RRC inactive data transmission method, device and computer program

Abstract

A wireless communication method is disclosed, which includes: a first base station (BS) sending, to a core network (CN), SDT mapping information for setting up an SDT between the CN and the first BS; and executing the SDT according to the settings set up by the SDT mapping information.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to wireless communications, and more particularly to wireless communications regarding data transmission in an RRC inactive state. [Background technology]

[0002] Wireless communication technologies are a key component of increasingly interconnected global communication networks. Wireless communication relies on precisely allocated time and frequency resources to send and receive radio signals. Mobile Terminated (MT) Small Data Transmission (SDT) allows mobile devices to send and receive data in RRC inactive states, but this technology is still immature. Summary of the Invention

[0003] This summary is a brief description of some aspects of the disclosure and is not intended to limit the scope of the disclosure.

[0004] According to some embodiments of the present disclosure, there is provided a wireless communication method, the wireless communication method including: transmitting, to a core network (CN), small data transmission (SDT) mapping information for setting up an SDT between the first BS and the first base station; and executing the SDT according to the setting set up by the SDT mapping information.

[0005] According to some embodiments of the present disclosure, there is provided a wireless communication method, the wireless communication method including: receiving, from a first base station (BS), SDT mapping information for setting up a small data transmission (SDT) between the CN and the first BS; and executing the SDT according to the settings set up by the SDT mapping information.

[0006] Yet another embodiment of the present disclosure provides a wireless communication device including a memory having one or more programs stored therein; and a processor electrically coupled to the memory and configured to execute the one or more programs to perform any method or step or combination thereof in the present disclosure.

[0007] Yet another embodiment of the present disclosure provides a non-transitory computer-readable storage medium having stored thereon one or more programs, the one or more programs being configured, when executed by a processor, to cause any method or step or combination thereof in the present disclosure to be performed.

[0008] According to some embodiments of the present disclosure, one or more wireless communication methods are further disclosed, which include combinations (general or specific views) of some of the methods, aspects, elements, and steps disclosed in various embodiments of the present disclosure.

[0009] These and other aspects and their implementation are described in more detail in the drawings, specification, and claims. [Brief explanation of the drawings]

[0010] Hereinafter, each exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. The drawings are provided for illustrative purposes only and depict only exemplary embodiments to facilitate understanding of the present disclosure. Therefore, the drawings should not be considered to limit the breadth, scope, or applicability of the present disclosure. Furthermore, for clarity and ease of illustration, these drawings are not necessarily drawn to scale. [Figure 1] A communication diagram between two gNBs exchanging MT-SDT support capabilities is shown. [Figure 2] A communication diagram between a gNB and a CN with SDT traffic information and SDT mapping information is shown. [Figure 3]A communication diagram between a gNB and a CN with SDT mapping information and resource change confirmation is shown. [Figure 4] A communication diagram for CN's MT-SDT bearer information is shown. [Figure 5] This shows a communication diagram in which the CN initiates the MT-SDT by directly transmitting small data. [Figure 6] 1 shows a communication diagram in which the CN initiates MT-SDT via NGAP signaling. [Figure 7] 1 shows the configuration of wireless communication. [Figure 8] 1 illustrates an exemplary wireless communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] With the development of smart terminals (e.g., realized by user equipment (UE)) and IoT terminals, the number of users of some instant messaging services (e.g., WeChat, Twitter, QQ messages, and other applications) is increasing. These services are usually always online during standby or when users send text messages, and generally transmit small amounts of data. Services with small amounts of data require the UE to frequently re-establish a signaling link with the random access network (RAN), which can cause problems such as increased signaling load in the RAN and increased energy consumption in the UE.

[0012] Although some newer technologies support an RRC inactive state for UEs, prior to recent updates, data transmission was not supported in the RRC inactive state. Therefore, for any downlink (DL) and uplink (UL) data transmission, the UE must resume the connection (i.e., transition to the RRC connected state). As a result, a connection is set up and then released to the inactive state for every data transmission, no matter how small or infrequent the data packets. This method results in unnecessary power consumption and signaling overhead.

[0013] Recently, the industry has addressed support for such small-volume and infrequent data transmissions in the Small Data Transmission (SDT) feature, which allows a UE in an RRC inactive state to perform data transmission. SDT is a procedure that enables data and / or signaling transmission while the UE remains in the RRC inactive state (i.e., does not transition to an RRC connected state). SDT is enabled on a per-Radio Bearer (RB) basis, and for example, an SDT RB refers to a radio bearer for which the SDT feature is configured.

[0014] For UL small data transmission in RRC inactive state, the UE can initiate a MO SDT (Mobile Originated SDT) procedure for UL data. However, if eDRX (Enhanced Discontinuous Reception) is used for MT (Mobile Terminated) SDT UEs, the issue of DL small data transmission in RRC inactive state still exists. eDRX is a technology used in cellular networks. This technology allows the device to remain in low power mode for longer periods by allowing a longer "sleep" state while still maintaining connectivity with the network.

[0015] Specifically, to save UE power, a long eDRX cycle (e.g., longer than 10.24 seconds) can be configured for the UE in the RRC inactive state. With this configuration, the UE only needs to monitor the paging channel for one paging occasion (PO) period in the long DRX cycle. However, due to the long eDRX cycle, the gNB (or base station BS) may have to wait a long period (e.g., longer than 10.24 seconds) for data transmission until the UE is successfully paged. During this period, the core network (CN) needs to buffer downlink data for each QoS flow, no matter how small or infrequent the data packets are, because it does not know whether the NG-RAN supports MT SDT or which QoS flows are mapped to SDT DRBs. After that, the NG-RAN needs to page the UE and transition it to the RRC connected state for DL ​​data transmission. This may result in an extra transmission delay for DL ​​data transmission.

