Data transmission method, communication device, communication system and storage medium

Abstract

The embodiment of the invention discloses a data transmission method, a communication device, a communication system and a storage medium, which are applied to the technical field of communication and are used for reducing L2 switching time delay. The method provided by the embodiment of the invention comprises the following steps: receiving a switching command, wherein the switching command is used for indicating the terminal equipment to be switched from a source node to a target node; and transmitting a first data packet with the target node by using a first parameter, the first parameter being a parameter used for transmission between the terminal device and the source node, and the first data packet being a data packet processed by the source node. According to the embodiment of the invention, data interruption caused by PDCP (Packet Data Convergence Protocol) reconstruction, data recovery and RLC (Radio Link Control) reconstruction is avoided by using the parameters used for transmission with the source node, so that time delay caused by data retransmission introduced in the processes is avoided.

Description

TECHNICAL FIELD

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

[0002] In a mobile communication system, when a terminal device is in a connected state, in order to ensure the continuity of communication and the quality of service, a handover process needs to be completed when the terminal device moves from one cell to another. However, a time delay occurs when the terminal device is handed over from a source cell to a target cell, causing service interruption and reducing handover efficiency.

[0003] Currently, in order to reduce the time delay and interruption time of handover, various mobility enhancement techniques are introduced. For example, in the L1 / L2-triggered mobility (LTM) enhancement technique, the base station can configure LTM candidate cells for the terminal device in advance, and the base station triggers the terminal device to connect with the target cell based on the L1 measurement result of the terminal device through the LTM handover MAC CE, wherein the target cell is one of the candidate cells. The terminal device can perform uplink (UL) synchronization and / or downlink (DL) synchronization of the candidate cell in advance before receiving the LTM handover MAC CE, thereby saving the handover time delay after receiving the LTM handover MAC CE.

[0004] However, in various mobility enhancement techniques including the above-mentioned LTM, none of them aims to reduce the time delay caused by the data interruption caused by L2 change and the time delay caused by the retransmission of data packets introduced by L2 change. SUMMARY

[0005] The present application provides a data transmission method, a communication device, a communication system and a storage medium, which avoids data interruption caused by PDCP re-establishment, data recovery and RLC re-establishment by using parameters for data transmission with the source node, thereby avoiding the time delay caused by data retransmission introduced by these processes.

[0006] The first aspect of the present application provides a data transmission method. Optionally, the execution subject of the method can be a terminal device, a component or apparatus (for example, a processor, a chip, or a chip system) applied to the terminal device, or a logic module or software capable of realizing all or part of the functions of the terminal device. Taking the terminal device as an example, in the method, the terminal device receives a handover command, and the handover command is used to instruct the terminal device to switch from a source node to a target node. The terminal device uses a first parameter to perform transmission of a first data packet with the target node, the first parameter is a parameter used for transmission between the terminal device and the source node, and the first data packet is a data packet processed by the source node.

[0007] In the embodiment, by using the parameter used for transmission between the terminal device and the source node, data interruption caused by PDCP reestablishment, data recovery, and RLC reestablishment is avoided, and further, latency caused by data retransmission introduced by these processes is avoided.

[0008] In some possible embodiments, a first radio bearer (RB) and a second RB use the same reordering window.

[0009] In some possible embodiments, the terminal device submits data packets on the second RB after submitting data packets on the first RB.

[0010] In some possible embodiments, the terminal device further establishes a second PDCP function entity and / or a second RLC, the second PDCP function entity and the second RLC use configurations of the target node, and the second PDCP function entity includes at least one of a first ciphering function entity, a first deciphering function entity, a first integrity protection function entity, or a first integrity check function entity.

[0011] The second aspect of the present application provides a data transmission method. Optionally, the execution subject of the method can be a target node, which can be a network device, a component or apparatus (for example, a processor, a chip, or a chip system) applied to the network device, or a logic module or software (for example, a central unit (CU), a distributed unit (DU), or a radio unit (RU)) capable of realizing all or part of the functions of the network device. In the method, the target node receives a second data packet from a source node, the second data packet is a data packet processed by the source node, and the second data packet is used to be delivered to a terminal device. The target node uses a first parameter to perform transmission of a first data packet with the terminal device, the first parameter is a parameter used for transmission between the terminal device and the source node, and the first data packet includes the second data packet.

[0012] Based on the first aspect or the second aspect of the present application, optionally, the terminal device can use the first parameter to perform transmission of the first data packet with the target node on the first radio bearer (RB), and correspondingly, the target node can use the first parameter to perform transmission of the first data packet with the terminal device on the first RB.

[0013] Alternatively,

[0014] The terminal device can use the first parameter to perform transmission of the first data packet with the target node on the first PDCP and / or the first RLC, and correspondingly, the target node can use the first parameter to perform transmission of the first data packet with the terminal device on the first PDCP and / or the first RLC.

[0015] Based on the first aspect or the second aspect of the present application, optionally, the first parameter includes a parameter of the first PDCP and / or a parameter of the first RLC.

[0016] Based on the first aspect or the second aspect of the present application, optionally, the parameter of the first PDCP includes at least one of a PDCP sequence number parameter, a compression parameter, a timer parameter, an integrity protection parameter, an encryption parameter, a security key, a status report parameter, a reordering parameter, and a PDCP duplication related parameter.

[0017] Based on the first aspect or the second aspect of the present application, optionally, the parameter of the first RLC includes at least one of a logical channel (LCH) identifier, an RLC mode, an RLC sequence number parameter, a timer parameter, and a threshold parameter.

[0018] Based on the first aspect or the second aspect of the present application, optionally, the terminal device receives first indication information, and correspondingly, the target node transmits the first indication information, the first indication information being used to indicate the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

[0019] Based on the first aspect or the second aspect of the present application, optionally, the first indication information is further used to indicate the terminal device to use a second parameter on one or more of a second RB, a second PDCP, or a second RLC, the second parameter being a parameter used for transmission between the terminal device and the target node.

[0020] Based on the first aspect or the second aspect of the present application, optionally, the terminal device receives second indication information, and correspondingly, the target node transmits the second indication information, the second indication information being used to indicate an association relationship between the first RB and the second RB.

[0021] Based on the first aspect or the second aspect of the present application, optionally, the first data packet includes third indication information, the third indication information being used to indicate that the first data packet uses the first parameter or the second parameter.

[0022] Based on the first aspect or the second aspect of the present application, optionally, the terminal device receives a reconfiguration message from the target node, and correspondingly, the target node sends the reconfiguration message to the terminal device, the reconfiguration message being used to instruct the terminal device to release at least one of the first PDCP, the first RLC or the first RB.

[0023] The third aspect of the present application provides a data transmission method, optionally, the execution subject of the method can be a source node, the source node can be a network device, or a component or device (such as a processor, a chip, or a chip system, etc.) applied to the network device, or a logic module or software (such as a CU, a DU, a RU, etc.) capable of realizing all or part of the network device functions. In the method, the source node sends a second data packet to a target node, the second data packet being a data packet processed by the source node, and the second data packet being used to be delivered to a terminal device. The source node sends a handover command to the terminal device, the handover command being used to instruct the terminal device to hand over to the target node.

[0024] In some possible implementation manners, the source node receives a third data packet from the target node, the third data packet being a data packet processed by the source node, and the third data packet being from the terminal device.

[0025] The fourth aspect of the present application provides a communication device, comprising:

[0026] an interface unit, configured to receive a handover command, the handover command being used to instruct a terminal device to hand over to a target node;

[0027] a processing unit, configured to maintain a first parameter;

[0028] the interface unit is further configured to perform transmission of a first data packet with the target node by using the first parameter, the first parameter being a parameter used for transmission between the terminal device and the source node.

[0029] In a possible implementation manner, the interface unit is specifically configured to perform transmission of the first data packet with the target node on a first radio bearer (RB) by using the first parameter;

[0030] or,

[0031] perform transmission of the first data packet with the target node on a first packet data convergence protocol (PDCP) and / or a first radio link control (RLC) by using the first parameter.

[0032] In another possible implementation manner, the first parameter comprises a parameter of a first PDCP and / or a parameter of a first RLC.

[0033] In another possible implementation, the interface unit is further configured to receive first indication information, the first indication information being used to instruct the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

[0034] In another possible implementation, the first indication information is further used to instruct the terminal device to use a second parameter on one or more of a second RB, a second PDCP, or a second RLC, the second parameter being a parameter used by the terminal device for transmission with the target node.

[0035] In another possible implementation, the first RB and the second RB use a same reordering window.

[0036] In another possible implementation, the interface unit is further configured to receive second indication information, the second indication information being used to indicate an association relationship between the first RB and the second RB.

[0037] In another possible implementation, the interface unit is further configured to deliver a data packet on the second RB after delivery of a data packet on the first RB is completed.

[0038] In another possible implementation, the processing unit is further configured to establish a second PDCP function entity and / or a second RLC, the second PDCP function entity and the second RLC using a configuration of the target node, the second PDCP function entity including at least one of a first ciphering function entity, a first deciphering function entity, a first integrity protection function entity, or a first integrity check function entity.

[0039] In another possible implementation, the first data packet includes third indication information, the third indication information being used to instruct the first data packet to use the first parameter or the second parameter.

[0040] In another possible implementation, the interface unit is further configured to receive a reconfiguration message from the target node, the reconfiguration message being used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

[0041] The fifth aspect of the present application provides a communication apparatus, comprising:

[0042] an interface unit configured to receive a second data packet from a source node, the second data packet being a data packet processed by the source node, the second data packet being used to deliver to a terminal device;

[0043] a processing unit configured to maintain a first parameter;

[0044] the interface unit is further configured to use the first parameter to perform transmission of a first data packet with the terminal device, the first parameter being a parameter used by the terminal device for transmission with the source node, the first data packet including the second data packet.

[0045] In a possible implementation, the interface unit is specifically configured to perform the transmission of the first data packet with the terminal device on the first RB using the first parameter.

[0046] Alternatively,

[0047] perform the transmission of the first data packet with the terminal device on the first PDCP and / or the first RLC using the first parameter.

[0048] In another possible implementation, the first parameter includes a parameter of the first PDCP and / or a parameter of the first RLC.

[0049] In another possible implementation, the interface unit is further configured to send first indication information, where the first indication information is used to instruct the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

[0050] In another possible implementation, the first indication information is further used to instruct the terminal device to use a second parameter on one or more of a second RB, a second PDCP, or a second RLC, where the second parameter is a parameter used by the terminal device for transmission with the target node.

