Data transmission method, storage medium, electronic device, and computer program product

Abstract

Embodiments of the present disclosure provide a data transmission method, a storage medium, an electronic device, and a computer program product. The method comprises: determining a type of a packet data convergence protocol protocol data unit (PDCP PDU) and an RLC transmission resource corresponding to the type; and sending or receiving the PDCP PDU by means of the RLC transmission resource.

Description

Data transmission methods, storage media, electronic devices and computer program products

[0001] Cross-references to related applications

[0002] This disclosure is based on and claims priority to Chinese patent application CN2025101123685, filed on January 22, 2025, entitled “Data Transmission Method, Storage Medium, Electronic Device and Computer Program Product”, and incorporates the entire contents of that patent application by reference. Technical Field

[0003] This disclosure relates to the field of communications, and more specifically, to a data transmission method, a storage medium, an electronic device, and a computer program product. Background Technology

[0004] In traditional wireless communication systems, such as 5G NR (New Radio), the Packet Data Convergence Protocol (PDCP) layer is responsible for key functions such as packet aggregation, header compression, encryption, and integrity protection, while the Radio Link Control (RLC) layer is responsible for radio link control, including fragmentation, reassembly, duplicate detection, and Automatic Repeat Request (ARQ) feedback. During data transmission, the PDCP layer generates two types of Protocol Data Units (PDUs): PDCP data PDUs, which carry user data; and PDCP control PDUs, which carry control information between the PDCP transmitter and receiver.

[0005] In traditional PDCP and RLC designs, such as in NR systems, both PDCP data PDUs and PDCP control PDUs are transmitted via RLC PDUs over the radio interface. If the RLC associated with the PDCP is in Acknowledged Mode (AM), the PDCP control PDU and PDCP data PDU are processed together in the same way, with transmission and reception constrained by the same transmit and receive windows (e.g., RLC PDUs exceeding the transmit window cannot be transmitted, nor can RLC PDUs exceeding the receive window be received). Because the PDCP PDUs carrying control information and user data use the same transmission mechanism at the RLC layer, when the amount of user data is large or retransmissions are frequent, the transmission of control information may be directly affected by the data transmission of user data, causing the PDCP control PDU to fail to reach the receiver in a timely manner, or even causing delays in control information due to retransmissions of user data.

[0006] There is no good solution to the above problems in the relevant technologies. Summary of the Invention

[0007] This disclosure provides a data transmission method, storage medium, electronic device, and computer program product to at least address the problem in the related art that the processing mechanism of PDCP PDU affects the timeliness of PDCP layer control information transmission.

[0008] According to one embodiment of this disclosure, a data transmission method is provided, comprising: determining the type of a Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resource corresponding to the type of the PDCP PDU; and transmitting the PDCP PDU through the RLC transmission resource.

[0009] According to another embodiment of this disclosure, a data transmission method is provided, comprising: determining the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resource corresponding to the type of PDCP PDU; and receiving the PDCP PDU through the RLC transmission resource.

[0010] According to another embodiment of this disclosure, a data transmission method is provided, comprising: in response to a Radio Link Control Service Data Unit (RLC SDU) to be transmitted being located outside a transmission window, transmitting a Radio Link Control Protocol Data Unit (RLC PDU) carrying first information, wherein the RLC PDU is used to carry an RLC SDU or an RLC SDU fragment of an RLC SDU; and adjusting the RLC transmitter variable and the position of the transmission window according to the first information.

[0011] According to another embodiment of this disclosure, a data transmission method is provided, comprising: receiving a Radio Link Control Protocol Data Unit (RLC PDU) carrying first information in response to a Radio Link Control Service Data Unit (RLC SDU) to be received being located outside a receiving window, wherein the RLC PDU is used to carry an RLC SDU or an RLC SDU fragment of an RLC SDU; and adjusting the RLC receiver variables and the position of the receiving window according to the first information.

[0012] According to yet another embodiment of this disclosure, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0013] According to yet another embodiment of this disclosure, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in any of the above method embodiments.

[0014] According to yet another embodiment of this disclosure, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0015] Through the above embodiments of this disclosure, different types of PDCP PDUs can be transmitted on different RLC transmission resources, realizing the independent transmission of PDCP control PDUs and PDCP data PDUs, thereby avoiding the impact of data PDUs on control PDU transmission. This solves the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieves the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission. Attached Figure Description

[0016] Figure 1 is a schematic diagram of the network architecture of a wireless access network according to an embodiment of the present disclosure;

[0017] Figure 2 is a schematic diagram of the user plane protocol stack between the access network element and the user equipment according to an embodiment of the present disclosure;

[0018] Figure 3 is a hardware structure block diagram of the mobile terminal operating in the embodiments of the method disclosed herein;

[0019] Figure 4 is a flowchart of a data transmission method of a transmitting end according to an embodiment of the present disclosure;

[0020] Figure 5 is a schematic diagram (a) of an RLC PDU header that does not include an RLC SN according to an embodiment of the present disclosure;

[0021] Figure 6 is a schematic diagram (a) of an RLC PDU header including an RLC SN according to an embodiment of the present disclosure;

[0022] Figure 7 is a schematic diagram (II) of an embodiment of the present disclosure where the RLC PDU header does not include the RLC SN;

[0023] Figure 8 is a schematic diagram (II) of an RLC PDU header including an RLC SN according to an embodiment of the present disclosure;

[0024] Figure 9 is a flowchart of a data transmission method of a receiving end according to an embodiment of the present disclosure;

[0025] Figure 10 is a flowchart of a data transmission method of a transmitting end according to another embodiment of the present disclosure;

[0026] Figure 11 is a flowchart of a data transmission method of a receiving end according to another embodiment of the present disclosure;

[0027] Figure 12 is a schematic block diagram of a data transmission system according to an embodiment of the present disclosure;

[0028] Figure 13 is a schematic diagram of the protocol architecture of a data transmission system in one embodiment of this disclosure (I);

[0029] Figure 14 is a schematic diagram of the protocol architecture of a data transmission system in one embodiment of this disclosure (II);

[0030] Figure 15 is a schematic diagram of the protocol architecture of a data transmission system in one embodiment of this disclosure (III). Detailed Implementation

[0031] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings and examples.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0033] The embodiments disclosed herein can be applied to wireless communication networks such as 5G and 6G networks. The following description uses a 5G wireless access network as an example, but this disclosure is not limited thereto.

[0034] Figure 1 is a schematic diagram of the network architecture of a wireless access network according to an embodiment of the present disclosure. The embodiments of the present disclosure can operate on the network architecture shown in Figure 1. As shown in Figure 1, the network architecture includes:

[0035] Access and Mobility Management Function (AMF) / User Plane Function (UPF) and 5G Node B (gNB), where AMF / UPF are core network elements and gNB is an access network element or base station.

[0036] The NG interface serves as the interface between the AMF / UPF and the gNB. The NG interface includes the NG User Plane Interface (NG-U) and the NG Control Plane Interface (NG-C). NG-C provides functions such as NG interface management, UE context management, UE mobility management, transmission of Non-Access Stratum (NAS) messages, paging, and PDU session management. NG-U is defined between the NG-RAN node (e.g., gNB) and the UPF.

[0037] Figure 2 is a schematic diagram of the user plane protocol stack between the access network element and the user equipment according to an embodiment of the present disclosure. As shown in Figure 2, the user plane protocol stack includes the following structure:

[0038] The layers are: Physical (PHY) layer, Medium Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, and Service Data Adaptation Protocol (SDAP) layer.

[0039] This disclosure mainly involves the PDCP layer function and the RLC layer function. The specific implementation methods of the PDCP layer function and the RLC layer function in the current standard protocol are as follows.

[0040] 1. PDCP layer functions

[0041] PDCP layer functions can be implemented through PDCP entities located in the PDCP sublayer. A user equipment (UE) can be configured with multiple PDCP entities. Each PDCP entity is used to carry data for a radio bearer, including the data radio bearer (DRB) and the signaling radio bearer (SRB).

[0042] The PDCP layer can perform the following functions: header compression and decompression, such as using the Robust Header Compression (ROHC) protocol or the Efficient Content Header (ECH) protocol; uplink data compression and decompression, such as using the Uplink Data Compression (UDC) protocol; ciphering and deciphering; integrity protection and integrity verification; timer-based SDU discard; reordering and in-order delivery; out-of-order delivery; duplication discarding; duplication; and routing for split bearers and DAPS bearers.

[0043] The PDCP layer includes the PDCP transmitter and the PDCP receiver.

[0044] The behavior of the PDCP sender includes:

[0045] 1) Receive Packet Data Convergence Protocol Service Data Unit (PDCP SDU) from the upper layer and associate a count (COUNT) value with the received PDCP SDU. The COUNT value consists of two parts: the Hyper Frame Number (HFN) and the Packet Data Convergence Protocol Sequence Number (PDCP SN). The PDCP SN is the low-order part of the COUNT, and the HFN is the high-order part.

[0046] 2) Based on the associated COUNT value, the PDCP sender may perform header compression, integrity protection, and encryption operations on the PDCP SDU.

[0047] 3) The PDCP sender constructs the PDCP PDU corresponding to the PDCP SDU. The PDCP PDU includes the PDCP SDU and the protocol header of the PDCP PDU, and the PDCP SN is included in the PDCP header.

[0048] 4) If a PDCP discard timer is configured, the PDCP transmitter starts a discard timer for each PDCP SDU received from the upper layer. When the PDCP transmitter receives a PDCP status report, or the lower layer confirms that the PDCP SDU has been successfully received, the timer is stopped. If the timer expires, the PDCP transmitter discards the PDCP SDU and its corresponding PDCP PDU, or all PDCP SDUs and their corresponding PDCP PDUs that belong to the same PDCP set as the PDCP SDU.

[0049] 5) The PDCP transmitter maintains the following variable: TX_NEXT, which is the COUNT value of the next PDCP SDU to be sent. Except for setting the SRB of the variable to be used, the initial value of this variable is 0.

[0050] The behavior of the PDCP receiver includes:

[0051] 1) Receives an RLC SDU, i.e., a PDCP PDU, from its lower layer protocol (RLC layer).

[0052] 2) Determine the COUNT value associated with the PDCP PDU based on the PDCP SN of the PDCP PDU.

[0053] 3) Based on the COUNT value, if the PDCP PDU is encrypted or protected for integrity, then the PDCP PDU is deciphered and its integrity is verified.

[0054] 4) Based on the COUNT value, determine whether this PDCP PDU has been received before. If so, discard the PDCP PDU; otherwise, put it into the receive buffer.

[0055] 5) If out-of-order delivery is not configured, or if in-order delivery is configured, the received PDCP SDUs are reordered based on the COUNT value, and the received PDCP SDUs are delivered to the upper layer in order according to their associated COUNT values.

[0056] 6) When PDCP detects a missing PDCP SDU, for example when the COUNT value of the received PDCP SDU is not continuous, PDCP can start a reordering timer to wait for the missing PDCP SDU. When the reordering timer times out, the PDCP layer gives up waiting for the missing PDCP SDU.

[0057] 7) The PDCP receiver maintains the following variables:

[0058] RX_DELIV is the COUNT value of the first PDCP SDU that has not been delivered to the upper layer but is still waiting to be received, and is the COUNT value of the next PDCP SDU that is delivered to the upper layer in sequence. In addition to the sidelink broadcast channel, the SRB and MRB are configured by variables, with an initial value of 0.

[0059] RX_NEXT is the next COUNT value after the maximum COUNT value in the PDCP SDU in the PDCP receive buffer, i.e., the COUNT value of the next PDCP SDU expected to be received.

[0060] RCVD_COUNT is the COUNT value of the currently received PDCP SDU.

[0061] RX_REORD is the next COUNT value of the PDCP data PDU that triggered the reordering timer.

[0062] 8) Reordering and sequential submission behaviors include:

[0063] Set RX_DELIV to the COUNT value of the first PDCP SDU that has not been submitted to the upper layer.

[0064] If RCVD_COUNT = RX_DELIV, then PDCP SDUs in the receive buffer starting from RX_RCVD with COUNT values greater than or equal to RX_DELIV and with consecutive COUNT values are delivered to the upper layer.

[0065] If RX_NEXT is greater than RX_DELIV, start the reordering timer and set the value of RX_REORD to RX_NEXT.

[0066] If the reordering timer is running and RX_DELIV is greater than or equal to RC_REORD, stop the reordering timer.

[0067] If the reordering timer expires, deliver PDCP SDUs with COUNT values less than RX_REORD in the buffer to its upper layer, and deliver consecutive PDCP SDUs starting from RX_REORD to its upper layer. Update the value of RX_DELIV. If RX_DELIV < RX_NEXT, start the reordering timer (at this time there are still undelivered / lost PDCP SDUs).

[0068] The PDCP layer may also have the function of PDCP re - establishment or PDCP recovery operations. The PDCP entity can perform PDCP re - establishment or PDCP recovery operations according to the instructions from the upper layer.

[0069] The behaviors of the PDCP sender include: 1) For DRBs in the acknowledged mode (AM) of PDCP without suspension, starting from the first PDCP data service data unit (PDCP data SDU) that has not been successfully acknowledged by its lower layer, send or re - send all PDCP SDUs associated with PDCP SN before PDCP re - establishment to its lower - layer protocol in ascending order of their COUNT values. 2) For AM DRBs of PDCP that are suspended, starting from the first PDCP data SDU that has not been successfully acknowledged by its lower layer, send each PDCP SDU associated with PDCP SN but not yet sent to its lower - layer protocol to the lower - layer protocol in ascending order of its COUNT value. 3) For DRBs in the unacknowledged mode (UM) of PDCP, send each PDCP SDU associated with PDCP SN but not yet sent to its lower - layer protocol to the lower - layer protocol in ascending order of its COUNT value.

[0070] The PDCP receiver's behavior includes: 1) For UM DRB and SRB, resetting RX_NEXT and RX_DELIV, stopping operation, and resetting the reordering timer. 2) For UM DRB, sending stored PDCP SDUs to its upper-layer protocol in the order of their COUNT values. For SRB, discarding all stored PDCP SDUs and PDCP PDUs. 3) Data recovery function for AM DRB. 4) Retransmitting PDCP SDUs that were previously sent to the reconstructed or released AM RLC entity and for which successful transmission was not confirmed by the lower-layer protocol, in ascending order of their COUNT values.

[0071] The PDCP layer also has a status reporting function.

[0072] The PDCP receiver constructs a PDCP status report based on instructions from its upper layer (e.g., the RRC layer) and sends it to the corresponding PDCP sender. Reasons that trigger a PDCP status report include: an upper layer requesting PDCP entity re-establishment; an upper layer requesting PDCP data recovery; an upper layer requesting uplink data switching; or an upper layer reconfiguring the PDCP to release the Data Aggregation and Protection Service (DAPS).

[0073] The PDCP status report includes one of the following:

[0074] The COUNT value of a lost PDCP SDU indicates the COUNT value of the first PDCP SDU that the PDCP receiver did not receive, i.e., the value of RX_DELIV.

[0075] A bitmap used to indicate the reception status of one or more PDCP SDUs. In order of COUNT values, one bit indicates the reception status of a PDCP SDU following the first unreceived PDCP SDU, i.e., whether the PDCP SDU has been received.

[0076] The PDCP transmitter determines whether a PDCP SDU has been received based on the contents of the PDCP status report. For a received PDCP SDU, the PDCP transmitter removes it from the transmit buffer queue.

[0077] 2. RLC layer functions

[0078] RLC layer functionality can be implemented through RLC entities located in the RLC sublayer, which sits below the PDCP layer and above the MAC layer in the protocol stack. A UE can configure one or more RLC entities. Each RLC entity carries data for a radio bearer, including the Data Radio Bearer (DRB) and the Signaling Radio Bearer (SRB). A PDCP entity may be associated with one or more RLC entities. For example, in PDCP duplication, one PDCP entity may be associated with two RLC entities, and one PDCP PDU may be sent to two RLC entities for transmission. In split radio bearer technology, i.e., split DRB / SRB, one PDCP entity is associated with two RLC entities, and each PDCP PDU is carried and transmitted by one RLC entity. The PDCP entity selects the RLC entity for transmission based on the implementation.

