CN111262660B - Data transmission method, equipment and system - Google Patents

Data transmission method, equipment and system Download PDF

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CN111262660B
CN111262660B CN201811459741.0A CN201811459741A CN111262660B CN 111262660 B CN111262660 B CN 111262660B CN 201811459741 A CN201811459741 A CN 201811459741A CN 111262660 B CN111262660 B CN 111262660B
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pdu
key
equal
receiving end
critical
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CN111262660A (en
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陈小冬
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H04L1/1621—Group acknowledgement, i.e. the acknowledgement message defining a range of identifiers, e.g. of sequence numbers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/02—Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/04—Error control

Abstract

The application discloses a data transmission method, equipment and a system, which relate to the field of communication technology application, wherein the method is applied to a sending end, and comprises the following steps: acquiring a Protocol Data Unit (PDU) to be sent, wherein the PDU comprises a Serial Number (SN); when the SN meets a marking condition, determining that the PDU is a key PDU, wherein the marking condition comprises: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2n1, p is the threshold of the total number of key PDUs, n is the size of the sequence number; after the key PDU is sent to a receiving end, whether the key PDU is received unsuccessfully is determined based on the received feedback information of the key PDU; and when the key PDU is determined to be failed to be received, retransmitting the key PDU to the receiving end. The method and the device can solve the problem that the data transmission reliability of the sending end and the receiving end is low in the current communication system. The application is used for data transmission.

Description

Data transmission method, equipment and system
Technical Field
The present application relates to the field of communication technology application, and in particular, to a data transmission method, device, and system.
Background
In a communication system, when a sending end performs Data transmission, Data to be transmitted is divided into a plurality of Protocol Data Units (PDUs), and then the PDUs are encrypted by a COUNT value (a concept proposed by the 3GPP standard) and sent to a receiving end, and the receiving end decrypts the received PDUs by the same COUNT value to obtain corresponding Data.
The COUNT value includes, among other things, a Hyper Frame Number (HFN) and a Sequence Number (SN). The sending end and the receiving end maintain HFN respectively, PDU transmitted between the sending end and the receiving end carries SN, and the sending end and the receiving end encrypt or decrypt the PDU through the locally maintained HFN and the SN carried in the PDU. The communication system is configured with SN size (SN size) in advance, and SN carried by the PDU satisfies the following conditions: SN is more than or equal to 0 and less than or equal to 2n-1, n is the sequence number size (i.e., SN size). SN of each PDU of the transmitting end is according to 0 to 2n-1, the SN reaching a maximum value of 2n1, then enter the next round 0 to 2n-1 configuration. Correspondingly, when the transmitting end transmits the PDU, the SN of the PDU reaches the SN maximum value of 2nAt-1, add 1 to the locally maintained HFN to update the HFN; the receiving end maintains local HFN according to the analyzed SN, and when the SN of the current received PDU is smaller than the SN of the previous adjacent PDU, the receiving end determines that the PDU contains the local HFNHas entered the next round 0 to 2n-configuration of 1, adding 1 to the locally maintained HFN to update the HFN. Under the condition that each PDU is not lost, the number of PDUs sent by the sending end and the number of PDUs received by the receiving end are the same, correspondingly, the SN of the PDU sent by the sending end is consistent with the SN of the PDU analyzed by the receiving end, and the HFNs respectively maintained by the sending end and the receiving end are consistent.
However, when the number of PDUs continuously lost exceeds the SN maximum value, the HFN maintained by the receiving end is not updated because the receiving end does not receive the corresponding PDU, which results in the HFN maintained by the receiving end and the transmitting end being inconsistent, resulting in the HFN desynchronization of the receiving end and the transmitting end, and the PDUs subsequently received by the receiving end cannot be decrypted and become illegal data, so the reliability of data transmission is low.
Disclosure of Invention
The application provides a data transmission method, equipment and a system, which can solve the problem that the data transmission reliability of a sending end and a receiving end is low in the existing communication system.
In a first aspect, a data transmission method is provided, which is applied to a sending end, and the method includes:
acquiring a Protocol Data Unit (PDU) to be sent, wherein the PDU comprises a Serial Number (SN);
when the SN meets a marking condition, determining that the PDU is a key PDU, wherein the marking condition comprises: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2n1, p is the threshold of the total number of key PDUs, n is the size of the sequence number;
after the key PDU is sent to a receiving end, whether the key PDU is received unsuccessfully is determined based on the received feedback information of the key PDU;
and when the key PDU is determined to be failed to be received, retransmitting the key PDU to the receiving end.
After the receiving end receives the key PDU, the receiving end acquires the SN in the key PDU under the current HFN of the sending end, and the receiving end can determine the current HFN based on the SN no matter whether the PDU is lost before the key PDU under the current HFN, so that the receiving end can decrypt the subsequent received PDU, and the reliability of data transmitted between the sending end and the receiving end is further improved. Therefore, the receiving end only needs to carry out normal decryption according to the current decryption rule, and the processing flow of the receiving end does not need to be improved.
Illustratively, the labeling conditions include: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is greater than or equal to 0 and less than or equal to p, and SN satisfies at least one of the following first condition, second condition, and third condition, each of which includes:
a first condition that SN is a multiple of a specified divisor and 0-2n-1；
Wherein the specified divisor is equal to 2n-kAnd k is more than or equal to 1 and less than n. The k value can be configured at the transmitting end in advance, and can be determined according to the reliability required to be achieved, and the k value is positively correlated with the transmission reliability.
The key PDU is determined through the first condition, at least two PDUs can be determined to be the key PDU under the current HFN, the probability of successful receiving of the key PDU is improved, and therefore the reliability of data transmission is improved. Furthermore, the PDU with the SN being the multiple of the designated divisor is determined as the key PDU, so that the key PDUs can be uniformly distributed under one HFN, and the success rate of the key PDUs transmitted to the receiving end is improved.
Under the second condition, the SN is a specified value N, and N is more than or equal to 0 and less than or equal to 2n-1；
In one HFN, there may be one or more designated values, the number of the designated values may be determined according to the required transmission reliability, and the more the designated values are, the more the key PDUs are, the higher the transmission reliability is.
Under the third condition, SN is a random number M, and M is more than or equal to 0 and less than or equal to 2n-1。
In one HFN, there may be one or more random numbers, the number of the random numbers may be determined according to the required transmission reliability, and the more random numbers, the more critical PDUs in one HFN, and correspondingly, the higher the transmission reliability. The random number may be generated using a specified random number generation algorithm.
In the conventional data transmission method, a sending end is provided with a waiting time threshold, and each PDU is released (i.e. discarded) when the sending waiting time exceeds the waiting time threshold. Thus, the method further comprises:
when acquiring a PDU to be sent, timing a sending waiting time length of the PDU;
when the sending waiting time of the PDU reaches a waiting time threshold and the PDU is the key PDU, restarting the sending waiting time timing, or canceling the sending waiting time timing;
when the PDU is a key PDU, the sending end may restart the waiting duration timing, or cancel the waiting duration timing, to ensure that the key PDU can continue to wait for sending, so that the RLC layer can send the key PDU in the subsequent process.
