Method and user equipment for pre-configuring resources in an inactive state

Abstract

The present invention relates to a method for pre-configuring resources for small data transmission by a user equipment in an inactive state and a user equipment using the method. In an exemplary embodiment, the present invention relates to a method for pre-configuring resources for small data transmission by a user equipment in an inactive state. The method will include, but is not limited to: receiving a configured permission configuration for small data transmission before entering the inactive state; verifying the configured permission resources of the resident cell associated with the configured permission configuration by determining whether the resident cell meets a verification condition before triggering the small data transmission procedure, wherein the configured permission configuration includes a configured permission configuration list associated with a cell list; and when it is determined that the verification condition is met, utilizing the configured permission resources for the small data transmission procedure.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 092,506, filed on October 15, 2020. The entire contents of the above patent application are hereby incorporated by reference herein and made a part of this specification. Technical Field

[0003] The present invention relates to a method for pre-configuring resources for small data transmission by user equipment (UE) in an inactive state and the user equipment using the method. Background Art

[0004] Currently, for the fifth generation (5G) communication system or the new radio (NR), when the device is operating in an inactive state, there is an increasing need to transmit small data. Small data generally refers to data of about a few kilobytes or tens of kilobytes. Small data services are generally referred to as small and infrequent data services and usually appear in smartphone-related applications, such as instant messaging (IM) services, heartbeat or keep-alive services from IM or email clients, push notifications from various applications, etc. Small data services can also appear in non-smartphone-related applications, such as data services and positioning information from wearables, periodic or non-periodic sensor readings from industrial applications, smart meter readings, etc.

[0005] One goal of small data transmission (SDT) is to transmit uplink (UL) data on pre-configured UL resources by reusing the configured grant (CG) type 1 scheme when the timing alignment (TA) information is still valid. CG type 1 in New Radio (NR) can be used by UEs operating in connected mode to transmit UL data without requesting UL resources. The UE's CG type 1 resource configuration can be released by a dedicated RRC message (e.g., an RRC reconfiguration message). In previous Long-Term Evolution (LTE) communication systems, UEs operating in idle mode can also transmit UL data without requesting UL resources. In such cases, the UE can transmit UL data by using pre-configured UL resources (PUR). However, in LTE communication systems, the use of PUR is only applicable to specific UEs, such as Node B (NB) Internet of Things (IoT) UEs, and the UE's PUR resource configuration can be released when the PUR resource is no longer valid.

[0006] The PUR resource configuration may be valid under certain conditions, such as for a UE maintaining valid timing alignment (TA) information. The PUR resource configuration will be valid in the cell that receives the release message, but will become invalid upon cell reselection due to the UE reselecting to another cell. The main reason why the PUR configuration is only valid on the last serving cell is that after camping on another cell, the UL TA may become unknown. Therefore, based on the PUR validity conditions described above, the PUR solution in LTE is only applicable to UEs in stationary or stable idle mode.

[0007] Currently, for 5G or NR communication systems, reserved resources for cells of inactive UEs (e.g., pre-CG configuration) have been introduced. Under such schemes, only the CG-SDT configuration of the last serving cell will be considered valid. This means that when an inactive UE resides on another cell or reselects another cell, the CG-SDT configuration will become invalid. Therefore, the inactive UE will need to establish a connection for small UL data transmission, even if the inactive UE has been configured with a CG for SDT. Considering that NR cells typically have a smaller coverage area than LTE cells, mobile UEs operating in an inactive state may be more prone to cell reselection. Therefore, for such mobile UEs operating in an inactive state, the efficacy of the CG-SDT scheme will be reduced. However, for NR, reselecting another cell or a UE residing on another cell may not always make the UE's UL TA unknown.

[0008] Figures 1 to 3 Three scenarios are shown where TA is predictable even when a UE operating in inactive state camps on an NR cell other than the last serving cell. Figure 1 In the case of LTE, a Radio Access Network (RAN) based tracking area (RNA) contains multiple cells operating in millimeter wave (mmWave), where the cell size is smaller than that of LTE cells. Figure 1 As shown in , cells with smaller cell sizes may have UL TA of zero or close to zero. This means that for smaller NR cells within RNA, the UL TA information may be predictable when the UE camps on such cells. Figure 2 In the case of a high-speed train passing through a High-Speed ​​Dedicated Network (HSDN) at very high speed, the HSDN is a small cell deployed to provide network access to users on the high-speed train. The UL TA of these small cells can also be zero or close to zero. Figure 3 For example, in the case where cell 1, cell 2, and cell 3 are co-located, then for UE 1, the UL TA of UE 1 associated with cell 1, cell 2, and cell 3 will be the same. Therefore, regardless of whether UE 1 camps on cell 1, cell 2, or cell 3, the UL TA will still be known.

[0009] Therefore, if the CG-SDT configuration can be configured for Figures 1 to 3, or cells in similar situations, then the efficacy of the CG-SDT scheme can be increased. However, if this is to be achieved, the CG-SDT scheme must be effective not only at one cell, but must be extended to other cells. Therefore, when a UE operating in an inactive state moves from one cell to another, the UE can still experience the benefits of the improved CG-SDT scheme. For example, the improved CG-SDT scheme can be deployed in an HSDN scenario to reduce the signaling overload caused by constant connection setup and release when the UE travels quickly between cells. For example, the network may distribute inactive UEs to perform SDT by configuring multiple CG-SDT configurations associated with multiple co-located cells in order to achieve load balancing. However, there is currently no known mechanism for configuring a CG-SDT scheme for multiple cells. Therefore, an enhanced CG-SDT scheme for configuring multiple CG-SDT configurations with multiple cells will be needed in order to achieve the benefits described above. Summary of the Invention

[0010] Therefore, the present invention relates to a method for pre-configuring resources for small data transmission by a UE in an inactive state and a user equipment using the method.

[0011] In an exemplary embodiment, the present invention relates to a method for pre-configuring resources for small data transmission by a UE in an inactive state. The method includes, but is not limited to: receiving a configured grant (CG) configuration for small data transmission before entering the inactive state; verifying the CG resources of a resident cell associated with the CG configuration by determining whether the resident cell meets a verification condition before triggering a small data transmission (SDT) procedure, wherein the CG configuration includes a CG configuration list associated with a cell list; and utilizing the CG resources for the SDT procedure when it is determined that the verification condition is met.

[0012] In an exemplary embodiment, the present invention relates to a user equipment, including but not limited to: a transceiver, operating at a millimeter wave (mmWave) frequency; and a processor, coupled to the transceiver and configured to at least: receive a configured grant (CG) configuration for small data transmission before entering an inactive state; verify the CG resources of a resident cell associated with the CG configuration by determining whether the resident cell meets a verification condition before triggering a small data transmission (SDT), wherein the CG configuration includes a CG configuration list associated with a cell list; and when it is determined that the verification condition is met, utilize the CG resources for the SDT procedure.

[0013] To make the aforementioned features and advantages of the present invention understandable, exemplary embodiments are described in detail below with accompanying drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further explanation of the invention as claimed.

