Data transmission method and device and communication system

Abstract

A data transmission method, device and communication system, the method comprising: acquiring a first DRB, the first DRB being used by a terminal device to send uplink data of a first QoS flow to a first network device; obtaining a second DRB, wherein the second DRB is used by the terminal device to receive downlink data of the first QoS flow from a second network device; in the embodiment of the invention, the uplink data of the first QoS flow is sent to the first network equipment through the first DRB, and / or the downlink data of the first QoS flow from the second network equipment through the second DRB, so that the end-to-end transmission of the uplink data and the downlink data of the first QoS flow is separated, the uplink data transmission flexibility is improved, and the uplink data transmission delay is reduced.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly, to a data transmission method, apparatus, and communication system. Background Art

[0002] In a mobile communication system, a terminal device (such as a user equipment (UE)) can establish a connection with one or more network devices (such as a base station) for transmitting uplink data and / or downlink data.

[0003] Exemplarily, in dual connection (DC) technology, it generally means allowing a UE to be connected to two base stations simultaneously. The UE can transmit data with the two base stations, that is, the two base stations can provide services for the UE, which can effectively improve the UE rate. For example, a long term evolution (LTE) base station and a new radio (NR) base station can provide services for a UE simultaneously. In downlink data transmission, the core network sends data to the NR base station, and the data is sent to the UE through the air interface of the NR base station, or a part of the data is sent to the UE through the air interface of the NR base station, and the other part of the data is sent to the UE through the air interface of the LTE base station. In uplink data transmission, the UE sends data to the LTE base station, the data is sent to the NR base station through the air interface of the LTE base station, and then the data is sent to the core network through the air interface of the NR base station. Since the NR base station includes a Packet Data Convergence Protocol (PDCP) anchor point, the end-to-end transmission of uplink and downlink data (i.e., between the UE and the core network) needs to pass through the NR base station, resulting in an increase in data transmission delay. Summary of the Invention

[0004] This application provides a data transmission method and apparatus, which can achieve separate transmission of uplink and downlink data of a first QoS flow and improve transmission performance.

[0005] In a first aspect, a data transmission method is provided. This method can be executed by a first network device, or can also be executed by a chip or circuit of the first network device. This application does not limit this. For ease of description, the following takes the execution by the first network device as an example for illustration.

[0006] The method includes: sending first configuration information to a terminal device, where the first configuration information is used to configure a first data radio bearer (DRB), and the first DRB is used for the first network device to receive uplink data of a first quality of service (QoS) flow; sending second configuration information to the terminal device, where the second configuration information is used to configure a second DRB, and the second DRB is used for receiving downlink data of the first QoS flow from a second network device.

[0007] According to the above solution, by sending the first configuration information, the uplink data of the first QoS flow is transmitted by the first network device through the first DRB, and by sending the second configuration information, the downlink data of the first QoS flow is transmitted by the second network device through the second DRB, realizing the separate transmission of the uplink and downlink data of the first QoS flow, thus avoiding the uplink data of the first QoS flow from being transmitted between the first network device and the second network device, thereby reducing the transmission delay of the uplink data of the first QoS flow and improving the transmission performance.

[0008] In an optional implementation manner, before sending the second configuration information to the terminal device, the method further includes: receiving the second configuration information from the second network device.

[0009] In an optional implementation manner, before sending the second configuration information to the terminal device, the first DRB is further used by the first network device to send the downlink data of the first QoS flow.

[0010] That is to say, in the first case, the first DRB may be established by the first network device before establishing the dual connection. At this time, the first DRB is further used by the first network device to send the downlink data of the first QoS flow to the terminal device, or rather, the terminal device can also use the first DRB to receive the downlink data of the first QoS flow from the first network device. That is to say, before establishing the dual connection, the first DRB is used to transmit the uplink and downlink data of the first QoS flow between the first network device and the terminal device, or rather, the transmission of the uplink and downlink data of the first QoS flow between the terminal device and the core network element (end-to-end) is completed through the first network device.

[0011] In an optional implementation manner, before receiving the second configuration information from the second network device, the method further includes: sending a first request message to the second network device, where the first request message is used to request the second network device to transmit the downlink data of the first QoS flow for the terminal device, and the first request message includes the information of the first QoS flow.

[0012] In an optional implementation manner, before receiving the second configuration information from the second network device, the method further includes: sending a second request message to the second network device, where the second request message is used to request the second network device to transmit the first QoS flow for the terminal device, and the second request message includes the information of the first QoS flow.

[0013] Based on the above solution, the first network device or the second network device can autonomously decide that the second network device transmits the downlink data of the first QoS flow for the terminal device, and then the first network device transmits the uplink data of the first QoS flow for the terminal device, so as to realize the separate transmission of the uplink and downlink data of the first QoS flow, avoid the uplink data of the first QoS flow from being transmitted between the first network device and the second network device, thereby reducing the transmission delay of the uplink data of the first QoS flow and improving the transmission performance.

[0014] In an optional implementation manner, before sending the second configuration information to the terminal device, the second DRB is used for the first network device to receive the uplink data of the first QoS flow and for the first network device to send the downlink data of the first QoS flow.

[0015] That is to say, in the second case, the second DRB may be established by the first network device before establishing the dual connection. At this time, the second DRB is also used for the first network device to send the downlink data of the first QoS flow to the terminal device, or rather, the terminal device can also use the second DRB to receive the downlink data of the first QoS flow from the first network device. That is to say, before establishing the dual connection, the second DRB is used for transmitting the uplink and downlink data of the first QoS flow between the first network device and the terminal device.

[0016] In an optional implementation manner, before receiving the second configuration information from the second network device, the method further includes: sending a third request message to the second network device, where the third request message is used to request the second network device to transmit the downlink data of the first QoS flow for the terminal device, and the third request message includes the packet data convergence protocol (PDCP) configuration of the second DRB and the mapping relationship between the second DRB and the first QoS flow.

[0017] In an optional implementation manner, before receiving the second configuration information from the second network device, the method further includes: sending a fourth request message to the second network device, where the fourth request message is used to request the second network device to transmit the first QoS flow for the terminal device, and the fourth request message includes the PDCP configuration of the second DRB and the mapping relationship between the second DRB and the first QoS flow.

[0018] Based on the above solution, the first network device or the second network device can autonomously decide that the second network device transmits the downlink data of the first QoS flow for the terminal device, and then the first network device transmits the uplink data of the first QoS flow for the terminal device, so as to realize the separate transmission of the uplink and downlink data of the first QoS flow, avoid the uplink data of the first QoS flow from being transmitted between the first network device and the second network device, thereby reducing the transmission delay of the uplink data of the first QoS flow and improving the transmission performance.

[0019] In an alternative implementation, receiving second configuration information from a second network device, including: receiving a response message from the second network device, where the response message is used to indicate that the second network device transmits downlink data of a first QoS flow for a terminal device, and the response message includes the second configuration information.

[0020] In an alternative implementation, before sending the second configuration information to the terminal device, the first configuration information is further used to configure a second DRB, and the second DRB is used for the first network device to send downlink data of the first QoS flow.

[0021] That is to say, in the third case, the first DRB and the second DRB may be established by the first network device before establishing a dual connection. At this time, before sending the second configuration information to the terminal device, the second DRB is used for the first network device to send downlink data of the first QoS flow to the terminal device. Among them, the second DRB is also established by the first network device. That is to say, before establishing a dual connection, the first network device can configure both the first DRB and the second DRB through the first configuration information, and the first network device receives uplink data of the first QoS flow from the terminal device through the first DRB, and sends downlink data of the first QoS flow to the terminal device through the second DRB.

[0022] In an alternative implementation, before receiving the second configuration information from the second network device, the method further includes: sending third indication information to the second network device, where the third indication information is used to indicate that the second network device sends downlink data of the first QoS flow to the terminal device through the second DRB.

[0023] Based on the above solution, the first network device can independently decide that the second network device transmits downlink data of the first QoS flow for the terminal device, and then the first network device transmits uplink data of the first QoS flow for the terminal device, realizing separate transmission of uplink and downlink data of the first QoS flow, avoiding the uplink data of the first QoS flow from being transmitted between the first network device and the second network device, thereby reducing the transmission delay of the uplink data of the first QoS flow and improving the transmission performance.

[0024] In an alternative implementation, before sending the first configuration information to the terminal device, the method further includes: obtaining capability information of the terminal device, where the capability information is used to indicate that the terminal device supports establishing DRBs for uplink data and downlink data of the first QoS flow respectively.

[0025] In an alternative implementation, the method further includes: receiving first indication information from the second network device, where the first indication information indicates that the first network device establishes a radio link control (RLC) bearer for the second DRB.

[0026] In an alternative implementation, the method further includes: sending the RLC configuration of the second DRB to the terminal device, where the RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB.

[0027] Based on the above solution, the downlink data of the first QoS flow can be transmitted in a split-bearing manner. That is, the second network device can send the downlink data of the first QoS flow to the first network device, and the first network device sends it to the terminal device through the air interface of the first network device to improve the transmission efficiency of the downlink data.

[0028] In an alternative implementation, the method further includes: sending to the second network device the endpoint information indicating the third tunnel, where the third tunnel is used for the first network device to receive the downlink data of the first QoS flow from the second network device.

[0029] It should be understood that the third tunnel is a tunnel between the first network device and the second network device, and the third tunnel is used for the first network device and the second network device to transmit the downlink data of the first QoS flow. For example, after the second network device receives the downlink data of the first QoS flow from the core network element, it can send the downlink data of the first QoS flow to the first network device through the third tunnel.

[0030] Exemplarily, the endpoint information represents the endpoint information of the third tunnel on the first network device side, and the endpoint information includes the endpoint identifier of the first network device and / or the endpoint address information of the first network device. The second network device can determine the information of the third tunnel on the first network device side (such as endpoint #1) according to the endpoint information, and then establish the third tunnel with the first network device. Subsequently, the second network device can send the downlink data of the first QoS flow to the endpoint #1.

[0031] In an alternative implementation, the method further includes: sending the second indication information to the second network device, where the second indication information instructs the second network device to establish a second tunnel, and the second tunnel is used for the second network device to receive the downlink data of the first QoS flow from the core network element.

[0032] In an alternative implementation, the method further includes: sending to the core network element the endpoint information indicating the second tunnel.

[0033] It should be understood that the second tunnel is a tunnel between the second network device and the core network element, and the second tunnel is used for the second network device to receive the downlink data of the first QoS flow from the core network element. That is, for the downlink data of the first QoS flow, the second network device can receive the downlink data of the first QoS flow from the core network element through the second tunnel, and send the downlink data of the first QoS flow to the terminal device through the second DRB, completing the transmission of the downlink data of the first QoS flow.

[0034] Exemplarily, the second indication information includes endpoint information for indicating a second tunnel, where the endpoint information represents the endpoint information of the second tunnel on the core network element side, and the endpoint information includes the endpoint identifier of the core network element and / or the endpoint address information of the core network element. Based on the endpoint information, the second network device can determine the information of the second tunnel on the core network element side (such as endpoint #2), and then establish a second tunnel with the core network element. Subsequently, the second network device can receive the downlink data of the first QoS flow from the endpoint #2.

[0035] In an alternative implementation, the method further includes: sending a message to the core network element for indicating to retain a first tunnel, where the first tunnel is established by the first network device and is used for the first network device to send the uplink data of the first QoS flow to the core network element.

[0036] It should be understood that retaining the first tunnel can be understood as: indicating to the core network element to retain the endpoint information of the first tunnel on the first network device side, or in other words, indicating to the core network element not to delete the first tunnel, that is, the first tunnel is still used for transmitting the uplink data of the first QoS flow between the core network element and the first network device. Wherein, the endpoint information includes the endpoint identifier of the first network device and / or the endpoint address information of the first network device. Based on this, the core network element can transmit the uplink data of the first QoS flow with the first network device through the first tunnel, and / or, the core network element can transmit the downlink data of the first QoS flow with the second network device through the second tunnel.

[0037] In a second aspect, a data transmission method is provided. This method can be executed by a second network device, or can also be executed by a chip or circuit of the second network device. This application does not make any limitations in this regard. For ease of description, the following takes the execution by the second network device as an example for illustration.

[0038] The method includes: sending second configuration information to the first network device, where the second configuration information is used to configure a second data radio bearer (DRB), and the second DRB is used for the second network device to send the downlink data of the first quality of service (QoS) flow to the terminal device.

[0039] In an alternative implementation, the uplink data of the first QoS flow is carried on a first DRB, and the first DRB is configured by first configuration information.