And when the sending waiting time of the PDU reaches a waiting time threshold and the PDU is not a key PDU, releasing the PDU.
Illustratively, the feedback information includes positive feedback information or negative feedback information, and the determining whether the critical PDU is failed to be received based on the received feedback information of the critical PDU includes:
determining that the critical PDU failed to receive when W consecutive negative feedback information for the critical PDU is received, W being an integer greater than 1.
After determining that the key PDU fails to be received, it may be detected whether the key PDU meets a retransmission condition, and if the key PDU meets the retransmission condition, retransmitting the key PDU to a receiving end, before retransmitting the key PDU to the receiving end, the method further includes:
detecting whether the key PDU meets a retransmission condition;
correspondingly, the retransmitting the critical PDU to the receiving end includes:
when the key PDU meets the retransmission condition, retransmitting the key PDU to the receiving end;
wherein the retransmission condition comprises at least one of:
a first condition that the number of retransmissions of the critical PDU is less than a specified threshold number of retransmissions;
a second condition, the critical PDU is in a retransmission capable period.
In general, the RLC layer of the receiving end is configured with a receiving time window, and each PDU needs to be received within a corresponding time window range; when the receiving end receives the PDU sent by the sending end outside the time window range, the receiving end can determine the PDU as an illegal PDU and discard the PDU.
Then, for the key PDU, it needs to be sent to the receiving end within the corresponding time window range of the receiving end, and at the sending end, the time window range corresponds to a retransmission time period, and when the key PDU is in the retransmission time period, it can be effectively sent.
Since the critical PDU is transmitted when the retransmission condition is not satisfied, on one hand, the probability of loss during transmission is high, and on the other hand, even if the receiving end receives the critical PDU, the receiving end will regard the critical PDU as an illegal PDU, after the detecting whether the critical PDU satisfies the retransmission condition, the method further includes:
releasing the critical PDU when the critical PDU does not satisfy the retransmission condition.
And releasing the key PDU which does not meet the retransmission condition, so that the key PDU can avoid occupying storage resources.
When the transmission mode is the UM mode, when the PDU reception fails, the receiving end fails to decrypt the subsequent received PDU, marks the PDU with failed decryption as an error and delivers the PDU to the upper layer, or directly discards and reports the PDU to the upper layer, thereby causing the PDU to be lost, and therefore, when the data transmission method is applied to the UM mode, before the PDU is determined to be a key PDU, the method further includes:
detecting whether the current transmission mode is a non-definite UM mode;
when the current transmission mode is an UM mode, determining the PDU as a key PDU.
In a second aspect, a data transmission device is provided, which is applied to a sending end, and the device may include at least one module, where the at least one module may be configured to implement the data transmission method in the first aspect.
In a third aspect, a data transmission device is provided, including:
a processor;
a memory for storing executable instructions of the processor;
wherein the processor, when executing the executable instructions, is capable of implementing the data transmission method of any of the first aspects.
In a fourth aspect, a computer-readable storage medium having instructions stored therein is provided, which may be a non-volatile computer-readable storage medium. When the instructions are run on a processing component, the processing component is caused to perform the data transmission method of any one of the first aspect.
In a fifth aspect, a data transmission system is provided, which includes: a sending device and a receiving device, wherein the sending device comprises the data transmission device of any one of the second aspect.
In a sixth aspect, a data transmission system is provided, comprising: a sending device and a receiving device, wherein the sending device comprises the data transmission device of the third aspect.
In a seventh aspect, a chip is provided, where the chip includes a programmable logic circuit and/or program instructions, and when the chip is operated, the chip is configured to implement the data transmission method according to any one of the first aspect.
In an eighth aspect, there is provided a computer program product having instructions stored therein, which when run on a computer, cause the computer to perform the data transmission method of any one of the first aspect.
The beneficial effects that technical scheme that this application provided brought can include at least:
according to the data transmission method, the data transmission equipment and the data transmission system, the sending end determines the PDU with the SN meeting the marking condition as the key PDU, after the sending end sends the key PDU to the receiving end, whether the key PDU is failed to be received or not is determined based on the received feedback information, when the key PDU is failed to be received, the sending end retransmits the key PDU to the receiving end, the probability that the key PDU is lost is reduced, the probability that the quantity of the continuously lost PDU exceeds the maximum value of the SN is reduced, the probability that the HFNs of the receiving end and the sending end are equal is improved, the accuracy of data transmitted between the sending end and the receiving end is further improved, and the interruption of transmission service is effectively reduced.
Drawings
Fig. 1 is a schematic structural diagram of a communication system according to an exemplary embodiment of the present application.
Fig. 2 is a schematic diagram of protocol layers of an LTE wireless communication system according to an exemplary embodiment of the present application.
Fig. 3 is a schematic diagram of a data transmission process according to an exemplary embodiment of the present application.
Fig. 4 is a schematic diagram of a procedure of data transmission in a PDCP layer according to an embodiment of the present application.
Fig. 5 is a flowchart of a data transmission method according to an embodiment of the present application.
Fig. 6 is a flowchart of another data transmission method according to an embodiment of the present application.
Fig. 7 is a block diagram of a data transmission device according to an embodiment of the present application.
Fig. 8 is a block diagram of another data transmission device according to an embodiment of the present application.
Fig. 9 is a block diagram of another data transmission device according to an embodiment of the present application.
Fig. 10 is a block diagram of another data transmission device according to an embodiment of the present application.
Fig. 11 is a schematic structural diagram of a data transmission device according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a communication system according to a data transmission method provided in an exemplary embodiment of the present application, where the communication system includes a core network 10, an access network 20, and a user equipment 30 (also referred to as a terminal device). The core network 10 includes a user plane core network device 101 and a control plane core network device 102, the access network 20 includes an access device 201, such as a base station or various transmission and reception points such as a wireless local area network access point, and the access network 20 provides an access service for the user device. The user equipment 30 is accessed to the communication system through the access network 10 and the core network 20, so as to obtain various service services, such as multimedia audio and video, movie download, and the like.
In the communication system shown in fig. 1, communication systems of different communication systems are connected to each other through a core network 10. The user equipment 30 and the access equipment 201 serving the user equipment communicate various data, such as control signaling or traffic data. The access network 20 is used for accessing user equipment into the communication system.
For example, the communication system may be a Long Term Evolution (LTE) wireless communication system, the LTE wireless communication system may be divided into a User plane and a control plane according to different data to be transmitted, where data carried by the User plane is application data of a User, for example, when the User surfs the internet through a mobile phone, browses content in a webpage or content of a chat, please refer to fig. 2, fig. 2 is a schematic diagram of a protocol layer of the LTE wireless communication system provided in an exemplary embodiment of the present application, where the protocol layer is applied to the User plane, the protocol layer includes multiple layers connecting User Equipment (UE) and an access device, and the multiple layers sequentially include, from bottom to top: a Physical (PHY) layer, a Media Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer, where each layer completes different Data processing, and a Data unit when Data is transmitted between peer layers is a PDU. A path between the UE and the access device is called a Radio Bearer (RB), the RB provides a quality of service for Data transmitted between the UE and the access device, and further, when the RB is used for carrying application Data of a user plane, the RB may be called a Data Radio Bearer (DRB).
