Systems and Methods for Managing Small Data Transmissions

Abstract

A wireless communication method: including: determining small data transmission (SDT) information and performing an SDT process by using the network with the SDT information.

Description

[0001] This application is a divisional application. The application number of the original application is 202180090087.4, and the original application date is January 8, 2021. The entire content of the original application is incorporated herein by reference. Technical Field

[0002] The present disclosure generally relates to wireless communication, and more particularly, to systems and methods for managing small data transmission. Background Art

[0003] Small Data Transmission (SDT) allows a User Equipment (UE) to transmit (periodically and / or aperiodically) data in a Radio Resource Control (RRC) inactive state without migrating to the RRC connected state. SDT can improve UE power consumption and signaling overhead. Summary of the Invention

[0004] Example embodiments disclosed herein are intended to address problems related to one or more problems presented in the prior art and provide additional features, which will become apparent when considered in conjunction with the accompanying drawings and with reference to the following detailed description. According to various embodiments, example systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art reading this disclosure that various modifications can be made to the disclosed embodiments while remaining within the scope of this disclosure.

[0005] In some embodiments, the UE performs a method, which includes: determining SDT information; and performing an SDT process using the network with the SDT information.

[0006] In other embodiments, a Base Station (BS) performs a method, which includes determining SDT information; and performing an SDT process using the UE with the SDT information.

[0007] In other embodiments, a wireless communication device includes: a processor and a memory, wherein the processor is configured to read code from the memory and implement a method including determining SDT information and performing an SDT process using the network with the SDT information.

[0008] In other embodiments, a computer program product includes computer-readable program media code stored thereon that, when executed by a processor, causes the processor to implement a method including determining SDT information and performing an SDT process using the SDT information over a network.

[0009] The above and other aspects and their implementations are described in more detail in the drawings, the description, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various example embodiments of the present solution are described in detail below with reference to the following figures or drawings. The drawings are for illustrative purposes only and depict only example embodiments of the present solution to facilitate understanding by the reader. Therefore, the drawings should not be considered as limiting the breadth, scope, or applicability of the present solution. It should be noted that these drawings are not necessarily drawn to scale for clarity and ease of illustration.

[0011] Figure 1 is a flowchart of a time alignment method according to various embodiments, where maintenance is time-based.

[0012] Figure 2 is a flowchart of a time alignment method according to various embodiments, where maintenance is counter-based.

[0013] Figure 3 is a flowchart of a time alignment method for maintaining timing alignment during small data transmission according to various embodiments.

[0014] Figure 4 is a flowchart of a time alignment method for maintaining timing alignment during small data transmission according to various embodiments.

[0015] Figure 5 is a flowchart of a time alignment method for maintaining timing alignment during small data transmission according to various embodiments.

[0016] Figure 6 is a flowchart of a time alignment method for maintaining timing alignment during small data transmission according to various embodiments.

[0017] Figure 7 is a flowchart of a time alignment method according to various embodiments.

[0018] Figure 8 is a flowchart of a time alignment method according to various embodiments.

[0019] Figure 9 is a flowchart of a beam management method for beam failure detection in small data transmission according to various embodiments.

[0020] Figure 10A is a flowchart showing a method for responding to beam failure according to various embodiments.

[0021] Figure 10B is a flowchart showing a method for responding to beam failure according to various embodiments.

[0022] Figure 10C is a flowchart showing a method for responding to beam failure according to various embodiments.

[0023] Figure 10D is a flowchart showing a method for responding to beam failure according to various embodiments.

[0024] Figure 11 is a flowchart of a method for responding to a radio link failure according to various embodiments.

[0025] Figure 12 is a flowchart of a method for responding to a radio link failure according to various embodiments.

[0026] Figure 13 is a flowchart of a method for responding to a radio link failure according to various embodiments.

[0027] Figure 14 is a flowchart of a method for responding to a radio link failure according to various embodiments.

[0028] Figure 15 is a flowchart of a cell reselection method for cell reselection during small data transmission according to various embodiments.

[0029] Figure 16 is a flowchart of a cell reselection method for cell reselection during small data transmission according to various embodiments.

[0030] Figure 17 is a flowchart of a cell reselection method for cell reselection during small data transmission according to various embodiments.

[0031] Figure 18A is a flowchart showing an example wireless communication method for small data transmission according to various embodiments.

[0032] Figure 18B is a flowchart showing an example wireless communication method for small data transmission according to various embodiments.

[0033] Figure 19A shows a block diagram of an example user equipment according to various embodiments.

[0034] Figure 19BA block diagram showing an example base station according to various embodiments. Detailed implementation

[0035] Various example embodiments of the present solution are described below with reference to the accompanying drawings so that those of ordinary skill in the art can make and use the present solution. It will be obvious to those of ordinary skill in the art that after reading this disclosure, various changes or modifications can be made to the examples described herein without departing from the scope of the present solution. Therefore, the present solution is not limited to the exemplary embodiments and applications described and shown herein. In addition, the specific order or hierarchy of steps in the methods disclosed herein is merely an example method. Based on design preferences, the specific order or hierarchy of steps in the disclosed method or process can be rearranged while remaining within the scope of the present solution. Therefore, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or actions in an example order, and the present solution is not limited to the specific order or hierarchy presented unless otherwise expressly stated.

[0036] Work items in the New Radio (NR) SDT in the RRC inactive state are completed according to one of the following solutions. In the first solution, for the uplink (UL) SDT of the random access channel (RACH)-based scheme (i.e., 2-step RACH and 4-step RACH), the general process is to enable user plane (UP) data transmission of small data packets from the RRC inactive state (e.g., using MSGA or MSG3). The RACH-based scheme enables a flexible payload size larger than the common control channel (CCCH) message size, where the flexible payload size is currently feasible for supporting UP data transmission in the UL for the RRC inactive state for MSGA and MSG3 (when the actual payload size reaches the network configuration), and for the RACH-based solution, allows context acquisition and data forwarding in the RRC inactive state (with or without anchor relocation). In the second solution, UL data is transmitted on preconfigured physical uplink shared channel (PUSCH) resources (i.e., reusing configured grant type 1), and when the time alignment (TA) is valid, the general process is for SDT of the configured grant type 1 resources from the RRC inactive state, and for configuring the configured grant type 1 resources for SDT in the UL in the RRC inactive state.

