Data transmission method, communication apparatus, and communication device

Abstract

Embodiments of the present application relate to the field of communications. Disclosed are a data transmission method, an apparatus, and a communication device. The data transmission method of the embodiments of the present application comprises: a packet data convergence protocol (PDCP) entity or a media access control (MAC) entity of a sending end receives first information from a radio link control (RLC) entity of the sending end, the first information being used for indicating that the RLC entity has discarded or is about to discard at least one first data packet; and the PDCP entity or the MAC entity of the sending end discards, on the basis of the first information, at least one second data packet related to the at least one first data packet.

Description

Data transmission methods, communication devices and communication equipment

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024107019661, filed on May 31, 2024, entitled "Data Transmission Method, Communication Apparatus and Communication Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of communications, specifically relating to a data transmission method, a communication device, and a communication equipment. Background Technology

[0004] In New Radio (NR) systems, data packets may be dropped at the transmitting or receiving end due to congestion control, packet dependencies, or packet timeouts. When packet drop occurs at the Radio Link Control (RLC) layer, the upper Packet Data Convergence Protocol (PDCP) layer or the lower Media Access Control (MAC) layer may not be aware that the packets have been dropped and may still process or transmit these dropped packets, or packets associated with them. This could lead to a waste of data transmission resources and affect the data transmission efficiency between the transmitting and receiving ends. Therefore, how the PDCP or MAC layers handle data transmission when packet drop occurs at the RLC layer is a crucial issue that needs to be addressed. Summary of the Invention

[0005] This application provides a data transmission method, communication device, and communication equipment that can help avoid the PDCP layer or MAC layer from processing or transmitting data packets that have been discarded or are about to be discarded, thereby reducing the waste of data transmission resources and improving the data transmission efficiency between the sender and receiver.

[0006] Firstly, a data transmission method is provided, including:

[0007] The Packet Data Convergence Protocol (PDCP) entity or Media Access Control (MAC) entity at the transmitting end receives first information from the Radio Link Control (RLC) entity at the transmitting end. The first information is used to indicate that the RLC entity has dropped or is about to drop at least one first data packet.

[0008] The PDCP entity or MAC entity of the sending end discards at least one second data packet associated with the at least one first data packet based on the first information.

[0009] Secondly, a data transmission method is provided, including:

[0010] The Radio Link Control (RLC) entity at the receiving end sends third information to the PDCP entity at the receiving end, the third information being used to indicate that the RLC entity at the receiving end has discarded or is about to discard at least one third data packet.

[0011] Thirdly, a data transmission method is provided, including:

[0012] In the event of a cell handover or a change of primary / secondary cell, if packet loss occurs at the terminal, the terminal sends fourth information to the second network-side device to which the target cell or target cell group belongs after the handover or change. The fourth information is used to indicate at least one of the following:

[0013] The terminal's RLC entity has dropped or is about to drop at least one fourth data packet;

[0014] The terminal stops transmitting the at least one fourth data packet.

[0015] Fourthly, a communication device is provided, comprising:

[0016] The processing module is used for the Packet Data Convergence Protocol (PDCP) entity or Media Access Control (MAC) entity at the transmitting end to receive first information from the Radio Link Control (RLC) entity at the transmitting end, the first information being used to indicate that the RLC entity has discarded or is about to discard at least one first data packet.

[0017] The processing module is further configured to allow the PDCP entity or MAC entity at the sending end to discard at least one second data packet associated with the at least one first data packet based on the first information.

[0018] Fifthly, a communication device is provided, comprising:

[0019] The processing module is used for the Radio Link Control (RLC) entity of the receiving end to send third information to the PDCP entity of the receiving end, the third information being used to indicate that the RLC entity of the receiving end has discarded or is about to discard at least one third data packet.

[0020] Sixthly, a communication device is provided, comprising:

[0021] The sending module is configured to send fourth information to the second network-side equipment to which the target cell or target cell group belongs after the handover or change occurs, in the event of a cell handover or primary / secondary cell change. The fourth information is used to indicate at least one of the following:

[0022] The terminal's RLC entity has dropped or is about to drop at least one fourth data packet;

[0023] The terminal stops transmitting the at least one fourth data packet.

[0024] In a seventh aspect, a communication device is provided, the device being configured to perform the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect, or to implement the steps of the method described in the third aspect.

[0025] Eighthly, a communication device is provided, which serves as a transmitter and includes a transceiver, a processor, and a memory, wherein the memory stores a program or instructions executable on the processor, and the program or instructions, when executed by the processor, implement the steps of the method described in the first aspect.

[0026] Ninthly, a communication device is provided, which serves as a transmitter and includes a processor and a communication interface;

[0027] The processor is configured to allow the Packet Data Convergence Protocol (PDCP) entity or Media Access Control (MAC) entity at the transmitting end to receive first information from the Radio Link Control (RLC) entity at the transmitting end, the first information indicating that the RLC entity has discarded or is about to discard at least one first data packet; the processing module is further configured to allow the PDCP entity or MAC entity at the transmitting end to discard at least one second data packet associated with the at least one first data packet based on the first information.

[0028] In a tenth aspect, a communication device is provided, which serves as a receiving end and includes a transceiver, a processor, and a memory, wherein the memory stores a program or instructions executable on the processor, and the program or instructions, when executed by the processor, implement the steps of the method described in the second aspect.

[0029] Eleventhly, a communication device is provided, which serves as a receiving end and includes a processor and a communication interface;

[0030] The processor is used to send third information from the Radio Link Control (RLC) entity of the receiving end to the PDCP entity of the receiving end. The third information is used to indicate that the RLC entity of the receiving end has discarded or is about to discard at least one third data packet.

[0031] In a twelfth aspect, a communication device is provided, which serves as a terminal and includes a transceiver, a processor, and a memory, wherein the memory stores a program or instructions executable on the processor, and the program or instructions, when executed by the processor, implement the steps of the method described in the third aspect.

[0032] In a thirteenth aspect, a communication device is provided, which serves as a terminal and includes a processor and a communication interface;

[0033] The communication interface is used to send fourth information to the second network-side equipment to which the target cell or target cell group belongs after the handover or change occurs, in the event of a cell handover or primary / secondary cell change. The fourth information is used to indicate at least one of the following:

[0034] The terminal's RLC entity has dropped or is about to drop at least one fourth data packet;

[0035] The terminal stops transmitting the at least one fourth data packet.

[0036] In a fourteenth aspect, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or the steps of the method described in the second aspect, or the steps of the method described in the third aspect.

[0037] In a fifteenth aspect, a wireless communication system is provided, comprising: a transmitter and a receiver, the transmitter being configured to perform the steps of the method described in the first aspect, and the receiver being configured to perform the steps of the method described in the second aspect.

[0038] In a sixteenth aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being configured to run a program or instructions to implement the method as described in the first aspect, or the method as described in the second aspect, or the method as described in the third aspect.

[0039] In a seventeenth aspect, a computer program / program product is provided, the computer program / program product being stored in a storage medium, the computer program / program product being executed by at least one processor to implement the steps of the data transmission method as described in the first aspect, or the steps of the data transmission method as described in the second aspect, or the steps of the data transmission method as described in the third aspect.

[0040] In this embodiment, the PDCP or MAC entity at the sending end obtains first information from the RCL entity at the sending end, thereby instructing the PDCP or MAC layer at the sending end to discard or discard at least one first data packet. This allows the PDCP or MAC layer to discard at least one second data packet associated with the at least one first data packet based on the instruction. This helps avoid the PDCP or MAC entity from processing or transmitting data packets that have been or are about to be discarded, thus reducing the waste of data transmission resources and improving the data transmission efficiency between the sending and receiving ends. Attached Figure Description

[0041] Figure 1 is a schematic diagram of a communication system architecture provided in an embodiment of this application.

[0042] Figure 2 is a schematic flowchart of a data transmission method provided according to an embodiment of this application.

[0043] Figure 3 is a schematic flowchart of another data transmission method provided according to an embodiment of this application.

[0044] Figure 4 is a schematic flowchart of another data transmission method provided according to an embodiment of this application.

[0045] Figure 5 is a schematic block diagram of a communication device provided according to an embodiment of this application.

[0046] Figure 6 is a schematic block diagram of another communication device provided according to an embodiment of this application.

[0047] Figure 7 is a schematic block diagram of another communication device provided according to an embodiment of this application.

[0048] Figure 8 is a schematic block diagram of a communication device provided according to an embodiment of this application.

[0049] Figure 9 is a schematic diagram of the hardware structure of a terminal according to an embodiment of this application.

[0050] Figure 10 is a schematic block diagram of a network-side device provided according to an embodiment of this application. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0052] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, the scope of protection for "A or B" covers at least three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. In addition, the terms "A and / or B," "at least one of A and B," and "at least one of A or B" also cover at least the above three scenarios. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0053] The term "instruction" in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction). A direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent. An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.

[0054] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), Ambient Internet of Things (IoT) systems, or other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and the term NR is used in most of the following description; however, these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0055] Figure 1 shows a block diagram of a wireless communication system applicable to an embodiment of this application. The wireless communication system includes a terminal 11 and a network-side device 12.

[0056] Among them, terminal 11 can be a mobile phone, tablet computer, laptop computer, notebook computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR), virtual reality (VR) device, robot, wearable device, flight vehicle, vehicle user equipment (VUE), shipborne equipment, pedestrian user equipment (PUE), smart home (home devices with wireless communication functions, such as refrigerators, televisions, washing machines or furniture, etc.), game console, personal computer (PC), ATM or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart earphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among these, in-vehicle devices can also be referred to as in-vehicle terminals, in-vehicle controllers, in-vehicle modules, in-vehicle components, in-vehicle chips, or in-vehicle units, etc. It should be noted that the specific type of terminal 11 is not limited in the embodiments of this application.

[0057] Among them, network-side equipment 12 may include access network equipment or core network equipment.

