Data transmission method and device, terminal, network side equipment and readable storage medium

Abstract

The invention discloses a data transmission method and device, a terminal, network side equipment and a readable storage medium, and belongs to the technical field of communication, and the data transmission method comprises the steps that under the condition that the terminal is switched from a first cell to a second cell, a first protocol layer entity of a receiving end receives indication information from a sending end, the indication information is used for indicating related information of a first PDU of a first bearer sent by the sending end in a second cell, and the first bearer is a bearer corresponding to a first protocol layer entity; under the condition that the first protocol layer entity receives the first PDU, the first protocol layer entity submits at least one first service data unit (SDU) to a high layer, and the first SDU is the SDU corresponding to the received PDU; wherein under the condition that the receiving end is a terminal, the transmitting end is network side equipment corresponding to the second cell; or, under the condition that the sending end is the terminal, the receiving end is the network side equipment corresponding to the second cell.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication, and particularly relates to a data transmission method and device, a terminal, a network side equipment and a readable storage medium. BACKGROUND

[0002] At present, in the process of data transmission between a terminal and a network side equipment, the receiving end (i.e. the terminal or the network side equipment) can determine the count value corresponding to one PDCP data PDU sent by the RLC layer when the PDCP layer of the receiving end receives the PDCP data PDU, and determine whether there are some PDCP data PDUs that have not been received according to the count value. Thus, in the case where it is determined that there are the PDCP data PDUs, the terminal can start a timer t-Reordering, and in the case where the t-Reordering is timed out (or the t-Reordering is not timed out and the PDCP data PDUs are received), the terminal can submit the processed PDCP SDU to the upper layer.

[0003] However, since the terminal may perform cell switching in the process of data transmission between the terminal and the network side equipment, the time delay of the PDCP layer of the receiving end in submitting the processed PDCP SDU to the upper layer may be large at this time, and thus the time delay of data transmission is large. SUMMARY

[0004] The embodiments of the present application provide a data transmission method and device, a terminal, a network side equipment and a readable storage medium, which can solve the problem of large time delay of data transmission.

[0005] In a first aspect, a data transmission method is provided. The method comprises: in a case where a terminal is handed over from a first cell to a second cell, receiving, by a first protocol layer entity of the terminal, indication information from a sending terminal, the indication information being used to indicate related information of a first PDU of a first bearer transmitted by the sending terminal in the second cell, the first bearer being a bearer corresponding to the first protocol layer entity; and in a case where the first PDU has been received by the first protocol layer entity, submitting, by the first protocol layer entity, at least one first service data unit (SDU) to a higher layer, the first SDU being an SDU corresponding to the received PDU. In a case where the receiving terminal is the terminal, the sending terminal is a network side device corresponding to the second cell; or in a case where the sending terminal is the terminal, the receiving terminal is the network side device corresponding to the second cell.

[0006] In a second aspect, a data transmission apparatus is provided. The data transmission apparatus comprises: a receiving module and a processing module. The receiving module is configured to, in a case where a terminal is handed over from a first cell to a second cell, receive indication information from a sending terminal, the indication information being used to indicate related information of a first PDU of a first bearer transmitted by the sending terminal in the second cell, the first bearer being a bearer corresponding to the data transmission apparatus. The processing module is configured to, in a case where the first PDU has been received by the data transmission apparatus, submit at least one first SDU to a higher layer, the first SDU being an SDU corresponding to the received PDU. In a case where the receiving terminal is the terminal, the sending terminal is a network side device corresponding to the second cell; or in a case where the sending terminal is the terminal, the receiving terminal is the network side device corresponding to the second cell.

[0007] In a third aspect, a data transmission apparatus is provided. The apparatus is configured to perform the steps of the method of the first aspect.

[0008] In a fourth aspect, a terminal is provided. The terminal comprises a processor and a memory. The memory stores programs or instructions executable on the processor. When the programs or instructions are executed by the processor, the steps of the method of the first aspect are implemented.

[0009] In a fifth aspect, a terminal is provided. The terminal comprises a processor and a communication interface. The communication interface is configured to, in a case where the terminal is handed over from a first cell to a second cell, receive indication information from a sending terminal, the indication information being used to indicate related information of a first PDU of a first bearer transmitted by the sending terminal in the second cell, the first bearer being a bearer corresponding to a first protocol layer entity of the terminal. The processor is configured to, in a case where the first PDU has been received by the first protocol layer entity, submit at least one first service data unit (SDU) to a higher layer, the first SDU being an SDU corresponding to the received PDU. In a case where the receiving terminal is the terminal, the sending terminal is a network side device corresponding to the second cell; or in a case where the sending terminal is the terminal, the receiving terminal is the network side device corresponding to the second cell.

[0010] In a sixth aspect, a network-side device is provided, which includes a processor and a memory, the memory storing programs or instructions executable on the processor, and the programs or instructions, when executed by the processor, implement the steps of the method according to the first aspect.

[0011] In a seventh aspect, a network-side device is provided, which includes a processor and a communication interface, wherein the communication interface is configured to receive, in a case where a terminal is handed over from a first cell to a second cell, indication information from a sending terminal, the indication information being used to indicate related information of a first PDU of a first bearer sent by the sending terminal in the second cell, the first bearer being a bearer corresponding to a first protocol layer entity of the terminal; and the processor is configured to, in a case where the first protocol layer entity has received the first PDU, submit at least one first service data unit (SDU) to a higher layer, the first SDU being an SDU corresponding to the received PDU; wherein the sending terminal is the terminal, and the network-side device corresponds to the second cell.

[0012] In an eighth aspect, a readable storage medium is provided, which stores programs or instructions, and the programs or instructions, when executed by a processor, implement the steps of the method according to the first aspect.

[0013] In a ninth aspect, a chip is provided, which includes a processor and a communication interface, the communication interface being coupled to the processor, and the processor being configured to run programs or instructions to implement the steps of the method according to the first aspect.

[0014] In a tenth aspect, a computer program / program product is provided, which is stored in a storage medium, and the computer program / program product is executed by at least one processor to implement the steps of the method according to the first aspect.

[0015] In the embodiment of the present application, in the case that the terminal is handed over from the first cell to the second cell, the first protocol layer entity of the receiving end receives the information about the first PDU of the first bearer transmitted by the sending end in the second cell from the sending end, the first bearer being the bearer corresponding to the first protocol layer entity, and in the case that the first protocol layer entity has received the first PDU, submits at least one SDU corresponding to the received PDU to the upper layer; wherein, in the case that the receiving end is the terminal, the sending end is the network side device corresponding to the second cell; or in the case that the sending end is the terminal, the receiving end is the network side device corresponding to the second cell. Since in the case that the terminal is handed over from the first cell to the second cell, the first protocol layer entity can know the information about the first PDU of the first bearer transmitted by the sending end in the second cell through the indication information, thus in the case that the terminal is handed over from the first cell to the second cell, in the case that the first protocol layer entity receives the first PDU, the first protocol layer entity can directly submit at least one SDU (i.e. processed SDU) corresponding to the received PDU to the upper layer without waiting for t-Reordering timeout, thus the time required for submitting the processed SDU to the upper layer can be reduced, thereby the transmission delay of the SDU can be reduced, thus the transmission delay of data can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the architecture diagram of CU-DU in the related art;

[0017] Figure 2 is the block diagram of the wireless communication system provided by the embodiment of the present application;

[0018] Figure 3 is one of the flow diagrams of the data transmission method provided by the embodiment of the present application;

[0019] Figure 4 is the second flow diagram of the data transmission method provided by the embodiment of the present application;

[0020] Figure 5A is one of the structure diagrams of the data PDU provided by the embodiment of the present application;

[0021] Figure 5B is the second structure diagram of the data PDU provided by the embodiment of the present application;

[0022] Figure 5C is the third structure diagram of the data PDU provided by the embodiment of the present application;

[0023] Figure 6 is the structure diagram of the data transmission device provided by the embodiment of the present application;

[0024] Figure 7 This is a schematic diagram of the hardware structure of the communication device provided in the embodiments of this application;

[0025] Figure 8 This is a schematic diagram of the hardware structure of the terminal provided in the embodiments of this application;

[0026] Figure 9 This is a schematic diagram of the hardware structure of the network-side device provided in the embodiments of this application. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0028] The following will explain the technical terms used in the embodiments of this application.