[0037] The Configured Grant (CG) - based solution is only applicable to the in - cell scenario (i.e., the current cell is the same cell where the UE enters the RRC Inactive state) and requires the TA to be valid at the UE side. However, the RACH - based solution has no usage restrictions. For both CG - based and RACH - based solutions, there are two solutions: RRC - based solution (using RRC signaling, new security key or old security key) and RRC - free solution (not using RRC signaling, old security key).

[0038] For SDT, this document discusses the detailed solutions for each of TA, beam management, Radio Link Failure (RLF), and cell reselection.

[0039] Time alignment

[0040] In the RRC connected state, the gNB (New Generation Node B) is responsible for maintaining the TA to keep the Layer 1 (L1) synchronization. Similarly, when transmitting and receiving data in the RRC Inactive state, the UE needs to maintain UL synchronization. A new TA timer should be introduced for TA maintenance for specific configured - grant - based small - data transmissions in the RRC Inactive state. Further study (FFS) on the procedure, the validity of the TA, and how to handle the expiration of the TA timer. The TA timer is configured together with the CG configuration in the RRC Release message. For the RACH - based solution, the parameters are usually cell - specific and are configured via System Information (SI). For the CG - based solution, the parameters are usually UE - specific and are configured via dedicated RRC signaling. Therefore, there are some differences between the CG - based solution and the RACH - based solution in the TA procedure.

[0041] According to one or more embodiments, the validity of SDT CG resources can be maintained. Figure 1 A flowchart showing Method 100 in the first embodiment, where the maintenance is time - based. As Figure 1As shown, method 100 is executed by the UE. At block 110, method 100 starts, where a timer is defined together with the SDT CG resource. The timer is configured by the RRC for each UE, for each carrier (e.g., UL and Supplementary Uplink (SUL)), or for each CG resource. Subsequently, at block 120, once the UE receives the SDT CG configuration, the UE starts the timer. When the timer expires, at block 130, the UE releases the SDT resources based on the configuration. If the timer is configured for each UE, the UE releases all the SDT CG resources configured in the UE. If the timer is configured for each carrier, the UE releases all the SDT CG resources configured in the carrier. If the timer is configured for each CG resource, the UE releases the SDT CG resource associated with the timer.

[0042] Figure 2 A flowchart showing method 200 in the second embodiment, where the maintenance is counter-based. As Figure 2 As shown, method 200 is executed by the UE. At block 210, method 200 starts, where the UE defines a counter (e.g., N) using the SDT CG resource. The counter is configured by the RRC for each UE, for each carrier (i.e., UL and SUL), or for each CG resource. During the SDT process (i.e., after transmitting the SDT request), when N consecutive CG opportunities are skipped, at block 220, the UE releases the SDT CG resources according to the counter configuration. If the counter is configured for each UE, the UE releases all the SDT CG resources configured in the UE. In this configuration, the CG opportunities can only be counted according to each CG opportunity of the selected CG resource, or according to each CG opportunity of all the CG resources in the UE. If the counter is configured for each carrier, the UE releases all the SDT CG resources configured in the carrier. In this configuration, the CG opportunities can only be counted according to each CG opportunity of the selected CG resource, or according to each CG opportunity of all the CG resources in the current carrier. If the counter is configured for each CG resource, the UE releases the SDT CG resource associated with the counter. In this configuration, the CG opportunities can only be counted according to each CG opportunity of the selected CG resource, or according to each CG opportunity of the CG resource associated with the current counter. In the first embodiment or the second embodiment, the timer and / or the counter are optional. If the timer and / or the counter are not included, the CG resources are valid until the TA timer expires.

[0043] Upon receiving TA configuration for SDT, the UE starts a TA timer for SDT (e.g., timeAlignmentTimerSDT). Before SDT is initiated, when timeAlignmentTimerSDT expires, the UE releases or suspends the SDT CG configuration (i.e., when UL synchronization is obtained again, the UE will resume the SDT CG configuration). However, the current method does not consider maintaining the validity of TA and handling the expiration of the TA timer during SDT. To maintain UL TA, the gNB needs to measure TA and send a Timing Advance Command Medium Access Control–Control Element (MAC-CE) to the UE. When the TA timer expires, the UE will release or suspend the SDT CG configuration. At the same time, the UE enters the IDLE state, initiates an RRC reestablishment / resumption process, or initiates a Random Access (RA) process (e.g., an RA process in the RRC connected state) while still in the RRC inactive state. This is implemented according to various embodiments.

[0044] Figure 3 A flowchart showing a time alignment method 300 in a first embodiment for maintaining TA during SDT (i.e., after transmitting an SDT request) is shown. As Figure 3 shown, method 300 is executed by the MAC entity of the UE. When a Timing Advance Command MAC-CE is received, at step 310, method 300 begins. If TA has been maintained, at block 312, the MAC entity applies the Timing Advance Command, and at block 314, starts (or restarts) the TA timer for SDT. When the TA timer for SDT expires at block 320, at block 322, the MAC entity releases the SDT CG configuration, and at block 324, performs an action when entering RRC idle. Figure 4 A flowchart showing a time alignment method 400 in a second embodiment for maintaining TA during SDT (i.e., after transmitting an SDT request) is shown. As Figure 4 shown, method 400 is executed by the MAC entity of the UE. When a Timing Advance Command MAC-CE is received, at block 410, method 400 begins. If TA has been maintained, at block 412, the MAC entity applies the Timing Advance Command, and at block 414, starts (or restarts) the TA timer for SDT. When the TA timer for SDT expires at block 420, at block 422, the MAC entity releases the SDT CG configuration, and at block 424, starts an RRC reestablishment process. Figure 5A flowchart showing a time alignment method 500 in a third embodiment for maintaining TA during SDT (i.e., after transmitting an SDT request). As Figure 5 shown, method 500 is executed by the MAC entity of the UE. When a timing advance command MAC-CE is received, at block 510, method 500 starts. If TA has been maintained, at block 512, the MAC entity applies the timing advance command, and at block 514, starts (or restarts) the TA timer for SDT. When the TA timer for SDT expires at block 520, at block 522, the MAC entity releases the SDT CG configuration, and at block 524, starts an RRC resume procedure. Figure 6 A flowchart showing a time alignment method 600 in a fourth embodiment for maintaining TA during SDT (i.e., after transmitting an SDT request). As Figure 6 shown, method 600 is executed by the MAC entity. When a timing advance command MAC-CE is received, at block 610, method 600 starts. If TA has been maintained, at block 612, the MAC entity applies the timing advance command, and at block 614, starts (or restarts) the TA timer for SDT. When the TA timer for SDT expires at block 620, at block 622, the MAC entity suspends the SDT CG configuration, and while still in the RRC inactive state, at block 624, initiates a RA procedure to obtain UL synchronization again. In each of these embodiments, when the UE ends the SDT procedure and enters the normal RRC inactive state, the UE continues to maintain the timeAlignmentTimerSDT. When the timeAlignmentTimerSDT expires, the UE will release or suspend the SDT CG configuration.