[0079] The RLC layer can have the following functions: transmitting PDUs of its upper-layer protocols, such as PDCP PDUs; implementing transmission error correction, i.e., feedback retransmission, through ARQ function; fragmenting / re-fragmenting and reassembling RLC SDUs; performing duplicate detection on received RLC PDUs / SDUs; RLC SDU discarding function; RLC reconstruction function, etc.

[0080] The RLC layer includes an RLC transmitter and an RLC receiver.

[0081] The behavior of the RLC transmitter includes:

[0082] 1) Receive the PDCP PDU sent by PDCP, i.e., RLC SDU. Construct the RLC PDU based on the received RLC SDU.

[0083] 2) The operation of constructing an RLC PDU may include segmentation of the RLC SDU. Segmentation includes dividing an RLC SDU into several segments and constructing an RLC PDU for each RLC segment. The size of the RLC segment matches the size of the RLC PDU indicated by its underlying protocol. For example, the size of the RLC PDU constructed after segmentation is less than or equal to the size of the RLC PDU indicated by the MAC layer.

[0084] 3) An RLC PDU may contain a complete RLC SDU, or a fragment of an RLC SDU.

[0085] 4) An RLC PDU in Acknowledged Mode (AM) contains an RLC header, which includes an RLC sequence number, i.e., RLC SN.

[0086] 5) In Unacknowledged Mode (UM), the RLC determines whether to include the RLC SN based on whether the RLC PDU contains fragments of the RLC SDU.

[0087] 6) Send the RLC PDU to its lower-layer protocol, namely the MAC layer.

[0088] 7) The AM RLC transmitter maintains the RLC transmission window.

[0089] 8) The AM RLC transmitter maintains the following variables:

[0090] TX_Next_ACK is the RLC SN of the next RLC SDU waiting for successful reception confirmation within the RLC transmission window, and its initial value is 0.

[0091] TX_Next is the value of the RLC SN for the next RLC SDU, and its initial value is 0.

[0092] 9) The range of the RLC transmission window is the interval: [TX_Next_ACK, TX_Next_ACK + AM transmission window size].

[0093] 10) The RLC transmitter will not send RLC SDUs that exceed the transmission window range.

[0094] 11) When the RLC transmitter receives an RLC status report, it updates the value of TX_Next_ACK according to the RLC SN acknowledged in the RLC status report and moves the RLC transmission window. That is, the RLC transmission window moves by acknowledging the RLC SDU received by the receiver.

[0095] 12) The UM RLC transmitter maintains the following variable: TX_Next, which is the value of the RLC SN for the next RLC SDU.

[0096] The functions of the RLC receiver include:

[0097] 1) Receive RLC PDU from the MAC layer.

[0098] 2) The received RLC PDU is reassembled into an RLC SDU.

[0099] 3) Determine the RLC SN associated with the reassembled RLC SDU. The SN associated with the RLC SDU is the RLC SN carried in the header of the RLC PDU.

[0100] 4) AM RLC maintains the RLC receiving window.

[0101] 5) The AM RLC receiver maintains the following variables:

[0102] RX_NEXT is the next RLC SN after the SN of the last fully received RLC SDU, or the smallest RLC SN among the unreceived RLC SDUs. It is also the lower edge of the receive window, and its initial value is 0.

[0103] RX_Next_Highest is the maximum value of the RLC SN in the received RLC SDU plus 1.

[0104] RX_Next_Status_Trigger is the next RLC SN of the RLC SDU that triggers the recombination timer.

[0105] RX_Highest_Status is the highest possible RLC SN that can be indicated as the ACK_SN field when a status report is constructed; its initial value is 0.

[0106] 6) The range of the RLC receive window is the interval of RLC SN, [RX_Next, RX_Next + AM receive window size).

[0107] 7) If the SN of the received RLC PDU is not within the RLC receive window, the RLC will discard the RLC PDU.

[0108] 8) When the RLC receiver detects a lost RLC SDU or RLC SDU fragment, such as when there is a gap between RX_Next and RX_Next_Highest where no RLC SDU or RLC fragment has been received, the RLC receiver starts a reassembly timer and sets the value of RX_Next_Status_Trigger to RX_Next_Highest.

[0109] 9) If all RLC SDUs before RX_Next_Status_Trigger when the reassembly timer is started have been successfully received, or there are no RLC fragmentation holes, or because of the movement of the RLC receive window, RX_Next_Status_Trigger falls outside the receive window and is not equal to the size of the RX_Next+AM receive window, then the reassembly timer is stopped.

[0110] 10) When the reassembly timer times out, update the value of RX_Highest_Status to the RLC SN of the first RLC SDU that was not fully received, which is greater than or equal to the RLC SN of RX_Next_Status_Trigger. If there is an unreceived RLC SDU or RLC fragment hole between RX_Highest_Status and RX_Next_Highest, start the reassembly timer and update the value of RX_Next_Status_Trigger to RX_Next_Highest.

[0111] 11) The UM RLC receiver maintains the RLC reassemble window.

[0112] 12) UM RLC maintains the following variables:

[0113] RX_Next_Reassembly is the earliest RLC SN that has not yet been successfully assembled within the reassembly window. Its initial value is 0.

[0114] RX_Timer_Trigger is the next RLC SN after the RLC SN that triggers the recombination timer.

[0115] RX_Next_Highest is the next RLC SN after the highest RLC SN of the received RLC PDU. This variable is also the upper edge of the recombination window. Its initial value is 0.

[0116] 13) The range of the RLC reconstruction window is [RX_Next_Highest - UM reconstruction window size, RX_Next_Highest].

[0117] 14) The position of the RLC reassembly window changes according to the highest value of the received RLC SN. That is, the RLC reassembly window moves whenever an RLC SN value greater than the current RX_Next_Highest is received. After the RLC reassembly window moves, RLC discards RLC PDUs / SDUs that have fallen outside the RLC reassembly window but have not yet been successfully reassembled.

[0118] 15) When an unreceived RLC PDU appears within the reassembly window, for example, RX_Next_Highest>RX_Next_Reassemble+1, or when there are non-continuously received RLC fragments, start the reassembly timer and set the value of RX_Timer_Trigger to RX_Next_Highest.

[0119] 16) If the RX_Timer_Trigger falls outside the reassembly window after the reassembly window has moved, or if the RLC SDU that triggered the reassembly timer is successfully received, then stop and reset the reassembly timer.

[0120] 17) When the reassembly timer times out, set the value of RX_Next_Reassemble to the first RLC SN that has not been fully received after the RLC SN that triggered the reassembly timer, and discard RLC fragments with an RLC SN less than RX_Next_Reassemble. Check the start conditions of the reassembly timer; if they are met, start the reassembly timer.

[0121] AM RLC's RLC also has a status reporting function.

[0122] Reasons that trigger the AM RLC receiver to report a status include: the reassembly timer expires; the receiver receives a polling request from the RLC transmitter to request an RLC status report; the AM RLC receiver constructs an RLC status report and sends it to the RLC transmitter.

[0123] The AM RLC status report includes one of the following: the RLC SN of the unreceived RLC SDU, i.e., the Negative Acknowledgement Sequence Number (NACK SN); the position of the fragment of the unreceived RLC SDU within the RLC SDU, i.e., the segment offset start and segment offset end; a range of RLC SNs for the unreceived RLC SDUs; the Acknowledgement Sequence Number (ACK SN); the next unreceived RLC SN not indicated in the status report; and RLC SDUs with an RLC SN less than the ACK SN, except those indicated as NACK in the status report, are considered successfully received.

[0124] When the RLC transmitter receives the RLC status report, it executes the ARQ function based on the information in the RLC status report, which is to retransmit the lost RLC SDU or RLC SDU fragments.

[0125] When an RLC transmitter receives an instruction from its upper-layer protocol to discard an RLC SDU, it discards the RLC SDU if the RLC SDU or its fragments have not been sent to the lower layer. Discarding an RLC SDU must not create a gap in the RLC SN, i.e., a discontinuous RLC SN.

[0126] The RLC layer also has a reconstruction function. When the upper layer requests RLC reconstruction, the RLC's behavior includes: discarding all RLC SDUs, RLC SDU fragments, and RLC PDUs in the RLC cache; stopping all timers, including timer reassembly; and restoring the variables maintained by the RLC to the initial values ​​agreed upon by the protocol.

[0127] In this embodiment of the disclosure, the PDCP layer defines the following types of PDCP PDUs: PDCP data PDU and PDCP control PDU, wherein the PDCP control PDU is used to transmit control information between the PDCP receiver and the PDCP transmitter.

[0128] The PDCP layer may define various control PDUs. For example, the following control PDUs are defined in the NR system:

[0129] PDCP status report: The PDCP receiver constructs a PDCP status report based on the instructions of its upper layer (e.g., RRC layer) and sends it to the corresponding PDCP sender.

[0130] The Control PDU for interspersed ROHC feedback is used, where the interspersed ROHC feedback is generated at the RHOC protocol layer and submitted to the PDCP layer. The PDCP layer submits the Control PDU for interspersed ROHC feedback to the lower-layer protocol, but does not associate it with the PDCP SN. The PDCP receiver that receives the Control PDU for interspersed ROHC feedback forwards it to the ROHC protocol.

[0131] The control PDU for EHC feedback is used for EHC feedback. EHC feedback is generated at the EHC protocol layer and submitted to the PDCP layer. The PDCP layer submits the control PDU for EHC feedback to the lower-layer protocol, and the PDCP receiver that receives the control PDU for EHC feedback forwards it to the ECH protocol layer.

[0132] The control PDU for UDC feedback is used by the PDCP to receive the control PDU for UDC feedback and submit it to the UDC protocol layer.

[0133] The methods and embodiments provided in this disclosure can be run on access network elements or user equipment in a wireless communication network. For example, access network elements may include gNBs, ng-eNBs, other access network devices, etc., and user equipment may include mobile terminals, computer terminals, etc.

[0134] The method embodiments provided in this disclosure can be executed in a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, FIG3 is a hardware structure block diagram of the mobile terminal running the method embodiments of this disclosure. As shown in FIG3, the mobile terminal may include one or more (only one is shown in FIG3) processors 32 (processor 32 may include, but is not limited to, processing devices such as microprocessors MCUs or programmable logic devices FPGAs) and a memory 34 for storing data. The mobile terminal may also include a transmission device 36 for communication functions and an input / output device 38. Those skilled in the art will understand that the structure shown in FIG3 is only illustrative and does not limit the structure of the mobile terminal. For example, the mobile terminal may also include more or fewer components than shown in FIG3, or have a different configuration than shown in FIG3.

[0135] The memory 34 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the data processing method in this embodiment. The processor 32 executes various functional applications and data processing by running the computer program stored in the memory 34, thus implementing the above-described method. The memory 34 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 34 may further include memory remotely located relative to the processor 32, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0136] The transmission device 36 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 36 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 36 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0137] This disclosure provides a data transmission method operating on the aforementioned access network element or user equipment, applied at the transmitting end. Figure 4 is a flowchart of the data transmission method at the transmitting end according to an embodiment of this disclosure. As shown in Figure 4, the process includes the following steps:

[0138] Step S402: Determine the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resources corresponding to the type of PDCP PDU;

[0139] Step S404: Send PDCP PDU via RLC transmission resources.

[0140] Through the above steps S402 and S404, different types of PDCP PDUs can be transmitted on different RLC transmission resources, realizing the independent transmission of PDCP control PDUs and PDCP data PDUs. This avoids the impact of data PDUs on control PDU transmission, thereby solving the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieving the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission.

[0141] The entities that perform the above steps can be access network elements, user equipment, etc., but are not limited to these.

[0142] In this embodiment, the user plane protocol stack of the access network element or user equipment includes the following structure from bottom to top: PHY layer, MAC layer, RLC layer, PDCP layer, and SDAP layer. The RLC layer includes an RLC transmitter and an RLC receiver, and the PDCP layer includes a PDCP transmitter and a PDCP receiver.

[0143] The method in this embodiment is mainly applied to the RLC layer and implemented through an RLC entity (such as an RLC transmitter). The RLC transmitter receives data in the form of PDCP PDUs from the upper layer (such as the PDCP layer), encapsulates or segments the received PDCP PDUs into RLC PDUs, and then sends the RLC PDUs to the lower layer (such as the MAC layer). The PDCP PDUs may contain user data or control information. When sending RLC PDUs, the RLC transmitter must comply with the RLC transmission modes (such as AM, UM, TM), which determine the transmission, acknowledgment, and retransmission mechanisms of the RLC PDUs.

[0144] In some embodiments, the types of PDCP PDUs include PDCP control protocol data units and PDCP data protocol data units.

[0145] Example 1: Transmitting different types of PDCP PDUs based on different sub-channels or sub-bearers

[0146] In some embodiments, RLC transmission resources include subchannels or subbearers, wherein the subchannels or subbearers corresponding to PDCP control protocol data units and PDCP data protocol data units are different.

[0147] In some embodiments, step S404 may include: sending an RLC protocol data unit for carrying a PDCP PDU through an RLC entity, wherein the protocol header of the RLC protocol data unit contains an identifier of a subchannel or subbearer.

[0148] In this embodiment, each PDCP entity is used to carry data for a radio bearer (such as a DRB). Access network elements can configure one or more sub-channels or sub-bearers for a DRB, where each sub-channel or sub-bearer corresponds to an identifier. The value of the sub-channel identifier or sub-bearer identifier remains unique within the configuration of the DRB. One type of RLC PDU can correspond to one or more types of PDCP control PDUs, or one or more PDCP data PDUs, or an RLC data PDU, or an RLC control PDU.

[0149] In some embodiments, the configuration information for each subchannel or subbearer is configured separately, wherein the configuration information includes at least one of the following:

[0150] The transmission mode of the sub-channel or the sub-bearer includes Transparent Mode (TM), Unacknowledged Mode (UM), or Acknowledged Mode (AM).

[0151] Does the protocol header of the RLC protocol data unit of the sub-channel or the sub-bearer contain a Radio Link Control Sequence Number (RLC SN)?

[0152] The size of the reassembly timer for the sub-channel or the sub-bearer;

[0153] Whether the sub-channel or the sub-bearer uses a transmit window and a receive window;

[0154] The size of the transmit window and the size of the receive window of the sub-channel or the sub-bearer;

[0155] Whether the sub-channel or the sub-bearer provides feedback on the reception status via RLC status report.

[0156] In this embodiment, different sub-channels / sub-bearers can be associated with different types of PDCP PDUs. Based on this, the access network element can individually configure the above-mentioned configuration information (e.g., transmission mode, whether the protocol header contains an RLC SN, the size of the reassembly timer, whether to use a transmit window and a receive window, the size of the transmit window and the size of the receive window, whether to use an RLC status report, etc.) for each sub-channel or sub-bearer. This enables individual configuration of the transmission mechanism for different types of PDCP PDUs, making the transmission method more flexible. It can avoid mutual interference between different sub-channels / sub-bearers / different types of PDCP PDUs, improve the transmission efficiency of control-type PDCP PDUs, and ensure the timeliness of PDCP layer control information.

[0157] In this embodiment, the protocol header of the RLC PDU may or may not include an RLC SN. Different subchannels / subbearers or different types of PDCP PDUs may be transmitted using RLC PDUs with different protocol header formats.

[0158] Figure 5 is a schematic diagram (a) of an RLC PDU header that does not contain an RLC SN according to an embodiment of the present disclosure. As shown in Figure 5, the RLC PDU header contains a Sub-CH field, which is used to indicate the identifier of the sub-channel or sub-bearer to which the RLC PDU belongs, but the RLC PDU header does not contain an RLC SN.

[0159] The RLC PDU header may also include the following fields:

[0160] The D / C field, Data / Control indication field, indicates whether the RLC PDU is an RLC data PDU or an RLC control PDU.

[0161] P field, the polling indicator field.

[0162] The SI field, or Segment Indication field, is used to indicate whether an RLC PDU contains RLC fragments.

[0163] The payload of the RLC PDU in Figure 5 is a PDCP control PDU, but this disclosure is not limited to this. The type of PDCP PDU in the payload is related to the identifier of the subchannel / subbearer.

[0164] Figure 6 is a schematic diagram (a) of an RLC PDU header containing an RLC SN according to an embodiment of the present disclosure. As shown in Figure 6, the RLC PDU header contains a Sub-CH field, which is used to indicate the identifier of the sub-channel or sub-bearer to which the RLC PDU belongs, and the RLC PDU header contains an RLC SN.

