CN110708723A

CN110708723A - Data transmission method and device

Info

Publication number: CN110708723A
Application number: CN201910880977.XA
Authority: CN
Inventors: 周志伟; 石帅; 姜印清; 胡先专; 吴冬冬; 李哲
Original assignee: Huawei Device Co Ltd
Current assignee: Huawei Device Co Ltd
Priority date: 2019-09-18
Filing date: 2019-09-18
Publication date: 2020-01-17
Anticipated expiration: 2039-09-18
Also published as: CN110708723B

Abstract

The embodiment of the application provides a data transmission method and a device, wherein the data transmission method can determine the capacity of a first data packet mapped to a network layer by a data transmission block according to the capacity of the data transmission block transmitted last time by a physical layer; and comparing the capacity of the first data packet with the capacity of the maximum transmission unit preset by the network layer to determine the capacity of a plurality of unit data packets to be transmitted by the network layer. If it is detected that the physical layer has a data transmission block transmission failure, only the unit data packet corresponding to the data transmission block transmission failure may be retransmitted. The data transmission method can adjust the capacity of the unit data packet of the network layer according to the capacity of the data transmission block of the physical layer under the condition of poor wireless channel environment. When one or more data transmission blocks fail to transmit, the network layer only needs to retransmit the corresponding unit data packet, and the unit data packet which is successfully transmitted does not need to be retransmitted, which is beneficial to reducing network transmission overhead.

Description

Data transmission method and device

Technical Field

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

Background

When transmitting data service, if the service content is too long, the network layer may perform segmentation processing on an Internet Protocol (IP) data packet, so that the transmitted data does not exceed a Maximum Transmission Unit (MTU) that can be transmitted on the network layer. Correspondingly, other layers of communication, such as a Packet Data Convergence Protocol (PDCP) layer, a radio link control protocol (RLC) layer, etc., also process the transmitted data according to the capacity of the Service Data Unit (SDU) of each layer, and finally deliver the processed data to the physical layer to assemble into a Transport Block (TB) for transmission.

For a service with reliable transmission, one IP data packet may have N RLC PDUs corresponding to the RLC layer, and when any one of the N RLC PDUs fails to be transmitted, the whole IP data packet is triggered to be retransmitted, that is, the N RLC PDUs need to be retransmitted separately. The retransmission method also needs to retransmit the RLC PDU which is successfully transmitted, thereby increasing the network overhead and reducing the transmission efficiency. Then, how to reduce the overhead of data retransmission and improve the transmission efficiency becomes a problem to be solved.

Disclosure of Invention

The embodiment of the application provides a data transmission method and a device, wherein the data transmission method can determine the capacity of a first data packet mapped to a network layer by a data transmission block according to the capacity of the data transmission block transmitted last time by a physical layer; and comparing the capacity of the first data packet with the capacity of a maximum transmission unit preset by a network layer, determining a plurality of unit data packets to be transmitted by the network layer, and transmitting the data of the plurality of data packets. If it is detected that the physical layer has a data transmission block transmission failure, data retransmission can be performed only on the unit data packet with the transmission failure. The data transmission method can adjust the capacity of the data packet transmitted by the network layer according to the capacity of the data transmission block transmitted by the physical layer under the condition of poor wireless channel environment, so that when one or more data transmission blocks fail to transmit, the network layer only needs to retransmit the corresponding unit data packet, the unit data packet which is successfully transmitted does not need to be retransmitted, the network transmission overhead is favorably reduced, and the jitter of the transmission rate is reduced.

In a first aspect, an embodiment of the present application provides a data transmission method, which may be executed by a network device, where the network device determines, according to a capacity of a data transport block that is transmitted last time by a physical layer, a capacity of a first data packet that is mapped to a network layer by the data transport block; and comparing the capacity of the first data packet with the capacity of a maximum transmission unit preset by a network layer, determining that the smaller capacity is mapped to the capacity of the network layer as the capacity of a plurality of unit data packets to be transmitted by the network layer, and performing data transmission on the plurality of data packets. If it is detected that the physical layer has a data transmission block transmission failure, data retransmission can be performed only on the unit data packet with the transmission failure. The method can adjust the capacity of the data packet transmitted by the upper layer under the condition of poor wireless channel environment, so that when one or more data transmission blocks fail to transmit, the upper layer only needs to retransmit the corresponding unit data packet, and the unit data packet which is successfully transmitted does not need to be retransmitted, thereby being beneficial to reducing network transmission overhead and reducing the jitter of transmission rate.

In one possible design, the network device determines the capacity of the first packet to be the minimum capacity in a set of capacities of the first packet mapped to the network layer of the data transport block last transmitted by the physical layer; or, determining the capacity of the first data packet as an average value of all capacities in the capacity set; or, determining the capacity of the first data packet as a middle value of all the capacities in the capacity set. By adopting the design to carry out segmentation processing on the original data transmitted by the network layer, the capacity of the first data packet of the network layer can be more reasonable.

In one possible design, the plurality of unit packets includes N unit packets, the capacity of the 1 st to N-1 st unit packets is equal to the capacity of the first packet, and the capacity of the nth unit packet is smaller than or equal to the capacity of the first packet.

