Data processing method and device

Abstract

The present disclosure relates to a technology for processing service data in a mobile communication network, and the present embodiment may provide a method and an apparatus, the method comprising: a step of receiving upper layer signaling including PDCP configuration information configured to perform a PDU Set-based discard operation; a step of receiving a MAC control element for indicating the activation of a service data unit (SDU) drop operation based on the importance of PDU Set, and a step of receiving the MAC control element for indicating the activation of the service data unit (SDU) drop operation based on the importance of PDU Set; and a step of controlling the PDCP individual to start a PDU Set importance-based discard timer configured in association with a PDCP SDU, if an SDU discard operation based on the PDU Set importance is activated and the PDCP SDU of the PDU Set importance belonging to a preset standard is received from an upper layer.

Description

Technical Field

[0001] The present disclosure relates to a technology for processing service data in a mobile communication network. Background Art

[0002] XR (eXtended Reality) and CG (Cloud Gaming) are used as broad terms to mean various types of augmented, virtual, and mixed environments in human-machine and human-human communications performed with the help of handheld and wearable terminals. eXtended Reality (XR) is used as a broad term covering augmented reality (AR), mixed reality (MR), and virtual reality (VR). Cloud gaming refers to use cases where most of the computations related to the game are dumped from the terminal to the edge or remote servers. Together with cloud computing / cloud gaming, XR applications usually require high throughput and low latency.

[0003] As mentioned above, as services change, mobile communication systems that support high-speed data rates and low-latency services are needed. To this end, QoS policy control for multi-mode traffic, QoS processing support based on Protocol Data Unit Set (PDU Set), traffic assistance information transmission to support power consumption reduction, XR-specific capacity enhancement functions, etc. are being discussed.

[0004] In particular, the capacity boost function can increase the capacity of the radio interface by appropriately handling packets / PDUs that exceed the delay budget.

[0005] However, the current technology for discarding data packets in mobile communications has the problem of being unable to reflect the type and characteristics of data, and being unable to quickly provide capacity improvement when the amount of data surges. Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present disclosure aims to provide a technology for effectively discarding data of a terminal in a mobile communication network.

[0008] Solutions for solving problems

[0009] On the one hand, this embodiment can provide a method for a terminal to process data, including: a step of receiving upper layer signaling including PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on a PDU Set; a step of receiving a MAC control element, wherein the MAC control element is used to indicate the activation of an SDU (Service Data Unit) discard operation based on PDU Set importance; and if the SDU discard operation based on PDU Set importance is activated and a PDCP SDU with PDU Set importance belonging to a preset standard is received from an upper layer, a step of controlling the PDCP individual to start a discard timer based on PDU Set importance configured by associating with the PDCP SDU.

[0010] On the other hand, the present embodiment may provide a method for a base station to control data processing of a terminal, comprising: a step of setting PDCP configuration information configured to perform a discard operation based on a PDU Set; a step of transmitting an upper layer signaling containing the PDCP configuration information to the terminal; and a step of transmitting a MAC control element for indicating activation of an SDU discard operation based on PDU Set importance to the terminal. For the terminal, if the SDU discard operation based on PDU Set importance is activated and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the PDCP individual may start a discard timer based on PDU Set importance configured in association with the PDCP SDU.

[0011] On the other hand, the present embodiment may provide a terminal for processing data, comprising: a receiving unit, which receives upper layer signaling including PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on PDU Set, and receives a MAC control element, wherein the MAC control element is used to indicate activation of an SDU discard operation based on PDU Set importance; and a control unit, wherein if the SDU discard operation based on PDU Set importance is activated and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the control unit controls the PDCP individual to start a discard timer based on PDU Set importance configured by associating with the PDCP SDU.

[0012] On the other hand, the present embodiment may provide a base station for controlling data processing of a terminal, comprising: a control unit, which is configured to set PDCP configuration information for performing a discard operation based on a PDU Set; and a sending unit, which transmits an upper layer signaling including the PDCP configuration information to the terminal, and transmits a MAC control element for indicating activation of an SDU discard operation based on PDU Set importance to the terminal. For the terminal, if the SDU discard operation based on PDU Set importance is activated, and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the PDCP individual starts a discard timer based on PDU Set importance configured in association with the PDCP SDU.

[0013] Effects of the Invention

[0014] The present disclosure has the effect of providing a technology for effectively discarding data of a terminal in a mobile communication network. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram that simply shows the structure of an NR wireless communication system that is applicable to this embodiment.

[0016] Figure 2 This is a diagram used to illustrate the frame structure in the NR system to which this embodiment is applicable.

[0017] Figure 3 This is a diagram for explaining a resource grid supporting a wireless access technology to which this embodiment is applicable.

[0018] Figure 4 This is a diagram for explaining a bandwidth portion supporting a wireless access technology to which this embodiment is applicable.

[0019] Figure 5 The figure exemplarily shows a synchronization signal block in a wireless access technology to which the present embodiment is applicable.

[0020] Figure 6 This is a diagram for explaining a random access procedure in a wireless access technology to which this embodiment is applicable.

[0021] Figure 7 This is a diagram for explaining CORESET.

[0022] Figure 8 is a flowchart for explaining terminal operation according to one embodiment.

[0023] Fig. 9 is a flowchart for illustrating the operation of a base station according to one embodiment.

[0024] Fig.10is a diagram showing the composition of a terminal according to another embodiment.

[0025] Fig.11 is a diagram showing the composition of a base station according to another embodiment. DETAILED DESCRIPTION

[0026] Hereinafter, some embodiments of the present disclosure are described in detail with reference to the exemplary drawings. When assigning figure marks to the components of each figure, the same symbols may be assigned to the same components as much as possible even if they are displayed in different figures. In addition, when describing the present embodiment, if it is considered that the specific description of the relevant known structure or function will obscure the main idea of ​​the present technology, its detailed description may be omitted. In the case of "including", "having", "comprising" and the like mentioned in this specification, unless "only" is used, it means that other parts may be added. In the case of representing a component in the singular, the plural case may be included unless there is a special clear record.

[0027] In addition, when describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, sequence, or quantity of the component is not limited by the terms.

[0028] In the description of the positional relationship of components, if it is recorded that two or more components are "connected", "combined" or "accessed", the two or more components may be directly "connected", "combined" or "accessed", but it should be understood that other components may be "interposed" into the two or more components to thereby be "connected", "combined" or "accessed". Among them, other components may also be included in one or more of the two or more components that are "connected", "combined" or "accessed" to each other.

[0029] In the description of the time flow relationship related to components, operating methods or manufacturing methods, when the time sequence or process sequence is described by, for example, "afterwards", "subsequently", "next", "before", etc., discontinuous situations may also be included unless "immediately" or "directly" is used.

[0030] On the other hand, when referring to the numerical value of a component or its corresponding information (e.g., grade, etc.), even if there is no separate explicit record, the numerical value or its corresponding information should be interpreted as including the error range that may arise due to various factors (e.g., process factors, internal or external impact, noise, etc.).

[0031] The wireless communication system in this specification refers to a system that uses wireless resources to provide various communication services such as voice and data packets. The system may include: terminals, base stations or core networks, etc.

[0032] The present embodiment disclosed below may be applicable to wireless communication systems using a variety of wireless access technologies. For example, the present embodiment may be applicable to a variety of wireless access technologies, such as: CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access) or NOMA (non-orthogonal multiple access). In addition, wireless access technology not only means a specific access technology, but also means various generations of communication technologies specified by various communication protocol organizations, such as: 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, ITU, etc. For example, CDMA can be implemented through wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented through wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented through wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi, wireless LAN), IEEE 802.16 (WiMAX, Worldwide Interoperability for Microwave Access), IEEE 802-20, E-UTRA (evolved UTRA), etc. IEEE 802.16m, as an evolution of IEEE 802.16e, provides backward compatibility with systems based on IEEE802.16e. UTRA is part of UMTS (universal mobile telecommunications system).3GPP (3rd generation partnership project) LTE (long term evolution) as a part of E-UMTS (evolved UMTS) using E-UTRA (evolved-UMTS terrestrial radio access), adopts OFDMA in the downlink and SC-FDMA in the uplink. As described above, the present embodiment may be applicable to currently disclosed or commercialized wireless access technologies, and may also be applicable to wireless access technologies currently being developed or to be developed in the future.

[0033] On the other hand, the terminal in this specification, as a comprehensive concept, refers to a device including a wireless communication module that communicates with a base station in a wireless communication system, and should be interpreted as not only including UE (User Equipment) in WCDMA (Wideband Code Division Multiple Access), LTE, NR (New Radio), HSPA (High Speed ​​Packet Access) and IMT-2020 (5G or New Radio), but also including MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), wireless device (wireless device) and the like in GSM. In addition, the terminal can be a user portable device such as a smartphone according to the usage form, and in a V2X (vehicle to everything, connected car technology) communication system, it can also mean a vehicle, a device including a wireless communication module in a vehicle, etc. In addition, in a machine type communication (Machine Type Communication) system, it can also mean an MTC terminal equipped with a communication module to perform mechanical type communication, an M2M (Machine to machine) terminal, and an URLLC (Ultra-Reliable Low-Latency Communications) terminal, etc.

[0034] The base station or cell in this specification refers to a terminal that communicates with the terminal in terms of the network, which means covering a variety of coverage areas, such as: Node-B, eNB (evolved Node-B), gNB (gNode-B), LPN (Low Power Node), sector, site, various forms of antennas, BTS (Base Transceiver System, base station transmitter / receiver), access point, point (e.g., transmission point, receiving point, transmission / reception point), relay node, super large cell, macro cell, micro cell, micro cell, micro cell, RRH (Remote Radio Head), RU (Radio Unit), small cell, etc. In addition, the cell may mean a BWP (Bandwidth Part) in the frequency domain. For example, the serving cell may mean the Activation BWP of the terminal.

[0035] Since there are base stations controlling more than one cell in the various cells listed above, the base station can be interpreted in two ways. It can indicate: (1) the device itself, which provides a very large cell, macro cell, micro cell, pico cell, micro-micro cell or small cell related to the wireless area; (2) the wireless area itself. In case (1), all devices that interact so that the devices providing the specified wireless area are controlled by the same object or that configure the wireless area through collaboration are indicated as base stations. According to the configuration method of the wireless area, an embodiment of the base station is: point, transmission / reception point, transmission point, reception point, etc. In case (2), from the perspective of the user terminal or the standpoint of the adjacent base station, the wireless area itself that receives or sends signals can also be indicated as a base station.

[0036] In this specification, a cell may refer to a coverage component carrier having a signal transmitted from a transmission / reception point or a coverage component carrier of a signal transmitted from a transmission / reception point or a transmission / reception point itself.

[0037] Uplink (UL, or uplink) means a way of sending / receiving data from a terminal to a base station, and downlink (DL, or downlink) means a way of sending / receiving data from a base station to a terminal. Downlink may mean communication or a communication path from multiple transmission / reception points to a terminal, and uplink may mean communication or a communication path from a terminal to multiple transmission / reception points. At this time, in the downlink, the transmitter may be part of the multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in the uplink, the transmitter may be part of the terminal, and the receiver may be part of the multiple transmission / reception points.

[0038] The uplink and downlink transmit / receive control information through control channels such as PDCCH (Physical Downlink Control CHannel) and PUCCH (Physical Uplink Control Channel); transmit / receive data through data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel). In the following, the situation where signals are transmitted / received through channels such as PUCCH, PUSCH, PDCCH and PDSCH is also marked as "transmitting / receiving PUCCH, PUSCH, PDCCH and PDSCH".

[0039] For a clearer explanation, the following describes the technical concept mainly based on the 3GPP LTE / LTE-A / NR (New RAT) communication system, but the technical features are not limited to this communication system.

[0040] In 3GPP, after studying 4G (4th-Generation, the fourth generation of mobile information system) communication technology, 5G (5th-Generation, the fifth generation of mobile information system) communication technology is being developed that meets the requirements of ITU-R for next-generation wireless access technology. Specifically, 3GPP develops new NR communication technology through 5G communication technology, which is different from LTE-A pro and 4G communication technology that improves LTE-Advanced technology in a manner that meets the requirements of ITU-R. LTE-A pro and NR both mean 5G communication technology. In the following, unless a specific communication technology is specifically mentioned, 5G communication technology will be explained with NR as the center.

[0041] The operation scenarios in NR add satellite, automobile and new vertical considerations to the existing 4G LTE scenarios, and define multiple operation scenarios. In terms of services, it supports eMBB (Enhanced Mobile Broadband) scenarios; mMTC (Massive Machine Communication) scenarios, which have high terminal density and are deployed over a wide range and require low data rate and asynchronous access; URLLC (Ultra Reliability and Low Latency) scenarios, which require high responsiveness and reliability and can support high-speed mobility.

[0042] In order to meet these scenarios, NR discloses a wireless communication system that applies new waveform and frame structure technology, low latency technology, ultra-high frequency band (mmWave) support technology, and forward compatible technology. In particular, in the NR system, in order to provide forward compatibility, a variety of technical changes are proposed in terms of flexibility. The main technical features of NR will be described below with reference to the accompanying drawings.

[0043] <Normal NR system>

[0044] Figure 1 This is a diagram simply showing the structure of the NR system applicable to this embodiment.

[0045] Reference Figure 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN (New Radio Radio Access Network) parts. NG-RAN (Next Generation Radio Access Network) consists of gNB and ng-eNB that provide the user plane (SDAP (Service Data Adaptation Protocol) / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC (Medium Access Control) / PHY (Physical Layer)) and the control plane (RRC) protocol termination for the UE (User Equipment). gNBs are interconnected with each other or gNB and ng-eNB are interconnected via the Xn interface. gNB and ng-eNB are connected to 5GC via the NG interface respectively. 5GC may include: AMF (Access and Mobility Management Function), which is responsible for the control plane such as terminal access and mobility control functions; and UPF (User Plane Function), which is responsible for user data control functions. NR supports both frequency bands below 6 GHz (FR1, Frequency Range 1) and above 6 GHz (FR2, Frequency Range 2).

