its own device and execute data transmission control based on the information. The terminal 20 may execute measurement / calculation of the terminal retained data information to be notified to the network node 30 and obtain it.

[0048] Also, the network node 30 may transmit the received terminal retained data information to another network node 30.

[0049] Also, the terminal 20 may transmit newly defined terminal capability information regarding the reporting of the terminal retained data information to the network node 30.

[0050] Terminal data retention information may include at least one of the following pieces of information: • Amount of data retained in terminal 20 / remaining buffer space (terminal data retention amount) • Amount of data for a bearer retained in terminal 20 / remaining buffer space (retention amount for a specific bearer in terminal 20) • The percentage of data retained in terminal 20 that a portion of the data retained in terminal 20 accounts for of the total retained data • The amount of data retained by a specified bearer in relation to the total retained data amount in terminal 20 • The percentage of data retained in terminal 20 that accounts for the buffer size • The available buffer space in terminal 20 • The size of the buffer in terminal 20 • Information regarding whether new data can be received in terminal 20

[0051] (Method 1-1) Terminal 20 may report terminal dwell data information to network node 30 via NAS(N1), RRC (e.g., User Assistance Info), MAC CE (Control Element), and Layer 1 (L1) / Layer 2 (L2) signals. Here, the report may be included in a PDCP control PDU such as a PDCP status report (it may also be piggybacked).

[0052] Furthermore, terminal 20 may report terminal dwell data information in the following triggers. Here, the trigger may be set by sending configuration information, including settings related to the trigger, from network node 30 to terminal 20. The trigger may also be set by multiple settings, and conditions (such as deciding to enable all settings or enable at least one setting, AND conditions / OR conditions, etc.) may be set for each setting. Furthermore, the trigger may be set on a communication channel (bearer, PDU session, etc.) unit / QoS unit, or on a unit that combines (groups) the communication channel and QoS. - When a message instructing the reporting of terminal stagnant data information is received from the network node 30 (e.g., RRC, MAC CE, L1 signal) - When a predetermined time has elapsed since the last report of terminal stagnant data information (the network node 30 may set the predetermined time in the configuration information) - When the amount of stagnant data exceeds a threshold, or when the duration of this condition exceeds a predetermined time (the network node 30 may set the threshold and the predetermined time in the configuration information) - When the buffer free capacity falls below a threshold, or when the duration of this condition has elapsed a predetermined time (the network node 30 may set the predetermined time in the configuration information) - When the cell to which terminal 20 belongs changes (i.e., when the number of terminals 20 accommodated by the base station 10 increases / decreases) - When the cell to which terminal 20 belongs changes - When the PDCP of the network node 30 terminating the terminal bearer changes - When there is a concern that the terminal 20's L2 buffer will overflow due to the reception of new data

[0053] (Method 1-2) Terminal 20 may also report terminal data information implicitly triggered by the reception / setting / deletion of the following information: ・RRC connection setup ・RRC connection resume / suspend ・RRC connection re-establishment ・UE capability enquiry ・RB setup / modification / release ・PDCP re-establishment / PDCP data recovery / PDCPOnDiscard / PDCP establishment / PDCP release / PDCP status report ・RLC re-establishment / RLC establishment / RLC release ・LCH establishment / LCH release ・MAC reset ・Reconfiguration with synchronization (reconfigurationWithsync), e.g., handover, secondary cell group change (SCG change), cell change, etc. ・Change of bearer type ・Setting / deletion of CA (Carrier Aggregation), MR-DC (Multi-RAT Dual Connectivity), CN aggregation

[0054] (Method 2-1) Reporting of terminal dwell data information between network nodes Network node 30 may report terminal dwell data information that it is aware of to one or more other network nodes 30. Here, this information may be notified between CU-DU, CU-UP, CU-CP, and RAN-CN. Alternatively, it may be notified using interfaces defined between network nodes 30 (F1 (between CU and DU), E1 (between CU-CP and CU-UP), N2 (between base station 10 and AMF, N3 (between base station 10 and UPF)), etc.

