Data transmission method, apparatus and system

Abstract

The application provides a data transmission method, device and system, and applies to the technical field of communication. The data transmission method comprises the following steps: a service access network device receives a first radio resource control (RRC) message from a terminal device, and the first RRC message is used for establishing small data packet transmission (SDT). If the service access network device does not meet the requirement of SDT, the second RRC message or the third RRC message can be sent to the terminal device, wherein the second RRC message can be used for instructing the terminal device to terminate SDT, and the third RRC message can be used for instructing the service access network device to reject SDT. Based on the scheme, once the service access network device does not meet the requirement of SDT, the SDT can be rejected or terminated, so that the terminal device can reselect a cell and initiate SDT again in the future. Compared with the scheme that the terminal continues to wait in the cell, the data transmission efficiency of the terminal device can be improved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a data transmission method, apparatus and system. Background Technology

[0002] In 5G NR systems, an RRC_INACTIVE state is introduced at the radio resource control (RRC) layer. User equipment (UE) can be in an RRC_INACTIVE state when there is no data transmission. When the UE needs to transmit data, it can switch from the RRC_INACTIVE state to the RRC_CONNECTED state to perform data transmission.

[0003] In some transmission scenarios, although the data packets transmitted by the UE are small, the frequency of transmissions leads to frequent RRC state switching by the UE, thus consuming a large amount of signaling resources. However, consuming a large amount of signaling resources for transmitting small data packets results in a waste of signaling resources. To address this issue, existing technologies have proposed a small data transmission (SDT) technology, based on which the UE can transmit data even in an RRC inactive state. Summary of the Invention

[0004] This application provides a data transmission method, apparatus, and system, offering a solution for situations where the serving base station or anchor base station does not meet the requirements for SDT (Service Data Transmission), such as when the serving base station experiences resource congestion or the anchor base station is overloaded. This invention does not limit the reasons why the serving base station or anchor base station fails to meet the requirements for SDT.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] Firstly, a data transmission method is provided, which can be applied to a serving access network device. This data transmission method may include: firstly, receiving a first RRC message from a terminal device, the first RRC message being used to establish a Service Dependency Test (SDT). If the serving access network device does not meet the requirements for performing the SDT, for example due to resource congestion or network load, it may send a second RRC message or a third RRC message to the terminal device. The second RRC message may be used to instruct the terminal device to terminate the SDT, and the third RRC message may be used to instruct the serving access network device to refuse to perform the SDT.

[0007] Based on this scheme, if the serving access network device does not meet the requirements for performing SDT, it can promptly reject or terminate SDT, so that the terminal device can reselect a cell and re-initiate SDT. Compared with the scheme of letting the terminal device continue to wait in the cell, it can reduce latency and improve the data transmission efficiency of the terminal device.

[0008] In conjunction with the first aspect above, in one possible implementation, the failure of the serving access network device to meet the SDT requirements may include: when the first RRC message is received, the serving access network device does not support SDT, or the serving access network device is congested, or the load of the serving access network device is greater than a threshold.

[0009] In conjunction with the first aspect above, in one possible implementation, the failure of the serving access network device to meet the SDT requirements may include: during the SDT process, the serving access network device experiences congestion or the load of the serving access network device exceeds a threshold.

[0010] Based on the two implementation methods mentioned above, if the service access network device does not meet the requirements of SDT when requesting to establish SDT or during the SDT process, the subsequent SDT process can be terminated or rejected, which improves the applicability and flexibility of the solution.

[0011] In conjunction with the first aspect mentioned above, in one possible implementation, both the second RRC message and the third RRC message include a waiting time, which is used to indicate the time the terminal device waits before initiating the next communication connection.

[0012] Based on this scheme, it is possible to avoid the SDT failing again if the terminal device selects the current cell again after immediately initiating a communication connection.

[0013] In conjunction with the first aspect above, in one possible implementation, the second RRC message includes a first redirection parameter or a first cell reselection priority parameter, wherein the first redirection parameter is used for redirection and the first cell reselection priority parameter is used for cell reselection.

[0014] Based on this scheme, while instructing the terminal device to terminate SDT transmission, the serving access network device can also provide the terminal device with parameters for redirection or cell reselection. This allows the terminal device to reselect a cell based on the instructions from the serving access network device. This scheme enables the terminal device to select a more suitable cell for SDT or initiate other services, thereby improving the data transmission efficiency of the terminal device.

[0015] In conjunction with the first aspect above, in one possible implementation, the second RRC message includes a suspend configuration, which is used to instruct the terminal device to suspend the context of the terminal device.

[0016] In conjunction with the first aspect described above, in one possible implementation, the serving access network device is not the anchor access network device. Before sending the second RRC message to the terminal device, the data transmission method may further include: sending a fourth RRC message to the anchor access network device, the fourth RRC message being used to request the anchor access network device to send the second RRC message; and receiving a fifth RRC message from the anchor access network device, the fifth RRC message being a response message to the fourth RRC message, the fifth RRC message including the second RRC message. It can be seen that the second RRC message used to instruct the terminal device to terminate SDT is generated by the anchor access network device.

[0017] In conjunction with the first aspect above, in one possible implementation, the fourth RRC message includes any one of the following: a request indication, a redirection indication, or a cell reselection indication. The request indication is used to request the anchor access network device to send a second RRC message. The redirection indication is used to instruct the serving access network device to suggest that the terminal device perform a redirection. The cell reselection indication is used to instruct the serving access network device to suggest that the terminal device perform a cell reselection.

[0018] Based on this scheme, when the serving access network device requests the anchor access network device to send a second RRC message for terminating SDT, it can also suggest that the terminal device perform redirection. This allows the terminal device to select a more suitable cell for SDT, thereby improving the efficiency of data transmission.

[0019] In conjunction with the first aspect described above, in one possible implementation, when the second RRC message includes the first redirection parameter, the fourth RRC message includes the second redirection parameter, which is used to determine the first redirection parameter. When the second RRC message includes the first cell reselection priority parameter, the fourth RRC message includes the second cell reselection priority parameter, which is used to determine the first cell reselection priority parameter.

[0020] Based on this scheme, the parameters that instruct terminal devices to perform redirection or cell reselection can be suggested by the serving access network equipment.

[0021] In conjunction with the first aspect above, in one possible implementation, the fourth RRC message includes a waiting time indication and / or a first reason value. The waiting time indication is used to indicate the waiting time for the anchor access network device to send the message, and the first reason value is used to indicate the reason why the serving access network device requests the anchor access network device to send the second RRC message.

[0022] In conjunction with the first aspect above, in one possible implementation, if the serving access network device determines that the requirements for SDT are not met when it receives the first RRC message, the fourth RRC message may include a transmission indication, which is used to instruct the terminal device to request SDT.

[0023] In conjunction with the first aspect described above, in one possible implementation, if the serving access network device determines that the SDT requirements are not met during the SDT process, the fifth RRC message can also be used to instruct the serving access network device to delete the context of the terminal device. The data transmission method may further include deleting the locally stored context of the terminal device.

[0024] In conjunction with the first aspect described above, in one possible implementation, the first RRC message includes a first SDT data packet. If the serving access network device does not meet the SDT requirements upon receiving the first RRC message, the fourth RRC message also includes the first SDT data packet.

[0025] Based on this scheme, even if it has been decided to terminate or reject SDT, data packets already sent by the terminal device will not be discarded, thus avoiding the waste of signaling resources.

[0026] In conjunction with the first aspect above, in one possible implementation, if the serving access network device determines that the SDT requirements are not met during the SDT process, after sending a third RRC message to the terminal device, the data transmission method may further include: sending a sixth RRC message to the anchor access network device, the sixth RRC message being used to instruct the anchor access network device to cancel the SDT.

[0027] In conjunction with the first aspect mentioned above, in one possible implementation, the sixth RRC message also includes a second reason value, which is used to indicate the reason for canceling the SDT.

[0028] Secondly, a data transmission method is provided, which can be applied to an anchor access network device. This data transmission method may include: first, receiving a fourth RRC message from a serving access network device, the fourth RRC message being used to request the anchor access network device to send a second RRC message; then, sending a fifth RRC message to the serving access network device based on the fourth RRC message, the fifth RRC message including the second RRC message, the second RRC message being used to instruct the terminal device to terminate SDT.

[0029] Based on this scheme, when the serving access network device does not meet the requirements of SDT, the serving access network device can request the anchor access network device to send a second RRC message. The serving access network device can then forward this second RRC message to the terminal device, thereby instructing the terminal device to terminate SDT. Timely termination of SDT when the serving access network device does not meet the requirements avoids the terminal device continuing to wait in the serving access network device's cell. This scheme can reduce SDT latency and improve the data transmission efficiency of the terminal device.

[0030] In conjunction with the second aspect above, in one possible implementation, the fourth RRC message includes any one of the following: a request indication, a redirection indication, or a cell reselection indication. The request indication is used to request the anchor access network device to send the second RRC message; the redirection indication is used to instruct the serving access network device to suggest that the terminal device perform redirection; and the cell reselection indication is used to instruct the serving access network device to suggest that the terminal device perform cell reselection. The data transmission method may further include: determining, based on the request indication, redirection indication, or cell reselection indication, that the fifth RRC message includes the second RRC message.

[0031] Based on this scheme, the serving access network device can explicitly (e.g., by requesting an instruction) request the anchor access network device to terminate the SDT, or it can implicitly (e.g., by redirection instruction or cell reselection instruction) request the anchor access network device to terminate the SDT, which improves the flexibility of the scheme in this application.

[0032] In conjunction with the second aspect above, in one possible implementation, the second RRC message includes a first redirection parameter or a first cell reselection priority parameter, wherein the first redirection parameter is used for redirection and the first cell reselection priority parameter is used for cell reselection.

[0033] In conjunction with the second aspect above, in one possible implementation, when the second RRC message includes a first redirection parameter, the fourth RRC message also includes a second redirection parameter, and the data transmission method further includes: determining the first redirection parameter based on the second redirection parameter. When the second RRC message includes a first cell reselection priority parameter, the fourth RRC message also includes a second cell reselection priority parameter, and the data transmission method further includes: determining the first cell reselection priority parameter based on the second cell reselection priority parameter.

[0034] Based on this scheme, the anchor access network device can determine the parameters used by the terminal device for redirection or cell reselection based on the redirection parameters or cell reselection priority parameters suggested by the serving access network device.

[0035] In conjunction with the second aspect above, in one possible implementation, the second RRC message includes a waiting time, which indicates the time the terminal device waits before initiating the next communication connection.

[0036] In conjunction with the second aspect above, in one possible implementation, the fourth RRC message may also include a waiting time indication, and the data transmission method further includes: determining a waiting time based on the waiting time indication.

[0037] In conjunction with the second aspect above, in one possible implementation, the fourth RRC message further includes a first reason value, which is used to indicate the reason why the serving access network device requests the anchor access network device to send the second RRC message.

[0038] In conjunction with the second aspect above, in one possible implementation, the fourth RRC message further includes a transmission indication, which is used to instruct the terminal device to request SDT.

[0039] In conjunction with the second aspect described above, in one possible implementation, the fourth RRC message further includes a first SDT data packet. The data transmission method may also include sending the first SDT data packet to the user plane network element. Based on this scheme, even if the terminal device has been instructed to terminate SDT, the already sent data packets are still forwarded normally to the user plane network element, preventing the first data packet from being discarded and thus wasting signaling resources.

[0040] In conjunction with the second aspect above, in one possible implementation, the fifth RRC message is also used to instruct the serving access network device to delete the context of the terminal device.

[0041] Thirdly, a data transmission method is provided, which can be applied to anchor access network devices. This data transmission method may include: first, receiving a sixth RRC message from a serving access network device, the sixth RRC message instructing the anchor access network device to cancel SDT; and then suspending the context of the terminal device performing SDT based on the sixth RRC message.

[0042] Based on this scheme, when the serving access network device does not meet the requirements of SDT, the serving access network device can instruct the anchor access network device to cancel the subsequent SDT. It can be seen that there is more than one way to terminate SDT, and this scheme improves the flexibility of the data transmission method in this application.

[0043] In conjunction with the third aspect mentioned above, in one possible implementation, the sixth RRC message also includes a second reason value, which is used to indicate the reason for canceling the SDT.

[0044] Fourthly, a data transmission method is provided, which can be applied to anchor access network devices. This data transmission method may include: first, determining to terminate SDT; then, sending a seventh RRC message to the serving access network device, the seventh RRC message including a second RRC message, the second RRC message being used to instruct the terminal device to terminate SDT.

[0045] Based on this scheme, anchor access network devices can also actively terminate SDT, which improves the flexibility of the data transmission method in this application.

[0046] In conjunction with the fourth aspect above, in one possible implementation, the second RRC message includes a first redirection parameter or a first cell reselection priority parameter, wherein the first redirection parameter is used for redirection and the first cell reselection priority parameter is used for cell reselection.

[0047] In conjunction with the fourth aspect above, in one possible implementation, the second RRC message includes a waiting time, which indicates the time the terminal device waits before initiating the next communication connection.

[0048] Fifthly, a data transmission method is provided, which can be applied to a terminal device. This data transmission method may include: firstly, sending a first RRC message to a serving access network device, the first RRC message being used to establish a Service Dependency Test (SDT). When a second or third RRC message is received from the serving access network device, the terminal device stops the SDT timer, wherein the second RRC message is used to instruct the terminal device to terminate the SDT, and the third RRC message is used to instruct the serving access network device to refuse to perform the SDT.