[0014] However, it should be understood that the present disclosure may not contain all aspects and embodiments of the present invention and is therefore not intended to be limiting or restrictive in any way. In addition, the present invention will encompass improvements and modifications that are obvious to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0016] Figure 1 Shows the situation where a cell operating at mmWave frequencies and having a small size exists in RNA, where the TA within the cell can be zero;

[0017] Figure 2 shows a scenario where a high-speed train travels through multiple cells within a HSDN, where the TA within the cells may be zero;

[0018] Figure 3 shows the scenario where a UE travels among multiple co-located cells, where the TA within the cell may be zero;

[0019] Figure 4 A method for pre-configuring resources for small data transmission by a UE in an inactive state according to an exemplary embodiment of the present invention is shown;

[0020] Figure 5 A partial hardware block diagram of a UE according to an exemplary embodiment of the present invention is shown;

[0021] Figure 6 A procedure for configuring multiple CG configurations associated with multiple cells according to an exemplary embodiment of the present invention is shown, wherein the procedure includes at least one CG-SDT resource adjustment procedure and a CG-SDT failure handling procedure;

[0022] Figure 7 An example of CG-SDT resource negotiation according to an exemplary embodiment of the present invention is shown;

[0023] Figure 8 The exemplary embodiment of the present invention is shown in FIG. Figure 7 Provide details of the reserved CG-SDT resource status in the instance of CG-SDT resource negotiation;

[0024] Figure 9 FIG. 1 shows an exemplary embodiment of the present invention. Figure 7 Details of the CG-SDT resource release message in the instance of CG-SDT resource negotiation;

[0025] Figure 10shows an example of CG-SDT resource configuration according to an exemplary embodiment of the present invention;

[0026] Figure 11 An example of a UE triggering CG-SDT according to an exemplary embodiment of the present invention is shown;

[0027] Figure 12 An example of a UE triggering CG-SDT when the reserved CG-SDT resource state is cell-based according to an exemplary embodiment of the present invention is shown;

[0028] Figure 13 An example of a UE triggering CG-SDT when a reserved CG-SDT resource state is based on a CG-SDT configuration according to an exemplary embodiment of the present invention is shown;

[0029] Figure 14 An example of a UE triggering CG-SDT when the reserved CG-SDT resource state is hybrid according to an exemplary embodiment of the present invention is shown;

[0030] Figure 15 A procedure for determining whether CG-SDT transmission succeeds or fails based on the first exemplary embodiment of the present invention is shown;

[0031] Figure 16 A method 1 for processing CG-SDT transmission failure according to a first exemplary embodiment of the present invention is shown;

[0032] Figure 17 A method 2 for processing CG-SDT transmission failure according to the first exemplary embodiment of the present invention is shown;

[0033] Figure 18 A method 3 for processing CG-SDT transmission failure according to the first exemplary embodiment of the present invention is shown;

[0034] Figure 19 An example of CG-SDT resource negotiation according to a second exemplary embodiment of the present invention is shown;

[0035] Figure 20 illustrating providing a reserved CG-SDT resource state in an instance of CG-SDT resource negotiation for supporting CG-SDT configuration update according to a second exemplary embodiment of the present invention;

[0036] Figure 21 illustrating providing a version number in a reserved CG-SDT resource state for supporting CG-SDT configuration update according to a second exemplary embodiment of the present invention;

[0037] Figure 22An example of a UE triggering CG-SDT in a case where CG-SDT resource update is supported according to a second exemplary embodiment of the present invention is shown;

[0038] Figure 23 An example of a UE triggering CG-SDT in a case where CG-SDT resource update is supported when CG-SDT configuration is valid according to a second exemplary embodiment of the present invention is shown;

[0039] Figure 24 An example of a UE triggering CG-SDT in a case where CG-SDT resource update is supported is shown when the CG-SDT configuration is invalid according to the version information;

[0040] Figure 25 The second exemplary embodiment according to the present invention is shown. Figure 24 Alternatives to instances of ;

[0041] Figure 26 An example of processing an invalid CG-SDT configuration by discarding a stored CG-SDT configuration according to a second exemplary embodiment of the present invention is shown;

[0042] Figure 27 An example of using CG-Cofigschedule to describe how a camped cell will provide CG-SDT resource configuration according to an exemplary embodiment of the present invention is shown;

[0043] Figure 28 An example of using a release message to transmit a CG-SDT configuration including a CG-Cofigschedule according to an exemplary embodiment of the present invention is shown;

[0044] Figure 29 A UE is shown that verifies whether a CG-SDT configuration is valid according to a CG-Cofigschedule when the UE triggers CG-SDT according to an exemplary embodiment of the present invention;

[0045] Figure 30 illustrates a procedure of a UE triggering CG-SDT in response to receiving reserved CG-SDT resources according to an exemplary embodiment of the present invention;

[0046] Figure 31 A procedure for a UE to determine whether to release a stored CG-SDT configuration of a camped cell based on the validity of the CG-SDT configuration according to an exemplary embodiment of the present invention is shown;

[0047] Figure 32 A UE is shown acquiring the CG resource configuration of a camped cell based on the CG-CofigSchedule within the stored CG-SDT configuration according to an exemplary embodiment of the present invention.

[0048] Explanation of Figure Numbers

[0049] 501: processor;

[0050] 502: transceiver;

[0051] 503: storage media;

[0052] 611:UE;

[0053] 612: the last serving cell;

[0054] 613: Community;

[0055] 801, 2001: cell-based reserved CG-SDT resource status;

[0056] 802, 2002: reserved CG-SDT resource status based on CG-SDT configuration;

[0057] 803, 2003: Hybrid reserved CG-SDT resource status;

[0058] 2802: table;

[0059] 3102: Reserved CG-SDT resource status;

[0060] S401, S402, S403, S601, S602, S603, S701, S702a, S702b, S703, S704a, S704b, S1001, S1002, S1003, S1101, S1102, S1103, S1104, S1105, S1106, S1107, S1201, S1202, S1203, S1301, S1302, S1303, S1401, S1402, S1403, S1501, S1502, S1503, S1601 , S1701, S1801, S1802, S1901, S1902, S2201, S2202, S2203, S2204, S2206, S2207, S2210, S2211, S2301, S2302, S2303, S2304, S2401, S2501, S2601, S2701, S2801, S2901, S3001, S3002, S3003, S3004, S3005, S3006, S3007, S3101, S3201, S3202: steps;

[0061] S604: CG-SDT resource adjustment procedure / step;

[0062] S605: CG-SDT failure handling procedure / steps;

[0063] S2208: First alternative;

[0064] S2209: Second alternative;

[0065] S2401a: Recovery procedure;

[0066] S2501a: RACH-based SDT procedure. DETAILED DESCRIPTION

[0067] Reference will now be made in detail to the present exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0068] In solving the previously described problem, the present invention provides a mechanism for a UE to be configured with multiple CG-SDT configurations associated with multiple cells so that when the UE migrates from one cell to another, the last CG-SDT configuration of the UE will still be valid without subjecting the UE to unnecessary signaling and configuration procedures, so as to potentially relieve the burden on the network by reducing signaling overhead and by allowing the network to redistribute UEs operating in an inactive state, thereby better achieving load rebalancing. Figure 4 and Figure 5 The inventive concepts of the present invention are shown in FIG. 1 and described by its corresponding written description.

[0069] Figure 4 A method for pre-configuring resources for small data transmission by a UE in an inactive state according to an exemplary embodiment of the present invention is shown. In step S401, the UE will receive a configured grant (CG) configuration for small data transmission before entering the inactive state. In step S402, the UE will verify the CG resources of the resident cell associated with the CG configuration by determining whether the resident cell meets the verification condition before triggering the small data transmission (SDT) procedure. The CG configuration may include a CG configuration list associated with a cell list. In step S403, when it is determined that the verification condition is met, the UE will utilize the CG resources for the SDT procedure.

[0070] Figure 5 Show use Figure 4 The UE may include, but is not limited to, a processor 501, a transceiver 502, and a storage medium 503. The processor 501 is electrically connected to the transceiver 502 and the storage medium 503, and is configured to at least implement the method described in Figure 4 The methods described in and subsequent exemplary embodiments.

[0071] Transceiver 502 may be one or more integrated or separate transceiver modules, and each of the transceiver modules may include one or more integrated or separate transmitters and receivers configured to transmit and receive signals at radio frequencies or at millimeter wave frequencies, respectively. Transceiver 502 may also perform operations such as low-noise amplification, impedance matching, frequency mixing, up-conversion or down-conversion, filtering, amplification, etc. Transceivers 502 may each include one or more analog-to-digital (D / A) converters or digital-to-analog (D / A) converters configured to convert from an analog signal format to a digital signal format during uplink signal processing and from a digital signal format to an analog signal format during downlink signal processing. Transceivers 502 may each further include an antenna array, which may include one or more antennas that transmit and receive omnidirectional antenna beams or directional antenna beams.