[0029] 1. Central Unit-Distributed Unit (CU-DU) Architecture

[0030] Currently, New Radio (NR) access networks split the Next Generation Node B (gNB) into a central unit (gNB-CU) and distributed units (gNB-DU), connected via the F1 interface. The architecture diagram of the CU-DU is shown below. Figure 1 As shown.

[0031] A gNB contains only one CU, one or more DUs, and one DU contains one or more cells.

[0032] CU contains protocol stacks at or above PDCP, while DU contains protocol stacks below PDCP (such as Radio Link Control (RLC) layer, Media Access Control (MAC) layer, and Physical (PHY) layer).

[0033] In the control plane, the CU includes the Radio Resource Control (RRC) layer and the PDCP (PDCP-C) of the control plane.

[0034] On the user plane, the CU includes the Service Data Adaptation Protocol (SDAP) layer and the user plane PDCP (PDCP-U).

[0035] 2. Cell handover

[0036] Cell handover includes:

[0037] Intra-CU handover means that the source cell and the target cell are in the same CU. Since the PDCP position remains unchanged, the key does not need to be changed during the handover process.

[0038] Inter-CU handover occurs when the source and target cells are in different CUs, requiring a key change during the handover process.

[0039] 5th generation (5) th Existing cell modification methods in Generation (5G) NR include:

[0040] L3 handover triggered by RRC means that the terminal is instructed to perform a handover or primary / secondary cell change by carrying ReconfigurationWithSync in the RRC reconfiguration signaling.

[0041] Conditional Handover (CHO) / ​​Conditional Primary / Secondary Cell Change (CPC) / Layer 1 / Layer 2-Triggered Mobility (LTM) means that RRC pre-configures at least one candidate target cell, the terminal evaluates the handover execution conditions of the candidate cell, and the terminal initiates handover or primary / secondary cell change after the conditions are met.

[0042] LTM (L1 / L2-Triggered Mobility) cell switch, i.e., RRC pre-configures at least one candidate target cell, DU sends MAC control element CE to instruct the terminal to perform handover or PSCellChange.

[0043] 3. PDCP

[0044] The PDCP layer is responsible for the encryption and integrity protection of data packets. The COUNT value associated with the PDCP SDU is one of the algorithm inputs to implement the above process. Therefore, when the key remains unchanged, the same COUNT value cannot be used to encrypt or protect different PDCP SDUs in order to ensure the security of data packet transmission.

[0045] Normally, when outOfOrderDelivery is not configured, the PDCP layer needs to ensure that the received data packets are delivered to the upper layer in order. The receiving end processing mechanism is as follows:

[0046] When in-order delivery is configured at the receiving end, the receiving entity of the PDCP at the receiving end needs to maintain the following state variables:

[0047] RX_DELIV: This variable indicates the COUNT value of the first PDCP SDU that has not been delivered to the upper layer but is waiting to be delivered.

[0048] RX_NEXT: This variable indicates the COUNT value of the PDCP data PDU corresponding to the next expected PDCP SDU to be received. Here, the PDCP data PDU corresponding to the PDCP SDU can be understood as the PDCP SDU obtained by the PDCP layer's processing of this PDCP data PDU.

[0049] RX_REORD: This variable indicates the COUNT + 1 of the PDCP data PDU that triggers the t-Reordering timer, which is RX_NEXT at this time.

[0050] When the receiving entity of the PDCP receives a PDCP data PDU delivered by the RLC layer, it calculates the RCVD_COUNT of this PDU. After completing the corresponding decryption and integrity check processing, it performs the following operations:

[0051] A1. If RCVD_COUNT < RX_DELIV or the received COUNT = RCVD_COUNT has already been received, discard this PDCP PDU. If it is not discarded, continue with the following processing.

[0052] B1. If RCVD_COUNT >= RX_NEXT, update RX_NEXT = RCVD_COUNT + 1.

[0053] C1. If RCVD_COUNT = RX_DELIV, deliver the processed PDCP SDUs to the upper layer in ascending order of COUNT, and update RX_DELIV to point to the first PDCP SDU that has not been delivered to the upper layer.

[0054] D1. If the t-Reordering timer is running and RX_DELIV >= RX_REORD, stop t-Reordering.

[0055] E1. If timer t-Reordering is not running and RX_DELIV < RX_NEXT, then update RX_REORD = RX_NEXT and start t-Reordering.

[0056] In case of timeout of t-Reordering, it is considered that the packet reception of [RX_NEXT, RX_REORD] fails, and the following operations are performed:

[0057] A2. The PDCP SDUs with received COUNT < RX_REORD and completed downlink reception processing are delivered to the upper layer in ascending order.

[0058] B2. For the PDCP SDUs with received COUNT >= RX_REORD and completed downlink reception processing, if COUNT is consecutive, they are delivered to the upper layer in ascending order.

[0059] C2. Update RX_DELIV to point to the first PDCP SDU that has not been delivered to the upper layer.

[0060] D2. If RX_DELIV < RX_NEXT, then update RX_REORD = RX_NEXT and start t-Reordering.

[0061] 4. Other terms

[0062] The terms "first", "second", etc. in this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first" and "second" are usually of the same category, and do not limit the number of objects. For example, the first object can be one or more. In addition, "or" in this application means at least one of the connected objects. For example, the protection scope of "A or B" covers at least three scenarios, namely, Scenario 1: including A and not including B; Scenario 2: including B and not including A; Scenario 3: including both A and B. In addition, the terms "A and / or B", "at least one of A and B", "at least one of A or B" also cover at least the above three scenarios respectively. The character " / " generally means that the associated objects before and after are in an "or" relationship.

[0063] The term "instruction" in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction). A direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent. An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.

[0064] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), or other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and NR terminology is used in most of the following description; however, these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0065] Figure 2This diagram illustrates a block diagram of a wireless communication system applicable to embodiments of this application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 can be a mobile phone, tablet computer, laptop computer, notebook computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR), virtual reality (VR) device, robot, wearable device, flight vehicle, vehicle user equipment (VUE), shipboard equipment, pedestrian user equipment (PUE), smart home devices (home appliances with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game consoles, personal computers (PCs), ATMs, or self-service machines, etc. Wearable devices include: smartwatches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among these, in-vehicle devices can also be referred to as in-vehicle terminals, in-vehicle controllers, in-vehicle modules, in-vehicle components, in-vehicle chips, or in-vehicle units, etc. It should be noted that the specific type of terminal 11 is not limited in this application embodiment. Network-side equipment 12 may include access network equipment or core network equipment, wherein access network equipment may also be referred to as Radio Access Network (RAN) equipment, radio access network function, or radio access network unit. Access network equipment may include base stations, Wireless Local Area Network (WLAN) access points (AS), or Wireless Fidelity (WiFi) nodes, etc.In this context, a base station may be referred to as a Node B (NB), Evolved Node B (eNB), Next Generation Node B (gNB), New Radio Node B (NRNode B), Access Point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), Radio Base Station, Radio Transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B, Transmit / Receive Point (TRP), or any other suitable term in the relevant field, as long as the same technical effect is achieved. The base station is not limited to any specific technical terminology. It should be noted that in this application embodiment, only a base station in an NR system is used as an example for introduction, and the specific type of base station is not limited.