[0051] In another possible implementation, the first RB and the second RB use a same reordering window.

[0052] In another possible implementation, the interface unit is further configured to send second indication information, where the second indication information is used to indicate an association relationship between the first RB and the second RB.

[0053] In another possible implementation, the first data packet includes third indication information, where the third indication information is used to instruct the first data packet to use the first parameter or the second parameter.

[0054] In another possible implementation, the interface unit is further configured to send a reconfiguration message to the terminal device, where the reconfiguration message is used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

[0055] In another possible implementation, the interface unit is further configured to send, to the source cell, a third data packet, where the third data packet is a data packet processed by the source node, the third data packet is from the terminal device, and the first data packet includes the third data packet. The interface unit 1301 is configured to send, to the target node, a second data packet, where the second data packet is a data packet processed by the source node, and the second data packet is used to be delivered to the terminal device.

[0056] The sixth aspect of the present application provides a communication apparatus, comprising:

[0057] a processing unit configured to generate a handover command;

[0058] The interface unit is further configured to send a switching command to the terminal device, where the switching command is used to instruct the terminal device to switch to the target node.

[0059] In a possible implementation, the interface unit is further configured to receive a third data packet from the target node, where the third data packet is a data packet processed by the source node, and the third data packet is from the terminal device.

[0060] A seventh aspect of the embodiments of the present application provides a communication apparatus, which can be a terminal device, a target node, or a source node, can be a component (for example, a processor, a chip, or a chip system) applied to a terminal device, a target node, or a source node, and can also be a logic module or software (for example, a CU, a DU, or a RU) capable of realizing all or part of the functions of a terminal device, a target node, or a source node. The communication apparatus comprises:

[0061] The processor is configured to execute a program, so that the communication apparatus performs the method in the first aspect, the second aspect, or the third aspect, and any possible implementation manner thereof.

[0062] Optionally, the communication apparatus further comprises a memory, and the processor is coupled to the memory; and the memory is configured to store the program.

[0063] An eighth aspect of the present application provides a chip or a chip system, which comprises at least one processor and a communication interface, the communication interface and the at least one processor are interconnected through a line, and the at least one processor is configured to run a computer program or an instruction to perform the information transmission method in the first aspect, the second aspect, or the third aspect, and any possible implementation manner thereof.

[0064] The communication interface in the chip can be an input / output interface, a pin, or a circuit, etc.

[0065] In a possible implementation, the chip or the chip system described above in the present application further comprises at least one memory, and the at least one memory stores instructions. The memory can be a storage unit inside the chip, for example, a register, a cache, etc., or can be a storage unit of the chip, for example, a read-only memory, a random access memory, etc.

[0066] A ninth aspect of the present application provides a communication system, which comprises a communication apparatus for performing the first aspect and any possible implementation manner thereof, a communication apparatus for performing the second aspect and any possible implementation manner thereof, and a communication apparatus for performing the third aspect and any possible implementation manner thereof.

[0067] The tenth aspect of the present application provides a computer readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the method of the first aspect as described above, or cause the computer to perform the method of the second aspect as described above, or cause the computer to perform the method of the third aspect as described above.

[0068] The eleventh aspect of the present application provides a computer program product comprising instructions which, when executed on a computer, cause the computer to perform the method of the first aspect as described above, or cause the computer to perform the method of the second aspect as described above, or cause the computer to perform the method of the third aspect as described above. BRIEF DESCRIPTION OF DRAWINGS

[0069] Figure 1 An embodiment of a username protocol stack between a terminal device and a base station in the present application;

[0070] Figure 2 Another embodiment of a username protocol stack between a terminal device and a base station in the present application;

[0071] Figure 3 A network structure diagram in the embodiment of the present application;

[0072] Figure 4 A possible application scenario of the data transmission method in the embodiment of the present application;

[0073] Figure 5 An embodiment of a radio resource control (RRC) handover process in the embodiment of the present application;

[0074] Figure 6 An embodiment of handover delay in the embodiment of the present application;

[0075] Figure 7 An embodiment of the data transmission method in the embodiment of the present application;

[0076] Figure 8 Another embodiment of a username protocol stack between a terminal device and a base station in the embodiment of the present application;

[0077] Figure 9 An embodiment of data transmission in the embodiment of the present application;

[0078] Figure 10 Another embodiment of a username protocol stack between a terminal device and a base station in the embodiment of the present application;

[0079] Figure 11 Another embodiment of data transmission in the embodiment of the present application;

[0080] Figure 12 FIG. 3 is a schematic diagram of another embodiment of the RRC handover procedure in the embodiments of the present application;

[0081] Figure 13 FIG. 4 is a schematic diagram of one embodiment of the uplink data packet transmission in the RRC handover procedure in the embodiments of the present application;

[0082] Figure 14 FIG. 5 is a schematic diagram of another embodiment of the uplink data packet transmission in the RRC handover procedure in the embodiments of the present application;

[0083] Figure 15 FIG. 6 is a schematic diagram of one embodiment of the downlink data packet transmission in the RRC handover procedure in the embodiments of the present application;

[0084] Figure 16 FIG. 7 is a schematic diagram of another embodiment of the downlink data packet transmission in the RRC handover procedure in the embodiments of the present application;

[0085] Figure 17 FIG. 8 is a schematic diagram of one embodiment of the communication device in the embodiments of the present application;

[0086] Figure 18 FIG. 9 is a schematic diagram of another embodiment of the communication device in the embodiments of the present application;

[0087] Figure 19 FIG. 10 is a schematic diagram of another embodiment of the communication device in the embodiments of the present application;

[0088] Figure 20 FIG. 11 is a schematic diagram of another embodiment of the communication device in the embodiments of the present application;

[0089] Figure 21 FIG. 12 is a schematic diagram of another embodiment of the communication device in the embodiments of the present application. DETAILED DESCRIPTION

[0090] The present application provides a data transmission method, a communication device, a communication system and a storage medium, which avoids data interruption caused by PDCP reestablishment, data recovery and RLC reestablishment by using the parameters used for transmission with the source node, and further avoids the time delay caused by data retransmission introduced by these processes.

[0091] The embodiments of the present application are described below with reference to the accompanying drawings. It is known to those skilled in the art that, with the development of technology and the appearance of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0092] The terms "first", "second", and the like in the description, claims, and drawings of the application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of use in either order. Moreover, the terms "include", "have", and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, product, or apparatus that comprises a list of elements is not necessarily limited to those elements but can include other elements not expressly listed or inherent to such process, method, system, product, or apparatus.

[0093] Firstly, some technical terms involved in the embodiments of the application are introduced.

[0094] 1) Mobility:

[0095] Mobility refers to the ability of a terminal device to change its location or connection state during its communication process. This ability is a core feature of modern wireless communication systems (such as cellular networks, wireless local area networks, satellite communication systems, etc.), which allows users to maintain continuous connection and communication ability when using telephone, Internet, data transmission, etc. services without being limited by geographical location. Mobility management is achieved by changing the service cell of the terminal device, so that the terminal device can enjoy network services regardless of how it moves within the network coverage. Among them, mobility includes handover, i.e. when a terminal device moves from the coverage of one base station or access point to another base station or access point, the communication system needs to support seamless handover process to ensure the continuity and quality of communication. Handover involves transferring the connection of the terminal device from one base station or access point to another base station or access point without affecting the user's communication experience.

[0096] 2) Protocol stack:

[0097] Protocol stack refers to the sum of protocols at each layer in the network, which vividly reflects the process of data transmission in a network: from upper layer protocol to lower layer protocol, and from lower layer protocol to upper layer protocol. This process is similar to a stack of stacks, each layer is responsible for different functions and tasks, and cooperates together to achieve data transmission and communication. Taking the user plane as an example, the protocol stack between the terminal device and the base station is as follows: Figure 1As shown. Among them, the physical layer (physical layer, PHY) is layer 1 (level 1, L1), the service data adaptation protocol (service data adaptation protocol, SDAP) layer, the packet data convergence protocol (packet data convergence protocol, PDCP) layer, the radio link control (radio link control, RLC) layer and the media access control (media access control, MAC) layer are layer 2 (level 2, L2). For example, the following downlink (downlink, DL) data transmission, the main division of each layer of L2 is as follows Figure 2 As shown.

[0098] The main function of the SDAP layer is to complete the mapping of the quality of service (quality of service, QoS) flow to the data radio bearer (data radio bearer, DRB);

[0099] The main functions of the PDCP layer include compression / decompression, security processing (including encryption and decryption and integrity protection / verification), etc.

[0100] The main functions of the RLC layer include data segmentation and automatic repeat request (automatic repeat request, ARQ).

[0101] The main functions of the MAC layer include scheduling, multiplexing and hybrid automatic repeat request (hybrid automatic repeat request, HARQ) process. The HARQ process is a technology combining forward error correction (forward error correction, FEC) and ARQ method.

[0102] Please refer to Figure 3 , the network architecture based on the data transmission method in the embodiment of the application is described briefly as follows:

[0103] Figure 3 It is a possible, non-limiting system schematic diagram. As Figure 3 shown, the communication system 10 includes a radio access network (radio access network, RAN) 100 and a core network (core network, CN) 200. The RAN 100 includes at least one RAN node (such as 110a and 110b in Figure 3 , collectively referred to as 110) and at least one terminal (such as Figure 3RAN 100 can further include other RAN nodes (not shown in FIG. 1) such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 1) etc. The terminals 120 are connected by wireless links to the RAN nodes 110. The RAN nodes 110 are connected by wireless or wired links to the core network 200. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 can be the same physical device or different physical devices. Figure 3

[0104] The RAN 100 can be a 3rd generation partnership project (3GPP) related cellular system, e.g., a 4G, 5G mobile communication system, or a future mobile communication system. The RAN 100 can also be an open radio access network (ORAN), a cloud-radio access network (CRAN), or a wireless fidelity (WiFi) system. The RAN 100 can also be a communication system in which two or more of the above systems are integrated.

