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

Abstract

The embodiments of the present application disclose a data transmission method, a communication apparatus, a communication system, and a storage medium, which are applied to the technical field of communications and are used for reducing L2 handover latency. The method in the embodiments of the present application comprises: receiving a handover command, wherein the handover command is used for instructing a terminal device to hand over from a source node to a target node; and using a first parameter to perform data packet transmission with the target node, wherein 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. According to the embodiments of the present application, using parameters employed for performing transmission with a source node prevents data interruptions caused by PDCP reestablishment, data recovery, and RLC reestablishment, thereby preventing latency caused by the data retransmission introduced in these processes.

Description

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

[0001] The present application claims priority from the Chinese patent application No. CN202410969946.2 filed on July 18, 2024, and entitled "A data transmission method, communication device, communication system and storage medium", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of communication technology, in particular to a data transmission method, communication device, communication system and storage medium. BACKGROUND

[0003] In a mobile communication system, when a terminal device moves from one cell to another cell while in a connected state, in order to ensure the continuity of communication and the quality of service, a handover process needs to be completed. However, the terminal device will generate a time delay in the process of switching from the source cell to the target cell, causing service interruption and thus reducing the efficiency of handover.

[0004] 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, so as to save the handover time delay after receiving the LTM handover MAC CE.

[0005] 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 of L2 change and the retransmission of data packets introduced by L2 change. SUMMARY

[0006] The present application provides a data transmission method, communication device, communication system and 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.

[0007] 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.

[0008] 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.

[0009] In some possible embodiments, a first radio bearer (RB) and a second RB use a same reordering window.

[0010] In some possible embodiments, the terminal device submits data packets on the second RB after submitting data packets on the first RB.

[0011] 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 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.

[0012] 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.

[0013] 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.

[0014] Alternatively,

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] The fourth aspect of the present application provides a communication device, comprising:

[0027] an interface module, configured to receive a handover command, the handover command being used to instruct a terminal device to hand over to a target node;

[0028] a processing module, configured to maintain a first parameter;

[0029] the interface module 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.

[0030] In a possible implementation manner, the interface module 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;

[0031] or,

[0032] 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.

[0033] In another possible implementation manner, the first parameter comprises a parameter of a first PDCP and / or a parameter of a first RLC.

[0034] In another possible implementation, the interface module 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.

[0035] 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 for transmission between the terminal device and the target node.

[0036] In another possible implementation, the first RB and the second RB use a same reordering window.

[0037] In another possible implementation, the interface module 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.

[0038] In another possible implementation, the interface module is further configured to submit the data packet on the second RB after submission of the data packet on the first RB is completed.

[0039] In another possible implementation, the processing module 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.

[0040] 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.

[0041] In another possible implementation, the interface module 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.

[0042] The fifth aspect of the present application provides a communication apparatus, comprising:

[0043] an interface module 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 be delivered to a terminal device;

[0044] a processing module configured to maintain a first parameter;

[0045] the interface module 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 for transmission between the terminal device and the source node, the first data packet including the second data packet.

[0046] In a possible implementation, the interface module is specifically configured to perform the transmission of the first data packet with the terminal device on the first RB using the first parameter.

[0047] Alternatively,

[0048] 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.

[0049] In another possible implementation, the first parameter includes a parameter of the first PDCP and / or a parameter of the first RLC.

[0050] In another possible implementation, the interface module 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.

[0051] 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.

[0052] In another possible implementation, the first RB and the second RB use a same reordering window.

[0053] In another possible implementation, the interface module 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.

[0054] 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.

[0055] In another possible implementation, the interface module 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.

[0056] In another possible implementation, the interface module 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 module 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.

[0057] The sixth aspect of the present application provides a communication apparatus, comprising:

[0058] The processing module is configured to generate a handover command.

[0059] The interface module 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.

[0060] In a possible implementation, the interface module 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.

[0061] The seventh aspect 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:

[0062] 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.

[0063] 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.

[0064] The 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 connected through a line. The at least one processor is configured to run a computer program or an instruction, so as to perform the information transmission method in the first aspect, the second aspect, or the third aspect, and any possible implementation manner thereof.

[0065] The communication interface in the chip can be an input / output interface, a pin, or a circuit.

[0066] In a possible implementation, the chip or the chip system described in the present application further comprises at least one memory, and the at least one memory stores an instruction. The memory can be a storage unit inside the chip, for example, a register, a cache, or the like. The memory can also be a storage unit of the chip, for example, a read-only memory, a random access memory, or the like.

[0067] The 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.

[0068] 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.

[0069] 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

[0070] Fig. 1 is a schematic diagram of one embodiment of a username protocol stack between a terminal device and a base station in the embodiments of the present application;

[0071] Fig. 2 is a schematic diagram of another embodiment of a username protocol stack between a terminal device and a base station in the embodiments of the present application;

[0072] Fig. 3 is a network structure diagram in the embodiments of the present application;

[0073] Fig. 4 is a possible application scenario of a data transmission method in the embodiments of the present application;

[0074] Fig. 5 is a schematic diagram of one embodiment of a radio resource control (RRC) handover procedure in the embodiments of the present application;

[0075] Fig. 6 is a schematic diagram of one embodiment of handover latency in the embodiments of the present application;

[0076] Fig. 7 is a schematic diagram of one embodiment of a data transmission method in the embodiments of the present application;

[0077] Fig. 8 is a schematic diagram of another embodiment of a username protocol stack between a terminal device and a base station in the embodiments of the present application;

[0078] Fig. 9 is a schematic diagram of one embodiment of data transmission in the embodiments of the present application;

[0079] Fig. 10 is a schematic diagram of another embodiment of a username protocol stack between a terminal device and a base station in the embodiments of the present application;

[0080] Fig. 11 is a schematic diagram of another embodiment of data transmission in the embodiments of the present application;

[0081] Fig. 12 is a schematic diagram of another embodiment of an RRC handover procedure in the embodiments of the present application;

[0082] Fig. 13 is a schematic diagram of one embodiment of uplink data packet transmission in an RRC handover procedure in the embodiments of the present application;

[0083] FIG. 14 is another embodiment of uplink data packet transmission in the RRC handover procedure according to the embodiments of the present application;

[0084] FIG. 15 is an embodiment of downlink data packet transmission in the RRC handover procedure according to the embodiments of the present application;

[0085] FIG. 16 is another embodiment of downlink data packet transmission in the RRC handover procedure according to the embodiments of the present application;

[0086] FIG. 17 is an embodiment of a communication device according to the embodiments of the present application;

[0087] FIG. 18 is another embodiment of a communication device according to the embodiments of the present application;

[0088] FIG. 19 is another embodiment of a communication device according to the embodiments of the present application;

[0089] FIG. 20 is another embodiment of a communication device according to the embodiments of the present application;

[0090] FIG. 21 is another embodiment of a communication device according to the embodiments of the present application. DETAILED DESCRIPTION

[0091] The present application provides a data transmission method, a communication device, a communication system and a storage medium. By using the parameters used for transmission with the source node, the data interruption caused by PDCP reestablishment, data recovery and RLC reestablishment is avoided, and the latency caused by data retransmission introduced by these processes is also avoided.

