Data transmission method, apparatus, and communication device

Abstract

The present application relates to the technical field of communications, and discloses a data transmission method, an apparatus, and a communication device. The data transmission method in the embodiments of the present application comprises: a sending end acquires transmission feedback information of transmission data; on the basis of the transmission feedback information of the transmission data and data feature information of the transmission data, the sending end determines whether to perform retransmission, wherein the data feature information of the transmission data is associated with at least one of the following: a reliability requirement of the transmission data; a remaining delay budget or a packet delay budget (PDB) of the transmission data; and configuration information of a radio link control (RLC) entity, a logical channel, or a packet data convergence protocol (PDCP) entity corresponding to the transmission data.

Description

Data transmission methods, devices and communication equipment

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510493658.9, filed in China on April 18, 2025, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] In related technologies, data transmission reliability between the sending and receiving ends is ensured through transmission feedback information. The sending end uses the transmission feedback information to determine whether to retransmit, and retransmits successfully when the transmission feedback information indicates that the transmission was unsuccessful. However, transmission feedback information is not always completely accurate, and not all unsuccessfully transmitted data needs to be retransmitted; relying solely on transmission feedback information to determine whether to retransmit is inflexible. Summary of the Invention

[0005] This application provides a data transmission method, apparatus, and communication device that can solve the problem of poor flexibility in determining whether to retransmit based solely on transmission feedback information.

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

[0007] The sending end obtains transmission feedback information for the transmitted data;

[0008] The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data.

[0009] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0010] Secondly, a data transmission method is provided, the method comprising:

[0011] The receiving end performs a third operation;

[0012] The execution of the third operation includes at least one of the following:

[0013] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0014] CRC verification is performed through the MAC layer;

[0015] The MAC CE sends HARQ feedback information to the sending end;

[0016] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0017] Thirdly, a data transmission method is provided, including:

[0018] The sending end's RLC layer performs the first retransmission operation;

[0019] The first retransmission operation includes at least one of the following:

[0020] When the RLC layer determines to retransmit the first RLC PDU, if the transmission resources are sufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is set not to carry the sequence number (SN) and segmentation information; or, if the transmission resources are insufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is segmented, and the header of each segment of the retransmitted first RLC PDU is filled with segmentation information and the SN allocated for retransmission, and the first RLC PDU is an RLC PDU containing the complete SDU.

[0021] When the RLC layer determines that the second RLC PDU needs to be retransmitted, the RLC PDUs in the retransmission buffer that contain the same SDU as the second RLC PDU are merged, and the merged information is retransmitted. The second RLC PDU is an RLC PDU containing the segmented SDU.

[0022] If the RLC layer determines to retransmit the third RLC PDU, and if the transmission resources are insufficient to transmit the third RLC PDU, the retransmitted third RLC PDU is re-segmented, and the header of each segment of the re-segmented third RLC PDU is filled with the original SN. The third RLC PDU is an RLC PDU containing segmented SDUs.

[0023] Fourthly, a data transmission method is provided, including:

[0024] The MAC layer at the sending end performs a second retransmission operation;

[0025] The second retransmission operation includes at least one of the following:

[0026] When the MAC layer determines to retransmit the first MAC sub-PDU, if the transmission resources are sufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is set not to carry SN and segmentation information; or, if the transmission resources are insufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is segmented, and the header of each segment of the retransmitted first MAC sub-PDU is filled with segmentation information and the SN allocated for retransmission, and the first MAC sub-PDU is a MAC sub-PDU containing a complete SDU.

[0027] When the MAC layer determines that the second MAC sub-PDU needs to be retransmitted, the MAC sub-PDUs in the retransmission buffer that contain the same SDU as the second MAC sub-PDU are merged, and the merged information is retransmitted. The second MAC sub-PDU is a MAC sub-PDU containing the segmented SDU.

[0028] If the MAC layer determines to retransmit the third MAC sub-PDU, and if the transmission resources are insufficient to transmit the segments of the third MAC sub-PDU, then the segments of the retransmitted third MAC sub-PDU are re-segmented, and the header of each segment of the re-segmented third MAC sub-PDU is filled with the original SN. The third MAC sub-PDU is a MAC sub-PDU containing segmented SDUs.

[0029] Fifthly, a data transmission method is provided, including:

[0030] The PDCP layer at the sending end performs a third retransmission operation;

[0031] The third retransmission operation includes at least one of the following:

[0032] When the PDCP layer determines to retransmit the first PDCP PDU, if the transmission resources are sufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is configured to carry a SN but not segmentation information; or, if the transmission resources are insufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is segmented, and the header of each segment of the retransmitted first PDCP PDU is filled with a SN and segmentation information, and the first PDCP PDU is a PDCP PDU containing a complete SDU.

[0033] When the PDCP layer determines that the second PDCP PDU needs to be retransmitted, the PDCP PDUs in the retransmission buffer that contain the same SDU as the second PDCP PDU are merged, and the merged information is retransmitted. The second PDCP PDU is a PDCP PDU containing the segmented SDU.

[0034] If the PDCP layer determines to retransmit the third PDCP PDU, and if the transmission resources are insufficient to transmit the segments of the third PDCP PDU, then the segments of the retransmitted third PDCP PDU are re-segmented, and the header of each segment of the re-segmented third PDCP PDU is filled with the original SN. The third PDCP PDU is a PDCP PDU containing segmented SDUs.

[0035] Sixthly, a data transmission apparatus is provided, comprising:

[0036] The processing module is used to obtain transmission feedback information of the transmitted data;

[0037] The processing module is further configured to: determine whether to retransmit based on the transmission feedback information of the transmitted data and the data characteristic information of the transmitted data;

[0038] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0039] In a seventh aspect, a data transmission apparatus is provided, comprising:

[0040] The processing module is used to perform the third operation;

[0041] The execution of the third operation includes at least one of the following:

[0042] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0043] CRC verification is performed through the MAC layer;

[0044] The MAC CE sends HARQ feedback information to the sending end;

[0045] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0046] Eighthly, a data transmission apparatus is provided, the apparatus being configured to perform the steps of the method as described in the first, third, fourth, or fifth aspects, or to implement the steps of the method as described in the second aspect.

[0047] A ninth aspect provides a transmitting end comprising a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the methods described in the first, third, fourth, or fifth aspects.

[0048] In a tenth aspect, a transmitting end is provided, including a processor and a communication interface, wherein,

[0049] The processor is used to obtain transmission feedback information of the transmitted data;

[0050] The processing module is further configured to: determine whether to retransmit based on the transmission feedback information of the transmitted data and the data characteristic information of the transmitted data;

[0051] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0052] Eleventhly, a receiving end is provided, the receiving end including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the second aspect.

[0053] In a twelfth aspect, a receiver is provided, including a processor and a communication interface, wherein...

[0054] The processor is used to perform third operations;

[0055] The execution of the third operation includes at least one of the following:

[0056] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0057] CRC verification is performed through the MAC layer;

[0058] The MAC CE sends HARQ feedback information to the sending end;

[0059] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0060] In a thirteenth 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 as described in the first, third, fourth, or fifth aspect, or implement the steps of the method as described in the second aspect.

[0061] In a fourteenth aspect, a wireless communication system is provided, comprising: a transmitter and a receiver, wherein the transmitter is configured to perform steps of the method as described in the first, third, fourth, or fifth aspect, and the receiver is configured to perform steps of the method as described in the second aspect.

[0062] In a fifteenth 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 steps of the methods described in the first, third, fourth, or fifth aspects, or to implement the steps of the methods described in the second aspect.

[0063] In a sixteenth 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 method as described in the first aspect, third aspect, fourth aspect or fifth aspect, or to implement the method as described in the second aspect.

[0064] In this embodiment, the transmitting end obtains transmission feedback information of the transmitted data; the transmitting end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data; wherein, the data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or PDB of the transmitted data; and the configuration information of the RLC entity, logical channel, or PDCP entity corresponding to the transmitted data. Thus, by determining whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, the transmitting end can make data retransmission decisions based on the transmission feedback information and the data characteristic information of the transmitted data, thereby improving the flexibility of data retransmission decisions. Attached Figure Description

[0065] Figure 1 is a block diagram of a wireless communication system applicable to an embodiment of this application;

[0066] Figure 2a is a schematic diagram of the user plane protocol stack in related technologies;

[0067] Figure 2b is a schematic diagram of the uplink L2 architecture in related technologies;

[0068] Figure 2c is a schematic diagram of L2 data flow in related technologies;

[0069] Figure 3 is a flowchart of one of the data transmission methods provided in an embodiment of this application;

[0070] Figure 4a is one of the schematic diagrams of an RLC PDU format provided in the embodiments of this application;

[0071] Figure 4b is a second schematic diagram of an RLC PDU format provided in an embodiment of this application;

[0072] Figure 4c is a third schematic diagram of an RLC PDU format provided in an embodiment of this application;

[0073] Figure 5 is a schematic diagram of one of the uplink L2 architectures provided in an embodiment of this application;

[0074] Figure 6a is one of the schematic diagrams of a MAC subPDU format provided in the embodiments of this application;

[0075] Figure 6b is a second schematic diagram of a MAC subPDU format provided in an embodiment of this application;

[0076] Figure 7 is one of the schematic diagrams of an L2 data flow provided in an embodiment of this application;

[0077] Figure 8 is a schematic diagram of a DC architecture provided in an embodiment of this application;

[0078] Figure 9 is a schematic diagram of a CA architecture provided in an embodiment of this application;

[0079] Figure 10 is a schematic diagram of packet transmission for CA duplication provided in an embodiment of this application;

[0080] Figure 11 is a second schematic diagram of an uplink L2 architecture provided in an embodiment of this application;

[0081] Figure 12 is a schematic diagram of a PDCP PDU format provided in an embodiment of this application;

[0082] Figure 13 is a second schematic diagram of an L2 data flow provided in an embodiment of this application;

[0083] Figure 14 is a second flowchart of a data transmission method provided in an embodiment of this application;

[0084] Figure 15 is a schematic diagram of one of the structures of a data transmission device provided in an embodiment of this application;

[0085] Figure 16 is a second schematic diagram of a data transmission device provided in an embodiment of this application;

[0086] Figure 17 is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0087] Figure 18 is a schematic diagram of the structure of a terminal provided in an embodiment of this application;

[0088] Figure 19 is one of the structural schematic diagrams of a network-side device provided in an embodiment of this application;

[0089] Figure 20 is a second schematic diagram of the structure of a network-side device provided in an embodiment of this application. Detailed Implementation

[0090] 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.

[0091] 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.

[0092] 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 the sender explicitly informing the receiver of specific information, the required operation, or the requested result in the instruction sent. An indirect instruction can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the required operation or requested result based on the judgment result.

[0093] 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), or other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used in the systems and radio technologies mentioned above, as well as in 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) communication systems.

[0094] 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. The terminal 11 can also be referred to as User Equipment (UE), and 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), shipboard equipment, pedestrian user equipment (PUE), smart home (home devices with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game console, personal computer (PC), ATM, or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart headphones, 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 this application embodiment. Network-side equipment 12 may include access network equipment or core network equipment, wherein 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.Among them, base stations 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, Transmission and Reception Point (TRP), and Non-Terrestrial Network (NTN) equipment (such as satellite or high altitude platform). The term "base station" can be any suitable term in the field, such as "station" or any other appropriate 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 of this application only use the base station in the NR system as an example for introduction, and do not limit the specific type of base station.

[0095] Core network equipment, also known as core network nodes, core network functions, or core network elements, 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 (L-NEF), and Binding Support. Functions include BSF, Application Function (AF), Location Management Function (LMF), Gateway Mobile Location Centre (GMLC), Network Data Analytics Function (NWDAF), and Non-Terrestrial Network (NTN) equipment (such as satellite or high altitude platform station).It should be noted that the embodiments of this application only use the core network equipment in the NR system as an example for introduction, and do not limit the specific type of core network equipment. If the name of the core network equipment mentioned in the embodiments of this application changes in subsequent protocol versions (e.g., 6G), it is also within the scope of protection of this application.

[0096] 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).

[0097] For ease of understanding, the following explains some aspects of the embodiments of this application:

[0098] 1. Data processing in the user plane

[0099] In existing NR networks, the user plane protocol stack mainly includes the Medium Access Control (MAC) layer, the Radio Link Control (RLC) layer, the Packet Data Convergence Protocol (PDCP) layer, the Service Data Adaptation Protocol (SDAP) layer, and the Physical (PHY) layer, as shown in Figure 2a.

[0100] The protocol stack consists of four layers: PHY (Layer 1, L1) and MAC (Layer 2, L2). The MAC layer is primarily responsible for mapping between logical and transport channels, prioritizing logical channels, multiplexing and demultiplexing MAC Service Data Units (SDUs), scheduling, and Hybrid Automatic Repeat Request (HARQ) operations. The RLC layer provides data transmission in Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM), segmentation and reassembly, Automatic Repeat Request (ARQ), and independent sequence numbers. The PDCP layer provides header compression and decompression, secure operation, separate bearer routing, and replication. The SDAP layer maps Quality of Service (QoS) flows to radio bearers and marks uplink and downlink packets with QoS flow IDs (QFIs). (See Figure 2b.)

[0101] An example of an L2 data stream is shown in Figure 2c. A transport block generated by the MAC layer consists of concatenated RLC PDUs from two radio bearers, RBx and RBy. The two RLC PDUs of RBx are obtained by adding headers to two complete IP packets at each level, and the RLC PDU of RBy is a segment from an IP packet.

[0102] The data transmission method, apparatus, and related equipment provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0103] Referring to Figure 3, which is a flowchart of a data transmission method provided in an embodiment of this application, the data transmission method includes the following steps:

[0104] Step 101: The sending end obtains the transmission feedback information of the transmitted data;

[0105] Step 102: The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data;

[0106] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, logical channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0107] The transmission feedback information can be used to indicate whether data transmission was successful or failed. The transmission feedback information may include air interface feedback information between the receiving end and the sending end; and / or, the transmission feedback information may include inter-layer feedback information between the MAC layer and the RLC layer or PDCP layer generated by the sending end based on the air interface feedback information. For example, the transmission feedback information may include first indication information, which indicates whether the previous data was successfully transmitted; or, the transmission feedback information may include HARQ feedback information sent by the receiving end based on MAC CE; or, the transmission feedback information may include transmission feedback information sent by the receiving end based on PUSCH resources; etc. This embodiment does not limit the specific form of the transmission feedback information.

[0108] In one embodiment, the data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or PDB of the transmitted data; and the configuration information of the RLC entity, logical channel, or PDCP entity corresponding to the transmitted data. Specifically, the data characteristic information of the transmitted data can determine at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or PDB of the transmitted data; and the configuration information of the RLC entity, logical channel, or PDCP entity corresponding to the transmitted data. This application does not limit the specific form of the data characteristic information.

[0109] In one implementation, the data characteristic information of the transmitted data is associated with the reliability requirements of the transmitted data, and the sending end can determine the reliability requirements of the transmitted data based on the data characteristic information. For data whose transmission feedback information indicates transmission failure, if it is determined that its reliability requirements meet preset conditions, the sending end can initiate retransmission of the data; if it is determined that its reliability requirements do not meet preset conditions, the sending end can choose not to retransmit the data. For example, for data whose transmission feedback information indicates transmission failure, if it is determined that its reliability requirements are high, the sending end can initiate retransmission of the data; if it is determined that its reliability requirements are low, the sending end can choose not to retransmit the data.

[0110] In one embodiment, the data characteristic information of the transmitted data is associated with the remaining delay budget or PDB of the transmitted data. The sending end can determine the remaining delay budget or PDB of the transmitted data based on the data characteristic information. For data whose transmission feedback information indicates transmission failure, if it is determined that its remaining delay budget or PDB meets the retransmission requirement, the sending end can initiate a retransmission of the data; if it is determined that its remaining delay budget or PDB does not meet the retransmission requirement, the sending end can choose not to initiate a retransmission of the data.

