RRC inactive data transmission method and device and computer readable storage medium

Abstract

A wireless communication method is disclosed. A wireless communication method includes: a first base station (BS) transmitting SDT mapping information to a core network (CN) for establishing SDT between the CN and the first BS; and executing the SDT according to the configuration established by the SDT mapping information.

Description

Technical Field

[0001] The present disclosure generally relates to wireless communication, and more particularly, to wireless communication regarding data transmission in the RRC inactive state. Background Art

[0002] Wireless communication technology is a key component of an increasingly interconnected global communication network. Wireless communication relies on precisely allocated time and frequency resources to transmit and receive wireless signals. MT (Mobile Terminal) SDT (Small Data Transmission) allows a mobile device to receive and send data in the RRC inactive state, but this technology is not yet mature. Summary of the Invention

[0003] This summary of the invention is a brief description of certain aspects of the present disclosure. It is not intended to limit the scope of the present disclosure.

[0004] According to some embodiments of the present disclosure, a wireless communication is provided. The wireless communication method includes: a first base station BS sending small data transmission SDT mapping information to a core network CN for establishing SDT between the CN and the first BS; and performing SDT according to a configuration established based on the SDT mapping information.

[0005] According to some embodiments of the present disclosure, a wireless communication is provided. The wireless communication method includes: a core network CN receiving SDT mapping information from a first base station BS for establishing small data transmission SDT between the CN and the first BS; and performing SDT according to a configuration established based on the SDT mapping information.

[0006] Another embodiment of the present disclosure provides a wireless communication device, including: a memory storing one or more programs; and a processor electrically coupled to the memory and configured to execute one or more programs to perform any method or step or a combination thereof in the present disclosure.

[0007] Another embodiment of the present disclosure provides a non - transitory computer - readable storage medium storing one or more programs, the one or more programs being configured to, when executed by a processor, cause the execution of any method or step or a combination thereof in the present disclosure.

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

[0009] The above aspects and other aspects and their implementation manners are described in more detail in the drawings, the description, and the claims. Brief Description of the Drawings

[0010] The following describes in detail various exemplary embodiments of the present disclosure with reference to the following drawings. The drawings are provided for illustrative purposes only and depict only the exemplary embodiments of the present disclosure to facilitate understanding of the present disclosure. Therefore, the drawings should not be considered as limiting the breadth, scope, or applicability of the present disclosure. It should be noted that these drawings are not necessarily drawn to scale for clarity and ease of illustration.

[0011] Figure 1 A communication diagram between two gNBs with MT-SDT support capability exchange is shown;

[0012] Figure 2 A communication diagram between a gNB with SDT traffic information and SDT mapping information and the CN is shown;

[0013] Figure 3 A communication diagram between a gNB with SDT mapping information and resource modification confirmation and the CN is shown;

[0014] Figure 4 A communication diagram regarding the MT-SDT bearer information of the CN is shown;

[0015] Figure 5 A communication diagram regarding the CN initiating MT-SDT by directly sending small data is shown;

[0016] Figure 6 A communication diagram regarding the CN initiating MT-SDT by NGAP signaling is shown;

[0017] Figure 7 A wireless communication structure is shown;

[0018] Figure 8 An exemplary wireless communication system according to an embodiment of the present disclosure is shown. Detailed Embodiments

[0019] With the development of intelligent terminals (exemplarily implemented by user equipment (UE)) and IoT terminals, the number of users of some instant messaging services (such as WeChat, Twitter, QQ messages, and other applications) is increasing. These services are usually always online when in standby and when the user sends text messages, and usually only transmit a small amount of data. Since the small data volume services require the UE to frequently reconstruct the signaling link with the random access network (RAN), this will lead to problems such as an increase in signaling load on the RAN and an increase in power consumption on the UE.

[0020] Some new developments support the RRC Inactive state of the UE. However, before the most recent update, the RRC Inactive state did not support data transmission. Therefore, for any downlink (DL) and uplink (UL) data transmission, the UE had to resume the connection (i.e., move to the RRC connected state). As a result, regardless of how small and infrequent the data packets were, a connection was established and subsequently released to the Inactive state for each data transmission. This method led to unnecessary power consumption and signaling overhead.

[0021] The industry has recently addressed the support for such small and infrequent packet transmissions under the Small Data Transmission (SDT) function, which enables a UE in the RRC Inactive state to perform data transmission. SDT is a process that allows data and / or signaling transmission while the UE remains in the RRC Inactive state (i.e., without transitioning to the RRC connected state). SDT is enabled on a Radio Bearer (RB); for example, an SDT RB is a radio bearer configured with the SDT function.

[0022] For UL small data transmission in the RRC Inactive state, the UE can initiate a MO SDT (Mobile Originated SDT) process for UL data. However, when eDRX (Extended Discontinuous Reception) is used for a UE in MT (Mobile Terminated) SDT, the problem of DL small data transmission in the RRC Inactive state still exists. eDRX is a technology used in cellular networks. It allows a device to "sleep" for an extended period without losing its connection to the network, enabling the device to maintain a low-power mode for a longer period.

[0023] Specifically, to save the power of the UE, a long eDRX cycle (e.g., longer than 10.24 seconds) can be configured for the UE in the RRC Inactive state. With such a setting, the UE only needs to monitor the paging channel during one paging occasion (PO) in the long DRX cycle. However, due to the long eDRX cycle, the gNB (or base station BS) may have to wait for a long period (e.g., longer than 10.24 seconds) for data transmission until the UE is successfully paged. During this period, since the CN (Core Network) does not know whether the NG-RAN supports MT SDT and also does not know which QoS flows are mapped to the SDT DRB, the CN may need to buffer the downlink data of each QoS flow, regardless of how small and infrequent the data packets are. Then, the NG-RAN has to page the UE to transition to the RRC connected state for DL data transmission. Therefore, additional transmission delays for DL data transmission can be introduced.