[0016] Exchange of MT-SDT capability information between gNBs According to some embodiments of the present disclosure, different BSs may exchange information regarding whether the BSs support MT-SDT, thereby allowing a BS to use another BS to perform MT-SDT via another BS.

[0017] As shown in step 11 of Figure 1, a gNB may send an Xn Setup Request or an NG-RAN Node Configuration Update message to another gNB to set up or modify the interface between the two gNBs. The Xn Setup Request or the NG-RAN Node Configuration Update message may include MT-SDT support capability information. The MT-SDT support capability information may indicate whether the gNB supports MT-SDT functionality for DL ​​data.

[0018] As shown in step 12 of Figure 1, another gNB may receive an Xn Setup Request or NG-RAN Node Configuration Update message with MT-SDT support capability information and store the received MT-SDT support capability information in the message. The other gNB then sends an Xn Setup Response or RAN Configuration Update Confirm message to the first gNB. The Xn Setup Response or RAN Configuration Update Confirm message may include MT-SDT support capability information, which may indicate whether the gNB sending the MT-SDT support capability information supports MT-SDT functionality for DL ​​data.

[0019] This allows the anchor gNB, when attempting to page a UE via another gNB for MT-SDT service, to determine whether the other gNB supports MT-SDT functionality. The anchor gNB may send an XnAP paging message to the other gNB, which includes an MT-SDT indicator indicating that MT-SDT service is expected. The other gNB then recognizes that the paging will be used for MT-SDT service, and as a result, the other gNB may include an MD-SDT indicator in an RRC paging message to the UE.

[0020] MT-SDT bearer information provided to the CN during the PDU session setup / modification procedure As shown in step 21 of Figure 2, the core network (CN) may send an initial context setup request or a PDU session resource setup / modification message to the gNB to set up or modify resources for one or more PDU sessions of the UE. The initial context setup request or the PDU session resource setup / modification message may include SDT traffic information, which may include at least one of: at least one SDT traffic indicator for each QoS flow; and at least one SDT traffic indicator for one PDU session and the entire underlying QoS flows.

[0021] At least one SDT traffic indicator corresponding to each QoS flow may indicate that the respective QoS flow has characteristics of DL and / or UL small data transmission, i.e., indicates that the traffic of the corresponding QoS flow may include DL and / or UL SDT data within a certain period of time. Similarly, at least one SDT traffic indicator at the PDU session level may indicate that all QoS flows within the corresponding PDU session have characteristics of downlink and / or uplink small data transmission.

[0022] As shown in step 22 of Figure 2, the gNB receives SDT traffic information from the CN and determines, based on the received SDT traffic information (including the SDT traffic indicator), to map a single QoS flow to one or more SDT RBs of the UE. For example, all mapped QoS flows in one SDT RB (radio bearer supporting SDT functionality) should have downlink and / or uplink SDT characteristics indicated by the SDT traffic indicator in the SDT traffic information.

[0023] The gNB may send a response message, such as an initial context setup response or a PDU session resource setup / modification response, which includes SDT mapping information. According to some examples, the SDT mapping information includes at least one of an SDT mapping indicator for each QoS flow, an SDT mapping indicator corresponding to one PDU session and all underlying QoS flows, a downlink data volume threshold for all QoS flows for which the SDT mapping indicator is set, and a downlink data volume threshold for all PDU sessions for which the SDT mapping indicator is set.

[0024] The SDT mapping indicator of each QoS flow may indicate the mapping of the corresponding QoS flow to an SDT RB. Similarly, the SDT mapping indicator of a PDU session (and its underlying QoS flows) may indicate the mapping of all QoS flows within this PDU session to one or more SDT RBs.

[0025] CN's MT-SDT bearer information during the PDU session modification procedure initiated by the gNB As shown in step 31 of Figure 3, the gNB may send a PDU session resource change instruction message to the CN (core network) to change the resources of one or more PDU sessions of the UE, and the PDU session resource change instruction message may include changed SDT mapping information. The SDT mapping information may have the same content as above, but with updated information.

[0026] As shown in step 32 of Figure 3, the CN receives the SDT mapping information and updates the stored SDT mapping information. The CN may send a PDU session resource change confirmation message to the gNB.

[0027] This allows updated information to be provided to the CN, and the CN can confirm any updates it receives.

[0028] CN's MT-SDT bearer information during the period when the UE is released to the RRC inactive state As shown in step 40 of Figure 4, the UE, gNB, and CN have set up one or more PDU sessions, and the UE is in an RRC connected state.

[0029] As shown in step 41 of Figure 4, the gNB may determine a long eDRX cycle value for the UE in the RRC inactive state, for example, a value longer than 10.24 seconds, and may decide to transition the UE to the RRC inactive state. Transitioning the UE to the RRC inactive state may save power consumption of the UE.

[0030] As shown in step 42 of Figure 4, the gNB sends an RRC message to the UE over the air interface to release the UE into an RRC inactive state with a long eDRX cycle. eDRX is a power-saving feature that allows a device to remain in low power mode for an extended period of time while still being able to receive incoming data. The eDRX cycle defines the duration of the low power mode before the UE wakes up to check for incoming data. The eDRX cycle may range from a few seconds to several hours, depending on the specific network and application requirements. During the eDRX cycle, the device's air interface can be turned off, thereby significantly reducing power consumption. When the device wakes up to check for incoming data, it turns on the air interface again to monitor incoming transmissions.

[0031] As shown in step 43 of Figure 4, the gNB sends an RRC Inactive Transition Report message to the CN indicating that the UE is in an RRC inactive state. The gNB may also send a UE Context Suspend Request message to the CN to suspend the UE context and transition the UE to the RRC inactive state. As described above, the RRC Inactive Transition Report message or the UE Context Suspend Request message may include at least one of eDRX information (e.g., including an inactive eDRX cycle value and a paging time window) or SDT mapping information.