[0058] Alternatively, access network equipment may also be referred to as Radio Access Network (RAN) equipment, radio access network function, or radio access network unit. Access network equipment may include base stations, wireless local area network (WLAN) access points (APs), or wireless Fidelity (WiFi) nodes, etc. The term "base station" can be referred to as Node B (NB), Evolved Node B (eNB), Next Generation Node B (gNB), New Radio Node B (NR Node B), Access Point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), Radio Base Station, Radio Transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B, Transmit / Receive Point (TRP), or any other suitable term in the relevant field, as long as the same technical effect is achieved. The term "base station" is not limited to specific technical terms. It should be noted that the embodiments in this application only use base stations in NR systems as examples for description and do not limit the specific type of base station.

[0059] Optionally, core network equipment may also be referred to as core network nodes, core network functions, or core network elements, and includes, but is not limited to, at least one of the following: Mobility Management Entity (MME), Access and Mobility Management Function (AMF), Session Management Function (SMF), User Plane Function (UPF), Policy Control Function (PCF), Policy and Charging Rules Function (PCRF), Edge Application Server Discovery Function (EASDF), Unified Data Management (UDM), Unified Data Repository (UDR), Home Subscriber Server (HSS), Centralized network configuration (CNC), Network Repository Function (NRF), Network Exposure Function (NEF), Local NEF (or L-NEF), and Binding Support. The core network functions include: BSF (Block Network Function), Application Function (AF), Location Management Function (LMF), Gateway Mobile Location Centre (GMLC), and Network Data Analytics Function (NWDAF). It should be noted that this application embodiment only uses core network equipment in the NR system as an example and does not limit the specific type of core network equipment. If the name of the core network equipment mentioned in this application embodiment changes in subsequent protocol versions (e.g., 6G), it will still be within the scope of protection of this application.

[0060] Optionally, the core network equipment can be implemented by one or more functional modules in a single device, or by multiple devices working together; this application does not specifically limit this. It is understood that the aforementioned functional modules can be network elements in hardware devices, software functional modules running on dedicated hardware, or virtualized functional modules instantiated on a platform (e.g., a cloud platform).

[0061] To facilitate a better understanding of the embodiments of this application, the relevant terms in the embodiments of this application will be explained.

[0062] Radio Link Control (RLC) Acknowledged Mode (AM): One of the operating modes of RLC, supporting packet retransmission. After receiving a Status Protocol Data Unit (PDU) from the receiver, the transmitting RLC AM entity will retransmit the RLC Service Data Unit (SDU) or RLC SDU segment that the receiver failed to receive.

[0063] A PDU set contains one or more PDUs, each carrying a set of unit information generated by the application layer, such as a frame or a video slice.

[0064] PDU Set Integrated Handling Information (PSIHI): This indicates whether the application layer needs all PDUs in the PDU set to be received correctly when using the PDU set. When a QoS flow is configured with PSIHI, if one PDU in the PDU set is lost, the remaining PDUs in the PDU set are considered no longer needed and can be discarded.

[0065] For PSIHI, R-18 introduces a PDU set-based discard function. When a Data Radio Bearer (DRB) is configured with this function, if one PDU in the PDU set is discarded, the other PDUs in the PDU set are also discarded.

[0066] Logical channel multiplexing at the Media Access Control (MAC) layer: After the RLC layer delivers the RLC SDU to the MAC layer, it becomes an RLC PDU (i.e., a MAC SDU). The MAC layer, based on the available schedulable resources and scheduling priorities, multiplexes the MAC SDUs submitted by the RLC layer into a single MAC PDU, which is then delivered to the physical layer for transmission. During multiplexing, multiple MAC SDUs are processed separately, becoming multiple MAC sub-PDUs, and then these MAC sub-PDUs are concatenated together to form a single MAC PDU.

[0067] RLC Reconstruction: RLC reconstruction discards all RLC SDUs, RLC SDU segments, and RLC PDUs, stops and resets all related timers in the RLC layer, and resets all state variables in the RLC layer to their initial values. Optionally, whether to perform RLC reconstruction during handover is configured by the network side.

[0068] To facilitate a better understanding of the embodiments of this application, the receiving end processing procedure of the Packet Data Convergence Protocol (PDCP) is described.

[0069] The receiving PDCP entity needs to maintain the following state variables:

[0070] RX_DELIV: This variable indicates the COUNT value of the first PDCP SDU that has not yet been submitted to the upper layer but is waiting to be submitted;

[0071] RX_NEXT: This variable indicates;

[0072] RX_REORD: This variable indicates the COUNT+1 of the PDCP data PDU that triggered the t-reordering timer, which is RX_NEXT at this time;

[0073] Reordering timer (t-Reordering): Used to detect packet loss (discontinuous sequence numbers).

[0074] When the PDCP entity receives the PDCH PDU submitted by the RLC, it calculates the RCVD_COUNT of the PDU. After completing the corresponding decryption and integrity verification processes, it performs the following operations:

[0075] 1. If RCVD_COUNT < RX_DELIV or COUNT = RCVD_COUNT, the PDCP PDU has been received and is discarded. If it is not discarded, the following processing continues;

[0076] 2. If RCVD_COUNT >= RX_NEXT, that is, RCVD_COUNT is the highest value in the receive window, update RX_NEXT = RCVD_COUNT + 1;

[0077] 3. If RCVD_COUNT = RX_DELIV, deliver the processed PDCP SDU to the upper layer in ascending order of COUNT, and update RX_DELIV to point to the first PDCP SDU that has not been delivered to the upper layer;

[0078] 4. If the timer t-Reordering is running and the last delivered COUNT value is greater than or equal to the COUNT value bound by the timer, that is, RX_DELIV >= RX_REORD, stop t-Reordering;

[0079] 5. If the timer t-Reordering is not running and there is a COUNT hole between RX_DELIV and RX_NEXT, that is, RX_DELIV < RX_NEXT, update RX_REORD = RX_NEXT and start t-Reordering.

[0080] When t-Reordering times out, it is considered that the data packet in [RX_NEXT, RX_REORD] has failed to be received, and the following operations are performed:

[0081] 1. The received PDCP SDUs with COUNT < RX_REORD and completed downlink receive processing are delivered to the upper layer in ascending order;

[0082] 2. The received PDCP SDUs with COUNT >= RX_REORD and completed downlink receive processing are delivered to the upper layer in ascending order if COUNT is consecutive;

[0083] 3. Update RX_DELIV to point to the first PDCP SDU that has not been delivered to the upper layer;

[0084] 4. If there is a COUNT hole between RX_DELIV and RX_NEXT, that is, RX_DELIV < RX_NEXT, update RX_REORD = RX_NEXT and start t-Reordering.

[0085] To facilitate a better understanding of the embodiments of this application, RLC AM optimization for Extended Reality (XR) will be described.

[0086] XR services typically have latency requirements, specifically packet delay budget (PDB) requirements. Only packets that meet the PDB requirements are valuable when delivered to the peer. However, the retransmission count for RLC AM is configured by the network and is fixed for each logical channel. Even if the transmission delay of a packet exceeds the PDB, the sending RLC AM entity will still retransmit the packet until a positive ACK is received or the maximum retransmission count is reached. This wastes resources, reduces system capacity, and increases the transmission delay of subsequent packets. Therefore, optimizing the RLC AM retransmission mechanism—for example, adjusting the retransmission count based on packet delay information or stopping RLC retransmission and discarding the corresponding RLC layer data packets—can improve system capacity and meet PDB requirements.

[0087] When a packet is dropped at the RLC layer, the upper PDCP layer or the lower MAC layer may still process or transmit these dropped packets, or packets associated with them. This could lead to a waste of data transmission resources and affect the data transmission efficiency between the sender and receiver. Therefore, how the PDCP and MAC layers handle the corresponding packets when a packet is dropped at the RLC layer remains to be addressed.

[0088] Based on the above-mentioned technical problems, this application provides a data transmission scheme in which the RLC entity of the sending end indicates to the PDCP layer or MAC layer of the sending end that at least one first data packet has been discarded or is about to be discarded, so that the PDCP layer or MAC layer can discard at least one second data packet associated with the at least one first data packet according to the indication. This helps to avoid the PDCP layer or MAC layer from processing or transmitting data packets that have been discarded or are about to be discarded, which helps to reduce the waste of data transmission resources and improve the data transmission efficiency between the sending end and the receiving end.

[0089] The wireless communication provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings and through some examples and application scenarios.

[0090] Figure 2 is a schematic flowchart of a data transmission method 200 according to an embodiment of this application, which is applied at a sending end. As shown in Figure 2, the data transmission method 200 may include at least some of the following:

[0091] S210, the PDCP entity or MAC entity of the sending end receives first information from the RLC entity, the first information being used to indicate that the RLC entity of the sending end has discarded or is about to discard at least one first data packet.

[0092] S220, the PDCP layer or MAC layer discards at least one second data packet associated with the aforementioned at least one first data packet based on the first information.

[0093] Therefore, in this embodiment of the application, the PDCP or MAC entity of the sending end obtains first information from the RCL entity of the sending end, and instructs the PDCP or MAC layer of the sending end to discard or discard at least one first data packet. This allows the PDCP or MAC layer to discard at least one second data packet associated with the at least one first data packet according to the instruction. This helps to avoid the PDCP or MAC layer from processing or transmitting data packets that have been discarded or are about to be discarded, thereby reducing the waste of data transmission resources and improving the data transmission efficiency between the sending end and the receiving end.

[0094] It should be understood that Figure 2 illustrates the steps or operations of the data transmission method 200, but these steps or operations are merely examples, and other operations or variations of the operations shown in Figure 2 may also be performed in this application.

[0095] The sending end described in this application embodiment is the party that sends data during data transmission. Optionally, this application embodiment may also involve a receiving end, which is the party that receives data during data transmission. Optionally, the sending end may include a network-side device or a PDCP entity, RLC entity, and MAC entity of a network-side device, and the receiving end may include a terminal or a terminal's PDCP entity, RLC entity, and MAC entity; or, the sending end may be a terminal or a terminal's PDCP entity, RLC entity, and MAC entity, and the receiving end may be a network-side device or a network-side device's PDCP entity, RLC entity, and MAC entity. This application embodiment does not limit this.