[0046] gNB means a base station that provides the NR user plane and control plane protocol termination to the terminal, and ng-eNB means a base station that provides the E-UTRA user plane and control plane protocol termination to the terminal. The base station described in this specification should be understood to cover the meanings of gNB and ng-eNB, and can also be used according to the meaning of distinguishing gNB or ng-eNB as needed.

[0047] <Waveform, Parameter Set, and Frame Structure in NR>

[0048] In NR, for downlink transmission, the CP-OFDM (Cyclic prefix Orthogonal Frequency Division Multiplexing) waveform with Cyclic prefix is used, and for uplink transmission, CP-OFDM or DFT-s-OFDM (Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing) is used. The OFDM technology is easy to combine with MIMO (Multiple Input Multiple Output), and its advantages are high frequency efficiency and the ability to use a low-complexity receiver.

[0049] On the other hand, in NR, since the requirements for data speed, delay speed, coverage, etc. of the above three scenarios are different, it is necessary to effectively meet the requirements of each scenario through the frequency band that constitutes any NR system. To this end, a technology for effectively multiplexing wireless resources based on different multiple parameter sets (numerology) is proposed.

[0050] Specifically, the NR transmission parameter set is determined based on the sub-carrier spacing and CP (Cyclic prefix), as shown in Table 1 below. Taking 15kHz as the benchmark, the μ value is used as an exponential value of 2 and changes in an exponential form.

[0051] Table 1

[0052]

[0053]

[0054] As shown in Table 1 above, according to the subcarrier spacing, the parameter set of NR can be divided into 5 types. This is different from the subcarrier spacing of LTE, one of the 4G communication technologies, which is fixed at 15kHz. Specifically, the subcarrier spacing used for data transmission in NR is 15kHz, 30kHz, 60kHz and 120kHz, and the subcarrier spacing used for synchronization signal transmission is 15kHz, 30kHz, 120kHz and 240kHz. In addition, the extended CP is only applicable to 60kHz subcarrier spacing. On the other hand, a frame with a length of 10ms is defined in the frame structure in NR, and the above frame consists of 10 subframes with the same length of 1ms. A frame can be divided into half frames of 5ms, each half frame includes 5 subframes. In the case of 15kHz subcarrier spacing, a subframe consists of a slot, and each slot consists of 14 OFDM symbols.

[0055] Figure 2 This is a diagram used to illustrate the frame structure in the NR system to which this embodiment is applicable.

[0056] Reference Figure 2In the case of normal CP, the time slot is fixedly composed of 14 OFDM symbols, but in the time domain of the time slot, the length can vary according to the subcarrier spacing. For example, in the case of a parameter set with a 15kHz subcarrier spacing, the length of the time slot is 1ms, which is the same as the length of the subframe. Differently, in the case of a parameter set with a 30kHz subcarrier spacing, although the time slot consists of 14 OFDM symbols, the length is 0.5ms, and two time slots can be included in one subframe. That is, subframes and frames are defined by a fixed time length, while the time slot is defined by the number of symbols, and the time length can vary according to the subcarrier spacing.

[0057] In addition, the basic unit of scheduling in NR is defined as a time slot. In order to reduce the transmission delay in the wireless interval, micro-time slots (or sub-time slots or non-slot based schedules) are also introduced. If a wide subcarrier spacing is used, the length of a time slot will be inversely shortened, thereby reducing the transmission delay in the wireless interval. Micro-time slots (or sub-time slots) are used to effectively support URLLC scenarios and can be scheduled in units of 2, 4, or 7 symbols.

[0058] In addition, unlike LTE, NR defines uplink and downlink resource allocation as symbol levels within a time slot. In order to reduce HARQ (hybrid automatic repeat request) delay, a time slot structure is defined in which HARQ ACK / NACK (hybrid automatic repeat request-acknowledgement / negative) can be directly sent within the transmission time slot, and this time slot structure is named self-contained structure for explanation.

[0059] NR is designed to support a total of 256 time slot formats, of which 62 time slot formats are used for 3GPP Rel-15. In addition, through the combination of various time slots, a common frame structure that constitutes an FDD or TDD frame is supported. For example, a time slot structure in which all symbols of the time slot are set to the downlink and a time slot structure in which all symbols are set to the uplink, as well as a time slot structure in which downlink symbols and uplink symbols are combined. In addition, NR supports data transmission to be scheduled in more than one time slot. Therefore, the base station can use a time slot format indicator (SFI) to notify the terminal whether the time slot is a downlink time slot, an uplink time slot or a flexible time slot. The base station can use SFI to indicate a table index formed by terminal-specific (UE-specific) RRC signaling to indicate the time slot format, or it can be dynamically indicated through DCI (Downlink Control Information) or statically or quasi-statically indicated through RRC.

[0060] <Physical Resources in NR>

[0061] Regarding the physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, bandwidth parts, etc. can be considered.

[0062] An antenna port is defined as a channel carrying symbols on the antenna port can be inferred from a channel carrying other symbols on the same antenna port. If the large-scale properties of a channel carrying symbols on one antenna port can be inferred from a channel carrying symbols on another antenna port, then the two antenna ports can be considered to have a QC / QCL (quasico-located or quasico-location) relationship. Among them, the large-scale properties include more than one of the following: Delay spread, Doppler spread, Frequency shift, Average received power, and Received Timing.

[0063] Figure 3 It is a diagram for explaining the resource grid of the radio access technology applicable to support this embodiment.

[0064] Refer to Figure 3 For the Resource Grid, since NR supports multiple parameter sets in the same carrier, the resource grid can exist according to each parameter set. In addition, the resource grid can exist according to the antenna port, subcarrier spacing, and transmission direction.

[0065] A resource block consists of 12 subcarriers and is defined only in the frequency domain. In addition, a resource element consists of one OFDM symbol and one subcarrier. Therefore, as Figure 3 shown, the size of a resource block can vary according to the subcarrier spacing. In addition, NR defines "Point A" which serves as a common reference point for the resource block grid, common resource blocks, virtual resource blocks, etc.

[0066] Figure 4 It is a diagram for explaining the bandwidth part of the radio access technology applicable to support this embodiment.

[0067] In NR, different from LTE where the carrier bandwidth is fixed at 20 MHz, the maximum carrier bandwidth for each subcarrier spacing is set to 50 MHz to 400 MHz. Therefore, it is not assumed that all terminals use these carrier bandwidths. Thus, in NR, as Figure 4 shown, a bandwidth part (BWP) can be specified within the carrier bandwidth for use by the terminal. In addition, the bandwidth part is associated with a parameter set, consists of a subset of consecutive common resource blocks, and can be dynamically activated according to time. The terminal is configured to have up to 4 bandwidth parts for the uplink and downlink respectively, and transmits / receives data using the activated bandwidth part within a specified time.

[0068] In the case of paired spectrum, the uplink and downlink bandwidth parts are set independently. In the case of unpaired spectrum, to prevent unnecessary frequency re-tuning between downlink and uplink operations, the downlink and uplink bandwidth parts are paired and set to be able to share the center frequency.

[0069] <Initial Access in NR>

[0070] In NR, in order for a terminal to access a base station for communication, it performs a cell search and a random access procedure.

[0071] Cell search is a process that uses the synchronization signal block (SSB, Synchronization Signal Block) transmitted by the base station to synchronize the terminal with the cell of the above base station, obtain the physical layer cell ID, and obtain system information.

[0072] Figure 5 is a diagram exemplarily showing the synchronization signal block in a radio access technology to which this embodiment is applicable.

[0073] Refer to Figure 5 , the SSB consists of a PSS (primary synchronization signal), which occupies 1 symbol and 127 subcarriers, an SSS (secondary synchronization signal), which also occupies 1 symbol and 127 subcarriers, and a PBCH that spans 3 OFDM symbols and 240 subcarriers.

[0074] The terminal receives the SSB by monitoring the SSB in the time and frequency domains.

[0075] SSB can be transmitted up to 64 times within 5ms. Most SSBs are transmitted in different transmission beams within 5ms. If the terminal uses a specific beam for transmission as a reference, it is assumed that SSB is transmitted once every 20ms and detection is performed. Within 5ms, the number of beams available for SSB transmission increases as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3GHz, up to 8 beams can be used in the frequency band from 3GHz to 6GHz, and up to 64 different beams can be used to transmit SSB in the frequency band above 6GHz.

[0076] SSB includes two in one time slot, and the starting symbol and the number of repetitions in the time slot are determined as follows according to the subcarrier spacing.

[0077] On the other hand, unlike the existing LTE SS, SSB is not transmitted at the center frequency of the carrier bandwidth. That is, SSB can be transmitted at a place other than the center of the system frequency band, and when broadband operation is supported, multiple SSBs can be transmitted in the frequency domain. As a result, the terminal uses a synchronization raster as a candidate frequency position for monitoring SSB to monitor SSB. In NR, the carrier raster and the synchronization raster are redefined as the center frequency position of the channel for initial access, and the synchronization raster is set to a wider frequency interval than the carrier raster, so that the terminal can support fast SSB search.

[0078] The terminal can obtain the MIB (Master Information Block) through the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information of the remaining minimum system information (RMSI, Remaining Minimum System Information) used by the terminal to receive network broadcasts. In addition, the PBCH may include: the position information of the first DM-RS symbol in the time domain, the information used by the terminal to monitor SIB1 (for example, SIB1 parameter set information, information related to SIB1 CORESET, search space information, and PDCCH-related parameter information, etc.), the offset information between the common resource block and the SSB (the absolute position of the SSB in the carrier is transmitted through SIB1), etc. Among them, the SIB1 parameter set information is also applicable to some messages used in the random access process for accessing the base station after the terminal completes the cell search process. For example, the parameter set information of SIB1 can be applicable to at least one of messages 1 to 4 used for the random access process.

[0079] The above-mentioned RMSI may mean SIB1 (System Information Block 1), which is broadcast periodically (for example: 160ms) in the cell. SIB1 includes the information required for the terminal to perform the initial random access process, and is periodically transmitted through PDSCH. In order to receive SIB1, the terminal needs to receive parameter set information for SIB1 transmission and CORESET (Control Resource Set) information for SIB1 scheduling through PBCH. The terminal uses SI-RNTI in CORESET to confirm the scheduling information for SIB1, and obtains SIB1 on PDSCH according to the scheduling information. Other SIBs except SIB1 can be transmitted periodically or according to the requirements of the terminal.

[0080] Figure 6 This is a diagram for explaining a random access procedure in a wireless access technology to which this embodiment is applicable.

[0081] Reference Figure 6 , when the cell search is completed, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted via PRACH. Specifically, the random access preamble is transmitted to the base station via PRACH consisting of continuous radio resources in a specific time slot that is repeated periodically. Generally, when the terminal initially accesses a cell, a contention-based random access procedure is performed, and when random access is performed for beam failure recovery (BFR, Beam Failure Recovery), a non-contention-based random access procedure is performed.

[0082] The terminal receives a random access response to the transmitted random access preamble. The random access response may include: a random access preamble identifier (ID), a UL Grant (uplink grant) (uplink radio resources), a temporary C-RNTI (Temporary Cell-Radio Network Temporary Identifier), and a TAC (Time Alignment Command). Since a random access response may include random access response information for more than one terminal, a random access preamble identifier may be included to notify which terminal the included UL Grant, temporary C-RNTI, and TAC are valid for. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the terminal to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, i.e., an RA-RNTI (Random Access-Radio Network Temporary Identifier).

[0083] The terminal that receives a valid random access response processes the information contained in the random access response and performs a transmission scheduled to the base station. For example, the terminal applies the TAC and stores the temporary C-RNTI. Additionally, the data stored in the terminal buffer or newly generated data is transmitted to the base station using the UL Grant. In this case, information capable of identifying the terminal should be included.

[0084] Finally, the terminal receives a downlink message for contention resolution.

[0085] <CORESET in NR>

[0086] The downlink control channel in NR is transmitted by a CORESET (Control Resource Set) with a length of 1 to 3 symbols and transmits uplink / downlink scheduling information and SFI (Slot format Index), TPC (Transmit Power Control) information, etc.

[0087] As mentioned above, in order to ensure the flexibility of the system, the concept of CORESET is introduced in NR. CORESET (Control Resource Set) refers to the time-frequency resources (i.e., time-frequency resources) used for downlink control signals. The terminal can use more than one search space in the CORESET time-frequency resources to decode control channel candidates. A QCL (Quasi CoLocation) assumption is set for each CORESET, the purpose of which is to notify the characteristics of the simulated beam direction in addition to the characteristics based on the existing QCL assumption: delay spread, Doppler spread, Doppler shift, and average delay.

[0088] Figure 7 This is a diagram for explaining CORESET.

[0089] Reference Figure 7 ,CORESET can exist in multiple forms within the carrier bandwidth within a time slot.,In the time domain, a CORESET can consist of up to 3 OFDM symbols.,Also, in the frequency domain, a CORESET is defined as a multiple of six resource blocks, up to the carrier bandwidth.

[0090] The first CORESET is part of the initial bandwidth component and is indicated by the MIB to receive additional configuration information and system information from the network. After establishing a connection with the base station, the terminal can receive and configure more than one CORESET information through RRC signaling.

[0091] In this specification, frequency, frame, subframe, resource, resource block, region, frequency band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) may be interpreted as the meaning used in the past or present or multiple meanings used in the future.

[0092] XR (eXtended Reality) is used as a broad term to mean various types of augmented, virtual, and hybrid environments in human-machine and human-human communications performed with the help of handheld and wearable terminals. eXtended Reality (XR) is used as a broad term covering augmented reality (AR), mixed reality (MR), and virtual reality (VR). XR and interactive media application services such as cloud gaming, tactile / multimodal communication services require high data rates and low latency communications.

[0093] 3GPP is currently standardizing high-speed data transmission rates and low-latency services to support XR and interactive media application services in Rel-18. In order to effectively support XR and media services in mobile communication networks, QoS policy control for multi-mode traffic, QoS processing support based on PDU Set, traffic assistance information transmission to support power consumption reduction, and XR-specific capacity enhancement functions are being discussed in the above standardization.

[0094] In particular, XR-specific capacity enhancements require the ability to increase the capacity of the radio interface by discarding packets / PDUs that exceed the above delay budget. Currently, the PDCP discard timer is used to model PDU Set discards, which does not properly handle data overflow situations.