[0032] As shown in step 44 of Figure 4, the CN then enters the CM-IDLE state, the RRC is inactive, and the CN stops sending DL data to the gNB. CM-IDLE is a power-saving state that allows the device to conserve battery power by communicating with the network less frequently. In the CM-IDLE state, the device's radio interface may be turned off and it may wake up periodically to check for incoming data.

[0033] The CN initiates the MT-SDT by directly transmitting small data.

[0034] As shown in step 50 of Figure 5, the UE, gNB, and CN set up one or more PDU sessions. After a data transmission period, the UE may be released to an RRC inactive state.

[0035] As shown in step 51 of Figure 5, user plane data or NAS PDUs (Non-Access Stratum Protocol Data Units) of a UE arrive at the CN. The CN can determine whether and how to trigger MT-SDT based on the stored SDT mapping information. If at least one of the following conditions (1) or (2) is met, the CN can decide to send the data and / or NAS PDUs to the gNB to trigger MT-SDT:

[0036] (1) All of the data arriving at the CN belongs to a QoS flow with an SDT mapping indicator set, and the data volume is less than (or equal to) the set downlink data volume threshold for all QoS flows.

[0037] (2) All of the data arriving at the CN belongs to a PDU session with an SDT mapping indicator set, and the data volume is less than (or equal to) the set downlink data volume threshold of all PDU sessions. These two conditions correspond to two possible implementations, and the SDT mapping indicator can correspond to a QoS flow or a PDU session, respectively.

[0038] As shown in step 52 of Figure 5, if the conditions are met, the CN sends DL data or NAS PDU to the gNB.

[0039] As shown in step 53 of Figure 5, when the gNB receives DL data or a NAS PDU, the gNB recognizes that the arriving data is used for MT-SDT functionality. The gNB can then send an RRC paging message to the UE to page the corresponding UE for MT-SDT. The RRC paging message may include an MT-SDT indicator that indicates to the UE that MT-SDT is expected. The RRC paging message notifies the UE that there is incoming data or a network event that requires the UE's attention.

[0040] The RRC (Radio Resource Control) layer may be responsible for paging the UE and instructing it to initiate a connection to the network. The RRC paging message may be broadcast by the network using a paging channel. The paging channel may be a dedicated channel for transmitting paging messages to all UEs that are in RRC idle state and monitoring incoming data. The RRC paging message may further include information such as UE identity, the type of incoming data or event, and the frequency and timing of the paging message. The RRC paging message may be transmitted using a specific paging format, which includes a paging message header and a paging message content.

[0041] Also, if the anchor gNB attempts to page the UE via another gNB for MT-SDT, and the other gNB also supports the MT-SDT feature, the anchor gNB can send an Xn paging message to the other gNB via the Xn interface. The Xn paging message includes an MT-SDT indicator indicating that MT-SDT is expected. The other gNB then recognizes that the paging will be used for MT-SDT, and as a result, the other gNB can include an MD-SDT indicator in the RRC paging message sent to the UE.

[0042] Similarly, if an anchor gNB with a CU / DU (aggregated unit / distributed unit) split architecture wishes to page a UE via its DU for MT-SDT, the gNB's CU can send an F1 paging message to its DU over the F1 interface. The F1 paging message includes an MT-SDT indicator, which indicates to the DU that MT-SDT is expected. The gNB's DU then knows that paging will be used for MT-SDT, and as a result, the DU can include an MD-SDT indicator in the RRC paging message sent to the UE.

[0043] As shown in step 54 of Figure 5, after receiving the RRC paging message, the UE sends an RRC resume request message to the gNB (e.g., gNB-DU), where the RRC resume request message includes an MT-SDT indicator indicating that MT-SDT is expected and requesting the resumption of the UE that is in an inactive state for MT-SDT.

[0044] As shown in step 55 of Figure 5, this allows the UE to resume transmission with the gNB in ​​an RRC inactive state and transmit or receive subsequent MT-SDT data to or from the gNB via RACH (Random Access Channel) or CG (Cell Group) resources.

[0045] The CN initiates MT-SDT via NGAP signaling.

[0046] As shown in step 60 of Figure 6, the UE, gNB, and CN set up one or more PDU sessions. After a data transmission period, the UE may be released to an RRC inactive state.

[0047] As shown in step 61 of Figure 6, user plane data or NAS PDUs of a UE arrive at the CN. The CN can then determine whether and how to trigger MT-SDT based on the stored SDT mapping information. For example, if there is no downlink data volume threshold in the SDT mapping information and at least one of the following conditions is met, the CN can decide to send an NGAP (Next Generation Core Network (NGCN) Application Protocol) message to the gNB to trigger MT-SDT: (1) all of the arriving data belongs to at least one QoS flow with an SDT mapping indicator configured, and (2) all of the arriving data belongs to at least one PDU session with an SDT mapping indicator configured.

[0048] As shown in step 62 of FIG. 6, the CN may buffer the DL data until the UE is able to arrive.

[0049] As shown in step 63 of Figure 6, the CN may send an NGAP message to the gNB. The NGAP message may include at least one of: (1) an MT-SDT indicator indicating that MT-SDT is expected, (2) buffered data sizes of all QoS flows or PDU sessions (having SDT mapping indicators) indicating the buffered data sizes of MT-SDT, (3) for one PDU session, a list of QoS flows through which any data can arrive, and (4) a list of PDU sessions through which any data can arrive.

[0050] For example, the NGAP message may be an NGAP paging message, a DL data notification message, or a message required for UE context resumption.