[0072] Processor 501 is configured to process digital signals and execute the program of the proposed method according to the proposed exemplary embodiment of the present invention. Furthermore, processor 501 can access storage medium 503, which stores programming code, codebook configuration, buffered data, and recording configuration specified by processor 501. Processor 501 can be implemented using a programmable unit such as a microprocessor, microcontroller, DSP chip, or FPGA. The functions of processor 501 can also be implemented using a separate electronic device or IC. It should be noted that the functions of processor 501 can be implemented using hardware or software.

[0073] To further clarify the Figure 4 and Figure 5

[0026] With reference to the inventive concepts shown in the accompanying drawings and described in its corresponding written description, the present invention provides various exemplary embodiments as shown in the subsequent drawings and described in its corresponding written description. Figure 6 A signaling diagram is provided to describe a procedure for configuring multiple CG configurations associated with multiple cells as an overview of various exemplary embodiments. Figure 6 The procedure may include a CG-SDT resource adjustment procedure S604 and a CG-SDT failure handling procedure S605. Generally speaking, the CG resources of a cell are usually divided into several CG resource sets, because each CG resource set may have a predetermined resource location, resource size, periodicity, characteristics, etc. Each CG resource set is associated with a different CG-SDT resource configuration and can therefore be obtained by selecting the corresponding CG-SDT resource configuration. The present invention will allow a UE operating in an inactive state to obtain resources for SDT by obtaining a CG-SDT resource configuration that can be used once it is determined to be valid when the UE migrates between cells.

[0074] Figure 6 is implemented as follows. In step S601, the last serving cell 612 of the UE 611 will negotiate with multiple neighboring cells 613 in the network for CG resources (CG-SDT resources) for the SDT procedure. The purpose of step S601 is to decide a common CG-SDT resource principle from multiple CG-SDT resource principles based on the service type or the type of UE 611. CG-SDT resources can be resources reserved for a dedicated UE (e.g., 611) or a group of UEs based on network policy. In step S602, the last serving cell 612 of the UE 611 will transmit a message (i.e., a CG-SDT configuration message) containing the CG configuration (CG-SDT configuration) to be used for SDT to the UE 611. The CG-SDT configuration message contains the CG configuration to be used by the UE 611 for the upcoming SDT procedure. In step S603, the UE 611 will perform cell selection among the cells 613 before entering into an inactive state, which may be, for example, a sleep mode, a low power mode, or disconnected.

[0075] In step S604, the UE may perform a CG-SDT resource adjustment procedure S604, during which the UE 611 will verify the validity of the CG-SDT configuration based on the latest reserved CG-SDT status, while both the last serving cell 612 and the multiple neighboring cells 613 will provide the latest reserved CG-SDT status. Therefore, depending on the current cell status, the reserved CG-SDT status may need to be updated. Therefore, the latest reserved CG-SDT status is used to inform the UE 611 whether the CG-SDT resources are still valid. Since the status of any cell within the multiple cells 613 may change over time, each cell may need to adjust its reserved CG-SDT resources. The adjustment of the reserved CG-SDT resources may cause the UE (e.g., 611) to be in an inactive state, in which it is necessary to check the validity of the cell's CG-SDT configuration after camping on the cell before performing SDT by using the CG resource (i.e., CG-SDT transmission) trigger procedure. In step S605, the UE 611 may perform a CG-SDT failure handling procedure S605. The CG-SDT failure handling procedure S605 may include the following two cases: the first case involves handling CG-SDT transmission failure and the second case involves handling invalid CG-SDT configuration.

[0076] For the CG-SDT resource adjustment procedure S604, the present invention provides two different exemplary embodiments, which may affect how the cell provides the latest reserved CG-SDT resource status information in different ways. For the first exemplary embodiment, the cell is allowed to configure and release the configuration of the CG-SDT resources. For the second exemplary embodiment, the cell is allowed to modify the configuration of the CG-SDT resources in order to configure, reconfigure, update and release the configuration of the CG-SDT resources. For the first exemplary embodiment, the UE (e.g., 611) may obtain the CG-SDT resource configuration before entering the inactive state. For the second exemplary embodiment, the UE (e.g., 611) may obtain a valid CG-SDT resource configuration just before triggering the CG-SDT procedure or just after verifying that the CG-SDT resource configuration is invalid.

[0077] At least in the present invention Figure 22 The general concept of the second exemplary embodiment is shown in For both the first and second embodiments, the UE will obtain the CG-SDT resource set configuration of the camped cell in the previous serving cell. Figure 27 Describes an alternative scenario where the UE may not obtain the CG-SDT resource set configuration of the resident cell in the previous serving cell. Instead, the UE may obtain the CG-CofigSchedule from the resident cell. Therefore, the CG-CofigSchedule may be used by the resident cell to schedule its own CG-SDT resource set configuration. Therefore, the UE may obtain the resident CG-SDT resource set configuration from the resident cell itself using the CG-CofigSchedule.

[0078] To further explain the configuration and Figure 6 The procedure for configuring multiple CGs associated with multiple cells is expanded upon, and the subsequent invention content provides a more detailed explanation. Figures 7 to 17 This is an embodiment directed to the first exemplary embodiment, wherein the UE may obtain the CG-SDT resource configuration before entering the inactive state. Figures 19 to 32 This is an embodiment for the second exemplary embodiment, wherein the UE may obtain the CG-SDT resource configuration just before triggering the CG-SDT procedure.

[0079] Figure 7 An example of a CG-SDT resource negotiation procedure (eg, S601) between cell A and cell X according to the first exemplary embodiment is shown, wherein the UE may obtain a CG-SDT resource configuration before entering an inactive state. Figure 7In step S701, cell A and cell X may perform CG-SDT resource negotiation. Cell A may initiate the negotiation by transmitting a CG-SDT resource request message. In response to receiving the CG-SDT resource request message, cell X may transmit a CG-SDT resource response message containing a CG-SDT resource configuration to cell A.

[0080] Depending on network policy and cell conditions, CG-SDT resources for a cell may be reserved for another cell or may be reserved for a group of cells. The CG-SDT resources of cell X may be divided into several CG-SDT resource sets because each CG-SDT resource set may have different resource sizes, different periodicities, different characteristics, etc. Each CG-SDT resource set may be configured by a CG-SDT resource configuration. Therefore, once cell X receives a CG-SDT resource request from another cell (e.g., cell A), cell X may reserve a CG-SDT resource set for cell A and provide the corresponding CG-SDT resource configuration within the CG-SDT resource response message. Cell X may use the information of the CG-SDT resource request message to determine how to reserve CG-SDT resources. For example, if cell A requests CG-SDT resources with a smaller resource size and shorter periodicity, cell X may reserve such a CG-SDT resource set for cell A. Based on the information in the CG-SDT resource request message, cell X may be able to provide multiple CG-SDT resource sets to cell A.

[0081] After performing CG-SDT resource negotiation S701, cell A may then begin configuring the CG-SDT resources of cell X to the UE in step S702a. Furthermore, in step S702b, cell X may provide the latest reserved CG-SDT resource status. The purpose of the reserved CG-SDT resource status is to inform UEs currently residing in cell A and operating in an inactive state about the stored CG-SDT configuration status of cell X. Therefore, based on the latest reserved CG-SDT resource status, the UE operating in an inactive state can decide to release, update, or use the stored CG-SDT configuration of cell X.