[0105] The RAN nodes 110, which can also be referred to as access network devices, RAN entities or access nodes etc., form part of the communication system 10 and are configured to facilitate wireless access to the communication system 10 for terminals. The RAN nodes 110 in the communication system 10 can be the same type of node or different types of nodes. In some scenarios, the roles of a RAN node 110 and a terminal 120 are relative, e.g., Figure 3 In some scenarios, the RAN nodes 110 and the terminals 120 are sometimes referred to as communication devices, e.g., a communication device can be a RAN node 110 or a terminal 120. Figure 1 In some scenarios, the RAN nodes 110 and the terminals 120 are sometimes referred to as communication devices, e.g., a communication device can be a RAN node 110 or a terminal 120.

[0106] ​In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a future mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc. A RAN node can also be a macro base station (such as...) Figure 1 110a), micro base stations or indoor stations (such as Figure 4 The RAN node can be a relay node or donor node (as described in section 110b), or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node can also be equipped with communication modules, circuits, or chips that perform corresponding communication functions. The RAN node can also be configured with program instructions for performing corresponding communication functions and corresponding program instructions. The RAN node in this application can also be a logical node, logical module, or software capable of implementing all or part of the RAN node functions.

[0107] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with each RAN node performing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-CPs, CU-UPs, or radio units (RUs). CUs and DUs can be configured separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0108] In different systems, the CU (or CU-CP and CU-UP), DU or RU can also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU can also be referred to as O-CU (open CU), the DU can also be referred to as O-DU, the CU-CP can also be referred to as O-CU-CP, the CU-UP can also be referred to as O-CU-UP, and the RU can also be referred to as O-RU. For the convenience of description, the CU, CU-CP, CU-UP, DU and RU are taken as examples for description in this application. Any one of the CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0109] A terminal can access the above-mentioned communication system and has corresponding communication functions. The terminal can also be referred to as a terminal device, a user equipment (UE), a mobile station, a mobile terminal, etc. The terminal can be widely used in various scenarios, such as device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-type communication (MTC), internet of things (IOT), virtual reality, augmented reality, industrial control, autonomous driving, remote medical treatment, smart power grid, smart home, smart office, smart wear, smart transportation, smart city, etc. The terminal can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, a wireless communication function transport vehicle, a communication module, etc. Embodiments of the present application do not limit the device form of the terminal. The terminal usually has a communication module, circuit or chip for executing corresponding communication functions. The terminal can also be configured with program instructions for executing corresponding communication functions.

[0110] In addition, the embodiments of the present application can also be applicable to other future-oriented communication technologies. The network architecture and service scenarios described in the present application are for more clearly illustrating the technical solutions of the present application, and do not constitute a limitation on the technical solutions provided by the present application. Those skilled in the art can know that, with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the present application are also applicable to similar technical problems.

[0111] Figure 5An application scenario applicable to the embodiments of the present application is shown. The terminal device 401 is handed over from the RAN node 402 to the RAN node 403, wherein the RAN node 402 is referred to as a source node or a source RAN node, and the RAN node 403 is referred to as a target node or a target RAN node. In the embodiments of the present application, the RAN node 402 and the RAN node 403 can be any possible implementation of the RAN node described above, and the specific implementation is not limited here.

[0112] Please refer to Figure 6 The mobility of the terminal in the connected state is completed through handover (HO), and the handover procedure of the radio resource control (RRC) is as follows:

[0113] 1. The source node configures the terminal device for measurement, and the measurement result of the terminal device is used to assist the source node to make a handover decision;

[0114] 2. The terminal device performs measurement reporting according to the measurement configuration;

[0115] 3. The source node refers to the reporting result of the terminal device, and makes a handover decision according to its own handover algorithm;

[0116] 4. The source node sends a handover request to the target node, and transmits necessary information for handover preparation, which at least includes the target node identifier, the key, the terminal ID in the source node, the basic access layer configuration, etc;

[0117] 5. The target node performs access control;

[0118] 6. The target node performs L1 / L2 handover preparation, and sends a handover request acknowledgement message (ACK) to the source node, wherein the handover command sent to the terminal device is contained in the ACK message in the form of an RRC container;

[0119] 7. The source node triggers HO, and sends a handover command (HO Command) to the terminal device. The handover command message is generated by the target node and is transparently transmitted by the source node, and the source node will perform necessary encryption and integrity protection on the message. The handover command contains information required for accessing the target node, at least including the target node identifier, the new terminal device ID, the security algorithm identifier of the target node, and possibly carrying the dedicated random access channel (RACH) resource for accessing the target node, etc;

[0120] 8. The source node sends a sequence number status transfer (SN STATUS TRANSFER) to the target node. The sequence number (SN) status transfer can include the uplink (UL) PDCP SN reception status and the downlink PDCP SN transmission status of the DRB. The UL PDCP SN reception status includes at least the PDCP SN number of the first missing UL PDCP service data unit (SDU) and can also include a bitmap of the reception status of the out-of-sequence UL PDCP SDUs that need to be retransmitted by the terminal device to the target node. The downlink PDCP SN transmission status indicates the next PDCP SN that the target node should assign to a new PDCP SDU (which does not have a PDCP SN yet).

[0121] The source node can also perform data forwarding to the target node. The data packets forwarded by the source node to the target node can include data packets that have been assigned a PDCP SN by the source node and data packets that have not been assigned a PDCP SN.

[0122] 9. After receiving the handover command, the terminal device performs synchronization with the target node for communication with the target node after the handover is successful;

[0123] 10. The target node replies with a random access response (RAR) to allocate uplink resources and timing advance;

[0124] 11. The terminal device sends an RRC reconfiguration complete message to the target node to confirm that the handover process is complete. The target node confirms that the handover process is successful by receiving the RRC reconfiguration complete message. At this point, the target node can start sending data to the terminal device;

[0125] 12. The target node sends a path switch request message to the access and mobility management (AMF) network element to inform the AMF network element that the cell has been changed, triggering the core network to switch the DL data path to the target node and establishing an NG-C interface to the target node. At this point, the air interface handover has been successfully completed;

[0126] 13. The AMF network element sends a user plane update request message to the user plane function (UPF) network element;

[0127] 14. The UPF network element switches the DL data path to the target node. The UPF network element sends one or more endmarkers to the source node and then releases the remaining UP plane / transport network layer resources between the source node.

[0128] 15. The UPF network element sends a UP update response message to the AMF network element;

[0129] 16. The AMF network element sends a path switch ACK message to the target node;

[0130] 17. After receiving the path switch ACK message, the target node sends a terminal device context release message to the source node, notifying the source node of the successful switching and triggering the source node to release the terminal device context;

[0131] 18. After receiving the terminal device context release message, the source node can release the radio bearer and the resources related to the terminal device context. If data forwarding has not been completed, the source node will not release the related resources and continue data forwarding until the data forwarding is completed and the related resources are released.

[0132] According to the above process, the switching delay (or interruption time) of RRC switching is as shown in Figure 7 . The meanings of the components of the delay are as follows:

[0133] (1) Handover command: The terminal device receives the RRC handover command at this time. After receiving the handover command, the terminal device disconnects the connection with the source node;

[0134] The delay generated in the reconfiguration phase of the terminal device includes:

[0135] (2) RRC processing: The delay required for the terminal device to process the RRC message of the handover command;

[0136] (3) Terminal device processing: Including the time for the terminal device to use the target node configuration and L1 / L2 change;

[0137] The delay generated in the downlink synchronization phase includes:

[0138] (4) The time required for the terminal device to detect the first available synchronization signal and PBCH block (SSB) to obtain the DL timing;

[0139] (5) The time required for the terminal device to process the SSB;

[0140] The delay generated in the uplink synchronization phase includes:

[0141] (6) The time required for the terminal device to obtain the first UL transmission (i.e., PRACH occasion);

[0142] (10) The delay introduced by the terminal device waiting for RAR;

[0143] and

[0144] (9) The terminal device waits for the time delay introduced by the handover;

[0145] Among the above-mentioned time delays, the uplink synchronization and the downlink synchronization can be completed in advance before receiving the handover command, thereby saving the time delay introduced by the two parts. For example, in the L1 / L2 triggered mobility, the base station can configure multiple candidate cells for the terminal device in advance (at this time, the terminal device is not disconnected with the source node), and trigger or enable the terminal device to perform the UL synchronization or the DL synchronization of the candidate cell in advance before issuing the L1 / L2 handover command, thereby reducing the time delay introduced by the handover.

[0146] The L1 / L2 change can include the change of PDCP, RLC and MAC, and the change of L1. After receiving the handover command, the terminal device needs to perform MAC reset, RLC re-establishment, and may also perform PDCP re-establishment or data recovery. The time delay of L2 change includes:

[0147] 1) The time delay caused by PDCP re-establishment / data recovery;

[0148] 2) The time delay caused by RLC re-establishment;

[0149] 3) The time delay caused by MAC reset;

[0150] 4) The retransmission of data packets introduced by the above-mentioned L2 re-establishment / reset will also introduce additional service time delay.

[0151] At present, in the process of mobility enhancement, the base station can configure LTM candidate cells for the terminal device in advance, and the base station triggers the terminal device to connect with the target cell based on the L1 measurement result of the terminal device through the LTM handover MAC control element (CE), wherein the target cell is one of the candidate cells. The terminal device can perform the UL synchronization and / or the DL synchronization of the candidate cell in advance before receiving the LTM handover MAC CE, thereby saving the handover time delay after receiving the LTM handover MAC CE.

[0152] However, the above-mentioned process triggers or enables the UE to perform the UL synchronization or the DL synchronization of the candidate cell in advance before issuing the L1 / L2 handover command, thereby reducing the time delay introduced by the handover, and thus fails to reduce the time delay caused by the L2 change.

[0153] Based on this, the embodiment of the present application provides a method. It should be noted that the embodiment of the present application takes RRC switching as an example for description, and in actual application, it can also be applied to other mobility enhancement technologies, such as conditional switching (CHO), dual active protocol stack (DAPS), LTM, etc.

[0154] Please refer to Figure 5 The data transmission method in the embodiment of the present application comprises:

[0155] 701、The source node sends a switching command to the terminal device, and correspondingly, the terminal device receives the switching command from the source node;

[0156] The source node sends a switching command to the terminal device, and correspondingly, the terminal device receives the switching command from the source node; Figure 8 The switching command shown in step 7 in the above method, or a cell switching command MAC CE in LTM, or a switching command in CHO or DAPS, without limitation. It can be understood that in CHO, the switching command can be understood as an RRC message including CHO candidate cell configuration.

[0157] In a possible implementation manner, the switching command comprises first indication information, and the first indication information is used to instruct the terminal device to use a first parameter on one or more of a first radio bearer (RB), a first PDCP or a first RLC.