The PDCP layer is configured to encrypt and decrypt data, add an SN to the data, and maintain an HFN, and when transmitting the data, the PDCP layer divides the data to be transmitted into data frames (frames), that is, PDUs in the PDCP layer are data frames; the RLC layer is used for realizing functions of segmented concatenation, sequential delivery, Automatic Repeat reQuest (ARQ) data transmission guarantee of data, and duplicate removal of a PDU transmitted repeatedly; the MAC layer is used to implement functions related to data processing and to perform a Hybrid Automatic Repeat reQuest (HARQ) operation when the receiving end does not receive the PDU; the PHY layer is used to implement channel coding, physical channel mapping, rate matching, power control, time-frequency synchronization, and radio measurement.
The RLC layer supports three transmission modes, which are: an Unacknowledged Mode (UM), a Transparent Mode (TM), and an Acknowledged Mode (AM), in which the RLC layer has no retransmission protocol when transmitting data, and when a transmitted PDU is lost, reports it directly to an upper layer of the communication network without retransmitting the lost PDU. In the AM mode, the RLC layer has a retransmission protocol, and can ensure ARQ data transmission, and when a transmitted PDU is lost or an error occurs, the RLC layer of the transmitting end may retransmit the PDU to the receiving end.
When the PDCP layer of the user plane transmits data, in order to ensure reliability of the data, data encryption and decryption need to be performed, that is, a sending end encrypts actually output data and sends the encrypted data to a receiving end, and the receiving end performs corresponding decryption on the received data to obtain actually transmitted data. For example, referring to fig. 3, fig. 3 is a schematic diagram of a data transmission process according to an exemplary embodiment of the present application, where a sending end uses an encryption KEY (KEY), a COUNT value, a BEARER identifier (BEARER), a DIRECTION (direct) and a KEY stream LENGTH (LENGTH) as input parameters of an encryption algorithm, inputs a specified encryption algorithm model, generates a KEY stream BLOCK (KEYSTREAM BLOCK), performs xor processing on the KEY stream BLOCK and a PLAINTEXT BLOCK (PLAINTEXT BLOCK), generates a CIPHERTEXT BLOCK (CIPHERTEXT BLOCK), and sends the CIPHERTEXT BLOCK to a receiving end. And the receiving end calculates a key stream block by using the same encryption key, the COUNT value, the bearing identifier, the key stream length, the specified encryption algorithm and the uplink and downlink directions corresponding to the receiving end as the transmitting end, and performs exclusive OR processing on the key stream block and the received ciphertext block to generate a plaintext block. The uplink and downlink directions are used for representing the data transmission direction and correspond to the encryption and decryption phases of the data. The uplink and downlink directions include: the method comprises the following steps that (1) in an uplink direction or a downlink direction, when the direction is the uplink direction, received data are represented, namely the data need to be decrypted; when the direction is a downlink direction, the data is represented and transmitted, that is, the data needs to be encrypted. For example, when a sending end sends data to a receiving end, the direction of the sending end is a downlink direction, the data to be sent is encrypted, and the direction of the receiving end is an uplink direction, and the received data is decrypted. For example, the specified Encryption Algorithm model may be an Evolved Packet System (EPS) Encryption Algorithm model, and fig. 2 illustrates an EPS Encryption Algorithm (EEA) model as an example.
The data transmission method provided in the embodiment of the present application may also be applied to other communication systems, for example, a 5G communication system, and in the 5G communication system, the hierarchy of the user plane may be simply modified based on the structure shown in fig. 2, which is not limited in this application.
In the embodiment of the present application, the receiving end and the transmitting end are relative terms, and both are one of the UE and the access device, respectively. For example, in the LTE system, the transmitting end is a UE and the receiving end is an Evolved Node B (eNB), or the transmitting end is an eNB and the receiving end is a UE. Of course, in other communication systems, the access device may also be a wireless local area network access point or a base station (Node B, NB), which is not limited in this embodiment of the present application.
For example, please refer to fig. 4, fig. 4 is a schematic diagram of data transmission provided in the embodiment of the present application, and the embodiment of the present application takes fig. 4 as an example to further explain a transmission process of data in a PDCP layer. When the PDCP layer transmits data, each data is divided into a plurality of PDUs for transmission, namely, a transmitting end transmits the PDCP PDUs to a receiving end, each RB of the PDCP layer of the transmitting end distributes a COUNT value for each PDU for encryption, and the RB of the receiving end uses the same COUNT value for decryption. The COUNT value includes HFN and SN, and for example, the COUNT value includes HFN of a higher bit and SN of a lower bit.
Each RB of the sending end and the receiving end maintains a corresponding COUNT value respectively, the sending end and the receiving end encrypt or decrypt the PDU through the HFN maintained locally and the SN carried in the PDU, and the sending end encrypts or decrypts the SN of each PDU to be sent according to 0-2n-1, the SN reaching a maximum value of 2n1, then enter the next round 0 to 2n-1 configuration. Correspondingly, when the sending end sends the PDU with SN to the receiving end, when the SN of the PDU reaches the SN maximum value 2 of RB configurationn-1, adding 1 to the locally maintained HFN to update the HFN. After receiving PDU, receiving end analyzes SN from PDU, when SN of current received PDU is less than SN of previous adjacent PDU, receiving end determines SN in PDU has entered next round 0-2n-SN configuration of 1, adding 1 to the locally maintained HFN to update the HFN. Correspondingly, when decrypting the received PDU, the receiving end analyzes the SN from the PDU, and forms a COUNT value together with the HFN maintained locally, and decrypts the received PDU through the COUNT value. Under the condition that each PDU is not lost, the number of PDUs sent by the sending end and the number of PDUs received by the receiving end are the same, correspondingly, the SN of the PDU sent by the sending end is consistent with the SN of the PDU analyzed by the receiving end, and the HFNs respectively maintained by the sending end and the receiving end are consistent.
As shown in FIG. 4, when the number of consecutive lost PDUs exceeds the SN max value of 2n1(n is the sequence number size), at least one round of 0 to 2 is missed because the transmitting end has updated HFN to HFN +1 and the receiving end has not received the corresponding PDUnSN configuration of-1, it is only possible to update the locally maintained HFN when a PDU is received again, which results in the HFN at the receiving end being smaller than that at the transmitting endAnd HFN, generating HFN desynchronization of the receiving side PDCP layer and the transmitting side PDCP layer. For example, if the HFN currently maintained at the transmitting end and the HFN locally maintained at the receiving end are both 1, and the sequence number size n is 5, the maximum value of SN is 251, that is, the maximum value of SN is 31, when the transmitting end transmits 34 consecutive PDUs to the receiving end, the SN of the 34 consecutive PDUs is SN 15, SN 16, SN 17 … SN 31, SN 0, SN 1, and SN 3 … SN 16, when the transmitting end transmits the PDU with SN 31 to the receiving end, the locally maintained HFN is updated from 1 to 2, and the PDU with SN 0 of the next round is transmitted to the receiving end, assuming that the receiving end receives the PDU with SN 15 which is transmitted when the transmitting end HFN 1, the next PDU received by the receiving end is the PDU with SN 16 which is transmitted when the transmitting end HFN 2, the next PDU received by the receiving end is the PDU with SN 15 which is received, since the currently received PDU is larger than the previous PDU, the next PDU is determined as the previous PDU 15, and the previous PDU 16, the next PDU is the same as the previous PDU of the previous round as the next PDU which is received when the receiving end 16 is determined as the previous PDU, therefore, the receiving end does not update the HFN maintained locally, that is, the HFN of the receiving end is still 1, so that the receiving end cannot decrypt the subsequently received PDU, and the PDU becomes illegal data, which is discarded by an upper layer in the communication system.