[0066] The data transmission method, apparatus, terminal, network-side device, and readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0067] The data transmission method provided in this application embodiment can be applied to scenarios where the terminal performs cell handover.

[0068] In a scenario, the terminal performs cell handover during the process of data transmission with the network-side device, and the source cell and the target cell are within the same CU. At this time, since the PDCP position remains unchanged, the key can be unchanged during the handover process. In the related art, assuming that the receiving end is the terminal, the terminal is configured for in-sequence delivery, the count value COUNT of the last downlink PDCP data PDU received by the terminal in the source cell is 5, and the PDCP data PDU corresponding to the COUNT value of 6 is not successfully received in the source cell due to the terminal performing cell handover. The COUNT value of the first downlink PDCP data PDU received by the terminal in the target cell is 7 (since the COUNT value of 6 has been used up, the network-side device can only start sending data from COUNT = 7 in the target cell). At this time, since the terminal will determine that RX_DELIV < RX_NEXT when receiving the downlink PDCP data PDU with the COUNT value of 7, the terminal will start t-Reordering. Moreover, since the PDCP data PDU with the COUNT value of 6 fails to be received due to the terminal performing cell handover (i.e., switching from the source cell to the target cell), the terminal may deliver the PDCP SDU corresponding to the PDCP data PDU with the COUNT value less than or equal to 7 to the upper layer only when the t-Reordering times out. As a result, the transmission delay of the PDCP SDU corresponding to the downlink PDCP data PDU with the COUNT value of 7 becomes larger.

[0069] However, in the embodiments of this application, when the terminal switches from the source cell to the target cell, the terminal's PDCP entity can receive indication information from the network-side device. This indication information is used to indicate the relevant information of the first PDCPPDU carried by the PDCP entity sent by the network-side device in the target cell. In this way, the PDCP entity can know whether it has received the first PDCPPDU based on the relevant information. If the first PDCPPDU is received, the PDCP entity can directly submit at least one PDCP SDU corresponding to the PDCP dataPDU with a COUNT value greater than or equal to 7 to the higher layer. It is understandable that since the PDCP entity can accurately obtain the first PDCPPDU based on the relevant information of the first PDCPPDU indicated by the network-side device, and upon receiving the first PDCPPDU, directly submit at least one PDCP SDU corresponding to the PDCP dataPDU with a COUNT value less than or equal to 7 to the higher layer without waiting for the t-Reordering timeout, the waiting time required to submit at least one PDCP SDU corresponding to the PDCP dataPDU with a COUNT value less than or equal to 7 to the higher layer can be reduced, thereby reducing the transmission latency of at least one PDCP SDU corresponding to the PDCP dataPDU with a COUNT value less than or equal to 7, thus reducing the data transmission latency.

[0070] It should be noted that the above illustration uses the terminal as the receiving end and the network-side device as the sending end. In actual applications, the terminal can also be the sending end and the network-side device can also be the receiving end. This will not be repeated here in the embodiments of this application.

[0071] The data transmission method provided in this application can be executed by a data transmission device, a terminal, a functional module or entity within a terminal, or a functional module or entity within a network-side device. This application uses the execution of the data transmission method by a first protocol layer entity at the receiving end (e.g., a terminal or a network-side device) as an example to illustrate the data transmission method provided in this application.

[0072] Figure 3 A schematic flowchart of a data transmission method provided in an embodiment of this application is shown. Figure 3 As shown, a data transmission method provided in this application embodiment may include the following steps 101 and 102.

[0073] Step 101: When the terminal switches from the first cell to the second cell, the first protocol layer entity of the receiving end receives the indication information from the sending end.

[0074] In this embodiment of the application, when the receiving end is a terminal, the sending end is the network-side device corresponding to the second cell; or, when the sending end is a terminal, the receiving end is the network-side device corresponding to the second cell.

[0075] In some examples, the network-side equipment corresponding to the second cell can specifically be the access network equipment (e.g., a base station) corresponding to the second cell.

[0076] It is understood that, since this embodiment specifies that the receiving end is a terminal and the sending end is the network-side device corresponding to the second cell, in subsequent steps, the terminal's first protocol layer entity can accurately receive the indication information sent by the network-side device corresponding to the second cell, and accurately submit at least one SDU to the higher layers when the first protocol layer entity receives the first PDU sent by the network-side device corresponding to the second cell on the first bearer of the second cell. Therefore, the downlink transmission latency can be reduced. Alternatively, since this embodiment specifies that the receiving end is the network-side device corresponding to the second cell and the sending end is a terminal, in subsequent steps, the first protocol layer entity of the network-side device can accurately receive the indication information sent by the terminal, and accurately submit at least one SDU to the higher layers when the first protocol layer entity receives the first PDU sent by the terminal on the first bearer of the second cell. Therefore, the uplink transmission latency can be reduced.

[0077] In some embodiments of this application, the first protocol layer entity can be a PDCP entity. Of course, the first protocol layer entity can also be other protocol entities, and this application does not limit this.

[0078] In this embodiment of the application, the first cell and the second cell are in the same CU, and the terminal switches from the first cell to the second cell as an intra-CU switch.

[0079] In some embodiments of this application, the first cell can be the cell where the terminal is camped. The first cell can be the terminal's primary cell or a primary-secondary cell.

[0080] It is understandable that the process of the terminal switching from the first cell to the second cell can be interpreted as a cell handover or a change of primary / secondary cell. This cell handover can be initiated by the terminal or by network-side equipment, and the change of primary / secondary cell can also be initiated by the terminal or by network-side equipment. No key change is performed during this cell handover or primary / secondary cell change.

[0081] In some embodiments of this application, the first key and the second key are the same; wherein, the first key is used to encrypt or protect the integrity of data between the terminal and the first cell; and the second key is used to encrypt or protect the integrity of data between the terminal and the second cell.

[0082] The first cell mentioned above can be understood as the source cell, and the second cell mentioned above can be understood as the target cell.

[0083] In this embodiment of the application, the above-mentioned indication information is used to indicate the relevant information of the first protocol data unit (PDU) of the first bearer sent by the sending end in the second cell, wherein the first bearer is the bearer corresponding to the first protocol layer entity.

[0084] The first PDU mentioned above can be a PDU that the transmitting end has already transmitted in the second cell or a PDU that will be transmitted in the future.

[0085] In some embodiments of this application, the first PDU mentioned above may specifically be a PDCP data PDU.

[0086] In some embodiments of this application, the first bearer may include at least one of the following: Unacknowledged Mode (UM) data bearer (DRB) and signaling bearer (SRB).

[0087] In some embodiments of this application, the above-mentioned indication information is carried by at least one of the following:

[0088] Control PDU;

[0089] The first bit in the data PDU.

[0090] In some embodiments of this application, after the terminal handover is completed, or after the configuration of the second cell is applied, the first protocol layer entity can receive the control PDU.

[0091] In some embodiments of this application, the first bit may specifically be a reserved bit. Of course, the first bit may also be other bits, and this application does not limit this.

[0092] In some embodiments of this application, the order in which control PDUs and data PDUs are received is not limited, and those skilled in the art can make selections according to their needs.

