CN108282442B

CN108282442B - Data sending method and device and user plane entity

Info

Publication number: CN108282442B
Application number: CN201710007896.XA
Authority: CN
Inventors: 何青春; 黄河
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2017-01-05
Filing date: 2017-01-05
Publication date: 2022-03-01
Anticipated expiration: 2037-01-05
Also published as: CN108282442A

Abstract

The invention provides a data sending method, a data sending device and a user plane entity, wherein the method comprises the following steps: adding second length indication information in a second user plane entity protocol data unit, wherein the second length indication information is used for indicating whether a first fragment participating in cascade connection in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the second user plane entity protocol data unit added with the second length indication information to a third user plane entity.

Description

Data sending method and device and user plane entity

Technical Field

The present invention relates to the field of communications, and in particular, to a data transmission method, an apparatus, and a user plane entity.

Background

In a Long Term Evolution (LTE) system, a user plane Protocol stack includes three parts, namely, a Packet Data Convergence Protocol (PDCP), a Radio Link Control (RLC), and a Medium Access Control (MAC). The data transmission among the three parts of data has the problems of high complexity of data package, low processing efficiency and high processing time delay. For example, the RLC performs concatenation and segmentation on Data packets from the PDCP according to a scheduling instruction of the MAC, or performs re-segmentation on an RLC Protocol Data Unit (PDU). Since PDCP PDUs participating in concatenation or segmentation are dynamically changed according to the size of granted resources, the header of RLC PDU will be made flexible, for example, the RLC PDU header in Unacknowledged Mode (UM) and Acknowledged Mode (AM) transmission modes includes two parts: a fixed domain and an extended domain.

For the two PDU frame structures, due to the dynamic flexibility of the RLC header information, and the header information can only be generated according to the size of the scheduling resource, it cannot be generated in advance, which increases the processing delay of the data packet, and is difficult to adapt to the high-rate and low-delay scenarios.

On the other hand, the length indication information L in each MAC subheader in LTE is used to indicate the size of the MAC SDU corresponding to each subheader, and the receiving end can acquire the following MAC SDU only after analyzing all the subheader information and/or MAC CEs one by one, so the analysis efficiency of the receiving end is low, and it is difficult to meet the requirements of high rate and low delay.

Therefore, in the related art, the sending end can send the data packet to the physical layer for processing after cascading, multiplexing and adding header information to the data packet according to the size of authorized resources, the complexity of the data packet is high, the data processing efficiency is low, and a decoder in the receiving end can know the initial position of the data after analyzing the complex header information, so that the receiving analysis efficiency is low, and the requirements of high speed and low time delay in 5G are not facilitated.

Disclosure of Invention

The embodiment of the invention provides a data sending method, a data sending device and a user plane entity, which are used for at least solving the problems of high complexity, low processing efficiency and high processing time delay of data package in the related technology.

According to an embodiment of the present invention, there is provided a data transmission method including: adding second length indication information in a second user plane entity protocol data unit, wherein the second length indication information is used for indicating whether a first fragment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a fragment of the first user plane entity protocol data unit, and when the second length indication information indicates the fragment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the fragment of the first user plane entity protocol data unit, the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the second user plane entity protocol data unit added with the second length indication information to a third user plane entity.

Optionally, the value of the second length indication information is used to identify a position of a first complete first user plane entity protocol data unit included in a second user plane entity protocol data unit.

Optionally, the step of using the value of the second length indication information to identify the position of a first complete first user plane entity protocol data unit included in a second user plane entity protocol data unit includes: when the value of the second length indication information is zero, it indicates that a first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; when the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; and under the condition that the value of the second length indication information is a preset default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit.

Optionally, adding the second length indication information in the second user plane entity protocol data unit includes: and adding the second length indication information in the header information of the second user plane entity protocol data unit.

Optionally, the header information of the second user plane entity protocol data unit further includes at least one of the following information: a D/C indication for indicating whether the second user plane entity protocol data unit is a control protocol data unit or a data protocol control unit; a sequence number, SN, for indicating the second user plane entity protocol data unit; a reallocation identification RF for indicating whether the second user plane entity protocol data unit is a complete protocol data unit or a segment of a protocol data unit; a polling P indication for indicating whether an opposite end receiving the second user plane entity protocol data unit needs to feed back a status report; a segment offset SO indication indicating an offset of a protocol data unit and/or a traffic data unit of the second user plane entity protocol data unit with respect to an initial protocol data unit and/or an initial traffic data unit.

According to another embodiment of the present invention, there is provided a data transmission method including: adding third length indication information to a third user plane entity protocol data unit, where the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case where a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate a number of bytes between the third length indication information and a next third user plane entity subheader in the third user plane entity protocol data unit, where the second user plane entity protocol data unit carries second length indication information used to indicate that a first slice participating in concatenation in the second user plane entity protocol data unit is a complete third slice A user plane entity protocol data unit or a segment of a first user plane entity protocol data unit, wherein the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit under the condition that the second length indication information indicates the segment of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the third user plane entity protocol data unit added with the third length indication information to a physical layer.

Optionally, adding the third length indication information in the third user plane entity protocol data unit includes: and adding the third length indication information in the header information of the third user plane entity protocol data unit.

According to an embodiment of the present invention, there is provided a data transmission apparatus including: a first adding module, configured to add second length indication information in a second user plane entity protocol data unit, where the second length indication information is used to indicate whether a first segment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and when the second length indication information indicates the segment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the segment of the first user plane entity protocol data unit, where the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used to indicate a length of the first user plane entity protocol data unit; a first sending module, configured to send the second user plane entity protocol data unit to which the second length indication information is added to a third user plane entity.