[0092] The embodiments of the present application are described below in conjunction with the accompanying drawings. It is obvious to those skilled in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0093] The terms "first", "second", etc. in the specification, claims and drawings of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged, and this is only a distinguishing way adopted in the description of the embodiments of the present application to describe the objects with the same attributes. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, so that the processes, methods, systems, products or devices containing a series of units do not have to be limited to those units, but can include other units not clearly listed or inherent to these processes, methods, products or devices.

[0094] First, some technical terms involved in the embodiments of the present application are introduced.

[0095] 1) Mobility:

[0096] 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 capabilities when using phone, internet, data transmission, etc. services without being restricted 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 its movement within the network coverage. Among them, mobility includes handover, i.e. when the terminal device moves from the coverage of one base station or access point to another, 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 without affecting the user's communication experience.

[0097] 2) Protocol stack:

[0098] 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 stacked stack, 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 shown in Figure 1. 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, taking the downlink (downlink, DL) data transmission as an example, the main division of each layer of L2 is shown in Figure 2.

[0099] The main function of the SDAP layer is to complete the mapping of quality of service (quality of service, QoS) flow to data radio bearer (data radio bearer, DRB);

[0100] The main functions of the PDCP layer include compression / decompression, security processing (including encryption and decryption and integrity protection / checking), etc.

[0101] The main functions of the RLC layer include data segmentation and automatic repeat request (ARQ).

[0102] The main functions of the MAC layer include scheduling, multiplexing and hybrid automatic repeat request (HARQ) procedures. The HARQ procedure is a technique combining forward error correction (FEC) and ARQ methods.

[0103] Referring to FIG. 3, a network architecture on which the data transmission method in the embodiments of the present application is based is described as follows:

[0104] FIG. 3 is a possible, non-limiting system diagram. As shown in FIG. 3, the communication system 10 includes a radio access network (RAN) 100, a core network (CN) 200 and the Internet 300. The RAN 100 includes at least one RAN node (e.g., 110a and 110b in FIG. 3, collectively referred to as 110) and at least one terminal (e.g., 120a-120j in FIG. 3, collectively referred to as 120). The RAN 100 can further include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 3), etc. The terminal 120 is connected to the RAN node 110 in a wireless manner. The RAN node 110 is connected to the core network 200 in a wireless or wired manner. The core network device in the core network 200 and the RAN node 110 in the RAN 100 can be different physical devices respectively, or can be the same physical device integrated with the logical functions of the core network and the logical functions of the radio access network.

[0105] The RAN 100 can be a 3rd generation partnership project (3GPP) related cellular system, such as 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.

[0106] The RAN node 110, which can also be referred to as an access network device, a RAN entity, or an access node, etc., forms part of the communication system, and is configured to facilitate the wireless access by the terminals. The RAN nodes 110 in the communication system 10 can be of the same type or different types. In some scenarios, the roles of the RAN node 110 and the terminal 120 are relative, e.g., the network element 120i in Figure 3 can be a helicopter or a drone, which can be configured to be a mobile base station, and for those terminals 120j accessing the RAN 100 via the network element 120i, the network element 120i is a base station; but for the base station 110a, the network element 120i is a terminal. Both the RAN node 110 and the terminal 120 are sometimes referred to as communication apparatuses, e.g., the network elements 110a and 110b in Figure 3 can be understood as communication apparatuses with base station functionalities, and the network elements 120a-120j can be understood as communication apparatuses with terminal functionalities.

[0107] In a possible scenario, the 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. The RAN node can be a macro base station (e.g., 110a in Figure 3), a micro base station or an indoor station (e.g., 110b in Figure 3), a relay node or a donor node, or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in vehicle to everything (V2X) technology can be a road side unit (RSU). All or part of the functions of the RAN node in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (e.g., a cloud platform). The RAN node can also be provided with a communication module, circuit or chip for performing corresponding communication functions, and program instructions for performing corresponding communication functions. The RAN node in the present application can also be a logic node, a logic module or software capable of implementing all or part of the functions of the RAN node.

[0108] In another possible scenario, multiple RAN nodes cooperate to assist a terminal to implement wireless access, and different RAN nodes respectively implement part of functions of a base station. For example, a RAN node can be a central unit (CU), a distributed unit (DU), a CU-CP, a CU-UP, or a radio unit (RU), etc. The CU and the DU can be separately arranged, or can also be included in the same network element, for example, in a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, for example, included in a remote radio unit (RRU), an active antenna processing module (AAU), or a remote radio head (RRH).

[0109] 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 an ORAN system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. For the convenience of description, the CU, the CU-CP, the CU-UP, the DU and the RU are taken as examples for description in this application. Any one of the CU (or the CU-CP, the CU-UP), the DU and the 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.

[0110] A terminal can be a device or module with corresponding communication functions and can access the above-mentioned communication system. The terminal can also be referred to as a terminal device, user equipment (UE), mobile station, 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 grid, smart home, smart office, smart wear, smart transportation, smart city, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, unmanned aerial vehicle, helicopter, airplane, ship, robot, mechanical arm, smart home device, transport vehicle with wireless communication function, 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 performing corresponding communication functions. The terminal can also be configured with program instructions for performing corresponding communication functions.

[0111] In addition, the embodiments of the present application can also be applicable to other communication technologies facing the future. 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.

[0112] FIG. 4 shows an application scenario to which the embodiments of the present application are applicable. A terminal device 401 is handed over from a RAN node 402 to a RAN node 403, where the RAN node 402 is referred to as a source node or source RAN node, and the RAN node 403 is referred to as a target node or 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 above-mentioned RAN node, which is not limited specifically here.