In a possible design, the network device obtains the transmission quality of the last data transmission of the physical layer, and if the transmission quality of the last data transmission does not meet a preset condition, the data transmission method may be adopted to perform segmentation processing on the original data transmitted by the network layer.

In a possible design, the transmission quality includes an error rate of physical layer transmission, and if the network device detects that the error rate of the last transmission of the physical layer is greater than a preset error rate threshold, the data transmission method of the first aspect may be used to perform segment processing on the original data transmitted by the network layer, which is beneficial to reducing network transmission overhead during data retransmission.

In a possible design, if a non-acknowledgement message sent by a receiving end of a data transport block is received, a network device determines that the data transport block fails to be transmitted, and retransmits a target data packet in a network layer, which has the same identifier as the data transport block that failed to be transmitted. The design can ensure that the network layer only retransmits the unit data packet corresponding to the data transmission block which fails to be transmitted by the physical layer, and the unit data packet which is successfully transmitted does not need to be retransmitted, thereby being beneficial to reducing the network transmission overhead.

In one possible design, the data transmission of each network layer includes transmitting a unit data packet of the network layer to a packet data convergence protocol layer to form a plurality of service data units of the packet data convergence protocol layer, wherein the plurality of service data units of the packet data convergence protocol layer are added with headers and processed to form a plurality of protocol data units of the packet data convergence protocol layer; transmitting a plurality of protocol data units of a packet data convergence protocol layer from the packet data convergence protocol layer to a wireless link control layer to form a plurality of service data units of the wireless link control layer, wherein the plurality of service data units of the wireless link control layer are added with headers and processed to form a plurality of protocol data units of the wireless link control layer; a plurality of protocol data units of a radio link control layer are transmitted to a medium access control layer from the radio link control layer to form a plurality of service data units of the medium access control layer, and the plurality of service data units of the medium access control layer are added with headers and processed to form a plurality of protocol data units of the medium access control layer; transmitting a plurality of protocol data units of a medium access control layer from the medium access control layer to a physical layer to form a plurality of data transmission blocks of the physical layer; and a plurality of data transmission blocks of the physical layer transmit the original data of the bearing network layer to a receiving end of the data.

In a second aspect, an embodiment of the present application provides a data transmission apparatus, where the apparatus has a function of implementing the data transmission method provided in the first aspect. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a third aspect, an embodiment of the present application provides a network device, which includes a processor and a memory; the memory is used for storing a computer program, and the processor executes the computer program stored in the memory to cause the network device to perform the method of the first aspect or any of the possible implementations of the first aspect.

In a fourth aspect, embodiments of the present application provide a readable storage medium, which includes a program or instructions, which when executed on a computer, causes the computer to perform the method of the first aspect or any one of the possible implementations of the first aspect.

The system-on-chip in the above aspect may be a system-on-chip (SOC), a baseband chip, and the like, where the baseband chip may include a processor, a channel encoder, a digital signal processor, a modem, an interface module, and the like.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a diagram illustrating a data segmentation scenario in the prior art;

fig. 2 is a schematic flow chart of a data retransmission method in the prior art;

fig. 3 is a schematic diagram of a communication system according to an embodiment of the present application;

fig. 4 is a schematic flowchart of a data transmission method according to an embodiment of the present application;

fig. 5 is a schematic view of a data segmentation scenario provided in an embodiment of the present application;

fig. 6 is a schematic view of a data retransmission scenario provided in an embodiment of the present application;

fig. 7 is a schematic flowchart of another data transmission method according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a data transmission device according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of another data transmission device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

The embodiment of the application can be applied to various types of communication systems, such as: long Term Evolution (LTE) systems, future fifth Generation (5th Generation, 5G) systems, such as new radio access technology (NR), and future communication systems, such as 6G systems; it may also be applied in future UE-centric (UE-centric) networks; the method can also be applied to a Vehicle-to-outside information exchange (V2X) system, a Vehicle networking over cellular technology (LTE Vehicle, LTE-V) system, a Vehicle-to-Vehicle communication (V2V) system, a Vehicle networking over cellular (IoV), a Machine Type Communication (MTC) system, a cellular-based internet of things (LTE machine-to-machine, LTE-M) system, an object-to-machine communication (M2M) system, an internet of things (IoT), and the like.

For evolved universal mobile telecommunications system terrestrial radio access network (E-UTRAN), the data flows of the layers of the E-UTRAN protocol layer as shown in fig. 1 are as follows:

original data is transmitted in an Internet Protocol (IP) layer, and when the data volume of the original data is large, a Transmission Control Protocol (TCP) layer may perform segmentation processing on the original data to obtain a plurality of IP packets. The capacity of an IP packet is determined by the capacity of a Maximum Transmission Unit (MTU) of a network layer, for example, for most networks using packet transmission, the value of MTU is typically 1500 bytes (byte). For a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Medium Access Control (MAC) layer, a Service Data Unit (SDU) is usually used to represent a data set of a user service transmitted by a certain layer, and after a header is added to the SDU and encryption processing is performed, a Protocol Data Unit (PDU) of the layer can be obtained. For example, the PDCP layer may compress headers of IP packets and add PDCP SDUs to the PDCP headers to form PDCP PDUs. After the processing is completed, the PDCP layer delivers the PDCP PDUs to the RLC layer as RLC PDUs. The physical layer generally uses a Transport Block (TB) to encapsulate received upper layer data, and then transmits the TB block to a corresponding data receiving end. If the TB block provided by the physical layer is smaller, as shown in fig. 1, the MAC layer may perform fragmentation processing on the MAC PDU according to the capacity indicated by the TB block, and then deliver the MAC PDU to the physical layer to assemble into the TB block, which is transmitted by the physical layer.