Optionally, the first adding module is further configured to add the second length indication information in header information of the second user plane entity protocol data unit.

According to an embodiment of the present invention, there is provided a second user plane entity, where functions of the second user plane entity correspond to a radio link control, RLC, function of a long term evolution, LTE, system and an evolution enhancement function of the RLC function, and the second user plane entity includes any one of the above apparatuses.

According to an embodiment of the present invention, there is provided a data transmission apparatus including: a second adding module, configured to add third length indication information in a third user plane entity protocol data unit, where the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case that a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate a number of bytes between the third length indication information and a next third user plane entity subheader in the third user plane entity protocol data unit, where the second user plane entity protocol data unit carries second length indication information, and the second length indication information is used to indicate a third length indication information that participates in cascade connection in the second user plane entity protocol data unit One fragment is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit under the condition that the second length indication information indicates the segment of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit; a second sending module, configured to send the third user plane entity protocol data unit to which the third length indication information is added to a physical layer.

Optionally, the second adding module is further configured to add the third length indication information in header information of the third user plane entity protocol data unit.

According to another embodiment of the present invention, there is provided a third user plane entity, where the functions of the third user plane entity correspond to a medium access control MAC function of a long term evolution LTE system and an evolution enhancement function of the MAC function, and the third user plane entity includes the above apparatus.

According to still another embodiment of the present invention, a user plane entity, a first user plane entity, a second user plane entity, and a third user plane entity are provided, where a function of the first user plane entity corresponds to a packet data convergence protocol PDCP function of a long term evolution LTE system and an evolution enhancement function of the PDCP function, and the first user plane entity is configured to add first length indication information in a first user plane entity protocol data unit and send the first user plane entity protocol data unit added with the first length indication information to the second user plane entity, where the first length indication information is used to indicate a length of the first user plane entity protocol data unit.

According to still another embodiment of the present invention, there is also provided a storage medium. The storage medium is configured to store program code for performing the steps of: adding second length indication information in a second user plane entity protocol data unit, wherein the second length indication information is used for indicating whether a first fragment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a fragment of the first user plane entity protocol data unit, and when the second length indication information indicates the fragment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the fragment of the first user plane entity protocol data unit, the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the second user plane entity protocol data unit added with the second length indication information to a third user plane entity.

Optionally, the storage medium is further arranged to store program code for performing the steps of: and the value of the second length indication information is used for identifying the position of a first complete first user plane entity protocol data unit contained in a second user plane entity protocol data unit.

Optionally, the storage medium is further arranged to store program code for performing the steps of: the value of the second length indication information is used for identifying the position of a first complete first user plane entity protocol data unit contained in a second user plane entity protocol data unit, and the position comprises the following steps: when the value of the second length indication information is zero, it indicates that a first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; when the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; and under the condition that the value of the second length indication information is a preset default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit.

Optionally, the storage medium is further arranged to store program code for performing the steps of: adding the second length indication information in the second user plane entity protocol data unit comprises: and adding the second length indication information in the header information of the second user plane entity protocol data unit.

Optionally, the storage medium is further arranged to store program code for performing the steps of: the header information of the second user plane entity protocol data unit further includes at least one of the following information: a D/C indication for indicating whether the second user plane entity protocol data unit is a control protocol data unit or a data protocol control unit; a sequence number, SN, for indicating the second user plane entity protocol data unit; a reallocation identification RF for indicating whether the second user plane entity protocol data unit is a complete protocol data unit or a segment of a protocol data unit; a polling P indication for indicating whether an opposite end receiving the second user plane entity protocol data unit needs to feed back a status report; a segment offset SO indication indicating an offset of a protocol data unit and/or a traffic data unit of the second user plane entity protocol data unit with respect to an initial protocol data unit and/or an initial traffic data unit.

According to another embodiment of the present invention, there is also provided a storage medium. The storage medium is configured to store program code for performing the steps of: adding third length indication information to a third user plane entity protocol data unit, where the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case where a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate a number of bytes between the third length indication information and a next third user plane entity subheader in the third user plane entity protocol data unit, where the second user plane entity protocol data unit carries second length indication information used to indicate that a first slice participating in concatenation in the second user plane entity protocol data unit is a complete third slice A user plane entity protocol data unit or a segment of a first user plane entity protocol data unit, wherein the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit under the condition that the second length indication information indicates the segment of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the third user plane entity protocol data unit added with the third length indication information to a physical layer.

Optionally, the storage medium is further arranged to store program code for performing the steps of: adding the third length indication information in the third user plane entity protocol data unit comprises: and adding the third length indication information in the header information of the third user plane entity protocol data unit.

According to the invention, second length indication information is added in a second user plane entity protocol data unit, wherein the second length indication information is used for indicating whether a first fragment participating in cascade in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a fragment of the first user plane entity protocol data unit; the second user plane entity protocol data unit added with the second length indication information is sent to a third user plane entity, namely, the data can be directly sent after the length of the data unit is known, the data does not need to be sent after the complex header processing is finished, and the receiving end knows the initial position of the data after the length indication information of the data unit is obtained and can analyze the data.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a block diagram of a hardware configuration of a mobile terminal of a data transmission method according to an embodiment of the present invention;

fig. 2 is a flowchart of a first data transmission method according to an embodiment of the present invention;

fig. 3 is a flowchart of a second data transmission method according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a user plane protocol entity provided in an embodiment of the present invention;

fig. 5 is a schematic diagram of a UMD PDU with a sequence number SN of 10 according to an embodiment of the present invention;