[0096] The embodiments of this application can be applied to Acknowledged Mode (AM).

[0097] In this embodiment, the RLC entity can also be called the RLC layer. The two have the same or similar meanings and can be equivalently substituted in some scenarios. This embodiment does not limit this.

[0098] In this embodiment, the PDCP entity is a layer above the RLC layer, also referred to as the upper layer, and this application is not limited in this regard. In this embodiment, the MAC entity is a layer below the RLC layer, also referred to as the lower layer, and this application is not limited in this regard. The PDCP entity can also be referred to as the PDCP layer, and the MAC entity can also be referred to as the MAC layer.

[0099] For example, in a communication device, the RLC entity is located between the PDCP entity and the MAC entity. The RLC layer communicates with the PDCP layer through a Service Access Port (SAP) and with the MAC layer through a logical channel.

[0100] The first information described in the embodiments of this application can also be referred to as packet loss indication information. For example, the RLC layer of the sending end can send the first information to the PDCP layer through SAP, and this application does not limit this.

[0101] In some embodiments, the at least one first data packet includes, but is not limited to, at least one of the following:

[0102] Radio Link Control service data unit (RLC SDU), Radio Link Control Protocol Data Unit (RLC PDU), and RLC SDU segment.

[0103] As an example, during data transmission, the data packets delivered by the PDCP layer to the RLC layer are called PDCP PDUs from the PDCP perspective. Correspondingly, the RLC layer receives data packets (PDCP PDUs) from the PDCP layer, which are called RLC SDUs from the RLC layer's perspective. Optionally, the RLC layer can segment the RLC SDUs to obtain RLC SDU segments. As another example, when the RLC layer needs to send information to the PDCP layer or the MAC layer, it packages the data into RLC PDUs.

[0104] In some embodiments, prior to step S210, the sending PDCP entity delivers at least one data packet to the RLC layer. For example, the at least one data packet is at least one data packet within a data packet set, such as at least one PDU within a PDU set. Correspondingly, the RLC entity receives the at least one data packet and discards at least one first data packet from the at least one data packet, or is about to discard at least one first data packet from the at least one data packet.

[0105] In some embodiments, the first information includes a sequence number (SN) or a range of SNs for at least one first data packet. The SN is a unique identifier assigned to each data packet by the sending RCL entity. Thus, the PDCP entity or MAC entity can determine at least one first data packet that has been discarded, or at least one first data packet that is about to be discarded, based on the SN or range of SNs included in the first information.

[0106] In some embodiments, if the data radio bearer (DRB) associated with the sending RLC entity is configured with packet set-based packet loss, and if the RLC entity has already dropped or is about to drop at least one first packet, the sending RLC entity will also drop at least one second packet from the packet set to which the first packet belongs. Here, the second packet refers to other packets from the packet set to which at least one first packet belongs in the RLC entity.

[0107] For example, when a DRB of the sending RLC entity is configured with PDU set-based discard, when the sending RLC entity discards at least one first data packet (such as a first PDU), other PDUs belonging to the same PDU set are also considered unnecessary and can be discarded. Based on this, the RLC entity can also simultaneously discard other PDUs that have already been submitted to the RLC layer and belong to the same PDU set as the at least one first data packet. This reduces the transmission of unnecessary data packets, helps avoid wasting data transmission resources, and improves system capacity.

[0108] In some embodiments, the sending end's RLC entity may discard or intend to discard at least one first data packet based on at least one of the following: the remaining time information of the data packet, its importance, and its dependency on other data packets. That is, at least one first data packet in step S210 above is discarded by the RLC entity based on at least one of the following: the remaining time information of the data packet, its importance, and its dependency on other data packets.

[0109] For example, RX services typically have latency requirements, such as packet delay budget (PDB) requirements. Only packets that meet the PDB requirements are valuable when delivered to the peer. The remaining time information indicates the time remaining before a data packet times out (e.g., the discard timer in the PDCP layer). When the remaining time of a data packet is less than a preset value, the packet cannot meet the PDB requirements and is determined to be discarded by the RLC layer. Similarly, data packets of less importance to the service may be determined to be discarded by the RLC layer when data transmission resources are insufficient. Furthermore, when a data packet is determined to be discarded, other data packets that depend on it may also be determined to be discarded.

[0110] In some embodiments, when the RLC entity sends the first information to the PDCP entity, at least one second data packet includes, but is not limited to, at least one of the following:

[0111] Packet Data Convergence Protocol service data unit (PDCP SDU) and Packet Data Convergence Protocol Protocol Data Unit (PDCP PDU).

[0112] Specifically, in the PDCP layer, PDCP SDUs are the input to the PDCP layer and can be data packets from upper layers (such as the Service Data Adaptation Protocol (SDAP) layer). The PDCP layer processes these PDCP SDUs, such as by compressing and encrypting headers, and then outputs them as PDCP PDUs. The PDCP PDUs are then passed to the lower layer, the RLC layer, for further processing.

[0113] Wherein, at least one second data packet is associated with at least one first data packet, meaning that at least one second data packet includes at least one data packet associated with the first data packet at the PDCP layer. Here, at least one first data packet is a data packet in the RLC layer, and the data packet associated with the at least one first data packet can refer to the data packet in the PDCP layer corresponding to the first data packet, such as the first data packet corresponding to a PDCP PDU or PDCP SDU in the PDCP layer, etc., which is not limited in this embodiment. As an example, the associated data packet in the PDCP layer corresponding to the first data packet sent to the RLC layer can be referred to as the data packet associated with the first data packet in the PDCP layer.

[0114] In some embodiments, step S220 above can be specifically implemented as follows:

[0115] When the DRB associated with the RLC entity is configured for packet loss based on packet set, the PDCP entity discards the second packet of the packet set to which the first packet belongs, based on the first information.

[0116] In other words, when the DRB associated with the RLC entity is configured for packet loss based on the packet set, at least one second packet may include at least one other packet in the packet set to which the packet associated with the PDCP entity belongs.

[0117] For example, when a DRB associated with the sending RLC entity is configured with PDU set-based discard, and at least one first data packet corresponding to a related data packet within the PDU set is discarded by the RLC entity, the sending PDCP entity can discard other data packets within that PDU set. That is, these other data packets are also considered unnecessary and can be discarded. Here, the at least one related data packet within the PDU set refers to the data packet associated with the at least one data packet discarded by the RLC entity.

[0118] In this way, the PDCP entity can discard other data packets in the PDU set associated with at least one data packet that has been discarded by the RLC layer, based on the instructions of the first information. As a result, the PDCP layer will no longer send these data packets to the RLC layer, which can help reduce the transmission of unnecessary data packets, avoid the waste of data transmission resources, and improve system capacity.

[0119] In some embodiments, step S220 above can be specifically implemented as follows:

[0120] Based on the first information, the PDCP entity at the sending end discards the second data packet that has a synchronization requirement or dependency requirement with the first data packet.

[0121] For example, the PDCP entity may, based on the first information, discard a second data packet that has a synchronization requirement or dependency requirement with the data packet associated with the first data packet in the PDCP entity, or discard a second data packet that has a synchronization transmission requirement or dependency transmission requirement in the data packet set to which the data packet associated with the first data packet in the PDCP entity belongs.

[0122] For example, while discarding at least one other data packet in the PDU set to which the first data packet belongs in the PDCP layer, the PDCP layer may also discard other data packets or PDU sets that have synchronous transmission requirements or depend on transmission requirements with the data packet associated with the first data packet in the PDCP layer. This application embodiment does not limit this. Synchronous transmission requirements may refer to requirements for simultaneous transmission to the receiving end within a certain time difference, and dependent transmission requirements may refer to requirements for the reception of one data packet or PDU set to depend on the reception of another data packet or PDU set.

[0123] Therefore, when a data packet or PDU set is discarded by the PDCP entity, data packets or PDU sets that have synchronous transmission requirements with that data packet or PDU set will inevitably fail to meet the synchronous transmission requirements, or data packets or PDU sets that have dependent transmission requirements with that data packet or PDU set will inevitably fail to meet the dependent transmission requirements. Therefore, the PDCP layer discards these data packets or PDU sets that have synchronous transmission requirements or dependent transmission requirements at the same time, which can help reduce the transmission of unnecessary data packets, avoid the waste of data transmission resources, and improve system capacity.

[0124] In some embodiments, when an RLC entity sends first information to a MAC, at least one second data packet includes, but is not limited to, at least one of the following:

[0125] At least one of RLC PDU, Media Access Control Service Data Unit (MAC SDU), and MAC Sub PDU.

[0126] Specifically, the RLC layer sends RLC SDUs to the MAC layer to become RLC PDUs; these packets are referred to as MAC SDUs from the MAC perspective. Optionally, the MAC layer encapsulates MAC SDUs into MAC PDUs and delivers them to the lower layer of the MAC layer, such as the physical layer. Optionally, the MAC layer processes multiple MAC SDUs separately, turning them into multiple MAC sub-PDUs, and then concatenates these multiple MAC sub-PDUs together into a single MAC PDU. Therefore, the MAC layer can, based on the indication information from the RLC layer, discard at least one packet corresponding to at least one of the RLC PDU, MAC SDU, and MAC sub-PDUs in the MAC layer.

[0127] Wherein, at least one second data packet is associated with at least one first data packet, which may mean that at least one second data packet includes at least one data packet associated with the first data packet at the MAC layer. Here, the associated data packet may refer to the data packet in the MAC layer corresponding to the first data packet, such as the RLC PDU, MAC SDU, or MAC sub-PDU in the MAC layer after the first data packet is submitted to the MAC layer. This application embodiment does not limit this.

[0128] In some embodiments, step S220 above can be specifically implemented as follows:

[0129] Based on the first information, the MAC entity at the sending end discards at least one data packet that has not been multiplexed by SDU corresponding to the first data packet.