[0024] Exchange of MT-SDT capability information between gNBs

[0025] According to some embodiments of the present disclosure, different BSs may exchange information on whether the BS supports MT-SDT, and thus, a BS may use another BS to perform MT-SDT via other BSs.

[0026] Referring Figure 1 to step 11 of [], the gNB may send an Xn establishment request or an NG-RAN node configuration update message to another gNB to establish or modify the interface between the two gNBs. The Xn establishment request or the NG-RAN node configuration update message may include MT-SDT support capability information in the message. The MT-SDT support capability information may indicate whether the gNB supports the MT-SDT function for DL data.

[0027] Referring Figure 1 to step 12 of [], another gNB receives the Xn establishment request or the NG-RAN node configuration update message with the MT-SDT support capability information, and it may save the received MT-SDT support capability information in the message. The other gNB sends an Xn establishment response or an RAN configuration update confirmation message to the first gNB. The Xn establishment response or the RAN configuration update confirmation message may include MT-SDT support capability information in the message, where the MT-SDT support capability information may indicate whether the gNB that sends the MT-SDT support capability information supports the MT-SDT function for DL data.

[0028] Thus, when the anchor gNB wants to page the UE via another gNB for MT-SDT service, it may know whether the other gNB supports the MT-SDT function. The anchor gNB may send an XnAP paging message to the other gNB, and the message includes an MT-SDT indicator in the paging message to indicate the expected MT-SDT service. Then, the other gNB knows that the paging is for the MT-SDT service; thus, the other gNB may include an MD-SDT indicator in the RRC paging message to the UE.

[0029] MT-SDT bearer information provided to the CN during the PDU session establishment / modification process

[0030] Referring Figure 2 to step 21 of [], the core network (CN) may send an initial context establishment request or a PDU session resource establishment / modification message to the gNB to establish or modify the resources of one or more PDU sessions of the UE. The initial context establishment request or the PDU session resource establishment / modification message may include SDT traffic information, and the SDT traffic information may include at least one of the following: at least one SDT traffic indicator for a corresponding QoS flow, at least one SDT traffic indicator for one PDU session and the entire underlying QoS flow.

[0031] At least one SDT traffic indicator corresponding to a respective QoS flow may indicate the respective QoS flow having DL and / or UL small data transfer characteristics, i.e., indicating that the traffic of the corresponding QoS flow may include DL and / or UL SDT data within a certain time period. Similarly, at least one SDT traffic indicator at the PDU session level may indicate that all QoS flows in the corresponding PDU session have the characteristics of downlink and / or uplink small data transfer.

[0032] Refer to Figure 2 In step 22 of [reference], the gNB receives SDT traffic information from the CN, and the gNB decides to map a single QoS flow to one or more SDT RBs of the UE based on the received SDT traffic information (including the SDT traffic indicator). For example, all mapped QoS flows in one SDT RB (radio bearer supporting SDT function) should have the characteristics of downlink and / or uplink SDT indicated by the SDT traffic indicator in the SDT traffic information.

[0033] The gNB may send a response message, e.g., 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 the following: an SDT mapping indicator for the respective 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 configured with the SDT mapping indicator, a downlink data volume threshold for all PDU sessions configured with the SDT mapping indicator.

[0034] The SDT mapping indicator of the respective QoS flow may indicate the mapping of the corresponding QoS flow to the SDT RB. Similarly, the SDT mapping indicator of a PDU session (and its underlying QoS flows) may indicate the mapping of all QoS flows in this PDU session to one or more SDT RBs.

[0035] MT-SDT bearer information of the CN during the PDU session modification procedure initiated by the gNB

[0036] Refer to Figure 3 In step 31 of [reference], the gNB may send a PDU session resource modification indication message to the CN (core network) to modify the resources of one or more PDU sessions of the UE; the PDU session resource modification indication message may include the modified SDT mapping information in the message. The SDT mapping information may have similar content as explained above, but with updated information.

[0037] Refer to Figure 3In step 32, the CN receives the SDT mapping information and updates the SDT mapping information it stores. The CN may send a PDU session resource modification confirmation message to the gNB.

[0038] Thus, the updated information can be provided to the CN, and the CN can confirm the received update.

[0039] MT-SDT bearer information of the CN during the release of the UE to the RRC inactive state

[0040] Reference Figure 4 In step 40, one or more PDU sessions have been established between the UE, the gNB, and the CN; additionally, the UE is in the RRC connected state.

[0041] Reference Figure 4 In step 41, the gNB may determine the long eDRX cycle value of the UE in the RRC inactive state, for example, longer than 10.24 seconds, and decide to transfer the UE to the RRC inactive state. Transferring the UE to the RRC inactive state can save the UE's power consumption.

[0042] Reference Figure 4 In step 42, the gNB sends an RRC message to the UE via the radio interface to release the UE to the RRC inactive state with a long eDRX cycle. eDRX is an energy-saving function that allows the device to remain in a low-power mode for an extended period while still being able to receive incoming data. The eDRX cycle defines the duration for which the UE remains in the low-power mode before waking up to check for incoming data. The eDRX cycle can range from a few seconds to several hours, depending on the requirements of the network and the application. During the eDRX cycle, the radio interface of the device can be turned off, thus significantly reducing power consumption. When the device wakes up to check for incoming data, it reopens the radio interface and listens for incoming transmissions.

[0043] Reference Figure 4 In step 43, the gNB sends an RRC inactive transition report message to the CN to indicate that the UE is in the RRC inactive state. The gNB may also send a UE context suspension request message to the CN to suspend the UE context and put the UE into the RRC inactive state. As explained above, the RRC inactive transition report message or the UE context suspension request message may include at least one of the eDRX information (e.g., including the inactive eDRX cycle value and the paging time window) or the SDT mapping information in the message.