[0093] Thus, since the embodiments of this application specify the specific information carrying the indication information, the first protocol layer entity can accurately receive the indication information based on the specific information. Therefore, it can be ensured that the first protocol layer entity can accurately know whether the first PDU has been received.

[0094] In some embodiments of this application, the above-mentioned indication information is used to indicate at least one of the following:

[0095] The first count value of the first PDU;

[0096] The first sequence number of the first PDU;

[0097] Is the PDU carrying the indication information the first PDU?

[0098] In some embodiments of this application, the first count value mentioned above may specifically be a PDCPCOUNT value.

[0099] In some embodiments of this application, the first sequence number mentioned above is also specifically the PDCP sequence number (SN) value.

[0100] In some embodiments of this application, when the indication information is carried by the first bit in the data PDU, the indication information is used to indicate whether the data PDU carrying the indication information is the first PDU; wherein, when the value of the first bit is a first value, the indication information is used to indicate that the data PDU is the first PDU; or, when the value of the first bit is a second value, the indication information is used to indicate that the data PDU is not the first PDU.

[0101] In one example, the first value can be 0 and the second value can be 1; or, the first value can be 1 and the second value can be 0. Of course, the first value and the second value can also be other different values, and this application embodiment does not limit this.

[0102] Thus, since the embodiments of this application specify the specific content indicated by the information when the first bit takes different values, the receiving end can accurately indicate the specific content indicated by the information based on the specific content and the specific value of the first bit.

[0103] In summary, since the specific content indicated by the instruction information is specified in the embodiments of this application, the terminal can accurately know the specific content and, based on the specific content, accurately know whether the first PDU has been received.

[0104] In some embodiments of this application, the first protocol layer entity can receive indication information from a second protocol layer entity at the sending end. The second protocol layer entity and the first protocol layer entity may be the same or different.

[0105] For example, the first protocol layer entity is a PDCP entity, and the second protocol layer entity is also a PDCP entity, that is, the second protocol layer entity and the first protocol layer entity are the same.

[0106] Step 102: If the first protocol layer entity has received the first PDU, the first protocol layer entity submits at least one first service data unit (SDU) to the higher layer.

[0107] In some embodiments of this application, the at least one SDU is obtained by a first protocol layer entity processing the at least one PDU upon receiving it. The at least one SDU may be a continuous SDU or a discontinuous SDU.

[0108] In this context, continuous SDUs can be understood as PDUs with continuous count values. Discontinuous SDUs can be understood as PDUs with discontinuous count values.

[0109] In some embodiments of this application, the first protocol layer entity has received the first PDU satisfying at least one of the following:

[0110] The count value of the PDUs received by the first protocol layer entity matches the first count value;

[0111] The sequence number of the PDU received by the first protocol layer entity matches the first sequence number;

[0112] The first bit of the data PDU received by the first protocol layer entity has a first value; when the first bit has a first value, the indication information is used to indicate that the data PDU is the first PDU.

[0113] Thus, since the embodiments of this application specify the various conditions that the first protocol layer entity must meet to have received the first PDU, the first protocol layer entity can accurately determine whether it has received the first PDU based on these conditions.

[0114] In this embodiment of the application, each of the at least one first SDU is the SDU corresponding to the received PDU.

[0115] In some embodiments of this application, the at least one first SDU may include an SDU obtained by processing the first PDU by a first protocol entity.

[0116] In some embodiments of this application, combined with Figure 3 ,like Figure 4 As shown, step 102 above can be specifically implemented through step 102a below.

[0117] Step 102a: If the first protocol layer entity has received the first PDU and the value of the first state variable is less than the first count value of the first PDU, the first protocol layer entity shall sequentially submit at least one first SDU to the higher layer based on the count value of the PDU corresponding to at least one first SDU.

[0118] In this embodiment of the application, the value of the first state variable is used to indicate the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer.

[0119] It should be noted that the phrase "waiting to submit to higher management" can be understood as: it has not yet been submitted to higher management but is awaiting submission.

[0120] In some embodiments of this application, the first state variable mentioned above may be RX_DELIV.

[0121] In some embodiments of this application, the first protocol layer entity may submit at least one first SDU to the higher layer in ascending order of the count values ​​of the PDUs corresponding to at least one first SDU. Alternatively, it may submit at least one first SDU to the higher layer in descending order of the count values ​​of the PDUs corresponding to at least one first SDU. Of course, the first protocol layer entity may also submit at least one first SDU to the higher layer in other orders, which is not limited in this embodiment.

[0122] Thus, since the embodiments of this application specify the specific method by which the first protocol layer entity submits at least one first SDU to the higher layer, the first protocol layer entity can accurately submit the at least one first SDU to the higher layer in accordance with the specific method after receiving the first PDU.

[0123] This application provides a data transmission method in which, when a terminal switches from a first cell to a second cell, a first protocol layer entity at the receiving end receives information from the sending end regarding the first PDU of a first bearer to be transmitted by the sending end in the second cell. The first bearer is a bearer corresponding to the first protocol layer entity. If the first protocol layer entity has received the first PDU, it submits at least one SDU corresponding to the received PDU to a higher layer. In this case, if the receiving end is a terminal, the sending end is a network-side device corresponding to the second cell; or, if the sending end is a terminal, the receiving end is a network-side device corresponding to the second cell. When a terminal switches from the first cell to the second cell, the first protocol layer entity can obtain information about the first PDU of the first bearer sent by the sender in the second cell through the indication information. In this case, if some PDCPdataPDUs are not received due to the terminal switching from the first cell to the second cell, the first protocol layer entity can directly submit at least one SDU (i.e., the processed SDU) corresponding to the received PDU to the higher layer when it receives the first PDU, without waiting for the t-Reordering timeout. Therefore, the waiting time required to submit the processed SDU to the higher layer can be reduced, thereby reducing the transmission latency of the SDU. In this way, the data transmission latency can be improved.

[0124] Of course, the first protocol layer entity can also perform other steps after receiving the first PDU, as illustrated below.

[0125] In some embodiments of this application, the data transmission method provided in this application may further include at least one of the following steps 201 to 204.

[0126] Step 201: If the first protocol layer entity has received the first PDU and the first timer is running, the first protocol layer entity determines that the first timer has timed out.

[0127] In this embodiment of the application, the first timer is used to determine the duration during which the first protocol layer entity has not received a PDU.

[0128] It is understood that the aforementioned first timer can specifically be t-Reordering. When the first protocol layer entity determines that it has not received a certain PDU, the first timer can be started, thereby determining the duration for which the first protocol layer entity has not received that certain PDU.

[0129] In this embodiment of the application, if the first PDU has been received, it can be assumed that the PDU that triggered the first timer may have failed to be received due to cell handover of the terminal. Therefore, the first protocol layer entity can directly determine that the first timer has expired and perform subsequent processing according to the first timer expiration, so as to avoid the situation where other PDUs cannot trigger the first timer to run.

[0130] Thus, it can be seen that when the first protocol layer entity has received the first PDU, that is, when the PDU that triggers the first timer to run may fail to be received due to cell handover at the terminal, the first protocol layer entity can directly determine that the first timer has expired without waiting for the first timer to expire. Therefore, it can avoid waiting for the PDU that fails to be received due to cell handover, thereby reducing the transmission delay of the target cell data.

[0131] Step 202: If the first protocol layer entity has received the first PDU, the first protocol layer entity updates the value of the first state variable to the first numerical value.

[0132] In this embodiment of the application, the value of the first state variable is used to indicate the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer; the first value is equal to the count value of the PDU corresponding to the second SDU, and the second SDU is the first SDU whose count value is greater than the first count value of the first PDU and is waiting to be submitted to the higher layer. The indication information includes the first count value.

