Method and apparatus for small data transmission in non-terrestrial networks

Abstract

The invention relates to a method and apparatus for small data transmission (SDT) in a non-terrestrial network (NTN). One embodiment of the present disclosure provides a user equipment (UE) comprising: a medium access control (MAC) entity; a radio resource control (RRC) entity; a transceiver; and a processor coupled with the transceiver and configured to: receive a configuration associated with an SDT in an NTN; and determining whether to initiate an SDT program based on the configuration.

Description

Technical Field

[0001] The present disclosure relates to wireless communications, and in particular, to methods and apparatus for small data transmission (SDT) in non-terrestrial networks (NTNs). Background Art

[0002] The SDT procedure is a procedure that allows data and / or signaling transmission while the UE remains in the RRC_INACTIVE state (ie, does not transition to the RRC_CONNECTED state).

[0003] NTN refers to a network or network segment that can transmit using radio frequency (RF) resources on a space or aviation vehicle (e.g., a satellite). For example, a satellite in an NTN can be a geostationary earth orbit (GEO) satellite with a fixed position relative to the earth or a low earth orbit (LEO) satellite orbiting the earth.

[0004] During Rel-17, NTN and SDT were discussed and specified in parallel, NTN enhancements did not consider cases involving SDT, and SDT did not consider any potential problems when applied in NTN scenarios. Therefore, it is desirable to provide solutions to the problems when implementing SDT in NTN. Summary of the invention

[0005] One embodiment of the present disclosure provides a user equipment (UE), comprising: a medium access control (MAC) entity; a radio resource control (RRC) entity; a transceiver; and a processor, which is coupled to the transceiver and configured to: receive a configuration associated with SDT in an NTN; and determine whether to trigger an SDT procedure based on the configuration.

[0006] In some embodiments, the configuration includes at least one of: an SDT termination time threshold; a first valid time threshold associated with triggering the SDT procedure; or a first indication that indicates whether the SDT data volume includes a certain amount of timing advance report (TAR) medium access control (MAC) control elements (CE) when comparing the SDT data volume with the SDT data volume threshold.

[0007] In some embodiments, the RRC entity is configured to send a request for initiating the SDT procedure to the MAC entity in response to satisfying at least one of the following conditions: the received SDT request is no later than the SDT termination time threshold; or the valid duration of the ephemeris data of the serving cell of the UE is longer than the first valid time threshold.

[0008] In some embodiments, the RRC entity is configured to indicate to the MAC layer at least one of: the SDT termination time threshold; the out-of-service time of the serving cell of the UE; the valid duration of the ephemeris data of the serving cell of the UE and the first valid time threshold; or the first indication of the TARMAC CE indicating whether the SDT data amount includes the amount.

[0009] In some embodiments, the SDT procedure is triggered in response to the MAC entity determining that at least one of the following conditions is met: the SDT request is received no later than the SDT termination time threshold; the effective duration of the ephemeris data of the serving cell of the UE is longer than the first effective time threshold; or when the first indication indicates that the SDT data amount includes the TAR MAC CE of the amount, the SDT data amount and the amount of the TAR MAC CE are less than or equal to the SDT data amount threshold; or when the first indication indicates that the SDT data amount does not include the TARMAC CE of the amount, the SDT data amount is less than or equal to the SDT data amount threshold.

[0010] In some embodiments, the RRC entity is configured to: receive a satisfied indication from the MAC entity; and determine to trigger the SDT procedure in response to satisfying at least one of the following conditions: the received SDT request is no later than the SDT termination time threshold; or the valid duration of the ephemeris data of the serving cell of the UE is longer than the first valid time threshold.

[0011] In some embodiments, the configuration includes a second validity time threshold associated with uplink timing alignment of the SDT procedure.

[0012] In some embodiments, the RRC entity is configured to: send a third indication to a MAC entity indicating the start of a timer associated with a configured grant (CG)-SDT time alignment in response to the valid duration of the ephemeris data of the serving cell of the UE being longer than the second valid time threshold; or send a fourth indication to the MAC entity indicating the stop of the timer associated with the CG-SDT time alignment in response to the valid duration associated with the ephemeris data of the serving cell of the UE being not longer than the second valid time threshold.

[0013] In some embodiments, the RRC entity is configured to indicate the second validity time threshold and a validity duration of the ephemeris data of the serving cell of the UE to the MAC layer.

[0014] In some embodiments, the MAC entity is configured to perform timing alignment in response to: a valid duration of ephemeris data of a serving cell of the UE is longer than the second valid time threshold.

[0015] In some embodiments, the configuration includes one or more indications associated with the triggered SDT procedure, wherein the one or more indications include at least one of the following: an indication indicating to ignore parameters associated with triggering TAR; an indication indicating to ignore parameters associated with triggering TAR when the triggered SDT procedure does not have subsequent uplink transmission; an indication indicating to exclude TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication indicating to exclude the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; an indication indicating to include the TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication indicating to include the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; an indication indicating to ignore a scheduling request (SR) that triggers the triggered SDT procedure; or an indication indicating to suspend uplink transmission of the triggered SDT procedure to obtain valid ephemeris data for a serving cell of the UE.

[0016] In some embodiments, the RRC entity is further configured to send parameters associated with the one or more indications to the MAC entity.

[0017] In some embodiments, the MAC entity is further configured to: ignore parameters associated with triggering TAR; ignore parameters associated with triggering TAR in signaling when the triggered SDT procedure does not have subsequent uplink transmission; exclude the TAR MAC CE in the initial UL transmission of the triggered SDT procedure; exclude the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; include the TAR MAC CE in the initial UL transmission of the triggered SDT procedure; include the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; ignore the scheduling request (SR) that triggers the triggered SDT procedure; or suspend the uplink transmission of the triggered SDT procedure to obtain valid ephemeris data of the serving cell of the UE.

[0018] Another embodiment of the present disclosure provides a base station (BS) including: a transceiver; and a processor coupled with the transceiver and configured to: transmit a configuration associated with an SDT in an NTN; and receive the SDT.

[0019] In some embodiments, the configuration includes at least one of: an SDT termination time threshold; a first valid time threshold associated with triggering the SDT procedure; or a first indication indicating whether the SDT data volume includes a certain amount of TAR MAC CE when comparing the SDT data volume with the SDT data volume threshold.

[0020] In some embodiments, the configuration includes a second validity time threshold associated with uplink timing alignment of the SDT procedure.