fig. 6 is a diagram of an AMD PDU with a sequence number SN of 10 according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a MAC PDU frame structure of LTE according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a MAC header and a MAC CE behind a transport block according to an embodiment of the present invention;

fig. 9 is a schematic diagram of an RLC header, an MAC header and a MAC CE provided in an embodiment of the present invention behind a transport block;

fig. 10 is a first schematic diagram illustrating FI-free indication in an RLC header according to an embodiment of the present invention;

fig. 11 is a second schematic diagram illustrating FI-free indication in an RLC header according to an embodiment of the present invention;

fig. 12 is a schematic diagram of a PDCP PDU corresponding to an RLC PDU according to an embodiment of the present invention;

fig. 13 is a block diagram of a first data transmission device according to an embodiment of the present invention;

fig. 14 is a block diagram of a second user plane entity according to an embodiment of the present invention;

fig. 15 is a block diagram of a second data transmission device according to an embodiment of the present invention;

fig. 16 is a block diagram of a third user plane entity according to an embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

Example 1

The method provided by the first embodiment of the present application may be executed in a mobile terminal, a computer terminal, or a similar computing device. Taking an example of the operation on a mobile terminal, fig. 1 is a hardware structure block diagram of the mobile terminal of a data transmission method according to an embodiment of the present invention. As shown in fig. 1, the mobile terminal 10 may include one or more (only one shown) processors 102 (the processor 102 may include, but is not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 104 for storing data, and a transmitting device 106 for communication functions. It will be understood by those skilled in the art that the structure shown in fig. 1 is only an illustration and is not intended to limit the structure of the electronic device. For example, the mobile terminal 10 may also include more or fewer components than shown in FIG. 1, or have a different configuration than shown in FIG. 1.

The memory 104 may be used to store software programs and modules of application software, such as program instructions/modules corresponding to the data transmission method in the embodiment of the present invention, and the processor 102 executes various functional applications and data processing by executing the software programs and modules stored in the memory 104, so as to implement the method described above. The memory 104 may include high speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory located remotely from the processor 102, which may be connected to the mobile terminal 10 via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The transmission device 106 is used for receiving or transmitting data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the mobile terminal 10. In one example, the transmission device 106 includes a Network adapter (NIC) that can be connected to other Network devices through a base station to communicate with the internet. In one example, the transmission device 106 can be a Radio Frequency (RF) module, which is used to communicate with the internet in a wireless manner.

In this embodiment, a data transmission method is provided, and fig. 2 is a flowchart of a first data transmission method according to an embodiment of the present invention, as shown in fig. 2, the flowchart includes the following steps:

step S202, adding second length indication information in a second user plane entity protocol data unit, wherein the second length indication information is used for indicating whether a first segment participating in cascade in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and under the condition that the second length indication information indicates the segment of the first user plane entity protocol data unit, the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used for indicating the length of the first user plane entity protocol data unit;

step S204, the second user plane entity protocol data unit added with the second length indication information is sent to a third user plane entity.

Through the steps, the data can be directly sent after the length of the data unit is known, the data does not need to be sent after the complex head processing is finished, the receiving end knows the initial position of the data after the length indication information of the data unit is obtained, and the data can be analyzed, so that the problems of high data package complexity, low processing efficiency and high processing delay in the related technology can be effectively solved, the data package complexity is reduced, the processing efficiency is improved, and the processing delay is reduced.

Optionally, the value of the second length indication information is used to identify a position of a first complete first user plane entity protocol data unit included in a second user plane entity protocol data unit. Wherein, the value of the second length indication information is used for identifying the position of a first complete first user plane entity protocol data unit contained in a second user plane entity protocol data unit, and comprises: when the value of the second length indication information is zero, the first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; under the condition that the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; and under the condition that the value of the second length indication information is a preset default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit.

Optionally, adding the second length indication information in the second user plane entity protocol data unit includes: and adding second length indication information in the header information of the second user plane entity protocol data unit.

Optionally, the header information of the second user plane entity protocol data unit further includes at least one of the following information: a D/C indication for indicating whether the second user plane entity protocol data unit is a control protocol data unit or a data protocol control unit; a sequence number SN used for indicating a second user plane entity protocol data unit; a reassignment identity RF for indicating whether the second user plane entity protocol data unit is a complete protocol data unit or a segment of a protocol data unit; a polling P indication for indicating whether an opposite end receiving the second user plane entity protocol data unit needs to feed back a status report; a segment offset SO indication indicating an offset of a protocol data unit and/or a traffic data unit of the second user plane entity protocol data unit with respect to the initial protocol data unit and/or the initial traffic data unit.

A data transmission method is provided in this embodiment, fig. 3 is a flowchart of a second data transmission method according to the embodiment of the present invention, and as shown in fig. 3, the flowchart includes the following steps:

step S302, add third length indication information to a third user plane entity protocol data unit, where the third length indication information is used to indicate the number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case that a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate the number of bytes between the third length indication information in the third user plane entity protocol data unit and a next third user plane entity subheader, the second user plane entity protocol data unit carries the second length indication information, and the second length indication information is used to indicate whether a first slice participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a first user plane entity protocol data unit Segmenting the body protocol data unit, wherein under the condition that the second length indication information indicates the segmentation of the first user plane entity protocol data unit, the value of the second length indication information is the length of the segmentation of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit;

step S304, sending the third user plane entity protocol data unit added with the third length indication information to the physical layer.

Optionally, adding the third length indication information in the third user plane entity protocol data unit includes: and adding third length indication information in the header information of the third user plane entity protocol data unit.

