CN109039548A - Sending method, device and the computer readable storage medium of PDCP state report - Google Patents

Abstract

The invention discloses a method for sending a Packet Data Convergence Protocol (PDCP) status report, which includes: when a PDCP status report trigger condition is satisfied, a first PDCP entity generates a PDCP status report according to the reordering result of received data packets; sending the PDCP status report to a second PDCP entity. The invention also discloses a PDCP report sending device and a computer-readable storage medium.

Description

Sending method, device and computer-readable storage medium of PDCP status report

technical field

The present invention relates to the field of wireless communication, in particular to a method, device and computer-readable storage medium for sending a Packet Data Convergence Protocol (PDCP, Packet Data Convergence Protocol) status report.

Background technique

Currently, the Packet Data Convergence Protocol (PDCP, Packet Data Convergence Protocol) status report is used to indicate: in the process of link re-establishment, protocol data units (PDUs, Protocol Data Units) that have not been received by the bottom layer or received but not sent confirmation The case of the corresponding service data unit (SDU, Service Data Unit). The SDU corresponding to the PDU that has not been received by the bottom layer needs to be fed back in the PDCP status report. After the link is re-established, according to the content of the ODCP status report, retransmit the data packets that have not received the confirmation.

However, currently, the PDCP status report can be used in very single scenarios, which reduces the reliability of the communication system.

Contents of the invention

In order to solve existing technical problems, embodiments of the present invention provide a method, device and computer-readable storage medium for sending a PDCP status report.

The technical scheme of the embodiment of the present invention is realized like this:

An embodiment of the present invention provides a method for sending a PDCP status report, including:

When the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets;

sending the PDCP status report to a second PDCP entity.

In the above solution, the PDCP status report trigger condition includes one of the following conditions:

During PDCP re-establishment;

The first timer expires;

A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity.

In the above scheme, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets, including:

The first PDCP entity obtains the sequence number of the PDCP SDU corresponding to the incorrectly received PDCP PDU according to the reordering result;

Generate a PDCP status report according to the obtained serial number.

In the above solution, the first network element in the new radio access (NR) system is a logical node that realizes some base station functions, and the second network element is a logical node that realizes other base station functions except the functions realized by the first network element , the first network element can control the second network element, the first network element is connected to at least two of the second network elements; the PDCP entity is located in the first network element; the radio link control (RLC, Radio The Link Control) entity is located in the second network element; the terminal (UE) is connected to the second network element; the PDCP re-establishment process includes:

A PDCP re-establishment process caused when the UE is handed over between two first network elements, or handed over between multiple second network elements within a first network element.

In the above solution, the RLC entity corresponding to the PDCP entity is an AM (Acknowledged Mode) RLC entity or a UM (Unacknowledged Mode) RLC entity.

In the above solution, the duration of the first timer is greater than the first value; the first value is the product of the number of RLC retransmissions and the duration of the second timer; and the second timer is a retransmission timer.

In the above scheme, the method also includes:

receiving duration information of the first timer configured by a corresponding radio resource control (RRC, Radio Resource Control) entity;

The first timer is set by using the received duration information.

In the above solution, receiving the status report request sent by the second PDCP entity includes:

A status report request sent by the second PDCP entity based on a polling (polling) mechanism is received.

The embodiment of the present invention also provides a device for sending a PDCP status report, which is set in the first PDCP entity, and the device includes:

The first processing unit is configured to generate a PDCP status report according to the reordering result of the received data packets by the first PDCP entity itself when the PDCP status report trigger condition is met;

The second processing unit is configured to send the PDCP status report to the second PDCP entity.

An embodiment of the present invention further provides a device for sending a PDCP status report, which is set at a first PDCP entity, and includes: a processor and a memory for storing a computer program that can run on the processor,

Wherein, when the processor is used to run the computer program, it executes the steps of the above method.