[0021] In some embodiments, the configuration includes one or more indications associated with the triggered SDT procedure, wherein the one or more indications include at least one of the following: an indication indicating to ignore parameters associated with triggering TAR; an indication indicating to ignore parameters associated with triggering TAR when the triggered SDT procedure does not have subsequent uplink transmission; an indication indicating to exclude TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication indicating to exclude the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; an indication indicating to include the TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication indicating to include the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; an indication indicating to ignore a scheduling request (SR) that triggers the triggered SDT procedure; or an indication indicating to suspend uplink transmission of the triggered SDT procedure to obtain valid ephemeris data for a serving cell of the UE.

[0022] Yet another embodiment of the present disclosure provides a method performed by a UE, comprising: receiving a configuration associated with an SDT procedure in an NTN; and determining whether to trigger the SDT procedure based on the configuration.

[0023] Yet another embodiment of the present disclosure provides a method performed by a base station (BS), comprising: transmitting a configuration associated with an SDT procedure in an NTN; and receiving the SDT. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to describe the manner in which the advantages and features of the present application can be obtained, the description of the present application is presented with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of the present application and are therefore not to be considered limiting of its scope.

[0025] Figure 1 A schematic diagram illustrating a wireless communication system according to some embodiments of the present disclosure.

[0026] Figure 2A flow chart illustrating a method for SDT in an NTN performed by a UE and a BS according to some embodiments of the present disclosure.

[0027] Figure 3 A method for SDT in an NTN performed by a UE according to some embodiments of the present disclosure is described.

[0028] Figure 4 A method for SDT in an NTN performed by a BS according to some embodiments of the present disclosure is described.

[0029] Figure 5 A simplified block diagram illustrating an apparatus for SDT in an NTN according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0030] The detailed description of the drawings is intended as a description of the presently preferred embodiments of the invention and is not intended to represent the only form in which the invention can be practiced. It should be understood that the same or equivalent functions can be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the invention.

[0031] Although the operations are depicted in a particular order in the drawings, it should be readily recognized by those skilled in the art that such operations need not be performed in the particular order shown or in sequential order or that all of the illustrated operations need not be performed to achieve a desired result; one or more operations may sometimes be skipped. In addition, the drawings may schematically depict one or more example processes in the form of a flow chart. However, other operations not depicted may be incorporated into the schematically illustrated example processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In certain scenarios, multitasking and parallel processing may be advantageous.

[0032] Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided in specific network architectures and new service scenarios, such as cellular telephone networks, networks based on time division multiple access (TDMA), networks based on code division multiple access (CDMA), networks based on orthogonal frequency division multiple access (OFDMA), LTE networks, networks based on the third generation partnership project (3GPP), LTE, LTE advanced (LTE-A), 3GPP 4G, 3GPP 5G NR, 3GPP release 16 and higher, satellite communication networks, high altitude platform networks, etc. It should be considered that, with the development of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and in addition, the terms listed in the present disclosure may be changed, which should not affect the principles of the present disclosure.

[0033] Figure 1 A schematic diagram illustrating a wireless communication system 100 according to some embodiments of the present application.

[0034] like Figure 1 As shown in FIG. 1 , a wireless communication system 100 includes two UEs (UE 101-A and UE 101-B) and a BS 102, such as a satellite BS. Figure 1 For simplicity, only one BS is described in FIG. 1 , but it should be considered that in some other embodiments of the present application, the wireless communication system 100 may include more BSs. Figure 1 For simplicity, only two UEs are illustrated in FIG. 1 , but it should be considered that in some other embodiments of the present application, the wireless communication system 100 may include more UEs.

[0035] BS 102 may also be referred to as an access point, an access terminal, a base, a macro cell, a Node B, a radio access network (RAN) node, an enhanced Node B (eNB), a gNB, a home Node B, a relay node or device, or described using other terms used in the art. BS 102 is generally part of a radio access network that may include a controller communicatively coupled to BS 102.

[0036] UE 101-A may include a computing device, such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart TV (such as a TV connected to the Internet), a set-top box, a game console, a security system (including a security camera), a car computer, a network device (such as a router, a switch and a modem), or the like. According to an embodiment of the present application, UE 101-A may include a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identification module, a personal computer, a selective call receiver, or any other device capable of sending and receiving communication signals on a wireless network. In some embodiments, UE 101-A may include a wearable device, such as a smart watch, a fitness bracelet, an optical head-mounted display, or the like. In addition, UE 101-A may be referred to as a subscriber unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal or a device, or described using other terms used in the art.

[0037] The wireless communication system 100 is compatible with any type of network capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with wireless communication networks, cellular telephone networks, time division multiple access (TDMA)-based networks, code division multiple access (CDMA)-based networks, orthogonal frequency division multiple access (OFDMA)-based networks, LTE networks, 3GPP-based networks, 3GPP 5G networks, satellite communication networks, high altitude platform networks, and / or other communication networks.

[0038] The UE (e.g., 101-A and UE 101-B) may perform an SDT procedure. The SDT procedure is triggered by the UE when SDT is activated based on a radio bearer and the following conditions are met:

[0039] - Less than the configured amount of uplink data awaits transmission across all radio bearers for which SDT is enabled;

[0040] - Downlink (DL) Reference Signal Received Power (RSRP) is above a configured threshold; and

[0041] - Valid SDT resources are available.

[0042] The present disclosure relates to two types of SDT procedures, which are: 1) configured grant SDT, (CG-SDT), which is SDT of type 1 CG resources configured via dedicated signaling; and 2) random access SDT (RA-SDT), which is SDT of resources configured via system information.

[0043] About CG-SDT:

[0044] -The CG resources of SDT are only valid within the cell where the UE receives the SDT configuration in the dedicated signaling and transitions to the RRC_INACTIVE state.

[0045] -When using CG resources for an initial SDT transmission, if the UE does not receive an acknowledgement (dynamic UL grant or DL ​​assignment) from the network before the configuration timer expires, the UE may perform an autonomous retransmission of the initial transmission.

[0046] - The network may schedule subsequent UL transmissions using dynamic grant or they may occur on the following CG resource opportunities.

[0047] -DL transmissions may use dynamic assignment scheduling.

[0048] - The UE may initiate subsequent UL transmissions only after receiving an acknowledgement (dynamic UL grant or DL ​​assignment) of the initial PUSCH (Physical Uplink Shared Channel) transmission from the network.

[0049] -For subsequent UL transmissions, the UE may not trigger retransmissions through CG resources.

[0050] -SDT procedures through CG resources can only be triggered with valid UL timing alignment.

[0051] About RA-SDT:

[0052] - The network may configure 2-step RA resources, 4-step RA resources, or both for RA-SDT.

[0053] - The network may schedule subsequent UL and DL transmissions using dynamic UL grants and DL assignments, respectively, after completing the RA procedure.