[0113] Referring to FIG. 5, the mobility of the connected terminal is completed through handover (HO), and the handover procedure of the radio resource control (RRC) is as follows:

[0114] 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;

[0115] 2. The terminal device performs measurement reporting according to the measurement configuration;

[0116] 3. The source node refers to the reporting result of the terminal device, and performs handover decision according to its own handover algorithm;

[0117] 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 at the source node, the basic access layer configuration, etc.;

[0118] 5. The target node performs access control;

[0119] 6. The target node performs L1 / L2 handover preparation, and sends an access request response 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;

[0120] 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 of the target node for access, etc.;

[0121] Specifically, the source node sends an RRC reconfiguration message (RRCReconfiguration) to the terminal device, which includes a reconfigWithSync field, used to indicate that the terminal device needs to perform time and frequency synchronization with the target node. After receiving the message, the terminal device will disconnect the connection with the source node, try to access the target node, and complete the handover process.

[0122] 8. The source node sends a sequence number status transmission (SN STATUS TRANSFER) to the target node. The sequence number (SN) status transmission can include the uplink (UL) PDCP SN reception status and the downlink PDCP SN transmission status of the DRB. The uplink (UL) PDCP SN reception status at least includes the PDCP SN number of the first missing UL PDCP service data unit (SDU), and can also include the bit map of the reception status of the out-of-order UL PDCP SDU that needs to be retransmitted by the terminal device to the target node. The downlink PDCP SN transmission status indicates the next PDCP SN that should be allocated by the target node to the new PDCP SDU (which does not have a PDCP SN).

[0123] 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.

[0124] 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;

[0125] 10. The target node replies to the random access response (RAR) to allocate uplink resources (UL grant) and timing advance (TA);

[0126] 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;

[0127] 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 replaced, 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;

[0128] 13. The AMF network element sends a user plane update request message to the user plane function (UPF) network element;

[0129] 14. The UPF network element switches the DL data path to the target node. The UPF network element sends one or more end markers to the target node, and then releases the remaining UP plane / transmission network layer resources between the candidate nodes. Among them, the target node is at least one candidate node, which is determined by the terminal device to switch.

[0130] 15. The UPF network element sends a UP update response message to the AMF network element;

[0131] 16. The AMF network element sends a path switch ACK message to the target node;

[0132] 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 that the handover is successful and triggering the source node to release the terminal device context;

[0133] 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 the data forwarding has not been completed, the source node will not release the related resources, and continue the data forwarding until the data forwarding is completed, and then release the related resources.

[0134] According to the above flow, the handover delay (or interruption time) of the RRC handover is shown in FIG. 6. The meanings of the partial delay components are as follows:

[0135] (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;

[0136] The delay generated in the reconfiguration phase of the terminal device includes:

[0137] (2) RRC processing: the delay required for the terminal device to process the RRC message of the handover command;

[0138] (3) Terminal device processing: including the time for the terminal device to use the target node configuration, and the L1 / L2 change;

[0139] The delay generated in the downlink synchronization phase includes:

[0140] (4) The time required for the terminal device to detect the first available synchronization signal and PBCH block (SSB) to obtain the DL timing;

[0141] (5) The time required for the terminal device to process the SSB;

[0142] The delay generated in the uplink synchronization phase includes:

[0143] (6) The time required for the terminal device to obtain the first UL transmission (i.e. PRACH occasion);

[0144] (10) The delay introduced by the terminal device waiting for the RAR;

[0145] And:

[0146] (9) The delay introduced by the terminal device waiting for the completion of the handover;

[0147] Among the above-mentioned time delays, the uplink synchronization and the downlink synchronization can be completed in advance before the reception of the switching 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 the L1 / L2 switching command is issued, thereby reducing the time delay introduced by the switching.

[0148] The L1 / L2 change can include the change of PDCP, RLC and MAC, and the change of L1. After receiving the switching command, the terminal device needs to perform MAC reset, RLC reestablishment, and may also perform PDCP reestablishment or data recovery. The time delay of L2 change includes:

[0149] 1) the time delay caused by PDCP reestablishment / data recovery;

[0150] 2) the time delay caused by RLC reestablishment;

[0151] 3) the time delay caused by MAC reset;

[0152] 4) the retransmission of data packets introduced by the above-mentioned L2 reestablishment / reset also introduces additional service time delay.

[0153] 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 switching 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 switching MAC CE, thereby saving the switching time delay after receiving the LTM switching MAC CE.

[0154] 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 the L1 / L2 switching command is issued, thereby reducing the time delay introduced by the switching, and thus fails to reduce the time delay caused by the L2 change.

[0155] Based on this, the embodiment of the present application provides a method. It should be noted that the embodiment of the present application takes the RRC switching as an example for description, and in actual application, it can also be applied to other mobility enhancement technologies, such as conditional handover (CHO), dual active protocol stack (DAPS), LTM, etc.

[0156] Please refer to FIG. 7, a data transmission method in the embodiment of the application includes:

[0157] 701, the source node sends a handover command to the terminal device, and correspondingly, the terminal device receives the handover command from the source node;

[0158] The source node sends a handover command to the terminal device, and the handover command is used to instruct the terminal device to switch from the source node to the target node. The handover command can be the handover command shown in step 7 in FIG. 5, can also be a cell handover command MAC CE in LTM, and can also be a handover command in CHO or DAPS, without limitation. It can be understood that in CHO, the handover command can be understood as an RRC message including CHO candidate cell configuration.

[0159] In a possible implementation, the handover command includes 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.

[0160] The first parameter is a parameter used by the terminal device for transmission with the source node. The first parameter can also be understood as a parameter of one or more of part or all of the RB, the PDCP, or the RLC of the source node, or the first parameter is a parameter currently used or used before handover 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 handover. The terminal device maintaining one or more of the first RB, the first PDCP, or the first RLC can include maintaining the corresponding entities, state variables, related timers, and configurations of the first RB, the first PDCP, or the first RLC.

[0161] The first parameter can include one or more of a parameter of the first RB, a parameter of the first PDCP, or a parameter of the first RLC.

[0162] For example, the parameter of the first RB includes at least one of an identifier of the first RB, a security configuration, and the like. The security configuration includes security algorithm configuration and the like.

[0163] For example, 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, 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 for integrity protection and verification and a key for encryption and decryption.

[0164] 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.

[0165] Optionally, the first indication information can also be used to instruct 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 instruct the terminal device to use the parameters of the source node or the parameters of the target node on a specific RB.

[0166] 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 instruct the terminal device to use the new parameters of the target node.

[0167] 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.

[0168] 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.

[0169] 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 reporting 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 for integrity protection and verification and a key for encryption and decryption.

[0170] 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.

[0171] Optionally, the first indication information is used to instruct the terminal device to use the first parameters on the first LCH. At this time, the first parameters can be understood as the parameters 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.

[0172] 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.