[0044] Reference Figure 4In step 44, the CN then enters the CM-IDLE state, the RRC is in the inactive state, and the CN stops sending DL data to the gNB. CM-IDLE is an energy-saving state that allows the device to save battery power by reducing the communication frequency with the network. In the CM-IDLE state, the radio interface of the device can be turned off and periodically woken up to check for incoming data.

[0045] The CN initiates MT-SDT by directly sending small data

[0046] Reference Figure 5 In step 50, one or more PDU sessions have been established between the UE, gNB, and CN. After the data transfer period, the UE can be released to the RRC inactive state.

[0047] Reference Figure 5 In step 51, the user plane data or NAS PDU (Non-Access Stratum Protocol Data Unit) of the UE arrives at the CN. The CN can decide whether to trigger MT-SDT 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 data and / or NAS PDU to the gNB to trigger MT-SDT.

[0048] (1) When all the data arriving at the CN belongs to the QoS flow configured with the SDT mapping indicator, and the data volume is less than (or not greater than) the configured downlink data volume threshold of all QoS flows.

[0049] (2) When all the data arriving at the CN belongs to the PDU session configured with the SDT mapping indicator, and the data volume is less than (or not greater than) the configured downlink data volume threshold of all PDU sessions. These two conditions correspond to two possible implementation methods, where the SDT mapping indicator can correspond to the QoS flow or the PDU session respectively.

[0050] Reference Figure 5 In step 52, when the condition is met, the CN sends DL data or NAS PDU to the gNB.

[0051] Reference Figure 5In step 53, when the gNB receives DL data or a NAS PDU, the gNB knows that the received data is for the MT-SDT function. Then, the gNB can send an RRC paging message to the UE to page the corresponding UE for MT-SDT. The RRC paging message can include an MT-SDT indicator in the message to indicate the expected MT-SDT to the UE. The RRC paging message is used to notify the UE of incoming data or network events that require the UE's attention. The RRC (Radio Resource Control) layer can be responsible for paging the UE and instructing it to initiate a connection to the network. The RRC paging message can be broadcast by the network using the paging channel. The paging channel can be a dedicated channel for sending paging messages to all UEs in the RRC idle state and listening for incoming data. The RRC paging message can also include information such as the identity of the UE, the type of incoming data or event, and the frequency and timing of the paging message. The RRC paging message can be sent using a specific paging format that includes a paging message header and a paging message content.

[0052] In addition, when the anchor gNB wants to page the UE for MT-SDT via another gNB, if the other gNB also supports the MT-SDT function, the anchor gNB can send an Xn paging message to the other gNB via the Xn interface. The Xn paging message contains an MT-SDT indicator to indicate the expected MT-SDT. Then, the other gNB knows that the paging is for MT-SDT; therefore, the other gNB can include the MD-SDT indicator in the RRC paging message to be sent to the UE.

[0053] Similarly, when the anchor gNB with a CU / DU (Centralized Unit / Distributed Unit) split architecture wants to page the UE for MT-SDT via its DU, the CU of the gNB can send an F1 paging message to its DU via the F1 interface. The F1 paging message contains an MT-SDT indicator to indicate the expected MT-SDT to the DU. Then, the DU of the gNB knows that the paging is for MT-SDT; therefore, the DU can include the MD-SDT indicator in the RRC paging message to be sent to the UE.

[0054] Reference Figure 5 In step 54, after the UE receives the RRC paging message, it sends an RRC resume request message to the gNB (such as gNB-DU); the RRC resume request message includes an MT-SDT indicator to indicate the expected MT-SDT and requests to resume the UE in the inactive state for MT-SDT.

[0055] Reference Figure 5In step 55, the UE resumes transmission with the gNB in the RRC inactive state, and the UE can send or receive subsequent MT-SDT data between the UE and the gNB via the RACH (Random Access Channel) or CG (Cell Group) resources.

[0056] The CN initiates MT-SDT via NGAP signaling

[0057] Reference Figure 6 In step 60, one or more PDU sessions have been established between the UE, gNB, and CN. After the data transmission period, the UE can be released to the RRC inactive state.

[0058] Reference Figure 6 In step 61, the user plane data or NAS PDU of the UE arrives at the CN. Thereby, the CN can decide whether to trigger MT-SDT and how to trigger MT-SDT based on the stored SDT mapping information. For example, if the downlink data volume threshold does not exist 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) if all the arriving data belongs to at least one QoS flow configured with an SDT mapping indicator; (2) if all the arriving data belongs to at least one PDU session configured with an SDT mapping indicator.

[0059] Reference Figure 6 In step 62, the CN can cache the DL data until the UE is reachable.

[0060] Reference Figure 6 In step 63, the CN can send an NGAP message to the gNB. The NGAP message can include at least one of the following: (1) an MT-SDT indicator to indicate the expected MT-SDT; (2) the buffered data size of all QoS flows or PDU sessions (with SDT mapping indicators) to indicate the buffered data size of MT-SDT; (3) for a PDU session, the list of QoS flows through which any data can arrive; (4) the list of PDU sessions through which any data can arrive. For example, the NGAP message can be an NGAP paging message, a DL data notification message, or a message required for UE context recovery.

[0061] Reference Figure 6In step 64, when the gNB receives an NGAP message, for one or more paging cells, when at least one of the following conditions is met, the gNB may send an RRC paging message to the UE to page the corresponding UE for MT-SDT: (1) Receive the MT-SDT indicator; (2) Receive the buffered data size information, and the size is less than the MT-SDT threshold of the paging cell. That is, the gNB can determine whether it can support transmitting this buffered data using SDT based on its own network resources and the buffered data size, and then the gNB can determine whether to carry the MT-SDT indicator to page the UE on the air interface. The paging message may include the MT-SDT indicator to indicate the expected MT-SDT.