[0158] The first parameter is a parameter used for transmission between the terminal device and the source node. The first parameter can also be understood as a parameter of one or more of part or all of the RB, PDCP and RLC of the source node, or the first parameter is a parameter currently used or used before switching by the terminal device. Therefore, the first indication information can also be understood as being used to instruct the terminal device to maintain one or more of the first RB, the first PDCP, the first RLC or the first LCH before the current or switching. The terminal device maintaining one or more of the first RB, the first PDCP and the first RLC can include maintaining the corresponding entity, state variable, related timer and configuration of the first RB, the first PDCP and the first RLC.

[0159] The first parameter can include one or more of a parameter of the first RB, a parameter of the first PDCP and a parameter of the first RLC.

[0160] For example, the parameter of the first RB includes at least one of an identifier of the first RB and a security configuration. The security configuration includes security algorithm configuration, etc.

[0161] Exemplarily, the parameters of the first PDCP include at least one of a PDCP sequence number parameter, a compression parameter, a timer parameter, an integrity protection parameter, an encryption parameter, a security key, a status report parameter, a reordering parameter, or a PDCP duplication related parameter. The security key of the first PDCP is a security key used by the terminal device and the network node, including a key used for integrity protection and verification and a key used for encryption and decryption.

[0162] Exemplarily, the parameters of the first RLC include at least one of a logical channel (LCH) identifier, an RLC mode, an RLC sequence number parameter, a timer parameter, and a threshold parameter.

[0163] Optionally, the first indication information can also be used to indicate the terminal device to use the second parameters on one or more of the second RB, the second PDCP, or the second RLC. That is, the second indication information is used to indicate the terminal device to use the parameters of the source node or the parameters of the target node on a specific RB.

[0164] The second parameters are parameters used by the terminal device for transmission with the target node. The second parameters can also be understood as parameters of one or more of the RB, the PDCP, or the RLC of the target node, or the second parameters are new parameters of the terminal device from the target node. Therefore, the first indication information can also be understood as being used to indicate the terminal device to use the new parameters of the target node.

[0165] The second parameters can include one or more of the parameters of the second RB, the parameters of the second PDCP, or the parameters of the second RLC.

[0166] Exemplarily, the parameters of the second RB include at least one of an identifier of the second RB and a security configuration. The security configuration includes a security algorithm configuration, etc.

[0167] Exemplarily, the parameters of the second PDCP include at least one of a PDCP sequence number parameter, a compression parameter, a timer parameter, an integrity protection parameter, an encryption parameter, a security key, a status report parameter, a reordering parameter, or a PDCP duplication related parameter. The security key of the first PDCP is a security key used by the terminal device and the network node, including a key used for integrity protection and verification and a key used for encryption and decryption.

[0168] Exemplarily, the parameters of the second RLC include at least one of a logical channel (LCH) identifier, an RLC mode, an RLC sequence number parameter, a timer parameter, and a threshold parameter.

[0169] Optionally, the first indication information is used to instruct the terminal device to use the first parameter on the first LCH. At this time, the first parameter can be understood as the parameter of part or all of the LCHs of the source node. Therefore, the first indication information is used to instruct the terminal device to maintain the first LCH.

[0170] In another possible implementation, the first indication information is not included in the handover command and is sent by the target node, which is specifically described in step 701a.

[0171] 702、the terminal device uses the first parameter to perform transmission of the first data packet with the target node, and correspondingly, the target node uses the first parameter to perform transmission of the first data packet with the terminal device;

[0172] Specifically, the first data packet is a data packet processed by the source node. In a possible implementation, the processing by the source node can be PDCP processing by the source node, or PDCP processing and RLC processing by the source node.

[0173] The first data packet includes a first uplink data packet and / or a first downlink data packet.

[0174] The first uplink data packet is a data packet sent by the terminal device to the target node, and the terminal device sends the first uplink data packet to the target node according to the first parameter. Correspondingly, the target node receives the first uplink data packet according to the first parameter. The first data packet is a data packet processed by the source node, which means that the first uplink data packet is a data packet processed by the terminal device using the first parameter. After reaching the network side, the source node needs to process the data packet. For example, after receiving the first uplink data packet, the target node forwards it to the source node for processing. The PDCP processing by the source node can include one or more operations of removing the PDCP header, decryption, integrity check, reordering, and decompression performed by the source node on the first uplink data packet. The RLC processing by the source node can include one or more operations of routing, removing the RLC header, and SDU recombination performed by the source node on the first uplink data packet.

[0175] The first downlink data packet is a data packet sent by the target node to the terminal device. The target node sends the first downlink data packet to the terminal device according to the first parameter, and correspondingly, the terminal device receives the first downlink data packet according to the first parameter. The first data packet is a data packet processed by the source node, which means that the first downlink data packet is a data packet processed by the source node using the first parameter, and the data packet reaches the terminal device after being sent by the target node. For example, the source node sends the processed first downlink data packet to the target node, and the target node forwards the first downlink data packet to the terminal device. The data packet sent by the target node using the configuration of the source node can be understood as not being processed by the PDCP and / or RLC of the target node. The PDCP processing of the source node can include one or more operations of the source node on the first downlink data packet, such as numbering, compression, integrity protection, encryption, adding a PDCP header, routing, and duplication. The RLC processing of the source node can include one or more operations of the source node on the first downlink data packet, such as adding an RLC header, segmentation, and the like.

[0176] After the terminal device switches from the source node to the target node, the terminal device disconnects the connection with the source node, but retains the part of the parameters of the source node, that is, there are part of the parameters of the source node that are not released by the terminal device. For example, the part of the parameters can include the security parameters of the PDCP of the protocol stack between the terminal device and the source node and the parameters of the RLC of the protocol stack. For details, please refer to the description of the first parameter, the first PDCP parameter, and the first RLC parameter, which will not be described here.

[0177] In a possible implementation, the terminal device uses the first parameter to perform transmission of the first data packet with the target node on the first RB.

[0178] Before the switching, there is one or more RBs between the terminal device and the source node, and the transmission of data packets is performed on the one or more RBs. After the switching, the terminal device and the target node can also maintain one or more RBs, and the transmission of data packets is performed on the one or more RBs. Among the one or more RBs maintained between the terminal device and the target node, at least one RB, for example, the first RB, established between the terminal device and the source node can be included. That is, after the terminal device switches to the target node, the terminal device continues to use the PDCP parameter of the source node and / or the RLC parameter of the source node to perform transmission on the at least one RB. The terminal device continues to maintain the PDCP and / or RLC entity on the at least one RB, as shown in the figure, the at least one DRB includes the first RB. The terminal device sends the first uplink data packet to the target node on the uplink RB in the at least one RB, and the target node sends the first downlink data packet to the terminal device on the downlink RB in the at least one RB. Optionally, the terminal device can also newly establish the MAC entity of the target node. Figure 9

[0179] ​Optionally, the terminal device maintains the PDCP entity including one or more functional entities of the PDCP entity, including an encryption / decryption entity, an integrity protection / verification entity, and the like.

[0180] Optionally, the terminal device and the target node can also newly establish a RB for data packet transmission, for example, a second RB. The terminal device newly establishes a PDCP entity and / or an RLC entity of the second RB, and uses the new parameters of the target node for transmission.

[0181] In the embodiments of the present application, after the handover, the terminal device and the target node continue to receive or send data packets processed by the source node on part of the DRBs, thereby avoiding data interruption caused by PDCP reestablishment or data recovery and RLC reestablishment, and avoiding the time delay caused by data retransmission introduced by these processes, reducing the time delay of service interruption caused by handover, and improving user experience.

[0182] It should be noted that the terminal device also receives a fourth data packet sent by the target node on the second RB using the second parameters, wherein the fourth data packet is a data packet processed by the target node. In a possible implementation, the processing by the target node can be PDCP processing by the target node, or PDCP processing and RLC processing by the target node.

[0183] The fourth data packet includes a fourth uplink data packet and / or a fourth downlink data packet.

[0184] The fourth uplink data packet is a data packet sent by the terminal device to the target node, and the terminal device sends the fourth uplink data packet to the target node according to the second parameters. Correspondingly, the target node receives the fourth uplink data packet according to the second parameters. The fourth data packet is a data packet processed by the target node, which means that the fourth uplink data packet is a data packet processed by the terminal device using the second parameters. After reaching the network side, the target node needs to process the data packet. The PDCP processing by the target node can include one or more operations of removing the PDCP header, decryption, integrity verification, reordering, and decompression performed by the target node on the fourth uplink data packet. The RLC processing by the target node can include one or more operations of routing, removing the RLC header, and SDU recombination performed by the target node on the fourth uplink data packet.

[0185] The fourth downlink data packet is a data packet sent by the target node to the terminal device. The target node sends the fourth downlink data packet to the terminal device according to the second parameter, and correspondingly, the terminal device receives the fourth downlink data packet according to the second parameter. The fourth data packet is a data packet processed by the target node, which means that the fourth downlink data packet is a data packet processed by the target node using the second parameter, and the data packet reaches the terminal device after being sent by the target node. The PDCP processing performed by the target node can include one or more operations of performing numbering, compression, integrity protection, encryption, adding a PDCP header, routing, and duplication on the fourth downlink data packet by the source node. The RLC processing performed by the target node can include one or more operations of adding an RLC header, segmentation, and the like on the fourth downlink data packet by the source node.

[0186] Optionally, the terminal device can determine, according to the first indication information, whether the first parameter or the second parameter is used in each of the at least one RB between the terminal device and the target node.

[0187] Optionally, the first RB and the second RB can use the same reordering window. The first RB and the second RB are associated with each other. Specifically, the terminal device receives the first data packet on the first RB and receives the fourth data packet on the second RB, and the first data packet and the fourth data packet belong to the same data flow, so that the receiving order of the first data packet and the fourth data packet can be determined by using the same reordering window at the terminal device side. For example, the second RB is an RB maintained by the terminal device with the source node before the switching, and after the switching to the target node, the terminal device continues to use the first RB to transmit the data packet to the target node, including the first data packet. Correspondingly, the target node can instruct the terminal device to add the second RB, the second RB corresponding to the first RB, to transmit subsequent data packets of the first data packet. The first RB and the second RB use the same reordering window, which can be understood as that the data packets submitted by the first RB and the second RB to the lower layer entity (for example, RLC) or LCH are sorted by a unified reordering window after decryption or integrity check and the like. Optionally, the second RB and the second RB can also use the same compression or decompression entity.