An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

The PDCP status report sending method, device, and computer-readable storage medium provided by the embodiments of the present invention, when the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to the reordering result of the received data packets; sending the PDCP status report to a second PDCP entity. In the solution provided by the embodiment of the present invention, as long as the trigger condition is met, the sending of the PDCP status report will be triggered, which expands the use range of the PDCP status report, thus improving the reliability of the communication system.

Description of drawings

In the drawings (which are not necessarily drawn to scale), like reference numerals may describe like parts in different views. The drawings generally illustrate the various embodiments discussed herein, by way of example and not limitation.

FIG. 1 is a schematic flowchart of a method for sending a PDCP status report according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a two-level system architecture of CU/DU in an NR system according to an embodiment of the present invention;

3 is a schematic structural diagram of a device for sending a PDCP status report according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a hardware structure of a device for sending a PDCP status report according to an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

On the one hand, currently, in Long Term Evolution (LTE, Long Term Evolution), there are only bearers mapped to RLC AM, and when PDCP re-establishment occurs, a PDCP status report is triggered (see 3GPP 36.323 regulations). The main reason is that the data mapped to the RLC AM bearer generally has a high reliability requirement for the data, so it is required to keep the data lossless during re-establishment or handover. Therefore, there are only a few scenarios where the PDCP status report can be used in the LTE protocol.

On the other hand, in NR (that is, 5G system), the functions of the PDCP entity are enhanced, such as moving the reordering function from the RLC entity to the PDCP entity; in this way, the PDCP entity itself can perceive packet loss information, without relying on the RLC entity to provide it.

In addition, in the two-level architecture for the centralized processing unit (CU, Centralized Unit)/distributed processing unit (DU, Distributed Unit), the PDCP function is located in the CU, RLC, media access control (MAC, MediaAccess Control) and physical layer ( In the case where the PHY function is located in a DU, when a CU is connected to at least two DUs, the mobile handover scenario of the UE is divided into mobile handover between CUs and mobile handover between multiple DUs in a CU. During the handover process, when the UE When switching RLC, considering the need to keep data lossless during switching, PDCP status reporting is very necessary.

Under such a premise, it is necessary to expand the range of triggering conditions of the PDCP status report in NR.

Based on this, in various embodiments of the present invention: when the PDCP status report trigger condition is satisfied, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets; sends the PDCP status report to the second PDCP entity PDCP status report.

Specifically, the PDCP status report trigger condition includes one of the following conditions:

During PDCP re-establishment;

The first timer expires;

A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity.

As long as one of the above three trigger conditions is satisfied, the PDCP status report will be triggered to be sent, which expands the scope of use of the PDCP status report, thus improving the reliability of the communication system.

The method for sending a PDCP status report provided by the embodiment of the present invention is applied to a first PDCP entity.

Here, in actual application, the first PDCP entity may be located in a UE or a base station (such as a 5G Node B (gNB), etc.).

The solution provided by the embodiment of the present invention can be applied to the NR system, because: in the NR system, the L2 function of the protocol stack changes greatly, which is specifically reflected in: in order to realize the preprocessing of the PDCP layer, if the RLC entity does not need to reassemble the packet ( reassembly), the RLC receiver will directly submit the received MAC SDU to the PDCP layer. That is to say, for a complete (no segmentation (segmentation) is not required), the RLC layer at the receiving end does not process it, and directly submits it to the PDCP layer, so that the PDCP entity can perform decryption and other processing in advance. Preprocessing is a main starting point for the change of the NR protocol stack. In this processing method, the order of data submitted to the PDCP layer cannot be guaranteed. Therefore, in the NR system, the PDCP entity needs to reorder the PDCP PDUs, which is the biggest difference from the LTE system. That is to say, in the NR system, the PDCP entity has the reordering function, while in the LTE system, the RLC entity has the reordering function.

It should be noted that: the solutions provided by the embodiments of the present invention can also be applied to communication systems more advanced than 5G, as long as the PDCP entity has a reordering function, the solutions of the embodiments of the present invention can be used.

