Method and apparatus for optimizing MT-SDT operation in mobile communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a user equipment (UE) in a wireless communication system may comprise the steps of: receiving a radio resource control (RRC) release message including configuration information on small data transmission (SDT) from a base station; when a paging message containing an SDT indication is received from the base station, executing an RRC recovery process for the SDT based on the configuration information; and when the SDT fails, sending information indicating the reason of the SDT failure to the base station.

Description

Technical Field

[0001] This disclosure relates to wireless communication systems, and more specifically, to methods and apparatus for optimizing small data transmission (MT-SDT) operations of mobile terminals in mobile communication systems. Background Technology

[0002] 5G mobile communication technology defines a wide frequency band, enabling high transmission rates and new services. It can be deployed not only in "sub-6GHz" bands such as 3.5GHz, but also in "above 6GHz" bands, including 28GHz and 39GHz, known as millimeter waves. Furthermore, to achieve the goal of increasing transmission rates by 50 times and reducing latency to one-tenth of 5G mobile communication technology, the industry is considering deploying 6G mobile communication technology (also known as super 5G systems) in terahertz (THz) bands (such as the 95GHz to 3THz band).

[0003] In the early stages of 5G mobile communication technology development, standardization efforts have been underway to support and meet the performance requirements of services related to enhanced mobile bandwidth (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). These efforts encompass technologies including: beamforming and massive MIMO techniques to mitigate path loss in millimeter waves and improve radio wave transmission distance; parameter set support for efficient utilization of millimeter wave resources and dynamic time slot format operation (such as operating multiple subcarrier spacings); initial access technologies supporting multi-beam transmission and broadband; the definition and operation of the bandwidth portion (BWP); novel channel coding methods such as LDPC codes suitable for large data transmission and polar codes suitable for highly reliable transmission of control information; L2 preprocessing technology; and network slicing technology to provide dedicated networks for specific services.

[0004] Currently, in light of the services that 5G mobile communication technology needs to support, the industry is discussing improvements and performance enhancements for the first-generation 5G mobile communication technology, and promoting the standardization of several technologies at the physical layer, including: V2X (vehicle-to-everything) technology, which uses vehicle location and status information to assist autonomous vehicles in making driving decisions and improve user convenience; NR-U (New Radio Unlicensed) technology, which aims to enable the system to meet various regulatory requirements in unlicensed frequency bands; NR UE power saving technology; UE-satellite direct communication type NTN (non-terrestrial network) technology, which provides coverage for areas where terrestrial network communication is unavailable; and positioning technology.

[0005] Furthermore, at the air interface architecture / protocol level, standardization efforts are ongoing, involving technologies including: IIoT (Industrial Internet of Things) technology to support new services through interoperability and integration with other industries; IAB (Integrated Access and Backhaul) technology to provide nodes for expanding network service areas by supporting wireless backhaul and access links in an integrated manner; mobility enhancement technologies including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access (NR's two-step RACH) technology to simplify the random access process. At the system architecture / service level, standardization efforts are also progressing, involving: 5G infrastructure (e.g., service-based architectures or service-based interfaces) for converging Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) technology based on UE location reception services.

[0006] With the commercialization of 5G mobile communication systems, the number of connected devices will increase exponentially in the communication network. Therefore, there is an urgent need to improve the functionality and performance of 5G mobile communication systems and achieve integrated operation of connected devices. To this end, new research has been initiated, including: XR (Extended Reality) technology for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), and MR (Mixed Reality); technologies that utilize artificial intelligence (AI) and machine learning (ML) to improve 5G performance and reduce complexity; AI service support technologies; metaverse service support technologies; and drone communication technologies.

[0007] Furthermore, this development of 5G mobile communication systems will not only lay the foundation for the development of technologies such as: novel waveform technologies for providing coverage in the terahertz band of 6G mobile communication technology; multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO; metamaterial-based lenses and antennas for improving the signal coverage of the terahertz band; high-dimensional spatial multiplexing technologies utilizing OAM (orbital angular momentum) and RIS (reconfigurable smart surface) technologies; and full-duplex technologies for improving the frequency efficiency of 6G mobile communication technology and optimizing system networks, but also lay the foundation for technologies such as: AI-based communication technologies that combine satellite and AI (artificial intelligence) from the design stage to achieve system optimization and have built-in end-to-end AI support functions, and next-generation distributed computing technologies that utilize ultra-high-performance communication and computing resources to achieve service complexity levels beyond the limits of UE computing power. Summary of the Invention

[0008] [Technical Issues]

[0009] According to embodiments of this disclosure, an apparatus and method are provided that can efficiently provide services in a mobile communication system.

[0010] Solution to the problem

[0011] According to embodiments of this disclosure, a method performed by a user equipment (UE) in a wireless communication system includes: receiving a radio resource control (RRC) release message from a base station, the RRC release message including configuration information regarding small data transmission (SDT); upon receiving a paging message containing an SDT indication from the base station, performing an RRC recovery procedure for the SDT based on the configuration information; and, in the event of an SDT failure, sending information indicating the reason for the SDT failure to the base station.

[0012] [Beneficial effects of the invention]

[0013] According to embodiments of this disclosure, an apparatus and method capable of efficiently providing services in a mobile communication system can be provided.

[0014] The beneficial effects achievable by this disclosure are not limited to those described above, and other effects not mentioned herein can be clearly understood by those skilled in the art from the following description. Attached Figure Description

[0015] Figure 1a This diagram illustrates the structure of a mobile communication system according to an embodiment of the present disclosure; Figure 1b This illustrates a wireless access state transition in a mobile communication system according to an embodiment of the present disclosure; Figure 1c A flowchart illustrating a process for reporting information related to establishment or recovery in the event of establishment or recovery failure according to an embodiment of this disclosure; Figure 1d A flowchart illustrating the process of performing a random access (RA) report according to an embodiment of this disclosure; Figure 1e A flowchart illustrating the process of performing MT-SDT operation according to an embodiment of the present disclosure; Figure 1f A flowchart illustrating UE operation of storing information related to MT-SDT operation according to an embodiment of this disclosure; Figure 1g A flowchart illustrating base station operation for storing information related to MT-SDT operation according to embodiments of the present disclosure; Figure 1h A block diagram illustrating the internal structure of a UE according to an embodiment of the present disclosure; Figure 1i A block diagram illustrating the structure of a base station according to an embodiment of the present disclosure. Detailed Implementation

[0016] In the following description of this disclosure, descriptions of known functions or configurations incorporated herein will be omitted where such detailed descriptions would obscure the inventive subject matter. Embodiments of this disclosure will now be described in conjunction with the accompanying drawings.

[0017] Figure 1a The structure of a mobile communication system according to an embodiment is shown.

[0018] Reference Figure 1a According to embodiments of the present disclosure, the radio access network of a mobile communication system (New Radio, NR) may include a next-generation base station (new radio node B, hereinafter referred to as gNB) 1a-10 and an access and mobility management function (AMF) (NR core network) 1a-05. A user terminal (NR user equipment, hereinafter referred to as NR UE or terminal) 1a-15 can access an external network through gNB 1a-10 and AMF 1a-05.