[0188] For example, the initial value of the PDCP SN on the second RB is not 0. The initial value can be the SN of the last data packet on the second RB plus 1. The initial value can be indicated by the network. As shown in Figure 10 , the SN of the last data packet of the first RB is 100, and the sequence number of the first data packet on the second RB is 101, so that the last data packet on the first RB is sorted after the first data packet on the second RB.

[0189] For another example, the second RB can continue to use the reordering window shared before the first RB is released. The specific implementation is not limited here.

[0190] Optionally, the data packets on the second RB cannot start submitting to the upper layer until the data packets on the first RB are submitted to the upper layer. In this implementation, the first RB and the second RB use different reordering windows.

[0191] Optionally, the data packets on the second RB can start from PDCP SN 0, and the data packets on the first RB and the second RB are sorted by the upper layer (e.g., IP layer, TCP layer or APP layer).

[0192] Optionally, the data transmission on the second RB does not start until the data transmission on the first RB is completed.

[0193] It should be understood that the target node does not instruct the UPF to release the data path between the source node before the data transmission of the DRB of the source cell is completed.

[0194] Optionally, the association relationship between the first RB and the second RB can be configured by the network, for example, the association relationship can be included in the handover command.

[0195] It should be noted that the above-mentioned operations in the reordering of the data packets can be combined with each other to form a new independent embodiment, and the present application does not limit this.

[0196] In another possible implementation, the terminal device uses the first parameter to perform the transmission of the first data packet on the first PDCP and / or the first RLC with the target node.

[0197] Before the handover, the terminal device and the source node have one or more RBs, and the transmission of the data packets is performed on the one or more RBs. After the handover or after the handover, the terminal device can continue to maintain the corresponding PDCP and / or RLC entity or PDCP and / or RLC parameter on at least one RB maintained before. Specifically, after the terminal device switches from the source node to the target node, the terminal device disconnects the connection with the source node, and the terminal device continues to maintain the PDCP entity and the RLC entity of the source node. The terminal device can also establish a second PDCP function entity and / or a second RLC on the at least one RB, as shown in the following table. Figure 11 The second PDCP function entity and the second RLC use the configuration of the target node, and the second PDCP function entity includes at least one of the first encryption function entity, the first decryption function entity, the first integrity protection function entity or the first integrity check function entity. The second PDCP function entity and / or the second RLC use the configuration or parameter of the target node.

[0198] The terminal device uses the first parameter to perform transmission of first data packets with the target node on the first PDCP and / or the first RLC, and uses the second parameter to perform transmission of fourth data packets with the target node on the second PDCP and / or the second RLC. The first data packets and the fourth data packets are transmitted on the same RB, as shown in Figure 7

[0199] For example, the first data packets include data packets with sequence numbers 12, 15, 25,..., 100, and the fourth data packets include data packets with sequence numbers 101, 102, 103,..., 200. The first data packets in the RB are transmitted by the first PDCP and / or the first RLC, and the fourth data packets are transmitted by the second PDCP and / or the second RLC.

[0200] Optionally, the terminal device receives or sends third indication information, which indicates whether a specific data packet is processed by the source node or the target node, or indicates whether the specific data packet is processed by the first PDCP and / or the RLC entity or the second PDCP and / or the RLC. The third indication information can be included in the header of the data packet, for example, the third indication information is included in the PDCP header or the RLC header.

[0201] In the embodiments of the present application, the terminal device continues to receive or send data packets processed by the source node after the handover, thereby avoiding data interruption caused by PDCP reestablishment or data recovery and RLC reestablishment, and avoiding the time delay caused by data retransmission introduced by these processes, reducing the time delay of service interruption caused by handover, and improving user experience.

[0202] Optionally, Figure 5 The embodiments shown in FIG. 7 further include step 700. Step 700 can be performed before step 701.

[0203] 700. The source node sends second data packets to the target node, and correspondingly, the target node receives the second data packets from the source node.

[0204] Optionally, the second data packets can be data packets processed by the source node. The data packets processed by the source node are described above and will not be repeated here.

[0205] It should be noted that the source node can also send data packets that have not been processed by the source node to the target node.

[0206] Optionally, the source node can also send SN status to the target node, wherein the SN status can be used to indicate the SN of the first data packet that has not been acknowledged by the terminal device.

[0207] ​Optionally, the SN status can also be used to indicate the SNs of the multiple data packets that are not responded by the terminal device. For example, the SNs of the data packets that are not acknowledged by the terminal device are indicated in a bitmap manner. The SN status can be sent through the SN status transmission message, for example, the step 8 in the message in Figure 7

[0208] It should be noted that the above various operations of the source node sending the SN status to the target node can be combined to form new independent embodiments, and the present application does not limit this.

[0209] Optionally, Figure 7 The embodiment shown also includes step 701a. Step 701a can be performed after step 701.

[0210] 701a. The target node sends first indication information to the terminal device, and correspondingly, the terminal device receives the first indication information from the target node;

[0211] The target node can send first indication information to the terminal device, which is used to instruct the terminal device to use the first parameter on one or more of the first RB, the first PDCP or the first RLC. It is also used to instruct the terminal device to use the second parameter on one or more of the second RB, the second PDCP or the second RLC.

[0212] Optionally, Figure 7 The embodiment shown also includes step 701b. Step 701b can be performed after step 701.

[0213] 701b. The target node sends second indication information to the terminal device, and correspondingly, the terminal device receives the second indication information from the target node;

[0214] In one possible implementation, the second indication information is used to indicate the association relationship between the first RB and the second RB, so that the terminal device can perform continuous allocation of the PDCP SN number.

[0215] Optionally, the second indication information can be carried in the handover command sent by the source node to the terminal device, and the present application does not limit this.

[0216] In another possible implementation, the second indication information is used to indicate the initial value of the PDCP SN number of the second RB.

[0217] Optionally, Figure 7 The embodiment shown also includes step 703. Step 703 can be performed after step 702.

[0218] 703. The target node sends a third data packet to the source node, and correspondingly, the source node receives the third data packet from the target node;​

[0219] Specifically, the third data packet is a data packet processed by the source node, and the third data packet is from the terminal device, that is, the third data packet can be the first uplink data packet in the first data packet. The target node forwards the data packet processed by the source node and uploaded by the terminal device to the source node.

[0220] Optionally, Figure 12 The embodiment shown also includes step 704. Step 704 can be performed after step 703.

[0221] 704. The target node sends a reconfiguration message to the terminal device, and correspondingly, the terminal device receives the reconfiguration message from the target node.

[0222] Specifically, the reconfiguration message can be an RRC reconfiguration message, which is used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

[0223] In one possible implementation, the target node releases the first RB through the RRC reconfiguration message. The RRC reconfiguration message can also indicate the addition of a new DRB, and the newly added DRB uses the configuration of the target cell for data packet transmission.

[0224] In another possible implementation, the target cell can instruct the UE to release the first PDPC and / or the first RLC entity of the source node through the RRC reconfiguration message.

[0225] It should be noted that step 704 is only an example. In actual applications, the terminal device can also release the entity related to the source node by itself, and the specific implementation is not limited here.

[0226] Based on the above embodiment, one possible implementation of the RRC handover process of the terminal device in the present application is shown as follows: Figure 7

[0227] 1201. The source node sends a handover request to the target node, and correspondingly, the target node receives the handover request from the source node.

[0228] Specifically, the handover request includes the configuration of the source node, such as the RB configuration between the source node and the terminal device. This step is an optional step.

[0229] 1202. The target node sends a handover request confirmation to the source node.

[0230] Specifically, the handover request confirmation includes the configuration of the target node. This step is an optional step.

[0231] 1203. The source node performs data forwarding to the target node. This step is an optional step. ​

[0232] Specifically, the source node sends the second data packet to the target node, which can be referred to the step 701 in the foregoing Figure 7 embodiment, and details are not described herein again.

[0233] 1204, the source node sends a handover command to the terminal device, and correspondingly, the terminal device receives the handover command from the source node;

[0234] The step can be referred to the step 701 in the foregoing Figure 5 embodiment, and details are not described herein again.

[0235] 1205, the source node sends an SN status report to the target node, and correspondingly, the target node receives the SN status report from the source node:

[0236] The step can be referred to the step 8 in the foregoing Figure 7 embodiment, and details are not described herein again. The SN status report can be used to indicate the SN of the first data packet that is not confirmed by the terminal device, which can be referred to the description in the step 700. The step is an optional step.

[0237] 1206, the terminal device performs a RACH process with the target node;

[0238] 1207, the terminal device performs data packet transmission with the target node;

[0239] The data packet includes the first data packet and / or the fourth data packet. Specifically, the terminal device uses the first parameter to perform the first data packet transmission with the target node, and correspondingly, the target node uses the first parameter to perform the first data packet transmission with the terminal device. The terminal device uses the second parameter to perform the fourth data packet transmission with the target node, and correspondingly, the target node uses the fourth parameter to perform the first data packet transmission with the terminal device.

[0240] The first data packet includes the first uplink data packet and / or the first downlink data packet. The fourth data packet includes the fourth uplink data packet and / or the fourth downlink data packet. The explanation of the first data packet and the fourth data packet can be referred to the step 702 in the foregoing Figure 13 embodiment, and details are not described herein again.

[0241] As Figure 14 shown, the terminal device can send the first uplink data packet to the target node on the first RB according to the first parameter, and correspondingly, the target node receives the first uplink data packet from the terminal device on the first RB according to the first parameter. The terminal device can send the fourth uplink data packet to the target node on the second RB according to the second parameter, and correspondingly, the target node receives the fourth uplink data packet from the terminal device on the second RB according to the second parameter.

[0242] For example, the first RBs are DRB1 and DRB2, and the second RBs are DRB3 and DRB4. Before the handover, the terminal device sends uplink data packets to the source node via DRB1, including uplink data packets with SN=0 to SN=20, and sends uplink data packets with SN=30 to SN=60 via DRB2. The SN status report mentioned in step 1205 above is used to indicate uplink data packets not received by the source node during this process. After the handover, the terminal device retains DRB1 and DRB2, and sends a first uplink data packet processed using source node parameters (e.g., the first parameter) to the target node via DRB1 and DRB2. This first uplink data packet may include data packets that have been processed or buffered using the first parameter before the handover; see the explanation of the first data packet above for details, which will not be repeated here. This first uplink data packet may also include data packets that have been processed using the first parameter but have not yet been sent to the source node. Simultaneously, the terminal device sends a fourth uplink data packet to the target node via DRB3 and DRB4, i.e., the second RBs; see the explanation of the fourth data packet above for details, which will not be repeated here. The target node will forward the first uplink data packet processed using the first parameter to the source node.