[0049] Based on this scheme, the terminal device can initiate SDT via the first RRC message. Furthermore, after initiating SDT, if the terminal device receives an instruction to terminate SDT or the access network device refuses to perform SDT, the terminal device can stop the SDT timer. This method can avoid long data transmission delays caused by the terminal device waiting for an extended period in a particular cell.

[0050] In conjunction with the fifth aspect mentioned above, in one possible implementation, the second RRC message is an RRC release message, and the third RRC message is an RRC rejection message.

[0051] In conjunction with the fifth aspect above, in one possible implementation, when a third RRC message is received, the data transmission method may further include: notifying the upper-layer SDT of failure and restarting the RNA timer, the RNA timer being used to indicate that the terminal device is in an RRC inactive state.

[0052] In conjunction with the fifth aspect above, in one possible implementation, when the second RRC message is received, the data transmission method may further include: notifying the upper-layer SDT to terminate.

[0053] In conjunction with the fifth aspect above, in one possible implementation, the second RRC message may include a suspension configuration, and the data transmission method may further include: suspending the context of the terminal device and restarting the RNA timer.

[0054] In conjunction with the fifth aspect above, in one possible implementation, after the terminal device sends the first RRC message, the method further includes: starting the SDT timer and stopping the RNA timer.

[0055] In conjunction with the fifth aspect above, in one possible implementation, when a third RRC message is received, the data transmission method may further include: notifying the upper-layer SDT of failure and continuing to run the suspended RNA timer, which is used to indicate that the terminal device is in an RRC inactive state.

[0056] In conjunction with the fifth aspect above, in one possible implementation, when the second RRC message is received, the data transmission method may further include: notifying the upper-layer SDT to terminate.

[0057] In conjunction with the fifth aspect above, in one possible implementation, the second RRC message may include a suspension configuration, and the data transmission method may further include: suspending the context of the terminal device and continuing to run the paused RNA timer.

[0058] In conjunction with the fifth aspect above, in one possible implementation, after the terminal device sends the first RRC message, the method further includes: starting the SDT timer and pausing the RNA timer.

[0059] In conjunction with the fifth aspect above, in one possible implementation, the second or third RRC message includes a waiting time, which indicates the time the terminal device waits before initiating the next communication connection.

[0060] Based on this scheme, it is possible to avoid the SDT failing again if the terminal device selects the current cell again after immediately initiating a communication connection.

[0061] In conjunction with the fifth aspect mentioned above, in one possible implementation, the second RRC message includes a first redirection parameter, which is used for redirection. Based on this scheme, while instructing the terminal device to terminate SDT transmission, the serving access network device can also provide the terminal device with parameters for redirection or cell reselection, so that the terminal device can reselect a cell according to the instructions of the serving access network device.

[0062] Based on this scheme, terminal devices can select more suitable cells for SDT, which can improve the data transmission efficiency of terminal devices performing SDT.

[0063] In conjunction with the fifth aspect above, in one possible implementation, if there are unsent SDT data packets in the cache of the terminal device, the data transmission method may further include: ignoring the waiting time, performing redirection according to the first redirection parameter, triggering SDT in the first cell to send the unsent SDT data packets in the cache, wherein the first cell is the serving cell after the terminal device performs the redirection.

[0064] Based on this scheme, when there are incomplete SDT data packets, redirection can be performed immediately regardless of the waiting time. Furthermore, the redirection is based on the first redirection parameters sent by the access network device, ensuring that SDT initiated by the terminal device in the new cell can be successfully performed. This method can reduce SDT latency and ensure that SDT data packets to be sent are delivered in a timely manner.

[0065] In conjunction with the fifth aspect above, in one possible implementation, the second RRC message includes a first cell reselection priority parameter, which is used for cell reselection.

[0066] Based on this scheme, terminal devices can select more suitable cells for SDT, which can improve the data transmission efficiency of terminal devices performing SDT.

[0067] In conjunction with the fifth aspect above, in one possible implementation, if there are unsent SDT data packets in the cache of the terminal device, the data transmission method may further include: ignoring the waiting time, performing cell reselection according to the first cell reselection priority parameter, triggering SDT in the second cell to send the unsent SDT data packets in the cache, wherein the second cell is the serving cell after cell reselection.

[0068] Based on this scheme, when there are incomplete SDT data packets, cell reselection can be performed immediately regardless of the waiting time. Furthermore, cell reselection is performed based on the first cell reselection priority parameter sent by the access network equipment, ensuring that the SDT initiated by the terminal device in the new cell can be successfully performed. This method can reduce SDT latency and ensure that SDT data packets to be sent are transmitted in a timely manner.

[0069] Sixthly, a communication apparatus is provided for implementing the above-described method. This communication apparatus may be a service access network device as described in the first aspect, an anchor access network device as described in the second to fourth aspects, or a terminal device as described in the fifth aspect. The communication apparatus may include modules, units, or means corresponding to the above-described method. These modules, units, or means may be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above-described functions.

[0070] In one possible implementation, the communication device includes a processing module and a transceiver module. The transceiver module is used to perform message receiving and sending operations performed by the communication device side in the methods of the first, second, third, fourth, or fifth aspects described above. The processing module is used to invoke instructions to perform message processing or control operations performed by the communication device side in the methods of the first, second, third, fourth, or fifth aspects described above.

[0071] A seventh aspect provides a communication device comprising: a processor; the processor being configured to be coupled to a memory, and after reading computer instructions stored in the memory, to execute, according to the instructions, the method described in the first, second, third, fourth, or fifth aspect above.

[0072] In one possible implementation, the communication device further includes a memory for storing computer instructions.

[0073] In one possible implementation, the communication device further includes a communication interface for communicating with other devices. For example, the communication interface may be a transceiver, an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuitry.

[0074] In one possible implementation, the communication device can be a chip or a chip system. When the communication device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0075] In one possible implementation, when the communication device is a chip or chip system, the aforementioned communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The aforementioned processor can also be embodied as a processing circuit or logic circuit.

[0076] Eighthly, a computer-readable storage medium is provided that stores instructions which, when executed on a computer, enable the computer to perform the methods described in the first, second, third, fourth, or fifth aspects above.

[0077] Ninthly, a computer program product containing instructions is provided, which, when run on a computer, enables the computer to perform the methods described in the first, second, third, fourth, or fifth aspects above.

[0078] In a tenth aspect, a communication system is provided, comprising a generator that performs the data transmission method described in the first aspect, an updater that performs the data transmission method described in the second aspect, and an updater that performs the data transmission method described in the third aspect.

[0079] The technical effects of any of the possible implementations in aspects six through ten can be found in the technical effects of different implementations in aspects one, two, three, four, or five above, and will not be repeated here. Attached Figure Description

[0080] Figure 1 A communication network architecture diagram provided for an embodiment of this application;

[0081] Figure 2 This application provides a schematic diagram of an interaction process for a UE to request the restoration of an RRC connection, as illustrated in an embodiment of the present application.

[0082] Figure 3 A flowchart of an SDT provided in this application embodiment;

[0083] Figure 4 A flowchart of another SDT provided for embodiments of this application;

[0084] Figure 5 This application provides a schematic diagram of the structure of a communication system according to an embodiment of the present application.

[0085] Figure 6 This is a schematic diagram of another communication system provided in an embodiment of this application;

[0086] Figure 7 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0087] Figure 8 A schematic diagram of the hardware structure of a UE provided in an embodiment of this application;

[0088] Figure 9 A flowchart illustrating a data transmission method provided in an embodiment of this application;

[0089] Figure 10a A flowchart of a data transmission method provided in this application embodiment when the service access network device and the anchor access network device are the same access network device;

[0090] Figure 10b for Figure 10a A flowchart illustrating a specific implementation of the data transmission method shown;

[0091] Figure 11aA flowchart of another data transmission method provided in this application embodiment when the service access network device and the anchor access network device are the same access network device;

[0092] Figure 11b for Figure 11a A flowchart illustrating a specific implementation of the data transmission method shown;

[0093] Figure 12a A flowchart of a data transmission method is provided in this application embodiment to address the situation where the service access network device and the anchor access network device are different.

[0094] Figure 12b for Figure 12a A flowchart illustrating a specific implementation of the data transmission method shown;

[0095] Figure 13a A flowchart of a data transmission method is provided in this application embodiment to address the situation where the service access network device and the anchor access network device are different.

[0096] Figure 13b for Figure 13a A flowchart illustrating a specific implementation of the data transmission method shown;

[0097] Figure 14a A flowchart of a data transmission method provided in this application embodiment when the service access network device and the anchor access network device are different;

[0098] Figure 14b for Figure 14a A flowchart illustrating a specific implementation of the data transmission method shown;

[0099] Figure 15a A flowchart of a data transmission method is provided in this application embodiment to address the situation where the service access network device and the anchor access network device are different.

[0100] Figure 15b for Figure 15a A flowchart illustrating a specific implementation of the data transmission method shown;

[0101] Figure 16a A flowchart of a data transmission method is provided in this application embodiment to address the situation where the service access network device and the anchor access network device are different.

[0102] Figure 16b for Figure 16a A flowchart illustrating a specific implementation of the data transmission method shown;

[0103] Figure 17 A flowchart illustrating the establishment of a transmission link for SDT between a service access network device and an anchor access network device, as provided in an embodiment of this application;

[0104] Figure 18 A flowchart illustrating a data transmission method provided in an embodiment of this application;

[0105] Figure 19 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0106] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. Meanwhile, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0107] For ease of understanding, the following is a brief introduction to several terms and related technologies involved in this application.

[0108] 1. Fifth-generation (5G) network architecture:

[0109] Please refer to Figure 1 , Figure 1 A schematic diagram of a 5G network architecture is shown. Among them, Figure 1Taking the network service architecture of a 5G system as an example, this paper illustrates the interaction relationship between network functions and entities, as well as the corresponding interfaces. The service-based architecture (SBA) of the 3rd generation partnership project (3GPP) of this 5G system mainly includes the following network functions and entities: user equipment (UE), access network (AN) or radio access network (RAN), user plane function (UPF), data network (DN), access management function (AMF), session management function (SMF), authentication server function (AUSF), policy control function (PCF), application function (AF), network slice selection function (NSSF), unified data management (UDM), network exposure function (NEF), and network repository function (NRF).

[0110] A network function can be implemented as a network element running on proprietary hardware, or as a software instance running on proprietary hardware, or as a virtual function instantiated on a suitable platform, such as a cloud infrastructure.

[0111] The main functions of each network element are described in detail below.

[0112] AN / RAN: AN / RAN can include various types of base stations, such as macro base stations, micro base stations (also known as "small stations"), and distributed unit-control units (DU-CUs). Additionally, these base stations can also be radio controllers in cloud radio access network (CRAN) scenarios, or relay stations, access points, vehicle-mounted equipment, wearable devices, or network equipment in future evolved public land mobile networks (PLMNs). AN / RAN can also include broadband network gateways (BNGs), aggregation switches, and non-3GPP access equipment.

[0113] The AN / RAN is primarily responsible for air interface-side radio resource management, uplink / downlink data classification, quality of service (QoS) management, data compression and encryption, signaling processing with control plane network elements, and data forwarding with user plane function network elements. This application does not limit the specific form and structure of the AN / RAN. For example, in systems employing different radio access technologies, the names of devices with base station functions may differ. For instance, a base station can be an evolved universal terrestrial radio access network (E-UTRAN) device in LTE, such as an evolved NodeB (eNB or e-NodeB), or a next-generation radio access network (NG-RAN) device (such as a gNB) in a 5G system.

[0114] UPF: Primarily responsible for packet routing and forwarding, as well as QoS processing and billing information statistics for user plane data. The transmission resources and scheduling functions that provide services to the UE in UPF are managed and controlled by SMF.

[0115] DN: DN is a network used for transmitting data. For example, DN can be a carrier service network, Internet access, or a third-party service network.

[0116] For an introduction to the functions of network elements such as AUSF, NSSF, NEF, NRF, and UDM, please refer to the explanations and descriptions in the conventional technical documentation; they will not be elaborated upon here.

[0117] 2. Radio Resource Control (RRC) Status:

[0118] 5G NR defines three RRC states: inactive state, connected state, and idle state. These three states are described below:

[0119] 1) Connected State: Also known as RRC_CONNECTED state. The connected state indicates that an RRC connection has been established between the UE and the access network. When the UE is in the connected state, connections are established between the UE and the access network (e.g., base station) and the core network (e.g., AMF unit). If data needs to be transmitted, it can be done directly through the established connection. The RRC connection is used to process control plane messages between the UE and the access network.

[0120] 2) Inactive State: Also known as RRC_INACTIVE state, deactivated state, or third state. The inactive state means that the RRC connection between the UE and the access network (e.g., base station) is disconnected, but the connection between the UE's corresponding access network (e.g., base station) and the core network (e.g., AMF) remains open. In existing technology, when the UE is in the deactivated state, if data needs to be transmitted, the RRC connection between the UE and the access network (e.g., base station) must be restored before data transmission can occur.