[0019] In this disclosure Figure 1a In this context, gNB can correspond to the evolved Node B (eNB) in a traditional LTE system. For example, gNB can connect to NR UEs via radio channels and provide superior service compared to traditional Node Bs (1a-20). In next-generation mobile communication systems, since all user services are carried through shared channels, a device is needed to collect status information such as UE buffer status, available transmit power status, and channel status, and to perform scheduling accordingly. gNB 1a-10 can undertake the task of collecting UE buffer status, available transmit power status, and channel status and performing scheduling operations.

[0020] According to embodiments, typically one gNB can control multiple cells. To achieve ultra-high-speed data transmission beyond existing LTE systems, next-generation mobile communication systems can support bandwidths wider than the current maximum bandwidth, employing orthogonal frequency division multiplexing (hereinafter referred to as OFDM) as the radio access technology, and additionally using beamforming technology.

[0021] According to an embodiment, the next-generation mobile communication system may employ an adaptive modulation and coding (AMC) scheme to determine the modulation scheme and channel coding rate based on the channel state of the UE.

[0022] According to an embodiment, the AMF 1a-05 can perform functions such as mobility support, bearer configuration, and QoS configuration. For example, in addition to performing mobility management functions for the UE, the AMF is also responsible for various control functions and can connect to multiple base stations.

[0023] According to the embodiment, the next-generation mobile communication system can interoperate with the traditional LTE system, and the AMF 1a-05 can connect to the LTE Mobility Management Entity (MME) 1a-25 via a network interface. This MME connects to the traditional base station, i.e., the eNB 1a-30. UEs supporting LTE-NR dual connectivity (DC) can send / receive data (1a-35) while maintaining connections with both the gNB and eNB.

[0024] Figure 1b This illustrates the wireless access state transition in a next-generation mobile communication system.

[0025] Reference Figure 1b In the next-generation mobile communication system according to embodiments, the UE may have three radio access states (Radio Resource Control (RRC) states). For example, connected mode (or connected state) (RRC_CONNECTED) 1b-05 can be a radio access state in which the UE can send and / or receive data. For example, idle mode (or idle state) (RRC_IDLE) 1b-30 is a radio access state in which the UE monitors for paging messages for itself. The above two modes (such as connected mode and idle mode) are also radio access states applicable in conventional LTE systems, and their technical details can be consistent with conventional LTE systems. In the next-generation mobile communication system, an inactive mode (RRC_INACTIVE) 1b-15 is added as one of the radio access states. For example, in the inactive mode (RRC_INACTIVE) radio access state, the UE context is preserved in both the base station and the UE, and paging based on the Radio Access Network (RAN) is supported. The features of the above new radio access states can be listed as follows: - Cell reselection mobility; - CN (Core Network) - NR RAN connection (to establish C / U plane for UE); - The UE AS (access stratum) context is stored in at least one gNB and the UE; - Paging is initiated by NR RAN; - RAN-based notification areas are managed by NR RAN; - The NR RAN knows the RAN-based notification area to which the UE belongs.

[0026] According to embodiments, the INACTIVE radio access state can use a specified procedure, and the UE can transition from the RRC_INACTIVE state to connected mode or idle mode. The UE can transition from INACTIVE mode to connected mode via a recovery procedure, or via a release procedure including suspended configuration information (1b-10). In the above procedures, the UE and the base station can send and / or receive one or more RRC messages and set one or more steps. Furthermore, the UE can transition from INACTIVE mode to idle mode via a release procedure after the recovery procedure (1b-20). The transition between connected mode and idle mode follows conventional LTE technology. That is, the transition between the above modes (such as RRC_CONNECTED, RRC_INACTIVE, or RRC_IDLE) can be achieved through an establishment or release procedure.

[0027] Figure 1c This is a flowchart illustrating a process for reporting information related to creation or recovery in the event of creation failure or recovery failure, according to an embodiment of this disclosure.

[0028] Reference Figure 1c The report, according to the embodiment, may be called a Connection Establishment Failure (CEF) report.

[0029] According to an embodiment, UE 1c-00 can trigger a connection request in operation 1c-10. In the case of RRSetupRequest or RRCResumeRequest, UE 1c-00 can send an RRCSetupRequest message or an RRCResumeRequest message to the base station and start a T300, T319, or T319a timer depending on whether an establishment, recovery, or recovery procedure with SDT is applied.

[0030] According to an embodiment, if the aforementioned establishment, recovery, or recovery process with SDT fails to complete successfully before the timer (such as timer T300, T319, or T319a) expires, UE 1c-00 may consider or identify the failure of the establishment, recovery, or recovery process with SDT attempted in operation 1c-15. In this case, in operation 1c-20, UE 1c-00 may store preset information and report the stored information to the base station to achieve network optimization (i.e., log information related to establishment or recovery failure).

[0031] According to an embodiment, during the RRC connection establishment or recovery process, UE 1c-00 can execute a random access procedure. The UE can achieve uplink synchronization with the serving cell and send relevant RRC messages through random access. For example, the random access procedure may include a total of four steps or two steps.

[0032] For example, taking a four-step random access procedure as an example, UE 1c-00 can send a random access preamble to the base station in the first step. In the second step, the base station, having received the random access preamble, can send a random access response message. This random access response message may contain synchronization information, scheduling information to be used by UE 1c-00 in the third step, and / or a temporary UE ID value. In the third step, the UE sends msg3, and if a recovery procedure is being performed, this message (such as msg3) may contain an RRC ResumeRequest message. In the fourth step, a contention-based access scheme can be used to complete the random access, and finally, the base station sends a message to the UE indicating that the UE has successfully completed the random access procedure through contention. The random access (RA) procedure is a crucial step in the RRC connection establishment or recovery process. Whether a random access channel (RACH) problem occurs before the T300 timer expires is valuable information for locating the cause of failure.

[0033] According to the embodiment, after a failure, UE 1c-00 can re-trigger the connection request in operation 1c-25. (Connection Request)

[0034] According to the embodiment, in operation 1c-30, UE 1c-00 may send an RRCSetupRequest message or an RRCResumeRequest message to base station 1c-05.

[0035] According to the embodiment, in operation 1c-35, base station 1c-05 may send an RRCSetup message or an RRCResume message to the UE.

[0036] According to an embodiment, in operation 1c-40, if the selected Public Land Mobile Network (PLMN) value stored in UE 1c-00 matches the currently registered PLMN (RPLMN) value, and UE 1c-00 has valid information recorded when RRC connection establishment or recovery fails, UE 1c-00 can trigger the connEstFailInfoAvailable information element (IE). For example, the triggered IE can be an indicator used by UE 1c-00 to inform the base station that it has information (such as valid information recorded when RRC connection establishment or recovery fails).

[0037] According to an embodiment, in operation 1c-45, UE 1c-00 may send an RRCSetupComplete message or an RRCResumeComplete message containing a connEstFailInfoAvailable IE to base station 1c-05. Base station 1c-05 may determine in operation 1c-50 that it needs to receive information (such as valid information recorded when RRC connection establishment or recovery fails) and send a UEInformationRequest message containing a connEstFail-ReportReq IE to the UE.