By analysis of the related art: in the Fifth-Generation mobile communication (5G for short) in the future, if the frame structure of the user plane packet in LTE is still adopted, the complexity of the packet is high, the sending end can send the packet to the physical layer for processing after cascading, multiplexing and adding header information to the packet according to the size of authorized resources, the data processing efficiency is low, and the decoder in the receiving end also needs to analyze the complex header information to know the initial position of the data, so the receiving analysis efficiency is low, which is not favorable for the requirements of high rate and low delay in 5G. Furthermore, the above embodiments and preferred embodiments provide a protocol data unit processing method, that is, a new protocol data unit construction method to simplify the flow of packet packing and transmission of data: adding length indication information in a protocol data unit of a user plane entity, wherein the length indication information is used for indicating the structure and the position of a data packet. By the method, the complexity of data package of the protocol data unit can be effectively reduced, the processing time delay of the sending end is reduced, and the data analysis efficiency of the receiving end is improved.

The following briefly describes a method for processing a new pdu provided in the embodiments of the present invention. Before briefly describing a new protocol data unit processing method, a user plane protocol entity according to an embodiment of the present invention is described.

Fig. 4 is a schematic diagram of a user plane protocol entity provided in an embodiment of the present invention, and as shown in fig. 4, the user plane protocol entity of a future mobile communication system includes: the system comprises a first user plane entity, a second user plane entity and a third user plane entity. The function of the first user plane entity may correspond to a PDCP function and an evolution enhancement function thereof in the LTE system, the function of the second user plane entity may correspond to an RLC function and an evolution enhancement function thereof in the LTE system, and the function of the third user plane entity may correspond to an MAC function and an evolution enhancement function thereof in the LTE system. The first user plane entity is used for adding first length indication information in a first user plane entity protocol data unit and sending the first user plane entity protocol data unit added with the first length indication information to a second user plane entity, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit.

The new processing method of the protocol data unit comprises the following steps: the third user plane entity protocol data unit may contain first length indication information, second length indication information and third length indication information.

The first length indication information is located in header information of a first user plane entity protocol data unit. The second length indication information is located in header information of a second user plane entity protocol data unit. The third length indication information is located in header information of a third user plane entity protocol data unit.

The first length indication information is used for indicating the length of the first user plane entity protocol data unit. The first length indication information is further used for indicating a starting position of an immediately next first user plane entity protocol data unit.

The value of the second length indication information is determined by whether the first segment participating in the cascade connection is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit.

And each second user plane entity protocol data unit corresponds to a piece of third length indication information.

The third length indication information is used for indicating the number of bytes between the third length indication information and the corresponding second user plane entity protocol data unit PDU. Or the third length indication information is used for indicating the number of bytes between the third length indication information and the corresponding second user plane entity service data unit SDU.

The third length indication information in the third user plane entity subheader is used to indicate the number of bytes between the third length indication information and the next third user plane entity subheader if the third user plane entity subheader corresponds to the control unit of the third user plane entity.

The following describes preferred embodiments of the invention.

To illustrate the preferred embodiment of the present invention, the frame structures of the UMD PDU, AMD PDU and MAC PDU in the LTE system are described below.

Fig. 5 is a schematic diagram of a UMD PDU (the number of LI is an even number) with a sequence number SN of 10 according to an embodiment of the present invention, as shown in fig. 5, in an LTE system, a frame structure of the UMP PDU is specifically as follows: the UMD PDU header information includes: the fixed domain and the extended domain. The fixed domain mainly includes information such as a fragmentation indication (frame Info, FI for short), an extension bit E, and a Sequence Number (SN for short); the extended field information comprises a series of length indication LI information, since the extended field is dynamically changed, the extended field contains n length indication LI, the value of n corresponds to the number of RLC SDUs participating in the concatenation, the RLC concatenates the RLC SDUs according to the MAC scheduling indication, due to the dynamic nature of the scheduling, the resources allocated to the same logical channel each time are not necessarily the same, and thus the size of the RLC PDU packet is also dynamically changed, and the dynamic change is indicated by the extended field part. In the LTE protocol architecture of the related art, the size of the space occupied by the extension domain cannot be determined only by the indication information of the fixed domain in the RLC PDU header information, and it cannot be known how many length indications LI and how many RLC SDUs are concatenated in the extension domain, and after receiving data, the receiving end must analyze all the length indication information LI in the extension domain to know the starting position of the data.

Fig. 6 is a schematic diagram of An (AMD) PDU with a sequence number SN of 10 (i.e. an even number), as shown in fig. 6, in an LTE system, an AMP PDU frame structure is specifically as follows: similar to fig. 5, AMD PDU header information includes: the fixed domain and the extended domain. The fixed domain mainly comprises Data Control (Data/Control, abbreviated as D/C) indication, Re-segmentation Flag (Re-segmentation Flag, abbreviated as RF), Polling (abbreviated as P) bit, segmentation indication (Framing Info, abbreviated as FI), extension bit E, sequence number SN and other information; the extended field information includes some length indication (Long Index, abbreviated as LI) information, since the extended field is dynamically changed, the extended field includes n length indications LI, where the value of n corresponds to the number of RLC SDUs participating in concatenation, the RLC performs concatenation of RLC SUD according to the MAC scheduling indication, and due to the dynamic nature of scheduling, the resources allocated to the same logical channel each time are not necessarily the same, so that the size of the RLC PDU packet is also dynamically changed, and the dynamic change is indicated by the extended field portion. In the LTE protocol architecture of the related art, the size of the space occupied by the extension domain cannot be determined only by the indication information of the fixed domain in the RLC PDU header information, and also cannot know how many length indications LI exist in the extension domain, and after receiving data, the receiving end must analyze all the length indication information LI in the extension domain to know the starting position of the data.