An embodiment of the present application provides a data transmission method, and if the method is applied to a sending end, please refer to fig. 5, where the method takes a PDU to be sent as an example for description, and a transmission method of another PDU may refer to a transmission method of the PDU to be sent, where the method may include the following steps:
step 501, acquiring a PDU to be sent, where the PDU includes an SN.
Referring to fig. 2, the process of obtaining the PDU to be sent in step 501 may be performed by the RLC layer of the sending end, as described above, the sending end sends the PDUs according to the sequence of SNs, and the RLC layer obtains the PDU to be sent, where the PDU to be sent includes a plurality of PDUs, each of which includes an SN, and the SNs are used to sequence the PDUs. In the RLC layer, the PDU is a data frame.
Step 502, when the SN satisfies the marking condition, determining the PDU as a key PDU.
Wherein the marking conditions include: under the current HFN (i.e. the same HFN that has not been updated recently), the total number m of existing critical PDUs satisfies: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2n1, p is the threshold value of the total number of key PDUs, and p ≦ 2nThe total number threshold may be configured at the sending end in advance, and may be determined according to the transmission reliability that needs to be achieved, where the total number threshold is positively correlated with the transmission reliability, that is, the greater the total number threshold is, the higher the transmission reliability is, n is a sequence number size, and the sequence number size may be 7, 12, 15, or 18.
For example, in the current HFN, when the total number of existing critical PDUs satisfies: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2nWhen the SN meets the marking condition, the PDU corresponding to the SN is a key PDU; under the current HFN, the total number of the existing key PDUs does not satisfy: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2nWhen-1, it can be determined that the SN does not satisfy the flag condition, then the PDU corresponding to the SN is not a critical PDU. For example, if m +1 is greater than P in the current HFN, the PDU corresponding to the SN is not a critical PDU.
Where m +1 refers to the assumption that under the current HFN, the current PDU is set as the critical PDU, plus the total number of existing critical PDUs needs to be guaranteed to be within the threshold of the total number of critical PDUs.
For example, assuming that the serial number size n is 7 and P is 10, the marking condition includes: under the current HFN, the total number m of the existing key PDUs satisfies: m +1 is more than or equal to 0 and less than or equal to 10, and SN is more than or equal to 0 and less than or equal to 127. If the total number of existing critical PDUs in the current HFN is 0, that is, m is 0, for example, when the PDU to be transmitted is obtained in step 501 as a PDU (SN is 0), it may be determined that the PDU is a critical PDU. If the total number of existing critical PDUs is 10 in the current HFN, that is, m is 10, when the PDU to be sent is obtained in step 501 as a PDU (SN is 0), since the value of m +1 is 11 at this time and the value is greater than the total number threshold P, it is determined that the PDU is not a critical PDU.
Step 503, after sending the key PDU to the receiving end, determining whether the key PDU fails to be received based on the feedback information of the received key PDU.
For example, the process of sending the key PDU to the receiving end in step 503 may be executed by the RLC layer of the sending end, after the RLC layer sends the key PDU to the receiving end, the receiving end sends a status report feedback to the sending end, where the status report feedback carries an Acknowledgement (ACK) to indicate that the key PDU is received, and when the key PDU is lost, the status report feedback carries a Negative Acknowledgement (NACK) to indicate that the key PDU is lost.
For example, after the RLC layer sends the key PDU to the receiving end, the receiving end may send the status report feedback to the sending end by sending HARQ feedback information to the sending end, and after the MAC layer of the sending end receives the HARQ feedback information sent by the receiving end, it may determine whether the key PDU is failed to be received based on the HARQ feedback information. The HARQ feedback information comprises positive feedback information and negative feedback information, wherein the positive feedback information can be represented by ACK (acknowledgement character), the negative feedback information can be represented by NACK (negative acknowledgement character), when a receiving end receives the key PDU (protocol data unit), the ACK can be sent to a sending end, and after an MAC (media access control) layer of the sending end receives the ACK sent by the receiving end, the key PDU is determined not to be failed to receive; when the receiving end does not receive the key PDU, NACK can be sent to the sending end, and after the MAC layer of the sending end receives the NACK sent by the receiving end, the receiving failure of the key PDU is determined.
Step 504, when the receiving of the key PDU is determined to fail, the key PDU is retransmitted to the receiving end.
For example, the procedure of retransmitting the critical PDU to the receiving end in step 504 may be performed by the RLC layer of the transmitting end, and after the MAC layer determines that the transmission of the critical PDU fails, the RLC layer may be notified to retransmit the critical PDU to the receiving end.
After the receiving end receives the key PDU, the receiving end acquires the SN in the key PDU under the current HFN of the sending end, and the receiving end can determine the current HFN based on the SN no matter whether the PDU is lost before the key PDU under the current HFN, so that the receiving end can decrypt the subsequent received PDU, and the reliability of data transmitted between the sending end and the receiving end is further improved. Therefore, the receiving end only needs to carry out normal decryption according to the current decryption rule, and the processing flow of the receiving end does not need to be improved.
For example, if the HFN currently maintained at the transmitting end and the HFN locally maintained at the receiving end are both 1, and the sequence number size n is 5, the maximum value of SN is 251, i.e., a maximum value of SN of 31, when the transmitting end transmits 34 consecutive PDUs to the receiving end, the SN of the 34 consecutive PDUs is SN 15, SN 16, SN 17 … SN 31, SN 0, SN 1, SN 3 … SN 16, when the transmitting end transmits PDU with SN being 31 to the receiving end, updating the HFN maintained locally from 1 to 2, and then transmitting PDU with SN being 0 in the next round to the receiving end, wherein, when HFN being 2, the PDU with SN being 5 is determined as a key PDU, even if all PDUs with SN 16 at HFN 1 to SN 4 at HFN 2 are lost, since the critical PDU is retransmitted, the probability that the receiving end receives the critical PDU is increased, and assuming that the receiving end can receive the critical PDU, the last received PDU is the PDU with HFN 1 SN 15, and if the SN in the key PDU received this time is 5 or less than 15, the receiving end directly updates the HFN maintained locally to 2. Out-of-sync after the critical PDU is avoided.