[0062] Similarly, when the anchor gNB wants to page the UE for MT-SDT via another gNB, if the other gNB supports MT-SDT, the anchor gNB may send an Xn paging message to the other gNB via the Xn interface. The paging message may include at least one of the following in the message: the MT-SDT indicator to indicate the expected MT-SDT; the buffered data size information of all QoS flows or PDU sessions with the SDT mapping indicator to indicate the buffered data size of MT-SDT.

[0063] When the other gNB receives the Xn paging message, the other gNB may decide how to send an RRC paging message to the UE according to step 64.

[0064] Similarly, when the anchor gNB configured with the CU / DU (Centralized Unit / Distributed Unit) split architecture wants to page the UE for MT-SDT via its DU, the CU of the gNB may send an F1 paging message to its DU via the F1 interface. The F1 paging message may include at least one of the following in the message: the MT-SDT indicator to indicate the expected MT-SDT; the buffered data size information of all QoS flows or PDU sessions (with the SDT mapping indicator) to indicate the buffered data size of MT-SDT. When the DU receives the F1 paging message, the DU of the gNB may decide how to send an RRC paging message to the UE according to step 64.

[0065] Reference Figure 6 In step 65, after the UE receives the RRC paging message, the UE may send an RRC resume request message to the gNB (such as gNB-DU). The RRC resume request message may include the MT-SDT indicator to indicate the expected MT-SDT and request to resume the UE in the inactive state for MT-SDT.

[0066] Reference Figure 6In step 66, after the UE successfully resumes the RRC inactive state, the gNB sends a message to the CN via the NG interface to indicate that the UE is reachable and keep the RRC in the inactive state for small data transmission. For example, the message sent by the gNB can be a UE context recovery request or an RRC inactive transition report. The message sent by the gNB can include an MT-SDT indicator in the message to trigger MT-SDT.

[0067] Reference Figure 6 In step 67, the CN then sends DL small data to the gNB.

[0068] Reference Figure 6 In step 68, the UE can resume with the gNB in the RRC inactive state to receive subsequent MT-SDT data between the UE and the gNB via the RACH or CG (cell group) resources.

[0069] Figure 7 is a system architecture that can be used to implement any steps, methods, or combinations thereof in the present disclosure. The core network is the core network architecture. It can include several network functions working together to enable communication between the UE and the network. The 5G core network can have several network functions, including: AMF (Access and Mobility Management Function), SMF (Session Management Function), UPF (User Plane Function), NRF (Network Repository Function), and / or AUSF (Authentication Server Function).

[0070] gNB stands for Next Generation Node B or gNodeB. It is a type of base station in the 5G network that connects the UE to the 5G core network. The gNB is responsible for providing wireless access to the UE and sending and receiving user data and control signals between the UE and the 5G core network. The gNB can support advanced functions such as massive MIMO (Multiple-Input Multiple-Output), beamforming, and dynamic spectrum sharing to improve network capacity, coverage, and efficiency.

[0071] Figure 8 Shows a block diagram of an exemplary wireless communication system 10 according to some embodiments of the present disclosure. The system 10 can execute various methods / steps disclosed in the present disclosure. The system 10 can include components and elements configured to support operational features not detailed herein.

[0072] System 10 may include a base station (BS) 110 and a user equipment (UE) 120. The 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 the BS 110 may be electrically coupled and communicate with each other via a data communication bus 180 as needed. Similarly, the 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 the UE 120 may be electrically coupled and communicate with each other via a data communication bus 190 as needed. The BS 110 communicates with the UE 120 via a communication channel therebetween, which may be any wireless channel or other medium known in the art suitable for transmitting data as described herein.

[0073] The processor modules 113, 123 may be implemented or realized using a general-purpose processor, 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. In this way, the processor modules may be implemented as a microprocessor, a controller, a microcontroller, a state machine, etc. The processor modules may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

[0074] In addition, the steps of the methods or algorithms described in connection with the embodiments disclosed herein may be embodied directly in hardware, firmware, software modules executed by processor modules 113 and 123 respectively, or any practicable combination thereof. The memory modules 113 and 123 may be implemented as RAM memory, flash memory, EEPROM memory, registers, ROM memory, EPROM memory, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. In this regard, the memory modules 114 and 124 may be coupled to the processor modules 113 and 123 respectively, such that the processor modules 113 and 123 can read information, instructions, or programs from and write information to the memory modules 114 and 124 respectively. The memory modules 114 and 124 may also be integrated into their respective processor modules 113 and 123. In some embodiments, the memory modules 114 and 124 may each include a cache memory for storing temporary variables or other intermediate information during the execution of instructions to be executed by the processor modules 113 and 123 respectively. The memory modules 114 and 124 may also each include a non-volatile memory for storing instructions to be executed by the processor modules 113 and 123 respectively.

[0075] According to some embodiments of the present disclosure, a wireless communication method is disclosed. The method includes: sending SDT mapping information from a first base station (BS) to a core network (CN) for establishing an SDT between the CN and the first BS; and performing the SDT according to a configuration established based on the SDT mapping information.

[0076] According to some examples, the SDT mapping information includes at least one of the following: at least one SDT mapping indicator, where the at least one SDT mapping indicator indicates the mapping of at least one QoS flow to at least one SDT radio bearer (RB); a first downlink (DL) data volume threshold.

[0077] According to some examples, the SDT mapping indicator corresponds to a PDU session and indicates the overall mapping of all at least one QoS flow under the PDU session to at least one SDT RB.