[0130] Specifically, after the RLC entity submits the RLC SDU to the MAC layer, it becomes an RLC PDU (i.e., a MAC SDU). The MAC layer, based on at least one of the current schedulable resource size and scheduling priority, multiplexes the data MAC SDU submitted by the RLC entity into a MAC PDU (this process is called SDU multiplexing), and then submits it to the physical layer for transmission. When the MAC layer obtains the first information, it can discard data packets that have not yet undergone MAC SDU multiplexing in at least one data packet associated with the first data packet according to the packet loss information indicated by the first information. This helps reduce the transmission of unnecessary data packets, avoids waste of data transmission resources, and improves system capacity.

[0131] In some embodiments, the sending end may also send second information to the receiving end, the second information being used to indicate at least one of the following:

[0132] The sending RLC entity has dropped or is about to drop at least one first data packet;

[0133] The sending end stops transmitting at least one first data packet.

[0134] Specifically, the sending end's RLC entity can send second information to the receiving end's RLC entity to indicate that the sending end's RLC entity has dropped or is about to drop at least one first data packet, or to instruct the sending end to stop retransmitting at least one first data packet. In this way, the receiving end can determine, based on the second information, which first data packet the sending end has dropped or is about to drop, or whether the sending end will stop retransmitting at least one data packet, and then perform the corresponding packet loss processing.

[0135] For example, the receiving end has already received a partial segment of a certain SN, but according to the packet loss information, it is determined that the sending end has discarded the data packet corresponding to that SN, or no longer transmits (such as the initial transmission or retransmission) the data packet corresponding to that SN. Therefore, the receiving end needs to discard the segment of that SN that has already been received, so the segment corresponding to that SN can no longer be received.

[0136] In one possible implementation, when the sending end's RLC entity determines that at least one first data packet needs to be discarded, or determines that at least one first data packet will be discarded, the sending end's RLC entity can send second information to the receiving end's RLC entity to instruct the sending end to stop the initial transmission or retransmission of the at least one first data packet. At this time, the sending end does not discard the at least one first data packet. Upon receiving the second information, the receiving end can send feedback to the sending end regarding the second information. When the sending end receives the feedback from the receiving end regarding the second information, it can confirm that the receiving end is aware that the sending end has stopped retransmitting the at least one data packet, or that the sending end will discard the at least one first data packet. Based on this, the sending end's RLC layer can implement the action of discarding the at least one first data packet.

[0137] In some embodiments, the second information may include the SN or SN range of at least one data packet.

[0138] Specifically, the SN can be used by the receiving end to reassemble received data packets to ensure data integrity and accuracy. If the receiving end does not receive a data packet from a certain SN, nor does it receive a packet loss indication related to that SN, it can request a retransmission of the data packet from the sending end according to the retransmission mechanism to ensure data reliability.

[0139] Therefore, the embodiments of this application directly include the SN or SN range of at least one first data packet that the sender has discarded or is about to discard through the second information, or indicate the SN or SN range of at least one first data packet that stops retransmission through the second information, which enables the receiver to directly determine the data packet to be discarded or the data packet to stop retransmission based on the second information, thereby improving data transmission efficiency.

[0140] Figure 3 is a schematic flowchart of a data transmission method 300 according to an embodiment of this application, the method 300 being used at a receiving end. As shown in Figure 3, the data transmission method 300 may include at least some of the following:

[0141] S310, the Radio Link Control (RLC) entity of the receiving end sends third information to the PDCP entity of the receiving end, which is used to indicate that the RLC entity of the receiving end has discarded or will discard at least one third data packet.

[0142] Therefore, in the embodiments of the present application, the RLC entity at the receiving end instructs the PDCP entity at the receiving end that the RLC entity has discarded or will discard at least one third data packet, so that the PDCP entity at the receiving end can determine that the at least one third data packet has been discarded according to this instruction.

[0143] For the receiving end described in the embodiments of the present application, reference can be made to the relevant descriptions above, which will not be elaborated here. Optionally, the embodiments of the present application may also relate to the sending end. Specifically, for the sending end, reference can be made to the relevant descriptions above, which will not be elaborated here.

[0144] It should be understood that FIG. 3 shows the steps or operations of the data transmission method 300, but these steps or operations are only examples, and the present application can also perform other operations or variations of each operation in FIG. 3.

[0145] The third information described in the embodiments of the present application can also be referred to as packet loss indication information. Exemplarily, the RLC layer at the receiving end can send the first information to the PDCP layer through the SAP, and the present application does not limit this.

[0146] In some embodiments, the at least one third data packet includes but is not limited to at least one of the following:

[0147] RLC SDU, RLC PDU, segments of RLC SDU.

[0148] In some embodiments, the third information includes the SN or SN range of at least one third data packet.

[0149] Specifically, the at least one third data packet is similar to the at least one first data packet above, and reference can be made to the relevant descriptions above; the third information is similar to the above first information, and reference can be made to the relevant descriptions above.

[0150] Optionally, in some embodiments, the method 300 may further include the following step S320:

[0151] The PDCP entity at the receiving end stops the running reordering timer according to the above third information.

[0152] Specifically, when the reordering timer is running, it means that there is a COUNT hole between RX_DELIV (that is, the COUNT of the first PDCP SDU that has not been delivered to the upper layer but is waiting to be delivered) and RX_NEXT (the COUNT value of the next PDCP SDU expected to be received), that is, RX_DELIV < RX_NEXT, and there are data packets that have not been received. At this time, the PDCP entity at the receiving end can determine that the data packet that has not been received has been discarded, and at this time, the running reordering timer can be stopped.

[0153] Optionally, when the PDCP entity at the receiving end receives the third information, if the reordering timer is not running, it indicates that the PDCP entity at the receiving end can still receive data packets normally at present. At this time, the PDCP entity at the receiving end will start the reordering timer subsequently because the third data packet indicated by the third information cannot be received normally. After starting the reordering timer, the PDCP entity can perform step S320 above, that is, stop the running reordering timer according to the third information.

[0154] Optionally, in some embodiments, method 300 may further include the following step S330:

[0155] S330, after the PDCP entity stops the reordering timer, perform the actions after the reordering timer expires.

[0156] As an example, the PDCP entity may deliver the PDCP SDUs that have been received with COUNT < RX_REORD and have completed the downlink reception processing to the upper layer in ascending order; deliver the PDCP SDUs that have been received with COUNT >= RX_REORD and have completed the downlink reception processing to the upper layer in ascending order if COUNT is consecutive; update RX_DELIV to point to the first PDCP SDU that has not been delivered to the upper layer; if there is a COUNT hole between RX_DELIV and RX_NEXT, that is, RX_DELIV < RX_NEXT, then update RX_REORD = RX_NEXT and start t-Reordering.

[0157] Therefore, in the embodiment of the present application, the RLC entity at the receiving end indicates to the PDCP entity at the receiving end that the RLC entity at the receiving end has discarded or will discard at least one third data packet, so that the PDCP layer can determine to stop the reordering timer according to this indication without waiting for the reordering timer to expire, and perform the actions after the reordering timer expires, thereby promoting the movement of the receiving window to accelerate the reception of subsequent data packets and improving the data transmission efficiency between the sending end and the receiving end.

[0158] In some embodiments, the above step S310 may be specifically implemented as at least one of the following:

[0159] When the RLC entity at the receiving end determines to discard at least one third data packet, send the above third information to the PDCP entity at the receiving end; where the determination of discarding here includes: determining that it has been discarded or determining that it will be discarded;

[0160] When the RLC entity at the receiving end receives the second information from the RLC entity at the sending end, send the above third information to the PDCP entity at the receiving end; the second information is used to indicate at least one of the following:

[0161] The sending RLC entity has dropped or is about to drop at least one first data packet;

[0162] The sending end stops transmitting at least one first data packet.

[0163] Specifically, if the receiving RLC entity determines that it will discard at least one third data packet, the sending end may have already successfully sent the at least one third data packet to the receiving end, but the at least one third data packet was discarded by the receiving RLC entity. In this case, the RLC entity can send third information to its upper layer, namely the receiving end's PDCP entity, to indicate that the receiving end's RLC entity has discarded or is about to discard at least one third data packet.

[0164] Optionally, in this embodiment, when the DRB associated with the RLC entity is configured to drop packets based on the packet set, the PDCP entity can discard other packets in the packet set to which the third packet belongs, or discard packets that have synchronization or dependency requirements with the third packet, based on the third information. This application embodiment does not limit this.

[0165] Optionally, in this embodiment, the receiving RLC entity may also send packet loss indication information to the sending RLC entity to indicate that the receiving RLC entity has discarded or is about to discard at least one third data packet. Correspondingly, after receiving the packet loss indication information, the sending RLC entity may discard at least one data packet related to the at least one third data packet, such as other data packets in the data packet set to which the at least one third data packet belongs, or other data packets with synchronization requirements or dependency requirements. This embodiment of the application does not limit this.

[0166] In the case where the receiving RLC entity receives second information from the sending RLC entity, at least one third data packet includes at least one first data packet. Since the sending end has discarded or is about to discard at least one first data packet, or has stopped the initial transmission or retransmission of at least one first data packet, the RLC entity may not receive the at least one first data packet.

[0167] For details on the second piece of information, please refer to the relevant description on the sending end; it will not be repeated here.

[0168] Optionally, the receiving end may discard or intend to discard at least one third data packet based on the second information. That is, the packet loss behavior of the receiving end's RLC entity may be based on the indication of the sending end's RLC entity. For example, the RLC entity may discard at least one third data packet belonging to the data packet set to which the first data packet belongs, or discard a third data packet that has synchronization requirements or dependency requirements with at least one first data packet, based on the second information. This application embodiment does not limit this.

[0169] In some embodiments, if a terminal experiences cell handover or primary / secondary cell change after packet loss in the source cell, the packet loss information sent by the terminal in the source cell may not be successfully received. This could result in the receiving end being unable to respond to the packet loss or affecting subsequent data reception at the receiving end's RLC layer. Therefore, ensuring that network-side devices can correctly receive packet loss information when a terminal undergoes handover remains a problem to be solved.