Fig. 7 is a schematic diagram of a MAC PDU frame structure of LTE according to an embodiment of the present invention, and as shown in fig. 7, in an LTE system, the frame structure of MAC PDU is specifically as follows: one MAC PDU may include one or more MAC subheaders, one or more MAC CEs, one or more MAC SDUs (RLC PDUs), one or more Padding. The size of the corresponding MAC SDU is indicated by L in the MAC subheader, i.e. the size of the RLC PDU on a certain logical channel for multiplexing. After receiving the MAC PDU of the opposite end, the receiving end needs to parse the data packet according to the frame structure logic, and can obtain the starting position of the MAC SDU only after parsing all sub-headers, MAC CEs, and the like, and deliver the MAC SDU to the higher layer, which has no problem in a scenario with low rate and low delay requirement, but needs to optimize the frame structure in a scenario with 5G high rate and low delay, so as to improve parsing efficiency.

Preferred embodiment 1

Fig. 8 is a schematic diagram of the MAC header and the MAC CE behind the transport block according to the embodiment of the present invention, and as shown in fig. 8, the MAC subheader and the MAC CE of the third user plane entity are located behind the MAC SDU, which has the advantage that the transmitting end can put data into the physical layer in time after knowing the size of the transport block, and the MAC subheaders are calculated in parallel when the data is transmitted to the physical layer, so that the scheduling processing can be accelerated, and the scheduling transmission delay can be reduced. The method comprises the following specific steps:

each third user plane entity MAC subheader is provided with third length indication information L, and the third length indication information is used for indicating the number of bytes between the third length indication information and the corresponding second user plane entity protocol data unit PDU.

The MAC subheader and MAC CE of the third user plane entity are located behind the transport block.

The third user plane entity protocol data unit comprises one or more second user plane entity protocol data units.

The header information of each second user plane entity protocol data unit comprises a second length indication information LI.

The value of the second length indication information is determined by whether the first segment participating in the cascade connection is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit. As shown in fig. 4, if the first user plane entity protocol data unit participating in the concatenation is a complete PDCP PDU, the second length indication information LI is 0, and if the first user plane entity protocol data unit participating in the concatenation is a complete PDCP PDU segment (e.g., a partial PDCP SDU), the second length indication information LI is the length of the PDCP SDU.

The header information of the second user plane entity protocol data unit further includes at least one of the following: data or control indication information D/C, sequence number SN, resegmentation indication information RF, status report feedback indication information P, segment indication information FI, segment offset indication information SO.

The D/C is used to indicate whether the protocol data unit of the second user plane entity is a control PDU or a data PDU, meaning similar to the LTE system.

The SN is used to indicate a sequence number corresponding to the second user plane entity protocol data unit, and the meaning is similar to that of the LTE system.

RF is used to indicate whether the second user plane entity protocol data unit is a complete PDU or a PDU segment.

P is used to indicate whether the peer needs to feed back the status report, and the meaning is similar to that of the LTE system.

FI is used to indicate whether the second user plane entity service data unit is segmented or not.

The SO (segment offset) is used to indicate the offset of the PDU and/or SDU of the second user plane entity with respect to the initial PDU and/or SDU, i.e. both the segmentation of the SDU of the second user plane entity and the re-segmentation of the PDU are indicated by the offset in SO.

The header information of each first user plane entity protocol data unit comprises a first length indication information L.

The first length indication information is located at the start position of the first user plane entity protocol data unit and is used for indicating the length of the first user plane entity protocol data unit. Thereby indicating the starting position of the immediately next first user plane entity protocol data unit.

Preferred embodiment 2

Fig. 9 is a schematic diagram of the RLC header, the MAC header, and the MAC CE behind the transport block according to the embodiment of the present invention, and as shown in fig. 9, the header information of the second user entity protocol data unit RLC PDU, the MAC subheader of the third user entity, and the MAC CE are all located behind the transport block, which has the advantage that the sending end can put data into the physical layer in time after knowing the size of the transport block, and the RLC header and the MAC subheader are calculated in parallel when the data is sent to the physical layer, so that the scheduling processing can be accelerated, and the scheduling transmission delay can be reduced. The method comprises the following specific steps:

each third user plane entity MAC subheader has third length indication information L, where the third length indication information is used to indicate the number of bytes between the third length indication information and the corresponding second user plane entity service data unit SDU.

The header information of the second user plane entity protocol data unit is located after the transport block.

The value of the second length indication information is determined by whether the first segment participating in the cascade connection is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit. As shown in fig. 6, if the first user plane entity protocol data unit participating in the concatenation is a complete PDCP PDU, the second length indication information LI is 0, and if the first user plane entity protocol data unit participating in the concatenation is a complete PDCP PDU segment (e.g., a partial PDCP SDU), the second length indication information LI is the length of the PDCP SDU.

RF is used to indicate whether the second user plane entity protocol data unit is a PDU or a PDU segment.

The SO is used to indicate the offset of the PDU and/or SDU of the second user plane entity with respect to the initial PDU and/or SDU, i.e. both the segmentation of the SDU of the second user plane entity and the re-segmentation of the PDU are indicated by the offset of the SO.

The first length indication information is located at a start position of the first user plane entity protocol data unit and is used for indicating the length of the first user plane entity protocol data unit. Thereby indicating the starting position of the immediately next first user plane entity protocol data unit.