[0111] In one embodiment, the data characteristic information of the transmitted data is associated with the configuration information of the corresponding RLC entity, logical channel, or PDCP entity. The transmitting end can determine the configuration information of the corresponding RLC entity, logical channel, or PDCP entity based on the data characteristic information of the transmitted data. For data whose transmission feedback information indicates transmission failure, the transmitting end can initiate retransmission of the data if the configuration information of its RLC entity, logical channel, or PDCP entity meets preset conditions; if the configuration information of its RLC entity, logical channel, or PDCP entity does not meet preset conditions, the transmitting end may not initiate retransmission of the data. Taking the configuration information of the RLC entity as an example, for data whose transmission feedback information indicates transmission failure, if the configuration information of its RLC entity indicates that its RLC entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, the transmitting end's RLC layer can initiate retransmission of the data; if the configuration information of its RLC entity indicates that its RLC entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback, the transmitting end's RLC layer may not initiate retransmission of the data.

[0112] It should be noted that in this embodiment, the sending end can quickly reassemble and retransmit the data that requires reliability assurance based on the rapid feedback from the receiving end and the data characteristics of the transmitted data.

[0113] In this embodiment, the transmitting end obtains transmission feedback information of the transmitted data; the transmitting end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data; wherein, the data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or PDB of the transmitted data; and the configuration information of the RLC entity, logical channel, or PDCP entity corresponding to the transmitted data. Thus, by determining whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, the transmitting end can make data retransmission decisions based on the transmission feedback information and the data characteristic information of the transmitted data, thereby improving the flexibility of data retransmission decisions.

[0114] Optionally, the method further includes:

[0115] The sending end performs the first operation;

[0116] The execution of the first operation includes at least one of the following:

[0117] Sending or receiving Physical downlink control channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0118] Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE);

[0119] Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

[0120] In this embodiment, the transmitting end sends or receives Physical Downlink Control Channel (PDCCH) scheduling information, which carries first indication information. The first indication information is used to indicate whether the previous data was successfully transmitted. In this way, by enhancing the PDCCH scheduling information to carry more explicit information indicating the transmission result, the reliability of the feedback can be improved.

[0121] In this implementation, the sending end receives HARQ feedback information sent by the receiving end based on MAC CE. MAC CE itself transmits data on PUSCH and is equipped with CRC check and retransmission, which can improve the reliability of the feedback.

[0122] In this embodiment, the sending end receives the transmission feedback information sent by the receiving end based on the PUSCH resources. The PUSCH itself has ample resources and is equipped with CRC check, which makes it highly reliable, thereby improving the reliability of the feedback.

[0123] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0124] The RLC layer of the transmitting end receives the first feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the first feedback information and the data feature information of the transmission data. The RLC layer does not buffer the transmitted RLC PDU after sending the RLC protocol data unit (PDU) to the MAC layer.

[0125] The RLC layer of the transmitting end receives the second feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the second feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0126] The RLC layer of the transmitting end receives the first feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the first feedback information. The RLC layer does not buffer the sent RLC PDU after sending it to the MAC layer.

[0127] The RLC layer of the transmitting end receives the second feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the second feedback information. The RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0128] The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

[0129] In one implementation, the RLC layer can determine whether to initiate a retransmission based on the first feedback information of the transmitted data sent by the MAC layer and the data characteristic information of the transmitted data. The first feedback information of the transmitted data may include the RLC PDU of the transmitted data and the ACK / NACK indicator of the transmitted data. The RLC layer obtains the RLC PDUs to be retransmitted from the first feedback information and performs the retransmission of these RLC PDUs.

[0130] In one implementation, the RLC layer can determine whether to initiate a retransmission based on the second feedback information of the transmitted data sent by the MAC layer and the data characteristic information of the transmitted data. The second feedback information of the transmitted data may include an SN-based ACK / NACK indicator of the RLC layer. If it is determined that a retransmission should be initiated, the RLC layer obtains the RLC PDUs to be retransmitted from the RLC PDU buffer and performs the retransmission of these RLC PDUs.

[0131] For example, the MAC layer can always send transmission feedback information to the RLC layer, which dynamically determines whether retransmission is needed based on the data characteristics of each packet, such as the remaining PDB.

[0132] In one implementation, the RLC layer receives first feedback information corresponding to the data to be retransmitted sent by the MAC layer. This first feedback information may include the RLC PDU of the data to be retransmitted. Optionally, the first feedback information may also include an ACK / NACK indication of the data to be retransmitted. The MAC layer can determine whether to initiate a retransmission based on the transmission feedback information sent by the receiving end and the data characteristic information of the transmitted data, and only send the RLC PDUs that need to be retransmitted to the RLC layer, which then performs the retransmission of these RLC PDUs.

[0133] In one implementation, the RLC layer receives second feedback information corresponding to the data to be retransmitted sent by the MAC layer. This second feedback information may include an RLC layer SN-based ACK / NACK indicator for the data to be retransmitted. The MAC layer can determine whether to initiate a retransmission based on the transmission feedback information sent by the receiver and the data characteristic information of the transmitted data. It only sends the identifier (e.g., sequence number) of the RLC PDUs to be retransmitted to the RLC layer as the second feedback information. The RLC layer retrieves the RLC PDUs to be retransmitted from the RLC PDU buffer based on the second feedback information, and then performs the retransmission of these RLC PDUs.

[0134] For example, it is possible to configure whether the RLC entity corresponding to the logical channel needs to be retransmitted. The MAC layer determines whether the data of the RLC entity needs to be retransmitted. For data that does not need to be retransmitted, transmission feedback information can be directly not sent to the RLC layer. Transmission feedback information is only sent to the RLC layer for data that needs to be retransmitted, thereby minimizing feedback overhead.

[0135] It should be noted that after the RLC layer sends the RLC protocol data unit (PDU) to the MAC layer, it does not need to buffer the sent RLC PDU. Therefore, after the RLC layer sends the RLC PDU, it clears its buffer. For data that may need to be retransmitted, the MAC layer retrieves the MAC PDU from the HARQ buffer, extracts the RLC PDU, and sends the RLC PDU back to the RLC layer for processing.

[0136] Alternatively, the RLC layer can store the data that may be retransmitted, and when the MAC layer sends feedback information to the RLC layer, it can only send back the RLC layer's SN-based ACK / NACK indicator.

[0137] In this embodiment, the RLC layer of the transmitting end receives first feedback information of the transmitted data sent by the MAC layer, and determines whether to initiate a retransmission based on the first feedback information and the data characteristic information of the transmitted data; or, the RLC layer of the transmitting end receives second feedback information of the transmitted data sent by the MAC layer, and determines whether to initiate a retransmission based on the second feedback information and the data characteristic information of the transmitted data. In this way, the RLC layer of the transmitting end can make data retransmission decisions based on the feedback information from the MAC layer of the transmitting end, considering the data characteristic information of the transmitted data, thus improving the flexibility of data retransmission decisions.

[0138] In this embodiment, the RLC layer of the transmitting end receives first feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission based on the first feedback information; or, the RLC layer of the transmitting end receives second feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission based on the second feedback information. This allows the MAC layer of the transmitting end to consider the data characteristics of the transmitted data for inter-layer feedback, and the RLC layer of the transmitting end to initiate retransmission based on the feedback information from the MAC layer, thereby improving the flexibility of data retransmission decisions.

[0139] In this embodiment, after the RLC layer sends the RLC protocol data unit (PDU) to the MAC layer, it does not cache the sent RLC PDU; and / or, if it is determined that a retransmission is to be initiated, the RLC layer obtains the RLC PDU to be retransmitted from the MAC layer; thus, the L2 cache space can be saved.

[0140] In this implementation, when it is determined that a retransmission is to be initiated, the RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer; in this way, the inter-layer interaction overhead between the RLC layer and the MAC layer can be reduced.

[0141] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0142] The MAC layer of the transmitting end sends the first feedback information of the transmitted data to the RLC layer;

[0143] The MAC layer of the transmitting end sends a second feedback message of the transmitted data to the RLC layer;

[0144] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the first feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0145] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the second feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0146] The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

[0147] In one implementation, the MAC layer retrieves the RLC PDU to be retransmitted from the MAC HARQ buffer and sends the RLC PDU to be retransmitted to the RLC layer.

[0148] And / or,

[0149] The MAC layer stores information from the RLC PDUs contained in each HARQ process.

[0150] The data to be retransmitted may be transmission data whose reliability requirements meet preset conditions; and / or transmission data whose remaining delay budget or PDB meets the retransmission requirements; and / or transmission data whose configuration information of the RLC entity indicates that the RLC entity supports interaction with the MAC layer or retransmission based on feedback from the MAC layer.

[0151] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0152] The MAC layer of the transmitting end sends the first feedback information of the transmitted data to the RLC layer;

[0153] The RLC layer of the transmitting end receives the first feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the first feedback information and the data characteristic information of the transmission data. The RLC layer does not buffer the transmitted RLC PDU after sending the RLC protocol data unit (PDU) to the MAC layer.

[0154] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0155] The MAC layer of the transmitting end sends a second feedback message of the transmitted data to the RLC layer;

[0156] The RLC layer of the transmitting end receives the second feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the second feedback information and the data characteristic information of the transmission data. If it is determined to initiate a retransmission, the RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0157] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0158] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the first feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0159] The RLC layer of the transmitting end receives the first feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the first feedback information. The RLC layer does not buffer the sent RLC PDU after sending it to the MAC layer.

[0160] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0161] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the second feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0162] The RLC layer of the transmitting end receives the second feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the second feedback information. The RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0163] In this embodiment, the MAC layer of the transmitting end sends a first feedback information of the transmitted data to the RLC layer, or the MAC layer of the transmitting end sends a second feedback information of the transmitted data to the RLC layer. The RLC layer of the transmitting end determines whether to initiate a retransmission based on the feedback information and the data characteristic information of the transmitted data, thereby improving the flexibility of the data retransmission decision.

[0164] In this embodiment, the MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data and sends the first feedback information corresponding to the data that needs to be retransmitted to the RLC layer; or, the MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data and sends the second feedback information corresponding to the data that needs to be retransmitted to the RLC layer; this can support the MAC layer of the transmitting end to consider the data feature information of the transmitted data for inter-layer feedback, and the RLC layer of the transmitting end to initiate retransmission based on the feedback information of the MAC layer, thereby improving the flexibility of data retransmission decision-making.

[0165] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0166] The relevant information of the RLC PDU corresponding to the transmitted data; the first configuration information of the RLC entity corresponding to the transmitted data;

[0167] The relevant information of the RLC PDU includes at least one of the following: the reliability requirements corresponding to the RLC PDU, and the remaining latency budget or PDB of the RLC PDU;

[0168] The first configuration information is used to indicate that the RLC entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the first configuration information is used to indicate that the RLC entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

[0169] Specifically, for data whose transmission feedback indicates a transmission failure, if the first configuration information indicates that its RLC entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, the sending end's RLC layer may initiate a retransmission of the data; if the first configuration information indicates that its RLC entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback, the sending end's RLC layer may not initiate a retransmission of the data.

[0170] It is understandable that the RLC PDU corresponding to the transmitted data can refer to the RLC PDU that forms or constitutes the transmitted data, or the transmitted data is obtained by encapsulating the RLC PDU.

[0171] In this embodiment, the data characteristic information of the transmitted data includes at least one of the following: relevant information of the RLC PDU corresponding to the transmitted data; and first configuration information of the RLC entity corresponding to the transmitted data. The sending end considers at least one of the following when making a data retransmission decision: the reliability requirements corresponding to the RLC PDU, the remaining delay budget or PDB of the RLC PDU, and the first configuration information. This improves the flexibility of the data retransmission decision.

[0172] Optionally, the method further includes:

[0173] The RLC layer at the transmitting end performs the first retransmission operation;

[0174] The first retransmission operation includes at least one of the following:

[0175] When the RLC layer determines to retransmit the first RLC PDU, if the transmission resources are sufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is set not to carry the sequence number (SN) and segmentation information; or, if the transmission resources are insufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is segmented, and the header of each segment of the retransmitted first RLC PDU is filled with segmentation information and the SN allocated for retransmission, and the first RLC PDU is an RLC PDU containing the complete SDU.

[0176] When the RLC layer determines that the second RLC PDU needs to be retransmitted, the RLC PDUs in the retransmission buffer that contain the same SDU as the second RLC PDU are merged, and the merged information is retransmitted. The second RLC PDU is an RLC PDU containing the segmented SDU.

[0177] If the RLC layer determines to retransmit the third RLC PDU, and if the transmission resources are insufficient to transmit the third RLC PDU, the retransmitted third RLC PDU is re-segmented, and the header of each segment of the re-segmented third RLC PDU is filled with the original SN. The third RLC PDU is an RLC PDU containing segmented SDUs.

[0178] In this embodiment, the RLC layer of the transmitting end performs a first retransmission operation, and the retransmission function of the RLC layer can be realized through the first retransmission operation.

[0179] Optionally, the MAC layer of the transmitting end is configured with at least one of the following for each logical channel:

[0180] Send cache; Backup cache; Retransmission cache;

[0181] The transmit buffer is used to store data in the logical channel that is waiting for the first transmission;

[0182] The backup cache is used to store data that has been transmitted through the logical channel but has not been confirmed with ACK.

[0183] The retransmission buffer is used to store data that needs to be retransmitted.

[0184] In this embodiment, the MAC layer of the transmitting end is configured with at least one of the following for each logical channel: a transmit buffer; a backup buffer; and a retransmission buffer. Thus, by using at least one of the transmit buffer, backup buffer, and retransmission buffer, the MAC layer can support segmentation and / or feedback-based retransmission functions, thereby supporting the MAC layer's ability to merge RLC layers, supporting the elimination of RLC layers, and achieving a simpler and more efficient user plane design.

[0185] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0186] The relevant information of the MAC sub-PDU corresponding to the transmitted data; the second configuration information of the logical channel corresponding to the transmitted data;

[0187] The relevant information of the MAC sub-PDU includes at least one of the following: the reliability requirements corresponding to the MAC sub-PDU, and the remaining latency budget or PDB of the MAC sub-PDU;

[0188] The second configuration information is used to indicate that the logical channel corresponding to the transmitted data supports feedback-based retransmission, or the second configuration information is used to indicate that the logical channel corresponding to the transmitted data does not support feedback-based retransmission.

[0189] Specifically, for data whose transmission feedback information indicates transmission failure, if the second configuration information indicates that the logical channel corresponding to the transmitted data supports feedback-based retransmission, the MAC layer of the sending end can initiate retransmission of the data; if the second configuration information indicates that the logical channel corresponding to the transmitted data does not support feedback-based retransmission, the MAC layer of the sending end can choose not to initiate retransmission of the data.

[0190] It is understandable that the MAC sub-PDU corresponding to the transmitted data can refer to the MAC sub-PDU that forms or constitutes the transmitted data, or the transmitted data is encapsulated from this MAC sub-PDU. The logical channel corresponding to the transmitted data can refer to the logical channel used by the MAC layer of the transmitting end to transmit the MAC sub-PDU corresponding to the transmitted data.

[0191] It should be noted that the reliability requirements or PDB of a MAC sub-PDU can be configured values ​​or fixed values ​​carried in the configuration. Reliability requirements or PDBs can be configured uniformly based on the logical channel, with all data on a logical channel having the same value; alternatively, each data packet can carry its own reliability requirements or PDB. Furthermore, the remaining delay budget of a MAC sub-PDU is a parameter unique to that PDU. For example, if the transmission delay is 50ms, and the MAC sub-PDU has already spent 20ms waiting and processing, then it has 30ms remaining. The remaining delay budget is calculated independently for each packet.

[0192] In this embodiment, the data characteristic information of the transmitted data includes at least one of the following: relevant information of the MAC sub-PDU corresponding to the transmitted data; and second configuration information of the logical channel corresponding to the transmitted data. The sending end considers at least one of the following when making a data retransmission decision: the reliability requirements corresponding to the MAC sub-PDU, the remaining delay budget of the MAC sub-PDU, or the PDB and the second configuration information. This improves the flexibility of the data retransmission decision.

