Data transmission method and apparatus, and device, chip and storage medium

Abstract

The embodiments of the present application are applied to a terminal device. Provided is a data transmission method. The method comprises: sending first uplink data and second uplink data to a first network device, wherein the first uplink data and the second uplink data are processed by means of the same media access control (MAC) entity of a terminal device, the first uplink data is sent on the basis of first configuration information, and the second uplink data is sent on the basis of second configuration information.

Description

A data transmission method, device, apparatus, chip and storage medium TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of communication technology, and in particular to a data transmission method, device, apparatus, chip and storage medium. BACKGROUND

[0002] In the current mobility mechanism, the terminal device needs to reconstruct the protocol stack from the media access control (MAC) layer to the packet data convergence protocol (PDCP) layer or perform dual active protocol stack (DAPS) handover when performing handover. The protocol stack from the MAC layer to the PDCP layer is reconstructed, which causes a large data interruption delay. The DAPS handover needs to maintain two sets of MAC entities at the same time, which requires a higher capability / implementation complexity of the terminal device. Therefore, in the scenario of performing handover by the terminal device, how to reduce the data interruption delay and the implementation complexity is a problem to be solved.

[0003] SUMMARY

[0004] Embodiments of the present application provide a data transmission method, device, apparatus, chip and storage medium.

[0005] In a first aspect, embodiments of the present application provide a data transmission method applied to a terminal device, the method comprising: sending first uplink data and second uplink data to a first network device, the first uplink data and the second uplink data being processed via a same media access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0006] In a second aspect, embodiments of the present application provide a data transmission method applied to a first network device, the method comprising: receiving first uplink data and second uplink data sent by a terminal device, the first uplink data and the second uplink data being processed via a same media access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0007] In a third aspect, an embodiment of the present application provides a data transmission method applied to a second network device, the second network device being connected with a terminal device through a first network device, and the second network device being a source network device of the terminal device or a network device connected with the terminal device before performing handover, the method comprising: receiving first uplink data and second uplink data sent by the first network device, the first uplink data and the second uplink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0008] In a fourth aspect, an embodiment of the present application provides a data transmission method applied to a terminal device, the method comprising: receiving first downlink data and second downlink data sent by a first network device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

[0009] In a fifth aspect, an embodiment of the present application provides a data transmission method applied to a first network device, the method comprising: sending first downlink data and second downlink data to a terminal device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

[0010] In a sixth aspect, an embodiment of the present application provides a data transmission method applied to a second network device, the second network device being connected with a terminal device through a first network device, and the second network device being a source network device of the terminal device or a network device connected with the terminal device before performing handover, the method comprising: sending first downlink data to the first network device; or sending first downlink data and second downlink data to the first network device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information; the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device.

[0011] In a seventh aspect, an embodiment of the present application provides a data transmission apparatus, the apparatus comprising: a first communication unit configured to send first uplink data and second uplink data to a first network device, the first uplink data and the second uplink data being processed by a same medium access control (MAC) entity of the apparatus; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0012] In an eighth aspect, an embodiment of the present application provides a data transmission apparatus, the apparatus comprising: a second communication unit configured to receive first uplink data and second uplink data sent by a terminal device, the first uplink data and the second uplink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0013] In a ninth aspect, an embodiment of the present application provides a data transmission apparatus, the apparatus being connected with a terminal device through a first network device, and the apparatus being a source network device of the terminal device or a network device connected before handover of the terminal device is performed, the apparatus comprising: a third communication unit configured to receive first uplink data and second uplink data sent by the first network device, the first uplink data and the second uplink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0014] In a tenth aspect, an embodiment of the present application provides a data transmission apparatus, the apparatus comprising: a fourth communication unit configured to receive first downlink data and second downlink data sent by a first network device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the apparatus; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

[0015] In an eleventh aspect, an embodiment of the present application provides a data transmission apparatus, the apparatus comprising: a fifth communication unit configured to send first downlink data and second downlink data to a terminal device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

[0016] In a twelfth aspect, an embodiment of the present application provides a data transmission apparatus, the apparatus being connected with a terminal device through a first network device, and the apparatus being a source network device of the terminal device or a network device connected before handover of the terminal device is performed, the apparatus comprising: a sixth communication unit configured to send first downlink data to the first network device; or send first downlink data and second downlink data to the first network device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information; the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device.

[0017] In a thirteenth aspect, an embodiment of the present application provides a communication device, comprising: a memory configured to store a computer program; a processor connected to the memory, configured to invoke and run the computer program from the memory, and implement the method according to any one of the first aspect to the sixth aspect; and a transceiver configured to receive and send information in a process of transmitting information with other devices.

[0018] In a fourteenth aspect, an embodiment of the present application provides a chip. The chip comprises: a processor configured to invoke and run a computer program from a memory, so that a device installed with the chip implements the method according to any one of the first aspect to the sixth aspect; and a transceiver configured to receive and send information in a process of transmitting information with devices or chips.

[0019] In a fifteenth aspect, an embodiment of the present application provides a computer readable storage medium configured to store a computer program, the computer program causing a computer to implement the method according to any one of the first aspect to the sixth aspect.

[0020] In the embodiment of the present application, the terminal device can send first uplink data and second uplink data to the first network device, and the first uplink data and the second uplink data can be processed via a same MAC entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information. That is, the terminal device can use the same MAC entity to process data transmitted based on different configuration information. In this way, the terminal device does not need to rebuild the MAC entity or maintain two sets of MAC entities during the execution of the handover. Compared with the method of rebuilding the protocol stack from the MAC layer to the PDCP layer, the method reduces the data interruption delay because the MAC entity does not need to be rebuilt. Compared with the method of performing DAPS handover, the method reduces the capability requirement and implementation complexity of the terminal device because two sets of MAC entities do not need to be maintained. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, illustrate certain illustrative embodiments of the present application and together with the description help explain the present application. In the drawings:

[0022] FIG. 1 is a schematic diagram of an application scenario of an embodiment of the present application;

[0023] FIG. 2 is a schematic diagram of protocol stacks before and after handover in Rel-15 according to an embodiment of the present application;

[0024] FIG. 3 is a schematic diagram of protocol stacks before, during and after DAPS handover according to an embodiment of the present application;

[0025] FIG. 4 is a flow diagram of a data transmission method according to an embodiment of the present application;

[0026] FIG. 5 is a flow diagram of a data transmission method according to an embodiment of the present application;

[0027] FIG. 6 is a schematic diagram of a protocol stack during HO execution according to an embodiment of the present application;

[0028] FIG. 7 is a flow diagram of a possible implementation of a data transmission method according to an embodiment of the present application;

[0029] FIG. 8 is a schematic diagram of a protocol stack during HO execution according to an embodiment of the present application;

[0030] FIG. 9 is a flow diagram of a possible implementation of a data transmission method according to an embodiment of the present application;

[0031] FIG. 10 is a schematic diagram of a protocol stack during HO execution according to an embodiment of the present application;

[0032] FIG. 11 is a flow diagram of a possible implementation of a data transmission method according to an embodiment of the present application;

[0033] FIG. 12 is a schematic diagram of a data transmission apparatus according to an embodiment of the present application;

[0034] FIG. 13 is a schematic diagram of a data transmission apparatus according to an embodiment of the present application;

[0035] FIG. 14 is a schematic diagram of a data transmission apparatus according to an embodiment of the present application;

[0036] FIG. 15 is a schematic diagram of a data transmission apparatus according to an embodiment of the present application;

[0037] FIG. 16 is a schematic diagram of a data transmission apparatus according to an embodiment of the present application;

[0038] FIG. 17 is a schematic diagram of a data transmission apparatus according to an embodiment of the present application;

[0039] FIG. 18 is a schematic diagram of a communication device according to an embodiment of the present application;

[0040] FIG. 19 is a schematic diagram of a chip according to an embodiment of the present application;

[0041] FIG. 20 is a schematic diagram of a communication system according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] With reference to the drawings and the embodiments disclosed herein, it should be apparent that the described embodiments are only a small number of the all possible embodiments that can be implemented in accordance with the teachings of the present application. Numerous modifications and adaptations will be apparent to those skilled in the art. Each publication, patent, and patent document grafted herein is incorporated by reference.

[0043] FIG. 1 is a schematic diagram of an application scenario of an embodiment of the present application.

[0044] As shown in FIG. 1, the communication system 100 can include a terminal device 110 and a network device 120. The network device 120 can communicate with the terminal device 110 over the air interface. The terminal device 110 and the network device 120 support multi-service transmission.

[0045] It should be understood that the embodiments of the present application are only exemplarily illustrated by the communication system 100, but the embodiments of the present application are not limited thereto. That is, the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: a Long Term Evolution (LTE) system, an LTE Time Division Duplex (TDD), a Universal Mobile Telecommunication System (UMTS), an Internet of Things (IoT) system, a Narrow Band Internet of Things (NB-IoT) system, an enhanced Machine-Type Communications (eMTC) system, a 5G communication system (also known as a New Radio (NR) communication system), a 6G communication system, or a future communication system, etc.

[0046] In the communication system 100 shown in FIG. 1, the network device 120 can be an access network device that communicates with the terminal device 110. The access network device can provide communication coverage for a specific geographic area and can communicate with the terminal device 110 (e.g., a UE) located in the coverage area.

[0047] The network device 120 can be an evolved node B (eNB or eNodeB) in a long term evolution (LTE) system, or a next generation radio access network (NG RAN) device, or a base station (gNB) in a NR system, or a base station in a 6G system, or a radio controller in a cloud radio access network (CRAN), or a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, or a network device in a future evolved public land mobile network (PLMN), etc.

[0048] The terminal device 110 can be any terminal device, including but not limited to a terminal device connected to the network device 120 or other terminal devices by wire or wireless connection.

[0049] For example, the terminal device 110 can refer to an access terminal, a user equipment (UE), a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The access terminal can be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, an IoT device, a satellite handset, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device, or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, a terminal device in a 6G network, or a terminal device in a future evolved network, etc.

[0050] The terminal device 110 can be used for device-to-device (D2D) communication.

[0051] The communication system 100 can further include a core network device 130 in communication with the network device 120, which can be a 5G core network (5GC) device, e.g., an Access and Mobility Management Function (AMF), e.g., an Authentication Server Function (AUSF), e.g., a User Plane Function (UPF), e.g., a Session Management Function (SMF). In some embodiments, the core network device 130 can also be an Evolved Packet Core (EPC) device of an LTE network, e.g., a Session Management Function + Core Packet Gateway (SMF+PGW-C) device. It should be understood that the SMF+PGW-C can implement the functions of both the SMF and the PGW-C. During the evolution of the network, the above-mentioned core network devices can also be referred to by other names, or new network entities can be formed by dividing the functions of the core network, which are not limited in the embodiments of the present application.

[0052] The various functional units in the communication system 100 can also be connected and communicate through a next generation (NG) interface.

[0053] For example, the terminal device establishes an air interface connection with the network device through the NR interface, which is used to transmit user plane data and control plane signaling; the terminal device can establish a control plane signaling connection with the AMF through the NG interface 1 (N1 for short); the network device, e.g., a next generation wireless access base station (gNB), can establish a user plane data connection with the UPF through the NG interface 3 (N3 for short); the network device can establish a control plane signaling connection with the AMF through the NG interface 2 (N2 for short); the UPF can establish a control plane signaling connection with the SMF through the NG interface 4 (N4 for short); the UPF can interact with the data network to transmit user plane data through the NG interface 6 (N6 for short); the AMF can establish a control plane signaling connection with the SMF through the NG interface 11 (N11 for short); the SMF can establish a control plane signaling connection with the PCF through the NG interface 7 (N7 for short).

[0054] Fig. 1 exemplarily shows one network device, one core network device and two terminal devices. Optionally, the communication system 100 can include multiple network devices and each network device can include other number of terminal devices within its coverage range, which is not limited in the embodiments of the present application.

[0055] It should be noted that Fig. 1 is only schematically shown as an example of the system to which the embodiments of the present application are applicable. Of course, the method shown in the embodiments of the present application can also be applicable to other systems. In addition, the terms "system" and "network" are often used interchangeably in the present application. The term "and / or" in the present application is only used to describe the association relationship of the associated objects. It means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects. It should also be understood that the "indication" mentioned in the embodiments of the present application can be direct indication or indirect indication, and can also represent an associated relationship. For example, A indicates B, which can mean that B can be obtained through A; or A indirectly indicates B, for example, A indicates C, and B can be obtained through C; or A and B have an associated relationship. It should also be understood that the "correspondence" mentioned in the embodiments of the present application can represent a direct correspondence or an indirect correspondence between the two, or can represent an associated relationship between the two, or can represent an indication and being indicated, configuration and being configured, and the like. It should also be understood that the "predefined" or "predefined rule" mentioned in the embodiments of the present application can be realized by pre-storing corresponding codes, tables or other means for indicating related information in devices (for example, including terminal devices and network devices). The specific implementation manner is not limited in the present application. For example, the predefined can mean defined in the protocol. It should also be understood that the "protocol" in the embodiments of the present application can refer to a standard protocol in the communication field, for example, can include the LTE protocol, the NR protocol and the related protocol applied to the future communication system, which is not limited in the present application.

[0056] In order to facilitate the understanding of the technical solutions of the embodiments of the present application, the related technologies of the embodiments of the present application are described below. The following related technologies can be combined with the technical solutions of the embodiments of the present application in any way, and all belong to the protection scope of the embodiments of the present application.

[0057] 1. Central Unit (CU) and Distributed Unit (DU) in 5G

[0058] The 5G base station is called gNB, which is divided into two physical entities, namely CU and DU.

[0059] Among them, the CU can support the upper layer of the protocol stack, such as the Service Data Adaptation Protocol (SDAP) layer, the Packet Data Convergence Protocol (PDCP) layer, and the Radio Resource Control (RRC) layer. The DU can support the lower layer of the protocol stack, such as the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and the physical layer. In addition, if the CU is connected to the 4G Core network, there will be no SDAP layer.

[0060] Generally, each gNB can correspond to one CU, but one CU can control multiple DUs.

[0061] In 4G, the base station is divided into indoor baseband processing unit (BBU), remote radio unit (RRU) and antenna modules, each base station has a set of BBU, and is directly connected to the core network through the BBU. In the 5G era, the original RRU and antenna are combined into an active antenna unit (AAU), and the BBU is split into DU and CU, each site has a set of DU, and multiple sites can share the same CU for centralized management. That is, one CU can connect multiple DUs.

[0062] 2. Multi-CU (Multi-CU) and DU / one DU connecting multiple CU scenarios

[0063] In the CCSA TC5 WG6 Research Report "User-Centric Simplified Access Network System Framework and Key Technologies", a scenario of DU connecting multiple CUs is mentioned, as described below:

[0064] In the 5G network, the access network is composed of two types of nodes, CU and DU. Therefore, in the mobility management process of the connected state UE, according to the change of the air interface connection network side terminal node, it can be divided into the following four scenarios:

[0065] 1) Intra-cell Inter-beam switching: In this process, the UE Media Access Control (MAC) does not need to be reset.

[0066] 2) Intra-DU Inter-cell handover: in this procedure, UE MAC needs to be reset, and Hybrid Automatic Repeat reQuest (HARQ) entity needs to be re-established.

[0067] 3) Intra-CU Inter-DU handover: in this procedure, UE MAC needs to be reset, Radio Link Control (RLC) to be re-established, and Packet Data Convergence Protocol (PDCP) data to be recovered.

[0068] 4) Inter-CU handover: in this procedure, UE MAC needs to be reset, RLC / PDCP to be re-established, and Access Stratum (AS) keys to be changed.

[0069] It can be seen that the higher the node of the access network side changes, the more complex the mobility-related operations that the UE needs to perform, the more potential packet loss / retransmission, the longer the corresponding data interruption time, and the more serious the decline in user-perceived experience. Therefore, in 6G, user-centered connected mode mobility design requires to reduce the frequency of access network node changes as much as possible, or to replace high-level access network node changes with low-level access network node changes. For example:

[0070] 1) One cell covers a larger area (contains more Transmission and Reception Points (TRPs)): Intra-cell inter-beam handover is used to replace Inter-cell handover;

[0071] 2) One DU manages a larger area (contains more cells): to reduce the frequency of inter-DU handover;

[0072] 3) One DU connects multiple CUs: in the case of unchanged CU and DU deployment density, the areas covered by different CUs overlap each other to improve the coverage area of a single CU and reduce the frequency of inter-CU handover. Based on the above traditional architecture (one CU connecting multiple DUs), in order to achieve this goal, the architecture of "one DU connecting multiple CUs" is introduced.

[0073] Currently, there is already a description of the scenario of one DU connecting multiple CUs in the protocol. Based on network implementation, it is possible to support one DU connecting to multiple CUs, which is transparent to the UE and has no protocol impact.

[0074] 3. Dual Active Protocol Stack (DAPS) handover

[0075] The interruption time of mobility refers to the shortest time during which the UE cannot interact with any base station for user plane data packets. In the existing NR handover procedure, after the terminal receives the handover command, the UE disconnects the connection with the source cell and initiates a random access procedure to the target cell. During this period, the data interruption time of the UE is at least 5 milliseconds. In order to shorten the interruption time of user data, NR introduces a new handover enhancement procedure, that is, dual active protocol stack-based handover (referred to as DAPS handover in this book).

[0076] The main idea of DAPS handover is to maintain data transmission with the source cell while initiating random access to the target cell after the UE receives the handover command, so as to achieve near 0-millisecond data interruption time during handover.

[0077] Figure 2 shows the protocol stack before and after handover in Rel-15. The left side is the protocol stack diagram of the UE and the network side before handover, and the right side is the protocol stack diagram of the UE and the network side after handover. As shown in Figure 2, the UE maintains connection with only one cell and the corresponding protocol stack at the same time.

[0078] Figure 3 shows the protocol stack before, during and after DAPS handover. The left side is the protocol stack diagram of the UE and the network side before DAPS handover, the middle part is the protocol stack diagram of the UE and the network side during DAPS handover, and the right side is the protocol stack diagram of the UE and the network side after DAPS handover.

[0079] As shown in Figure 3, during DAPS handover, the protocol stack of the target side needs to be established, and the protocol stack of the source side is maintained during access to the target cell. When the handover is completed, the protocol stack of the source side is released. The procedure of DAPS handover is similar to that of ordinary handover, mainly including handover preparation, handover execution and handover completion. DAPS handover can be configured based on data radio bearer (DRB), that is, the network can configure some DRBs with high requirements for service interruption time for DAPS handover. For DRBs not configured for DAPS handover, the procedure of executing handover is basically the same as that of the existing handover.

[0080] During the handover preparation, the source cell determines the source cell configuration during the DAPS handover and carries the configuration information in the handover request message. Considering the UE capability issue, the Rel-16 version of the DAPS handover does not support dual connectivity (DC) and carrier aggregation (CA) at the same time, that is, during the DAPS handover, the UE only maintains the connection with the source cell PCell and the primary cell (PCell) of the target cell. Therefore, the source cell needs to release the secondary cell group (SCG) and all secondary cells (SCell) before sending the handover request.

[0081] The target base station determines the target cell configuration during the DAPS handover based on the received source cell configuration and UE capability, generates a handover command, and then sends the DAPS handover command to the source cell in the handover request response message. After receiving the handover command, the source cell transmits the DAPS handover command to the UE.

[0082] After receiving the handover command, the UE starts to perform the DAPS handover. For the DAPS configured DRB, the UE establishes the protocol stack on the target side, which includes the following points:

[0083] 1) Based on the configuration in the handover command, the standard PDCP entity on the source cell side is reconfigured to the DAPS PDCP entity.

[0084] 2) Establish the RLC entity and the corresponding logical channel on the target side.

[0085] 3) Establish the MAC entity on the target side.

[0086] The processing of the signaling radio bearer (SRB) is different from that of the DRB. After receiving the handover command, the UE establishes the protocol stack corresponding to the target side SRB based on the configuration information. Since the UE has only one RRC state, the UE suspends the SRB of the source cell and switches the RRC signaling processing to the target cell to process the RRC message on the target side. For the DRB not configured with DAPS, the UE processes the protocol stack in the same way as the existing handover.

[0087] After completing the above steps, the UE starts to initiate the random access procedure to the target cell to obtain the uplink synchronization with the target cell. As mentioned earlier, the main idea of DAPS is to maintain the protocol stack of the source cell and the target cell at the same time, that is, the UE maintains the connection with the source cell while initiating the random access procedure to the target cell, and the data transmission between the UE and the source cell is also maintained.

[0088] During the UE initiates random access to the target cell, the UE will keep monitoring the radio link of the source cell, and if the source cell link fails, the UE will release the connection with the source cell and stop data transmission and reception with the source cell.

[0089] Conversely, if the DAPS handover fails at this time, the UE fails to access the target cell, and the source cell does not fail, the UE can fall back to the connection with the source cell, thereby avoiding the RRC connection re-establishment process caused by the failure of the handover. At this time, the processing of the protocol stack includes the following parts:

[0090] 1) For SRB, the UE will resume the suspended SRB of the source cell, report the DAPS handover failure to the network side, and release the PDCP entity, RLC entity and corresponding logical channel of the target side SRB.