[0165] The RLC PDU header may also include the following fields:

[0166] The D / C field, the Data / Control indication field, indicates whether the RLC PDU is an RLC data PDU or an RLC control PDU.

[0167] P field, the polling indicator field.

[0168] The SI field, or Segment Indication field, is used to indicate whether an RLC PDU contains RLC fragments.

[0169] The payload of the RLC PDU in Figure 6 is a PDCP control PDU, but this disclosure is not limited to this. The type of PDCP PDU in the payload is related to the identifier of the subchannel / subbearer.

[0170] In some embodiments, the method may further include: responding to the transmission mode of the subchannel or the subbearer being the UM or the AM, or responding to the protocol header of the RLC protocol data unit of the subchannel or the subbearer containing the RLC SN, wherein the RLC entity (such as an RLC transmitter) maintains a set of RLC transmitter variables and / or the transmission window for the subchannel or the subbearer, wherein the transmission window is used to control the transmission of the RLC protocol data unit.

[0171] In an exemplary embodiment, if the transmission mode of a subchannel or subbearer is AM mode, the RLC variables to be maintained by the corresponding RLC entity may include TX_Next and TX_Next_Ack.

[0172] In one exemplary embodiment, if an RLC PDU of a subchannel or subbearer contains an RLC SN, then the RLC SN of that subchannel or subbearer is a value space of maintained RLC SNs, that is, different from the value space of RLC SNs of other subchannels or subbearers. For example, the value of the RLC SN of the constructed RLC PDU can be set to the value of the corresponding variable TX_Next, and TX_Next can be incremented by one.

[0173] In this embodiment, the RLC entity (such as the RLC transmitter) can determine the sub-channel or sub-bearer corresponding to the RLC PDU and include the identifier of the corresponding sub-channel or sub-bearer in the RLC PDU header. The RLC transmitter can send the PDU to its lower-layer protocol according to the transmission window corresponding to its sub-channel or sub-bearer and maintain the RLC transmitter variables corresponding to the sub-channel or sub-bearer. Furthermore, the RLC receiver can determine the sub-channel or sub-bearer to which the RLC PDU belongs based on the identifier of the sub-channel or sub-bearer included in the RLC PDU header. The RLC receiver processes the PDU according to the reception window or reassembly window corresponding to the sub-channel or sub-bearer to which the RLC PDU belongs and maintains the corresponding RLC receiver variables.

[0174] In one exemplary embodiment, if a subchannel or subbearer is configured to support status reporting, the RLC receiver can indicate the identifier of the subchannel or subbearer in the generated RLC status report. The RLC transmitter that receives the RLC status report determines the subchannel or subbearer to which the RLC status report belongs based on the identifier of the subchannel or subbearer.

[0175] In this embodiment of the disclosure, by introducing the concept of sub-channels or sub-bearers, the transmission mode and behavior of each sub-channel and sub-bearer can be configured separately, so as to realize different processing of RLC PDUs carrying PDCP data PDUs and RLC PDUs carrying PDCP control PDUs. This avoids the impact of the transmission of RLC PDUs carrying PDCP data PDUs on the transmission of PDCP control PDUs, and maximizes the flexibility of processing different RLC bearer contents.

[0176] Example 2: Sending different types of PDCP PDUs based on different types of RLC PDUs

[0177] In other embodiments, the RLC transport resource includes RLC protocol data units, wherein the types of the RLC protocol data units corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit are different.

[0178] In one exemplary embodiment, an RLC control PDU can be used to carry a PDCP control PDU, and an RLC data PDU can be used to carry a PDCP data PDU. Furthermore, one type of RLC control PDU can carry one or more types of PDCP control PDUs. The type of one or more PDCP control PDUs can correspond to the type of one RLC control PDU.

[0179] In traditional RLC technology, RLC control PDUs are only used to carry RLC layer control information, such as RLC status reports. The transmission of various types of PDCP PDUs is performed through RLC data PDUs. However, embodiments of this disclosure can use different types of RLC PDUs to carry different types of PDCP PDUs, performing different transmission processing on PDCP control PDUs and PDCP data PDUs, thereby avoiding the impact of PDCP data PDU transmission on PDCP control PDU transmission.

[0180] In some embodiments, step S404 may include: sending an RLC protocol data unit for carrying the PDCP PDU via an RLC entity, wherein the protocol header of the RLC protocol data unit contains the type of the RLC protocol data unit.

[0181] In one exemplary embodiment, the type of an RLC protocol data unit can be indicated by a type field, the value of which can indicate that the RLC PDU is a data type or one of a variety of control types.

[0182] In another exemplary embodiment, the type of an RLC protocol data unit can be indicated by a type field and a control type field, wherein the value of the type field can indicate whether the RLC PDU is an RLC data PDU or an RLC control PDU, and the control type field can indicate which control type the RLC control PDU is specifically.

[0183] In some embodiments, the configuration information for each type of RLC protocol data unit is configured by the access network element or agreed upon by the protocol, wherein the configuration information includes at least one of the following:

[0184] The correspondence between the types of PDCP PDUs and the types of RLC protocol data units;

[0185] The transmission mode of the RLC protocol data unit type includes transparent mode TM, unacknowledged mode UM, or acknowledged mode AM;

[0186] The type of the RLC protocol data unit; whether the protocol header of the RLC protocol data unit contains a Radio Link Control Sequence Number (RLC SN);

[0187] The size of the reassembly timer for the type of RLC protocol data unit;

[0188] Whether the type of the RLC protocol data unit uses a transmit window and a receive window;

[0189] The size of the sending window and the size of the receiving window for the type of RLC protocol data unit;

[0190] Whether the type of the RLC protocol data unit is reported in the RLC status report indicates the reception status.

[0191] In this embodiment, different types of RLC PDUs can be associated with different types of PDCP PDUs. Based on this, access network elements can individually configure the above-mentioned configuration information (e.g., transmission mode, whether the protocol header contains an RLC SN, the size of the reassembly timer, whether to use a transmit window and a receive window, the size of the transmit window and the receive window, whether to use RLC status reports, etc.) for each type of RLC PDU. This enables individual configuration of the transmission mechanism for different types of PDCP PDUs, making the transmission method more flexible. It can avoid mutual interference between different types of RLC PDUs / different types of PDCP PDUs, improve the transmission efficiency of control type PDCP PDUs, and ensure the timeliness of PDCP layer control information.

[0192] In some embodiments, the types of the RLC protocol data units include: RLC control protocol data units (RLC control PDUs) and RLC data protocol data units (RLC data PDUs), wherein the correspondence between the types of the PDCP PDUs and the types of the RLC protocol data units includes at least one of the following:

[0193] A correspondence between one or more PDCP control protocol data units and one RLC control protocol data unit;

[0194] A correspondence between one or more PDCP data protocol data units and one RLC data protocol data unit.

[0195] In some embodiments, the PDCP control PDU may include the following types: PDCP status report, control PDU for interleaved ROHC feedback, control PDU for EHC feedback, control PDU for UDC feedback, etc.

[0196] In some embodiments, the RLC control PDU may include the following types: RLC status report, control PDU for interleaved ROHC feedback, control PDU for EHC feedback, control PDU for UDC feedback, etc.

[0197] In this embodiment, the protocol header of the RLC PDU may or may not include an RLC SN. Different types of RLC PDUs or different types of PDCP PDUs may use different RLC PDU protocol header formats.

[0198] Figure 7 is a schematic diagram (II) of an RLC PDU header that does not contain an RLC SN according to an embodiment of the present disclosure. As shown in Figure 7, the RLC PDU header contains a CPT field to indicate the type of RLC control PDU, but the RLC PDU header does not contain an RLC SN.

[0199] The RLC PDU header may also include a D / C field, which is the Data / Control indication field, indicating whether the RLC PDU is an RLC data PDU or an RLC control PDU.

[0200] The payload of the RLC PDU in Figure 7 is a PDCP control PDU, but this disclosure is not limited to this. The type of PDCP PDU in the payload is related to the type of RLC PDU (i.e., the values ​​of the CPT field and D / C field).

[0201] Figure 8 is a schematic diagram (II) of an RLC PDU header containing an RLC SN according to an embodiment of the present disclosure. As shown in Figure 8, the RLC PDU header contains a CPT field to indicate the type of RLC control PDU, and the RLC PDU header contains an RLC SN.

[0202] The RLC PDU header may also include a D / C field, indicating whether the RLC PDU is an RLC data PDU or an RLC control PDU.

[0203] The payload of the RLC PDU in Figure 8 is a PDCP control PDU, but this disclosure is not limited to this. The type of PDCP PDU in the payload is related to the type of RLC PDU (i.e., the values ​​of the CPT field and D / C field).

[0204] In some embodiments, the method may further include: responding to the transmission mode corresponding to the type of the RLC protocol data unit being the UM or the AM, or responding to the protocol header of the RLC protocol data unit corresponding to the type of the RLC protocol data unit containing the RLC SN, wherein the RLC entity maintains a set of RLC transmitter variables and / or the transmission window for the type of the RLC protocol data unit, wherein the transmission window is used to control the transmission of the RLC protocol data unit.

[0205] In one exemplary embodiment, if the transmission mode of an RLC PDU of type RLC control PDU is UM or AM, or if an RLC SN is configured, the RLC transmitter (separately) maintains a set of RLC variables and / or a transmission window, such as the TX_Next variable. The RLC receiver (separately) maintains a set of RLC variables and / or a receive window or reassembly window for it.

[0206] In one exemplary embodiment, if an RLC PDU of a certain type contains an RLC SN, then the RLC SN of that RLC control PDU is a value space of maintained RLC SNs, that is, different from the RLC SN used for RLC data PDUs and different from the RLC SNs used by other types of RLC control PDUs. For example, the value of the RLC SN of the constructed RLC PDU is set to the value of the corresponding TX_Next, and TX_Next is incremented by one.

[0207] In one exemplary embodiment, the RLC transmitter may maintain a set of RLC transmitter variables, and / or a transmission window, as well as a separate space for the RLC data PDU.

[0208] In an exemplary embodiment, the RLC transmitter can wrap the PDCP control PDU in the RLC control PDU, indicate its corresponding RLC control PDU type in the RLC control PDU, send it to its lower layer protocol according to the transmission window corresponding to the RLC control PDU type, and maintain the RLC transmitter variable corresponding to the RLC control PDU type.

[0209] In an exemplary embodiment, the RLC transmitter can wrap the PDCP data PDU in the RLC data PDU, send it to its lower-layer protocol according to the transmission window corresponding to the RLC data PDU, and maintain the RLC transmitter variables corresponding to the RLC data PDU.

[0210] In one exemplary embodiment, the RLC receiver can process the RLC PDU according to the type of the RLC control PDU or the type of the RLC PDU contained in the RLC PDU header. If the received RLC PDU is an RLC data PDU, it is received according to the receiving window or reassembly window corresponding to the RLC data PDU, and the corresponding RLC receiver variables are maintained. If the received RLC PDU is of type T of the RLC control PDU, it is received according to the receiving window and / or reassembly window corresponding to type T, and the corresponding RLC receiver variables are maintained.

[0211] In one exemplary embodiment, if an RLC control PDU type is configured to support status reporting, the RLC receiver indicates the type of RLC control PDU in the generated RLC status report. The RLC transmitter that receives the RLC status report determines the type of RLC control PDU to which the RLC status report belongs based on the RLC control PDU type.

[0212] In this embodiment, by using different types of RLC PDUs to carry different types of PDCP PDUs, especially by carrying PDCP control PDUs within RLC control PDUs, and configuring the transmission modes and behaviors of different types of RLC PDUs separately, independent transmission of PDCP control PDUs and PDCP data PDUs is achieved. This avoids the impact of the transmission of RLC PDUs carrying PDCP data PDUs on the transmission of PDCP control PDUs. This embodiment also avoids introducing the concept of subchannels or subbearers at the RLC layer, reducing modifications to the protocol.

[0213] Example 3: Sending different types of PDCP PDUs based on different RLC entities

[0214] In other embodiments, the RLC transport resource includes an RLC entity, wherein the RLC entity corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit is different.

[0215] In some embodiments, step S404 may include: sending an RLC protocol data unit for carrying the PDCP PDU through the RLC entity corresponding to the type of the PDCP PDU.

[0216] In this embodiment, an access network element can be configured to associate a PDCP entity with one or more RLC entities, and the associated RLC entity can be configured to transmit either PDCP data PDUs or PDCP control PDUs. Each RLC entity includes an RLC transmitter and an RLC receiver, wherein the RLC transmitter is used to implement the data transmission function of the RLC layer, and the RLC receiver is used to implement the data reception function of the RLC layer.

[0217] In one exemplary embodiment, a PDCP entity can be associated with two RLC entities, such as a first RLC entity and a second RLC entity. The first RLC entity is used for the transmission of PDCP data PDUs, and the second RLC entity is used for the transmission of PDCP control PDUs. By using different RLC entities to process different types of PDCP PDUs separately, independent transmission of PDCP data PDUs and PDCP control PDUs can be achieved, avoiding the influence of PDCP data PDUs on PDCP control PDUs and improving the transmission efficiency of control information.

[0218] In some embodiments, different types of PDCP control PDUs can be controlled by the same or different RLC entities, and access network elements can be configured to handle one or more types of PDCP control PDUs for each RLC entity.

[0219] In some embodiments, the configuration information for each RLC entity is configured separately, wherein the configuration information includes at least one of the following:

[0220] Logical Channel Identification (LCID) is used to identify the RLC entity in the lower-layer protocol entity;

[0221] The transmission modes of the RLC entity include transparent mode TM, unacknowledged mode UM, or acknowledged mode AM;

[0222] Does the protocol header of the RLC protocol data unit of the RLC entity contain a Radio Link Control Sequence Number (RLC SN)?

[0223] The size of the recombination timer for the RLC entity;

[0224] Whether the RLC entity uses a send window and a receive window;

[0225] The size of the transmit window and the size of the receive window of the RLC entity;

[0226] Whether the RLC entity reports its reception status via the RLC status report.

[0227] In this embodiment, different RLC entities can be associated with different types of PDCP PDUs. Based on this, the access network elements can individually configure the above-mentioned configuration information of each RLC entity (e.g., LCID, transmission mode, whether the protocol header contains an RLC SN, the size of the reassembly timer, whether to use a transmit window and a receive window, the size of the transmit window and the size of the receive window, whether to use an RLC status report, etc.). This enables individual configuration of the transmission mechanism for different RLC entities and different types of PDCP PDUs, making the transmission method more flexible, avoiding mutual interference between different types of PDCP PDUs, improving the transmission efficiency of control-type PDCP PDUs, and ensuring the timeliness of PDCP layer control information.

[0228] In this embodiment, the protocol header of the RLC PDU may or may not include an RLC SN. Different RLC entities / different types of PDCP PDUs may be transmitted using RLC PDUs with different protocol header formats.

[0229] In this embodiment of the disclosure, the PDCP transmitter can send PDCP PDUs to the corresponding RLC transmitters according to the type of PDCP PDU. For example, the PDCP control PDU is sent to the first RLC transmitter, and the PDCP data PDU is sent to the second RLC transmitter. The PDCP control PDU and PDCP data PDU are transmitted through the first and second RLC transmitters respectively. The first and second RLC receivers receive the RLC PDUs respectively and deliver them to the PDCP receiver.

[0230] In some embodiments, the PDCP control PDU can be transmitted in the form of an RLC data PDU or an RLC control PDU.

[0231] In one exemplary embodiment, the first RLC entity and the second RLC entity can respectively perform RLC status reporting operations.

[0232] In one exemplary embodiment, the first RLC entity and the second RLC entity may each be configured with different identifiers for identification by their underlying protocol entities, such as the MAC layer. This identifier may be a Logical Channel Identifier (LCID). When an RLC PDU is carried at the MAC protocol layer, its corresponding RLC entity's LCID is identified.

[0233] This embodiment associates at least two RLC entities with one PDCP entity, enabling independent transmission of different PDCP PDU types. Access network elements can configure different transmission modes and parameters for different RLC entities. This embodiment maximizes the utilization of the existing RLC layer functionality, achieving independent transmission of PDCP control PDUs and PDCP data PDUs without requiring major modifications to existing RLC functions.