To sum up, in the data transmission method provided in this embodiment of the present application, the sending end determines the PDU whose SN meets the marking condition as the key PDU, and after the sending end sends the key PDU to the receiving end, it is determined whether the key PDU fails to be received based on the received feedback information, and when the key PDU fails to be received, the sending end retransmits the key PDU to the receiving end, so as to reduce the probability of losing the key PDU, and reduce the probability that the number of consecutive lost PDUs exceeds the maximum SN value, thereby improving the probability that HFNs of the receiving end and the sending end are equal, further improving the accuracy of data transmitted between the sending end and the receiving end, and effectively reducing the interruption of transmission service.
As described above, the RLC layer has three transmission modes, in the UM mode, when the PDU reception fails, the RLC layer of the receiving end fails to decrypt the subsequent received PDU, and then marks the PDU that fails to decrypt as an error, and submits the PDU to the upper layer, or directly discards and reports the PDU to the upper layer, thereby causing the PDU to be lost, and the application takes the application of the data transmission method in the UM mode of the RLC layer as an example for explanation, please refer to fig. 6, and the method may include the following steps:
step 601, the sending end obtains a PDU to be sent, where the PDU includes an SN.
In step 601, reference may be made to step 501 in the process of acquiring, by the sending end, the PDU to be sent, which is not described in detail in this embodiment of the present application.
Step 602, the sending end detects whether the current transmission mode is the UM mode. If the current transmission mode is the UM mode, go to step 603.
Step 603, the sending end detects whether the SN meets the marking condition, if the SN meets the marking condition, step 604 is executed, and if the SN does not meet the marking condition, the sending end determines that the PDU is not a key PDU. The step 601 may be executed again to continue to acquire a new PDU to be transmitted.
Step 604, when the SN meets the marking condition, the transmitting end determines that the PDU is a key PDU.
For example, the above-mentioned marking conditions may include: under the current HFN, the total number m of the existing key PDUs satisfies: m +1 is 0. ltoreq. p, and SN satisfies at least one of the following first condition, second condition, and third condition. The three conditions respectively include:
a first condition that SN is a multiple of a specified divisor and 0-2n-1。
The specified divisor is equal to 2n-kAnd k is more than or equal to 1 and less than n. The k value can be configured at the sending end in advance, and can be determined according to the transmission reliability required to be achieved, and the k value is positively correlated with the transmission reliability. Under one HFN, the number of key PDUs can be multiple, and the larger the k value is, the more key frames are under one HFN, and the higher the transmission reliability is.
For example, let n be 12 and k be 1, with a divisor of 211That is, the divisor is designated to be 2048, and when the SN corresponding to the PDU to be sent is a multiple of 2048, the sending end determines that the PDU to be sent is a key PDU; when the SN corresponding to the PDU to be transmitted is not a multiple of 2048, the PDU to be transmitted is not a critical PDU.
For example, if p is 4 and the sequence number size is 7, that is, n is 7, then SN is greater than or equal to 0 and less than or equal to 127, and the PDU that the transmitting end needs to transmit is: PDU (SN ═ 0), PDU (SN ═ 1), PDU (SN ═ 2), PDU (SN ═ 3) · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·PDU (SN 127). Assuming that k is 1, the divisor is designated 26That is, the divisor is designated to be 64, assuming that the total number of existing critical PDUs is 0 under the current HFN, that is, m is 0, when a PDU to be sent by the sending end is a PDU (SN is 0), determining that the PDU is a critical PDU; when the PDU to be sent by the sending end is PDU (SN ═ 2), the PDU is not a critical PDU. Assuming that the total number of existing critical PDUs is 4, that is, m is 4, under the current HFN, when the PDU to be sent by the sending end is a PDU (SN is 64), since the total number m of existing critical PDUs is 4 and the value of m +1 is 5, the value is greater than the total threshold P, the PDU is not a critical PDU.
The key PDU is determined through the first condition, at least two PDUs can be determined to be the key PDU under the current HFN, the probability of successful receiving of the key PDU is improved, and therefore the reliability of data transmission is improved. Furthermore, the PDU with the SN being the multiple of the designated divisor is determined as the key PDU, so that the key PDUs can be uniformly distributed under one HFN, and the success rate of the key PDUs transmitted to the receiving end is improved. For example, when k is 1, the key PDUs are PDU (SN is 0) and PDU (SN is 2)n-1) The two are respectively positioned at the front end and the middle part of the PDU to be transmitted under one HFN, and are distributed more uniformly.
A second condition that SN is a specified value N, N is greater than or equal to 0 and less than or equal to 2n-1。
In one HFN, there may be one or more designated values, the number of the designated values may be determined according to the required transmission reliability, and the more the designated values are, the more the key PDUs are, the higher the transmission reliability is.
It should be noted that, when there are a plurality of designated values, the difference between every two of the plurality of designated values may be greater than the preset difference, so as to ensure that the plurality of designated values are relatively dispersed under one HFN, and improve the success rate of the key PDU sent to the receiving end.
For example, the plurality of specified values may be arranged in an arithmetic or geometric series. For example, assume 2nIf-1 is 127, the specified values may be 5, 55 and 105, and if the PDU to be transmitted is PDU (SN ═ 5), it may be determined to be a critical PDU。
The third condition is that SN is a random number M, and M is more than or equal to 0 and less than or equal to 2n-1。
In one HFN, there may be one or more random numbers, the number of the random numbers may be determined according to the required transmission reliability, and the more random numbers, the more critical PDUs in one HFN, and correspondingly, the higher the transmission reliability. The random number may be generated using a specified random number generation algorithm.
When there are a plurality of random numbers, the plurality of random numbers may be 0 to 2n-1, the difference between each two can be larger than a specified difference threshold, so as to ensure that multiple random numbers are more dispersed in one HFN, thereby increasing the success rate of the key PDU sent to the receiving end.
By way of example, assume 2nIf-1 is 127 and the generated random numbers are 0 and 100, then if the PDU to be transmitted is a PDU (SN ═ 0), it can be determined to be a critical PDU.
It should be noted that the three conditions may be executed separately, or may be combined according to an actual situation, and the three conditions are only schematic illustrations, and this is not limited in this application, as long as it is ensured that at least one critical PDU is sent to the receiving end under one HFN.
Step 605, the transmitting end transmits the key PDU to the receiving end.
For example, the procedure of the transmitting end transmitting the critical PDU to the receiving end in step 605 may be performed by an RLC layer of the transmitting end, and the RLC layer transmits the critical PDU to the receiving end according to an RLC layer protocol.
Step 606, the receiving end sends the feedback information of the key PDU to the sending end.
The feedback information includes positive feedback information or negative feedback information, please refer to step 503 above, the positive feedback information may be represented by ACK, the negative feedback information may be represented by NACK, and when the receiving end receives the key PDU, ACK may be sent to the sending end; when the receiving end does not receive the key PDU, NACK may be sent to the transmitting end.
Step 607, the transmitting end determines whether the key PDU is received unsuccessfully based on the feedback information of the received key PDU. The transmitting end performs step 608 when determining that the key PDU fails to be received, and performs step 601 when determining that the key PDU fails to be received.