[0051] As shown in step 64 of Figure 6, when the gNB receives the NGAP message, if at least one of the following conditions is met for one or more paging cells, the gNB can send an RRC paging message to the UE for MT-SDT to page the corresponding UE: (1) an MT-SDT indicator is received, and (2) buffered data size information is received, and the size is less than the MT-SDT threshold of the paging cell. That is, the gNB can determine whether to support transmitting these buffered data in SDT based on its network resources and the buffered data size, and then the gNB can determine whether to page the UE over the air interface with the MT-SDT indicator included.

[0052] The paging message may include an MT-SDT indicator that indicates that MT-SDT is expected.

[0053] Similarly, if the anchor gNB intends to page the UE via another gNB for MT-SDT, the anchor gNB may send an Xn paging message to the other gNB via the Xn interface if the other gNB supports MT-SDT. The paging message may include at least one of an MT-SDT indicator indicating that MT-SDT is expected and buffered data size information of all QoS flows or PDU sessions (with SDT mapping indicators) indicating the buffered data size for MT-SDT.

[0054] When another gNB receives the Xn paging message, the other gNB may determine how to send an RRC paging message to the UE according to step 64.

[0055] Similarly, when an anchor gNB with a CU / DU (aggregated unit / distributed unit) split architecture intends to page a UE via its DU for MT-SDT, the CU of the gNB can send an F1 paging message to the DU via the F1 interface. The F1 paging message may include at least one of an MT-SDT indicator indicating that MT-SDT is expected and buffered data size information of all QoS flows or PDU sessions (with SDT mapping indicators) indicating the buffered data size for MT-SDT. When the DU receives the F1 paging message, the DU of the gNB can determine how to send an RRC paging message to the UE according to step 64.

[0056] As shown in step 65 of Figure 6, after receiving the RRC paging message, the UE may send an RRC Resume Request message to the gNB (e.g., gNB-DU). The RRC Resume Request message may include an MT-SDT indicator indicating that MT-SDT is expected and requesting the resumption of the UE in an inactive state for MT-SDT.

[0057] As shown in step 66 of Figure 6, after the UE has successfully resumed in the RRC inactive state, the gNB sends a message to the CN via the NG interface to indicate that the UE is reachable and is being maintained in the RRC inactive state for small data transmission. For example, the message sent by the gNB may be a UE context resume request or an RRC inactive transition report. The message sent by the gNB may include an MT-SDT indicator to trigger MT-SDT.

[0058] As shown in step 67 of Figure 6, the CN then transmits the DL small data to the gNB.

[0059] As shown in step 68 of Figure 6, the UE resumes with the gNB in ​​an RRC inactive state and can receive subsequent MT-SDT data from the gNB via RACH or CG (cell group) resources.

[0060] 7 illustrates a system configuration for implementing any step, method, or combination thereof in the present disclosure. The core network is a core network architecture. It may include multiple network functions that cooperate to enable communication between a UE and a network. The 5G core network may have several network functions, including an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a network repository function (NRF), and / or an authentication server function (AUSF).

[0061] gNB stands for next generation Node B, or gNodeB. A gNB is a type of base station in a 5G network that connects UEs to the 5G core network. The gNB provides radio access to UEs and is responsible for transmitting and receiving user data and control signals between the UE and the 5G core network. gNBs can support advanced features such as massive MIMO (multiple-input multiple-output), beamforming, and dynamic spectrum sharing to improve network capacity, coverage, and efficiency.

[0062] 8 illustrates a block diagram of an exemplary wireless communication system 10 according to some embodiments of the present disclosure. The system 10 is capable of performing various methods / steps disclosed herein. The system 10 may include components and elements configured to support operational features that do not require detailed description herein.

[0063] System 10 may include a base station (BS) 110 and a user equipment (UE) 120. BS 110 includes a BS transceiver or transceiver module 112, a BS antenna system 116, a BS memory or memory module 114, a BS processor or processor module 113, and a network interface 111. The components of BS 110 may be electrically coupled and communicate as needed via a data communication bus 180. Similarly, UE 120 includes a UE transceiver or transceiver module 122, a UE antenna system 126, a UE memory or memory module 124, a UE processor or processor module 123, and an I / O interface 121. The components of UE 120 may be electrically coupled and communicate as needed via a data communication bus 190. BS 110 communicates with UE 120 via any wireless channel or other medium known in the art suitable for data transmission as described herein.

[0064] Processor modules 113 and 123 may be implemented or realized with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. As such, a processor module may be realized as a microprocessor, a controller, a microcontroller, a state machine, etc. A processor module may also be implemented as a combination of computing devices, for example, a combination of a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a digital signal processor core, or any other such configuration.

[0065] Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, firmware, a software module executed by processor modules 113 and 123, respectively, or any practical combination thereof. Memory modules 113 and 123 may be implemented as RAM memory, flash memory, EEPROM memory, registers, ROM memory, EPROM memory, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0066] In this aspect, memory modules 114 and 124 may be coupled to processor modules 113 and 123, respectively, such that processor modules 113 and 123 can read information, instructions, or programs from and write information to memory modules 114 and 124, respectively. Memory modules 114 and 124 may be incorporated into their respective processor modules 113 and 123.

[0067] In some embodiments, memory modules 114 and 124 may each include cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules 113 and 123. Memory modules 114 and 124 may each include non-volatile memory for storing instructions to be executed by processor modules 113 and 123, respectively.

[0068] According to some embodiments of the present disclosure, a wireless communication method is disclosed, the method including: a first base station (BS) sending, to a core network (CN), SDT mapping information for setting up an SDT between the CN and the first BS; and executing the SDT according to a configuration set up by the SDT mapping information.

[0069] According to some examples, the SDT mapping information includes at least one of: at least one SDT mapping indicator indicating a mapping of at least one QoS flow to at least one SDT RB (Radio Bearer); and a first downlink (DL) data volume threshold.