[0234] In the above embodiments of this disclosure, by distinguishing different types of PDCP PDUs and configuring corresponding RLC layer transmission resources, the purpose of independently transmitting PDCP control PDUs and PDCP data PDUs can be achieved by using different sub-channels / sub-bearers, different types of RLC PDUs, or different RLC entities. This can avoid mutual interference between different types of PDCP PDUs, solve the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieve the effect of improving the efficiency, flexibility, and reliability of data transmission.

[0235] This disclosure also provides a data transmission method operating on the aforementioned access network element or user equipment, applied at a receiving end. Figure 9 is a flowchart of the data transmission method at the receiving end according to an embodiment of this disclosure. As shown in Figure 9, the process includes the following steps:

[0236] Step S902: Determine the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resources corresponding to the type of PDCP PDU;

[0237] Step S904: Receive PDCP PDU via RLC transmission resources.

[0238] Through the above steps S902 and S904, different types of PDCP PDUs can be transmitted on different RLC transmission resources. Independent processing of PDCP control PDUs and PDCP data PDUs can be achieved at the receiving end, thereby avoiding the impact of data PDUs on control PDU transmission. This solves the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieves the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission.

[0239] The entities that perform the above steps can be access network elements, user equipment, etc., but are not limited to these.

[0240] In this embodiment, the user plane protocol stack of the access network element or user equipment includes the following structure from bottom to top: PHY layer, MAC layer, RLC layer, PDCP layer, and SDAP layer. The RLC layer includes an RLC transmitter and an RLC receiver, and the PDCP layer includes a PDCP transmitter and a PDCP receiver.

[0241] The method in this embodiment is mainly applied to the RLC layer and implemented through an RLC entity, such as an RLC receiver. The RLC receiver receives data in RLC PDU format (including PDCP PDUs or PDCP PDUs) from the next lower layer (e.g., the MAC layer), decapsulates or reassembles the received RLC PDU into a PDCP PDU, and then transmits the PDCP PDU to the next higher layer (e.g., the PDCP layer). The PDCP PDU may contain user data or control information. When receiving the RLC PDU, the RLC receiver must comply with the RLC transmission mode (e.g., AM, UM, TM), which determines the transmission, acknowledgment, and retransmission mechanisms of the RLC PDU.

[0242] In some embodiments, the type of the PDCP PDU includes PDCP control protocol data unit and PDCP data protocol data unit.

[0243] Example 4: Receiving different types of PDCP PDUs based on different sub-channels or sub-bearers

[0244] In some embodiments, RLC transmission resources include subchannels or subbearers, wherein the subchannels or subbearers corresponding to PDCP control protocol data units and PDCP data protocol data units are different.

[0245] In some embodiments, step S904 may include: receiving an RLC protocol data unit for carrying the PDCP PDU via an RLC entity, wherein the protocol header of the RLC protocol data unit contains an identifier of the subchannel or the subbearer.

[0246] In this embodiment, each PDCP entity is used to carry data for a radio bearer (such as a DRB). Access network elements can configure one or more sub-channels or sub-bearers for a DRB, where each sub-channel or sub-bearer corresponds to an identifier. The value of the sub-channel identifier or sub-bearer identifier remains unique within the configuration of the DRB. One type of RLC PDU can correspond to one or more types of PDCP control PDUs, or one or more PDCP data PDUs, or an RLC data PDU, or an RLC control PDU.

[0247] In some embodiments, the configuration information for each subchannel or subbearer is configured separately, wherein the configuration information includes at least one of the following:

[0248] The transmission mode of the sub-channel or the sub-bearer includes transparent mode TM, unacknowledged mode UM, or acknowledged mode AM;

[0249] Does the protocol header of the RLC protocol data unit of the sub-channel or the sub-bearer contain a Radio Link Control Sequence Number (RLC SN)?

[0250] The size of the reassembly timer for the sub-channel or the sub-bearer;

[0251] Whether the sub-channel or the sub-bearer uses a transmit window and a receive window;

[0252] The size of the transmit window and the size of the receive window of the sub-channel or the sub-bearer;

[0253] Whether the sub-channel or the sub-bearer provides feedback on the reception status via RLC status report.

[0254] In this embodiment, different sub-channels / sub-bearers can be associated with different types of PDCP PDUs. Based on this, the access network element can individually configure the above-mentioned configuration information (e.g., transmission mode, whether the protocol header contains an RLC SN, the size of the reassembly timer, whether to use a transmit window and a receive window, the size of the transmit window and the size of the receive window, whether to use an RLC status report, etc.) for each sub-channel or sub-bearer. This enables individual configuration of the transmission mechanism for different types of PDCP PDUs, making the transmission method more flexible. It can avoid mutual interference between different sub-channels / sub-bearers / different types of PDCP PDUs, improve the transmission efficiency of control-type PDCP PDUs, and ensure the timeliness of PDCP layer control information.

[0255] In some embodiments, the method may further include: in response to the transmission mode of the subchannel or the subbearer being the UM or the AM, or in response to the protocol header of the RLC protocol data unit of the subchannel or the subbearer containing the RLC SN, the RLC entity (such as an RLC receiver) maintains a set of RLC receiver variables and / or a receive window and / or a reassembly window for the subchannel or the subbearer, wherein the receive window is used to control the reception of the RLC protocol data unit, and the reassembly window is used to control the reassembly of the RLC protocol data unit.

[0256] In an exemplary embodiment, if the transmission mode of a subchannel or subbearer is AM mode, the RLC variables to be maintained by the corresponding RLC entity may include TX_Next and TX_Next_Ack.

[0257] In one exemplary embodiment, if an RLC PDU of a subchannel or subbearer contains an RLC SN, then the RLC SN of that subchannel or subbearer is a value space of maintained RLC SNs, that is, different from the value space of RLC SNs of other subchannels or subbearers. For example, the value of the RLC SN of the constructed RLC PDU can be set to the value of the corresponding variable TX_Next, and TX_Next can be incremented by one.

[0258] In this embodiment, an RLC entity (such as an RLC receiver) can determine the sub-channel or sub-bearer to which the RLC PDU belongs based on the identifier of the sub-channel or sub-bearer contained in the RLC PDU header. The RLC receiver processes the PDU according to the receive window or reassembly window corresponding to the sub-channel or sub-bearer to which it belongs and maintains the corresponding RLC receiver variables. Furthermore, when transmitting an RLC PDU, the RLC entity (such as an RLC transmitter) also needs to determine the sub-channel or sub-bearer corresponding to the RLC PDU and include the identifier of the corresponding sub-channel or sub-bearer in the RLC PDU header. The RLC transmitter can transmit the PDU to its lower-layer protocol according to the transmit window corresponding to its sub-channel or sub-bearer and maintain the RLC transmitter variables corresponding to the sub-channel or sub-bearer.

[0259] In one exemplary embodiment, if a subchannel or subbearer is configured to support status reporting, the RLC receiver indicates the identifier of the subchannel or subbearer in the generated RLC status report. The RLC transmitter that receives the RLC status report determines the subchannel or subbearer to which the RLC status report belongs based on the identifier of the subchannel or subbearer.

[0260] In this embodiment of the disclosure, by introducing the concept of sub-channels or sub-bearers, the transmission mode and behavior of each sub-channel and sub-bearer can be configured separately, so as to realize different processing of RLC PDUs carrying PDCP data PDUs and RLC PDUs carrying PDCP control PDUs. This avoids the impact of the transmission of RLC PDUs carrying PDCP data PDUs on the transmission of PDCP control PDUs, and maximizes the flexibility of processing different RLC bearer contents.

[0261] Example 5: Receiving different types of PDCP PDUs based on different types of RLC PDUs

[0262] In other embodiments, the RLC transport resource includes RLC protocol data units, wherein the types of the RLC protocol data units corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit are different.

[0263] In one exemplary embodiment, an RLC control PDU can be used to carry a PDCP control PDU, and an RLC data PDU can be used to carry a PDCP data PDU. Furthermore, one type of RLC control PDU can carry one or more types of PDCP control PDUs. The type of one or more PDCP control PDUs can correspond to the type of one RLC control PDU.

[0264] In traditional RLC technology, RLC control PDUs are only used to carry RLC layer control information, such as RLC status reports. The transmission of various types of PDCP PDUs is performed through RLC data PDUs. However, embodiments of this disclosure can use different types of RLC PDUs to carry different types of PDCP PDUs, performing different transmission processing on PDCP control PDUs and PDCP data PDUs, thereby avoiding the impact of PDCP data PDU transmission on PDCP control PDU transmission.

[0265] In some embodiments, step S904 may include: receiving an RLC protocol data unit for carrying the PDCP PDU via an RLC entity, wherein the protocol header of the RLC protocol data unit contains the type of the RLC protocol data unit.

[0266] In one exemplary embodiment, the type of an RLC protocol data unit can be indicated by a type field, the value of which can indicate that the RLC PDU is a data type or one of a variety of control types.

[0267] In another exemplary embodiment, the type of an RLC protocol data unit can be indicated by a type field and a control type field, wherein the value of the type field can indicate whether the RLC PDU is an RLC data PDU or an RLC control PDU, and the control type field can indicate which control type the RLC control PDU is specifically.

[0268] In some embodiments, the configuration information for each type of RLC protocol data unit is configured by the access network element or agreed upon by the protocol, wherein the configuration information includes at least one of the following:

[0269] The correspondence between the types of PDCP PDUs and the types of RLC protocol data units;

[0270] The transmission mode of the RLC protocol data unit type includes transparent mode TM, unacknowledged mode UM, or acknowledged mode AM;

[0271] The type of the RLC protocol data unit; whether the protocol header of the RLC protocol data unit contains a Radio Link Control Sequence Number (RLC SN);

[0272] The size of the reassembly timer for the type of RLC protocol data unit;

[0273] Whether the type of the RLC protocol data unit uses a transmit window and a receive window;

[0274] The size of the sending window and the size of the receiving window for the type of RLC protocol data unit;

[0275] Whether the type of the RLC protocol data unit is reported in the RLC status report indicates the reception status.

[0276] In this embodiment, different types of RLC PDUs can be associated with different types of PDCP PDUs. Based on this, access network elements can individually configure the above-mentioned configuration information (e.g., transmission mode, whether the protocol header contains an RLC SN, the size of the reassembly timer, whether to use a transmit window and a receive window, the size of the transmit window and the receive window, whether to use RLC status reports, etc.) for each type of RLC PDU. This enables individual configuration of the transmission mechanism for different types of PDCP PDUs, making the transmission method more flexible. It can avoid mutual interference between different types of RLC PDUs / different types of PDCP PDUs, improve the transmission efficiency of control type PDCP PDUs, and ensure the timeliness of PDCP layer control information.

[0277] In some embodiments, the types of the RLC protocol data units include: RLC control protocol data units (RLC control PDUs) and RLC data protocol data units (RLC data PDUs), wherein the correspondence between the types of the PDCP PDUs and the types of the RLC protocol data units includes at least one of the following:

[0278] A correspondence between one or more PDCP control protocol data units and one RLC control protocol data unit;

[0279] A correspondence between one or more PDCP data protocol data units and one RLC data protocol data unit.

[0280] In some embodiments, the PDCP control PDU may include the following types: PDCP status report, control PDU for interleaved ROHC feedback, control PDU for EHC feedback, control PDU for UDC feedback, etc.

[0281] In some embodiments, the RLC control PDU may include the following types: RLC status report, control PDU for interleaved ROHC feedback, control PDU for EHC feedback, control PDU for UDC feedback, etc.

[0282] In some embodiments, the method may further include: responding to the transmission mode corresponding to the type of the RLC PDU being the UM or the AM, or responding to the protocol header of the RLC protocol data unit corresponding to the type of the RLC PDU containing the RLC SN, the RLC entity (such as an RLC receiver) maintaining a set of RLC receiver variables, a receive window, and / or a reassembly window for the type of the RLC protocol data unit, wherein the transmit window is used to control the reception of the RLC PDU, and the reassembly window is used to control the reassembly of the RLC PDU.

[0283] In one exemplary embodiment, if the transmission mode of an RLC PDU of type RLC control PDU is UM or AM, or if an RLC SN is configured, the RLC transmitter (separately) maintains a set of RLC variables and / or a transmission window, such as the TX_Next variable. The RLC receiver (separately) maintains a set of RLC variables, a reception window, and / or a reassembly window for it.

[0284] In one exemplary embodiment, if an RLC PDU of a certain type contains an RLC SN, then the RLC SN of that RLC control PDU is a value space of maintained RLC SNs, that is, different from the RLC SN used for RLC data PDUs and different from the RLC SNs used by other types of RLC control PDUs. For example, the value of the RLC SN of the constructed RLC PDU is set to the value of the corresponding TX_Next, and TX_Next is incremented by one.

[0285] In one exemplary embodiment, the RLC receiver can process the RLC PDU according to the type of the RLC control PDU or the type of the RLC PDU contained in the RLC PDU header. If the received RLC PDU is an RLC data PDU, it is received according to the receiving window or reassembly window corresponding to the RLC data PDU, and the corresponding RLC receiver variables are maintained. If the received RLC PDU is of type T of the RLC control PDU, it is received according to the receiving window and / or reassembly window corresponding to type T, and the corresponding RLC receiver variables are maintained.

[0286] In this embodiment, by using different types of RLC PDUs to carry different types of PDCP PDUs, especially by carrying PDCP control PDUs within RLC control PDUs, and configuring the transmission modes and behaviors of different types of RLC PDUs separately, independent transmission of PDCP control PDUs and PDCP data PDUs is achieved. This avoids the impact of the transmission of RLC PDUs carrying PDCP data PDUs on the transmission of PDCP control PDUs. This embodiment also avoids introducing the concept of subchannels or subbearers at the RLC layer, reducing modifications to the protocol.

[0287] Example 6: Receiving different types of PDCP PDUs based on different RLC entities

[0288] In other embodiments, the RLC transport resource includes an RLC entity, wherein the RLC entity corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit is different.

[0289] In some embodiments, step S904 may include: receiving an RLC protocol data unit for carrying the PDCP PDU through the RLC entity corresponding to the type of the PDCP PDU.

[0290] In this embodiment, an access network element can be configured to associate a PDCP entity with one or more RLC entities, and the associated RLC entity can be configured to transmit either PDCP data PDUs or PDCP control PDUs. Each RLC entity includes an RLC transmitter and an RLC receiver, wherein the RLC transmitter is used to implement the data transmission function of the RLC layer, and the RLC receiver is used to implement the data reception function of the RLC layer.

[0291] In one exemplary embodiment, a PDCP entity can be associated with two RLC entities, such as a first RLC entity and a second RLC entity. The first RLC entity is used for the transmission of PDCP data PDUs, and the second RLC entity is used for the transmission of PDCP control PDUs. By using different RLC entities to handle different types of PDCP PDUs, independent transmission of PDCP data PDUs and PDCP control PDUs can be achieved, avoiding the influence of PDCP data PDUs on PDCP control PDUs and improving the transmission efficiency of control information. Different types of PDCP control PDUs can be controlled using the same or different RLC entities, and access network elements can be configured to handle one or more types of PDCP control PDUs with each RLC entity.

[0292] In some embodiments, the configuration information for each RLC entity is configured separately, wherein the configuration information includes at least one of the following:

[0293] Logical Channel Identifier (LCID) is used to identify the RLC entity in the lower-layer protocol entity;

[0294] The transmission modes of the RLC entity include transparent mode TM, unacknowledged mode UM, or acknowledged mode AM;

[0295] Does the protocol header of the RLC protocol data unit of the RLC entity contain a Radio Link Control Sequence Number (RLC SN)?

[0296] The size of the recombination timer for the RLC entity;

[0297] Whether the RLC entity uses a send window and a receive window;

[0298] The size of the transmit window and the size of the receive window of the RLC entity;

[0299] Whether the RLC entity reports its reception status via the RLC status report.

[0300] In this embodiment, different RLC entities can be associated with different types of PDCP PDUs. Based on this, the access network elements can individually configure the above-mentioned configuration information of each RLC entity (e.g., LCID, transmission mode, whether the protocol header contains an RLC SN, the size of the reassembly timer, whether to use a transmit window and a receive window, the size of the transmit window and the size of the receive window, whether to use an RLC status report, etc.). This enables individual configuration of the transmission mechanism for different RLC entities and different types of PDCP PDUs, making the transmission method more flexible, avoiding mutual interference between different types of PDCP PDUs, improving the transmission efficiency of control-type PDCP PDUs, and ensuring the timeliness of PDCP layer control information.