[0133] Thus, since the first protocol layer entity can directly update the value of the first state variable to the first value after receiving the first PDU, it can obtain the correct count value indicated by the value of the first state variable. Therefore, it can avoid the situation where the first protocol layer entity knows an inaccurate first SDU waiting to be submitted to the higher layer due to the incorrect count value indicated by the value of the first state variable.

[0134] Step 203: If the first protocol layer entity has received the first PDU, and if the first timer is running and the value of the first state variable is greater than or equal to the value of the second state variable, then the first protocol layer entity stops and resets the first timer.

[0135] In this embodiment of the application, the first timer is used to determine the duration during which the first protocol layer entity has not received a PDU.

[0136] In this embodiment of the application, the value of the first state variable is used to indicate the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer; the value of the second state variable is used to indicate the count value of the next PDU of the PDU that triggers the start of the first timer.

[0137] In some embodiments of this application, the aforementioned second state variable may specifically be: RX_REORD.

[0138] In this embodiment of the application, if the first PDU has been received and the value of the first state variable is greater than or equal to the value of the second state variable, it can be assumed that the PDU that triggered the first timer may have failed to be received due to cell handover at the terminal. Therefore, the first protocol layer entity can stop and reset the first timer.

[0139] Thus, it can be seen that when the first protocol layer entity has received the first PDU, that is, when the PDU that triggers the first timer to run may fail to be received due to cell handover at the terminal, the first protocol layer entity can directly stop and reset the first timer without waiting for the first timer to expire. Therefore, it can avoid waiting for the PDU that fails to be received due to cell handover, thereby reducing the transmission delay of the target cell data.

[0140] Step 204: If the first protocol layer entity has received the first PDU, and if the first timer is not running and the value of the first state variable is less than the value of the third state variable, then the first protocol layer entity updates the value of the third state variable to the value of the second state variable and starts the first timer.

[0141] In this embodiment of the application, the first timer is used to determine the duration during which the first protocol layer entity has not received a PDU.

[0142] In this embodiment of the application, the value of the first state variable is used to indicate the count value of the PDU corresponding to the first SDU waiting to be delivered to the higher layer; the value of the second state variable is used to indicate the count value of the next PDU of the PDU that triggers the start of the first timer; and the value of the third state variable is used to indicate the count value of the next PDU that the first protocol layer entity expects to receive.

[0143] In some embodiments of this application, the aforementioned third state variable may specifically be: RX_NEXT.

[0144] In some embodiments of this application, the first protocol layer entity may determine the value of the third state variable as the value of the second state variable.

[0145] In this embodiment of the application, if the first PDU has been received and the value of the first state variable is less than the value of the third state variable, it can be assumed that there is an unreceived PDU. Therefore, the first protocol layer entity can update the value of the third state variable to the value of the second state variable, so as to determine the count value of the next PDU that the first protocol layer entity expects to receive as the count value of the next PDU that triggers the start of the first timer.

[0146] Thus, it can be seen that when the first timer is not running and the value of the first state variable is less than the value of the third state variable, that is, when there is a PDU that has not been received, the first protocol layer entity can accurately determine the count value of the next PDU that the first protocol layer entity expects to receive as the count value of the next PDU that triggered the start of the first timer. Therefore, the situation where the count value of the next PDU that triggered the start of the first timer cannot be determined can be avoided.

[0147] The following two complete examples illustrate the specific flow of the data transmission method provided in the embodiments of this application.

[0148] Example 1: Instruction information is carried by the control PDU.

[0149] The data transmission method provided in this application embodiment may include the following steps:

[0150] Step 11: The terminal performs cell handover or primary / secondary cell change. For example, the terminal switches from the first cell to the second cell. The first key corresponding to the first cell and the second key corresponding to the second cell are the same.

[0151] Step 12: The first protocol layer entity (e.g., PDCP entity) of the receiving end (e.g., terminal) receives a control PDU in the second cell. The control PDU carries indication information, which is used to indicate the relevant information (e.g., first count value and / or first sequence number, etc.) of the first PDU of the first bearer that the sending end (e.g., the network side device corresponding to the second cell) has sent or will send in the second cell.

[0152] Step 13: Upon receiving the first PDU, the PDCP entity of the terminal may submit at least one SDU to the higher layer in ascending order of COUNT (which may not be consecutive).

[0153] Step 14: Upon receiving the first PDU, the PDCP entity of the terminal may also perform at least one of the following:

[0154] If the first timer (e.g., t-Reordering) is running, then determine that the first timer has timed out, and proceed with subsequent processing according to the first timer timeout.

[0155] Update the value of the first state variable (e.g., RX_DELIV) to the first numerical value;

[0156] If the first timer (e.g., t-Reordering) is running and the value of the first state variable (e.g., RX_DELIV) is greater than or equal to the value of the second state variable (e.g., RX_REORD), then stop and reset the first timer (e.g., t-Reordering).

[0157] If the first timer (e.g., t-Reordering) is not running and the value of the first state variable (e.g., RX_DELIV) is less than the value of the third state variable (e.g., RX_NEXT), then the value of the third state variable (e.g., RX_NEXT) is updated to the value of the second state variable (e.g., RX_REORD), and the first timer (e.g., t-Reordering) is started.

[0158] The following line is an example:

[0159] The terminal's PDCP entity receives a downlink PDU with a COUNT value of 5 in the source cell (i.e., the first cell); the PDU with a COUNT value of 6 is not successfully received in the source cell (i.e., the first cell); at this time, RX_NEXT = RX_DELIV = 6;

[0160] When the terminal's PDCP entity receives a PDU with PDCPCOUNT=7, RX_NEXT is updated to 8, t-Reordering is started, and RX_REORD=7;

[0161] The terminal's PDCP entity receives a control PDU in the target cell (i.e., the second cell) and indicates that the COUNT value associated with the first downlink PDU sent by the second cell is 7;

[0162] The terminal's PDCP entity determines that t-Reordering has timed out immediately and executes the action in the existing protocol after the timeout; and / or, the terminal submits the SDU corresponding to PDCPCOUNT=7 (i.e., at least one SDU in the above embodiments) to the higher layer, updates RX_DELIV to COUNT=8, and stops and resets t-Reordering.

[0163] Example 2: The indication information is carried by the first bit of the data PDU.

[0164] Step 21: The terminal performs cell handover or primary / secondary cell change. For example, the terminal switches from the first cell to the second cell. The first key corresponding to the first cell and the second key corresponding to the second cell are the same.

[0165] Step 22: The first protocol layer entity (e.g., PDCP entity) of the receiving end (e.g., terminal) receives a data PDU in the second cell. The reserved bits of the data PDU (e.g., the first bit in the above embodiment) carry indication information. The indication information is used to indicate whether the data PDU is the first PDU of the first bearer that the sending end (e.g., the network-side device corresponding to the second cell) has sent or will send in the second cell, or the indication information is used to indicate the first sequence number (SN) of the first PDU of the first bearer that the sending end (e.g., the network-side device corresponding to the second cell) has sent or will send in the second cell.

[0166] For example, Figure 5A A schematic diagram of a data PDU is shown, which can be an SRB data PDU. As shown in Figure 5, the data PDU includes N octets, such as octets Oct 1 to Oct N. The reserved bits (e.g., the first bit) include: bits 5 to 8 of the first Oct 1, and 8 bits of the second Oct 2. Bits 5 to 8 of Oct 1 and 8 bits of the second Oct 2 carry the SN of the first PDU of the first bearer that the transmitting end (e.g., the network-side equipment corresponding to the second cell) has already transmitted or will transmit in the second cell.