As shown in Figure 1, the method includes the following steps:

Step 101: When the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets;

Wherein, the trigger condition of the PDCP status report includes one of the following conditions:

During PDCP re-establishment;

The first timer expires;

A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity.

Here, the first PDCP entity is the receiving end of the data connection, and the second PDCP entity is the sending end of the data. Therefore, the first PDCP entity can be called the PDCP receiving end. Correspondingly, the second PDCP entity An entity may be referred to as a PDCP sender.

In practical application, the first PDCP entity obtains the sequence number (SN) of the PDCP SDU corresponding to the incorrectly received PDCP PDU according to the reordering result; and then generates a PDCP status report according to the obtained sequence number.

Wherein, the generated PDCP status report carries the SN of the PDCP SDU corresponding to the incorrectly received PDCP PDU.

The PDCP status report is used to feed back whether all PDCP PDUs have been received correctly since the status report was triggered, so that the second PDCP entity can retransmit data packets according to the PDCP status report.

There is a CU/DU two-level system architecture in the NR system, for example, the application scenario shown in Figure 2. In this scenario, the network elements involved may include: a core network (NG core), multiple CUs, and multiple DUs. Among them, the NG core is connected to the CU through the NG interface, the CU is connected to the CU through the Xn interface, the DU can be directly connected to the UE, and the CU is connected to the DU through the F1 interface. Among them, the gNB can be divided into two logical nodes, CU and DU, and a CU is connected to at least two DUs. When the UE performs mobile handover between CUs, or between multiple DUs in a CU, and when the UE switches RLC during the handover process, a PDCP status report will be triggered.

That is to say, one implementation of triggering the PDCP status report during the above PDCP re-establishment process is: the first network element (ie CU) in the NR system is a logical node that implements part of the base station functions, and the second network element (ie DU ) is a logical node that implements base station functions other than the functions implemented by the first network element, the first network element can control the second network element, and the first network element is connected to at least two of the second network elements The network element; the PDCP entity is located in the first network element; the RLC entity is located in the second network element (PHY and MAC functions are also located in the second network element); the UE is connected to the second network element; the PDCP is re-established process, including:

A PDCP re-establishment process caused when the UE is handed over between two first network elements, or handed over between multiple second network elements within a first network element.

In practical application, the solutions in the embodiments of the present invention can be applied to RLC AM and RLC UM. In these two modes, the RLC entities corresponding to the PDCP entities are AM RLC entities and RLC UM entities respectively.

Among them, RLC AM is the acknowledgment mode of RLC. In RLC AM, the RLC receiving end needs to feed back a status report to the RLC sending end, and the RLC sending end retransmits the data packets that are not correctly received by the RLC receiving end according to the status report; RLC UM is RLC mode that does not require confirmation.

In one embodiment, the duration of the first timer is greater than the first value; the first value is the product of the number of RLC retransmissions and the duration of the second timer; the second timer is the retransmission timing device.

Wherein, the duration of the first timer is configured by the RRC entity. Based on this, the first PDCP entity receives the duration information of the first timer configured by the corresponding RRC entity; uses the received duration information to set the First timer.

For the trigger condition of receiving the status report request sent by the second PDCP entity, in actual application, the second PDCP entity may actively send a status report request to the first PDCP entity based on the polling mechanism as needed, then for For the first PDCP entity, it will receive the status report request sent by the second PDCP entity based on the polling mechanism, and then generate a PDCP status report.

Wherein, the polling mechanism refers to: the packet header sent by the second PDCP entity carries a polling indication, and the indication indicates whether the PDCP sending end (that is, the second PDCP entity) needs the PDCP receiving end (that is, the first PDCP entity) to form a PDCP Status report, when the polling indication indicates that a PDCP status report needs to be formed, it means that the second PDCP entity has received the status report request sent by the second PDCP entity.

In practical applications, for the polling indication, generally there is a 1-bit indication in the packet header sent by the PDCP sending end, such as setting it to 1, indicating that a trigger is required. When the data packet carrying the polling bit=1 arrives at the PDCP receiving end, the PDCP receiving end will send The PDCP sender sends a PDCP status report.