[0038] For example, the connEstFail-ReportReq IE can be used to request UE 1c-00 report information (such as valid information recorded when RRC connection establishment or recovery fails). For example, the connEstFail-ReportReq IE can be configured to the value "True" and can be included in the UE information request message.

[0039] According to the embodiment, in operation 1c-55, if the selected PLMN value stored in UE 1c-00 matches the current RPLMN value, UE 1c-00 has valid information recorded when RRC connection establishment or recovery fails, and the connEstFail-ReportReq IE received from the base station is configured as "True", then UE 1c-00 can include the recorded information in connEstFail-Report IE.

[0040] According to an embodiment, in operation 1c-60, UE 1c-00 may send a UEInformationResponse message containing a connEstFail-Report IE to base station 1c-05. For example, the base station may use the information in this report for network optimization.

[0041] Figure 1d A flowchart illustrating the process of reporting random access (RA) reports according to an embodiment of this disclosure is provided.

[0042] Reference Figure 1d Although the next-generation mobile communication system, NR, introduced two-step RA technology in Release 16, the RA report in Release 16 could only record and report information related to four-step RA. However, in the RA report of Release 17, not only information related to four-step RA can be recorded and reported, but also information related to two-step RA can be reported.

[0043] According to an embodiment, UE 1d-05 can perform a random access procedure with base station 1d-10 (such as a next-generation node B (gNB)). For example, UE 1d-05 can store preset information (operation 1d-15) related to the most recently successfully completed random access procedure. Subsequently, if the random access procedure is executed again and successfully completed, UE 1d-05 can delete the previously stored information and store the preset information related to the newly executed random access procedure.

[0044] The random access procedure executed within the most recent preset time period can be considered, or the random access procedure executed in the most recent N times. For example, UE 1d-05 can store information related to random access procedures executed in the specified recent period and / or the most recent N times.

[0045] According to an embodiment, depending on the purpose of random access, UE 1d-05 can store not only information related to successful random access procedures but also information related to failed random access procedures. For example, information related to random access procedures can be stored in an abstract syntax markup (ASN.1) structure and reported to base station 1d-10. For example, information related to a successfully completed random access procedure can be stored in the RA-Report IE and reported to base station 1d-10, and the RA-ReportList IE can contain up to 8 RA reports.

[0046] According to an embodiment, a single RA-Report IE (Per-RAInfoList IE) may contain information related to multiple random access attempts in chronological order.

[0047] According to an embodiment, the PerRAInfo IE included in the Per-RAInfoList may include the aforementioned information (such as information related to the random access procedure and information related to the random access attempt) for each synchronization signal block (SSB) or channel state information-reference signal (CSI-RS) used in the random access attempt.

[0048] For example, the PerRAAttemptInfo IE in PerRAAttemptInfoList can contain information about each random access attempt, such as contentionDetected and / or dlRSRPAboveThreshold.

[0049] Table 1 describes the RA report (RA-report). Table 1 is only an example. The information contained in the RA-report may include only a portion of the information shown in Table 1, or it may also include information not shown in Table 1.

[0050] [Table 1]

[0051] According to an embodiment, a UE in idle mode or inactive mode can send an RRCSetupRequest or RRCResumeRequest message to the base station to switch to connected mode (operation 1d-20). Base station 1d-10 can send an RRCSetup or RRCResume message to UE 1d-05 (operation 1d-25), and UE 1d-05 that receives the RRCSetup or RRCResume message can switch to connected mode.

[0052] According to the embodiment, when UE 1d-05 stores random access related information, UE 1d-05 can send an RRCSetupComplete or RRCResumeComplete message (operation 1d-30) to the base station containing an available indicator indicating the existence of random access related information.

[0053] For example, base station 1d-10, which receives this indicator (such as the availability indicator), can request UE1d-05 to report relevant information (such as random access information) via a preset RRC message (operation 1d-35).

[0054] According to an embodiment, upon receiving a report request, UE 1d-05 can send a preset RRC response message (operation 1d-40) containing stored information (such as random access related information) to the base station. For example, RA report information reported to base station 1d-10 can be deleted from UE 1d-05. For example, even if the stored RA report information is not reported to the base station, the UE can delete the information after a specific time.

[0055] Figure 1e A flowchart illustrating the process of performing (MT)SDT operations of a mobile terminal according to an embodiment of the present disclosure.

[0056] Reference Figure 1e In this embodiment, Small Data Transmission (SDT) refers to the technique where, when the amount of data to be transmitted and / or received between base station 1e-10 and UE 1e-05 is small, UE 1e-05 does not need to switch to connected mode (RRC_CONNECTED), but instead remains in inactive mode (RRC_INACTIVE) during the random access procedure, or uses configuration authorization (CG) related technologies to transmit and / or receive small amounts of data.

[0057] Typically, the UE needs to switch to connected mode to send and / or receive data. To switch to connected mode, the base station and UE can exchange preset control messages. Furthermore, to send and / or receive data, base station 1e-10 may need to perform scheduling for UE 1e-05. If the amount of data to be sent and / or received is small, performing the above operations (such as control message exchange and scheduling) may be inefficient. To improve this inefficiency, SDT (Software-Defined Data Transmission) technology can be used.

[0058] According to embodiments, SDT can be divided into Mobile Initiated Small Data Transmission (MO-SDT) and Mobile Termination Small Data Transmission (MT-SDT). For example, MO-SDT is the scheme used when UE 1d-05 sends data to base station 1d-10. That is, MO-SDT is the procedure executed when sending small data in uplink transmission. For example, MT-SDT is the scheme used when the base station sends data to the UE. That is, MT-SDT is the procedure executed when sending small data in downlink transmission. Furthermore, when random access is used for SDT, SDT can be classified as RA-SDT, and if CG is used for SDT, then SDT can be classified as CG-SDT. For example, in MO-SDT and MT-SDT, whether the data volume is small enough to be transmitted through the MO-SDT or MT-SDT procedure can be determined based on the value configured by the base station. For example, in MT-SDT, base station 1e-10 can compare the configured threshold with the data volume to be transmitted, and if the data volume is less than the threshold, it is determined that the data can be transmitted through MT-SDT. For example, in MO-SDT, base station 1e-10 can configure a threshold for UE 1e-05 to determine whether data can be transmitted via MO-SDT. In this case, UE 1e-05 can compare this threshold with the amount of data it needs to transmit. If the amount of data is less than the threshold, it can be determined that the data can be transmitted via MO-SDT.

[0059] According to an embodiment, base station 1e-10 can send configuration information (such as CG-SDT configuration information) applicable to SDT configuration authorization to UE 1e-05 via an RRC message during operation 1e-15. For example, base station 1e-10 can include the CG-SDT configuration information in an RRC message and send it to UE 1e-05. For example, the SDT-Config IE included in the RRC message can contain or include configuration information (such as CG-SDT configuration information) (RRCRelease(SDT-Config: cg-SDT-MaxDurationToNext-CG-Occasion)).