[0082] Figure 8It is shown that there may be different types of reserved CG-SDT resource states, which may be cell-based 801, CG-SDT configuration-based 802, or hybrid 803. For the cell-based reserved CG-SDT resource state 801, the reserved CG-SDT resource state may be valid or invalid for each reservation target, which may include a large number of cells (e.g., cell A, cell B, etc.). In this example, both cell A and cell B contain valid reserved CG-SDT resource states, and this means that all CG-SDT configurations reserved for cell A and cell B are valid. For the CG-SDT configuration-based reserved CG-SDT resource state 802, the reserved CG-SDT resource state may be valid or invalid for each different CG-SDT configuration identifier (ID). The CG-SDT configuration ID for each CG-SDT configuration may be unique. In this example, both CG configuration 1 and CG configuration 2 contain valid reserved CG-SDT resource states. In addition, when the type of the reserved CG-SDT resource state is hybrid 803, both the cell-based reserved CG-SDT resource state and the CG-SDT configuration-based reserved CG-SDT resource state are adopted and combined. For the hybrid type reserved CG-SDT resource state 803, a plurality of CG-SDT configurations can be supported as a reservation target of the cell, and each CG-SDT configuration can be valid or invalid. Figure 8 In the example, cell B supports CG-SDT configuration 1 and CG-SDT configuration 3, and both CG-SDT configurations are valid.

[0083] Next, return to the reference Figure 7 After completing steps S702a and S702b, in step S703, cell X may transmit a CG-SDT resource release message to cell A. In response to receiving the CG-SDT resource release message, in step S704a, cell A may stop configuring the CG-SDT resources of cell X to the UE (e.g., 611), and in step S704b, cell X may provide the latest reserved CG-SDT resource status. Once the cell conditions of cell X change (e.g., the load has become heavier), cell X may decide to release some reserved CG-SDT resources. To achieve this, cell X may use the CG-SDT resource release message of step S703 to notify the reservation target (e.g., cell A) which CG-SDT configurations will be released. After receiving the CG-SDT resource release message from cell X, cell A will stop configuring the CG-SDT resources released by cell X to the UE.

[0084] Figure 9An example of updating the reserved CG-SDT resource state by cell X is shown. Assuming that the reserved CG-SDT resource state is based on the cell (e.g., 801), cell X may release the CG-SDT configuration by deleting the entry associated with the reservation target. For example, in order to release the CG-SDT configuration, in step S901, cell X may delete the entry corresponding to the released CG-SDT configuration from the reserved CG-SDT resource state to indicate that the CG-SDT configuration corresponding to cell X is invalid. Similarly, assuming that the reserved CG-SDT resource state is based on the CG-SDT configuration (e.g., 802), cell X may release the CG-SDT configuration by changing the state of the CG-SDT resource ID. For example, in order to release the CG-SDT configuration, in step S902, cell X may change or mark the state of the CG-SDT resource ID corresponding to the released CG-SDT configuration from the reserved CG-SDT resource state to invalid, thereby indicating that the CG-SDT resource corresponding to the CG-SDT configuration ID has been released.

[0085] Next, refer to Figure 10 In step S1001, the last serving cell (e.g., 612 or cell A) may transmit a release message to the UE (e.g., 611), and the release message may include, but is not limited to, a suspension indicator, an inactive state configuration, an SDT configuration, and a CG-SDT configuration. In response to receiving the release message, in step S1002, the UE may enter an inactive state. After being in the inactive state, in step S1003, the SDT may be triggered. The suspension indicator is used to notify the UE to enter the inactive state. The inactive state configuration may include, but is not limited to, an I-radio network temporary identifier (I-RNTI), a radio network access (RAN) networking area (RNA) configuration, and security-related information. The SDT configuration may include information related to SDT parameters, such as SDT triggering conditions, applied DRB information, etc. The CG-SDT configuration may include entries describing which CG-SDT configurations will be applied for each cell ID.

[0086] exist Figure 10In the example, CG-SDT configuration 1 will be applied to cell X, CG-SDT configuration 2 will be applied to cell Y, and so on. Each different CG-SDT resource configuration may include at least a CG-SDT configuration ID, a CG-SDT resource location, a CG_Timer, a CG resource size, a periodicity, and some L1 parameters, such as a demodulation reference signal (DMRS) and a CG-RNTI for transmitting SDT. The UE may use the DMRS and CG-RNTI to transmit uplink (UL) data at the reserved CG resources. The UE may also use the configured DMRS to transmit SDT and may use the CG-RNTI to scramble the SDT data.

[0087] Assuming that the UE has migrated from the last serving cell and camped at cell X, the UE will determine whether CG-SDT can be triggered. Figure 11 An example of a UE determining whether to trigger CG-SDT when camping on cell X is shown. In step S1101, it is assumed that the UE has entered an inactive state. In step S1102, when the UE camps on cell X, in step S1103, the UE can determine whether to receive the latest reserved CG-SDT resource status by determining whether the camping cell (e.g., cell X) is found in the stored CG-SDT configuration. If cell X is not in the stored CG-SDT configuration, then in step S1104, the UE will determine that CG-SDT should not be triggered. If cell X is in the stored CG-SDT configuration, then in step S1105, the UE will receive the latest reserved CG-SDT resource status. In this case, in step S1106, the UE will receive the reserved CG-SDT resource status from cell X. In step S1107, the UE can trigger SDT.

[0088] Figures 12 to 14 Different embodiments of a UE triggering SDT when the reserved CG-SDT resource status is in different formats are shown. Figure 12 An example of a UE triggering CG-SDT when the reserved CG-SDT resource status is cell-based is shown. In response to receiving the reserved CG-SDT resource status (e.g., S1103) from cell X, in step S1201, the UE will determine whether the CG-SDT resources of the resident cell are valid. Assuming that the CG-SDT resources of the resident cell are valid, then in step S1202, the UE will determine that CG-SDT can be triggered at the resident cell which is cell X. Assuming that the CG-SDT resources of the resident cell are not valid, then in step S1203, the UE will delete the stored CG-SDT configuration corresponding to the resident cell. Figure 12In the example of , the stored reserved CG-SDT resource status has entries corresponding to the previously camped cells being cell A and cell B. This means that the reserved CG-SDT resource status is valid only when the last serving cell is cell A or cell B. If the UE's last serving cell is not cell A or cell B, the CG-SDT configuration for cell X will be invalid, and the UE will then delete any entry containing cell X in the reserved CG-SDT resource status (if any).

[0089] Figure 13 An example of a UE triggering CG-SDT when the reserved CG-SDT resource status is based on the CG-SDT configuration is shown. In response to receiving the reserved CG-SDT resource status (e.g., S1103) from cell X, in step S1301, the UE will determine whether the CG-SDT resources of the resident cell are valid. Assuming that the CG-SDT resources of the resident cell are valid, then in step S1302, the UE will determine that CG-SDT can be triggered at the resident cell which is cell X. Assuming that the CG-SDT resources of the resident cell are not valid, then in step S1303, the UE will delete the stored CG-SDT configuration corresponding to the resident cell. Figure 13 In the example of , the stored reserved CG-SDT resource status has entries corresponding to CG-SDT configuration 1 and CG-SDT configuration 2. This means that the configured CG-SDT resources are valid only when the CG-SDT configuration ID of cell X is CG-SDT configuration 1 or CG-SDT configuration 2. Otherwise, if the CG-SDT configuration of cell X is neither CG-SDT configuration 1 nor CG-SDT configuration 2, the CG-SDT configuration of cell X is invalid and the UE shall then delete any entry containing cell X in the reserved CG-SDT resource status (if any).

[0090] Figure 14 An example of a UE triggering CG-SDT when the reserved CG-SDT resource status is hybrid is shown. In response to receiving the reserved CG-SDT resource status (e.g., S1103) from cell X, in step S1401, the UE will determine whether the CG-SDT resources of the resident cell are valid. Assuming that the CG-SDT resources of the resident cell are valid, then in step S1402, the UE will determine that CG-SDT can be triggered at the resident cell which is cell X. Assuming that the CG-SDT resources of the resident cell are not valid, then in step S1403, the UE will delete the stored CG-SDT configuration corresponding to the resident cell. Figure 14In the example, if the last serving cell is cell B and the CG-SDT configuration ID of cell X is CG-SDT configuration 1 or CG-SDT configuration 3, then the configured CG-SDT resources of cell X are considered valid. Similarly, if the last serving cell of the UE is cell A and the CG-SDT configuration ID of cell X is CG-SDT configuration 2, then the configured CG-SDT resources of cell X are considered valid. Otherwise, the CG-SDT configuration of cell X is considered invalid.