[0193] Optionally, the method further includes:

[0194] The MAC layer of the sending end performs a second retransmission operation;

[0195] The second retransmission operation includes at least one of the following:

[0196] When the MAC layer determines to retransmit the first MAC sub-PDU, if the transmission resources are sufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is set not to carry SN and segmentation information; or, if the transmission resources are insufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is segmented, and the header of each segment of the retransmitted first MAC sub-PDU is filled with segmentation information and the SN allocated for retransmission, and the first MAC sub-PDU is a MAC sub-PDU containing a complete SDU.

[0197] When the MAC layer determines that the second MAC sub-PDU needs to be retransmitted, the MAC sub-PDUs in the retransmission buffer that contain the same SDU as the second MAC sub-PDU are merged, and the merged information is retransmitted. The second MAC sub-PDU is a MAC sub-PDU containing the segmented SDU.

[0198] If the MAC layer determines to retransmit the third MAC sub-PDU, and if the transmission resources are insufficient to transmit the segments of the third MAC sub-PDU, then the segments of the retransmitted third MAC sub-PDU are re-segmented, and the header of each segment of the re-segmented third MAC sub-PDU is filled with the original SN. The third MAC sub-PDU is a MAC sub-PDU containing segmented SDUs.

[0199] In this embodiment, the MAC layer of the sending end performs a second retransmission operation. Through the above-mentioned second retransmission operation, the retransmission function of the MAC layer merging the RLC layer can be realized, the RLC layer can be canceled, buffering and inter-layer interaction can be reduced, and it is more conducive to simplifying the user plane design.

[0200] Optionally, the method further includes:

[0201] The MAC layer of the transmitting end receives the PDCP PDU sent by the PDCP layer;

[0202] The MAC layer of the transmitting end adds a MAC header to the received PDCP PDU to obtain a MAC sub-PDU.

[0203] In this embodiment, the MAC layer of the transmitting end receives the PDCP PDU sent by the PDCP layer; the MAC layer of the transmitting end adds a MAC header to the received PDCP PDU to obtain a MAC sub-PDU. Through the direct connection between the MAC layer and the PDCP layer, the function of merging the RLC layer with the MAC layer can be realized, supporting the elimination of the RLC layer, reducing buffering and inter-layer interaction, and is more conducive to simplifying the user plane design.

[0204] Optionally, the MAC header carries second indication information, which is used to indicate whether segmentation is required.

[0205] The second indication information can be a segment indicator (SI) field. The second indication information can be 2 bits long, with a value of 00 representing the complete PDU, 01 representing the first segment, 10 representing the middle segment, and 11 representing the last segment.

[0206] In this embodiment, the MAC header carries second indication information, which is used to indicate whether segmentation is required. By adding second indication information to the MAC header, the enhanced design of the MAC sub-PDU can be achieved, enabling the MAC layer to merge the segmentation function of the RLC layer, supporting the cancellation of the RLC layer, reducing caching and inter-layer interaction, and making it more conducive to simplifying the user plane design.

[0207] Optionally, the MAC header also carries third indication information, which is used to indicate the segment offset value.

[0208] The third indication information can be the Segment Offset (SO) field. The third indication information can be 16 bits long and is the number of the starting bytes of the segment in the original data packet. It can be used by the receiving end to reassemble the segments in byte order.

[0209] In this embodiment, the MAC header carries third indication information, which is used to indicate the segment offset value. By adding third indication information to the MAC header, the enhanced design of the MAC sub-PDU can be realized, enabling the MAC layer to merge the segmentation function of the RLC layer, supporting the cancellation of the RLC layer, reducing caching and inter-layer interaction, and making it more conducive to simplifying the user plane design.

[0210] Optionally, the method further includes:

[0211] The PDCP layer of the sending end receives the resource size sent by the MAC layer;

[0212] The PDCP layer at the sending end determines whether to segment the data packet based on the resource size.

[0213] In one implementation, when the resource size can accommodate an integer number of data packets, the data packets do not need to be segmented; when the resource size is insufficient to accommodate an integer number of data packets, the data packets can be segmented.

[0214] For example, the PDCP layer transmits PDCP PDUs to the MAC layer based on the resource size. For instance, if a packet is 10,000 bytes in size, transmitting ten 1,000-byte PDUs does not require packet segmentation; however, if transmitting an 800-byte PDU, the last packet needs to be segmented based on the remaining resources.

[0215] In this embodiment, the PDCP layer of the sending end receives the resource size sent by the MAC layer; the PDCP layer of the sending end determines whether to segment the data packet based on the resource size. Thus, through the interaction between the PDCP layer and the MAC layer, the segmentation function of the RLC layer can be merged by the PDCP layer, and the RLC layer can be eliminated, achieving a simpler and more efficient user plane design.

[0216] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0217] The relevant information of the PDCP PDU corresponding to the transmitted data; the third configuration information of the PDCP entity corresponding to the transmitted data;

[0218] The relevant information of the PDCP PDU includes at least one of the following: the reliability requirements corresponding to the PDCP PDU, and the remaining latency budget or PDB of the PDCP PDU;

[0219] The third configuration information is used to indicate that the PDCP entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the third configuration information is used to indicate that the PDCP entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

[0220] Specifically, for data whose transmission feedback indicates a transmission failure, the PDCP layer at the sending end can initiate a retransmission of the data if the third configuration information indicates that its PDCP entity supports interaction with the MAC layer or retransmission based on MAC layer feedback; if the third configuration information indicates that its PDCP entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback, the PDCP layer at the sending end may not initiate a retransmission of the data.

[0221] It is understandable that the PDCP PDU corresponding to the transmitted data can refer to the PDCP PDU that forms or constitutes the transmitted data, or the transmitted data is obtained by encapsulating the PDCP PDU.

[0222] In this embodiment, the data characteristic information of the transmitted data includes at least one of the following: relevant information of the PDCP PDU corresponding to the transmitted data; and third configuration information of the PDCP entity corresponding to the transmitted data. The sending end considers at least one of the following when making a data retransmission decision: the reliability requirements corresponding to the PDCP PDU, the remaining delay budget of the PDCP PDU, or the PDB and the third configuration information. This improves the flexibility of the data retransmission decision.

[0223] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0224] The PDCP layer of the transmitting end receives the third feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the third feedback information and the data feature information of the transmission data. The PDCP layer does not buffer the sent PDCP PDU after sending it to the MAC layer.

[0225] The PDCP layer of the transmitting end receives the fourth feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the fourth feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0226] The PDCP layer of the transmitting end receives the third feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the third feedback information. In this case, after the PDCP layer sends the PDCP PDU to the MAC layer, it does not buffer the sent PDCP PDU.

[0227] The PDCP layer of the transmitting end receives the fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the fourth feedback information. The PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0228] The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

[0229] In one implementation, the PDCP layer can determine whether to initiate a retransmission based on the third feedback information of the transmitted data sent by the MAC layer and the data characteristic information of the transmitted data. The third feedback information of the transmitted data may include the PDCP PDU of the transmitted data and the ACK / NACK indicator of the transmitted data. The PDCP layer obtains the PDCP PDU to be retransmitted from the third feedback information and performs the retransmission of these PDCP PDUs.

[0230] In one implementation, the PDCP layer can determine whether to initiate a retransmission based on the fourth feedback information of the transmitted data sent by the MAC layer and the data characteristic information of the transmitted data. The fourth feedback information of the transmitted data may include the PDCP layer SN-based ACK / NACK indicator. If it is determined that a retransmission should be initiated, the PDCP layer obtains the PDCP PDUs to be retransmitted from the PDCP PDU buffer and performs the retransmission of these PDCP PDUs.

[0231] For example, the MAC layer can always send transmission feedback information to the PDCP layer, which dynamically determines whether retransmission is needed based on the data characteristics of each packet, such as the remaining PDB.

[0232] In one implementation, the PDCP layer receives third feedback information corresponding to the data to be retransmitted sent by the MAC layer. This third feedback information may include the PDCP PDU of the data to be retransmitted. Optionally, the third feedback information may also include an ACK / NACK indication of the data to be retransmitted. The MAC layer can determine whether to initiate a retransmission based on the transmission feedback information sent by the receiving end and the data characteristic information of the transmitted data, and only send the PDCP PDUs that need to be retransmitted to the PDCP layer, which then performs the retransmission of these PDCP PDUs.

[0233] In one implementation, the PDCP layer receives fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer. This fourth feedback information may include a PDCP layer SN-based ACK / NACK indicator for the data to be retransmitted. The MAC layer can determine whether to initiate a retransmission based on the transmission feedback information sent by the receiver and the data characteristic information of the transmitted data. It only sends the identifier (e.g., sequence number) of the PDCP PDUs to be retransmitted to the PDCP layer as the fourth feedback information. The PDCP layer retrieves the PDCP PDUs to be retransmitted from the PDCP PDU buffer based on the fourth feedback information, and the PDCP layer performs the retransmission of these PDCP PDUs.

[0234] For example, it is possible to configure whether the PDCP entity corresponding to the logical channel needs to be retransmitted. The MAC layer determines whether the data of the PDCP entity needs to be retransmitted. For data that does not need to be retransmitted, transmission feedback information can be directly not sent to the PDCP layer. Transmission feedback information is only sent to the PDCP layer for data that needs to be retransmitted, thereby minimizing feedback overhead.

[0235] It should be noted that after the PDCP layer sends the PDCP PDU to the MAC layer, it does not need to buffer the sent PDCP PDU. Therefore, after the PDCP layer sends the PDCP PDU, it clears the buffer. For data that may need to be retransmitted, the MAC layer retrieves the MAC PDU from the HARQ buffer, extracts the PDCP PDU, and sends the PDCP PDU back to the PDCP layer for processing.

[0236] Alternatively, the PDCP layer can store the data that may be retransmitted, and when the MAC layer sends feedback information to the PDCP layer, it can only send back the PDCP layer's SN-based ACK / NACK indicator.

[0237] In this embodiment, the PDCP layer at the transmitting end receives third feedback information of the transmitted data sent by the MAC layer, and determines whether to initiate retransmission based on the third feedback information and the data characteristic information of the transmitted data; or, the PDCP layer at the transmitting end receives fourth feedback information of the transmitted data sent by the MAC layer, and determines whether to initiate retransmission based on the fourth feedback information and the data characteristic information of the transmitted data. In this way, the PDCP layer at the transmitting end can make data retransmission decisions based on the feedback information from the MAC layer at the transmitting end, considering the data characteristic information of the transmitted data, thus improving the flexibility of data retransmission decisions.

[0238] In this embodiment, the PDCP layer of the transmitting end receives third feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission based on the third feedback information; or, the PDCP layer of the transmitting end receives fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission based on the fourth feedback information. This allows the MAC layer of the transmitting end to consider the data characteristics of the transmitted data for inter-layer feedback, and the PDCP layer of the transmitting end to initiate retransmission based on the feedback information from the MAC layer, thereby improving the flexibility of data retransmission decisions.

[0239] In this embodiment, after the PDCP layer sends the PDCP PDU to the MAC layer, it does not cache the sent PDCP PDU; and / or, if it is determined that a retransmission is to be initiated, the PDCP layer obtains the PDCP PDU to be retransmitted from the MAC layer; thus, the space occupied by the L2 cache can be saved.

[0240] In this implementation, when it is determined that a retransmission is to be initiated, the PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer; in this way, the inter-layer interaction overhead between the PDCP layer and the MAC layer can be reduced.

[0241] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0242] The MAC layer of the transmitting end sends the third feedback information of the transmitted data to the PDCP layer;

[0243] The MAC layer of the transmitting end sends the fourth feedback information of the transmitted data to the PDCP layer;

[0244] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the third feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0245] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the fourth feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0246] The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

[0247] In one implementation, the MAC layer retrieves the PDCP PDU to be retransmitted from the MAC HARQ buffer and sends the PDCP PDU to be retransmitted to the PDCP layer.

[0248] And / or,

[0249] The MAC layer stores information from the PDCP PDUs contained in each HARQ process.

[0250] The data to be retransmitted may be transmission data whose reliability requirements meet preset conditions; and / or transmission data whose remaining delay budget or PDB meets the retransmission requirements; and / or transmission data whose configuration information of the PDCP entity indicates that the PDCP entity supports interaction with the MAC layer or retransmission based on feedback from the MAC layer.

[0251] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0252] The MAC layer of the transmitting end sends the third feedback information of the transmitted data to the PDCP layer;

[0253] The PDCP layer at the transmitting end receives the third feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the third feedback information and the data characteristic information of the transmission data. The PDCP layer does not buffer the sent PDCP PDU after sending it to the MAC layer.

[0254] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0255] The MAC layer of the transmitting end sends the fourth feedback information of the transmitted data to the PDCP layer;

[0256] The PDCP layer of the transmitting end receives the fourth feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the fourth feedback information and the data feature information of the transmission data. If it is determined to initiate a retransmission, the PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0257] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0258] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the third feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0259] The PDCP layer of the transmitting end receives the third feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the third feedback information. In this case, after the PDCP layer sends the PDCP PDU to the MAC layer, it does not buffer the sent PDCP PDU.

[0260] In one embodiment, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including:

[0261] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the fourth feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0262] The PDCP layer of the transmitting end receives the fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the fourth feedback information. The PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0263] In this embodiment, the MAC layer of the transmitting end sends a first feedback information of the transmitted data to the PDCP layer, or the MAC layer of the transmitting end sends a second feedback information of the transmitted data to the PDCP layer. The PDCP layer of the transmitting end determines whether to initiate a retransmission based on the feedback information and the data characteristic information of the transmitted data, thereby improving the flexibility of the data retransmission decision.

[0264] In this embodiment, the MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data and sends the first feedback information corresponding to the data that needs to be retransmitted to the PDCP layer; or, the MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data and sends the second feedback information corresponding to the data that needs to be retransmitted to the PDCP layer; this can support the MAC layer of the transmitting end to consider the data feature information of the transmitted data for inter-layer feedback, and the PDCP layer of the transmitting end to initiate retransmission based on the feedback information of the MAC layer, thereby improving the flexibility of data retransmission decision-making.

[0265] Optionally, the method further includes:

[0266] The PDCP layer at the transmitting end performs a third retransmission operation;

[0267] The third retransmission operation includes at least one of the following:

[0268] When the PDCP layer determines to retransmit the first PDCP PDU, if the transmission resources are sufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is configured to carry a SN but not segmentation information; or, if the transmission resources are insufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is segmented, and the header of each segment of the retransmitted first PDCP PDU is filled with a SN and segmentation information, and the first PDCP PDU is a PDCP PDU containing a complete SDU.

[0269] When the PDCP layer determines that the second PDCP PDU needs to be retransmitted, the PDCP PDUs in the retransmission buffer that contain the same SDU as the second PDCP PDU are merged, and the merged information is retransmitted. The second PDCP PDU is a PDCP PDU containing the segmented SDU.

[0270] If the PDCP layer determines to retransmit the third PDCP PDU, and if the transmission resources are insufficient to transmit the segments of the third PDCP PDU, then the segments of the retransmitted third PDCP PDU are re-segmented, and the header of each segment of the re-segmented third PDCP PDU is filled with the original SN. The third PDCP PDU is a PDCP PDU containing segmented SDUs.

[0271] In this embodiment, the PDCP layer of the transmitting end does perform a third retransmission operation. Through the above-mentioned third retransmission operation, the retransmission function of the PDCP layer merging the RLC layer can be realized, the RLC layer can be canceled, buffering and inter-layer interaction can be reduced, and it is more conducive to simplifying the user plane design.

[0272] Optionally, the method further includes:

[0273] The PDCP layer at the sending end adds a PDCP header to the IP data packet to obtain a PDCP PDU;

[0274] The PDCP header carries a fourth indication information, which is used to indicate whether segmentation is required.

[0275] The fourth indicator information can be the SI (Segment Indicator) field. The fourth indicator information can be 2 bits long, with a value of 00 representing the complete PDU, 01 representing the first segment, 10 representing the middle segment, and 11 representing the last segment.