[0045] In the RACH-based solution, there are two ways to configure TA parameters (e.g., the TA timer is named timeAlignmentTimerSDT_SIB) for RACH-based SDT. In the first way, the TA parameters are broadcast via SI together with the SDT RACH parameters. In the second way, the TA parameters are defined as default TA parameters. Since the UE uses the common SDT RACH resource to initiate SDT, TA maintenance in the RACH-based solution before SDT initiation is unnecessary. When initiating SDT, the UE applies the timing advance command and starts timeAlignmentTimerSDT_SIB upon receiving msg2 / msgB including the timing advance command. During SDT, the gNB needs to measure TA and send a timing advance command MAC-CE to the UE (similar to CG-based SDT). When the TA timer expires, the UE will enter the idle state, initiate an RRC reconstruction / resumption procedure, or initiate an RA procedure while still in the RRC inactive state (e.g., an RA procedure in the RRC connected state) (similar to CG-based SDT). When the UE ends the SDT process and enters the normal RRC inactive state, the UE stops timeAlignmentTimerSDT_SIB.

[0046] If the UE supports both CG-based and RACH-based SDT, and if the network (NW) configures both CG-based and RACH-based resources simultaneously, the UE preferentially uses the CG-based resources to initiate SDT. CG-based SDT requires an association between CG resources and Synchronization Signal Blocks (SSBs). A Synchronization Signal Reference Signal Received Power (SS-RSRP) threshold is configured for SSB selection. If the SS-RSRP of all SSBs associated with the CG resources is below the threshold, the UE can only use the RACH-based resources to initiate SDT. Various embodiments implement how to handle TA in these cases (where the TA timer for CG-based SDT is called timeAlignmentTimerSDT, and the TA timer for RACH-based SDT is called timeAlignmentTimerSDT_SIB).

[0047] Figure 7 is a flowchart showing a time alignment method 700 in the first embodiment. As Figure 7As shown in . If the UE supports CG-based and RACH-based SDT, and if the NW can configure CG-based and / or RACH-based SDT, then method 700 is performed by the UE. When the UE receives the RACH configuration for SDT, at block 710, method 700 begins. At block 720, the UE receives the CG configuration for SDT, where the UE stores the CG configuration for SDT and then, at block 722, starts timeAlignmentTimerSDT. If either timeAlignmentTimerSDT or timeAlignmentTimerSDT_SIB expires, then at block 730, the UE releases the SDT CG configuration, and at block 732, the UE releases the parameter timeAlignmentTimerSDT (if it exists). In some embodiments, at block 740, the UE initiates CG-based SDT and, at block 742, continues to use timeAlignmentTimerSDT. In other embodiments, at block 750, the UE initiates RACH-based SDT, at block 752, receives the timing advance command in msg2 or msgB, and at block 754, applies the timing advance command. From here, at block 760, if timeAlignmentTimerSDT is running and one or more of the following are started, the UE also stops timeAlignmentTimerSDT: 1) at block 762, timeAlignmentTimerSDT_SIB; 2) at block 764, timeAlignmentTimerSDT (if it exists, otherwise timeAlignmentTimerSDT_SIB); 3) at block 766, whichever of timeAlignmentTimerSDT_SIB and timeAlignmentTimerSDT (if it exists, otherwise timeAlignmentTimerSDT_SIB) is longer; or 4) at block 768, whichever of timeAlignmentTimerSDT_SIB and timeAlignmentTimerSDT (if it exists, otherwise timeAlignmentTimerSDT_SIB) is shorter. Blocks 740 through 742 and blocks 750 through 768 can be executed in any order such that in some embodiments, blocks 740 through 742 are executed before blocks 750 through 768, and in other embodiments, blocks 750 through 768 are executed before blocks 740 through 742. From here, at block 770, if the UE does not reselect another cell, the UE determines whether the CG resources are valid in response to determining that the SDT procedure has ended.From here, at block 772, if the CG resource is valid, then at block 774, the UE maintains the TA timer, otherwise at block 776, the TA timer is stopped. Alternatively, at block 770, if the UE reselects another cell, then at block 778, the UE stops the TA timer (if it is running) and if the UE stops the TA timer occurs, then at block 780, the SDT CG configuration and the parameter timeAlignmentTimerSDT are released / suspended.