[0070] According to some examples, the SDT mapping indicator corresponds to a PDU session and indicates the overall mapping of all of the at least one QoS flow under the PDU session to at least one SDT RB.

[0071] According to some examples, an SDT mapping indicator corresponds to each QoS flow.

[0072] According to some examples, the first DL data volume threshold corresponds to all of the PDU session and its at least one QoS flow, or the first DL data volume threshold corresponds to each of the at least one QoS flow.

[0073] According to some examples, the method further includes, before transmitting the SDT mapping information, the first BS receiving SDT traffic information from the CN, the information including at least one SDT traffic indicator indicating characteristics of DL and / or uplink (UL) small data transmission of at least one QoS flow.

[0074] According to some examples, the method further includes, before transmitting the SDT mapping information, a step in which the first BS receives SDT traffic information from the CN, the information including at least one SDT traffic indicator indicating characteristics of all DL and / or UL small data transmissions of at least one QoS flow under the PDU session.

[0075] According to some examples, the method further includes mapping the at least one QoS flow to the at least one SDT RB based on the SDT traffic information.

[0076] According to some examples, the step of the first BS receiving SDT traffic information from the CN includes the step of the first BS receiving the SDT traffic information in an SDT initial context setup request from the CN, or receiving the SDT traffic information from the CN in a PDU session resource setup or modification message in a PDU session setup or modification procedure.

[0077] According to some examples, the step of the first BS sending the SDT mapping information to the CN includes sending the SDT mapping information in a PDU session resource change indication message.

[0078] According to some examples, the method further includes the first BS sending to the CN at least one of an RRC Inactive Transition Report message indicating that the user equipment (UE) is in an RRC inactive state, the RRC Inactive Transition Report message including SDT mapping information, and a UE Context Suspend Request message for suspending the UE context from entering the RRC inactive state, the UE Context Suspend Request message including the SDT mapping information.

[0079] According to some examples, the method further includes a step in which, if all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information and the data volume of the received data is less than a DL data volume threshold of the at least one QoS flow, the first BS receives data from the CN via the SDT, wherein the at least one SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

[0080] According to some examples, the method further includes a step in which the first BS receives data from the CN via an SDT if all data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information and the data volume of the data is less than a configured DL data volume threshold of the at least one PDU session, wherein the SDT mapping indicator indicates mapping of all of the at least one QoS flow under the PDU session to at least one SDT RB.

[0081] According to some examples, the method further includes a step in which, if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN for triggering an SDT, wherein the at least one SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

[0082] According to some examples, the method further includes a step in which, if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one PDU session set by the SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN for triggering SDT, wherein the SDT mapping indicator indicates mapping of all of at least one QoS flow under the at least one PDU session to at least one SDT RB.

[0083] According to some examples, the NGAP message includes at least one of an MT-SDT indicator indicating to the BS that an MT-SDT transmission is expected, a buffered data size of all QoS flows or all PDU sessions having an SDT mapping indicator indicating the buffered data size of MT-SDT, and for one PDU session, a list of QoS flows on which any data will arrive and a list of PDU sessions on which any data will arrive.

[0084] According to some examples, the NGAP message may be at least one of an NGAP paging message, a DL data notification, or a UE context resume request message.

[0085] According to some examples, the method further includes a step in which the first BS sends an Xn paging message to the second BS via the Xn interface, the Xn paging message including at least one of an MT-SDT indicator indicating that an MT-SDT transmission is expected and a buffered data size of all QoS flows or all PDU sessions having an SDT mapping indicator indicating a total buffered data size of the SDT.

[0086] According to some examples, the method further includes a step in which an aggregation unit (CU) of the first BS sends an F1 paging message to a DU (distributed unit) of the first BS via an F1 interface, the F1 paging message including at least one of an MT-SDT indicator indicating that an MT-SDT transmission is expected and a buffered data size of all QoS flows or all PDU sessions having an SDT mapping indicator indicating a total buffered data size of the MT-SDT.

[0087] According to some examples, the method further includes a step in which the first BS sends an NGAP message to the CN over the NG interface indicating that the UE is available for SDT in an RRC inactive state, the NGAP message including an MT-SDT indicator for triggering SDT.

[0088] According to some examples, the NGAP message includes a UE context resume request or an RRC inactivity transition report.

[0089] According to some embodiments, a wireless communication method is disclosed, the method including: a core network (CN) receiving, from a first base station (BS), small data transmission (SDT) mapping information for setting up SDT between the CN and the first BS; and performing the SDT according to the configuration set up by the SDT mapping information.

[0090] According to some examples, the SDT mapping information includes at least one of: at least one SDT mapping indicator indicating a mapping of at least one QoS flow to at least one SDT RB (Radio Bearer); and a first downlink (DL) data volume threshold.

[0091] According to some examples, the SDT mapping indicator corresponds to a PDU session and indicates the overall mapping of all of the at least one QoS flow under the PDU session to at least one SDT RB.

[0092] According to some examples, an SDT mapping indicator corresponds to each QoS flow.

[0093] According to some examples, the first DL data volume threshold corresponds to all of the PDU session and its at least one QoS flow, or the first DL data volume threshold corresponds to each of the at least one QoS flow.

[0094] According to some examples, the method further includes, before receiving the SDT mapping information, a step in which the CN transmits SDT traffic information to the first BS, the information including at least one SDT traffic indicator indicating characteristics of DL and / or uplink (UL) small data transmission of at least one QoS flow.

[0095] According to some examples, the method further includes a step in which, before receiving the SDT mapping information, the CN sends SDT traffic information to the first BS, the information including at least one SDT traffic indicator indicating characteristics of all DL and / or UL small data transmissions of at least one QoS flow under the PDU session.

[0096] According to some examples, the SDT traffic information is for mapping at least one QoS flow to at least one SDT RB.