[0173] 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;

[0174] 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.

[0175] The first data packet includes a first uplink data packet and / or a first downlink data packet.

[0176] 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, and 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.

[0177] 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 it to the terminal device. The data packet sent by the target node using the source node configuration processing can be understood as not being processed by the PDCP and / or RLC of the target node. The PDCP processing by the source node can include one or more operations of numbering, compression, integrity protection, encryption, adding a PDCP header, routing, and duplication performed by the source node on the first downlink data packet. The RLC processing by the source node can include one or more operations of adding an RLC header, segmentation, and the like performed by the source node on the first downlink data packet.

[0178] 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 parameters of the source node, i.e., the part of parameters of the source node are not released by the terminal device. For example, the part of 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, refer to the description of the first parameters, the first PDCP parameters and the first RLC parameters, which are not described herein again.

[0179] In a possible implementation, the terminal device uses the first parameters to perform the transmission of the first data packet with the target node on the first RB.

[0180] 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, one or more RBs can also be maintained between the terminal device and the target node, 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 parameters of the source node and / or the RLC parameters of the source node to perform the transmission on the at least one RB. The terminal device continues to maintain the PDCP and / or RLC entities on the at least one RB, as shown in FIG. 8, 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.

[0181] Optionally, the terminal device maintaining the PDCP entity includes maintaining one or more function entities of the PDCP entity, including the encryption / decryption entity, the integrity protection / verification entity, etc.

[0182] Optionally, the terminal device and the target node can also newly establish an RB, for example, a second RB, to perform the transmission of data packets. The terminal device newly establishes the PDCP entity and / or the RLC entity of the second RB, and uses the new parameters of the target node to perform the transmission.

[0183] In the embodiments of the present application, after the switching, the terminal device and the target node continue to receive or send the data packets processed by the source node on part of the DRBs, so as to avoid the data interruption caused by the PDCP reestablishment or data recovery and the RLC reestablishment, and at the same time avoid the time delay caused by the data retransmission introduced by these processes, reduce the time delay of the service interruption caused by the switching, and improve the user experience.

[0184] It should be noted that the terminal device also uses the second parameter to receive a fourth data packet sent by the target node on the second RB, 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.

[0185] The fourth data packet includes a fourth uplink data packet and / or a fourth downlink data packet.

[0186] 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 parameter, and correspondingly, the target node receives the fourth uplink 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 uplink data packet is a data packet processed by the terminal device using the second parameter, and the target node needs to process the data packet after reaching the network side. The PDCP processing by the target node can include one or more operations of removing the PDCP header, deciphering, integrity checking, reordering, and decompressing 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.

[0187] 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 by the target node can include one or more operations of numbering, compression, integrity protection, encryption, adding a PDCP header, routing, and duplication performed by the source node on the fourth downlink data packet. The RLC processing by the target node can include one or more operations of adding an RLC header, segmentation, and the like performed by the source node on the fourth downlink data packet.

[0188] Optionally, the terminal device can determine, according to the first indication information, whether the first parameter or the second parameter is used in each RB between the terminal device and the target node.

[0189] 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 terminal device can determine the receiving order of the first data packet and the fourth data packet by using the same reordering window. For example, the second RB is the 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 corresponding to the first RB to transmit the data packet subsequent to 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.

[0190] 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 FIG. 9, 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.

[0191] For another example, after the first RB is released, the second RB can continue to use the reordering window shared before.

[0192] Optionally, the data packet on the second RB cannot start to be submitted to the upper layer until the data packet on the first RB is submitted to the upper layer. In this implementation manner, the first RB and the second RB use different reordering windows.

[0193] Optionally, the data packet of the second RB can start from the PDCP SN of 0, and the data packets on the first RB and the second RB are sorted by the upper layer (for example, IP layer, TCP layer or APP layer).

[0194] Optionally, the data transmission on the second RB is not started until the data transmission on the first RB is completed.

[0195] 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 in the source cell is completed.

[0196] 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.

[0197] It should be noted that the 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.

[0198] In another possible implementation, the terminal device uses the first parameter to perform transmission of the first data packets with the target node on the first PDCP and / or the first RLC.

[0199] Before the handover, there is one or more RBs between the terminal device and the source node, and the transmission of the data packets is performed on the one or more RBs. After the handover or during 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 FIG. 10. 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 a first encryption function entity, a first decryption function entity, a first integrity protection function entity, or a first integrity check function entity. The second PDCP function entity and / or the second RLC use the configuration or parameter of the target node.

[0200] The terminal device uses the first parameter to perform transmission of the 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 the 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 FIG. 11.

[0201] For example, the first data packets include data packets with sequence numbers 12, 15, 25,..., and 100, and the fourth data packets include data packets with sequence numbers 101, 102, 103,..., and 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.

[0202] Optionally, the terminal device receives or sends third indication information, which is used to indicate whether the specific data packet is processed by the source node or the target node. Or the third indication information indicates whether the specific data packet is processed by the first PDCP and / or RLC entity or the second PDCP and / or RLC. The third indication information can be contained in the header of the data packet, for example, the third indication information is contained in the PDCP header or the RLC header.

[0203] In the embodiments of the present application, by continuing to receive or send the data packet processed by the source node after the handover, the data interruption caused by the PDCP reestablishment or data recovery and the RLC reestablishment is avoided, and the time delay caused by the data retransmission introduced by these processes is avoided, the time delay of service interruption caused by the handover is reduced, and the user experience is improved.

[0204] Optionally, the embodiment shown in FIG. 7 further includes step 700. Step 700 can be performed before step 701.

[0205] 700、the source node sends the second data packet to the target node, and correspondingly, the target node receives the second data packet from the source node;

[0206] Optionally, the second data packet can be a data packet processed by the source node. The data packet processed by the source node is described above and will not be repeated here.

[0207] It should be noted that the source node can also send the data packet not processed by the source node to the target node.

[0208] Optionally, the source node can also send the SN status to the target node, wherein the SN status can be used to indicate the SN of the first data packet not acknowledged by the terminal device.

[0209] Optionally, the SN status can also be used to indicate the SN of multiple data packets not acknowledged by the terminal device. For example, using the bitmap method, the SN of the data packet not acknowledged by the terminal device is indicated. The SN status can be sent through the SN status transmission message, for example, step 8 in FIG. 5.

[0210] It should be noted that the above-mentioned operations of the source node sending the SN status to the target node can be combined with each other to form a new independent embodiment, and the present application does not limit this.

[0211] Optionally, the embodiment shown in FIG. 7 further includes step 701a. Step 701a can be performed after step 701.