Step 102: the first PDCP entity sends the PDCP status report to the second PDCP entity.

Here, after the second PDCP entity receives the report, it will discard (discard) the PDCP SDU corresponding to the correctly received PDCP PDU according to the acceptance information (ACK/NACK) fed back by the status report; The underlying link (including links between RLC entities, MAC entities, and PHY entities) is retransmitted, or transmitted on a newly established underlying link.

It can be seen from the above description that the PDCP entity in the embodiment of the present invention has a reordering function, so this function is more beneficial for the PDCP receiving end to form a PDCP status report. This is because: In the NR system, the PDCP entity always needs to read the PDCP PDU SN, not the behavior of the receiving end after the PDCP reconstruction process is triggered, and the SN is required when generating the PDCP status report , and the PDCP entity can obtain the SN in real time, so this is conducive to forming a PDCP status report.

In the method for sending a DCP status report provided by an embodiment of the present invention, when the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to the reordering result of the received data packets; and sends the PDCP status report to the second PDCP entity. PDCP status report. In the solution provided by the embodiment of the present invention, as long as the trigger condition is met, the sending of the PDCP status report will be triggered, which expands the application range of the PDCP status report, thus improving the reliability of the communication system.

The trigger condition of the PDCP status report includes one of the following conditions: during the PDCP re-establishment process; the first timer expires; the status report request sent by the second PDCP entity is received; When the second PDCP entity sends the PDCP status report, as long as one of the above three trigger conditions is met, the sending of the PDCP status report will be triggered, which expands the scope of use of the PDCP status report, thus improving the reliability of the communication system.

In order to implement the method provided by the embodiment of the present invention, the embodiment of the present invention also provides a device for sending a DCP status report, which is set in the first PDCP entity, as shown in FIG. 3 , the device includes:

The first processing unit 31 is configured to generate a PDCP status report according to the reordering result of the received data packets by the first PDCP entity itself when the PDCP status report trigger condition is met;

The second processing unit 32 is configured to send the PDCP status report to the second PDCP entity.

Wherein, the trigger condition of the PDCP status report includes one of the following conditions:

During PDCP re-establishment;

The first timer expires;

A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity.

Here, the first PDCP entity is the receiving end of the data connection, and the second PDCP entity is the sending end of the data. Therefore, the first PDCP entity can be called the PDCP receiving end. Correspondingly, the second PDCP entity An entity may be referred to as a PDCP sender.

Wherein, the first processing unit 31 is specifically used for:

Obtain the SN of the PDCP SDU corresponding to the incorrectly received PDCP PDU according to the reordering result;

Generate a PDCP status report based on the obtained SN.

Wherein, the generated PDCP status report carries the SN of the PDCP SDU corresponding to the incorrectly received PDCP PDU.

In one embodiment, the duration of the first timer is greater than the first value; the first value is the product of the number of RLC retransmissions and the duration of the second timer; the second timer is the retransmission timing device.

Wherein, the duration of the first timer is configured by the RRC entity, based on this, the first processing unit 31 is further configured to:

receiving the duration information of the first timer configured by the corresponding RRC entity;

The first timer is set by using the received duration information.

For the trigger condition of receiving the status report request sent by the second PDCP entity, in actual application, the second PDCP entity may actively send a status report request to the first PDCP entity based on the polling mechanism as needed, then for For the first PDCP entity, it will receive the status report request sent by the second PDCP entity based on the polling mechanism, and then generate a PDCP status report.

Based on this, in an embodiment, the first processing unit 31 is specifically configured to:

The status report request sent by the second PDCP entity based on the polling mechanism is received.

In practical application, the first processing unit 31 and the second processing unit 32 may be implemented by a processor in the device for sending the PDCP status report.