For reliably transmitted data, when an IP packet is lost, the lost IP packet needs to be retransmitted. If one IP data packet corresponds to multiple TB blocks in the physical layer, the multiple TB blocks need to be retransmitted independently. For example, in the flow diagram of data transmission shown in fig. 2, when the receiving end of the data confirms that the data is not correctly received, the MAC layer of the transmitting end of the data is notified to perform data retransmission. If the MAC layer data of the data sending end is successfully retransmitted, determining that the transmission of the corresponding IP data packet is finished; and if the retransmission of the MAC layer data at the data sending end fails, triggering the IP data packet corresponding to the network layer to retransmit. Optionally, when the receiving end of the data confirms that the data is not correctly received, the receiving end of the data may also notify the RLC layer of the transmitting end of the data to perform data retransmission. If the RLC layer data of the data sending end is successfully retransmitted, determining that the transmission of the corresponding IP data packet is finished; if the retransmission of the RLC layer data at the data sending end fails, the IP data packet corresponding to the network layer is triggered to be retransmitted. It can be understood that, if any one of the plurality of TB blocks corresponding to one IP data packet fails to be transmitted, which may trigger retransmission of the entire IP data packet, the TB block that has been successfully transmitted is also retransmitted, which may cause extra network resource overhead, decrease transmission efficiency, and increase jitter of transmission rate.

In order to solve the above problem, an embodiment of the present application provides a data transmission method, where a capacity of a first data packet mapped to a network layer by a data transport block may be determined according to a capacity of the data transport block that is transmitted last time by a physical layer; and comparing the capacity of the first data packet with the capacity of a maximum transmission unit preset by a network layer, determining a plurality of unit data packets to be transmitted by the network layer, and transmitting the data of the plurality of data packets. If it is detected that the physical layer has a data transmission block transmission failure, data retransmission can be performed only on the unit data packet with the transmission failure. The data transmission method can adjust the capacity of the data packet transmitted by the upper layer according to the capacity of the data transmission block transmitted by the physical layer under the condition of poor wireless channel environment, so that when one or more data transmission blocks fail to transmit, the upper layer only needs to retransmit the corresponding unit data packet, and the unit data packet which is successfully transmitted does not need to be retransmitted, thereby being beneficial to reducing network overhead and reducing the jitter of transmission rate.

The following describes embodiments of the present application in detail with reference to the drawings.

The data transmission method, the data transmission device, and the related apparatus provided in the embodiments of the present application may be applied to various communication systems, and for facilitating understanding of the embodiments of the present application, first, a communication system applicable to the embodiments of the present application is described by taking the communication system shown in fig. 3 as an example. As shown in fig. 3, the communication system 300 includes a network device 301 and a terminal device 302, wherein the network device 301 may be configured with a plurality of antennas, and the terminal device 302 may also be configured with a plurality of antennas; it should be understood that network device 301 or terminal device 302 may also include a number of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, etc.). When performing data transmission, the network device 301 correspondingly includes a network layer, a packet data convergence protocol layer, a radio link control layer, a medium access control layer, and a network layer according to a communication protocol, where transmission units of data carried by each layer are different, but data carried by each transmission unit is the same, and the carried data includes a part or all of original data of the network layer. For example, a unit data packet of the network layer may carry original data to be transmitted to the packet data convergence protocol layer, forming a service data unit of the packet data convergence protocol layer.

Among them, the network device 301 shown in fig. 3 may be used as a data transmitting end. The network device may be any device with a wireless transceiving function, which provides a wireless communication service for a terminal device in a coverage area, and may include but is not limited to: an evolved Node B (NodeB or eNB or e-NodeB, evolved Node B) in a Long Term Evolution (LTE) system, a base station (gnnodeb or gNB) or a transmission point (TRP) in a new radio access technology (NR) in a new radio access technology (new radio access technology), a base station of 3GPP subsequent evolution, an access Node in a WiFi system, a wireless relay Node, a wireless backhaul Node, and the like; wherein, the base station may be: macro base stations, micro base stations, pico base stations, small stations, relay stations, or balloon stations, etc. Multiple base stations may support the same technology network as mentioned above, or different technologies networks as mentioned above. The base station may contain one or more co-sited or non co-sited TRPs. The network device may also be a radio controller, a Central Unit (CU), and/or a Distributed Unit (DU) in a Cloud Radio Access Network (CRAN) scenario. The network device may also be a server, a wearable device, or a vehicle mounted device, etc. The following description will take a network device as an example of a base station. The multiple network devices may be base stations of the same type or different types. The base station may communicate with the terminal device, and may also communicate with the terminal device through the relay station. The terminal device may communicate with a plurality of base stations of different technologies, for example, the terminal device may communicate with a base station supporting an LTE network, may communicate with a base station supporting a 5G network, and may support dual connectivity with the base station of the LTE network and the base station of the 5G network.