[0167] For example, Figure 5BA schematic diagram of another data PDU is shown in Figure 5. The data PDU includes N octets, for example, octets Oct 1 to Oct N. The reserved bits (e.g., the first bit) include bits 5 to 8 of the first Oct 1 and 8 bits of the second Oct 2. These bits 5 to 8 of Oct 1 and 8 bits of the second Oct 2 carry the serial number (SN) of the first PDU in the first bearer that the transmitting end (e.g., the network-side equipment corresponding to the second cell) has already transmitted or will transmit in the second cell.

[0168] For example, Figure 5C This diagram illustrates yet another type of data PDU, which can be a data PDU from a DRB. For example... Figure 5C As shown, a data PDU includes N octets, such as octets Oct 1 to Oct N. The reserved bits (e.g., the first bit) include: the 7th and 8th bits of the first Oct 1, 8 bits of the second Oct 2, and 8 bits of the third Oct 3. These 7th and 8th bits of Oct 1, 8 bits of the second Oct 2, and 8 bits of the third Oct 3 carry the SN of the first PDU of the first bearer that the transmitting end (e.g., the network-side equipment corresponding to the second cell) has already transmitted or will transmit in the second cell.

[0169] It should be noted that, in the above Figure 5A - Figure 5C In this diagram, each small square represents a bit.

[0170] Step 23: Upon receiving the first PDU, the PDCP entity of the terminal may submit at least one SDU to the higher layer in ascending order of COUNT (which may not be consecutive).

[0171] Step 24: Upon receiving the first PDU, the PDCP entity of the terminal may also perform at least one of the following:

[0172] If the first timer (e.g., t-Reordering) is running, then the first timer is determined to have timed out;

[0173] Update the value of the first state variable (e.g., RX_DELIV) to the first numerical value;

[0174] If the first timer (e.g., t-Reordering) is running and the value of the first state variable (e.g., RX_DELIV) is greater than or equal to the value of the second state variable (e.g., RX_REORD), then stop and reset the first timer (e.g., t-Reordering).

[0175] If the first timer (e.g., t-Reordering) is not running and the value of the first state variable (e.g., RX_DELIV) is less than the value of the third state variable (e.g., RX_NEXT), then the value of the third state variable (e.g., RX_NEXT) is updated to the value of the second state variable (e.g., RX_REORD), and the first timer (e.g., t-Reordering) is started.

[0176] In summary, the solution provided by the embodiments of this application can solve the problem that, in the event of cell handover and unchanged key, the SN gap caused by data interruption results in the inability of data packets transmitted in the second cell to be delivered to higher layers in a timely manner.

[0177] The data transmission method provided in this application can be executed by a data transmission device. This application uses a data transmission device executing the data transmission method as an example to illustrate the data transmission device provided in this application.

[0178] This application provides a data transmission device. As an example, the data transmission device may be a communication device or a component within a communication device, such as a chip. The communication device may be a terminal, a network-side device, or a server, etc. Exemplarily, the terminal may include, but is not limited to, the type of terminal 11 listed above, and the network-side device may include, but is not limited to, the type of network-side device 12 listed above. This application does not impose specific limitations.

[0179] The data transmission device includes a receiving module, a transmitting module, and a processing module. These modules can be implemented in software or hardware. When implemented in hardware, the processing module can be implemented by a processor. Exemplarily, the processor can include general-purpose processors, special-purpose processors, such as a Central Processing Unit (CPU), microprocessor, Digital Signal Processor (DSP), Artificial Intelligence (AI) processor, Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), Network Processor (NP), Field Programmable Gate Array (FPGA), or other programmable logic devices, gate circuits, transistors, discrete hardware components, etc. The receiving and transmitting modules can be implemented by a communication interface, which can include one or more of the following: transceiver, pins, circuits, bus, radio frequency unit, etc.

[0180] For details, see Figure 6 When the data transmission device is a terminal or a component in a terminal, the data transmission device 40 includes a receiving module 41 and a processing module 42.

[0181] The receiving module 41 is configured to receive indication information from the transmitting end when the terminal switches from the first cell to the second cell. This indication information indicates relevant information about the first PDU of the first bearer transmitted by the transmitting end in the second cell. The first bearer is the bearer corresponding to the data transmission device 40. The processing module 42 is configured to submit at least one first SDU to a higher layer when the data transmission device 40 has received the first PDU. The first SDU is the SDU corresponding to the received PDU. Wherein, if the receiving end is a terminal, the transmitting end is the network-side device corresponding to the second cell; or, if the transmitting end is a terminal, the receiving end is the network-side device corresponding to the second cell.

[0182] This application provides a data transmission apparatus. When a terminal switches from a first cell to a second cell, the data transmission apparatus can obtain information about the first PDU of the first bearer sent by the sending end in the second cell through indication information. In the event that some PDCPdataPDUs are not received due to the terminal switching from the first cell to the second cell, the data transmission apparatus can directly submit at least one SDU (i.e., a processed SDU) corresponding to the received PDU to the higher layer upon receiving the first PDU, without waiting for the t-Reordering timeout. Therefore, the waiting time required to submit the processed SDU to the higher layer can be reduced, thereby reducing the transmission latency of the SDU and improving the data transmission latency.

[0183] In one possible implementation, the aforementioned indication information is carried by at least one of the following: a control PDU; or the first bit of a data PDU.

[0184] In one possible implementation, the above-mentioned indication information is used to indicate at least one of the following: a first count value of the first PDU; a first sequence number of the first PDU; and whether the PDU carrying the indication information is the first PDU.

[0185] In one possible implementation, when the indication information is carried by the first bit in the data PDU, the indication information is used to indicate whether the data PDU carrying the indication information is the first PDU; wherein, when the value of the first bit is a first value, the indication information is used to indicate that the data PDU is the first PDU; or, when the value of the first bit is a second value, the indication information is used to indicate that the data PDU is not the first PDU.

[0186] In one possible implementation, the data transmission device 40 has received a first PDU satisfying at least one of the following: the count value of the PDU received by the data transmission device 40 matches a first count value; the sequence number of the PDU received by the data transmission device 40 matches a first sequence number; the first bit of the data PDU received by the data transmission device 40 has a first value; and when the first bit has a first value, an indication message is used to indicate that the data PDU is the first PDU.

[0187] In one possible implementation, the processing module 42 is specifically used to, when the value of the first state variable is less than the first count value of the first PDU, sequentially submit at least one first SDU to the higher layer according to the count value of the PDU corresponding to at least one first SDU; wherein, the value of the first state variable is used to indicate: the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer.

[0188] In one possible implementation, the processing module 42 is further configured to: determine if the first timer has timed out if the first timer is running when the data transmission device 40 has received the first PDU; update the value of the first state variable to a first value when the data transmission device 40 has received the first PDU; stop and reset the first timer if the first timer is running and the value of the first state variable is greater than or equal to the value of the second state variable when the data transmission device 40 has received the first PDU; and change the value of the third state variable to a third value if the first timer is not running and the value of the first state variable is less than the value of the third state variable when the data transmission device 40 has received the first PDU. The value of the variable is updated to the value of the second state variable, and the first timer is started; wherein, the first timer is used to determine the duration during which the data transmission device 40 has not received a PDU; the value of the first state variable is used to indicate: the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer; the first value is equal to the count value of the PDU corresponding to the second SDU, the second SDU is: the first SDU whose count value is greater than the first count value of the first PDU and is waiting to be submitted to the higher layer, the indication information includes the first count value; the value of the second state variable is used to indicate: the count value of the next PDU of the PDU that triggered the start of the first timer; the value of the third state variable is used to indicate: the count value of the next PDU that the data transmission device 40 expects to receive.