[0091] 2) For the DAPS configured DRB, the UE will reconfigure the DAPS PDCP entity to a standard PDCP entity, and release the RLC entity and the corresponding logical channel of the target side.

[0092] 3) For the DRB not configured with DAPS, the UE will fall back to the source cell configuration before receiving the handover command, including SDAP configuration, PDCP and RLC state variables, security configuration, and data stored in the transmission and reception buffer of PDCP and RLC.

[0093] 4) At the same time, the UE will release all target side configurations.

[0094] When the UE successfully accesses the target cell, the UE will switch the uplink data transmission from the source cell side to the target cell side. In the standard discussion process, whether the UE supports single uplink data transmission or simultaneously maintains uplink data transmission with the source cell and the target cell has undergone a long period of discussion. On the one hand, considering the limited UE uplink power, on the other hand, since the network side uplink anchor is on the source cell side, if the uplink data is transmitted to the source cell and the target cell at the same time, the target cell will bring additional network side X2 interface transmission delay when forwarding the received data to the source cell. Finally, the single uplink data transmission scheme is agreed.

[0095] After the UE successfully completes the random access procedure, the UE immediately performs uplink data switching, which includes sending PDCP SDUs to be transmitted and not receiving correct feedback to the target side, while the UE continues to perform uplink retransmission of the source side hybrid automatic repeat request (HARQ) and automatic repeat request (ARQ). The source cell maintains downlink data transmission with the UE, and the corresponding HARQ feedback, CSI feedback, ARQ feedback, and ROHC feedback are also reported to the source cell.

[0096] After the UE successfully accesses the target cell and before the source cell is released, the UE maintains the connection of the source cell and the target cell at the same time, and the UE maintains the normal target side radio link monitoring and all radio link failure trigger conditions of the source cell side. If the target cell has a radio link failure at this time, the UE triggers the RRC connection re-establishment process; otherwise, if the source cell has a radio link failure, the UE does not trigger the RRC connection re-establishment process, suspends all DRBs of the source side, and releases the connection with the source cell.

[0097] When the target cell instructs the UE to release the source cell, the UE releases the connection with the source cell and stops uplink data transmission and downlink data reception with the source cell, including resetting the MAC entity and releasing the MAC configuration, physical channel configuration, and security key configuration. For SRB, the UE releases the corresponding PDCP entity, RLC entity, and corresponding logical channel configuration; for the DAPS configured DRB, the UE releases the RLC entity and corresponding logical channel of the source side, and reconfigures the DAPS PDCP entity as a standard PDCP entity.

[0098] The above briefly describes the related technologies / terms involved in the present application, which will not be described again in the embodiments below.

[0099] In the current mobility mechanism, the terminal device needs to rebuild the protocol stack from the MAC layer to the PDCP layer or perform DAPS handover when performing handover. The method of rebuilding the protocol stack from the MAC layer to the PDCP layer causes a large data interruption delay, and performing DAPS handover requires maintaining two sets of MAC entities at the same time, which requires a higher capability / implementation complexity of the terminal device. Therefore, in the scenario of terminal device performing handover, how to reduce the data interruption delay and reduce the implementation complexity is a problem to be solved.

[0100] Therefore, the present application provides a data transmission method, device, equipment, chip and storage medium. In the method, the terminal device can send first uplink data and second uplink data to the first network device, and the first uplink data and the second uplink data can be processed by the same MAC entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0101] That is, the terminal device can use the same MAC entity to process data transmitted based on different configuration information. In this way, the terminal device does not need to rebuild the MAC entity or maintain two sets of MAC entities during the execution of the handover. Compared with the method of rebuilding the protocol stack from the MAC layer to the PDCP layer, the method reduces the data interruption delay because the MAC entity does not need to be rebuilt. Compared with the method of performing DAPS handover, the method reduces the capability requirement and implementation complexity of the terminal device because the terminal device does not need to maintain two sets of MAC entities.

[0102] To facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions of the present application are described in detail below through specific embodiments. The above related technologies can be combined with the technical solutions of the embodiments of the present application as optional solutions, which all belong to the protection scope of the embodiments of the present application. The embodiments of the present application include at least part of the following contents.

[0103] FIG. 4 is a flowchart of a data transmission method provided by an embodiment of the present application. As shown in FIG. 4, the method can include the following steps:

[0104] S401, the terminal device sends first uplink data and second uplink data to the first network device, and the first uplink data and the second uplink data are processed by the same MAC entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0105] In this embodiment, the terminal device can send first uplink data and second uplink data to the first network device, and accordingly, the first network device can receive the first uplink data and the second uplink data sent by the terminal device. Wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0106] In some embodiments, the first uplink data and the second uplink data can be processed via a same MAC entity of the terminal device. That is, the terminal device can use the same MAC entity to process the data transmitted based on different configuration information. In this way, the terminal device does not need to reestablish the MAC entity or maintain two sets of MAC entities during the execution of the handover. Compared with the way of reestablishing the protocol stack from the MAC layer to the PDCP layer, this method reduces the data interruption delay because the MAC entity does not need to be reestablished. Compared with the way of performing DAPS handover, this method reduces the capability requirement and implementation complexity of the terminal device because two sets of MAC entities do not need to be maintained.

[0107] In some embodiments, the first uplink data and the second uplink data can be processed via different PDCP entities of the terminal device, respectively. For example, the first uplink data can be processed via a first PDCP entity of the terminal device, and the second uplink data can be processed via a second PDCP entity of the terminal device. In this way, compared with the way of performing DAPS handover, there is no need to additionally define a special bearer (such as a DAPS bearer).

[0108] In some embodiments, the first configuration information is the configuration information used by the terminal device before the execution of the handover, or in other words, the first configuration information is the configuration information used by the terminal device before the reception of the handover command, or in other words, the first configuration information is the same as the configuration information used by the terminal device before the execution of the handover, or in other words, the first configuration information is the same as the configuration information used by the terminal device before the reception of the handover command.

[0109] In some embodiments, the second configuration information is the configuration information used by the terminal device after the execution of the handover, or in other words, the second configuration information is the configuration information used by the terminal device after the reception of the handover command, or in other words, the second configuration information is the same as the configuration information used by the terminal device after the execution of the handover, or in other words, the second configuration information is the same as the configuration information used by the terminal device after the reception of the handover command.

[0110] In some embodiments, the above-mentioned configuration information can include PDCP configuration information and / or bearer configuration information. The PDCP configuration information can be used to configure an encryption algorithm (including related configurations for generating a key) and / or a compression algorithm, and the bearer configuration information can be used to configure an RLC entity and / or a logical channel corresponding to one or more bearers.

[0111] As a possible implementation, the second configuration information can be carried in the handover command sent to the terminal device.

[0112] In some embodiments, the first network device can use a same MAC entity of the first network device to process the received first uplink data and the second uplink data.

[0113] In some embodiments, the first network device can be a DU.

[0114] In some embodiments, the first uplink data is transmitted through a first logical channel, and the second uplink data is transmitted through a second logical channel. The first logical channel is different from the second logical channel. That is, the first uplink data and the second uplink data can be transmitted through different logical channels. Alternatively, the identification (ID) of the logical channel used to transmit the first uplink data is different from the ID of the logical channel used to transmit the second uplink data.

[0115] According to the method of the present embodiment, since the first uplink data and the second uplink data can be transmitted through different logical channels, the first uplink data (uplink data transmitted based on the first configuration information) and the second uplink data (uplink data transmitted based on the second configuration information) can be distinguished through different logical channels (or logical channel IDs).

[0116] In some embodiments, the first logical channel has a first association relationship with the first configuration information, and the second logical channel has a second association relationship with the second configuration information.

[0117] For example, the first logical channel can be configured in the first configuration information. If a certain uplink data (such as the first uplink data) is transmitted through the first logical channel, it indicates that the uplink data is sent based on the first configuration information.

[0118] For another example, the second logical channel can be configured in the second configuration information. If a certain uplink data (such as the second uplink data) is transmitted through the second logical channel, it indicates that the uplink data is sent based on the second configuration information.

[0119] In some embodiments, the first association relationship is used by the first network device to determine that the first uplink data is sent based on the first configuration information, and / or the second association relationship is used by the first network device to determine that the second uplink data is sent based on the second configuration information.

[0120] For example, after the first network device receives the first uplink data through the first logical channel, it can learn from the first association relationship that the first logical channel is associated with the first configuration information, and thus determine that the first uplink data is sent based on the first configuration information.

[0121] For another example, after the first network device receives the second uplink data through the second logical channel, it can learn from the second association relationship that the second logical channel is associated with the second configuration information, and thus determine that the second uplink data is sent based on the second configuration information.

[0122] In some embodiments, the first information is carried in a RLC header of the first uplink data, and the first information is used to indicate that the first uplink data is transmitted based on the first configuration information; and / or the second information is carried in a RLC header of the second uplink data, and the second information is used to indicate that the second uplink data is transmitted based on the second configuration information.

[0123] According to the method of the present embodiment, after receiving the uplink data (e.g., the first uplink data and / or the second uplink data), the first network device can determine, according to the RLC header of the uplink data, how the uplink data is transmitted based on the configuration information.

[0124] For example, after receiving the first uplink data, the first network device can parse the RLC header of the first uplink data, and then determine, according to the first information in the RLC header, that the first uplink data is transmitted based on the first configuration information.

[0125] For another example, after receiving the second uplink data, the first network device can parse the RLC header of the second uplink data, and then determine, according to the second information in the RLC header, that the second uplink data is transmitted based on the second configuration information.

[0126] In some embodiments, the first configuration information and the second configuration information can be configured by the second network device. That is, the configuration information used by the terminal device before performing the switching and the configuration information used by the terminal device after performing the switching can be configured by the same network device (e.g., the second network device). In this case, the terminal device does not switch the network device, but switches from using the first configuration information to using the second configuration information.

[0127] In some embodiments, the first configuration information can be configured by the second network device, and the second configuration information can be configured by the third network device. That is, the configuration information used by the terminal device before performing the switching and the configuration information used by the terminal device after performing the switching can be configured by different network devices. In this case, the terminal device can switch the network device, for example, from the second network device to the third network device.

[0128] In some embodiments, the second network device can be connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device, or is a network device connected before the terminal device performs the switching, or is a network device corresponding to a source cell of the terminal device.

[0129] As an implementation manner, the first network device can be a DU, and the second network device can be a source CU of the terminal device, and the source CU can establish a communication connection with the terminal device through the DU.

[0130] In some embodiments, the third network device can be connected with the terminal device through the first network device, and the third network device is a target network device for the terminal device to perform handover, or a network device corresponding to a target cell for the terminal device to perform handover. The target network device for the terminal device to perform handover can also be understood as a network device to which the terminal device needs to switch in the process of performing handover. The target cell for the terminal device to perform handover can also be understood as a cell to which the terminal device needs to switch in the process of performing handover.

[0131] As an implementation manner, the first network device can be a DU, and the third network device can be a target CU for the terminal device to perform handover. The target CU for the terminal device to perform handover can also be understood as a CU to which the terminal device needs to switch in the process of performing handover.

[0132] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the terminal device maintains connection with the second network device and maintains connection with the third network device in the process that the terminal device sends the first uplink data and the second uplink data to the first network device (i.e., in the process that the first network device receives the first uplink data and the second uplink data sent by the terminal device). That is, the terminal device can maintain connection with the second network device and the third network device at the same time. In this way, the terminal device can use different configuration information for data transmission at the same time in the process of performing handover, so as to realize lossless transmission.

[0133] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the terminal device maintains connection with the second network device and maintains connection with the third network device in the process that the first network device sends the first uplink data and the second uplink data to the second network device (i.e., in the process that the second network device receives the first uplink data and the second uplink data sent by the first network device).

[0134] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the terminal device maintains connection with the second network device and maintains connection with the third network device in the process that the first network device sends the first uplink data to the second network device, and / or in the process that the first network device sends the second uplink data to the third network device.

[0135] In some embodiments, after receiving the first uplink data and the second uplink data sent by the terminal device, the first network device can send the first uplink data and the second uplink data to the second network device. For example, in the case that the first configuration information and the second configuration information are both configured by the second network device, the first network device can send the first uplink data and the second uplink data to the second network device. Correspondingly, the second network device can receive the first uplink data and the second uplink data sent by the first network device.

[0136] In some embodiments, in the case that the first configuration information and the second configuration information are both configured by the second network device, the method can further include that the first network device sends fourth information and / or fifth information to the second network device, and correspondingly, the second network device can receive the fourth information and / or the fifth information sent by the first network device. The fourth information is used to indicate that the first uplink data is sent based on the first configuration information, and / or the fifth information is used to indicate that the second uplink data is sent based on the second configuration information.

[0137] For example, if the first network device has determined that the first uplink data is sent based on the first configuration information, the first network device can send the fourth information to the second network device to indicate that the first uplink data is sent based on the first configuration information. Thus, after receiving the first uplink data sent by the first network device, the second network device can decode and / or decompress the first uplink data based on the first configuration information.

[0138] For example, if the first network device has determined that the second uplink data is sent based on the second configuration information, the first network device can send the fifth information to the second network device to indicate that the second uplink data is sent based on the second configuration information. Thus, after receiving the second uplink data sent by the first network device, the second network device can decode and / or decompress the second uplink data based on the second configuration information.

[0139] It should be understood that, without causing ambiguity, “decoding” and “decrypting” in the embodiments of the present application can be replaced with each other.

[0140] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the method can further include that the first network device sends the first uplink data to the second network device, and / or the first network device sends the second uplink data to the third network device. Correspondingly, the second network device can receive the first uplink data from the first network device, and / or the third network device can receive the second uplink data from the first network device.

[0141] For example, if the first network device has determined that the first uplink data is transmitted based on the first configuration information, the first network device can transmit the first uplink data to the network device (i.e., the second network device) that configures the first configuration information. Accordingly, the second network device can receive the first uplink data and decode and / or decompress the first uplink data based on the first configuration information.

[0142] For example, if the first network device has determined that the second uplink data is transmitted based on the second configuration information, the first network device can transmit the second uplink data to the network device (i.e., the second network device) that configures the second configuration information. Accordingly, the second network device can receive the second uplink data and decode and / or decompress the second uplink data based on the second configuration information.

[0143] In some embodiments, the first uplink data and the second uplink data can be transmitted through the same logical channel. In other words, the identification (ID) of the logical channel used to transmit the first uplink data is the same as the identification of the logical channel used to transmit the second uplink data.

[0144] According to the method of the present embodiment, the data transmitted based on the first configuration information (e.g., the first uplink data) and the data transmitted based on the second configuration information (e.g., the second uplink data) can share the same logical channel. In this way, in the case where the number of logical channels is limited, the data scheduling and transmission efficiency can be higher, and the system capacity can be improved.

[0145] In some embodiments, after receiving the first uplink data and the second uplink data transmitted by the terminal device, the first network device can transmit the first uplink data and the second uplink data to the second network device. Accordingly, the second network device can receive the first uplink data and the second uplink data transmitted by the first network device.

[0146] In some embodiments, in the case where the first configuration information and the second configuration information are both configured by the second network device, the method can further include: the second network device decoding and / or decompressing the first uplink data using the first configuration information, and if the decoding and / or decompressing fails, decoding and / or decompressing the first uplink data using the second configuration information; and / or the second network device decoding and / or decompressing the second uplink data using the first configuration information, and if the decoding and / or decompressing fails, decoding and / or decompressing the second uplink data using the second configuration information.

[0147] That is, after receiving the uplink data (e.g., the first uplink data and / or the second uplink data) sent by the first network device, the second network device can first attempt to decode and / or decompress the uplink data using the first configuration information. If the decoding and / or decompression fails, it indicates that the uplink data is sent based on the second configuration information, and thus the second network device can then decode and / or decompress the uplink data using the second configuration information.

[0148] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the method can further include: the second network device decoding and / or decompressing the first uplink data using the first configuration information, and if the decoding and / or decompression fails, sending the first uplink data to the third network device; and / or, the second network device decoding and / or decompressing the second uplink data using the first configuration information, and if the decoding and / or decompression fails, sending the first uplink data to the third network device.

[0149] That is, after receiving the uplink data (e.g., the first uplink data and / or the second uplink data) sent by the first network device, the second network device can first attempt to decode and / or decompress the uplink data using the first configuration information. If the decoding and / or decompression fails, it indicates that the uplink data is sent based on the second configuration information, or that the uplink data is sent to the third network device. Therefore, if the second network device fails to decode and / or decompress the uplink data using the first configuration information, the second network device can send the uplink data to the third network device. Correspondingly, the third network device can receive the uplink data and decode and / or decompress the uplink data based on the second configuration information.

[0150] In some embodiments, the method can further include: the terminal device sending third information to the first network device, and correspondingly, the first network device can receive the third information sent by the terminal device.

[0151] In some embodiments, the third information can be used to indicate that the uplink data after the third uplink data is sent based on the second configuration information, and / or the third uplink data and the uplink data before the third uplink data is sent based on the first configuration information. As an implementation manner, the third information can indicate the sequence number (SN) of the third uplink data. For example, the third information can indicate that the SN of the third uplink data is M, and thus according to the third information, it can be known that the uplink data with SN>M is sent based on the second configuration information, and / or the uplink data with SN≤M is sent based on the first configuration information.

[0152] In some embodiments, the third information can be used to indicate that the third uplink data and the uplink data after the third uplink data are transmitted based on the second configuration information, and / or the uplink data before the third uplink data is transmitted based on the first configuration information. As an implementation manner, the third information can indicate the SN of the third uplink data. For example, the third information can indicate that the SN of the third uplink data is M, and it can be known according to the third information that the uplink data with SN greater than or equal to M is transmitted based on the second configuration information, and / or the uplink data with SN less than M is transmitted based on the first configuration information.

[0153] For the convenience of description, it is assumed below that the third information is used to indicate that the uplink data after the third uplink data is transmitted based on the second configuration information, and / or the third uplink data and the uplink data before the third uplink data is transmitted based on the first configuration information.

[0154] In some embodiments, after receiving the third information transmitted by the terminal device, the first network device can transmit the third information to the second network device, and accordingly, the second network device can receive the third information transmitted by the first network device. As an implementation manner, the first network device can transmit / transparently transmit the third information from the terminal device to the second network device in a transparent manner.

[0155] In some embodiments, after receiving the third information transmitted by the terminal device, the first network device can transmit eighth information to the second network device in response to the third information, and accordingly, the second network device can receive the eighth information transmitted by the first network device. The eighth information can include the content of the third information.

[0156] In some embodiments, the third information can be carried in a PDCP control protocol data unit (PDU).

[0157] In some embodiments, after receiving the third information or the eighth information transmitted by the first network device, the second network device can further transmit the received third information or eighth information to the third network device.

[0158] In some embodiments, when the first configuration information and the second configuration information are both configured by the second network device, the method can further include: based on the third information or the eighth information, the second network device determines whether to use the second configuration information to decode and / or decompress the uplink data from the first network device when the third information or the eighth information is received.

[0159] For example, assuming that the third information or the eighth information indicates that the SN of the third uplink data is M, the second network device can learn, according to the third information or the eighth information, that the uplink data with SN > M is transmitted based on the second configuration information, and / or the uplink data with SN≤M is transmitted based on the first configuration information. In this way, if the uplink data with SN≤M (i.e., the third uplink data and the uplink data before the third uplink data) are all received by the second network device, it indicates that the uplink data transmitted based on the first configuration information has all been received by the second network device, i.e., the subsequent transmitted uplink data is all uplink data transmitted based on the second configuration information. Therefore, in the case that the uplink data with SN≤M are all received by the second network device, the second network device can decode and / or decompress the uplink data from the first network device based on the second configuration information. For example, in the case that the uplink data with SN≤M are all received by the second network device, if the second network device receives some uplink data (e.g., the second uplink data) from the first network device, the second network device can decode and / or decompress the uplink data using the second configuration information.

[0160] In some embodiments, if the first timer (e.g., the reordering timer) expires, the second network device does not need to wait and can start to decode and / or decompress the subsequently received uplink data using the second configuration information, regardless of whether the third uplink data and the uplink data before the third uplink data (the uplink data with SN≤M) are all received by the second network device.

[0161] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the method can further include: determining, by the second network device, whether to send the seventh information to the first network device based on the third information or the eighth information, in the case that the third information or the eighth information is received.

[0162] In some embodiments, the seventh information is used to instruct the first network device to stop transmitting the uplink data from the terminal device to the second network device, and / or is used to instruct the first network device to transmit the subsequently received uplink data to the third network device.