[0243] The target node can indicate the association relationship between DRB1 and DRB3, and the association relationship between DRB2 and DRB4, to the terminal device. This association relationship can be included in the handover command in step 1204.

[0244] like Figure 14 As shown, the terminal device can send a first uplink data packet to the target node on the first PDCP and / or the first RLC according to the first parameter. Correspondingly, the target node receives the first uplink data packet from the terminal device on the first PDCP and / or the first RLC according to the first parameter. The terminal device can send a fourth uplink data packet to the target node on the second PDCP and / or the second RLC according to the second parameter. Correspondingly, the target node receives the fourth uplink data packet from the terminal device on the second PDCP and / or the second RLC according to the second parameter.

[0245] For example, such as Figure 7 As shown, after handover, the terminal device maintains the first PDCP and / or the first RLC entity and creates a second PDCP and / or the second RLC entity. The terminal device sends a first uplink data packet, such as a data packet with SN=12, SN=15, SN=25, ..., SN=100, through the first PDCP and / or the first RLC entity, and sends a fourth uplink data packet, such as a data packet with SN=101, SN=102, through the second PDCP and / or the second RLC entity. See details for further information. Figure 15 Step 702 in the illustrated embodiment will not be repeated here.

[0246] As shown in Figure 7 the target node can send the first downlink data packets to the terminal device on the first RB according to the first parameter, and correspondingly, the terminal device receives the first downlink data packets from the target node on the first RB according to the first parameter. The target node can send the fourth downlink data packets to the terminal device on the second RB according to the second parameter, and correspondingly, the terminal device receives the fourth downlink data packets from the target node on the second RB according to the second parameter.

[0247] For example, the first RB is DRB1 and DRB2, and the second RB is DRB3 and DRB4. Before the terminal device switches, the source node sends the data packets to the terminal device through DRB1, including the downlink data packets with SN=0 to SN=20, and sends the data packets to the terminal device through DRB2, including the downlink data packets with SN=30 to SN=60. After the source node receives the switching request confirmation of the target node, the source node sends the first downlink data packets that have been processed by the source node to the target node, i.e. the data packets that are not responded by the terminal device and the data packets that have not been sent to the terminal device, for example, the data packets with SN=10, SN=11, SN=12, …, SN=100 on DRB1, the data packets with SN=20, SN=21, SN=22, …, SN=70 on DRB2, and the data packets that have not been processed by the source node, for example, the data packets with SN=101, SN=102 on DRB1, and the data packets with SN=71, SN=72 on DRB2. The target node sends the data packets processed by the source node to the terminal device through DRB1 and DRB2, and sends the data packets processed by the target node to the terminal device through DRB3 and DRB4. For details, refer to step 702 in the embodiment shown in Figure 16

[0248] As shown in Figure 7 the target node can send the first downlink data packets to the terminal device on the first PDCP and / or the first RLC according to the first parameter, and correspondingly, the terminal device receives the first downlink data packets from the target node on the first PDCP and / or the first RLC according to the first parameter. The target node can send the fourth downlink data packets to the terminal device on the second PDCP and / or the second RLC according to the second parameter, and correspondingly, the terminal device receives the fourth downlink data packets from the target node on the second PDCP and / or the second RLC according to the second parameter.

[0249] ​For example, the terminal device maintains the first PDCP and / or the first RLC entity after the handover, and newly builds the second PDCP and / or the second RLC entity. The target node sends the first downlink data packet, for example, the data packet with SN=12, SN=15, SN=25, …, SN=100, to the terminal device through the first PDCP and / or the first RLC entity, and sends the fourth downlink data packet, for example, the data packet with SN=101, SN=102, to the terminal device through the second PDCP and / or the second RLC entity. For details, refer to the foregoing Figure 7 Step 702 in the embodiment shown, which will not be repeated here.

[0250] The target node can indicate the terminal device of the association relationship of DRB1 and DRB3, and the association relationship of DRB2 and DRB4. The association relationship can be contained in the handover command in step 1204.

[0251] 1208. The target node sends the third data packet to the source node, and correspondingly, the source node receives the third data packet from the target node.

[0252] This step can refer to the foregoing Figure 7 Step 703 in the embodiment shown, which will not be repeated here. This step is an optional step.

[0253] 1209. The target node sends the reconfiguration message to the terminal device, and correspondingly, the terminal device receives the reconfiguration message from the target node.

[0254] 1210. The terminal device releases the first RB, the first PDCP and / or the first RLC entity.

[0255] Steps 1209 to 1210 can refer to the foregoing Figure 17 Step 704 in the embodiment shown, which will not be repeated here. Steps 1209 and 1210 are optional steps.

[0256] The information transmission method in the embodiments of the present application is described above, and the communication device in the embodiments of the present application is described below. Please refer to Figure 7 , the communication device 1700 can be used to execute Figure 7 the process performed by the terminal device in the embodiment shown, and for details, refer to the related description in the foregoing method embodiments. The communication device 1700 can be a terminal device, or a component or device (such as a processor, a chip, or a chip system) applied to a terminal device, or a logic module or software that can realize all or part of the terminal device functions.

[0257] The communication device 1700 includes an interface module 1701 and a processing module 1702.

[0258] The processing module 1702 is used for data processing. The interface module 1701 can implement corresponding communication functions. The interface module 1701 can also be called a communication interface or a communication module.

[0259] Optionally, the communication device 1700 may further include a storage module, which can be used to store program code, program instructions and / or data. The processing module 1702 can read the instructions and / or data in the storage module so that the communication device 1700 can implement the aforementioned method embodiments.

[0260] The communication device 1700 can be used to perform the actions performed by the terminal device in the above method embodiments. For example, it can be a terminal device, a communication module within a terminal device, or a circuit or chip within a terminal device responsible for communication functions. The communication device 1700 can be a terminal device or a component configurable on a terminal device. The processing module 1702 is used to perform processing-related operations on the terminal device side in the above method embodiments. The interface module 1701 is used to perform reception-related operations on the terminal device side in the above method embodiments.

[0261] Optionally, interface module 1701 may include a sending module and a receiving module. The sending module is used to perform the sending operation in the above method embodiments. The receiving module is used to perform the receiving operation in the above method embodiments.

[0262] It should be noted that the communication device 1700 may include a transmitting module but not a receiving module. Alternatively, the communication device 1700 may include a receiving module but not a transmitting module. Specifically, it depends on whether the above-described scheme performed by the communication device 1700 includes both transmitting and receiving actions. For example, the communication device 1700 is used to perform the above-described... Figure 7 The actions performed by the terminal device in the illustrated embodiment are shown above. For details, please refer to the above. Figure 18 The relevant descriptions in the illustrated embodiments will not be elaborated here.

[0263] For example, the communication device 1700 is used to execute the following scheme:

[0264] Interface unit 1701 is used to receive a handover command, which instructs the terminal device to switch to the target node.

[0265] Processing unit 1702 is used to maintain the first parameter;

[0266] Interface unit 1701 is also used to transmit a first data packet with the target node using a first parameter, wherein the first parameter is the parameter used for transmission between the terminal device and the source node.

[0267] In a possible implementation, the interface unit 1701 is configured to perform the transmission of the first data packet with the target node on the first radio bearer (RB) using the first parameter.

[0268] Alternatively,

[0269] perform the transmission of the first data packet with the target node on the first packet data convergence protocol (PDCP) and / or the first radio link control (RLC) using the first parameter.

[0270] In another possible implementation, the first parameter includes a parameter of the first PDCP and / or a parameter of the first RLC.

[0271] In another possible implementation, the interface unit 1701 is further configured to receive first indication information, where the first indication information is used to instruct the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

[0272] In another possible implementation, the first indication information is further used to instruct the terminal device to use a second parameter on one or more of a second RB, a second PDCP, or a second RLC, where the second parameter is a parameter used for transmission between the terminal device and the target node.

[0273] In another possible implementation, the first RB and the second RB use a same reordering window.

[0274] In another possible implementation, the interface unit 1701 is further configured to receive second indication information, where the second indication information is used to indicate an association relationship between the first RB and the second RB.

[0275] In another possible implementation, the interface unit 1701 is further configured to deliver the data packet on the second RB after the delivery of the data packet on the first RB is completed.

[0276] In another possible implementation, the processing unit 1702 is further configured to establish a second PDCP function entity and / or a second RLC, where the second PDCP function entity and the second RLC use a configuration of the target node, and the second PDCP function entity includes at least one of a first ciphering function entity, a first deciphering function entity, a first integrity protection function entity, or a first integrity check function entity.

[0277] In another possible implementation, the first data packet includes third indication information, where the third indication information is used to instruct the first data packet to use the first parameter or the second parameter.

[0278] In another possible implementation, the interface unit 1701 is further configured to receive a reconfiguration message from the target node, where the reconfiguration message is used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

[0279] It should be understood that the specific processes of each module performing the corresponding processes described above have been described in detail in the method embodiments described above, and for the sake of brevity, will not be repeated here.

[0280] Optionally, when the communication apparatus 1700 is a terminal device or a communication module in a terminal device, the processing module 1702 in the above embodiments can be implemented by at least one processor or processor-related circuit. Specifically, the processor can include a Modem chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a Modem core. The interface module 1701 can be implemented by a transceiver or a transceiver-related circuit. The interface module 1701 can also be referred to as a communication module or a communication interface. The storage module can be implemented by at least one memory.

[0281] Optionally, when the communication apparatus 1700 is a circuit or chip responsible for communication functions in a terminal device, such as a Modem chip or a SoC chip or a SIP chip containing a Modem core, the functions of the processing module 1702 can be implemented by the circuit system including one or more processors or processing cores in the above-mentioned chip. The function of the interface module 1701 can be implemented by the interface circuit or data transceiver circuit on the above-mentioned chip.