[0055] Furthermore, network node 30 may report terminal dwell data information to one or more other network nodes 30 at the triggers described below. Here, the setting information, including the setting related to the trigger, may be transmitted from the other network nodes 30 to network node 30. Also, the trigger may be set by multiple settings, and conditions (such as AND conditions / OR conditions that decide whether to enable all settings or at least one setting) may be set for each setting. - When a message instructing the reporting of terminal data retention information is received from network node 30 (for example, a signal on the X2 / Xn / Ng interface) - When a predetermined amount of time has elapsed since the last reporting of terminal data retention information to another network node 30 (other network nodes 30 may set the threshold and the predetermined time in their configuration information) - When the amount of data retention information known to network node 30 exceeds a threshold, or when the duration of this condition exceeds a predetermined time (other network nodes 30 may set the threshold and the predetermined time in their configuration information) - When the buffer's free capacity falls below a threshold, or when the duration of this condition exceeds a predetermined time (other network nodes 30 may set the threshold and the predetermined time in their configuration information) - The trigger for a new network node 30 being set up on terminal 20 which has information on stagnant data (for example, the trigger for terminal 20 connecting to a new base station 10, the trigger for terminal 20 connecting to a network node 30 (AMF, UPF, etc.) in a new core network, etc.) - The trigger for receiving stagnant data information from terminal 20 where the information on whether new data can be received is "no"

[0056] (Method 2-2) Network node 30 may report terminal dwell data information that network node 30 is aware of to one or more other network nodes 30. In this report, terminal 20 may report information regarding the downlink (DL) and information regarding the uplink (UL) independently, or it may report both together.

[0057] Furthermore, the report may be sent to a single network node 30, or multiple network nodes 30 may send and receive the report to each other.

[0058] Furthermore, the network node 30 may include DDDS (DL Data Delivery Status, see Non-Patent Document 5) in the report. Alternatively, the network node 30 may include wireless quality information (e.g., measurement report related to received signals, CSI (Channel State Information), PHR (Power Headroom Report), etc.) and terminal capabilities such as terminal category (UE category) in the report.

[0059] (Method 3) In a DC or C / U separation configuration, the network node 30 may transmit configuration information to the base station 10 / terminal 20 / other network nodes 30 that specifies the content of the terminal dwell data information to be reported (such as whether it includes any of the information shown in Method 1).

[0060] Terminal dwell data information may be split between DL and UL, and may be reported in different messages for DL ​​and UL.

[0061] Terminal dwell data information may be divided by QoS, and each QoS may be reported independently in different messages.

[0062] The information included in terminal dwell time data may be statistical values ​​that include values ​​calculated using moving averages or similar methods.

[0063] When sharing terminal lag data information among network nodes 30, the following information may be added to the terminal lag data information: • Target amount of lag data per QoS • Target buffer space per QoS • Percentage of buffer size occupied by target lag data per QoS The base station 10 / terminal 20 / network node 30 may assume that each QoS has a threshold for implementing DL PDCP stalling based on the terminal lag data information for each QoS.

[0064] Furthermore, the base station 10 / terminal 20 / network node 30 may be assumed to dynamically control / be controlled according to each QoS set on terminal 20, rather than fixing the threshold for each QoS. This allows for effective use of the terminal 20's buffer.

[0065] Furthermore, the base station 10 / terminal 20 / network node 30 may not use fixed values ​​for the information for each QoS, but rather assume that the threshold depends on the transmission rate of the PDCP layer or lower, and that the information for each QoS is dynamically updated.

[0066] (Method 4) In a DC or C / U separation configuration, the base station 10 / terminal 20 / network node 30 may assume that PDCP / RLC state variables are used for reporting / notifying information related to the amount of data held by the terminal. Here, the reporting / notification may be, for example, a report from the terminal 20 or a notification between network nodes 30. The network node 30 may transmit configuration information regarding the method of reporting / notification to the terminal 20 / other network nodes 30.

[0067] Figure 14 is a diagram illustrating a method for reporting the amount of data remaining at a terminal in an embodiment of the present invention.