[0301] In this embodiment, the protocol header of the RLC PDU may or may not include an RLC SN. Different RLC entities / different types of PDCP PDUs may be transmitted using RLC PDUs with different protocol header formats.

[0302] In this embodiment of the disclosure, the PDCP transmitter can send PDCP PDUs to the corresponding RLC transmitter according to the type of PDCP PDU. For example, the PDCP control PDU is sent to the first RLC transmitter, and the PDCP data PDU is sent to the second RLC transmitter. The PDCP control PDU and PDCP data PDU are transmitted through the first RLC transmitter and the second RLC transmitter, respectively. The first RLC receiver and the second RLC receiver respectively receive RLC PDUs carrying different types of PDCP PDUs and deliver them to the PDCP receiver. For example, the first RLC receiver receives the first RLC PDU carrying the PDCP control PDU and delivers the PDCP control PDU to the PDCP receiver, and the second RLC receiver receives the second RLC PDU carrying the PDCP data PDU and delivers the PDCP data PDU to the PDCP receiver.

[0303] In some embodiments, the PDCP control PDU can be transmitted in the form of an RLC data PDU or an RLC control PDU. The PDCP data PDU can also be transmitted in the form of an RLC data PDU.

[0304] In one exemplary embodiment, the first RLC entity and the second RLC entity can respectively perform RLC status reporting operations.

[0305] In one exemplary embodiment, the first RLC entity and the second RLC entity may each be configured with different identifiers for identification by their underlying protocol entities, such as the MAC layer. This identifier may be a Logical Channel Identifier (LCID). When an RLC PDU is carried at the MAC protocol layer, its corresponding RLC entity's LCID is identified.

[0306] This embodiment associates at least two RLC entities with one PDCP entity, enabling independent transmission of different PDCP PDU types. Access network elements can configure different transmission modes and parameters for different RLC entities. This embodiment maximizes the utilization of the existing RLC layer functionality, achieving independent transmission of PDCP control PDUs and PDCP data PDUs without requiring major modifications to existing RLC functions.

[0307] In the above embodiments of this disclosure, by distinguishing different types of PDCP PDUs and configuring corresponding RLC layer transmission resources, the purpose of independently transmitting PDCP control PDUs and PDCP data PDUs can be achieved by using different sub-channels / sub-bearers, different types of RLC PDUs, or different RLC entities. This can avoid mutual interference between different types of PDCP PDUs, solve the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieve the effect of improving the efficiency, flexibility, and reliability of data transmission.

[0308] In traditional AM RLC transmission mode, the transmission and reception of RLC SDUs are limited by the RLC transmit window and receive window. The RLC transmitter cannot transmit more RLC SDUs than the RLC transmit window, and the RLC receiver cannot receive more RLC SDUs than the RLC receive window. This is to ensure that the RLC receive window has the resources needed to reassemble the RLC SDUs within the receive window, and to avoid the receiver having too many RLC SDU fragments waiting to be reassembled at the same time. However, the traditional AM RLC transmission mode has the following drawbacks: if an RLC SDU cannot be reassembled for a long time, the RLC receive window cannot move forward, thus adversely affecting the RLC transmission efficiency. Therefore, embodiments of this disclosure also provide a method for managing the receive window and transmit window in RLC AM mode. The RLC receiver can adaptively adjust the receive window, thereby reducing the adverse impact on RLC transmission efficiency and improving the transmission efficiency of PDCP layer data, especially PDCP layer control information.

[0309] In another embodiment of this disclosure, a data transmission method operating on the aforementioned access network element or user equipment is provided, applied to a transmitting end. Figure 10 is a flowchart of a data transmission method at a transmitting end according to another embodiment of this disclosure. As shown in Figure 10, the process includes the following steps:

[0310] Step S1002: Send a Radio Link Control Protocol Data Unit (RLC PDU) carrying the first information, wherein the RLC PDU is used to carry a Radio Link Control Service Data Unit (RLC SDU) or an RLC SDU fragment of an RLC SDU.

[0311] Step S1004: Adjust the RLC transmitter variables and the position of the transmission window according to the first information.

[0312] Through the above steps S1002 and S1004, it is possible to support the transmission of RLC SDUs (i.e. PDCP PDUs) located outside the transmission window, and to achieve adaptive adjustment of RLC layer variables and transmission window position. This solves the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieves the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission.

[0313] The entities that perform the above steps can be access network elements, user equipment, etc., but are not limited to these.

[0314] In this embodiment, the user plane protocol stack of the access network element or user equipment includes the following structure from bottom to top: PHY layer, MAC layer, RLC layer, PDCP layer, and SDAP layer. The RLC layer includes an RLC transmitter and an RLC receiver, and the PDCP layer includes a PDCP transmitter and a PDCP receiver. Those skilled in the art will understand that the Protocol Data Unit (PDU) of the upper-layer protocol is the Service Data Unit (SDU) of the lower-layer protocol. For example, a PDCP PDU is called an RLC SDU in the RLC layer. The RLC layer segments or reassembles the RLC SDU, adds an RLC protocol header, and forms an RLC PDU.

[0315] The method in this disclosure is mainly applied to the RLC layer and implemented through an RLC entity (such as an RLC transmitter). The RLC transmitter receives data in the form of PDCP PDUs (i.e., RLC SDUs) from the upper layer (such as the PDCP layer), encapsulates or segments the received RLC SDUs into RLC PDUs, and then sends the RLC PDUs to the lower layer (such as the MAC layer). The RLC SDUs may contain user data or control information from the PDCP layer. When sending RLC PDUs, the RLC transmitter must comply with the RLC transmission mode (such as AM, UM, TM), which determines the transmission, acknowledgment, and retransmission mechanisms of the RLC PDUs. This disclosure adjusts the processing mechanism of the sending and receiving windows based on the traditional RLC transmission mode, allowing for adaptive adjustment of the sending window according to the data transmission situation, thereby improving data transmission efficiency.

[0316] In this embodiment, two different information indication methods are proposed to unify the data processing methods of the RLC receiver and the RLC transmitter through different types of first information. The type of first information includes RLC SN or indication information.

[0317] In some embodiments, the access network element can also instruct the user equipment RLC transmitter to use a specific information indication method (RLC SN or indication information) to support the transmission of RLC SDUs located outside the transmission window through the configuration of signaling transmission. Alternatively, the access network element can configure different triggering conditions for these two processing methods, such as a first triggering condition and a second triggering condition.

[0318] Example 7: Sending RLC SDUs located outside the transmission window

[0319] In some embodiments, step S1002 may include: step S1002A, in response to the RLC SDU to be transmitted being outside the transmission window, transmitting the RLC PDU carrying the Radio Link Control Sequence Number (RLC SN) of the RLC SDU, wherein the first information includes the RLC SN of the RLC SDU.

[0320] In some embodiments, step S1002A can be executed only when a preset first trigger condition is met. If the first trigger condition is not met, the transmission of the RLC SDU can be controlled by the transmission window according to the conventional RLC transmission mechanism. For example, when the RLC SDU is within the transmission window, the RLC PDU carrying the RLC SDU is transmitted.

[0321] In an exemplary embodiment, the first trigger condition can be set to wait timeout. When the waiting time of the RLC SDU to be sent exceeds a preset time and the RLC SDU is still outside the sending window, steps S1002A and S1004 are executed to send the RLC SDU and adjust the position of the sending window. For example, the sending window can be controlled to move forward until the RLC SDU is inside the sending window.

[0322] In an exemplary embodiment, the first triggering condition can be set to wait for confirmation timeout. When the waiting time for confirmation message of an already sent RLC SDU exceeds a preset time, steps S1002A and S1004 are executed to send another RLC SDU to be sent and adjust the position of the sending window. For example, if the RLC SDU to be sent is outside the sending window, the sending window can be controlled to move forward until the RLC SDU is inside the sending window.

[0323] In one exemplary embodiment, the first triggering condition may be set to exceed the number of RLC SNs of the transmission window, or to exceed the range of RLC SNs of the transmission window, for example, the difference between the RLC SN of the RLC SDU to be transmitted and the upper limit of the transmission window is less than or equal to a preset threshold. However, this disclosure is not limited thereto.

[0324] In some embodiments, prior to step S1002A, the access network element may instruct the user equipment (including the RLC transmitter) on at least one of the following information through the configuration of the signaling transmission:

[0325] The RLC transmitter sends the RLC SDU located outside the transmission window under a preset first trigger condition;

[0326] Does the RLC transmitter send the RLC SDU located outside the transmission window?

[0327] The RLC transmitter can send more than the maximum number of RLC SNs exceeding the upper limit of the transmission window, or it can send RLC SNs exceeding the range of the transmission window. For example, if the upper limit of the RLC transmission window is N, and the maximum number of RLC SNs that can exceed N is set to M, then the transmitter can send RLC SDUs with RLC SNs less than or equal to N+M.

[0328] In this embodiment, the RLC transmitter can decide, based on the above configuration, whether to use the method in steps S1002A and S1004 (supporting the transmission of RLC SDUs located outside the transmission window) or to use the traditional RLC transmission mechanism, that is, to control the transmission of RLC SDUs through the transmission window (only supporting the transmission of RLC SDUs located within the transmission window).

[0329] In some embodiments, prior to step S1002A, the method may further include one of the following:

[0330] 1) Determine whether the RLC transmitter meets the preset first triggering condition based on the configuration of the access network element;

[0331] 2) Based on the configuration of the access network elements, determine that the RLC transmitter sends the RLC SDU located outside the transmission window;

[0332] 3) Based on the configuration of the access network element, determine that the maximum number of Radio Link Control Sequence Numbers (RLC SNs) that the RLC transmitter can send outside the transmission window is M, and determine that the RLC SN of the RLC SDU to be sent is less than or equal to N+M, where N is the upper limit of the transmission window.

[0333] 4) Determine the range of Radio Link Control Sequence Numbers (RLC SNs) that the RLC transmitter can send outside the transmission window based on the configuration of the access network element, and determine that the RLC SN of the RLC SDU to be transmitted is within the range of the RLC SN.

[0334] In some embodiments, a judgment can be made first based on the configuration of the RLC transmitter and the RLC SN of the RLC SDU to be transmitted. If a positive judgment result is obtained, step S1002A is executed. If the judgment result is negative, the process can continue to wait according to the traditional RLC transmission mechanism.

[0335] In some embodiments, step S1004 may include the following steps:

[0336] Step S1004A-2: Adjust the RLC transmitter variables according to the RLC SN of the RLC SDU;

[0337] Step S1004A-4: Adjust the position of the transmission window according to the adjusted RLC transmitter variables.

[0338] In this embodiment, the RLC PDU carries an RLC SN, which can be used to instruct the RLC receiver to adjust the RLC receiver variables and the position of the receiving window, so that the RLC receiver can adjust the RLC receiver variables and the position of the receiving window according to the RLC CN of the received RLC PDU, and discard RLC fragments that are outside the receiving window and have not been successfully received.

[0339] In some embodiments, step S1004A-2 may include at least one of the following:

[0340] 1) Update the TX_Next variable to the RLC SN of the RLC SDU plus 1, wherein the TX_Next variable is used to identify the RLC SN of the next RLC SDU to be sent;

[0341] 2) In response to the TX_Next_Ack variable being less than the difference between the TX_Next variable and the transmission window size, the TX_Next_Ack variable is updated to the smallest RLC SN among all RLC SDUs that have not been successfully acknowledged for transmission, where the RLC SN is greater than or equal to the difference between the TX_Next variable and the transmission window size, wherein the TX_Next_Ack variable is used to identify the RLC SN of the next RLC SDU waiting to receive acknowledgment within the transmission window;

[0342] The RLC transmitter variables include the TX_Next variable and the TX_Next_Ack variable.

[0343] In some embodiments, step S1004A-4 may include:

[0344] 1) Update the lower limit of the sending window to the value of the TX_Next_Ack variable, and update the upper limit of the sending window to the sum of the TX_Next_Ack variable and the sending window size; or,

[0345] 2) Update the lower limit of the sending window to the difference between the TX_Next variable and the size of the sending window, and update the upper limit of the sending window to the value of the TX_Next variable.

[0346] In some embodiments, in addition to steps S1004A-2 and S1004A-4 described above, the data transmission method (i.e., the behavior of the RLC transmitter) may further include: discarding and / or treating RLC SDUs whose RLC SN is less than or equal to the difference between the TX_Next variable and the transmission window size as discarded or successfully transmitted.

[0347] In this embodiment, the RLC transmitter can determine whether to send an RLC SDU with an RLC SN greater than the upper limit of the RLC transmission window, based on the configuration of the access network element, and whether to instruct the RLC receiver to adjust the RLC receiver variables and the reception window by carrying the RLC SN in the RLC PDU.

[0348] In some embodiments, the RLC transmitter may also indicate in the header of the RLC data PDU or in the RLC control PDU whether the RLC receiver applies the data transmission method of the receiver corresponding to the above embodiments, such as adjusting the RLC receiver variables and the receiving window according to the RLC SN carried in the RLC PDU.

[0349] In this embodiment of the disclosure, by adjusting the transmitter variables and the transmission window based on the RLC SN, data transmission can be controlled more precisely, avoiding data retransmission and resource waste, thereby improving data transmission efficiency and user experience.

[0350] Example 8: The RLC transmitter instructs the RLC receiver to discard the RLC SDU.

[0351] In some other embodiments, step S1002 may include: step S1002B, sending the RLC PDU carrying indication information for instructing the RLC receiver to discard one or more RLC SDUs, wherein the first information includes the indication information.

[0352] In some embodiments, step S1002B may be performed only when a preset second triggering condition is met.

[0353] In an exemplary embodiment, the second triggering condition can be set to wait for confirmation timeout. When the waiting time for confirmation message of an already sent RLC SDU exceeds a preset time, step S1002B is executed.

[0354] In some embodiments, prior to step S1002B, the access network element may instruct the user equipment (including the RLC transmitter) on at least one of the following information through the configuration transmitted by signaling:

[0355] The RLC transmitter discards the RLC SDU;

[0356] The RLC transmitter indicates to the RLC receiver that the RLC SDU has been discarded.

[0357] In this embodiment, the RLC transmitter can decide whether to use the method in steps S1002B and S1004 (instructing the RLC receiver to discard the RLC SDU) based on the above configuration.

[0358] In some embodiments, step S1004 may include the following steps:

[0359] Step S1004B-2: Adjust the RLC transmitter variables according to the indication information used to instruct the RLC receiver to discard one or more RLC SDUs;

[0360] Step S1004B-4: Adjust the position of the transmission window according to the adjusted RLC transmitter variables.

[0361] In this embodiment, the RLC PDU carries indication information for instructing the RLC receiver to discard one or more RLC SDUs. This discard indication information can be used to instruct the RLC receiver to adjust the RLC receiver variables and the position of the receiver window.

[0362] In some embodiments, the RLC PDU type includes an RLC data protocol data unit (RLC data PDU) or an RLC control protocol data unit (RLC control PDU). Step S1002 may include: sending an RLC data PDU to the RLC receiver, wherein the protocol header of the RLC data PDU carries the indication information; or sending an RLC control PDU to the RLC receiver, wherein the RLC control PDU carries the indication information. This disclosure does not limit the format of the PDU carrying the indication information.

[0363] In some embodiments, the indication information may include at least one of the following:

[0364] The maximum RLC SN value of the discarded RLC SDU;

[0365] RLC SN values ​​of a set of discarded RLC SDUs;

[0366] A bitmap, wherein the bitmap contains the values ​​of multiple bits, each bit corresponding to an RLC SDU, and the value of each bit is used to indicate whether the corresponding RLC SDU is discarded;

[0367] An instruction is provided to instruct the RLC receiver to discard all RLC SDUs or RLC SDU fragments that were not successfully received.