[0095] Therefore, a technique is needed to properly handle data in the event of data overflow.

[0096] Currently, no specific detailed process and operation method for discarding data at a terminal sending / receiving XR and media application service data in order to improve the capacity of a mobile communication network has been proposed.

[0097] In this regard, the present disclosure will propose a detailed process and operation method and a device for effectively discarding terminal data in a mobile communication network that sends / receives application service data.

[0098] Below, a control method based on 5GS / NR technology is described. However, this is only for the sake of convenience of explanation, and this embodiment is also applicable to any system / radio access technology (for example: LTE, 6G). The embodiments described in this disclosure include information elements and operation contents specified in the NR / 5GS specifications (for example: MAC specification: TS 38.321, NR RRC specification: TS 38.331, system structure specification: TS23.501, etc.). Even if the definition of the above-mentioned information elements and the related terminal operation content are not included in this specification, in order to help understand the present invention, the relevant content specified in the standard specification may also be included in this embodiment.

[0099] Any function described below is defined as a separate terminal capability (UE radio capability or UE core network capability), and can be transmitted by the terminal to the base station / core network entity (e.g. AMF / SMF) through the above signaling. Alternatively, any function is combined / combined and defined as the above terminal capability, and can be transmitted to the base station / core network entity through the above signaling according to the request of the terminal.

[0100] For any function or any combination of functions described below, the base station may transmit / indicate information indicating the permission / support / configuration of the above function / combination of functions to the terminal through an upper layer message (e.g., an RRC message). For example, the above function / combination of functions may be indicated to the terminal before or while the above function / combination of functions is configured / applied. The above RRC message may be broadcast through system information. Alternatively, the terminal may be indicated through a dedicated RRC message.

[0101] For any function described below, the base station may transmit / indicate information for limiting the above function to the terminal through an RRC message. For example, a prohibition timer (Prohibit timer) of the above function may be indicated. Before starting the above function, or when starting the above function, the prohibition timer may be started / restarted. During the operation of the above timer, the terminal may restrict starting / execution of the above function.

[0102] The functions described below can be performed individually and independently. Moreover, the functions and embodiments described below can be implemented in any combination / combination, which is also self-evidently included in the scope of the present disclosure. For example, more than one function can be applied at the same time, and the embodiments of each part can also be implemented in any combination.

[0103] In addition, any information about XR applications in this specification may be traffic characteristic information obtained / calculated / induced by statistics / empirical experience in the terminal / network (for example, expected value / average, deviation, standard deviation, minimum, maximum, and other arbitrary statistics / statistics). Therefore, any information contained in this specification may show one or more values ​​of the average (expected value) / minimum / maximum / standard deviation value. For example, if information called update rate is included, it may refer to the average (expected value) / minimum / maximum / standard deviation update rate. This is for ease of explanation, and all information in this specification may be used as statistical information. Alternatively, it may be information pre-configured for the terminal / network or configured through OAM / application server / application function / UDM.

[0104] PDU Set, PDU Set QoS parameters, and PDU Set information are defined in 3GPP SA2 WG to effectively identify and process XR application data in Rel-18. PDU Set refers to one or more PDUs carrying the payload of one unit of information generated at the application level (eg frame(s) or video slice(s) etc for XR Services)). PDU Set Integrated Handling Information (PSIHI), one of the PDU Set QoS parameters, indicates whether all PDUs of the PDU Set are needed for the usage of PDU Set by application layer. PDU Set Importance (PSI) shows information used to identify the relative importance compared with other PDU Sets in a QoS flow.

[0105] The above terms are used for convenience of description and may be changed to any other names for use.

[0106] The PCF may determine the PDU Set QoS parameters based on information provided by the Application Function (AF) and / or local configuration. The PDU Set QoS parameters are sent to the SMF as part of the PCC rules. The SMF sends it to the base station as part of the QoS Profile. If the base station receives and supports the parameters, the base station can use them for PDU Set-based QoS processing.

[0107] Figure 8 is a flowchart for explaining terminal operation according to one embodiment.

[0108] Reference Figure 8 The method for processing data by a terminal may include: step S810 of receiving upper layer signaling including PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on a PDU Set.

[0109] For example, the terminal may receive the PDCP configuration information via an RRC message. As an example, the RRC message may be an RRC reconfiguration message. The terminal may receive the PDCP configuration information via upper layer signaling periodically or according to the occurrence of a specific event.

[0110] For example, the PDCP configuration information may include information for instructing to perform a discard operation based on a PDU Set and discard timer information based on the importance of a PDU Set.

[0111] As an example, information for indicating the execution of a discard operation based on a PDU Set may be included as an information element of the PDCP configuration information. For example, information for indicating the execution of a discard operation based on a PDU Set may be included as a pdu-SetDiscard information element. If the above information element is set to true, the terminal may confirm that the execution of a PDU Set-based discard operation has been indicated for the above PDCP individual. For another example, discard timer information based on the importance of PDU Set may be included as an information element that is distinguished from previous PDCP discard timer information. Discard timer information based on the importance of PDU Set may be included as a discard timer for low importance (discardTimerForLowImportance) information element. For example, the discard timer information based on the importance of PDU Set may include a timer value applicable when the terminal performs an SDU (Service Data Unit) discard operation based on the importance of PDU Set.

[0112] In addition, the discard timer based on the importance of PDU Set is indicated by an information element distinguished from the PDCP discard timer. The value of the discard timer based on the importance of PDU Set can be set in a value greater than 0 to less than the value of the PDCP discard timer. For example, the value of the discard timer based on the importance of PDU Set can be set to 0. The value of the PDCP discard timer cannot be set to 0. In addition, the value of the discard timer based on the importance of PDU Set is set to a value less than the value of the PDCP discard timer. The value of the timer is set in time units, and therefore, a small value means a value indicating a short time.

[0113] The SDU discard operation based on the importance of PDU Set is deactivated after receiving the RRC reconfiguration message. For example, when the terminal receives the RRC reconfiguration message, the SDU discard operation based on the importance of PDU Set can be configured to a deactivated state. Specifically, when a reconfiguration message (e.g., reconfiguration with sync) containing a handover command is received according to the movement of the terminal, it can be considered that the SDU discard operation function based on the importance of PDU Set is in a disabled / deactivated state.

[0114] The method for processing data by a terminal may include: step S820 of receiving a MAC control element, where the MAC control element is used to indicate activation of an SDU (Service Data Unit) discard operation based on PDU Set importance.

[0115] For example, the SDU discard operation based on the importance of PDU Set refers to an operation that uses the importance information of PDU Set set in PDU Set to distinguish and apply the discard operation of PDCP SDU. As an example, when the importance of PDU Set is set to be low, the PDCP discard timer is not used, but the discard timer based on the importance of PDU Set is used to perform the discard operation. As the value of the discard timer based on the importance of PDU Set is set to be less than the value of the PDCP discard timer, the PDCP SDU with low importance is discarded more quickly, thereby reducing the load of the mobile communication system in terms of capacity assurance.

[0116] The terminal may receive, through MAC CE, an indication that a discard operation of an SDU (Service Data Unit) based on the importance of a PDU Set in a deactivated state is converted to an activated state. Alternatively, the terminal may receive, through MAC CE, an indication that a discard operation of an SDU (Service Data Unit) based on the importance of a PDU Set in an activated state is converted to a deactivated state.

[0117] For example, the MAC control element may include a field for indicating activation or deactivation of the SDU discarding operation based on the importance of the PDU Set. The MAC control element may indicate activation or deactivation of the SDU discarding operation based on the importance of the PDU Set according to the DRB.

[0118] The MAC control element used to indicate activation or deactivation of the SDU discard operation based on the importance of the PDU Set may be a newly defined MAC control element instead of a previous MAC control element.

[0119] The method for the terminal to process data may include: if the SDU discard operation based on PDU Set importance is activated and a PDCP SDU with PDU Set importance belonging to a preset standard is received from an upper layer, step S830 of controlling the PDCP individual to start a discard timer based on PDU Set importance configured in association with the PDCP SDU.

[0120] For example, the terminal may activate or deactivate the SDU discard operation based on the PDU Set importance by receiving a MAC control element. If the SDU discard operation based on the PDU Set importance is activated, the terminal may confirm the PDU Set importance of the PDCP SDU transmitted by the upper layer. In the case where the PDCP SDU belongs to a low PDU Set importance, the discard timer based on the PDU Set importance configured in association with the PDCP SDU may be started.

[0121] For example, the importance of the PDU Set may be distinguished according to a preset standard. As an example, the importance of the PDU Set may be further divided into two stages: high and low. Alternatively, the importance of the PDU Set may be further divided into N levels. In addition, the importance of the PDU Set may be distinguished and set in a variety of ways, without limitation thereto.

[0122] If a PDCP individual receives a PDCP SDU belonging to a low PDU Set importance, it is not associated with the PDCP discard timer, but is associated with the discard timer based on the PDU Set importance to start. That is, the terminal can distinguish the timer used to discard the PDU according to the PDU Set importance information and apply it.

[0123] For example, in the control step, when the discard timer based on the importance of PDU Set expires, the PDCP individual can be controlled to discard the PDCP data PDU and all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs. For example, the PDCP individual is associated with a PDCP SDU belonging to a low PDU Set importance to start the discard timer based on the importance of PDU Set. If the discard timer based on the importance of PDU Set expires, all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs can be discarded.

[0124] In addition, in the control step, if the PDCP individual receives a PDCP SDU to be included in the PDU Set to which the PDCP SDU belongs from the upper layer, the PDCP individual may be controlled to also discard the received PDCP SDU. For example, after the discard timer based on the importance of the PDU Set expires, the PDCP individual may discard all PDCP SDUs of the PDU Set to which the PDCP SDU belongs, and may also discard the PDCP SDUs received (continuously) from the upper layer and distinguished by being included in the above-mentioned PDU Set.

[0125] In addition, in the control step, when the SDU discard operation based on the importance of PDU Set is in a deactivated state or the discard timer based on the importance of PDU Set is not configured, control can be performed by starting the PDCP discard timer associated with the PDCP SDU. For example, when the discard timer based on the importance of PDU Set is configured in the terminal and the SDU discard operation based on the importance of PDU Set is activated, the terminal starts the discard timer based on the importance of PDU Set for the PDCP SDU. Different from this, when the SDU discard operation based on the importance of PDU Set is deactivated, the terminal associates the previous PDCP discard timer with the PDCP SDU to start it. In addition, even if the SDU discard operation based on the importance of PDU Set is activated, when the discard timer based on the importance of PDU Set is not configured in the terminal, the terminal can also associate the previous PDCP discard timer with the PDCP SDU to start it.

[0126] Through the aforementioned operations, the terminal uses the PDU Set importance information to distinguish the PDCP SDU of the uplink data, and can apply other discard timers to ensure the capacity of the mobile communication system. That is, in the case of a PDCP SDU belonging to a PDU Set of low importance, it can be associated with a discard timer set to a smaller value for operation, thereby quickly eliminating data backlogs in the case of a sharp surge in capacity. In addition, not only the above-mentioned PDCP SDU is discarded, but all PDCP SDUs belonging to the same PDU Set are also discarded, thereby ensuring capacity more quickly and smoothly to improve the high throughput of the mobile communication system.

[0127] In the following, the operation is described from the perspective of a base station.

[0128] Fig. 9 is a flowchart for explaining the operation of a base station according to one embodiment.

[0129] Reference Fig. 9The method for a base station to control data processing of a terminal may include: step S910 of setting PDCP configuration information configured to perform a discard operation based on a PDU Set.

[0130] For example, the PDCP configuration information may include information for instructing to perform a discard operation based on a PDU Set and discard timer information based on the importance of a PDU Set.

[0131] As an example, information for indicating the execution of a discard operation based on a PDU Set may be included as an information element of the PDCP configuration information. For example, information for indicating the execution of a discard operation based on a PDU Set may be included as a pdu-SetDiscard information element. If the above information element is set to true, the terminal may confirm that the execution of a PDU Set-based discard operation has been indicated for the above PDCP individual. For another example, discard timer information based on the importance of PDU Set may be included as an information element that is different from the previous PDCP discard timer information. Discard timer information based on the importance of PDU Set may be included as a discard timer for low importance (discardTimerForLowImportance) information element. For example, the discard timer information based on the importance of PDU Set may include a timer value applicable when the terminal performs an SDU (Service Data Unit) discard operation based on the importance of PDU Set.

[0132] In addition, the discard timer based on the importance of PDU Set is indicated by an information element distinguished from the PDCP discard timer. The value of the discard timer based on the importance of PDU Set can be set in a value greater than 0 to less than the value of the PDCP discard timer. For example, the value of the discard timer based on the importance of PDU Set can be set to 0. The value of the PDCP discard timer cannot be set to 0. In addition, the value of the discard timer based on the importance of PDU Set is set to a value less than the value of the PDCP discard timer. The value of the timer is set in time units, and therefore, a small value means a value indicating a short time.

[0133] The method for a base station to control data processing of a terminal may include: step S920 of transmitting upper layer signaling including PDCP configuration information to the terminal.

[0134] For example, the base station may send the PDCP configuration information via an RRC message. As an example, the RRC message may be an RRC reconfiguration message. The base station may transmit the PDCP configuration information to the terminal via upper layer signaling periodically or according to the occurrence of a specific event.

[0135] The method for a base station to control data processing of a terminal may include: a step S930 of transmitting a MAC control element to the terminal, where the MAC control element is used to indicate activation of an SDU discard operation based on the importance of a PDU Set.

[0136] For example, the SDU discard operation based on the importance of PDU Set refers to an operation that uses the importance information of PDU Set set in PDU Set to distinguish and apply the discard operation of PDCP SDU. As an example, when the importance of PDU Set is set to be low, the PDCP discard timer is not used, but the discard timer based on the importance of PDU Set is used to perform the discard operation. As the value of the discard timer based on the importance of PDU Set is set to be less than the value of the PDCP discard timer, the PDCP SDU with low importance is discarded more quickly, thereby reducing the load of the mobile communication system in terms of capacity assurance.