[0189] In one possible implementation, the first key and the second key are the same; wherein the first key is used to encrypt or protect the integrity of data between the terminal and the first cell; and the second key is used to encrypt or protect the integrity of data between the terminal and the second cell.

[0190] The data transmission device provided in this application embodiment can achieve... Figure 2 The various processes implemented in the method embodiment shown in Figure 5 achieve the same technical effect, and will not be described again here to avoid repetition.

[0191] like Figure 7 As shown in the illustration, this application also provides a communication device 50, including a processor 51 and a memory 52. ​​The memory 52 stores a program or instructions that can run on the processor 51. For example, when the communication device 50 is a terminal, the program or instructions executed by the processor 51 implement the various steps of the above-described data transmission method embodiment and achieve the same technical effect. When the communication device 50 is a network-side device, the program or instructions executed by the processor 51 implement the various steps of the above-described data transmission method embodiment and achieve the same technical effect. To avoid repetition, further details are omitted here.

[0192] This application embodiment also provides a terminal, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement, for example... Figure 2 The steps in the method embodiment shown in Figure 5 are as follows. This terminal embodiment corresponds to the terminal-side method embodiment described above. All implementation processes and methods of the above method embodiments can be applied to this terminal embodiment and achieve the same technical effect. The terminal can be... Figure 6 The data transmission device shown. Specifically, Figure 8 A schematic diagram of the hardware structure of a terminal to implement an embodiment of this application.

[0193] The terminal 600 includes, but is not limited to, at least some of the following components: radio frequency unit 601, network module 602, audio output unit 603, input unit 604, sensor 605, display unit 606, user input unit 607, interface unit 608, memory 609, and processor 610.

[0194] Those skilled in the art will understand that the terminal 600 may also include a power supply (such as a battery) for supplying power to various components. The power supply may be logically connected to the processor 610 through a power management system, thereby enabling functions such as managing charging, discharging, and power consumption through the power management system. Figure 8 The terminal structure shown does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0195] It should be understood that, in this embodiment, the input unit 604 may include a graphics processor 6041 and a microphone 6042. The graphics processor 6041 processes image data of still images or videos obtained by an image capture device (such as a camera) in video capture mode or image capture mode. The display unit 606 may include a display panel 6061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like. The user input unit 607 includes at least one of a touch panel 6071 and other input devices 6072. The touch panel 6071 is also called a touch screen. The touch panel 6071 may include two parts: a touch detection device and a touch controller. Other input devices 6072 may include, but are not limited to, a physical keyboard, function keys (such as volume control buttons, power buttons, etc.), a trackball, a mouse, and a joystick, which will not be described in detail here.

[0196] In this embodiment, after receiving downlink data from the network-side device, the radio frequency unit 601 can transmit it to the processor 610 for processing; in addition, the radio frequency unit 601 can send uplink data to the network-side device. Typically, the radio frequency unit 601 includes, but is not limited to, antennas, amplifiers, transceivers, couplers, low-noise amplifiers, duplexers, etc.

[0197] The memory 609 can be used to store software programs or instructions, as well as various data. The memory 609 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, the memory 609 may include volatile memory or non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory 609 in this embodiment includes, but is not limited to, these and any other suitable types of memory.

[0198] Processor 610 may include one or more processing units; optionally, processor 610 integrates an application processor and a modem processor, wherein the application processor mainly handles operations involving the operating system, user interface, and applications, and the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into processor 610.

[0199] The radio frequency unit 601 is used to receive indication information from the transmitting end when the terminal switches from the first cell to the second cell. The indication information is used to indicate the relevant information of the first PDU of the first bearer transmitted by the transmitting end in the second cell. The first bearer is the bearer corresponding to the first protocol layer entity of the terminal.

[0200] The processor 610 is configured to submit at least one first SDU to a higher layer upon receiving a first PDU, the first SDU being the SDU corresponding to the received PDU.

[0201] The sending end is the network-side device corresponding to the second cell.

[0202] This application provides a terminal that, when switching from a first cell to a second cell, can obtain information about the first PDU of the first bearer sent by the transmitter in the second cell through indication information. Thus, in cases where some PDCP data PDUs are not received due to the switch, the terminal can directly submit at least one SDU (i.e., a processed SDU) corresponding to the received PDU to the higher layer when the first protocol layer entity receives the first PDU, without waiting for t-Reordering timeout. This reduces the waiting time required to submit the processed SDU to the higher layer, thereby reducing the transmission latency of the SDU and improving data transmission latency.

[0203] In some embodiments of this application, the processor 610 is specifically configured to, when the value of the first state variable is less than the first count value of the first PDU, sequentially submit at least one first SDU to the higher layer according to the count value of the PDU corresponding to at least one first SDU.

[0204] The value of the first state variable mentioned above is used to indicate the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer.

[0205] In some embodiments of this application, the processor 610 is further configured to: upon receiving a first PDU, if a first timer is running, determine that the first timer has timed out; upon receiving a first PDU, update the value of a first state variable to a first value; upon receiving a first PDU, if the first timer is running and the value of the first state variable is greater than or equal to the value of a second state variable, stop and reset the first timer; upon receiving a first PDU, if the first timer is not running and the value of the first state variable is less than the value of a third state variable, update the value of the third state variable to the value of the second state variable and start the first timer.

[0206] Wherein, the first timer is used to determine the duration of no PDU received; the value of the first state variable is used to indicate: the count value of the PDU corresponding to the first SDU waiting to be delivered to the higher layer; the first value is equal to the count value of the PDU corresponding to the second SDU, which is: the first SDU whose count value is greater than the first count value of the first PDU and is waiting to be delivered to the higher layer, and the indication information includes the first count value; the value of the second state variable is used to indicate: the count value of the next PDU after the PDU that triggered the start of the first timer; the value of the third state variable is used to indicate: the count value of the next expected PDU to be received.

[0207] It is understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the method embodiment and achieve the same or corresponding technical effect. To avoid repetition, it will not be described again here.

[0208] This application embodiment also provides a network-side device, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement, for example... Figure 2 The steps of the method embodiment shown in Figure 5 are as follows. This network-side device embodiment corresponds to the network-side device method embodiment described above. All implementation processes and methods of the above method embodiments can be applied to this network-side device embodiment and can achieve the same technical effect.

[0209] Specifically, embodiments of this application also provide a network-side device, which can be... Figure 6 The data transmission device shown. (For example...) Figure 9 As shown, the network-side device 700 includes: an antenna 701, a radio frequency (RF) device 702, a baseband device 703, a processor 704, and a memory 705. The antenna 701 is connected to the RF device 702. In the uplink direction, the RF device 702 receives information through the antenna 701 and transmits the received information to the baseband device 703 for processing. In the downlink direction, the baseband device 703 processes the information to be transmitted and sends it to the RF device 702. The RF device 702 processes the received information and transmits it through the antenna 701.

[0210] The method executed by the network-side device in the above embodiments can be implemented in the baseband device 703, which includes a baseband processor.

[0211] The baseband device 703 may, for example, include at least one baseband board on which multiple chips are disposed, such as... Figure 9 As shown, one of the chips is, for example, a baseband processor, which is connected to the memory 705 via a bus interface to call the program in the memory 705 and execute the network device operations shown in the above method embodiment.

[0212] The network-side device may also include a network interface 706, such as a Common Public Radio Interface (CPRI).