[0282] Another structural schematic of the communication apparatus of the embodiments of the present application is shown below. Please refer to Figure 7 , the communication apparatus 1800 can be used to execute the processes performed by the target node in the embodiments shown in Figure 7 , and the specific implementation can refer to the related description in the foregoing method embodiments. The communication apparatus 1800 can be a network device, or a component or apparatus (such as a processor, a chip, or a chip system, etc.) applied to a network device, and can also be a logic module or software that can realize all or part of the network device functions. The communication apparatus can also be a terminal device, or a component or apparatus (such as a processor, a chip, or a chip system, etc.) applied to a terminal device, and can also be a logic module or software that can realize all or part of the terminal device functions.

[0283] The communication apparatus 1800 includes an interface module 1801 and a processing module 1802.

[0284] The processing module 1802 is configured to perform data processing. The interface module 1801 can implement corresponding communication functions. The interface module 1801 can also be referred to as a communication interface or a communication module.

[0285] Optionally, the communication device 1800 may further include a storage module, which can be used to store program code, program instructions and / or data. The processing module 1802 can read the instructions and / or data in the storage module so that the communication device 1800 can implement the aforementioned method embodiments.

[0286] The communication device 1800 can be used to perform the actions performed by the target node in the above method embodiments. For example, it can be the target node, a communication module within the target node, or a circuit or chip within the target node responsible for communication functions. The communication device 1800 can be the target node or a component configurable on the target node. The processing module 1802 is used to perform processing-related operations on the target node side in the above method embodiments. The interface module 1801 is used to perform reception-related operations on the target node side in the above method embodiments.

[0287] Optionally, the interface module 1801 may include a sending module and a receiving module. The sending module is used to perform the sending operation in the above method embodiments. The receiving module is used to perform the receiving operation in the above method embodiments.

[0288] It should be noted that the communication device 1800 may include a transmitting module but not a receiving module. Alternatively, the communication device 1800 may include a receiving module but not a transmitting module. Specifically, it depends on whether the above-described scheme performed by the communication device 1800 includes both transmitting and receiving actions. For example, the communication device 1800 is used to perform the above-described... Figure 7 The actions performed by the target node in the illustrated embodiment are shown above. For details, please refer to the above. Figure 19 The relevant descriptions in the illustrated embodiments will not be elaborated here.

[0289] For example, the communication device 1800 is used to execute the following scheme:

[0290] Interface unit 1801 is used to receive a second data packet from the source node. The second data packet is a data packet processed by the source node and is used to pass the second data packet to the terminal device.

[0291] Processing unit 1802 is used to maintain the first parameter;

[0292] Interface unit 1801 is also used to transmit a first data packet with the terminal device using a first parameter. The first parameter is the parameter used for transmission between the terminal device and the source node. The first data packet includes a second data packet.

[0293] In one possible implementation, the interface unit 1801 is specifically used to transmit a first data packet with the terminal device on the first RB using the first parameter;

[0294] or,

[0295] transmit, using the first parameter, the first data packet with the terminal device on the first PDCP and / or the first RLC.

[0296] In another possible implementation, the first parameter includes a parameter of the first PDCP and / or a parameter of the first RLC.

[0297] In another possible implementation, the interface unit 1801 is further configured to send first indication information, where the first indication information is used to instruct the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

[0298] In another possible implementation, the first indication information is further used to instruct the terminal device to use a second parameter on one or more of a second RB, a second PDCP, or a second RLC, where the second parameter is a parameter used by the terminal device for transmission with the target node.

[0299] In another possible implementation, the first RB and the second RB use a same reordering window.

[0300] In another possible implementation, the interface unit 1801 is further configured to send second indication information, where the second indication information is used to instruct an association relationship between the first RB and the second RB.

[0301] In another possible implementation, the first data packet includes third indication information, where the third indication information is used to instruct the first data packet to use the first parameter or the second parameter.

[0302] In another possible implementation, the interface unit 1801 is further configured to send, to the terminal device, a reconfiguration message, where the reconfiguration message is used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

[0303] In another possible implementation, the interface unit 1801 is further configured to send, to the source cell, a third data packet, where the third data packet is a data packet processed by the source node, the third data packet is from the terminal device, and the first data packet includes the third data packet.

[0304] It should be understood that the specific processes in which the modules perform the corresponding processes described above have been described in detail in the method embodiments described above, and thus will not be described again here for brevity.

[0305] The processing module 1802 in the above embodiments can be implemented by at least one processor or processor-related circuit. The interface module 1801 can be implemented by a transceiver or transceiver-related circuit. The interface module 1801 can also be referred to as a communication module or a communication interface. The storage module can be implemented by at least one memory.

[0306] Another structural diagram of the communication apparatus in the embodiments of the present application is shown below. Please refer to Figure 7 The communication apparatus 1900 can be used to perform the processes performed by the source node in the embodiments shown in Figure 7 Please refer to the related descriptions in the foregoing method embodiments. The communication apparatus 1900 can be a network device, or a component or apparatus (for example, a processor, a chip, or a chip system) applied to a network device, or a logic module or software capable of realizing all or part of the functions of a network device. The communication apparatus 1900 can also be a terminal device, or a component or apparatus (for example, a processor, a chip, or a chip system) applied to a terminal device, or a logic module or software capable of realizing all or part of the functions of a terminal device.

[0307] The communication apparatus 1900 includes an interface module 1901 and a processing module 1902.

[0308] The processing module 1902 is configured to perform data processing. The interface module 1901 can realize corresponding communication functions. The interface module 1901 can also be referred to as a communication interface or a communication module.

[0309] Optionally, the communication apparatus 1900 can further include a storage module, which can be used to store program codes, program instructions and / or data. The processing module 1902 can read the instructions and / or data in the storage module, so that the communication apparatus 1900 realizes the foregoing method embodiments.

[0310] The communication apparatus 1900 can be used to perform the actions performed by the source node in the foregoing method embodiments. For example, the communication apparatus 1900 can be the source node or a communication module in the source node, or a circuit or chip responsible for communication functions in the source node. The communication apparatus 1900 can be the source node or a component configurable to the source node. The processing module 1902 is configured to perform operations related to processing on the source node side in the foregoing method embodiments. The interface module 1901 is configured to perform operations related to receiving on the source node side in the foregoing method embodiments.

[0311] Optionally, the interface module 1901 can include a sending module and a receiving module. The sending module is configured to perform the sending operations in the foregoing method embodiments. The receiving module is configured to perform the receiving operations in the foregoing method embodiments.

[0312] It should be noted that the communication apparatus 1900 can include the sending module and not include the receiving module. Alternatively, the communication apparatus 1900 can include the receiving module and not include the sending module. Whether the sending module and the receiving module are included in the communication apparatus 1900 can depend on whether the communication apparatus 1900 performs the sending actions and the receiving actions in the foregoing schemes. For example, the communication apparatus 1900 is used to perform the actions performed by the source node in the embodiments shown in Figure 7 The foregoing method embodiments. Please refer to the foregoing Figure 20The related description in the illustrated embodiment is not expanded here.

[0313] For example, the communication device 1900 is configured to perform the following scheme:

[0314] The interface unit 1901 is configured to send a second data packet to a target node, the second data packet being a data packet processed by a source node, and the second data packet being used to deliver to a terminal device.

[0315] The processing unit 1902 is configured to generate a handover command.

[0316] The interface unit 1901 is further configured to send the handover command to the terminal device, the handover command being used to instruct the terminal device to hand over to the target node.

[0317] In a possible implementation, the interface unit 1901 is further configured to receive a third data packet from the target node, the third data packet being a data packet processed by the source node, and the third data packet being from the terminal device.

[0318] It should be understood that the specific processes of the modules for performing the corresponding processes have been described in detail in the above method embodiments, and thus will not be repeated here for brevity.

[0319] The processing module 1902 in the above embodiment can be implemented by at least one processor or processor-related circuit. The interface module 1901 can be implemented by a transceiver or transceiver-related circuit. The interface module 1901 can also be referred to as a communication module or a communication interface. The storage module can be implemented by at least one memory.

[0320] Next, a communication device provided by an embodiment of the present application is introduced. Please refer to Figure 20 , Figure 20 A structural schematic diagram of the communication device provided by an embodiment of the present application is shown. The communication device can be a terminal device, a source node or a target node in the above method embodiments, and can also be a chip, a chip system, or a processor, etc. that supports the terminal device, the source node or the target node to implement the above method. The communication device can be used to implement the method described in the above method embodiments, and specific implementation can be referred to the description in the above method embodiments.

[0321] The communication device can include one or more processors 2001, the processor 2001 being connected with a memory 2002, an input and output unit 2003, and a bus 2004. The processor 2001 can be a general-purpose processor or a special-purpose processor, etc. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal, a terminal chip, a DU or a CU, etc.), execute a software program, and process data of the software program.

[0322] Optionally, the communication apparatus can include one or more memories 2002, which can store instructions that can be executed by the processor 2001, so that the communication apparatus performs the methods described in the above method embodiments. Optionally, the memory 2002 can also store data. The processor 2001 and the memory 2002 can be separately arranged, or can be integrated together.

[0323] Optionally, the communication apparatus can further include a transceiver, an antenna. The transceiver can be referred to as a transceiving unit, a transceiver, or a transceiving circuit, etc., and is used to realize the transceiving function. The transceiver can include a receiver and a transmitter. The receiver can be referred to as a receiver or a receiving circuit, etc., and is used to realize the receiving function. The transmitter can be referred to as a transmitter or a transmitting circuit, etc., and is used to realize the transmitting function.

[0324] In another possible design, the processor 2001 can include a transceiver for realizing the receiving and transmitting functions. For example, the transceiver can be a transceiving circuit, or an interface, or an interface circuit. The transceiving circuit, the interface, or the interface circuit for realizing the receiving and transmitting functions can be separate, or can be integrated together. The transceiving circuit, the interface, or the interface circuit described above can be used for reading and writing of codes / data, or the transceiving circuit, the interface, or the interface circuit described above can be used for transmission or transfer of signals.

[0325] In yet another possible design, optionally, the processor 2001 can store instructions, which, when executed on the processor 2001, can cause the communication apparatus to perform the methods described in the above method embodiments. The instructions can be fixed in the processor 2001, and in this case, the processor 2001 can be implemented by hardware.