[0068] The base station 10 / terminal 20 / network node 30 may assume that the terminal 20 will notify the PDCP sequence number (SN), or the PDCP SN and HFN (Hyper Frame Number), or the COUNT value for the SDU / PDU that was last sent to the upper layer.

[0069] The base station 10 / terminal 20 / network node 30 may assume that the terminal 20 will be notified of the PDCP SN, or the PDCP SN and HFN, or the COUNT value (for example, RX_DELIV (see Non-Patent Document 6)) for the first SDU / PDU that has not been sent to the upper layer (and is scheduled to be sent to the upper layer next).

[0070] The base station 10 / terminal 20 / network node 30 may assume that the terminal 20 will be notified of the PDCP SN, or the PDCP SN and HFN, or the COUNT value (for example, RX_NEXT (see Non-Patent Document 6)) for the SDU / PDU that it expects to receive next.

[0071] The base station 10 / terminal 20 / network node 30 may assume that the terminal 20 will notify the SDU / PDU with the largest SN (or COUNT) value among the received SDU / PDUs.

[0072] The base station 10 / terminal 20 / network node 30 may assume that values ​​related to the reception status in PDCP / RLC are notified.

[0073] The base station 10 / terminal 20 / network node 30 may expect to report at least one of the following values: the number of stagnant PDCP SDU / PDU, RLC SDU / PDU, and SDAP SDU / PDU, the average / maximum / minimum data size, and statistical information.

[0074] (Method 5) In a DC or C / U separation configuration, the base station 10 / terminal 20 / network node 30 may assume that the reports from terminal 20 regarding terminal dwell data information are layer-by-layer reports or reports that include multiple layers.

[0075] The layers subject to reporting may be limited to layers with buffering functionality (e.g., PDCP / RLC). Furthermore, if terminal 20 implements other buffers, the report may take into account / include the amount of data stagnating in those buffers, or it may not take into account / include the amount of data stagnating in those buffers. Terminal 20 may notify network node 30 of whether or not to take into account / include the amount of data stagnating in those buffers.

[0076] The granularity / precision in the report (e.g., bytes, kilobytes, megabytes, an indicator showing the amount of data) may differ for each reporting layer. Furthermore, the network node 30 may notify terminal 20 / other networks 30 of the configuration information regarding this granularity / precision.

[0077] (Method 6) Notification of Terminal Capabilities The network node 30 may maintain information on whether or not terminal 20 has the following terminal capabilities. Alternatively, terminal 20 may report to the network node 30 information on whether or not it has the following terminal capabilities: - Capability to notify terminal stagnant data information - Capability to notify terminal stagnant data information using PDCP control PDU / MAC CE / L1 signal / L2 signal such as NAS / RRC / PDCP status report - Capability to set reporting triggers, the number of configurable reporting triggers, and the types of configurable triggers - Types of information that can be notified as terminal stagnant data information, and the method for reporting the amount of terminal stagnant data - Granularity that can be reported as terminal stagnant data information (for example, reporting feasibility per layer, reporting feasibility encompassing layers, granularity / precision (byte, kbyte, Mbyte), reporting feasibility per UL / DL, reporting feasibility per QoS)

[0078] (Method 7) Assistance Info. Terminal 20 may notify network node 30 using RRC / NAS that it has entered the following state as supplementary information: - A state in which it is difficult to set up / continue the expected service due to insufficient remaining capacity in the L2 buffer. This state may be, for example, a state in which there is insufficient free space in the L2 buffer when providing a high-function (XR, etc.) service.

[0079] Terminal 20 may notify network node 30 of insufficient buffer space as User Assistance Info, and at the same time, may notify terminal 20 of bearers that are experiencing problems or that terminal 20 recommends releasing.

[0080] Terminal 20 may explicitly notify network node 30 that "insufficient buffer space" is the reason for the failure if the bearer configuration fails due to insufficient buffer space.

[0081] Terminal 20 may explicitly notify network node 30 that "insufficient buffer space" is the reason for the release of the bearer due to insufficient buffer space.