[0097] According to some examples, the step of the CN transmitting the SDT traffic information to the first BS includes transmitting the SDT traffic information in an SDT initial context setup request from the CN, or transmitting the SDT traffic information in a PDU session resource setup or modification message in a PDU session setup or modification procedure.

[0098] According to some examples, the CN receiving the SDT mapping information from the first BS includes receiving the SDT mapping information in a PDU session resource change indication message.

[0099] According to some examples, the method further includes the CN receiving, from the first BS, at least one of an RRC Inactive Transition Report message indicating that a user equipment (UE) is in an RRC inactive state, the RRC Inactive Transition Report message including SDT mapping information, and a UE Context Suspend Request message for suspending a UE context from entering the RRC inactive state, the UE Context Suspend Request message including the SDT mapping information.

[0100] According to some examples, the method further includes a step in which, if all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information and the data volume of the received data is less than a DL data volume threshold of the at least one QoS flow, the CN transmits data to the first BS via an SDT, wherein the at least one SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

[0101] According to some examples, the method further includes a step in which, if all data received by the CN belongs to at least one PDU session set by an SDT mapping indicator in the SDT mapping information and the data volume of the data is less than a set DL data volume threshold of the at least one PDU session, the CN transmits data to the first BS via an SDT, wherein the SDT mapping indicator indicates mapping of all of the at least one QoS flow under the PDU session to at least one SDT RB.

[0102] According to some examples, the method further includes a step in which, if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information, the CN sends an NGAP message to the first BS to trigger an SDT, wherein the at least one SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

[0103] According to some examples, the method further includes a step in which, if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one PDU session set by the SDT mapping indicator in the SDT mapping information, the CN sends an NGAP message to the first BS to trigger SDT, wherein the SDT mapping indicator indicates mapping of all of at least one QoS flow under the at least one PDU session to at least one SDT RB.

[0104] According to some examples, the NGAP message includes at least one of an MT-SDT indicator indicating to the BS that an MT-SDT transmission is expected, a buffered data size of all QoS flows or all PDU sessions having an SDT mapping indicator indicating the buffered data size of MT-SDT, and for one PDU session, a list of QoS flows on which any data will arrive and a list of PDU sessions on which any data will arrive.

[0105] According to some examples, the NGAP message is at least one of an NGAP paging message, a DL data notification, or a UE context resume request message.

[0106] According to some examples, the method further includes a step in which the CN receives, via the NG interface, an NGAP message from the first BS indicating that the UE is available for SDT in an RRC inactive state, the NGAP message including an MT-SDT indicator for triggering SDT.

[0107] According to some examples, the NGAP message includes a UE context resume request or an RRC inactivity transition report.

[0108] This specification describes exemplary embodiments of the present disclosure with reference to the drawings, so that those skilled in the art can make and use the present disclosure. The present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Furthermore, the specific order and / or hierarchy of steps in the methods disclosed herein is merely an example approach. Based on design preferences, the specific order or hierarchy of steps in a disclosed method or process can be rearranged while remaining within the scope of the present disclosure. Thus, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or operations in an example order, and that the present disclosure is not limited to the specific order or hierarchy presented, unless otherwise specified.

[0109] The present disclosure is intended to cover any conceivable variation, use, combination, or adaptive modification of the present disclosure in accordance with the general principles of the present disclosure, and includes well-known knowledge and conventional technical means in the art that are not disclosed in this application.

[0110] It should be understood that the present disclosure is not limited to the exact construction or operation described above and illustrated in the drawings, and that various modifications and changes are possible without departing from the scope of the present application, which is limited only by the appended claims.

[0111] The methods, devices, processes, and logic described above may be implemented in many different ways and in many different combinations of hardware and software. For example, all or part of each implementation may be circuitry including an instruction processor such as a central processing unit (CPU), microcontroller, or microprocessor, or an application specific integrated circuit (ASIC), programmable logic device (PLD) or field programmable gate array (FPGA), or circuitry including discrete logic or other circuit components, including analog circuit components, digital circuit components, or both, or any combination thereof.

[0112] The circuitry may, for example, include discrete hardware components interconnected together, or may be combined on a single integrated circuit die, distributed among multiple integrated circuit dies, or implemented in a multi-chip module (MCM) of multiple integrated circuit dies within a common package.

[0113] Thus, the circuitry may further include or access instructions that are executed by the circuitry, or the functionality may be realized solely in hardware. The instructions may be stored in a tangible storage medium other than a transitory signal, such as flash memory, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or a magnetic or optical disk, such as a compact disc read-only memory (CD-ROM), a hard disk drive (HDD) or other magnetic or optical disk, or in or on another machine-readable medium. An article of manufacture (such as a computer program product) may include the storage medium and instructions stored in or on the medium, which, when executed by circuitry in a device, may cause the device to implement any of the processes described above or illustrated in the figures.

[0114] Implementations may be distributed. For example, circuitry may include multiple different system components, such as multiple processors and memories, or may span multiple distributed processing systems. Parameters, databases, and other data structures may be stored and managed separately, incorporated into a single memory or database, and may be logically and physically organized and implemented in many different ways. Exemplary implementations include linked lists, program variables, hash tables, arrays, records (e.g., database records), objects, and implicit storage mechanisms.

[0115] The instructions may be part of a single program (e.g., a subroutine or other code segment), separate programs, or distributed among several memories and processors, and may be implemented in many different forms. Exemplary implementations include independent programs and libraries as part of a shared library, such as a dynamic link library (DLL). For example, the library may include shared data and one or more shared programs that contain instructions that, when executed by a circuit arrangement, perform any of the processes described above or illustrated in the figures.