[0054] Once triggered, the SDT procedure can be successfully completed after the UE is directed to RRC_IDLE mode, RRC_INACTIVE mode, or RRC_CONNECTED mode. In some other cases, the triggered SDT procedure cannot be successfully completed when one of the following occurs:

[0055] -Cell reselection procedure;

[0056] -SDT failure detection timer expires;

[0057] -The UE's MAC entity reaches the configured maximum Physical Random Access Channel (PRACH) preamble transmission threshold;

[0058] - The UE's RLC entity reaches the configured maximum retransmission threshold; or

[0059] -The SDT specific timing alignment timer expires when the SDT procedure is in progress over CG resources and the UE does not receive a response from the network after the initial PUSCH transmission.

[0060] While an SDT procedure is ongoing, if data appears in the buffer of any radio bearer not enabled for SDT, the UE may trigger the transmission of a non-SDT data arrival indication to the network using a message such as a UEAssistanceInformation message and if available, the message may include a resumption cause.

[0061] For SDT in NTNs, several issues may occur, for example, the present disclosure seeks to address some issues associated with the following aspects of SDT in NTNs: 1) TAR; 2) out-of-service time of NTNs; and 3) UL timing alignment based on valid ephemeris data.

[0062] Problems associated with TAR

[0063] In Rel-17 NR NTN, in order to help the network schedule UL resources for the UE, TAR is introduced to allow the UE to report its calculated TA in the MAC CE to the network. The UE can be triggered to transmit TAR in the following occasions: 1) after initiating a RA procedure, such as for RRC establishment or recovery, if the parameter (i.e., ta-Report) is configured to be enabled in the system information block (e.g., SIB19), then TAR is triggered; and 2) when the UE is in RRC_CONNECTED mode, if the TA change (i.e., the current TA compared to the TA included in the previous TAR) is equal to or greater than a threshold (offsetThresholdTA) that can be configured via dedicated signaling, then TAR can also be triggered.

[0064] In some cases, if TAR is triggered and there are not enough uplink shared control channel (UL-SCH) resources for transmitting TAR, the UE may further trigger SR when the parameter (ie, TimingAdvanceSR) is configured to be enabled via dedicated signaling.

[0065] In an NTN cell, when the UE receives a system information block (e.g., SIB19) in which a parameter (i.e., ta-Report) is enabled, the SDT procedure may be triggered. For CG-SDT, the UE may neither initiate a RA procedure nor transition to RRC_CONNECTED mode, and therefore, TAR is not triggered. For RA-SDT, an RRC recovery message (e.g., MSG3 in a 4-step RA procedure) is used to transmit initial SDT data or signaling and initiate a RA procedure. In the case where the parameter in SIB19 (i.e., ta-Report) is enabled, TAR will be triggered.

[0066] In the above scenario, several issues regarding TAR may occur:

[0067] Question 1-1:

[0068] For SDT procedures, there may be no need to trigger TAR. TAR is provided to the network for subsequent UL scheduling. In the absence of subsequent UL transmission for SDT procedures, this means that the network may not perform subsequent UL scheduling, so there may be no need to trigger TAR. However, if the parameter ta-Report in SIB19 is enabled, TAR may still be triggered, which may be optional.

[0069] Question 1-2:

[0070] In the case where TAR needs to be triggered, TAR can be transmitted using TAR MAC CE according to Rel-17 SDT, and the use of SDT resources to transmit MAC CE is not prohibited. That is, TAR MAC CE can be transmitted using SDT resources. However, TAR is not so urgent because the network can schedule subsequent UL transmissions based on the current UL timing without knowing the TA of the UE. In addition, MAC CE can be prioritized over data, that is, the transmission of TAR MAC CE can be prioritized over SDT transmission, and TAR MAC CE can occupy limited SDT resources.

[0071] Since SDT resources are limited, it is unclear whether the TAR MAC CE can be transmitted using the SDT resources of the initial UL transmission.

[0072] In the case of transmitting a TAR MAC CE using SDT resources for initial UL transmission according to the requirement of the amount of uplink data of the SDT procedure (which should not be greater than a threshold value, i.e., sdt-DataVolumeThreshold), it is unclear whether the amount of TAR MAC CE should be considered as part of the UL data waiting to be transmitted or should not be considered as part of the UL data waiting to be transmitted. In addition, it is unclear which one of the TAR MAC CE or the SDT initial UL data should be prioritized for initial UL transmission.

[0073] Questions 1-3:

[0074] In case the TAR MAC CE is not transmitted using the SDT resources of the initial UL transmission but is transmitted using the SDT resources of the subsequent UL transmission, it is also unclear which one should be prioritized, ie, the TAR MAC CE or the subsequent UL transmission of the SDT transmission.

[0075] In summary, regarding TAR, questions may include whether to trigger TAR for an SDT procedure and how to handle a triggered TAR during the SDT procedure.

[0076] Issues associated with downtime

[0077] In NTN, NTN cells may be out of service at a specific time, which may be referred to as: out of service time. For example, there may be an out of service time for NTN cells managed by mobile satellites (e.g., LEO satellites), and when the time exceeds the out of service time, the cell managed by the mobile satellite may disappear. For quasi-Earth fixed cells, satellites may form maneuverable cells on the Earth, and the out of service time may be cell-specific and broadcasted using parameters (i.e., t-Service). For Earth mobile cells, cells may follow satellite coverage and move at the speed of the satellite, and the out of service time is UE-specific and may be estimated by the UE based on the UE's position and satellite ephemeris.

[0078] In some cases, in an NTN cell with an out-of-service time, the SDT procedure may be triggered close to the out-of-service time, in other words, there may not be enough time for the SDT procedure.

[0079] For CG-SDT, the UE needs to transmit SDT UL data at the scheduled timing and can receive SDT DL data afterwards, and this process requires a duration of at least one round trip time (RTT), which can be as high as 500ms in NTN due to the large propagation delay via satellite. For RA-SDT, more than one RTT is required because the UE needs to additionally perform random access first.

[0080] When there is little time left before the out-of-service time (e.g., 1 or 2 RTTs left), triggering the SDT procedure may not be necessary because it cannot be completed in time. In addition, according to Rel-17 NTN, at least for Quasi-Geo-Fixed cells, the cell reselection procedure should be triggered before the out-of-service time (e.g., t-Service) of the NTN cell. The cell reselection procedure may terminate the triggered SDT procedure, which will further limit the time available for the SDT procedure before the out-of-service time.

[0081] In summary, regarding the out-of-service time of the NTN cell, the problem may include that the SDT procedure triggered close to the out-of-service time of the NTN cell cannot be successfully completed in time, which is due to the out-of-service time of the NTN cell and the mandatory cell reselection triggered before the out-of-service time of the NTN cell.