[0060] According to an embodiment, the configuration information described above (such as CG-SDT configuration information) may include a cg-SDT-MaxDurationToNext-CG-Occasion field. For example, this cg-SDT-MaxDurationToNext-CG-Occasion field can be used to determine whether the UE uses RA-SDT or CG-SDT. For example, cg-SDT-MaxDurationToNext-CG-Occasion may indicate at least one of RA-SDT or CG-SDT.

[0061] For example, after the SDT procedure is initialized, if the time interval until the first CG timing is less than the value indicated by a field (such as the cg-SDT-MaxDurationToNext-CG-Occasion field), UE 1e-05 can select or recognize CG-SDT. Otherwise (if the time interval until the first CG timing is greater than or equal to the value indicated by that field after the SDT procedure is initialized), UE 1e-05 can select RA-SDT. This design is to avoid excessive delays in SDT data transmission due to an excessively long time interval between the initialization of the SDT procedure and the first CG timing.

[0062] According to an embodiment, after receiving an RRC Release message in operation 1e-20, UE 1e-05 can switch to inactive mode. For example, UE 1e-05 can receive an RRC Release message from base station 1e-10, and the state of UE 1e-05 changes to inactive mode.

[0063] According to an embodiment, base station 1e-10 may broadcast configuration information (such as RA-SDT configuration information) for random access applicable to SDT to the UE via System Information Block 1 (SIB1) in operation 1e-25. For example, this configuration information (such as random access configuration information) may include the sdt-RSRP-Threshold field. SIB1(mt-SDT-ConfigCommonSIB-r18: sdt-RSRP-Threshold).

[0064] According to an embodiment, the sdt-RSRP-Threshold field can be used to determine whether the UE uses SDT. For example, UE 1e-05 may trigger SDT if the reference received signal power (RSRP) for downlink path loss reference is higher than the value indicated by the sdt-RSRP-Threshold field. For example, UE 1e-05 will not trigger SDT if the RSRP for downlink path loss reference is less than or equal to the value indicated by the sdt-RSRP-Threshold field.

[0065] According to an embodiment, base station 1e-10 may send a paging message containing an mt-SDT indicator to UE 1e-05 in operation 1e-30. For example, the mt-SDT indicator may instruct UE 1e-05 to perform MT-SDT when specified conditions are met. For example, the specified conditions (such as SDT execution conditions) may include a condition that the RSRP value of the received signal is higher than the value indicated by the sdt-RSRP-Threshold field (Paging (mt-SDT)).

[0066] According to an embodiment, a UE 1e-05 receiving a paging message containing an mt-SDT indicator can determine or identify in operation 1e-35 whether the RSRP of the downlink path loss reference is higher than the value indicated by a field (such as the sdt-RSRP-Threshold field). For example, the RSRP of the downlink path loss reference may be the RSRP of a reference signal (such as an SSB).

[0067] If the RSRP is higher than the value indicated by this field, UE 1e-05 may trigger SDT. Otherwise (e.g., if the RSRP is less than or equal to the value indicated by this field), UE 1e-05 may trigger or execute a normal recovery procedure in operation 1e-40. In this case, in operation 1e-45, UE 1e-05 may send an RRCResumeRequest message containing a ResumeCause field indicating mt-Access to base station 1e-10. Simultaneously with sending this message to base station 1e-10, UE 1e-05 may start a T319 timer. If the recovery procedure does not complete successfully before the T319 timer expires, UE 1e-05 may consider or identify the recovery procedure failure. In this embodiment, in the event of a recovery procedure failure, UE 1e-05 stores preset information related to SDT.

[0068] According to an embodiment, if the downlink path loss reference RSRP is higher than the value indicated by a field (such as the sdt-RSRP-Threshold field), UE 1e-05 can initiate the SDT procedure in operation 1e-50 and can determine or identify whether the time interval to the arrival of the first CG timing is less than the value indicated by that field (such as the sdt-RSRP-Threshold field). If the time interval to the first CG timing is less than the value indicated by that field, UE 1e-05 can trigger CG-SDT in operation 1e-55.

[0069] According to the embodiment, otherwise (if the time interval to the first CG timing is greater than or equal to the value indicated by the field), UE 1e-05 may trigger RA-SDT in operation 1e-60.

[0070] According to an embodiment, during the CG-SDT or RA-SDT procedure (or during the execution of the procedure), UE 1e-05 may send an RRC message (such as an RRC ResumeRequest message) containing a ResumeCause field indicating mt-SDT to base station 1e-10 in operation 1e-65.

[0071] According to the embodiment, determining whether the time interval between the initialization of the SDT procedure by UE 1e-05 and the arrival of the first CG timing is less than the value indicated by the field (such as the cg-SDT-MaxDurationToNext-CG-Occasion field) can be understood as substantially equivalent to determining whether UE 1e-05 performs CG-SDT or RA-SDT.

[0072] According to an embodiment, after receiving a message (such as an RRRCResumeRequest message), base station 1e-10 can send a small amount of user data (Dedicated Service Channel (DTCH)) to UE 1e-05 in operation 1e-70. For example, the amount of user data transmitted to UE 1e-05 through the MT-SDT procedure can be determined according to the implementation or configuration of the base station.

[0073] For example, whether the data volume is small enough to be transmitted via MO-SDT or MT-SDT can be determined based on the configuration values ​​of base station 1e-10. For instance, in MT-SDT, base station 1e-10 can compare a configured threshold with the amount of data to be transmitted, and if the data volume is less than the threshold, it can determine that the data can be transmitted via MT-SDT. Similarly, in MO-SDT, base station 1e-10 can configure a threshold for UE 1e-05 to determine whether data can be transmitted via MO-SDT. In this case, UE 1e-05 can compare this threshold with its own amount of data to be transmitted, and if the data volume is less than the threshold, it can determine that the data can be transmitted via MO-SDT.

[0074] According to an embodiment, UE 1e-05 can activate the T319a timer while sending an RRC message (such as an RRC Resume Request message). UE 1e-05 can consider or identify that the triggered SDT procedure cannot continue execution and switch to idle mode if at least one of the following conditions is met; that is, UE 1e-05 can consider or identify the SDT failure: - If, during the execution of the SDT procedure, an indication is received from the Primary Cell Group (MCG) Radio Link Control (RLC) that the maximum number of retransmissions has been reached; - If a random access problem indication is received from the MCG MAC during the execution of the SDT process; - If, during the execution of the SDT procedure, the lower layer indicates that the cg-SDT-TimeAlignmentTimer or configuredGrantTimer expires before receiving a network response for the uplink CG-SDT transmission with a CCCH message; - If an integrity verification failure indication is received from the lower layer during the execution of the SDT process; - Timer T319a expired.

[0075] The feature of this embodiment is that, in the event of SDT failure, UE 1e-05 stores preset information related to SDT. This information stored in UE 1e-05 can be reported to base station 1e-10 through UE information flows (such as UEInformationRequest and UEInformationResponse messages). This information reported to base station 1e-10 can be used by the network to optimize SDT operations.