[0116] In some examples, each unit, subunit, and / or module of a system may include a logical component. Each logical component may be hardware or a combination of hardware and software. For example, each logical component may include an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), digital logic circuitry, analog circuitry, a combination of discrete circuitry, gates, or any other type of hardware, or a combination thereof.

[0117] Alternatively or additionally, each logical component may include memory hardware, such as a portion of memory containing instructions executable by a processor or other processors, to implement one or more features of the logical component. If any logical component includes a portion of memory containing instructions executable by a processor, the logical component may or may not include a processor.

[0118] In some examples, each logical component may be only a portion of memory or other physical memory, includes instructions executable by a processor or other processors, and implements the features of the corresponding logical component, and the logical component does not include any other hardware. Because each logical component includes at least some hardware, even if the included hardware includes software, each logical component may be referred to interchangeably as a hardware logical component.

[0119] A second action is said to occur "in response to" a first action, regardless of whether the second action is directly or indirectly caused by the first action. A second action can still be considered a response to a first action even if it occurs significantly later than the first action. Similarly, a second action can be said to be responsive to a first action even if intervening actions occur between the first and second actions, or if one or more intervening actions directly cause the second action to be performed. For example, if a first action sets a flag, a second action may occur in response to the first action, and a third action may subsequently initiate the second action upon setting the flag.

[0120] In order to clarify its use and to inform the public hereby, 、 , ...and <n> At least one of the following" or "< / n> 、 、... <n> ", at least one of or a combination thereof" or "< / n> 、 , ...and / or <n> The phrase "is defined by applicant in its broadest sense and supersedes any other implied definition above or below, unless expressly asserted to the contrary by applicant, to mean one or more elements selected from the group including A, B... and N. In other words, the phrase refers to any combination of one or more of the elements A, B,... or N, including any one element alone or that one element in combination with one or more of the other elements, which may also include additional, unlisted elements.< / n>

Claims

1. a first base station BS sending small data transmission SDT mapping information to a core network CN for setting up an SDT between the first base station BS and the core network CN; and executing the SDT according to the configuration set up by the SDT mapping information.

2. The SDT mapping information is at least one SDT mapping indicator indicating a mapping of at least one QoS flow to at least one SDT radio bearer (RB); a first downlink DL data volume threshold.

3. 3. The wireless communication method according to claim 2, wherein the SDT mapping indicator corresponds to a PDU session and indicates an overall mapping of all of at least one QoS flow under the PDU session to at least one SDT RB.

4. The wireless communication method of claim 2 , wherein the SDT mapping indicator corresponds to a respective QoS flow.

5. 3. The wireless communication method according to claim 2, wherein the first DL data volume threshold corresponds to all of a PDU session and its at least one QoS flow, or the first DL data volume threshold corresponds to each of the at least one QoS flow.

6. 2. The wireless communication method of claim 1, further comprising: before transmitting the SDT mapping information, the first BS receives SDT traffic information from the CN, the SDT traffic information including at least one SDT traffic indicator indicating characteristics of DL and / or uplink UL small data transmission of the at least one QoS flow.

7. 2. The wireless communication method of claim 1, further comprising a step in which the first BS receives SDT traffic information from the CN before transmitting the SDT mapping information, the SDT traffic information including at least one SDT traffic indicator indicating characteristics of all DL and / or UL small data transmissions of at least one QoS flow under a PDU session.

8. The wireless communication method according to claim 6 or 7, further comprising the step of mapping the at least one QoS flow to at least one SDT RB based on the SDT traffic information.

9. 8. The wireless communication method according to claim 6 or 7, wherein the step of the first BS receiving the SDT traffic information from the CN includes the step of the first BS receiving the SDT traffic information in an SDT initial context setup request from the CN, or receiving the SDT traffic information from the CN in a PDU session resource setup or modification message in a PDU session setup or modification procedure.

10. The wireless communication method of claim 1 , wherein the first BS transmitting the SDT mapping information to the CN comprises transmitting the SDT mapping information in a PDU Session Resource Change Indication message.

11. The first BS an RRC inactivity transition report message indicating that a user equipment (UE) is in an RRC inactive state, the RRC inactivity transition report message including the SDT mapping information; a UE context suspension request message for suspending the UE context from entering an RRC inactive state, the UE context suspension request message including the SDT mapping information.

12. 2. The wireless communication method of claim 1, further comprising: if all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information and the data volume of the received data is less than a DL data volume threshold of the at least one QoS flow, the first BS receiving data from the CN via the SDT, wherein the SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

13. 2. The wireless communication method of claim 1, further comprising: if all data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information and the data amount of the data is less than a configured DL data amount threshold of the at least one PDU session, the first BS receiving data from the CN via the SDT, wherein the SDT mapping indicator indicates mapping of all of the at least one QoS flow under the PDU session to at least one SDT RB.

14. 2. The wireless communication method of claim 1, further comprising the step of: if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information, the first BS receiving from the CN a NGAP message for triggering the SDT, wherein the SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

15. 2. The wireless communication method of claim 1, further comprising: if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one PDU session set by an SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN for triggering the SDT, wherein the SDT mapping indicator indicates mapping of all of the at least one QoS flow under the at least one PDU session to at least one SDT RB.

16. The NGAP message an MT-SDT indicator that indicates to the BS that an MT-SDT transmission is expected; The buffered data size of all QoS flows or all PDU sessions indicating the buffered data size of the SDT; For one PDU session, a list of QoS flows through which any data may arrive; and a list of PDU sessions through which any data arrives.

17. The wireless communication method according to claim 14 or 15, wherein the NGAP message is at least one of an NGAP paging message, a DL data notification, and a UE context resume request message.

18. 2. The wireless communication method of claim 1, further comprising the step of: the first BS sending an Xn paging message to the second BS via an Xn interface, the Xn paging message including at least one of an MT-SDT indicator indicating that an MT-SDT transmission is expected, and a buffered data size of all QoS flows or all PDU sessions indicating a total buffered data size of the SDT.