For example, when the transmitting end receives W consecutive pieces of negative feedback information for the key PDU, it may be determined that the key PDU reception fails; when the transmitting end does not receive W consecutive negative feedback information for the critical PDU, it may be determined that the critical PDU has not failed to be received (i.e., is successfully received). Where W is an integer greater than 1, for example, W may be 4, 5, or 6.
Please refer to step 503 above, ACK may be used to represent positive feedback information, NACK may be used to represent negative feedback information, in step 607, the process of determining whether the key PDU fails to be received may be executed by the MAC layer of the sending end based on the feedback information of the received key PDU, when the MAC layer receives NACK for the key PDU, the MAC layer retransmits the key PDU to the receiving end, and when the MAC layer receives W consecutive negative feedback information for the key PDU, the MAC layer determines that the key PDU fails to be received, and notifies the RLC layer that the key PDU fails to be received; when the MAC layer does not receive W consecutive NACKs for a key PDU, the MAC layer determines that the key PDU has not failed to be received, for example, after the MAC layer receives a NACK for the key PDU, the MAC layer retransmits the key PDU to the receiving end and receives an ACK for the key PDU, and then determines that the key PDU has not failed to be received.
For example, assume that the critical PDU determined by step 604 is: PDU (SN ═ 5), W is 4, when the MAC layer receives consecutive 4 NACKs for PDU (SN ═ 5), the MAC layer determines that PDU (SN ═ 5) reception failed and notifies the RLC layer that PDU (SN ═ 5) reception failed; when the MAC layer does not receive 4 consecutive NACKs for the PDU (SN ═ 5), the MAC layer determines that the PDU (SN ═ 5) has not failed to receive, for example, after the MAC layer receives 3 consecutive NACKs for the PDU (SN ═ 5), an ACK for the PDU (SN ═ 5) is received, and at this time, determines that the PDU (SN ═ 5) has not failed to receive.
Step 608, when the sending end determines that the key PDU fails to be received, it detects whether the key PDU meets the retransmission condition. Step 609 or step 610 is performed.
For example, the process of detecting whether the critical PDU satisfies the retransmission condition in this step 608 may be performed by the RLC layer.
Wherein the retransmission condition includes at least one of:
in a first condition, the number of retransmissions of the critical PDU is less than a specified threshold number of retransmissions.
For example, the upper retransmission limit of the key PDU may be set to a specified number threshold, and when the number of retransmission times of the key PDU is smaller than the specified number threshold, the RLC layer may resend the key PDU to the receiving end; and when the retransmission times of the key PDU are not less than the specified time threshold value, the RLC layer does not resend the key PDU to the receiving end.
The second condition, critical PDUs are in a retransmission-capable period.
When a sending end and a receiving end transmit data on an RLC layer, when the PDU is failed to be received, the receiving end waits for the RLC layer of the sending end to retransmit the lost PDU, however, even if the PDU is sent out, the PDU is possibly failed after the receiving end receives the PDU, so that the waiting time cannot be too long, under a normal condition, the RLC layer of the receiving end is configured with a receiving time window, and each PDU is required to be received in a corresponding time window range; when the receiving end receives the PDU sent by the sending end outside the time window range, the receiving end can determine the PDU as an illegal PDU and discard the PDU.
Then, for the key PDU, it needs to be sent to the receiving end within the corresponding time window range of the receiving end, and at the sending end, the time window range corresponds to a retransmission time period, and when the key PDU is in the retransmission time period, it can be effectively sent.
Step 609, when the key PDU does not meet the retransmission condition, the transmitting end releases the key PDU.
Because the key PDU is not satisfied with the retransmission condition, even if it is sent, on one hand, the probability of loss during transmission is high, and on the other hand, even if the receiving end receives the key PDU, it will be regarded as an illegal PDU, so it is not necessary to send it out, and in order to avoid the occupation of the storage resource by the key PDU, it can be released.
And step 610, when the key PDU meets the retransmission condition, the transmitting end retransmits the key PDU to the receiving end.
As an example, when the critical PDU satisfies the retransmission condition in this step 610, the process of retransmitting the critical PDU to the receiving end may be performed by the RLC layer of the transmitting end, when the critical PDU meets the retransmission condition, after the RLC layer transmits the critical PDU to the receiving end, the above steps 606 to 609 may be performed again, that is, after the RLC layer retransmits the key PDU to the receiving end, the receiving end transmits the feedback information of the key PDU to the transmitting end, at this time, referring to step 607, the MAC layer of the transmitting end receives the feedback information, when the feedback information is NACK, the MAC layer retransmits the key PDU to the receiving end, when the MAC layer continuously transmits W times of key PDUs to the receiving end, after receiving the NACK for the critical PDU as it is, i.e. the MAC layer receives W consecutive NACKs for the critical PDU, the RLC layer is informed to retransmit the critical PDU, when the key PDU meets the retransmission condition, the RLC layer retransmits the key PDU to the receiving end again.
The process of retransmitting the key PDU may refer to step 504, which is not described in detail herein.
It should be noted that, in the conventional data transmission method, a waiting duration threshold is set at a sending end, and each PDU is released (that is, discarded) when a sending waiting duration exceeds the waiting duration threshold. Therefore, the data transmission method of the embodiment of the present application may further include:
and step X1, when the sending end obtains the PDU to be sent, the sending waiting time length of the PDU is timed.
The step X1 may be executed by the PDCP layer of the sending end, where the PDCP layer performs timing on a sending waiting duration of a PDU when obtaining the PDU to be sent, where the timing may be implemented by a software program or a hardware timer. This step X1 may be performed after step 601 described above.
And step X2, when the transmission waiting time of the PDU reaches the waiting time threshold and the PDU is a key PDU, the transmitting end restarts the timing of the transmission waiting time or cancels the timing of the transmission waiting time.
The step X2 may be performed by the PDCP layer of the sending end, where for the PDU to be sent of each PDCP layer, the sending wait duration refers to a duration that the PDU of the PDCP layer waits for the RLC layer to send, and if a PDU is sent by the RLC layer, the waiting duration is timed out; if a PDU is not sent by the RLC layer within the waiting duration threshold, that is, the sending waiting duration of the PDU reaches the waiting duration threshold, at this time, the PDCP layer may detect whether the PDU is a key PDU, the detection process may be performed after step 603, and based on the detection result of step 603, it may be determined whether the PDU is a key PDU, which is not described herein again.
When the PDU is a key PDU, the sending end may restart the sending wait time timing, or cancel the sending wait time timing, to ensure that the key PDU can continue to be sent and wait, so that the RLC layer can send the key PDU in the subsequent process.
It should be noted that, in order to ensure the effective transmission of the key PDU, the transmitting end may also cancel the transmission waiting duration timing mechanism of the key PDU, that is, after determining that the PDU is the key PDU, cancel the timing of the transmission waiting duration of the key PDU before cancellation.
It should be further noted that the PDCP layer may determine whether a PDU is transmitted within the transmission waiting time by actively querying the RLC layer or reporting by the RLC layer.
And step X3, when the transmission waiting time of the PDU reaches the waiting time threshold and the PDU is not a key PDU, the transmitting end releases the PDU.