Wherein, the terminal device 302 can be used as a receiving end of data. The terminal equipment can be equipment with a wireless transceiving function, can be deployed on land and comprises an indoor or outdoor, a handheld, a wearable or a vehicle-mounted terminal; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a vehicle-mounted terminal device, a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), a wearable terminal device, and the like. The embodiments of the present application do not limit the application scenarios. The terminal device may also be referred to as a User Equipment (UE), an access terminal device, a vehicle-mounted terminal, an industrial control terminal, a UE unit, a UE station, a mobile station, a remote terminal device, a mobile device, a UE terminal device, a wireless communication device, a UE agent, or a UE apparatus, etc. The terminals may also be fixed or mobile. The terminal device of the present application may also be an on-board module, an on-board component, an on-board chip, or an on-board unit built into the vehicle as one or more components or units, and the vehicle may implement the method of the present application through the built-in on-board module, on-board component, on-board chip, or on-board unit.

An embodiment of the present application provides a data transmission method, please refer to fig. 4, where the data transmission method may be executed by a network device, and specifically includes the following steps:

s401, according to the capacity of the data transmission block transmitted last time by the physical layer, determining the capacity of the first data packet mapped to the network layer by the data transmission block.

The capacity of a data transport block (TB block) transmitted by a physical layer is generally determined by values of a modulation and coding scheme index (MCS index) and a Physical Resource Block (PRB), wherein the MCS index and the number of scheduled PRBs are related to a channel environment, network traffic, a cell resource capacity, and the like. The capacity of the data transmission block in this embodiment is the capacity of the TB block. According to the protocol 36.213, the correspondence between the capacity of the TB block and the MCS index and the number of PRBs is shown in table 1.

Table 1: correspondence between capacity of TB block and MCS index and PRB number

Wherein, the MCSindex and the number of the scheduled PRBs can be determined according to the current channel environment, the network traffic, the cell resource capacity and other parameters, and then the corresponding capacity of the TB block is searched in table 1 according to the MCS index and the number of the PRBs. For example, when the MCS index is 9 and the number of PRBs is 8, the capacity of the corresponding TB block is 1256 bits (bit). It should be understood that the correspondence between the capacity of the TB block and the MCS index and the number of PRBs shown in table 1 is only a part of the content in the protocol 36.213, and the embodiment of the present application is not limited thereto.

When the radio channel environment is poor, the capacity of the TB blocks that the physical layer can schedule is small, for example, the capacity of the TB blocks may vary from several hundreds to several thousands of bits. Correspondingly, in the case that the capacity of the TB block is small, the data in one IP packet may need to be transmitted by a plurality of TB blocks. In order to enable one TB block to complete all data transmission in one IP packet, the capacity of the IP packet transmitted by the network layer may be dynamically adjusted according to the capacity of the TB block transmitted last time by the physical layer. Wherein, the last transmission of the physical layer can be the data transmission in the previous second or the previous ten seconds. In this embodiment, the capacity of the first packet in the network layer is used to indicate the capacity of the corresponding IP packet when the capacity of the TB block is mapped to the network layer. For example, the capacity of TB blocks transported by the physical layer is measured in bits, and the capacity of IP packets transported by the network layer is measured in bytes (bytes). If the capacity of the TB block transmitted last time by the physical layer is 1736 bits, the capacity of the first packet mapped to the network layer by the TB block is 217 byte.

The last transmission of the physical layer may include a plurality of TB blocks, and the capacities of the plurality of TB blocks may be different, so that the capacities of the plurality of TB blocks last transmitted by the physical layer may form a capacity set. Wherein the capacity of the network layer to which the minimum value of the set of capacities is mapped may be determined as the capacity of the first packet. For example, if the capacity set is {968bit, 1096bit, 1256bit, 1416bit, 1544bit, 1384bit, 1736bit }, it may be determined that the capacity of the first packet mapped to the network layer by the TB block is 121 byte. Wherein the average value in the set of capacities may be mapped to a capacity of the network layer to determine the capacity of the first packet. For example, if the capacity set is {968bit, 1096bit, 1256bit, 1416bit, 1544bit, 1384bit, 1736bit }, and the average value of the capacity set is 1344bit, it may be determined that the capacity of the first packet mapped to the network layer by the TB block is 168 byte. The capacity of the network layer may be determined as the capacity of the first packet by mapping an intermediate value of the capacity set to a capacity of the network layer, where the intermediate value of the capacity set is a capacity value at an intermediate position in the capacity set after the capacity set is sorted (processed in an ascending order or a descending order). For example, the capacity set is {968bit, 1096bit, 1256bit, 1416bit, 1544bit, 1384bit, 1736bit }, the capacity set may be sorted to obtain the sorted capacity set as {968bit, 1096bit, 1256bit, 1384bit, 1416bit, 1544bit, 1736bit }, and a median of the sorted set is 1384bit, so that it may be determined that the capacity of the first packet mapped to the network layer by the TB block is 173 byte.