[0121] When a UE enters an inactive state, its context is suspended on both the terminal and base station sides. The UE's context is stored in the last cell it camped on before entering the inactive state, or in the last cell that provided service to the UE (also known as the anchor cell). When data and / or signaling transmission is required, the UE can obtain its context by initiating an RRC Resume Request (RRCResume Request) to restore the RRC connection based on the UE's context. For example, the UE's context includes: the UE's security context, UE capability information, etc.

[0122] 3) Idle State: This refers to RRC_IDLE. The idle state means that the RRC connection between the UE and the access network device (e.g., base station) is not established, and the connection between the corresponding access network device (e.g., base station) and the core network device (e.g., AMF) is not established. When the UE is in the idle state, if data needs to be transmitted, the connection between the UE and the access network device (e.g., base station), and the connection between the access network device (e.g., base station) and the core network device (e.g., AMF) must be established before data transmission can occur.

[0123] Additionally, the base station belonging to the cell where the UE is currently camped, or the base station currently providing service to the UE, can be called the serving base station. The base station belonging to the last cell the UE camped before entering the inactive state, or the last base station providing service to the UE before entering the inactive state, can be called the anchor base station. It should be noted that the UE is mobile; after entering the inactive state, the UE may move, and therefore the UE's serving base station and anchor base station may be different.

[0124] 3. Switching from RRC inactive state to RRC connected state:

[0125] In existing technology, if a UE needs to send data while in RRC inactive state, the UE can first switch to RRC connected state and then send data and / or signaling. For example, Figure 2 This illustrates a complete process for switching from an RRC inactive state to an RRC connected state, as follows: Figure 2 As shown, the switching process may include the following steps.

[0126] Step 201: The UE in the RRC inactive state sends an RRC recovery request (RRCResumeRequest) message to the serving base station.

[0127] Step 202: If the serving base station of the UE is not the anchor base station of the UE, the serving base station sends a Retrieve UE CONTEXT REQUEST message to the anchor base station to request the UE's context.

[0128] Step 203: The anchor base station sends a Retrieve UE CONTEXTRSPONSE message to the serving base station. This message includes the context of the UE.

[0129] Step 204: After receiving the retrieval context response message, the serving base station sends an RRC recovery (RRCResume) message to the UE to enable the UE to switch to the RRC connection state.

[0130] Step 205: After receiving the RRC recovery message, the UE switches to the RRC connection state.

[0131] Step 206: After the UE recovers to the RRC connection state, it sends an RRC recovery complete message to the serving base station.

[0132] Step 207: After receiving the RRC recovery completion message, the serving base station sends the Xn interface address indication (Xn-U address indication) information to the anchor base station.

[0133] Step 208: The serving base station sends a path switch request message to the AMF and receives a path switch response message to perform a channel switch, so that the channel of the core network equipment is switched to the serving base station.

[0134] Step 209: After the channel switch, the serving base station sends a UE context release message to the anchor base station to instruct the anchor base station to release the UE context.

[0135] It should be understood that after step 208, the serving base station becomes the new anchor base station. Therefore, the original anchor base station (i.e., Figure 2 The anchor base station in the network no longer needs to retain the UE's context, thus the UE's context can be released.

[0136] Step 210: After channel switching, the UE in RRC connection state can transmit data with the UPF.

[0137] Step 211: After the data transmission is completed, the serving base station (which is also the anchor base station) can send an RRC release message to the UE, causing the UE to switch to the RRC inactive state.

[0138] The RRC release message may include a suspendconfig, which instructs the UE to suspend the UE's context.

[0139] If a UE that has been restored to an inactive state needs to send data again, it can repeat steps 201 to 211 above.

[0140] However, as can be seen from steps 201 to 211 above, if data transmission occurs frequently, the UE needs to frequently switch between inactive and connected states, thus consuming a large amount of signaling resources. However, consuming a large amount of signaling resources for transmitting small data packets leads to a waste of signaling resources. Therefore, in one possible implementation, a small data transmission (SDT) technology is proposed, which allows the UE to transmit data in the RRC inactive state.

[0141] 4. SDT:

[0142] When a UE performs SDT in an inactive state, it can be divided into two scenarios: anchor migration and no anchor migration. Anchor migration refers to a scenario where, when a UE requests SDT in an inactive state, it can execute a scheme similar to steps 206 to 208 above, switching the AMF channel to the current serving base station, making the current serving base station the anchor base station (i.e., anchor base station migration), before data transmission. No anchor migration means that there is no need to switch the AMF channel to the current serving base station; the previous anchor base station still controls data transmission.

[0143] For example, Figure 3 This is a flowchart of SDT in an anchor point migration scenario, such as... Figure 3 As shown, the process may include the following steps:

[0144] Step 301: When the UE is in the RRC inactive state, it carries an SDT data packet in the RRC recovery request message sent to the serving base station. The RRC recovery request message carrying the SDT data packet can be used to request SDT.

[0145] Step 302: If the serving base station of the UE is not the anchor base station of the UE, the serving base station sends a retrieval context request message to the anchor base station. The retrieval context request message may include an SDT indication to instruct the anchor base station to perform SDT.

[0146] Step 303: The anchor base station sends a retrieval context response message to the serving base station.

[0147] Step 304: After receiving the retrieval context response message, the serving base station sends the address indication information of the Xn interface to the anchor base station.

[0148] Step 305: The serving base station sends a channel switching request message to the AMF and receives a channel switching response message to perform channel switching, so that the channel of the core network equipment is switched to the serving base station.

[0149] Step 306: After the channel handover, the serving base station directly sends the SDT data packet carried by the UE in the RRC recovery request message to the UPF.

[0150] Step 307: After the channel switch, the serving base station also sends a UE context release message to the anchor base station to instruct the anchor base station to release the UE context.

[0151] Step 308: After the channel switch, the UE transmits subsequent SDT data packets to the UPF through the serving base station.

[0152] Step 309: After the data transmission is completed, the serving base station (which is also the anchor base station) sends an RRC release message to the UE.

[0153] The RRC release message may include a suspend configuration, which instructs the UE to suspend the UE's context.

[0154] For example, Figure 4 The flowchart for SDT in a scenario where the anchor point does not migrate is as follows: Figure 4 As shown, the process may include the following steps:

[0155] Step 401: When the UE is in the RRC inactive state, it carries an SDT data packet in the RRC recovery request message sent to the serving base station. The RRC recovery request message carrying the SDT data packet can be used to request SDT.

[0156] Step 402: If the serving base station of the UE is not the anchor base station of the UE, the serving base station sends a retrieval context request message to the anchor base station. The retrieval context request message may include an SDT indication to instruct the anchor base station to perform SDT.

[0157] Step 403: The anchor base station sends a retrieval context response message to the serving base station.

[0158] Step 404: The serving base station sends the SDT data packet carried by the UE in the RRC recovery request message to the UPF through the anchor base station.

[0159] Step 405: The UE transmits subsequent SDT data packets to the UPF through the serving base station and the anchor base station.

[0160] Step 406: After the data transmission is completed, the serving base station sends an RRC release message to the UE.

[0161] The RRC release message may include a suspend configuration, which instructs the UE to suspend the UE's context.

[0162] However, in practical applications, the serving base station or anchor base station may not meet the requirements for SDT for some reason. There is currently no solution for how to handle this situation.

[0163] This application provides a data transmission method and a solution for handling situations where the serving base station or anchor base station does not meet the requirements of SDT.

[0164] The embodiments of this application may be applied to, but are not limited to, the following communication systems: narrowband Internet of Things (NB-IoT) systems, wireless local access network (WLAN) systems, long term evolution (LTE) systems, 5G mobile communication systems, or communication systems after 5G, such as 6G systems, device to device (D2D) communication systems, vehicle-to-everything (V2X) communication systems, etc.

[0165] The following is based on Figure 5 For example, the communication system provided in the embodiments of this application will be described, such as Figure 5 As shown, the communication system may include terminal device 501 and serving access network device 502. The serving access network device 502 refers to the access network device currently providing services to terminal device 501.

[0166] It should be noted that, in this embodiment, the access network device to which the cell the terminal device is currently camped belongs, or the access network device currently providing services to the terminal device, can be referred to as the serving access network device (e.g., the serving base station described above). The access network device to which the last cell the terminal device camped before entering the inactive state belongs, or the last access network device providing services to the terminal device, can be referred to as the anchor access network device (e.g., the anchor base station described above). The serving access network device can be the same as the anchor access network device, or the serving access network device can be different from the anchor access network device.

[0167] Optionally, such as Figure 6 As shown, when the serving access network device and the anchor access network device are different, the communication system includes an anchor access network device 603 in addition to the terminal device 601 and the serving access network device 602. The anchor access network device 603 is the last access network device to provide services to the terminal device 601 before the terminal device 601 enters the inactive state, and this anchor access network device 603 is different from the serving access network device 602.

[0168] Optionally, taking a 5G communication system as an example, one possible embodiment of this application is applicable to... Figure 5 or Figure 6 The network architecture diagram corresponding to the communication system shown can be interpreted as follows: Figure 1 As shown. For example, terminal device 601 can be Figure 1 The UE in the network, the serving access network device 602 or the anchor access network device 603 can be Figure 1 The devices shown in the AN or RAN.

[0169] The system architecture described in this application is for the purpose of more clearly illustrating the technical solutions of this application, and does not constitute a limitation on the technical solutions provided in this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0170] The access network equipment involved in this application can be a device deployed in a wireless access network to provide wireless communication functions for terminal devices. In the embodiments of this application, the access network equipment can be a base station; therefore, the aforementioned serving access network equipment 602 can be a serving base station, and the anchor access network equipment 603 can be an anchor base station. Base stations can include various forms, such as macro base stations, micro base stations (also called small stations), relay stations, and access points. In systems employing different wireless access technologies, the names of the access network equipment may differ, for example: Base Transceiver Station (BTS) in Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) networks; NB (NodeB) in Wideband Code Division Multiple Access (WCDMA); eNB or eNodeB (evolutionary NodeB) in Long Term Evolution (LTE); and base stations in 5G networks or future public land mobile networks (PLMNs). Access network equipment can also be a broadband network gateway (BNG), an aggregation switch, or a non-3GPP access device. Furthermore, access network equipment can also be a radio controller in a cloud radio access network (CRAN), a transmission and reception point (TRP), or a device including a TRP, etc., and this application embodiment does not specifically limit these aspects.

[0171] The terminal device involved in the embodiments of this application can be a device with wireless transceiver capabilities, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water (such as ships); and it can also be deployed in the air (such as airplanes, balloons, and satellites). The terminal device can be a UE, access terminal, terminal unit, subscriber unit, terminal station, mobile station (MS), mobile station, remote station, remote terminal, mobile device, wireless communication device, terminal agent, or terminal device in a 5G network or a future evolved public land mobile network (PLMN). Access terminals can be cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices or wearable devices, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, etc. Terminals can be mobile or fixed.

[0172] Optionally, the terminal device, serving access network device, and anchor access network device in the embodiments of this application may adopt... Figure 7 The shown composition or includes Figure 7 The components shown. Figure 7 This is a schematic diagram of the structure of a communication device 70 provided in an embodiment of this application, as shown below. Figure 7 As shown, the communication device 70 includes one or more processors 701, a communication line 702, and at least one communication interface. Figure 7 (This is merely an example illustration, using a communication interface 703 and a processor 701 as examples. Optionally, a memory 704 may also be included.)

[0173] The processor 701 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present application.

[0174] Communication line 702 may include a path for communication between different components.

[0175] The communication interface 703 can be a transceiver module used to communicate with other devices or communication networks, such as Ethernet, RAN, and wireless local area networks (WLAN). For example, the transceiver module can be a transceiver or similar device. Optionally, the communication interface 703 can also be a transceiver circuit located within the processor 701, used to implement the processor's signal input and signal output.

[0176] The memory 704 can be a device with storage functionality. For example, it can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions; random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions; electrically erasable programmable read-only memory (EEPROM); compact disc read-only memory (CD-ROM) or other optical disc storage; optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.); magnetic disk storage media or other magnetic storage devices; or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to these. The memory can exist independently and be connected to the processor via communication line 702. The memory can also be integrated with the processor.

[0177] The memory 704 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 701. The processor 701 executes the computer execution instructions stored in the memory 704, thereby implementing the data transmission method provided in the embodiments of this application.

[0178] Alternatively, in this embodiment, the processor 701 may execute the processing-related functions in the data transmission method provided in the following embodiments of this application, and the communication interface 703 may be responsible for communicating with other devices or communication networks. This embodiment does not specifically limit this.

[0179] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0180] In a specific implementation, as one example, the processor 701 may include one or more CPUs, for example... Figure 7 CPU0 and CPU1 in the CPU.

[0181] In a specific implementation, as one example, the communication device 70 may include multiple processors, such as... Figure 7 The processors 701 and 707 are described herein. Each of these processors may be a single-core processor or a multi-core processor. The processors herein may include, but are not limited to, at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, and other computing devices that run software. Each computing device may include one or more cores for executing software instructions to perform calculations or processing.

[0182] In a specific implementation, as one embodiment, the communication device 70 may further include an output device 705 and an input device 706. The output device 705 communicates with the processor 701 and can display information in various ways. For example, the output device 705 may be a liquid crystal display (LCD), a light-emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device 706 communicates with the processor 701 and can receive user input in various ways. For example, the input device 706 may be a mouse, keyboard, touchscreen device, or sensing device, etc.