19. 2. The wireless communication method of claim 1, further comprising the step of: an aggregation unit CU of the first BS sending an F1 paging message to a distribution unit DU of the first BS via an F1 interface, the F1 paging message including at least one of an MT-SDT indicator indicating that an MT-SDT transmission is expected, and a buffered data size of all QoS flows or all PDU sessions indicating a total buffered data size of the SDT.

20. 2. The wireless communication method of claim 1, further comprising the step of: the first BS transmitting an NGAP message to the CN via an NG interface indicating that the UE is enabled for SDT in an RRC inactive state, the NGAP message including an MT-SDT indicator for triggering the SDT.

21. The wireless communication method of claim 20 , wherein the NGAP message comprises a UE context resume request or an RRC inactivity transition report.

22. a core network (CN) receiving, from a first base station (BS), small data transmission (SDT) mapping information for setting up an SDT between the CN and the first BS; and executing the SDT according to the configuration set up by the SDT mapping information.

23. The SDT mapping information is at least one SDT mapping indicator indicating a mapping of at least one QoS flow to at least one SDT radio bearer (RB); a first downlink (DL) data volume threshold.

24. 24. The wireless communication method of claim 23, wherein the SDT mapping indicator corresponds to a PDU session and indicates an overall mapping of all of at least one QoS flow under the PDU session to at least one SDT RB.

25. 24. The wireless communication method of claim 23, wherein the SDT mapping indicator corresponds to a respective QoS flow.

26. 24. The wireless communication method of claim 23, wherein the first DL data volume threshold corresponds to all of a PDU session and its at least one QoS flow, or the first DL data volume threshold corresponds to each of the at least one QoS flow.

27. 23. The wireless communication method of claim 22, further comprising the step of: before receiving the SDT mapping information, the CN transmitting SDT traffic information to the first BS, the SDT traffic information including at least one SDT traffic indicator indicating characteristics of DL and / or uplink (UL) small data transmission of the at least one QoS flow.

28. 23. The wireless communication method of claim 22, further comprising a step in which the CN sends SDT traffic information to the first BS before receiving the SDT mapping information, the SDT traffic information including at least one SDT traffic indicator indicating characteristics of all DL and / or UL small data transmissions of at least one QoS flow under the PDU session.

29. The wireless communication method according to claim 27 or 28, wherein the SDT traffic information is for mapping the at least one QoS flow to at least one SDT RB correspondingly.

30. 29. The wireless communication method according to claim 27 or 28, wherein the step of the CN transmitting the SDT traffic information to the first BS includes a step of transmitting the SDT traffic information in an SDT initial context setup request from the CN, or transmitting the SDT traffic information in a PDU session resource setup or modification message in a PDU session setup or modification procedure.

31. The wireless communication method of claim 22, wherein the CN receiving the SDT mapping information from the first BS comprises receiving the SDT mapping information in a PDU Session Resource Change Indication message.

32. The CN is an RRC inactivity transition report message indicating that a user equipment (UE) is in an RRC inactive state, the RRC inactivity transition report message including the SDT mapping information; and a UE context suspend request message for suspending the UE context from entering an RRC inactive state, the UE context suspend request message including the SDT mapping information, from the first BS.

33. 23. The wireless communication method of claim 22, further comprising the step of: if all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information and the data volume of the received data is less than a DL data volume threshold of the at least one QoS flow, the CN transmitting data to the first BS via the SDT, wherein the SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

34. 23. The wireless communication method of claim 22, further comprising: if all data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information and the data amount of the data is less than a configured DL data amount threshold of the at least one PDU session, the CN transmits data to the first BS via the SDT, wherein the SDT mapping indicator indicates mapping of all of the at least one QoS flow under the PDU session to at least one SDT RB.

35. 23. The wireless communication method of claim 22, further comprising the step of: if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one QoS flow set by an SDT mapping indicator in the SDT mapping information, the CN sending an NGAP message to the first BS to trigger the SDT, wherein the SDT mapping indicator indicates mapping of the at least one QoS flow to at least one SDT RB.

36. 23. The wireless communication method of claim 22, further comprising the step of: if there is no DL data volume threshold setting in the SDT mapping information and all data received by the CN belongs to at least one PDU session set by an SDT mapping indicator in the SDT mapping information, the CN sending an NGAP message to the first BS to trigger the SDT, wherein the SDT mapping indicator indicates mapping of all of the at least one QoS flow under the at least one PDU session to at least one SDT RB.

37. The NGAP message an MT-SDT indicator that indicates to the BS that an MT-SDT transmission is expected; The buffered data size of all QoS flows or all PDU sessions indicating the buffered data size of MT-SDT; For one PDU session, a list of QoS flows through which any data may arrive; and a list of PDU sessions through which any data arrives.

38. The wireless communication method according to claim 35 or 36, wherein the NGAP message is at least one of an NGAP paging message, a DL data notification, and a UE context resume request message.

39. The wireless communication method of claim 22, further comprising the step of: the CN receiving, via an NGAP interface, from the first BS, an NGAP message indicating that the UE is enabled for SDT in an RRC inactive state, the NGAP message including an MT-SDT indicator for triggering the SDT.

40. 40. The wireless communication method of claim 39, wherein the NGAP message comprises a UE context resume request or an RRC inactivity transition report.

41. A wireless communication device comprising: a memory in which one or more programs are stored; and one or more processors electrically coupled to the memory and configured to execute the one or more programs to perform the wireless communication method described in any one of claims 1 to 40.

42. A non-transitory computer-readable storage medium having stored thereon one or more programs, the one or more programs being configured, when executed by a processor, to perform the wireless communication method of any one of claims 1 to 40.

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