[0078] According to some examples, the SDT mapping indicator corresponds to the corresponding QoS flow.

[0079] According to some examples, the first DL data volume threshold corresponds to a PDU session and all its at least one QoS flows, or the first DL data volume threshold corresponds to at least one QoS flow respectively.

[0080] According to some examples, the method further includes: before sending the SDT mapping information, the first BS receives 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 transmissions of at least one QoS flow.

[0081] According to some examples, the method further includes: before sending the SDT mapping information, the first BS receives SDT traffic information from the CN, the information including: at least one SDT traffic indicator indicating characteristics of DL and / or UL small data transmissions of all at least one QoS flow under a PDU session.

[0082] According to some examples, the method further includes: mapping at least one QoS flow to at least one SDT RB according to the SDT traffic information.

[0083] According to some examples, the first BS receiving SDT traffic information from the CN includes: the first BS receiving the SDT traffic information in an initial context setup request for SDT from the CN, or receiving the SDT traffic information from the CN in a PDU session resource setup or modification message during a PDU session establishment or modification procedure.

[0084] According to some examples, the first BS sending the SDT mapping information to the CN includes: sending the SDT mapping information in a PDU session resource modification indication message.

[0085] According to some examples, the method further includes: the first BS sending to the CN at least one of the following: an RRC inactivity transition report message for indicating that a user equipment (UE) is in an RRC inactivity state, wherein the SDT mapping information is included in the RRC inactivity transition report message; a UE context suspension request message for suspending the UE context from entering the RRC inactivity state, wherein the SDT mapping information is included in the UE context suspension request message.

[0086] According to some examples, the method further includes: the first BS receiving data from the CN via SDT in the following cases: all data received by the CN belongs to at least one QoS flow configured by an SDT mapping indicator in the SDT mapping information, wherein the at least one SDT mapping indicator indicates the mapping of at least one QoS flow to at least one SDT RB; and the amount of data received is less than a DL data volume threshold of at least one QoS flow.

[0087] According to some examples, the method further includes: receiving, by the first BS via SDT from the CN, data when all data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information, where the SDT mapping indicator indicates the mapping of all at least one QoS flow under the PDU session to at least one SDT RB; and the data volume of the data is less than the configured DL data volume threshold of at least one PDU session.

[0088] According to some examples, the method further includes: when there is no setting of the DL data volume threshold in the SDT mapping information and all data received by the CN belongs to at least one QoS flow configured by an SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN to trigger SDT, where at least one SDT mapping indicator indicates the mapping of at least one QoS flow to at least one SDT RB.

[0089] According to some examples, the method further includes: when there is no setting of the DL data volume threshold in the SDT mapping information and all data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN to trigger SDT, where the SDT mapping indicator indicates the mapping of all at least one QoS flow under at least one PDU session to at least one SDT RB.

[0090] According to some examples, the NGAP message includes at least one of the following: an MT-SDT indicator for indicating to the BS an expected MT-SDT transmission; the buffered data size of all QoS flows or all PDU sessions with an SDT mapping indicator for indicating the buffered data size of the MT-SDT; for one PDU session, a list of QoS flows through which any data will arrive; a list of PDU sessions through which any data will arrive.

[0091] According to some examples, the NGAP message can be at least one of an NGAP paging message, a DL data notification, or a UE context recovery request message.

[0092] According to some examples, the method further includes: the first BS sending an Xn paging message to the second BS via the Xn interface, where the Xn paging information includes at least one of the following: an MT-SDT indicator for indicating an expected MT-SDT transmission; the buffered data size of all QoS flows or all PDU sessions with an SDT mapping indicator for indicating the total buffered data size of the SDT.

[0093] According to some examples, the method further includes: sending, by a central unit (CU) of a first base station (BS) via an F1 interface, an F1 paging message to a distributed unit (DU) of the first BS, where the F1 paging message includes at least one of the following: an MT-SDT indicator for indicating an expected MT-SDT transmission; buffer data sizes of all QoS flows or all PDU sessions with SDT mapping indicators for indicating a total buffer data size of the MT-SDT.

[0094] According to some examples, the method further includes: sending, by the first BS via an NG interface, an NGAP message to a core network (CN) to indicate that a user equipment (UE) is available for SDT in an RRC inactive state, where the NGAP message includes an MT-SDT indicator for triggering SDT.

[0095] According to some examples, the NGAP message includes a UE context recovery request or an RRC inactive transition report.

[0096] According to some embodiments, a wireless communication method is disclosed. The method includes: receiving, by a core network (CN) from a first base station (BS), SDT mapping information for establishing small data transmission (SDT) between the CN and the first BS; performing SDT according to a configuration established based on the SDT mapping information.

[0097] According to some examples, the SDT mapping information includes at least one of the following: at least one SDT mapping indicator, where the at least one SDT mapping indicator indicates a mapping of at least one QoS flow to at least one SDT radio bearer (RB); a first downlink (DL) data volume threshold.

[0098] According to some examples, the SDT mapping indicator corresponds to a PDU session and indicates an overall mapping of all at least one QoS flows under the PDU session to at least one SDT RB.

[0099] According to some examples, the SDT mapping indicator corresponds to a corresponding QoS flow.

[0100] According to some examples, the first DL data volume threshold corresponds to a PDU session and all its at least one QoS flows, or the first DL data volume threshold corresponds to at least one QoS flow respectively.

[0101] According to some examples, the method further includes: before receiving the SDT mapping information, sending, by the CN to the first BS, SDT traffic information, where the information includes: at least one SDT traffic indicator for indicating characteristics of DL and / or uplink (UL) small data transmission of at least one QoS flow.