[0137] The base station can convert the SDU (Service Data Unit) discarding operation based on the importance of PDU Set in the deactivated state to the activated state through MAC CE indication. Alternatively, the base station can convert the SDU (Service Data Unit) discarding operation based on the importance of PDU Set in the activated state to the deactivated state through MAC CE indication.

[0138] For example, the MAC control element may include a field for indicating activation or deactivation of the SDU discarding operation based on the importance of the PDU Set. The MAC control element may indicate activation or deactivation of the SDU discarding operation based on the importance of the PDU Set according to the DRB.

[0139] The MAC control element used to indicate activation or deactivation of the SDU discard operation based on the importance of the PDU Set may be a newly defined MAC control element instead of a previous MAC control element.

[0140] In addition, for the terminal, if the SDU discard operation based on PDU Set importance is activated and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the PDCP individual starts a discard timer based on PDU Set importance configured in association with the PDCP SDU.

[0141] The SDU discard operation based on the importance of PDU Set is deactivated after receiving the RRC reconfiguration message. For example, when the terminal receives the RRC reconfiguration message, the SDU discard operation based on the importance of PDU Set can be configured to a deactivated state. Specifically, when a reconfiguration message (e.g., reconfiguration with sync) containing a handover command is received according to the movement of the terminal, it can be considered that the SDU discard operation function based on the importance of PDU Set is in a disabled / deactivated state.

[0142] For example, the terminal may activate or deactivate the SDU discard operation based on the PDU Set importance by receiving a MAC control element. If the SDU discard operation based on the PDU Set importance is activated, the terminal may confirm the PDU Set importance of the PDCP SDU transmitted by the upper layer. In the case where the PDCP SDU belongs to a low PDU Set importance, the discard timer based on the PDU Set importance configured in association with the PDCP SDU may be started.

[0143] For example, the importance of the PDU Set may be distinguished according to a preset standard. As an example, the importance of the PDU Set may be further divided into two stages: high and low. Alternatively, the importance of the PDU Set may be further divided into N levels. In addition, the importance of the PDU Set may be distinguished and set in a variety of ways, without limitation thereto.

[0144] If a PDCP individual receives a PDCP SDU belonging to a low PDU Set importance, it is not associated with the PDCP discard timer, but is associated with the discard timer based on the PDU Set importance to start. That is, the terminal can distinguish the timer used to discard the PDU according to the PDU Set importance information and apply it.

[0145] For example, when the discard timer based on the importance of PDU Set expires, the terminal can control the PDCP individual to discard the PDCP data PDU and all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs. For example, the PDCP individual of the terminal is associated with a PDCP SDU belonging to a low PDU Set importance to start the discard timer based on the importance of PDU Set. If the discard timer based on the importance of PDU Set expires, all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs can be discarded.

[0146] In addition, if the PDCP entity receives a PDCP SDU from an upper layer that is to be included in the PDU Set to which the PDCP SDU belongs, the terminal may control the PDCP entity to discard the received PDCP SDU as well. For example, the PDCP entity may discard all PDCP SDUs of the PDU Set to which the PDCP SDU belongs after the discard timer based on the importance of the PDU Set expires, and may also discard the PDCP SDUs received (continuously) from the upper layer and distinguished by being included in the above-mentioned PDU Set.

[0147] In addition, when the SDU discard operation based on PDU Set importance is in a deactivated state or the discard timer based on PDU Set importance is not configured, the terminal can start the PDCP discard timer associated with the PDCP SDU. For example, when the discard timer based on PDU Set importance is configured in the terminal and the SDU discard operation based on PDU Set importance is activated, the terminal starts the discard timer based on PDU Set importance for the PDCP SDU. Different from this, when the SDU discard operation based on PDU Set importance is deactivated, the terminal associates the previous PDCP discard timer with the PDCP SDU to start it. In addition, even if the SDU discard operation based on PDU Set importance is activated, when the discard timer based on PDU Set importance is not configured in the terminal, the terminal can also associate the previous PDCP discard timer with the PDCP SDU to start it.

[0148] Through this operation, the base station quickly eliminates unnecessary backlog of uplink data of low importance and can ensure system capacity.

[0149] The present embodiment that can be performed by the above-mentioned terminal and base station will be described in more detail below. In particular, each operation and distinguishing embodiments are described below by recording more detailed embodiments. Each operation described below can be performed by the terminal and base station in any combination. In addition, each detailed embodiment described below can also be performed by the terminal and base station in any combination.

[0150] In the following, the above-mentioned discard timer based on the importance of PDU Set can be described as a discard timer associated with PDU Set, a discard timer set to a shorter / smaller value than the existing PDCP discard timer, and a PDU Set discard timer.

[0151] Timer-based PDU Set PDUs discard configuration and operation method

[0152] First, a specific configuration method related to a method for discarding PDUs of a specific PDU Set(s) using a PDCP discard timer is described.

[0153] The PDCP discard timer is indicated to the terminal through the PDCP configuration information included in the RRC reconfiguration message. When the terminal receives a PDCP SDU from the upper layer, the sending PDCP entity starts the discard timer associated with the PDCP SDU. As mentioned above, in the prior art, the PDCP discard timer is associated with each PDCP SDU and operates in units of PDCP SDU.

[0154] In order to handle the PDU Set-based discard function, the PDU Set discard indication information for the uplink may be indicated to the terminal through the PDCP configuration information included in the RRC reconfiguration message. For ease of explanation, the following PDU-Set-based discard function is used to indicate the function of discarding all / remaining / remaining packets / PDUs (or packets / PDUs of the indicated traffic / size / packet number ratio) in the PDU Set when a PDU is discarded, and the name may be changed to any other name.

[0155] For example, the PDU Set discard indication information may indicate the PDU Set integration processing information. Alternatively, when the PDU Set integration processing information is set, the PDU Set discard indication information may allow the terminal to perform the PDU Set discard function. The PDU Set discard indication information may be set by the terminal for instructing the PDUs of the PDU Set to be discarded by considering whether the application layer needs all the PDUs of the PDU Set to use the PDU Set for the above-mentioned DRB.

[0156] If (at the base station / terminal) PDU-Set-discard-indication information / PDU-Set-integration-processing-information is set / configured / indicated for a QoS flow (or for more than one PDU-Set(s) included in a QoS flow, or for a DRB associated with the PDU Set, or for a PDCP entity associated with the PDU Set), if the terminal knows (or confirms) that a PDU of a PDU-Set is lost, it can be considered that the application layer no longer needs the remaining PDUs of the PDU Set. And, in order to prevent unnecessary use of radio resources, a discard operation can be performed.

[0157] For another example, the PDU Set discard indication information may be indicated as information distinguished from the PDU Set integration processing information. Alternatively, the PDU Set discard indication information may be indicated as information distinguished for enabling the terminal to perform the PDU Set discard function when the PDU Set integration processing information is set.

[0158] If (at the base station / terminal) PDU-Set-integration-processing-information is set / configured / indicated for a QoS flow (or for more than one PDU-Set(s) included in a QoS flow, or for a DRB associated with the PDU Set through RRC signaling, or for a PDCP entity associated with the PDU Set through RRC signaling, or for an upper layer of a QoS flow through NAS signaling), for a DRB with PDU Set discard indication information set, if the terminal knows (or confirms) that a PDU of a PDU-Set is lost, it can be considered that the application layer no longer needs the remaining PDUs of the PDU Set. And, in order to prevent unnecessary use of radio resources, a discard operation can be performed.

[0159] For another example, the PDU Set discard indication information may be indicated as new / another PDU Set parameter information distinguished from the PDU Set integration processing information. As an example, the PDU level / ratio of the PDU Set required for the application layer to use the PDU Set may be indicated. This is information used in the application layer for the above-mentioned PDU Set processing (e.g., decoding, etc.), and for a PDU Set, it may be indicated as the ratio of the number of PDUs required for successful processing to the total number of PDUs contained in the PDU Set, the ratio of the number of PDU Set Sequence Numbers required for successful processing to the number of (all) PDU Set Sequence Numbers associated with the PDU Set, the ratio of the size (byte) of the PDU Set PDUs required for successful processing to the size (byte) of the (all) PDU Set PDUs associated with the PDU Set, etc. As another example, it may be indicated with different weights according to the PDU Set Importance. As another example, the PCF may determine the above PDU Set QoS parameters based on information provided by the application function (AF) and / or local configuration. The PDU Set QoS parameters are sent to the SMF as part of the PCC rules. The SMF sends it to the base station as part of the QoS profile. If the base station receives and supports the parameters, the base station may use it for PDU Set-based QoS processing.

[0160] If (at the base station / terminal) PDU-Set-aggregation-processing-information is set / configured / indicated for a QoS flow (or for more than one PDU-Set(s) included in a QoS flow, or for a DRB associated with the PDU Set through RRC signaling, or for a PDCP entity associated with the PDU Set through RRC signaling, or for an upper layer of a QoS flow through NAS signaling), for a DRB with PDU Set discard indication information set, if the terminal knows (or confirms) that the corresponding level / ratio of a PDU-Set is lost, it can be considered that the application layer no longer needs the remaining PDUs of the PDU Set. And, in order to prevent unnecessary use of radio resources, a discard operation can be performed.

[0161] For another example, the PDU Set PDUs discard indication information may include information for indicating the availability (enable) / activation (activation) of the above-mentioned function. For the terminal, when the information for indicating the availability (enable) / activation (activation) of the above-mentioned function is set / indicated / configured, the terminal (RRC of the terminal) may indicate the above-mentioned function (or the start / start of the above-mentioned function) to the lower layer (e.g., PDCP). And / or the terminal (RRC / PDCP of the terminal) may be configured to consider the above-mentioned function available / activated. Otherwise, the terminal (RRC / PDCP of the terminal) may be configured to consider the above-mentioned function unavailable (disable) / deactivated (deactivated).

[0162] For another example, the PDU Set discard indication information may be indicated by PDU Set discard timer information and / or PDU Set discard enable / activate information.

[0163] If (at the base station / terminal) PDU-Set-integration-processing-information is set / configured / indicated for a QoS flow (or for more than one PDU-Set(s) included in a QoS flow, or for a DRB associated with the PDU Set through RRC signaling, or for a PDCP entity associated with the PDU Set through RRC signaling, or for an upper layer of a QoS flow through NAS signaling), for the terminal, when PDU Set discard timer information and / or PDU Set discard enable / activate information is set / configured / indicated, for the above-mentioned DRB, if the terminal knows (or confirms) that a PDU of a PDU-Set is lost, it can be considered that the application layer no longer needs the remaining PDUs of the PDU Set. And, in order to prevent unnecessary use of radio resources, a discard operation can be performed.

[0164] For another example, when a discard timer for a PDU included in a PDU-Set expires, the terminal may know (or may confirm) that a PDU of the PDU-Set is lost. The base station may set the PDCP discard timer value by considering the PDU Set Delay Budget (PSDB) (of the radio network), the upper bound for the duration between the reception time of the first PDU (at the UPF for DL, at the UE for UL), the time when all PDUs of a PDU Set have been successfully received (at the UE in DL, at the UPF in UL). A QoS Flow is associated with only one PSDB, and when available, it applies to both DL and UL and supersedes the PDB of the QoS flow. When the PDCP discard timer set to this value expires, the terminal may consider that the PDU Set delay budget cannot be met and discard the PDCP SDU. The terminal may discard any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the PDU Set together with the PDCP data PDU. In the case that the PDCP discard timer for any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the PDU Set has not expired, the terminal may also discard the PDCP SDU(s) together with the PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer. The terminal may maintain / store discard related information (for example, PDU Set related information associated with the discarded PDCP SDU).When the terminal receives a PDCP SDU associated with / contained in (continuous with) the PDU Set(s) from an upper layer, the PDCP SDU is discarded (or, without starting a discard timer associated with the PDCP SDU, the PDCP SDU is discarded. Alternatively, the discard timer is set / configured / indicated to 0 and operated. Alternatively, without starting a discard timer associated with the PDCP SDU, the PDCP SDU is discarded. Since the PDCP SDU is discarded, the terminal (or the sending PDCP entity) does not associate the PDCP SDU with the COUNT value (corresponding to TX_NEXT). For the PDCP SDU, the terminal (or the sending PDCP entity) does not perform more than one of the following: header compression, uplink data compression, integrity protection, ciphering, setting the PDCP SN of the PDCP data PDU, incrementing TX_NEXT, and submitting the obtained PDCP Data PDU to the lower layer (incrementing TX_NEXT by on.submit the resulting PDCPData PDU to lower layer), store the PDCP SDU).

[0165] For another example, in order to distinguish the loss of a PDU included in a PDU-Set, when the above-mentioned discard timer (indicated by the base station) reaches a threshold, the terminal may know that a PDU of the above-mentioned PDU-Set is lost (or can be confirmed to be lost, or can be considered to be lost). The base station may set / configure / indicate the threshold to the terminal considering the PDU Set delay budget (of the wireless network). If the PDCP discard timer reaches the above-mentioned threshold, the terminal considers that the PDU Set delay budget cannot be met, and thus the above-mentioned PDCP SDU may be discarded. The terminal may discard any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the PDU Set together with the PDCP data PDU. In the case where the PDCP discard timer for any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the PDU Set has not expired, the terminal may also discard the PDCP SDU(s) together with the PDCP data PDU. If the PDCP data PDU has been submitted to lower layers, the discard may be indicated to the lower layers.

[0166] For another example, in order to distinguish / identify the loss of a PDU included in a PDU-Set, before the above-mentioned discard timer expires, if relevant indication information is received from the base station, the terminal can know that a PDU of the above-mentioned PDU-Set is lost (or can confirm the loss, or can be considered to be lost). The base station can indicate the above-mentioned indication information to the terminal through a PDCP control PDU (PDCP Control PDU).