[0183] The aforementioned communication device 70 may sometimes be referred to as a communication apparatus, which can be a general-purpose device or a dedicated device. For example, communication device 70 may be a desktop computer, portable computer, network server, PDA (personal digital assistant), mobile phone, tablet computer, wireless terminal device, embedded device, the aforementioned terminal device, the aforementioned network device, or a device with... Figure 7 Devices with similar structures. This application does not limit the type of communication device 70 to any particular embodiment.

[0184] Optionally, Figure 8 A schematic diagram of the hardware structure of a UE is shown. For example... Figure 8 As shown, in some embodiments, the structure of the UE can be as follows: Figure 8 As shown, the UE may include: a processor 810, an external memory interface 820, an internal memory 821, a universal serial bus (USB) interface 830, a charging management module 840, a power management module 841, a battery 842, an antenna 1, an antenna 2, a mobile communication module 850, a wireless communication module 860, an audio module 870, a speaker 870A, a receiver 870B, a microphone 870C, a headphone jack 870D, a sensor module 880, buttons 890, a motor 891, an indicator 892, a camera 893, a display screen 894, and a subscriber identification module (SIM) card interface 895, etc. The sensor module 880 may include a pressure sensor 880A, a gyroscope sensor 880B, a barometric pressure sensor 880C, a magnetic sensor 880D, an accelerometer sensor 880E, a distance sensor 880F, a proximity light sensor 880G, a fingerprint sensor 880H, a temperature sensor 880J, a touch sensor 880K, an ambient light sensor 880L, a bone conduction sensor 880M, etc.

[0185] It is understood that the structure illustrated in this embodiment does not constitute a specific limitation on the UE. In other embodiments, the UE may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0186] The processor 810 may include one or more processing units, such as an application processor (AP), a modem, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). These different processing units may be independent devices or integrated into one or more processors.

[0187] The charging management module 840 is used to receive charging input from the charger. The charger can be a wireless charger or a wired charger.

[0188] The power management module 841 is used to connect the battery 842, the charging management module 840, and the processor 810. The power management module 841 receives input from the battery 842 and / or the charging management module 840 to power the processor 810, internal memory 821, display 894, camera 893, and wireless communication module 860, etc.

[0189] The UE's wireless communication function can be implemented through antenna 1, antenna 2, mobile communication module 850, wireless communication module 860, modem, and baseband processor.

[0190] Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the UE can be used to cover one or more communication frequency bands. Different antennas can also be reused to improve antenna utilization.

[0191] The mobile communication module 850 can provide solutions for wireless communication applications, including 2G / 3G / 4G / 5G, on the UE.

[0192] The wireless communication module 860 can provide solutions for wireless communication applications on the UE, including wireless local area networks (WLANs) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies. The wireless communication module 860 can be one or more devices integrating at least one communication processing module. The wireless communication module 860 receives electromagnetic waves via antenna 2, performs frequency modulation and filtering of the electromagnetic wave signals, and sends the processed signal to processor 810. The wireless communication module 860 can also receive signals to be transmitted from processor 810, perform frequency modulation and amplification, and convert them into electromagnetic waves for radiation via antenna 2.

[0193] In this embodiment of the application, the wireless communication module 860 can be used by the UE to send a request to the network node to restore the RRC connection, and to receive the response message from the network node.

[0194] The UE implements display functions through the GPU, display 894, and application processor. The GPU is a microprocessor for image processing, connecting the display 894 and the application processor.

[0195] Display screen 894 is used to display images, videos, etc. A series of graphical user interfaces (GUIs) can be displayed on the UE's display screen 894.

[0196] The UE can achieve shooting functions through the ISP, camera 893, video codec, GPU, display 894 and application processor.

[0197] Camera 893 is used to capture still images or videos.

[0198] The external memory interface 820 can be used to connect external memory cards, such as Micro SD cards, to expand the storage capacity of the UE.

[0199] Internal memory 821 can be used to store computer executable program code, which includes instructions. Processor 810 executes various functional applications and data processing of the UE by running the instructions stored in internal memory 821.

[0200] The UE can implement audio functions such as music playback and recording through an audio module 870, speaker 870A, receiver 870B, microphone 870C, headphone jack 870D, and application processor. The UE may also include a pressure sensor 880A, a barometric pressure sensor 880C, a gyroscope sensor 880B, a magnetometer sensor 880D, an accelerometer sensor 880E, a proximity sensor 880F, a proximity light sensor 880G, an ambient light sensor 880L, a fingerprint sensor 880H, a temperature sensor 880J, a touch sensor 880K, a bone conduction sensor 880M, buttons 890, a motor 891, and an indicator 892.

[0201] The SIM card interface 895 is used to connect a SIM card. The SIM card can be inserted into or removed from the SIM card interface 895 to establish contact with the UE. The UE can support one or N SIM card interfaces, where N is a positive integer greater than 1. The SIM card interface 895 supports Nano SIM cards, Micro SIM cards, and other SIM cards. Multiple cards can be inserted into the same SIM card interface 895 simultaneously. The SIM card interface 895 is also compatible with external memory cards. The UE interacts with the network through the SIM card to perform functions such as calls and data communication.

[0202] In addition, an operating system, such as HarmonyOS, iOS, Android, or Windows, runs on top of the aforementioned components. Applications can be installed and run on this operating system. In some embodiments, multiple operating systems may run within the UE.

[0203] It should be understood that Figure 8 The hardware modules included in the UE shown are merely illustrative and do not limit the specific structure of the UE. In fact, the UE provided in this application embodiment may also include other hardware modules that interact with the hardware modules shown in the figure, which are not specifically limited here. For example, the UE may also include a flash, a miniature projection device, etc. Furthermore, if the UE is a PC, then the UE may also include components such as a keyboard and a mouse.

[0204] The following will combine Figures 1 to 8 The data transmission method provided in the embodiments of this application will be described. The device in the following embodiments may have… Figure 8 The components are shown. The actions, terminology, etc., involved in the various embodiments of this application can be referenced interchangeably without limitation. The message names or parameter names in the messages used for interaction between devices in the embodiments of this application are merely examples; other names may be used in specific implementations without limitation.

[0205] Figure 9This is a flowchart of a data transmission method provided in an embodiment of this application, such as... Figure 9 As shown, the data transmission method may include the following steps:

[0206] Step 901: The terminal device sends a first RRC message to the serving access network device. Correspondingly, the serving access network device receives the first RRC message from the terminal device. The first RRC message is used to establish a Service Decentralized Network (SDT).

[0207] Optionally, the first RRC message can be an RRC recovery request message. It should be understood that implementing the first RRC message through an RRC recovery request message can ensure compatibility with existing communication systems and improve the compatibility and availability of the data transmission method of this application.

[0208] Optionally, the first RRC message may include a first SDT data packet, which is a data packet that needs to be sent via SDT.

[0209] Optionally, the first SDT data packet carried in the first RRC message can be used to enable the serving access network device to identify that the first RRC message is for establishing an SDT. This can be understood as an implicit indication.

[0210] Optionally, the first RRC message may include indication or identification information to explicitly instruct the serving access network device to establish an SDT. This implementation can be understood as an explicit indication.

[0211] It should be noted that in this embodiment of the application, the terminal device is in an RRC inactive state when sending the first RRC message.

[0212] Step 902: If the serving access network device does not meet the requirements of SDT, the serving access network device sends a second RRC message or a third RRC message to the terminal device. Correspondingly, the terminal device receives the second RRC message or the third RRC message from the serving access network device. The second RRC message instructs the terminal device to terminate SDT, and the third RRC message instructs the serving access network device to refuse to perform SDT.

[0213] Optionally, when the serving access network device does not meet the SDT requirements, it can mean that the serving access network device does not meet the SDT requirements when receiving the first RRC message. Alternatively, it can mean that the serving access network device does not meet the SDT requirements during the SDT process.

[0214] It should be understood that if the serving access network device does not meet the requirements for SDT upon receiving the first RRC message, it means that the serving access network device has not yet started SDT. If the serving access network device does not meet the requirements for SDT during the SDT process, it means that the serving access network device successfully established SDT after receiving the first RRC message, and this SDT process can be triggered by the first RRC message.

[0215] Optionally, if the serving access network does not meet the SDT requirements upon receiving the first RRC message, it could mean that the serving access network device does not support SDT, the serving access network device is congested, or the load on the serving access network device exceeds a threshold. During the SDT process, if the serving access network does not meet the SDT requirements, it could mean that the serving access network device is congested or the load on the serving access network exceeds a threshold. Here, the load exceeding the threshold could be due to congestion in the serving access network leading to excessive load. Alternatively, based on network load balancing requirements, the serving access network device may need to redirect terminals to different frequency layers.

[0216] Step 903: When the terminal device receives a second RRC message or a third RRC message from the serving access network device, the terminal device stops the SDT timer. The second RRC message instructs the terminal device to terminate SDT, and the third RRC message instructs the serving access network device to refuse to perform SDT.

[0217] Optionally, the terminal device may start the SDT timer when sending the first RRC message. Therefore, the SDT timer can be stopped when the SDT terminates or fails.

[0218] In this embodiment of the application, when the serving access network device does not meet the requirements of SDT, the serving access network device can send a second RRC message to instruct the terminal device to terminate SDT or send a third RRC message to instruct the serving access network device to refuse to perform SDT. This allows the terminal device to stop the SDT timer in a timely manner (meaning the termination of SDT) and avoid the terminal device continuing to wait in the cell, which would result in a long data transmission delay.

[0219] Additionally, reasons why a serving access network device may not meet the requirements of SDT (Service Demand Response) can include a load exceeding a threshold. Terminating or rejecting SDT when the load exceeds the threshold can prevent SDT from increasing the burden on the serving access network device and achieve load balancing.

[0220] Optionally, Figure 9 The serving access network device and the anchor access network device in the illustrated embodiments can have two relationships: they are the same access network device, or they are different access network devices. The following sections will discuss these two relationships respectively. Figure 9 The specific implementation of the illustrated embodiment will be described.

[0221] like Figure 10a As shown, this is a case where the serving access network device and the anchor access network device are the same access network device, and the serving access network device does not meet the SDT requirements when receiving the first RRC message. Figure 9 A specific implementation of the illustrated embodiment. (See reference...) Figure 10a The method may include the following steps:

[0222] Step 1001a: The terminal device sends a first RRC message to the serving access network device (which is also the anchor access network device). Correspondingly, the serving access network device receives the first RRC message from the terminal device. The first RRC message is used to establish an SDT.

[0223] Step 1001a can be referred to the description of step 901, and will not be repeated here.

[0224] Step 1002a: If the serving access network device does not meet the requirements of SDT, the serving access network device sends a second RRC message to the terminal device. Correspondingly, the terminal device receives the second RRC message from the serving access network device. The second RRC message is used to instruct the terminal device to terminate SDT.

[0225] For an explanation of why access network equipment does not meet the requirements of SDT, please refer to the description in step 902, which will not be repeated here.

[0226] When the serving access network device and the anchor access network device are the same access network device, the second RRC message is generated by the serving access network device.

[0227] Optionally, the second RRC message can be implemented by an RRC release message.

[0228] Optionally, the second RRC message may include a suspend configuration to instruct the terminal device to suspend its context. This method facilitates the terminal device's subsequent use of the context to re-initiate the communication connection.

[0229] Optionally, the second RRC message may include a wait time, which can be used to indicate the time the terminal device waits before initiating the next communication connection. It should be noted that this embodiment does not limit the next communication connection initiated by the terminal device. A communication connection can refer to the terminal device sending signaling to the access network device to establish a connection between the terminal device and the access network device, enabling communication between them. For example, this communication connection can be an RRC connection, an SDT connection, etc.

[0230] It should be understood that if the terminal device immediately re-initiates a communication connection after receiving the second RRC message (e.g., re-triggers SDT), it may still select the current serving access network device. However, if the current serving access network device does not meet the requirements of SDT, the communication connection initiated by the terminal device will terminate, resulting in a waste of signaling resources. When the second RRC message includes a waiting time, the terminal device can re-initiate the communication connection after the waiting time. If, during the waiting period, the serving access network device's capabilities recover to a level sufficient for SDT, then even if the terminal device subsequently selects the current serving access network device, its re-triggered SDT will succeed. For example, assuming the serving access network device is congested, if the serving access network device is no longer congested after a period of waiting, the terminal device's subsequent re-triggering of SDT will succeed.

[0231] As one possible implementation, the format of the wait time in the second RRC message can be as follows:

[0232]

[0233] Optionally, the second RRC message may include a first redirection parameter or a first cell reselection priority parameter, wherein the first redirection parameter is used for redirection and the first cell reselection priority parameter is used for cell reselection. By carrying the first redirection parameter or the first cell reselection priority parameter in the second RRC, the terminal device can perform redirection or cell reselection based on the first redirection parameter or the first cell reselection priority parameter, thereby improving the success rate of the terminal device re-triggering SDT.

[0234] As one possible implementation, the first redirection parameter can be a carrier redirection parameter. This first redirection parameter may include at least one of the following: redirection frequency layer, priority, redirection radio access technology (RAT) type (e.g., LTE), redirection core network type (e.g., evolved packet core network (EPC), 5G core), redirection frequency information (e.g., subcarrier spacing, absolute radio frequency channel number (ARFCN), synchronization signal block measurement timing configuration (SSB-MTC)).