[0091] After executing the CG-SDT resource adjustment procedure (e.g., S604), if the CG-SDT configuration is valid, the UE may trigger CG-SDT transmission. If the CG-SDT transmission is unsuccessful, the UE may execute a CG-SDT failure handling procedure for CG-SDT transmission failure. Figure 15 A procedure for determining whether CG-SDT transmission is successful or failed based on the first exemplary embodiment of the present invention is shown. In step S1501, a UE in an inactive state may transmit a radio resource control (RRC) message carrying UL data within a CG-SDT resource to a resident cell. The CG-SDT resource is a reserved CG-SDT resource, which may be dedicated to the UE or shared among a UE group depending on network policy. After step S1501, the UE will wait for a response message and will determine whether a response message is received within a time window defined by, for example, a CG_Timer. The purpose of the response message is to inform the UE whether the CG-SDT has been successful. The response message may be transmitted via a layer 1 message, such as an acknowledgment (ACK) message, a media access control (MAC) control element (CE), or an RRC SDT comprehensive message. The UE may also receive the response message using the CG-RNTI configured by the CG resource configuration.

[0092] When the UE transmits small data by using CG-SDT resources, CG_Timer will start. When the UE receives a response message, CG_Timer will stop. In step S1502, the UE will receive a response message from the camped cell. If the response message is received before the CG_Timer expires, the CG-SDT is considered successful. Figure 15 In the top signaling diagram of , assuming that the response message is received before the CG_Timer expires, then the CG-SDT has succeeded. Figure 15In the bottom signaling diagram of FIG, if a response message is received after the CG_Timer has expired or no response message is received, then the CG-SDT is considered to have failed. Assuming that the CG-SDT has failed, then in step S1503, three different methods can be used to handle the CG-SDT failure as part of the CG-SDT failure handling procedure (e.g., S605).

[0093] Figures 16 to 18 Three methods of handling CG-SDT transmission failure when executing the CG-SDT failure handling procedure (e.g., S605) are shown. In method 1, assuming that the RACH-based procedure is enabled at the resident cell, the UE in the inactive state can use the random-access channel (RACH)-based procedure to retry SDT. In method 2, the UE in the inactive state can fall back to the recovery procedure to resume transmission. In method 3, the UE in the inactive state can randomly skip some CG-SDT resources and trigger CG-SDT by using the CG-SDT resources.

[0094] References Figure 16 In the signaling diagram of method 1 shown in , before step S1601, the UE in the inactive state may start a timer of a specific duration set according to the parameter CG_Timer, and the UE will then use the CG-SDT resources to transmit an RRC message carrying UL data. The UE will then determine whether there is a CG-SDT failure based on whether the corresponding response message is received before the CG_Timer expires. Assuming that a CG-SDT failure has occurred, in step S1601, if the RACH-based SDT procedure has been initiated by the camped cell, the UE in the active state and the inactive state UE may use the RACH-based SDT procedure to retry SDT. The RACH-based SDT procedure includes the UE transmitting a dedicated preamble reserved for the RACH-based SDT procedure to request UL resources for the RACH-based SDT. If the random-access response (RAR) includes an indicator indicating that the request has been approved, the UE will use the UL resources indicated in the RAR to transmit a ResumeRequest message carrying UL data for the RACH-based SDT. If the RAR does not indicate approval, the UE shall perform a resume procedure to restore the connection to the camped cell. The UE shall send a ResumeRequest with UL data using the UL resources indicated in the RAR. The camped cell may then respond to step S1601 by transmitting a Release message to the UE to instruct the UE to return to inactive state operation.

[0095] References Figure 17, a signaling diagram of Method 2 is shown in FIG. Prior to step S1701, operations are assumed to be the same or similar to those of Method 1. In step S7101, the inactive UE may fall back to a recovery procedure to restore connectivity with the camped cell. The inactive UE may also transmit UL data using the signaling involved in the recovery procedure or additional signaling. In other words, the UL data may be embedded in the signaling of the recovery procedure or may be part of additional signaling after the recovery procedure.

[0096] References Figure 18 . Before step S1801, it is assumed that the operations are the same as or similar to those of method 1. In step S1801, the UE in an inactive state may randomly skip one or some CG-SDT resources. In step S1802, the UE may trigger CG-SDT by using a randomly selected CG-SDT resource after the skipped CG-SDT resource. For example, the UE may randomly skip the Nth CG-SDT resource and trigger CG-SDT at the (n+1)th CG-SDT resource, where N is an integer greater than zero.

[0097] Next, the subsequent invention content relates to a second exemplary embodiment, in which the UE can obtain the CG-SDT resource configuration just before triggering the CG-SDT procedure. For the first exemplary embodiment, the CG-SDT configuration only involves procedures related to configuration and release, but does not update the CG-SDT configuration. However, since the conditions of the cell and its CG-SDT situation do not remain unchanged, it may be necessary to update the CG-SDT configuration in order to optimize the utilization of resources and the success rate of CG-SDT. For example, when the load of the cell becomes heavier, the success rate of CG-SDT may decrease, and therefore the CG-SDT resources may need to be updated.

[0098] Figure 19 An example of a CG-SDT resource negotiation procedure (e.g., S601) between cell A and cell X based on the second exemplary embodiment is shown, wherein the UE can obtain the CG-SDT resource configuration before entering the inactive state, and the cell is allowed to modify the CG-SDT configuration, for example, by reconfiguring, releasing, and updating the CG-SDT configuration. In addition, another purpose of the CG-SDT negotiation is to support CG-SDT configuration updates. Figure 19 In step S1901, cell A and cell X may perform CG-SDT resource negotiation. Cell A may initiate the negotiation by transmitting a CG-SDT resource request message. In response to receiving the CG-SDT resource request message, cell X may transmit a CG-SDT resource response message to cell A containing a CG-SDT resource configuration and additional version information.

[0099] Figure 19The CG-SDT resource negotiation procedure is Figure 7 The resource negotiation procedure for Cell X is very similar. However, for this example, the CG-SDT configuration of Cell X may be updated due to changes in the conditions experienced by Cell X. Configuration versioning may be used to assist the UE in verifying whether the CG-SDT configuration has been updated. To support CG-SDT resource updates, the cell that reserves the CG-SDT resources (i.e., Cell X) will need to provide version information of the CG-SDT configuration in order to request CG-SDT resources from another cell (e.g., Cell A).

[0100] After cell A negotiates CG-SDT resources with cell X, in step S1902, cell X must provide a reserved CG-SDT resource status. Providing the reserved CG-SDT resource status is another primary purpose for enabling cell X to provide CG-SDT version information to cell A to support CG-SDT resource (or configuration) updates. Figure 20 Different types of reserved CG-SDT resource states are shown, which may be cell-based 2001, CG-SDT configuration-based 2002, or hybrid 2003. For the cell-based reserved CG-SDT resource state 2001, for each reservation target, which may include a large number of cells (e.g., cell A, cell B, etc.), the reserved CG-SDT resource state includes a version number of the CG-SDT resource configuration. For the CG-SDT-based reserved CG-SDT resource state 2002, each different CG-SDT configuration ID may be associated with a version number. In this example, CG configuration 1 is associated with version number 1, and CG configuration 2 is associated with version number 2. In addition, when the type of reserved CG-SDT resource state is hybrid 2003, both the cell-based reserved CG-SDT resource state and the CG-SDT configuration-based reserved CG-SDT resource state are then adopted and merged. For the mixed type reserved CG-SDT resource state 2003, the reservation target of the cell can support multiple CG-SDT configurations, and each CG-SDT configuration is associated with a version number. Figure 20 In the example, cell B supports CG-SDT configuration 1 associated with version number 2 and CG-SDT configuration 3 associated with version number 1, and cell A supports CG-SDT configuration 2 associated with version 3.