[0368] In some embodiments, the RLC transmitter variables may include TX_Next and TX_Next_Ack variables, and the adaptive adjustment of the RLC transmitter variables varies depending on the type / content of the indication information. Step S1004B-2 may include at least one of the following:

[0369] 1) In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, update the TX_Next_Ack variable to the minimum RLC SN among one or more RLC SNs whose RLC SN is greater than the maximum RLC SN value among all RLC SDUs that have not been acknowledged for successful transmission;

[0370] 2) In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the TX_Next_Ack variable being equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, update the TX_Next_Ack variable to the smallest RLC SN among one or more RLC SNs whose RLC SN is greater than the value of the TX_Next_Ack variable among all RLC SDUs that have not been acknowledged for successful transmission and have not been discarded;

[0371] 3) In response to the indication information being an indication for the RLC receiver to discard all unsuccessfully received RLC SDUs, update the TX_Next_Ack variable to the value of the TX_Next variable.

[0372] In this embodiment, the adjustment of the position of the transmission window (i.e., step S1004B-4) can be done in a conventional way. For example, based on the updated TX_Next_ACK variable, the range of the new transmission window is determined as: [TX_Next_ACK, TX_Next_ACK + transmission window size].

[0373] In some embodiments, the method (i.e., the behavior of the RLC transmitter) may also include one of the following:

[0374] In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, RLC SDUs with an RLC SN less than or equal to the updated TX_Next_Ack variable are considered discarded or dropped.

[0375] In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, the corresponding set of RLC SDUs is regarded as discarded or discarded;

[0376] In response to the indication information being an indication for the RLC receiver to discard all RLC SDUs that were not successfully received, all RLC SDUs that were not successfully received are considered to be discarded or dropped.

[0377] In some embodiments, the method (i.e., the behavior of the RLC transmitter) may further include at least one of the following:

[0378] 1) Instruct the indication information to the Packet Data Convergence Protocol (PDCP) transmitter associated with the RLC transmitter, so that the PDCP transmitter discards the Packet Data Convergence Protocol Data Unit (PDCP PDU) or Packet Data Convergence Protocol Service Data Unit (PDCP SDU) corresponding to the one or more RLC SDUs;

[0379] 2) The indication information is sent to the PDCP receiver through the PDCP transmitter.

[0380] In one exemplary embodiment, the PDCP transmitter can discard the PDCP SDU or PDCP PDU corresponding to these discarded RLC SDUs according to the indication information; and / or, the PDCP transmitter can also send a message to the PDCP receiver to indicate the PDCP SDU or PDU information that needs to be discarded. In another exemplary embodiment, after receiving the indication information from the RLC transmitter, the RLC receiver can instruct the associated PDCP receiver on the information of the discarded RLC SDU.

[0381] In this embodiment, by indicating the information of RLC SDUs that have been discarded by the PDCP transmitter, it is beneficial for the PDCP transmitter to discard the data discarded by the RLC transmitter, that is, to discard the PDCP SDU or PDCP PDU corresponding to the RLC SDU discarded by the RLC transmitter. By indicating the information of RLC SDUs or PDCP SDUs that have been discarded by the PDCP receiver, it is beneficial for the PDCP receiver to be unaffected by the discarded RLC SDUs or PDCP SDUs when deciding to submit data upwards or generate a PDCP status report.

[0382] In this embodiment, the AM mode RLC entity can adjust the transmission and reception windows by discarding some RLC SDUs, or the RLC receiver can adaptively adjust the reception window to achieve AM mode RLC transmission that breaks through the limitations of traditional RLC transmission and reception windows. The method in this embodiment is suitable for applications with time-sensitive data transmission requirements, such as live streaming applications. The RLC transmitter can decide whether to discard some RLC SDUs or move the transmission window forward based on the waiting time for RLC SDU reception confirmation, thereby solving the problem that the PDCP PDU processing mechanism in related technologies affects the timeliness of PDCP layer control information transmission, achieving the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission. Furthermore, the method in this embodiment can not only improve the transmission efficiency of control information but also improve the transmission efficiency of user data.

[0383] In another embodiment of this disclosure, a data transmission method operating on the aforementioned access network element or user equipment is provided, applied to a receiving end. Figure 11 is a flowchart of the data transmission method of the receiving end according to another embodiment of this disclosure. As shown in Figure 11, the process includes the following steps:

[0384] Step S1102: Receive Radio Link Control Protocol Data Unit (RLC PDU) carrying first information;

[0385] Step S1104: Adjust the RLC receiver variables and the position of the receiver window according to the first information.

[0386] Through the above steps S1102 and S1104, it is possible to support the reception of RLC SDUs (i.e. PDCP PDUs) located outside the receiving window, and to achieve adaptive adjustment of RLC layer variables and transmission window position. This solves the problem that the processing mechanism of PDCP PDUs in related technologies affects the timeliness of PDCP layer control information transmission, and achieves the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission.

[0387] The entities that perform the above steps can be access network elements, user equipment, etc., but are not limited to these.

[0388] In this embodiment, the user plane protocol stack of the access network element or user equipment includes the following structure from bottom to top: PHY layer, MAC layer, RLC layer, PDCP layer, and SDAP layer. The RLC layer includes an RLC transmitter and an RLC receiver, and the PDCP layer includes a PDCP transmitter and a PDCP receiver. Those skilled in the art will understand that the Protocol Data Unit (PDU) of the upper-layer protocol is the Service Data Unit (SDU) of the lower-layer protocol; for example, a PDCP PDU is referred to as an RLC SDU in the RLC layer. The RLC layer decapsulates and reassembles the RLC PDU to obtain the RLC SDU.

[0389] In this embodiment, two different information indication methods are proposed to unify the data processing methods of the RLC receiver and the RLC transmitter through different types of first information. The type of first information includes RLC SN or indication information.

[0390] In some embodiments, the access network element can also instruct the user equipment RLC receiver to process the RLC SDU based on which information indication method (RLC SN or indication information) through the configuration of signaling transmission, and adjust the RLC receiving window. Alternatively, the access network element can configure different triggering conditions for these two processing methods, such as a third triggering condition or a fourth triggering condition.

[0391] Example 9: Receiving an RLC SDU located outside the receiving window

[0392] In some embodiments, step S1102 may include: step S1102A, in response to the Radio Link Control Service Data Unit (RLC SDU) to be received being located outside the receiving window, receiving the RLC PDU carrying the Radio Link Control Sequence Number (RLC SN) of the RLC SDU, wherein the first information includes the RLC SN of the RLC SDU, and the RLC PDU is used to carry the RLC SDU or an RLC SDU fragment of the RLC SDU.

[0393] In some embodiments, step S1102A may be performed only when a preset third trigger condition is met. If the third trigger condition is not met, the reception of the RLC SDU may be controlled by the receiving window according to the conventional RLC transmission mode. For example, the RLC PDU carrying the RLC SDU or RLC SDU fragments may be received only when the RLC SDU is within the receiving window.

[0394] In one exemplary embodiment, the third triggering condition may be set to exceed the number of RLC SNs of the receiving window, or to exceed the range of RLC SNs of the receiving window, for example, the difference between the RLC SN of the RLC SDU to be received and the upper limit of the receiving window is less than or equal to a preset threshold. However, this disclosure is not limited thereto.

[0395] In some embodiments, access network elements may instruct user equipment (including RLC receivers) on at least one of the following information through signaling transmission configuration:

[0396] The RLC receiver receives the third trigger condition of the RLC SDU located outside the receiving window;

[0397] The RLC receiver supports receiving the RLC SDU located outside the receiving window;

[0398] The maximum number of RLC SNs received by an RLC receiver that exceed the upper limit of the receiving window. For example, if the upper limit of the RLC receiving window is P, and the maximum number of RLC SNs that can exceed P is set to K, then the receiver can receive RLC SDUs with RLC SNs less than or equal to P+K.

[0399] The RLC receiver can receive RLC SDUs whose RLC SNs exceed the upper limit of the reception window.

[0400] In this embodiment, the RLC receiver can decide, based on the above configuration, whether to use the method in steps S1102A and S1104 (supporting the reception of RLC SDUs located outside the reception window) or to use the traditional RLC transmission mechanism, that is, to control the reception of RLC SDUs through the reception window (only supporting the reception of RLC SDUs located within the reception window).

[0401] In some embodiments, prior to step S1102A, the method may further include one of the following:

[0402] 1) Determine whether the RLC receiver meets the preset third triggering condition based on the configuration of the access network elements;

[0403] 2) Based on the configuration of the access network element, determine that the RLC receiver receives the RLC SDU located outside the receiving window;

[0404] 3) Based on the configuration of the access network element, determine that the maximum number of Radio Link Control Sequence Numbers (RLC SNs) outside the reception window received by the RLC receiver is K, and determine that the RLC SN of the RLC SDU to be received is less than or equal to P+K, where P is the upper limit of the reception window.

[0405] 4) Determine the range of RLC SNs outside the receiving window received by the RLC receiver based on the configuration of the access network element, and determine that the RLC SN of the RLC SDU to be received is within the range of the RLC SN.

[0406] In some embodiments, a judgment can be made first based on the configuration of the RLC receiver and the RLC SN of the RLC SDU to be received. If a positive judgment result is obtained, step S1102A is executed. If the judgment result is negative, the process can continue to wait according to the traditional RLC transmission mechanism.

[0407] In some embodiments, the first information includes the RLC SN of the RLC SDU, and step S1104 may include the following steps:

[0408] Step S1104A-2: Adjust the RLC receiver variables according to the RLC SN of the RLC SDU;

[0409] Step S1104A-4: Adjust the position of the receiving window according to the adjusted RLC receiver variables.

[0410] In this embodiment, the RLC PDU carries the RLC SN, and the RLC transmitter uses the RLC SN to instruct the RLC receiver to adjust the corresponding RLC receiver variables and the position of the receiver window.

[0411] In some embodiments, the RLC receiver variables include the RX_Next_Highest variable and / or the RX_Next variable, and step S1104A-2 may include at least one of the following:

[0412] 1) Update the RX_Next_Highest variable to the value of the RLC SN plus 1, wherein the RX_Next_Highest variable is used to identify the next RLC SN after the highest RLC SN of the received RLC SDU;

[0413] 2) Update the RX_Next variable to the smallest RLC SN among all RLC SDUs that failed to receive data, where the RLC SN is greater than or equal to the difference between the RX_Next_Highest variable and the receive window size.

[0414] In some embodiments, step S1104A-4 may include:

[0415] 1) Update the lower limit of the receiving window to the difference between the RX_Next_Highest variable and the size of the receiving window, and update the upper limit of the receiving window to the value of the RX_Next_Highest variable; or,

[0416] 2) Update the lower limit of the receiving window to the value of the RX_Next variable, and update the upper limit of the receiving window to the sum of the RX_Next variable and the size of the receiving window.

[0417] In some embodiments, in addition to steps S1104A-2 and S1104A-4 described above, the data transmission method (i.e., the behavior of the RLC receiver) may also include: treating RLC SDUs located outside the receiving window and not successfully received as either discarded or successfully received, and discarding RLC SDU fragments located outside the receiving window that have been received.

[0418] In some embodiments, the RLC receiver can decide whether to apply the above data transmission method based on the configuration of the access network element. For example, whether the RLC receiver can receive an RLC SDU with an RLC SN greater than the upper limit of the RLC receiving window, and whether the RLC receiver can adjust the RLC receiver variables and receiving window based on the RLC SN carried in the RLC PDU.

[0419] In other embodiments, the RLC transmitter may also indicate in the header of the RLC data PDU or in the RLC control PDU whether the RLC receiver should apply the above-described data transmission method. The RLC receiver can then decide whether to use the conventional method or the above-described data transmission method based on the indication in the RLC PDU.

[0420] In this embodiment of the disclosure, by adjusting the receiver variables and the receiver window based on the RLC SN, data reception can be controlled more precisely, avoiding data retransmission and resource waste, thereby improving data transmission efficiency and user experience.

[0421] Example 10: RLC receiver receives indication to discard RLC SDU

[0422] In some other embodiments, step S1102 may include: step S1102B, receiving the RLC PDU carrying indication information for instructing the RLC receiver to discard one or more Radio Link Control Service Data Units (RLC SDUs), wherein the first information includes the indication information.

[0423] In this embodiment, the triggering condition (i.e. the fourth triggering condition) or application scenario of step S1102B is similar to the triggering condition or application condition of the RLC transmitter in embodiment 8 above, and will not be repeated here.

[0424] In some embodiments, step S1104 may include the following steps:

[0425] Step S1104B-2: Adjust the RLC receiver variables according to the indication information used to instruct the RLC receiver to discard one or more RLC SDUs;

[0426] Step S1104B-4: Adjust the position of the receiving window according to the adjusted RLC receiver variables.

[0427] In this embodiment, the RLC PDU carries indication information for instructing the RLC receiver to discard one or more RLC SDUs. The RLC transmitter uses this discard indication information to instruct the RLC receiver to discard the specified RLC SDU and adjusts the RLC receiver variables and the position of the receiver window accordingly.

[0428] In some embodiments, the indication information includes one of the following:

[0429] The maximum RLC SN value of the discarded RLC SDU;

[0430] RLC SN values ​​of a set of discarded RLC SDUs;

[0431] A bitmap, wherein the bitmap contains the values ​​of multiple bits, each bit corresponding to an RLC SDU, and the value of each bit is used to indicate whether the corresponding RLC SDU is discarded;

[0432] An instruction is provided to instruct the RLC receiver to discard all RLC SDUs or RLC SDU fragments that were not successfully received.

[0433] In some embodiments, RLC receiver variables include the RX_Next variable, the RX_Next_Highest variable, and the RX_Highest_Status variable. The adaptive adjustment of the RLC receiver variables varies depending on the type / content of the indication information.

[0434] In one exemplary embodiment, step S1104B-2 may include at least one of the following:

[0435] 1) In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, update the RX_Next variable to the minimum RLC SN among one or more RLC SNs whose RLC SN is greater than the maximum RLC SN value among all RLC SDUs that were not successfully received;

[0436] 2) In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, and the value of the RX_Next_Highest variable being less than the updated value of the RX_Next variable, the RX_Next_Highest variable is updated to the updated value of the RX_Next variable;

[0437] 3) In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, and the value of the RX_Highest_Status variable being less than or equal to the maximum RLC SN value, update the RX_Highest_Status variable to the minimum RLC SN among one or more RLC SNs whose RLC SN is greater than the maximum RLC SN value among all RLC SDUs that were not successfully received.

[0438] In yet another exemplary embodiment, step S1104B-2 may include at least one of the following:

[0439] 1) In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Next variable being equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, update the RX_Next variable to the smallest RLC SN among one or more RLC SNs whose RLC SN is greater than the value of the RX_Next variable among all RLC SDUs that were not successfully received and were not discarded;

[0440] 2) In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Next_Highest variable being less than or equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, update the RX_Next_Highest variable to the maximum value of the RLC SN values ​​of the set of discarded RLC SDUs plus 1;

[0441] 3) In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Next_Highest variable being less than the value of the updated RX_Next variable, update the RX_Next_Highest variable to the value of the updated RX_Next variable;

[0442] 4) In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Highest_Status variable being equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, update the RX_Highest_Status variable to the smallest RLC SN among one or more RLC SNs whose RLC SN is greater than the value of the RX_Highest_status variable among all RLC SDUs that were not successfully received and were not discarded.

[0443] In another exemplary embodiment, step S1104B-2 may include at least one of the following:

[0444] 1) In response to the indication information being an indication for instructing the RLC receiver to discard all unsuccessfully received RLC SDUs, update the RX_Next variable to the value of the RX_Next_Highest variable;

[0445] 2) In response to the indication information being an indication for the RLC receiver to discard all unsuccessfully received RLC SDUs, update the RX_Highest_Status variable to the updated value of the RX_Next variable.

[0446] In some embodiments, step S1104B-4 may include: updating the lower limit value of the receiving window to the value of the RX_Next variable, and updating the upper limit value of the receiving window to the sum of the RX_Next variable and the size of the receiving window.

[0447] In some embodiments, the method (i.e., the behavior of the RLC receiver) may also include one of the following:

[0448] In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, RLC SDUs with an RLC SN less than the indicated value and which were not successfully received are considered to be discarded or successfully received; and / or, fragments of RLC SDUs that fell outside the reception window and were not successfully received are discarded.

[0449] In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, the indicated set of RLC SDUs is regarded as either discarded or successfully received; and / or, the RLC fragments of the received indicated RLC SDUs are discarded;

[0450] In response to the indication information being an indication for instructing the RLC receiver to discard all RLC SDUs that were not successfully received, all RLC SDUs that were not successfully received (within the receive window) are regarded as either discarded or successfully received; and / or, RLC fragments of RLC SDUs that were not successfully received within the receive window are discarded.