[0076] Figure 1f A flowchart illustrating UE operation of storing information related to MT-SDT operation according to an embodiment of this disclosure is provided.

[0077] Reference Figure 1f In operation 1f-00, the UE (such as Figure 1e UE 1e-05 in the data can send data to the base station (such as...) Figure 1e The base station (1e-10) reports its own capability information. For example, the UE capability information may include an indicator indicating whether the UE supports MT-SDT, and an indicator indicating whether the UE can store SDT-related information and report it to the base station. For example, the UE capability information may include a first indicator indicating whether MT-SDT is supported and / or a second indicator indicating whether SDT-related information can be reported.

[0078] According to an embodiment, in operation 1f-05, the UE may receive an RRC message (such as an RRC Release message) containing configuration information related to CG-SDT from the base station. For example, the configuration information related to CG-SDT may include the cg-SDT-MaxDurationToNext-CG-Occasion field.

[0079] According to an embodiment, in operation 1f-10, the UE may receive system information (such as SIB1) broadcast by the base station that includes configuration information related to RA-SDT. For example, the configuration information may include the sdt-RSRP-Threshold field (receiving SIB1 with mt-SDT-ConfigCommonSIB).

[0080] According to an embodiment, in operation 1f-15, the UE may receive a paging message containing an mt-SDT indication from the base station.

[0081] According to an embodiment, in operation 1f-20, the UE may determine or identify whether the RSRP of the downlink path loss reference is higher than a value indicated by a field (e.g., the sdt-RSRP-Threshold field). For example, the RSRP of the downlink path loss reference may be the RSRP of a reference signal (e.g., SSB).

[0082] According to an embodiment, in operation 1f-25, if the RSRP referenced for downlink path loss is not higher than the value indicated by this field, the UE may need to switch to connected mode to receive user data, and a recovery procedure for switching to connected mode may be triggered. In this case, the UE can configure the ResumeCause field contained in the RRCResumeRequest message as mt-Access.

[0083] According to the embodiment, in operation 1f-30, if the UE considers the recovery process to have failed based on preset conditions, the UE can store the following SDT-related information. For example, this SDT-related information can be stored as CEF report content: - An indication that the paging message contains an mt-SDT indication but the DL RSRP is not higher than sdt-RSRP-Threshold. For example, this SDT-related information could indicate that a regular recovery procedure corresponding to a ResumeCause value of mt-Access was triggered because the condition associated with sdt-RSRP-Threshold was not met (as shown below, RSRP is higher than this threshold). In other words, this indication that the mt-SDT indication is included in the paging message but the DL RSRP is not higher than sdt-RSRP-Threshold can be used to distinguish between SDT failure and recovery procedure failure. - Configuration value for sdt-RSRP-Threshold.

[0084] According to an embodiment, in operation 1f-35, if the RSRP referenced for downlink path loss is higher than the value indicated by a field (such as sdt-RSRP-Threshold), the UE may initiate a CG-SDT transmission and subsequently determine or identify whether the time interval until the arrival of the first CG timing is less than the value indicated by that field. For example, the initiation of a CG-SDT transmission may refer to receiving a paging message containing an mt-SDT indicator, or the fulfillment of all CG-SDT triggering conditions.

[0085] According to an embodiment, in operation 1f-40, if the time interval between the initiation of the SDT procedure and the arrival of the first CG timing is less than the value indicated by a field (such as the cg-SDT-MaxDurationToNext-CG-Occasion field), the UE may trigger CG-SDT.

[0086] According to an embodiment, in operation 1f-45, if the CG-SDT or the recovery procedure corresponding to the CG-SDT has failed based on preset conditions, the UE may store the following SDT-related information. For example, the following information may be stored as CEF report content: - An indication that a CG-SDT has been triggered for an MT-SDT but there is no SSB configured for the CG-SDT with an SS-RSRP higher than the CG-SDT-RSRP-ThresholdSSB. For example, this indication can be used to indicate a (beam) failure of a CG-SDT triggered for an MT-SDT; - The configuration value for sdt-RSRP-Threshold; - Configuration value for cg-SDT-MaxDurationToNextCG-Occasion; - Configuration value for cg-SDT-RSRP-ThresholdSSB; - SSB selected for CG-SDT; - The time between the initiation of a CG-SDT transmission and the first available CG opportunity for the initial CG-SDT transmission; - The time between receiving a paging request and sending an RRRCResumeRequest; - The time between receiving a paging request and considering or identifying the configured uplink authorization as invalid; - SDT failure reason information, that is, it can store at least one of the following reasons. For example, this information (e.g., SDT failure reason information) can be represented in an enumerated format in ASN.1: ■ Indicate whether an indication indicating that the maximum number of retransmissions has been reached has been received from the MCG RLC layer during the execution of the SDT procedure. ■ Indicator if a random access problem indication is received from the MCG MAC layer during the execution of the SDT procedure. ■ Indicator: During the execution of the SDT procedure, if the lower layer indicates that the cg-SDT-TimeAlignmentTimer or configuredGrantTimer expires before receiving the network response with a CCCH message for UL CG-SDT transmission. ■ Indicator: If an integrity verification failure indication is received from a lower layer during the execution of the SDT process. ■ Indication indicating whether T319a has expired.

[0087] Due to the various reasons mentioned above, the UE may consider the SDT (Signaled Delay Test) to have failed. In this case, the UE can record (or identify) the reason for the SDT failure and report it to the base station subsequently. However, to indicate all the various reasons, the number of bits in the field used to indicate these reasons increases, leading to increased signaling overhead. On the other hand, some of the reasons for SDT failure have an extremely low probability of occurrence, or can be easily inferred by the base station from other relevant information. Reporting such reasons (e.g., reasons with low probability of occurrence, or reasons that can be inferred from other information) to the base station by the UE will only bring limited practical value while increasing signaling overhead. This disclosure proposes that, in the UE's report, for reasons other than the preset important SDT failure reasons that must be explicitly indicated, a preset single coding point can be used to indicate them. For example, when the SDT failure caused by the expiration of the T319a timer is considered an important reason, and other reasons are considered non-important reasons, the field used to indicate the SDT failure can be defined as follows: [Table 2]

[0088] In this case, if the SDT failure is due to the T319a timer expiring, the configuration value is "t319a-Expiry"; and if the SDT failure is caused by a reason other than the T319a timer expiring, the configuration value is "other". Since multiple reasons can correspond to the "other" value, a base station receiving a field configured with "other" may need to use other information to identify the cause of failure in a specific way. In cases where there are other important reasons besides the T319a timer expiring that require separate indication, a new coding point corresponding to that reason needs to be added to the information field described below.

[0089] However, the correspondence between multiple reasons and the "other" value is only an example; a single reason may also correspond to the "other" value.

[0090] According to an embodiment, in operation 1f-50, after initiating the SDT procedure, if the time interval until the first CG timing arrives is not less than the value indicated by a field (such as the cg-SDT-MaxDurationToNext-CG-Occasion field), the UE may trigger RA-SDT.