[0040] In an alternative implementation, before sending the second configuration information to the first network device, the first DRB is also used to carry the downlink data of the first QoS flow.

[0041] In an alternative implementation, before sending the second configuration information to the first network device, the method further includes: receiving a first request message from the first network device, where the first request message is used to request the second network device to transmit downlink data of a first QoS flow for the terminal device, and the first request message includes information about the first QoS flow.

[0042] In an alternative implementation, before sending the second configuration information to the first network device, the method further includes: receiving a second request message from the first network device, where the second request message is used to request the second network device to transmit a first QoS flow for the terminal device, and the second request message includes information about the first QoS flow.

[0043] In an alternative implementation, before sending the second configuration information to the first network device, the second DRB is used for the first network device to receive uplink data of the first QoS flow and for the first network device to send downlink data of the first QoS flow.

[0044] In an alternative implementation, before sending the second configuration information to the first network device, the method further includes: receiving a third request message from the first network device, where the third request message is used to request the second network device to transmit downlink data of a first QoS flow for the terminal device, and the third request message includes the PDCP configuration of the second DRB and the mapping relationship between the second DRB and the first QoS flow.

[0045] In an alternative implementation, before sending the second configuration information to the first network device, the method further includes: receiving a fourth request message from the first network device, where the fourth request message is used to request the second network device to transmit a first QoS flow for the terminal device, and the fourth request message includes the PDCP configuration of the second DRB and the mapping relationship between the second DRB and the first QoS flow.

[0046] In an alternative implementation, sending the second configuration information to the first network device includes: sending a response message to the first network device, where the response message is used to indicate that the second network device transmits downlink data of a first QoS flow for the terminal device, and the response message includes the second configuration information.

[0047] In an alternative implementation, before sending the second configuration information to the first network device, the second DRB is used for the first network device to send downlink data of the first QoS flow.

[0048] In an alternative implementation, the method further includes: receiving third indication information from the first network device, where the third indication information is used to indicate that the second network device sends downlink data of a first QoS flow to the terminal device through the second DRB.

[0049] In an alternative implementation, the method further includes: receiving downlink data of a first QoS flow from a core network element through a second tunnel; and sending the downlink data of the first QoS flow to a terminal device through a second DRB.

[0050] In an alternative implementation, the method further includes: establishing a second tunnel for a second network device to receive downlink data of a first QoS flow from a core network element.

[0051] In an alternative implementation, the method further includes: sending first indication information to a second network device, where the first indication information instructs a first network device to establish a radio link control (RLC) bearer for a second DRB.

[0052] In an alternative implementation, the method further includes: receiving endpoint information for indicating a third tunnel from a first network device, where the third tunnel is for the first network device to receive downlink data of a first QoS flow from the second network device.

[0053] In an alternative implementation, before establishing the second tunnel, the method further includes:

[0054] receiving second indication information from a first network device, where the second indication information instructs the second network device to establish the second tunnel.

[0055] The beneficial effects of the second aspect and its alternative implementations can be correspondingly referred to the descriptions related to the first aspect, which will not be elaborated here.

[0056] In a third aspect, a data transmission method is provided. This method can be executed by a terminal device, or by a chip or circuit of the terminal device. This application does not make any limitation in this regard. For ease of description, the following takes the execution by the terminal device as an example for illustration.

[0057] The method includes: obtaining a first data radio bearer (DRB), where the first DRB is used for the terminal device to send uplink data of a first quality of service (QoS) flow to a first network device; obtaining a second DRB, where the second DRB is used for the terminal device to receive downlink data of the first QoS flow from a second network device; sending the uplink data of the first QoS flow to the first network device through the first DRB, and / or receiving the downlink data of the first QoS flow from the second network device through the second DRB.

[0058] In an alternative implementation, the first DRB comes from the first network device.

[0059] In an alternative implementation, before obtaining the second DRB, the first DRB is further used for the terminal device to receive downlink data of the first QoS flow from the first network device.

[0060] In an alternative implementation, the second DRB comes from the first network device, or the second DRB comes from the second network device.

[0061] In an alternative implementation, obtaining the first DRB includes: receiving first configuration information from the first network device, where the first configuration information is used to configure the first DRB.

[0062] In an alternative implementation, obtaining the second DRB includes: receiving second configuration information from the first network device, where the second configuration information is used to configure the second DRB.

[0063] In an alternative implementation, the method further includes: obtaining the radio link control (RLC) configuration of the second DRB, where the RLC configuration of the second DRB is used to configure the RLC bearer of the second DRB; receiving the downlink data of the first QoS flow from the first network device through the RLC bearer of the second DRB.

[0064] The beneficial effects of the third aspect and its alternative implementations can be correspondingly referred to the description related to the first aspect, and will not be elaborated here.

[0065] Fourth aspect, a data transmission method is provided. This method can be executed by a core network element, or can be executed by a chip or circuit of the core network element. This application does not make any limitation in this regard. For ease of description, the following takes the execution by the core network element as an example for illustration.

[0066] The method includes: receiving endpoint information indicating a second tunnel, where the second tunnel is used for the core network element to send downlink data of the first quality of service (QoS) flow to the second network device; where the uplink data of the first QoS flow is received by the core network element from the first network device through a first tunnel.

[0067] In an alternative implementation, before receiving the endpoint information indicating the second tunnel, the downlink data of the first QoS flow is sent by the core network element to the first network device through the first tunnel.

[0068] In an alternative implementation, the method further includes: receiving a message indicating to retain the first tunnel.

[0069] The beneficial effects of the fourth aspect and its alternative implementations can be correspondingly referred to the description related to the first aspect, and will not be elaborated here.

[0070] Fifth aspect, a data transmission device is provided. This data transmission device can be used for the first network device of the first aspect, and may include modules or units corresponding one by one to the methods / operations / steps / actions described in the first aspect. These modules or units can be hardware circuits, software, or a combination of hardware circuits and software.

[0071] In an alternative implementation, the apparatus includes: a transceiver unit configured to send first configuration information to a terminal device, where the first configuration information is used to configure a first data radio bearer (DRB), the first DRB is used for a first network device to receive uplink data of a first QoS flow, and for the first network device to send downlink data of the first QoS flow; and the transceiver unit is further configured to send second configuration information to the terminal device, where the second configuration information is used to configure a second DRB, and the second DRB is used for receiving downlink data of the first QoS flow from a second network device.

[0072] The transceiver unit may perform the receiving and sending processes in the foregoing first aspect and its possible implementations. Optionally, the apparatus further includes a processing unit, and the processing unit may perform other processes in the foregoing first aspect and its possible implementations except for receiving and sending.

[0073] In a sixth aspect, a data transmission apparatus is provided. The data transmission apparatus may be used for the second network device in the second aspect, and may include modules or units corresponding one by one to the methods / operations / steps / actions described in the second aspect. The module or unit may be a hardware circuit, software, or a combination of a hardware circuit and software.

[0074] In an alternative implementation, the apparatus includes: a transceiver unit configured to send second configuration information to a first network device, where the second configuration information is used to configure a second data radio bearer (DRB), and the second DRB is used for the second network device to send downlink data of a first quality of service (QoS) flow to the terminal device.

[0075] The transceiver unit may perform the receiving and sending processes in the foregoing second aspect and its possible implementations. Optionally, the apparatus further includes a processing unit, and the processing unit may perform other processes in the foregoing second aspect and its possible implementations except for receiving and sending.

[0076] In a seventh aspect, a data transmission apparatus is provided. The data transmission apparatus may be used for the terminal device in the third aspect, and may include modules or units corresponding one by one to the methods / operations / steps / actions described in the third aspect. The module or unit may be a hardware circuit, software, or a combination of a hardware circuit and software.

[0077] In some alternative implementations, the apparatus includes: a transceiver unit configured to obtain a first DRB, where the first DRB is used for the terminal device to send uplink data of a first QoS flow to a first network device; the transceiver unit is further configured to obtain a second DRB, where the second DRB is used for the terminal device to receive downlink data of the first QoS flow from a second network device; the transceiver unit is further configured to send, via the first DRB, the uplink data of the first QoS flow to the first network device, and / or receive, via the second DRB, the downlink data of the first QoS flow from the second network device.

[0078] The transceiver unit may perform the receiving and sending processes in the foregoing third aspect and its possible implementations. Optionally, the apparatus further includes a processing unit, and the processing unit may perform other processes in the foregoing third aspect and its possible implementations except for receiving and sending.

[0079] In an eighth aspect, a data transmission apparatus is provided. The data transmission apparatus may be used for a core network element in the fourth aspect, and may include modules or units corresponding one by one to the methods / operations / steps / actions described in the fourth aspect. The modules or units may be hardware circuits, software, or a combination of hardware circuits and software.

[0080] In some alternative implementations, the apparatus includes: a transceiver unit configured to receive endpoint information indicating a second tunnel, where the second tunnel is used for the core network element to send downlink data of a first QoS flow to a second network device; wherein the uplink data of the first QoS flow is received by the core network element from a first network device through a first tunnel.

[0081] The transceiver unit may perform the receiving and sending processes in the foregoing fourth aspect and its possible implementations. Optionally, the apparatus further includes a processing unit, and the processing unit may perform other processes in the foregoing fourth aspect and its possible implementations except for receiving and sending.

[0082] In a ninth aspect, a data transmission apparatus is provided, including at least one processor. The at least one processor is configured to execute a computer program or instruction, and / or through a logic circuit, to cause the data transmission apparatus to execute the methods in any one of the first aspect to the fourth aspect, or any possible implementation manner of these aspects.

[0083] In an alternative implementation, the at least one processor is coupled to at least one memory, and the at least one memory stores the foregoing computer program or instruction. Optionally, the data transmission apparatus further includes the foregoing at least one memory. Optionally, the at least one processor and the at least one memory are integrated together.

[0084] In a tenth aspect, a chip is provided, including a processor and / or a communication interface. The communication interface is configured to receive information and / or data to be processed and send the information and / or data to be processed to the processor. The processor is configured to process the information and / or data to be processed, such that a data transmission device installed with the chip executes the method in any one of the first aspect to the fourth aspect, or any possible implementation manner of these aspects.

[0085] In an eleventh aspect, a computer-readable storage medium is provided, in which computer instructions are stored. When the computer instructions are run on a computer, the method in any one of the first aspect to the fourth aspect, or any possible implementation manner of these aspects is implemented.

[0086] In a twelfth aspect, a computer program product is provided, including computer program code or instructions. When the computer program code or instructions are run on a computer, the method in any one of the first aspect to the fourth aspect, or any possible implementation manner of these aspects is implemented.

[0087] In a thirteenth aspect, a communication system is provided, including a data transmission device according to any one or more of the fifth aspect, the sixth aspect, and the eighth aspect.

[0088] Optionally, the communication system may further include a data transmission device according to the seventh aspect.

[0089] Among them, for the technical effects of the technical solutions in the fifth aspect to the thirteenth aspect, reference may be made to the descriptions of the corresponding technical effects in the first aspect to the fourth aspect, and details are not repeated here. Description of the Drawings

[0090] Figures 1 to 3 is a schematic diagram of a network architecture applicable to an embodiment of the present application;

[0091] Figure 4 is an interaction process schematic diagram of a data transmission method provided by an embodiment of the present application;

[0092] Figure 5 is a schematic diagram of a first tunnel and a second tunnel provided by an embodiment of the present application;

[0093] Figures 6 to 8 is a schematic diagram of a protocol stack provided by an embodiment of the present application;

[0094] Figure 9 is a schematic diagram of a data transmission device provided by an embodiment of the present application;

[0095] Figure 10 is a schematic diagram of another data transmission device provided by an embodiment of the present application. Detailed Embodiments

[0096] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0097] The technical solutions provided by the present application can be applied to various communication systems, such as: the fifth generation (5G) or new radio (NR) system, the long term evolution (LTE) system, the LTE frequency division duplex (FDD) system, the LTE time division duplex (TDD) system, etc. The technical solutions provided by the present application can also be applied to future communication systems, such as the sixth generation (6G) mobile communication system. The technical solutions provided by the present application can also be applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (M2M) communication, machine type communication (MTC), and the Internet of Things (IoT) communication system or other communication systems.