[0170] Based on the above-mentioned technical problems, this application provides a data transmission scheme. When a cell handover or a change of primary or secondary cell occurs, the terminal sends packet loss information in the target cell or target cell group, which helps to ensure that the network-side equipment can correctly receive the packet loss information and is conducive to ensuring the normal transmission of service data.

[0171] Figure 4 is a schematic flowchart of a data transmission method 400 according to an embodiment of this application, which is used in a terminal. As shown in Figure 4, the data transmission method 400 may include at least some of the following:

[0172] S410, in the event of cell handover or change of primary / secondary cell, if packet loss occurs in the terminal, the terminal sends fourth information to the second network-side device to which the target cell or target cell group belongs after the handover or change, the fourth information indicating at least one of the following:

[0173] The terminal's RLC entity has dropped or is about to drop at least one fourth data packet;

[0174] The terminal stops transmitting at least one fourth data packet.

[0175] Therefore, in this embodiment of the application, when a cell handover or change of primary or secondary cell occurs, the terminal can send packet loss information in the target cell or target cell group, which helps to ensure that the network-side equipment can correctly receive the packet loss information and is conducive to ensuring the normal transmission of service data.

[0176] Optionally, in some embodiments, before step S410, method 400 may further include the following step S420:

[0177] S420, the terminal sends fifth information to the first network-side device to which the source cell before the handover or change belongs, the fifth information indicating at least one of the following:

[0178] The terminal's RLC entity has dropped or is about to drop at least one fifth data packet; wherein at least one fourth data packet includes at least one fifth data packet;

[0179] The terminal stops transmitting at least one fifth data packet.

[0180] Therefore, in this embodiment of the application, after the terminal sends packet loss information in the source cell, a cell handover or change of primary and secondary cells occurs, the terminal can resend the packet loss information in the target cell or target cell group. This helps to ensure that the network-side equipment can correctly receive the packet loss information even if the source cell does not receive the packet loss information correctly, which is beneficial to ensuring the normal transmission of service data.

[0181] It is understood that the terminal in this application embodiment can be the sending end or the receiving end as described in the above embodiments, and this application embodiment does not limit this. For example, when the terminal is the sending end, the first network-side device or the second network-side device can be the receiving end. Optionally, the terminal may include the terminal's RLC entity, the first network-side device may include the RLC entity of the first network-side device, and the second network-side device may include the RLC entity of the second network-side device, and this application embodiment does not limit this.

[0182] The first network-side device is the network-side device to which the source cell belongs, and can also be called the source network-side device. This application embodiment does not limit this. The second network-side device is the network-side device to which the target cell or target cell group belongs, and can also be called the target network-side device. This application embodiment does not limit this.

[0183] The first network-side device and the second network-side device can be the same communication device or different communication devices; this application does not limit this. As an example, when the RLC entity is not rebuilt, it means that the position of the RLC entity remains unchanged. At this time, the source cell and the target cell are on the same communication device, that is, the first network-side device and the second network-side device are the same communication device.

[0184] The embodiments of this application can be applied to Acknowledged Mode (AM).

[0185] The fourth information described in this application embodiment can also be referred to as packet loss indication information. For example, the RLC entity of the terminal can send the fourth information to the RLC entity of the second network-side device, and this application does not limit this.

[0186] In some embodiments, the at least one fourth data packet includes, but is not limited to, at least some of the following:

[0187] RLC SDU, RLC PDU, RLC SDU segmentation.

[0188] In some embodiments, the fourth information includes at least one sequence number (SN) or SN range of a fourth data packet.

[0189] Specifically, the at least one fourth data packet is similar to the at least one first data packet mentioned above, and can be referred to the relevant description above; the fourth information is similar to the second information mentioned above, and can be referred to the relevant description above.

[0190] Therefore, after a handover, the terminal can send fourth information to the second network-side device to which the target cell or target cell group belongs, thereby indicating that the terminal's RLC entity has dropped or is about to drop at least one fourth data packet, or instructing the terminal to stop the initial transmission or retransmission of at least one fourth data packet.

[0191] The fifth information described in this application embodiment can also be referred to as packet loss indication information. For example, the RLC entity of the terminal can send the fifth information to the RLC entity of the first network-side device, and this application does not limit this.

[0192] In some embodiments, the at least one fifth data packet includes, but is not limited to, at least some of the following:

[0193] RLC SDU, RLC PDU, RLC SDU segmentation.

[0194] In some embodiments, the fifth information includes at least one sequence number (SN) or SN range of a fifth data packet.

[0195] Specifically, the at least one fifth data packet is similar to the at least one first data packet mentioned above, and can be referred to the relevant description above; the fifth information is similar to the second information mentioned above, and can be referred to the relevant description above.

[0196] Therefore, before handover, the terminal can send the fifth information to the first network-side device to which the source cell belongs, thereby instructing the terminal's RLC entity that it has dropped or is about to drop at least one fifth data packet, or instructing the terminal to stop retransmitting at least one fifth data packet.

[0197] It is understood that in the embodiments of this application, at least one fourth data packet includes at least one fifth data packet as described above, including the following two cases.

[0198] In one possible scenario, the at least one fourth data packet indicated in step S410 is the same as the at least one fifth data packet indicated in step S420. In this case, the packet loss information indicated to the network-side device before and after the terminal handover is the same.

[0199] In another possible scenario, the at least one fifth data packet indicated in step S420 is a subset of the at least one fourth data packet indicated in step S410. In this case, the terminal not only indicates to the network-side device before the handover the data packets to be discarded or to be discarded, or the data packets to be stopped from initial transmission or retransmission, but also indicates to the network-side device after the handover the data packets to be discarded or to be discarded, or the data packets to be stopped from transmission or retransmission.

[0200] In some embodiments, the terminal performs cell handover or primary / secondary cell change, including at least one of the following:

[0201] Layer 3 (L3) handover or Primary Secondary Cell (PSCell) change is performed based on the RRC reconfiguration message sent by the network-side equipment. The RRC reconfiguration message includes synchronization reconfiguration information (reconfigurationWithSync).

[0202] Perform a Conditional handover (CHO) or a Conditional Primary / Secondary Cell Change (CPC);

[0203] Executes L1 / L2 Triggered Mobility.

[0204] The RRC reconfiguration message is sent by the first network-side device. When the first network-side device sends the RRC reconfiguration message to the terminal, the terminal performs an L3 handover or a PSCell change based on the RRC reconfiguration message.

[0205] CHO includes CHOs that meet network configuration conditions, or handover conditions that are met by the terminal; CPC includes CPCs that meet network configuration conditions, or handover conditions that are met by the terminal, etc. For example, handover conditions can be configured based on the signal strength and interference levels of the terminal's current cell and neighboring cells, or primary and secondary cell change conditions can be configured based on the signal strength and interference levels of the primary and secondary cells. This application embodiment does not limit this.

[0206] In some embodiments, step S410 above may include at least one of the following:

[0207] If the terminal does not perform RLC reconstruction during cell handover or primary / secondary cell change, the terminal sends the fourth information to the second network-side device.

[0208] If the terminal sends the fifth information at least once before receiving the cell handover command or the primary / secondary cell change command or before performing the cell handover or the primary / secondary cell change, the terminal sends the fourth information to the second network-side device.

[0209] As an example, the time unit may include at least one of seconds, milliseconds, frames, subframes, and time slots.

[0210] If the terminal does not receive feedback from the first network-side device regarding the fifth information before cell handover or primary / secondary cell change, the terminal sends the fourth information to the second network-side device.

[0211] Specifically, if the terminal performs RLC reconstruction during cell handover or primary / secondary cell change, the RLC layer buffer is completely cleared, making it meaningless to indicate packet loss information to the network side. Therefore, this embodiment allows the terminal to send fourth information to the second network-side device even if RLC reconstruction is not performed during cell handover or primary / secondary cell change. This helps ensure that the network-side device correctly receives the packet loss information, thereby resolving the problem of packet loss information sent in the source cell not being successfully received.

[0212] If the terminal sends the fifth message to the first network-side device of the source cell within X time units before receiving the handover command, receiving the primary / secondary cell change command, or performing a cell handover or primary / secondary cell change, the first network-side device may fail to receive the fifth message due to the handover or primary / secondary cell change. Therefore, after the handover or primary / secondary cell change, the terminal resends the fourth message to the second network-side device of the target cell or target cell group to indicate packet loss information. This helps ensure that the network-side device correctly receives the packet loss information, thereby resolving the problem of packet loss information sent in the source cell not being successfully received.

[0213] Optionally, X can be determined based on the time unit required for the terminal to perform cell handover or primary / secondary cell handover, where X can be a positive number.

[0214] Optionally, if the terminal sends the fifth message to the first network-side device X time units before receiving the handover command, receiving the primary / secondary cell change command, or performing a cell handover or primary / secondary cell change, then the first network-side device is considered to have successfully received the fifth message. In this case, the terminal may not send the fourth message to the second network-side device.

[0215] If the terminal does not receive feedback on the fifth information from the network-side device (such as the first or second network-side device) before cell handover or primary / secondary cell change, it indicates that the network-side device has not successfully received the fifth information. Therefore, after cell handover or primary / secondary cell change, the terminal can send the fourth information to the second network-side device, which helps ensure that the network-side device correctly receives the packet loss information, thereby resolving the problem of packet loss information sent in the source cell not being successfully received.

[0216] It should be noted that the embodiments of this application also apply to PDCP packet loss. For example, if a handover occurs after the terminal sends PDCP packet loss information to the first network-side device of the source cell, the terminal will retransmit the PDCP packet loss information in the target cell or target cell group. Here, PDCP packet loss information refers to at least one data packet that the terminal's PDCP entity has dropped or is about to drop. Specifically, the process of the terminal sending PDCP packet loss information to the first network-side device and retransmitting PDCP packet loss information to the second network-side device is similar to sending RLC packet loss information, and can be referred to the relevant description above.

[0217] Optionally, if the terminal does not perform PDCP reconstruction during cell handover or primary / secondary cell change, the terminal will retransmit the PDCP packet loss information to the second network-side device. Specifically, if the terminal performs PDCP reconstruction during cell handover or primary / secondary cell change, the PDCP layer buffer is completely cleared, and indicating packet loss information to the network side at this time is meaningless.