[0167] As an example, the above indication information may be transmitted via a PDCP status report (PDCP Statusreport) having a PDU type 000 value. To this end, the base station (or the sending PDCP entity of the base station or the receiving PDCP entity of the base station) may generate / compile a PDCP status report and indicate it to the terminal. The FMC (First Missing COUNT) field indicating the COUNT value of the first lost PDCP SDU in the reordering window may include the COUNT value of the above SDU / PDU of the above PDU Set. The base station may transmit without a bitmap field (this field indicates which SDUs are missing and which SDUs are correctly received in the receiving PDCP entity.) or by setting the length of the bitmap field to 0. Alternatively, the base station may include, for more than one PDU Set(s), a bitmap field information that uses 0 or 1 to distinguish whether a PDU included in the above PDU Set is lost for transmission. The position of the Nth bit of the above-mentioned bitmap can be used to distinguish whether a PDU included in the Nth PDU Set is lost in the PDU Set having the first lost PDU / SDU. If the above-mentioned PDCP status report is received, the terminal (or the sending PDCP entity of the terminal) may know that the PDCP SDU / PDU having the COUNT value included in the FMC field value is lost. And / or, the terminal (or the sending PDCP entity of the terminal) may know that the PDU Set (or a PDU / SDU of the above-mentioned PDU Set) containing the PDCP SDU / PDU having the COUNT value included in the FMC field value and the PDU Set (or a PDU / SDU of the above-mentioned PDU Set) with the bitmap set to 0 (or 1) are lost. The terminal may discard the above-mentioned PDCP SDU. The terminal may discard any / remaining / all / all stored / all not discarded / all / not discarded remaining / remaining not discarded PDCP SDU(s) contained in the PDU Set together with the PDCP data PDU. The terminal may also discard the PDCP SDU(s) together with the PDCP data PDU if the PDCP discard timer for any / remaining / all / all stored / all not discarded / all / remaining not discarded PDCP SDU(s) contained in the PDU Set has not expired. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0168] As another example, a PDCP control PDU (for example, having a value of PDU type 100-111) different from a PDCP status report (PDCP Statusreport) having a value of PDU type 000 may be defined to transmit the above indication information. To this end, the base station (or the sending PDCP entity of the base station or the receiving PDCP entity of the base station) may generate / compile the above PDCP control PDU and indicate it to the terminal. The above PDCP control PDU may include a field for indicating a lost PDCP SDU (or a lost PDCP SDU / PDU of a PDU Set). The above field may include the COUNT value (or PDCP SN) of the above SDU / PDU of the above PDU Set. And / or, the base station may include, for more than one PDU Set(s), a bitmap field information for transmission that uses 0 or 1 to distinguish whether an SDU / PDU included in the above PDU Set is lost. The base station may transmit without a bitmap field or by setting the length of the bitmap field to 0. Alternatively, the base station may use the position of the Nth bit of the above-mentioned bitmap to distinguish whether a PDU included in the Nth PDU Set is lost in the PDU Set having the first lost PDU / SDU. If the above-mentioned PDCP control PDU is received, the terminal (or the transmitting PDCP entity of the terminal) may know that the above-mentioned PDCP SDU / PDU is lost through the field used to indicate the lost PDCP SDU (or the lost PDCP SDU / PDU of the PDU Set). And / or, the terminal (or the transmitting PDCP entity of the terminal) may know that the PDU Set (or a PDU / SDU of the above-mentioned PDU Set) with the bitmap set to 0 (or 1) is lost. The terminal may discard the above-mentioned PDCP SDU. The terminal may discard any / remaining / all / all stored / all not discarded / all / not discarded remaining / remaining not discarded PDCP SDU(s) contained in the PDU Set together with the PDCP data PDU. In the case that the PDCP discard timer for any / remaining / all / all stored / all / not discarded / remaining / not discarded PDCP SDU(s) contained in the PDU Set has not expired, the terminal may also discard the PDCP SDU(s) together with the PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0169] For another example, when setting / configuring / indicating PDU Set discard timer information and / or PDU Set discard available (enable) / activated (activate) information, if the first SDU associated with a PDU Set / included in a PDU Set is received from an upper layer, the terminal (or sending PDCP entity) starts the PDU Set discard timer associated with the PDCP SDU. When the above-mentioned PDU Set discard timer expires, the terminal may know (or confirm) that an SDU / PDU of the above-mentioned PDU-Set is lost. The base station may set the PDU Set discard timer value considering the PDU Set delay budget. When the PDU Set discard timer set to the above-mentioned value expires, the terminal may consider that the PDU Set delay budget cannot be met and discard the above-mentioned PDCP SDU. The terminal may discard any / remaining / all / all stored / all not discarded all / not discarded remaining / remaining not discarded PDCP SDU(s) contained in the PDU Set. In the case that the PDCP discard timer for any / remaining / all / all stored / all / not discarded / remaining / not discarded PDCP SDU(s) contained in the PDU Set has not expired, the terminal may also discard the PDCP SDU(s) together with the PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0170] For another example, in order to distinguish / identify the loss of a PDU included in a PDU-Set, when the above-mentioned PDU Set discard timer (indicated by the base station) reaches a threshold, the terminal may know that a PDU of the above-mentioned PDU-Set is lost (or confirmed to be lost, or considered to be lost). The base station may set the threshold considering the PDU Set delay budget. If the PDU Set discard timer reaches the above-mentioned threshold, the terminal considers that the PDU Set delay budget cannot be met, and thus the above-mentioned PDCP SDU may be discarded. The terminal may discard any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the PDU Set. In the case where the PDCP discard timer for any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the PDU Set has not expired, the terminal may also discard the PDCP SDU(s) together with the PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0171] PDU Set PDUs discard configuration and operation method based on PSI (PDUSetImportance, PDU set importance)

[0172] The following is a method for discarding PDUs of a specific PDU Set(s) based on PSI (PDU Set Importance). The method described below can be combined / integrated with the above-mentioned method for discarding PDUs of any PDU Set based on a timer as required.

[0173] In the event of congestion in the network, the base station may limit the uplink traffic transmission of the terminal. As mentioned above, for a specific QoS flow (for example, a QoS flow that sets / configures / indicates PDU Set integrated processing information), if the traffic associated with a specific PDU Set exceeds the above-mentioned PDU Set delay budget, it does not need to be transmitted. Therefore, if the base station transmits indication information for limiting the uplink traffic transmission of the terminal to the terminal due to any reason such as congestion, the terminal preferably considers it and discards PDUs that may exceed the above-mentioned PDU Set delay budget and do not need to be transmitted during the duration of the above-mentioned congestion. When PDUs are discarded by network instructions, PSI may be considered to discard PDUs.

[0174] For example, the PSI-based PDU Set PDUs discard configuration information may be indicated to the terminal through an RRC reconfiguration message. The above configuration information may be indicated as configuration information that is distinguished from any of the above configuration information. Alternatively, the above configuration information may be indicated using one of any of the above configuration information. Alternatively, the above configuration information may be indicated when setting / indicating / configuring any of the above configuration information. The above configuration information may be configured according to the terminal. Alternatively, the above configuration information may be configured in the SDAP configuration information. Thus, a PSI-based PDU Set PDUs discard function may be provided for more than one DRBs that provide more than one QoS-flows / PDU-Sets through one configuration. Alternatively, the above configuration information may be configured according to the DRB (for example, in the PDCP configuration information).

[0175] For another example, the PSI-based PDU Set PDUs discard configuration information may include information for indicating the availability (enable) / activation (activate) of the above-mentioned function. When the availability (enable) / activation (activate) information of the above-mentioned function is set / indicated / configured for indication, the terminal (RRC of the terminal) may indicate the above-mentioned function (or the start / start of the above-mentioned function) to the lower layer (e.g., PDCP). And / or the terminal (RRC / PDCP of the terminal) may be configured to consider the above-mentioned function available / activated. Otherwise, the terminal (RRC / PDCP of the terminal) may be configured to consider the above-mentioned function unavailable (disable) / deactivated (deactivated).

[0176] For another example, the PSI-based PDU Set PDUs discard configuration information may include information for instructing to discard the above PDU Set(s) (or the above PDU Set(s) PDUs) based on PSI differentiation. As an example, the discarded PSI level information may be included (or a discarded PSI level set, or a discarded PSI level group, or a discarded minimum PSI level, or a discarded maximum PSI level, or a discarded standard / critical PSI level, or any of the above PSI levels discarded except the default PSI level, wherein the default PSI level may represent a PSI level applicable to PDUs that do not include a PSI level differentiated by the application layer in a QoS flow). When the above function is enabled / activated, and / or when the indication information of the above function is received, and / or when the above PSI level information is received (changed), the terminal (or the sending PDCP entity) may discard any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) associated with the PDU Set(s) having the above PSI level (or an importance lower than the above PSI level, or an importance / importance value lower than the above PSI level, or an importance lower than the above PSI level including the above PSI level). For any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the above PDU Set, the terminal may discard the above PDCP SDU(s) together with the above PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0177] For another example, before the above-mentioned function becomes unavailable / deactivated, and / or before receiving the indication information that makes the above-mentioned function unavailable / deactivated, the terminal (or the sending PDCP entity) may discard any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) associated with the PDU Set(s) having the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance lower than the above-mentioned PSI level including the above-mentioned PSI level). For any / remaining / all / all stored / not discarded all / not discarded remaining / remaining non-discarded PDCP SDU(s) contained in the above-mentioned PDU Set, the terminal may discard the above-mentioned PDCP SDU(s) together with the above-mentioned PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0178] For another example, before the above-mentioned function is unavailable / deactivated, and / or before receiving the indication information that makes the above-mentioned function unavailable / deactivated, if the terminal receives from the upper layer a PDCP SDU associated / included with a PDU Set(s) having the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance lower than the above-mentioned PSI level including the above-mentioned PSI level), the above-mentioned PDCP SDU is discarded (or, without starting the discard timer associated with the PDCP SDU, the above-mentioned PDCP SDU is discarded. Alternatively, the discard timer is set / configured / indicated to 0 and the operation is performed. Alternatively, without starting the discard timer associated with the PDCP SDU, the PDCP SDU is discarded. Since the PDCP SDU is discarded, the terminal (or the sending PDCP entity) does not associate the PDCP SDU with the COUNT value (corresponding to TX_NEXT). For this PDCP For a PDCP SDU, the terminal (or sending PDCP entity) does not perform more than one of the following: header compression, uplink data compression, integrity protection, ciphering, setting the PDCP SN of the PDCP Data PDU, incrementing TX_NEXT by on.submit the resulting PDCP Data PDU to lower layer, and storing the PDCP SDU.

[0179] For another example, before the above-mentioned function becomes unavailable / deactivated and / or before receiving the indication information that makes the above-mentioned function unavailable / deactivated, when the terminal (or sending PDCP entity, or sending SDAP entity) receives PDCP-SDU / SDAP-SDU from the upper layer, the terminal (or sending PDCP entity, or sending SDAP entity) may check whether it is an SDU associated with / included in a PDU Set(s) having the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance value including the above-mentioned PSI level) and discard the above-mentioned PDCP-SDU / SDAP-SDU.

[0180] For another example, before the above-mentioned function becomes unavailable / deactivated, and / or before receiving the indication information that makes the above-mentioned function unavailable / deactivated, when the terminal (or the sending PDCP entity, or the sending SDAP entity) receives the PDCP-SDU / SDAP-SDU from the upper layer, if it is an SDU associated with / included in the PDU Set(s) having the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance lower than the above-mentioned PSI level including the above-mentioned PSI level), the above-mentioned PDCP-SDU / SDAP-SDU may be discarded. Otherwise, the terminal may start the discard timer associated with the above-mentioned PDCP SDU. For the discarded PDCP SDU, it is not associated with the COUNT value (corresponding to TX_NEXT). For the PDCP SDU, the terminal (or sending PDCP entity) may perform one or more of the following: header compression, uplink data compression, integrity protection, ciphering, setting the PDCP SN of the PDCP data PDU, incrementing TX_NEXT by on. submitting the resulting PDCP Data PDU to lower layer, and storing the PDCP SDU).

[0181] For another example, until the above-mentioned function becomes unavailable / deactivated, and / or before receiving the indication information that makes the above-mentioned function unavailable / deactivated, the terminal may be configured so that the above-mentioned PDU Set PDU (or the PDCP SDU associated with the above-mentioned PDU Set) operates with a PDU Set importance-based discard timer value associated / mapped to the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance lower than the above-mentioned PSI level including the above-mentioned PSI level). As one example, the above-mentioned PDCP SDU is directly discarded by having a specific PDU Set importance-based discard timer value such as 0. For another example, the possibility of being discarded without transmission is greater by having a PDU Set importance-based discard timer value that is shorter / smaller than the PDCP discard timer value used under usual / normal circumstances. The above-mentioned PDU Set importance-based discard timer can be indicated by an information element that is distinguished from the previous PDCP discard timer. The above-mentioned discard timer based on the importance of PDU Set may be used when the above-mentioned function is available / activated, and / or when the indication information for making the above-mentioned function available / activated is received, and / or before it is unavailable / deactivated, and / or before it is received before the indication information for making the above-mentioned function unavailable / deactivated is received. Otherwise, the previous PDCP discard timer may be used / started.

[0182] For another example, when the above function is applied, the PDU Set discard timer is made to have a specific discard timer value such as 0 to directly discard the above PDCP SDU. For another example, the possibility of not transmitting and being discarded is greater by having a PDU Set discard timer (discard timer based on PDU Set importance) value that is shorter / smaller than the PDU Set discard timer value used in normal circumstances. The above discard timer can be indicated by an information element (e.g., PDU Set discard timer 2) that is distinguished from the PDU Set discard timer (e.g., PDU Set discard timer 1). The above discard timer (e.g., PDU Set discard timer 2) can be used when the above function is available / activated, and / or when the indication information that makes the above function available / activated is received, and / or before it is unavailable / deactivated, and / or before it is received. Otherwise, the PDU Set discard timer (e.g., PDU Set discard timer 1) can be used.