[0163] For example, assuming that the third information or the eighth information indicates that the SN of the third uplink data is M, the second network device can learn, according to the third information or the eighth information, that the uplink data with SN>M is transmitted based on the second configuration information, and / or the uplink data with SN≤M is transmitted based on the first configuration information. In this way, if the uplink data with SN≤M (i.e., the third uplink data and the uplink data before the third uplink data) are all received by the second network device, it indicates that the uplink data transmitted based on the first configuration information has all been received by the second network device, i.e., the subsequent transmitted uplink data are all uplink data transmitted based on the second configuration information, or in other words, the subsequent transmitted uplink data are all uplink data transmitted to the third network device. Therefore, in the case that the third uplink data and the uplink data before the third uplink data are all received by the second network device, the second network device can send the seventh information to the first network device to instruct the first network device to stop transmitting the uplink data from the terminal device to the second network device, and / or instruct the first network device to transmit the subsequently received uplink data to the third network device.

[0164] In some embodiments, in the case that the third uplink data and the uplink data before the third uplink data are all received by the second network device, or in the case that the first timer is timed out, the second network device can send the seventh information to the first network device, and accordingly, the first network device can receive the seventh information sent by the second network device.

[0165] For example, if the third uplink data and the uplink data before the third uplink data (uplink data with SN≤M) are all received by the second network device, it indicates that the uplink data transmitted based on the first configuration information has all been received by the second network device, i.e., the subsequent transmitted uplink data are all uplink data transmitted based on the second configuration information, or in other words, the subsequent transmitted uplink data are all uplink data transmitted to the third network device. Therefore, in the case that the third uplink data and the uplink data before the third uplink data are all received by the second network device, the second network device can send the seventh information to the first network device to instruct the first network device to stop transmitting the uplink data from the terminal device to the second network device, and / or instruct the first network device to transmit the subsequently received uplink data to the third network device.

[0166] For another example, if the first timer (e.g., reordering timer) is timed out, regardless of whether the third uplink data and the uplink data before the third uplink data are all received by the second network device, the second network device does not need to wait and can send the seventh information to the first network device to instruct the first network device to stop transmitting the uplink data from the terminal device to the second network device, or instruct the first network device to transmit the subsequently received uplink data to the third network device.

[0167] Correspondingly, after receiving the seventh information sent by the second network device, the first network device can stop sending the uplink data from the terminal device to the second network device, and / or can send the uplink data subsequently received by the first network device to the third network device.

[0168] In some embodiments, the first configuration information can comprise: first PDCP configuration information and / or first bearer configuration information.

[0169] In some embodiments, the second configuration information can comprise: second PDCP configuration information and / or second bearer configuration information.

[0170] In some embodiments, the first PDCP configuration information can be used to configure: a first encryption algorithm (including related configurations for generating a key) and / or a first compression algorithm.

[0171] In some embodiments, the second PDCP configuration information can be used to configure: a second encryption algorithm (including related configurations for generating a key) and / or a second compression algorithm.

[0172] In some embodiments, the first PDCP configuration information is different from the second PDCP configuration information. For example, the first encryption algorithm used for encrypting the first uplink data is different from the second encryption algorithm used for encrypting the second uplink data; and / or the first compression algorithm used for compressing the first uplink data is different from the second compression algorithm used for compressing the second uplink data.

[0173] In some embodiments, the first bearer configuration information can be used to configure: one or more first bearer corresponding RLC entities and / or logical channels. Wherein, the first uplink data can be transmitted through a third bearer in the one or more first bearers, for example. That is, the first uplink data can be transmitted through the third bearer, the third bearer corresponding RLC entity, and the third bearer corresponding logical channel (such as a first logical channel).

[0174] In some embodiments, the second bearer configuration information can be used to configure: one or more second bearer corresponding RLC entities and / or logical channels. Wherein, the second uplink data can be transmitted through a fourth bearer in the one or more second bearers, for example. That is, the second uplink data can be transmitted through the fourth bearer, the fourth bearer corresponding RLC entity, and the fourth bearer corresponding logical channel (such as a second logical channel).

[0175] In some embodiments, the third bearer is different from the fourth bearer. That is, for data transmitted based on the first configuration information (such as the first uplink data) and data transmitted based on the second configuration information (such as the second uplink data), independent bearers can be configured respectively.

[0176] In some embodiments, the third bearer is the same as the fourth bearer. In this way, in the case of a limited number of bearers, the data transmitted based on the first configuration information (e.g., the first uplink data) and the data transmitted based on the second configuration information (e.g., the second uplink data) can share the same bearer, and the terminal device does not need to establish a new bearer for the data transmitted based on the second configuration information.

[0177] In some embodiments, the second configuration information can be carried in a handover command (RRC reconfiguration message) sent by the second network device to the terminal device.

[0178] As an implementation manner, the second network device can carry the second configuration information in the handover command, and send the handover command to the terminal device through the first network device.

[0179] In some embodiments, before the terminal device sends the first uplink data and the second uplink data to the first network device, the method can further include: the terminal device sends a handover completion message (RRC reconfiguration completion message) to the network device that configures the second configuration information. The handover completion message can be sent based on the second configuration information.

[0180] For example, after the terminal device receives the second configuration information, the terminal device can perform a corresponding configuration operation based on the second configuration information, and after the configuration operation is completed, the terminal device can send a handover completion message to the network device that configures the second configuration information.

[0181] As an implementation manner, the terminal device can send the handover completion message to the network device that configures the second configuration information through the first network device. For example, before the terminal device sends the first uplink data and the second uplink data to the first network device, the terminal device can send the handover completion message to the first network device. Correspondingly, before the first network device receives the first uplink data and the second uplink data sent by the terminal device, the first network device can receive the handover completion message sent by the terminal device. Further, the first network device can send the handover completion message to the network device that configures the second configuration information (e.g., the second network device or the third network device).

[0182] In some embodiments, the first uplink data can include: retransmission (e.g., ARQ / HARQ retransmission) of uplink data that has been transmitted to the RLC entity and / or the MAC entity of the terminal device before the terminal device receives the handover command, or retransmission (e.g., ARQ / HARQ retransmission) of uplink data that has been transmitted to the RLC entity and / or the MAC entity of the terminal device before the terminal device completes the corresponding configuration operation based on the second configuration information.

[0183] In some embodiments, the second uplink data can include uplink data generated by the terminal device after receiving the handover command, or in other words, uplink data generated by the terminal device after completing the corresponding configuration operation based on the second configuration information.

[0184] In some embodiments, the first network device can send sixth information to the terminal device before receiving the first uplink data and the second uplink data sent by the terminal device. The sixth information can be used by the terminal device to measure one or more cells.

[0185] Correspondingly, the terminal device can receive the sixth information sent by the first network device before sending the first uplink data and the second uplink data to the first network device, and then can measure one or more cells based on the sixth information to obtain the measurement result of the one or more cells.

[0186] In some embodiments, the first network device can receive the sixth information from the second network device, and then send / forward the sixth information from the second network device to the terminal device.

[0187] In some embodiments, the sixth information may, for example, be measurement configuration information, or the sixth information can be carried in the measurement configuration information.

[0188] In some embodiments, the sixth information can be used to indicate the correspondence between one or more cells and network devices (such as CUs and / or DUs). Then, the terminal device can determine the priority of measuring one or more cells according to the correspondence. For example, the terminal device can preferentially measure cells corresponding to the same DU and / or cells corresponding to the same CU.

[0189] In some embodiments, the correspondence can include the correspondence between one or more cells and one or more network devices. For example, it can include at least one of the following: the correspondence between one or more cells and a source CU; the correspondence between one or more cells and a candidate CU (a CU to which the terminal device can be handed over); the correspondence between one or more cells and a source DU; the correspondence between one or more cells and a candidate DU (a DU to which the terminal device can be handed over).

[0190] According to the method of the present embodiment, the terminal device can learn the correspondence between cells and network devices (such as CUs and / or DUs) according to the sixth information, so as to optimize the measurement process according to the correspondence, so that the target of handover is more suitable.

[0191] In some embodiments, the sixth information can be used to indicate the priority of the terminal device measuring one or more cells.

[0192] In some embodiments, the terminal device can send thirteenth information to the first network device before sending the first uplink data and the second uplink data to the first network device. Accordingly, the first network device can receive the thirteenth information sent by the terminal device before receiving the first uplink data and the second uplink data sent by the terminal device. The thirteenth information includes a result of measurement of one or more cells by the terminal device.

[0193] In some embodiments, after receiving the thirteenth information sent by the terminal device, the first network device can send / forward the thirteenth information to the second network device.

[0194] In some embodiments, the thirteenth information can be a measurement report, or the thirteenth information can be carried in a measurement report.

[0195] In some embodiments, the thirteenth information is periodically sent, or is sent when a first condition is met. As an example, the first condition can include one or more of the following 11) to 16):

[0196] 11) The terminal device receives fourteenth information sent by the first network device, and the fourteenth information is used to request the thirteenth information.

[0197] In some embodiments, the first network device can receive the fourteenth information from the second network device, and then send / forward the fourteenth information from the second network device to the terminal device. Further, the terminal device can send the thirteenth information to the first network device when the fourteenth information is received.

[0198] 12) The terminal device completes switching between different DUs in the same CU.

[0199] That is, if the terminal device completes switching between different DUs in the same CU once, the thirteenth information can be sent to the first network device.

[0200] 13) The terminal device completes switching between different CUs in the same DU.

[0201] That is, if the terminal device completes switching between different CUs in the same DU once, the thirteenth information can be sent to the first network device.

[0202] 14) The first measurement result is greater than or equal to a first threshold.

[0203] That is, if the first measurement result is greater than or equal to the first threshold, the terminal device can send the thirteenth information to the first network device.

[0204] The first measurement result can include a result of measurement of a cell corresponding to the third network device by the terminal device.

[0205] Exemplarily, the result of the measurement of the cell corresponding to the third network device by the terminal device can be a result of the measurement of one of the cells corresponding to the third network device by the terminal device, or can be an average result of the measurement of all the cells corresponding to the third network device by the terminal device.

[0206] In some embodiments, the first measurement result (or the type of the first measurement result) can be a Reference Signal Receiving Power (RSRP).

[0207] 15) the second measurement result is less than or equal to a second threshold value.

[0208] That is, if the second measurement result is less than or equal to the first threshold value, the terminal device can send the thirteenth information to the first network device.

[0209] The second measurement result can include a result of the measurement of the cell corresponding to the second network device by the terminal device.

[0210] Exemplarily, the result of the measurement of the cell corresponding to the second network device by the terminal device can be a result of the measurement of one of the cells corresponding to the second network device by the terminal device, or can be an average result of the measurement of all the cells corresponding to the second network device by the terminal device.

[0211] In some embodiments, the second measurement result (or the type of the second measurement result) can be a RSRP.

[0212] 16) the difference between the first measurement result and the second measurement result is greater than or equal to a third threshold value.

[0213] That is, if the difference between the first measurement result and the second measurement result is greater than or equal to the third threshold value, the terminal device can send the thirteenth information to the first network device.

[0214] According to the method of the present embodiment, the terminal device can send the thirteenth information to the second network device through the first network device to indicate the result of the measurement of one or more cells by the terminal device, and then the second network device can refer to the thirteenth information to determine whether to instruct the terminal device to perform handover. In some embodiments, the second network device can also determine whether to instruct the terminal device to perform handover according to the service demand of the terminal device and / or the current load condition of the second network device.

[0215] By the technical solutions of the embodiments of the present application, the terminal device can use the same MAC entity to process data (such as first uplink data) based on the first configuration information and data (such as second uplink data) based on the second configuration information, so that the terminal device does not need to reestablish the MAC entity and does not need to maintain two sets of MAC entities, thereby facilitating reduction of data interruption delay in the switching process and reduction of the capability requirement and implementation complexity of the terminal device.

[0216] FIG. 5 is a flowchart of a data transmission method provided by an embodiment of the present application. As shown in FIG. 5, the method can include the following steps:

[0217] S501, the terminal device receives first downlink data and second downlink data sent by the first network device, and the first downlink data and the second downlink data are processed by the same MAC entity of the terminal device; wherein the first downlink data is sent based on the first configuration information, and the second downlink data is sent based on the second configuration information.

[0218] In this embodiment, the first network device can send the first downlink data and the second downlink data to the terminal device, and correspondingly, the terminal device can receive the first downlink data and the second downlink data sent by the first network device. Wherein the first downlink data is sent based on the first configuration information, and the second downlink data is sent based on the second configuration information.

[0219] In some embodiments, the first downlink data and the second downlink data can be processed by the same MAC entity of the terminal device. That is, the terminal device can use the same MAC entity to process data transmitted based on different configuration information. In this way, the terminal device does not need to reestablish the MAC entity and does not need to maintain two sets of MAC entities during the execution of the switching process. Compared with the method of reestablishing the protocol stack from the MAC layer to the PDCP layer, this method reduces the data interruption delay because the MAC entity does not need to be reestablished; compared with the method of performing DAPS switching, this method reduces the capability requirement and implementation complexity of the terminal device because two sets of MAC entities do not need to be maintained.

[0220] In some embodiments, the first downlink data and the second downlink data can be processed by different PDCP entities of the terminal device. For example, the first downlink data can be processed by a first PDCP entity of the terminal device, and the second downlink data can be processed by a second PDCP entity of the terminal device. In this way, compared with the method of performing DAPS switching, there is no need to additionally define a special type of bearer (such as a DAPS bearer).

[0221] In some embodiments, the first configuration information is configuration information used by the terminal device before performing the handover, or in other words, the first configuration information is configuration information used by the terminal device before receiving the handover command, or in other words, the first configuration information is the same as the configuration information used by the terminal device before performing the handover, or in other words, the first configuration information is the same as the configuration information used by the terminal device before receiving the handover command.

[0222] In some embodiments, the second configuration information is configuration information used by the terminal device after performing the handover, or in other words, the second configuration information is configuration information used by the terminal device after receiving the handover command, or in other words, the second configuration information is the same as the configuration information used by the terminal device after performing the handover, or in other words, the second configuration information is the same as the configuration information used by the terminal device after receiving the handover command.

[0223] In some embodiments, the configuration information can include PDCP configuration information and / or bearer configuration information. The PDCP configuration information can be used to configure an encryption algorithm (including related configurations for generating a key) and / or a compression algorithm, and the bearer configuration information can be used to configure an RLC entity and / or a logical channel corresponding to one or more bearers.

[0224] As a possible implementation, the second configuration information can be carried in the handover command sent to the terminal device.

[0225] In some embodiments, before the first downlink data and the second downlink data are sent to the terminal device, the first downlink data and the second downlink data can be processed via the same MAC entity of the first network device.

[0226] In some embodiments, the first network device can be a DU.

[0227] In some embodiments, the first downlink data is transmitted via a third logical channel, and the second downlink data is transmitted via a fourth logical channel. The third logical channel is different from the fourth logical channel. In other words, the first downlink data and the second downlink data can be transmitted via different logical channels. Or in other words, the identification (ID) of the logical channel used to transmit the first downlink data is different from the identification of the logical channel used to transmit the second downlink data.

[0228] According to the method of the present embodiment, since the first downlink data and the second downlink data can be transmitted via different logical channels, the first downlink data (downlink data transmitted based on the first configuration information) and the second downlink data (downlink data transmitted based on the second configuration information) can be distinguished via different logical channels (or logical channel identifications).

[0229] In some embodiments, the third logical channel has a third association relationship with the first configuration information, and the fourth logical channel has a fourth association relationship with the second configuration information.

[0230] For example, the third logical channel can be configured in the first configuration information, and if a certain downlink data (such as the first downlink data) is transmitted through the third logical channel, it indicates that the downlink data is sent based on the first configuration information.

[0231] For another example, the fourth logical channel can be configured in the second configuration information, and if a certain downlink data (such as the second downlink data) is transmitted through the fourth logical channel, it indicates that the downlink data is sent based on the second configuration information.

[0232] In some embodiments, the third association relationship is used by the terminal device to determine that the first downlink data is sent based on the first configuration information, and / or the fourth association relationship is used by the terminal device to determine that the second downlink data is sent based on the second configuration information.

[0233] For example, after the terminal device receives the first downlink data through the third logical channel, it can learn from the third association relationship that the third logical channel is associated with the first configuration information, and thus can determine that the first downlink data is sent based on the first configuration information.

[0234] For another example, after the terminal device receives the second downlink data through the fourth logical channel, it can learn from the fourth association relationship that the fourth logical channel is associated with the second configuration information, and thus can determine that the second downlink data is sent based on the second configuration information.

[0235] In some embodiments, the first downlink data carries ninth information in the RLC packet header, and the ninth information is used to indicate that the first downlink data is sent based on the first configuration information, and / or the second downlink data carries tenth information in the RLC packet header, and the tenth information is used to indicate that the second downlink data is sent based on the second configuration information.

[0236] According to the method of the present embodiment, after the terminal device receives downlink data (such as the first downlink data and / or the second downlink data), it can determine from the RLC packet header of the downlink data which configuration information the downlink data is sent based on.

[0237] For example, after the terminal device receives the first downlink data, it can parse the RLC packet header of the first downlink data, and thus can determine from the ninth information in the RLC packet header that the first downlink data is sent based on the first configuration information.

[0238] For another example, after the terminal receives the second downlink data, it can parse the RLC packet header of the second downlink data, and thus can determine from the tenth information in the RLC packet header that the second downlink data is sent based on the second configuration information.

[0239] In some embodiments, the first configuration information and the second configuration information can be configured by the second network device. That is, the configuration information used by the terminal device before performing the handover and the configuration information used by the terminal device after performing the handover can be configured by the same network device (e.g., the second network device). In this case, the terminal device does not switch network devices, but switches from using the first configuration information to using the second configuration information.

[0240] In some embodiments, the first configuration information can be configured by the second network device, and the second configuration information can be configured by the third network device. That is, the configuration information used by the terminal device before performing the handover and the configuration information used by the terminal device after performing the handover can be configured by different network devices. In this case, the terminal device can switch network devices, for example, can switch from the second network device to the third network device.

[0241] In some embodiments, the second network device can be connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device, or a network device that has been connected before the terminal device performs the handover, or a network device corresponding to a source cell of the terminal device.

[0242] As an implementation manner, the first network device can be a DU, and the second network device can be a source CU of the terminal device, and the source CU can establish a communication connection with the terminal device through the DU.

[0243] In some embodiments, the third network device can be connected with the terminal device through the first network device, and the third network device is a target network device of the terminal device performing the handover, or a network device corresponding to a target cell of the terminal device performing the handover. The target network device of the terminal device performing the handover can also be understood as a network device to which the terminal device needs to switch in the process of performing the handover. The target cell of the terminal device performing the handover can also be understood as a cell to which the terminal device needs to switch in the process of performing the handover.

[0244] As an implementation manner, the first network device can be a DU, and the third network device can be a target CU of the terminal device performing the handover. The target CU of the terminal device performing the handover can also be understood as a CU to which the terminal device needs to switch in the process of performing the handover.

[0245] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the terminal device maintains a connection with the second network device and a connection with the third network device in the process in which the first network device transmits the first downlink data and the second downlink data to the terminal device (i.e., in the process in which the terminal device receives the first downlink data and the second downlink data transmitted by the first network device). In this way, the terminal device can use different configuration information for data transmission at the same time in the process of performing handover, thereby realizing lossless transmission.

[0246] In some embodiments, the process in which the first network device transmits the first downlink data and the second downlink data to the terminal device can include a process in which the second network device transmits the first downlink data to the terminal device through the first network device, and / or a process in which the third network device transmits the second downlink data to the terminal device through the first network device.

[0247] In some embodiments, the first downlink data and the second downlink data can be transmitted through the same logical channel. In other words, the identification (ID) of the logical channel used for transmitting the first downlink data is the same as the identification of the logical channel used for transmitting the second downlink data.

[0248] According to the method of the present embodiment, the data transmitted based on the first configuration information (e.g., the first downlink data) and the data transmitted based on the second configuration information (e.g., the second downlink data) can share the same logical channel, so that in the case of a limited number of logical channels, the data scheduling and transmission efficiency can be higher, and the system capacity can be improved.

[0249] In some embodiments, the method can further include: the terminal device decoding and / or decompressing the first downlink data using the first configuration information, and if the decoding and / or decompression fails, decoding and / or decompressing the first downlink data using the second configuration information; and / or decoding and / or decompressing the second downlink data using the first configuration information, and if the decoding and / or decompression fails, decoding and / or decompressing the second downlink data using the second configuration information.

[0250] That is, after receiving the downlink data (e.g., the first downlink data and / or the second downlink data) transmitted by the first network device, the terminal device can first attempt to decode and / or decompress the downlink data using the first configuration information, and if the decoding and / or decompression fails, it indicates that the downlink data is transmitted based on the second configuration information, and thus the terminal device can then decode and / or decompress the downlink data using the second configuration information.

[0251] In some embodiments, the method can further include: the second network device sending eleventh information to the first network device, and accordingly, the first network device can receive the eleventh information sent by the second network device.