Preferred embodiment 3

Fig. 10 is a first schematic diagram illustrating that there is no FI indication in the RLC header according to the embodiment of the present invention, and as shown in fig. 10, this preferred embodiment 3 is similar to the above preferred embodiment 1, except that there is no FI indication in the header information of the second user plane entity protocol data unit. The method comprises the following specific steps:

The value of the second length indication information is determined by whether the first segment participating in the cascade connection is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit. As shown in fig. 7, if the first user plane entity protocol data unit participating in the concatenation is a complete PDCP PDU, the second length indication information LI is 0, and if the first user plane entity protocol data unit participating in the concatenation is a complete PDCP PDU segment (e.g., a partial PDCP SDU), the second length indication information LI is the length of the PDCP SDU.

The header information of the second user plane entity protocol data unit further includes at least one of the following: data or control indication information D/C, sequence number SN, resegmentation indication information RF, status report feedback indication information P, segment offset indication information SO.

Preferred embodiment 4

Fig. 11 is a schematic diagram of no FI indication in the RLC header according to the embodiment of the present invention, and as shown in fig. 11, this preferred embodiment 4 is similar to the preferred embodiment 2, except that no FI indication is in header information of a second user plane entity protocol data unit. The method comprises the following specific steps:

each third user plane entity MAC sub-header is provided with third length indication information L, and the third length indication information is used for indicating the number of bytes between the third length indication information and the corresponding second user plane entity service data unit SDU.

Preferred embodiment 5

Fig. 12 is a schematic diagram of one PDCP PDU corresponding to one RLC PDU according to an embodiment of the present invention, and as shown in fig. 12, length indication information L only exists in a MAC subheader for indicating a length of each MAC SDU, and a Logical Channel Identity (LCID) is added in the MAC subheader for facilitating MAC demultiplexing. The advantage of this scheme lies in that the sending end once receives the authorization, just can be one by one send RLC PDU to the physical layer, and the PDU size that sends to whole physical layer equals the size of authorization, the pipelining of being convenient for reduces transmission delay, specifically as follows:

each first user plane entity and the second user plane entity maintain independent serial numbers, and the length of the protocol data unit of the second user plane entity is indicated through length indication information L in the MAC subheader of the third user plane entity.

The first user plane entity protocol data units correspond to the second user plane entity protocol data units one by one, namely the second user plane entity is used for cascading the protocol data units of the first user plane entity.

The MAC subheader of the third user plane entity is staggered and placed in front of each second user plane entity protocol data unit.

The MAC subheader of the third user plane protocol data unit at least includes a logical channel identifier LCID and length indication information L.

If the protocol data unit PDU or service data unit SDU of the last second user plane entity is segmented, adding segment offset indication information SO in the header information of the protocol data unit of the second user plane entity to indicate the offset of the segment.

The logical channel identification LCID is used to determine which logical channel the MAC SDU data is when the MAC is demultiplexed.

Through the above description of the embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but the former is a better implementation mode in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (such as a mobile phone, a computer, a server, or a network device) to execute the method according to the embodiments of the present invention.

Example 2

In this embodiment, a data sending device is further provided, and the data sending device is used to implement the foregoing embodiments and preferred embodiments, and the description of the data sending device is omitted. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 13 is a block diagram of a first data transmitting apparatus according to an embodiment of the present invention, and as shown in fig. 13, the first data transmitting apparatus includes: a first adding module 132 and a first sending module 134, which will be described below.

A first adding module 132, configured to add second length indication information in a second user plane entity protocol data unit, where the second length indication information is used to indicate whether a first segment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and when the second length indication information indicates the segment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the segment of the first user plane entity protocol data unit, where the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used to indicate a length of the first user plane entity protocol data unit; a first sending module 134, connected to the first adding module 132, configured to send the second user plane entity protocol data unit to which the second length indication information is added to a third user plane entity.

Optionally, the value of the second length indication information is used to identify a position of a first complete first user plane entity protocol data unit included in the second user plane entity protocol data unit.

Optionally, the step of using the value of the second length indication information to identify the position of the first complete first user plane entity protocol data unit included in the second user plane entity protocol data unit includes: when the value of the second length indication information is zero, the first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; under the condition that the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; and under the condition that the value of the second length indication information is a preset default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit.

Optionally, the first adding module 132 is further configured to add second length indication information in header information of the second user plane entity protocol data unit.

Fig. 14 is a block diagram of a second user plane entity according to an embodiment of the present invention, and as shown in fig. 14, the function of the second user plane entity 140 corresponds to an RLC function of a long term evolution LTE system and an enhanced RLC function of the RLC function, and the second user plane entity 140 includes the first data transmitting device 142.

Fig. 15 is a block diagram of a second data transmitting apparatus according to an embodiment of the present invention, and as shown in fig. 15, the apparatus includes: a second adding module 152 and a second sending module 154, which will be explained below.

A second adding module 152, configured to add third length indication information in a third user plane entity protocol data unit, where the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case that a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a next subheader of the third user plane entity, the second user plane entity protocol data unit carries the second length indication information, and the second length indication information is used to indicate whether a first slice participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a second user plane entity service data unit When the second length indication information indicates the segmentation of the first user plane entity protocol data unit, the value of the second length indication information is the length of the segmentation of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit; a second sending module 154, connected to the second adding module 152, for sending the third user plane entity protocol data unit added with the third length indication information to the physical layer.

Optionally, the second adding module 152 is further configured to add third length indication information in header information of a third user plane entity protocol data unit.

Fig. 16 is a block diagram of a third user plane entity according to an embodiment of the present invention, and as shown in fig. 16, the function of the third user plane entity 160 corresponds to a MAC function of a long term evolution LTE system and an enhanced MAC function of the third user plane entity, and the second data transmitting device 162 of the third user plane entity 160 is described above.