[0098] In the embodiments of the present application, the terminal device may also be referred to as a terminal, an access terminal, a user unit, a user equipment (UE), a user station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user device. The terminal device is a device that includes a wireless communication function (providing voice / data connectivity to users). For example, a handheld device with a wireless connection function, or a vehicle-mounted device, etc. The terminal device in the embodiments of the present application may be a mobile phone, a tablet computer, a computer with a wireless transceiver function, a train, an airplane, a mobile internet device (MID), a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control (such as a robot, etc.), a wireless terminal in vehicle networking, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with a wireless communication function, a computing device, or other processing devices connected to a wireless modem, a wearable device, etc. The terminal device can also be applied to scenarios such as driverless, remote medical treatment, smart grid, transportation safety, smart city, smart city, and smart home. The terminal device can also be a terminal device in an IoT system. IoT is an important part of the future development of information technology. Its main technical feature is to connect items to the network through communication technology, so as to achieve an intelligent network of human-machine interconnection and thing-thing interconnection. In the embodiments of the present application, IoT technology can achieve massive connection, deep coverage, and power saving of the terminal through, for example, narrow band (NB) technology. In the embodiments of the present application, the device for implementing the functions of the terminal device may be the terminal device, or a device capable of supporting the terminal device to implement the functions, such as a chip system or a combined device or component that can implement the functions of the terminal device. This device may be installed in the terminal device. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the terminal device.

[0099] In the embodiments of the present application, the network device can be any device with wireless transceiver functions for communicating with a terminal device. This network device can also be referred to as an access network device or a radio access network device. For example, the network device can be a base station. The network device in the embodiments of the present application can refer to a radio access network (RAN) node (or RAN device, or RAN entity) that connects a terminal device to a wireless network. The above RAN can be a cellular system related to the 3rd generation partnership project (3GPP), such as a 5G mobile communication system or an evolved system for the future (such as a 6G mobile communication system). The RAN can also be an open radio access network (openRAN, O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. The RAN can also be a communication system that integrates two or more of the above systems. The network device can generally cover various names as follows, or be replaced with the following names. For example: Node B, evolved Node B (eNB), next generation Node B (gNB), or base station equipment in a future evolved communication system. It can also be a server, a wearable device, a vehicle-mounted device, a wireless relay node, a wireless backhaul node, a transmission point (TP), or a transmission and reception point (TRP), etc. It can also be one or a group (including multiple antenna panels) of antenna panels of a base station. Or, it can also be a network node that constitutes a base station, such as a baseband unit (BBU), a centralized unit (CU), a distributed unit (DU), or a radio unit (RU), etc. The function of the RU can be implemented by the radio frequency device of the base station. For example, the radio frequency device of the base station can be a remote radio unit (RRU), a pico remote radio unit (pRRU), an active antenna unit (AAU), or other units, modules, or devices with radio frequency processing functions, etc.The communication interface protocol between the BBU and the radio frequency device can be a Common Public Radio Interface (CPRI) interface protocol, an Enhanced Common Public Radio Interface (eCPRI) interface protocol, or a fronthaul interface protocol between the DU and the RU in the O-RAN system, etc., without limitation. The network device can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The network device can also refer to a communication module, a modem or a chip used to be disposed in the foregoing device or apparatus. The network device can also be a mobile switching center and a device that undertakes the function of the network device in D2D, V2X, M2M communications, a network-side device in a 6G network, a device that undertakes the function of the network device in a future communication system, etc. The network device can support networks of the same or different access technologies. In the embodiments of the present application, the apparatus for implementing the function of the network device can be the network device or an apparatus capable of supporting the network device to implement the function, such as a chip system or a combined device or component that can implement the function of the network device, and this apparatus can be installed in the network device. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the network device.

[0100] The network device and the terminal device can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on airplanes, balloons and satellites in the air. In the embodiments of the present application, the scenarios where the network device and the terminal device are located are not limited. The network device and the terminal device can be fixed or mobile.

[0101] In some deployments, the network device in the embodiments of this application may refer to the CU and / or DU. The network device may also include an active antenna unit (AAU). Exemplarily, the CU and DU may be divided according to the protocol layers of the wireless network. The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, and implements the functions of the radio resource control (RRC) layer, the service data adaptation protocol (SDAP) layer, and the packet data convergence protocol (PDCP) layer. The DU is responsible for processing physical layer protocols and real-time services, and implements the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing, and functions related to active antennas. Since the information in the RRC layer will ultimately become the information in the PHY layer, or is transformed from the information in the PHY layer, thus, in this architecture, high-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or sent by the DU + AAU. It can be understood that the network device may be a device including one or more of the CU node, DU node, and AAU node. In addition, the CU may be classified as a network device in the radio access network (RAN), or the CU may be classified as a network device in the core network (CN). This application does not make any limitations in this regard.

[0102] Furthermore, the CU can also be divided into a central unit for the control plane (central unit-control plane, CU-CP) and a central unit for the user plane (central unit-user plane, CU-UP). Among them, the CU-CP and CU-UP can also be deployed on different physical devices. The CU-CP is responsible for control plane functions, mainly including the RRC layer and the PDCP-C layer. The PDCP-C layer is mainly responsible for functions such as encryption, decryption, integrity protection, and data transmission of control plane data. The CU-UP is responsible for user plane functions, mainly including the service data adaptation protocol (SDAP) layer and the PDCP-U layer. Among them, the SDAP layer is mainly responsible for processing the data of the core network and mapping the flow to the bearer. The PDCP-U layer is mainly responsible for at least one function such as encryption, decryption, integrity protection, header compression, sequence number maintenance, or data transmission of the data plane. For example, the CU-CP and CU-UP are connected through a communication interface (such as, the E1 interface). The CU-CP represents the network device and is connected to the core network device through a communication interface (such as, the Ng interface), and is connected to the DU through a communication interface (such as, the F1-C (control plane) interface). The CU-UP is connected to the DU through a communication interface (such as, the F1-U (user plane) interface).

[0103] In different systems, the CU (including CU-CP or CU-UP), or DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the O-RAN system, the CU can also be called O-CU (Open CU), the DU can also be called O-DU, the CU-CP can also be called O-CU-CP, the CU-UP can also be called O-CU-UP, and the RU can also be called O-RU. For the convenience of description, in this application, the CU, CU-CP, CU-UP, DU, and RU are used as examples for description. Any unit in the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0104] It can be understood that the above protocol layer division of the CU and DU, as well as the CU-CP and CU-UP, is only an example, and there may be other division methods, which are not limited herein. The network device involved in the embodiments of this application can be a device including the CU, or DU, or a device including the CU and DU, or a device including a control plane CU node (CU-CP node), a user plane CU node (CU-UP node), and a DU node.

[0105] In the embodiments of the present application, the core network device refers to a device in the core network (CN) that provides service support for terminal devices. The core network device may include one or more core network elements. Taking the 5G core network as an example, the 5G core network includes an access and mobility management function (AMF) element responsible for services such as mobility management and access management, a session management function (SMF) element responsible for session management, a user plane function (UPF) element responsible for packet routing and forwarding of the user plane and quality of service (QoS) control, a policy control function (PCF) element, etc. The above-mentioned core network elements can work independently or be combined together to implement certain control functions. For example, AMF, SMF, and PCF can be combined together as a core network device.

[0106] It should be understood that the above naming is only defined for the convenience of distinguishing different functions and should not constitute any limitation to the present application. The present application does not exclude the possibility of using other naming in 5G networks and future other networks. For example, in a 6G network, some or all of the above-mentioned elements may continue to use the terms in 5G, or other names may be used.

[0107] For ease of understanding the embodiments of the present application, the following will be combined with Figures 1 to 3 to detail the communication system applicable to the embodiments of the present application.

[0108] Figure 1 is a schematic diagram of a communication system 100 applicable to the embodiments of the present application. As Figure 1 shown, the communication system 100 includes a network device 110 and a terminal device 120. In this communication system, the terminal device 120 can send uplink data / signals / information to the network device 110, and the network device 110 can send downlink data / signals / information to the terminal device 120. Optionally, the data transmission method provided in the embodiments of the present application may also involve Figure 1 devices or transmission nodes not shown in the figure, and the embodiments of the present application do not limit this.

[0109] Figure 2 is a schematic diagram of a communication system 200 applicable to the embodiments of the present application. As Figure 2As shown, the RAN can be a CU and DU separation architecture. The CU and DU can be understood as a division of the RAN from a logical function perspective. The CU and DU can be physically separated or deployed together. Multiple DUs can share a single CU. In the scenario of RAN sharing, a single DU can also be connected to multiple CUs ( Figure 2 not shown in). The CU and DU can be connected through an interface, such as the F1 interface. In this communication system, the core network can interact with the gNB information, for example, the core network can interact with the CU information. In one implementation, the CU can have one or more functions of the core network. One or more CUs can be centrally arranged or separately arranged. The core network devices in the core network and the RAN nodes in the RAN can be different physical devices respectively, or can be the same physical device integrating the core network logic function and the RAN logic function.

[0110] In a wireless network, a terminal device may communicate with multiple network devices (e.g., base stations), i.e., dual connectivity (DC), also known as multi-radio dual connectivity (MR-DC). These multiple base stations may be base stations belonging to the same radio access technology (RAT) (such as all 6G base stations or all 5G base stations), or may be base stations of different RATs (such as one being a sixth-generation 6G base station and one being a fifth-generation 5G base station).

[0111] Figure 3 is a schematic diagram of a communication system 300 applicable to the embodiments of the present application. Refer to Figure 3 , taking the terminal device as the UE and the network device as the base station as an example, the UE 320 can communicate with the base station 311 and the base station 312 through the DC technology. The base station 311 and the base station 312 are jointly connected to the core network 330. There can be a direct or indirect communication interface between the base station 311 and the base station 312. The core network 330 can be connected to the base station 311 and the base station 312 in a wired or wireless manner. The core network 330 can be a 6G core network, a 5G core network, or an evolved 5G core network.

[0112] The network side can use the resources of multiple base stations to provide communication services for the UE, thereby providing high-rate transmission for the UE. In the DC scenario, for a certain UE, the base station that has control plane signaling interaction with the core network is called the master node (MN), and other base stations are called secondary nodes (SN). The MN can also be called the master base station (or master station), and the SN can also be called the secondary base station (or secondary station). Each base station has different RLC entities and MAC entities. For ease of description, in the embodiments of the present application, the first network device is used as the master base station MN and the second network device is used as the secondary base station SN as an example for illustration.

[0113] Optionally, Figures 1 to 3 the communication system in the above Figures 1 to 3 may further include an application function (AF) network element. The AF network element is a control plane network function provided by the operator network and is used to provide application layer information. It should be understood that the above

[0114] is only an example given for ease of understanding. The communication system shown in the figure may further include other network devices or may further include other terminal devices, which are not shown.

[0115] To facilitate the understanding of the embodiments of the present application, the terms or technologies involved in the present application are described first.

[0116] 1. Dual connection (DC);

[0117] Dual connection means allowing the UE to be connected to two base stations simultaneously, that is, the two base stations provide services for the UE, and the UE can perform data transmission with the two base stations, which can effectively improve the rate and reliability of the UE. For example, Figure 3 in the network architecture 300 shown, the UE 320 can interact with the base station 311 and the secondary base station 312. In the dual connection technology, the base station carrying the control plane connection is the master base station (also called the master station, MN), and the other base station is the secondary base station (also called the secondary station, SN).

[0118] 2. Radio Bearer;

[0119] A radio bearer (RB) is the general term for the base station to allocate different layer protocol entities and configurations for a UE, including a series of resources allocated to PDCP protocol entities, RLC protocol entities, MAC protocol entities, and PHY protocol entities. The RB is the channel (including PHY, MAC, RLC, and PDCP) connecting the base station and the UE on the radio interface, and any data transmitted on the radio interface has to pass through the RB. The RB includes a signalling radio bearer (SRB) and a data radio bearer (DRB).

[0120] 3. Split Bearer;

[0121] A split bearer means that a bearer uses both the air interface of the primary base station and the air interface of the secondary base station for data transmission, which can greatly improve the data transmission rate.

[0122] Exemplarily, taking the user plane data anchor point (such as the PDCP anchor point) in the secondary base station as an example, for downlink transmission, after the downlink data is transmitted from the core network to the secondary base station, the secondary base station can send the downlink data to the UE through the air interface of the secondary base station, or the secondary base station can also divide the downlink data into two parts, one part is sent to the UE through the air interface of the secondary base station, and the other part is sent to the primary base station through the interface between the base stations and then sent to the UE by the primary base station through the air interface of the primary base station. For uplink transmission, the UE sends uplink data to the primary base station through the air interface of the primary base station. After receiving the uplink data, the primary base station needs to forward the uplink data to the secondary base station through the interface between the primary and secondary base stations, and then the secondary base station sends the uplink data to the core network, so as to achieve the effect of separating uplink and downlink data.