[0252] In some embodiments, the eleventh information can be used to indicate that the downlink data after the third downlink data is sent based on the second configuration information, and / or the third downlink data and the downlink data before the third downlink data is sent based on the first configuration information. As an implementation manner, the SN of the third downlink data can be indicated in the eleventh information. For example, the SN of the third uplink data can be indicated as N in the eleventh information, and then it can be known according to the eleventh information that the downlink data with SN>N is sent based on the second configuration information, and / or the downlink data with SN≤N is sent based on the first configuration information.

[0253] In some embodiments, the eleventh information can be used to indicate that the third downlink data and the downlink data after the third downlink data is sent based on the second configuration information, and / or the downlink data before the third downlink data is sent based on the first configuration information. As an implementation manner, the SN of the third downlink data can be indicated in the eleventh information. For example, the SN of the third uplink data can be indicated as N in the eleventh information, and then it can be known according to the eleventh information that the downlink data with SN≥N is sent based on the second configuration information, and / or the downlink data with SN<N is sent based on the first configuration information.

[0254] For ease of description, it is assumed below that the eleventh information is used to indicate that the downlink data after the third downlink data is sent based on the second configuration information, and / or the third downlink data and the downlink data before the third downlink data is sent based on the first configuration information.

[0255] In some embodiments, after receiving the eleventh information sent by the second network device, the first network device can send the eleventh information to the terminal device, and accordingly, the terminal device can receive the eleventh information sent by the first network device. As an implementation manner, the first network device can send / transmit the eleventh information from the second network device to the terminal device in a transparent manner.

[0256] In some embodiments, after receiving the eleventh information sent by the second network device, the first network device can send twelfth information to the terminal device in response to the eleventh information, and accordingly, the terminal device can receive the twelfth information sent by the first network device. The twelfth information can include the content of the eleventh information.

[0257] In some embodiments, the eleventh information can be carried in a PDCP control PDU.

[0258] In some embodiments, the method can further include: determining, by the terminal device, whether to decode and / or decompress the downlink data from the first network device based on the eleventh information or the twelfth information.

[0259] For example, assuming that the eleventh information or the twelfth information indicates that the SN of the third downlink data is N, the terminal device can learn from the eleventh information or the twelfth information that the downlink data with SN>N is transmitted based on the second configuration information, and / or the downlink data with SN≤N is transmitted based on the first configuration information. In this way, if the downlink data with SN≤N (i.e., the third downlink data and the downlink data before the third downlink data) are all received by the terminal device, it indicates that the downlink data transmitted based on the first configuration information has all been received by the terminal device, i.e., the subsequent transmitted downlink data are all downlink data transmitted based on the second configuration information. Therefore, in the case that the downlink data with SN≤N are all received by the terminal device, the terminal device can decode and / or decompress the downlink data from the first network device based on the second configuration information. For example, in the case that the downlink data with SN≤N are all received by the terminal device, if the terminal device receives a certain downlink data (e.g., the second downlink data) from the first network device, the terminal device can decode and / or decompress the downlink data using the second configuration information.

[0260] In some embodiments, in the case that the third downlink data and the downlink data before the third downlink data are all received by the terminal device, or in the case that the second timer is timed out, the terminal device can decode and / or decompress the downlink data from the first network device based on the second configuration information.

[0261] For example, if the third downlink data and the downlink data before the third downlink data (i.e., the downlink data with SN≤N) are all received by the terminal device, it indicates that the downlink data transmitted based on the first configuration information has all been received by the terminal device, i.e., the subsequent transmitted downlink data are all downlink data transmitted based on the second configuration information, and therefore, in the case that the third downlink data and the downlink data before the third downlink data are all received by the terminal device, the terminal device can decode and / or decompress the subsequently received downlink data based on the second configuration information.

[0262] For another example, if the second timer (e.g., reordering timer) is timed out, regardless of whether the third downlink data and the downlink data before the third downlink data are all received by the terminal device, the terminal device does not need to wait and can start to decode and / or decompress the subsequently received downlink data using the second configuration information.

[0263] In some embodiments, the first configuration information can include: first PDCP configuration information and / or first bearer configuration information.

[0264] In some embodiments, the second configuration information can comprise: second PDCP configuration information and / or second bearer configuration information.

[0265] In some embodiments, the first PDCP configuration information can be used to configure: a first encryption algorithm (including related configuration for generating a key) and / or a first compression algorithm.

[0266] In some embodiments, the second PDCP configuration information can be used to configure: a second encryption algorithm (including related configuration for generating a key) and / or a second compression algorithm.

[0267] In some embodiments, the first PDCP configuration information is different from the second PDCP configuration information. For example, the first encryption algorithm used for encrypting the first downlink data is different from the second encryption algorithm used for encrypting the second downlink data; and / or, the first compression algorithm used for compressing the first downlink data is different from the second compression algorithm used for compressing the second downlink data.

[0268] In some embodiments, the first bearer configuration information can be used to configure: one or more first bearer corresponding RLC entities and / or logical channels. Wherein, the first downlink data can be transmitted through a fifth bearer in the one or more first bearers, for example. That is, the first downlink data can be transmitted through the fifth bearer, the fifth bearer corresponding RLC entity, and the fifth bearer corresponding logical channel (e.g., a third logical channel).

[0269] In some embodiments, the second bearer configuration information can be used to configure: one or more second bearer corresponding RLC entities and / or logical channels. Wherein, the second downlink data can be transmitted through a sixth bearer in the one or more second bearers, for example. That is, the second downlink data can be transmitted through the sixth bearer, the sixth bearer corresponding RLC entity, and the sixth bearer corresponding logical channel (e.g., a fourth logical channel).

[0270] In some embodiments, the fifth bearer is different from the sixth bearer. That is, for data transmitted based on the first configuration information (e.g., the first downlink data) and data transmitted based on the second configuration information (e.g., the second downlink data), independent bearers can be configured respectively.

[0271] In some embodiments, the fifth bearer is the same as the sixth bearer. In this way, in the case of limited number of bearers, data transmitted based on the first configuration information (e.g., the first downlink data) and data transmitted based on the second configuration information (e.g., the second downlink data) can share the same bearer, and the terminal device does not need to establish a new bearer for data transmitted based on the second configuration information.

[0272] In some embodiments, the second configuration information can be carried in a handover command (RRC reconfiguration message) sent by the second network device to the terminal device.

[0273] As an implementation manner, the second network device can carry the second configuration information in the handover command, and send the handover command to the terminal device through the first network device.

[0274] In some embodiments, before the terminal device receives the first downlink data and the second downlink data sent by the first network device, the method can further include: the terminal device sends a handover completion message (RRC reconfiguration completion message) to the network device that configures the second configuration information. The handover completion message can be sent based on the second configuration information.

[0275] For example, after the terminal device receives the second configuration information, the terminal device can perform a corresponding configuration operation based on the second configuration information. After the configuration operation is completed, the terminal device can send a handover completion message to the network device that configures the second configuration information.

[0276] As an implementation manner, the terminal device can send the handover completion message to the network device that configures the second configuration information through the first network device. For example, before the terminal device receives the first downlink data and the second downlink data sent by the first network device, the terminal device can send the handover completion message to the first network device. Correspondingly, before the first network device sends the first downlink data and the second downlink data to the terminal device, the first network device can receive the handover completion message sent by the terminal device. Further, the first network device can send the handover completion message to the network device that configures the second configuration information (such as the second network device or the third network device).

[0277] In some embodiments, the first downlink data can come from the second network device. For example, the second network device can send the first downlink data to the first network device, and then the first network device can send the first downlink data to the terminal device. The first downlink data is sent based on the first configuration information.

[0278] In some embodiments, the first downlink data can include: retransmission (such as ARQ / HARQ retransmission) of downlink data that the second network device has transmitted to the RLC entity and / or the MAC entity of the first network device before the second network device sends the handover command to the terminal device.

[0279] In some embodiments, the second downlink data can come from the second network device. For example, in the case that the second configuration information is configured by the second network device, the second network device can send the second downlink data to the first network device based on the second configuration information, and then the first network device can send the second downlink data to the terminal device.

[0280] In some embodiments, in a case that the second configuration information is configured by the second network device, or in a case that the second downlink data is from the second network device, the second downlink data can comprise downlink data generated by the second network device after the second network device receives the handover completion message from the terminal device.

[0281] In some embodiments, the second downlink data can be from the third network device. For example, in a case that the second configuration information is configured by the third network device, the third network device can send the second downlink data to the first network device based on the second configuration information, and then the first network device can send the second downlink data to the terminal device.

[0282] In some embodiments, in a case that the second configuration information is configured by the third network device, or in a case that the second downlink data is from the third network device, the second downlink data can comprise downlink data generated by the third network device after the third network device receives the handover completion message from the terminal device.

[0283] In some embodiments, before the first network device sends the first downlink data and the second downlink data to the terminal device, the first network device can send sixth information to the terminal device. The sixth information can be used by the terminal device to measure one or more cells.

[0284] Correspondingly, before the terminal device receives the first downlink data and the second downlink data sent by the first network device, the terminal device can receive the sixth information sent by the first network device, and then can measure one or more cells based on the sixth information to obtain a result of measuring the one or more cells.

[0285] In some embodiments, the first network device can receive the sixth information from the second network device, and then send / forward the sixth information from the second network device to the terminal device.

[0286] In some embodiments, the sixth information can be, for example, measurement configuration information, or the sixth information can be carried in the measurement configuration information.

[0287] In some embodiments, the sixth information can be used to indicate a correspondence between one or more cells and network devices (such as CUs and / or DUs). Then, the terminal device can determine a priority of measuring the one or more cells according to the correspondence. For example, the terminal device can preferentially measure cells corresponding to the same DU and / or cells corresponding to the same CU.

[0288] In some embodiments, the correspondence can include a correspondence between the one or more cells and one or more network devices. For example, the correspondence can include at least one of: a correspondence between the one or more cells and the source CU; a correspondence between the one or more cells and a candidate CU (a CU to which the terminal device can be handed over); a correspondence between the one or more cells and the source DU; and a correspondence between the one or more cells and a candidate DU (a DU to which the terminal device can be handed over).

[0289] According to the method of the present embodiment, the terminal device can learn the correspondence between the cells and the network devices (e.g., CUs and / or DUs) according to the sixth information, so that the measurement process can be optimized according to the correspondence, so that the target of the handover is more suitable.

[0290] In some embodiments, the sixth information can be used to indicate a priority of the measurement of the one or more cells by the terminal device.

[0291] In some embodiments, the terminal device can send thirteenth information to the first network device before receiving the first downlink data and the second downlink data sent by the first network device. Accordingly, the first network device can receive the thirteenth information sent by the terminal device before sending the first downlink data and the second downlink data to the terminal device. The thirteenth information includes a result of the measurement of the one or more cells by the terminal device.

[0292] In some embodiments, after receiving the thirteenth information sent by the terminal device, the first network device can send / forward the thirteenth information to the second network device.

[0293] In some embodiments, the thirteenth information can be, for example, a measurement report, or the thirteenth information can be carried in a measurement report.

[0294] In some embodiments, the thirteenth information is periodically sent, or is sent when a first condition is met.

[0295] As an example, the first condition can include one or more of the following:

[0296] The terminal device receives fourteenth information sent by the first network device, the fourteenth information being used to request the thirteenth information;

[0297] The terminal device completes the handover between different DUs of the same CU;

[0298] The terminal device completes the handover between different CUs of the same DU;

[0299] The first measurement result is greater than or equal to a first threshold value;

[0300] The second measurement result is less than or equal to a second threshold value;

[0301] a difference between the first measurement result and the second measurement result is greater than or equal to a third threshold value;

[0302] The first measurement result can include a result of measurement of a cell corresponding to the third network device by the terminal device, and the second measurement result can include a result of measurement of a cell corresponding to the second network device by the terminal device.

[0303] The first condition can be described in the foregoing embodiments, and details are not described herein.

[0304] According to the method, the terminal device can send the thirteenth information to the second network device through the first network device to indicate the result of measurement of one or more cells by the terminal device, and then the second network device can refer to the thirteenth information to determine whether to instruct the terminal device to perform handover. In some embodiments, the second network device can also determine whether to instruct the terminal device to perform handover according to the service requirement of the terminal device and / or the current load of the second network device.

[0305] According to the technical solution of the embodiments of the present application, the terminal device can use the same MAC entity to process data (such as first downlink data) based on the first configuration information and data (such as second downlink data) based on the second configuration information, so that the terminal device does not need to rebuild the MAC entity and maintain two sets of MAC entities, thereby facilitating reduction of data interruption delay in the handover process and reduction of the capability requirement and implementation complexity of the terminal device.

[0306] The above describes the data transmission method provided by the embodiments of the present application. In order to facilitate understanding of the embodiments of the present application, the following describes possible implementation schemes of the data transmission method applicable to the embodiments of the present application.

[0307] The following describes three implementation schemes (referred to as scheme one, scheme two and scheme three) provided by the embodiments of the present application.

[0308] Scheme one

[0309] In scheme one, the UE can use the same MAC entity for data transmission with the source side (source CU side) and the target side (target CU side), but use different logical channels (LCHs) / channel IDs.

[0310] For example, the UE can establish separate bearers for the source CU and the target CU according to network configuration, and transmit through different RLCs and LCHs. Thus, the DU can identify the corresponding bearers according to different LCHs, and then determine to which CU to deliver the bearers.

[0311] FIG. 6 is a schematic diagram of a protocol stack in a handover (HO) execution process according to an embodiment of the present application, which can be applied to solution one. As shown in (a) of FIG. 6, the UE side can maintain one MAC entity, two RLC entities and two PDCP entities. In the PDCP entity, a bearer #1 can be established for the source CU and a bearer #2 can be established for the target CU. In the MAC entity, an LCH #1 corresponding to the bearer #1 can be established and an LCH #2 corresponding to the bearer #2 can be established. As shown in (b) of FIG. 6, the protocol stack of the network side (DU, source CU, target CU side) corresponds to that of the UE side.

[0312] FIG. 7 shows a schematic diagram of a possible implementation process of solution one. As shown in FIG. 7, the implementation process can include the following steps:

[0313] S701, the UE performs transmission of measurement configuration and measurement report with the source CU.

[0314] In this step, the source CU can send the measurement configuration to the UE through the DU. Exemplarily, the measurement configuration can include measurement configuration of the source CU (cell A) and the target CU (cell B), where the cell A and the cell B correspond to the source CU and the target CU respectively.

[0315] In some embodiments, the measurement configuration can indicate the correspondence between the cell and the CU and / or DU, so that the UE can determine the measurement priority of the CU / cell according to the correspondence. For example, the UE can preferentially measure the (cell of) the same DU and / or the same CU.

[0316] After completing the measurement, the UE can send the measurement report to the source CU through the DU. Exemplarily, the measurement report can include measurement results of the source CU (cell A) and the target CU (cell B).

[0317] In some embodiments, the UE can periodically report the measurement report, or the UE can report the measurement report in the case that one or more of the following events a to f are triggered.

[0318] Event a: network request. That is, if the source CU requests the UE to report the measurement report, the UE can send the measurement report to the source CU through the DU.

[0319] Event b: the UE completes the handover / conditional handover between different DUs of the same CU, that is, intra-CU inter-DU handover / conditional handover.

[0320] Event c: the UE completes the handover / conditional handover between different CUs of the same DU, that is, inter-CU intra-DU handover / conditional handover.

[0321] Event d: the measurement result of one of the cells associated with a certain CU (e.g., target CU) is better than / higher than a first threshold, or the average measurement result of all the cells associated with the CU is better than / higher than the first threshold.

[0322] Event e: the measurement result of one of the cells associated with the source CU is worse than / lower than a second threshold, or the average measurement result of all the cells associated with the source CU is worse than / lower than the second threshold.

[0323] Event f: the difference between the measurement result (or the average measurement result of all the cells) of one of the cells associated with a certain CU (e.g., target CU) and the measurement result (or the average measurement result of all the cells) of one of the cells associated with the source CU is greater than or equal to a third threshold.

[0324] Currently, the UE cannot see the relationship between the cells, CUs and DUs, which leads to the UE being unable to identify different handover scenarios and optimize the measurement process. Through the above technical solutions, the corresponding relationship between the cells and the CUs and / or DUs can be indicated in the measurement configuration, so that the UE can optimize the measurement process, so that the target of the HO is more suitable.

[0325] In some embodiments, S701 can be omitted.

[0326] S702: The source CU determines to hand over the UE to the target CU.

[0327] Exemplarily, the source CU can decide to hand over the UE to the target CU (cell B) according to one or more of the following a1) to a3):

[0328] a1) Measurement report (e.g., the measurement report reported by the UE in S701).

[0329] a2) Traffic demand of the UE. For example, different cells\frequency layers\CUs are responsible for different traffic, so that the source CU can determine the target CU for the UE to perform handover according to the traffic demand of the UE.

[0330] a3) Load balancing reason. For example, the source CU can decide to hand over the UE to other CU (e.g., target CU) in the case of heavy load.

[0331] S703: The source CU transmits the handover request message and the handover reception message with the target CU.

[0332] In this step, the source CU can share the current configuration of the UE (e.g., PDCP configuration and bearer configuration) to the target CU by sending the handover request message to the target CU.

[0333] S704: The target CU sends a configuration message for the UE to the source CU.

[0334] In this step, the target CU can configure the UE on the target side and send a configuration message to the source CU.

[0335] Exemplarily, the configuration message can include PDCP configuration and bearer configuration on the target side. The PDCP configuration can include encryption algorithm configuration (including related configuration for generating a key) and compression algorithm configuration, and the bearer configuration can include RLC and LCH configuration corresponding to one or more bearers (different LCHs from those used by the source CU).

[0336] According to the method of this embodiment, the source CU can reconfigure or newly create PDCP entities and bearers for the UE, so that the UE does not need to reestablish the entire protocol stack, thereby avoiding additional latency. Moreover, the UE does not need to maintain two MAC entities, thereby avoiding excessive load and reducing implementation complexity.

[0337] S705. The source CU sends an RRC reconfiguration message to the UE through the DU.

[0338] In this step, the source CU can send an RRC reconfiguration message (i.e., a handover command) to the UE through the DU. The RRC reconfiguration message can include the configuration message sent by the target CU to the source CU (the configuration message for the UE).

[0339] S706. The UE performs a configuration operation.

[0340] After receiving the RRC reconfiguration message (the handover command) from the source CU, the UE can establish new PDCP entities, bearers, RLC entities, and LCHs for the target CU according to the PDCP configuration and the bearer configuration carried in the RRC reconfiguration message.

[0341] S707. The UE sends an RRC reconfiguration complete message to the target CU through the DU.

[0342] In this step, the UE can send an RRC reconfiguration complete message (i.e., a handover complete message) to the target CU through the DU. The transmission of the handover complete message (transmitted through an SRB) can use the bearer configuration configured by the target CU.

[0343] According to the method of this embodiment, in the scenario of intra-DU handover, the UE does not need to re-perform a random access (RA) / synchronization procedure and can directly send a handover complete (HO complete) message to complete the handover, thereby further reducing handover latency.

[0344] S708. The target CU and the source CU perform UE release request and confirmation.

[0345] In this step, the target CU can send a UE release request message to the source CU, and the source CU can send a confirmation message to the target CU accordingly.

[0346] It should be noted that the embodiments do not limit the execution order of S708, S709, S710 and S711. For example, in some scenarios, S708 can be executed simultaneously with one or more of S709, S710 and S711.

[0347] S709, the UE sends uplink data to the DU.

[0348] Exemplarily, the uplink data sent by the UE to the DU can include uplink data sent to the source CU and uplink data sent to the target CU.

[0349] The uplink data sent to the source CU can use the configuration on the source side, for example, the PDCP configuration (such as key / compression algorithm configuration) and bearer configuration (such as RLC, LCH configuration corresponding to the bearer) configured by the source CU for the UE; the uplink data sent to the target CU can use the configuration on the target side, for example, the PDCP configuration (such as key / compression algorithm configuration) and bearer configuration (such as RLC, LCH configuration corresponding to the bearer) configured by the target CU for the UE.

[0350] In some embodiments, the uplink data sent to the source CU can include ARQ / HARQ retransmission of data already submitted to the RLC entity and / or the MAC entity before the UE receives the handover command (or in other words, before the UE establishes a new PDCP entity / bearer for the target CU).

[0351] In some embodiments, the uplink data sent to the target CU can include all uplink data generated after the UE receives the handover command (or in other words, after the UE establishes a new PDCP entity / bearer for the target CU).

[0352] Further, after the DU receives the uplink data from the UE, the DU can send the uplink data to the source CU or the target CU according to the mapping of the LCH transmitting the uplink data to the bearer / PDCP entity (see S710 and S711).

[0353] S710, the DU sends the uplink data from the UE to the source CU.

[0354] Exemplarily, after the DU receives the uplink data from the UE, if it is found that the bearer / PDCP entity corresponding to the LCH transmitting the uplink data is associated with the source CU (for example, configured by the source CU), the DU can send the uplink data to the source CU.

[0355] S711, the DU sends the uplink data from the UE to the target CU.