It should be noted that, the above modules may be implemented by software or hardware, and for the latter, the following may be implemented, but not limited to: the modules are all positioned in the same processor; alternatively, the modules are respectively located in different processors in any combination.

The embodiment of the invention also provides a storage medium. Alternatively, in the present embodiment, the storage medium may be configured to store program codes for performing the following steps:

s1, adding second length indication information in a second user plane entity protocol data unit, where the second length indication information is used to indicate whether a first segment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and when the second length indication information indicates the segment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the segment of the first user plane entity protocol data unit, and the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used to indicate a length of the first user plane entity protocol data unit;

and S2, sending the second user plane entity protocol data unit added with the second length indication information to a third user plane entity.

Optionally, the storage medium is further arranged to store program code for performing the steps of:

s1, the value of the second length indication information is used to identify the location of the first complete first user plane entity protocol data unit contained in the second user plane entity protocol data unit.

s1, the value of the second length indication information is used to identify a position of a first complete first user plane entity protocol data unit included in the second user plane entity protocol data unit, and the position includes: when the value of the second length indication information is zero, the first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; under the condition that the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; and under the condition that the value of the second length indication information is a preset default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit.

adding the second length indication information in the second user plane entity protocol data unit comprises:

s1, adding the second length indication information in the header information of the second user plane entity protocol data unit.

s1, the header information of the second user plane entity protocol data unit further includes at least one of the following information: a D/C indication for indicating whether the second user plane entity protocol data unit is a control protocol data unit or a data protocol control unit; a sequence number SN used for indicating a second user plane entity protocol data unit; a reassignment identity RF for indicating whether the second user plane entity protocol data unit is a complete protocol data unit or a segment of a protocol data unit; a polling P indication for indicating whether an opposite end receiving the second user plane entity protocol data unit needs to feed back a status report; a segment offset SO indication indicating an offset of a protocol data unit and/or a traffic data unit of the second user plane entity protocol data unit with respect to the initial protocol data unit and/or the initial traffic data unit.

s1, adding third length indicating information in a third user plane entity protocol data unit, where the third length indicating information is used to indicate the number of bytes between the third length indicating information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indicating information, or, in case that a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indicating information is used to indicate the number of bytes between the third length indicating information in the third user plane entity protocol data unit and a next third user plane entity subheader, the second user plane entity protocol data unit carries the second length indicating information, and the second length indicating information is used to indicate whether a first slice participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a first user plane entity protocol data unit When the second length indication information indicates the segment of the first user plane entity protocol data unit, the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the third user plane entity protocol data unit added with the third length indication information to the physical layer.

adding the third length indication information in the third user plane entity protocol data unit comprises:

s1, adding a third length indication information in the header information of the third user plane entity protocol data unit.

Optionally, in this embodiment, the storage medium may include, but is not limited to: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: adding second length indication information into a second user plane entity protocol data unit, wherein the second length indication information is used for indicating whether a first fragment participating in cascade connection in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a fragment of the first user plane entity protocol data unit, and under the condition that the second length indication information indicates the fragment of the first user plane entity protocol data unit, the value of the second length indication information is the length of the fragment of the first user plane entity protocol data unit, the first user plane entity protocol data unit carries first length indication information, and the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the second user plane entity protocol data unit added with the second length indication information to a third user plane entity.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: the value of the second length indication information is used for identifying the position of a first complete first user plane entity protocol data unit contained in a second user plane entity protocol data unit.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: the value of the second length indication information is used for identifying the position of a first complete first user plane entity protocol data unit contained in a second user plane entity protocol data unit, and the position comprises the following steps: when the value of the second length indication information is zero, the first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; under the condition that the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; and under the condition that the value of the second length indication information is a preset default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: adding the second length indication information in the second user plane entity protocol data unit comprises: and adding second length indication information in the header information of the second user plane entity protocol data unit.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: the header information of the second user plane entity protocol data unit further includes at least one of the following information: a D/C indication for indicating whether the second user plane entity protocol data unit is a control protocol data unit or a data protocol control unit; a sequence number SN used for indicating a second user plane entity protocol data unit; a reassignment identity RF for indicating whether the second user plane entity protocol data unit is a complete protocol data unit or a segment of a protocol data unit; a polling P indication for indicating whether an opposite end receiving the second user plane entity protocol data unit needs to feed back a status report; a segment offset SO indication indicating an offset of a protocol data unit and/or a traffic data unit of the second user plane entity protocol data unit with respect to the initial protocol data unit and/or the initial traffic data unit.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: adding third length indication information in a third user plane entity protocol data unit, wherein the third length indication information is used for indicating the number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in the case that a subheader of a third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used for indicating the number of bytes between the third length indication information in the third user plane entity protocol data unit and a next third user plane entity subheader, the second user plane entity protocol data unit carries the second length indication information, and the second length indication information is used for indicating whether a first slice participating in cascade connection in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a first user plane entity protocol data unit According to the segmentation of the unit, under the condition that the second length indication information indicates the segmentation of the first user plane entity protocol data unit, the value of the second length indication information is the length of the segmentation of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit; and sending the third user plane entity protocol data unit added with the third length indication information to the physical layer.

Optionally, in this embodiment, the processor executes, according to the program code stored in the storage medium: adding the third length indication information in the third user plane entity protocol data unit comprises: and adding third length indication information in the header information of the third user plane entity protocol data unit.

Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation manners, and this embodiment is not described herein again.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A data transmission method, comprising:

adding second length indication information in a second user plane entity protocol data unit, wherein the second length indication information is used to indicate whether a first fragment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and when the second length indication information indicates the segment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit carries first length indication information, the first length indication information is used to indicate a length of the first user plane entity protocol data unit, wherein, when the value of the second length indication information is zero, indicating that a first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; when the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; when the value of the second length indication information is a predetermined default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit;

and sending the second user plane entity protocol data unit added with the second length indication information to a third user plane entity.