[0091] According to an embodiment, in operation 1f-55, if a failure of the RA-SDT or the recovery procedure corresponding to the RA-SDT is considered or identified based on preset conditions, the UE may store SDT-related information. For example, this information may be stored as CEF report content or RA report content.

[0092] - The configuration value for sdt-RSRP-Threshold; - Configuration value for cg-SDT-MaxDurationToNextCG-Occasion; - Configuration value for cg-SDT-RSRP-ThresholdSSB; - SSB selected for CG-SDT; - The time between the initiation of a CG-SDT transmission and the first available CG opportunity for the initial CG-SDT transmission; - The time between receiving a paging request and sending an RRRCResumeRequest; - The time between receiving a paging request and considering the configured uplink authorization as invalid; - SDT failure reason information, that is, it can store at least one of the following reasons. For example, this information (such as SDT failure reason information) can be represented in an enumerated format in ASN.1: ■ Indication during SDT process execution: If an indication is received from the MCG RLC layer that the maximum number of retransmissions has been reached. ■ Indicator if a random access problem indication is received from the MCG MAC layer during the execution of the SDT procedure. ■ Indicates that during the execution of the SDT process, the lower layer indicates that the cg-SDT-TimeAlignmentTimer or configuredGrantTimer expires before receiving the network response with CCCH message for UL CG-SDT transmission; ■ Indicator: If an integrity verification failure indication is received from a lower layer during the execution of the SDT process. ■ Indicator to show whether the T319a timer has expired - An indication of whether the RA-SDT process was successful. This indication of whether the RA-SDT process was successful can be provided through the following options (e.g., options 1 through 3): ● Option 1: Explicitly indicate MO-SDT failure and MT-SDT failure in the enumeration type; ● In conjunction with MT-SDT version 18, explicitly indicate MO-SDT failure or MT-SDT failure; ● sdtFailureType-r18: ENUMERATED {mo-SdtFailure, mt-SdtFailure, spare2, spare}; ● Option 2: Do not distinguish between MO-SDT and MT-SDT, and uniformly indicate SDT failure. MT-SDT failure can be identified or determined using the MT-SDT-related information presented in this disclosure. Furthermore, in MO-SDT, dedicated RACH radio resources can be used, while in MT-SDT, dedicated RACH radio resources are not allocated separately. Therefore, the network can determine or identify whether it is MO-SDT or MT-SDT by using the information about the RACH radio resources used stored in the RA report.

[0093] ● Regardless of the SDT type, only indicate SDT failure.

[0094] ● sdtFailure-r18: ENUMERATED {true}

[0095] ● By incorporating any new information related to MT-SDT failures, an implicit distinction between MT-SDT and MO-SDT can be achieved.

[0096] ● Option 3: Explicitly indicate MO-SDT failure and MT-SDT failure through separate corresponding fields.

[0097] ● Individually and independently indicated; ● mo-SdtFailure-r18: ENUMERATED {true}; ● mt-SdtFailure-r18: ENUMERATED {true}.

[0098] According to an embodiment, when random access information related to an action performed due to the fulfillment of RA-SDT triggering conditions is stored in the RA report, the raPurpose field (which is an entry in the RA report content) can indicate that this random access was performed by RA-SDT. For example, a new coding point can be defined as follows: ● Option 1: Define a new coding point indicating that the random access corresponding to the RA report corresponds to the RA-SDT (e.g., Table 3). See the ASN.1 example below.

[0099] [Table 3]

[0100] ● Option 2: Define multiple new coding points to indicate that the random access corresponding to the RA report is MO-SDT or MT-SDT corresponding to the RA-SDT (e.g., Table 4). See the example in ASN.1 below.

[0101] [Table 4]

[0102] ● Option 3: Random access corresponding to the RA report is always indicated by the existing code point accessRelated. Whether the random access corresponds to RA-SDT or MO / MT-SDT can be indicated by a separate field.

[0103] According to an embodiment, at least a portion of the SDT-related information that can be stored by the UE performing the SDT procedure may remain stored even after the SDT procedure has successfully completed. For example, even if the SDT procedure has successfully completed, the SDT-related information may include at least one of the following: the configuration value of sdt-RSRP-Threshold, the configuration value of cg-SDT-MaxDurationToNextCG-Occasion, the configuration value of cg-SDT-RSRP-ThresholdSSB, the SSB selected for CG-SDT, the time between the initiation of CG-SDT transmission and the first available CG timing for the initial CG-SDT transmission, the time between receiving a paging request and sending an RRRCResumeRequest, the time between receiving a paging request and considering the uplink grant invalidity configuration, the reason for SDT failure, and an indicator indicating whether the RA-SDT procedure was successful.

[0104] Figure 1g A flowchart illustrating base station operation for storing information related to MT-SDT operation according to an embodiment of this disclosure is provided.

[0105] Reference Figure 1g In operation 1g-05, the base station (e.g.) Figure 1e The base station 1e-10 in the middle can receive UE (such as Figure 1eThe capability information of UE 1e-05. For example, the capability information may include an indicator indicating whether the UE supports MT-SDT, and an indicator indicating whether the UE can store SDT-related information and report it to the base station. For example, the UE capability information may include a first indicator indicating whether MT-SDT is supported and / or a second indicator indicating whether SDT-related information can be reported.

[0106] According to an embodiment, in Operation 1g-10, the base station may send an RRC message (e.g., an RRC Release message) containing configuration information related to CG-SDT to the UE. For example, the configuration information related to CG-SDT may include the cg-SDT-MaxDurationToNext-CG-Occasion field.

[0107] According to an embodiment, in operation 1g-15, the base station may broadcast system information (e.g., SIB1) containing configuration information related to RA-SDT. For example, the configuration information related to RA-SDT may include the sdt-RSRP-Threshold field (broadcasting SIB1 carrying mt-SDT-ConfigCommonSIB).

[0108] According to an embodiment, in operation 1g-20, the base station may send a paging message containing an mt-SDT indicator to the UE.

[0109] According to an embodiment, in operation 1g-25, the base station can receive from the UE a preset RRC message containing an indicator indicating that the UE itself has stored CEF report and / or RA report content.

[0110] According to an embodiment, in operation 1g-30, the base station may send a UEInformationRequest message to the UE, which requests the UE to report its stored information (such as CEF report, RA report content).

[0111] According to an embodiment, in operation 1g-35, the base station can receive a CEF report or RA report containing information related to SDT from the UE.

[0112] According to an embodiment, in operation 1g-40, the base station may forward received information (e.g., information related to SDT) to the base station or network entity associated with that information, or the base station may use the received information to optimize SDT operation. For example, the base station may adjust the SDT triggering frequency or shorten the latency of data transmission via SDT by adjusting the values ​​of sdt-RSRP-Threshold or cg-SDT-MaxDurationToNext-CG-Occasion related to the SDT triggering conditions, using the received information (e.g., SDT-related information).

[0113] Figure 1h A block diagram illustrating the internal structure of a UE according to an embodiment of the present disclosure.