[0276] In this embodiment, the PDCP header carries a fourth indication information, which is used to indicate whether segmentation is required. By adding the fourth indication information to the PDCP header, the enhanced design of the PDCP PDU can be achieved, enabling the PDCP layer to merge the segmentation function of the RLC layer, supporting the cancellation of the RLC layer, reducing caching and inter-layer interaction, and making it more conducive to simplifying the user plane design.

[0277] Optionally, the PDCP header also carries fifth indication information, which is used to indicate segment offset values.

[0278] The fifth indication information can be the SO (Segment Offset) field. The fifth indication information can be 16 bits long, which is the starting byte number of the segment in the original data packet. It can be used by the receiving end to reassemble the segments in byte order.

[0279] In this embodiment, the PDCP header also carries a fifth indication information, which is used to indicate the segment offset value. By adding the fifth indication information to the PDCP header, the enhanced design of the PDCP PDU can be realized, enabling the PDCP layer to merge the segmentation function of the RLC layer, supporting the cancellation of the RLC layer, reducing caching and inter-layer interaction, and making it more conducive to simplifying the user plane design.

[0280] Optionally, when the sending end is a terminal, the sending or receiving of PDCCH scheduling information includes: receiving the PDCCH scheduling information sent by the network-side device;

[0281] or,

[0282] When the sending end is a network-side device, sending or receiving PDCCH scheduling information includes: sending the PDCCH scheduling information to the terminal, wherein the first indication information is used to indicate the transmission feedback information received by the sending end, and the transmission feedback information is used to indicate whether the previous data was successfully transmitted.

[0283] Optionally, the method further includes:

[0284] The sending end performs the second operation;

[0285] The second operation includes at least one of the following:

[0286] F1 interface partitioning; dual-connection operation; carrier aggregation; carrier aggregation copy transmission.

[0287] Optionally, when the second operation includes carrier aggregation replication transmission, the method further includes:

[0288] The MAC layer of the transmitting end configures two transmit buffers for a logical channel, and transmits the data in the two transmit buffers on two carrier aggregation groups respectively. The data stored in the two transmit buffers are the same.

[0289] In this embodiment, the RLC function is reconstructed based on the high reliability of the MAC or PHY transmission feedback. Necessary functions such as segmentation, resegmentation and / or retransmission are retained in the RLC sublayer, or incorporated into the MAC or PDCP. A fast retransmission mechanism is triggered based on the underlying transmission feedback, and whether to retransmit is determined according to the semi-static or dynamic data characteristics. This further optimizes the L2 processing flow and efficiency, simplifies the functional overlap between layers, and improves the user experience while ensuring system efficiency.

[0290] In related technologies, RLC UM data transmission latency is relatively low, but it can only achieve a low block error rate (BER) requirement, such as 10^-3. While RLC AM data can achieve a higher BER requirement, such as 10^-6, its latency performance is poor due to the tens or even hundreds of milliseconds of latency in the ARQ function of the RLC layer. Extended Reality (XR), immersive experiences, real-time interaction, and robotics services for 6G typically have high requirements for both latency and BER, such as meeting a 20ms latency requirement while simultaneously achieving a 10^-5 BER requirement. To better meet the characteristics of these services, the 6G user plane design needs to balance BER and latency requirements, achieving a better user experience with lower overhead.

[0291] Meanwhile, in 5G design, PDCP and RLC layers each have sequence number (SN) and sorting functions, and RLC's ARQ and MAC's HARQ also have feedback and retransmission functions. The overall design has redundancy and overlap. The user plane design of 6G aims to be more streamlined and efficient.

[0292] The embodiments of this application can improve the efficiency of user plane feedback and retransmission, so as to ensure that high block error rate and latency performance are met at the same time, while taking into account system efficiency. In addition, the embodiments of this application can reduce user plane overlap design, simplify the process, improve efficiency and reduce processing complexity. Furthermore, the embodiments of this application also consider the adaptability issues in different network architectures and scenarios.

[0293] To achieve a simpler and more efficient user plane design for 6G, this application embodiment restructures the functions and processes of the user plane, mainly including the following:

[0294] (1) Improve the efficiency and reliability of physical layer or MAC feedback to obtain timely and stable feedback for timely data retransmission and recovery;

[0295] (2) Reconstruct the RLC layer function. The RLC layer only supports segmentation and resegmentation functions. It can perform fast retransmission based on local feedback. It can dynamically decide whether to retransmit by considering QoS parameters such as remaining PDB and Packet Error Rate (PER). Alternatively, it can maintain the semi-static configuration of RLC AM and UM entities according to QoS requirements. Compared with UM entities, AM entities can support retransmission functions.

[0296] or,

[0297] The segmentation and resegmentation functions of RLC are merged into the MAC layer, the RLC layer is removed, the PDCP layer interacts directly with the MAC layer, the MAC header format is redesigned, various MAC transmit buffering and retransmission buffering operations are introduced, and fast retransmission operations are performed based on feedback. This applies to operations under F1 interface, dual connectivity (DC) scenarios, carrier aggregation (CA) configuration, and CA duplication configuration.

[0298] or,

[0299] The RLC segmentation and resegmentation functions are merged into PDCP, the RLC layer is removed, the PDCP layer header structure is redesigned, various PDCP transmit buffer and retransmission buffer operations are enhanced, and fast retransmission operations are performed based on feedback, under F1 interface, DC scenario, CA configuration, and CA duplication configuration.

[0300] The following examples illustrate this:

[0301] Example 1:

[0302] This example enhances MAC feedback.

[0303] In existing 5G systems, RLC functions mainly include segmentation, resegmentation, and ARQ (Arrival and Retransmission) functions. ARQ functions include packet loss detection, status report discovery, status report feedback, and retransmission. ARQ functions are based on the feedback and retransmission mechanism of this layer, offering high reliability, but with poor latency performance, typically exhibiting delays of tens or even hundreds of milliseconds.

[0304] First, consider enhancing the feedback functionality of the PHY and / or MAC layers to obtain timely and reliable feedback results while controlling overhead and improving efficiency. Replace the ARQ functionality of the RLC layer with enhanced feedback functionality at the PHY and / or MAC layers to achieve a streamlined and efficient design.

[0305] The first and / or third operations that enhance the feedback functionality of the PHY and / or MAC may include at least one of the following:

[0306] Method 1 enhances the PDCCH scheduling information to carry more explicit information. For example, the traditional New Data Indicator (NDI) only has 1 bit. Whether the NDI is flipped indicates whether it is new data. If it is not flipped, it indicates a retransmission scheduling in the HARQ process; if it is flipped, it indicates new data scheduling. Here, flipping means 1->0 or 0->1; not flipping means maintaining the previous value. A 1-bit NDI can only indicate two states: retransmission or new transmission. However, it cannot reflect the difference between new transmission due to the success of the previous transmission and new data scheduled because the previous transmission failed. Therefore, more bits are needed, such as 2-bit NDI or more-bit NDI, or the new bit can be defined as a new field. These additional bit fields can at least additionally indicate whether the previous data was successful.

[0307] For uplink (UL), the network side is the receiver, and in related technologies, UL does not provide explicit feedback indication. However, in this example, if new data is scheduled in the PDCCH and the previous data is indicated as successful, it is equivalent to the UL transmission providing explicit ACK feedback. If new data is scheduled in the PDCCH and the previous data is indicated as failed, it is equivalent to the UL transmission providing explicit NACK feedback. In this way, the MAC HARQ process and the corresponding MAC PDU obtain explicit ACK / NACK feedback.

[0308] For downlink (DL), the network side is the sender. In related technologies, the terminal performs HARQ ACK / NACK feedback at fixed intervals after each transmission. However, since this HARQ ACK / NACK feedback typically only contains 1 bit of information and does not perform cyclic redundancy check (CRC) checks, there is a certain probability of false ACK->NACK and NACK->ACK detections. In this example, the network-side DL scheduling also explicitly carries the received ACK / NACK information, indicating whether the previous data transmission was successful. This allows the UE to further determine whether an error has occurred, facilitating more precise feedback and remediation.

[0309] In summary, extending the PDCCH information is more effective for UL, as it can directly feed back the received result information, and can be extended separately for uplink or for both uplink and downlink.

[0310] Method 2 enhances the feedback method. In related technologies, HARQ feedback is transmitted on the PUCCH and only applies to DL data. The UE sends an ACK upon successful reception and a NACK upon failure. As mentioned earlier, the 1-bit feedback information lacks protection such as CRC checksum, making it prone to false detections. Therefore, to further improve the feedback effect, the feedback overhead can be increased, for example, by increasing the number of CRC checksum bits to improve accuracy; or by utilizing PUSCH resources, as PUSCH resources are relatively abundant and include CRC checksum, resulting in high reliability; or by using MAC CE for HARQ feedback, as MAC CE transmits data on the PUSCH, includes CRC checksum, and also handles retransmission, further improving feedback reliability.

[0311] The purpose of enhancing the feedback method is to obtain more reliable feedback results through greater overhead. It can be mainly used for DL ​​transmission, or as an enhancement of UL transmission feedback.

[0312] It should be noted that Method 1 can be selected as an enhancement for UL transmission and Method 2 as an enhancement for DL ​​transmission. Alternatively, Method 1 and Method 2 can be applied simultaneously to the same transmission enhancement, such as DL transmission enhancement.

[0313] Example 2:

[0314] This example combines with Example 1 to implement enhanced MAC feedback and simplify RLC functionality.

[0315] With the introduction of reliable and timely feedback in Example 1, the ARQ function of the RLC layer loses its usefulness for most or specific data. For this data, the RLC layer only needs to perform functions such as segmentation, resegmentation, reassembly, and retransmission based on local feedback.

[0316] The interaction between the RLC entity and the MAC layer can include at least one of the following:

[0317] As with related technologies, when scheduling resources arrive, the MAC layer allocates the resource size to the RLC entity corresponding to a logical channel according to the Logical Channel Prioritization (LCP), requests data from the RLC layer, and the RLC organizes one or more RLC PDUs according to the resource size, which may include complete data and data segments, and sends them to the MAC packet for transmission.

[0318] This example applies a new inter-layer interaction mechanism. The MAC layer, based on reliable MAC or PHY feedback, passes information on whether the transmission was successful to the corresponding RLC layer. The RLC layer then decides whether to initiate a retransmission based on the nature of the data.

[0319] A cache-efficient inter-layer interaction mechanism works as follows: For example, after the RLC layer organizes RLC PDUs according to resource size and sends them to the MAC layer, it no longer caches the data already sent to the MAC layer. In contrast, traditional RLC AM needs to cache sent RLC PDUs for retransmission. Only when the MAC layer sends a precise ACK or NACK does it return the RLC PDUs belonging to that RLC entity from the MAC HARQ cache to the RLC, which then decides whether to retransmit. This significantly reduces the size of the L2 cache.

[0320] Another inter-layer interaction mechanism is as follows: For example, the RLC or MAC layer records the information of the RLC PDU contained in each HARQ process. When the precise feedback arrives, the MAC returns the feedback information to the RLC, such as which PDU in the RLC, and which PDU segment transmission was successful / failed. The RLC makes the decision, and the RLC may need to store or retain the original RLC PDU cache and information.

[0321] The mechanisms for inter-layer interaction and RLC's decision on whether to retransmit can be divided into the following two feasible approaches:

[0322] One approach is dynamic decision-making: In this approach, each RLC entity's RLC PDU decides whether to retransmit based on dynamic real-time information (such as relevant information about the RLC PDU). For example, if the reliability requirement for the RLC PDU is high, it is retransmitted; otherwise, it is not. Or, if the remaining delay budget / PDB (packet delay budget) of the RLC PDU meets the retransmission requirement, it is retransmitted; otherwise, it is not. In this approach, since the RLC maintains information for each RLC PDU or segment, the MAC layer can exchange the transmission feedback ACK / NACK information of all RLC PDUs included in the HARQ process with the RLC, allowing the RLC to ultimately decide on subsequent operations.

[0323] Another approach is the semi-static decision-making method: In this method, each RLC entity already has different attributes based on the data type it maps to (such as configuring the first configuration information). For example, an RLC entity may not support inter-layer interaction with the MAC layer or retransmission based on local feedback; or an RLC entity may support inter-layer interaction with the MAC layer or retransmission based on local feedback. This semi-static configuration information can also be configured to the MAC layer simultaneously. After reliable feedback is obtained from a HARQ process, the MAC layer can directly delete data from RLC entities that do not support inter-layer interaction or retransmission based on local feedback. For data from RLC entities that support inter-layer interaction or retransmission based on local feedback, the MAC layer provides precise ACK / NACK information to the RLC entity, which then organizes subsequent operations, such as retransmission.

[0324] When an RLC entity receives inter-layer interaction or local feedback from the MAC layer, it determines, based on semi-static or dynamic information, that the data or segment needs to be retransmitted. If so, it adds the data or segment to the retransmission buffer, awaiting a transmission opportunity. The inter-layer interaction or local feedback can be the PDU or segment data itself or data information. If it is the data itself, it is added to the retransmission buffer based on the determination; if it is data information, the corresponding data is retrieved from the RLC layer backup buffer based on the data information and added to the retransmission buffer based on the determination. It should be noted that a complete RLC PDU can be operated independently; for RLC PDU segments, appropriate merging operations can be performed. For example, two consecutive segments with RLC PDU SN=1, a segment of [0-100 bytes] and a segment of [101-300 bytes], can be directly merged into a segment of [0-300 bytes] or even a complete data PDU, awaiting retransmission.

[0325] Operations related to RLC segmentation, resegmentation, and retransmission (such as the first retransmission operation) include at least one of the following:

[0326] (1) During the first transmission, if the resources are sufficient to accommodate the entire RLC PDU size, the RLC PDU may not be allocated or carry a SN; only when the resources are insufficient and the RLC needs to be segmented, an RLC SN is allocated to the RLC PDU, and the SN value and segmentation information are carried in the header of each segment.

[0327] (2) When a complete RLC PDU is scheduled for retransmission, if the resources are sufficient to accommodate the entire RLC PDU size, the RLC PDU may still not be assigned or carry a SN during retransmission; only when insufficient resources cause the RLC to need to be segmented will a new RLC SN be assigned to the RLC PDU, and the SN value and segmentation information will be carried in the header of each segment; the new RLC SN can be a SN that is not currently used by the RLC PDU in the transmission unacknowledged state, and there is no need to strictly adhere to the order.

[0328] (3) When an RLC PDU segment is scheduled for retransmission, consecutive segments belonging to the same RLC PDU in the retransmission buffer can be merged first. For example, two or more segments with the same SN number and explicitly consecutive segment information can be merged to form a larger segment or even a complete RLC PDU. For a complete RLC PDU, if resources are sufficient, it can be transmitted as a complete PDU without a SN, or it can carry a SN to facilitate duplicate detection or reassembly operations at the receiving end. When resources are insufficient and RLC needs to be segmented or resegmented, the original SN of the RLC PDU is used to fill the RLC SN field in the header, and segmentation or resegmentation information is carried in the header of each segment. For example, if a segment of SN=2 [200-400 bytes] needs to be retransmitted, but the resource size is only 100 bytes, the segment can be resegmented into a first segment of SN=2 [200-300 bytes] for retransmission, and the remaining 100-byte segment waits for the next resource transmission.

[0329] The format of RLC PDU and PDU segments can adopt at least one of the following:

[0330] (1) RLC complete PDU: SI value displays the complete PDU, as shown in Figure 4a;

[0331] (2) RLC segment PDU: SI value displays the first segment, SO defaults to 0 so SO is not needed, as shown in Figure 4b;

[0332] (3) RLC segment PDU: SI value is used to display the middle or last segment, so the SO field needs to be carried, as shown in Figure 4c.

[0333] A complete RLC PDU can refer to an RLC PDU containing a complete SDU; a segmented RLC PDU can refer to an RLC PDU containing segmented SDUs.

[0334] in,

[0335] SI (Segment Indicator) field: 2 bits long, with values ​​of 00 representing the complete PDU, 01 representing the first segment, 10 representing the middle segment, and 11 representing the last segment.