[0102] According to some examples, the method further includes: 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 the characteristics of DL and / or UL small data transmission of all at least one QoS flow under the PDU session.

[0103] According to some examples, the SDT traffic information is used to map at least one QoS flow to at least one SDT RB accordingly.

[0104] According to some examples, the CN sending the SDT traffic information to the first BS includes: sending the SDT traffic information in an initial context setup request of the SDT from the CN, or sending the SDT traffic information in a PDU session resource setup or modification message during the PDU session establishment or modification process.

[0105] 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 modification indication message.

[0106] According to some examples, the method further includes: the CN receiving from the first BS at least one of the following: an RRC inactive transition report message for indicating that the user equipment (UE) is in the RRC inactive state, wherein the SDT mapping information is included in the RRC inactive transition report message; a UE context suspension request message for suspending the UE context from entering the RRC inactive state, wherein the SDT mapping information is included in the UE context suspension request message.

[0107] According to some examples, the method further includes: the CN sending data to the first BS via SDT in the following cases: all data received by the CN belongs to at least one QoS flow configured by the SDT mapping indicator in the SDT mapping information, wherein at least one SDT mapping indicator indicates the mapping of at least one QoS flow to at least one SDT RB; and the data volume of the received data is less than the DL data volume threshold of at least one QoS flow.

[0108] According to some examples, the method further includes: the CN sending data to the first BS via SDT in the following cases: all data received by the CN belongs to at least one PDU session configured by the SDT mapping indicator in the SDT mapping information, wherein the SDT mapping indicator indicates the mapping of all at least one QoS flow under the PDU session to at least one SDT RB; and the data volume of the data is less than the configured DL data volume threshold of at least one PDU session.

[0109] According to some examples, the method further includes: when there is no setting of a DL data volume threshold in the SDT mapping information and all data received by the CN belongs to at least one QoS flow configured by the SDT mapping indicator in the SDT mapping information, the CN sends an NGAP message to the first BS to trigger SDT, where at least one SDT mapping indicator indicates the mapping of at least one QoS flow to at least one SDT RB.

[0110] According to some examples, the method further includes: when there is no setting of a DL data volume threshold in the SDT mapping information and all data received by the CN belongs to at least one PDU session configured by the SDT mapping indicator in the SDT mapping information, the CN sends an NGAP message to the first BS to trigger SDT, where the SDT mapping indicator indicates the mapping of all at least one QoS flow under at least one PDU session to at least one SDT RB.

[0111] According to some examples, the NGAP message includes at least one of the following: an MT-SDT indicator for indicating to the BS an expected MT-SDT transmission; the buffered data size of all QoS flows or all PDU sessions with an SDT mapping indicator for indicating the buffered data size of the MT-SDT; for one PDU session, a list of QoS flows through which any data will arrive; a list of PDU sessions through which any data will arrive.

[0112] According to some examples, the NGAP message is at least one of an NGAP paging message, a DL data notification, or a UE context recovery request message.

[0113] According to some examples, the method further includes: the CN receives an NGAP message from the first BS via the NG interface to indicate that the UE is available for SDT in the RRC inactive state, and the NGAP message includes an MT-SDT indicator for triggering SDT.

[0114] According to some examples, the NGAP message includes a UE context recovery request or an RRC inactive transition report.

[0115] This disclosure describes various exemplary embodiments of the present disclosure with reference to the accompanying drawings, so that those of ordinary skill 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. Additionally, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be rearranged while remaining within the scope of the present disclosure. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in an exemplary order, and the present disclosure is not limited to the specific order or hierarchy presented, unless otherwise expressly stated.

[0116] The present disclosure is intended to cover any conceivable variations, uses, combinations, or adaptive changes of the present disclosure that follow the general principles of the present disclosure, and includes known knowledge and conventional technical means in the art and not disclosed in this application.

[0117] It should be understood that the present disclosure is not limited to the exact structures or operations described above and shown in the drawings, and various modifications and changes can be made without departing from the scope of this application. The scope of this application is only limited by the appended claims.

[0118] The above methods, devices, processes, circuits, and logics can be implemented in many different ways and in many different combinations of hardware and software. For example, all or part of the implementations can be circuits including an instruction processor or controller, such as a central processing unit (CPU), a microcontroller, or a microprocessor; or as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA); or as a circuit including discrete logic or other circuit components, including analog circuit components, digital circuit components, or both; or any combination thereof. For example, the circuit can include discrete interconnected hardware components, or can 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 in a common package.

[0119] Thus, the circuit can store or access instructions for execution, or can implement its functions only in hardware. The instructions can be stored in a tangible storage medium other than transient signals, such as flash memory, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM); or stored on a magnetic disk or optical disk, such as a compact disc read only memory (CDROM), a hard disk drive (HDD), or other magnetic disk or optical disk; or in or on another machine-readable medium. A product (such as a computer program product) can include a storage medium and instructions stored in or on the medium, and when the instructions are executed by a circuit in a device, the instructions can cause the device to implement any of the processes described above or shown in the drawings.

[0120] The implementation can be distributed. For example, the circuit can include multiple different system components, such as multiple processors and memories, and can span multiple distributed processing systems. Parameters, databases, and other data structures can be stored and managed separately, can be combined into a single memory or database, can be logically and physically organized in many different ways, and can be 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. The instructions can form part of a single program (e.g., a subroutine or other code segment), can form multiple separate programs, can be distributed across multiple memories and processors, and can be implemented in many different ways. Exemplary implementations include stand-alone programs, and as part of a library, such as a shared library like a Dynamic Link Library (DLL). For example, the library can contain shared data and one or more shared programs that include instructions for performing any of the processes described above or shown in the figures when executed by the circuit.