[0082] Issues associated with UL timing alignment based on valid ephemeris data

[0083] In NTN, a UE in RRC-IDLE mode or RRC_INACTIVE mode requires valid satellite ephemeris data to calculate TA for UL timing alignment. The UE may attempt to reacquire the satellite ephemeris data before the validity duration (i.e., ntn-ULSyncValidityDuration starting at time (i.e., epochTime)) of the satellite ephemeris data in the system information block (i.e., SIB19) ends based on the UE implementation.

[0084] In NTN cells, valid satellite ephemeris data is required for UL timing alignment and can trigger the SDT procedure.

[0085] For RA-SDT, although RA-SDT does not require UL timing alignment, the UE in the NTN cell needs to obtain satellite ephemeris data for TA pre-compensation before initiating the RA procedure. Therefore, for RA-SDT, initiating the SDT procedure requires waiting for satellite ephemeris data acquisition anyway.

[0086] For CG-SDT, UL timing alignment (i.e., TA verification) is partially determined in the MAC entity by a timer (cg-SDT-TimeAlignmentTimer) configured by the network, and in NTN, the validity of satellite ephemeris data also affects the UL timing alignment. From the perspective of network implementation, when configuring cg-SDT-TimeAlignmentTimer, the serving BS may or may not consider the ephemeris data valid duration, that is, the expiration time of cg-SDT-TimeAlignmentTimer may be earlier than the end of the ephemeris data valid duration or may not be earlier than the end of the ephemeris data valid duration.

[0087] In case the network configures the timer (ie, cg-SDT-TimeAlignmentTimer) so that it does not exceed the ephemeris data valid duration, after successfully reacquiring the ephemeris data, it is unclear whether the UL timing alignment of the CG-SDT can be considered valid or invalid.

[0088] In this case, restricting the use of CG-SDT may be unnecessary because the UE may attempt to acquire new ephemeris data to maintain valid UL timing alignment, and the expiration of the timer (ie, cg-SDT-TimeAlignmentTimer) may cause the UE to stop using CG-SDT.

[0089] In case the network configures a timer (ie, cg-SDT-TimeAlignmentTimer) such that it exceeds the ephemeris data valid duration, it is unclear how to handle the initiation of the SDT procedure or the continued transmission of the SDT procedure when the SDT procedure is triggered close to an attempt to reacquire ephemeris data.

[0090] When the UE tries to reacquire ephemeris data, this means that UL timing alignment cannot be guaranteed temporarily because the current ephemeris data may expire immediately and the UE needs to calculate TA based on new ephemeris received at the broadcast period of the system information block (ie, SIB19).

[0091] For an SDT procedure triggered close to this attempt, at least the initial transmission of the SDT procedure or the autonomous retransmission of the initial transmission may be suspended to wait while a new TA is calculated. Subsequent UL transmissions may not need to be suspended because the UE may receive a timing advance command (TAC) from the network before subsequent UL transmissions.

[0092] In summary, in NTNs where the validity duration of ephemeris data may affect UL timing alignment, the initiation or continuation of the SDT procedure may be interrupted by the UE's attempt to reacquire ephemeris data and subsequent calculations based on the ephemeris data.

[0093] The present disclosure proposes some solutions for solving the above problems.

[0094] Figure 2 A flow chart illustrating a method for SDT in an NTN performed by a UE and a BS according to some embodiments of the present disclosure.

[0095] In operation 201, a BS may transmit a configuration to a UE. The configuration may be associated with an SDT.

[0096] According to the different information contained in the configuration, several solutions are proposed as follows.

[0097] Solution A

[0098] In some embodiments, the configuration includes at least one of:

[0099] -SDT termination time threshold;

[0100] - an effective time threshold associated with triggering an SDT procedure; or

[0101] - an indication, which indicates whether the SDT data volume contains a certain amount of TAR MAC CE when comparing the SDT data volume with the SDT data volume threshold.

[0102] The SDT termination time threshold may be expressed as: t-SDT, which may be a time point before the out-of-service time of the serving cell. The value of the SDT termination time threshold may be based on the out-of-service time of the serving cell.

[0103] In some embodiments, the service time (i.e., t-Service) may be broadcast by the NTN quasi-terrestrial fixed cell or may be based on the out-of-service time of the NTN terrestrial mobile cell derived from the coverage information (including satellite ephemeris) and the location of the UE. In some other embodiments, the value of the SDT termination time threshold may be based on the timing advance (TA) or RTT of the UE.

[0104] After receiving the above configuration, in operation 202, the UE may determine whether to trigger an SDT procedure based on the configuration.

[0105] Specifically, after receiving an SDT request from upper layers (RRC entity, MAC entity, or both), the following options may be performed:

[0106] Option A1:

[0107] The RRC entity may determine whether at least one of the following conditions for inducing SDT is satisfied and send a request for inducing the SDT procedure to the MAC entity in response to being satisfied:

[0108] Condition A1: The SDT request received from the upper layer is not later than the SDT termination time threshold. That is, condition A1 is satisfied when the RRC entity receives an SDT request from the upper layer before the SDT termination time threshold (i.e., t-SDT) or at the SDT termination time threshold. The SDT termination time threshold may be an absolute time, such as 15:00 (UTC time) on June 13, 2022, and if the RRC entity receives an SDT request from the upper layer before 15:00 (UTC time) on June 13, 2022 or receives an SDT request from the upper layer at 15:00 (UTC time) on June 13, 2022, then condition A1 is satisfied. The SDT termination time threshold may be a relative time or a time in other forms.

[0109] Condition A2: The validity duration of the ephemeris data of the UE's serving cell is longer than the validity time threshold associated with initiating the SDT procedure. That is, the satisfaction of this condition may imply that the ephemeris data of the UE's serving cell may remain valid during the SDT procedure.

[0110] In the case where condition A2 is not satisfied, i.e., the valid duration of the ephemeris data of the serving cell of the UE is not longer than the valid time threshold associated with initiating the SDT procedure, the RRC entity may suspend sending the SDT request to the MAC entity and wait for obtaining valid ephemeris data. Alternatively, the RRC entity may trigger the acquisition of valid ephemeris data to satisfy condition A2.

[0111] After the UE successfully obtains valid ephemeris data of the UE's serving cell, the RRC entity may resume initiating the SDT procedure.

[0112] Option A2:

[0113] The RRC entity may indicate at least one of the following to the MAC entity and cause the MAC entity to determine whether at least one condition for inducing SDT is satisfied:

[0114] -SDT termination time threshold;

[0115] -The out-of-service time of the UE's serving cell;

[0116] - the validity duration of the ephemeris data of the UE's serving cell and the validity time threshold associated with triggering the SDT procedure; or

[0117] - An indication indicating whether the SDT data volume includes the volume of TAR MAC CE.