[0082] When terminal 20 notifies network node 30 of User Assistance Info, network node 30 may send configuration information to terminal 20 to set the frequency of such notification. This configuration information may include at least one of the following as information for specifying the frequency: minimum transmission interval, transmission period, and number of transmissions per hour.

[0083] The above-described embodiment makes it possible to prevent buffer overflow at terminals in a wireless communication network.

[0084] (Device Configuration) Next, an example of the functional configuration of the base station 10, network node 30, and terminal 20 that perform the processing and operations described above will be explained. The base station 10, network node 30, and terminal 20 include the functions to perform the embodiments described above. However, the base station 10, network node 30, and terminal 20 may each be equipped with only some of the functions in the embodiments.

[0085] <Base Station 10 and Network Node 30> Figure 15 shows an example of the functional configuration of a base station 10 and a network node 30. As shown in Figure 15, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 15 is merely an example. The functional classifications and names of the functional units can be anything as long as they can perform the operations according to the embodiment of the present invention. The network node 30 may have the same functional configuration as the base station 10. Furthermore, a network node 30 having multiple different functions on the system architecture may be composed of multiple network nodes 30 separated by function.

[0086] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 or other network node 30 and transmitting the signal by wire or wireless. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 or other network node 30 and obtaining information from the received signal, for example, information from a higher layer. A communication unit including the transmitting unit 110 and the receiving unit 120 may be configured.

[0087] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads them from the storage device as needed.

[0088] The control unit 140 performs the processing described in the embodiment. The signal transmission function in the control unit 140 may be included in the transmission unit 110, and the signal reception function in the control unit 140 may be included in the reception unit 120.

[0089] <Terminal 20> Figure 16 is a diagram showing an example of the functional configuration of terminal 20. As shown in Figure 16, terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Figure 16 is merely an example. Any functional classification and name of functional unit is acceptable as long as it can perform the operations according to the embodiment of the present invention. Furthermore, a communication device that acts as a resource holder may have a functional configuration similar to that of terminal 20.

[0090] The transmitting unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and obtains signals from higher layers from the received physical layer signals. The receiving unit 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals or reference signals transmitted from the network node 30. A communication unit including the transmitting unit 210 and the receiving unit 220 may be configured.

[0091] The setting unit 230 stores various setting information received from the network node 30 by the receiving unit 220 in its storage device and reads it from the storage device as needed. The setting unit 230 also stores pre-configured setting information.

[0092] The control unit 240 performs the processing described in the embodiment. The signal transmission function in the control unit 240 may be included in the transmission unit 210, and the signal reception function in the control unit 240 may be included in the reception unit 220.

[0093] (Hardware Configuration) The block diagrams (Figures 15 and 16) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the above one device or the above multiple devices with software.

[0094] Functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0095] For example, the network node 30, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 17 is a diagram showing an example of the hardware configuration of a base station 10 and terminal 20 according to one embodiment of the present disclosure. The network node 30 may have the same hardware configuration as the base station 10. The base station 10 and terminal 20 described above may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0096] In the following explanation, the term "device" can be read as "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0097] Each function in the base station 10 and terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the storage device 1002 and auxiliary storage device 1003.

[0098] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0099] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station 10 shown in Figure 15 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in Figure 16 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-described processes have been explained as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may also be transmitted from the network via a telecommunications line.

[0100] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of the present disclosure.

[0101] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital multipurpose disk, a Blu-ray® disk), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0102] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, duplexer, filter, frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the transmitting and receiving antenna, amplifier section, transmitting and receiving section, transmission path interface, etc., may be implemented by the communication device 1004. The transmitting and receiving section may be implemented in a physically or logically separated manner, with a transmitting section and a receiving section.

[0103] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0104] Furthermore, each device, such as the processor 1001 and the storage device 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0105] Furthermore, the base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0106] Figure 18 shows an example of the configuration of vehicle 2001. As shown in Figure 18, vehicle 2001 includes an operating unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in this disclosure may be applied to a communication device mounted on vehicle 2001, for example, to the communication module 2013.