The step X3 may be executed by the PDCP layer of the transmitting end, and referring to step X2, when the transmission waiting duration of the PDU reaches the waiting duration threshold and the PDU is not a critical PDU, the PDCP layer may control the PDU to be released.
To sum up, in the data transmission method provided in this embodiment of the present application, when the current transmission mode is the UM mode, the sending end determines the PDU with SN meeting the marking condition as the key PDU, sends the key PDU to the receiving end, and determines whether the key PDU fails to be received based on the received feedback information, when the key PDU fails to be received, and when the key PDU meets the retransmission condition, the sending end retransmits the key PDU to the receiving end, so as to reduce the probability of the key PDU being lost, and reduce the probability that the number of consecutive lost PDUs exceeds the maximum SN value, thereby making HFNs of the receiving end and the sending end equal in the UM mode, further improving the accuracy of data transmitted between the sending end and the receiving end, and effectively reducing the interruption of transmission service.
It should be noted that the execution subject of each step is determined only according to the function of each layer, and in actual implementation, the execution subject of each step may be selected, which is not limited in the embodiment of the present application.
The sequence of the data transmission method provided in this embodiment of the present application may be appropriately adjusted, and the steps may also be increased or decreased according to the circumstances, for example, the sequence of step 609 and step 610 may be interchanged, and step 602 may be deleted, and any method that can be easily changed by those skilled in the art within the technical scope disclosed in this application should be covered in the protection scope of this application, and therefore, will not be described again.
An embodiment of the present application provides a data transmission device, which is applied to a sending end, please refer to fig. 7, where fig. 7 is a block diagram of the data transmission device provided in the embodiment of the present application, and the data transmission device 700 includes:
an obtaining module 701, configured to obtain a PDU to be sent, where the PDU includes an SN.
A first determining module 702, configured to determine that the PDU is a critical PDU when the SN satisfies a marking condition, where the marking condition includes: under the current HFN, the total number m of the existing key PDUs satisfies: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2n-1, p is the threshold for the total number of critical PDUs and n is the sequence number size.
A second determining module 703 is configured to determine whether the key PDU fails to be received based on the feedback information of the received key PDU after the key PDU is sent to the receiving end.
A retransmission module 704, configured to retransmit the critical PDU to the receiving end when it is determined that the critical PDU fails to be received.
To sum up, the data transmission device provided by the embodiment of the application, the sending end determines the PDU with SN meeting the mark condition as the key PDU through the first determining module, after the sending end sends the key PDU to the receiving end through the second determining module, and determines whether the key PDU fails to be received based on the received feedback information, when the key PDU fails to be received, the sending end retransmits the key PDU to the receiving end through the retransmission module, so as to reduce the probability that the key PDU is lost, and reduce the probability that the number of consecutive lost PDUs exceeds the maximum value of SN, thereby improving the probability that HFN of the receiving end and the sending end is equal, further improving the accuracy of data transmitted between the sending end and the receiving end, and effectively reducing the interruption of transmission service.
For example, the above-mentioned marking conditions include: under the current HFN, the total number m of the existing key PDUs satisfies: m +1 is not less than 0 and not more than p, and SN satisfies at least one of the following conditions:
SN is a multiple of a designated divisor, and SN is more than or equal to 0 and less than or equal to 2n-1. The specified divisor is equal to 2n-k，1≤k＜n。
SN is a designated numerical value N, N is more than or equal to 0 and less than or equal to 2n-1。
SN is a random number M, M is more than or equal to 0 and less than or equal to 2n-1。
Optionally, please refer to fig. 8, fig. 8 is a block diagram of another data transmission device provided in the embodiment of the present application, where the data transmission device 700 further includes:
the timing module 705 is configured to time a transmission waiting duration for the PDU when the PDU to be transmitted is acquired.
A cancellation module 706, configured to restart timing of the sending wait duration or cancel the timing of the sending wait duration when the sending wait duration of the PDU reaches the wait duration threshold and the PDU is a key PDU.
A first releasing module 707, configured to release the PDU when the transmission waiting duration of the PDU reaches the waiting duration threshold and the PDU is not a critical PDU.
Optionally, if the feedback information includes positive feedback information or negative feedback information, the second determining module 703 is configured to:
determining that the reception of the key PDU fails when W consecutive negative feedback information for the key PDU is received, wherein W is an integer greater than 1.
Optionally, referring to fig. 9, fig. 9 is a block diagram of another data transmission device provided in the embodiment of the present application, where the data transmission device further includes:
a first detecting module 708, configured to detect whether the critical PDU meets a retransmission condition before the retransmitting module 704 retransmits the critical PDU to the receiving end.
Optionally, the retransmission module 704 is configured to:
and when the key PDU meets the retransmission condition, retransmitting the key PDU to the receiving end.
Wherein the retransmission condition includes at least one of:
the retransmission times of the key PDUs are less than a specified time threshold.
The critical PDUs are in a retransmission-capable period.
As shown in fig. 9, the data transmission device further includes:
a second releasing module 709, configured to release the key PDU when the key PDU does not satisfy the retransmission condition after the first detecting module 708 detects whether the key PDU satisfies the retransmission condition.
Optionally, referring to fig. 10, fig. 10 is a block diagram of another data transmission device provided in the embodiment of the present application, where the data transmission device 700 further includes:
a second detecting module 710, configured to detect whether the current transmission mode is the UM mode before the first determining module 702 determines that the PDU is the critical PDU.
Optionally, the first determining module 702 is configured to determine that the PDU is a key PDU when the current transmission mode is the UM mode.
To sum up, in the data transmission device provided in the embodiment of the present application, when the sending end detects that the current transmission mode is the UM mode through the second detection module, determining the PDU with SN meeting the marking condition as a key PDU through a first determining module, transmitting the key PDU to a receiving end through a second determining module, and determines whether the key PDU failed to be received based on the received feedback information, and, when the key PDU failed to be received, when the first detection module detects that the key PDU meets the retransmission condition, the transmitting end retransmits the key PDU to the receiving end through the retransmission module, so as to reduce the probability of losing the key PDU, reduce the probability that the number of the continuously lost PDUs exceeds the maximum SN value, therefore, in the UM mode, the HFNs of the receiving end and the sending end are equal, the accuracy of data transmitted between the sending end and the receiving end is further improved, and the interruption of transmission service is effectively reduced. Further, when the first detection module detects that the key PDU does not meet the retransmission condition, the transmitting end releases the key PDU through the release module.
Referring to fig. 11, fig. 11 is a schematic structural diagram of a data transmission device 120 according to an embodiment of the present disclosure, where the data transmission device may be a UE or a base station. The data transmission device 120 may include: processor 140, memory 150, receiver 160, and transmitter 170.
Those skilled in the art will appreciate that the data transfer device configuration shown in fig. 11 does not constitute a limitation of the data transfer device and may include more or fewer components than those shown, or some components in combination, or a different arrangement of components. Wherein:
the processor 140 is a control center of the data transmission device 120, connects various parts of the entire data transmission device using various interfaces and lines, performs various functions of the data transmission device 120 and processes data by operating or executing software programs and/or modules stored in the memory 150 and calling up the data stored in the memory 150, thereby performing overall control of the data transmission device 120. Optionally, processor 140 may include one or more processing cores; optionally, the processor 140 may integrate an application processor and a modem processor, wherein the application processor mainly handles operating systems, user interfaces, application programs, and the like, and the modem processor mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 140.