Alternatively, when the capacity of the TB block transmitted last time by the physical layer is small, the capacity of the IP packet (the capacity of the first packet) mapped to the network layer is also small. Since the header overhead of the PDCP/RLC/MAC layers is about 10 bytes, if the capacity of the first packet of the network layer is too small, the header overhead may be increased. To ensure that the header overhead is not excessive when the size of the first packet at the network layer is small, a minimum threshold may be used to limit the size of the first packet. For example, the minimum threshold may be determined to be half the capacity of the MTU of the network layer. And when the capacity of the first data packet of the network layer is larger than the minimum threshold and smaller than the capacity of the MTU of the network layer, determining that the capacity of the first data packet is still the capacity of the IP data packet mapped to the network layer by the TB block transmitted last time by the physical layer. When the capacity of a first data packet of a network layer is smaller than or equal to the minimum threshold, replacing the capacity of the first data packet with the minimum threshold. When the capacity of a first data packet of a network layer is larger than the capacity of an MTU of the network layer, replacing the capacity of the first data packet with the capacity of the MTU of the network layer. It is understood that the minimum threshold may also be determined according to other methods, for example, the minimum threshold is determined to be one third of the capacity of the MTU of the network layer, and the embodiment is not limited.

S402, if the capacity of the first data packet is smaller than that of a second data packet, carrying out segmentation processing on a third data packet to be transmitted by a network layer according to the capacity of the first data packet to obtain a plurality of unit data packets, wherein the second data packet is a maximum transmission unit preset by the network layer.

And if the second data packet is the MTU preset by the network layer, the capacity of the second data packet is the capacity of the MTU preset by the network layer. The third data packet to be transmitted by the network layer comprises original data to be transmitted by the network layer. If the capacity of the first data packet is smaller than that of the second data packet, the original data to be transmitted by the network layer is segmented according to the capacity of the first data packet, so that one TB block of the physical layer correspondingly bears the data of one IP data packet of the network layer. The method comprises the steps of carrying out segmentation processing on original data to be transmitted of a network layer according to the capacity of a first data packet, namely dividing the original data to be transmitted of the network layer into a plurality of unit data packets according to the capacity of the first data packet, wherein the capacity of each unit data packet is smaller than or equal to the capacity of the first data packet. For example, the original data to be transmitted by the network layer is split into N unit data packets for transmission according to the capacity of the first data packet, where the capacity of the 1 st to N-1 st unit data packets is equal to the capacity of the first data packet, and the capacity of the nth unit data packet is less than or equal to the capacity of the first data packet. In a possible case, when the wireless channel environment becomes better, and the capacity of the first data packet may be larger than the capacity of the second data packet, the original data to be transmitted by the network layer may be segmented according to the capacity of the second data packet, so as to obtain a plurality of unit data packets. The method is adopted to carry out segmentation processing on the original data to be transmitted by the network layer, so that one TB block of the physical layer correspondingly bears the data of one IP data packet of the network layer. Wherein the capacity of each unit packet is less than or equal to the capacity of the second packet.

And S403, transmitting the plurality of unit data packets.

After segmenting original data to be transmitted by a network layer to a plurality of unit data packets according to the capacity of a first data packet for transmission, the plurality of unit data packets of the network layer are transmitted to a physical layer downwards layer by layer and are transmitted to a data receiving end through a TB block of the physical layer. As shown in fig. 5, transmitting a plurality of unit packets in each layer of the network side may include the following steps:

transmitting the plurality of unit data packets of the network layer to a packet data convergence protocol layer to form a plurality of service data units of the packet data convergence protocol layer;

transmitting the plurality of protocol data units of the grouped data convergence protocol layer from the grouped data convergence protocol layer to a wireless link control layer to form a plurality of service data units of the wireless link control layer, wherein the plurality of protocol data units of the grouped data convergence protocol layer are generated after the plurality of service data units of the grouped data convergence protocol layer are respectively added with a first head;

transmitting the plurality of protocol data units of the radio link control layer from the radio link control layer to a medium access control layer to form a plurality of service data units of the medium access control layer, wherein the plurality of protocol data units of the radio link control layer are generated by adding second headers to the plurality of service data units of the radio link control layer respectively;

transmitting the multiple protocol data units of the medium access control layer from the medium access control layer to a physical layer to form multiple data transmission blocks of the physical layer, wherein the multiple protocol data units of the medium access control layer are generated after third headers are respectively added to the multiple service data units of the medium access control layer;

and sending the plurality of data transmission blocks to a receiving end of the data.

When an IP data packet of an IP layer is transmitted to a PDCP layer, SDU of the PDCP layer is formed; adding a header to SDUs of the PDCP layer and performing corresponding processing (e.g., ciphering processing) may form PDUs of the PDCP layer. When the PDU of the PDCP layer is transferred to the RLC layer, the PDU of the PDCP layer may be used as an SDU of the RLC layer; adding a header to the SDU of the RLC layer and performing corresponding processing can form a PDU of the RLC. By analogy, as shown in fig. 5, a PDU of the RLC layer may be used as an SDU of the MAC layer, and a PDU of the MAC layer may be used as a TB block of the physical layer. The TB block will be sent by the sending end of the data to the receiving end of the data. It will be appreciated that for each IP data packet, SDU, PDU or TB block of each layer there is correspondingly an identification distinguishing the respective IP data packet, SDU, PDU or TB block. For example, after the IP packet 1 of the network layer is transferred to the PDCP layer, PDCP SDU1 and PDCP PDU1 correspond. The PDCP PDU1 transferred to the RLC layer corresponds to RLC SDU1 and RLC PDU 1. The RLC PDU1 transferred to the MAC layer corresponds to MAC SDU1 and MAC PDU 1. The MAC PDU1 transferred to the physical layer corresponds to PHY TB 1 as shown in fig. 5.