[0356] Exemplarily, after receiving the uplink data from the UE, if the DU finds that the LCH corresponding to the uplink data is associated with the target CU (e.g. configured by the target CU), the DU can send the uplink data to the target CU.

[0357] Further, the source CU can forward the received uplink data (if any) to the target CU.

[0358] In some embodiments, the source CU and / or the target CU can send downlink data to the DU, and the DU can send the downlink data to the UE.

[0359] The downlink data sent by the source CU can use the configuration on the source side, e.g. the PDCP configuration (e.g. key / compression algorithm configuration) and bearer configuration (e.g. RLC, LCH configuration corresponding to the bearer) configured by the source CU for the UE; the downlink data sent by the target CU can use the configuration on the target side, e.g. the PDCP configuration (e.g. key / compression algorithm configuration) and bearer configuration (e.g. RLC, LCH configuration corresponding to the bearer) configured by the target CU for the UE.

[0360] In some embodiments, the downlink data sent by the source CU can include the ARQ / HARQ retransmission of the data already submitted to the RLC entity and / or the MAC entity of the DU by the source CU before sending the handover command to the UE.

[0361] In some embodiments, the downlink data sent by the target CU can include all the downlink data for the UE generated by the target CU after receiving the handover complete message from the UE.

[0362] Further, after receiving the downlink data from the DU, the UE can decrypt (decode) and decompress the downlink data according to the mapping of the LCH transmitting the downlink data to the bearer / PDCP entity.

[0363] For example, after receiving the downlink data from the DU, if the UE finds that the LCH corresponding to the downlink data is associated with the source CU (e.g. configured by the source CU), the UE can decrypt and decompress the downlink data using the PDCP configuration used before receiving the handover command.

[0364] For another example, after receiving the downlink data from the DU, if the UE finds that the LCH corresponding to the downlink data is associated with the target CU (e.g. configured by the target CU), the UE can decrypt and decompress the downlink data using the PDCP configuration in the handover command.

[0365] S712, the target CU sends a source side release command to the UE through the DU.

[0366] Exemplarily, the target CU can send a source side release command to the UE through the DU in a case where it is determined that the source side data transmission has been completed.

[0367] S713, the UE performs a release operation on the source side.

[0368] After receiving the source side release command, the UE can release the source side PDCP entity, the bearer, and the source side related configurations such as the corresponding RLC entity and LCH.

[0369] According to the method of the embodiment, the UE can send new transmission and / or retransmission data to the target side (target CU) on a new path according to the configuration, and at the same time, send retransmission data to the source side (source CU) on an old path, so as to realize lossless transmission.

[0370] Scheme two

[0371] In scheme two, the UE can use the same MAC entity and the same LCH to perform data transmission with the source side (source CU side) and the target side (target CU side), and can indicate in the RLC layer whether the transmission of the data uses a new configuration (such as a new key) or an old configuration (such as an old key).

[0372] Exemplarily, the UE can establish separate bearers for the source CU and the target CU according to the network configuration, wherein the bearers corresponding to the source CU and the bearers corresponding to the target CU can be transmitted in the same RLC and LCH. Further, the DU can identify different bearers according to the indication information (such as an identifier) in the RLC packet header, and deliver the bearers to the associated CU.

[0373] FIG. 8 is a schematic diagram of a protocol stack in a HO execution process according to an embodiment of the present application, which can be applied to scheme two. As shown in (a) of FIG. 8, the UE side can maintain one (a set) MAC entity, one (a set) RLC entity, and two (two sets) PDCP entities. In the PDCP entity, a bearer #1 can be established for the source CU, and a bearer #2 can be established for the target CU. As shown in (b) of FIG. 8, the protocol stack of the network side (DU, source CU, target CU side) corresponds to the UE side.

[0374] FIG. 9 shows a possible implementation flowchart of scheme two. As shown in FIG. 9, the implementation flowchart can include the following steps:

[0375] S901, the UE performs measurement configuration and measurement report transmission with the source CU.

[0376] S902, the source CU determines to hand over the UE to the target CU.

[0377] S903, the source CU and the target CU perform transmission of a handover request message and a handover reception message.

[0378] The implementation manners of S901 to S903 are the same as those of the aforementioned S701 to S703, which will not be described herein.

[0379] S904, the target CU sends a configuration message for the UE to the source CU.

[0380] In this step, the target CU can perform target-side configuration for the UE and send the configuration message to the source CU.

[0381] Exemplarily, the configuration message can include target-side PDCP configuration and bearer configuration. The PDCP configuration can include encryption algorithm configuration (including related configuration for generating a key) and compression algorithm configuration, and the bearer configuration can include RLC and LCH configuration corresponding to one or more bearers.

[0382] In this embodiment, the RLC and LCH configuration corresponding to one or more bearers in the target-side configuration can be the same as the RLC and LCH configuration corresponding to one or more bearers in the source-side configuration, that is, the UE can share RLC and LCH for data transmission in the source-side (source CU side) and the target-side (target CU side). In the case where the number of LCHs is limited, sharing LCHs can make data scheduling and transmission more efficient and help improve system capacity.

[0383] S905, the source CU sends an RRC reconfiguration message to the UE through a DU.

[0384] In this step, the source CU can send an RRC reconfiguration message (that is, a handover command) to the UE through a DU, and the RRC reconfiguration message can include the configuration message (configuration message for the UE) sent by the target CU to the source CU in S904.

[0385] S906, the UE performs a configuration operation.

[0386] After receiving the RRC reconfiguration message (handover command) from the source CU, the UE can establish a new PDCP entity and bearers for the target CU according to the PDCP configuration and bearer configuration carried in the RRC reconfiguration message. In some scenarios, if the network configures new RLC and LCH configurations as needed, the UE can also establish new RLC entities and LCHs according to the network configuration.

[0387] S907, the UE sends an RRC reconfiguration complete message to the target CU through a DU.

[0388] In this step, the UE can send an RRC reconfiguration complete message (i.e., a handover complete message) to the target CU via the DU, the transmission of which (via SRB) can use the bearer configuration configured by the target CU.

[0389] S908, the target CU and the source CU perform UE release request and acknowledgement.

[0390] In this step, the target CU can send a UE release request message to the source CU, and the source CU can send an acknowledgement message to the target CU accordingly.

[0391] It should be noted that the embodiments do not limit the execution order of S908, S909, S910 and S911. For example, in some scenarios, S908 can be executed simultaneously with one or more of S909, S910 and S911.

[0392] S909, the UE sends uplink data to the DU.

[0393] Exemplarily, the uplink data sent by the UE to the DU can include uplink data sent to the source CU and uplink data sent to the target CU.

[0394] The uplink data sent to the source CU can use the configuration on the source side, for example, the PDCP configuration (such as key / compression algorithm configuration) and bearer configuration (such as RLC, LCH configuration corresponding to the bearer) configured by the source CU for the UE; the uplink data sent to the target CU can use the configuration on the target side, for example, the PDCP configuration (such as key / compression algorithm configuration) and bearer configuration (such as RLC, LCH configuration corresponding to the bearer) configured by the target CU for the UE.

[0395] In some embodiments, the uplink data sent to the source CU can include ARQ / HARQ retransmission of data that has been submitted to the RLC entity and / or the MAC entity before the UE receives the handover command (or in other words, before the UE establishes a new PDCP entity / bearer for the target CU).

[0396] In some embodiments, the uplink data sent to the target CU can include all uplink data generated after the UE receives the handover command (or in other words, after the UE establishes a new PDCP entity / bearer for the target CU).

[0397] In this embodiment, the UE needs to indicate in the RLC layer whether each uplink data is uplink data sent to the source end (source CU) or uplink data sent to the target end (target CU). The indication can be made in the RLC packet header. For example, for a certain uplink data, 1 bit of indication information (such as an identifier) can be added in the RLC packet header of the uplink data to indicate S or T. S indicates that the uplink data is uplink data sent to the source end (source CU), and T indicates that the uplink data is uplink data sent to the target end (target CU).

[0398] Further, after receiving the uplink data from the UE, the DU can deliver the uplink data to the source CU or the target CU according to the indication in the RLC packet header (see S910 and S911).

[0399] S910, the DU sends the uplink data from the UE to the source CU.

[0400] For example, after receiving the uplink data from the UE, if the DU finds that the RLC packet header of the uplink data indicates S, the DU can send the uplink data to the source CU.

[0401] S911, the DU sends the uplink data from the UE to the target CU.

[0402] For example, after receiving the uplink data from the UE, if the DU finds that the RLC packet header of the uplink data indicates T, the DU can send the uplink data to the target CU.

[0403] Further, the source CU can forward the received uplink data (if any) to the target CU.

[0404] In some embodiments, the source CU and / or the target CU can send downlink data to the DU, and the DU sends the downlink data to the UE.

[0405] The downlink data sent by the source CU can use the configuration on the source side, for example, the PDCP configuration (such as key / compression algorithm configuration) and bearer configuration (such as RLC, LCH configuration corresponding to the bearer) configured by the source CU for the UE; the downlink data sent by the target CU can use the configuration on the target side, for example, the PDCP configuration (such as key / compression algorithm configuration) and bearer configuration (such as RLC, LCH configuration corresponding to the bearer) configured by the target CU for the UE.

[0406] In some embodiments, the downlink data sent by the source CU can include ARQ / HARQ retransmission of data that has been delivered to the RLC entity and / or the MAC entity of the DU by the source CU before sending the handover command to the UE.

[0407] In some embodiments, the downlink data sent by the target CU can include all downlink data for the UE generated by the target CU after the target CU receives the handover complete message from the UE.

[0408] In the present embodiment, the DU needs to indicate in the RLC layer whether each downlink data is downlink data from the source end (source CU) or downlink data from the target end (target CU). The indication can be made in the RLC packet header. For example, for a certain downlink data, 1 bit of indication information (such as an identifier) can be added in the RLC packet header of the downlink data to indicate S or T. S indicates that the downlink data is downlink data from the source end (source CU), and T indicates that the downlink data is downlink data from the target end (target CU).

[0409] Further, after the UE receives the downlink data from the DU, the UE can use the corresponding configuration to decrypt and decompress the downlink data according to the indication in the RLC packet header.

[0410] For example, after the UE receives the downlink data from the DU, if the UE finds that the RLC packet header of the downlink data indicates S, the UE can use the PDCP configuration used before receiving the handover command to decrypt and decompress the downlink data.

[0411] For another example, after the UE receives the downlink data from the DU, if the UE finds that the RLC packet header of the downlink data indicates T, the UE can use the PDCP configuration in the handover command to decrypt and decompress the downlink data.

[0412] S912, the target CU sends a source side release command to the UE through the DU.

[0413] Exemplarily, the target CU can send the source side release command to the UE through the DU in a case where it is determined that the source side data transmission has been completed.

[0414] S913, the UE performs a release operation on the source side.

[0415] After receiving the source side release command, the UE can release the PDCP entity and the bearer on the source side. In some scenarios, if the UE establishes a new RLC entity and LCH according to the network configuration, the UE can also release the RLC entity and LCH on the source side.

[0416] Scheme three

[0417] In scheme three, the UE can use the same MAC entity and the same LCH to perform data transmission with the source side (source CU side) and the target side (target CU side), and can indicate the handover node (i.e., handover to the newly configured node) in the PDCP layer.

[0418] Exemplarily, the source CU and the target CU can use the same bearer, but have different PDCP configurations. The UE can indicate the switching node to the source CU at the PDCP layer. In some embodiments, the DU can deliver the received data packets to the source CU, and the source CU can instruct the DU to stop delivering data packets to the source CU according to the switching node indicated at the PDCP layer. After receiving the instruction of the source CU, the DU can deliver the subsequently received data packets to the target CU.

[0419] FIG. 10 is a schematic diagram of a protocol stack in a HO execution process according to an embodiment of the present application, which can be applicable to scheme three. As shown in (a) of FIG. 10, the UE side can maintain one (or a set of) MAC entity, one (or a set of) RLC entity, and one (or a set of) PDCP entity. As shown in (b) of FIG. 10, the DU side can maintain one (or a set of) MAC entity and one (or a set of) RLC entity, and the source CU and the target CU can use the same bearer but different PDCP configurations.

[0420] FIG. 11 shows a schematic diagram of a possible implementation process of scheme three. As shown in FIG. 11, the implementation process can include the following steps:

[0421] S1101, the UE performs transmission of measurement configuration and measurement report with the source CU.

[0422] S1102, the source CU determines to switch the UE to the target CU.

[0423] S1103, the source CU performs transmission of a switching request message and a switching reception message with the target CU.

[0424] The implementation manners of S1101 to S1103 are the same as those of S701 to S703, which will not be described herein.

[0425] S1104, the target CU sends a configuration message for the UE to the source CU.

[0426] In this step, the target CU can perform target-side configuration for the UE and send the configuration message to the source CU.

[0427] Exemplarily, the configuration message can include target-side PDCP configuration, which can include encryption algorithm configuration (including related configuration for generating a key) and compression algorithm configuration.

[0428] In some embodiments, the configuration message can further include bearer configuration, which can include RLC, LCH configuration corresponding to one or more bearers. In this embodiment, the bearer configuration on the target side can be the same as that on the source side. In some scenarios, the bearer configuration on the target side can further include bearer configuration different from that on the source side (if needed).

[0429] S1105, the source CU sends an RRC reconfiguration message to the UE through the DU.

[0430] In this step, the source CU can send an RRC reconfiguration message (i.e., a handover command) to the UE through the DU, which can include the configuration message sent by the target CU to the source CU in S1104 (the configuration message for the UE).

[0431] S1106, the UE performs a configuration operation.

[0432] After receiving the RRC reconfiguration message (the handover command) from the source CU, the UE can start using the new encryption algorithm, key and compression algorithm according to the PDCP configuration carried in the RRC reconfiguration message.

[0433] S1107, the UE sends an RRC reconfiguration complete message to the target CU through the DU.

[0434] In this step, the UE can send an RRC reconfiguration complete message (i.e., a handover complete message) to the target CU through the DU.

[0435] S1108, the target CU and the source CU perform UE release request and confirmation.

[0436] In this step, the target CU can send a UE release request message to the source CU, and the source CU can send a confirmation message to the target CU accordingly.

[0437] S1109, the UE sends uplink data and handover node indication information to the DU.

[0438] Exemplarily, the uplink data sent by the UE to the DU can include: uplink data sent using the source side configuration and uplink data sent using the target side configuration.

[0439] In some embodiments, the uplink data sent using the source side configuration can include: ARQ / HARQ retransmission of data already submitted to the RLC entity and / or the MAC entity before the UE receives the handover command (or in other words, before the UE starts using the new encryption algorithm, key and compression algorithm).

[0440] In some embodiments, the uplink data sent using the target side configuration can include: all uplink data generated after the UE receives the handover command (or in other words, after the UE starts using the new encryption algorithm, key and compression algorithm).

[0441] In this embodiment, the UE can also send the switching node indication information to the DU, for indicating the switching node (i.e. the node to which the switching is made, i.e. the node configured at the target side). For example, the switching node indication information can indicate that the target side configuration is to be used from SN number M onwards (e.g. by indicating SN = M). As an example, the switching node indication information can be carried by a PDCP control PDU.

[0442] S1110, the DU sends the uplink data and the switching node indication information to the source CU.

[0443] Upon receiving the uplink data from the UE, the DU can send the uplink data to the source CU, and can send the switching node indication information from the UE to the source CU

[0444] S1111, the source CU decodes the uplink data and / or determines whether to send the switching indication information.

[0445] Upon receiving the uplink data, the source CU can perform one or more of the following operations A, B and C.

[0446] Operation A: if the uplink data (packets) fails to be decrypted and / or decompressed, the uplink data is not discarded and is forwarded to the target CU (i.e. S1113).

[0447] Operation B: upon receiving the switching node indication information (e.g. indicating SN = M), the switching node indication information is sent to the target CU (i.e. S1113).

[0448] Operation C: if there is uplink data (packets) with SN < M waiting to be received, the waiting continues; if all uplink data (packets) with SN < M have been received, or a timer (e.g. reordering timer) expires (indicating that there is no need to wait), the source CU sends the switching indication information to the DU (i.e. S1112), for instructing the DU to hand over all subsequently received uplink data (packets) to the target CU.

[0449] S1112, the source CU sends the switching indication information to the DU.

[0450] S1113, the source CU sends the switching node indication information and the uplink data to the target CU.

[0451] In this step, the source CU can send the switching node indication information to the target CU, and can send the uplink data (packets) that fail to be decrypted and / or decompressed to the target CU.

[0452] In some embodiments, the source CU and / or the target CU can send downlink data to the DU, and the DU can send the downlink data to the UE.

[0453] In some embodiments, the source CU can send a handover node indication information to the UE through the DU, which can indicate, for example, SN=N, indicating that the target side configuration will be used from SN number N.

[0454] After the UE receives the downlink data (data packet) from the DU, the UE can perform operation D and / or operation E.

[0455] Operation D: decrypt and / or decompress the downlink data using the source side configuration, if failed, decrypt and / or decompress the downlink data using the target side configuration, if both failed, discard the downlink data.

[0456] Operation E: if the downlink data (data packet) up to SN < N has been received, or the timer (such as reordering timer) is expired, decrypt and / or decompress the downlink data using the target side configuration.

[0457] S1114, the target CU sends a source side release command to the UE through the DU.

[0458] Exemplarily, the target CU can send the source side release command to the UE through the DU in a case where it is determined that the source side data transmission has been completed.

[0459] S1115, the UE performs a release operation of the source side.

[0460] After receiving the source side release command, the UE can release the PDCP configuration of the source side.

[0461] According to the method of the present embodiment, the use of the source side configuration or the target side configuration for data transmission can be distinguished by the handover node in the time domain, so that the UE does not need to establish a new bearer, and thus the source side and the target side data transmission can share the same bearer in the case where the number of bearers is limited. It should be noted that in some scenarios, if there is a new requirement, a new bearer can also be established, and the implementation manner of data transmission through the newly established bearer can refer to the aforementioned scheme one and scheme two.

[0462] At present, in the 5G mobility mechanism, in the Intra-DU handover scenario (for example, in the Intra-DU Inter-CU handover scenario, or in the Intra-cell handover scenario), the UE needs to reestablish the protocol stack from the MAC layer to the PDCP layer, or perform DAPS handover. The method of reestablishing the protocol stack from the MAC layer to the PDCP layer will cause a large data interruption delay, and the method of DAPS handover needs to maintain two sets of MAC entities at the same time, which requires a higher UE capability / implementation complexity, and thus has not been well commercialized.

[0463] To this end, the embodiments of the present application provide a data transmission method. In the handover scenario of Intra-DU, since the MAC entity and the RLC entity are entities between the UE and the DU, and the PDCP entity is an entity between the UE and the CU, the embodiments of the present application consider a scheme of maintaining only two sets / two PDCP entities and sharing the same set / one MAC entity, so that, compared with the traditional handover mode, the delay caused by releasing / rebuilding the entire protocol stack is reduced, and compared with the DAPS handover, the complexity and load requirements of the UE are reduced.

[0464] It should be noted that the scheme of the embodiments of the present application can also be applied to the scenario of intra-cell handover. In some embodiments, the UE does not need to identify which handover scenario, and only needs to perform data transmission according to the configuration of the network.

[0465] In some embodiments, the UE can also establish separate MAC entities for the source side and the target side. This implementation is similar to scheme one, except that the UE performs data transmission with the source side and the target side through different MAC entities, respectively.

[0466] The preferred embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the specific details in the above-described embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical scheme of the present application, and these simple modifications all belong to the protection scope of the present application. For example, in the above-described specific embodiments, various specific technical features described in the embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application does not further describe various possible combination manners. For another example, various different embodiments of the present application can also be combined arbitrarily, as long as it does not deviate from the idea of the present application, it should also be considered as disclosed by the present application. For another example, under the premise of no conflict, each embodiment described in the present application and / or technical features in each embodiment can be combined with any prior art, and the technical scheme obtained after combination should also fall within the protection scope of the present application.

[0467] It should also be understood that the size of the sequence number of the above-mentioned processes does not mean the order of execution in various method embodiments of the present application, and the execution order of the processes should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In addition, in the embodiments of the present application, the terms "downlink", "uplink" and "sidelink" are used to represent the transmission direction of signals or data, wherein "downlink" is used to represent the first direction of the transmission direction of signals or data from the station to the user equipment of the cell, "uplink" is used to represent the second direction of the transmission direction of signals or data from the user equipment of the cell to the station, and "sidelink" is used to represent the third direction of the transmission direction of signals or data from user equipment 1 to user equipment 2. For example, "downlink signal" represents that the transmission direction of the signal is the first direction. In addition, in the embodiments of the present application, the term "and / or" is only used to describe the association relationship of the associated objects, and indicates that there can be three relationships. Specifically, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.

[0468] Based on the foregoing embodiments, the embodiments of the present application provide corresponding data transmission devices.