[0326] In yet another possible design, a communication apparatus can include circuitry that can implement the functions of the transmitting or receiving or communicating of the terminal device, the source node or the target node in the foregoing method embodiments. The processor and the transceiver described in the embodiments of the present application can be implemented on an integrated circuit (IC), an analog IC, an RFIC, a mixed-signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and the transceiver can also be manufactured using various IC process technologies, such as a complementary metal oxide semiconductor (CMOS), an N-type metal oxide semiconductor (NMOS), a P-type metal oxide semiconductor (PMOS), a bipolar junction transistor (BJT), a bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0327] The communication apparatus described in the foregoing embodiments can be a terminal device, a source node or a target node, but the scope of the communication apparatus described in the embodiments of the present application is not limited thereto, and the structure of the communication apparatus can not be limited by Figure 21 The communication apparatus can be a standalone device or can be a part of a larger device. For example, the communication apparatus can be:

[0328] (1) a standalone integrated circuit (IC), or a chip, or a chip system or subsystem;

[0329] (2) a set of one or more ICs, optionally including memory units for storing data, instructions, etc.

[0330] (3) an ASIC, such as a modem (KSK);

[0331] (4) a module that can be embedded within other devices;

[0332] (5) a receiver, a terminal, a smart terminal, a cellular phone, a wireless device, a handset, a mobile unit, a car device, a network device, a cloud device, an artificial intelligence device, etc.

[0333] (6) other, etc.

[0334] For the case that the communication device can be a chip or a chip system, refer to Figure 21 a structural diagram of the chip. ​ The chip 2100 shown includes a processor 2101, an interface 2102. Optionally, it can also include a memory 2103. Among them, the number of processors 2101 can be one or more, and the number of interfaces 2102 can be multiple.

[0335] For the case that the chip is used to implement the functions of the network device or the first device in the embodiments of the present application:

[0336] The interface 2102 is configured to receive or output a signal.

[0337] The processor 2101 is configured to perform data processing operations of the network device or the terminal device.

[0338] It can be understood that some optional features in the embodiments of the present application can be implemented independently in some scenarios, without relying on other features, such as the scheme currently based on, to solve the corresponding technical problems and achieve the corresponding effects. Also, in some scenarios, it can be combined with other features according to the demand. Correspondingly, the communication device given in the embodiments of the present application can also implement these features or functions, which will not be described here.

[0339] It should be understood that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above method embodiments can be completed by integrated logic circuits or instruction in the form of software in the processor. The processor 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, discrete gate or transistor logic device, discrete hardware component.

[0340] It can be appreciated that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (read-only memory, ROK), a programmable read-only memory (programmable read-only memory, PROK), an erasable programmable read-only memory (erasable programmable read-only memory, EPROK), an electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROK) or a flash memory. The volatile memory can be a random access memory (random access memory, RAK) used as an external cache. By way of example but not limitation, many forms of RAK are available, such as static random access memory (static random access memory, SRAK), dynamic random access memory (dynamic random access memory, DRAK), synchronous dynamic random access memory (synchronous dynamic random access memory, SDRAK), double data rate synchronous dynamic random access memory (double data rate synchronous dynamic random access memory, DDR SDRAK), enhanced synchronous dynamic random access memory (enhanced synchronous dynamic random access memory, ESDRAK), synchronous link dynamic random access memory (synchronous link dynamic random access memory, SLDRAK) and direct memory bus random access memory (direct memory bus random access memory, DR RAK). 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.

[0341] The embodiments of the present application also provide a computer readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the method in the foregoing embodiments.

[0342] The embodiments of the present application also provide a computer program product comprising instructions which, when executed on a computer, cause the computer to perform the method in the foregoing embodiments.

[0343] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0344] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiments are merely schematic. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation. 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 displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0345] The units described as separated components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. In actual implementation, some or all of the units can be selected according to the actual needs to achieve the purposes of the embodiments of the present application.

[0346] In addition, each function unit in the embodiments of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be implemented in the form of hardware or in the form of software function unit.

[0347] When the integrated unit is implemented in the form of software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such an understanding, the technical solutions of the present application essentially or substantially or partially contribute to the prior art, or the whole or part of the technical solutions of the present application 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 embodiments of the present application. The foregoing storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), magnetic disk or optical disk, and various other media that can store program codes.

[0348] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a high-density digital video disc (digital video disc, DVD)), or a semiconductor medium (such as a solid state disk (solid state disk, SSD)), etc.

Claims

1. A data transmission method, characterized in that, include: Receive a handover command, the handover command being used to instruct the terminal device to switch from the source node to the target node; The first data packet is transmitted with the target node using the first parameter, which is the parameter used for transmission between the terminal device and the source node, and the first data packet is a data packet processed by the source node.

2. The method according to claim 1, characterized in that, The transmission of the first data packet with the target node using the first parameter includes: The first data packet is transmitted to the target node using the first parameter on the first radio bearer RB; or, The first data packet is transmitted with the target node using the first parameter on the first Packet Data Convergence Protocol (PDCP) and / or the first Radio Link Control (RLC).

3. The method according to claim 1 or 2, characterized in that, The first parameter includes the parameters of the first PDCP and / or the parameters of the first RLC.

4. The method according to any one of claims 2 or 3, characterized in that, The method further includes: The terminal device receives a first instruction message, which instructs the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

5. The method according to claim 4, characterized in that, The first indication information is also used to instruct the terminal device to use a second parameter on one or more of the second RB, the second PDCP, or the second RLC, wherein the second parameter is a parameter used for transmission between the terminal device and the target node.

6. The method according to claim 5, characterized in that, The first RB and the second RB use the same reordering window.

7. The method according to claim 5 or 6, characterized in that, The method further includes: Receive second indication information, which is used to indicate the association relationship between the first RB and the second RB.

8. The method according to claim 5, characterized in that, The method further includes: After the data packet on the first RB is delivered, the data packet on the second RB is delivered.

9. The method according to claim 5, characterized in that, Before transmitting the first data packet with the target node using the first parameter, the method further includes: Establish the second PDCP functional entity and / or the second RLC, the second PDCP functional entity and the second RLC use the configuration of the target node, and the second PDCP functional entity includes at least one of the first encryption functional entity, the first decryption functional entity, the first integrity protection functional entity or the first integrity verification functional entity.

10. The method according to any one of claims 6 to 9, characterized in that, The first data packet includes third indication information, which is used to indicate that the first data packet uses either the first parameter or the second parameter.

11. The method according to any one of claims 2 to 10, characterized in that, The method further includes: The terminal device receives a reconfiguration message from the target node, the reconfiguration message being used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

12. A data transmission method, characterized in that, include: Receive a second data packet from the source node, the second data packet being processed by the source node, the second data packet being used to pass to the terminal device; The terminal device transmits a first data packet using a first parameter, which is a parameter used for transmission between the terminal device and the source node. The first data packet includes the second data packet.

13. The method according to claim 12, characterized in that, The transmission of the first data packet with the terminal device using the first parameter includes: The first data packet is transmitted with the terminal device on the first RB using the first parameter; or, The first data packet is transmitted with the terminal device using the first parameter on the first PDCP and / or the first RLC.

14. The method according to claim 12 or 13, characterized in that, The first parameter includes the parameters of the first PDCP and / or the parameters of the first RLC.

15. The method according to any one of claims 13 or 14, characterized in that, The method further includes: Send a first indication message, which is used to instruct the terminal device to use the first parameter on one or more of the first RB, the first PDCP, or the first RLC.

16. The method according to claim 15, characterized in that, The first indication information is also used to instruct the terminal device to use a second parameter on one or more of the second RB, the second PDCP, or the second RLC, wherein the second parameter is a parameter used for transmission between the terminal device and the target node.

17. The method according to claim 16, characterized in that, The first RB and the second RB use the same reordering window.

18. The method according to claim 16 or 17, characterized in that, The method further includes: Send a second indication message, which is used to indicate the association relationship between the first RB and the second RB.

19. The method according to any one of claims 16 to 18, characterized in that, The first data packet includes third indication information, which is used to indicate that the first data packet uses either the first parameter or the second parameter.

20. The method according to any one of claims 13 to 19, characterized in that, The method further includes: A reconfiguration message is sent to the terminal device, the reconfiguration message being used to instruct the terminal device to release at least one of the first PDCP, the first RLC, or the first RB.

21. The method according to any one of claims 12 to 20, characterized in that, The method further includes: A third data packet is sent to the source cell. The third data packet is a data packet processed by the source node and originates from the terminal device. The first data packet includes the third data packet.

22. A data transmission method, characterized in that, include: A second data packet is sent to the target node. This second data packet is a data packet processed by the source node and is used to pass the data packet to the terminal device. A handover command is sent to the terminal device, which instructs the terminal device to switch to the target node.

23. The method according to claim 22, characterized in that, The method further includes: Receive a third data packet from the target node, the third data packet being a data packet processed by the source node, and the third data packet originating from the terminal device.

24. A communication device, characterized in that, include: An interface unit is used to receive a switching command, which instructs the terminal device to switch to the target node. The processing unit is used to maintain the first parameter; The interface unit is further configured to transmit a first data packet with the target node using the first parameter, wherein the first parameter is a parameter used for transmission between the terminal device and the source node.

25. A communication device, characterized in that, include: An interface unit is used to receive a second data packet from a source node, the second data packet being a data packet processed by the source node, and the second data packet being used to transmit to a terminal device; The processing unit is used to maintain the first parameter; The interface unit is further configured to transmit a first data packet with the terminal device using the first parameter, wherein the first parameter is a parameter used for transmission between the terminal device and the source node, and the first data packet includes the second data packet.

26. A communication device, characterized in that, include: An interface unit is used to send a second data packet to the target node. The second data packet is a data packet processed by the source node and is used to pass the second data packet to the terminal device. The processing unit is used to generate switching commands; The interface unit is also used to send the switching command to the terminal device, the switching command being used to instruct the terminal device to switch to the target node.

27. A communication device, characterized in that, include: A processor for executing a program that causes the communication device to perform the method as claimed in any one of claims 1 to 11, or causes the communication device to perform the method as claimed in any one of claims 12 to 21, or causes the communication device to perform the method as claimed in any one of claims 22 to 23.

28. A communication system, characterized in that, include: A communication device for performing any of the methods described in steps 1 to 11, a communication device for performing any of the methods described in steps 12 to 21, and a communication device for performing any of the methods described as claimed in claims 22 to 23.

29. A computer-readable storage medium comprising instructions that, when executed on a computer, cause the computer to perform the method as claimed in any one of claims 1 to 11, or cause the computer to perform the method as claimed in any one of claims 12 to 21, or cause the computer to perform the method as claimed in any one of claims 22 to 23.

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