[0235] As one possible implementation, the format of the first redirection parameter in the second RRC message can be as follows:

[0236]

[0237] The first cell reselection priority parameter can be a parameter of the surrounding cells (also known as neighboring cells) of the currently accessing cell. The first cell reselection priority parameter can include at least one of the following: frequency priority list (e.g., NR frequency priority, LTE frequency priority), cell selection priority list (e.g., cell frequency priority, cell absolute priority).

[0238] As one possible implementation, the format of the first cell reselection priority parameter in the second RRC message can be as follows:

[0239]

[0240]

[0241] Step 1003a: The terminal device stops the SDT timer.

[0242] Optionally, the terminal device may start the SDT timer when sending the first RRC message. Since the second RRC message is used to instruct the terminal device to terminate the SDT, the terminal device may stop the SDT timer after receiving the second RRC message.

[0243] Optionally, the terminal device can also notify the upper-layer SDT to terminate. Here, "upper layer" refers to the layer above the terminal device's protocol layer, such as the non-access stratum (NAS).

[0244] Optionally, the second RRC message may include a suspension configuration, and the terminal device may also suspend its context. Suspending the terminal device's context means that the terminal device remains in an RRC inactive state. In this case, the terminal device may restart the RNA timer or continue running a paused RNA timer. Here, RNA refers to the RAN-based notification area, and the RNA timer is used to indicate that the terminal device is in an RRC inactive state. Based on this scheme, the inactive terminal device can subsequently send the first RRC message to the access network device again to re-request SDT.

[0245] Optionally, the terminal device may stop or pause the RNA timer when sending the first RRC message.

[0246] It should be noted that restarting the RNA timer and continuing to run the RNA timer are two different implementation methods provided in this application.

[0247] Optionally, if the second RRC message is an RRC release message and does not carry a suspend configuration, the terminal device can release its context and switch from the RRC inactive state to the RRC idle state after receiving the second RRC message. It should be noted that after the terminal device enters the RRC idle state, if it needs to initiate another communication connection later, it needs to switch to the RRC connected state first before initiating the communication connection.

[0248] Optionally, if the second RRC message includes a waiting time, the terminal device can initiate the next communication connection after the waiting time, which begins at a certain moment. For example, this moment could be the moment the terminal device receives the second RRC message.

[0249] Optionally, if the second RRC message includes a first redirection parameter or a first cell reselection priority parameter, the terminal device can perform redirection based on the first redirection parameter or cell reselection based on the first cell reselection priority parameter when initiating the next communication connection. Then, the terminal device can initiate the next communication connection in the redirected serving cell or the reselected serving cell.

[0250] It should be noted that the embodiments of this application do not limit the next communication connection initiated by the terminal device. A communication connection can refer to the terminal device sending signaling to the access network device to establish a connection between the terminal device and the access network device, enabling communication between them. For example, this communication connection can be an RRC connection, an SDT connection, etc.

[0251] Optionally, if the second RRC message includes a waiting time, and there are unsent SDT packets in the terminal device's buffer, the terminal device can ignore the waiting time and immediately re-trigger the SDT.

[0252] As another possible implementation, if the second RRC message includes a waiting time and a first redirection parameter, and there are unsent SDT data packets in the terminal device's buffer, the terminal device can ignore the waiting time, perform redirection according to the first redirection parameter, trigger SDT in the first cell, and send the unsent SDT data packets in the buffer. The first cell is the serving cell after the terminal device performs the redirection.

[0253] As one possible implementation, if the second RRC message includes a waiting time and a first cell reselection priority parameter, and there are unsent SDT data packets in the terminal device's buffer, the terminal device can ignore the waiting time, perform cell reselection according to the first cell reselection priority parameter, and trigger SDT in the second cell to send the unsent SDT data packets in the buffer. The second cell is the serving cell after cell reselection.

[0254] Optionally, since the serving access network device is also the anchor access network device, if the first RRC message includes the first SDT data packet, the serving access network device can also send the first SDT data packet to the user plane network element (such as the UPF). This ensures that the first SDT data packet carried in the first RRC message is not discarded, improving signaling utilization efficiency.

[0255] according to Figure 10a As can be seen from the data transmission method illustrated in this embodiment, when the serving access network device does not meet the requirements of SDT, the serving access network device can send a second RRC message to terminate SDT, thereby preventing the terminal from continuing to wait in the same cell. This method improves the data transmission efficiency of the terminal device. Furthermore, the second RRC message may include waiting time, redirection parameters, or cell reselection parameters, enabling the terminal device to perform redirection or cell reselection according to the instructions of the access network device. This method avoids increasing the burden on the serving access network device due to SDT, achieving load balancing.

[0256] Taking the terminal device as the UE, the access network device as the base station, and the first RRC message as the RRC recovery request message and the second RRC message as the RRC release message as an example, let's explain again. Figure 10a The data transmission method flow shown is as follows: Figure 10b As shown, the data transmission method may include the following steps:

[0257] Step 1001b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0258] Step 1002b: If the serving base station does not meet the requirements of SDT, the serving base station sends an RRC release message to the UE. The RRC release message is used to instruct the UE to terminate SDT.

[0259] Step 1003b: The UE stops the SDT timer.

[0260] like Figure 11a As shown, when the serving access network device and the anchor access network device are the same access network device, and the serving access network device does not meet the SDT requirements when receiving the first RRC message, Figure 9A specific implementation of the illustrated embodiment. (See reference...) Figure 11a The method may include the following steps.

[0261] Step 1101a: The terminal device sends a first RRC message to the serving access network device (which is also the anchor access network device). The first RRC message is used to establish SDT.

[0262] Step 1101a can be referred to the description of step 901, and will not be repeated here.

[0263] Step 1102a: If the serving access network device does not meet the requirements of SDT, the serving access network device sends a third RRC message to the terminal device. Correspondingly, the terminal device receives the third RRC message from the serving access network device. The third RRC message is used to instruct the serving access network device to refuse SDT.

[0264] For an explanation of why access network equipment does not meet the requirements of SDT, please refer to the description in step 902, which will not be repeated here.

[0265] When the serving access network device and the anchor access network device are the same access network device, the third RRC message is generated by the serving access network device.

[0266] Optionally, the third RRC message can be implemented using an RRC rejection message.

[0267] Optionally, the third RRC message may include a waiting time, which can be used to indicate the time the terminal device waits before initiating the next communication connection.

[0268] As one possible implementation, the message body format of a third RRC message can be as follows:

[0269]

[0270] Step 1103a: The terminal device stops the SDT timer.

[0271] Optionally, the terminal device may start the SDT timer when sending the first RRC message. Since the third RRC message is used to indicate that the serving access network device refuses to perform SDT, meaning that SDT has failed, the terminal device may stop the SDT timer after receiving the second RRC message.

[0272] Optionally, the terminal device can notify the upper-layer SDT of failure and can restart or resume the RNA timer that is in a paused state.

[0273] Optionally, the terminal device may stop or pause the RNA timer when sending the first RRC message.

[0274] It should be noted that restarting the RNA timer and continuing to run the RNA timer are two different implementation methods provided in this application.

[0275] It should be noted that after receiving the third RRC message, the terminal device can know that the SDT has been rejected. In this case, the terminal device will subsequently send the first RRC message again to continue requesting the establishment of the SDT. In this scenario, the terminal device needs to remain in an inactive RRC state in order to resend the first RRC message. Thus, after receiving the third RRC message, the terminal device can restart or continue running the suspended RNA timer.

[0276] Optionally, if the third RRC message includes a wait time, the terminal device will wait for the wait time in the third RRC message before initiating the next communication connection.

[0277] Optionally, since the serving access network device is also the anchor access network device, if the first RRC message includes the first SDT data packet, the serving access network device can also send the first SDT data packet to the user plane network element (such as the UPF). This ensures that the first SDT data packet carried in the first RRC message is not discarded, improving signaling utilization efficiency.

[0278] Taking the terminal device as the UE, the access network device as the base station, the first RRC message as the RRC recovery request message, and the third RRC message as the RRC rejection message as an example, let's explain again. Figure 11a The data transmission method flow shown is as follows: Figure 11b As shown, the data transmission method may include the following steps:

[0279] Step 1101b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0280] Step 1102b: If the serving base station does not meet the requirements of SDT, the serving base station sends an RRC rejection message to the UE. The RRC rejection message indicates that the serving base station refuses to perform SDT.

[0281] Step 1103b: The UE stops the SDT timer.

[0282] like Figure 12a As shown, the serving access network device differs from the anchor access network device. When the serving access network device receives the first RRC message, if it does not meet the SDT requirements, Figure 9 A specific implementation of the illustrated embodiment. (See reference...) Figure 12a The method may include the following steps.

[0283] Step 1201a: The terminal device sends a first RRC message to the serving access network device. Correspondingly, the serving access network device receives the first RRC message from the terminal device. The first RRC message is used to establish a Service Decentralized Network (SDT).

[0284] Step 1202a: If the serving access network device does not meet the requirements of SDT, the serving access network device sends a third RRC message to the terminal device. Correspondingly, the terminal device receives the third RRC message from the serving access network device. The third RRC message is used to instruct the serving access network device to refuse SDT.

[0285] Step 1203a: The terminal device stops the SDT timer.

[0286] It should be noted that steps 1201a to 1203a can be referred to the relevant descriptions of steps 1101a to 1103a, and will not be repeated here.

[0287] Optionally, if the first RRC message includes a first SDT data packet, the method may further include: step 1204a, the serving access network device sending the first SDT data packet to the anchor access network device. Then, after receiving the first SDT data packet, the anchor access network device may forward the first SDT data packet to the user plane network element (…). Figure 12a (Not shown in the image). Based on this, the first SDT data packet carried in the first RRC message will not be discarded, improving the efficiency of signaling utilization. It should be noted that this application does not limit the execution order of step 1204a. For example, step 1204a can also be executed before step 1202a or 1203a.

[0288] Taking the terminal device as the UE, the access network device as the base station, the first RRC message as the RRC recovery request message, and the third RRC message as the RRC rejection message as an example, let's explain again. Figure 12a The data transmission method flow shown is as follows: Figure 12b As shown, the data transmission method may include the following steps:

[0289] Step 1201b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0290] Step 1202b: If the serving base station does not meet the requirements of SDT, the serving base station sends an RRC rejection message to the UE. The RRC rejection message indicates that the serving base station refuses to perform SDT.

[0291] Step 1203b: The UE stops the SDT timer.

[0292] Step 1204b: The serving base station sends the first SDT data packet carried in the RRC recovery request message to the anchor base station.

[0293] like Figure 13a As shown, the serving access network device differs from the anchor access network device. When the serving access network device receives the first RRC message, if it does not meet the SDT requirements, Figure 9 A specific implementation of the illustrated embodiment. (See reference...) Figure 13a The method may include the following steps.

[0294] Step 1301a: The terminal device sends a first RRC message to the serving access network device. Correspondingly, the anchor access network device receives the first RRC message from the serving access network device. The first RRC message is used to establish an SDT.

[0295] It should be noted that step 1301a can refer to the relevant description of step 901, and will not be repeated here.

[0296] Step 1302a: If the serving access network does not meet the SDT requirements, the serving access network device sends a fourth RRC message to the anchor access network device. Correspondingly, the anchor access network device receives the fourth RRC message from the serving access network device. The fourth RRC message is used to request the anchor access network device to send a second RRC message.

[0297] Optionally, the fourth RRC message requesting the anchor access network device to send the second RRC message can be implemented through a request indication, a redirection indication, or a cell reselection indication. That is, the fourth RRC message can include any one of a request indication, a redirection indication, or a cell reselection indication. Specifically, a request indication can be used to request the anchor access network device to send the second RRC message; a redirection indication can be used to instruct the serving access network device to suggest that the terminal device perform a redirection; and a cell reselection indication can be used to instruct the serving access network device to suggest that the terminal device perform a cell reselection. When the fourth RRC message includes a request indication, it can be understood as an explicit request; when the fourth RRC message includes a redirection indication or a cell reselection indication, it can be understood as an implicit request.

[0298] Optionally, the fourth RRC message can be a retrieval context request message. Since the fourth RRC message is a retrieval context request message, it is equivalent to the fourth RRC message reusing existing signaling messages. Therefore, this fourth RRC message needs to include additional indication information to enable the anchor access network device to distinguish the fourth RRC message from existing signaling messages.

[0299] For example, this additional indication information can be a transmission indication, which instructs the terminal device to request SDT. As one possible implementation, this transmission indication can be an SDT indictor.

[0300] Optionally, the fourth RRC message may include a second redirection parameter, which can be used to assist the anchor access network device in determining the first redirection parameter. Alternatively, the fourth RRC message may include a second cell reselection priority parameter, which can be used to assist the anchor access network device in determining the first cell reselection priority parameter.

[0301] The optional second redirection parameter sent by the serving access network device can be understood as a suggestion provided by the serving access network device to the anchor access network device, facilitating the anchor access network device in determining the first redirection parameter. The second cell reselection priority parameter can be found in the description of the second redirection parameter, and will not be repeated here.

[0302] Optionally, the fourth RRC message may include a waiting time indication and / or a first reason value, wherein the waiting time indication is used to indicate the waiting time for the anchor access network device to send the message, and the first reason value is used to indicate the reason why the serving access network device requests the anchor access network device to send the second RRC message.

[0303] For example, if a serving access network device fails to meet the SDT requirements due to network congestion, then the first cause value can be network congestion.