S404, if detecting that the physical layer has data transmission block transmission failure, then retransmitting data to a target unit data packet of the network layer, wherein the target unit data packet is at least one unit data packet determined according to the identification of the data transmission block transmission failure.

A sending end of the data (e.g., an access network base station) may send the multiple TB blocks to a receiving end of the data (e.g., a terminal device such as a mobile phone), where each TB block has an identifier. In one possible implementation, when the receiving end of the data successfully receives the TB block, an acknowledgement message (ACK) may be sent to the transmitting end of the data; when the receiving end of the data fails to receive the TB block (e.g., packet loss or TB block decoding failure), a non-acknowledgement message (NACK) may be transmitted to the transmitting end of the data. Each TB block corresponds to one ACK/NACK, for example, when the receiving end of the data successfully receives the PHY TB 1, the receiving end of the data may send ACK 1 to the transmitting end of the data. For another example, when the receiving end of the data fails to receive the PHY TB n, NACK n may be transmitted to the transmitting end of the data, where n is a positive integer greater than 1.

For reliable transmission, the sender of the data will perform data retransmission, which may be, for example, automatic repeat-request (ARQ) of the RLC layer or hybrid ARQ of the MAC layer. Among them, ARQ retransmission is one of the error correction protocols of the transport layer in the OSI model, including the stop-and-wait ARQ protocol and the continuous ARQ protocol, including error detection (error detection), positive acknowledgement (positive acknowledgement), time-out (retransmission after timeout) and negative acknowledgement followed by retransmission (negative acknowledgement and retransmission). HARQ retransmission is based on ARQ and introduces Forward Error Correction (FEC), which can be used to correct data errors during transmission, i.e. if the errors are within the error correction range of FEC, FEC corrects the errors, and if the errors are beyond the error correction range, retransmission is requested. The three standard HARQ protocols are the standby wait protocol (SAW), the back-off N-step protocol (GBN), and the selective repeat protocol (SR).

However, when the radio channel environment is poor, the ARQ of the RLC layer and/or the HARQ of the MAC layer may both fail to retransmit, and in order to achieve reliable transmission, retransmission of IP packets of the network layer will be triggered. In this embodiment, according to the description in S402, a TB block of the physical layer correspondingly carries data of an IP data packet of the network layer, and when the TB block of the physical layer at the data receiving end fails to receive or decode, only data retransmission needs to be performed on the target unit data packet of the network layer. Wherein, the target unit data packet of the network layer is at least one unit data packet determined according to the identification of the TB block with transmission failure. For example, the original data of the network layer is split into 3 IP packets for transmission, and if the transmitting end of the data receives NACK3 from the receiving end of the data, it is determined that the TB block that failed in transmission is PHY TB 3, as shown in fig. 6. And according to the NACK3 received by the physical layer, determining that the target unit data packet of the network layer is the IP data packet 3, only retransmitting the IP data packet 3 of the network layer, and not retransmitting other IP data packets 1 and 2 which are successfully transmitted, so that the transmission overhead of the network is favorably reduced.

The embodiment of the application provides a data transmission method, which can determine the capacity of a first data packet mapped to a network layer by a data transmission block according to the capacity of the data transmission block transmitted last time by a physical layer; and comparing the capacity of the first data packet with the capacity of a maximum transmission unit preset by a network layer, determining a plurality of unit data packets to be transmitted by the network layer, and transmitting the data of the plurality of data packets. If it is detected that the physical layer has a data transmission block transmission failure, data retransmission can be performed only on the unit data packet with the transmission failure. The data transmission method can adjust the capacity of the data packet transmitted by the network layer according to the capacity of the data transmission block transmitted by the physical layer under the condition of poor wireless channel environment, so that when one or more data transmission blocks fail to transmit, the network layer only needs to retransmit the corresponding unit data packet, and the unit data packet which is successfully transmitted does not need to be retransmitted, thereby being beneficial to reducing network overhead and reducing the jitter of transmission rate.

An embodiment of the present application provides another data transmission method, please refer to fig. 7, where the data transmission method may be executed by a network device, and specifically includes the following steps:

acquiring the transmission quality of the latest data transmission of a physical layer;

if the transmission quality of the last transmission of the physical layer meets a preset condition, carrying out segmentation processing on original data to be transmitted of the network layer according to the capacity of a preset maximum transmission unit of the network layer to obtain a plurality of unit data packets;

if the transmission quality of the last data transmission of the physical layer does not meet the preset condition, determining the capacity of a first data packet mapped to the network layer by the data transmission block according to the capacity of the last data transmission block of the physical layer; if the capacity of the first data packet is smaller than that of a second data packet, carrying out segmentation processing on a third data packet to be transmitted by a network layer according to the capacity of the first data packet to obtain a plurality of unit data packets, wherein the second data packet is a maximum transmission unit preset by the network layer;

transmitting the plurality of unit data packets;

if the physical layer is detected to have data transmission block transmission failure, data retransmission is carried out on a target unit data packet of the network layer, wherein the target unit data packet is at least one unit data packet determined according to the identification of the data transmission block with transmission failure.