[0212] 701a、the target node sends the first indication information to the terminal device, and correspondingly, the terminal device receives the first indication information from the target node;

[0213] The target node can send first indication information to the terminal device, 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. The first indication information 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.

[0214] Optionally, the embodiment shown in FIG. 7 further includes step 701b. Step 701b can be performed after step 701.

[0215] 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.

[0216] In one possible implementation, the second indication information is used to instruct the association relationship between the first RB and the second RB, so that the terminal device can perform continuous allocation of PDCP SN numbers.

[0217] Optionally, the second indication information can be carried in a handover command sent by the source node to the terminal device, which is not limited here.

[0218] In another possible implementation, the second indication information is used to instruct the initial value of the PDCP SN number of the second RB.

[0219] Optionally, the embodiment shown in FIG. 7 further includes step 703. Step 703 can be performed after step 702.

[0220] 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.

[0221] 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 uploaded by the terminal device and processed by the source node to the source node.

[0222] Optionally, the embodiment shown in FIG. 7 further includes step 704. Step 704 can be performed after step 703.

[0223] 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.

[0224] Specifically, the reconfiguration message can be an RRC reconfiguration message, and the RRC 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.

[0225] In a possible implementation, the target node releases the first RB through an RRC reconfiguration message. The RRC reconfiguration message can also indicate adding a new DRB, and the newly added DRB uses the configuration of the target cell to transmit data packets.

[0226] In another possible implementation, the target cell can indicate the UE to release the first PDCP entity and / or the first RLC entity of the source node through an RRC reconfiguration message.

[0227] It should be noted that step 704 is only an example, and in actual applications, the terminal device can also release the entities related to the source node by itself, which is not limited here.

[0228] Based on the above embodiments, a possible implementation of the RRC handover procedure of the terminal device in the application is shown in FIG. 12.

[0229] 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.

[0230] Specifically, the handover request includes the configuration of the source node, for example, the RB configuration between the source node and the terminal device. This step is an optional step.

[0231] 1202. The target node sends a handover request confirmation to the source node.

[0232] Specifically, the handover request confirmation includes the configuration of the target node. This step is an optional step.

[0233] 1203. The source node performs data forwarding to the target node. This step is an optional step.

[0234] Specifically, the source node sends a second data packet to the target node, which can refer to step 700 in the embodiment shown in FIG. 7, and details are not repeated here.

[0235] 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.

[0236] This step can refer to step 701 in the embodiment shown in FIG. 7, and details are not repeated here.

[0237] 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.

[0238] This step can refer to step 8 in FIG. 5, and details are not repeated here. 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 refer to the description in step 700. This step is an optional step.

[0239] 1206、the terminal device performs a RACH procedure with the target node;

[0240] 1207、the terminal device performs data packet transmission with the target node;

[0241] The data packets include first data packets and / or fourth data packets. Specifically, the terminal device uses the first parameters to perform first data packet transmission with the target node, and correspondingly, the target node uses the first parameters to perform first data packet transmission with the terminal device. The terminal device uses the second parameters to perform fourth data packet transmission with the target node, and correspondingly, the target node uses the fourth parameters to perform first data packet transmission with the terminal device.

[0242] The first data packets include first uplink data packets and / or first downlink data packets. The fourth data packets include fourth uplink data packets and / or fourth downlink data packets. For the explanation of the first data packets and the fourth data packets, reference can be made to the step 702 in the embodiment shown in FIG. 7, and details are not repeated here.

[0243] As shown in FIG. 13, the terminal device can send first uplink data packets to the target node on the first RB according to the first parameters, and correspondingly, the target node receives the first uplink data packets from the terminal device on the first RB according to the first parameters. The terminal device can send fourth uplink data packets to the target node on the second RB according to the second parameters, and correspondingly, the target node receives the fourth uplink data packets from the terminal device on the second RB according to the second parameters.

[0244] For example, the first RB is DRB1 and DRB2, and the second RB is DRB3 and DRB4. Before the handover, the terminal device sends data packets to the source node through DRB1, including uplink data packets with SN=0 to SN=20, and sends data packets to the source node through DRB2, including uplink data packets with SN=30 to SN=60. The SN status report described in the step 1205 is used to indicate the uplink data packets that are not received by the source node in the process. After the handover, the terminal device retains DRB1 and DRB2, and sends first uplink data packets processed using the parameters (for example, the first parameters) of the source node to the target node through DRB1 and DRB2, for example, data packets that have been processed or buffered using the first parameters before the handover. For details, reference can be made to the aforementioned explanation of the first data packets, and details are not repeated here. The first uplink data packets can also include data packets that have been processed using the first parameters but have not been sent to the source node. At the same time, the terminal device sends fourth uplink data packets to the target node through DRB3 and DRB4, that is, the second RB. For details, reference can be made to the aforementioned explanation of the fourth data packets, and details are not repeated here. The target node forwards the first uplink data packets processed using the first parameters to the source node.

[0245] The target node can indicate the terminal device 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.

[0246] As shown in FIG. 14, the terminal device can send the first uplink data packet to the target node on the first PDCP and / or the first RLC according to the first parameter, and 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 the fourth uplink data packet to the target node on the second PDCP and / or the second RLC according to the second parameter, and 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.

[0247] For example, as shown in FIG. 14, after the handover, the terminal device maintains the first PDCP and / or the first RLC entity, and newly creates the second PDCP and / or the second RLC entity. The terminal device sends the first uplink data packet, for example, the data packet with SN=12, SN=15, SN=25, …, SN=100, through the first PDCP and / or the first RLC entity, and sends the fourth uplink data packet, for example, the data packet with SN=101, SN=102, through the second PDCP and / or the second RLC entity. For details, refer to step 702 in the embodiment shown in FIG. 7, which will not be described here.

[0248] As shown in FIG. 15, the target node can send the first downlink data packet to the terminal device on the first RB according to the first parameter, and correspondingly, the terminal device receives the first downlink data packet from the target node on the first RB according to the first parameter. The target node can send the fourth downlink data packet to the terminal device on the second RB according to the second parameter, and correspondingly, the terminal device receives the fourth downlink data packet from the target node on the second RB according to the second parameter.