[0304] Optionally, if the first RRC message includes the first SDT data packet, the serving access network device can send the first SDT data packet to the anchor access network device in the fourth RRC message, that is, the fourth RRC message includes the first SDT data packet.

[0305] Step 1303a: The anchor access network device sends a fifth RRC message to the serving access network device. Correspondingly, the serving access network device receives the fifth RRC message from the anchor access network device.

[0306] The fifth RRC message is a response to the fourth RRC message. The fifth RRC message includes the second RRC message, which instructs the terminal device to terminate SDT. The content of the second RRC message can be found in the description of the second RRC message in step 1002a, and will not be repeated here.

[0307] Optionally, if the fourth RRC message is a retrieval context request message, then the fifth RRC message can be a retrieval context response message.

[0308] Optionally, the second RRC message can be encapsulated in the fifth RRC message as an RRC container.

[0309] Optionally, the fifth RRC message sent by the anchor access network device may be determined based on the fourth RRC message.

[0310] Optionally, if the fourth RRC message includes any one of a request indication, a redirection indication, or a cell reselection indication, the anchor access network device can determine that the fifth RRC message includes the second RRC message based on the request indication, redirection indication, or cell reselection indication. Upon receiving a redirection indication or a cell reselection indication, the anchor access network device can understand that the serving access network device is suggesting that the terminal device perform redirection or cell reselection, implying that the serving access network device wishes to terminate the current SDT. Therefore, it can determine that the fifth RRC message includes the second RRC message used to instruct the terminal device to terminate the SDT.

[0311] Optionally, if the fourth RRC message includes a second redirection parameter, the anchor access network device can determine the first redirection parameter based on the second redirection parameter. If the fourth RRC message includes a second cell reselection priority parameter, the anchor access network device can determine the first cell reselection priority parameter based on the second cell reselection priority parameter.

[0312] Optionally, if the fourth RRC message includes a waiting time indication, the anchor access network device can determine the waiting time based on the waiting time indication.

[0313] Step 1304a: The serving access network device sends a second RRC message to the terminal device. Correspondingly, the terminal device receives the second RRC message from the serving access network device. The second RRC message is used to instruct the terminal device to terminate SDT.

[0314] It should be understood that after receiving the fifth RRC message, the serving access network device can forward the second RRC message in the fifth RRC message to the terminal device.

[0315] Step 1305a: The terminal device stops the SDT timer.

[0316] It should be noted that step 1305a can refer to the relevant description of step 1003a, and will not be repeated here.

[0317] Optionally, if the first RRC message includes a first SDT data packet, the method may further include: step 1306a, the serving access network device sending the first SDT data packet to the anchor access network device. Step 1306a can be referred to the description of step 1204a, and will not be repeated here. It should be noted that step 1306a can be executed after step 1303a, and its execution order with steps 1304a and 1305a is not limited.

[0318] Taking the terminal device as the UE, the access network device as the base station, and the first RRC message as the RRC recovery request message, the second RRC message as the RRC release message, the fourth RRC message as the retrieval context request message, and the fifth RRC message as the retrieval context response message as an example, let's explain again. Figure 13a The data transmission method flow shown is as follows: Figure 13b As shown, the data transmission method may include the following steps:

[0319] Step 1301b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0320] Step 1302b: If the serving base station does not meet the requirements of SDT, the serving base station sends a retrieval context request message to the anchor base station.

[0321] Step 1303b: The anchor base station sends a retrieval context response message to the serving base station. This retrieval context response message carries an RRC release message.

[0322] Step 1304b: The serving base station sends an RRC release message to the UE. The RRC release message is used to instruct the terminal device to terminate SDT.

[0323] Step 1305b: The UE stops the SDT timer.

[0324] Step 1306b: The serving base station sends the first SDT data packet carried in the RRC recovery request message to the anchor base station.

[0325] like Figure 14a As shown, due to the difference between the service access network equipment and the anchor access network equipment, when the access network equipment does not meet the requirements of SDT during the SDT process, Figure 9 One specific implementation of the illustrated embodiment is as follows: Figure 14a As shown, the method may include the following steps.

[0326] Step 1401a: The terminal device sends a first RRC message to the serving access network device. Correspondingly, the serving access network device receives the first RRC message from the terminal device. The first RRC message is used to establish an SDT. Refer to the relevant description in step 901; it will not be repeated here.

[0327] It should be understood that, Figure 14a The method shown is applied in scenarios where the access network device does not meet the requirements of SDT during the SDT process, and it can be considered that the first RRC message successfully triggered SDT.

[0328] Step 1402a: The service access network device and the anchor access network device establish a transmission link for SDT.

[0329] It should be understood that when the serving access network device receives the first RRC message, the serving access network device's capabilities can meet the requirements for establishing an SDT. The serving access network device can interact with the anchor access network device through signaling to establish a transmission link for the SDT.

[0330] Step 1403a: The terminal equipment and the anchor access network equipment transmit subsequent SDT data.

[0331] After the transmission link for SDT is established, the terminal device can forward subsequent SDT data packets to the anchor access network device through the serving access network device, and the anchor access network device will send the SDT data packets to the user plane network element.

[0332] Step 1404a: If the serving access network device does not meet the SDT requirements, the serving access network device sends a fourth RRC message to the anchor access network device. Correspondingly, the anchor access network device receives the fourth RRC message from the serving access network device. The fourth RRC message is used to request the anchor access network device to send a second RRC message.

[0333] As can be seen from steps 1401a to 1403a, SDT data transmission has already begun before step 1404a. The fact that the serving access network device does not meet the SDT requirements in step 1404a occurs during the SDT process.

[0334] The content of the fourth RRC message in step 1404a can be similar to that of the fourth RRC message in step 1302a, except that the fourth RRC message in step 1404a can be an RRC release request (RRCReleaseRequest) message, and the fourth RRC message does not include the first SDT data packet. Figure 14a In this scenario, the first SDT data packet has already been sent to the anchor access network device after the transmission link used for SDT has been established.

[0335] Step 1405a: The anchor access network device sends a fifth RRC message to the serving access network device. The fifth RRC message is a response message to the fourth RRC message. The fifth RRC message includes the second RRC message, which is used to instruct the terminal device to terminate SDT.

[0336] It should be noted that the content of the fifth RRC message can be found in the relevant description of the fifth RRC message in step 1303a, and will not be repeated here.

[0337] Optionally, if the fourth RRC message is an RRC release request message, the fifth RRC message can be an RRC release response (RRCReleaseResponse) message.

[0338] Optionally, the fifth RRC message can also be used to instruct the serving access network device to delete the context of the terminal device. Accordingly, after receiving the fifth RRC message, the serving access network device can delete the locally stored context of the terminal device.

[0339] Step 1406a: The serving access network device sends a second RRC message to the terminal device. Correspondingly, the terminal device receives the second RRC message from the serving access network device. The second RRC message is used to instruct the terminal device to terminate SDT.

[0340] It should be understood that after receiving the fifth RRC message, the serving access network device can forward the second RRC message in the fifth RRC message to the terminal device.

[0341] Step 1407a: The terminal device stops the SDT timer. Refer to the description in step 1003a for further details; it will not be repeated here.

[0342] Optionally, if the fifth RRC message is not a one-way message, then after the serving access network device deletes the locally stored context of the terminal device and sends the second RRC message to the terminal device, the method may further include: step 1408a, the serving access network device sending a response message of the fifth RRC message to the anchor access network device. As a possible implementation, the response message of the fifth RRC message may be an RRC release complete message (RRCReleaseComplete).

[0343] Optionally, if the first RRC message includes a first SDT data packet, then after step 1402a, the method may further include: step 1409a, the serving access network device sending the first SDT data packet to the anchor access network device. Step 1409a can be referred to the description of step 1204a, and will not be repeated here.

[0344] Taking the terminal device as the UE, the access network device as the base station, and the first RRC message as the RRC recovery request message, the second RRC message as the RRC release message, the fourth RRC message as the RRC release request message, the fifth RRC message as the RRC release response message, and the response message of the fifth RRC message as the RRC release completion message as an example, let's explain again. Figure 14a The data transmission method flow shown is as follows: Figure 14b As shown, the data transmission method may include the following steps:

[0345] Step 1401b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0346] Step 1402b: The serving base station and the anchor base station establish a transmission link for SDT.

[0347] Step 1409b: The serving base station sends the first SDT data packet carried in the RRC recovery request message to the anchor base station.

[0348] Step 1403b: The UE and the anchor base station transmit subsequent SDT data.

[0349] Step 1404b: If the serving base station does not meet the requirements of SDT, the serving base station sends an RRC release request message to the anchor base station.

[0350] Step 1405b: The anchor base station sends an RRC release response message to the serving base station. The RRC release response message carries the RRC release message.

[0351] Step 1406b: The serving base station sends an RRC release message to the UE. The RRC release message is used to instruct the terminal device to terminate SDT.

[0352] Step 1407b: UE stops the SDT timer.

[0353] Step 1408b: The serving base station sends an RRC release completion message to the anchor base station.

[0354] like Figure 15a As shown, the serving access network equipment differs from the anchor access network equipment. During the SDT process, if the serving access network equipment does not meet the SDT requirements, Figure 9 Another specific implementation of the illustrated embodiment. See reference. Figure 15a The method may include the following steps.

[0355] Step 1501a: The terminal device sends a first RRC message to the serving access network device. Correspondingly, the serving access network device receives the first RRC message from the terminal device. The first RRC message is used to establish a Service Decentralized Network (SDT).

[0356] Step 1502a: The service access network device and the anchor access network device establish a transmission link for SDT.

[0357] Step 1503a: The terminal equipment and the anchor access network equipment transmit subsequent SDT data.

[0358] Steps 1501a to 1503a can be referred to the relevant descriptions of steps 1401a to 1403a, and will not be repeated here.

[0359] Step 1504a: If the serving access network device does not meet the requirements of SDT, the serving access network device sends a third RRC message to the terminal device. Correspondingly, the terminal device receives the third RRC message from the serving access network device. The third RRC message is used to instruct the serving access network device to refuse SDT.

[0360] Step 1505a: The terminal device stops the SDT timer.

[0361] Steps 1504a and 1505a can be referred to the relevant descriptions of steps 1102a and 1103a, and will not be repeated here.

[0362] Step 1506a: The serving access network device sends a sixth RRC message to the anchor access network device. Correspondingly, the anchor access network device receives the sixth RRC message from the serving access network device. The sixth RRC message is used to instruct the anchor access network device to cancel subsequent SDTs.

[0363] Optionally, this sixth RRC message can be called an SDT cancel (i.e., SDT cancel) message.

[0364] Optionally, the sixth RRC message may also include a second reason value, which can be used to indicate the reason for canceling the SDT. For example, if the serving access network device decides to cancel the subsequent SDT due to network congestion, then the second reason value could be network congestion.

[0365] Step 1507a: The anchor access network device suspends the context of the terminal device performing SDT according to the sixth RRC message.

[0366] Optionally, if the first RRC message includes a first SDT data packet, then after step 1502a, the method may further include: step 1508a, the serving access network device sending the first SDT data packet to the anchor access network device. Step 1508a can be referred to the description of step 1204a, and will not be repeated here.

[0367] Taking the terminal device as the UE, the access network device as the base station, and the first RRC message as the RRC recovery request message, the third RRC message as the RRC rejection message, and the sixth RRC message as the RRC cancellation message as an example, let's explain again. Figure 15a The data transmission method flow shown is as follows: Figure 15b As shown, the data transmission method may include the following steps:

[0368] Step 1501b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0369] Step 1502b: The serving base station and the anchor base station establish a transmission link for SDT.

[0370] Step 1508b: The serving base station sends the first SDT data packet to the anchor base station.

[0371] Step 1503b: The UE and the anchor base station transmit subsequent SDT data.

[0372] Step 1504b: If the serving base station does not meet the requirements of SDT, the serving base station sends an RRC rejection message to the UE. The RRC rejection message indicates that the serving base station refuses to perform SDT.

[0373] Step 1505b: UE stops the SDT timer.

[0374] Step 1506b: The serving base station sends an RRC cancellation message to the anchor base station. The RRC cancellation message instructs the anchor base station to cancel subsequent SDTs.

[0375] Step 1507b: The anchor base station suspends the context of the UE performing SDT based on the RRC cancellation message.

[0376] It should be noted that the above Figures 9 to 15b The provided data transmission methods are all applied in scenarios where the serving access network device does not meet the requirements of SDT (Service Data Transmission). The termination or rejection of SDT is triggered by the serving access network device. It should be understood that the anchor access network device can also proactively terminate SDT.

[0377] Optionally, if the anchor access network device is the same as the serving access network device, the anchor access network device can actively terminate the SDT by sending a second RRC message to the terminal device. In this scenario, the process of the anchor access network device actively terminating the SDT can be as described in steps 1002a and 1003a, and will not be repeated here.

[0378] Optionally, if the anchor access network device is different from the serving access network device, the anchor access network device can perform the following: Figure 16a The data transmission method shown actively terminates SDT. For example... Figure 16a As shown, the method may include the following steps.

[0379] Step 1601a: The terminal device sends a first RRC message to the serving access network device. Correspondingly, the serving access network device receives the first RRC message from the terminal device. The first RRC message is used to establish a Service Decentralized Time (SDT).