[0114] Reference Figure 1h UE (e.g.) Figure 1e The UE (1e-05) includes a radio frequency (RF) processor 1h-10, a baseband processor 1h-20, a memory 1h-30, and a controller 1h-40. As another example, the UE may include a transceiver and a controller. In this case, the transceiver may be a component including the RF processor 1h-10 and the baseband processor 1h-20. This disclosure Figure 1h The UE in the middle can be with Figures 1a to 1g The corresponding UE in the text.

[0115] According to an embodiment, the RF processor 1h-10 can perform functions for transmitting / receiving signals via a wireless channel, such as signal band conversion and amplification. For example, the RF processing unit 1h-10 can upconvert a baseband signal provided by the baseband processor 1h-20 into an RF band signal and transmit it through an antenna, and can downconvert an RF band signal received through the antenna into a baseband signal.

[0116] For example, the RF processor 1h-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), and / or an analog-to-digital converter (ADC). Although this disclosure... Figure 1h Only one antenna is shown, but the UE may include multiple antennas. Furthermore, the RF processor 1h-10 may also include multiple RF links. Additionally, the RF processor 1h-10 can perform beamforming. To achieve beamforming, the RF processor 1h-10 can adjust the phase and amplitude of each signal transmitted and / or received through multiple antennas or antenna elements (e.g., phase shifters). Furthermore, the RF processor 1h-10 can perform multiple-input multiple-output (MIMO) operation, and can receive multiple layers when performing this MIMO operation.

[0117] According to an embodiment, the baseband processor 1h-20 can perform the conversion function between baseband signals and bitstreams according to the physical layer specifications of the system. For example, during data transmission, the baseband processor 1h-20 can encode and modulate the transmitted bitstream to generate complex symbols. Furthermore, during data reception, the baseband processor 1h-20 can demodulate and decode the baseband signal provided by the RF processor 1h-10 to recover the received bitstream. For example, when using an Orthogonal Frequency Division Multiplexing (OFDM) scheme, during data transmission, the baseband processor 1h-20 can encode and modulate the transmitted bitstream to generate complex symbols, map the complex symbols to subcarriers, and generate OFDM symbols through inverse Fast Fourier Transform (IFFT) operations and cyclic prefix (CP) insertion. Furthermore, during data reception, the baseband processor 1h-20 can decompose the baseband signal provided by the RF processor 1h-10 into OFDM symbols, recover the signals mapped to subcarriers through Fast Fourier Transform (FFT) operations, and recover the received bitstream through demodulation and decoding.

[0118] According to the embodiments, the baseband processor 1h-20 and the RF processor 1h-10 can transmit and receive signals in the manner described above. Therefore, the baseband processor 1h-20 and the RF processor 1h-10 can be collectively referred to as a transmitter, receiver, transceiver, or communication unit. Furthermore, at least one of the baseband processor 1h-20 and the RF processor 1h-10 may include multiple communication modules to support various wireless access technologies. Additionally, at least one of the baseband processor 1h-20 and the RF processor 1h-10 may include different communication modules to process signals in different frequency bands. For example, the aforementioned different wireless access technologies may include wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. Furthermore, the different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2 GHz) and millimeter wave bands (e.g., 60 GHz).

[0119] According to an embodiment, memory 1h-30 may store basic programs, application programs, and data such as configuration information for UE operation. In particular, memory 1h-30 may store information about a second access node configured to perform wireless communication using a second wireless access technology. Furthermore, memory 1h-30 may provide stored data upon request from controller 1h-40.

[0120] According to an embodiment, controller 1h-40 can control the overall operation of the UE. For example, controller 1h-40 can send and / or receive signals via baseband processor 1h-20 and RF processor 1h-10. Furthermore, controller 1h-40 can write data to or read data from memory 1h-30. For this purpose, controller 1h-40 may include at least one processor. For example, controller 1h-40 may include a communication processor (CP) configured to perform communication control and an application processor (AP) configured to control upper layers such as applications.

[0121] Figure 1i A block diagram illustrating the structure of a base station according to an embodiment of the present disclosure.

[0122] Reference Figure 1i Base stations (e.g.) Figure 1e The base station 1e-10 may include an RF processor 1i-10, a baseband processor 1i-20, a backhaul communication unit 1i-30, a memory 1i-40, and / or a controller 1i-50. As another example, the base station may include a transceiver and a controller. In this case, the transceiver may be a component including the RF processor 1i-10 and the baseband processor 1i-20. This disclosure Figure 1i The base station in the middle can correspond to Figures 1a to 1g Base stations in the region.

[0123] According to an embodiment, the RF processor 1i-10 can perform functions for transmitting and receiving signals via a wireless channel, such as frequency band conversion and amplification of signals. For example, the RF processor 1i-10 can upconvert a baseband signal provided by the baseband processor 1i-20 into an RF band signal and transmit it through an antenna, and can downconvert an RF band signal received through the antenna into a baseband signal.

[0124] For example, the RF processor 1i-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and / or an ADC. Although this disclosure... Figure 1i Only one antenna is shown, but the first access node may include multiple antennas. Furthermore, the RF processor 1i-10 may also include multiple RF links. Additionally, the RF processor 1i-10 can perform beamforming. To achieve beamforming, the RF processor 1i-10 can adjust the phase and amplitude of each signal transmitted and / or received through multiple antennas or antenna elements. The RF processor 1i-10 can transmit one or more data layers to perform downlink MIMO operation.

[0125] According to an embodiment, the baseband processor 1i-20 can perform the conversion function between baseband signals and bitstreams according to the physical layer specification of the first radio access technology. For example, during data transmission, the baseband processor 1i-20 can encode and modulate the transmitted bitstream to generate complex symbols. Furthermore, during data reception, the baseband processor 1i-20 can demodulate and decode the baseband signal provided by the RF processor 1i-10 to recover the received bitstream. For example, when using an OFDM scheme, during data transmission, the baseband processor 1i-20 can encode and modulate the transmitted bitstream to generate complex symbols, map the complex symbols to subcarriers, and generate OFDM symbols through IFFT operations and CP insertion. Furthermore, during data reception, the baseband processor 1i-20 can decompose the baseband signal provided by the RF processor 1i-10 into OFDM symbols, recover the signals mapped to subcarriers through FFT operations, and recover the received bitstream through demodulation and decoding. The baseband processor 1i-20 and the RF processor 1i-10 can transmit and receive signals in the manner described above. Therefore, the baseband processor 1i-20 and the RF processor 1i-10 can be referred to as transmitters, receivers, transceivers, or communication units.

[0126] According to an embodiment, the backhaul communication unit 1i-30 can provide an interface for communication with other nodes within the network. For example, the backhaul communication unit 1i-30 can convert bit streams sent by the primary base station to other nodes (such as secondary base stations, core networks, etc.) into physical signals, and can convert physical signals received from other nodes into bit streams.