[0218] It should be noted that the various embodiments provided in this application can be implemented individually or in various combinations, and the embodiments of this application do not limit this.

[0219] The data transmission method provided in this application can be executed by a communication device. This application uses a communication device executing the data transmission method as an example to illustrate the communication device provided in this application.

[0220] This application provides a wireless communication device. As an example, the communication device may be a communication equipment or a component within a communication equipment, such as a chip. The communication equipment may be a terminal, a network-side device, or a server, etc. Exemplarily, the terminal may include, but is not limited to, the type of terminal 11 listed above, and the network-side device may include, but is not limited to, the type of network-side device 12 listed above. This application does not impose specific limitations.

[0221] The communication device includes a receiving module, a transmitting module, and a processing module. These modules can be implemented in software or hardware. When implemented in hardware, the processing module can be implemented by a processor. For example, the processor can include general-purpose processors, special-purpose processors, such as a Central Processing Unit (CPU), microprocessor, Digital Signal Processor (DSP), Artificial Intelligence (AI) processor, Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), Network Processor (NP), Field Programmable Gate Array (FPGA), or other programmable logic devices, gate circuits, transistors, discrete hardware components, etc. The receiving and transmitting modules can be implemented by a communication interface, which can include one or more of the following: transceiver, pins, circuits, bus, radio frequency unit, etc.

[0222] Specifically, when the communication device is a transmitter or a component within a transmitter, wherein the transmitter is a terminal or a network-side device, as shown in Figure 5, the communication device 500 includes:

[0223] Processing module 501 is used for the Packet Data Convergence Protocol (PDCP) entity or Media Access Control (MAC) entity at the transmitting end to receive first information from the Radio Link Control (RLC) entity at the transmitting end, the first information being used to indicate that the RLC entity has discarded or is about to discard at least one first data packet.

[0224] The processing module 501 is further configured to have the PDCP entity or MAC entity at the sending end discard at least one second data packet associated with the at least one first data packet based on the first information.

[0225] Optionally, in some embodiments, the processing module 501 is specifically used for:

[0226] When the Data Radio Bearer (DRB) associated with the RLC entity is configured for packet loss based on a set of packets, the PDCP entity discards the second data packet in the set to which the first data packet belongs, based on the first information.

[0227] Optionally, in some embodiments, the processing module 501 is further configured to:

[0228] If the DRB associated with the RLC entity at the sending end is configured for packet loss based on a set of packets, and if the RLC entity has already dropped or is about to drop at least one first packet, the RLC entity drops the second packet in the set of packets to which the first packet belongs.

[0229] Optionally, in some embodiments, the processing module 501 is further configured to:

[0230] The sending end's RLC entity discards or is about to discard the at least one first data packet based on at least one of the following: the remaining time information of the data packet, its importance, and its dependency on other data packets.

[0231] Optionally, in some embodiments, the processing module 501 is specifically used for:

[0232] The PDCP entity discards a second data packet that has a synchronization requirement or dependency requirement with the first data packet, based on the first information.

[0233] Optionally, in some embodiments, the processing module 501 is specifically used for:

[0234] The MAC entity discards data packets that have not been multiplexed with SDU, corresponding to the at least one first data packet, based on the first information.

[0235] Optionally, in some embodiments, the communication device 500 further includes:

[0236] The sending module 502 is used to send second information from the sending end to the receiving end, the second information indicating at least one of the following:

[0237] The RLC entity of the sending end has discarded or is about to discard the at least one first data packet;

[0238] The sending end stops transmitting the at least one first data packet.

[0239] Optionally, in some embodiments, the first information includes the sequence number (SN) or SN range of the at least one first data packet.

[0240] In some embodiments, the processing module 501 described above may be embedded in or independent of the processor at the transmitting end in hardware form. The transmitting module 502 described above may be a communication interface or transceiver, or an input / output interface of a communication chip or system-on-a-chip.

[0241] It should be understood that the communication device 500 according to the embodiments of this application can correspond to the sending end in the method embodiments of this application, and each unit in the communication device 500 is for implementing the corresponding process of the method 200 shown in FIG2. For the sake of brevity, it will not be described in detail here.

[0242] Therefore, in this embodiment of the application, the PDCP or MAC entity of the sending end obtains first information from the RCL entity of the sending end, and instructs the PDCP or MAC layer of the sending end to discard or discard at least one first data packet. This allows the PDCP or MAC layer to discard at least one second data packet associated with the at least one first data packet according to the instruction. This helps to avoid the PDCP or MAC layer from processing or transmitting data packets that have been discarded or are about to be discarded, thereby reducing the waste of data transmission resources and improving the data transmission efficiency between the sending end and the receiving end.

[0243] When the communication device is a receiving end or a component within a receiving end, wherein the receiving end is a terminal or network-side device, as shown in Figure 6, the communication device 600 includes:

[0244] The processing module 601 is used for the Radio Link Control (RLC) entity of the receiving end to send third information to the PDCP entity of the receiving end, the third information being used to indicate that the RLC entity of the receiving end has discarded or is about to discard at least one third data packet.

[0245] Optionally, in some embodiments, the processing module 601 is further configured to:

[0246] The PDCP entity stops the running reordering timer based on the third information.

[0247] Optionally, in some embodiments, the processing module 601 is further configured to:

[0248] After stopping the reordering timer, the PDCP entity performs the behavior after the reordering timer times out.

[0249] Optionally, in some embodiments, the processing module 601 is specifically used for at least one of the following:

[0250] If the RLC entity of the receiving end determines that at least one third data packet will be discarded, the receiving end's PDCP entity will send the third information.

[0251] Upon receiving the second information from the RLC entity of the transmitting end, the processing module 601 sends the third information to the PDCP entity of the receiving end; wherein the second information is used to indicate at least one of the following:

[0252] The RLC entity of the sending end has discarded or is about to discard at least one first data packet;

[0253] The sending end stops transmitting at least one first data packet.

[0254] Optionally, in some embodiments, the third information includes the SN or SN range of the at least one third data packet.

[0255] In some embodiments, the processing module 601 described above may be embedded in or independent of the processor at the receiving end in hardware form. The receiving module 602 described above may be a communication interface or transceiver, or an input / output interface of a communication chip or system-on-a-chip.

[0256] It should be understood that the communication device 600 according to the embodiments of this application can correspond to the receiving end in the method embodiments of this application, and each unit in the communication device 600 is for implementing the corresponding process of the method 300 shown in FIG3. For the sake of brevity, it will not be described in detail here.

[0257] Therefore, in this embodiment of the application, the RLC entity of the receiving end indicates to the PDCP entity of the receiving end that the RLC entity has discarded or is about to discard at least one third data packet, so that the PDCP entity of the receiving end can determine that the at least one third data packet has been discarded based on the indication.

[0258] Furthermore, in this embodiment, the RLC entity at the receiving end indicates to the PDCP entity at the receiving end that the RLC entity at the receiving end has discarded or is about to discard at least one third data packet. This allows the PDCP layer to determine to stop the reordering timer based on the indication without waiting for the reordering timer to expire, and to execute the behavior after the reordering timer expires. This drives the movement of the receiving window to speed up the reception of subsequent data packets and improves the data transmission efficiency between the sending and receiving ends. When the communication device is a component in a terminal, referring to FIG7, the communication device 700 includes:

[0259] The sending module 701 is configured to send fourth information to the second network-side device to which the target cell or target cell group belongs after the handover or change occurs, in the event of a cell handover or primary / secondary cell change. The fourth information is used to indicate at least one of the following:

[0260] The terminal's RLC entity has dropped or is about to drop at least one fourth data packet;

[0261] The terminal stops transmitting the at least one fourth data packet.

[0262] Optionally, in some embodiments, the sending module 701 is further configured to:

[0263] Send a fifth message to the first network-side device to which the source cell before the handover or change belongs, the fifth message indicating at least one of the following:

[0264] The terminal's RLC entity has discarded or is about to discard at least one fifth data packet; wherein the at least one fourth data packet includes the at least one fifth data packet;

[0265] The terminal stops retransmitting the at least one fifth data packet.

[0266] Optionally, in some embodiments, the sending module 701 is specifically used for at least one of the following:

[0267] If the terminal does not perform RLC reconstruction during cell handover or primary / secondary cell change, the terminal sends the fourth information to the second network-side device.

[0268] If the terminal sends the fifth information within at least one time unit before receiving a cell handover command or a primary / secondary cell change command or before performing a cell handover or a primary / secondary cell change, then the terminal sends the fourth information to the second network-side device.

[0269] If the terminal does not receive feedback on the fifth information before cell handover or primary / secondary cell change, the terminal sends the fourth information to the second network-side device.

[0270] Optionally, in some embodiments, the fourth information includes the SN or SN range of the at least one fourth data packet, and the fifth information includes the SN or SN range of the at least one fifth data packet.

[0271] Optionally, in some embodiments, the communication device 700 further includes a processing unit 702 for performing cell handover or primary / secondary cell change.

[0272] In some embodiments, the receiving module 701 may be a communication interface or transceiver, or an input / output interface of a communication chip or system-on-a-chip. The processing module 702 may be embedded in or independent of the processor at the receiving end in hardware form.

[0273] It should be understood that the communication device 700 according to the embodiments of this application can correspond to the terminal in the method embodiments of this application, and each unit in the communication device 700 is for implementing the corresponding process of the method 400 shown in FIG4. For the sake of brevity, it will not be described in detail here.

[0274] Therefore, in this embodiment of the application, when a cell handover or change of primary or secondary cell occurs, the terminal can send packet loss information in the target cell or target cell group, which helps to ensure that the network-side equipment can correctly receive the packet loss information and is conducive to ensuring the normal transmission of service data.

[0275] Furthermore, if a cell handover or change of primary / secondary cell occurs after the terminal sends packet loss information in the source cell, the terminal can resend the packet loss information in the target cell or target cell group. This helps ensure that the network-side equipment can correctly receive the packet loss information even if the source cell does not receive it correctly, which is beneficial for ensuring the normal transmission of service data.