[0380] Step 1602a: The service access network device and the anchor access network device establish a transmission link for SDT.

[0381] Step 1603a: The terminal equipment and the anchor access network equipment transmit subsequent SDT data.

[0382] Steps 1601a to 1603a can be referred to the relevant descriptions of steps 1401a to 1403a, and will not be repeated here.

[0383] Step 1604a: If the anchor access network device determines to terminate SDT during the SDT process, the anchor access network device sends a seventh RRC message to the serving access network device. Correspondingly, the serving access network device receives the seventh RRC message. The seventh RRC message includes a second RRC message, which instructs the terminal device to terminate SDT.

[0384] Optionally, the reasons for the anchor access network device to terminate SDT may include, but are not limited to: the anchor access network device's capabilities do not meet the requirements for subsequent SDT (e.g., congestion occurs during SDT), and the anchor access network device's data packet reception timeout (e.g., no SDT data packets are received for a long time after the transmission link used for SDT is established).

[0385] Optionally, the seventh RRC message can be a context release request message.

[0386] Optionally, the seventh RRC message can also be used to instruct the serving access network device to release the context of the terminal device. Accordingly, after receiving the seventh RRC message, the serving access network device can delete the locally stored context of the terminal device.

[0387] The content of the second RRC message can be found in the description of the second RRC message in step 1002, and will not be repeated here.

[0388] Step 1605a: The serving access network device sends a second RRC message to the terminal device. Correspondingly, the terminal device receives the second RRC message from the serving access network device. The second RRC message is used to instruct the terminal device to terminate SDT.

[0389] It should be understood that after receiving the seventh RRC message, the serving access network device can forward the second RRC message in the seventh RRC message to the terminal device.

[0390] Step 1606a: The terminal device stops the SDT timer. Refer to the description in step 1003a for details; it will not be repeated here.

[0391] Optionally, if the seventh RRC message is not a one-way message, then after the serving access network device deletes the locally stored context of the terminal device and sends the second RRC message to the terminal device, the method may further include: step 1607a, the serving access network device sending a response message of the seventh RRC message to the anchor access network device. As a possible implementation, the response message of the seventh RRC message may be an RRC release completion message.

[0392] Optionally, if the first RRC message includes a first SDT data packet, then after step 1602a, the method may further include: step 1608a, the serving access network device sending the first SDT data packet to the anchor access network device. Step 1608a can be referred to the description of step 1204a, and will not be repeated here.

[0393] Taking the terminal device as the UE, the access network device as the base station, the first RRC message as the RRC recovery request message, the second RRC message as the RRC release message, the seventh RRC message as the RRC release request message, and the response message of the seventh RRC message as the RRC release completion message as an example, let's explain again. Figure 16a The data transmission method flow shown is as follows: Figure 16b As shown, the data transmission method may include the following steps:

[0394] Step 1601b: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0395] Step 1602b: The serving base station and the anchor base station establish a transmission link for SDT.

[0396] Step 1608b: The serving base station sends the first SDT data packet to the anchor base station.

[0397] Step 1603b: The UE and the anchor base station transmit subsequent SDT data.

[0398] Step 1604b: If the anchor base station determines to terminate SDT during the SDT process, the anchor base station sends an RRC release request message to the serving base station. The RRC release request message includes an RRC release message.

[0399] Step 1605b: The serving base station sends an RRC release message to the UE. The RRC release message is used to instruct the UE to terminate SDT.

[0400] Step 1606b: The UE stops the SDT timer.

[0401] Step 1607b: The serving base station sends an RRC release completion message to the anchor base station.

[0402] It should be noted that, Figure 16a and Figure 16b The illustrated scheme describes a scenario where the anchor access network device determines to terminate SDT during the SDT process. Furthermore, when the serving access network device sends an RRC message to the anchor access network device requesting the establishment of a transmission link for SDT, the anchor access network device can also proactively terminate SDT due to unmet SDT requirements (e.g., congestion or load exceeding a threshold). In this case, the process for the anchor access network device to proactively terminate SDT includes steps 1604a to 1606a as described above, which will not be repeated here.

[0403] Optionally, in this embodiment, if the serving access network device and the anchor access network device are different, and the anchor access network device terminates SDT due to not meeting the requirements of SDT, then after the anchor access network device terminates SDT, the anchor point can be migrated. The core network channel can be switched from the anchor access network device to the current serving access network device, and the anchor point can be migrated to the serving access network device, making the serving access network device the anchor access network device. Based on this scheme, SDT delays caused by the anchor access network device can be avoided. After the anchor point is migrated, the terminal device can perform SDT with the current serving access network device (which is also the anchor access network device), thereby ensuring the smooth progress of subsequent SDT.

[0404] Optionally, after receiving the first RRC message, the serving access network device can engage in signaling interaction with the anchor access network device to establish a transmission link for SDT. For example... Figure 17 As shown, the process of establishing a transport link for SDT may include the following steps:

[0405] Step 1701: The serving access network device sends an eighth RRC message to the anchor access network device. Correspondingly, the anchor access network device receives the eighth RRC message from the serving access network device. This eighth RRC message is used to indicate the establishment of an SDT.

[0406] Optionally, the eighth RRC message can be a retrieval context request message, or it can be a message similar to a retrieval context request message.

[0407] Optionally, the eighth RRC message may include a transmission indication, which instructs the terminal device to request SDT. For example, the transmission indication may be an SDT indication.

[0408] Optionally, the eighth RRC message may also include a MAC localeidentifier (MAC LCID) of the media access control (MAC) layer protocol data unit (PDU), which may be the MAC LCID of the first SDT packet received by the serving access network device, and the MAC LCID may identify the SDT bearer.

[0409] Step 1702: The anchor access network device sends a ninth RRC message to the serving access network device. Correspondingly, the serving access network device receives the ninth RRC message from the anchor access network device. The ninth RRC message is a response to the eighth RRC message and is used to indicate the address information for the anchor access network device to receive SDT data.

[0410] Optionally, if the eighth RRC message is a retrieval context request message, then the ninth RRC message can be a retrieval context response message.

[0411] Optionally, the ninth RRC message may include one or more sets of information element (TNL) addresses received by the anchor access network device for the SDT bearer. The TNL address consists of the transport layer Internet protocol (IP) address and the GTP (GPRS tunneling protocol) tunnel endpoint identifier (TEID) GTP-TEID, where different TNL addresses correspond to different SDT bearers.

[0412] Optionally, the ninth RRC message may also include a portion of the UE context. For example, this portion of the UE context may include configuration information of one or more sets of SDT-bearing radio link control (RLC) layers, and one or more sets of SDT-bearing QoS parameters. The QoS parameters may include, but are not limited to, the following information: 5G QoS identifier (5G QI), allocation and retention priority (ARP), packet delay budget (PDB), packet error rate (PER), or maximum data burst volume, etc.

[0413] Optionally, the ninth RRC message may also include the PDU session identifier of the SDT bearer and / or the LCID of the SDT bearer, wherein the SDT bearer and the LCID have a one-to-one mapping relationship.

[0414] Optionally, the ninth RRC message may also include an indication flag indicating whether the serving access network device is allowed to reject subsequent SDTs of the terminal device. In this embodiment, if the indication flag indicates that the serving access network device is allowed to reject subsequent SDTs of the terminal device, then during the SDT process, if the serving access network device is unable to perform subsequent SDTs for some reason, it has the right to send a third RRC message to directly reject subsequent SDTs. However, if the indication flag indicates that the serving access network device is not allowed to reject subsequent SDTs of the terminal device, then during the SDT process, if the serving access network device is unable to perform subsequent SDTs for some reason, the serving access network device needs to send a fourth RRC message to the anchor access network device to request the anchor access network device to send a second RRC message to terminate subsequent SDTs.

[0415] Step 1703: The serving access network device sends a tenth RRC message to the anchor access network device. Correspondingly, the anchor access network device receives the tenth RRC message from the serving access network device. The tenth RRC message is used to indicate the address information for the serving access network device to receive SDT data.

[0416] Optionally, the tenth RRC message can be an Xn address indication message, or an Xn address indication similar message.

[0417] Optionally, the tenth RRC message may include one or more sets of TNL addresses received by the serving access network device as SDT bearers.

[0418] Optionally, if the first RRC message received by the serving access network device includes a first SDT data packet, the serving access network device can carry the first SDT data packet in the tenth RRC message, which can save signaling resources and improve data transmission efficiency.

[0419] After steps 1701 to 1703, the serving access network device and the anchor access network device successfully establish a transmission link for SDT, so that the terminal device can transmit subsequent SDT data packets with the anchor access network device.

[0420] After establishing a transmission link for SDT, when the serving access network device receives uplink data carried by the SDT, it can map the LCID in the MAC header of the SDT data packet to the TNL address provided by the anchor access network device, encapsulate the data packet in a GTP message, and send it to the anchor access network device. When receiving downlink data carried by the SDT from the anchor access network device, it can forward it to the terminal device according to the TNL address.

[0421] Optional, Figure 17 The embodiments shown can be performed independently without depending on any of the foregoing embodiments. Alternatively, they can be combined with the foregoing embodiments to form new embodiments. For example, the process of establishing the transmission link for SDT in steps 1402a, 1402b, 1502a, 1402b, 1602a, or 1602b can all be as shown in steps 1701 to 1703.

[0422] For example, with Figure 14b Taking the data transmission method shown as an example, if step 1402 is implemented according to the process shown in steps 1701 to 1703, assuming the eighth RRC message is a retrieval context request message, the ninth RRC message is a retrieval context response message, and the tenth RRC message is an Xn address indication message, then as follows... Figure 18 As shown, the data transmission method may include the following steps:

[0423] Step 1801: The UE sends an RRC recovery request message to the serving base station. The RRC recovery request message is used to request SDT (Software-Defined Technology).

[0424] Step 1802: The serving base station sends a retrieval context request message to the anchor base station. The retrieval context request message is used to instruct the use of SDT (Search Context Request).

[0425] Step 1803: The anchor base station sends a retrieval context response message to the serving base station. The retrieval context response message includes the address information of the anchor base station receiving SDT data.

[0426] Step 1804: The serving base station sends an Xn address indication message to the anchor base station. This Xn address indication message includes the address information for the serving base station to receive SDT data.

[0427] Step 1805: The serving base station sends the first SDT data packet carried in the RRC recovery request message to the anchor base station.

[0428] Step 1806: The UE and the anchor base station transmit subsequent SDT data.

[0429] Step 1807: If the serving base station does not meet the requirements of SDT, the serving base station sends an RRC release request message to the anchor base station.

[0430] Step 1808: The anchor base station sends an RRC release response message to the serving base station. The RRC release response message carries the RRC release message.

[0431] Step 1809: The serving base station sends an RRC release message to the UE. The RRC release message is used to instruct the terminal device to terminate SDT.

[0432] Step 18010: UE stops SDT timer.

[0433] Step 18011: The serving base station sends an RRC release completion message to the anchor base station.

[0434] It should be noted that the actions of the serving access network device in the above method embodiments can be performed by... Figure 7 The processor 701 in the communication device 70 shown calls the application code stored in the memory 704 to instruct the service access network device to execute, and the actions of the anchor access network device can be performed by... Figure 7 The processor 701 in the communication device 70 shown calls the application code stored in the memory 704 to instruct the anchor access network device to execute the action of the terminal device. Figure 7 The processor 701 in the communication device 70 shown calls the application code stored in the memory 704 to instruct the terminal device to execute.

[0435] It is understood that the methods and / or steps implemented by the target node in the above embodiments can also be implemented by components (e.g., chips or circuits) that can be used by the target node.

[0436] Optionally, embodiments of this application also provide a communication device for implementing the various methods described above. This communication device can be a target node in the above method embodiments, a device containing the target node, or a component usable by the target node. It is understood that, in order to implement the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0437] This application embodiment can divide the communication device into functional modules according to the above method embodiment. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0438] Figure 19 A schematic diagram of a communication device 190 is shown. The communication device 190 includes a transceiver module 1901, which, also referred to as a transceiver unit, is used to implement transceiver functions. For example, it can be a transceiver circuit, transceiver, transceiver interface, or communication interface. Optionally, the communication device 190 may also include a processing module 1902.

[0439] In this example, the communication device 190 is a service access network device in the above method embodiment:

[0440] The transceiver module 1901 can be used to receive a first RRC message from the terminal device, which is used to establish SDT. If the serving access network device does not meet the requirements of SDT, the transceiver module 1901 can also be used to send a second RRC message or a third RRC message to the terminal device. The second RRC message is used to instruct the terminal device to terminate SDT, and the third RRC message is used to instruct the serving access network device to refuse to perform SDT.

[0441] Optionally, if the serving access network device is not the anchor access network device, before sending the second RRC message to the terminal device, the transceiver module 1901 can also be used to send a fourth RRC message to the anchor access network device. The fourth RRC message is used to request the anchor access network device to send the second RRC message. Furthermore, the transceiver module 1901 can also be used to receive a fifth RRC message from the anchor access network device. The fifth RRC message is a response message to the fourth RRC message and includes the second RRC message.

[0442] Optionally, if the serving access network device determines that the SDT requirements are not met during the SDT process, the fifth RRC message can also be used to instruct the serving access network device to delete the context of the terminal device. Processing module 1902 can be used to delete the locally stored context of the terminal device.