[0118] In some embodiments, the SDT termination time threshold may be an absolute time, such as 15:00 (UTC time) on June 13, 2022. In some other embodiments, the SDT termination time threshold may be a relative time, such as a 20 ms time period, where the end time of the time period is the out-of-service time of the UE's serving cell. In this case, the RRC entity may indicate both the SDT termination time threshold and the out-of-service time of the UE's serving cell to the MAC entity.

[0119] The indication may indicate that the SDT data amount includes a certain amount of TAR MAC CEs or indicate that the SDT data amount does not include a certain amount of TAR MAC CEs.

[0120] After receiving at least one of the above information from the RRC entity, the MAC entity may determine whether at least one of the following conditions is satisfied:

[0121] Condition A1': The SDT request is received no later than the SDT termination time threshold. That is, if the MAC entity receives the SDT request from the RRC entity before the SDT termination time threshold (ie, t-SDT) or at the SDT termination time threshold, the condition A1' is satisfied.

[0122] Condition A2: As described in Option A1, so such details are omitted here.

[0123] In the event that condition A2 is not met, ie, the validity duration of the ephemeris data of the UE's serving cell is not longer than the validity time threshold associated with initiating the SDT procedure, the MAC entity may suspend determination of condition A2 and wait to obtain valid ephemeris data to meet this condition.

[0124] After the UE successfully obtains valid ephemeris data of the UE's serving cell, the MAC entity may resume determination of condition A2.

[0125] Condition A3: The data amount of pending UL data across all RBs configured for SDT plus the data amount of the triggered TAR MAC CE is less than or equal to the SDT data amount threshold, such as sdt-DataVolumeThreshold.

[0126] In the case where the indication indicates that the amount of SDT data includes the amount of TAR MAC CE, the MAC entity may compare the amount of pending UL data across all RBs configured for SDT (denoted as V for simplicity). SDT ) and the amount of data triggered by the TAR MAC CE (for simplicity, denoted as V TAR ) and the SDT data volume threshold, such as sdt-DataVolumeThreshold (for simplicity, denoted as T SDT). Specifically, the MAC entity may determine whether V SDT +V TAR ≤T SDT . In V SDT +V TAR ≤T SDT In the case of V SDT +V TAR >T SDT In this case, the MAC entity may determine that condition A3 is not met.

[0127] In the case where the indication indicates that the amount of SDT data does not include the amount of TAR MAC CE, the MAC entity may compare the amount of pending UL data across all RBs configured for SDT (denoted as V for simplicity). SDT ) and the SDT data volume threshold, such as sdt-DataVolumeThreshold (for simplicity, denoted as T SDT ). Specifically, the MAC entity may determine whether V SDT ≤T SDT . In V SDT ≤T SDT In the case of V SDT >T SDT In this case, the MAC entity may determine that condition A3 is not met.

[0128] After determining that at least one of the above conditions is met, the MAC entity may send a satisfaction indication to the RRC layer.

[0129] Option A3:

[0130] In this option, the RRC entity may receive a satisfaction indication from the MAC entity. The satisfaction indication may indicate that a condition that triggers an SDT for which the MAC entity is responsible is satisfied. For example, the MAC entity may be responsible for determining whether condition A3 described in option A2 is satisfied.

[0131] The RRC entity may determine to trigger the SDT procedure in response to at least one of the following conditions being met:

[0132] Condition A1: As described in Option A1, so such details are omitted here.

[0133] Condition A2: As described in Option A1, so such details are omitted here.

[0134] In the case where condition A2 is not met, i.e., the valid duration of the ephemeris data of the UE's serving cell is not longer than the valid time threshold associated with initiating the SDT procedure, the RRC entity may suspend sending the SDT request to the MAC entity and wait when acquiring valid ephemeris data. Alternatively, the RRC entity may trigger the acquisition of valid ephemeris data to meet condition A2.

[0135] When at least one of the above conditions is met, the UE may trigger the SDT procedure, and in operation 203, the UE may transmit the SDT to the BS. In some embodiments, the UE may trigger the SDT procedure only when all conditions in each option are met. For example, in option A3, the UE may trigger the SDT procedure only when the RRC entity receives a satisfied indication from the MAC entity and both condition A1 and condition A2 are met.

[0136] Solution B

[0137] In some other embodiments, the configuration may include a validity time threshold associated with uplink timing alignment for the SDT procedure.

[0138] After receiving the above configuration, in operation 204, the UE may determine how to handle the timer associated with CG-SDT time alignment. Specifically, the RRC entity, the MAC entity, or both may adopt the following options:

[0139] Option B1

[0140] The RRC entity may determine whether the following conditions are met:

[0141] Condition B1: The valid duration of the ephemeris data of the serving cell of the UE is longer than a valid time threshold associated with the uplink timing alignment of the SDT procedure, and the valid time threshold is associated with the uplink timing alignment of the SDT procedure.

[0142] If condition B1 is met, the RRC entity may send a third indication to the MAC entity indicating to start (or restart) a timer associated with CG-SDT time alignment (ie, cg-SDT-TimeAlignmentTimer).

[0143] If condition B1 is not met, the RRC entity may send a fourth indication to the MAC entity indicating stopping of a timer associated with CG-SDT time alignment.

[0144] In addition, if condition B1 is not met, that is, the valid duration of the ephemeris data of the serving cell of the UE is not longer than the valid time threshold associated with the uplink timing alignment of the SDT procedure, the RRC entity may suspend sending the SDT request to the MAC entity and wait for obtaining valid ephemeris data. Alternatively, the RRC entity may trigger the acquisition of valid ephemeris data to meet condition B1.

[0145] Option B2

[0146] The RRC entity may indicate to the MAC entity a valid time threshold associated with uplink timing alignment of the SDT procedure and a valid duration of ephemeris data of the serving cell of the UE, and enable the MAC entity to determine whether the above-mentioned condition B1 is satisfied.

[0147] Therefore, at the MAC entity side, the MAC entity may receive from the RRC entity a valid time threshold associated with uplink timing alignment of the SDT procedure and a valid duration of ephemeris data of the UE's serving cell. The MAC entity then determines whether the above condition B1 is satisfied.

[0148] If condition B1 is met, the MAC entity may start (or restart) a timer associated with CG-SDT time alignment, ie, cg-SDT-TimeAlignmentTimer.

[0149] In case condition B1 is not met, the MAC entity may stop the timer associated with CG-SDT time alignment.