[0048] Figure 8 is a flowchart showing the time alignment method 800 in the second embodiment. As Figure 8As shown in [figure reference], if the UE supports SDT based on both CG and RACH, and if the NW can configure SDT based on CG and / or RACH, then method 800 is performed by the UE. When the UE receives the RACH configuration for SDT, at block 810, method 800 begins. At block 820, the UE receives the CG configuration for SDT, where the UE stores the CG configuration for SDT and then, at block 822, starts timeAlignmentTimerSDT. If timeAlignmentTimerSDT or timeAlignmentTimerSDT_SIB expires, then at block 830, the UE suspends the SDT CG configuration and at block 832, suspends the parameter timeAlignmentTimerSDT (if it exists). Then, in some embodiments, at block 840, the UE initiates SDT based on CG and, at block 842, continues to use timeAlignmentTimerSDT. In other embodiments, at block 850, the UE initiates SDT based on RACH, at block 852, receives the timing advance command in msg2 or msgB, and at block 854, applies the timing advance command. From here, in an example where the SDT CG configuration is suspended, at block 858, the UE resumes the SDT CG configuration and the parameter timeAlignmentTimerSDT. Then, at block 860, the UE stops timeAlignmentTimerSDT and starts one or more of the following: 1) at block 862, timeAlignmentTimerSDT_SIB; 2) at block 864, timeAlignmentTimerSDT (if it exists, otherwise timeAlignmentTimerSDT_SIB); 3) at block 866, the longer of timeAlignmentTimerSDT_SIB and timeAlignmentTimerSDT (if it exists, otherwise timeAlignmentTimerSDT_SIB); or 4) at block 868, the shorter of timeAlignmentTimerSDT_SIB and timeAlignmentTimerSDT (if it exists, otherwise timeAlignmentTimerSDT_SIB). Blocks 840 through 842 and blocks 850 through 868 can be executed in any order such that in some embodiments, blocks 840 through 842 are executed before blocks 850 through 868, while in other embodiments, blocks 850 through 868 are executed before blocks 840 through 842. From here, if the UE does not reselect a cell, then at block 872, in response to determining that the SDT procedure has ended, the UE determines whether the CG resources are valid.If the CG resource is valid at block 872, then at block 874, the UE maintains the TA timer, otherwise at block 876, the UE stops the TA timer. Alternatively, at block 870, if the UE reselects another cell, then at block 878, the UE stops the TA timer (if it is running), and if the UE stopping the TA timer occurs, then at block 880, the SDT CG configuration and the parameter timeAlignmentTimerSDT are released / suspended.

[0049] Beam management

[0050] Since NR is a multi-antenna communication system, beam management is a basic function in NR. From the perspective of RAN2: CG-based SDT requires an association between the CG resource and the SSB. For RAN1, how to configure or provide the association to the UE still needs further study. A liaison statement (LS) is sent to RAN1 to start a discussion on how to establish the association. One option that mentions the considerations of RAN2 is to use the RRC release message for explicit configuration.

[0051] For the CG-based solution, the configuration of the parameters can be given as an association between the SSB and the CG resource explicitly configured via the RRC release message. The current method provides two configuration methods: associating one CG resource to one SSB, or associating one CG timing of one CG resource to one SSB. However, further details of the configuration still need further study.

[0052] In one embodiment, the configuration needs to implicitly associate one CG resource to one SSB by configuring N CG resources, or explicitly associate one CG resource to one SSB by configuring an SSB index in one CG resource. Here, the CG resources can be configured through a list (e.g., SDTConfiguredGrantConfigToAddModList-r17), where N is equal to the number of actually transmitted SSBs determined by ssb-PositionsInBurst. The first entry on the list corresponds to the first SSB transmitted according to ssb-PositionsInBurst, the second entry in the list corresponds to the second SSB transmitted according to ssb-PositionsInBurst, and so on.

[0053] In another embodiment, configuring is required to implicitly associate a CG timing of a CG resource to an SSB by assuming that the number of actually transmitted SSBs determined by ssb - PositionsInBurst is equal to N, or to explicitly associate a CG timing of a CG resource to an SSB by configuring M SSB indices in a CG resource (configured by a list (e.g., SDTConfiguredGrantConfigToAddModList - r17)). Here, starting from the first CG timing of the CG resource, every N consecutive CG timings in a CG resource correspond to N SSBs. The first CG timing in every N consecutive CG timings corresponds to the first SSB transmitted according to ssb - PositionsInBurst, the second CG timing in every N consecutive CG timings corresponds to the second SSB transmitted according to ssb - PositionsInBurst, and so on. In addition, starting from the first CG timing of the CG resource, every M consecutive CG timings in a CG resource correspond to M SSBs. The first CG timing in every M consecutive CG timings corresponds to the first entry of the SSB - IndexList, the second CG timing in every M consecutive CG timings corresponds to the second entry of the SSB - IndexList, and so on. For any embodiment, the gNB needs to configure the parameters for beam failure detection and beam failure recovery via an RRC release with a pending configuration on the same bandwidth part (BWP) where the CG resource is configured. Optionally, the gNB may configure the transmission configuration indicator (TCI) state for the physical downlink control channel (Physical Downlink Control Channel, PDCCH) and configure the physical downlink shared channel (Physical Downlink Shared Channel, PDSCH) for SDT.

[0054] In some examples, for beam failure detection, the gNB configures the UE with a beam failure detection reference signal (SSB or Channel State Information Reference Signal (CSI - RS)), and the UE declares a beam failure when the number of beam failure instances indicated from the physical layer reaches a configured threshold before the expiration of a configured timer. Figure 9 A flowchart of a beam management method 900 for beam failure detection in SDT according to an example embodiment is shown. As Figure 9As shown, method 900 is executed by the MAC entity of the UE. At block 910, method 900 starts, where a beam selected by the CG is used. Then, during SDT (i.e., after transmitting the SDT request), at block 920, the UE receives a beam failure instance indication from the lower layer. From here, the MAC entity of the UE starts (or restarts) a beam-related timer (e.g., beamFailureDetectionTimerSDT), and at block 924, increments a beam-related counter (e.g., BFI-COUNTERSDT) by 1. Finally, at block 930, if the counter is greater than or equal to a threshold (e.g., BFI-COUNTER SDT > beamFailurelnstanceMaxCountSDT), then at block 932, the UE determines that a beam failure has occurred. In parallel operation, at block 940, if beamFailureDetectionTimerSDT expires, or at block 942, if beamFailureDetectionTimerSDT, beamFailurelnstanceMaxCountSDT, or any reference signal for beam failure detection is reconfigured by the higher layer, then at block 944, the UE sets BFI-COUNTER SDT to 0.