[0121] In some examples, each unit, subunit, and / or module of the system can include a logic component. Each logic component can be hardware or a combination of hardware and software. For example, each logic component can include an Application-Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), digital logic circuits, analog circuits, a combination of discrete circuits, gates, or any other type of hardware or a combination thereof. Alternatively or additionally, each logic component can include memory hardware, such as a portion of a memory that, for example, includes instructions executable by a processor or other processors to implement one or more features of the logic component. When any one logic component includes a portion of a memory that includes instructions executable by a processor, the logic component may or may not include a processor. In some examples, each logic component may simply be a portion of a memory or other physical memory that includes instructions executable by a processor or other processors to implement the features of the corresponding logic component, and the logic component does not include any other hardware. Since each logic component includes at least some hardware even if the included hardware includes software, each logic component can be interchangeably referred to as a hardware logic component.

[0122] A second action can be said to be "responsive to" a first action, regardless of whether the second action is directly or indirectly caused by the first action. The second action can occur much later in time than the first action and still be responsive to the first action. Similarly, even if intervening actions occur between the first action and the second action, and even if one or more intervening actions directly cause the execution of the second action, it can still be said that the second action is responsive to the first action. For example, if the first action sets a flag, the second action can be responsive to the first action, and a third action later initiates the second action when the flag is set.

[0123] To clarify the usage and hereby provide notice to the public, the applicant defines the phrase "at least one of , , … and <N>" or "at least one or a combination thereof of , , … <N>" or ", , … and / or <N>" in the broadest sense, superseding any other implicit definition above or below, and means one or more elements selected from A, B, … and N, unless the applicant expressly states otherwise. In other words, the phrase refers to any combination of one or more of the elements A, B, … or N, including any one of the elements alone or a combination of that element with one or more other elements, which other elements may also be combined to include additional elements not listed.

Claims

1. A wireless communication method, comprising: The first base station BS sends small data transmission (SDT) mapping information to the core network CN for establishing SDT between the CN and the first BS; Performing the SDT according to the configuration established based on the SDT mapping information.

2. The method according to claim 1, wherein The SDT mapping information includes at least one of the following: At least one SDT mapping indicator, wherein the at least one SDT mapping indicator indicates the mapping of at least one QoS flow to at least one SDT radio bearer (RB); A first downlink (DL) data volume threshold.

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

4. The method according to claim 2, wherein The SDT mapping indicator corresponds to the corresponding QoS flow.

5. The method according to claim 2, wherein, The first DL data volume threshold corresponds to the PDU session and all its at least one QoS flows, or the first DL data volume threshold corresponds to the at least one QoS flow respectively.

6. The method according to claim 1 further comprises: Before sending the SDT mapping information, the first BS receives SDT traffic information from the CN, and the SDT traffic information includes: At least one SDT traffic indicator indicating the characteristics of DL and / or uplink (UL) small data transmission of the at least one QoS flow.

7. The method according to claim 1, further comprising: Before sending the SDT mapping information, the first BS receives SDT traffic information from the CN, and the SDT traffic information includes: At least one SDT traffic indicator indicating the characteristics of DL and / or UL small data transmission of all at least one QoS flow under the PDU session.

8. The method according to claim 6 or 7, further comprising: Mapping the at least one QoS flow to at least one SDT RB according to the SDT traffic information.

9. The method according to claim 6 or 7, wherein The first BS receiving the SDT traffic information from the CN includes: the first BS receives the SDT traffic information in the initial context establishment request of the SDT from the CN, or receives the SDT traffic information from the CN in the PDU session resource establishment or modification message during the PDU session establishment or modification process.

10. The method according to claim 1, wherein, The first BS sending the SDT mapping information to the CN includes: sending the SDT mapping information in the PDU session resource modification indication message.

11. The method according to claim 1 further comprises: The first BS sends at least one of the following to the CN: An RRC inactivate transition report message for indicating that the user equipment (UE) is in the RRC inactivate state, wherein the SDT mapping information is included in the RRC inactivate transition report message; A UE context suspension request message for suspending the UE context from entering the RRC inactivate state, wherein the SDT mapping information is included in the UE context suspension request message.

12. The method according to claim 1 further comprises: The first BS receives data from the CN via the SDT in the following cases: All the data received by the CN belongs to at least one QoS flow configured by the SDT mapping indicator in the SDT mapping information, wherein the SDT mapping indicator indicates the mapping of the at least one QoS flow to at least one SDT RB; and The amount of the received data is less than the DL data volume threshold of the at least one QoS flow.

13. The method according to claim 1 further comprises: The first BS receives data from the CN via the SDT in the following cases: All the data received by the CN belongs to at least one PDU session configured by the SDT mapping indicator in the SDT mapping information, where the SDT mapping indicator indicates the mapping of all the at least one QoS flows under the PDU session to at least one SDT RB; and The amount of the data is less than the configured DL data volume threshold of the at least one PDU session.

14. The method according to claim 1 further comprises: In the case where there is no setting of the DL data volume threshold in the SDT mapping information and all the data received by the CN belongs to at least one QoS flow configured by the SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN to trigger the SDT, where the SDT mapping indicator indicates the mapping of the at least one QoS flow to at least one SDT RB.

15. The method according to claim 1 further comprises: In the case where there is no setting of the DL data volume threshold in the SDT mapping information and all the data received by the CN belongs to at least one PDU session configured by the SDT mapping indicator in the SDT mapping information, the first BS receives an NGAP message from the CN to trigger the SDT, where the SDT mapping indicator indicates the mapping of all the at least one QoS flows under the at least one PDU session to at least one SDT RB.

16. The method according to claim 14 or 15, wherein The NGAP message includes at least one of the following: MT-SDT indicator, used to indicate the expected MT-SDT transmission to the BS; The buffered data size of all QoS flows or all PDU sessions, used to indicate the buffered data size of the SDT; For one PDU session, the list of QoS flows through which any data will arrive; The list of PDU sessions through which any data will arrive.