It should be noted that: when the sending device of the PDCP status report provided by the above-mentioned embodiment is performing data, the division of the above-mentioned program modules is used as an example for illustration. In practical applications, the above-mentioned processing can be allocated by different program modules as required Completion means that the internal structure of the device is divided into different program modules to complete all or part of the processing described above.

Based on the hardware implementation of the above program modules, an embodiment of the present invention provides a hardware structure of a device for sending a PDCP status report, which is set in the first PDCP entity. As shown in FIG. 4 , the device 40 includes:

A processor 41 and a memory 42 for storing computer programs capable of running on the processor, wherein

When the processor 41 is used to run the computer program, execute:

When the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets;

sending the PDCP status report to a second PDCP entity.

Wherein, the PDCP status report trigger condition may include one of the following conditions:

During PDCP re-establishment;

The first timer expires;

A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity.

Wherein, in one embodiment, when the processor 41 is used to run the computer program, execute:

Obtain the sequence number of the PDCP SDU corresponding to the incorrectly received PDCP PDU according to the reordering result;

Generate a PDCP status report according to the obtained serial number.

Wherein, in an embodiment, the first network element in the NR system is a logical node that implements some base station functions, and the second network element is a logical node that implements base station functions other than the functions implemented by the first network element, so The first network element can control the second network element, the first network element is connected to at least two of the second network elements; the PDCP entity is located in the first network element; the RLC entity is located in the second network element; The UE is connected to the second network element; the PDCP re-establishment process includes:

A PDCP re-establishment process caused when the UE is handed over between two first network elements, or handed over between multiple second network elements within a first network element.

In practical application, the RLC entity corresponding to the PDCP entity may be an AM RLC entity or a UM RLC entity.

In one embodiment, the duration of the first timer is greater than the first value; the first value is the product of the number of RLC retransmissions and the duration of the second timer; the second timer is the retransmission timing device.

In one embodiment, the processor 41 is also configured to execute: when running the computer program:

receiving the duration information of the first timer configured by the corresponding RRC entity;

The first timer is set by using the received duration information.

In one embodiment, when the processor 41 is configured to run the computer program, execute:

The status report request sent by the second PDCP entity based on the polling mechanism is received.

The memory 42 in the embodiment of the present invention is used to store various types of data to support the operation of the sending device 40 of the PDCP status report.

Certainly, in actual application, as shown in FIG. 4 , various components in the device 40 for sending the PDCP status report are coupled together through the bus system 43 . It can be understood that the bus system 43 is used to realize connection and communication between these components. In addition to the data bus, the bus system 43 also includes a power bus, a control bus and a status signal bus. However, for clarity of illustration, the various buses are labeled bus system 43 in FIG. 4 .

The methods disclosed in the foregoing embodiments of the present invention may be applied to the processor 41 or implemented by the processor 41 . The processor 41 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor 41 or instructions in the form of software. The aforementioned processor 41 may be a general-purpose processor, a digital signal processor (DSP, Digital Signal Processor), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. The processor 41 may implement or execute various methods, steps and logic block diagrams disclosed in the embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the methods disclosed in the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, and the storage medium is located in the memory 42, and the processor 41 reads the information in the memory 42, and completes the steps of the foregoing method in combination with its hardware.

In an exemplary embodiment, the sending device 40 of the PDCP status report may be implemented by one or more Application Specific Integrated Circuits (ASIC, Application Specific Integrated Circuit), DSP, Programmable Logic Device (PLD, Programmable Logic Device), complex programmable Logic device (CPLD, Complex Programmable LogicDevice), field programmable gate array (FPGA, Field-Programmable Gate Array), general-purpose processor, controller, microcontroller (MCU, Micro Controller Unit), microprocessor (Microprocessor), or other electronic components to implement the aforementioned method.