[0055] According to various embodiments, beam failure recovery (BFR) can be completed in SDT. Figure 10A is a flowchart showing a method 1000a for responding to a beam failure according to a first embodiment. As Figure 10A shown, method 1000a is executed by the UE. At block 1010, method 1000a starts, where the UE detects a beam failure. At block 1012, the UE releases the SDT CG configuration, and at block 1014, performs an action when entering the RRC idle state. Figure 10B is a flowchart showing a method 1000b for responding to a beam failure according to a second embodiment. As Figure 10B shown, method 1000b is executed by the UE. At block 1020, method 1000b starts, where the UE detects a beam failure. At block 1022, the UE releases the SDT CG configuration, and at block 1024, initiates an RRC reconstruction process. Figure 10C is a flowchart showing a method 1000c for responding to a beam failure according to a third embodiment. As Figure 10CAs shown in [Figure 0], method 1000c is executed by the UE. At block 1030, method 1000c starts, where the UE detects a beam failure. At block 1032, the UE releases the SDT CG configuration, and at block 1034, initiates an RRC resume procedure. Figure 10D is a flowchart showing method 1000d for responding to a beam failure according to a fourth embodiment. As Figure 10D shown in [Figure 0], method 1000d is executed by the UE. At block 1040, method 1000d starts, where the UE detects a beam failure. At block 1042, the UE suspends the SDT CG configuration, and at block 1044, initiates a RA procedure to resume the beam that is still in the RRC inactive state.

[0056] In the RACH-based scheme, since the UE uses common resources to initiate SDT, due to the simplicity of the common resources, beam failure detection and beam failure recovery are not supported.

[0057] Radio link failure

[0058] In RRC connection, the UE performs Radio Link Monitoring (RLM) in the active BWP based on reference signals (SSB or CSI-RS) and a signal quality threshold configured by the NW. The UE performs RLM and RLF-related processing for SDT. For the CG-based scheme, the gNB configures RLM-related parameters (e.g., RadioLinkMonitoringConfigforSDT) for SDT via an RRC release with a suspended configuration on the same BWP where CG resources are configured. When the UE initiates an SDT request, the UE starts a timer (e.g., SDT_Timer) and enters the SDT process. During SDT, when "out-of-sync" and "in-sync" indications are received from the lower layer, there are two ways to handle such indications. In the first method, when Nxxx consecutive "out-of-sync" indications are received from the lower layer while the SDT_Timer is not running, the UE starts a timer (e.g., Txxx). When Nyyy consecutive "in-sync" indications are received from the lower layer while Txxx is running, the UE stops timer Txxx. When Txxx expires, the UE declares RLF. In the second method, when Nxxx consecutive "out-of-sync" indications are received from the lower layer (regardless of the state of the SDT_Timer), the UE starts a timer (e.g., Txxx). When Nyyy consecutive "in-sync" indications are received from the lower layer while Txxx is running, the UE stops timer Txxx. When Txxx expires, the UE declares RLF. In either method, Nxxx, Nyyy, and Txxx are newly introduced for SDT, or parameters (e.g., N310, N311, and T310) can be reused.

[0059] When one or more of the following criteria are met, the UE declares RLF during SDT: 1) The radio problem timer (e.g., Txxx) expires; 2) The RA procedure fails; or 3) The RLC fails. According to various embodiments, when RLF is declared during SDT, the UE processes the RLF. Figure 11 is a flowchart showing a method 1100 for responding to RLF according to a first embodiment. As Figure 11 shown, method 1100 is executed by the UE. At block 1105, method 1100 begins, where the UE declares RLF. At block 1110, method 1100 continues, where the UE determines whether the SDT_Timer is running after declaring RLF during SDT (i.e., after transmitting the SDT request). If the timer is running, at block 1120, the UE ignores the RLF. If the timer is not running, at block 1130, the UE releases the SDT CG configuration, and at block 1140, performs an action when entering RRC idle. Figure 12 is a flowchart showing a method 1200 for responding to RLF according to a second embodiment. As Figure 12 shown, method 1200 is executed by the UE. At block 1205, method 1200 begins, where the UE declares RLF. At block 1210, method 1200 continues, and the UE determines whether the SDT_Timer is running after declaring RLF during SDT (i.e., after transmitting the SDT request). If the timer is running, at block 1220, the UE ignores the RLF. If the timer is not running, at 1230, the UE releases the SDT CG configuration, and at block 1240, initiates an RRC reestablishment procedure. Figure 13 is a flowchart showing a method 1300 for responding to RLF according to a third embodiment. As Figure 13 shown, method 1300 is executed by the UE. At block 1305, method 1300 begins, where the UE declares RLF. At block 1310, method 1300 continues, where at block 1320, the UE releases the SDT CG configuration and performs an action when entering RRC idle. Figure 14 is a flowchart showing a method 1400 for responding to RLF according to a fourth embodiment. As Figure 14 shown, method 1400 is executed by the UE. At block 1405, method 1400 begins, where the UE declares RLF. At block 1410, method 1400 continues, where at block 1420, the UE releases the SDT CG configuration and initiates an RRC reestablishment procedure.

[0060] For a RACH-based solution, since the UE uses common resources to initiate SDT, due to the simplicity of the common resources, RLM is not supported, so the gNB does not configure RLM parameters for RACH-based SDT. However, even if the UE does not support RLM, the UE may support RLF-related processing. During SDT, when there is a RA procedure failure or an RLC failure, the UE declares RLF. When RLF is declared during SDT, according to various embodiments, the UE processes the RLF. In the first embodiment, after RLF is declared during SDT, if the SDT_Timer is running, the UE ignores the RLF, or otherwise releases the SDT CG configuration (if configured), and performs an action when entering RRC idle. In the second embodiment, after RLF is declared during SDT, if the SDT timer is running, the UE ignores the SDT_Timer, or otherwise releases the SDT CG configuration (if configured), and initiates an RRC reestablishment procedure. In the third embodiment, after RLF is declared during SDT, the UE releases the SDT CG configuration (if configured) and performs an action when entering RRC idle. In the fourth embodiment, after RLF is declared during SDT, the UE releases the SDT CG configuration (if configured) and initiates an RRC reestablishment procedure.