[0107] The operating unit 2002 consists of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel, which is operated by the user.

[0108] The electronic control unit 2010 consists of a microprocessor 2031, memory (ROM, RAM) 2032, and communication ports (IO ports) 2033. Signals from various sensors 2021 to 2029 installed in the vehicle 2001 are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0109] Signals from various sensors 2021 to 2029 include current signals from current sensor 2021 for sensing motor current, front and rear wheel rotation speed signals acquired by rotation speed sensor 2022, front and rear wheel air pressure signals acquired by air pressure sensor 2023, vehicle speed signals acquired by vehicle speed sensor 2024, acceleration signals acquired by acceleration sensor 2025, accelerator pedal depression signals acquired by accelerator pedal sensor 2029, brake pedal depression signals acquired by brake pedal sensor 2026, shift lever operation signals acquired by shift lever sensor 2027, and detection signals acquired by object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc.

[0110] The Information Service Unit 2012 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, television, and radio, and one or more ECUs that control these devices. The Information Service Unit 2012 uses information acquired from external devices via a communication module 2013, etc., to provide various multimedia information and multimedia services to the occupants of the vehicle 2001. The Information Service Unit 2012 may include input devices that accept input from the outside (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) and output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0111] The driver assistance system unit 2030 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System)), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driver assistance functions or autonomous driving functions.

[0112] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via its communication port. For example, the communication module 2013 sends and receives data via the communication port 2033 between the moving parts 2002, steering parts 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021-29 provided in the vehicle 2001.

[0113] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with external devices. For example, it can send and receive various types of information with external devices via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station or a mobile station.

[0114] The communication module 2013 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 2012. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include the information based on the above input.

[0115] The communication module 2013 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may also be called an output unit, which outputs information (for example, outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from the external device in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the operating unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021-2029, etc., provided in the vehicle 2001.

[0116] <Notes> (Note 1) A terminal comprising: a control unit that acquires terminal data retention information in the device itself; and a transmission unit that transmits notification information including the terminal data retention information to a network node, wherein the notification information includes, as terminal data retention information, at least one of the following in the device itself: the amount of data retention or buffer remaining; the amount of data retention for bearers retention or buffer remaining; the ratio of a portion of the data retention to the total data retention; the amount of data retention for a designated bearer in the total amount of data retention; the ratio of the data retention to the buffer size; the buffer's free capacity; the buffer's size; and information regarding whether new data can be received. (Note 2) The terminal according to Note 1, wherein the transmission unit transmits terminal capability information relating to the terminal data retention information to the network node. (Note 3) A network node having: a receiving unit that receives notification information including terminal stagnant data information from a terminal; and a control unit that performs data transmission control based on the terminal stagnant data information, wherein the notification information includes, as terminal stagnant data information, at least one of the following: the amount of stagnant data or buffer remaining amount in the device; the amount of data or buffer remaining amount for the stagnant bearer; the ratio of a portion of the stagnant data to the stagnant data; the amount of stagnant data of a designated bearer in the total amount of stagnant data; the ratio of the stagnant data to the buffer size; the free capacity of the buffer; the size of the buffer; and information regarding whether new data can be received. (Note 4) The network node according to Note 3, further having a transmitting unit that transmits second notification information including terminal stagnant data information to other network nodes. (Note 5) The network node according to Note 3, wherein the receiving unit receives terminal capability information relating to the terminal stagnant data information from the terminal.(Appendix 6) A communication method performed by a terminal, comprising the steps of: acquiring terminal data retention information in the device itself; and transmitting notification information including the terminal data retention information to a network node, wherein the notification information includes, as terminal data retention information, at least one of the following in the device itself: the amount of data retention or buffer remaining; the amount of data retention for a bearer or buffer remaining; the proportion of the data retention that a portion of the data retention accounts for the total data retention; the amount of data retention for a specified bearer in the total amount of data retention; the proportion of the data retention accounted for by the buffer size; the buffer's free capacity; the buffer's size; and information regarding whether new data can be received.