The network device may determine the current wireless channel environment by obtaining the transmission quality of the last data transmission of the physical layer. The transmission quality of the physical layer can be measured by the error rate of the physical layer transmission, and when the error rate of the physical layer transmission is low or no error exists, the current wireless channel environment can be determined to be good, and the transmission quality is high. The obtaining of the transmission quality of the last data transmission of the physical layer may be obtaining an error rate of the last data transmission of the physical layer. The calculation formula of the bit error rate of the physical layer transmission is as follows:

and when the error rate of the transmission of the physical layer is smaller than a preset error rate threshold value, carrying out segmentation processing on the original data to be transmitted of the network layer according to the capacity of an MTU (maximum transmission unit) preset by the network layer to obtain a plurality of unit data packets. The segmentation method is consistent with the segmentation scheme in the prior art, and is not described herein again.

When the error rate transmitted by the physical layer is greater than a preset error rate threshold value, the network layer determines the capacity of the TB block according to the capacity of the TB block transmitted by the physical layer at the last time and maps the capacity of the TB block to the capacity of a first data packet of the network layer; and if the capacity of the first data packet is smaller than the preset maximum transmission unit capacity of the network layer, carrying out segmentation processing on the original data to be transmitted by the network layer according to the capacity of the first data packet to obtain a plurality of unit data packets. For the above steps of determining the capacity of the first data packet and performing segmentation processing on the original data to be transmitted by the network layer according to the capacity of the first data packet, please refer to S401 and S402 in the embodiment shown in fig. 4, which is not described herein again. It can be understood that after the original data to be transmitted by the network layer is segmented, a plurality of unit data packets can be transmitted; and if the physical layer is detected to have data transmission block transmission failure, retransmitting the target unit data packet of the network layer. The above steps of transmitting the plurality of unit data packets and retransmitting the target unit data packet with failed transmission refer to S403 and S404 in the embodiment shown in fig. 4, which are not described herein again.

The embodiment of the application provides a data transmission method, which firstly needs to judge the transmission quality (such as transmission error rate) of the latest transmission of a physical layer, and if the transmission error rate is smaller than a preset error rate threshold value, the original data to be transmitted of a network layer does not need to be divided into smaller IP data packets for data transmission or retransmission according to the size of a TB block of the latest transmission of the physical layer. If the error rate of transmission is greater than the preset error rate threshold, the original data to be transmitted in the network layer is processed in a segmented manner according to the method in the embodiment shown in fig. 4, and then data transmission or retransmission is performed, which is beneficial to reducing network overhead and reducing jitter of transmission rate.

An embodiment of the present application provides a data transmission device, as shown in fig. 8. The data transmission apparatus 800 may be configured to perform the data transmission method described in fig. 4 and 7, and the data transmission apparatus includes:

a processing module 801, configured to determine, according to a capacity of a data transport block that is transmitted last time by a physical layer, a capacity of a first data packet that is mapped to a network layer by the data transport block;

the processing module 801 is further configured to, if the capacity of the first data packet is smaller than the capacity of a second data packet, perform segmentation processing on a third data packet to be transmitted by a network layer according to the capacity of the first data packet to obtain a plurality of unit data packets, where the second data packet is a maximum transmission unit preset by the network layer;

a transmission module 802, configured to transmit the plurality of unit packets;

the transmission module 802 is further configured to perform data retransmission on a target unit data packet of the network layer if it is detected that there is a transmission failure of the data transmission block in the physical layer, where the target unit data packet is at least one unit data packet determined according to an identifier of the data transmission block with the transmission failure.

In one implementation, the processing module 801 may specifically be configured to:

acquiring a capacity set formed by the capacities of different data transmission blocks transmitted by a physical layer at the last time;

determining the capacity mapped to the network layer by the minimum capacity in the capacity set as the capacity of the first data packet; alternatively, the first and second electrodes may be,

determining the capacity mapped to the network layer by the average value of all the capacities in the capacity set as the capacity of the first data packet; alternatively, the first and second electrodes may be,

determining a target capacity in the capacity set as a capacity of the first data packet, where the target capacity is a capacity mapped to a network layer by a capacity located in a middle position in a sorted capacity set, and the sorted capacity set is obtained by sorting each capacity in the capacity set.

In one implementation, the plurality of unit packets includes N unit packets, the capacity of the 1 st to N-1 st unit packets is equal to the capacity of the first packet, and the capacity of the nth unit packet is smaller than or equal to the capacity of the first packet.

and if the transmission quality of the last data transmission of the physical layer does not meet the preset condition, executing the step of determining the capacity of the first data packet mapped to the network layer by the data transmission block according to the capacity of the last data transmission block transmitted by the physical layer.

acquiring the error rate of the latest transmission of the physical layer;

and if the error rate of the latest transmission of the physical layer is greater than a preset error rate threshold value, executing the step of determining the capacity of the first data packet mapped to the network layer by the data transmission block according to the capacity of the latest transmission data transmission block of the physical layer.

In one implementation, the transmission module 802 may be specifically configured to:

if a non-confirmation message sent by a receiving end of the received data, determining that the transmission of the data transmission block fails;

and retransmitting the target data packet with the same identification as the data transmission block with the transmission failure in the network layer.