[0061] Cell reselection

[0062] When the UE initiates an SDT request, the UE starts a timer (e.g., SDT_Timer) and enters the SDT process. The UE may move to another cell during SDT, so the UE may need to perform measurements and evaluations related to cell reselection. When the UE moves to another cell during SDT, the UE may take actions according to various embodiments. Figure 15 A flowchart of a method 1500 for cell reselection according to the first embodiment is shown, where cell reselection occurs during SDT. As Figure 15 shown, the method 1500 is executed by the UE. At block 1505, the method starts, where the UE determines that cell reselection is occurring. At block 1510, the method 1500 continues, where the UE releases the SDT CG configuration (if configured). Then, at block 1520, the UE determines whether the SDT timer is running. If the timer is running, at block 1530, the UE performs an action when entering RRC idle, or if the timer is not running, at block 1540, an RRC reestablishment procedure is initiated. Figure 16 A flowchart of a method 1600 for cell reselection according to the second embodiment is shown, where cell reselection occurs during SDT. As Figure 16As shown, method 1600 is executed by the UE. At block 1605, the method starts where the UE determines that cell reselection is occurring. At block 1610, method 1600 continues where the UE releases the SDT CG configuration (if configured). Then, at block 1620, the UE determines whether the SDT_Timer is running. If the timer is running, at block 1630, the UE performs an action when entering RRC idle, or if the timer is not running, at block 1640, the UE initiates a new SDT request in the target cell (if the target cell supports SDT). Figure 17 A flowchart showing a method 1700 for cell reselection according to a third embodiment, where cell reselection occurs during SDT. As Figure 17 shown, method 1700 is executed by the UE. At block 1705, the method starts where the UE determines that cell reselection is occurring. At block 1710, method 1700 continues where the UE determines whether the SDT timer is running. If the timer is running, at block 1720, the UE releases the SDT CG configuration (if configured), and at block 1730, performs an action when entering RRC idle. If the timer is not running, at block 1740, the UE suspends the SDT CG configuration (if configured) (i.e., when returning to the previous cell and regaining UL synchronization, the UE will resume the SDT CG configuration), and at block 1750, initiates a new SDT request in the target cell (if the target cell supports SDT).

[0063] In a fourth embodiment, if cell reselection occurs during SDT, the UE releases the SDT CG configuration (if configured) and performs an action when entering RRC idle. In a fifth embodiment, if cell reselection occurs during SDT, the UE releases the SDT CG configuration (if configured) and initiates an RRC reconstruction procedure. In a sixth embodiment, if cell reselection occurs during SDT, the UE releases the SDT CG configuration (if configured), and initiates a new SDT request in the target cell (if the target cell supports SDT). In a seventh embodiment, if cell reselection occurs during SDT, the UE suspends the SDT CG configuration (if configured) (i.e., when returning to the previous cell and regaining UL synchronization, the UE resumes the SDT CG configuration), and initiates a new SDT request in the target cell (if the target cell supports SDT).

[0064] For each of the second, third, sixth, and seventh embodiments, if the UE initiates a new SDT request in the target cell, due to the security consideration of the UE reusing the NextHopChainingCount (NCC) configured in the previous RRC release for the target cell, the UE needs to limit the reuse count of the NCC. To solve this problem, the UE can configure the reuse count of the NCC in the RRC release or define a default count.

[0065] Figure 18A FIG. is a flowchart illustrating an example wireless communication method 1800a according to various arrangements. Method 1800a may be performed by a UE and begins at block 1810, where the UE determines SDT information. At block 1820, the UE performs an SDT procedure using the SDT information with the network.

[0066] Figure 18B FIG. is a flowchart illustrating an example wireless communication method 1800b according to various arrangements. Method 1800b may be performed by a network (e.g., a BS) and begins at block 1830, where the network determines SDT information. At block 1840, the network performs an SDT procedure using the SDT information with the UE.

[0067] Figure 19A FIG. shows a block diagram of an example UE 1901 according to some embodiments of the present disclosure. Figure 19B FIG. shows a block diagram of an example BS 1902 according to some embodiments of the present disclosure. The UE 1901 (e.g., a wireless communication device, a terminal, a mobile device, a mobile user, etc.) is an exemplary implementation of the UE described herein, and the BS 1902 is an exemplary implementation of the BS described herein.

[0068] The BS 1902 and the UE 1901 may include components and elements configured to support known or traditional operating features that are not required to be described in detail herein. In one illustrative implementation, the BS 1902 and the UE 1901 may be used to transmit (e.g., transmit and receive) data symbols in the wireless communication environment as described above. For example, the BS 1902 may be a BS (e.g., a gNB, an eNB, etc.), a server, a node, or any suitable computing device for implementing various network functions.

[0069] BS1902 includes a BS transceiver module 1910, a BS antenna 1912, a BS processor module 1914, a BS memory module 1916, and a network communication module 1918. The BS transceiver module 1910, the BS antenna 1912, the BS processor module 1914, the BS memory module 1916, and the network communication module 1918 are operably coupled and interconnected with each other via a data communication bus 1920. The UE 1901 includes a UE transceiver module 1930, a UE antenna 1932, a UE memory module 1934, and a UE processor module 1936. The UE transceiver module 1930, the UE antenna 1932, the UE memory module 1934, and the UE processor module 1936 are operably coupled and interconnected with each other via a data communication bus 1940. BS1902 communicates with the UE 1901 or another BS via a communication channel, where the communication channel can be any wireless channel or other medium suitable for data transmission described herein.

[0070] As will be understood by those of ordinary skill in the art, BS1902 and the UE 1901 may also include any number of modules other than Figure 19A and Figure 19B the modules shown. The various illustrative blocks, modules, circuits, and processing logics described in connection with the embodiments disclosed herein can be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To illustrate this interchangeability and compatibility of hardware, firmware, and software, the various illustrative components, blocks, modules, circuits, and steps are generally described in terms of their functionality. Whether this functionality is implemented as hardware, firmware, or software depends on the particular application and the design constraints imposed on the overall system. The embodiments described herein can be implemented in a suitable manner for each particular application, but any implementation decision should not be construed as limiting the scope of the present disclosure.

[0071] According to some embodiments, the UE transceiver module 1930 includes a Radio Frequency (RF) transmitter and an RF receiver, where the RF transmitter and the RF receiver each include circuitry coupled to the UE antenna 1932. A duplex switch (not shown) may alternatively couple the RF transmitter or the RF receiver to the antenna in a time-division duplex manner. Similarly, according to some embodiments, the BS transceiver module 1910 includes an RF transmitter and an RF receiver, where the RF transmitter and the RF receiver each have circuitry coupled to the BS antenna 1912 or an antenna of another BS. The duplex switch may alternatively couple the RF transmitter or the RF receiver to the BS antenna 1912 in a time-division duplex manner. The operations of the two BS transceiver modules 1910 and the UE transceiver module 1930 may be coordinated in time such that the receiver circuitry is coupled to the UE antenna 1932 to receive transmissions over a wireless transmission link while the transmitter is coupled to the BS antenna 1912. In some embodiments, there is tight time synchronization with a minimum guard time between changes in the duplex direction.