[0443] Optionally, if the serving access network device determines that the requirements of SDT are not met during the SDT process, after sending a third RRC message to the terminal device, the transceiver module 1901 can also be used to send a sixth RRC message to the anchor access network device. The sixth RRC message is used to instruct the anchor access network device to cancel SDT.

[0444] Taking communication device 190 as an example of an anchor access network device in the above method embodiment:

[0445] The transceiver module 1901 can be used to receive a fourth RRC message from the serving access network device, the fourth RRC message being used to request the anchor access network device to send a second RRC message. Furthermore, the transceiver module 1901 can also be used to send a fifth RRC message to the serving access network device based on the fourth RRC message, the fifth RRC message including the second RRC message, the second RRC message being used to instruct the terminal device to terminate SDT.

[0446] Optionally, the fourth RRC message includes any one of the following: a request indication, a redirection indication, or a cell reselection indication. The request indication is used to request the anchor access network device to send the second RRC message; the redirection indication is used to instruct the serving access network device to suggest that the terminal device perform redirection; and the cell reselection indication is used to instruct the serving access network device to suggest that the terminal device perform cell reselection. The processing module 1902 can also be used to determine, based on the request indication, the redirection indication, or the cell reselection indication, that the fifth RRC message includes the second RRC message.

[0447] Optionally, when the second RRC message includes the first redirection parameter, the fourth RRC message may also include the second redirection parameter, and the processing module 1902 may also be used to determine the first redirection parameter based on the second redirection parameter. When the second RRC message includes the first cell reselection priority parameter, the fourth RRC message may also include the second cell reselection priority parameter, and the processing module 1902 may also be used to determine the first cell reselection priority parameter based on the second cell reselection priority parameter.

[0448] Optionally, the fourth RRC message also includes a waiting time indication, and the processing module 1902 can also be used to determine the waiting time based on the waiting time indication.

[0449] Optionally, the fourth RRC message also includes a first SDT data packet. The transceiver module 1901 can also be used to send the first SDT data packet to user plane network elements.

[0450] Taking communication device 190 as another anchor access network device in the above method embodiment as an example:

[0451] The transceiver module 1901 can be used to receive a sixth RRC message from the serving access network device, which instructs the anchor access network device to cancel SDT. The processing module 1902 can be used to suspend the context of the terminal device performing SDT based on the sixth RRC message.

[0452] Taking communication device 190 as another anchor point access network device in the above method embodiment as an example:

[0453] Processing module 1902 can be used to determine the termination of SDT. Transceiver module 1901 can be used to send a seventh RRC message to the serving access network device. The seventh RRC message includes a second RRC message, which is used to instruct the terminal device to terminate SDT.

[0454] Taking the communication device 190 as an example of the terminal device in the above method embodiment:

[0455] The transceiver module 1901 can be used to send a first RRC message to the serving access network device, the first RRC message being used to establish SDT. The processing module 1902 can be used to stop the SDT timer when a second RRC message or a third RRC message is received from the serving access network device; wherein, the second RRC message is used to instruct the terminal device to terminate SDT, and the third RRC message is used to instruct the serving access network device to refuse to perform SDT.

[0456] Optionally, when a third RRC message is received, the processing module 1902 can also be used to notify the upper layer SDT of failure and restart the RNA timer, which is used to indicate that the terminal device is in an RRC inactive state.

[0457] Optionally, when a second RRC message is received, the processing module 1902 can also be used to notify the upper-layer SDT to terminate.

[0458] Optionally, the second RRC message may include a suspension configuration, processing module 1902, and may also be used to suspend the context of the terminal device and restart the RNA timer.

[0459] Optionally, after the terminal device sends the first RRC message, the processing module 1902 can also be used to start the SDT timer and pause the RNA timer.

[0460] Optionally, if there are unsent SDT data packets in the cache of the terminal device, the processing module 1902 can also ignore the waiting time, perform redirection according to the first redirection parameter, trigger SDT in the first cell to send the unsent SDT data packets in the cache, where the first cell is the serving cell after the terminal device performs the redirection.

[0461] Optionally, if there are unsent SDT data packets in the cache of the terminal device, the processing module 1902 can also ignore the waiting time, perform cell reselection according to the first cell reselection priority parameter, trigger SDT in the second cell to send the unsent SDT data packets in the cache, and the second cell is the serving cell after cell reselection.

[0462] It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here. Since the communication device 190 provided in this embodiment can execute the above data transmission method, the technical effects it can obtain can be referred to the above method embodiments, and will not be repeated here.

[0463] Optionally, the service access network device, anchor access network device, or terminal device in the embodiments of this application may also be referred to as a communication device. It may be a general-purpose device or a special-purpose device. The embodiments of this application do not make specific limitations on this.

[0464] In this embodiment, the communication device 190 is presented in an integrated manner, divided into various functional modules. Here, "module" can refer to a specific ASIC, circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices that can provide the aforementioned functions. In a simplified embodiment, those skilled in the art will recognize that the communication device 190 can employ... Figure 7 The communication device 70 shown is in the form of [example device 70].

[0465] for example, Figure 7 The processor 701 in the communication device 70 shown can execute the data transmission method in the above method embodiment by calling the computer execution instructions stored in the memory 704.

[0466] Specifically, Figure 19 The functions / implementation process of the transceiver module 1901 and the processing module 1902 can be obtained through Figure 7 The processor 701 in the communication device 70 shown calls computer execution instructions stored in memory 704 to implement the function. Alternatively, Figure 19 The function / implementation process of the processing module 1902 can be obtained through Figure 7 The processor 701 in the communication device 70 shown calls computer execution instructions stored in the memory 704 to implement this. Figure 19 The function / implementation process of the transceiver module 1901 can be obtained through Figure 7 This is achieved through the communication interface 703 in the communication device 70 shown.

[0467] Since the communication device 190 provided in this embodiment can execute the above data transmission method, the technical effects it can achieve can be referred to the above method embodiment, and will not be repeated here.

[0468] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0469] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0470] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0471] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0472] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0473] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0474] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0475] As used herein, the terms “component,” “module,” “system,” etc., are intended to refer to a computer-related entity, which may be hardware, firmware, a combination of hardware and software, software, or running software. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable file, a running thread, a program, and / or a computer. As an example, an application running on a computing device and the computing device itself can both be components. One or more components may reside in a running process and / or thread, and components may be located in a single computer and / or distributed among two or more computers. Furthermore, these components are capable of execution from various computer-readable media having various data structures thereon. These components may communicate locally and / or remotely via signals, such as based on one or more data packets (e.g., data from a component that interacts with a local system, another component in a distributed system, and / or signals that interact with other systems via a network such as the Internet).

[0476] This application presents various aspects, embodiments, or features relating to systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that individual systems may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these approaches are also possible.

[0477] Additionally, in the embodiments of this application, the term "exemplary" is used to indicate that it is an example, illustration, or illustration. Any embodiment or design scheme described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Rather, the use of the term "exemplary" is intended to present the concept in a specific manner.

[0478] In the embodiments of this application, the terms "information," "signal," "message," and "channel" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction, their intended meanings are consistent. Similarly, "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction, their intended meanings are consistent. "System" and "network" may sometimes be used interchangeably. Without emphasizing the distinction, their intended meanings are consistent; for example, "communication network" also refers to "communication system."

[0479] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0480] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A data transmission method, characterized in that, Applied to a serving access network device, the method includes: Receive a first Radio Resource Control (RRC) message from the terminal device, the first RRC message being used to establish Small Data Packet Transmission (SDT); If the Serving Access Network device does not meet the requirements of SDT, a second RRC message is sent to the terminal device. The second RRC message is used to instruct the terminal device to terminate SDT. The Serving Access Network device is not an anchor access network device. Before sending the second RRC message to the terminal device, the method further includes: Send a message to the anchor access network device requesting the anchor access network device to send the second RRC message to the serving access network device; The message sent to the anchor access network device includes a first reason value, which indicates the reason why the serving access network device requests the anchor access network device to send the second RRC message.

2. The method according to claim 1, characterized in that, The service access network equipment that does not meet the SDT requirements includes: When the first RRC message is received, the serving access network device does not support SDT, or the serving access network device is congested, or the load of the serving access network device is greater than a threshold.

3. The method according to claim 2, characterized in that, The service access network equipment that does not meet the SDT requirements includes: During the SDT process, the service access network device becomes congested or the load of the service access network device exceeds a threshold.

4. The method according to any one of claims 1-3, characterized in that, The second RRC message includes a waiting time, which indicates the time the terminal device waits before initiating the next communication connection.

5. The method according to any one of claims 1-3, characterized in that, The second RRC message includes a first redirection parameter or a first cell reselection priority parameter, wherein the first redirection parameter is used for redirection and the first cell reselection priority parameter is used for cell reselection.

6. The method according to any one of claims 1-3, characterized in that, The method further includes: Receive a response message from the anchor access network device, the response message including the second RRC message.

7. The method according to any one of claims 1-3, characterized in that, The message sent to the anchor access network device includes any one of the following: a request indication, a redirection indication, or a cell reselection indication. The request indication is used to request the anchor access network device to send the second RRC message. The redirection indication is used to instruct the serving access network device to suggest that the terminal device perform a redirection. The cell reselection indication is used to instruct the serving access network device to suggest that the terminal device perform a cell reselection.

8. The method according to claim 6, characterized in that, The response message is used to instruct the service access network device to delete the context of the terminal device.

9. A data transmission method, characterized in that, Applied to anchor point access network equipment, the method includes: Receive a message from the serving access network device, the message being used to request the anchor access network device to send a second RRC message to the serving access network device; Based on the received message, a second RRC message is sent to the serving access network device. The second RRC message is used to instruct the terminal device to terminate Small Data Packet Transmission (SDT). The received message includes a first reason value, which indicates the reason why the serving access network device requests the anchor access network device to send the second RRC message.

10. The method according to claim 9, characterized in that, The received message includes any one of the following: a request indication, a redirection indication, or a cell reselection indication. The request indication is used to request the anchor access network device to send the second RRC message. The redirection indication is used to instruct the serving access network device to suggest that the terminal device perform a redirection. The cell reselection indication is used to instruct the serving access network device to suggest that the terminal device perform a cell reselection.

11. The method according to claim 9 or 10, characterized in that, The second RRC message includes a first redirection parameter or a first cell reselection priority parameter. The first redirection parameter is used by the terminal device to perform redirection, and the first cell reselection priority parameter is used by the terminal device to perform cell reselection.

12. The method according to claim 9 or 10, characterized in that, The second RRC message includes a waiting time, which indicates the time the terminal device waits before initiating the next communication connection.

13. A data transmission method, characterized in that, Applied to a terminal device, the method includes: Send a first Radio Resource Control (RRC) message to the serving access network device. The first RRC message is used to establish Small Data Packet Transmission (SDT). When a second RRC message is received from the serving access network device, the SDT timer is stopped; wherein, the second RRC message is used to instruct the terminal device to terminate SDT; The serving access network device is not an anchor access network device. The serving access network device sends a message to the anchor access network device requesting the anchor access network device to send the second RRC message to the serving access network device. The message sent to the anchor access network device includes a first reason value, which indicates the reason why the serving access network device requests the anchor access network device to send the second RRC message.

14. The method according to claim 13, characterized in that, The first RRC message is an RRC recovery request message, and the second RRC message is an RRC release message.

15. The method according to claim 13 or 14, characterized in that, The method further includes: receiving the second RRC message forwarded by the serving access network device, the second RRC message being included in a response message, the response message being a response message to the message sent to the anchor access network device.

16. The method according to claim 13 or 14, characterized in that, When the second RRC message is received, the method further includes: Notify the upper-level SDT to terminate.

17. The method according to claim 16, characterized in that, If the second RRC message includes a suspend configuration, the method further includes: Suspend the context of the terminal device and restart the RNA timer.

18. The method according to any one of claims 13, 14 or 17, characterized in that, After the terminal device sends the first RRC message, the method further includes: Start the SDT timer and stop the RNA timer.

19. The method according to any one of claims 13, 14 or 17, characterized in that, The second RRC message includes a waiting time, which indicates the time the terminal device waits before initiating the next communication connection.

20. The method according to claim 19, characterized in that, The second RRC message includes a first redirection parameter, which is used by the terminal device to perform a redirection.

21. The method according to claim 20, characterized in that, If the terminal device has unsent SDT data packets in its cache, the method further includes: Ignoring the waiting time, a redirection is performed according to the first redirection parameter. An SDT is triggered in the first cell to send the SDT data packets that were not sent in the buffer. The first cell is the serving cell after the terminal device performs the redirection.

22. The method according to claim 19, characterized in that, The second RRC message includes a first cell reselection priority parameter, which is used by the terminal device to perform cell reselection.

23. The method according to claim 22, characterized in that, If the terminal device has unsent SDT data packets in its cache, the method further includes: Ignoring the waiting time, cell reselection is performed according to the first cell reselection priority parameter. SDT is triggered in the second cell to send the SDT data packets that were not sent in the buffer. The second cell is the serving cell after the terminal device performs the cell reselection.

24. A data processing apparatus, characterized in that, The data processing device includes: a processor and a memory; The memory is used to store computer execution instructions, which, when executed by the processor, cause the data processing device to perform the method as described in any one of claims 1-8, 9-12, or 13-23.

25. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a computer, causes the computer to perform the method of any one of claims 1-8, 9-12, or 13-23.

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