[0469] FIG. 12 is a structural composition schematic diagram of a data transmission device provided by the embodiments of the present application, which is applied to a terminal device. As shown in FIG. 12, a data transmission device 1200 (hereinafter referred to as device 1200) includes:

[0470] A first communication unit 1201 configured to send first uplink data and second uplink data to a first network device, wherein the first uplink data and the second uplink data are processed via a same medium access control (MAC) entity of the device 1200; and wherein the first uplink data is sent based on first configuration information.

[0471] In some embodiments, the second uplink data is sent based on second configuration information, the first configuration information is configuration information used by the device 1200 before performing handover, and the second configuration information is configuration information used by the device 1200 after performing handover.

[0472] In some embodiments, the first uplink data is transmitted through a first logical channel, and the second uplink data is transmitted through a second logical channel.

[0473] In some embodiments, the first logical channel has a first association relationship with the first configuration information, and the second logical channel has a second association relationship with the second configuration information.

[0474] In some embodiments, the first association relationship is used by the first network device to determine that the first uplink data is transmitted based on the first configuration information; and / or the second association relationship is used by the first network device to determine that the second uplink data is transmitted based on the second configuration information.

[0475] In some embodiments, first information is carried in a radio link control (RLC) header of the first uplink data, the first information being used to indicate that the first uplink data is transmitted based on the first configuration information; and / or second information is carried in an RLC header of the second uplink data, the second information being used to indicate that the second uplink data is transmitted based on the second configuration information.

[0476] In some embodiments, the first communication unit 1201 is further configured to: transmit, to the first network device, third information used to indicate that uplink data after third uplink data is transmitted based on the second configuration information, and / or that the third uplink data and uplink data before the third uplink data is transmitted based on the first configuration information.

[0477] In some embodiments, the third information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

[0478] In some embodiments, the first configuration information and the second configuration information are both configured by a second network device; or the first configuration information is configured by a second network device and the second configuration information is configured by a third network device; wherein the second network device is connected to the apparatus 1200 through the first network device, and is a source network device of the apparatus 1200 or a network device that has been connected before the apparatus 1200 performs handover; and the third network device is connected to the apparatus 1200 through the first network device, and is a target network device of the apparatus 1200 performing handover.

[0479] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, in the process of transmitting the first uplink data and the second uplink data to the first network device, the apparatus 1200 maintains connection with the second network device and maintains connection with the third network device.

[0480] In some embodiments, the first uplink data and the second uplink data are transmitted through the same logical channel.

[0481] In some embodiments, the first configuration information comprises: first PDCP configuration information and / or first bearer configuration information; and the second configuration information comprises: second PDCP configuration information and / or second bearer configuration information.

[0482] In some embodiments, the first PDCP configuration information is used to configure: a first encryption algorithm and / or a first compression algorithm; and the second PDCP configuration information is used to configure: a second encryption algorithm and / or a second compression algorithm.

[0483] In some embodiments, the first PDCP configuration information is different from the second PDCP configuration information.

[0484] In some embodiments, the first bearer configuration information is used to configure: one or more first bearer corresponding RLC entities and / or logical channels; and the second bearer configuration information is used to configure: one or more second bearer corresponding RLC entities and / or logical channels; wherein the first uplink data is transmitted through a third bearer in the one or more first bearers, and the second uplink data is transmitted through a fourth bearer in the one or more second bearers.

[0485] In some embodiments, the second configuration information is carried in a handover command sent by a second network device to the apparatus 1200; the second network device is connected with the apparatus 1200 through the first network device, and the second network device is a source network device of the apparatus 1200, or is a network device that has been connected before the apparatus 1200 performs handover.

[0486] In some embodiments, the first communication unit 1201 is further configured to: before the first uplink data and the second uplink data are sent to the first network device, send a handover completion message to a network device that configures the second configuration information, the handover completion message being sent based on the second configuration information.

[0487] In some embodiments, the first uplink data comprises: retransmission of uplink data that has been transmitted to an RLC entity and / or a MAC entity of the apparatus 1200 before the apparatus 1200 receives the handover command; and / or, the second uplink data comprises: uplink data generated after the apparatus 1200 receives the handover command.

[0488] In some embodiments, the first communication unit 1201 is further configured to: receive sixth information sent by the first network device, the sixth information being used for the apparatus 1200 to measure one or more cells; and the sixth information is used to indicate: a corresponding relationship between the one or more cells and a network device, and / or a priority of the apparatus 1200 measuring the one or more cells.

[0489] In some embodiments, the first communication unit 1201 is further configured to: before the sending of the first uplink data and the second uplink data to the first network device, send thirteenth information to the first network device; the thirteenth information includes: measurement results of one or more cells by the apparatus 1200; wherein the thirteenth information is periodically sent, or is sent when a first condition is met, the first condition including one or more of: the apparatus 1200 receives fourteenth information sent by the first network device, the fourteenth information being used to request the thirteenth information; the apparatus 1200 completes handover between different distributed units (DUs) of the same centralized unit (CU); the apparatus 1200 completes handover between different CUs of the same DU; a first measurement result is greater than or equal to a first threshold; a second measurement result is less than or equal to a second threshold; a difference between the first measurement result and the second measurement result is greater than or equal to a third threshold; wherein the first measurement result includes: measurement results of cells corresponding to a third network device by the apparatus 1200; the second measurement result includes: measurement results of cells corresponding to a second network device by the apparatus 1200, the second network device being connected to the apparatus 1200 through the first network device, and the second network device being a source network device of the apparatus 1200 or a network device that has been connected before the apparatus 1200 performs handover.

[0490] FIG. 13 is a schematic structural diagram of a data transmission apparatus according to an embodiment of the present application, which is applied to a first network device. As shown in FIG. 13, the data transmission apparatus 1300 (hereinafter referred to as apparatus 1300) includes:

[0491] A second communication unit 1301 configured to receive first uplink data and second uplink data sent by a terminal device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0492] In some embodiments, the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

[0493] In some embodiments, the first uplink data is transmitted through a first logical channel, and the second uplink data is transmitted through a second logical channel.

[0494] In some embodiments, the first logical channel has a first association relationship with the first configuration information, and the second logical channel has a second association relationship with the second configuration information.

[0495] In some embodiments, the first association relationship is used by the apparatus 1300 to determine that the first uplink data is transmitted based on the first configuration information; and / or the second association relationship is used by the apparatus 1300 to determine that the second uplink data is transmitted based on the second configuration information.

[0496] In some embodiments, first information is carried in a radio link control (RLC) header of the first uplink data, the first information being used to indicate that the first uplink data is transmitted based on the first configuration information; and / or second information is carried in an RLC header of the second uplink data, the second information being used to indicate that the second uplink data is transmitted based on the second configuration information.

[0497] In some embodiments, the first configuration information and the second configuration information are both configured by a second network device, the second network device being connected to the terminal device through the apparatus 1300, and the second network device being a source network device of the terminal device or a network device that has been connected to the terminal device before performing handover, and the second communication unit 1301 is further configured to: send fourth information to the second network device, the fourth information being used to indicate that the first uplink data is transmitted based on the first configuration information; and / or send fifth information to the second network device, the fifth information being used to indicate that the second uplink data is transmitted based on the second configuration information.

[0498] In some embodiments, the first configuration information is configured by a second network device, and the second configuration information is configured by a third network device, and the second communication unit 1301 is further configured to: send the first uplink data to the second network device; and send the second uplink data to the third network device; wherein the second network device is connected to the terminal device through the apparatus 1300, and the second network device is a source network device of the terminal device or a network device that has been connected to the terminal device before performing handover; and the third network device is connected to the terminal device through the apparatus 1300, and the third network device is a target network device of the terminal device performing handover.

[0499] In some embodiments, the second communication unit 1301 is further configured to: receive third information sent by the terminal device, the third information being used to indicate that uplink data after third uplink data is sent based on the second configuration information, and / or that the third uplink data and uplink data before the third uplink data is sent based on the first configuration information; and send the third information to a second network device, or send eighth information containing content of the third information to the second network device in response to the third information. The second network device is connected with the terminal device through the apparatus 1300, and is a source network device of the terminal device or a network device connected before performing handover of the terminal device.

[0500] In some embodiments, the third information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

[0501] In some embodiments, the second communication unit 1301 is further configured to: send the first uplink data and the second uplink data to a second network device. The second network device is a source network device of the terminal device or a network device connected before performing handover of the terminal device.

[0502] In some embodiments, the first configuration information and the second configuration information are both configured by a second network device, or the first configuration information is configured by the second network device and the second configuration information is configured by a third network device. The second network device is connected with the terminal device through the apparatus 1300, and is a source network device of the terminal device or a network device connected before performing handover of the terminal device. The third network device is connected with the terminal device through the apparatus 1300, and is a target network device of the terminal device performing handover.

[0503] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, the terminal device maintains connection with the second network device and maintains connection with the third network device in the process of receiving the first uplink data and the second uplink data sent by the terminal device.

[0504] In some embodiments, the first uplink data and the second uplink data are transmitted through the same logical channel.

[0505] In some embodiments, the first configuration information includes first PDCP configuration information and / or first bearer configuration information, and the second configuration information includes second PDCP configuration information and / or second bearer configuration information.

[0506] In some embodiments, the first PDCP configuration information is used to configure: a first encryption algorithm and / or a first compression algorithm; and the second PDCP configuration information is used to configure: a second encryption algorithm and / or a second compression algorithm.

[0507] In some embodiments, the first PDCP configuration information is different from the second PDCP configuration information.

[0508] In some embodiments, the first bearer configuration information is used to configure: one or more first bearers corresponding RLC entities and / or logical channels; and the second bearer configuration information is used to configure: one or more second bearers corresponding RLC entities and / or logical channels; wherein the first uplink data is transmitted through a third bearer in the one or more first bearers, and the second uplink data is transmitted through a fourth bearer in the one or more second bearers.

[0509] In some embodiments, the second configuration information is carried in a handover command sent by a second network device to the terminal device; the second network device is connected with the terminal device through the apparatus 1300, and the second network device is a source network device of the terminal device, or is a network device connected before performing handover for the terminal device.

[0510] In some embodiments, the second communication unit 1301 is further configured to: before the receiving of the first uplink data and the second uplink data sent by the terminal device, receive a handover completion message sent by the terminal device, the handover completion message being sent based on the second configuration information; and send the handover completion message to a network device that configures the second configuration information.

[0511] In some embodiments, the first uplink data includes: retransmission of uplink data that has been transmitted to an RLC entity and / or a MAC entity of the terminal device before the terminal device receives a handover command; and / or, the second uplink data includes: uplink data generated after the terminal device receives the handover command.

[0512] In some embodiments, the second communication unit 1301 is further configured to: send the sixth information to the terminal device, the sixth information being used for the terminal device to perform measurement on one or more cells; and the sixth information being used to indicate: a corresponding relationship between the one or more cells and a network device, and / or a priority of the terminal device performing measurement on the one or more cells.

[0513] Figure 14 is a schematic diagram of a structure of a data transmission apparatus according to an embodiment of the present application, which is applied to a second network device, the second network device is connected with a terminal device through a first network device, and the second network device is a source network device of the terminal device, or is a network device connected before performing handover of the terminal device. As shown in Figure 14, the data transmission apparatus 1400 (hereinafter referred to as apparatus 1400) comprises:

[0514] a third communication unit 1401 configured to receive first uplink data and second uplink data sent by the first network device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

[0515] In some embodiments, the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

[0516] In some embodiments, the first configuration information and the second configuration information are both configured by the apparatus 1400, and the third communication unit 1401 is further configured to receive fourth information sent by the first network device, the fourth information being used to indicate that the first uplink data is sent based on the first configuration information; and / or receive fifth information sent by the first network device, the fifth information being used to indicate that the second uplink data is sent based on the second configuration information.

[0517] In some embodiments, the first configuration information and the second configuration information are both configured by the apparatus 1400; and the apparatus 1400 further comprises a processing unit configured to decode and / or decompress the first uplink data using the first configuration information, and if decoding and / or decompressing fails, decode and / or decompress the first uplink data using the second configuration information; and / or decode and / or decompress the second uplink data using the first configuration information, and if decoding and / or decompressing fails, decode and / or decompress the second uplink data using the second configuration information.

[0518] In some embodiments, the first configuration information and the second configuration information are both configured by the apparatus 1400; the apparatus 1400 further comprises a processing unit configured to, in a case that the apparatus 1400 receives third information or eighth information, determine whether to use the second configuration information to decode and / or decompress the uplink data from the first network device based on the third information or the eighth information. In some embodiments, the third information is used to indicate that uplink data after third uplink data is transmitted based on the second configuration information, and / or the third uplink data and uplink data before the third uplink data is transmitted based on the first configuration information; and / or the eighth information contains the content of the third information.

[0519] In some embodiments, the first configuration information is configured by the apparatus 1400, and the second configuration information is configured by a third network device, the third network device is connected with the terminal device through the first network device, and the third network device is a target network device performing handover for the terminal device; the apparatus 1400 further comprises a processing unit configured to decode and / or decompress the first uplink data using the first configuration information, and if the decoding and / or decompression fails, send the first uplink data to the third network device; and / or decode and / or decompress the second uplink data using the first configuration information, and if the decoding and / or decompression fails, send the first uplink data to the third network device.

[0520] In some embodiments, the first configuration information is configured by the apparatus 1400, and the second configuration information is configured by a third network device, the third network device is connected with the terminal device through the first network device, and the third network device is a target network device performing handover for the terminal device; the apparatus 1400 further comprises a processing unit configured to, in a case that the apparatus 1400 receives third information or eighth information, determine whether to send seventh information to the first network device based on the third information or the eighth information; the seventh information is used to instruct the first network device to stop sending uplink data from the terminal device to the apparatus 1400, and / or is used to instruct the first network device to send subsequently received uplink data to the third network device.

[0521] In some embodiments, the third information is used to indicate that uplink data after third uplink data is transmitted based on the second configuration information, and / or the eighth information contains the content of the third information.

[0522] In some embodiments, the third communication unit 1401 is further configured to send the seventh information to the first network device in a case that the third uplink data and uplink data before the third uplink data are all received by the apparatus 1400, or in a case that the first timer is expired.

[0523] In some embodiments, the third information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

[0524] In some embodiments, the terminal device keeps connection with the second network device and keeps connection with the third network device in the process of receiving the first uplink data and the second uplink data sent by the first network device.

[0525] In some embodiments, the first uplink data includes retransmission of uplink data of a radio link control (RLC) entity and / or a MAC entity that has been transmitted to the terminal device before the terminal device receives the handover command, and / or the second uplink data includes uplink data generated after the terminal device receives the handover command.

[0526] FIG. 15 is a structural composition diagram of a data transmission apparatus according to an embodiment of the present application, which is applied to a terminal device. As shown in FIG. 15, a data transmission apparatus 1500 (hereinafter referred to as apparatus 1500) includes:

[0527] A fourth communication unit 1501 is configured to receive first downlink data and second downlink data sent by a first network device, the first downlink data and the second downlink data being processed by a same MAC entity of the apparatus 1500; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

[0528] In some embodiments, the first configuration information is configuration information used by the apparatus 1500 before performing handover, and the second configuration information is configuration information used by the apparatus 1500 after performing handover.

[0529] In some embodiments, the first downlink data is transmitted through a third logical channel, and the second downlink data is transmitted through a fourth logical channel.

[0530] In some embodiments, the third logical channel has a third association relationship with the first configuration information, and the fourth logical channel has a fourth association relationship with the second configuration information.

[0531] In some embodiments, the third association relationship is used by the apparatus 1500 to determine that the first downlink data is transmitted based on the first configuration information; and / or the fourth association relationship is used by the apparatus 1500 to determine that the second downlink data is transmitted based on the second configuration information.

[0532] In some embodiments, a ninth information is carried in a radio link control (RLC) header of the first downlink data, the ninth information being used to indicate that the first downlink data is transmitted based on the first configuration information; and / or a tenth information is carried in an RLC header of the second downlink data, the tenth information being used to indicate that the second downlink data is transmitted based on the second configuration information.

[0533] In some embodiments, the apparatus 1400 further includes a processing unit configured to decode and / or decompress the first downlink data using the first configuration information, and decode and / or decompress the first downlink data using the second configuration information if decoding and / or decompressing using the first configuration information fails; and / or decode and / or decompress the second downlink data using the first configuration information, and decode and / or decompress the second downlink data using the second configuration information if decoding and / or decompressing using the first configuration information fails.

[0534] In some embodiments, the fourth communication unit 1501 is further configured to receive an eleventh information or a twelfth information transmitted by the first network device; wherein the eleventh information is used to indicate that downlink data after third downlink data is transmitted based on the second configuration information, and / or the third downlink data and downlink data before the third downlink data is transmitted based on the first configuration information; and / or the twelfth information contains content of the eleventh information.

[0535] In some embodiments, the apparatus 1400 further includes a processing unit configured to determine, based on the eleventh information or the twelfth information, whether to decode and / or decompress downlink data from the first network device using the second configuration information.

[0536] In some embodiments, the apparatus 1400 further includes a processing unit configured to decode and / or decompress downlink data from the first network device based on the second configuration information, in a case that the third downlink data and downlink data before the third downlink data are all received by the apparatus 1500, or in a case that a second timer is expired.

[0537] In some embodiments, the eleventh information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

[0538] In some embodiments, the first configuration information and the second configuration information are both configured by a second network device; or the first configuration information is configured by the second network device, and the second configuration information is configured by a third network device; wherein the second network device is connected with the apparatus 1500 through the first network device, and the second network device is a source network device of the apparatus 1500 or a network device connected before the apparatus 1500 performs handover; the third network device is connected with the apparatus 1500 through the first network device, and the third network device is a target network device of the apparatus 1500 performing handover.

[0539] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, in the process of receiving the first downlink data and the second downlink data sent by the first network device, the apparatus 1500 maintains connection with the second network device and maintains connection with the third network device.

[0540] In some embodiments, the first downlink data and the second downlink data are transmitted through the same logical channel.

[0541] In some embodiments, the first configuration information includes first PDCP configuration information and / or first bearer configuration information; and the second configuration information includes second PDCP configuration information and / or second bearer configuration information.

[0542] In some embodiments, the first PDCP configuration information is used to configure a first encryption algorithm and / or a second compression algorithm; and the second PDCP configuration information is used to configure a second encryption algorithm and / or a second compression algorithm.

[0543] In some embodiments, the first PDCP configuration information is different from the second PDCP configuration information.

[0544] In some embodiments, the first bearer configuration information is used to configure one or more first bearer corresponding RLC entities and / or logical channels; and the second bearer configuration information is used to configure one or more second bearer corresponding RLC entities and / or logical channels; wherein the first downlink data is transmitted through a fifth bearer in the one or more first bearers, and the second downlink data is transmitted through a sixth bearer in the one or more second bearers.

[0545] In some embodiments, the second configuration information is carried in a handover command sent by a second network device to the apparatus 1500; the second network device is connected to the apparatus 1500 through the first network device, and the second network device is a source network device of the apparatus 1500 or a network device that has been connected to the apparatus 1500 before performing handover.

[0546] In some embodiments, the fourth communication unit 1501 is further configured to: before receiving the first downlink data and the second downlink data sent by the first network device, send a handover completion message to a network device that configures the second configuration information, and the handover completion message is sent based on the second configuration information.

[0547] In some embodiments, the first downlink data includes: retransmission of downlink data that the second network device has transmitted to an RLC entity and / or a MAC entity of the first network device before the second network device sends a handover command to the apparatus 1500; and / or, in the case that the second configuration information is configured by the second network device, the second downlink data includes: downlink data generated by the second network device after the second network device receives a handover completion message from the apparatus 1500; and / or, in the case that the second configuration information is configured by a third network device, the second downlink data includes: downlink data generated by the third network device after the third network device receives a handover completion message from the apparatus 1500; wherein the second network device is connected to the apparatus 1500 through the first network device, and the second network device is a source network device of the apparatus 1500 or a network device that has been connected to the apparatus 1500 before performing handover; the third network device is connected to the apparatus 1500 through the first network device, and the third network device is a target network device of the apparatus 1500 performing handover.

[0548] In some embodiments, the fourth communication unit 1501 is further configured to: receive sixth information sent by the first network device, the sixth information being used for the apparatus 1500 to perform measurement on one or more cells; and the sixth information is used to indicate: a corresponding relationship between the one or more cells and a network device, and / or a priority of the apparatus 1500 performing measurement on the one or more cells.

[0549] In some embodiments, the fourth communication unit 1501 is further configured to: before receiving the first downlink data and the second downlink data sent by the first network device, send thirteenth information to the first network device; the thirteenth information includes: measurement results of one or more cells by the apparatus 1500; wherein the thirteenth information is periodically sent, or is sent when a first condition is met, the first condition including one or more of: the apparatus 1500 receives fourteenth information sent by the first network device, the fourteenth information being used to request the thirteenth information; the apparatus 1500 completes handover between different distributed units (DUs) of the same centralized unit (CU); the apparatus 1500 completes handover between different CUs of the same DU; a first measurement result is greater than or equal to a first threshold; a second measurement result is less than or equal to a second threshold; a difference between the first measurement result and the second measurement result is greater than or equal to a third threshold; wherein the first measurement result includes: measurement results of cells corresponding to a third network device by the apparatus 1500; the second measurement result includes: measurement results of cells corresponding to a second network device by the apparatus 1500, the second network device being connected with the apparatus 1500 through the first network device, and the second network device being a source network device of the apparatus 1500 or a network device connected before the apparatus 1500 performs handover.