[0072] The UE transceiver module 1930 and the BS transceiver module 1910 are configured to communicate via a wireless data communication link and cooperate with a suitably configured RF antenna arrangement 1912 / 1932 that can support a specific wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver module 1930 and the BS transceiver module 1910 are configured to support industry standards such as Long Term Evolution (LTE) and emerging 5G (5th Generation) standards. However, it should be understood that the present disclosure is not necessarily limited to specific standards and related protocols in its application. Instead, the UE transceiver module 1930 and the BS transceiver module 1910 may be configured to support alternative or additional wireless data communication protocols including their future standards or variants.

[0073] The BS transceiver module 1910 and the transceiver of another BS (such as but not limited to the module transceiver 1910 module) are configured to communicate via a wireless data communication link and cooperate with a suitably configured RF antenna arrangement that can support a specific wireless communication protocol and modulation scheme. In some illustrative embodiments, the BS transceiver module 1910 and the transceiver of another BS are configured to support industry standards such as LTE and emerging 5G standards. However, it should be understood that the present disclosure is not necessarily limited to specific standards and related protocols in its application. Instead, the BS transceiver module 1910 and the transceiver of another BS may be configured to support alternative or additional wireless data communication protocols including their future standards or variants.

[0074] According to various embodiments, BS1902 may be a BS such as, by way of example but not limited to, an eNB (Evolved Node B), serving eNB, target eNB, femtocell, or picocell. BS1902 may be an RN (Relay Node), DeNB (Donor evolved Node B), or gNB. In some embodiments, UE 1901 may be embodied in various types of user equipment (such as mobile phones, smartphones, personal digital assistants (PDAs), tablet computers, laptop computers, wearable computing devices, etc.). The BS processor module 1914 and the UE processor module 1936 may be implemented or realized by: a general-purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, which is designed to perform the functions described herein. In this way, the processor may be implemented as a microprocessor, a controller, a microcontroller, a state machine, or the like. The processor may also be implemented as a combination of computing devices, for example, multiple microprocessors, one or more microprocessors in combination with a digital signal processor core, a combination of a digital signal processor and a microprocessor, or any other such configuration.

[0075] In addition, the methods or algorithms disclosed herein can be directly embodied in hardware, firmware, software modules executed by BS processor module 1914 and UE processor module 1936 respectively, or in any practical combination thereof. BS memory module 1916 and UE memory module 1934 can be implemented as RAM (Random Access Memory) memory, flash memory, ROM (Read Only Memory) memory, EPROM (Erasable Programmable Read Only Memory) memory, EEPROM (Electrically Erasable Programmable Read Only Memory) memory, registers, hard disks, removable disks, CD-ROM (Compact Disc Programmable Read Only Memory), or any other form of storage medium known in the art. In this regard, BS memory module 1916 and UE memory module 1934 can be coupled to BS processor module 1914 and UE processor module 1936 respectively, such that BS processor module 1914 and UE processor module 1936 can read information from and write information to BS memory module 1916 and UE memory module 1934 respectively. BS memory module 1916 and UE memory module 1934 can also be integrated into their respective BS processor module 1914 and UE processor module 1936. In some embodiments, BS memory module 1916 and UE memory module 1934 can each include a cache memory for storing temporary variables or other intermediate information during the execution of instructions executed by BS processor module 1914 and UE processor module 1936 respectively. BS memory module 1916 and UE memory module 1934 can also each include a non-volatile memory for storing instructions executed by BS processor module 1914 and UE processor module 1936 respectively.

[0076] The network communication module 1918 generally represents the hardware, software, firmware, processing logic, and / or other components of the BS 1902 that enable two-way communication between the BS transceiver module 1910 and other network components and communication nodes that communicate with the BS 1902. For example, the network communication module 1918 can be configured to support Internet or WiMAX (World Interoperability for Microwave Access) traffic. In a deployment, but not limited to, the network communication module 1918 provides a 502.3 Ethernet interface such that the BS transceiver module 1910 can communicate with a traditional Ethernet-based computer network. In this manner, the network communication module 1918 can include a physical interface for connecting to a computer network (e.g., a Mobile Switching Center (MSC)). In some embodiments, the network communication module 1918 includes an optical fiber transmission connection configured to connect the BS 1902 to a core network. As used herein, the terms "configured to," "configured for," and their combinations with respect to a specified operation or function refer to a device, component, circuit, structure, machine, signal, etc. that is physically constructed, programmed, formatted, and / or arranged to perform the specified operation or function.

[0077] Although various embodiments of the present solution have been described above, it should be understood that they are presented by way of example only and not by way of limitation. Similarly, the various figures may depict example architectures or configurations, where these figures are provided to enable a person of ordinary skill in the art to understand the example features and functions of the present solution. However, these persons will understand that the solution is not limited to the example architectures or configurations shown, but rather can be implemented using various alternative architectures and configurations. In addition, as will be understood by a person of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments.

[0078] It should also be understood that any reference to elements using names such as "first," "second," etc. generally does not limit the number or order of these elements. Instead, these names are used herein as a convenient method for distinguishing between two or more elements or instances of an element. Thus, the reference to a first element and a second element does not mean that only two elements can be used, or that the first element must somehow precede the second element.

[0079] In addition, those of ordinary skill in the art will understand that any technique or technology in a variety of different techniques and skills can be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, and symbols, which may be referred to in the above description, can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0080] Those of ordinary skill in the art will further understand that any of the various illustrative logic blocks, modules, processors, devices, circuits, methods, and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital implementations, analog implementations, or combinations of both), firmware, various forms of programs or design code incorporating instructions (where, for convenience, may be referred to herein as "software" or "software modules"), or any combination of these technologies. To clearly illustrate this interchangeability of hardware, firmware, and software, the various illustrative components, blocks, modules, circuits, and steps have been described above in terms of their functionality. Whether the described functionality is implemented as hardware, firmware, software, or a combination of these technologies depends on the particular application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in various ways for each particular application, but such implementation decisions will not result in a departure from the scope of the present disclosure.