[0336] The SO (Segment Offset) field is 16 bits long and represents the starting byte number of the segment in the original data packet. It is one of the important segmentation information and is used by the receiving end to reassemble the segments in byte order.

[0337] In this example, the PDCP, RLC, and MAC sublayer divisions are retained. The RLC function is simplified, MAC and PHY feedback is enhanced, and inter-layer interaction between RLC and MAC and RLC retransmission based on local feedback are introduced. Because these three layers remain unchanged, the base station's F1 interface division, DC (Dual Connection), CA (Carrier Aggregation), and CA Duplication carrier aggregation replication transmission modes can all operate in the traditional manner.

[0338] Example 3:

[0339] This example combines Example 1 to implement enhanced MAC feedback, merging the remaining RLC functionality into MAC.

[0340] This example is a simplified design based on Example 1.

[0341] First, we still need to rely on enhanced feedback functionality for the PHY and / or MAC, as the ability of the underlying layer to provide fast and reliable feedback will be the foundation for optimization. See Example 1 for details on enhancement methods.

[0342] Secondly, after introducing reliable and timely feedback in the first step, the ARQ function of the original RLC layer loses its usefulness for most or specific data. For this data, the original RLC only needs to perform segmentation, resegmentation, reassembly, and retransmission based on local feedback. The remaining functions of the original RLC layer can be merged into MAC to reduce caching and inter-layer interactions, which is more conducive to a streamlined design. SDAP functionality can also be merged into PDCP to further reduce layers and optimize the design. This example focuses on describing the merging of RLC and MAC, which will be explained in detail later.

[0343] As shown in Figure 5, the PDCP and MAC functions are as follows:

[0344] PDCP functions include: SN for security and re-ordering, etc.; Header compression; Security; Routing for CA duplication (&DC); and F1 QoS to RB mapping (removed from SDAP).

[0345] MAC functions include: multiplexing; concatenation; segmentation / re-segmentation; HARQ; BSR / SR; LCP; etc.

[0346] The operation of merging the remaining functionality of the original RLC entity into the MAC layer can include at least one of the following:

[0347] (1) Since the MAC layer handles the multiplexing of multiple logical channels and integrates TBs for transmission, after the segmentation and resegmentation functions of the original RLC entity and the feedback-based retransmission function are merged into the MAC layer, the MAC layer still needs to perform independent operations for each logical channel. For example, it needs at least an independent transmission buffer, and optionally, a retransmission buffer and / or backup buffer, etc. The transmission buffer is used to store the data waiting for the first transmission of the logical channel; the backup buffer is used to store the data that has been transmitted on the logical channel but has not been acknowledged by ACK, i.e., the data that may be retransmitted; the retransmission buffer is used to store the data that has been decided to be retransmitted and is waiting for resources. The retransmission buffer and / or backup buffer can be set only for data with high reliability requirements, and data with low reliability requirements can only have a transmission buffer set.

[0348] (2) After the MAC layer obtains the scheduling resources, it first allocates resources to each logical channel according to the LCP process, and then performs packet assembly according to the amount of resources allocated to each logical channel. The packet assembly process is as follows: the retransmission data of each logical channel generally has a higher priority than the initial transmission data. Therefore, the data in the retransmission buffer is assembled into packets first. If there are remaining resources, the initial transmission data is considered, that is, the data in the transmission buffer is sent.

[0349] The determination of retransmitted data is based on reliable feedback from the MAC or PHY layer. Since feedback and retransmission determination are handled only at the MAC layer, it saves inter-layer interaction compared to Example 2. The MAC layer, based on the feedback and the data content in the current HARQ process, determines whether to retransmit if it receives a NACK; if it receives an ACK, it can delete the corresponding backup cache data, as retransmission is no longer necessary. Specifically, this can be further divided into the following two feasible methods:

[0350] One feasible approach is dynamic decision-making. In this approach, each logical channel data packet determines whether to retransmit based on dynamic real-time information (such as information related to MAC subPDUs). For example, if the data packet has high reliability requirements, it is retransmitted; otherwise, it is not. Or, if the remaining delay budget / PDB (packet delay budget) of the data packet meets the retransmission requirement, retransmission is arranged; otherwise, it is not. In this approach, since the MAC layer maintains information for each MAC subPDU or segment, the MAC layer ultimately decides on subsequent operations.

[0351] Another feasible approach is a semi-static decision-making method. In this method, each logical channel already has different attributes during semi-static configuration (such as configuring the second configuration information) based on the data type it maps to. For example, there are logical channels that do not support feedback-based retransmission, and another type of logical channel that does support feedback-based retransmission. This semi-static configuration information can also be configured to the MAC layer simultaneously. After a reliable feedback is obtained from a HARQ process, the MAC layer can directly delete data belonging to logical channels that do not support feedback-based retransmission. For data belonging to logical channels that support feedback-based retransmission, the MAC layer determines subsequent operations based on precise ACK / NACK information, such as arranging retransmission, clearing the corresponding data from the backup cache, or discarding it directly.

[0352] Based on precise feedback and semi-static or dynamic information, if the MAC entity determines that data or segments need to be retransmitted, it adds the data or segments to the retransmission buffer of the corresponding logical channel, waiting for a transmission opportunity. Specifically, if the feedback result is ACK, the data is discarded directly, and if a backup buffer exists, the corresponding data is cleared. If the feedback result is NACK, the entity can dynamically or statically determine whether to retransmit based on data characteristics. For data that does not need to be retransmitted, the backup can be discarded and / or cleared. For data that needs to be retransmitted, the MAC subPDU (MAC sub-PDU) decoded from the MAC PDU in the HARQ buffer corresponding to the HARQ process is added to the retransmission buffer, or the corresponding data is retrieved from the backup buffer based on the data information and added to the retransmission buffer. In addition, complete MAC subPDUs can be operated independently; for MAC subPDU segments, appropriate merging operations can be performed. For example, two consecutive segments with MAC subPDU SN=1, the segment of [0-100 bytes] and the segment of [101-300 bytes], can be directly merged into a segment of [0-300 bytes] or even a complete data PDU, and wait for retransmission.

[0353] Operations involving MAC subPDU segmentation, resegmentation, and retransmission (such as a second retransmission operation) include at least one of the following:

[0354] (1) During the first transmission, if the resources are sufficient to accommodate the entire size of the MAC subPDU, the MAC subPDU may not be allocated or carry a SN; only when the resources are insufficient and segmentation is required will a SN be allocated to the MAC subPDU, and the SN value and segmentation information will be carried in the header of each segment.

[0355] (2) When a complete MAC subPDU is scheduled for retransmission, if the resources are sufficient to accommodate the entire size of the MAC subPDU, the MAC subPDU may still not be allocated or carry a SN during retransmission. Only when resources are insufficient and segmentation is required will a new SN be allocated to the MAC subPDU, and the SN value and segmentation information will be carried in the header of each segment. The new SN can be a SN that is not currently used by the MAC subPDU in the unacknowledged transmission state, and there is no need to strictly adhere to the order of priority.

[0356] (3) When a MAC subPDU segment is scheduled for retransmission, consecutive segments belonging to the same MAC subPDU in the retransmission buffer can be merged first. For example, two or more segments with the same SN number and explicitly consecutive segment information can be merged to form a larger segment or even a complete MAC subPDU. For a complete MAC subPDU, if resources are sufficient, it can be transmitted as a complete PDU without SN; or it can be transmitted with SN to facilitate duplicate detection or reassembly operations at the receiving end. When insufficient resources lead to the need for segmentation or resegmentation, the original SN of the MAC subPDU can be used to fill the SN field of the header, and segmentation or resegmentation information can be carried in the header of each segment. For example, if a segment with SN=2 [200-400 bytes] that needs to be retransmitted, and the resource size is only 100 bytes, the segment can be resegmented into a first segment with SN=2 [200-300 bytes] for retransmission, and the remaining 100-byte segment waits for the next resource.

[0357] It should be noted that, since each MAC subPDU carries a Logical Channel Identity (LCID) field, meaning that data belonging to the same logical channel has the same LCID, the SN only needs to allocate, maintain, and identify it within each logical channel.

[0358] The header format of MAC subPDU and subPDU segments can adopt at least one of the following:

[0359] (1) MAC complete subPDU header: SI value displays the complete PDU, as shown in Figure 6a;

[0360] (2) MAC segment subPDU header: SI value displays the first segment, SO defaults to 0 so SO is not needed, as shown in Figure 6a;

[0361] (3) MAC segmented subPDU: SI value is used to display the middle or last segment, so the SO field needs to be carried, as shown in Figure 6b.

[0362] A complete MAC subPDU can refer to a MAC subPDU that contains the complete SDU; a segmented MAC subPDU can refer to a MAC subPDU that contains segmented SDUs.

[0363] The definitions of SI and SO are the same as in Example 2, and will not be repeated here.

[0364] It should be noted that in this example, as shown in Figure 7, the PDCP and MAC sublayers are retained, the RLC sublayer is removed, MAC and PHY feedback are enhanced, and a fast retransmission function triggered by MAC feedback is used. Because the PDCP function remains unchanged, the division of the base station's F1 interface and the DC (Dual Connection) operation can be largely reused, similar to the common PDCP architecture. The split MAC entity is located in the DU or other SCG, as illustrated in Figure 8.

[0365] Carrier aggregation (CA) can also be reused in a basic way. When the MAC performs scheduling, it processes the resources of different carriers separately, assembles them into packets and sends them, as shown in Figure 9.

[0366] Carrier Duplication (CA) transmission mode: In this mode, data from the same logical channel, such as data from a PDCP entity, is duplicated and transmitted on CC group1 and CC group2 respectively. This reuse of different resources to transmit the same data repeatedly achieves low latency and high reliability. Figure 10 illustrates this example. y The data has CA duplication enabled, so it is copied and sent twice to the MAC entity. Alternatively, the MAC entity can instruct the MAC to enable duplication and copy the data itself. In any case, the MAC entity will prepare two transmit buffers for this logical channel, storing two identical copies of the data, and will transmit the data from the two transmit buffers on the designated CC group1 and CC group2 respectively. For other logical channels where duplication transmission is not enabled, such as RB... x Then it will not be affected and can carry out normal data transmission on different CCs according to LCP.

[0367] Example 3:

[0368] This example combines Example 1 to implement enhanced MAC feedback, merges the remaining RLC functionality into PDCP, and achieves a streamlined design.

[0369] First, we still need to rely on enhanced feedback functionality for the PHY and / or MAC, as the ability of the underlying layer to provide fast and reliable feedback will be the foundation for optimization. See Example 1 for details on enhancement methods.

[0370] Secondly, after introducing reliable and timely feedback in the first step, the ARQ function of the original RLC layer loses its usefulness for most or specific data. For this data, the original RLC only needs to perform functions such as segmentation, resegmentation, reassembly, and retransmission based on local feedback. The remaining functions of the original RLC layer can be merged into PDCP to reduce caching and inter-layer interactions, which is more conducive to a streamlined design.

[0371] As shown in Figure 11, the PDCP and MAC functions are as follows:

[0372] PDCP functions: Sequence number for security and re-ordering, etc.; Header compression; Security; Routing for CA duplication (&DC), F1 QoS to RB mapping (removed from SDAP); Concatenation; Segmentation / Re-segmentation; ARQ (optional)

[0373] MAC functions include: multiplexing, HARQ, BSR / SR, LCP, etc.

[0374] The operation of merging the remaining functionality of the original RLC entity into the PDCP layer can include at least one of the following:

[0375] (1) The MAC layer handles the multiplexing of multiple logical channels and integrates TBs for transmission. A PDCP entity corresponds to a radio bearer and is generally mapped one-to-one with a logical channel. Therefore, after the segmentation and resegmentation functions of the original RLC entity and the feedback-based retransmission function are merged into the PDCP layer, the PDCP layer adds, on the basis of the original processing, the reasonable segmentation of data packets according to the resource size provided by the MAC layer, and the determination of whether to retransmit data packets according to the transmission feedback of the MAC layer. In case of insufficient resources during retransmission, further resegmentation can be performed.

[0376] (2) After the MAC layer obtains the scheduling resources, it first allocates resources for each logical channel according to the LCP process, requests data from the corresponding PDCP entity, and performs packet assembly. The packet assembly process is as follows: The MAC requests data from the PDCP. The PDCP generally has a higher priority for retransmitted data of this logical channel than for the initial transmission data. Therefore, it first assembles the data in the retransmission buffer. If there are remaining resources, it then considers the initial transmission data, that is, sends the data in the buffer.

[0377] The determination of retransmitted data is based on reliable feedback from the MAC or PHY layer. The MAC layer feeds back to the PDCP layer, which then determines whether to retransmit based on the feedback result. If it is NACK, the PDCP layer determines whether to retransmit; if it is ACK, the corresponding data in the backup cache can be deleted because retransmission is no longer needed. Specifically, this can be divided into the following two feasible methods:

[0378] One feasible approach is dynamic decision-making. In this approach, PDCP determines whether to retransmit each logical channel data packet based on dynamic real-time information (such as relevant information from the PDCP PDU). For example, if the data packet has high reliability requirements, it is retransmitted; otherwise, it is not. Or, if the remaining delay budget / PDB (packet delay budget) of the data packet meets the retransmission requirement, retransmission is arranged; otherwise, it is not. In this approach, since PDCP maintains information for each PDU or segment, the PDCP layer ultimately decides on subsequent operations.

[0379] Another feasible approach is a semi-static decision-making method. In this method, the logical channels corresponding to the PDCP entity already have different attributes during semi-static configuration (such as configuring third-party configuration information) based on the data types mapped to them. For example, there are logical channels that do not support feedback-based retransmission, and another type of logical channel that does support feedback-based retransmission. This semi-static configuration information can also be configured to the MAC layer. After a reliable feedback is obtained from a HARQ process, the MAC layer can directly delete data belonging to logical channels that do not support feedback-based retransmission. For data belonging to logical channels that support feedback-based retransmission, the MAC layer reports back to the PDCP layer, which then determines the subsequent operation based on the precise ACK / NACK information, such as arranging retransmission, clearing the corresponding data from the backup cache, or discarding it directly.

[0380] A new mechanism is proposed: the MAC layer, based on reliable MAC or PHY feedback, passes information on whether the transmission was successful to the corresponding PDCP layer, which then decides whether to initiate a retransmission based on the nature of the data.

[0381] A buffer-saving inter-layer interaction mechanism: For example, after the PDCP layer organizes PDCP PDUs according to resource size and sends them to the MAC layer, it no longer buffers the data already sent to the MAC layer. Traditional AM, on the other hand, needs to buffer sent PDUs for retransmission. Only when the MAC layer sends a precise ACK or NACK does it return the PDCP PDUs belonging to that PDCP entity from the MAC HARQ buffer to the PDCP, which then decides whether to retransmit. This significantly saves L2 buffer size.

[0382] Another inter-layer interaction mechanism: For example, the PDCP layer or MAC layer records the information of the PDCP PDU contained in each HARQ process. When the precise feedback arrives, the MAC layer returns the feedback information to the PDCP layer, such as which PDU was successfully transmitted by the PDCP layer and which PDU segmentation was successful / failed. The PDCP layer may need to store or retain the original PDCP PDU cache and information.

[0383] When the PDCP entity receives inter-layer interaction or local feedback from the MAC layer, it determines, based on semi-static or dynamic information, that the data or segment needs to be retransmitted. If so, it adds the data or segment to the retransmission buffer, awaiting a transmission opportunity. The inter-layer interaction or local feedback can be the PDU or segment data itself or data information. If it is data itself, it adds the data to the retransmission buffer based on the determination; if it is data information, it retrieves the corresponding data from the PDCP layer backup buffer based on the data information and adds it to the retransmission buffer based on the determination. It should be noted that a complete PDCP PDU can be operated independently; for PDCP PDU segments, appropriate merging operations can be performed. For example, two consecutive segments with PDCP PDU SN=1, a segment of [0-100 bytes] and a segment of [101-300 bytes], can be directly merged into a segment of [0-300 bytes] or even a complete data PDU, awaiting retransmission.