[0550] FIG. 16 is a structural component diagram of a data transmission apparatus according to an embodiment of the present application, which is applied to a first network device. As shown in FIG. 16, the data transmission apparatus 1600 (hereinafter referred to as apparatus 1600) includes:

[0551] A fifth communication unit 1601 configured to send first downlink data and second downlink data to a terminal device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

[0552] In some embodiments, the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

[0553] In some embodiments, the first downlink data is transmitted through a third logical channel, and the second downlink data is transmitted through a fourth logical channel.

[0554] In some embodiments, the third logical channel has a third association relationship with the first configuration information, and the fourth logical channel has a fourth association relationship with the second configuration information.

[0555] In some embodiments, the third association relationship is used by the terminal device to determine that the first downlink data is transmitted based on the first configuration information; and / or the fourth association relationship is used by the terminal device to determine that the second downlink data is transmitted based on the second configuration information.

[0556] In some embodiments, a ninth information is carried in a radio link control (RLC) header of the first downlink data, the ninth information being used to indicate that the first downlink data is transmitted based on the first configuration information; and / or a tenth information is carried in an RLC header of the second downlink data, the tenth information being used to indicate that the second downlink data is transmitted based on the second configuration information.

[0557] In some embodiments, the fifth communication unit 1601 is further configured to: receive eleventh information transmitted by a second network device, the eleventh information being used to indicate that downlink data after third downlink data is transmitted based on the second configuration information, and / or that the third downlink data and downlink data before the third downlink data is transmitted based on the first configuration information; the second network device is connected to the terminal device through the apparatus 1600, and is a source network device of the terminal device or a network device connected before performing handover of the terminal device; transmit the eleventh information to the terminal device, or transmit twelfth information containing content of the eleventh information to the terminal device in response to the eleventh information.

[0558] In some embodiments, the eleventh information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

[0559] In some embodiments, the first configuration information and the second configuration information are both configured by a second network device; or the first configuration information is configured by a second network device and the second configuration information is configured by a third network device; wherein the second network device is connected to the terminal device through the apparatus 1600, and is a source network device of the terminal device or a network device connected before performing handover of the terminal device; and the third network device is connected to the terminal device through the apparatus 1600, and is a target network device of the terminal device performing handover.

[0560] In some embodiments, in the case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, in the process of transmitting the first downlink data and the second downlink data to the terminal device, the terminal device maintains connection with the second network device and maintains connection with the third network device.

[0561] In some embodiments, the first downlink data and the second downlink data are transmitted through a same logical channel.

[0562] In some embodiments, the first configuration information comprises first PDCP configuration information and / or first bearer configuration information; and the second configuration information comprises second PDCP configuration information and / or second bearer configuration information.

[0563] In some embodiments, the first PDCP configuration information is used to configure a first encryption algorithm and / or a first compression algorithm; and the second PDCP configuration information is used to configure a second encryption algorithm and / or a second compression algorithm.

[0564] In some embodiments, the first PDCP configuration information is different from the second PDCP configuration information.

[0565] In some embodiments, the first bearer configuration information is used to configure one or more first bearer corresponding RLC entities and / or logical channels; and the second bearer configuration information is used to configure one or more second bearer corresponding RLC entities and / or logical channels; wherein the first downlink data is transmitted through a fifth bearer in the one or more first bearers, and the second downlink data is transmitted through a sixth bearer in the one or more second bearers.

[0566] In some embodiments, the second configuration information is carried in a handover command sent by a second network device to the terminal device; the second network device is connected with the terminal device through the apparatus 1600, and the second network device is a source network device of the terminal device, or is a network device connected before the terminal device performs handover.

[0567] In some embodiments, the fifth communication unit 1601 is further configured to: before the first downlink data and the second downlink data are sent to the terminal device, receive a handover completion message sent by the terminal device, the handover completion message being sent based on the second configuration information; and send the handover completion message to a network device that configures the second configuration information.

[0568] In some embodiments, the first downlink data comprises: retransmission of downlink data that the second network device has transmitted to the RLC entity and / or the MAC entity of the apparatus 1600 before the second network device sends a handover command to the terminal device; and / or, in the case that the second configuration information is configured by the second network device, the second downlink data comprises downlink data generated by the second network device after the second network device receives a handover completion message from the terminal device; and / or, in the case that the second configuration information is configured by the third network device, the second downlink data comprises downlink data generated by the third network device after the third network device receives a handover completion message from the terminal device; wherein the second network device is connected to the terminal device through the apparatus 1600, and the second network device is a source network device of the terminal device, or a network device that has been connected before the terminal device performs handover; and the third network device is connected to the terminal device through the apparatus 1600, and the third network device is a target network device of the terminal device performing handover.

[0569] In some embodiments, the fifth communication unit 1601 is further configured to send sixth information to the terminal device, the sixth information being used for the terminal device to perform measurement on one or more cells; and the sixth information being used to indicate a corresponding relationship between the one or more cells and a network device, and / or a priority of the terminal device performing measurement on the one or more cells.

[0570] FIG. 17 is a structural component diagram of a data transmission apparatus according to an embodiment of the present application, which is applied to a second network device, the second network device being connected to a terminal device through a first network device, and the second network device being a source network device of the terminal device, or a network device that has been connected before the terminal device performs handover. As shown in FIG. 17, the data transmission apparatus 1700 (hereinafter referred to as apparatus 1700) comprises:

[0571] The sixth communication unit 1701 is configured to send first downlink data to the first network device; or send the first downlink data and second downlink data to the first network device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information; and the first downlink data and the second downlink data are processed by a same medium access control (MAC) entity of the terminal device.

[0572] In some embodiments, the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

[0573] In some embodiments, the sixth communication unit 1701 is further configured to send eleventh information to the first network device, where the eleventh information is used to indicate that the downlink data after the third downlink data is sent based on the second configuration information, and / or the third downlink data and the downlink data before the third downlink data is sent based on the first configuration information.

[0574] In some embodiments, the eleventh information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

[0575] In some embodiments, the first downlink data includes retransmission of downlink data of a radio link control (RLC) entity and / or a MAC entity that the apparatus 1700 has transmitted to the first network device before the apparatus 1700 sends a handover command to the terminal device, and / or the second downlink data includes downlink data generated by the apparatus 1700 after the apparatus 1700 receives a handover complete message from the terminal device.

[0576] Those skilled in the art should understand that the above description of the data transmission apparatus of the embodiments of the present application can be understood with reference to the description of the data transmission method of the embodiments of the present application.

[0577] FIG. 18 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication device can be a terminal device or a network device (e.g., a first network device, a second network device, or a third network device). The communication device 1800 shown in FIG. 18 includes a processor 1810, which can call and run a computer program from a memory to implement the method of the embodiments of the present application.

[0578] Optionally, as shown in FIG. 18, the communication device 1800 can further include a memory 1820. The processor 1810 can call and run a computer program from the memory 1820 to implement the method of the embodiments of the present application.

[0579] The memory 1820 can be a separate device independent of the processor 1810, or can be integrated in the processor 1810.

[0580] Optionally, as shown in FIG. 18, the communication device 1800 can further include a transceiver 1830, and the processor 1810 can control the transceiver 1830 to communicate with other devices, specifically, to send information or data to other devices or receive information or data sent by other devices.

[0581] The transceiver 1830 can include a transmitter and a receiver. The transceiver 1830 can further include an antenna, and the number of antennas can be one or more.

[0582] Optionally, the communication device 1800 can be specifically a terminal device of the embodiments of the present application, and the communication device 1800 can implement the corresponding processes in the various methods of the embodiments of the present application implemented by the terminal device. For the sake of brevity, details are not described herein.

[0583] Optionally, the communication device 1800 can be specifically a network device (such as a first network device / second network device / third network device) of the embodiments of the present application, and the communication device 1800 can implement the corresponding processes in the various methods of the embodiments of the present application implemented by the network device. For the sake of brevity, details are not described herein.

[0584] FIG. 19 is a schematic structural diagram of a chip according to the embodiments of the present application. The chip 1900 shown in FIG. 19 includes a processor 1910, which can call and run a computer program from a memory to implement the method in the embodiments of the present application.

[0585] Optionally, as shown in FIG. 19, the chip 1900 can further include a memory 1920. The processor 1910 can call and run a computer program from the memory 1920 to implement the method in the embodiments of the present application.

[0586] The memory 1920 can be a separate device independent of the processor 1910, or can be integrated in the processor 1910.

[0587] Optionally, the chip 1900 can further include an input interface 1930. The processor 1910 can control the input interface 1930 to communicate with other devices or chips, and specifically, can obtain information or data sent by other devices or chips.

[0588] Optionally, the chip 1900 can further include an output interface 1940. The processor 1910 can control the output interface 1940 to communicate with other devices or chips, and specifically, can output information or data to other devices or chips.

[0589] Optionally, the chip can be applied to the terminal device in the embodiments of the present application, and the chip can implement the corresponding processes in the various methods of the embodiments of the present application implemented by the terminal device. For the sake of brevity, details are not described herein.

[0590] Optionally, the chip can be applied to the network device (such as a first network device / second network device / third network device) in the embodiments of the present application, and the chip can implement the corresponding processes in the various methods of the embodiments of the present application implemented by the network device (such as a first network device / second network device / third network device). For the sake of brevity, details are not described herein.

[0591] It should be understood that the chip mentioned in the embodiments of the present application can also be referred to as a system chip, a system chip, a chip system, or a system on chip, etc.

[0592] The embodiments of the present application further provide a computer storage medium, which stores one or more programs, and the one or more programs can be executed by one or more processors to implement the method in the embodiments of the present application.

[0593] FIG. 20 is a schematic block diagram of a communication system provided by the embodiments of the present application. As shown in FIG. 20, the communication system 2000 includes a terminal device 2010, a first network device 2020, and a second network device 2030.

[0594] The terminal device 2010 can be used to implement the corresponding functions of the terminal device in the above method, the first network device 2020 can be used to implement the corresponding functions of the first network device in the above method, and the second network device 2030 can be used to implement the corresponding functions of the second network device in the above method. For brevity, details are not repeated here.

[0595] It should be understood that the processor of the embodiments of the present application can be an integrated circuit chip with processing capability of signals. In the implementation process, each step of the above method embodiments can be completed by integrated logic circuits or instructions in the form of software in the processor. The processor mentioned above can be a general processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. Each method, step and logic block disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware coding processor for execution, or a combination of hardware and software modules in the coding processor for execution. The software module can be located in a random access memory, a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register, etc. The storage medium in the art. The storage medium is located in the memory, and the processor reads the information in the memory, and combines the hardware to complete the steps of the above method.

[0596] It is to be understood that the memory in the embodiments of the present application can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the nonvolatile memory can be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or a flash memory. The volatile memory can be a random access memory (Random Access Memory, RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (Synchlink DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0597] It should be understood that the above-mentioned memory is exemplary but not limiting, for example, the memory in the embodiments of the present application can also be static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM) and the like. That is, the memory in the embodiments of the present application is intended to include, but not limited to, these and any other suitable types of memory.

[0598] The embodiment of the present application further provides a computer readable storage medium for storing the computer program.

[0599] Optionally, the computer readable storage medium can be applied to the terminal device in the embodiment of the present application, and the computer program makes the computer execute the corresponding process realized by the terminal device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0600] Optionally, the computer readable storage medium can be applied to the network device (such as the first network device / second network device / third network device) in the embodiment of the present application, and the computer program makes the computer execute the corresponding process realized by the network device (such as the first network device / second network device / third network device) in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0601] The embodiment of the present application further provides a computer program product comprising computer program instructions.

[0602] Optionally, the computer program product can be applied to the terminal device in the embodiment of the present application, and the computer program instructions make the computer execute the corresponding process realized by the terminal device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0603] Optionally, the computer program product can be applied to the network device (such as the first network device / second network device / third network device) in the embodiment of the present application, and the computer program instructions make the computer execute the corresponding process realized by the network device (such as the first network device / second network device / third network device) in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0604] The embodiment of the present application further provides a computer program.

[0605] Optionally, the computer program can be applied to the terminal device in the embodiment of the present application, and when the computer program runs on the computer, makes the computer execute the corresponding process realized by the terminal device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0606] Optionally, the computer program can be applied to the network device (such as the first network device / second network device / third network device) in the embodiment of the present application, and when the computer program runs on the computer, makes the computer execute the corresponding process realized by the network device (such as the first network device / second network device / third network device) in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0607] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0608] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0609] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0610] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0611] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit.

[0612] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0613] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A data transmission method applied to a terminal device, the method comprising: sending, to a first network device, first uplink data and second uplink data, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information. 2.The method of claim 1, wherein: the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover. 3.The method of claim 1 or 2, wherein: the first uplink data is transmitted via a first logical channel, and the second uplink data is transmitted via a second logical channel. 4.The method of claim 3, wherein: the first logical channel has a first association relationship with the first configuration information, and the second logical channel has a second association relationship with the second configuration information. 5.The method of claim 4, wherein: the first association relationship is used by the first network device to determine that the first uplink data is sent based on the first configuration information; and / or the second association relationship is used by the first network device to determine that the second uplink data is sent based on the second configuration information. 6.The method of claim 1 or 2, wherein: first information is carried in a radio link control (RLC) header of the first uplink data, the first information being used to indicate that the first uplink data is sent based on the first configuration information; and / or second information is carried in a RLC header of the second uplink data, the second information being used to indicate that the second uplink data is sent based on the second configuration information.

7. The method of claim 1 or 2, wherein, The method further comprises: sending, to the first network device, third information, the third information being used to indicate that uplink data after third uplink data is sent based on the second configuration information, and / or the third uplink data and uplink data before the third uplink data is sent based on the first configuration information. 8.The method of claim 7, wherein: the third information is carried in a packet data convergence protocol (PDCP) control protocol data unit. 9.The method of any one of claims 1 to 8, wherein: the first configuration information and the second configuration information are both configured by a second network device; or the first configuration information is configured by a second network device, and the second configuration information is configured by a third network device; wherein the second network device is connected with the terminal device via the first network device, and the second network device is a source network device of the terminal device or a network device that has been connected with the terminal device before performing handover by the terminal device, and the third network device is connected with the terminal device via the first network device, and the third network device is a target network device of the terminal device performing handover. 10.The method of claim 8, wherein: In a case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, during the process of sending the first uplink data and the second uplink data to the first network device, the terminal device keeps connection with the second network device and keeps connection with the third network device.

11. The method of any one of claims 1, 2, 6-8, wherein, the first uplink data and the second uplink data are transmitted through the same logical channel.

12. The method of any one of claims 1-11, wherein, the first configuration information comprises first PDCP configuration information and / or first bearer configuration information; the second configuration information comprises second PDCP configuration information and / or second bearer configuration information.

13. The method of claim 12, wherein, the first PDCP configuration information is used to configure a first encryption algorithm and / or a first compression algorithm; the second PDCP configuration information is used to configure a second encryption algorithm and / or a second compression algorithm.

14. The method of claim 12 or 13, wherein, the first PDCP configuration information is different from the second PDCP configuration information.

15. The method of any one of claims 12-14, wherein, the first bearer configuration information is used to configure one or more first bearer corresponding RLC entities and / or logical channels; the second bearer configuration information is used to configure one or more second bearer corresponding RLC entities and / or logical channels; wherein the first uplink data is transmitted through a third bearer in the one or more first bearers, and the second uplink data is transmitted through a fourth bearer in the one or more second bearers.

16. The method of any one of claims 1-15, wherein, the second configuration information is carried in a handover command sent by a second network device to the terminal device; the second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected before performing handover for the terminal device.

17. The method of any one of claims 1 to 16, wherein, before the first uplink data and the second uplink data are sent to the first network device, the method further comprises: sending a handover completion message to a network device that configures the second configuration information, the handover completion message being sent based on the second configuration information.

18. The method of any one of claims 1-17, wherein, the first uplink data comprises retransmission of uplink data that has been transmitted to an RLC entity and / or a MAC entity of the terminal device before the terminal device receives a handover command; and / or the second uplink data comprises uplink data generated after the terminal device receives a handover command.

19. The method of any one of claims 1 to 18, wherein, the method further comprises: receive sixth information sent by the first network device, the sixth information being used for the terminal device to perform measurement on one or more cells; the sixth information being used to indicate a corresponding relationship between the one or more cells and a network device, and / or a priority of the terminal device performing measurement on the one or more cells.

20. The method of any one of claims 1 to 19, wherein, Before the first uplink data and the second uplink data are sent to the first network device, the method further comprises: sending thirteenth information to the first network device; the thirteenth information comprises a result of the terminal device performing measurement on one or more cells; wherein the thirteenth information is periodically sent, or is sent when a first condition is met, the first condition comprising one or more of the following: the terminal device receives fourteenth information sent by the first network device, the fourteenth information being used to request the thirteenth information; the terminal device completes handover between different distributed units (DUs) of a same centralized unit (CU); the terminal device completes handover between different CUs of a same DU; the first measurement result is greater than or equal to a first threshold value; the second measurement result is less than or equal to a second threshold value; a difference between the first measurement result and the second measurement result is greater than or equal to a third threshold value; wherein the first measurement result comprises a result of the terminal device performing measurement on a cell corresponding to a third network device; the second measurement result comprises a result of the terminal device performing measurement on a cell corresponding to a second network device, the second network device being connected with the terminal device through the first network device, and the second network device being a source network device of the terminal device or a network device that has been connected with the terminal device before performing handover.

21. A data transmission method applied to a first network device, the method comprising: receiving first uplink data and second uplink data sent by a terminal device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

22. The method of claim 21, wherein the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

23. The method of claim 21 or 22, wherein the first uplink data is transmitted through a first logical channel, and the second uplink data is transmitted through a second logical channel.

24. The method of claim 23, wherein the first logical channel has a first association relationship with the first configuration information, and the second logical channel has a second association relationship with the second configuration information.

25. The method of claim 24, wherein the first association relationship is used by the first network device to determine that the first uplink data is sent based on the first configuration information; and / or, The second association relationship is used for the first network device to determine that the second uplink data is sent based on the second configuration information.

26. The method of claim 21 or 22, wherein, the first information is carried in a radio link control (RLC) header of the first uplink data, and the first information is used to indicate that the first uplink data is sent based on the first configuration information; and / or the second information is carried in an RLC header of the second uplink data, and the second information is used to indicate that the second uplink data is sent based on the second configuration information.

27. The method of any one of claims 21 to 26, wherein, the first configuration information and the second configuration information are both configured by a second network device, the second network device is connected to the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device that has been connected before performing handover of the terminal device, and the method further comprises: sending fourth information to the second network device, the fourth information being used to indicate that the first uplink data is sent based on the first configuration information; and / or sending fifth information to the second network device, the fifth information being used to indicate that the second uplink data is sent based on the second configuration information.

28. The method of any one of claims 21 to 26, wherein, the first configuration information is configured by a second network device, and the second configuration information is configured by a third network device, and the method further comprises: sending the first uplink data to the second network device; sending the second uplink data to the third network device; wherein the second network device is connected to the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device that has been connected before performing handover of the terminal device, and the third network device is connected to the terminal device through the first network device, and the third network device is a target network device of the terminal device performing handover.

29. The method of claim 21 or 22, wherein, The method further comprises: receiving third information sent by the terminal device, the third information being used to indicate that uplink data after third uplink data is sent based on the second configuration information, and / or the third uplink data and uplink data before the third uplink data is sent based on the first configuration information; sending the third information to a second network device, or sending eighth information to the second network device in response to the third information, the eighth information containing content of the third information; the second network device is connected to the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device that has been connected before performing handover of the terminal device.

30. The method of claim 29, wherein, the third information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

31. The method of any one of claims 21-27, 29, 30, wherein, The method further comprises: transmitting the first uplink data and the second uplink data to a second network device; the second network device being a source network device of the terminal device, or being a network device connected to the terminal device before performing handover of the terminal device.

32. The method of any one of claims 21-26, 29, 30, wherein the first configuration information and the second configuration information are both configured by a second network device; or the first configuration information is configured by a second network device, and the second configuration information is configured by a third network device. The second network device is connected to the terminal device through the first network device, and is a source network device of the terminal device, or is a network device connected to the terminal device before performing handover of the terminal device; and the third network device is connected to the terminal device through the first network device, and is a target network device of the terminal device performing handover.

33. The method of claim 28 or 32, wherein in a case where the first configuration information is configured by the second network device, and the second configuration information is configured by the third network device, the terminal device maintains connection with the second network device and maintains connection with the third network device during the process of receiving the first uplink data and the second uplink data transmitted by the terminal device.