[0276] The communication device provided in this application embodiment can implement the various processes implemented in the method embodiments of Figures 2 to 4 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0277] As shown in Figure 8, this application embodiment also provides a communication device 800, including a processor 801 and a memory 802, wherein the memory 802 stores a program or instructions that can be run on the processor 801.

[0278] For example, when the communication device 800 is the sending end, the program or instruction executed by the processor 801 implements the various steps executed by the sending end in the above data transmission method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0279] For example, when the communication device 800 is the receiving end, the program or instruction executed by the processor 801 implements the various steps executed by the receiving end in the above data transmission method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0280] For example, when the communication device 800 is a terminal, the program or instruction executed by the processor 801 implements the various steps executed by the terminal in the above data transmission method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0281] This application also provides a terminal, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the terminal in the method embodiments shown in Figures 2-4. The terminal embodiment corresponds to the above-described method embodiments on the sending or receiving side; all implementation processes and methods of the above method embodiments can be applied to this terminal embodiment and achieve the same technical effect. The terminal may be the wireless communication device 500 shown in Figure 5, or the terminal may be the wireless communication device 600 shown in Figure 6, or the terminal may be the wireless communication device 700 shown in Figure 7. Specifically, Figure 9 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of this application.

[0282] The terminal 900 includes, but is not limited to, at least some of the following components: radio frequency unit 901, network module 902, audio output unit 903, input unit 904, sensor 905, display unit 906, user input unit 907, interface unit 908, memory 909, and processor 910.

[0283] Those skilled in the art will understand that the terminal 900 may also include a power supply (such as a battery) for powering various components. The power supply can be logically connected to the processor 910 through a power management system, thereby enabling functions such as charging, discharging, and power consumption management through the power management system. The terminal structure shown in Figure 9 does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0284] It should be understood that, in this embodiment, the input unit 904 may include a graphics processor 9041 and a microphone 9042. The graphics processor 9041 processes image data of still images or videos obtained by an image capture device (such as a camera) in video capture mode or image capture mode. The display unit 906 may include a display panel 9061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like. The user input unit 907 includes at least one of a touch panel 9071 and other input devices 9072. The touch panel 9071 is also called a touch screen. The touch panel 9071 may include a touch detection device and a touch controller. Other input devices 9072 may include, but are not limited to, physical keyboards, function keys (such as volume control buttons, power buttons, etc.), trackballs, mice, and joysticks, which will not be described in detail here.

[0285] In this embodiment, after receiving downlink data from the network-side device, the radio frequency unit 901 can transmit it to the processor 910 for processing; in addition, the radio frequency unit 901 can send uplink data to the network-side device. Typically, the radio frequency unit 901 includes, but is not limited to, antennas, amplifiers, transceivers, couplers, low-noise amplifiers, duplexers, etc.

[0286] The memory 909 can be used to store software programs or instructions, as well as various data. The memory 909 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, the memory 909 may include volatile memory or non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory 909 in the embodiments of this application includes, but is not limited to, these and any other suitable types of memory.

[0287] Processor 910 may include one or more processing units; optionally, processor 910 integrates an application processor and a modem processor, wherein the application processor mainly handles operations involving the operating system, user interface, and applications, and the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into processor 910.

[0288] In some embodiments, the terminal 900 is a transmitting end;

[0289] The processor 910 is used for the Packet Data Convergence Protocol (PDCP) entity or Media Access Control (MAC) entity at the transmitting end to receive first information from the Radio Link Control (RLC) entity at the transmitting end. The first information is used to indicate that the RLC entity has dropped or is about to drop at least one first data packet.

[0290] The PDCP entity or MAC entity of the sending end discards at least one second data packet associated with the at least one first data packet based on the first information.

[0291] Therefore, in this embodiment of the application, the PDCP or MAC entity of the sending end obtains first information from the RCL entity of the sending end, and instructs the PDCP or MAC layer of the sending end to discard or discard at least one first data packet. This allows the PDCP or MAC layer to discard at least one second data packet associated with the at least one first data packet according to the instruction. This helps to avoid the PDCP or MAC layer from processing or transmitting data packets that have been discarded or are about to be discarded, thereby reducing the waste of data transmission resources and improving the data transmission efficiency between the sending end and the receiving end.

[0292] In some embodiments, the terminal 900 is a receiving end;

[0293] The processor 910 is used for the Radio Link Control (RLC) entity at the receiving end to send third information to the PDCP entity at the receiving end, the third information being used to indicate that the RLC entity at the receiving end has discarded or is about to discard at least one third data packet.

[0294] Optionally, the processor 910 is further configured to: stop the running reordering timer based on the aforementioned third information, by the PDCP entity at the receiving end.

[0295] Optionally, the processor 910 can also be used to: execute the behavior after the reorder timer times out after the PDCP entity stops the reorder timer.

[0296] Therefore, in this embodiment of the application, the RLC entity of the receiving end indicates to the PDCP entity of the receiving end that the RLC entity has discarded or is about to discard at least one third data packet, so that the PDCP entity of the receiving end can determine that the at least one third data packet has been discarded based on the indication.

[0297] Furthermore, in this embodiment of the application, the RLC entity of the receiving end indicates to the PDCP entity of the receiving end that the RLC entity of the receiving end has discarded or is about to discard at least one third data packet. This enables the PDCP layer to determine to stop the reordering timer based on the indication without waiting for the reordering timer to expire, and to execute the behavior after the reordering timer expires. This promotes the movement of the receiving window to speed up the reception of subsequent data packets and improves the data transmission efficiency between the sending end and the receiving end.

[0298] In some embodiments, the terminal 900 is a terminal;

[0299] The radio frequency unit 901 is used to send fourth information to the second network-side device to which the target cell or target cell group belongs after the handover or change if packet loss occurs in the event of cell handover or primary / secondary cell change. The fourth information is used to indicate at least one of the following:

[0300] The terminal's RLC entity has dropped or is about to drop at least one fourth data packet;

[0301] The terminal stops transmitting at least one fourth data packet.

[0302] Therefore, in this embodiment of the application, when a cell handover or change of primary or secondary cell occurs, the terminal can send packet loss information in the target cell or target cell group, which helps to ensure that the network-side equipment can correctly receive the packet loss information and is conducive to ensuring the normal transmission of service data.

[0303] Optionally, in some embodiments, the radio frequency unit 901 is further used for:

[0304] The terminal sends a fifth message to the first network-side device to which the source cell before the handover or change belongs, the fifth message indicating at least one of the following:

[0305] The terminal's RLC entity has dropped or is about to drop at least one fifth data packet; wherein at least one fourth data packet includes at least one fifth data packet;

[0306] The terminal stops transmitting at least one fifth data packet.

[0307] Therefore, in this embodiment of the application, after the terminal sends packet loss information in the source cell, a cell handover or change of primary and secondary cells occurs, the terminal can resend the packet loss information in the target cell or target cell group. This helps to ensure that the network-side equipment can correctly receive the packet loss information even if the source cell does not receive the packet loss information correctly, which is beneficial to ensuring the normal transmission of service data.

[0308] It is understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of data transmission methods 200 to 400 in the method embodiment, and achieve the same or corresponding technical effects. To avoid repetition, it will not be described again here.

[0309] This application also provides a network-side device, including a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method embodiment shown in FIG2, or to implement the steps of the method embodiment shown in FIG3. This network-side device embodiment corresponds to the above-described sending or receiving end-side method embodiments. All implementation processes and methods of the above-described method embodiments can be applied to this network-side device embodiment and can achieve the same technical effect.

[0310] Specifically, this application embodiment also provides a network-side device, which may be the wireless communication device 500 shown in FIG. 5, or the wireless communication device 500 shown in FIG. 6. As shown in FIG. 10, the network-side device 1000 includes: an antenna 101, a radio frequency device 102, a baseband device 103, a processor 104, and a memory 105. The antenna 101 is connected to the radio frequency device 102. In the uplink direction, the radio frequency device 102 receives information through the antenna 101 and sends the received information to the baseband device 103 for processing. In the downlink direction, the baseband device 103 processes the information to be transmitted and sends it to the radio frequency device 102. The radio frequency device 102 processes the received information and transmits it through the antenna 101.

[0311] The methods executed at the transmitting or receiving end in the above embodiments can be implemented in the baseband device 103, which includes a baseband processor.

[0312] The baseband device 103 may include at least one baseband board, on which multiple chips are disposed, as shown in FIG10. One of the chips is, for example, a baseband processor, which is connected to the memory 105 via a bus interface to call the program in the memory 105 to execute the operations performed by the transmitting end or the receiving end as shown in the above method embodiments.

[0313] The network-side device may also include a network interface 106, such as a Common Public Radio Interface (CPRI).

[0314] Specifically, the network-side device 1000 in this application embodiment further includes: instructions or programs stored in memory 105 and executable on processor 104. Processor 104 calls the instructions or programs in memory 75 to execute the methods executed by the modules shown in FIG2 to FIG4 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0315] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described data transmission method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0316] The processor mentioned above is the processor in the terminal or network-side device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0317] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above data transmission method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0318] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0319] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described data transmission method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0320] This application also provides a communication system, including: a receiving end and a transmitting end, wherein the receiving end can be used to perform the steps performed by the receiving end in the data transmission method described above, and the transmitting end can be used to perform the steps performed by the transmitting end in the data transmission method described above.

[0321] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0322] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0323] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A method of data transmission, wherein, Comprising: a packet data convergence protocol (PDCP) entity or a medium access control (MAC) entity of a transmitting end receives first information from a radio link control (RLC) entity of the transmitting end, the first information indicating that the RLC entity has discarded or is about to discard at least one first data packet; the PDCP entity or the MAC entity of the transmitting end discards at least one second data packet related to the at least one first data packet according to the first information.