It can be understood that the memory (such as the memory 42 ) in the embodiment of the present invention may be a volatile memory or a non-volatile memory, and may also include both volatile and non-volatile memories. Wherein, non-volatile memory can be read-only memory (ROM, Read Only Memory), programmable read-only memory (PROM, Programmable Read-Only Memory), erasable programmable read-only memory (EPROM, Erasable Programmable Read-Only Memory) Memory), Electrically Erasable Programmable Read-Only Memory (EEPROM, Electrically Erasable Programmable Read-Only Memory), Magnetic Random Access Memory (FRAM, ferromagnetic random access memory), Flash Memory (Flash Memory), Magnetic Surface Memory, Optical Disk , or CD-ROM (Compact Disc Read-OnlyMemory); the magnetic surface storage can be disk storage or tape storage. The volatile memory may be random access memory (RAM, Random Access Memory), which is used as an external cache. By way of illustration and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM, Static Random Access Memory), Synchronous Static Random Access Memory (SSRAM, Synchronous Static Random Access Memory), Dynamic Random Access Memory Memory (DRAM, Dynamic Random Access Memory), synchronous dynamic random access memory (SDRAM, Synchronous Dynamic Random Access Memory), double data rate synchronous dynamic random access memory (DDRSDRAM, Double Data Rate Synchronous Dynamic Random Access Memory), enhanced Type Synchronous Dynamic Random Access Memory (ESDRAM, Enhanced Synchronous Dynamic Random Access Memory), Synchronous Link Dynamic Random Access Memory (SLDRAM, SyncLink Dynamic Random Access Memory), Direct Memory Bus Random Access Memory (DRRAM, Direct Rambus Random Access Memory). The memory described by embodiments of the present invention is intended to include, but not be limited to, these and any other suitable types of memory.

In an exemplary embodiment, the embodiment of the present invention also provides a computer-readable storage medium, for example, including a memory 42 storing a computer program, and the above-mentioned computer program can be executed by the processor 41 of the PDCP status report sending device 40 to complete Steps described in the aforementioned method.

Specifically, the computer-readable storage medium provided by the embodiment of the present invention has a computer program stored thereon, and when the computer program is run by a processor, it executes:

When the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets;

sending the PDCP status report to a second PDCP entity.

Wherein, the PDCP status report trigger condition may include one of the following conditions:

During PDCP re-establishment;

The first timer expires;

A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity.

In one embodiment, when the computer program is executed by the processor, it executes:

Obtain the sequence number of the PDCP SDU corresponding to the incorrectly received PDCP PDU according to the reordering result;

Generate a PDCP status report according to the obtained serial number.

Wherein, in an embodiment, the first network element in the NR system is a logical node that implements some base station functions, and the second network element is a logical node that implements base station functions other than the functions implemented by the first network element, so The first network element can control the second network element, the first network element is connected to at least two of the second network elements; the PDCP entity is located in the first network element; the RLC entity is located in the second network element; The UE is connected to the second network element; the PDCP re-establishment process includes:

A PDCP re-establishment process caused when the UE is handed over between two first network elements, or handed over between multiple second network elements within a first network element.

Wherein, the RLC entity corresponding to the PDCP entity may be an AM RLC entity or a UM RLC entity.

In one embodiment, when the computer program is executed by the processor, it executes:

receiving the duration information of the first timer configured by the corresponding RRC entity;

The first timer is set by using the received duration information.

In one embodiment, when the computer program is executed by the processor, it executes:

The status report request sent by the second PDCP entity based on the polling mechanism is received.

It should be noted that: the computer-readable storage medium provided by the embodiment of the present invention can be FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disk, or CD-ROM, etc.; One or any combination of various devices.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (18)