[0123] It should be noted that the PDCP anchor point can be in the primary station or the secondary station. The above is only an example for easy understanding. In the dual-connection scenario, the base station where the PDCP anchor point is located is usually called the PDCP anchor point station, and the other base station is called the non-PDCP anchor point station. Therefore, for uplink transmission, after the non-PDCP anchor point station receives the uplink data from the UE, it needs to forward the uplink data to the PDCP anchor point station, and the PDCP anchor point station delivers it to the core network. That is to say, both uplink and downlink data need to pass through the PDCP anchor point station, resulting in an increased transmission delay of uplink data due to the interface delay between stations.

[0124] To solve the above problems, the present application provides a data transmission method and a data transmission device, which can separate the uplink and downlink data between the terminal device and the core network, and reduce the uplink data transmission delay. It should be noted that the technical solution of the present application can be applied to the above dual-connection scenario, or can be applied to other scenarios with this technical problem, and the present application does not limit this. For the convenience of description, the embodiments of the present application will be described by taking the dual-connection scenario as an example.

[0125] The following will describe in detail the data transmission method provided by the embodiments of the present application with reference to the accompanying drawings. The embodiments provided by the present application can be applied to a communication scenario where a sending device and a receiving device communicate. For example, it can be applied to the Figures 1 to 3 communication system shown above.

[0126] In the embodiments of the present application, before establishing a dual connection, the terminal device establishes a connection with the first network device for uplink and downlink data transmission. Among them, the first network device establishes DRB#1 and tunnel#1. The DRB#1 is used for transmitting the uplink data and downlink data of the first QoS flow between the terminal device and the first network device, and the tunnel#1 is used for transmitting the uplink data and downlink data of the first QoS flow between the first network device and the core network element. In the technical solution of the present application, the uplink data of the first QoS flow is transmitted from the terminal device to the core network element by the first network device through the first DRB and the first tunnel, and the downlink data of the first QoS flow is transmitted from the core network element to the terminal device by the second network device through the second tunnel and the second DRB, so that the uplink and downlink data transmission of the first QoS flow is separated, thereby reducing the transmission delay of the uplink data and improving the transmission performance.

[0127] Figure 4 is a schematic flowchart of the data transmission method 400 provided by the embodiments of the present application. As Figure 4 shown, this method process can be executed by the first network device, the second network device, the terminal device, and the core network element, or can be executed by modules and / or devices (such as chips or integrated circuits, etc.) with corresponding functions installed in the first network device, the second network device, the terminal device, and the core network element. The present application does not limit this. For the convenience of description, the following will be described with the first network device, the second network device, the terminal device, and the core network element as the execution subjects. This method includes the following steps.

[0128] S401, the terminal device obtains the first DRB.

[0129] Among them, the first DRB is used for the terminal device to send the uplink data of the first QoS flow to the first network device, or in other words, the first DRB is used for the first network device to receive the uplink data of the first QoS flow from the terminal device.

[0130] Optionally, in one implementation, the terminal device obtains the first DRB, including: the terminal device receives the first DRB from the first network device, that is, the method includes the following step S402.

[0131] S402, the first network device sends the first configuration information to the terminal device. Correspondingly, the terminal device receives the first configuration information from the first network device.

[0132] Among them, the first configuration information is used to configure the first DRB. Exemplarily, the first configuration information may be RRC configuration information or other configuration information, which is not limited in this application.

[0133] Optionally, before executing step S402, the first network device obtains the first configuration information, including: the first network device generates the first configuration information.

[0134] S403, the terminal device obtains the second DRB.

[0135] Among them, the second DRB is used for the terminal device to receive the downlink data of the first QoS flow from the second network device, or in other words, the second DRB is used for the second network device to send the downlink data of the first QoS flow to the terminal device.

[0136] Optionally, in one implementation, the terminal device obtains the second DRB, including: the terminal device receives the second DRB from the second network device. For example, the terminal device can directly receive the second DRB from the second network device, or the terminal device receives the second DRB from the second network device through the first network device, that is, it includes the following steps S404-S405.

[0137] S404, the second network device sends the second configuration information to the first network device. Correspondingly, the first network device receives the second configuration information from the second network device.

[0138] Among them, the second configuration information is used to configure the second DRB. Exemplarily, the second configuration information may be RRC configuration information or other configuration information, which is not limited in this application.

[0139] Optionally, before executing step S404, the second network device obtains the second configuration information, including: the second network device generates the second configuration information.

[0140] Optionally, in one implementation, the first network device or the second network device may include a CU and / or a DU, or the first network device or the second network device may include an O-CU and / or an O-DU in ORAN. Taking the first network device and the second network device including a CU and a DU as an example, exemplarily, the second network device obtaining the second configuration information may include: the CU of the second network device generating the second configuration information and sending the second configuration information to the DU of the second network device. Exemplarily, the second network device sending the second configuration information to the first network device may include: the DU of the second network device sending the second configuration information to the DU of the first network device. Further optionally, the DU of the first network device may send the second configuration information to the CU of the first network device.

[0141] S405, the first network device sends the second configuration information to the terminal device. Correspondingly, the terminal device receives the second configuration information from the first network device.

[0142] Optionally, in one implementation, the first network device may include a CU and / or a DU, or the first network device may include an O-CU and / or an O-DU in ORAN. Taking the first network device including a CU and a DU as an example, exemplarily, after the CU of the first network device receives the second configuration information from the DU of the first network device, it may send the second configuration information to the terminal device.

[0143] Next, an example is given for the bearer types of the first DRB and the second DRB before and after establishing the dual-connection scenario.

[0144] In the first case, the first DRB may be established by the first network device before establishing the dual connection. At this time, the first DRB is also used for the first network device to send the downlink data of the first QoS flow to the terminal device, or rather, the terminal device can also use the first DRB to receive the downlink data of the first QoS flow from the first network device. That is to say, before establishing the dual connection, the first DRB is used for transmitting the uplink and downlink data of the first QoS flow between the first network device and the terminal device, or rather, the transmission of the uplink and downlink data of the first QoS flow between the terminal device and the core network element (end-to-end) is completed by the first network device.

[0145] In this case, the first DRB established by the first network device may be retained as a UL DRB in the first network device, and the second network device establishes a second DRB as a DL DRB. The following steps can be regarded as an explanation of the negotiation between the first network device and the second network device for the second network device to transmit the downlink data of the first QoS flow to the terminal device after establishing the dual connection.

[0146] Exemplarily, the first configuration information includes the configuration of the first DRB. For example, the configuration of the first DRB includes the mapping relationship between the first QoS flow and the first DRB, where the mapping relationship between the first QoS flow and the first DRB includes that the first DRB is used to carry the uplink data of the first QoS flow. Exemplarily, the second configuration information includes the configuration of the second DRB. For example, the configuration of the second DRB includes the PDCP configuration of the second DRB and / or the RLC configuration of the second DRB, where the PDCP configuration of the second DRB is used to indicate the PDCP bearer of the second DRB, and the RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB.

[0147] Optionally, before performing the above step S404, the second network device may negotiate with the first network device, for example, decided by the first network device or autonomously decided by the second network device, that is, the second network device transmits the downlink data of the first QoS flow for the terminal device, and then the second network device establishes the second DRB.

[0148] In the first implementation manner, the first network device sends a first request message to the second network device. The first request message is used to request the second network device to transmit the downlink data of the first QoS flow for the terminal device, or rather, the first request message is used to request the second network device to establish the second DRB for the downlink data of the first QoS flow. Correspondingly, after receiving the first request message, the second network device determines to transmit the downlink data of the first QoS flow for the terminal device, and then establishes the second DRB, including: configuring the PDCP entity of the second DRB.

[0149] Exemplarily, the first request message includes the information of the first QoS flow. For example, the information of the first QoS flow includes one or more of the following:

[0150] (1) The QoS parameters of the first QoS flow, such as the bit rate required in the QoS parameters, etc.;

[0151] (2) The mapping relationship between the first QoS flow and the first DRB;

[0152] (3) The indication information, which is used to indicate that the second network device transmits the downlink data of the first QoS flow for the terminal device.

[0153] Optionally, the first request message includes the identifier of the DRB allowed to be used by the second network device, such as the second DRB ID.

[0154] Optionally, in response to the received first request message described above, the second network device sends a first response message to the first network device, and the first response message includes second configuration information. Optionally, the first response message can be used to indicate the result of the first network device establishing the second DRB, such as successful establishment or establishment failure. It should be understood that the technical solution of this application is based on the successful establishment of the second DRB, that is, the second network device supports transmitting downlink data of the first QoS flow for the terminal device. Optionally, if the establishment of the second DRB fails, a failure cause value can be carried in the first response message, such as the second network device being overloaded, etc.

[0155] Optionally, in one implementation, the first network device or the second network device may include a CU and / or a DU, or the first network device or the second network device may include an O-CU and / or an O-DU in ORAN. Taking the first network device including a CU and the second network device including a DU as an example, the CU of the first network device establishes the first DRB, and the CU of the first network device sends a first request message to the DU of the second network device. Correspondingly, the DU of the second network device establishes the second DRB, and the DU of the second network device sends a first response message to the CU of the first network device.

[0156] It should be noted that in this implementation, the first network device independently decides to retain the first DRB in the first network device, the second network device newly establishes the second DRB, and allocates the configuration of the second DRB for the terminal device, so that the uplink and downlink data of the first QoS flow are respectively carried on the first DRB and the second DRB. For example, the uplink data of the first QoS flow is sent by the terminal device directly to the core network through the first network device, and the downlink data of the first QoS flow is sent by the core network to the terminal device through the second network device, thereby realizing uplink and downlink data separation.

[0157] In the second implementation, the first network device sends a second request message to the second network device, and the second request message is used to request the second network device to transmit the first QoS flow for the terminal device. Correspondingly, after receiving the second request message, the second network device can independently decide to establish a second DRB for the transmission of downlink data of the first QoS flow, that is, independently decide to transmit the downlink data of the first QoS flow for the terminal device, and then establish the second DRB, including: configuring the PDCP entity of the second DRB.

[0158] Wherein, the second request message includes information about the first QoS flow. For example, the information about the first QoS flow includes one or more of the following:

[0159] (1) QoS parameters of the first QoS flow, such as the required bit rate in the QoS parameters, etc.;

[0160] (2) The mapping relationship between the first QoS flow and the first DRB;

[0161] (3) The configuration of the first DRB, for example, the PDCP configuration of the first DRB and / or the RLC configuration of the first DRB, etc.;

[0162] (4) Indication information, used to indicate that the second network device transmits the downlink data of the first QoS flow for the terminal device.

[0163] Exemplarily, the second network device can determine the uplink bit rate provided by the first network device for the first QoS flow according to the configuration of the first DRB carried in the information of the first QoS flow, and then make a decision. For example, when the uplink bit rate provided by the first network device for the first QoS flow is greater than or equal to the bit rate required in the QoS parameter, the second network device decides that it can transmit the downlink data of the first QoS flow for the terminal device, which also means that the uplink data transmission of this first QoS flow needs to be borne by the first network device, that is, the first network device transmits the uplink data of the first QoS flow for the terminal device, realizing the separate transmission of the uplink and downlink data of the first QoS flow.

[0164] Optionally, in response to the received second request message, the second network device can send a second response message to the first network device. This second response message is used to indicate that the second network device supports transmitting the downlink data of the first QoS flow for the terminal device, and this second response message includes second configuration information. That is to say, based on this second response message, the first network device can determine that the second network device supports transmitting the downlink data of the first QoS flow for the terminal device. Optionally, it can also determine that the downlink data of the first QoS flow is carried on the second DRB. Therefore, the first network device needs to transmit the uplink data of the first QoS flow for the terminal device, that is, the first network device retains the first DRB, and the uplink data of the first QoS flow is carried on the first DRB. Optionally, if the second network device does not support transmitting the first QoS flow for the terminal device, or in other words, the second network device fails to establish the second DRB, the second network device can send a failure cause value to the first network device, such as the second network device being overloaded, etc.

[0165] Optionally, in one implementation, the first network device or the second network device may include a CU and / or a DU. Alternatively, the first network device or the second network device may include an O-CU and / or an O-DU in ORAN. Taking the case where the first network device includes a CU and a DU and the second network device includes a DU as an example, the CU of the first network device may establish a first DRB, and the CU of the first network device sends a second request message to the DU of the first network device, and then the DU of the first network device sends the second request message to the DU of the second network device. Correspondingly, the DU of the second network device establishes a second DRB, and the DU of the second network device sends a first response message to the DU of the first network device, and then the DU of the first network device sends the first response message to the CU of the first network device.