[0150] In addition, if condition B1 is not met, that is, the valid duration of the ephemeris data of the serving cell of the UE is not longer than the valid time threshold associated with the uplink timing alignment of the SDT procedure, the RRC entity may suspend sending the SDT request to the MAC entity and wait for obtaining valid ephemeris data. Alternatively, the RRC entity may trigger the acquisition of valid ephemeris data to meet condition B1.

[0151] When the UE successfully acquires (or reacquires) the ephemeris data of the UE's serving cell (eg, updates ntn-ULSyncValidityDuration), a timer associated with CG-SDT time alignment, ie, cg-SDT-TimeAlignmentTimer, may be started (or restarted).

[0152] In some embodiments, when acquiring (or reacquiring) satellite ephemeris data of the UE's serving cell, the UE may suspend the triggered SDT procedure or the ongoing SDT procedure (initial SDT UL transmission or its autonomous retransmission) until the satellite ephemeris data is successfully received and decoded.

[0153] In some embodiments, when an SDT request is received from an upper layer or when an SDT procedure is triggered, the UE may determine whether to trigger acquisition (or reacquisition) of the ephemeris data of the serving cell. Specifically, the determination may be based on the remaining valid duration of the satellite ephemeris data (i.e., the valid duration of the ephemeris data of the serving cell) and the TA or RTT of the UE. The remaining valid duration of the satellite ephemeris data may be determined by a parameter (e.g., ntn-ULSyncValidityDuration).

[0154] For example, in the case where the remaining valid duration of the satellite ephemeris data is shorter than a valid time threshold associated with uplink timing alignment of the SDT procedure, the UE may determine to trigger acquisition (or reacquisition) of the ephemeris data of the serving cell.

[0155] Solution C

[0156] In some other embodiments, the configuration may include one or more indications associated with the induced SDT procedure, wherein the one or more indications include at least one of the following:

[0157] - An indication indicating to ignore the parameters associated with triggering TAR. The parameter may include a parameter (ta-Report) in a system information block (e.g., SIB19); the parameter may also include an offset threshold of TA in dedicated signaling (e.g., RRC signaling), such as offsetThresholdTA. In other words, this indication instructs the UE not to trigger a TAR for an SDT-induced procedure.

[0158] - An indication indicating that the parameters associated with triggering TAR are ignored if the triggered SDT procedure does not have a subsequent uplink transmission. The parameter may include a parameter (ta-Report) in a system information block (e.g., SIB19); the parameter may also include an offset threshold of TA in dedicated signaling (e.g., RRC signaling), such as offsetThresholdTA. In other words, this indication indicates that the UE does not trigger TAR for the triggered SDT procedure if the triggered SDT procedure does not have a subsequent uplink transmission.

[0159] - An indication from the RRC entity of the BS, which indicates to ignore the SDT procedure, ie, not to trigger the SDT procedure.

[0160] - an indication to exclude the TAR MAC CE in the initial UL transmission that triggers the SDT procedure;

[0161] - an indication to exclude the TAR MAC CE in subsequent UL transmissions for which the SDT procedure has been triggered;

[0162] - an indication to include a TAR MAC CE in the initial UL transmission that triggers the SDT procedure;

[0163] - an indication to include a TAR MAC CE in a subsequent UL transmission that triggers an SDT procedure;

[0164] - An indication indicating to ignore the SR that triggers the induced SDT procedure. In other words, this indication instructs the UE not to trigger the SR that triggers the SDT procedure.

[0165] - an instruction to suspend the uplink transmission triggered by the SDT procedure to obtain valid ephemeris data of the serving cell of the UE. The uplink transmission triggered by the SDT procedure may also include autonomous retransmission.

[0166] After receiving the one or more indications in the configuration from the BS, in operation 205, the RRC entity and the MAC entity may perform the following operations:

[0167] In some embodiments, the RRC entity may transfer the operating parameters associated with the induced SDT in the configuration to its MAC entity. For example, the parameters may include the above indication and related parameters, such as the validity duration of the ephemeris data of the UE's serving cell or any other associated parameters.

[0168] In some embodiments, based on the above indication, the MAC entity may perform at least one of the following operations:

[0169] - Ignore the parameters associated with triggering TAR. That is, the MAC entity may ignore the parameter ta-Report in SIB19 or the parameter offsetThresholdTA in the dedicated signaling, or both. In other words, the MAC entity may not trigger TAR for this SDT procedure.

[0170] - Ignore the parameters associated with the triggered TAR in the signaling in case the triggered SDT procedure does not have a subsequent uplink transmission. That is, in case the triggered SDT procedure does not have a subsequent uplink transmission, the MAC entity may ignore the parameter ta-Report in SIB19 or the parameter offsetThresholdTA in the dedicated signaling, or both. In other words, in case the triggered SDT procedure does not have a subsequent uplink transmission, the MAC entity may not trigger the TAR for this SDT procedure.

[0171] - Exclude TAR MAC CE in the initial UL transmission that triggers the SDT procedure.

[0172] - Exclude TAR MAC CE in subsequent UL transmissions that trigger the SDT procedure;

[0173] - Include the TAR MAC CE in the initial UL transmission that triggers the SDT procedure;

[0174] - Include the TAR MAC CE in the subsequent UL transmission that triggered the SDT procedure;

[0175] - Ignore the SR that triggered the triggered SDT procedure; or

[0176] - Suspend uplink transmission that triggers the SDT procedure to obtain valid ephemeris data of the UE's serving cell.

[0177] In some embodiments, when valid ephemeris data is acquired, the suspended uplink transmission that triggered the SDT procedure may be resumed.

[0178] In some embodiments, the indication may come from the RRC entity of the UE, which instructs the MAC entity to ignore the SDT procedure, ie, not trigger the SDT procedure.

[0179] It should be noted that although operation 202, operation 204, and operation 205 are depicted separately, in some scenarios, these operations may be performed simultaneously.

[0180] Figure 3 A method for wireless communication performed by a UE according to some embodiments of the present disclosure is described.

[0181] In operation 301, the UE may receive a configuration associated with SDT in the NTN; and in operation 302, determine whether to trigger an SDT procedure based on the configuration.

[0182] In some embodiments, the configuration includes at least one of: an SDT termination time threshold; a first valid time threshold associated with initiating an SDT procedure; or a first indication indicating whether the SDT data volume includes a certain amount of TAR MAC CE when comparing the SDT data volume with the SDT data volume threshold.

[0183] In some embodiments, the RRC entity is configured to send a request for initiating an SDT procedure to the MAC entity in response to satisfying at least one of the following conditions: the SDT request is received no later than an SDT termination time threshold (i.e., condition A1 in option A1); or the valid duration of the ephemeris data of the UE's serving cell is longer than a first valid time threshold (i.e., condition A2 in option A1).