[0384] Operations related to PDCP segmentation, resegmentation, and retransmission (such as third retransmission operations) include at least one of the following:

[0385] (1) During the first transmission, if the resources are sufficient to accommodate the entire PDCP PDU size, the PDCP PDU may not carry the segment offset SO; only when the resources are insufficient and PDCP needs to be segmented, detailed segmentation information is carried in the header of each segment; PDCP SN needs to be carried in each data packet, and the receiving end sequentially allocates it for each data packet. This SN was originally used for PDCP security processing and window operations, etc. After the introduction of segmentation, it can be used together with the segmentation information to assist in segmentation resegmentation and reassembly operations.

[0386] (2) When a complete PDCP PDU is scheduled for retransmission, if the resources are sufficient to accommodate the entire PDCP PDU size, the PDCP PDU may still not carry SO during retransmission; detailed segmentation information is only required when insufficient resources cause the PDCP to be segmented.

[0387] (3) When a PDCP PDU segment is scheduled for retransmission, consecutive segments belonging to the same PDCP PDU in the retransmission buffer can be merged first. For example, two or more segments with the same SN number and explicitly consecutive segment information can be merged to form a larger segment or even a complete PDCP PDU. For a complete PDCP PDU, if resources are sufficient, it can be transmitted as a complete PDU without SO. When resources are insufficient and PDCP needs to be segmented or re-segmented, the original SN of the PDCP PDU is used to fill the PDCP SN field in the header, and segmentation or re-segmentation information is carried in the header of each segment. For example, if a segment with SN=2 [200-400 bytes] that needs to be retransmitted, and the resource size is only 100 bytes, the segment can be re-segmented into a first segment with SN=2 [200-300 bytes] for retransmission, and the remaining 100-byte segment waits for the next resource.

[0388] As shown in Figure 12, the format of PDCP PDU and PDU segments can adopt at least one of the following:

[0389] PDCP Full PDU Header or First Segment Header: SI value displays the full PDU, SO is not required; SI value displays the first segment, SO defaults to 0 so SO is not required;

[0390] PDCP segmentation PDU: SI value indicates the middle or last segment, therefore the SO field needs to be included.

[0391] A complete PDCP PDU can refer to a PDCP PDU containing a complete SDU; a segmented PDCP PDU can refer to a PDCP PDU containing segmented SDUs.

[0392] The definitions of SI and SO are the same as in Example 2, and will not be repeated here.

[0393] It should be noted that in this example, as shown in Figure 13, the PDCP and MAC sub-layers are retained, while the RLC sub-layer is removed. Segmentation, resegmentation, and retransmission functions are added to the PDCP layer, enhancing MAC and PHY feedback and using a fast retransmission function triggered by MAC feedback. Because the PDCP function introduces the requirement for packet reassembly based on real-time resources, the segmentation of the base station's F1 interface and DC (Dual Connection) operations are essentially unusable unless there is ideal backhaul between CU and DU, or between MCG and SCG, in which case a common PDCP architecture can be reused, with the split MAC entity located in the DU or other SCG.

[0394] Carrier aggregation (CA) can be largely reused. When the MAC performs scheduling, it processes the resources of different carriers separately and then sends them as packets.

[0395] Carrier Duplication (CA) transmission mode: In this mode, data from the same logical channel, such as data from a single PDCP entity, is duplicated and transmitted twice, on CC group1 and CC group2 respectively. This reuse of different resources to transmit the same data repeatedly achieves low latency and high reliability. This architecture is configurable.

[0396] In this embodiment, by enhancing the reliability of fast feedback, a data packet retransmission and resegmentation mechanism based on fast feedback is introduced to achieve a dual improvement in latency and reliability, while also taking into account system efficiency. By reconstructing the L2 function, the overlapping functions and additional overhead between layers are reduced, improving processing efficiency and reducing complexity. The new architecture of this embodiment achieves a streamlined and efficient design in 6G and is compatible with most scenarios, with high adaptability.

[0397] This application also provides a data transmission method, including:

[0398] The sending end's RLC layer performs the first retransmission operation;

[0399] The first retransmission operation includes at least one of the following:

[0400] When the RLC layer determines to retransmit the first RLC PDU, if the transmission resources are sufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is set not to carry the sequence number (SN) and segmentation information; or, if the transmission resources are insufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is segmented, and the header of each segment of the retransmitted first RLC PDU is filled with segmentation information and the SN allocated for retransmission, and the first RLC PDU is an RLC PDU containing the complete SDU.

[0401] When the RLC layer determines that the second RLC PDU needs to be retransmitted, the RLC PDUs in the retransmission buffer that contain the same SDU as the second RLC PDU are merged, and the merged information is retransmitted. The second RLC PDU is an RLC PDU containing the segmented SDU.

[0402] If the RLC layer determines to retransmit the third RLC PDU, and if the transmission resources are insufficient to transmit the third RLC PDU, the retransmitted third RLC PDU is re-segmented, and the header of each segment of the re-segmented third RLC PDU is filled with the original SN. The third RLC PDU is an RLC PDU containing segmented SDUs.

[0403] Optionally, the method further includes:

[0404] The sending end performs the first operation;

[0405] The execution of the first operation includes at least one of the following:

[0406] Sending or receiving Physical Downlink Control Channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0407] Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE);

[0408] Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

[0409] Optionally, the method further includes:

[0410] The sending end obtains transmission feedback information for the transmitted data;

[0411] The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data.

[0412] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0413] The RLC layer of the transmitting end receives the first feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the first feedback information and the data feature information of the transmission data. The RLC layer does not buffer the transmitted RLC PDU after sending the RLC protocol data unit (PDU) to the MAC layer.

[0414] The RLC layer of the transmitting end receives the second feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the second feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0415] The RLC layer of the transmitting end receives the first feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the first feedback information. The RLC layer does not buffer the sent RLC PDU after sending it to the MAC layer.

[0416] The RLC layer of the transmitting end receives the second feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the second feedback information. The RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0417] The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

[0418] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0419] The MAC layer of the transmitting end sends the first feedback information of the transmitted data to the RLC layer;

[0420] The MAC layer of the transmitting end sends a second feedback message of the transmitted data to the RLC layer;

[0421] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the first feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0422] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the second feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0423] The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

[0424] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0425] The relevant information of the RLC PDU corresponding to the transmitted data; the first configuration information of the RLC entity corresponding to the transmitted data;

[0426] The relevant information of the RLC PDU includes at least one of the following: the reliability requirements corresponding to the RLC PDU, and the remaining latency budget or PDB of the RLC PDU;

[0427] The first configuration information is used to indicate that the RLC entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the first configuration information is used to indicate that the RLC entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

[0428] Optionally, when the sending end is a terminal, the sending or receiving of PDCCH scheduling information includes: receiving the PDCCH scheduling information sent by the network-side device;

[0429] or,

[0430] When the sending end is a network-side device, sending or receiving PDCCH scheduling information includes: sending the PDCCH scheduling information to the terminal, wherein the first indication information is used to indicate the transmission feedback information received by the sending end, and the transmission feedback information is used to indicate whether the previous data was successfully transmitted.

[0431] Optionally, the method further includes:

[0432] The sending end performs the second operation;

[0433] The second operation includes at least one of the following:

[0434] F1 interface partitioning; dual-connection operation; carrier aggregation; carrier aggregation copy transmission.

[0435] Optionally, when the second operation includes carrier aggregation replication transmission, the method further includes:

[0436] The MAC layer of the transmitting end configures two transmit buffers for a logical channel, and transmits the data in the two transmit buffers on two carrier aggregation groups respectively. The data stored in the two transmit buffers are the same.

[0437] It should be noted that the implementation method of this embodiment is similar to that of the embodiment shown in FIG3. For the specific implementation method, please refer to the relevant description of the embodiment shown in FIG3. To avoid repeated description, this embodiment will not be described again.

[0438] This application also provides a data transmission method, including:

[0439] The MAC layer at the sending end performs a second retransmission operation;

[0440] The second retransmission operation includes at least one of the following:

[0441] When the MAC layer determines to retransmit the first MAC sub-PDU, if the transmission resources are sufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is set not to carry SN and segmentation information; or, if the transmission resources are insufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is segmented, and the header of each segment of the retransmitted first MAC sub-PDU is filled with segmentation information and the SN allocated for retransmission, and the first MAC sub-PDU is a MAC sub-PDU containing a complete SDU.

[0442] When the MAC layer determines that the second MAC sub-PDU needs to be retransmitted, the MAC sub-PDUs in the retransmission buffer that contain the same SDU as the second MAC sub-PDU are merged, and the merged information is retransmitted. The second MAC sub-PDU is a MAC sub-PDU containing the segmented SDU.

[0443] If the MAC layer determines to retransmit the third MAC sub-PDU, and if the transmission resources are insufficient to transmit the segments of the third MAC sub-PDU, then the segments of the retransmitted third MAC sub-PDU are re-segmented, and the header of each segment of the re-segmented third MAC sub-PDU is filled with the original SN. The third MAC sub-PDU is a MAC sub-PDU containing segmented SDUs.

[0444] Optionally, the method further includes:

[0445] The sending end performs the first operation;

[0446] The execution of the first operation includes at least one of the following:

[0447] Sending or receiving Physical Downlink Control Channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0448] Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE);

[0449] Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

[0450] Optionally, the method further includes:

[0451] The sending end obtains transmission feedback information for the transmitted data;

[0452] The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data.

[0453] Optionally, the MAC layer of the transmitting end is configured with at least one of the following for each logical channel:

[0454] Send cache; Backup cache; Retransmission cache;

[0455] The transmit buffer is used to store data in the logical channel that is waiting for the first transmission;

[0456] The backup cache is used to store data that has been transmitted through the logical channel but has not been confirmed with ACK.

[0457] The retransmission buffer is used to store data that needs to be retransmitted.

[0458] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0459] The relevant information of the MAC sub-PDU corresponding to the transmitted data; the second configuration information of the logical channel corresponding to the transmitted data;

[0460] The relevant information of the MAC sub-PDU includes at least one of the following: the reliability requirements corresponding to the MAC sub-PDU, and the remaining latency budget or PDB of the MAC sub-PDU;

[0461] The second configuration information is used to indicate that the logical channel corresponding to the transmitted data supports feedback-based retransmission, or the second configuration information is used to indicate that the logical channel corresponding to the transmitted data does not support feedback-based retransmission.

[0462] Optionally, the method further includes:

[0463] The MAC layer of the transmitting end receives the PDCP PDU sent by the PDCP layer;

[0464] The MAC layer of the transmitting end adds a MAC header to the received PDCP PDU to obtain a MAC sub-PDU.

[0465] Optionally, the MAC header carries second indication information, which is used to indicate whether segmentation is required.

[0466] Optionally, the MAC header also carries third indication information, which is used to indicate the segment offset value.

[0467] Optionally, when the sending end is a terminal, the sending or receiving of PDCCH scheduling information includes: receiving the PDCCH scheduling information sent by the network-side device;

[0468] or,

[0469] When the sending end is a network-side device, sending or receiving PDCCH scheduling information includes: sending the PDCCH scheduling information to the terminal, wherein the first indication information is used to indicate the transmission feedback information received by the sending end, and the transmission feedback information is used to indicate whether the previous data was successfully transmitted.

[0470] Optionally, the method further includes:

[0471] The sending end performs the second operation;

[0472] The second operation includes at least one of the following:

[0473] F1 interface partitioning; dual-connection operation; carrier aggregation; carrier aggregation copy transmission.

[0474] Optionally, when the second operation includes carrier aggregation replication transmission, the method further includes:

[0475] The MAC layer of the transmitting end configures two transmit buffers for a logical channel, and transmits the data in the two transmit buffers on two carrier aggregation groups respectively. The data stored in the two transmit buffers are the same.

[0476] It should be noted that the implementation method of this embodiment is similar to that of the embodiment shown in FIG3. For the specific implementation method, please refer to the relevant description of the embodiment shown in FIG3. To avoid repeated description, this embodiment will not be described again.

[0477] This application also provides a data transmission method, including:

[0478] The PDCP layer at the sending end performs a third retransmission operation;

[0479] The third retransmission operation includes at least one of the following:

[0480] When the PDCP layer determines to retransmit the first PDCP PDU, if the transmission resources are sufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is configured to carry a SN but not segmentation information; or, if the transmission resources are insufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is segmented, and the header of each segment of the retransmitted first PDCP PDU is filled with a SN and segmentation information, and the first PDCP PDU is a PDCP PDU containing a complete SDU.

[0481] When the PDCP layer determines that the second PDCP PDU needs to be retransmitted, the PDCP PDUs in the retransmission buffer that contain the same SDU as the second PDCP PDU are merged, and the merged information is retransmitted. The second PDCP PDU is a PDCP PDU containing the segmented SDU.

[0482] If the PDCP layer determines to retransmit the third PDCP PDU, and if the transmission resources are insufficient to transmit the segments of the third PDCP PDU, then the segments of the retransmitted third PDCP PDU are re-segmented, and the header of each segment of the re-segmented third PDCP PDU is filled with the original SN. The third PDCP PDU is a PDCP PDU containing segmented SDUs.

[0483] Optionally, the method further includes:

[0484] The sending end performs the first operation;

[0485] The execution of the first operation includes at least one of the following:

[0486] Sending or receiving Physical Downlink Control Channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0487] Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE);

[0488] Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

[0489] Optionally, the method further includes:

[0490] The sending end obtains transmission feedback information for the transmitted data;

[0491] The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data.

[0492] Optionally, the method further includes:

[0493] The PDCP layer of the sending end receives the resource size sent by the MAC layer;

[0494] The PDCP layer at the sending end determines whether to segment the data packet based on the resource size.

[0495] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0496] The relevant information of the PDCP PDU corresponding to the transmitted data; the third configuration information of the PDCP entity corresponding to the transmitted data;

[0497] The relevant information of the PDCP PDU includes at least one of the following: the reliability requirements corresponding to the PDCP PDU, and the remaining latency budget or PDB of the PDCP PDU;

[0498] The third configuration information is used to indicate that the PDCP entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the third configuration information is used to indicate that the PDCP entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

[0499] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0500] The PDCP layer of the transmitting end receives the third feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the third feedback information and the data feature information of the transmission data. The PDCP layer does not buffer the sent PDCP PDU after sending it to the MAC layer.

[0501] The PDCP layer of the transmitting end receives the fourth feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the fourth feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0502] The PDCP layer of the transmitting end receives the third feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the third feedback information. In this case, after the PDCP layer sends the PDCP PDU to the MAC layer, it does not buffer the sent PDCP PDU.

[0503] The PDCP layer of the transmitting end receives the fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the fourth feedback information. The PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0504] The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

[0505] Optionally, the sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following:

[0506] The MAC layer of the transmitting end sends the third feedback information of the transmitted data to the PDCP layer;

[0507] The MAC layer of the transmitting end sends the fourth feedback information of the transmitted data to the PDCP layer;

[0508] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the third feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0509] The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the fourth feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0510] The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

[0511] Optionally, the method further includes:

[0512] The PDCP layer at the sending end adds a PDCP header to the IP data packet to obtain a PDCP PDU;

[0513] The PDCP header carries a fourth indication information, which is used to indicate whether segmentation is required.

[0514] Optionally, the PDCP header also carries fifth indication information, which is used to indicate segment offset values.

[0515] Optionally, when the sending end is a terminal, the sending or receiving of PDCCH scheduling information includes: receiving the PDCCH scheduling information sent by the network-side device;

[0516] or,

[0517] When the sending end is a network-side device, sending or receiving PDCCH scheduling information includes: sending the PDCCH scheduling information to the terminal, wherein the first indication information is used to indicate the transmission feedback information received by the sending end, and the transmission feedback information is used to indicate whether the previous data was successfully transmitted.

[0518] Optionally, the method further includes:

[0519] The sending end performs the second operation;

[0520] The second operation includes at least one of the following:

[0521] F1 interface partitioning; dual-connection operation; carrier aggregation; carrier aggregation copy transmission.