[0166] It should be noted that in this implementation, the second network device independently decides to transmit the downlink data of the first QoS flow, that is, the second network device newly establishes a second DRB and allocates the configuration of the second DRB to the terminal device. At the same time, the first network device transmits the uplink data of the first QoS flow to the terminal device, so that the uplink and downlink data of the first QoS flow are respectively carried on the first DRB and the second DRB. For example, the uplink data of the first QoS flow is sent by the terminal device directly to the core network through the first network device, and the downlink data of the first QoS flow is sent by the core network to the terminal device through the second network device, thereby realizing the separation of uplink and downlink data.

[0167] In the second case, the second DRB may be established by the first network device before the establishment of the dual connection. At this time, the second DRB is also used for the first network device to send the downlink data of the first QoS flow to the terminal device, or rather, the terminal device can also use the second DRB to receive the downlink data of the first QoS flow from the first network device. That is to say, before the establishment of the dual connection, the second DRB is used for transmitting the uplink and downlink data of the first QoS flow between the first network device and the terminal device.

[0168] In this case, the second DRB established by the first network device can be transferred to the second network device as a DL DRB, that is, the second network device can use the second DRB to transmit the downlink data of the first QoS flow. Therefore, it also shows that the first network device needs to re-establish a DRB as an UL DRB, that is, the first network device establishes a first DRB for transmitting the uplink data of the first QoS flow. The following steps can be regarded as an explanation of the negotiation between the first network device and the second network device for the second network device to transmit the downlink data of the first QoS flow to the terminal device after the establishment of the dual connection.

[0169] Exemplarily, the first configuration information includes the configuration of the first DRB. For example, the configuration of the first DRB includes one or more of the following: the PDCP configuration of the first DRB, the RLC configuration of the first DRB, the mapping relationship between the first DRB and the first QoS flow, or the RLC configuration of the second DRB. Among them, the PDCP configuration of the first DRB is used to indicate the PDCP bearer of the first DRB, the RLC configuration of the first DRB is used to indicate the RLC bearer of the first DRB, and the mapping relationship between the first DRB and the first QoS flow includes that the first DRB is used to carry the uplink data of the first QoS flow. Exemplarily, the second configuration information includes the PDCP configuration and the RLC configuration of the second DRB. Among them, the PDCP configuration of the second DRB includes a PDCP re-establishment indication and / or a key indication used by PDCP, and the RLC configuration of the second DRB includes an RLC re-establishment indication or RLC reconfiguration information. The PDCP configuration of the second DRB is used to indicate the PDCP bearer of the second DRB, and the RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB.

[0170] Optionally, this application does not limit the order of obtaining the first DRB and the second DRB in the above steps S401 and S402. For example, the terminal device can obtain the first DRB and the second DRB simultaneously, that is, the above steps S401 and S403 can be combined and executed. Optionally, the above steps S402 and S404 can also be combined and executed, that is, after the first network device generates the first configuration information and receives the second configuration information from the second network device, it can send the first configuration information and the second configuration information to the terminal device simultaneously.

[0171] Optionally, before executing the above step S404, the second network device can negotiate with the first network device, for example, the first network device makes a decision or the second network device makes an independent decision, that is, the second network device transmits the downlink data of the first QoS flow for the terminal device.

[0172] In the first implementation manner, the first network device sends a third request message to the second network device. The third request message is used to request the second network device to transmit the downlink data of the first QoS flow for the terminal device. Correspondingly, after receiving the third request message, the second network device determines to transmit the downlink data of the first QoS flow for the terminal device, and then updates the configuration of the second DRB, including: reconfiguring the PDCP entity of the second DRB.

[0173] Exemplarily, the third request message includes the PDCP configuration of the second DRB, where the PDCP configuration of the second DRB is used to indicate the PDCP bearer of the second DRB.

[0174] Optionally, the third request message includes an identifier of a DRB allowed to be used by the second network device, such as a second DRB ID.

[0175] Optionally, in response to the received third request message, the second network device sends a third response message to the first network device, and the third response message includes second configuration information. Optionally, the third response message may be used to indicate the reconfiguration result of the second DRB, such as successful reconfiguration or failure. It should be understood that the technical solution of this application is based on the successful reconfiguration of the second DRB, that is, the second network device supports transmitting downlink data of the first QoS flow for the terminal device, and the downlink data of the first QoS flow is carried on the second DRB. Optionally, if the second network device does not support transmitting the first QoS flow for the terminal device, or in other words, the reconfiguration of the second DRB fails, the third response message may carry a failure cause value, such as the second network device does not support transmitting downlink data of the first QoS flow for the terminal device.

[0176] Optionally, in one implementation, the first network device or the second network device may include a CU and / or a DU, or the first network device or the second network device may include an O-CU and / or an O-DU in ORAN. Taking the first network device including a DU and the second network device including a CU and a DU as an example, the DU of the first network device establishes a first DRB, and the DU of the first network device sends a third request message to the DU of the second network device. Correspondingly, the DU of the second network device sends a third request message to the CU of the second network device. Then, the CU of the second network device may establish a second DRB, and the CU of the second network device sends a third response message to the DU of the second network device, and then the DU of the second network device sends a third response message to the DU of the first network device.

[0177] It should be noted that in this implementation, the second DRB established by the first network device independently and first is transferred to the second network device as the DL DRB, that is, the second network device does not need to newly establish the second DRB, but only needs to update the configuration of the second DRB. That is to say, the second DRB updated by the second network device is used to transmit the downlink data of the first QoS flow. Therefore, the first network device needs to newly establish a first DRB for transmitting the uplink data of the first QoS flow, that is, the uplink and downlink data of the first QoS flow are respectively carried on the first DRB and the second DRB. For example, the uplink data of the first QoS flow is sent by the terminal device directly to the core network through the first network device, and the downlink data of the first QoS flow is sent by the core network to the terminal device through the second network device, so as to achieve uplink and downlink data separation.

[0178] In the second implementation manner, the first network device sends a fourth request message to the second network device. The fourth request message is used to request the second network device to transmit a first QoS flow for the terminal device. Correspondingly, after receiving the fourth request message, the second network device can autonomously decide to transmit the downlink data of the first QoS flow for the terminal device, and then update the configuration of the second DRB, including: reconfiguring the PDCP entity of the second DRB. The specific implementation manner in which the second network device autonomously decides to transmit the downlink data of the first QoS flow for the terminal device can refer to the relevant description in the above first case and will not be elaborated here.

[0179] Exemplarily, the second request message includes the PDCP configuration of the second DRB, where the PDCP configuration of the second DRB is used to indicate the PDCP bearer of the second DRB.

[0180] Optionally, in response to the received fourth request message, the second network device may send a fourth response message to the first network device. The fourth response message is used to indicate that the second network device supports transmitting the downlink data of the first QoS flow for the terminal device. The fourth response message includes second configuration information. That is, based on the fourth response message, the first network device can determine that the second network device supports transmitting the downlink data of the first QoS flow for the terminal device, and the downlink data of the first QoS flow is carried on the second DRB. Therefore, the first network device needs to transmit the uplink data of the first QoS flow for the terminal device, that is, the first network device creates a new first DRB, and the uplink data of the first QoS flow is carried on the first DRB. Optionally, if the second network device does not support transmitting the first QoS flow for the terminal device, or in other words, the reconfiguration of the second DRB fails, the second network device may send a failure cause value to the first network device, such as the second network device being overloaded, or the second network device not supporting transmitting the downlink data of the first QoS flow for the terminal device.

[0181] Optionally, the mapping relationship between the first QoS flow and the second DRB may not be carried in the second configuration information sent by the second network device. This is because the second DRB is used to carry the downlink data of the first QoS flow, and as the receiving end of the downlink data, the terminal device can directly receive the downlink data of the first QoS flow without knowing the mapping relationship between the first QoS flow and the second DRB.

[0182] Optionally, in one implementation, the first network device or the second network device may include a CU and / or a DU. Alternatively, the first network device or the second network device may include an O-CU and / or an O-DU in ORAN. Taking the first network device including a CU and a DU and the second network device including a CU and a DU as an example, the DU of the first network device establishes a first DRB, and the DU of the first network device sends a fourth request message to the CU of the first network device. Then, the CU of the first network device sends the fourth request message to the CU of the second network device. Correspondingly, the CU of the second network device sends the fourth request message to the DU of the second network device. Then, the DU of the second network device may establish a second DRB, and the DU of the second network device sends a fourth response message to the CU of the second network device. Then, the CU of the second network device sends the fourth response message to the CU of the first network device. Finally, the CU of the first network device sends the fourth response message to the DU of the first network device.

[0183] It should be noted that in this implementation, the second network device independently decides to transmit the downlink data of the first QoS flow, that is, the second network device updates the configuration of the second DRB. At the same time, the first network device newly establishes a first DRB to carry the uplink data of the first QoS flow, so that the uplink and downlink data of the first QoS flow are respectively carried on the first DRB and the second DRB. For example, the uplink data of the first QoS flow is sent by the terminal device directly to the core network through the first network device, and the downlink data of the first QoS flow is sent by the core network to the terminal device through the second network device, thereby realizing the separation of uplink and downlink data.

[0184] In the third case, the first DRB and the second DRB may be established by the first network device before establishing the dual connection. At this time, before executing step S404, the second DRB is used by the first network device to send the downlink data of the first QoS flow to the terminal device. Among them, the second DRB is also established by the first network device. That is to say, before establishing the dual connection, the first network device can configure the first DRB and the second DRB simultaneously through the first configuration information, and the first network device receives the uplink data of the first QoS flow from the terminal device through the first DRB, and sends the downlink data of the first QoS flow to the terminal device through the second DRB.

[0185] Optionally, before configuring the first information, the first network device obtains the capability information of the terminal device, where the capability information of the terminal device is used to indicate that the terminal device supports establishing DRBs for the uplink data and the downlink data of the first QoS flow respectively. Optionally, the capability information of the terminal device may be actively reported by the terminal device to the first network device, or may be obtained by the first network device sending a query message to the terminal device. This application does not make any limitations in this regard.

[0186] Optionally, if the first network device includes an O-CU and an O-DU, the capability information of the terminal device may be obtained by the O-CU or the O-DU of the first network device.

[0187] In this case, the first DRB established by the first network device may be retained as a UL DRB in the first network device, and the second DRB may be transferred to the second network device as a DL DRB, that is, the second network device may use the second DRB to transmit the downlink data of the first QoS flow. The following steps describe how the first network device instructs the second network device to transmit the downlink data of the first QoS flow for the terminal device after the dual connection is established.

[0188] Exemplarily, the first configuration information includes the configuration of the first DRB. For example, the configuration of the first DRB includes one or more of the following: the PDCP configuration of the first DRB, the RLC configuration of the first DRB, the mapping relationship between the first DRB and the first QoS flow, or the RLC configuration of the second DRB. Among them, the PDCP configuration of the first DRB is used to indicate the PDCP bearer of the first DRB, the RLC configuration of the first DRB is used to indicate the RLC bearer of the first DRB, the mapping relationship between the first DRB and the first QoS flow includes that the first DRB is used to carry the uplink data of the first QoS flow, and the RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB. Exemplarily, the second configuration information includes the PDCP configuration and the RLC configuration of the second DRB. Among them, the PDCP configuration of the second DRB includes a PDCP re-establishment indication and / or a key indication used by the PDCP, and the RLC configuration of the second DRB includes an RLC re-establishment indication or RLC re-configuration information. The PDCP configuration of the second DRB is used to indicate the PDCP bearer of the second DRB, and the RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB.

[0189] Optionally, before performing the above step S404, the second network device may instruct the second network device to transmit the downlink data of the first QoS flow for the terminal device.

[0190] In one implementation, the first network device sends third indication information to the second network device. The third indication information is used to instruct the second network device to send the downlink data of the first QoS flow to the terminal device through the second DRB. Correspondingly, the second network device receives the third indication information and updates the configuration of the second DRB, including: reconfiguring the PDCP entity of the second DRB.

[0191] Optionally, in one implementation, the first network device or the second network device may include a CU and / or a DU. Alternatively, the first network device or the second network device may include an O-CU and / or an O-DU in ORAN. Taking the example that the first network device includes a CU and a DU, and the second network device includes a CU and a DU, the DU of the first network device generates or obtains third indication information and sends the third indication information to the CU of the first network device. The CU of the first network device sends the third indication information to the CU of the second network device. Correspondingly, the CU of the second network device sends the third indication information to the DU of the second network device. The DU of the second network device may update the configuration of the second DRB. Further optionally, the DU of the second network device may also send the updated configuration of the second DRB to the first network device through the CU of the second network device, for the second network device and the terminal device to transmit the downlink data of the first QoS flow through the second DRB.