[0184] In some embodiments, the RRC entity is configured to indicate to the MAC layer at least one of the following: an SDT termination time threshold; an out-of-service time of a serving cell of the UE; a valid duration and a first valid time threshold of ephemeris data of a serving cell of the UE; or a first indication indicating whether the amount of SDT data includes an amount of TAR MAC CE. For example, the RRC entity may perform the operations described in Option A2.

[0185] In some embodiments, the SDT procedure is triggered in response to the MAC entity determining that at least one of the following conditions is met: the SDT request is received no later than the SDT termination time threshold (i.e., condition A1'); the valid duration of the ephemeris data of the UE's serving cell is longer than the first valid time threshold (i.e., condition A2); or when the first indication indicates that the SDT data amount includes the amount of TARMAC CE, the SDT data amount and the amount of TAR MAC CE are less than or equal to the SDT data amount threshold; or when the first indication indicates that the SDT data amount does not include the amount of TAR MAC CE, the SDT data amount is less than or equal to the SDT data amount threshold (i.e., condition A3).

[0186] In some embodiments, the RRC entity is configured to: receive a satisfaction indication from the MAC entity; and determine to trigger the SDT procedure in response to satisfying at least one of the following conditions: the received SDT request is no later than the SDT termination time threshold; or the valid duration of the ephemeris data of the serving cell of the UE is longer than the first valid time threshold. For example, the RRC entity and the MAC entity perform the operations described in option A3.

[0187] In some embodiments, the configuration includes a second validity time threshold associated with uplink timing alignment of the SDT procedure.

[0188] In some embodiments, the RRC entity is configured to: send a third indication to the MAC entity indicating the start of a timer associated with CG-SDT time alignment in response to the valid duration of the ephemeris data of the UE's service cell being longer than a second valid time threshold; or send a fourth indication to the MAC entity indicating the stop of the timer associated with CG-SDT time alignment in response to the valid duration associated with the ephemeris data of the UE's service cell being not longer than the second valid time threshold.

[0189] In some embodiments, the RRC entity is configured to indicate to the MAC layer the second validity time threshold and the validity duration of the ephemeris data of the UE's serving cell (ie, Solution B).

[0190] In some embodiments, the MAC entity is configured to perform timing alignment in response to: a valid duration of ephemeris data of a serving cell of the UE is longer than a second valid time threshold (ie, condition B1).

[0191] In some embodiments, the configuration includes one or more indications associated with a triggered SDT procedure, wherein the one or more indications include at least one of: an indication to ignore parameters associated with triggering a TAR; an indication to ignore parameters associated with triggering a TAR when the triggered SDT procedure does not have a subsequent uplink transmission; an indication to exclude the TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication to exclude the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; an indication to include the TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication to include the TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; an indication to ignore the SR that triggered the triggered SDT procedure; or an indication to suspend the uplink transmission of the triggered SDT procedure to obtain the ephemeris data of the UE's serving cell.

[0192] In some embodiments, the RRC entity is further configured to: transmit parameters associated with the one or more indications to the MAC entity.

[0193] In some embodiments, the MAC entity is further configured to: ignore parameters associated with triggering TAR; ignore parameters associated with triggering TAR in signaling when the triggered SDT procedure does not have subsequent uplink transmission; exclude TAR MAC CE in the initial UL transmission of the triggered SDT procedure; exclude TARMAC CE in the subsequent UL transmission of the triggered SDT procedure; include TAR MAC CE in the initial UL transmission of the triggered SDT procedure; include TAR MAC CE in the subsequent UL transmission of the triggered SDT procedure; ignore the SR that triggers the triggered SDT procedure; or suspend the uplink transmission of the triggered SDT procedure for valid ephemeris data acquisition.

[0194] Figure 4 A method for wireless communication performed by a BS according to some embodiments of the present disclosure is described.

[0195] In operation 401, the BS may transmit a configuration associated with an SDT in an NTN; and in operation 402, the BS may receive the SDT.

[0196] Figure 5 A simplified block diagram illustrating an apparatus according to some embodiments of the present disclosure.

[0197] like Figure 5 , an example of apparatus 500 may include at least one processor 504 and at least one transceiver 502 coupled to the processor 504. Apparatus 500 may be a UE, a BS, an access point, a satellite, a RAN node, or any other device having similar functionality.

[0198] Although in the figures, elements such as at least one transceiver 502 and processor 504 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the transceiver 502 may be divided into two devices, such as a receiving circuit system and a transmitting circuit system. In some embodiments of the present disclosure, the apparatus 500 may further include an input device, a memory, and / or other components.

[0199] In some embodiments of the present disclosure, the device 500 may be a UE. The transceiver 502 and the processor 504 may interact with each other to perform Figures 1 to 4 In some embodiments of the present disclosure, the device 500 may be a node. The transceiver 502 and the processor 504 may interact with each other to perform Figures 1 to 4 The operation of a node described by any of .

[0200] In some embodiments of the present disclosure, the apparatus 500 may further include at least one non-transitory computer-readable medium.

[0201] For example, in some embodiments of the present disclosure, a non-transitory computer-readable medium may store thereon computer-executable instructions to enable the processor 504 to implement the method for the UE as described above. For example, when the computer-executable instructions are executed, the processor 504 interacts with the transceiver 502 to perform Figures 1 to 4 The operations of the UE described by any of .

[0202] In some embodiments of the present disclosure, a non-transitory computer-readable medium may store thereon computer-executable instructions to cause the processor 504 to implement the method described above with respect to the node. For example, when the computer-executable instructions are executed, the processor 504 interacts with the transceiver 502 to perform Figures 1 to 4 The operation of a node described by any of .

[0203] The methods of the present disclosure may be implemented on a programmed processor. However, the controller, flow charts, and modules may also be implemented on a general or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit components, an integrated circuit, a hardware electronic or logic circuit (e.g., a discrete component circuit), a programmable logic device, or the like. In general, any device having a finite state machine capable of implementing the flow charts shown in the figures may be used to implement the processing functions of the present disclosure.

[0204] Although the present disclosure has been described using its specific embodiments, it is obvious that many substitutions, modifications and changes can be understood by those skilled in the art. For example, the various components of the embodiments can be interchanged, added or replaced in other embodiments. In addition, all elements shown in each figure are not necessary for the operation of the disclosed embodiments. For example, it will enable those skilled in the art of the disclosed embodiments to make and use the teachings of the present disclosure by simply adopting the elements of the independent claims. Therefore, the embodiments of the present disclosure as described herein are intended to be illustrative rather than restrictive. Various changes can be made without departing from the spirit and scope of the present disclosure.