[0522] Optionally, when the second operation includes carrier aggregation replication transmission, the method further includes:

[0523] The MAC layer of the transmitting end configures two transmit buffers for a logical channel, and transmits the data in the two transmit buffers on two carrier aggregation groups respectively. The data stored in the two transmit buffers are the same.

[0524] It should be noted that the implementation method of this embodiment is similar to that of the embodiment shown in FIG3. For the specific implementation method, please refer to the relevant description of the embodiment shown in FIG3. To avoid repeated description, this embodiment will not be described again.

[0525] Referring to Figure 14, which is a flowchart of a data transmission method provided in an embodiment of this application, the data transmission method includes the following steps:

[0526] Step 201: The receiving end performs the third operation;

[0527] The execution of the third operation includes at least one of the following:

[0528] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0529] CRC verification is performed through the MAC layer;

[0530] The MAC CE sends HARQ feedback information to the sending end;

[0531] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0532] It should be noted that this embodiment is an implementation of the receiving end corresponding to the embodiment shown in Figure 3. For the specific implementation, please refer to the relevant description of the embodiment shown in Figure 3. To avoid repetition, this embodiment will not be described again.

[0533] The data transmission method provided in this application can be executed by a data transmission device. This application uses a data transmission device executing the data transmission method as an example to illustrate the data transmission device provided in this application.

[0534] This application provides a data transmission device. As an example, the data transmission device may be a communication device or a component within a communication device, such as a chip. The communication device 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.

[0535] The data transmission 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, etc., such as central processing units (CPUs), microprocessors, digital signal processors (DSPs), artificial intelligence (AI) processors, graphics processing units (GPUs), application-specific integrated circuits (ASICs), network processors (NPs), field-programmable gate arrays (FPGAs), 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: transceivers, pins, circuits, buses, radio frequency units, etc.

[0536] Specifically, referring to Figure 15, when the data transmission device is a transmitter or a component within a transmitter, the data transmission device 300 includes:

[0537] Processing module 301 is used to acquire transmission feedback information of the transmitted data;

[0538] The processing module 301 is further configured to: determine whether to retransmit based on the transmission feedback information of the transmitted data and the data characteristic information of the transmitted data;

[0539] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0540] Optionally, the processing module is further configured to: perform a first operation;

[0541] The execution of the first operation includes at least one of the following:

[0542] Sending or receiving Physical Downlink Control Channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0543] Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE);

[0544] Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

[0545] Optionally, the processing module is specifically used for any of the following:

[0546] The RLC layer receives the first feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the first feedback information and the data characteristic information of the transmission data. The RLC layer does not buffer the sent RLC PDU after sending the RLC protocol data unit (PDU) to the MAC layer.

[0547] The RLC layer receives the second feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the second feedback information and the data feature information of the transmission data. If it is determined that a retransmission should be initiated, the RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0548] The RLC layer receives the first feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the first feedback information. The RLC layer does not buffer the sent RLC PDU after sending it to the MAC layer.

[0549] The RLC layer receives the second feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the second feedback information. The RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer.

[0550] The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

[0551] Optionally, the processing module is specifically used for any of the following:

[0552] The first feedback information of the transmitted data is sent from the MAC layer to the RLC layer;

[0553] The second feedback information for the transmitted data is sent from the MAC layer to the RLC layer.

[0554] The MAC layer determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the first feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0555] The MAC layer determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the second feedback information corresponding to the data that needs to be retransmitted to the RLC layer.

[0556] The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

[0557] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0558] The relevant information of the RLC PDU corresponding to the transmitted data; the first configuration information of the RLC entity corresponding to the transmitted data;

[0559] The relevant information of the RLC PDU includes at least one of the following: the reliability requirements corresponding to the RLC PDU, and the remaining latency budget or PDB of the RLC PDU;

[0560] The first configuration information is used to indicate that the RLC entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the first configuration information is used to indicate that the RLC entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

[0561] Optionally, the processing module is further configured to:

[0562] The first retransmission operation is performed through the RLC layer;

[0563] The first retransmission operation includes at least one of the following:

[0564] When the RLC layer determines to retransmit the first RLC PDU, if the transmission resources are sufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is set not to carry the sequence number (SN) and segmentation information; or, if the transmission resources are insufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is segmented, and the header of each segment of the retransmitted first RLC PDU is filled with segmentation information and the SN allocated for retransmission, and the first RLC PDU is an RLC PDU containing the complete SDU.

[0565] When the RLC layer determines that the second RLC PDU needs to be retransmitted, the RLC PDUs in the retransmission buffer that contain the same SDU as the second RLC PDU are merged, and the merged information is retransmitted. The second RLC PDU is an RLC PDU containing the segmented SDU.

[0566] If the RLC layer determines to retransmit the third RLC PDU, and if the transmission resources are insufficient to transmit the third RLC PDU, the retransmitted third RLC PDU is re-segmented, and the header of each segment of the re-segmented third RLC PDU is filled with the original SN. The third RLC PDU is an RLC PDU containing segmented SDUs.

[0567] Optionally, the MAC layer of the transmitting end is configured with at least one of the following for each logical channel:

[0568] Send cache; Backup cache; Retransmission cache;

[0569] The transmit buffer is used to store data in the logical channel that is waiting for the first transmission;

[0570] The backup cache is used to store data that has been transmitted through the logical channel but has not been confirmed with ACK.

[0571] The retransmission buffer is used to store data that needs to be retransmitted.

[0572] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0573] The relevant information of the MAC sub-PDU corresponding to the transmitted data; the second configuration information of the logical channel corresponding to the transmitted data;

[0574] The relevant information of the MAC sub-PDU includes at least one of the following: the reliability requirements corresponding to the MAC sub-PDU, and the remaining latency budget or PDB of the MAC sub-PDU;

[0575] The second configuration information is used to indicate that the logical channel corresponding to the transmitted data supports feedback-based retransmission, or the second configuration information is used to indicate that the logical channel corresponding to the transmitted data does not support feedback-based retransmission.

[0576] Optionally, the processing module is further configured to:

[0577] The second retransmission operation is performed through the MAC layer;

[0578] The second retransmission operation includes at least one of the following:

[0579] When the MAC layer determines to retransmit the first MAC sub-PDU, if the transmission resources are sufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is set not to carry SN and segmentation information; or, if the transmission resources are insufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is segmented, and the header of each segment of the retransmitted first MAC sub-PDU is filled with segmentation information and the SN allocated for retransmission, and the first MAC sub-PDU is a MAC sub-PDU containing a complete SDU.

[0580] When the MAC layer determines that the second MAC sub-PDU needs to be retransmitted, the MAC sub-PDUs in the retransmission buffer that contain the same SDU as the second MAC sub-PDU are merged, and the merged information is retransmitted. The second MAC sub-PDU is a MAC sub-PDU containing the segmented SDU.

[0581] If the MAC layer determines to retransmit the third MAC sub-PDU, and if the transmission resources are insufficient to transmit the segments of the third MAC sub-PDU, then the segments of the retransmitted third MAC sub-PDU are re-segmented, and the header of each segment of the re-segmented third MAC sub-PDU is filled with the original SN. The third MAC sub-PDU is a MAC sub-PDU containing segmented SDUs.

[0582] Optionally, the processing module is further configured to:

[0583] Receive PDCP PDUs sent by the PDCP layer through the MAC layer;

[0584] The MAC sub-PDU is obtained by adding a MAC header to the received PDCP PDU through the MAC layer.

[0585] Optionally, the MAC header carries second indication information, which is used to indicate whether segmentation is required.

[0586] Optionally, the MAC header also carries third indication information, which is used to indicate the segment offset value.

[0587] Optionally, the processing module is further configured to:

[0588] The size of the resources received by the PDCP layer from the MAC layer;

[0589] The PDCP layer determines whether to segment the data packet based on the resource size.

[0590] Optionally, the data characteristic information of the transmitted data includes at least one of the following:

[0591] The relevant information of the PDCP PDU corresponding to the transmitted data; the third configuration information of the PDCP entity corresponding to the transmitted data;

[0592] The relevant information of the PDCP PDU includes at least one of the following: the reliability requirements corresponding to the PDCP PDU, and the remaining latency budget or PDB of the PDCP PDU;

[0593] The third configuration information is used to indicate that the PDCP entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the third configuration information is used to indicate that the PDCP entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

[0594] Optionally, the processing module is specifically used for any of the following:

[0595] The PDCP layer receives the third feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the third feedback information and the data feature information of the transmission data. The PDCP layer does not buffer the sent PDCP PDU after sending it to the MAC layer.

[0596] The PDCP layer receives the fourth feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the fourth feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0597] The PDCP layer receives the third feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission based on the third feedback information. The PDCP layer does not buffer the sent PDCP PDU after sending it to the MAC layer.

[0598] The PDCP layer receives the fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission based on the fourth feedback information. The PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer.

[0599] The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

[0600] Optionally, the processing module is specifically used for any of the following:

[0601] The third feedback information for transmitting data is sent from the MAC layer to the PDCP layer.

[0602] The fourth feedback message for transmitting data is sent from the MAC layer to the PDCP layer.

[0603] The MAC layer determines the data that needs to be retransmitted based on the data characteristic information of the transmitted data, and sends the third feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0604] The MAC layer determines the data that needs to be retransmitted based on the data characteristic information of the transmitted data, and sends the fourth feedback information corresponding to the data that needs to be retransmitted to the PDCP layer.

[0605] The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

[0606] Optionally, the processing module is further configured to:

[0607] The third retransmission operation is performed through the PDCP layer;

[0608] The third retransmission operation includes at least one of the following:

[0609] When the PDCP layer determines to retransmit the first PDCP PDU, if the transmission resources are sufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is configured to carry a SN but not segmentation information; or, if the transmission resources are insufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is segmented, and the header of each segment of the retransmitted first PDCP PDU is filled with a SN and segmentation information, and the first PDCP PDU is a PDCP PDU containing a complete SDU.

[0610] When the PDCP layer determines that the second PDCP PDU needs to be retransmitted, the PDCP PDUs in the retransmission buffer that contain the same SDU as the second PDCP PDU are merged, and the merged information is retransmitted. The second PDCP PDU is a PDCP PDU containing the segmented SDU.

[0611] If the PDCP layer determines to retransmit the third PDCP PDU, and if the transmission resources are insufficient to transmit the segments of the third PDCP PDU, then the segments of the retransmitted third PDCP PDU are re-segmented, and the header of each segment of the re-segmented third PDCP PDU is filled with the original SN. The third PDCP PDU is a PDCP PDU containing segmented SDUs.

[0612] Optionally, the processing module is further configured to:

[0613] By adding a PDCP header to the IP packet through the PDCP layer, a PDCP PDU is obtained.

[0614] The PDCP header carries a fourth indication information, which is used to indicate whether segmentation is required.

[0615] Optionally, the PDCP header also carries fifth indication information, which is used to indicate segment offset values.

[0616] Optionally, when the sending end is a terminal, the sending or receiving of PDCCH scheduling information includes: receiving the PDCCH scheduling information sent by the network-side device;

[0617] or,

[0618] When the sending end is a network-side device, sending or receiving PDCCH scheduling information includes: sending the PDCCH scheduling information to the terminal, wherein the first indication information is used to indicate the transmission feedback information received by the sending end, and the transmission feedback information is used to indicate whether the previous data was successfully transmitted.

[0619] Optionally, the processing module is further configured to:

[0620] Perform the second operation;

[0621] The second operation includes at least one of the following:

[0622] F1 interface partitioning; dual-connection operation; carrier aggregation; carrier aggregation copy transmission.

[0623] Optionally, when the second operation includes carrier aggregation replication transmission, the processing module is further configured to:

[0624] Two transmit buffers are configured for a logical channel through the MAC layer, and the data in the two transmit buffers are transmitted on two carrier aggregation groups respectively. The data stored in the two transmit buffers are the same.

[0625] Referring to Figure 16, when the data transmission device is a receiving end or a component within a receiving end, the data transmission device 400 includes:

[0626] Processing module 401 is used to perform the third operation;

[0627] The execution of the third operation includes at least one of the following:

[0628] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0629] CRC verification is performed through the MAC layer;

[0630] The MAC CE sends HARQ feedback information to the sending end;

[0631] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0632] The data transmission device provided in this application embodiment can implement the various processes implemented in the method embodiments of FIG3 and FIG14 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0633] As shown in Figure 17, this application embodiment also provides a communication device 500, including a processor 501 and a memory 502. The memory 502 stores programs or instructions that can run on the processor 501. For example, when the communication device 500 is a terminal, the program or instructions executed by the processor 501 implement the various steps of the above-described data transmission method embodiment and achieve the same technical effect. When the communication device 500 is a network-side device, the program or instructions executed by the processor 501 implement the various steps of the above-described data transmission method embodiment and achieve the same technical effect. To avoid repetition, further details are omitted here.

[0634] 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 in the method embodiments shown in FIG3 or FIG14. This terminal embodiment corresponds to the above-described terminal-side method embodiments, and all implementation processes and methods of the above-described method embodiments can be applied to this terminal embodiment and can achieve the same technical effect. The terminal can be the data transmission device shown in FIG15. Specifically, FIG18 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of this application.

[0635] The terminal 600 includes, but is not limited to, at least some of the following components: radio frequency unit 601, network module 602, audio output unit 603, input unit 604, sensor 605, display unit 606, user input unit 607, interface unit 608, memory 609, and processor 610.

[0636] Those skilled in the art will understand that terminal 600 may also include a power supply (such as a battery) for powering various components. The power supply can be logically connected to processor 610 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 18 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.

[0637] It should be understood that, in this embodiment, the input unit 604 may include a graphics processor 6041 and a microphone 6042. The graphics processor 6041 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 606 may include a display panel 6061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like. The user input unit 607 includes at least one of a touch panel 6071 and other input devices 6072. The touch panel 6071 is also called a touch screen. The touch panel 6071 may include two parts: a touch detection device and a touch controller. Other input devices 6072 may include, but are not limited to, a physical keyboard, function keys (such as volume control buttons, power buttons, etc.), a trackball, a mouse, and a joystick, which will not be described in detail here.

[0638] In this embodiment, after receiving downlink data from the network-side device, the radio frequency unit 601 can transmit it to the processor 610 for processing; in addition, the radio frequency unit 601 can send uplink data to the network-side device. Typically, the radio frequency unit 601 includes, but is not limited to, antennas, amplifiers, transceivers, couplers, low-noise amplifiers, duplexers, etc.

[0639] The memory 609 can be used to store software programs or instructions, as well as various data. The memory 609 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 609 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 609 in this embodiment includes, but is not limited to, these and any other suitable types of memory.

[0640] Processor 610 may include one or more processing units; optionally, processor 610 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 610.

[0641] Where the terminal is the sending end:

[0642] Processor 610 is used for:

[0643] Obtain transmission feedback information for the transmitted data;

[0644] Whether to retransmit is determined based on the transmission feedback information and the data characteristic information of the transmitted data.

[0645] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0646] Where the terminal is a receiving end:

[0647] Processor 610 is used to: perform a third operation;

[0648] The execution of the third operation includes at least one of the following:

[0649] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0650] CRC verification is performed through the MAC layer;

[0651] The MAC CE sends HARQ feedback information to the sending end;

[0652] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0653] It is understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description in Figure 3 or Figure 14 of the method embodiment, and achieve the same or corresponding technical effects. To avoid repetition, it will not be described again here.

[0654] 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 embodiments shown in FIG3 or FIG14. This network-side device embodiment corresponds to the above-described network-side device method embodiment. 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.

[0655] Specifically, this application embodiment also provides a network-side device, which may be the data transmission device shown in FIG15 or FIG16. As shown in FIG19, the network-side device 700 includes: an antenna 701, a radio frequency device 702, a baseband device 703, a processor 704, and a memory 705. The antenna 701 is connected to the radio frequency device 702. In the uplink direction, the radio frequency device 702 receives information through the antenna 701 and sends the received information to the baseband device 703 for processing. In the downlink direction, the baseband device 703 processes the information to be transmitted and sends it to the radio frequency device 702, which processes the received information and then transmits it through the antenna 701.