[0213] Specifically, the network-side device 700 in this application embodiment further includes: instructions or programs stored in memory 705 and executable on processor 704, wherein processor 704 calls the instructions or programs in memory 705 to execute. Figure 6 The methods executed by each module shown achieve the same technical effect, and to avoid repetition, they will not be described in detail here.

[0214] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described data transmission method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0215] The processor mentioned above is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0216] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above data transmission method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0217] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0218] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described data transmission method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0219] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0220] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0221] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A data transmission method, characterized in that, include: When a terminal switches from the first cell to the second cell, the first protocol layer entity of the receiving end receives indication information from the sending end. The indication information is used to indicate the relevant information of the first protocol data unit (PDU) of the first bearer sent by the sending end in the second cell. The first bearer is the bearer corresponding to the first protocol layer entity. If the first protocol layer entity has received the first PDU, the first protocol layer entity submits at least one first service data unit (SDU) to the higher layer, wherein the first SDU is the SDU corresponding to the received PDU. Wherein, if the receiving end is the terminal, the sending end is the network-side device corresponding to the second cell; or, if the sending end is the terminal, the receiving end is the network-side device corresponding to the second cell.

2. The method according to claim 1, characterized in that, The indication information is carried by at least one of the following: Control PDU; The first bit in the data PDU.

3. The method according to claim 2, characterized in that, The instruction information is used to indicate at least one of the following: The first count value of the first PDU; The first sequence number of the first PDU; Whether the PDU carrying the indication information is the first PDU.

4. The method according to claim 3, characterized in that, When the indication information is carried by the first bit in the data PDU, the indication information is used to indicate whether the data PDU carrying the indication information is the first PDU; Wherein, if the first bit takes the first value, the indication information is used to indicate that the data PDU is the first PDU; or, When the value of the first bit is the second value, the indication information is used to indicate that the data PDU is not the first PDU.

5. The method according to any one of claims 2 to 4, characterized in that, The first protocol layer entity has received the first PDU satisfying at least one of the following: The count value of the PDUs received by the first protocol layer entity matches the first count value; The sequence number of the PDU received by the first protocol layer entity matches the first sequence number; The first bit of the data PDU received by the first protocol layer entity has a first value; when the first bit has the first value, the indication information is used to indicate that the data PDU is the first PDU.

6. The method according to any one of claims 1 to 5, characterized in that, The first protocol layer entity submits at least one first SDU to the higher layer, including: If the value of the first state variable is less than the first count value of the first PDU, the first protocol layer entity submits at least one of the first SDUs to the higher layer in sequence according to the count value of the PDU corresponding to at least one of the first SDUs; The value of the first state variable is used to indicate the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes at least one of the following: If the first protocol layer entity has received the first PDU, and the first timer is running, then the first timer is determined to have timed out. If the first protocol layer entity has received the first PDU, update the value of the first state variable to the first numerical value; If the first protocol layer entity has received the first PDU, and if the first timer is running and the value of the first state variable is greater than or equal to the value of the second state variable, then the first timer is stopped and reset. If the first protocol layer entity has received the first PDU, and if the first timer is not running and the value of the first state variable is less than the value of the third state variable, then the value of the third state variable is updated to the value of the second state variable, and the first timer is started. Wherein, the value of the first state variable is used to indicate: the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer; the first value is equal to the count value of the PDU corresponding to the second SDU, the second SDU is: the first SDU whose count value is greater than the first count value of the first PDU and is waiting to be submitted to the higher layer, and the indication information includes the first count value; The value of the second state variable is used to indicate the count value of the next PDU that triggers the start of the first timer; The value of the third state variable is used to indicate the count of the next PDU that the first protocol layer entity expects to receive.

8. The method according to any one of claims 1 to 7, characterized in that, The first key is the same as the second key; The first key is used to encrypt or protect the integrity of data between the terminal and the first cell; the second key is used to encrypt or protect the integrity of data between the terminal and the second cell.

9. A data transmission device, characterized in that, The data transmission device includes: a receiving module and a processing module; The receiving module is used to receive indication information from the sending end when the terminal switches from the first cell to the second cell. The receiving end or the sending end is the terminal. The indication information is used to indicate the relevant information of the first PDU of the first bearer sent by the sending end in the second cell. The first bearer is the bearer corresponding to the data transmission device. The processing module is configured to submit at least one first SDU to a higher layer when the data transmission device has received the first PDU, wherein the first SDU is the SDU corresponding to the received PDU; Wherein, if the receiving end is the terminal, the sending end is the network-side device corresponding to the second cell; or, if the sending end is the terminal, the receiving end is the network-side device corresponding to the second cell.

10. The apparatus according to claim 9, characterized in that, The indication information is carried by at least one of the following: Control PDU; The first bit in the data PDU.

11. The apparatus according to claim 10, characterized in that, The instruction information is used to indicate at least one of the following: The first count value of the first PDU; The first sequence number of the first PDU; Whether the PDU carrying the indication information is the first PDU.

12. The apparatus according to claim 11, characterized in that, When the indication information is carried by the first bit in the data PDU, the indication information is used to indicate whether the data PDU carrying the indication information is the first PDU; Wherein, if the first bit takes the first value, the indication information is used to indicate that the data PDU is the first PDU; or, When the value of the first bit is the second value, the indication information is used to indicate that the data PDU is not the first PDU.

13. The apparatus according to any one of claims 10 to 12, characterized in that, The data transmission device has received the first PDU that satisfies at least one of the following: The count value of the PDUs received by the data transmission device matches the first count value; The sequence number of the PDU received by the data transmission device matches the first sequence number; The data transmission device has received a data PDU whose first bit has a first value; when the first bit has a first value, the indication information is used to indicate that the data PDU is the first PDU.

14. The apparatus according to any one of claims 9 to 13, characterized in that, The processing module is specifically used to, when the value of the first state variable is less than the first count value of the first PDU, sequentially submit at least one of the first SDUs to the higher layer according to the count value of the PDU corresponding to at least one of the first SDUs; The value of the first state variable is used to indicate the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer.

15. The apparatus according to any one of claims 9 to 14, characterized in that, The processing module is also used for at least one of the following: If the data transmission device has received the first PDU, and the first timer is running, then the first timer is determined to have timed out. When the data transmission device has received the first PDU, the value of the first state variable is updated to the first numerical value; If the data transmission device has received the first PDU, and if the first timer is running and the value of the first state variable is greater than or equal to the value of the second state variable, then the first timer is stopped and reset. If the data transmission device has received the first PDU, and if the first timer is not running and the value of the first state variable is less than the value of the third state variable, then the value of the third state variable is updated to the value of the second state variable, and the first timer is started. Wherein, the value of the first state variable is used to indicate: the count value of the PDU corresponding to the first SDU waiting to be submitted to the higher layer; the first value is equal to the count value of the PDU corresponding to the second SDU, the second SDU is: the first SDU whose count value is greater than the first count value of the first PDU and is waiting to be submitted to the higher layer, and the indication information includes the first count value; The value of the second state variable is used to indicate the count value of the next PDU that triggers the start of the first timer; The value of the third state variable is used to indicate the count of the next PDU that the data transmission device is expected to receive.

16. The apparatus according to any one of claims 9 to 15, characterized in that, The first key is the same as the second key; The first key is used to encrypt or protect the integrity of data between the terminal and the first cell; the second key is used to encrypt or protect the integrity of data between the terminal and the second cell.

17. A terminal, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the data transmission method as described in any one of claims 1 to 8.

18. A network-side device, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the data transmission method as described in any one of claims 1 to 8.

19. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the data transmission method as described in any one of claims 1 to 8.

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