[0192] Optionally, in the embodiments of the present application, the downlink data of the first QoS flow may be transmitted in the form of a split bearer (SN-terminated split bearer), that is, the second network device may send the downlink data of the first QoS flow to the first network device, and the first network device sends it to the terminal device through the air interface of the first network device to improve the transmission efficiency of the downlink data.

[0193] Exemplarily, the second network device sends first indication information to the first network device. The first indication information is used to instruct the first network device to establish an RLC bearer for the second DRB. Correspondingly, after receiving the first indication information, the first network device establishes the RLC bearer of the second DRB and sends the RLC configuration of the second DRB to the terminal device. The RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB.

[0194] Optionally, in one implementation, the first network device includes an O-CU, and the second network device includes an O-DU. After the O-CU of the first network device receives the first indication information from the O-DU of the second network device, it establishes the RLC bearer of the second DRB and sends the RLC configuration of the second DRB to the terminal device, so that the terminal device can determine that it can subsequently receive the downlink data of the first QoS flow from the O-CU of the first network device or from the O-DU of the second network device, thereby improving the data transmission efficiency.

[0195] Based on this implementation method, after the second network device receives the downlink data of the first QoS flow from the core network element, it can directly send a part of the data to the terminal device, and send another part of the data to the first network device through the inter-station interface. The first network device then sends the data to the terminal device through the RLC bearer of the second DRB. That is to say, the terminal device can receive the downlink data of the first QoS flow from the first network device and the second network device.

[0196] Optionally, the first indication information may be sent simultaneously with the second configuration information or may not be sent simultaneously; alternatively, the first indication information and the second configuration information may be carried in one data packet for transmission, or may be carried in two data packets respectively for transmission. This application does not make any limitations in this regard.

[0197] Next, the implementation methods for the establishment or update of the first tunnel between the first network device and the core network element, the second tunnel between the second network device and the core network element, and the third tunnel between the first network device and the second network device will be described.

[0198] Exemplarily, the core network element may be a UPF, an AMF, or other core network elements. For ease of description, in the embodiments of this application, when the core network element is a UPF, the UPF can transmit the uplink and downlink data of the first QoS flow to or from the first network device or the second network device through a tunnel. When the core network element is an AMF, the AMF can establish or update a tunnel for transmitting the uplink and downlink data of the first QoS flow between the UPF and the first network device or the second network device.

[0199] Optionally, in one implementation method, since the downlink data of the first QoS flow can be transmitted in a split bearer manner, the first network device can send the endpoint information indicating the third tunnel to the second network device after establishing the RLC bearer of the second DRB. The third tunnel is the tunnel between the first network device and the second network device and is used for the first network device and the second network device to transmit the downlink data of the first QoS flow. For example, after the second network device receives the downlink data of the first QoS flow from the core network element, it can send the downlink data of the first QoS flow to the first network device through the third tunnel.

[0200] Among them, the endpoint information indicating the third tunnel represents the endpoint information #1 of the third tunnel on the first network device side. The endpoint information #1 includes the endpoint identifier of the first network device and / or the endpoint address information of the first network device. Based on the endpoint information #1, the second network device can determine the information of the third tunnel on the first network device side (such as endpoint #1), and then establish the third tunnel with the first network device. Subsequently, the second network device can send the downlink data of the first QoS flow to this endpoint #1.

[0201] Optionally, the third tunnel may be newly established by the second network device or an existing tunnel between the first network device and the second network device. This application does not make any limitations in this regard.

[0202] Based on the above solution, the second network device supports transmitting the downlink data of the first QoS flow for the terminal device. Next, the implementation manner of establishing the second tunnel between the second network device and the core network element will be described.

[0203] Optionally, in one implementation manner, the first network device sends second indication information to the second network device, where the second indication information is used to instruct the second network device to establish a second tunnel, and the second tunnel is a tunnel between the second network device and the core network element. The second tunnel is used for the second network device to receive the downlink data of the first QoS flow from the core network element. Correspondingly, after receiving the second indication information, the second network device establishes the second tunnel. That is, for the downlink data of the first QoS flow, the second network device can receive the downlink data of the first QoS flow from the core network element through the second tunnel and send the downlink data of the first QoS flow to the terminal device through the second DRB, completing the transmission of the downlink data of the first QoS flow.

[0204] Optionally, if the second network device includes a CU or a DU, the second tunnel may be established by the CU or DU of the second network device.

[0205] Optionally, the second indication information includes endpoint information #2 for indicating the second tunnel, where the endpoint information #2 for indicating the second tunnel represents the endpoint information #2 on the core network element side of the second tunnel. The endpoint information #2 includes the endpoint identifier of the core network element and / or the endpoint address information of the core network element. Correspondingly, based on the endpoint information #2, the second network device can determine the information of the second tunnel on the core network element side (such as endpoint #2), and then establish the second tunnel with the core network element. Subsequently, the second network device can receive the downlink data of the first QoS flow from this endpoint #2.

[0206] Optionally, in one implementation manner, the endpoint information #2 for indicating the second tunnel may be the endpoint information on the core network element side of the first tunnel established between the first network device and the core network element before establishing the dual connection. The endpoint information #2 may be obtained by the first network device from the core network element (such as the AMF). This application does not make any limitations in this regard.

[0207] Optionally, the second indication information may be sent simultaneously with the above first request message, or second request message, or third request message, or fourth request message, or may not be sent simultaneously; alternatively, the second indication information may be sent in a data packet together with the above first request message, or second request message, or third request message, or fourth request message, or may be carried in two data packets separately; alternatively, the second indication information may be carried in the above first request message, or second request message, or third request message, or fourth request message, and this application does not make any limitation in this regard.

[0208] Optionally, in an implementation, after establishing the second tunnel, the second network device may send to the first network device the endpoint information #3 for indicating the second tunnel, where the endpoint information #3 for indicating the second tunnel represents the endpoint information #3 of the second tunnel on the second network device side, and the endpoint information #3 includes the endpoint identifier of the second network device and / or the address information of the second network device. Correspondingly, subsequently, the first network device may send the endpoint information #3 to the core network element, so that the core network element can establish or update the second tunnel. According to the endpoint information #3, the information of the second tunnel on the second network device side (such as endpoint #3) can be determined, and then the core network element may send the downlink data of the first QoS flow to the endpoint #3. For details, refer to the following step S406.

[0209] S406. The first network device sends to the core network element the endpoint information #3 for indicating the second tunnel. Correspondingly, the core network element receives the endpoint information #3 for indicating the second tunnel from the first network device.

[0210] Optionally, if the first network device includes an O-CU and an O-DU, and the second network device includes a CU, after the O-CU of the first network device determines the endpoint information #3, the O-DU of the first network device may send the endpoint information #3, and then the O-DU of the first network device may send the endpoint information #3 to the CU of the second network device. Finally, the CU of the second network device sends the endpoint information #3 to the core network element, which is convenient for the subsequent CU of the second network device and the core network element to transmit the downlink data of the first QoS flow according to the endpoint information #3.

[0211] It should be understood that after receiving the endpoint information #3 for indicating the second tunnel, the core network element establishes or updates the second tunnel.

[0212] Optionally, the endpoint information #3 may be sent simultaneously with the above first response message, or second response message, or third response message, or fourth response message, or may not be sent simultaneously; alternatively, the endpoint information #3 may be carried in a data packet together with the above first response message, or second response message, or third response message, or fourth response message, or may be carried separately in two data packets; alternatively, the endpoint information #3 may be carried in the above first response message, or second response message, or third response message, or fourth response message, and this application does not make any limitation in this regard.

[0213] Optionally, the second tunnel may be newly established between the core network element and the second network device, or may be an existing tunnel between the core network element and the second network device, and this application does not make any limitation in this regard. Based on this, the core network element may determine the information of the second tunnel on the side of the second network device (such as endpoint #3), and then the core network element may send the downlink data of the first QoS flow to this endpoint #3.

[0214] It should be understood that before the establishment of the dual connection, the uplink data of the first QoS flow is transmitted by the first network device and the core network element through the first tunnel. That is to say, the first tunnel is established by the first network device before the establishment of the dual connection, and this first tunnel is used for the first network device to send the uplink data of the first QoS flow to the core network element, or rather, the core network element may send the uplink data of the first QoS flow to the first network device through this first tunnel.

[0215] Optionally, in one implementation manner, the first network device may send a message to the core network element for indicating to retain the first tunnel. It should be understood that retaining the first tunnel may be understood as: indicating to the core network element to retain the endpoint information #4 of the first tunnel on the side of the first network device, or rather, indicating to the core network element not to delete the first tunnel, that is, this first tunnel is still used for transmitting the uplink data of the first QoS flow between the core network element and the first network device. Among them, the endpoint information #4 includes endpoint identification and / or endpoint address information.

[0216] Optionally, the message for indicating to retain the first tunnel may be sent simultaneously with the endpoint information #3 in the above step S406, or may not be sent simultaneously; alternatively, the message for indicating to retain the first tunnel may be carried in a data packet together with the endpoint information #3 in the above step S406, or may be carried separately in two data packets, and this application does not make any limitation in this regard.

[0217] Based on this, the core network element may transmit the uplink data of the first QoS flow with the first network device through the first tunnel, and / or the core network element may transmit the downlink data of the first QoS flow with the second network device through the second tunnel.

[0218] Optionally, in one implementation, the endpoint information of the first tunnel on the core network element side may be the same as or different from the endpoint information of the second tunnel on the core network element side. This application does not limit this.

[0219] For example, if the endpoint information of the first tunnel on the core network element side is the same as the information of the second tunnel on the core network element side, such as the above endpoint #2, it means that endpoint #2 on the core network element side is associated with the first tunnel and the second tunnel. As shown in (a) of Figure 5 , subsequently, the first network device sends the uplink data of the first QoS flow to endpoint #2, and the second network device also receives the downlink data of the first QoS flow from endpoint #2.

[0220] For another example, if the endpoint information of the first tunnel on the core network element side is different from the endpoint of the second tunnel on the core network element side, the core network element may send endpoint information #5 to the first network device. This endpoint information #5 represents the endpoint information #5 on the core network element side. The endpoint #5 indicated by the endpoint information #5 and the endpoint #2 on the core network element side are two different endpoints, which are respectively used as the endpoints of the first tunnel and the second tunnel on the core network element side. That is to say, the first tunnel and the second tunnel are two independent tunnels. The core network element may receive the uplink data of the first QoS flow from the first network device from endpoint #5, and / or the core network element may send the downlink data of the first QoS flow to the second network device from endpoint #2, as shown in (b) of Figure 5

[0221] Based on the above first DRB, second DRB, first tunnel, and second tunnel, the terminal device and the core network element can transmit the uplink data of the first QoS flow and / or the downlink data of the first QoS flow. In one implementation, the transmission process of the uplink and downlink data of the first QoS flow includes the following steps S407 - S410. Among them, S407 and S408 are the transmission methods of the uplink data of the first QoS flow, and S409 and S410 are the transmission methods of the downlink data of the first QoS flow.

[0222] S407, the terminal device sends the uplink data of the first QoS flow to the first network device through the first DRB. Correspondingly, the first network device receives the uplink data from the first QoS flow through the first DRB.

[0223] S408, the first network device sends the uplink data of the first QoS flow to the core network element through the first tunnel. Correspondingly, the core network element receives the uplink data from the first network device through the first tunnel.

[0224] S409. The core network element sends the downlink data of the first QoS flow to the second network device through the second tunnel. Correspondingly, the second network device receives the downlink data of the first QoS flow from the core network element through the second tunnel.

[0225] S410. The second network device sends the downlink data of the first QoS flow to the terminal device through the second DRB. Correspondingly, the terminal device receives the downlink data of the first QoS flow from the second network device through the second DRB.

[0226] Optionally, in one implementation, when the downlink data of the first QoS flow is transmitted in a split bearer manner, the second network device may send a part of the downlink data of the first QoS flow to the terminal device through the second DRB, and send another part of the downlink data of the first QoS flow to the first network device through the third tunnel. The first network device sends it to the terminal device through the RLC bearer of the second DRB to improve the transmission rate of the downlink data of the first QoS flow.

[0227] Optionally, in the embodiments of the present application, if the first network device or the second network device includes a CU and a DU, for the implementation manners provided above, the actions of sending and receiving messages or data (such as the first configuration information, the second configuration information, the first request message, or the second request message, etc.) may be performed by the DU, and the actions of executing or processing the content of the message or data may be performed by the CU; or, the actions of sending and receiving messages or data may be performed by the CU, and the actions of executing or processing the content of the message or data may be performed by the DU. The present application does not limit this.