34. The method of any one of claims 21, 22, 26, 29, or 30, wherein the first uplink data and the second uplink data are transmitted through a same logical channel.

35. The method of any one of claims 21-34, wherein the first configuration information comprises first PDCP configuration information and / or first bearer configuration information; the second configuration information comprises second PDCP configuration information and / or second bearer configuration information.

36. The method of claim 35, wherein the first PDCP configuration information is used to configure a first encryption algorithm and / or a first compression algorithm; the second PDCP configuration information is used to configure a second encryption algorithm and / or a second compression algorithm.

37. The method of claim 35 or 36, wherein the first PDCP configuration information is different from the second PDCP configuration information.

38. The method of any one of claims 35-37, wherein the first bearer configuration information is used to configure one or more first bearer corresponding RLC entities and / or logical channels; the second bearer configuration information is used to configure one or more second bearer corresponding RLC entities and / or logical channels; the first uplink data is transmitted through a third bearer of the one or more first bearers, and the second uplink data is transmitted through a fourth bearer of the one or more second bearers.

39. The method of any one of claims 21-38, wherein The second configuration information is carried in a handover command sent by a second network device to the terminal device; the second network device is connected to the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected to the terminal device before performing handover.

40. The method of any one of claims 21 to 39, wherein, Before receiving the first uplink data and the second uplink data sent by the terminal device, the method further comprises: receiving a handover completion message sent by the terminal device, the handover completion message being sent based on the second configuration information; sending the handover completion message to a network device that configures the second configuration information.

41. The method of any of claims 21 to 40, wherein, the first uplink data comprises retransmission of uplink data that has been transmitted to an RLC entity and / or a MAC entity of the terminal device before the terminal device receives the handover command; and / or the second uplink data comprises uplink data generated after the terminal device receives the handover command.

42. The method of any one of claims 21 to 41, wherein, The method further comprises: sending, to the terminal device, sixth information used for the terminal device to perform measurement on one or more cells; the sixth information is used to indicate a corresponding relationship between the one or more cells and a network device, and / or a priority of the terminal device performing measurement on the one or more cells.

43. A data transmission method applied to a second network device, the second network device being connected to a terminal device through a first network device, and the second network device being a source network device of the terminal device or a network device connected to the terminal device before performing handover, the method comprising: receiving first uplink data and second uplink data sent by the first network device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

44. The method of claim 43, wherein, the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

45. The method of claim 43 or 44, wherein, The first configuration information and the second configuration information are both configured by the second network device, and the method further comprises: receiving fourth information sent by the first network device, the fourth information being used to indicate that the first uplink data is sent based on the first configuration information; and / or receiving fifth information sent by the first network device, the fifth information being used to indicate that the second uplink data is sent based on the second configuration information.

46. The method of claim 43 or 44, wherein, the first configuration information and the second configuration information are both configured by the second network device, and the method further comprises: decode and / or decompress the first uplink data using the first configuration information, and if the decoding and / or decompressing fails, decode and / or decompress the first uplink data using the second configuration information; and / or decode and / or decompress the second uplink data using the first configuration information, and if the decoding and / or decompressing fails, decode and / or decompress the second uplink data using the second configuration information.

47. The method of claim 43, 44 or 46, wherein the first configuration information and the second configuration information are both configured by the second network device, and the method further comprises: in a case where the second network device receives third information or eighth information, determining, based on the third information or the eighth information, whether to decode and / or decompress uplink data from the first network device using the second configuration information.

48. The method of claim 47, wherein the third information is used to indicate that uplink data after third uplink data is transmitted based on the second configuration information, and / or that the third uplink data and uplink data before the third uplink data is transmitted based on the first configuration information; and / or the eighth information contains content of the third information.

49. The method of claim 43 or 44, wherein the first configuration information is configured by the second network device, and the second configuration information is configured by a third network device, the third network device is connected with the terminal device through the first network device, and the third network device is a target network device performing handover for the terminal device, and the method further comprises: decode and / or decompress the first uplink data using the first configuration information, and if the decoding and / or decompressing fails, send the first uplink data to the third network device; and / or decode and / or decompress the second uplink data using the first configuration information, and if the decoding and / or decompressing fails, send the first uplink data to the third network device.

50. The method of claim 43, 44 or 49, wherein the first configuration information is configured by the second network device, and the second configuration information is configured by a third network device, the third network device is connected with the terminal device through the first network device, and the third network device is a target network device performing handover for the terminal device, and the method further comprises: in a case where the second network device receives third information or eighth information, determine, based on the third information or the eighth information, whether to send seventh information to the first network device; the seventh information is used to instruct the first network device to stop sending uplink data from the terminal device to the second network device, and / or to instruct the first network device to send subsequently received uplink data to the third network device.

51. The method of claim 50, wherein The third information is used to indicate that uplink data after third uplink data is transmitted based on the second configuration information, and / or the third uplink data and uplink data before the third uplink data is transmitted based on the first configuration information; and / or the eighth information contains the content of the third information.

52. The method of claim 51, wherein, The method further comprises: In a case where the third uplink data and uplink data before the third uplink data are all received by the second network device, or in a case where a first timer is timed out, the seventh information is transmitted to the first network device.

53. The method of any one of claims 47, 48, 50-52, wherein, The third information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

54. The method of any one of claims 49-52, wherein, In the process of receiving the first uplink data and the second uplink data transmitted by the first network device, the terminal device maintains connection with the second network device and maintains connection with the third network device.

55. The method of any one of claims 43-54, wherein, The first uplink data comprises retransmission of uplink data that has been transmitted to a radio link control (RLC) entity and / or a MAC entity of the terminal device before the terminal device receives a handover command; and / or The second uplink data comprises uplink data generated after the terminal device receives the handover command.

56. A data transmission method applied to a terminal device, the method comprising: receiving first downlink data and second downlink data transmitted by a first network device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is transmitted based on first configuration information, and the second downlink data is transmitted based on second configuration information.

57. The method of claim 56, wherein The first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover.

58. The method of claim 56 or 57, wherein The first downlink data is transmitted through a third logical channel, and the second downlink data is transmitted through a fourth logical channel.

59. The method of claim 58, wherein The third logical channel has a third association relationship with the first configuration information, and the fourth logical channel has a fourth association relationship with the second configuration information.

60. The method of claim 59, wherein The third association relationship is used by the terminal device to determine that the first downlink data is transmitted based on the first configuration information; and / or The fourth association relationship is used by the terminal device to determine that the second downlink data is transmitted based on the second configuration information.

61. The method of claim 56 or 57, wherein The first downlink data carries ninth information in a radio link control (RLC) header, where the ninth information is used to indicate that the first downlink data is transmitted based on the first configuration information; and / or The second downlink data carries tenth information in an RLC header, where the tenth information is used to indicate that the second downlink data is transmitted based on the second configuration information. The method further includes:

62. The method of claim 56 or 57, wherein, decoding and / or decompressing the first downlink data using the first configuration information, and if decoding and / or decompressing fails, decoding and / or decompressing the first downlink data using the second configuration information; and / or decoding and / or decompressing the second downlink data using the first configuration information, and if decoding and / or decompressing fails, decoding and / or decompressing the second downlink data using the second configuration information. The method further includes:

63. The method of claim 56, 57, or 62, wherein, receiving eleventh information or twelfth information transmitted by the first network device; wherein the eleventh information is used to indicate that downlink data after third downlink data is transmitted based on the second configuration information, and / or the third downlink data and downlink data before the third downlink data is transmitted based on the first configuration information; and / or the twelfth information contains content of the eleventh information. The method further includes:

64. The method of claim 63, wherein, based on the eleventh information or the twelfth information, determining whether to decode and / or decompress downlink data from the first network device using the second configuration information.

65. The method of claim 63 or 64, wherein, in a case where the third downlink data and downlink data before the third downlink data are both received by the terminal device, or in a case where a second timer expires, the method further includes: decoding and / or decompressing downlink data from the first network device based on the second configuration information.

66. The method of any one of claims 63 to 65, wherein, the eleventh information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

67. The method of any one of claims 56 to 66, wherein, the first configuration information and the second configuration information are both configured by a second network device; or the first configuration information is configured by a second network device, and the second configuration information is configured by a third network device; wherein the second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device that has been connected with the terminal device before performing handover of the terminal device; and the third network device is connected with the terminal device through the first network device, and the third network device is a target network device of the terminal device performing handover.

68. The method of claim 67, wherein, ​ In a case that the first configuration information is configured by the second network device and the second configuration information is configured by the third network device, in the process of receiving the first downlink data and the second downlink data sent by the first network device, the terminal device keeps connection with the second network device and keeps connection with the third network device.

69. The method of any one of claims 56, 57, 61-66, wherein, the first downlink data and the second downlink data are transmitted through the same logical channel.

70. The method of any one of claims 56-69, wherein, the first configuration information comprises first PDCP configuration information and / or first bearer configuration information; the second configuration information comprises second PDCP configuration information and / or second bearer configuration information.

71. The method of claim 70, wherein, the first PDCP configuration information is used to configure a first encryption algorithm and / or a second compression algorithm; the second PDCP configuration information is used to configure a second encryption algorithm and / or a second compression algorithm.

72. The method of claim 70 or 71, wherein, the first PDCP configuration information is different from the second PDCP configuration information.

73. The method of any one of claims 70-72, wherein, the first bearer configuration information is used to configure one or more first bearer corresponding RLC entities and / or logical channels; the second bearer configuration information is used to configure one or more second bearer corresponding RLC entities and / or logical channels; wherein the first downlink data is transmitted through a fifth bearer in the one or more first bearers and the second downlink data is transmitted through a sixth bearer in the one or more second bearers.

74. The method of any one of claims 56-73, wherein, the second configuration information is carried in a handover command sent by a second network device to the terminal device; the second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected before performing handover for the terminal device.

75. The method of any one of claims 56-74, wherein, before the receiving the first downlink data and the second downlink data sent by the first network device, the method further comprises: sending a handover complete message to a network device configuring the second configuration information, the handover complete message being sent based on the second configuration information.

76. The method of any one of claims 56-75, wherein, the first downlink data comprises retransmission of downlink data that the second network device has transmitted to an RLC entity and / or a MAC entity of the first network device before sending a handover command to the terminal device; and / or, in a case that the second configuration information is configured by the second network device, the second downlink data comprises downlink data generated by the second network device after receiving a handover complete message from the terminal device; and / or, In a case that the second configuration information is configured by a third network device, the second downlink data comprises downlink data generated by the third network device after the third network device receives a handover completion message from the terminal device. The second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected before the terminal device performs handover; the third network device is connected with the terminal device through the first network device, and the third network device is a target network device of the terminal device performing handover.

77. The method of any one of claims 56-76, wherein, The method further comprises: receiving sixth information sent by the first network device, the sixth information being used for the terminal device to perform measurement on one or more cells; the sixth information being used for indicating a corresponding relationship between the one or more cells and a network device, and / or a priority of the terminal device performing measurement on the one or more cells.

78. The method of any one of claims 56 to 77, wherein, Before the receiving the first downlink data and the second downlink data sent by the first network device, the method further comprises: sending thirteenth information to the first network device; the thirteenth information comprises a result of the terminal device performing measurement on one or more cells; wherein the thirteenth information is periodically sent, or is sent in a case that a first condition is met, the first condition comprising one or more of the following: the terminal device receives fourteenth information sent by the first network device, the fourteenth information being used for requesting the thirteenth information; the terminal device completes handover between different distributed units (DUs) of a same centralized unit (CU); the terminal device completes handover between different CUs of a same DU; the first measurement result is greater than or equal to a first threshold value; the second measurement result is less than or equal to a second threshold value; a difference between the first measurement result and the second measurement result is greater than or equal to a third threshold value; wherein the first measurement result comprises a result of the terminal device performing measurement on a cell corresponding to a third network device; the second measurement result comprises a result of the terminal device performing measurement on a cell corresponding to a second network device, the second network device being connected with the terminal device through the first network device, and the second network device being a source network device of the terminal device or a network device connected before the terminal device performs handover. 79.A data transmission method applied to a first network device, the method comprising: sending first downlink data and second downlink data to a terminal device, the first downlink data and the second downlink data being processed by a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information. 80.The method of claim 79, wherein the first configuration information is configuration information used by the terminal device before performing handover, and the second configuration information is configuration information used by the terminal device after performing handover. 81.The method of claim 79 or 80, wherein, the first downlink data is transmitted through a third logical channel, and the second downlink data is transmitted through a fourth logical channel. 82.The method of claim 81, wherein, the third logical channel has a third association relationship with the first configuration information, and the fourth logical channel has a fourth association relationship with the second configuration information. 83.The method of claim 82, wherein, the third association relationship is used by the terminal device to determine that the first downlink data is transmitted based on the first configuration information; and / or, the fourth association relationship is used by the terminal device to determine that the second downlink data is transmitted based on the second configuration information. 84.The method of claim 79 or 80, wherein, a ninth information is carried in a radio link control (RLC) header of the first downlink data, the ninth information being used to indicate that the first downlink data is transmitted based on the first configuration information; and / or, a tenth information is carried in a RLC header of the second downlink data, the tenth information being used to indicate that the second downlink data is transmitted based on the second configuration information. The method further comprises:

85. The method of claim 79 or 80, wherein, receiving an eleventh information transmitted by a second network device, the eleventh information being used to indicate that downlink data after third downlink data is transmitted based on the second configuration information, and / or the third downlink data and downlink data before the third downlink data is transmitted based on the first configuration information; the second network device being connected with the terminal device through the first network device, and the second network device being a source network device of the terminal device or a network device connected before performing handover of the terminal device; transmitting the eleventh information to the terminal device, or transmitting a twelfth information containing content of the eleventh information to the terminal device in response to the eleventh information. 86.The method of claim 85, wherein, the eleventh information is carried in a packet data convergence protocol (PDCP) control protocol data unit. 87.The method of any one of claims 79-86, wherein, the first configuration information and the second configuration information are both configured by a second network device; or, the first configuration information is configured by a second network device, and the second configuration information is configured by a third network device; wherein the second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected before performing handover of the terminal device; and the third network device is connected with the terminal device through the first network device, and the third network device is a target network device of the terminal device performing handover. 88.The method of claim 87, wherein, ​ In a case that the first configuration information is configured by the second network device, and the second configuration information is configured by the third network device, in the process of sending the first downlink data and the second downlink data to the terminal device, the terminal device keeps connection with the second network device and keeps connection with the third network device.

89. The method of any one of claims 79, 80, 84-86, wherein, the first downlink data and the second downlink data are transmitted through a same logical channel.

90. The method of any one of claims 79-89, wherein, the first configuration information comprises first PDCP configuration information and / or first bearer configuration information; the second configuration information comprises second PDCP configuration information and / or second bearer configuration information.

91. The method of claim 90, wherein, the first PDCP configuration information is used to configure a first ciphering algorithm and / or a second compression algorithm; the second PDCP configuration information is used to configure a second ciphering algorithm and / or a second compression algorithm.

92. The method of claim 90 or 91, wherein, the first PDCP configuration information is different from the second PDCP configuration information.

93. The method of any one of claims 90-92, wherein, the first bearer configuration information is used to configure one or more first bearer corresponding RLC entities and / or logical channels; the second bearer configuration information is used to configure one or more second bearer corresponding RLC entities and / or logical channels; wherein the first downlink data is transmitted through a fifth bearer of the one or more first bearers, and the second downlink data is transmitted through a sixth bearer of the one or more second bearers.

94. The method of any one of claims 79-93, wherein, the second configuration information is carried in a handover command sent by a second network device to the terminal device; the second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected before performing handover for the terminal device.

95. The method of any one of claims 79-94, wherein, Before the first downlink data and the second downlink data are sent to the terminal device, the method further comprises: receiving a handover completion message sent by the terminal device, the handover completion message being sent based on the second configuration information; sending the handover completion message to a network device that configures the second configuration information.

96. The method of any one of claims 79-95, wherein, the first downlink data comprises retransmission of downlink data that has been transmitted to an RLC entity and / or a MAC entity of the first network device by the second network device before the second network device sends a handover command to the terminal device; and / or, the second downlink data comprises downlink data that is transmitted to the terminal device by the second network device after the second network device sends the handover command to the terminal device. In a case that the second configuration information is configured by the second network device, the second downlink data comprises: downlink data generated by the second network device after the second network device receives a handover completion message from the terminal device; and / or, In a case that the second configuration information is configured by the third network device, the second downlink data comprises: downlink data generated by the third network device after the third network device receives a handover completion message from the terminal device. The second network device is connected with the terminal device through the first network device, and the second network device is a source network device of the terminal device or a network device connected before the terminal device performs handover; the third network device is connected with the terminal device through the first network device, and the third network device is a target network device of the terminal device performing handover.

97. The method of any one of claims 79 to 96, wherein, The method further comprises: sending sixth information to the terminal device, the sixth information being used for the terminal device to perform measurement on one or more cells; the sixth information being used for indicating: a corresponding relationship between the one or more cells and a network device, and / or a priority of the terminal device performing measurement on one or more cells.

98. A data transmission method applied to a second network device, the second network device being connected with a terminal device through a first network device, and the second network device being a source network device of the terminal device or a network device connected before the terminal device performs handover, the method comprising: sending first downlink data to the first network device; or, sending the first downlink data and second downlink data to the first network device; The first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information. The first downlink data and the second downlink data are processed by a same medium access control (MAC) entity of the terminal device.

99. The method of claim 98, wherein, The first configuration information is configuration information used before the terminal device performs handover, and the second configuration information is configuration information used after the terminal device performs handover.

100. The method of claim 98 or 99, wherein, The method further comprises: sending eleventh information to the first network device, the eleventh information being used for indicating: downlink data after third downlink data is sent based on the second configuration information, and / or the third downlink data and downlink data before the third downlink data is sent based on the first configuration information.

101. The method of claim 100, wherein, The eleventh information is carried in a packet data convergence protocol (PDCP) control protocol data unit.

102. The method of any of claims 98 to 101, wherein, The first downlink data comprises: retransmission of downlink data of a radio link control (RLC) entity and / or a MAC entity of the first network device, which has been transmitted by the second network device to the first network device before the second network device sends a handover command to the terminal device; and / or, The second downlink data comprises downlink data generated by the second network device after the second network device receives a handover completion message from the terminal device.

103. A data transmission apparatus, comprising: a first communication unit configured to send first uplink data and second uplink data to a first network device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the apparatus; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

104. A data transmission apparatus, comprising: a second communication unit configured to receive first uplink data and second uplink data sent by a terminal device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

105. A data transmission apparatus, connected to a terminal device by a first network device, and the apparatus is a source network device of the terminal device, or a network device connected to the terminal device before performing handover, comprising: a third communication unit configured to receive first uplink data and second uplink data sent by the first network device, the first uplink data and the second uplink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first uplink data is sent based on first configuration information, and the second uplink data is sent based on second configuration information.

106. A data transmission apparatus, comprising: a fourth communication unit configured to receive first downlink data and second downlink data sent by a first network device, the first downlink data and the second downlink data being processed via a same medium access control (MAC) entity of the apparatus; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

107. A data transmission apparatus, comprising: a fifth communication unit configured to send first downlink data and second downlink data to a terminal device, the first downlink data and the second downlink data being processed via a same medium access control (MAC) entity of the terminal device; wherein the first downlink data is sent based on first configuration information, and the second downlink data is sent based on second configuration information.

108. A data transmission apparatus, connected to a terminal device by a first network device, and the apparatus is a source network device of the terminal device, or a network device connected to the terminal device before performing handover, comprising: a sixth communication unit configured to send first downlink data to the first network device; or, send the first downlink data and second downlink data to the first network device; The first downlink data is transmitted based on first configuration information, and the second downlink data is transmitted based on second configuration information. The first downlink data and the second downlink data are processed by a same medium access control (MAC) entity of the terminal device.

109. A communication device, comprising: a memory for storing a computer program; a processor connected to the memory, for invoking and running the computer program from the memory, to implement the method of any one of claims 1-20, or the method of any one of claims 21-42, or the method of any one of claims 43-55, or the method of any one of claims 56-78, or the method of any one of claims 79-97, or the method of any one of claims 98-102; a transceiver for receiving and sending information in the process of transceiving information with other devices.

110. A chip, comprising: a processor for invoking and running a computer program from a memory, to enable a device installed with the chip to implement the method of any one of claims 1-20, or the method of any one of claims 21-42, or the method of any one of claims 43-55, or the method of any one of claims 56-78, or the method of any one of claims 79-97, or the method of any one of claims 98-102; a transceiver for receiving and sending information in the process of transceiving information with devices or chips.

111. A computer readable storage medium for storing a computer program, the computer program enabling a computer to implement the method of any one of claims 1-20, or the method of any one of claims 21-42, or the method of any one of claims 43-55, or the method of any one of claims 56-78, or the method of any one of claims 79-97, or the method of any one of claims 98-102.

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