2. The method of claim 1, wherein, The PDCP entity discarding the at least one second data packet related to the at least one first data packet according to the first information comprises: in a case where a data radio bearer (DRB) associated with the RLC entity is configured to discard packets based on a packet set, the PDCP entity discarding a second packet in a packet set to which the first data packet belongs according to the first information.

3. The method of claim 1 or 2, wherein, Further comprising: in a case where a DRB associated with the RLC entity of the transmitting end is configured to discard packets based on a packet set, if the RLC entity has discarded or is about to discard at least one first data packet, the RLC entity discarding a second packet in a packet set to which the first data packet belongs.

4. The method of claim 3, wherein, Further comprising: the RLC entity of the transmitting end discarding or about to discard the at least one first data packet based on at least one of a remaining time information of a packet, importance of the packet, and dependency of the packet on other packets.

5. The method according to any one of claims 1 to 4, wherein, The PDCP entity or the MAC entity discarding the at least one second data packet related to the at least one first data packet according to the first information comprises: the PDCP entity discarding a second data packet having a synchronization requirement or a dependency requirement with the first data packet according to the first information.

6. The method according to any one of claims 2-5, wherein, The at least one first data packet comprises at least one of a radio link control service data unit (RLC SDU), an RLC SDU segment, and a radio link control protocol data unit (RLC PDU), and the at least one second data packet comprises at least one of a PDCP SDU and a PDCP PDU.

7. The method of claim 1, wherein, The PDCP entity or the MAC entity discarding the at least one second data packet related to the at least one first data packet according to the first information comprises: the MAC entity discarding a data packet corresponding to the at least one first data packet without SDU multiplexing according to the first information.

8. The method of claim 7, wherein, The at least one second data packet comprises at least one of an RLC PDU, a MAC SDU, and a MAC sub-PDU.

9. The method of any one of claims 1-8, wherein, Further comprising: the transmitting end sending second information to a receiving end, the second information indicating at least one of: the RLC entity of the transmitting end having discarded or about to discard the at least one first data packet; the transmitting end stopping transmission of the at least one first data packet.

10. The method of any one of claims 1-9, wherein, The first information comprises a sequence number (SN) or an SN range of the at least one first data packet.

11. A data transmission method, wherein, Comprising: a radio link control (RLC) entity of a receiving end sending third information to a PDCP entity of the receiving end, the third information indicating that the RLC entity of the receiving end has discarded or is about to discard at least one third data packet.

12. The method of claim 11, wherein, Further comprising: The PDCP entity stops a running reordering timer according to the third information.

13. The method of claim 12, wherein, Further comprising: The PDCP entity performs an action after the reordering timer expires after being stopped.

14. The method of any one of claims 11-13, wherein, The radio link control (RLC) entity of the receiving end sends third information to the PDCP entity of the receiving end, the third information comprising at least one of: The RLC entity of the receiving end sends the third information to the PDCP entity of the receiving end in a case where it is determined to discard at least one third data packet; The RLC entity of the receiving end sends the third information to the PDCP entity of the receiving end in a case where it receives second information from the RLC entity of the sending end, the second information indicating at least one of: The RLC entity of the sending end has discarded or is about to discard at least one first data packet; The sending end stops transmitting the at least one first data packet.

15. The method of any one of claims 11-14, wherein, The third information comprises a sequence number (SN) or a range of SNs of the at least one third data packet.

16. A data transmission method, wherein, Further comprising: In a case where a cell handover or a primary-secondary cell change occurs, if the terminal has experienced packet loss, the terminal sends fourth information to a second network-side device to which a target cell or a target cell group after the handover or the change belongs, the fourth information indicating at least one of: The RLC entity of the terminal has discarded or is about to discard at least one fourth data packet; The terminal stops transmitting the at least one fourth data packet.

17. The method of claim 16, wherein, Further comprising: The terminal sends fifth information to a first network-side device to which a source cell before the handover or the change belongs, the fifth information indicating at least one of: The RLC entity of the terminal has discarded or is about to discard at least one fifth data packet; and the at least one fourth data packet comprises the at least one fifth data packet; The terminal stops retransmitting the at least one fifth data packet.

18. The method of claim 17, wherein, The terminal sends the fourth information to the second network-side device in at least one of the following cases: If the terminal does not perform RLC re-establishment during the cell handover or the primary-secondary cell change, the terminal sends the fourth information to the second network-side device; If the terminal sends the fifth information within at least one time unit before receiving a cell handover command or a primary-secondary cell change command or performing the cell handover or the primary-secondary cell change, the terminal sends the fourth information to the second network-side device; If the terminal does not receive feedback for the fifth information before the cell handover or the primary-secondary cell change, the terminal sends the fourth information to the second network-side device.

19. The method of claim 18, wherein, The time unit comprises at least one of seconds, milliseconds, frames, subframes, and slots.

20. The method of any one of claims 16-19, wherein, The fourth information comprises a sequence number (SN) or a range of SNs of the at least one fourth data packet.

21. A communications device, wherein, Further comprising: A processing module configured to receive, by a packet data convergence protocol (PDCP) entity or a medium access control (MAC) entity of a sending end, first information from a radio link control (RLC) entity of the sending end, the first information indicating that the RLC entity has discarded or is about to discard at least one first data packet; The processing module is further configured to cause the PDCP entity or the MAC entity of the sending end to discard at least one second data packet related to the at least one first data packet according to the first information.

22. The apparatus of claim 21, wherein, The processing module is specifically configured to: In a case where a data radio bearer (DRB) associated with the RLC entity of the sending end is configured to discard data packets on a packet basis, the PDCP entity discards a second data packet in a packet set to which the first data packet belongs according to the first information.

23. The apparatus of claim 21 or 22, wherein, The processing module is further configured to: In a case where a DRB associated with the RLC entity of the sending end is configured to discard data packets on a packet basis, if the RLC entity has discarded or is about to discard at least one first data packet, the RLC entity discards a second data packet in a packet set to which the first data packet belongs.

24. The apparatus of claim 23, wherein, The processing module is further configured to: The RLC entity of the sending end discards or is about to discard the at least one first data packet based on at least one of the remaining time information, the importance, and the dependency of the data packet on other data packets.

25. The apparatus of any one of claims 21-24, wherein, The processing module is specifically configured to: The PDCP entity discards a second data packet that has a synchronization requirement or a dependency requirement with the first data packet according to the first information.

26. The apparatus of claim 21, wherein, The processing module is specifically configured to: The MAC entity discards a data packet that is not multiplexed with an SDU corresponding to the at least one first data packet according to the first information.

27. The apparatus of any of claims 21-26, wherein, Further comprising: a sending module configured to send, by the sending end, second information to a receiving end, the second information being used to indicate at least one of the following: the RLC entity of the sending end has discarded or is about to discard the at least one first data packet; the sending end stops transmitting the at least one first data packet.

28. A communications device, comprising: comprising: a processing module configured to send, by a radio link control (RLC) entity of a receiving end, third information to a PDCP entity of the receiving end, the third information being used to indicate that the RLC entity of the receiving end has discarded or is about to discard at least one third data packet.

29. The apparatus of claim 28, wherein, The processing module is further configured to: The PDCP entity stops a running reordering timer according to the third information.

30. The apparatus of claim 29, wherein, The processing module is further configured to: The PDCP entity performs an action after the reordering timer times out after being stopped.

31. The apparatus of any one of claims 28-30, wherein, The processing module is specifically configured to at least one of the following: the RLC entity of the receiving end sends the third information to the PDCP entity of the receiving end upon determining to discard the at least one third data packet; the RLC entity of the receiving end sends the third information to the PDCP entity of the receiving end upon receiving second information from an RLC entity of a sending end, the second information being used to indicate at least one of the following: the RLC entity of the sending end has discarded or is about to discard at least one first data packet; the sending end stops transmitting the at least one first data packet.

32. A communications device, wherein, comprising: a sending module configured to send, in a case where a cell switching or a primary secondary cell change occurs, fourth information to a second network side device to which a target cell or a target cell group after the switching or the change belongs, the fourth information being used to indicate at least one of the following: the RLC entity of the terminal has discarded or is about to discard at least one fourth data packet; the terminal stops transmitting the at least one fourth data packet.

33. The apparatus of claim 32, wherein, The sending module is further configured to: send, to a first network-side device to which a source cell before handover or before change belongs, fifth information, the fifth information being used to indicate at least one of the following: the RLC entity of the terminal has discarded or is about to discard at least one fifth data packet; wherein the at least one fourth data packet comprises the at least one fifth data packet; the terminal stops retransmitting the at least one fifth data packet.

34. The apparatus of claim 33, wherein, The sending module is specifically configured to at least one of the following: if the terminal does not perform RLC reestablishment in the process of cell handover or PSCell change, the terminal sends the fourth information to the second network-side device; if the terminal sends the fifth information within at least one time unit before receiving a cell handover command or a PSCell change command or performing cell handover or performing PSCell change, the terminal sends the fourth information to the second network-side device; if the terminal does not receive feedback for the fifth information before cell handover or PSCell change, the terminal sends the fourth information to the second network-side device.

35. A communication device, the communication device operating as a transmitting end, wherein, The terminal comprises a transceiver, a processor and a memory, the memory stores programs or instructions executable on the processor, and the programs or instructions are executed by the processor to implement the steps of the data transmission method according to any one of claims 1 to 10.

36. A communication device, said communication device acting as a receiving end, wherein The terminal comprises a transceiver, a processor and a memory, the memory stores programs or instructions executable on the processor, and the programs or instructions are executed by the processor to implement the steps of the data transmission method according to any one of claims 11 to 15.

37. A terminal, wherein, The terminal comprises a transceiver, a processor and a memory, the memory stores programs or instructions executable on the processor, and the programs or instructions are executed by the processor to implement the steps of the data transmission method according to any one of claims 16 to 20.

38. A readable storage medium, wherein, The readable storage medium stores programs or instructions, and the programs or instructions are executed by the processor to implement the steps of the data transmission method according to any one of claims 1 to 10, or implement the steps of the data transmission method according to any one of claims 11 to 15, or implement the steps of the data transmission method according to any one of claims 16 to 20.

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