[0451] In some embodiments, the method (i.e., the behavior of the RLC receiver) may further include: indicating the indication information to a Packet Data Convergence Protocol (PDCP) receiver associated with the RLC receiver.

[0452] In this embodiment, by indicating the information of RLC SDUs or PDCP SDUs that have been discarded by the PDCP receiver, the PDCP receiver is able to avoid being affected by the discarded RLC SDUs or PDCP SDUs when deciding to submit data upwards or generate a PDCP status report.

[0453] In some embodiments, for the method in Embodiment 9 or Embodiment 10 above, the RLC receiver can also implement a reassembly function, and for the processing of the reassembly timer and RLC variables, the method can further include at least one of the following:

[0454] 1) In response to the fact that the reassembly timer at the RLC receiver is running and the reassembly timer meets the preset conditions, the reassembly timer is stopped and the reassembly timer is reset;

[0455] 2) In response to the RX_Next variable being greater than the RX_Highest_Status variable, update the RX_Highest_Status variable to the value of the RX_Next variable;

[0456] 3) In response to the RX_Next_Highest variable being greater than the RX_Next variable plus 1, or the RX_Next_Highest variable being equal to the RX_Next variable plus 1, and the RLC SDU with RLC SN equal to the RX_Next variable having a missing RLC SDU fragment, start the reassembly timer and update the RX_Next_Status_Trigger variable to the value of the RX_Next_Highest variable;

[0457] In this embodiment, the RX_Highest_Status variable is used to identify the maximum value of the ACK_SN field in the status report, and the RX_Next_Status_Trigger variable is used to identify the next RLC SN of the RLC SDU that triggered the reassembly timer.

[0458] In some embodiments, the preset conditions for the recombination timer include one of the following:

[0459] The value of the RX_Next_Status_Trigger variable is outside the adjusted receive window;

[0460] The value of the RX_Next_Status_Trigger variable is less than or equal to the adjusted value of the RX_Next variable;

[0461] The value of the RX_Next_Status_Trigger variable is less than or equal to the difference between the RX_Next_Highest variable and the receiving window size;

[0462] The value of the RX_Next_Status_Trigger variable is equal to the RX_Next variable plus 1, and the RLC SN is equal to the RLC SDU received by the RX_Next variable, where there are no missing bytes before the last byte;

[0463] There are no unreceived RLC SDU fragments, RLC SDUs, or RLC PDUs between the RX_Next_Status_Trigger variable and the RX_Next variable.

[0464] In this embodiment, the AM mode RLC entity can adjust the transmission and reception windows by discarding some RLC SDUs, or the RLC receiver can adaptively adjust the reception window to achieve AM mode RLC transmission that breaks through the limitations of traditional RLC transmission and reception windows. The method in this embodiment is suitable for applications with time-sensitive data transmission requirements, such as live streaming applications. The RLC transmitter can decide whether to discard some RLC SDUs or move the transmission window forward based on the waiting time for RLC SDU reception confirmation, thereby solving the problem that the PDCP PDU processing mechanism in related technologies affects the timeliness of PDCP layer control information transmission, achieving the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission. Furthermore, the method in this embodiment can not only improve the transmission efficiency of control information but also improve the transmission efficiency of user data.

[0465] In another embodiment of this disclosure, a data transmission system is also provided. FIG12 is a schematic block diagram of a data transmission system according to an embodiment of this disclosure. As shown in FIG12, the data transmission system includes:

[0466] Transmitting device 100 and receiving device 200.

[0467] In this embodiment, the transmitting device 100 can be an access network element, and the receiving device 200 can be a user equipment; or, the transmitting device 100 can be a user equipment, and the receiving device 200 can be an access network element.

[0468] In this embodiment, the user plane protocol stack of the access network element or user equipment includes the following structure from bottom to top: PHY layer, MAC layer, RLC layer, PDCP layer and SDAP layer.

[0469] In this embodiment, the transmitting device 100 can perform data transmission according to any of the above-described method embodiments applied to the transmitting end, while the receiving device 200 performs data transmission according to the corresponding method embodiment of the receiving end.

[0470] In some embodiments, the transmitting device 100 is configured to determine the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resource corresponding to the type of the PDCP PDU; and transmit the PDCP PDU through the RLC transmission resource. The receiving device 200 is configured to determine the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resource corresponding to the type of the PDCP PDU; and receive the PDCP PDU through the RLC transmission resource.

[0471] In this embodiment, the data transmission system can support the transmission of different types of PDCP PDUs on different RLC transmission resources, realize the independent transmission of PDCP control PDUs and PDCP data PDUs, thereby avoiding the impact of data PDUs on the transmission of control PDUs. This solves the problem in related technologies that the processing mechanism of PDCP PDUs affects the timeliness of PDCP layer control information transmission, and achieves the effect of improving transmission efficiency and meeting the timeliness requirements of data transmission.

[0472] In some embodiments, the transmitting device 100 is configured to transmit a Radio Link Control Service Data Unit (RLC SDU) carrying first information in response to the RLC SDU being located outside the transmission window, wherein the RLC PDU is used to carry the RLC SDU or RLC SDU fragments of the RLC SDU; and adjust the RLC transmitting end variables and the position of the transmission window according to the first information. The receiving device 200 is configured to receive a RLC PDU carrying first information in response to the RLC SDU being located outside the receiving window, wherein the RLC PDU is used to carry the RLC SDU or RLC SDU fragments of the RLC SDU; and adjust the RLC receiving end variables and the position of the receiving window according to the first information.

[0473] In this embodiment, the data transmission system can support sending RLC SDUs (i.e., PDCP PDUs) located outside the transmission window and receiving RLC SDUs (i.e., PDCP PDUs) located outside the reception window. This achieves adaptive adjustment of RLC layer variables and transmission / reception window positions, thereby solving the problem in related technologies where the PDCP PDU processing mechanism affects the timeliness of PDCP layer control information transmission. This improves transmission efficiency and meets the timeliness requirements of data transmission. Furthermore, this embodiment not only improves the transmission efficiency of control information but also enhances the transmission efficiency of user data.

[0474] Figure 13 is a schematic diagram of the protocol architecture of a data transmission system in one embodiment of the present disclosure (I). As shown in Figure 13, the RLC entity can maintain the corresponding transmission window, reception window and corresponding RLC variables for RLC sub-channel 1 and RLC sub-channel 2 respectively.

[0475] In this embodiment, different types of PDCP PDUs can be configured to be associated with different sub-channels or sub-bearers.

[0476] In this embodiment, a subchannel or subbearer can be configured to carry a type of RLC PDU. A type of RLC PDU may correspond to one or more types of PDCP control PDUs, or one or more PDCP data PDUs, or RLC data PDUs, or RLC control PDUs.

[0477] In this embodiment, the specific implementation of the transmitting end (e.g., an RLC transmitting end) can refer to the description in Embodiment 1 above. The specific implementation of the receiving end (e.g., an RLC receiving end) can refer to the description in Embodiment 4 above.

[0478] In this embodiment, by introducing the concept of sub-channels or sub-bearers, and configuring the transmission mode and behavior of each sub-channel and sub-bearer separately, different processing is achieved for RLC PDUs carrying PDCP data PDUs and RLC PDUs carrying PDCP control PDUs. This avoids the impact of the transmission of RLC PDUs carrying PDCP data PDUs on the transmission of PDCP control PDUs. This maximizes the flexibility of processing different RLC bearer contents differently.

[0479] Figure 14 is a schematic diagram of the protocol architecture of a data transmission system in one embodiment of the present disclosure (II). As shown in Figure 14, an RLC entity can maintain the corresponding sending window, receiving window and corresponding RLC variables for one type (such as type T) of RLC data PDU and RLC control PDU.

[0480] In this embodiment, the RLC data PDU is used to carry the PDCP data PDU, and the RLC control PDU is used to carry the PDCP control PDU. In this embodiment, one type of RLC control PDU can carry one or more types of PDCP control PDUs.

[0481] In this embodiment, the protocol header of the RLC PDU can indicate the type of the RLC control PDU. The RLC entity can maintain corresponding transmit windows, receive windows, and RLC variables for one or more types of RLC control PDUs.

[0482] In this embodiment, the specific implementation of the transmitting end (e.g., an RLC transmitting end) can refer to the description in Embodiment 2 above. The specific implementation of the receiving end (e.g., an RLC receiving end) can refer to the description in Embodiment 5 above.

[0483] In this embodiment, by carrying the PDCP control PDU on the RLC control PDU, the transmission of the PDCP control PDU can be made independent of the PDCP data PDU. Furthermore, this embodiment avoids introducing the concept of sub-channels or sub-bearers at the RLC layer, thus reducing modifications to the protocol.

[0484] Figure 15 is a schematic diagram of the protocol architecture of a data transmission system in one embodiment of the present disclosure (III). As shown in Figure 15, a PDCP entity can be associated with two RLC entities, and each RLC entity can maintain its own sending window, receiving window and corresponding RLC variables.

[0485] In this embodiment, the first RLC entity is used for the transmission of PDCP data PDUs, and the second RLC entity is used for the transmission of PDCP control PDUs.

[0486] In this embodiment, the PDCP transmitter can send PDCP PDUs to the corresponding RLC entity (RLC transmitter) according to the type of PDCP PDU. For example, the PDCP control PDU is sent to the first RLC entity (RLC transmitter), and the PDCP data PDU is sent to the second RLC entity (RLC transmitter). The first and second RLC entities then send the RLC PDUs carrying the PDCP control PDU or PDCP data PDU to the MAC protocol layer, respectively. When the MAC protocol layer of the transmitter carries the RLC PDU, it identifies the LCID of the RLC entity corresponding to the RLC PDU, so that the MAC protocol layer of the receiver can determine the RLC entity to which the RLC PDU belongs based on the LCID, and send the RLC PDU to the corresponding RLC entity (RLC receiver) for processing. The first and second RLC entities (RLC receivers) can receive the RLC PDUs from the MAC layer protocol and deliver them to the PDCP receiver, respectively.

[0487] In this embodiment, the specific implementation of the transmitting end (e.g., an RLC transmitting end) can refer to the description in Embodiment 3 above. The specific implementation of the receiving end (e.g., an RLC receiving end) can refer to the description in Embodiment 6 above.

[0488] In this embodiment, two RLC entities are associated with one PDCP entity, enabling independent transmission of different PDCP PDU types. Access network elements can configure different transmission modes and parameters for different RLC entities. This embodiment maximizes the utilization of the existing RLC layer functionality, achieving independent transmission of PDCP control PDUs and PDCP data PDUs without requiring major modifications to existing RLC functions.

[0489] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this disclosure.

[0490] Embodiments of this disclosure also provide a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps in any of the above method embodiments.

[0491] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0492] Embodiments of this disclosure also provide an electronic device including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0493] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0494] Embodiments of this disclosure also provide a computer program product, including a computer program that, when executed by a processor, implements the steps in any of the method embodiments described above.

[0495] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0496] It is obvious to those skilled in the art that the modules or steps of this disclosure described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this disclosure is not limited to any particular combination of hardware and software.

[0497] The above description is merely an exemplary embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A data transmission method, comprising: Determine the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resources corresponding to the type of the PDCP PDU; The PDCP PDU is transmitted via the RLC transport resources.

2. The method according to claim 1, wherein, The types of PDCP PDUs include PDCP control protocol data units and PDCP data protocol data units.

3. The method according to claim 2, wherein, The RLC transmission resources include sub-channels or sub-bearers, wherein the sub-channels or sub-bearers corresponding to the PDCP control protocol data units and the PDCP data protocol data units are different.

4. The method according to claim 3, wherein, The step of sending the PDCP PDU through the RLC transmission resources includes: The RLC entity transmits RLC protocol data units for carrying the PDCP PDU, wherein the protocol header of the RLC protocol data unit contains the identifier of the subchannel or the subbearer.

5. The method according to claim 4, wherein, The configuration information for each sub-channel or sub-bearer is configured individually, wherein the configuration information includes at least one of the following: The transmission mode of the sub-channel or the sub-bearer includes transparent mode TM, unacknowledged mode UM, or acknowledged mode AM; Does the protocol header of the RLC protocol data unit of the sub-channel or the sub-bearer contain a Radio Link Control Sequence Number (RLC SN)? The size of the reassembly timer for the sub-channel or the sub-bearer; Whether the sub-channel or the sub-bearer uses a transmit window and a receive window; The size of the transmit window and the size of the receive window of the sub-channel or the sub-bearer; Whether the sub-channel or the sub-bearer provides feedback on the reception status via RLC status report.

6. The method according to claim 5, wherein, The method further includes: In response to the transmission mode of the subchannel or the subbearer being the UM or the AM, or in response to the protocol header of the RLC protocol data unit of the subchannel or the subbearer containing the RLC SN, the RLC entity maintains a set of RLC transmitter variables and / or the transmission window for the subchannel or the subbearer, wherein the transmission window is used to control the transmission of the RLC protocol data unit.

7. The method according to claim 2, wherein, The RLC transmission resources include RLC protocol data units, wherein the types of RLC protocol data units corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit are different.

8. The method according to claim 7, wherein, The step of sending the PDCP PDU through the RLC transmission resources includes: The RLC entity sends an RLC protocol data unit for carrying the PDCP PDU, wherein the protocol header of the RLC protocol data unit contains the type of the RLC protocol data unit.

9. The method according to claim 8, wherein, The configuration information for each type of RLC protocol data unit is configured by the access network element or agreed upon by the protocol, wherein the configuration information includes at least one of the following: The correspondence between the types of PDCP PDUs and the types of RLC protocol data units; The transmission mode of the RLC protocol data unit type includes transparent mode TM, unacknowledged mode UM, or acknowledged mode AM; The type of the RLC protocol data unit; whether the protocol header of the RLC protocol data unit contains a Radio Link Control Sequence Number (RLC SN); The size of the reassembly timer for the type of RLC protocol data unit; Whether the type of the RLC protocol data unit uses a transmit window and a receive window; The size of the sending window and the size of the receiving window for the type of RLC protocol data unit; Whether the type of the RLC protocol data unit is reported in the RLC status report indicates the reception status.

10. The method according to claim 9, wherein, The method further includes: In response to the transmission mode corresponding to the type of the RLC protocol data unit being UM or AM, or in response to the protocol header of the RLC protocol data unit corresponding to the type of the RLC protocol data unit containing the RLC SN, the RLC entity maintains a set of RLC transmitter variables and / or the transmission window for the type of the RLC protocol data unit, wherein the transmission window is used to control the transmission of the RLC protocol data unit.

11. The method according to claim 9, wherein, The types of the RLC protocol data units include: RLC control protocol data units and RLC data protocol data units, wherein the correspondence between the types of the PDCP PDUs and the types of the RLC protocol data units includes at least one of the following: A correspondence between one or more PDCP control protocol data units and one RLC control protocol data unit; A correspondence between one or more PDCP data protocol data units and one RLC data protocol data unit.

12. The method according to claim 2, wherein, The RLC transmission resource includes an RLC entity, wherein the RLC entity corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit are different.

13. The method according to claim 12, wherein, The step of sending the PDCP PDU through the RLC transmission resources includes: The RLC entity corresponding to the type of the PDCP PDU sends the RLC protocol data unit used to carry the PDCP PDU.

14. The method according to claim 13, wherein, The configuration information for each RLC entity is configured individually, wherein the configuration information includes at least one of the following: Logical channel identifier, used to identify the RLC entity in the lower-layer protocol entity; The transmission modes of the RLC entity include transparent mode TM, unacknowledged mode UM, or acknowledged mode AM; Does the protocol header of the RLC protocol data unit of the RLC entity contain a Radio Link Control Sequence Number (RLC SN)? The size of the recombination timer for the RLC entity; Whether the RLC entity uses a send window and a receive window; The size of the transmit window and the size of the receive window of the RLC entity; Whether the RLC entity reports its reception status via the RLC status report.

15. A data transmission method, comprising: Determine the type of Packet Data Convergence Protocol Data Unit (PDCP PDU) and the Radio Link Control (RLC) transmission resources corresponding to the type of the PDCP PDU; The PDCP PDU is received through the RLC transport resources.