[0205] In the present disclosure, relational terms such as "first", "second" and the like may be used only to distinguish one entity or action from another entity or action, without necessarily requiring or implying any real such relationship or order between such entities or actions. The term "comprises / comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that the process, method, object or device including a series of elements not only includes the elements but also may include other elements that are not explicitly listed or inherent to the process, method, object or device. In the absence of more constraints, an element preceded by "a / an" or the like does not exclude the presence of additional identical elements in the process, method, object or device including the elements. In addition, the term "another" is defined as at least a second or more. The terms "include", "have" and the like used herein are defined as "include".

Claims

1. A user equipment UE, comprising: Media access control MAC entity; Radio Resource Control RRC entity; Transceiver; and a processor coupled to the transceiver and configured to: receiving a configuration associated with a small data transmission SDT in a non-terrestrial network NTN; and A determination is made based on the configuration whether to trigger an SDT procedure.

2. The UE according to claim 1, wherein the configuration comprises at least one of the following: SDT termination time threshold; a first validity time threshold associated with initiating said SDT procedure; or A first indication indicates, when comparing the SDT data volume with the SDT data volume threshold, whether the SDT data volume includes a certain amount of timing advance report TAR medium access control MAC control element CE.

3. The UE according to claim 2, wherein the RRC entity is configured to send a request for initiating the SDT procedure to the MAC entity in response to satisfying at least one of the following conditions: upon receiving the SDT request no later than the SDT expiration time threshold; or The valid duration of the ephemeris data of the serving cell of the UE is longer than the first valid time threshold.

4. The UE of claim 2, wherein the RRC entity is configured to indicate to the MAC layer at least one of: The SDT termination time threshold; An out-of-service time of the serving cell of the UE; The valid duration of the ephemeris data of the serving cell of the UE and the first valid time threshold; or The first indication indicating whether the SDT data volume includes the TAR MAC CE of the volume.

5. The UE of claim 2, wherein the SDT procedure is triggered in response to the MAC entity determining that at least one of the following conditions is satisfied: The SDT request is received no later than the SDT termination time threshold; The valid duration of the ephemeris data of the serving cell of the UE is longer than the first valid time threshold; or In a case where the first indication indicates that the SDT data amount includes the TAR MAC CE of the amount, the SDT data amount and the amount of the TAR MAC CE are less than or equal to the SDT data amount threshold; or In a case where the first indication indicates that the SDT data amount does not include the TAR MAC CE of the amount, the SDT data amount is less than or equal to the SDT data amount threshold.

6. The UE of claim 2, wherein the RRC entity is configured to: receiving a satisfied indication from the MAC entity; and The SDT procedure is determined to be triggered in response to at least one of the following conditions being met: upon receiving the SDT request no later than the SDT expiration time threshold; or The valid duration of the ephemeris data of the serving cell of the UE is longer than the first valid time threshold.

7. The UE of claim 1, wherein the configuration comprises a second validity time threshold associated with uplink timing alignment of the SDT procedure.

8. The UE of claim 7, wherein the RRC entity is configured to: sending a third indication indicating the start of a timer associated with a configured authorized CG-SDT time alignment to a MAC entity in response to the valid duration of the ephemeris data of the serving cell of the UE being longer than the second valid time threshold; or In response to the valid duration associated with the ephemeris data of the serving cell of the UE being not longer than the second valid time threshold, a fourth indication indicating stopping the timer associated with CG-SDT time alignment is sent to the MAC entity.

9. The UE of claim 1 , wherein the configuration comprises one or more indications associated with a triggered SDT procedure, wherein the one or more indications comprise at least one of: an indication to ignore parameters associated with triggering a TAR; an indication to ignore parameters associated with triggering a TAR if the triggered SDT procedure does not have a subsequent uplink transmission; an indication to exclude TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication to exclude the TAR MAC CE in a subsequent UL transmission of the triggered SDT procedure; an indication to include the TAR MAC CE in an initial UL transmission of the triggered SDT procedure; an indication to include the TAR MAC CE in a subsequent UL transmission of the triggered SDT procedure; an indication to ignore the scheduling request SR triggering the triggered SDT procedure; or An instruction to suspend the uplink transmission of the SDT procedure triggered to obtain valid ephemeris data of a serving cell of the UE.

10. The UE of claim 9, wherein the RRC entity is further configured to: Parameters associated with the one or more indications are sent to the MAC entity.

11. The UE of claim 10, wherein the MAC entity is further configured to: Ignore the parameters associated with triggering TAR; In case the triggered SDT procedure has no subsequent uplink transmission, ignoring parameters associated with triggering TAR in the signaling; excluding the TAR MAC CE in an initial UL transmission of the triggered SDT procedure; excluding the TAR MAC CE in subsequent UL transmissions of the triggered SDT procedure; including the TAR MAC CE in an initial UL transmission of the triggered SDT procedure; including the TAR MAC CE in a subsequent UL transmission of the triggered SDT procedure; Ignoring the scheduling request SR that triggered the triggered SDT procedure; or The uplink transmission of the SDT procedure triggered is suspended to obtain valid ephemeris data of the serving cell of the UE.

12. A base station BS, comprising: Transceiver; and a processor coupled to the transceiver and configured to: transmitting a configuration associated with a small data transmission SDT in a non-terrestrial network NTN; and The SDT is received.

13. The BS of claim 12, wherein the configuration comprises at least one of: SDT termination time threshold; a first validity time threshold associated with initiating said SDT procedure; or A first indication indicates, when comparing the SDT data volume with the SDT data volume threshold, whether the SDT data volume includes a certain amount of timing advance report TAR medium access control MAC control element CE.

14. The BS of claim 12, wherein the configuration comprises one or more indications associated with an induced SDT procedure, wherein the one or more indications comprise at least one of: an indication to ignore parameters associated with triggering a TAR; an indication to ignore parameters associated with triggering a TAR if the triggered SDT procedure does not have a subsequent uplink transmission; an indication to exclude TAR MAC CE in the initial UL transmission of the triggered SDT procedure; an indication to exclude the TAR MAC CE in a subsequent UL transmission of the triggered SDT procedure; an indication to include the TAR MAC CE in an initial UL transmission of the triggered SDT procedure; an indication to include the TAR MAC CE in a subsequent UL transmission of the triggered SDT procedure; an indication to ignore the scheduling request SR triggering the triggered SDT procedure; or An instruction to suspend the uplink transmission of the SDT procedure triggered to obtain valid ephemeris data of a serving cell of the UE.

15. A method performed by a user equipment UE, comprising: receiving a configuration associated with a small data transmission SDT procedure in a non-terrestrial network NTN; and A determination is made based on the configuration whether to trigger the SDT procedure.

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