1. A sending method of Packet Data Convergence Protocol PDCP Status Report, characterized in that, the method comprises: When the PDCP status report trigger condition is met, the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets; sending the PDCP status report to a second PDCP entity. 2. The method according to claim 1, wherein the PDCP status report trigger condition includes one of the following conditions: During PDCP re-establishment; The first timer expires; A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity. 3. The method according to claim 1, wherein the first PDCP entity generates a PDCP status report according to its own reordering result of the received data packets, including: The first PDCP entity obtains the sequence number of the PDCP service data unit SDU corresponding to the incorrectly received PDCP protocol data unit PDU according to the reordering result; Generate a PDCP status report according to the obtained serial number. 4. The method according to claim 2, characterized in that, the first network element in the new wireless access NR system is a logical node that realizes part of the base station functions, and the second network element is a logical node that implements functions other than the first network element. A logical node other than the function of the base station, the first network element can control the second network element, and the first network element is connected to at least two of the second network elements; the PDCP entity is located in the first network element The radio link control RLC entity is located in the second network element; the terminal is connected to the second network element; the PDCP re-establishment process includes: A PDCP re-establishment process caused when the terminal switches between two first network elements, or switches between multiple second network elements in a first network element. 5. The method according to claim 1, wherein the RLC entity corresponding to the PDCP entity is an AM RLC entity or a UM RLC entity. 6. The method according to claim 2, characterized in that, the duration of the first timer is greater than the first value; the first value is the result of the product of the RLC retransmission times and the duration of the second timer; The second timer is a retransmission timer. 7. according to the described method of claim 2,3,5 or 6, it is characterized in that, described method also comprises: receiving the duration information of the first timer configured by the corresponding radio resource control RRC entity; The first timer is set by using the received duration information. 8. The method according to claim 2, 3 or 5, wherein receiving the status report request sent by the second PDCP entity includes: A status report request sent by the second PDCP entity based on a polling mechanism is received. 9. A device for sending a PDCP status report, characterized in that it is set at the first PDCP entity, and the device includes: The first processing unit is configured to generate a PDCP status report according to the reordering result of the received data packets by the first PDCP entity itself when the PDCP status report trigger condition is met; The second processing unit is configured to send the PDCP status report to the second PDCP entity. 10. A device for sending a PDCP status report, characterized in that it is set at the first PDCP entity, including: a processor and a memory for storing a computer program that can run on the processor, Wherein, when the processor is used to run the computer program, it executes: When the PDCP status report trigger condition is met, generate a PDCP status report according to the reordering result of the received data packets by the first PDCP entity itself; sending the PDCP status report to a second PDCP entity. 11. The device according to claim 10, wherein the PDCP status report trigger condition includes one of the following conditions: During PDCP re-establishment; The first timer expires; A status report request sent by the second PDCP entity is received; the status report request is used to request to send a PDCP status report to the second PDCP entity. 12. The device according to claim 10, wherein when the processor is used to run the computer program, execute: Obtain the sequence number of the PDCP SDU corresponding to the incorrectly received PDCP PDU according to the reordering result; Generate a PDCP status report according to the obtained serial number. 13. The device according to claim 11, wherein the first network element in the NR system is a logical node that realizes part of the functions of the base station, and the second network element is a logical node that realizes functions other than the functions realized by the first network element. A logical node of the base station function, the first network element can control the second network element, the first network element is connected to at least two of the second network elements; the PDCP entity is located in the first network element; the wireless link The control RLC entity is located in the second network element; the terminal is connected to the second network element; the PDCP re-establishment process includes: A PDCP re-establishment process caused when the terminal switches between two first network elements, or switches between multiple second network elements in a first network element. 14. The apparatus according to claim 10, wherein the RLC entity corresponding to the PDCP entity is an AM RLC entity or a UM RLC entity. 15. The device according to claim 11, wherein the duration of the first timer is greater than a first value; the first value is the result of the product of the RLC retransmission times and the duration of the second timer; The second timer is a retransmission timer. 16. The device according to claim 11, 12, 14 or 15, wherein when the processor is running the computer program, it executes: receiving the duration information of the first timer configured by the corresponding RRC entity; The first timer is set by using the received duration information. 17. The device according to claim 11, 12 or 14, wherein when the processor is used to run the computer program, it executes: A status report request sent by the second PDCP entity based on a polling mechanism is received. 18. A computer-readable storage medium, on which a computer program is stored, wherein, when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are realized.