[0127] According to an embodiment, memory 1i-40 may store basic programs, applications, and data such as configuration information for the operation of the main base station. In particular, memory 1i-40 may store information about bearers allocated to connected UEs, measurement results reported by connected UEs, etc. Furthermore, memory 1i-40 may store information for determining whether to provide multiple connections to a UE or suspend multiple connections. Additionally, memory 1i-40 may provide the stored data upon request from controller 1i-50.

[0128] According to an embodiment, the controller 1i-50 can control the overall operation of the main base station. For example, the controller 1i-50 can send and / or receive signals via the baseband processor 1i-20 and the RF processor 1i-10 or via the backhaul communication unit 1i-30. Furthermore, the controller 1i-50 can write data to or read data from the memory 1i-40. For this purpose, the controller 1i-50 may include at least one processor.

[0129] The methods disclosed in the claims or the methods described in the embodiments of the specification can be implemented by hardware, software, or a combination of hardware and software.

[0130] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). The one or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within an electronic device. The at least one program includes instructions that cause the electronic device to perform a method according to the embodiments of this disclosure as defined by the appended claims and / or the disclosure herein.

[0131] These programs (software modules or software) can be stored in non-volatile memory including random access memory, flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), disk storage devices, read-only optical discs (CD-ROM), digital versatile optical discs (DVDs) or other types of optical storage devices, and cassette storage. Alternatively, the memory storing the program can be composed of some or all of the above storage media. Furthermore, electronic devices may contain multiple such memories.

[0132] Furthermore, the aforementioned programs can be stored in external storage devices that are accessible to electronic devices via communication networks such as the Internet, intranets, local area networks (LANs), wide area LANs (WLANs), and storage area networks (SANs) or combinations thereof. Such storage devices can access electronic devices via external ports. Simultaneously, independent storage devices on communication networks can also access portable electronic devices.

[0133] In the specific embodiments of this disclosure described in detail above, the elements included in this disclosure are expressed in a singular or plural form according to the illustrated embodiments. However, for ease of description, the singular or plural form may be selected according to the actual scenario, and this disclosure is not limited by the form in which the elements are expressed. Therefore, an element expressed in a plural form may include a single element, or an element expressed in a singular form may include multiple elements.

[0134] The embodiments of this disclosure described and illustrated in the specification and accompanying drawings are merely specific examples provided to facilitate the explanation of the technical content of this disclosure and to aid in understanding it, and are not intended to limit the scope of protection of this disclosure. That is, those skilled in the art will recognize that other modifications can be implemented based on the technical concept of this disclosure. Furthermore, the above embodiments can be combined and implemented as needed. For example, parts of one embodiment of this disclosure can be combined with parts of another embodiment to achieve the operation of a base station and a terminal. In addition, the embodiments of this disclosure can also be applied to other communication systems, and other modifications based on the technical concept of these embodiments can also be implemented.

Claims

1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: Receive a Radio Resource Control (RRC) release message from the base station, the RRC release message including configuration information about Small Data Transmission (SDT); Upon receiving a paging message containing an SDT indication from the base station, an RRC recovery procedure for the SDT is executed based on the configuration information; as well as In the event of a SDT failure, information indicating the reason for the SDT failure is sent to the base station.

2. The method according to claim 1, wherein, The reasons for the SDT failure include the expiration of timers associated with the SDT failure.

3. The method according to claim 1, further comprising: Receive system information block 1 (SIB1) from the base station. SIB1 includes first information related to a threshold used to determine whether a mobile terminal can initiate an MT SDT, and The configuration information includes second information related to the maximum duration until the next configuration authorization CG SDT timing.

4. The method according to claim 3, wherein, The SDT is performed according to the CG-SDT if the Reference Received Power (RSRP) for the downlink DL path loss reference is higher than the value configured based on the first information, and the duration between the initiation of the SDT and the next CG-SDT timing is shorter than the maximum duration configured based on the second information.

5. A method performed by a base station in a wireless communication system, the method comprising: Send a Radio Resource Control (RRC) release message to the User Equipment (UE), the RRC release message including configuration information about Small Data Transmission (SDT); Send a paging message containing an SDT indication to the UE; as well as In the event of an SDT failure based on the configuration information, information indicating the reason for the SDT failure is received from the UE.

6. The method according to claim 5, wherein, The reasons for the SDT failure include the expiration of timers associated with the SDT failure.

7. The method according to claim 5, further comprising: Send System Information Block 1 (SIB1) to the UE. SIB1 includes first information related to a threshold used to determine whether a mobile terminal can initiate an MT SDT, and The configuration information includes second information related to the maximum duration until the next configuration authorization CG SDT timing.

8. The method according to claim 7, wherein, The SDT is performed according to the CG-SDT if the Reference Received Power (RSRP) for the downlink DL path loss reference is higher than the value configured based on the first information, and the duration between the initiation of the SDT and the next CG-SDT timing is shorter than the maximum duration configured based on the second information.

9. A user equipment (UE) in a wireless communication system, the UE comprising: transceiver; as well as The controller is coupled to the transceiver. The controller is configured as follows: Receive a Radio Resource Control (RRC) release message from the base station, the RRC release message including configuration information about Small Data Transmission (SDT); Upon receiving a paging message containing an SDT indication from the base station, an RRC recovery procedure for the SDT is executed based on the configuration information; as well as In the event of a SDT failure, information indicating the reason for the SDT failure is sent to the base station.

10. The UE according to claim 9, wherein, The reasons for the SDT failure include the expiration of timers associated with the SDT failure.

11. The UE according to claim 9, wherein, The controller is also configured to receive system information block 1SIB1 from the base station. SIB1 includes first information related to a threshold used to determine whether a mobile terminal can initiate an MT SDT, and The configuration information includes second information related to the maximum duration until the next configuration authorization CG SDT timing.

12. The UE according to claim 11, wherein, The SDT is performed according to the CG-SDT if the Reference Received Power (RSRP) for the downlink DL path loss reference is higher than the value configured based on the first information, and the duration between the initiation of the SDT and the next CG-SDT timing is shorter than the maximum duration configured based on the second information.

13. A base station in a wireless communication system, the base station comprising: transceiver; as well as The controller is coupled to the transceiver. The controller is configured as follows: Send a Radio Resource Control (RRC) release message to the User Equipment (UE), the RRC release message including configuration information about Small Data Transmission (SDT); Send a paging message containing an SDT indication to the UE; as well as In the event of an SDT failure based on the configuration information, information indicating the reason for the SDT failure is received from the UE.

14. The base station according to claim 13, wherein, The reasons for the SDT failure include the expiration of timers associated with the SDT failure.

15. The base station according to claim 13, wherein, The controller is also configured to: Send System Information Block 1 (SIB1) to the UE. SIB1 includes first information related to a threshold used to determine whether a mobile terminal can initiate an MT SDT. The configuration information includes second information related to the maximum duration until the next configuration authorization CG SDT timing, and Specifically, if the reference received power (RSRP) for downlink path loss (DL) is higher than the value configured based on the first information, and the duration between the initiation of SDT and the next CG-SDT timing is shorter than the maximum duration configured based on the second information, then the SDT is performed according to the CG-SDT.

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