[0249] For example, the first RBs are DRB1 and DRB2, and the second RBs are DRB3 and DRB4. Before the terminal device switches, the source node sends, to the terminal device through the DRB1, data packets including downlink data packets with SN=0 to SN=20, and sends, to the terminal device through the DRB2, data packets including 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, to the target node, the first downlink data packets that have been processed by the source node, i.e., the data packets that are not responded by the terminal device and the data packets that are not sent to the terminal device, such as the data packets with SN=10, SN=11, SN=12, …, SN=100 on the DRB1, the data packets with SN=20, SN=21, SN=22, …, SN=70 on the DRB2, and the data packets that have not been processed by the source node, such as the data packets with SN=101, SN=102 on the DRB1 and the data packets with SN=71, SN=72 on the DRB2. The target node sends, to the terminal device, the data packets processed by the source node through the DRB1 and the DRB2, and sends, to the terminal device, the data packets processed by the target node through the DRB3 and the DRB4. For details, refer to step 702 in the embodiment shown in FIG. 7, which will not be described here.

[0250] As shown in FIG. 16, the target node can send, to the terminal device, the first downlink data packets on the first PDCP and / or the first RLC according to the first parameter, and correspondingly, the terminal device receives, from the target node, the first downlink data packets on the first PDCP and / or the first RLC according to the first parameter. The target node can send, to the terminal device, the fourth downlink data packets on the second PDCP and / or the second RLC according to the second parameter, and correspondingly, the terminal device receives, from the target node, the fourth downlink data packets on the second PDCP and / or the second RLC according to the second parameter.

[0251] For example, after the terminal device switches, the terminal device maintains the first PDCP and / or the first RLC entity, and newly creates the second PDCP and / or the second RLC entity. The target node sends, to the terminal device, the first downlink data packets, such as data packets with SN=12, SN=15, SN=25, …, SN=100, through the first PDCP and / or the first RLC entity, and sends, to the terminal device, the fourth downlink data packets, such as data packets with SN=101, SN=102, through the second PDCP and / or the second RLC entity. For details, refer to step 702 in the embodiment shown in FIG. 7, which will not be described here.

[0252] The target node can indicate, to the terminal device, the association relationship between the DRB1 and the DRB3, and the association relationship between the DRB2 and the DRB4. The association relationship can be included in the switching command in step 1204.

[0253] 1208、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;

[0254] This step can refer to step 703 in the embodiment shown in FIG. 7, and details are not described here. This step is an optional step.

[0255] 1209、the target node sends a reconfiguration message to the terminal device, and correspondingly, the terminal device receives the reconfiguration message from the target node;

[0256] 1210、the terminal device releases the first RB, the first PDCP and / or the first RLC entity;

[0257] Steps 1209 to 1210 can refer to step 704 in the embodiment shown in FIG. 7, and details are not described here. Both step 1209 and step 1210 are optional steps.

[0258] 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. Referring to FIG. 17, the communication device 1700 can be used to execute the process executed by the terminal device in the embodiment shown in FIG. 7, and details can be referred 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 capable of realizing all or part of the functions of a terminal device.

[0259] The communication device 1700 includes an interface module 1701 and a processing module 1702.

[0260] The processing module 1702 is configured to perform data processing. The interface module 1701 can implement corresponding communication functions. The interface module 1701 can also be referred to as a communication interface or a communication module.

[0261] Optionally, the communication device 1700 can further include a storage module, which can be used to store program codes, program instructions and / or data. The processing module 1702 can read instructions and / or data in the storage module, so that the communication device 1700 implements the foregoing method embodiments.

[0262] The communication device 1700 can be used to execute the actions performed by the terminal device in the foregoing method embodiments. For example, the terminal device or a communication module in the terminal device, or a circuit or chip responsible for communication functions in the terminal device. The communication device 1700 can be a terminal device or a component configurable to a terminal device. The processing module 1702 is configured to execute the processing-related operations of the terminal device side in the foregoing method embodiments. The interface module 1701 is configured to execute the receiving-related operations of the terminal device side in the foregoing method embodiments.

[0263] 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.

[0264] 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 actions performed by the terminal device in the embodiment shown in FIG. 7. For details, please refer to the relevant descriptions in the embodiment shown in FIG. 7; they will not be elaborated upon here.

[0265] For example, the communication device 1700 is used to execute the following scheme:

[0266] Interface module 1701 is used to receive switching commands, which instruct the terminal device to switch to the target node;

[0267] Processing module 1702 is used to maintain the first parameter;

[0268] Interface module 1701 is also used to transmit a first data packet with the target node using a first parameter, which is the parameter used for transmission between the terminal device and the source node.

[0269] In one possible implementation, the interface module 1701 is specifically used to transmit a first data packet with the target node on the first radio bearer RB using the first parameters;

[0270] or,

[0271] 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).

[0272] In another possible implementation, the first parameter includes parameters of the first PDCP and / or parameters of the first RLC.

[0273] In another possible implementation, the interface module 1701 is also used to receive first indication information, 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.

[0274] In another possible implementation, 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, where the second parameter is the parameter used for transmission between the terminal device and the target node.

[0275] In another possible implementation, the first RB and the second RB use a same reordering window.

[0276] In another possible implementation, the interface module 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.

[0277] In another possible implementation, the interface module 1701 is further configured to submit the data packet on the second RB after submission of the data packet on the first RB is completed.

[0278] In another possible implementation, the processing module 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.

[0279] In another possible implementation, the first data packet includes third indication information, where the third indication information is used to indicate that the first data packet uses the first parameter or the second parameter.

[0280] In another possible implementation, the interface module 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.

[0281] It should be understood that specific processes in which the modules perform the corresponding processes described above are described in detail in the method embodiments described above, and thus are not described herein again for brevity.

[0282] 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 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.

[0283] Optionally, when the communication apparatus 1700 is a circuit or chip responsible for communication function in a terminal device, such as a Modem chip or a SoC chip containing a Modem core or a SIP chip, the functions of the processing module 1702 can be implemented by the circuit system containing one or more processors or processing cores in the above chip. The functions of the interface module 1701 can be implemented by the interface circuit or data transceiver circuit on the above chip.

[0284] Another structural schematic of the communication apparatus in the embodiments of the present application is shown below. Please refer to FIG. 18. The communication apparatus 1800 can be used to execute the process performed by the target node in the embodiments shown in FIG. 7. For details, please refer to the related description in the foregoing method embodiments. The communication apparatus 1800 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 network device functions. The communication apparatus 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 terminal device functions.

[0285] The communication apparatus 1800 includes an interface module 1801 and a processing module 1802.

[0286] 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.

[0287] Optionally, the communication apparatus 1800 can further include a storage module, which can be used to store program codes, program instructions, and / or data. The processing module 1802 can read the instructions and / or data in the storage module, so that the communication apparatus 1800 implements the foregoing method embodiments.