2. The method of claim 1, wherein adding the second length indication information in the second user plane entity protocol data unit comprises:

and adding the second length indication information in the header information of the second user plane entity protocol data unit.

3. The method of claim 2, wherein the header information of the second user plane entity protocol data unit further comprises at least one of the following information:

a D/C indication for indicating whether the second user plane entity protocol data unit is a control protocol data unit or a data protocol control unit;

a sequence number, SN, for indicating the second user plane entity protocol data unit;

a reallocation identification RF for indicating whether the second user plane entity protocol data unit is a complete protocol data unit or a segment of a protocol data unit;

a polling P indication for indicating whether an opposite end receiving the second user plane entity protocol data unit needs to feed back a status report;

a segment offset SO indication indicating an offset of a protocol data unit and/or a traffic data unit of the second user plane entity protocol data unit with respect to an initial protocol data unit and/or an initial traffic data unit.

4. A data transmission method, comprising:

adding third length indication information to a third user plane entity protocol data unit, where the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case where a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate a number of bytes between the third length indication information and a next third user plane entity subheader in the third user plane entity protocol data unit, where the second user plane entity protocol data unit carries second length indication information used to indicate that a first slice participating in concatenation in the second user plane entity protocol data unit is a complete third slice A user plane entity protocol data unit or a segment of a first user plane entity protocol data unit, wherein the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit under the condition that the second length indication information indicates the segment of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit;

and sending the third user plane entity protocol data unit added with the third length indication information to a physical layer.

5. The method of claim 4, wherein adding the third length indication information in the third user plane entity protocol data unit comprises:

and adding the third length indication information in the header information of the third user plane entity protocol data unit.

6. A data transmission apparatus, comprising:

a first adding module, configured to add second length indication information in a second user plane entity protocol data unit, where the second length indication information is used to indicate whether a first segment participating in concatenation in the second user plane entity protocol data unit is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and when the second length indication information indicates the segment of the first user plane entity protocol data unit, a value of the second length indication information is a length of the segment of the first user plane entity protocol data unit, and the first user plane entity protocol data unit carries first length indication information, where the first length indication information is used to indicate a length of the first user plane entity protocol data unit, and where, when the value of the second length indication information is zero, indicating that a first user plane entity protocol data unit contained in the second user plane entity protocol data unit is complete; when the value of the second length indication information is the length x of the segment of the first user plane entity protocol data unit, the first user plane entity protocol data unit after the length x is represented to be complete; when the value of the second length indication information is a predetermined default value or is greater than the length of the second user plane entity protocol data unit, indicating that the second user plane entity protocol data unit does not contain a complete first user plane entity protocol data unit;

a first sending module, configured to send the second user plane entity protocol data unit to which the second length indication information is added to a third user plane entity.

7. The apparatus of claim 6, wherein a value of the second length indication information is used to identify a location of a first complete first user plane entity protocol data unit included in a second user plane entity protocol data unit.

8. The apparatus of claim 6,

the first adding module is further configured to add the second length indication information in header information of the second user plane entity protocol data unit.

9. A second user plane entity, wherein the functionality of the second user plane entity corresponds to the radio link control, RLC, functionality of the long term evolution, LTE, system and evolution enhancement functionality of the RLC functionality, and wherein the second user plane entity comprises the apparatus of any of claims 6 to 8.

10. A data transmission apparatus, comprising:

a second adding module, configured to add third length indication information in a third user plane entity protocol data unit, where the third length indication information is used to indicate a number of bytes between the third length indication information in the third user plane entity protocol data unit and a second user plane entity protocol data unit or a second user plane entity service data unit corresponding to the third length indication information, or, in a case that a subheader of the third user plane entity corresponds to a control unit of the third user plane entity, the third length indication information is used to indicate a number of bytes between the third length indication information and a next third user plane entity subheader in the third user plane entity protocol data unit, where the second user plane entity protocol data unit carries second length indication information, and the second length indication information is used to indicate a third length indication information that participates in cascade connection in the second user plane entity protocol data unit One fragment is a complete first user plane entity protocol data unit or a segment of the first user plane entity protocol data unit, and the value of the second length indication information is the length of the segment of the first user plane entity protocol data unit under the condition that the second length indication information indicates the segment of the first user plane entity protocol data unit; the first user plane entity protocol data unit carries first length indication information, wherein the first length indication information is used for indicating the length of the first user plane entity protocol data unit;

a second sending module, configured to send the third user plane entity protocol data unit to which the third length indication information is added to a physical layer.

11. The apparatus of claim 10,

the second adding module is further configured to add the third length indication information in header information of the third user plane entity protocol data unit.

12. A third user plane entity, wherein the functionality of the third user plane entity corresponds to a medium access control, MAC, functionality of a long term evolution, LTE, system and an evolution enhancement functionality of the MAC functionality, and wherein the third user plane entity comprises the apparatus of claim 10 or 11.

13. A user plane entity, comprising a first user plane entity, the second user plane entity of claim 9 and the third user plane entity of claim 12, wherein the function of the first user plane entity corresponds to a packet data convergence protocol PDCP function of a long term evolution LTE system and an evolution enhancement function of the PDCP function, the first user plane entity is configured to add first length indication information in a first user plane entity protocol data unit, and send the first user plane entity protocol data unit to which the first length indication information is added to the second user plane entity, wherein the first length indication information is used to indicate a length of the first user plane entity protocol data unit.