[0101] Then, similar to Figure 10 , the last serving cell (eg, 612 or cell A) may transmit a release message to the UE (eg, 611), the release message may include but is not limited to the following: Figure 21, the pause indicator, inactive state configuration, SDT configuration and CG-SDT configuration shown in . However, for the second exemplary embodiment, the CG-SDT configuration may further include a version number. In response to receiving a release message, the UE may enter an inactive state. After being in the inactive state, the SDT may be triggered. The pause indicator is used to notify the UE to enter the inactive state. The inactive state configuration may include but is not limited to an I-Radio Network Temporary Identifier (I-RNTI), a Radio Network Access (RAN) Networking Area (RNA) configuration and security-related information. The SDT configuration may include information related to SDT parameters, such as SDT triggering conditions, applied DRB information, etc. The CG-SDT configuration may include entries describing which CG-SDT configurations will be applied for each cell ID, and each CG-SDT configuration may be associated with a different version number.

[0102] exist Figure 21 In the example of , CG-SDT configuration 1 will be applied to cell X, CG-SDT configuration 2 will be applied to cell Y, and CG-SDT configuration 3 will be applied to cell Z. In addition, each CG-SDT configuration can be associated with the latest CG-SDT configuration version number. Figure 21 In the example of , CG-SDT configuration 1 is associated with version 1, CG-SDT configuration 2 is associated with version 0, and CG-SDT configuration 3 is associated with version 2. Each different CG-SDT resource configuration may include at least a CG-SDT configuration ID, a CG-SDT resource location, a CG_Timer, a CG resource size, a periodicity, and some L1 parameters, such as a demodulation reference signal (DMRS) and a CG-RNTI for transmitting SDT. The UE may use the DMRS and the CG-RNTI to transmit uplink (UL) data at the reserved CG resources. The UE may also use the configured DMRS to transmit SDT and may use the CG-RNTI to scramble the SDT data.

[0103] exist Figures 22 to 27 The procedure for triggering CG-SDT for an active UE is shown in , where it is assumed that the UE obtains CG-SDT resource configuration before entering the inactive state, and the handling of invalid CG-SDT resources is also described. Figure 22 The procedure of triggering CG-SDT in a UE supporting CG-SDT resource update as part of step S605 according to the second exemplary embodiment of the present invention is shown. Figure 22In step S2201, the UE in the inactive state will receive the latest reserved CG-SDT resource status that will update the CG-SDT configuration. In step S2202, the UE will determine whether the currently stored CG-SDT configuration is still valid in response to receiving the reserved CG-SDT resource status. In step S2203, the UE has determined that the currently stored CG-SDT configuration is valid, and Figure 23 The meaning of step S2203 is further described in the corresponding written description. Assuming the stored CG-SDT configuration is no longer considered valid, in step S2204, the UE determines whether the stored CG-SDT configuration is invalid due to version information. If so, the process continues with step S2206 or, alternatively, step S2207, which discards the stored CG-SDT configuration. If not, in step S2205, the UE discards the stored CG-SDT configuration.

[0104] Assuming the procedure continues from step S2206, the UE will obtain the latest CG-SDT configuration after determining that the current version information is outdated or invalid. Step S2206 has two alternatives, where the first alternative S2208 involves the UE obtaining the latest CG-SDT configuration just after discovering that the CG-SDT configuration is invalid, or alternatively, the second alternative S2209 involves the UE obtaining the latest CG-SDT configuration when the UE triggers SDT. For the second alternative S2209, the UE can obtain the latest CG-SDT configuration when the UE triggers SDT by using a recovery procedure that requests the latest CG configuration (S2210) or by using a RACH-based SDT that requests the latest CG configuration and transmits UL data (S2211).

[0105] exist Figure 23 The procedure for triggering CG-SDT using a UE that supports CG-SDT resource update is shown in FIG. Figure 23 For further details, we assume that the CG-SDT configuration is valid. Figure 23 In step S2301, the UE in the inactive state resides on cell X. In step S2302, the UE receives the reserved CG-SDT resource status from cell X. Figure 23In the example, it is assumed that the reserved CG-SDT resource state is a cell-based CG-SDT resource state, but the reserved CG-SDT resource state may also be of other types, such as based on CG-SDT configuration or a hybrid. In addition, according to the reserved CG-SDT resource state, in this example, cell A has CG-SDT configuration version 2, while cell B has CG-SDT configuration version 1. This means that assuming cell A is the last serving cell of the UE before cell X, the version of the stored CG-SDT configuration must be version 2. In step S2303, the UE will check its stored CG-SDT configuration version. Assuming that the stored CG-SDT configuration version matches the required version information according to the reserved CG-SDT resource state, the stored CG-SDT resource state is considered to be valid. Therefore, if the stored CG-SDT configuration version of the UE is version 2, the stored CG-SDT configuration version is valid. In step S2304, the UE can trigger SDT by using the CG-SDT resources of cell X.

[0106] exist Figure 24 The procedure for handling invalid CG-SDT configuration is shown in . Figure 24 Steps and Figure 23 Similarly, except that after checking the CG-SDT configuration version (S2303), the UE discovers that the stored CG-SDT configuration version is invalid as required by the reserved CG-SDT resource status, this is because the stored cell X CG-SDT configuration version is version 1, which is not the latest version. In step S2401, the UE will respond to the invalid CG-SDT configuration by obtaining the latest CG-SDT configuration (i.e., S2208) just after discovering that the CG configuration is invalid due to the version information. The UE can do this by using a recovery procedure (i.e., S2210) to request the latest CG-SDT configuration. During the recovery procedure (S2401a), the UE will transmit a recovery request message containing a request for the updated CG-SDT configuration to the camped cell (cell X). The UE will then receive a release message containing the latest CG-SDT configuration from cell X. After receiving the latest CG-SDT configuration, the UE can trigger SDT by using the latest CG-SDT configuration.

[0107] Figure 25 Show Figure 24 An alternative to the example of . Figure 25 In the steps Figure 24The same as S2501, except that when the UE needs to transmit UL data through the SDT procedure, it uses the RACH-based SDT procedure (S2501a) instead of the recovery procedure (S2401a) to obtain the latest CG-SDT configuration. For the RACH-based SDT procedure (S2051a), the UE will transmit a recovery request message containing a request for the updated CG-SDT configuration and UL data to the camped cell, which is cell X. In response to transmitting the recovery request message, the UE will receive an RA response (RAR) message containing the latest CG-SDT configuration from cell X. After receiving the latest CG-SDT configuration, the UE can trigger SDT by using the latest CG-SDT configuration.

[0108] Figure 26 Show Figure 24 and Figure 25 Another alternative to the example of . Figure 26 In the steps Figure 24 or Figure 25 Similarly, except that after determining that the CG-SDT configuration version is invalid, the UE will discard the stored CG-SDT configuration in step S2601. However, assuming that the RACH-based procedure is enabled at the camping cell X, the UE can still use the RACH-based procedure for SDT even if the CG-SDT configuration stored in the UE is discarded.

[0109] Alternative Figure 26 , another situation where the CG-SDT configuration is invalid is because the stored CG-SDT configuration in the UE does not exist in the reserved CG-SDT resource state. This type of situation may occur if it is assumed that the last serving cell of the UE is cell C, and it is assumed that the version of the stored cell X CG-SDT configuration of the UE is version 1. In this type of situation, after the UE has checked the reserved CG-SDT resource state, the UE will consider the currently stored CG-SDT configuration of cell X to be invalid because the last serving cell of the UE is cell C that does not exist in the reserved CG-SDT resource state. When the CG-SDT configuration is invalid due to the non-existence of the CG-SDT configuration in the reserved CG-SDT resource state, the UE may discard the stored CG-SDT configuration corresponding to cell X. Subsequently, assuming that the RACH-based procedure has been enabled at the camped cell X, the UE may use the RACH-based procedure for SDT.