[0288] The communication apparatus 1800 can be used to execute the actions performed by the target node in the foregoing method embodiments. For example, the target node or a communication module in the target node, or a circuit or chip responsible for communication function in the target node. The communication apparatus 1800 can be the target node or a component configurable to the target node. The processing module 1802 is configured to perform the processing-related operations of the target node side in the foregoing method embodiments. The interface module 1801 is configured to perform the receiving-related operations of the target node side in the foregoing method embodiments.

[0289] Optionally, the interface module 1801 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.

[0290] It should be noted that the communication apparatus 1800 can include the sending module but not the receiving module. Alternatively, the communication apparatus 1800 can include the receiving module but not the sending module. Whether the communication apparatus 1800 includes the sending module or the receiving module can depend on whether the communication apparatus 1800 performs the sending action or the receiving action in the above-mentioned schemes. For example, the communication apparatus 1800 is configured to perform the actions performed by the target node in the embodiment of FIG. 7. Details can be referred to the related description of the embodiment of FIG. 7, which will not be repeated here.

[0291] For example, the communication apparatus 1800 is configured to perform the following scheme.

[0292] The interface module 1801 is configured 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 be transmitted to a terminal device.

[0293] The processing module 1802 is configured to maintain a first parameter.

[0294] The interface module 1801 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 for transmission between the terminal device and the source node, and the first data packet including the second data packet.

[0295] In a possible implementation, the interface module 1801 is specifically configured to use the first parameter to perform transmission of the first data packet with the terminal device on a first RB.

[0296] Alternatively,

[0297] The first parameter is used to perform transmission of the first data packet with the terminal device on the first PDCP and / or the first RLC.

[0298] In another possible implementation, the first parameter includes a parameter of the first PDCP and / or a parameter of the first RLC.

[0299] In another possible implementation, the interface module 1801 is further configured to send 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.

[0300] 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 for transmission between the terminal device and a target node.

[0301] In another possible implementation, the first RB and the second RB use a same reordering window.

[0302] In another possible implementation, the interface module 1801 is further configured to send second indication information, where the second indication information is used to indicate the association relationship between the first RB and the second RB.

[0303] In another possible implementation, the first data packet comprises third indication information, where the third indication information is used to indicate that the first data packet uses the first parameter or the second parameter.

[0304] In another possible implementation, the interface module 1801 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.

[0305] In another possible implementation, the interface module 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 comprises the third data packet.

[0306] 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 are not described herein again for the sake of brevity.

[0307] 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.

[0308] Another structural schematic diagram of a communication apparatus according to an embodiment of the present application is shown below. Please refer to FIG. 19. The communication apparatus 1900 can be used to execute the processes performed by the source node in the embodiments shown in FIG. 7, and details can be referred to the related descriptions in the method embodiments described above. 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 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.

[0309] The communication apparatus 1900 comprises an interface module 1901 and a processing module 1902.

[0310] The processing module 1902 is used for 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.

[0311] Optionally, the communication apparatus 1900 further includes 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 implements the foregoing method embodiments.

[0312] The communication apparatus 1900 can be used to perform the actions performed by the source node in the foregoing method embodiments. For example, 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 the processing-related operations of the source node side in the foregoing method embodiments. The interface module 1901 is configured to perform the receiving-related operations of the source node side in the foregoing method embodiments.

[0313] 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.

[0314] 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. Specifically, whether the sending module and the receiving module are included in the communication apparatus 1900 can depend on whether the sending actions and the receiving actions are included in the foregoing schemes performed by the communication apparatus 1900. For example, the communication apparatus 1900 is configured to perform the actions performed by the source node in the embodiment shown in FIG. 7. Details can be referred to the related description in the embodiment shown in FIG. 7, which will not be described here in detail.

[0315] For example, the communication apparatus 1900 is configured to perform the following scheme:

[0316] The interface module 1901 is configured to send, to the target node, a second data packet, the second data packet being a data packet processed by the source node, and the second data packet being used to be delivered to the terminal device.

[0317] The processing module 1902 is configured to generate a switching command.

[0318] The interface module 1901 is further configured to send, to the terminal device, the switching command, the switching command being used to instruct the terminal device to switch to the target node.

[0319] In a possible implementation, the interface module 1901 is further configured to receive, from the target node, a third data packet, the third data packet being a data packet processed by the source node, and the third data packet being from the terminal device.

[0320] It should be understood that the specific processes in which each module performs the corresponding processes have been described in detail in the foregoing method embodiments, and will not be described here in detail for the sake of brevity.

[0321] The processing module 1902 in the above embodiments 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.

[0322] Next, a communication apparatus provided by an embodiment of the present application is introduced. Referring to FIG. 20, FIG. 20 is a structural schematic diagram of the communication apparatus provided by an embodiment of the present application. The communication apparatus 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 apparatus can be used to implement the method described in the above method embodiments. For details, refer to the description in the above method embodiments.

[0323] The communication apparatus can include one or more processors 2001, which are 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 a communication protocol and communication data, and the central processing unit can be used to control the communication apparatus (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.

[0324] Optionally, the communication apparatus can include one or more memories 2002, which can store instructions. The instructions can be run on the processor 2001, so that the communication apparatus executes the method 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 integrated together.

[0325] Optionally, the communication apparatus can also include a transceiver, an antenna. The transceiver can be referred to as a transceiving unit, a transceiver, or a transceiving circuit, etc., which 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., which is used to realize the receiving function. The transmitter can be referred to as a transmitter or a transmitting circuit, etc., which is used to realize the transmitting function.

[0326] 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 integrated together. The above transceiving circuit, interface or interface circuit can be used for reading and writing of codes / data, or the above transceiving circuit, interface or interface circuit can be used for transmission or transfer of signals.

[0327] In yet another possible design, the processor 2001 can optionally store instructions that, when executed by the processor 2001, can cause the communication device to perform the methods described in the above method embodiments. The instructions can be embedded in the processor 2001, in which case the processor 2001 can be implemented by hardware.

[0328] In yet another possible design, the communication device 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 above 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 IC (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and the transceiver can also be manufactured using various IC technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), P-type metal oxide semiconductor (PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0329] The communication device described in the above embodiments can be a terminal device, a source node, or a target node, but the scope of the communication device described in the embodiments of the present application is not limited thereto, and the structure of the communication device can not be limited by FIG. 20. The communication device can be a standalone device or can be part of a larger device. For example, the communication device can be:

[0330] (1) a standalone integrated circuit (IC), or a chip, or a chip system or subsystem;

[0331] (2) a set of one or more ICs, which can optionally also include storage components for storing data, instructions;

[0332] (3) an ASIC, such as a modem (KSK);

[0333] (4) a module that can be embedded in other devices;

[0334] (5) receivers, terminals, intelligent terminals, cellular phones, wireless devices, handsets, mobile units, car kits, network devices, cloud devices, artificial intelligence devices, and the like;

[0335] (6) others, and the like.