16. The method according to claim 15, wherein, The types of PDCP PDUs include PDCP control protocol data units and PDCP data protocol data units.

17. The method according to claim 16, wherein, The RLC transmission resources include sub-channels or sub-bearers, wherein the sub-channels or sub-bearers corresponding to the PDCP control protocol data units and the PDCP data protocol data units are different.

18. The method according to claim 17, wherein, Receiving the PDCP PDU through the RLC transmission resources includes: The RLC entity receives an RLC protocol data unit for carrying the PDCP PDU, wherein the protocol header of the RLC protocol data unit contains an identifier of the subchannel or the subbearer.

19. The method of claim 16, wherein, The RLC transmission resources include RLC protocol data units, wherein the types of RLC protocol data units corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit are different.

20. The method according to claim 19, wherein, Receiving the PDCP PDU through the RLC transmission resources includes: The RLC entity receives RLC protocol data units for carrying the PDCP PDU, wherein the protocol header of the RLC protocol data unit contains the type of the RLC protocol data unit.

21. The method according to claim 16, wherein, The RLC transmission resource includes an RLC entity, wherein the RLC entity corresponding to the PDCP control protocol data unit and the PDCP data protocol data unit are different.

22. The method according to claim 21, wherein, Receiving the PDCP PDU through the RLC transmission resources includes: The RLC entity corresponding to the type of the PDCP PDU receives the RLC protocol data unit used to carry the PDCP PDU.

23. A data transmission method, comprising: Send a Radio Link Control Protocol Data Unit (RLC PDU) carrying first information, wherein the RLC PDU is used to carry a Radio Link Control Service Data Unit (RLC SDU) or an RLC SDU fragment of the RLC SDU. Adjust the RLC transmitter variables and the position of the transmitter window based on the first information.

24. The method according to claim 23, wherein, The transmission of the Radio Link Control Protocol Data Unit (RLC PDU) carrying first information includes: In response to the RLC SDU to be transmitted being outside the transmission window, the RLC PDU carrying the Radio Link Control Sequence Number (RLC SN) of the RLC SDU is transmitted, wherein the first information includes the RLC SN of the RLC SDU.

25. The method according to claim 24, wherein, The step of adjusting the RLC transmitter variables and the position of the transmission window based on the first information includes: The RLC transmitter variable is adjusted according to the RLC SN of the RLC SDU; The position of the transmission window is adjusted according to the adjusted RLC transmitter variables.

26. The method of claim 25, wherein, The adjustment of the RLC transmitter variable based on the RLC SN of the RLC SDU includes at least one of the following: Update the TX_Next variable to the RLC SN of the RLC SDU plus 1, wherein the TX_Next variable is used to identify the RLC SN of the next RLC SDU to be sent; In response to the TX_Next_Ack variable being less than the difference between the TX_Next variable and the transmission window size, the TX_Next_Ack variable is updated to the smallest RLC SN among all RLC SDUs that have not been successfully acknowledged for transmission, where the RLC SN is greater than or equal to the difference between the TX_Next variable and the transmission window size. The TX_Next_Ack variable is used to identify the RLC SN of the next RLC SDU waiting to receive acknowledgment within the transmission window. The RLC transmitter variables include the TX_Next variable and the TX_Next_Ack variable.

27. The method according to claim 26, wherein, The step of adjusting the position of the transmission window according to the adjusted RLC transmitter variables includes: Update the lower limit of the sending window to the value of the TX_Next_Ack variable, and update the upper limit of the sending window to the sum of the TX_Next_Ack variable and the sending window size; or, The lower limit of the sending window is updated to the difference between the TX_Next variable and the sending window size, and the upper limit of the sending window is updated to the value of the TX_Next variable.

28. The method according to claim 26, wherein, The method further includes: An RLC SDU whose RLC SN is less than or equal to the difference between the TX_Next variable and the transmission window size is considered to have been discarded or successfully transmitted.

29. The method according to claim 24, wherein, Before transmitting the RLC PDU carrying the Radio Link Control Sequence Number (RLC SN) of the RLC SDU in response to the RLC SDU being outside the transmission window, the method further includes one of the following: Based on the configuration of the access network elements, it is determined that the RLC transmitter meets the preset first triggering condition; Based on the configuration of the access network element, the RLC transmitter is determined to transmit the RLC SDU located outside the transmission window; Based on the configuration of the access network element, the maximum number of Radio Link Control Sequence Numbers (RLC SNs) that the RLC transmitter can send outside the transmission window is determined to be M, and the RLC SN of the RLC SDU to be sent is determined to be less than or equal to N+M, where N is the upper limit of the transmission window.

30. The method according to claim 23, wherein, The transmission of the Radio Link Control Protocol Data Unit (RLC PDU) carrying first information includes: The RLC PDU is transmitted carrying indication information for instructing the RLC receiver to discard one or more RLC SDUs, wherein the first information includes the indication information.

31. The method according to claim 30, wherein, The step of adjusting the RLC transmitter variables and the position of the transmission window based on the first information includes: Adjust the RLC transmitter variables according to the indicated information; The position of the transmission window is adjusted according to the adjusted RLC transmitter variables.

32. The method according to claim 31, wherein, The transmission of the Radio Link Control Protocol Data Unit (RLC PDU) carrying first information includes: Send an RLC data protocol data unit to the RLC receiver, wherein the header of the RLC data protocol data unit carries the indication information; or, An RLC control protocol data unit is sent to the RLC receiver, wherein the RLC control protocol data unit carries the indication information.

33. The method according to claim 31, wherein, The indication information includes at least one of the following: The maximum RLC SN value of the discarded RLC SDU; RLC SN values ​​of a set of discarded RLC SDUs; A bitmap, wherein the bitmap contains the values ​​of multiple bits, each bit corresponding to an RLC SDU, and the value of each bit is used to indicate whether the corresponding RLC SDU is discarded; An instruction is provided to instruct the RLC receiver to discard all RLC SDUs or RLC SDU fragments that were not successfully received.

34. The method according to claim 33, wherein, The adjustment of the RLC transmitter variables according to the indication information includes at least one of the following: In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, the TX_Next_Ack variable is updated to the minimum RLC SN among one or more RLC SNs whose RLC SN is greater than the maximum RLC SN value among all RLC SDUs that have not been acknowledged for successful transmission; In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the TX_Next_Ack variable being equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, the TX_Next_Ack variable is updated to the smallest RLC SN among one or more RLC SNs whose RLC SN is greater than the value of the TX_Next_Ack variable among all RLC SDUs that were neither acknowledged as successfully transmitted nor discarded; In response to the indication information being an indication for the RLC receiver to discard all unsuccessfully received RLC SDUs, the TX_Next_Ack variable is updated to the value of the TX_Next variable; The RLC transmitter variables include the TX_Next variable and the TX_Next_Ack variable.

35. The method according to claim 30, wherein, The method further includes at least one of the following: The indication information is given to the Packet Data Convergence Protocol (PDCP) transmitter associated with the RLC transmitter, so that the PDCP transmitter discards the Packet Data Convergence Protocol Data Unit (PDCP PDU) or Packet Data Convergence Protocol Service Data Unit (PDCP SDU) corresponding to the one or more RLC SDUs. The indication information is transmitted from the PDCP transmitter to the PDCP receiver. The indication information is transmitted from the RLC receiver to the PDCP receiver.

36. A data transmission method, comprising: Receive Radio Link Control Protocol Data Unit (RLC PDU) carrying first information; Adjust the RLC receiver variables and the position of the receiver window based on the first information.

37. The method of claim 36, wherein, The receiving of the Radio Link Control Protocol Data Unit (RLC PDU) carrying first information includes: In response to a Radio Link Control Service Data Unit (RLC SDU) to be received being located outside the receiving window, the RLC PDU carrying the Radio Link Control Sequence Number (RLC SN) of the RLC SDU is received, wherein the first information includes the RLC SN of the RLC SDU, and the RLC PDU is used to carry the RLC SDU or an RLC SDU fragment of the RLC SDU.

38. The method according to claim 37, wherein, The step of adjusting the RLC receiver variables and the position of the receiver window based on the first information includes: The RLC receiver variables are adjusted according to the RLC SN of the RLC SDU; The position of the receiving window is adjusted according to the adjusted RLC receiver variables.

39. The method according to claim 38, wherein, The adjustment of the RLC receiver variables based on the RLC SN of the RLC SDU includes at least one of the following: Update the RX_Next_Highest variable to the value of the RLC SN plus 1, wherein the RX_Next_Highest variable is used to identify the next RLC SN after the maximum RLC SN of the received RLC SDU; Update the RX_Next variable to the smallest RLC SN among all RLC SDUs that failed to receive data, where the RLC SN is greater than or equal to the difference between the RX_Next_Highest variable and the receive window size; The RLC receiver variables include the RX_Next_Highest variable and / or the RX_Next variable.

40. The method according to claim 39, wherein, The step of adjusting the position of the receiving window according to the adjusted RLC receiver variables includes: Update the lower limit of the receiving window to the difference between the RX_Next_Highest variable and the size of the receiving window, and update the upper limit of the receiving window to the value of the RX_Next_Highest variable; or, Update the lower limit of the receiving window to the value of the RX_Next variable, and update the upper limit of the receiving window to the sum of the RX_Next variable and the size of the receiving window.

41. The method according to claim 38, wherein, The method further includes: RLC SDUs located outside the receiving window and not successfully received are considered either discarded or successfully received, and RLC SDU fragments located outside the receiving window and already received are discarded.

42. The method according to claim 37, wherein, Before receiving the RLC PDU carrying the Radio Link Control Sequence Number (RLC SN) of the RLC SDU in response to the RLC SDU being outside the receiving window, the method further includes one of the following: The RLC receiver is determined to meet the preset third triggering condition based on the configuration of the access network element. Based on the configuration of the access network element, the RLC receiver is determined to receive the RLC SDU located outside the receiving window; Based on the configuration of the access network element, the maximum number of Radio Link Control Sequence Numbers (RLC SNs) outside the reception window received by the RLC receiver is determined to be K, and the RLC SN of the RLC SDU to be received is determined to be less than or equal to P+K, where P is the upper limit of the reception window. Based on the configuration of the access network element, determine the range of RLC SNs outside the receiving window received by the RLC receiver, and determine that the RLC SN of the RLC SDU to be received is within the range of the RLC SN.

43. The method according to claim 36, wherein, The receiving of the Radio Link Control Protocol Data Unit (RLC PDU) carrying first information includes: The RLC PDU is received, carrying indication information for instructing the RLC receiver to discard one or more Radio Link Control Service Data Units (RLC SDUs), wherein the first information includes the indication information.

44. The method according to claim 43, wherein, The step of adjusting the RLC receiver variables and the position of the receiver window based on the first information includes: Adjust the RLC receiver variables according to the indicated information; The position of the receiving window is adjusted according to the adjusted RLC receiver variables.

45. The method according to claim 43, wherein, The instruction information includes one of the following: The maximum RLC SN value of the discarded RLC SDU; RLC SN values ​​of a set of discarded RLC SDUs; A bitmap, wherein the bitmap contains the values ​​of multiple bits, each bit corresponding to an RLC SDU, and the value of each bit is used to indicate whether the corresponding RLC SDU is discarded; An instruction is provided to instruct the RLC receiver to discard all RLC SDUs or RLC SDU fragments that were not successfully received.

46. ​​The method of claim 44, wherein, The adjustment of the RLC receiver variables according to the indication information includes at least one of the following: In response to the indication that the maximum RLC SN value of the discarded RLC SDU is, the RX_Next variable is updated to the minimum RLC SN among one or more RLC SNs whose RLC SN is greater than the maximum RLC SN value among all RLC SDUs that were not successfully received; In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, and the value of the RX_Next_Highest variable being less than the updated value of the RX_Next variable, the RX_Next_Highest variable is updated to the updated value of the RX_Next variable; In response to the indication information being the maximum RLC SN value of the discarded RLC SDU, and the value of the RX_Highest_Status variable being less than or equal to the maximum RLC SN value, the RX_Highest_Status variable is updated to the minimum RLC SN among one or more RLC SNs whose RLC SN is greater than the maximum RLC SN value among all RLC SDUs that were not successfully received; The RLC receiver variables include the RX_Next variable, the RX_Next_Highest variable, and the RX_Highest_Status variable.

47. The method of claim 44, wherein, The adjustment of the RLC receiver variables according to the indication information includes at least one of the following: In response to the indication information being the RLC SN value of a set of discarded RLC SDUs, and the value of the RX_Next variable being equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, the RX_Next variable is updated to the smallest RLC SN among one or more RLC SNs whose RLC SN is greater than the value of the RX_Next variable among all RLC SDUs that were not successfully received and were not discarded. In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Next_Highest variable being less than or equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, the RX_Next_Highest variable is updated to the maximum value of the RLC SN values ​​of the set of discarded RLC SDUs plus 1; In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Next_Highest variable being less than the updated value of the RX_Next variable, the RX_Next_Highest variable is updated to the updated value of the RX_Next variable; In response to the indication information being the RLC SN value of the set of discarded RLC SDUs, and the value of the RX_Highest_Status variable being equal to one of the RLC SN values ​​of the set of discarded RLC SDUs, the RX_Highest_Status variable is updated to the smallest RLC SN among one or more RLC SNs whose RLC SN is greater than the value of the RX_Highest_status variable among all RLC SDUs that were not successfully received and were not discarded. The RLC receiver variables include the RX_Next variable, the RX_Next_Highest variable, and the RX_Highest_Status variable.

48. The method according to claim 44, wherein, The adjustment of the RLC receiver variables according to the indication information includes at least one of the following: In response to the indication information being an indication to the RLC receiver to discard all unsuccessfully received RLC SDUs, the RX_Next variable is updated to the value of the RX_Next_Highest variable; In response to the indication information being an indication for the RLC receiver to discard all unsuccessfully received RLC SDUs, the RX_Highest_Status variable is updated to the updated value of the RX_Next variable; The RLC receiver variables include the RX_Next variable, the RX_Next_Highest variable, and the RX_Highest_Status variable.

49. The method according to claim 44, wherein, The step of adjusting the position of the receiving window according to the adjusted RLC receiver variables includes: Update the lower limit of the receiving window to the value of the RX_Next variable, and update the upper limit of the receiving window to the sum of the RX_Next variable and the size of the receiving window.

50. The method according to claim 43, wherein, The method further includes: The instruction information is directed to the Packet Data Convergence Protocol (PDCP) receiver associated with the RLC receiver.

51. The method according to claim 36, wherein, The method further includes at least one of the following: In response to the fact that the reassembly timer at the RLC receiver is running and the reassembly timer meets a preset condition, the reassembly timer is stopped and reset. In response to the RX_Next variable being greater than the RX_Highest_Status variable, the RX_Highest_Status variable is updated to the value of the RX_Next variable; In response to the RX_Next_Highest variable being greater than the RX_Next variable plus 1, or the RX_Next_Highest variable being equal to the RX_Next variable plus 1, and the RLC SDU with RLC SN equal to the RX_Next variable having a missing RLC SDU fragment, the reassembly timer is started, and the RX_Next_Status_Trigger variable is updated to the value of the RX_Next_Highest variable; The RX_Highest_Status variable is used to identify the maximum value of the ACK_SN field in the status report, and the RX_Next_Status_Trigger variable is used to identify the next RLC SN of the RLC SDU that triggered the reassembly timer.

52. The method according to claim 51, wherein, The preset conditions include one of the following: The value of the RX_Next_Status_Trigger variable is outside the adjusted receive window; The value of the RX_Next_Status_Trigger variable is less than or equal to the adjusted value of the RX_Next variable; The value of the RX_Next_Status_Trigger variable is less than or equal to the difference between the RX_Next_Highest variable and the receiving window size; The value of the RX_Next_Status_Trigger variable is equal to the RX_Next variable plus 1, and the RLC SN is equal to the RLC SDU received by the RX_Next variable, where there are no missing bytes before the last byte; There are no unreceived RLC SDU fragments, RLC SDUs, or RLC PDUs between the RX_Next_Status_Trigger variable and the RX_Next variable.

53. A computer-readable storage medium storing a computer program, wherein, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1 to 52.

54. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1 to 52.

55. A computer program product comprising a computer program, wherein, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1 to 52.

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