[0228] It should be noted that for the Figure 4 scheme shown above, by executing steps S401, S403, S407 to S410, the uplink and downlink data of the first QoS flow on the terminal device side can be separated and transmitted, improving the end-to-end transmission performance between the terminal device and the core network element. Among them, one or more of steps S402, S404, S405, or S406 are optional steps, which are only an optional example for easy understanding and can be all executed, or partially executed, or not executed at all. The present application does not limit this.

[0229] Based on the above solution, the uplink data of the first QoS flow is transmitted from the terminal device to the core network element by the first network device through the first DRB and the first tunnel, and the downlink data of the first QoS flow is transmitted from the core network element to the terminal device by the second network device through the second DRB and the second tunnel. Optionally, the downlink data of the first QoS flow can also be transmitted by the second network device to the first network device, and then transmitted by the first network device to the terminal device, realizing the separate transmission of the uplink and downlink data of the first QoS flow. At the same time, the uplink data of the first QoS flow does not need to be forwarded by the second network device and can be transmitted by the first network device to the core network element, which can reduce the transmission delay of the uplink data of the first QoS flow and improve the transmission performance.

[0230] Next, the protocol stacks in the following three cases in the above method 400 will be described. Figures 6 to 8

[0231] Figure 6 FIG. is a schematic diagram of a protocol stack provided by an embodiment of the present application. For the first case, as shown in (a) of Figure 6 Before establishing the dual connection, data is transmitted between the terminal device and the core network element through the first network device. For example, the first network device establishes DRB#1 and tunnel#1. For uplink transmission, the terminal device sends uplink data to the first network device through DRB#1, and the first network device then sends the uplink data to the core network element through tunnel#1. For downlink transmission, the core network element sends downlink data to the first network device through tunnel#1, and the first network device then sends the downlink data to the terminal device through DRB#1, that is, the uplink and downlink data between the terminal device and the core network element are transmitted by the first network device through DRB#1 and tunnel#1.

[0232] As shown in Figure 6 ​As shown in (b), after the establishment of the dual connection, the previously established DRB#1 and tunnel#1 of the first network device are used for the transmission of the uplink data of the first QoS flow. The second network device newly establishes DRB#2 and tunnel#2 for the transmission of the downlink data of the first QoS flow. It can be seen from the figure that the second network device side includes the SDAP layer, PDCP layer, RLC layer, MAC layer and PHY layer of DRB#2, and the second network device sends the DRB#2 configuration to the terminal device for the terminal device to newly establish DRB#2. The terminal device side includes the SDAP layer, PDCP layer, RLC layer, MAC layer and PHY layer of DRB#2. For example, for uplink transmission, the terminal device sends uplink data to the first network device through DRB#1, and the first network device then sends the uplink data to the core network element through tunnel#1; for downlink transmission, the core network element sends downlink data to the second network device through tunnel#2, and the second network device then sends the downlink data to the terminal device through DRB#2. That is, the uplink data of the first QoS flow is transmitted by the first network device through DRB#1 and tunnel#1, and the downlink data of the first QoS flow is transmitted by the first network device through DRB#2 and tunnel#2.

[0233] Optionally, the downlink data of the first QoS flow can also be transmitted in a split bearer manner. For example, the first network device side newly establishes the RLC bearer of DRB#2 and sends the RLC configuration of DRB#2 to the terminal device. That is, after the second network device receives the downlink data from the core network element, the second network device can directly send a part of the downlink data to the terminal device, and send another part of the downlink data to the first network device through the inter-station interface. The first network device then sends it to the terminal device through the RLC bearer of DRB#2.

[0234] Figure 7 It is a schematic diagram of a protocol stack provided by an embodiment of the present application. For the second case, as Figure 7 As shown in (a), before the establishment of the dual connection, data is transmitted between the terminal device and the core network element through the first network device. For example, the first network device establishes DRB#2 and tunnel#1. For uplink transmission, the terminal device sends uplink data to the first network device through DRB#2, and the first network device then sends the uplink data to the core network element through tunnel#1; for downlink transmission, the core network element sends downlink data to the first network device through tunnel#1, and the first network device then sends the downlink data to the terminal device through DRB#2. That is, the uplink and downlink data between the terminal device and the core network element are transmitted by the first network device through DRB#2 and tunnel#1.

[0235] Such as Figure 7As shown in (b), after the dual connection is established, the previously established DRB#2 of the first network device is used by the second network device to transmit the downlink data of the first QoS flow, and the first network device newly creates DRB#2 to transmit the uplink data of the first QoS flow. It can be seen from the figure that the first network device side includes the SDAP layer, PDCP layer, RLC layer, MAC layer, and PHY layer of DRB#1, and the first network device sends the DRB#1 configuration to the terminal device for the terminal device to establish DRB#1. The terminal device side includes the SDAP layer, PDCP layer, RLC layer, MAC layer, and PHY layer of DRB#1. For example, for uplink transmission, the terminal device sends uplink data to the first network device through DRB#1, and the first network device then sends the uplink data to the core network element through tunnel#1; for downlink transmission, the core network element sends downlink data to the second network device through tunnel#2, and the second network device then sends the downlink data to the terminal device through DRB#2. That is, the uplink data of the first QoS flow is transmitted by the first network device through DRB#1 and tunnel#1, and the downlink data of the first QoS flow is transmitted by the first network device through DRB#2 and tunnel#2.

[0236] Optionally, the downlink data of the first QoS flow can also be transmitted in a split bearer manner. For example, the first network device side newly creates the RLC bearer of DRB#2 and sends the RLC configuration of DRB#2 to the terminal device. That is, after the second network device receives the downlink data from the core network element, the second network device can directly send a part of the downlink data to the terminal device, and send another part of the downlink data to the first network device through the inter-station interface. The first network device then sends it to the terminal device through the RLC bearer of DRB#2.

[0237] Figure 8 It is a schematic diagram of a protocol stack provided by an embodiment of the present application. For the third case, as Figure 8 As shown in (a), before the dual connection is established, data is transmitted between the terminal device and the core network element through the first network device. For example, the first network device establishes DRB#1, DRB#2, and tunnel#1. For uplink transmission, the terminal device sends uplink data to the first network device through DRB#1, and the first network device then sends the uplink data to the core network element through tunnel#1; for downlink transmission, the core network element sends downlink data to the first network device through tunnel#1, and the first network device then sends the downlink data to the terminal device through DRB#2. That is, the uplink and downlink data between the terminal device and the core network element are transmitted by the first network device through DRB#1, DRB#2, and tunnel#1.

[0238] As Figure 8As shown in (b) of , after the dual connection is established, the previously established DRB #1 and tunnel #1 of the first network device are used for the first network device to transmit the uplink data of the first QoS flow, and DRB #2 is used for the second network device to transmit the downlink data of the first QoS flow. In addition, the second network device newly creates tunnel #2 for the uplink and downlink data transmission between the core network element and the second network device. For example, for uplink transmission, the terminal device sends uplink data to the first network device through DRB #1, and the first network device then sends the uplink data to the core network element through tunnel #1; for downlink transmission, the core network element sends downlink data to the second network device through tunnel #2, and the second network device then sends the downlink data to the terminal device through DRB #2. That is, the uplink data of the first QoS flow is transmitted by the first network device through DRB #1 and tunnel #1, and the downlink data of the first QoS flow is transmitted by the first network device through DRB #2 and tunnel #2.

[0239] Optionally, the downlink data of the first QoS flow can also be transmitted in a split bearer manner. For example, the first network device newly creates the RLC bearer of DRB #2 and sends the RLC configuration of DRB #2 to the terminal device. That is, after the second network device receives the downlink data from the core network element, the second network device can directly send a part of the downlink data to the terminal device, and send another part of the downlink data to the first network device through the inter-station interface. The first network device then sends it to the terminal device through the RLC bearer of DRB #2.

[0240] As described above in combination with Figures 1 to 8 the method embodiments of the present application for data transmission have been described. Next, the device embodiments of the present application for data transmission will be described in detail in combination with Figure 9 and Figure 10 It should be understood that the description of the device embodiments corresponds to the description of the method embodiments. Therefore, for the parts not described in detail, reference can be made to the previous method embodiments.

[0241] Figure 9 is a schematic diagram of a data transmission device 1000 provided by an embodiment of the present application. As shown in Figure 9As shown in the figure, the data transmission device 1000 includes a communication module 1002. Optionally, it may further include a processing module 1001. The data transmission device 1000 may be a first network device (such as an MN), or it may be a data transmission device applied to the first network device or used in conjunction with the first network device and capable of implementing the methods executed by the first network device, such as a chip, a chip system, or a circuit. Alternatively, the data transmission device 1000 may be a second network device (such as an SN), or it may be a data transmission device applied to the second network device or used in conjunction with the second network device and capable of implementing the methods executed by the second network device, such as a chip, a chip system, or a circuit. Alternatively, the data transmission device 1000 may be a terminal device (such as a UE), or it may be a data transmission device applied to the terminal device or used in conjunction with the terminal device and capable of implementing the methods executed by the terminal device, such as a chip, a chip system, or a circuit. Alternatively, the data transmission device 1000 may be a core network element (such as an AMF / UPF), or it may be a data transmission device applied to the core network element or used in conjunction with the core network element and capable of implementing the methods executed by the core network element, such as a chip, a chip system, or a circuit.

[0242] Among them, the communication module may also be referred to as a transceiver module, a transceiver, a transceiver unit, or a transceiver device, etc. The processing module may also be referred to as a processor, a processing board, a processing unit, or a processing device, etc. Optionally, the communication module is used to perform the sending and receiving operations of the first network device, the second network device, the terminal device, or the core network element in the above methods. The devices in the communication module used to implement the receiving function can be regarded as a receiving unit, and the devices in the communication module used to implement the sending function can be regarded as a sending unit. That is, the communication module includes a receiving unit and a sending unit.

[0243] When the data transmission device 1000 is applied to the first network device, the processing module 1001 can be used to implement the processing function of the first network device in the above embodiments, and the communication module 1002 can be used to implement the sending and receiving functions of the first network device in the above embodiments.

[0244] When the data transmission device 1000 is applied to the second network device, the processing module 1001 can be used to implement the processing function of the second network device in the above embodiments, and the communication module 1002 can be used to implement the sending and receiving functions of the second network device in the above embodiments.

[0245] When the data transmission device 1000 is applied to the terminal device, the processing module 1001 can be used to implement the processing function of the terminal device in the above embodiments, and the communication module 1002 can be used to implement the sending and receiving functions of the terminal device in the above embodiments.

[0246] When the data transmission device 1000 is applied to a core network element, the processing module 1001 can be used to implement the processing functions of the core network element in the above embodiments, and the communication module 1002 can be used to implement the receiving and transmitting functions of the core network element in the above embodiments.

[0247] In addition, it should be noted that the foregoing communication module and / or processing module can be implemented by a virtual module. For example, the processing module can be implemented by a software functional unit or a virtual device, and the communication module can be implemented by a software function or a virtual device. Alternatively, the processing module or the communication module can also be implemented by a physical device. For example, if the device is implemented by a chip / circuit (such as an integrated circuit or a logic circuit, etc.). The communication module can be an input / output circuit and / or a communication interface, and performs an input operation (corresponding to the foregoing receiving operation) and an output operation (corresponding to the foregoing sending operation); the processing module is an integrated processor or a microprocessor or a circuit (such as an integrated circuit or a logic circuit, etc.).

[0248] The division of modules in this application is illustrative, and is only a logical function division. In actual implementation, there may be other division methods. In addition, in each example of this application, each functional module can be integrated in one processor, can also exist independently physically, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0249] Figure 10 It is a schematic diagram of another data transmission device 2000 provided by an embodiment of this application. As Figure 10 shown, optionally, the data transmission device 2000 can be a chip or a chip system. Optionally, in this application, a chip system can be composed of chips, or can include chips and other discrete devices.

[0250] The data transmission device 2000 can be used to implement the functions of any network element (such as a first network device, a second network device, a terminal device, or a core network element) in the communication system described in the foregoing examples. The data transmission device 2000 can include a communication interface 2030, and the data transmission device 2000 can interact with other devices through the communication interface 2030. Exemplarily, the communication interface 2030 can be a transceiver, a circuit, a bus, a module, a pin, or other types of communication interfaces. When the data transmission device 2000 is a chip-type device or a circuit, the communication interface 2030 in the device 2000 can also be an input / output circuit, which can input information (or, receive information) and output information (or, send information), and the processor 2010 is an integrated processor, a microprocessor, an integrated circuit, or a logic circuit, etc., and the processor can determine the output information according to the input information.