[0336] For the case that the communication apparatus can be a chip or a chip system, refer to the structural schematic diagram of the chip shown in FIG. 21. The chip 2100 shown in FIG. 21 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.

[0337] 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:

[0338] The interface 2102 is configured to receive or output a signal.

[0339] The processor 2101 is configured to perform data processing operations of the network device or the terminal device.

[0340] 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 needs. Correspondingly, the communication apparatus given in the embodiments of the present application can also implement these features or functions, which will not be described here.

[0341] 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 devices, discrete gates or transistor logic devices, discrete hardware components.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] 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.

[0346] 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.

[0347] 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.

[0348] In addition, each function unit in the embodiments of the present application can be integrated in a processing module, or each unit can be a physical unit, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware, or in the form of a software function unit.

[0349] When the integrated unit is realized in the form of a 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 all or part of the technical solutions, can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several 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: a U disk, a mobile hard disk, a read-only memory (ROM, read-only memory), a random access memory (RAM, random access memory), a magnetic disk or an optical disk, and various other media that can store program codes.

[0350] 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 by, The method comprises: receiving a handover command, the handover command being used to instruct a terminal device to hand over from a source node to a target node; transmitting a first data packet with the target node using a first parameter, the first parameter being a parameter used for transmission between the terminal device and the source node, the first data packet being a data packet processed by the source node.

2. The method of claim 1, wherein, The transmitting a first data packet with the target node using a first parameter comprises: transmitting the first data packet with the target node on a first radio bearer (RB) using the first parameter; or transmitting the first data packet with the target node on a first packet data convergence protocol (PDCP) and / or a first radio link control (RLC) using the first parameter. The first parameter comprises a parameter of a first PDCP and / or a parameter of a first RLC.

3. The method according to claim 1 or 2, characterized in that, The method further comprises:

4. The method according to any one of claims 2 or 3, characterized in that, receiving 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. 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 for transmission between the terminal device and the target node.

5. The method of claim 4, wherein, The first RB and the second RB use a same reordering window.

6. The method of claim 5, wherein, The method further comprises:

7. The method according to claim 5 or 6, characterized in that, receiving second indication information, the second indication information being used to indicate an association relationship between the first RB and the second RB. The method further comprises:

8. The method of claim 5, wherein, after packet delivery on the first RB is completed, delivering a packet on the second RB. Before the transmitting a first data packet with the target node using a first parameter, the method further comprises:

9. The method of claim 5, wherein, establishing a second PDCP functional entity and / or a second RLC, the second PDCP functional entity and the second RLC using a configuration of the target node, the second PDCP functional entity comprising at least one of a first ciphering functional entity, a first deciphering functional entity, a first integrity protection functional entity, or a first integrity check functional entity. The first data packet comprises third indication information, the third indication information being used to instruct the first data packet to use the first parameter or the second parameter.

10. The method according to any one of claims 6 to 9, characterized in that, The method further comprises:

11. The method according to any one of claims 2 to 10, characterized in that, receiving 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. The method comprises:

12. A data transmission method, characterized by, receiving 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; transmitting a first data packet with the terminal device using a first parameter, the first parameter being a parameter used for transmission between the terminal device and the source node, the first data packet comprising the second data packet. The transmitting a first data packet with the terminal device using a first parameter comprises:

13. The method of claim 12, wherein, ​ transmitting the first data packet with the terminal device on the first RB using the first parameter; or, transmitting the first data packet with the terminal device on the first PDCP and / or the first RLC using the first parameter.

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

15. The method according to any one of claims 13 or 14, characterized in that, The method further comprises: sending 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.

16. The method of claim 15, wherein, 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 by the terminal device for transmission with the target node.

17. The method of claim 16, wherein, The first RB and the second RB use a same reordering window.

18. The method of claim 16 or 17, wherein, The method further comprises: sending second indication information, the second indication information being used to indicate an association relationship between the first RB and the second RB.

19. The method of any one of claims 16-18, wherein, The first data packet comprises third indication information, the third indication information being used to indicate the first data packet to use the first parameter or the second parameter.

20. The method of any one of claims 13-19, wherein, The method further comprises: sending a reconfiguration message to the terminal device, the reconfiguration message being used to indicate the terminal device to release at least one of the first PDCP, the first RLC or the first RB.

21. The method of any one of claims 12-20, wherein, The method further comprises: sending a third data packet to the source cell, the third data packet being a data packet processed by the source node, the third data packet being from the terminal device, the first data packet comprising the third data packet.

22. A data transmission method, characterized by, comprising: sending a second data packet to a target node, the second data packet being a data packet processed by a source node, the second data packet being for delivery to a terminal device; sending a handover command to the terminal device, the handover command being used to indicate the terminal device to hand over to the target node.

23. The method of claim 22, wherein, The method further comprises: receiving a third data packet from the target node, the third data packet being a data packet processed by the source node, the third data packet being from the terminal device.

24. A communications device, characterized by comprising: an interface module configured to receive a handover command, the handover command being used to indicate the terminal device to hand over to a target node; a processing module configured to maintain a first parameter; the interface module is further configured to transmit a first data packet with the target node using the first parameter, the first parameter being a parameter used by the terminal device for transmission with a source node.

25. A communications device, characterized by comprising: an interface module 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 for delivery to a terminal device; a processing module configured to maintain a first parameter; the interface module is further configured to transmit a first data packet with the terminal device using the first parameter, the first parameter being a parameter used by the terminal device for transmission with the source node, the first data packet comprising the second data packet.

26. A communications device, characterized by comprising: an interface module configured to send a second data packet to the target node, the second data packet being a data packet processed by the source node, the second data packet being for delivery to the terminal device; a processing module configured to generate a handover command; the interface module is further configured to send the handover command to the terminal device, the handover command being configured to instruct the terminal device to handover to the target node.

27. A communications device, characterized by comprising: a processor configured to execute a program, so that the communication device performs the method of any one of claims 1 to 11, or so that the communication device performs the method of any one of claims 12 to 21, or so that the communication device performs the method of any one of claims 22 to 23.

28. A communication system, characterized by comprising: a communication device configured to perform the method of any one of steps 1 to 11, a communication device configured to perform the method of any one of steps 12 to 21, and a communication device configured to perform the method of any one of claims 22 to 23.

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

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