[0183] For another example, after the above-mentioned function is unavailable / deactivated, and / or after receiving indication information that makes the above-mentioned function unavailable / deactivated, if the terminal is set / configured / indicated to integrate and process PDU Set information, then for the terminal, the PDU Set that is discarded when the above-mentioned function is activated is useless even if the PDCP SDU associated with the above-mentioned PDU Set arrives successively afterwards. For example, although the transmission difficulty caused by network congestion is solved, if a PDCP SDU of the above-mentioned PDU Set has been discarded before, even if the remaining / all PDCP SDUs associated with the above-mentioned PDU Set arrive again, they may need to be discarded. The terminal can maintain / store discard-related information (for example, PDU Set-related information associated with the discarded PDCP SDU). When the terminal receives a PDCP SDU associated with / contained in (continuous with) the PDU Set(s) from an upper layer, the PDCP SDU is discarded (or, without starting a discard timer associated with the PDCP SDU, the PDCP SDU is discarded. Alternatively, the discard timer is set / configured / indicated to 0 and the operation is performed. Alternatively, without starting a discard timer associated with the PDCP SDU, the PDCP SDU is discarded. Since the PDCP SDU is discarded, the terminal (or the transmitting PDCP entity) does not associate the PDCP SDU with the COUNT value (corresponding to TX_NEXT). For the PDCP SDU, the terminal (or the transmitting PDCP entity) does not perform one or more of the following: header compression, uplink data compression, integrity protection, ciphering, setting the PDCP SN of the PDCP data PDU, incrementing TX_NEXT, and submitting the obtained PDCP Data PDU to the lower layer (increment TX_NEXT by on.submit the resulting PDCP Data PDU to lower layer) and store the PDCP SDU).

[0184] For another example, the base station (L2 entity of the base station) may transmit to the terminal (L2 entity of the terminal) any control signal (e.g., PDCCH / DCI, MAC CE, RLC control PDU, PDCP control PDU, SDAP control PDU) for indicating that any of the above functions are available / activated and / or unavailable / deactivated. For ease of description, the method of using PDCP control PDU is described below. This is for ease of description, and it is obvious that the use of any other control signal is also included in the scope of the present invention.

[0185] The base station may indicate to the terminal a PDCP control PDU for indicating that any of the above functions is available / activated and / or unavailable / deactivated. As an example, the above PDCP control PDU may distinguish between the available / activated indication and the unavailable / deactivated indication through different PDU type (PDU type) values ​​and indicate them to the terminal. As another example, the above PDCP control PDU has a PDU type value and may include a 1-bit field for distinguishing between the available / activated indication and the unavailable / deactivated indication. For another example, when the above PDCP control PDU has a PDU type value and does not include a 1-bit field for distinguishing between the available / activated indication and the unavailable / deactivated indication, when the terminal receives the above data from the base station, it may distinguish between the available / activated indication and the unavailable / deactivated indication through a trigger (toggle) / switch. For example, when the above-mentioned terminal receives the first PDCP control PDU (and / or transmits any confirmation message for it to the base station (for example, HARQ, RLC ACK, RLC Status report (RLC Status report), PDCP control PDU ACK, etc.)) in the state (the above-mentioned function is configured as unavailable / deactivated (or available / activated)), the terminal may be considered as available / activated (or unavailable / deactivated). When the above-mentioned terminal receives the above-mentioned PDCP control PDU (and / or transmits any confirmation message for it to the base station (for example, HARQ, RLC ACK, RLC Status report (RLC Status report), PDCP control PDU ACK, etc.)) in the state (the above-mentioned function is configured as available / activated (or unavailable / deactivated)), the terminal may be considered as unavailable / deactivated (or available / activated).

[0186] For another example, the PDCP control PDU may include discarded PSI level information (or a discarded PSI level set, or a discarded PSI level group, or a discarded minimum PSI level, or a discarded maximum PSI level, or a discarded standard / critical PSI level, or any of the above PSI levels discarded except the default PSI level). For another example, the PDCP control PDU may be composed of a 1-bit field containing a discarded minimum / critical / maximum PSI level information. For another example, the PDCP control PDU can indicate the discarded PSI level information in the form of a bitmap. For example, there are 16 bits from PSI level 0 (in the case where the PSI level has a value of 0 to 15, the PSI level has a value of 1 to 16) to PSI level 15 (or 16), and the PDU Set(s) PDUs of the above PSI level can be distinguished by 1 bit of 1 or 0 to distinguish between the cases where the PDUs are discarded and the cases where they are not discarded.

[0187] As another example, the PDCP control PDU can indicate the discarded PSI level group information in the form of a bitmap. The 16 PSI levels can be distinguished by a smaller number (for example, according to importance / discarding priority) of PSI level groups that are associated and mapped to 1 bit (2 groups) or 2 bits (3 groups or 4 groups). The above association / mapping information can be pre-configured in the terminal through RRC signaling. The cases where the PDU Set(s) PDUs associated with the above PSI level group are discarded and the cases where they are not discarded can be distinguished by 1 bit of 1 or 0. As another example, the PDCP control PDU may include timer information for limiting the time during which the above function operates. When the terminal receives the PDCP control PDU for making the above function available / activated, the above timer can be started / restarted. When the above timer expires, the terminal can make the above function unavailable / deactivated. In the present invention, any PSI level can also be mapped to any PSI level group and is applicable.

[0188] For another example, the PDCP control PDU may include timer information for limiting / indicating the execution time of a discard function for any PDU Set.

[0189] For another example, the PDCP control PDU may include discard timer (PDCP discard timer or PDU Set discard timer) information applicable to the discarded PSI level (or discarded PSI level group). If the terminal receives the PDCP control PDU, when the terminal (or the sending PDCP entity) receives the PDCP-SDU from the upper layer, for the PDCP SDU associated / included with the PDU Set(s) having the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance lower than the above-mentioned PSI level including the above-mentioned PSI level), the discard timer with the received discard timer value (expiration / duration value) may be started. When receiving the above-mentioned PDCP control PDU, in the case that the PDCP discard timer of the PDCP SDU associated / included in the PDU Set(s) having the above-mentioned PSI level (or an importance lower than the above-mentioned PSI level, or an importance / importance value lower than the above-mentioned PSI level, or an importance lower than the above-mentioned PSI level including the above-mentioned PSI level) exceeds the above-mentioned received discard timer expiration / duration value, the terminal may consider the above-mentioned discard timer to be expired (or the terminal stops the above-mentioned discard timer. Or the terminal releases / deletes / removes / expires the above-mentioned discard timer.). The terminal may discard the above-mentioned (stored) PDCP SDU(s). The terminal may discard the above-mentioned PDCP SDU(s) together with the above-mentioned PDCP data PDU(s). If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0190] How to change / modify / reconfigure the PDU Set discard timer

[0191] The above-mentioned arbitrary PDC Set discarding function and related information can be set / configured / indicated to the terminal through RRC signaling. For example, the discarding timer can be modified / changed to indicate. When the discarding timer is modified, if the modified value has a smaller value, the above-mentioned discarding timer may expire when the PDCP-SDU has been received from the upper layer and the above-mentioned discarding timer has been started. In this case, the terminal can modify / change / reconfigure the expiration / duration value of the above-mentioned discarding timer. When any discarding timer in operation exceeds the modified / changed / reconfigured discarding timer duration, the terminal can discard the above-mentioned PDCP SDU. The terminal can consider the above-mentioned discarding timer to expire (or the terminal stops the above-mentioned discarding timer. Or the terminal cancels / deletes / removes / expires the above-mentioned discarding timer.). The terminal can discard the above-mentioned PDCP SDU(s). The terminal can discard the above-mentioned PDCP SDU(s) together with the above-mentioned PDCP data PDU. For any / remaining / all / all stored / all / not discarded / remaining / not discarded PDCP SDU(s) contained in the above PDU Set, the terminal may discard the above PDCP SDU(s) together with the above PDCP data PDU. If the PDCP data PDU has been submitted to the lower layer, the discard may be indicated to the lower layer.

[0192] PDU Set discard unavailable / deactivation timer configuration and operation method

[0193] In any of the above embodiments, when the above-mentioned PDU Set PDUs are discarded and available / activated, other signaling is generated to indicate that the above-mentioned function is unavailable / deactivated. To prevent this, when the base station indicates to the terminal through RRC signaling, timer information for limiting the time for the above-mentioned function to operate in an available / activated state when the above-mentioned function is available / activated may be included. For example, when the above-mentioned timer information and / or any PDU Set discard available / activated indication information are received / configured through an RRC message, the terminal may start / restart the above-mentioned timer. For another example, when the above-mentioned timer information and / or any PDU Set discard available / activated indication information are received / configured through a PDCP control PDU, the terminal may start / restart the above-mentioned timer. For another example, when any PDU Set discard available / activated indication information is received / configured through a PDCP control PDU, the terminal may start / restart the above-mentioned timer received through RRC. When the above-mentioned timer expires, the terminal may make the above-mentioned function unavailable / deactivated. During the operation of the above-mentioned timer, the terminal may perform the corresponding arbitrary PDU Set PDUs discard operation.

[0194] For another example, in order to modify / reconfigure the above-mentioned PDCP entity, the base station may indicate an RRC reconfiguration message to the terminal. When the terminal receives an RRC reconfiguration message containing information for reconfiguring / modifying the above-mentioned PDCP entity, if any PDU Set discard available / activation indication information is not included, the terminal may be configured to consider the above-mentioned function as unavailable (disabled) / deactivated (deactivated). For example, even if there is no change in the above-mentioned function according to the incremental configuration and it is not included, if any PDU Set discard available / activation indication information is not included, the terminal may be configured to consider the above-mentioned function as unavailable (disabled) / deactivated (deactivated). When the above-mentioned function is to be maintained, even in the case of indicating incremental configuration, the above-mentioned PDU Set discard available / activation indication information may be included. In the case of receiving a reconfiguration message containing a handover command (for example, synchronous reconfiguration (reconfiguration with sync)) according to the movement of the terminal, the terminal may also be configured to consider the above-mentioned function as unavailable (disabled) / deactivated (deactivated). When the above-mentioned function is to be maintained during the handover process, even in the case of indicating incremental configuration, the above-mentioned PDU Set discard available / activation indication information may be included.

[0195] Another embodiment of the present disclosure is further described below.

[0196] If SDUs / PDUs are discarded at the terminal (base station) through any of the above functions, the terminal (base station) preferably indicates the discarded sequence number (SN) to the base station (terminal). The discarding of PDCP SDU(s) that have been associated with the PDCP SN by the terminal (or the transmitting PDCP entity of the terminal / base station) may cause an SN gap in the transmitted PDCP data PDUs of the terminal / base station. This may increase the PDCP reordering delay in the receiving PDCP entity of the base station / terminal. The terminal or base station may be delayed based on a variety of factors. In order to support the rapid processing of XR and media application data that requires low-latency and high-speed transmission, it is best to provide discarded information. In particular, during the switching process, this information can be used to avoid unnecessary transmission / retransmission of discarded PDCP SDU / PDU, while reducing the reordering delay on the receiving side, thereby effectively sending and receiving PDCP data.

[0197] For example, a terminal (or a transmitting PDCP entity of the terminal) may trigger a discard status report. For ease of explanation, the status report including the discard information of PDU Set PDUs is marked as a discard status report below. This is for ease of explanation and may be replaced by any other term. As an example, a discard status report may be triggered in one or more of the PDCP entity reestablishment request of the upper layer (RRC) and the PDCP data recovery request of the upper layer. As another example, a discard status report may be triggered when any discard timer associated with a PDU Set (or a discard timer of a PDU Set, or a PDCP discard timer of a PDCP SDU associated with a PDU Set) expires. As another example, a discard status report may be triggered when any discard timer associated with a PDU Set (or a discard timer of a PDU Set, or a PDCP discard timer of a PDCP SDU associated with a PDU Set) reaches a specific threshold indicated by a base station. As another example, a discard status report may be triggered when the discard of PDU Set PDUs based on PSI (PDU Set Importance) is set / configured / indicated by a base station. As another example, for DRBs configured to send discard status reports in uplink via RRC, the terminal (sending PDCP entity) may trigger a discard status report when the upper layer indicates one of PDCP reestablishment and PDCP data resumption.

[0198] For another example, when a discard status report is triggered, the terminal (or the transmitting PDCP entity of the terminal) may generate / compile a discard status report. The terminal (or the transmitting PDCP entity of the terminal) may submit the discard status report to the lower layer in the first PDCP PDU for transmission.

[0199] For another example, when a PDCP status report in the prior art is triggered, the terminal (or the transmitting PDCP entity of the terminal) may compile a PDCP status report. The terminal (or the transmitting PDCP entity of the terminal) may submit the PDCP status report in the prior art to the lower layer in the first PDCP PDU for transmission. The terminal (or the transmitting PDCP entity of the terminal) may submit the discard status report to the lower layer in the second PDCP PDU for transmission.

[0200] For another example, when a discard status report is triggered, the terminal (or the transmitting PDCP entity of the terminal) may compile a discard status report. For UM DRBs, the terminal (or the transmitting PDCP entity of the terminal) may submit the discard status report to the lower layer in the first PDCP PDU for transmission.

[0201] For another example, when a discard status report is triggered, the terminal (or the transmitting PDCP entity of the terminal) may compile a discard status report. If the PDCP status report in the prior art is not triggered (or not compiled, or the PDCP status report is not configured / set (statusReportRequired) for sending for the AM DRB), the discard status report may be submitted to the lower layer in the first PDCP PDU for transmission.

[0202] For another example, the information for instructing to send a discard status report in the uplink may be set by the target base station and indicated to the terminal through the source base station.

[0203] For another example, when the terminal sends synchronization to the target cell and / or sends an RRC reconfiguration complete message to the target base station to complete the RRC switching procedure, the discard status report may include the above information in the RRC reconfiguration complete message and send it.

[0204] For another example, when the terminal sends synchronization to the target cell and / or sends an RRC reconfiguration completion message to the target base station to complete the RRC switching procedure, the discard status report can be sent together with the RRC reconfiguration completion message (or the first PUSCH of the DRB connected to the RRC reconfiguration completion message).

[0205] As another example, a terminal (or a transmitting RLC entity of the terminal) may trigger a discard status report. As an example, for a PDCP SDU(s) that has been submitted to the RLC by the PDCP layer, a discard status report may be triggered by a PDCP discard indication associated with a PDU Set discard. As another example, a discard status report may be triggered when any discard timer associated with a PDU Set (or a discard timer of a PDU Set, or a PDCP discard timer of a PDCP SDU associated with a PDU Set) expires. As another example, a discard status report may be triggered when any discard timer associated with a PDU Set (or a discard timer of a PDU Set, or a PDCP discard timer of a PDCP SDU associated with a PDU Set) reaches a specific threshold indicated by the base station. As another example, a discard status report may be triggered when PDU Set PDUs discard based on PSI (PDU Set Importance) is set / configured / indicated by the base station. As another example, for DRBs configured to send discard status reports in the uplink via RRC, the terminal (sending RLC entity) can trigger a discard status report when the PDCP layer indicates PDU Set discard.