[0251] The data transmission device 2000 may further include at least one processor 2010. Optionally, the processor 2010 is coupled to a memory, which may be located within the device, or the memory may be integrated with the processor, or the memory may be located outside the device. For example, the data transmission device 2000 may further include at least one memory 2020. The memory 2020 stores the necessary computer programs, computer programs or instructions and / or data for implementing any of the above examples; the processor 2010 may execute the computer programs stored in the memory 2020 to complete the methods in any of the above examples.

[0252] The coupling in this application is an indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information interaction between devices, units or modules. The processor 2010 may cooperate with the memory 2020 and the communication interface 2030. In this application, the specific connection medium between the above-mentioned processor 2010, memory 2020 and communication interface 2030 is not limited.

[0253] Optionally, as Figure 10 shown, the processor 2010, the memory 2020 and the communication interface 2030 are interconnected via a bus 2040. Optionally, the bus may include types of buses such as an address bus, a data bus, a control bus, etc. In addition, for the sake of representation, Figure 10 only one bus 2040 is shown in

[0254] It should be understood that the processor mentioned in the embodiments of this application may be the following devices or a part of the circuit for processing functions in the following devices: a central processing unit (CPU), and may also be other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0255] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, the RAM can be used as an external cache. By way of example and not limitation, the RAM includes the following various forms: static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0256] It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, the memory (storage module) may be integrated in the processor.

[0257] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0258] The embodiments of the present application also provide a computer-readable storage medium, on which computer instructions for implementing the methods executed by the first network device, the second network device, the terminal device, or the core network element in the above method embodiments are stored.

[0259] The embodiments of the present application also provide a computer program product, including instructions, which when executed by a computer, implement the methods executed by the first network device, the second network device, the terminal device, or the core network element in the above method embodiments.

[0260] An embodiment of this application further provides a communication system, which includes one or more of the first network device, the second network device, or the core network element in the above embodiments. Optionally, the communication system further includes a terminal device.

[0261] For the explanations and beneficial effects of the relevant content in any of the above provided devices, reference can be made to the corresponding method embodiments provided above, and details will not be described herein.

[0262] For the convenience of understanding the above embodiments provided in this application, the following points are explained:

[0263] 1) In this application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0264] 2) In this application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or multiple items (items). For example, at least one (item) of a, b, and c can represent: a, or, b, or, c, or, a and b, or, a and c, or, b and c, or, a, b, and c. Where a, b, and c can be single or multiple respectively.

[0265] 3) In this application, "first", "second", and various numerical numbers (for example, #1, #2, etc.) are used for distinction for the convenience of description, and are not used to limit the scope of the embodiments of this application. For example, to distinguish different messages, etc., rather than for describing a specific order or sequence. It should be understood that the objects described in this way can be interchanged under appropriate circumstances so as to be able to describe the solutions other than the embodiments of this application.

[0266] 4) In this application, descriptions such as "when...", "in the case of...", and "if" all refer to the device will make corresponding processing under a certain objective situation, not to limit time, and it is not required that the device must have a judgment action when implemented, nor does it mean that there are other limitations.

[0267] 5) In this application, "for indicating" may include direct indication and indirect indication. When it is described that a certain indication information is used to indicate A, it may include that the indication information directly indicates A or indirectly indicates A, and it does not necessarily mean that A is carried in the indication information.

[0268] The indication methods involved in the embodiments of this application should be understood to cover various methods that can enable the party to be indicated to obtain the indication information. The indication information can be sent as a whole, or can be divided into multiple sub-information and sent separately, and the sending periods and / or sending timings of these sub-information can be the same or different. This application does not limit, for example, the sending method.

[0269] The "indication information" in the embodiments of this application can be explicit indication, that is, directly indicated by signaling, or obtained by combining other rules or other parameters or by derivation according to the parameters indicated by the signaling. It can also be implicit indication, that is, obtained according to rules or relationships, or other parameters, or by derivation. This application does not make specific limitations on this.

[0270] 6) In this application, "protocol" may refer to standard protocols in the communication field. For example, it may include 5G protocols, NR protocols, and related protocols applied to future communication systems. This application does not make limitations on this. "Pre-defined" may include pre-definition. For example, protocol definition. "Pre-configuration" can be implemented by pre-saving corresponding codes, tables, or other ways that can be used to indicate relevant information in the device. This application does not limit, for example, its implementation method.

[0271] 7) In this application, "communication" can also be described as "data transmission", "information transmission", "data processing", etc. "Transmission" includes "sending" and "receiving".

[0272] In this application, configuration may refer to signaling configuration, and can also be described as configuration signaling. For example, the signaling configuration can be configured by a second device (such as a network device) sending signaling, and these signals can be radio resource control (RRC) messages, downlink control information (DCI), or system information block (SIB). For another example, the signaling configuration can be pre-configured signaling sent to the first device (such as a terminal device), or configured for the first device (such as a terminal device) in a pre-configured manner. Here, the pre-configuration is to pre-define or configure the value of the corresponding parameter in a protocol manner, and can be stored in the first device (such as a terminal device) when communicating with the first device (such as a terminal device). This application does not make limitations on this.

[0273] In various embodiments of the present application, the sequence numbers of the above processes do not indicate the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0274] In the present application, on the premise of no logical contradiction, the examples can refer to each other. For example, the methods and / or terms between method embodiments can refer to each other, for example, the functions and / or terms between device embodiments can refer to each other, for example, the functions and / or terms between device examples and method examples can refer to each other.

[0275] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0276] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be described herein again.

[0277] In several embodiments provided by the present 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 example, the division of units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces, and the indirect coupling or communication connection of devices or units can be in an electrical, mechanical, or other form.

[0278] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0279] In addition, the functional units in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0280] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0281] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A data transmission method, characterized in that, Including: Sending first configuration information to a terminal device, where the first configuration information is used to configure a first data radio bearer (DRB), and the first DRB is used for a first network device to receive uplink data of a first quality of service (QoS) flow; Sending second configuration information to the terminal device, where the second configuration information is used to configure a second DRB, and the second DRB is used for receiving downlink data of the first QoS flow from a second network device.

2. The method according to claim 1, characterized in that, Before sending the second configuration information to the terminal device, the method further includes: Receiving second configuration information from the second network device.

3. The method according to claim 1 or 2, characterized in that Before sending the second configuration information to the terminal device, the first DRB is further used for the first network device to send downlink data of the first QoS flow.

4. The method according to claim 3, wherein Before receiving the second configuration information from the second network device, the method further includes: Sending a first request message to the second network device, where the first request message is used to request the second network device to transmit downlink data of the first QoS flow for the terminal device, and the first request message includes information about the first QoS flow.

5. The method according to claim 3, characterized in that, Before receiving the second configuration information from the second network device, the method further includes: Sending a second request message to the second network device, where the second request message is used to request the second network device to transmit the first QoS flow for the terminal device, and the second request message includes information about the first QoS flow.

6. The method according to claim 1 or 2, characterized in that, Before sending the second configuration information to the terminal device, the second DRB is used for the first network device to receive uplink data of the first QoS flow, and for the first network device to send downlink data of the first QoS flow.

7. The method according to claim 6, characterized in that, Before receiving the second configuration information from the second network device, the method further includes: Sending a third request message to the second network device, where the third request message is used to request the second network device to transmit downlink data of the first QoS flow for the terminal device, and the third request message includes the packet data convergence protocol (PDCP) configuration of the second DRB, and the mapping relationship between the second DRB and the first QoS flow.

8. The method according to claim 6, characterized in that, Before receiving the second configuration information from the second network device, the method further includes: Sending a fourth request message to the second network device, where the fourth request message is used to request the second network device to transmit the first QoS flow for the terminal device, and the fourth request message includes the PDCP configuration of the second DRB, and the mapping relationship between the second DRB and the first QoS flow.

9. The method according to any one of claims 4 to 8, characterized in that The receiving the second configuration information from the second network device includes: Receiving a response message from the second network device, where the response message is used to indicate that the second network device transmits downlink data of the first QoS flow for the terminal device, and the response message includes the second configuration information.

10. The method according to claim 1 or 2, characterized in that, Before sending the second configuration information to the terminal device, the first configuration information is further used to configure the second DRB, and the second DRB is used for the first network device to send downlink data of the first QoS flow.

11. The method according to claim 10, wherein Before receiving the second configuration information from the second network device, the method further includes: Sending third indication information to the second network device, where the third indication information is used to indicate that the second network device sends downlink data of the first QoS flow to the terminal device through the second DRB.

12. The method according to claim 10 or 11, characterized in that, Before sending the first configuration information to the terminal device, the method further includes: Obtaining capability information of the terminal device, where the capability information is used to indicate that the terminal device supports establishing DRBs for uplink data and downlink data of the first QoS flow respectively.

13. The method according to any one of claims 1 to 12, characterized in that, The method further includes: Receiving first indication information from the second network device, where the first indication information is used to indicate that the first network device establishes a radio link control (RLC) bearer for the second DRB.

14. The method according to claim 13, wherein The method further includes: Sending RLC configuration of the second DRB to the terminal device, where the RLC configuration of the second DRB is used to indicate the RLC bearer of the second DRB.

15. The method according to claim 13 or 14, characterized in that, The method further includes: Sending endpoint information for indicating a third tunnel to the second network device, where the third tunnel is used for the first network device to receive downlink data of the first QoS flow from the second network device.

16. The method according to any one of claims 1 to 15, characterized in that, The method further includes: Sending second indication information to the second network device, where the second indication information is used to indicate that the second network device establishes a second tunnel, and the second tunnel is used for the second network device to receive downlink data of the first QoS flow from a core network element.

17. The method according to claim 16, wherein The method further includes: Sending endpoint information for indicating the second tunnel to the core network element.

18. The method according to any one of claims 1 to 17, characterized in that The method further includes: Sending a message for indicating to retain a first tunnel to the core network element, where the first tunnel is established by the first network device, and the first tunnel is used for the first network device to send uplink data of the first QoS flow to the core network element.

19. A data transmission method, characterized in that, Includes: Obtaining a first data radio bearer (DRB), where the first DRB is used for the terminal device to send uplink data of a first quality of service (QoS) flow to the first network device; Obtaining a second DRB, where the second DRB is used for the terminal device to receive downlink data of the first QoS flow from the second network device; Sending uplink data of the first QoS flow to the first network device through the first DRB, and / or receiving downlink data of the first QoS flow from the second network device through the second DRB.

20. The method according to claim 19, wherein The obtaining of the first DRB includes: Obtaining the first DRB from the first network device.

21. The method according to claim 19 or 20, characterized in that, Before obtaining the second DRB, the first DRB is further used for the terminal device to receive downlink data of the first QoS flow from the first network device.

22. The method according to claim 19, wherein The obtaining of the first DRB includes: Receiving first configuration information, where the first configuration information is used to configure the first DRB.

23. The method according to claim 22, wherein The obtaining of the second DRB includes: Receiving second configuration information, where the second configuration information is used to configure the second DRB.

24. The method according to any one of claims 19 to 23, characterized in that, The method further includes: Obtaining the radio link control (RLC) configuration of the second DRB, where the RLC configuration of the second DRB is used to configure the RLC bearer of the second DRB; Receiving the downlink data of the first QoS flow from the first network device through the RLC bearer of the second DRB.

25. A data transmission device, characterized in that, Including: A module or unit for implementing the method according to any one of claims 1 to 24.

26. A data transmission device, characterized in that, Including at least one processor, where the at least one processor is coupled to at least one memory, and the at least one processor is configured to execute computer programs or instructions stored in the at least one memory, so that the communication device executes the method according to any one of claims 1 to 24.

27. A chip, characterized in that, Including a communication interface, where the communication interface is configured to receive data and / or information, and transmit the received data and / or information to a processor, and the processor processes the data and / or information to execute the method according to any one of claims 1 to 24.

28. A computer-readable storage medium, characterized in that, For storing computer program code or instructions, where the computer program code or instructions are used to implement the method according to any one of claims 1 to 24.

29. A computer program product, characterized in that, The computer program product includes computer program code or instructions, and when the computer program code or instructions are run by a data transmission device, the data transmission device is caused to execute the method according to any one of claims 1 to 24.

30. A communication system, characterized in that, Including a first network device and a terminal device, where the first network device is configured to execute the method according to any one of claims 1 to 18, and the terminal device is configured to execute the method according to any one of claims 19 to 24.

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