[0656] The method executed by the network-side device in the above embodiments can be implemented in the baseband device 703, which includes a baseband processor.

[0657] The baseband device 703 may include at least one baseband board, on which multiple chips are disposed, as shown in FIG19. One of the chips is, for example, a baseband processor, which is connected to the memory 705 via a bus interface to call the program or instructions in the memory 705 to execute the network-side device operation shown in the above method embodiment.

[0658] The network-side device may also include a network interface 706, such as a Common Public Radio Interface (CPRI).

[0659] Where the network-side device is the transmitting end:

[0660] Processor 704 is used for:

[0661] Obtain transmission feedback information for the transmitted data;

[0662] Whether to retransmit is determined based on the transmission feedback information and the data characteristic information of the transmitted data.

[0663] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0664] Where the network-side device is a receiving end:

[0665] Processor 704 is used to: perform a third operation;

[0666] The execution of the third operation includes at least one of the following:

[0667] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0668] CRC verification is performed through the MAC layer;

[0669] The MAC CE sends HARQ feedback information to the sending end;

[0670] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0671] In addition, the network-side device 700 of this application embodiment also includes: a program or instructions stored in a memory 705 and executable on a processor 704. The processor 704 calls the program or instructions in the memory 705 to execute the methods executed by the modules shown in FIG15 or FIG16 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0672] Specifically, this application also provides a network-side device. As shown in FIG20, the network-side device 800 includes a processor 801, a network interface 802, and a memory 803. The network-side device may be the data transmission device shown in FIG15 or FIG16. The network interface 802 is, for example, a common public radio interface (CPRI).

[0673] Where the network-side device is the transmitting end:

[0674] Processor 801 is used for:

[0675] Obtain transmission feedback information for the transmitted data;

[0676] Whether to retransmit is determined based on the transmission feedback information and the data characteristic information of the transmitted data;

[0677] The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

[0678] Where the network-side device is a receiving end:

[0679] Processor 801 is used to: perform a third operation;

[0680] The execution of the third operation includes at least one of the following:

[0681] Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted;

[0682] CRC verification is performed through the MAC layer;

[0683] The MAC CE sends HARQ feedback information to the sending end;

[0684] Based on the PUSCH resource, transmission feedback information is sent to the sending end.

[0685] In addition, the network-side device 800 of this application embodiment also includes: a program or instructions stored in a memory 803 and executable on a processor 801. The processor 801 calls the program or instructions in the memory 803 to execute the methods executed by the modules shown in FIG15 or FIG16 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0686] 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.

[0687] The processor mentioned above is either the processor in the terminal described in the above embodiments or the processor in the network-side device. 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.

[0688] 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.

[0689] 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.

[0690] 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.

[0691] This application also provides a wireless communication system, including a transmitter and a receiver. The transmitter can be used to execute the steps of the data transmission method applied to the transmitter as described above, and the receiver can be used to execute the steps of the data transmission method applied to the receiver as described above.

[0692] 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.

[0693] 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 the computer software product includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0694] 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 data transmission method, comprising: The sending end obtains transmission feedback information for the transmitted data; The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data. The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

2. The method according to claim 1, further comprising: The sending end performs the first operation; The execution of the first operation includes at least one of the following: Sending or receiving Physical Downlink Control Channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted; Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE); Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

3. The method according to claim 1 or 2, wherein, The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following: The RLC layer of the transmitting end receives the first feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the first feedback information and the data feature information of the transmission data. The RLC layer does not buffer the transmitted RLC PDU after sending the RLC protocol data unit (PDU) to the MAC layer. The RLC layer of the transmitting end receives the second feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the second feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer. The RLC layer of the transmitting end receives the first feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the first feedback information. The RLC layer does not buffer the sent RLC PDU after sending it to the MAC layer. The RLC layer of the transmitting end receives the second feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the second feedback information. The RLC layer obtains the RLC PDU to be retransmitted from the RLC PDU buffer. The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

4. The method according to any one of claims 1-3, wherein, The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following: The MAC layer of the transmitting end sends the first feedback information of the transmitted data to the RLC layer; The MAC layer of the transmitting end sends a second feedback message of the transmitted data to the RLC layer; The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the first feedback information corresponding to the data that needs to be retransmitted to the RLC layer. The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the second feedback information corresponding to the data that needs to be retransmitted to the RLC layer. The first feedback information includes the RLC PDU, and the second feedback information includes the identifier of the RLC PDU.

5. The method according to any one of claims 1-4, wherein, The data characteristic information of the transmitted data includes at least one of the following: The relevant information of the RLC PDU corresponding to the transmitted data; the first configuration information of the RLC entity corresponding to the transmitted data; The relevant information of the RLC PDU includes at least one of the following: the reliability requirements corresponding to the RLC PDU, and the remaining latency budget or PDB of the RLC PDU; The first configuration information is used to indicate that the RLC entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the first configuration information is used to indicate that the RLC entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

6. The method according to any one of claims 1-5, further comprising: The RLC layer at the transmitting end performs the first retransmission operation; The first retransmission operation includes at least one of the following: When the RLC layer determines to retransmit the first RLC PDU, if the transmission resources are sufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is set not to carry the sequence number (SN) and segmentation information; or, if the transmission resources are insufficient to transmit the first RLC PDU, the retransmitted first RLC PDU is segmented, and the header of each segment of the retransmitted first RLC PDU is filled with segmentation information and the SN allocated for retransmission. The first RLC PDU is an RLC PDU containing the complete SDU. When the RLC layer determines that the second RLC PDU needs to be retransmitted, the RLC PDUs in the retransmission buffer that contain the same SDU as the second RLC PDU are merged, and the merged information is retransmitted. The second RLC PDU is an RLC PDU containing the segmented SDU. If the RLC layer determines to retransmit the third RLC PDU, and if the transmission resources are insufficient to transmit the third RLC PDU, the retransmitted third RLC PDU is re-segmented, and the header of each segment of the re-segmented third RLC PDU is filled with the original SN. The third RLC PDU is an RLC PDU containing segmented SDUs.

7. The method according to claim 1 or 2, wherein, The MAC layer of the transmitting end is configured with at least one of the following for each logical channel: Send cache; Backup cache; Retransmission cache; The transmit buffer is used to store data in the logical channel that is waiting for the first transmission; The backup cache is used to store data that has been transmitted through the logical channel but has not been confirmed with ACK. The retransmission buffer is used to store data that needs to be retransmitted.

8. The method according to claim 1, 2 or 7, wherein, The data characteristic information of the transmitted data includes at least one of the following: The relevant information of the MAC sub-PDU corresponding to the transmitted data; the second configuration information of the logical channel corresponding to the transmitted data; The relevant information of the MAC sub-PDU includes at least one of the following: the reliability requirements corresponding to the MAC sub-PDU, and the remaining latency budget or PDB of the MAC sub-PDU; The second configuration information is used to indicate that the logical channel corresponding to the transmitted data supports feedback-based retransmission, or the second configuration information is used to indicate that the logical channel corresponding to the transmitted data does not support feedback-based retransmission.

9. The method according to claim 1, 2, 7 or 8, further comprising: The MAC layer of the sending end performs a second retransmission operation; The second retransmission operation includes at least one of the following: When the MAC layer determines to retransmit the first MAC sub-PDU, if the transmission resources are sufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is set not to carry SN and segmentation information; or, if the transmission resources are insufficient to transmit the first MAC sub-PDU, the retransmitted first MAC sub-PDU is segmented, and the header of each segment of the retransmitted first MAC sub-PDU is filled with segmentation information and the SN allocated for retransmission, and the first MAC sub-PDU is a MAC sub-PDU containing a complete SDU. When the MAC layer determines that the second MAC sub-PDU needs to be retransmitted, the MAC sub-PDUs in the retransmission buffer that contain the same SDU as the second MAC sub-PDU are merged, and the merged information is retransmitted. The second MAC sub-PDU is a MAC sub-PDU containing the segmented SDU. If the MAC layer determines to retransmit the third MAC sub-PDU, and if the transmission resources are insufficient to transmit the third MAC sub-PDU, then the retransmitted third MAC sub-PDU is re-segmented, and the header of each segment of the re-segmented third MAC sub-PDU is filled with the original SN. The third MAC sub-PDU is a MAC sub-PDU containing segmented SDUs.

10. The method according to claim 1, 2, 7, 8 or 9, further comprising: The MAC layer of the transmitting end receives the PDCP PDU sent by the PDCP layer; The MAC layer of the transmitting end adds a MAC header to the received PDCP PDU to obtain a MAC sub-PDU.

11. The method according to claim 10, wherein, The MAC header carries a second indication information, which is used to indicate whether segmentation is required.

12. The method according to claim 11, wherein, The MAC header also carries third indication information, which is used to indicate the segment offset value.

13. The method according to claim 1 or 2, further comprising: The PDCP layer of the sending end receives the resource size sent by the MAC layer; The PDCP layer at the sending end determines whether to segment the data packet based on the resource size.

14. The method according to claim 1, 2 or 13, wherein, The data characteristic information of the transmitted data includes at least one of the following: The relevant information of the PDCP PDU corresponding to the transmitted data; the third configuration information of the PDCP entity corresponding to the transmitted data; The relevant information of the PDCP PDU includes at least one of the following: the reliability requirements corresponding to the PDCP PDU, and the remaining latency budget or PDB of the PDCP PDU; The third configuration information is used to indicate that the PDCP entity supports interaction with the MAC layer or retransmission based on MAC layer feedback, or the third configuration information is used to indicate that the PDCP entity does not support interaction with the MAC layer or retransmission based on MAC layer feedback.

15. The method according to claim 1, 2, 13 or 14, wherein, The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following: The PDCP layer of the transmitting end receives the third feedback information of the transmission data sent by the MAC layer, and determines whether to initiate a retransmission based on the third feedback information and the data feature information of the transmission data. The PDCP layer does not buffer the sent PDCP PDU after sending it to the MAC layer. The PDCP layer of the transmitting end receives the fourth feedback information of the transmission data sent by the MAC layer, and determines whether to initiate retransmission based on the fourth feedback information and the data feature information of the transmission data. If it is determined to initiate retransmission, the PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer. The PDCP layer of the transmitting end receives the third feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the third feedback information. In this case, after the PDCP layer sends the PDCP PDU to the MAC layer, it does not buffer the sent PDCP PDU. The PDCP layer of the transmitting end receives the fourth feedback information corresponding to the data to be retransmitted sent by the MAC layer, and initiates retransmission according to the fourth feedback information. The PDCP layer obtains the PDCP PDU to be retransmitted from the PDCP PDU buffer. The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

16. The method according to claim 1, 2, 13, 14 or 15, wherein, The sending end determines whether to retransmit based on the transmission feedback information and the data characteristic information of the transmitted data, including any one of the following: The MAC layer of the transmitting end sends the third feedback information of the transmitted data to the PDCP layer; The MAC layer of the transmitting end sends the fourth feedback information of the transmitted data to the PDCP layer; The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the third feedback information corresponding to the data that needs to be retransmitted to the PDCP layer. The MAC layer of the transmitting end determines the data that needs to be retransmitted based on the data feature information of the transmitted data, and sends the fourth feedback information corresponding to the data that needs to be retransmitted to the PDCP layer. The third feedback information includes the PDCP PDU, and the fourth feedback information includes the identifier of the PDCP PDU.

17. The method according to claim 1, 2, 13, 14, 15 or 16, further comprising: The PDCP layer at the transmitting end performs a third retransmission operation; The third retransmission operation includes at least one of the following: When the PDCP layer determines to retransmit the first PDCP PDU, if the transmission resources are sufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is configured to carry a SN but not segmentation information; or, if the transmission resources are insufficient to transmit the first PDCP PDU, the retransmitted first PDCP PDU is segmented, and the header of each segment of the retransmitted first PDCP PDU is filled with a SN and segmentation information, and the first PDCP PDU is a PDCP PDU containing a complete SDU. When the PDCP layer determines that the second PDCP PDU needs to be retransmitted, the PDCP PDUs in the retransmission buffer that contain the same SDU as the second PDCP PDU are merged, and the merged information is retransmitted. The second PDCP PDU is a PDCP PDU containing the segmented SDU. If the PDCP layer determines to retransmit the third PDCP PDU, and if the transmission resources are insufficient to transmit the third PDCP PDU, then the retransmitted third PDCP PDU is re-segmented, and the header of each segment of the re-segmented third PDCP PDU is filled with the original SN. The third PDCP PDU is a PDCP PDU containing segmented SDUs.

18. The method according to claim 1, 2, 13, 14, 15, 16 or 17, further comprising: The PDCP layer at the sending end adds a PDCP header to the IP data packet to obtain a PDCP PDU; The PDCP header carries a fourth indication information, which is used to indicate whether segmentation is required.

19. The method according to claim 18, wherein, The PDCP header also carries a fifth indication information, which is used to indicate the segment offset value.

20. The method according to claim 2, wherein, When the sending end is a terminal, sending or receiving PDCCH scheduling information includes: receiving the PDCCH scheduling information sent by the network-side device; or, When the sending end is a network-side device, sending or receiving PDCCH scheduling information includes: sending the PDCCH scheduling information to the terminal, wherein the first indication information is used to indicate the transmission feedback information received by the sending end, and the transmission feedback information is used to indicate whether the previous data was successfully transmitted.

21. The method according to any one of claims 1-20, further comprising: The sending end performs the second operation; The second operation includes at least one of the following: F1 interface partitioning; dual-connection operation; carrier aggregation; Carrier aggregation replication transmission.

22. The method according to claim 21, wherein, When the second operation includes carrier aggregation replication transmission, the method further includes: The MAC layer of the transmitting end configures two transmit buffers for a logical channel, and transmits the data in the two transmit buffers on two carrier aggregation groups respectively. The data stored in the two transmit buffers are the same.

23. A data transmission method, comprising: The receiving end performs a third operation; The execution of the third operation includes at least one of the following: Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted; CRC verification is performed through the MAC layer; The MAC CE sends HARQ feedback information to the sending end; Based on the PUSCH resource, transmission feedback information is sent to the sending end.

24. A data transmission apparatus, comprising: The processing module is used to obtain transmission feedback information of the transmitted data; The processing module is further configured to: determine whether to retransmit based on the transmission feedback information of the transmitted data and the data characteristic information of the transmitted data; The data characteristic information of the transmitted data is associated with at least one of the following: the reliability requirements of the transmitted data; the remaining delay budget or packet delay budget (PDB) of the transmitted data; and the configuration information of the Radio Link Control (RLC) entity, Logical Channel, or Packet Data Convergence Protocol (PDCP) entity corresponding to the transmitted data.

25. The apparatus of claim 24, wherein the processing module is further configured to: perform a first operation; in, The execution of the first operation includes at least one of the following: Sending or receiving Physical Downlink Control Channel (PDCCH) scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted; Receive Hybrid Automatic Repeat Request (HARQ) feedback information sent by the receiving end based on the Media Access Control (MAC) control unit (CE); Receive transmission feedback information sent by the receiving end based on the Physical Uplink Shared Channel (PUSCH) resources.

26. A data transmission apparatus, comprising: The processing module is used to perform the third operation; The execution of the third operation includes at least one of the following: Sending or receiving PDCCH scheduling information, wherein the PDCCH scheduling information carries first indication information, the first indication information being used to indicate whether the previous data was successfully transmitted; CRC verification is performed through the MAC layer; The MAC CE sends HARQ feedback information to the sending end; Based on the PUSCH resource, transmission feedback information is sent to the sending end.

27. A communication device comprising a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the data transmission method as claimed in any one of claims 1 to 22, or implementing the steps of the data transmission method as claimed in claim 23.

28. A readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the data transmission method as claimed in any one of claims 1 to 22, or implement the steps of the data transmission method as claimed in claim 23.

Images