17. The 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 recovery request message.

18. The method according to claim 1 further comprises: The first BS sends an Xn paging message to the second BS via the Xn interface, and the Xn paging information includes at least one of the following: MT-SDT indicator, used to indicate the expected MT-SDT transmission; The buffered data size of all QoS flows or all PDU sessions, used to indicate the total buffered data size of the SDT.

19. The method according to claim 1 further comprises: The central unit CU of the first BS sends an F1 paging message to the distributed unit DU of the first BS via the F1 interface, and the F1 paging message includes at least one of the following: MT-SDT indicator, used to indicate the expected MT-SDT transmission; The buffered data size of all QoS flows or all PDU sessions, used to indicate the total buffered data size of the SDT.

20. The method according to claim 1 further comprises: The first BS sends an NGAP message to the CN via the NG interface to indicate that the UE is available for the SDT in the RRC inactive state, and the NGAP message includes the MT-SDT indicator for triggering the SDT.

21. The method according to claim 20, wherein, The NGAP message includes a UE context restoration request or an RRC inactive transition report.

22. A wireless communication method, comprising: A core network CN receives small data transmission (SDT) mapping information from a first base station BS for establishing SDT between the CN and the first BS; Performing the SDT according to a configuration established based on the SDT mapping information.

23. The method according to claim 22, wherein The SDT mapping information includes at least one of the following: At least one SDT mapping indicator, where the at least one SDT mapping indicator indicates a mapping of at least one QoS flow to at least one SDT radio bearer (RB); A first downlink (DL) data volume threshold.

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

25. The method according to claim 23, wherein, The SDT mapping indicator corresponds to a corresponding QoS flow.

26. The method according to claim 23, wherein, The first DL data volume threshold corresponds to a PDU session and all at least one QoS flow thereof, or the first DL data volume threshold corresponds to the at least one QoS flow respectively.

27. The method according to claim 22, further comprising: Before receiving the SDT mapping information, the CN sends SDT traffic information to the first BS, and the SDT traffic information includes: 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. The method according to claim 22 further comprises: Before receiving the SDT mapping information, the CN sends SDT traffic information to the first BS, and the SDT traffic information includes: At least one SDT traffic indicator indicating characteristics of DL and / or UL small data transmission of all at least one QoS flow under a PDU session.

29. The method according to claim 27 or 28, wherein The SDT traffic information is used to map the at least one QoS flow to at least one SDT RB accordingly.

30. The method according to claim 27 or 28, wherein The CN sending the SDT traffic information to the first BS includes: sending the SDT traffic information in an initial context establishment request of the SDT from the CN, or sending the SDT traffic information in a PDU session resource establishment or modification message during a PDU session establishment or modification process.

31. The method according to claim 22, wherein The CN receiving the SDT mapping information from the first BS includes: receiving the SDT mapping information in a PDU session resource modification indication message.

32. The method according to claim 22, further comprising: The CN receives at least one of the following from the first BS: An RRC inactive transition report message for indicating that a user equipment (UE) is in an RRC inactive state, where the SDT mapping information is included in the RRC inactive transition report message; A UE context suspension request message for suspending the UE context from entering the RRC inactive state, where the SDT mapping information is included in the UE context suspension request message.

33. The method according to claim 22 further comprises: The CN sends data to the first BS via the SDT in the following cases: All data received by the CN belongs to at least one QoS flow configured by an SDT mapping indicator in the SDT mapping information, where the SDT mapping indicator indicates the mapping of the at least one QoS flow to at least one SDT RB; and The amount of data of the received data is less than the DL data volume threshold of the at least one QoS flow.

34. The method according to claim 22 further comprises: The CN sends data to the first BS via the SDT in the following cases: All data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information, where the SDT mapping indicator indicates the mapping of all the at least one QoS flow under the PDU session to at least one SDT RB; and The amount of the data is less than the configured DL data volume threshold of the at least one PDU session.

35. The method according to claim 22 further comprises: In the case where there is no setting of the DL data volume threshold in the SDT mapping information and all data received by the CN belongs to at least one QoS flow configured by an SDT mapping indicator in the SDT mapping information, the CN sends an NGAP message to the first BS to trigger the SDT, where the SDT mapping indicator indicates the mapping of the at least one QoS flow to at least one SDT RB.

36. The method according to claim 22 further comprises: In the case where there is no setting of the DL data volume threshold in the SDT mapping information and all data received by the CN belongs to at least one PDU session configured by an SDT mapping indicator in the SDT mapping information, the CN sends an NGAP message to the first BS to trigger the SDT, where the SDT mapping indicator indicates the mapping of all the at least one QoS flow under the at least one PDU session to at least one SDT RB.

37. The method according to claim 35 or 36, wherein The NGAP message includes at least one of the following: An MT-SDT indicator for indicating to the BS an expected MT-SDT transmission; The buffered data size of all QoS flows or all PDU sessions for indicating The buffered data size of the MT-SDT; For a PDU session, a list of QoS flows through which any data will arrive; A list of PDU sessions through which any data will arrive.

38. The 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 recovery request message.

39. The method according to claim 22, further comprising: The CN receives an NGAP message from the first BS via the NG interface to indicate that the UE is available for SDT in the RRC inactive state, and the NGAP message includes an MT-SDT indicator for triggering the SDT.

40. The method according to claim 39, wherein, The NGAP message includes a UE context recovery request or an RRC inactive transition report.

41. A wireless communication device, comprising: A memory storing one or more programs; And One or more processors electrically coupled to the memory and configured to execute the one or more programs to perform the method according to any one of claims 1 to 40.

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

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