[0206] For another example, when a discard status report is triggered, the terminal (or the transmitting RLC entity of the terminal) may generate / construct a discard status report. The terminal (or the transmitting RLC entity of the terminal) may create a discard status report at the first transmission opportunity indicated by the lower layer (e.g., MAC) and indicate it to the lower layer.

[0207] For another example, when a discard status report is triggered, the terminal (or the transmitting RLC entity of the terminal) may generate / construct a discard status report. If a prohibition timer for the status report is running, the prohibition timer expires, and the terminal (or the transmitting RLC entity of the terminal) may create a discard status report at the first transmission opportunity indicated by the lower layer (e.g., MAC) and indicate it to the lower layer.

[0208] For another example, even if the terminal (or the transmitting RLC entity of the terminal) receives a negative acknowledgement for the discarded RLC SDU, it may be considered as receiving a negative acknowledgement for the purpose of retransmitting the RLC SDU. For another example, even if the terminal (or the transmitting RLC entity of the terminal) receives a negative acknowledgement for the discarded RLC SDU, it may be considered as receiving a positive acknowledgement for the purpose of retransmitting the RLC SDU.

[0209] For another example, the discard status report can reuse the PDCP Status report format. The corresponding indication information can be transmitted through a PDCP status report with a PDU type 000 value. As an example, in the FMC (First Missing COUNT) field indicating the COUNT value of the first lost PDCP SDU in the reordering window, the COUNT value of the first discarded PDCP SDU (or the first PDCP SDU of the first discarded PDU Set) can be included. As another example, for more than one PDCP SDU, bitmap field information that uses 0 or 1 to distinguish whether the above PDCP SDU is lost can be included for transmission. As another example, it can be transmitted without a bitmap field (this field indicates which SDUs are missing and which SDUs are correctly received in the receiving PDCP entity.), or the length of the bitmap field is set to 0. As another example, a bitmap field is allocated whose bit length is the same as the number of COUNTs that arrives first of the following two: excluding the first discarded PDCP SDU and including the last discarded PDCP SDU, from the first discarded PDCP SDU (excluding itself) to the last discarded PDCP SDU (including itself), rounded to the next multiple of 8, or to the size of the resulting PDCP Control PDU equal to 9000 bytes. The Nth bit position of the bitmap can be used to distinguish whether the Nth SDU is discarded in the first discarded SDU.

[0210] As another example, for more than one PDU Set(s), bitmap field information for distinguishing whether a PDU included in the PDU Set is lost by 0 or 1 is transmitted.

[0211] As another example, a bitmap field is allocated whose bit length is the same as the number of COUNTs that arrives first: excluding the first discarded PDU Set and including the last discarded PDU Set, from the first discarded PDU Set (excluding itself) to the last discarded PDU Set (including itself), rounded to the next multiple of 8, or to the size of the final PDCP Control PDU equal to 9000 bytes. The Nth bit position of the bitmap can be used to distinguish whether the SDU included in the Nth PDU Set is discarded in the PDU Set with the first discarded SDU.

[0212] For another example, the discard status report may define a PDCP control PDU (e.g., having a value among PDU type 100-111) that is different from the PDCP Status report having a PDU type 000 value to transmit corresponding indication information. As an example, the above-mentioned PDCP control PDU may include a field for indicating the COUNT / HFN / PDCP_SN value of the first discarded PDCP SDU. As another example, the above-mentioned PDCP control PDU may include a field for indicating the COUNT / HFN / PDCP_SN value of the last discarded PDCP SDU. As another example, the above-mentioned PDCP control PDU may include a field for indicating the total / all discarded PDCP SDUs (or PDCP SDUs COUNTs) number from the first discarded PDCP SDU to the last discarded PDCP SDUs. As another example, the PDCP control PDU may include a field for indicating the number of PDCP SDUs (or PDCP SDUs COUNTs) discarded from the first discarded PDCP SDU (excluding itself) to the last discarded PDCP SDU (e.g., the number of all discarded PDCP SDUs - 1). As another example, the PDCP control PDU may include a field for indicating the COUNT / HFN / PDCP_SN value of the PDCP SDU included in the first discarded PDU Set. As another example, the PDCP control PDU may include a field for indicating the COUNT / HFN / PDCP_SN value of the PDCP SDU included in the last discarded PDU Set. As another example, the PDCP control PDU may include a field for indicating the number of PDCP SDUs included from the first discarded PDU Set to the last discarded PDU Set. As another example, it may include, for more than one PDCP SDU, bitmap field information for distinguishing whether the PDCP SDU is lost using 0 or 1 for transmission. As another example, the bitmap field may be transmitted without or with the length of the bitmap field set to 0. As another example, the bitmap field may be allocated with a bit length equal to the number of COUNTs that arrives first, excluding the first discarded PDCP SDU and including the last discarded PDCP SDU, from the first discarded PDCP SDU (excluding itself) to the last discarded PDCP SDU (including itself), rounded to the next multiple of 8, or to the size of the final PDCP Control PDU equal to 9000 bytes.The position of the Nth bit of the bitmap may be used to distinguish whether the Nth SDU is discarded in the first discarded SDU.

[0213] As another example, for more than one PDU Set(s), a bitmap field information may be transmitted using 0 or 1 to distinguish whether a PDU included in the above PDU Set is lost. As another example, a bitmap field is allocated, and its bit length is the same as the number of COUNTs that arrives first in the following two ways: excluding the first discarded PDU Set and including the last discarded PDU Set, from the first discarded PDU Set (excluding itself) to the last discarded PDU Set (including itself), rounded to the next multiple of 8, or to the PDU Set whose size of the final PDCP control PDU is equal to 9000 bytes. The Nth bit position of the bitmap can be used to distinguish whether the SDU included in the Nth PDU Set is discarded in the PDU Set with the first discarded SDU.

[0214] For another example, the discard status report may define an RLC control PDU (e.g., CPT value 001 or 000) to transmit corresponding indication information. As an example, the above-mentioned RLC Control PDU may include a field for indicating the SN (sequence number) value of the first discarded RLC (or RLC segment (RLC segment)). As another example, the above-mentioned RLC control PDU may include a field for indicating the SN value of the last discarded RLC SDUs (or RLC SDUs SNs). As another example, the above-mentioned RLC control PDU may include a field for indicating the total / all discarded RLC SDUs (or RLC SDUs SNs) from the first discarded RLC SDU (or the above-mentioned RLC segment) to the last discarded RLC SDU (or the above-mentioned RLC segment). As another example, the RLC Control PDU may include a field for indicating the number of RLC SDUs (or RLC SDUs SNs) discarded from the first discarded RLC SDU (or the RLC segment) (excluding itself) to the last discarded RLC SDU (or the RLC segment) (e.g., the number of all discarded RLC SDUs - 1). As another example, the RLC Control PDU may include a field for indicating the SN value of the RLC SDU (or the RLC segment) included in the first discarded PDU Set. As another example, the RLC Control PDU may include a field for indicating the SN value of the RLC SDU (or the RLC segment) included in the last discarded PDU Set. As another example, the RLC Control PDU may include a field for indicating the number of RLC SDUs (or the RLC segment) included in the first discarded PDU Set to the last discarded PDU Set. As another example, for more than one RLC SDU, bitmap field information for distinguishing whether the above RLC SDU is lost by 0 or 1 can be included for transmission. As another example, it can be transmitted without a bitmap field, or the length of the bitmap field is set to 0. As another example, a bitmap field (bitmapfield) is allocated, and its bit length is the same as the number of SNs that arrive first in the following two types: excluding the first discarded RLC SDU and including the last discarded RLC SDU, from the first discarded RLC SDU (excluding itself) to the last discarded RLC SDU (including itself), rounded to the next multiple of 8, or to the size of the final RLC control PDU equal to the byte with a specific value.

[0215] As described above, through this embodiment, the PDUs associated with the PDU Set can be effectively discarded at the terminal.

[0216] The following is an exemplary description of the operations of a terminal and a base station to which the above-mentioned embodiment can be applied.

[0217] Fig.10 is a diagram showing the composition of a terminal according to another embodiment.

[0218] Reference Fig.10 , the terminal 1000 for processing data may include: a receiving unit 1030, which receives upper layer signaling including PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on a PDU Set, and receives a MAC control element for indicating activation of an SDU discard operation based on PDU Set importance; and a control unit 1010, wherein if the SDU discard operation based on PDU Set importance is activated and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the control unit controls the PDCP individual to start a discard timer based on PDU Set importance configured in association with the PDCP SDU.

[0219] For example, the receiving unit 1030 may receive the PDCP configuration information via an RRC message. As an example, the RRC message may be an RRC reconfiguration message. The receiving unit 1030 may receive the PDCP configuration information via upper layer signaling periodically or according to the occurrence of a specific event.

[0220] For example, the PDCP configuration information may include information for instructing to perform a discard operation based on a PDU Set and discard timer information based on the importance of a PDU Set.

[0221] As an example, information for indicating the execution of a discard operation based on a PDU Set may be included as an information element of the PDCP configuration information. For example, information for indicating the execution of a discard operation based on a PDU Set may be included as a pdu-SetDiscard information element. If the above information element is set to true, the control unit 1010 may confirm that the execution of a discard operation based on a PDU Set has been indicated for the above PDCP individual. For another example, discard timer information based on the importance of PDU Set may be included as an information element that is distinguished from the previous PDCP discard timer information. Discard timer information based on the importance of PDU Set may be included as a discard timer for low importance (discardTimerForLowImportance) information element. For example, the discard timer information based on the importance of PDU Set may include a timer value applicable when the terminal performs an SDU (Service Data Unit) discard operation based on the importance of PDU Set.

[0222] In addition, the discard timer based on the importance of PDU Set is indicated by an information element distinguished from the PDCP discard timer. The value of the discard timer based on the importance of PDU Set can be set in a value greater than 0 to less than the value of the PDCP discard timer. For example, the value of the discard timer based on the importance of PDU Set can be set to 0. The value of the PDCP discard timer cannot be set to 0. In addition, the value of the discard timer based on the importance of PDU Set is set to a value less than the value of the PDCP discard timer. The value of the timer is set in time units, and therefore, a small value means a value indicating a short time.

[0223] The SDU discard operation based on the importance of PDU Set is deactivated after receiving the RRC reconfiguration message. For example, the control unit 1010 may configure the SDU discard operation based on the importance of PDU Set to a deactivated state when receiving the RRC reconfiguration message. Specifically, in the case of receiving a reconfiguration message (e.g., reconfiguration with sync) containing a handover command according to the movement of the terminal, it can be considered that the SDU discard operation function based on the importance of PDU Set is in a disabled / deactivated state.

[0224] The receiving unit 1020 may receive an indication through MAC CE that a discard operation of a SDU (Service Data Unit) based on the importance of a PDU Set in a deactivated state is converted to an activated state. Alternatively, the receiving unit 1020 may receive an indication through MAC CE that a discard operation of a SDU (Service Data Unit) based on the importance of a PDU Set in an activated state is converted to a deactivated state.

[0225] For example, the MAC control element may include a field for indicating activation or deactivation of the SDU discarding operation based on the importance of the PDU Set. The MAC control element may indicate activation or deactivation of the SDU discarding operation based on the importance of the PDU Set according to the DRB.

[0226] The MAC control element used to indicate activation or deactivation of the SDU discard operation based on the importance of the PDU Set may be a newly defined MAC control element instead of a previous MAC control element.

[0227] In addition, the control unit 1010 can activate or deactivate the SDU discard operation based on the PDU Set importance by receiving the MAC control element. If the SDU discard operation based on the PDU Set importance is activated, the control unit 1010 can confirm the PDU Set importance of the PDCP SDU transmitted by the upper layer. In the case where the PDCP SDU belongs to the low PDU Set importance, the discard timer based on the PDU Set importance configured in association with the PDCP SDU can be started.

[0228] For example, the importance of the PDU Set may be distinguished according to a preset standard. As an example, the importance of the PDU Set may be further divided into two stages: high and low. Alternatively, the importance of the PDU Set may be further divided into N levels. In addition, the importance of the PDU Set may be distinguished and set in a variety of ways, without limitation thereto.

[0229] If a PDCP individual receives a PDCP SDU belonging to a low PDU Set importance, it is not associated with the PDCP discard timer, but is associated with the discard timer based on the PDU Set importance to start. That is, the terminal can distinguish the timer used to discard the PDU according to the PDU Set importance information and apply it.

[0230] For example, when the discard timer based on the importance of PDU Set expires, the control unit 1010 may control the PDCP entity to discard the PDCP data PDU and all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs. For example, the PDCP entity is associated with a PDCP SDU belonging to a low PDU Set importance to start the discard timer based on the importance of PDU Set, and when the discard timer based on the importance of PDU Set expires, all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs may be discarded.

[0231] In addition, if the PDCP entity receives a PDCP SDU from an upper layer that is to be included in the PDU Set to which the PDCP SDU belongs, the control unit 1010 may control the PDCP entity to also discard the received PDCP SDU. For example, the PDCP entity may discard all PDCP SDUs of the PDU Set to which the PDCP SDU belongs after the discard timer based on the importance of the PDU Set expires, and may also discard the PDCP SDUs received (continuously) from the upper layer and distinguished by being included in the above-mentioned PDU Set.

[0232] In addition, when the SDU discard operation based on the importance of PDU Set is in a deactivated state or the discard timer based on the importance of PDU Set is not configured, the control unit 1010 can control by starting the PDCP discard timer associated with the PDCP SDU. For example, when the discard timer based on the importance of PDU Set is configured in the terminal and the SDU discard operation based on the importance of PDU Set is activated, the terminal starts the discard timer based on the importance of PDU Set for the PDCP SDU. Different from this, when the SDU discard operation based on the importance of PDU Set is deactivated, the terminal associates the previous PDCP discard timer with the PDCP SDU to start it. In addition, even if the SDU discard operation based on the importance of PDU Set is activated, when the discard timer based on the importance of PDU Set is not configured in the terminal, the terminal can also associate the previous PDCP discard timer with the PDCP SDU to start it.