[0117] Any of the provisions of Appendix 1 to Appendix 6 can prevent buffer overflow at terminals in a wireless communication network.

[0118] (Supplement to Embodiments) Embodiments of the present invention have been described above, but the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. The processing procedures described in the embodiments may be rearranged as long as they do not contradict each other. For the convenience of explaining the processing, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be realized in hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to an embodiment of the present invention and the software operated by the processor of the terminal 20 according to an embodiment of the present invention may be stored in any suitable storage medium such as random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or other appropriate storage medium.

[0119] Furthermore, notification of information is not limited to the embodiments described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0120] Each aspect / embodiment described in this disclosure refers to LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (where x is, for example, an integer or decimal)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20 may apply to at least one system utilizing UWB (Ultra-WideBand), Bluetooth®, or other appropriate systems, and to next-generation systems extended, modified, created, or defined based thereon. Alternatively, multiple systems may be applied in combination (e.g., a combination of at least one of LTE and LTE-A with 5G).

[0121] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0122] In this specification, specific operations performed by the base station 10 may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station 10, it is clear that various operations performed for communication with the terminal 20 can be performed by the base station 10 and at least one of the other network nodes (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station 10, the other network node may be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0123] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0124] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0125] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a Boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0126] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0127] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0128] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0129] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0130] The terms “system” and “network” as used in this disclosure are interchangeable.

[0131] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0132] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0133] In this disclosure, terms such as "Base Station (BS)", "wireless base station", "base station equipment", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0134] A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0135] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform control or operation based on the information.

[0136] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0137] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or several other appropriate terms.

[0138] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes the case when the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station may include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0139] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminals 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0140] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

[0141] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in a table, database, or other data structure), or ascertaining. “Determining” may also include receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0142] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0143] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

[0144] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0145] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

[0146] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0147] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0148] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0149] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0150] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0151] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way.

[0152] 10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 30 Network node 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

1. A terminal comprising: a control unit that acquires terminal data retention information in the device itself; and a transmission unit that transmits notification information including the terminal data retention information to a network node, wherein the notification information includes, as terminal data retention information, at least one of the following in the device itself: the amount of data retention or buffer remaining; the amount of data retention for the bearer retention or buffer remaining; the proportion of the data retention that a portion of the data retention accounts for the total data retention; the amount of data retention for a specified bearer in the total amount of data retention; the proportion of the data retention accounted for by the buffer size; the buffer's free capacity; the buffer's size; and information regarding whether new data can be received.

2. The terminal according to claim 1, wherein the transmitting unit transmits terminal capability information relating to the terminal dwell data information to the network node.

3. A network node comprising: a receiving unit that receives notification information including terminal data retention information from a terminal; and a control unit that performs data transmission control based on the terminal data retention information, wherein the notification information includes, as terminal data retention information, at least one of the following: the amount of data retention or buffer remaining amount in the device; the amount of data retention or buffer remaining amount for the bearer retention; the ratio of a portion of the data retention to the total data retention; the amount of data retention for a specified bearer in the total amount of data retention; the ratio of the data retention to the buffer size; the buffer's free capacity; the buffer's size; and information regarding whether new data can be received.

4. The network node according to claim 3, further comprising a transmitting unit that transmits a second notification information, including the terminal dwell data information, to other network nodes.

5. The network node according to claim 3, wherein the receiving unit receives terminal capability information relating to terminal dwell data information from the terminal.

6. A communication method performed by a terminal, comprising the steps of: acquiring terminal data retention information in the device itself; and transmitting notification information including the terminal data retention information to a network node, wherein the notification information includes, as terminal data retention information, at least one of the following in the device: the amount of data retention or buffer remaining; the amount of data retention for a bearer or buffer remaining; the proportion of the data retention that a portion of the data retention accounts for the total data retention; the amount of data retention for a specified bearer in the total amount of data retention; the proportion of the data retention accounted for by the buffer size; the free capacity of the buffer; the size of the buffer; and information regarding whether new data can be received.

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