[0110] for Figures 19 to 26In the example, the UE may obtain the CG-SDT resource configuration just before entering the inactive state, and the UE will subsequently store the CG-SDT resource configuration during the inactive state. In these examples, the cell that reserves the CG resources may need to broadcast the reserved CG-SDT resource status in the system information broadcast message. Therefore, the timing of updating the reserved CG-SDT resources may be limited by the modification period of the system information broadcast message. In addition, the UE will need to perform a verification process to verify the validity of the stored CG-SDT configuration after camping on the cell. If the UE does not trigger the CG-SDT, the verification process is redundant and results in waste. However, instead of Figures 19 to 26 In the example, when the UE is triggered to trigger CG-SDT, the UE can actually obtain the CG-SDT resource configuration for the camped cell (i.e., S2209). Therefore, the camped cell can dynamically update the reserved CG-SDT resources, and the UE will only need to obtain the CG-SDT resource configuration from the camped cell when the UE needs to trigger CG-SDT. Figures 27 to 32 A related example is provided, in which when the UE triggers CG-SDT, the UE obtains CG-SDT resource configuration from the resident cell.

[0111] Figure 27 An example of how CG-SDT resources are negotiated between cell A and cell X using CG-Cofigschedule is shown to describe how the camped cell will provide CG-SDT resource configuration. Figure 27 In step S2701, cell A will transmit a CG-SDT request message to cell X, and cell X will respond by transmitting a CG-SDT response message including the parameter CG-Cofigschedule. In this example, cell X, which reserves CG-SDT resources, will provide CG-SDT resource configuration by itself, and therefore cell X does not need to provide CG-SDT resource configuration during the negotiation of CG-SDT resources. Instead, in step S2702, cell X will provide CG-CofigSchedule within the CG-SDT response message. CG-CofigSchedule is information on how cell X will schedule CG-SDT resource configuration. For example, CG-CofigSchedule may include at least a search space for CG configuration and a CG_config-RNTI (CGC-RNTI) for receiving CG configuration and / or scheduling transmission of CG configuration.

[0112] The CG-CofigSchedules for different CG-SDT configurations may be the same or different. For example, cell X may reserve CG-SDT resource 1 for cell A and may reserve CG-SDT resource 2 for cell B. The CG-CofigSchedule for the CG-SDT configuration associated with CG-SDT resource 1 and the CG-CofigSchedule for the CG-SDT configuration associated with CG-SDT resource 2 may be different. However, if cell X may reserve both CG-SDT resource 1 and CG-SDT resource 2 for cell A, then the CG-CofigSchedule for the CG-SDT configuration associated with CG resource 1 and the CG-CofigSchedule for the CG-SDT configuration associated with CG-SDT resource 2 may be the same.

[0113] After the UE migrates to another cell, a release message is transmitted from the last serving cell to the UE. Figure 28 An example of using a release message to transmit a CG-SDT configuration including a CG-Cofigschedule is shown in FIG. 2801. In step S2801, the last serving cell transmits a release message including a CG-CofigSchedule to the UE. In response to receiving the release message, the UE may enter an inactive state and then the UE may trigger a CG-SDT. The release message may include a pause indicator, an inactive state configuration, an SDT configuration, and a CG-SDT configuration. The pause indicator is used to notify the UE to enter an inactive state. The inactive state configuration may include an I-RNTI, an RNA configuration, and security-related information. The SDT configuration includes information related to SDT parameters, such as SDT triggering conditions, applied DRB information, etc. The CG-SDT configuration may include at least a CG-CofigSchedule, and may also include Table 2802 describing which CG-SDT configurations will be applied for a particular cell. For example, Table 2802 shows that CG-SDT configuration 3 will be applied when the UE resides on cell Z.

[0114] Figure 29The example shows an inactive UE residing on cell X. In step S2901, before the UE triggers CG-SDT, the UE may obtain the CG-SDT resource configuration. However, in this example, cell X may not provide a reserved CG-SDT resource status. Therefore, before the UE triggers CG-SDT, the UE will verify whether the CG-SDT configuration is valid according to the CG-Cofigschedule before the UE triggers CG-SDT. If the CG-SDT configuration is valid according to the CG-Cofigschedule before the UE triggers CG-SDT, the UE will use the configured CG-SDT resources for CG-SDT. If the CG-SDT configuration is invalid according to the CG-Cofigschedule before the UE triggers CG-SDT, the UE cannot obtain the CG-SDT resource configuration through the corresponding CG-CofigSchedule. Therefore, failure may occur due to the fact that the CG-SDT resource configuration does not exist in the resident cell. Assuming that the RACH-based procedure has been enabled at the resident cell, the UE may then actually use the RACH-based procedure for SDT. Otherwise, the UE will consider that SDT is invalid in the camped cell X.

[0115] Figure 30 An example of a CG-SDT triggering procedure is shown. In this example, it is assumed that the inactive UE has a pre-existing stored CG-SDT configuration, and it is assumed that the inactive UE resides on cell X that is within the list of stored CG-SDT configurations. However, in this example, cell X may provide a reserved CG-SDT resource status indicating a valid CG configuration. Figure 30The procedure is as follows. In step S3001, the UE will obtain and store the reserved CG-SDT resources from cell X. In step S3002, the UE will determine whether the stored CG-SDT configuration of the resident cell is valid in the reserved CG-SDT resource state. If the stored CG-SDT configuration of the resident cell is invalid in the reserved CG-SDT resource state, then in step S3003, the UE will consider the stored CG-SDT configuration of the resident cell to be invalid. If the stored CG-SDT configuration of the resident cell is valid in the reserved CG-SDT resource state, then in step S3004, the UE will maintain the stored CG-SDT configuration of the resident cell. In step S3005, the UE will determine whether to trigger CG-SDT. If not, the process continues from step S3004. If yes, then in step S3006, the UE will obtain the CG-SDT resource configuration through CG-CofigSchedule information. In step S3007, the UE triggers CG-SDT. The entire mechanism in this example uses the status of reserved CG-SDT resources provided by the camped cell. Therefore, based on the status of reserved CG-SDT resources, the UE can first determine whether the stored CG-SDT configuration is valid. The advantage of this mechanism is that the UE can first decide whether to obtain the configuration. For example, if the stored CG-SDT configuration is known to have expired, the UE does not need to spend time trying to obtain the configuration each time it decides to trigger SDT.

[0116] Figure 31 An example of a UE that releases the stored CG-SDT configuration of a resident cell in response to a valid CG-SDT configuration and subsequently does not trigger CG-SDT is shown. Assume that an inactive UE has a stored CG-SDT configuration and the UE resides on cell X that is in the list of cells in the stored CG-SDT configuration. In step S3101, cell X provides a reserved CG-SDT resource status, which indicates that the CG configuration is valid for cell A and cell B. In principle, if the CG-SDT resource status received from the last serving cell or the last gNB is invalid, the UE in the inactive state will release the corresponding CG-SDT configuration. If the stored CG-SDT configuration is indicated as invalid according to the reserved CG-SDT resource status, then invalid CG-SDT resource status may occur. In addition, if the reserved CG-SDT resource status is cell-based and the last serving cell of the UE does not exist in the reserved CG-SDT resource status, the UE will consider the stored CG-SDT configuration of the resident cell to be invalid. In the Figure 31In the example of , since cell X is not in the reserved CG-SDT resource state 3102, the UE will then consider the stored CG-SDT configuration of cell X to be invalid and will subsequently release the stored CG-SDT configuration. The UE will then not use the stored CG-SDT configuration of the camped cell for the final SDT.