[0233] Furthermore, the control unit 1010 controls the overall operation of the terminal 1000 according to the data processing operation required to perform the above-described present embodiment.

[0234] The sending unit 1020 and the receiving unit 1030 are used to send and receive signals, messages and data required to execute the above-mentioned embodiment to and from the base station.

[0235] Fig.11is a diagram showing the composition of a base station according to another embodiment.

[0236] Reference Fig.11 , the base station 1100 for controlling data processing of the terminal may include: a control unit 1110, which is configured to set PDCP configuration information for performing a discard operation based on a PDU Set; and a sending unit 1120, which transmits an upper layer signaling including the PDCP configuration information to the terminal, and transmits a MAC control element for indicating activation of an SDU discard operation based on PDU Set importance to the terminal. For the terminal, if the SDU discard operation based on PDU Set importance is activated, and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the PDCP individual starts a discard timer based on PDU Set importance configured in association with the PDCP SDU.

[0237] For example, the PDCP configuration information may include information for instructing to perform a discard operation based on a PDU Set and discard timer information based on the importance of a PDU Set.

[0238] As an example, information for indicating the execution of a discard operation based on a PDU Set may be included as an information element of the PDCP configuration information. For example, information for indicating the execution of a discard operation based on a PDU Set may be included as a pdu-SetDiscard information element. If the above information element is set to true, the terminal may confirm that the execution of a PDU Set-based discard operation has been indicated for the above PDCP individual. For another example, discard timer information based on the importance of PDU Set may be included as an information element that is distinguished from previous PDCP discard timer information. Discard timer information based on the importance of PDU Set may be included as a discard timer for low importance (discardTimerForLowImportance) information element. For example, the discard timer information based on the importance of PDU Set may include a timer value applicable when the terminal performs an SDU (Service Data Unit) discard operation based on the importance of PDU Set.

[0239] In addition, the discard timer based on the importance of PDU Set is indicated by an information element distinguished from the PDCP discard timer. The value of the discard timer based on the importance of PDU Set can be set in a value greater than 0 to less than the value of the PDCP discard timer. For example, the value of the discard timer based on the importance of PDU Set can be set to 0. The value of the PDCP discard timer cannot be set to 0. In addition, the value of the discard timer based on the importance of PDU Set is set to a value less than the value of the PDCP discard timer. The value of the timer is set in time units, and therefore, a small value means a value indicating a short time.

[0240] The sending unit 1120 may send the PDCP configuration information via an RRC message. As an example, the RRC message may be an RRC reconfiguration message. The sending unit 1120 may transmit the PDCP configuration information to the terminal via upper layer signaling periodically or according to the occurrence of a specific event.

[0241] The sending unit 1120 may convert the SDU (Service Data Unit) discarding operation based on the importance of PDU Set in the deactivated state to the activated state through the MAC CE indication. Alternatively, the sending unit 1120 may convert the SDU (Service Data Unit) discarding operation based on the importance of PDU Set in the activated state to the deactivated state through the MAC CE indication.

[0242] For example, the MAC control element may include a field for indicating activation or deactivation of the SDU discarding operation based on the importance of the PDU Set. The MAC control element may indicate activation or deactivation of the SDU discarding operation based on the importance of the PDU Set according to the DRB.

[0243] The MAC control element used to indicate activation or deactivation of the SDU discard operation based on the importance of the PDU Set may be a newly defined MAC control element instead of a previous MAC control element.

[0244] The SDU discard operation based on the importance of PDU Set is deactivated after receiving the RRC reconfiguration message. For example, when the terminal receives the RRC reconfiguration message, the SDU discard operation based on the importance of PDU Set can be configured to a deactivated state. Specifically, when a reconfiguration message (e.g., reconfiguration with sync) containing a handover command is received according to the movement of the terminal, it can be considered that the SDU discard operation function based on the importance of PDU Set is in a disabled / deactivated state.

[0245] For example, the terminal may activate or deactivate the SDU discard operation based on the PDU Set importance by receiving a MAC control element. If the SDU discard operation based on the PDU Set importance is activated, the terminal may confirm the PDU Set importance of the PDCP SDU transmitted by the upper layer. In the case where the PDCP SDU belongs to a low PDU Set importance, the discard timer based on the PDU Set importance configured in association with the PDCP SDU may be started.

[0246] For example, the importance of the PDU Set may be distinguished according to a preset standard. As an example, the importance of the PDU Set may be further divided into two stages: high and low. Alternatively, the importance of the PDU Set may be further divided into N levels. In addition, the importance of the PDU Set may be distinguished and set in a variety of ways, without limitation thereto.

[0247] If a PDCP individual receives a PDCP SDU belonging to a low PDU Set importance, it is not associated with the PDCP discard timer, but is associated with the discard timer based on the PDU Set importance to start. That is, the terminal can distinguish the timer used to discard the PDU according to the PDU Set importance information and apply it.

[0248] For example, when the discard timer based on the importance of PDU Set expires, the terminal can control the PDCP individual to discard the PDCP data PDU and all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs. For example, the PDCP individual of the terminal is associated with a PDCP SDU belonging to a low PDU Set importance to start the discard timer based on the importance of PDU Set. If the discard timer based on the importance of PDU Set expires, all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs can be discarded.

[0249] In addition, if the PDCP entity receives a PDCP SDU from an upper layer that is to be included in the PDU Set to which the PDCP SDU belongs, the terminal may control the PDCP entity to discard the received PDCP SDU as well. For example, the PDCP entity may discard all PDCP SDUs of the PDU Set to which the PDCP SDU belongs after the discard timer based on the importance of the PDU Set expires, and may also discard the PDCP SDUs received (continuously) from the upper layer and distinguished by being included in the above-mentioned PDU Set.

[0250] In addition, when the SDU discard operation based on PDU Set importance is in a deactivated state or the discard timer based on PDU Set importance is not configured, the terminal can start the PDCP discard timer associated with the PDCP SDU. For example, when the discard timer based on PDU Set importance is configured in the terminal and the SDU discard operation based on PDU Set importance is activated, the terminal starts the discard timer based on PDU Set importance for the PDCP SDU. Different from this, when the SDU discard operation based on PDU Set importance is deactivated, the terminal associates the previous PDCP discard timer with the PDCP SDU to start it. In addition, even if the SDU discard operation based on PDU Set importance is activated, when the discard timer based on PDU Set importance is not configured in the terminal, the terminal can also associate the previous PDCP discard timer with the PDCP SDU to start it.

[0251] Furthermore, the control section 1110 controls the overall operation of the base station 1100 according to the data processing operation required to perform the above-described present embodiment.

[0252] The sending unit 1120 and the receiving unit 1130 are used to send and receive signals, messages and data required to execute the above-mentioned embodiment to and from the terminal.

[0253] The above embodiment may be supported by a standard document disclosed in at least one of IEEE 802, 3GPP and 3GPP2 as a wireless access system. That is, in this embodiment, the steps, components and parts not described in order to clearly reveal the technical concept may be supported by the above standard document. In addition, all terms disclosed in this specification may be interpreted by the above standard document.

[0254] The above-mentioned embodiment can be implemented by various means. For example, the embodiment can be implemented by hardware, firmware, software or a combination thereof.

[0255] In the case of hardware implementation, the method according to the present embodiment can be implemented by one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers or microprocessors, etc.

[0256] In the case of implementation by firmware or software, the method according to this embodiment can be implemented in the form of a device, process or function that performs the functions or operations described above. The software code can be stored in a storage unit and driven by a processor. The storage unit is located inside or outside the processor and can exchange data with the processor through a variety of known devices.

[0257] In addition, the above-mentioned terms such as "system", "processor", "controller", "component", "module", "interface", "model" or "unit" may generally refer to physical hardware related to a computer, a combination of hardware and software, software or running software. For example, the aforementioned components may be processes driven by a processor, processors, controllers, control processors, individuals, execution threads, programs and / or computers, but are not limited to these. For example, an application running in a controller or processor and the controller or processor may become components. More than one component may be located in a process and / or execution thread, and a component may be located in one device (such as a system, a computing device, etc.) or distributed in two or more devices.

[0258] The above description is only an exemplary description of the technical idea of ​​the present disclosure, and those skilled in the art to which the present disclosure belongs can make various modifications and changes without departing from the essential features of the present application. In addition, the present embodiment is to illustrate the technical idea of ​​the present disclosure rather than to limit it, and therefore, the scope of the present technical idea is not limited by these embodiments. The scope of protection of the present disclosure shall be interpreted in accordance with the following claims, and all technical ideas within the equivalent scope thereof shall be interpreted as included in the scope of rights of the present disclosure.

Claims

1. A method for processing data by a terminal, comprising: The step of receiving upper layer signaling including PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on PDUSet; The step of receiving a MAC control element, wherein the MAC control element is used to indicate the activation of an SDU discard operation based on the importance of a PDU Set; as well as If the SDU discard operation based on the PDU Set importance is activated and a PDCP SDU of a preset standard PDU Set importance is received from an upper layer, the PDCP individual is controlled to start a discard timer based on the PDU Set importance configured in association with the PDCP SDU.

2. The method for processing data by a terminal according to claim 1, wherein: The PDCP configuration information includes information for instructing to perform a discard operation based on the PDU Set and discard timer information based on the importance of the PDU Set.

3. The method for terminal processing data according to claim 1, wherein: The discard timer based on the importance of the PDU Set is indicated by an information element distinguished from the PDCP discard timer, The value of the discard timer based on the importance of the PDU Set is set in a value greater than 0 and less than the value of the PDCP discard timer.

4. The method for processing data by a terminal according to claim 1, wherein: The SDU discarding operation based on the importance of the PDU Set is deactivated after receiving the RRC reconfiguration message.

5. The method for terminal processing data according to claim 1, wherein: The MAC control element includes a field for indicating activation or deactivation of an SDU discard operation based on the importance of the PDU Set.

6. The method for terminal processing data according to claim 1, wherein: In the controlling step, if a discard timer based on the importance of the PDU Set expires, the PDCP entity is controlled to discard the PDCP data PDU and all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs.

7. The method for terminal processing data according to claim 6, wherein: In the controlling step, if the PDCP entity receives from the upper layer a PDCP SDU to be included in the PDU Set to which the PDCP SDU belongs, the PDCP entity is controlled to also discard the received PDCP SDU.

8. The method for processing data by a terminal according to claim 1, wherein: In the controlling step, when the SDU discard operation based on the importance of the PDU Set is in a deactivated state or the discard timer based on the importance of the PDU Set is not configured, the PDCP discard timer associated with the PDCP SDU is controlled to start.

9. A method for a base station to control data processing of a terminal, comprising: A step of setting PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on a PDU Set; The step of transmitting an upper layer signaling including the PDCP configuration information to a terminal; as well as a step of transmitting a MAC control element to the terminal, wherein the MAC control element is used to indicate activation of an SDU discard operation based on PDU Set importance, For the terminal, if the SDU discard operation based on the PDU Set importance is activated and a PDCP SDU of PDU Set importance belonging to a preset standard is received from an upper layer, the PDCP individual starts a discard timer based on PDU Set importance configured in association with the PDCP SDU.

10. The method for data processing of a base station control terminal according to claim 9, wherein: The PDCP configuration information includes information for instructing to perform a discard operation based on the PDU Set and discard timer information based on the importance of the PDU Set.

11. The method for data processing of a base station control terminal according to claim 9, wherein: The discard timer based on the importance of the PDU Set is indicated by an information element distinguished from the PDCP discard timer, The value of the discard timer based on the importance of the PDU Set is set in a value greater than 0 and less than the value of the PDCP discard timer.

12. The method for data processing of a base station control terminal according to claim 9, wherein: The MAC control element includes a field for indicating activation or deactivation of an SDU discard operation based on the importance of the PDU Set.

13. A terminal for processing data, comprising: a receiving unit, which receives upper layer signaling including PDCP configuration information, wherein the PDCP configuration information is configured to perform a discard operation based on PDUSet, and the receiving unit receives a MAC control element, wherein the MAC control element is used to indicate activation of an SDU discard operation based on PDUSet importance; as well as The control unit controls the PDCP individual to start a discard timer based on the PDU Set importance configured in association with the PDCP SDU if the SDU discard operation based on the PDU Set importance is activated and a PDCP SDU of a PDU Set importance belonging to a preset standard is received from an upper layer.

14. The data processing terminal according to claim 13, wherein: The PDCP configuration information includes information for instructing to perform a discard operation based on the PDU Set and discard timer information based on the importance of the PDU Set.

15. The data processing terminal according to claim 13, wherein: The discard timer based on the importance of the PDU Set is indicated by an information element distinguished from the PDCP discard timer, The value of the discard timer based on the importance of the PDU Set is set in a value greater than 0 and less than the value of the PDCP discard timer.

16. The data processing terminal according to claim 13, wherein: The SDU discarding operation based on the importance of the PDU Set is deactivated after receiving the RRC reconfiguration message.

17. The data processing terminal according to claim 13, wherein: The MAC control element includes a field for indicating activation or deactivation of an SDU discard operation based on the importance of the PDU Set.

18. The data processing terminal according to claim 13, wherein: If the discard timer based on the importance of the PDU Set expires, the control unit controls the PDCP entity to discard the PDCP data PDU and all PDCP SDUs included in the PDU Set to which the PDCP SDU belongs.

19. The data processing terminal according to claim 18, wherein: If the PDCP entity receives, from the upper layer, a PDCP SDU to be included in the PDU Set to which the PDCP SDU belongs, the control unit controls the PDCP entity to also discard the received PDCP SDU.

20. The data processing terminal according to claim 13, wherein: When the SDU discard operation based on the PDU Set importance is in a deactivated state or the discard timer based on the PDU Set importance is not configured, the control unit controls the PDCP discard timer associated with the PDCP SDU to start.

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