The embodiment of the present application provides another data transmission apparatus, as shown in fig. 9. The data transmission apparatus 900 may include a processor 901 for performing the steps corresponding to the embodiments shown in fig. 4 and 7; the processing module 801 and the transmission module 802 shown in fig. 8 may be implemented by the processor 901. The processor 901 may include one or more processors, for example, the processor 901 may be one or more Central Processing Units (CPUs), Network Processors (NPs), hardware chips, or any combination thereof. In the case where the processor 901 is a single CPU, the CPU may be a single-core CPU or a multi-core CPU.

The data transmission apparatus 900 may also include a memory 902, the memory 902 for storing program code, etc. The memory 902 may include volatile memory (volatile memory), such as Random Access Memory (RAM); the memory 902 may also include a non-volatile memory (non-volatile memory), such as a read-only memory (ROM), a flash memory (flash memory), a Hard Disk Drive (HDD) or a solid-state drive (SSD); the memory 902 may also comprise a combination of the above-described types of memory.

The processor 901 and the memory 902 may be configured to implement the data transmission method described in fig. 4 and fig. 7, where the processor 901 is configured to determine, according to a capacity of a data transport block last transmitted by a physical layer, a capacity of a first data packet mapped to a network layer by the data transport block;

if the capacity of the first data packet is smaller than that of a second data packet, carrying out segmentation processing on a third data packet to be transmitted by a network layer according to the capacity of the first data packet to obtain a plurality of unit data packets, wherein the second data packet is a maximum transmission unit preset by the network layer;

transmitting the plurality of unit data packets;

In one implementation, the processor 901 may be specifically configured to:

acquiring the error rate of the latest transmission of the physical layer;

In one implementation, the processor 901 may be specifically configured to:

The apparatus in the above embodiments may be a network device, or may be a chip applied to a network device, or other combined devices and components having the functions of the network device.

The embodiment of the present application further provides a readable storage medium, which includes a program or an instruction, and when the program or the instruction is run on a computer, the program or the instruction causes the computer to execute the data transmission method executed by the data transmission device in the above method embodiment.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., Digital Video Disk (DVD)), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A method of data transmission, comprising:

determining the capacity of a first data packet mapped to a network layer by the data transmission block according to the capacity of the data transmission block transmitted last time by a physical layer;

transmitting the plurality of unit data packets;

2. The method of claim 1, wherein the determining the capacity of the first data packet mapped to the network layer according to the capacity of the data transport block last transmitted by the physical layer comprises:

3. The method according to claim 1, wherein the plurality of unit packets includes N unit packets, a capacity of the 1 st to N-1 st unit packets is equal to a capacity of the first packet, and a capacity of the nth unit packet is less than or equal to the capacity of the first packet.

4. The method of claim 1, wherein before determining the capacity of the first data packet mapped to the network layer according to the capacity of the data transport block last transmitted by the physical layer, the method further comprises:

5. The method of claim 4, wherein the transmission quality comprises a bit error rate of a physical layer transmission; before determining the capacity of the first data packet mapped to the network layer by the data transport block according to the capacity of the data transport block transmitted last time by the physical layer, the method further includes:

acquiring the error rate of the latest transmission of the physical layer;

6. The method of claim 1, wherein the retransmitting the target unit data packet of the network layer if it is detected that there is a data transport block transmission failure in the physical layer, comprises:

7. The method of claim 1, wherein said transmitting said plurality of unit packets comprises:

8. A data transmission apparatus, comprising:

the processing module is used for determining the capacity of a first data packet mapped to the network layer by the data transmission block according to the capacity of the data transmission block transmitted last time by the physical layer;

the processing module is further configured to, if the capacity of the first data packet is smaller than the capacity of a second data packet, perform segmented processing on a third data packet to be transmitted by a network layer according to the capacity of the first data packet to obtain a plurality of unit data packets, where the second data packet is a maximum transmission unit preset by the network layer;

a transmission module, configured to transmit the plurality of unit data packets;

the transmission module is further configured to perform data retransmission on a target unit data packet of the network layer if it is detected that there is a data transmission block transmission failure in the physical layer, where the target unit data packet is at least one unit data packet determined according to an identifier of the data transmission block transmission failure.

9. The apparatus according to claim 8, wherein the processing module, when determining, according to the capacity of the data transport block last transmitted by the physical layer, the capacity of the first data packet mapped to the data transport block in the network layer, is specifically configured to:

10. The apparatus of claim 8, wherein the plurality of unit packets comprises N unit packets, wherein the capacity of the 1 st to N-1 st unit packets is equal to the capacity of the first packet, and the capacity of the nth unit packet is less than or equal to the capacity of the first packet.

11. The apparatus of claim 8, wherein the processing module is further configured to:

12. The apparatus of claim 11, wherein the transmission quality comprises a bit error rate of a physical layer transmission; the processing module is further configured to:

acquiring the error rate of the latest transmission of the physical layer;

13. The apparatus of claim 8, wherein the transmission module, when detecting that there is a data transport block transmission failure in the physical layer, and performing data retransmission on a target unit data packet in the network layer, is specifically configured to:

14. The apparatus according to claim 8, wherein the transmission module, when transmitting the plurality of unit packets, is specifically configured to:

15. A readable storage medium, comprising a program or instructions for performing the method of any of claims 1 to 7 when the program or instructions are run on a computer.