[0117] Figure 32 An example of a UE obtaining the CG resource configuration of the camped cell based on the CG-CofigSchedule within the stored CG-SDT configuration and then performing CG-SDT by using the reserved CG resources is shown. In this example, an inactive UE with a stored CG-SDT configuration camps on a cell X that is within the stored CG-SDT configuration. Cell X may provide a reserved CG-SDT resource status indicating a valid CG configuration for cell A and cell B. Figure 32 , in step S3201, cell X transmits its reserved CG-SDT resource status to the UE that is in active state and resides on cell X. Then, the UE determines whether the stored CG-SDT configuration of the resident cell is valid in the reserved CG-SDT resource status. According to the reserved CG-SDT resource status, the UE can obtain the resource status within the reserved CG-SDT resource status, and the resource status can indicate whether the stored CG-SDT configuration of the resident cell is valid or invalid. If the resource status indicates that the stored CG-SDT configuration of the resident cell is valid, then the UE in step S3202 can obtain the CG resource configuration of the resident cell based on the CG-CofigSchedule within the stored CG-SDT configuration. If the resource status indicates that the stored CG-SDT configuration of the resident cell is invalid, then the UE in step S3202 can trigger SDT by using other methods, such as by using a RACH-based procedure or a recovery procedure.

[0118] In view of the foregoing description, the present invention is applicable to use in a wireless communication system and can configure CG-SDT resources in the following manner: allowing an inactive UE to transmit small data more efficiently when the UE migrates among different cells.

[0119] Unless clearly so described, the elements, actions or instructions used in the detailed description of the invented embodiments of the present application should not be interpreted as being absolutely critical or necessary for the present invention. In addition, as used herein, each of the indefinite article "a / an" can include more than one project. If intention has only one project, the term "single" or similar language can be used. In addition, as used herein, the term "any one of" before the list of multiple projects and / or multiple project types is intended to include the project and / or project types individually or in conjunction with other projects and / or other project types "any one of," "any combination of," "any multiple of" and / or "any combination of multiple of." In addition, as used herein, the term "set" is intended to include any number of projects, including zero. In addition, as used herein, the term "number" is intended to include any number, including zero.

[0120] It will be apparent to those skilled in the art that various modifications and variations may be made to the structure of the embodiments of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention encompasses modifications and variations of the invention that fall within the scope of the appended claims and their equivalents.

Claims

1. A method for preconfiguring resources in an inactive state, the method comprising: receiving a configured permission configuration for small data transfers prior to entering an inactive state; Enter the inactive state; verifying the configured permitted resources of the camped cell associated with the configured permitted configuration by determining whether the camped cell satisfies a verification condition before triggering small data transmission, wherein the configured permitted configuration includes a configured permitted resource configuration list associated with a cell list, the verification condition includes whether the camped cell is in the cell list of the configured permitted configuration, and the verification condition further includes whether the configured permitted resources of the camped cell are valid; When it is determined that the verification condition is satisfied, the configured permitted resources are utilized for the small data transmission. 2 . The method for pre-configuring resources in an inactive state according to claim 1 , wherein each configured permitted resource configuration in the configured permitted configuration list comprises a configured permitted resource set to be used for small data transmission. 3 . The method for pre-configuring resources in an inactive state according to claim 1 , wherein each configured permitted resource configuration in the configured permitted configuration list comprises CG-CofigSchedule information for scheduling the configured permitted resource.

4. The method for pre-configuring resources in an inactive state according to claim 1, wherein whether the configured permitted resources of the camped cell are valid is judged according to the configured permitted resource status of the reserved small data transmission received from the camped cell.

5. The method for pre-configuring resources in an inactive state according to claim 4 , wherein verifying the configured permitted resources of the camped cell associated with the configured permitted configuration by determining whether the camped cell satisfies the verification condition comprises: Determining whether the last serving cell belongs to the configured permitted resource state of the reserved small data transmission according to the configured permitted resource state of the reserved small data transmission, and whether the resource state of the last serving cell is indicated as valid; as well as When, according to the configured permitted resource status of the reserved small data transmission, the last serving cell belongs to the configured permitted resource status of the reserved small data transmission and the resource status of the last serving cell is indicated as valid, it is determined that the verification condition is met.

6. The method for pre-configuring resources in an inactive state according to claim 4 , wherein verifying the configured permitted resources of the camped cell associated with the configured permitted configuration by determining whether the camped cell satisfies the verification condition comprises: Determining whether the number of configured permitted resource states for small data transmission in the resident cell is valid according to the configured permitted resource states for the reserved small data transmission; as well as When it is determined that the number of configured permitted resource states for the small data transmission of the resident cell is valid according to the configured permitted resource states for the reserved small data transmission, it is determined that the verification condition is satisfied.

7. The method for pre-configuring resources in an inactive state according to claim 1 , wherein utilizing the configured permitted resources for the small data transmission comprises: performing the small data transmission by transmitting uplink data to the camped cell using the configured granted resources; as well as A response message is received from the camped cell in response to transmitting the uplink data.

8. The method for preconfiguring resources in an inactive state according to claim 7, further comprising: By using a timer to determine whether the small data transmission is successful; as well as If the response message is received before the timer expires, the small data transmission is successful; as well as If the response message is not received before the timer expires or the response message is received after the timer has expired, the small data transmission fails.

9. The method for preconfiguring resources in an inactive state according to claim 8, further comprising: In response to the small data transmission having failed, the uplink data is retransmitted using a random access channel based procedure.

10. The method for preconfiguring resources in an inactive state according to claim 8, further comprising: In response to the small data transmission having failed, the uplink data is retransmitted using signaling within a recovery procedure.

11. The method for preconfiguring resources in an inactive state according to claim 8, further comprising: In response to the small data transmission having failed, the uplink data is retransmitted using another configured granted resource after randomly skipping some of the configured granted resources.

12. The method for pre-configuring resources in an inactive state according to claim 1, wherein each configured allowed resource configuration in the configured allowed resource configuration list associated with the cell list is further associated with a version number.

13. The method for pre-configuring resources in an inactive state according to claim 12, wherein the verification condition further comprises whether the configured permitted configuration of the camped cell is valid according to the version number.

14. The method for preconfiguring resources in an inactive state according to claim 13, further comprising: Immediately after determining that the configured permitted configuration of the camped cell is invalid, the configured permitted configuration is reacquired from the camped cell.

15. The method for preconfiguring resources in an inactive state according to claim 13, further comprising: The configured grant configuration is re-acquired from the camped cell just before performing the small data transmission.

16. The method for preconfiguring resources in an inactive state according to claim 14, further comprising: When the configured permitted resource of the resident cell is invalid due to incorrect version number, the configured permitted configuration is discarded.

17. The method for pre-configuring resources in an inactive state according to claim 3, wherein each configured permitted resource configuration of the configured permitted resource configuration list is associated with the CG-CofigSchedule from which the configured permitted resource was obtained.

18. The method for pre-configuring resources in an inactive state according to claim 17, further comprising: Verify whether the configured license resources are valid according to the CG-CofigSchedule; If the configured permitted resources are valid according to the CG-CofigSchedule, performing the small data transmission by using the configured permitted resources; and If the configured grant resources are not available according to the CG-CofigSchedule, the small data transmission is performed by using a random access channel based procedure.

19. The method for pre-configuring resources in an inactive state according to claim 18, wherein in response to the configured permitted resource being valid due to satisfying the verification condition, obtaining the configured permitted resource configuration before performing the small data transfer.

20. The method for pre-configuring resources in an inactive state according to claim 19, wherein in response to the configured permitted resource being valid, the configured permitted resource configuration is obtained from the CG-CofigSchedule before performing the small data transmission.

21. A user equipment comprising: transceivers, operating at millimeter waves; a processor coupled to the transceiver and configured to at least: receiving a configured permission configuration for small data transfers prior to entering an inactive state; verifying the configured permitted resources of the camped cell associated with the configured permitted configuration by determining whether the camped cell satisfies a verification condition before triggering a small data transmission procedure, wherein the configured permitted configuration includes a configured permitted configuration list associated with a cell list, the verification condition includes whether the camped cell is in the cell list of the configured permitted configuration, and the verification condition further includes whether the configured permitted resources of the camped cell are valid; and When it is determined that the verification condition is satisfied, the configured permission resources for the small data transfer program are utilized.

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