[0081] In addition, those of ordinary skill in the art will understand that the various illustrative logic blocks, modules, devices, components, and circuits described herein can be implemented within or executed by an integrated circuit (IC), where the IC may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, or any combination thereof. The logic blocks, modules, and circuits may also include antennas and / or transceivers to communicate with various components within a network or within a device. The general-purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., multiple microprocessors, one or more microprocessors in combination with a DSP core, a combination of a DSP and a microprocessor, or any other suitable configuration for performing the functions described herein.

[0082] If these functions are implemented in software, these functions can be stored as one or more instructions or codes on a computer-readable medium. Accordingly, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium. The computer-readable medium includes both computer storage media and communication media, where the communication media includes any medium that can transfer a computer program or code from one place to another. The storage media can be any available medium accessible by a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0083] In this document, the term "module" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the related functions described herein. Additionally, for purposes of discussion, the various modules are described as discrete modules; however, it will be apparent to one of ordinary skill in the art that, in accordance with embodiments of the present solution, two or more modules can be combined to form a single module that performs related functions.

[0084] Furthermore, a memory or other memory and communication components can be employed in embodiments of the present solution. It should be understood that, for clarity, the above description has described embodiments of the present solution with reference to different functional units and processors. However, it is apparent that, without departing from the present solution, any suitable functional distribution between different functional units, processing logic elements, or domains can be used. For example, functions shown to be performed by separate processing logic elements or controllers can be performed by the same processing logic element or controller. Accordingly, the reference to a particular functional unit is only a reference to a suitable means for providing the described function and does not represent a strict logical or physical structure or organization.

[0085] For those skilled in the art, various modifications to the embodiments described in this disclosure will be apparent, and the general principles defined herein can be applied to other embodiments without departing from the scope of this disclosure. Accordingly, this disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims.

Claims

1. A wireless communication method, comprising: A wireless communication device determines small data transmission (SDT) information, wherein the SDT information includes SDT configured grant (CG) configuration; and The wireless communication device uses the network to perform an SDT process using the SDT information; The wireless communication device receives timing alignment (TA) information from the network to maintain the TA of the SDT CG configuration, the TA information including a timing advance timer configured to be applied by the wireless communication device to maintain the TA; In response to receiving the TA information, the wireless communication device initiates a timer; and In response to determining that the timer has expired, the wireless communication device releases SDT CG resources.

2. The wireless communication method according to claim 1, wherein The wireless communication method includes: In response to receiving the TA information and determining that the TA information is maintained: Apply the TA information; and Start or restart the timer.

3. The wireless communication method according to claim 1, wherein The SDT information includes SDT random access channel (RACH) configuration; The wireless communication method includes: Receiving the TA information with the SDT RACH configuration from the network.

4. The wireless communication method according to claim 1, wherein, The SDT information includes SDT RACH configuration, and the wireless communication method includes: During the initiation of the SDT process, apply first TA information and initiate another timer; During the execution of the SDT process, in response to determining that the other timer is not running, initiate a random access (RA) process, wherein uplink synchronization is obtained in the radio resource control (RRC) inactive state; In response to determining that the SDT process ends and the wireless communication device enters the RRC inactive state, terminate the other timer; Wherein the other timer is re-initiated in response to receiving any TA information.

5. The wireless communication method according to claim 1, wherein The SDT information includes SDT RACH configuration; In response to determining an SDT CG configuration failure, use the SDT RACH configuration for the SDT process.

6. The wireless communication method according to claim 5, wherein, The timer includes a first timer corresponding to the SDT CG configuration, and a second timer corresponds to the SDT RACH configuration; the wireless communication method further includes: In response to determining that the first timer has expired, release the SDT CG resources; In response to initiating the SDT process using the SDT RACH configuration and receiving TA information from the network: Apply the TA information; Stop the first timer; Start the second timer; and In response to determining that another cell of the network has been selected: Stop the first timer or the second timer; and Release or suspend the SDT CG configuration; In response to determining that the SDT process has ended and the wireless communication device is set to the RRC inactive state: Maintain the first timer or the second timer when determining that the CG resources are valid; and Stop the first timer or the second timer when determining that the CG resource is invalid.

7. The wireless communication method according to claim 1, comprising: During the execution of the SDT process, determine that a Radio Link Failure (RLF) has occurred in response to determining at least one of the following: RA process failure, or Radio Link Control (RLC) failure.

8. The wireless communication method according to claim 7, comprising: In response to determining that the RLF has occurred during the execution of the SDT process, release the SDT CG configuration and set the wireless communication device to the RRC idle state.

9. The wireless communication method according to claim 1, comprising: In response to determining that cell reselection has occurred during the execution of the SDT process: Release the SDT CG configuration; and Set the wireless communication device to the RRC idle state.

10. A wireless communication device, comprising: At least one processor configured to: Determine Small Data Transmission (SDT) information, where the SDT information includes SDT Configuration Grant (CG) configuration; Execute the SDT process using the SDT information with the network; Receive Time Alignment (TA) information from the network for maintaining the TA of the SDT CG configuration, the TA information including a timing advance timer configured to be applied by the wireless communication device to maintain the TA; In response to receiving the TA information, initiate a timer; and In response to determining that the timer has expired, release the SDT CG resource.

11. The wireless communication device according to claim 10, wherein The at least one processor is configured to: In response to receiving the TA information and determining that the TA information is maintained: Apply the TA information; and Start or restart the timer.

12. The wireless communication device according to claim 10, wherein The SDT information includes SDT Random Access Channel (RACH) configuration; The at least one processor is configured to: Receive the TA information with the SDT RACH configuration from the network.

13. The wireless communication device according to claim 10, wherein, The SDT information includes SDT RACH configuration, and the at least one processor is configured to: During the initiation of the SDT process, apply first TA information and initiate another timer; During the execution of the SDT process, in response to determining that the other timer is not running, initiate a Random Access (RA) process, where uplink synchronization is obtained in the Radio Resource Control (RRC) inactive state; In response to determining that the SDT process ends and the wireless communication device enters the RRC inactive state, terminate the other timer; wherein the other timer is re-initiated in response to receiving any TA information.

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