The memory 150 may be used to store software programs and modules. The processor 140 executes various functional applications and data processing by executing software programs and modules stored in the memory 150. The memory 150 may mainly include a storage program area and a storage data area, wherein the storage program area may store one or more of an operating system 151, a detection module 152, a redirection module 153, a reading module 154, a synchronization module 155, a recording module 156, and a setting module 157, and application programs 158 (such as a sound playing function, an image playing function, and the like) required for the respective functions, and the like; the stored data area may store data (such as audio data, a phonebook, etc.) created according to the use of the data transmission apparatus 120, and the like. In addition, the Memory 150 may be implemented by any type of volatile or non-volatile Memory device or combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic Memory, flash Memory, magnetic disk or optical disk. Accordingly, the memory 150 may also include a memory controller to provide the processor 140 access to the memory 150.
The receiver 160 is used to receive data, which is sent to the processor 140 for processing or to the memory 150 for storage, and the receiver 160 may be a receiving antenna.
The transmitter 170 is used to transmit data in the processor 140 and also to transmit data stored in the memory 150, and the transmitter 170 may be a transmitting antenna.
The data transmission device 120 further includes a power supply (not shown) for supplying power to each component, and optionally, the power supply may be logically connected to the processor 140 through a power management system, so as to implement functions of managing charging, discharging, and power consumption through the power management system. The power supply may also include any component of one or more dc or ac power sources, recharging systems, power failure detection circuitry, power converters or inverters, power status indicators, and the like.
Embodiments of the present application provide a computer-readable storage medium, in which instructions are stored, and the computer-readable storage medium may be a non-volatile computer-readable storage medium. When the instructions are executed on the processing component, the processing component is caused to execute any one of the data transmission methods provided by the embodiments of the present application.
An embodiment of the present application provides a data transmission system, including: a sending device and a receiving device, wherein the sending device comprises the data transmission device shown in the above-mentioned fig. 7, fig. 8, fig. 9 or fig. 10.
An embodiment of the present application provides a data transmission system, including: a transmitting device and a receiving device, the transmitting device including the data transmission device shown in fig. 11 described above. As an example, the structure of the data transmission system may refer to fig. 1.
The embodiments of the present application provide a chip, where the chip includes a programmable logic circuit and/or a program instruction, and when the chip runs, the chip is configured to implement any one of the data transmission methods provided in the embodiments of the present application.
The embodiment of the present application provides a computer program product, in which instructions are stored, and when the computer program product runs on a computer, the computer is enabled to execute any one of the data transmission methods provided in the embodiment of the present application.
It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the working processes of the system, the device and the module described above may refer to corresponding processes in the foregoing method embodiments, and are not described herein again.
In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.
In the embodiment of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone.

Claims (18)

1. A data transmission method is applied to a sending end, and the method comprises the following steps:
acquiring a Protocol Data Unit (PDU) to be sent, wherein the PDU comprises a Serial Number (SN);
detecting whether the current transmission mode is a non-definite UM mode;
when the current transmission mode is a UM mode and the SN meets a marking condition, determining the PDU as a key PDU, wherein the marking condition comprises: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2n1, p is the threshold of the total number of key PDUs, n is the size of the sequence number;
after the key PDU is sent to a receiving end, whether the key PDU is received unsuccessfully is determined based on the received feedback information of the key PDU;
and when the key PDU is determined to be failed to be received, retransmitting the key PDU to the receiving end.
2. The method of claim 1,
the marking conditions include: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is not less than 0 and not more than p, and SN satisfies at least one of the following conditions:
SN is a multiple of a designated divisor, and SN is more than or equal to 0 and less than or equal to 2n-1；
The SN is a specified numerical value N, and N is more than or equal to 0 and less than or equal to 2n-1；
The SN is a random number M, and M is more than or equal to 0 and less than or equal to 2n-1。
3. The method of claim 2,
the specified divisor is equal to 2n-k，1≤k＜n。
4. The method of claim 1, further comprising:
when acquiring a PDU to be sent, timing a sending waiting time length of the PDU;
when the sending waiting time of the PDU reaches a waiting time threshold and the PDU is the key PDU, restarting the sending waiting time timing, or canceling the sending waiting time timing;
and when the sending waiting time of the PDU reaches a waiting time threshold and the PDU is not a key PDU, releasing the PDU.
5. The method according to any of claims 1 to 4, wherein the feedback information comprises positive feedback information or negative feedback information,
the determining whether the key PDU was received with failure based on the received feedback information of the key PDU comprises:
determining that the critical PDU failed to receive when W consecutive negative feedback information for the critical PDU is received, W being an integer greater than 1.
6. The method according to any of claims 1 to 4, wherein before said retransmitting said critical PDU to said receiving end, said method further comprises:
detecting whether the key PDU meets a retransmission condition;
the retransmitting the critical PDU to the receiving end includes:
when the key PDU meets the retransmission condition, retransmitting the key PDU to the receiving end;
wherein the retransmission condition comprises at least one of:
the retransmission times of the key PDU are less than a specified time threshold value;
the critical PDU is in a retransmission capable period.
7. The method of claim 6, wherein after said detecting whether the critical PDU satisfies a retransmission condition, the method further comprises:
releasing the critical PDU when the critical PDU does not satisfy the retransmission condition.
8. A data transmission device, applied to a transmitting end, the device comprising:
the device comprises an acquisition module, a transmission module and a receiving module, wherein the acquisition module is used for acquiring a Protocol Data Unit (PDU) to be transmitted, and the PDU comprises a Serial Number (SN);
a second detection module, configured to detect whether a current transmission mode is a non-deterministic UM mode before the first determination module determines that the PDU is a critical PDU;
a first determining module, configured to determine that the PDU is a key PDU when the current transmission mode is an UM mode and the SN satisfies a marking condition, where the marking condition includes: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is more than or equal to 0 and less than or equal to p, and SN is more than or equal to 0 and less than or equal to 2n1, p is the threshold of the total number of key PDUs, n is the size of the sequence number;
a second determining module, configured to determine whether the key PDU is failed to be received based on the received feedback information of the key PDU after the key PDU is sent to a receiving end;
and the retransmission module is used for retransmitting the key PDU to the receiving end when the key PDU is determined to be failed to receive.
9. The apparatus of claim 8,
the marking conditions include: under the current hyper frame number HFN, the total number m of the existing key PDUs meets the following requirements: m +1 is not less than 0 and not more than p, and SN satisfies at least one of the following conditions:
SN is a multiple of a designated divisor, and SN is more than or equal to 0 and less than or equal to 2n-1；
The SN is a specified numerical value N, and N is more than or equal to 0 and less than or equal to 2n-1；
The SN is a random number M, and M is more than or equal to 0 and less than or equal to 2n-1。
10. The apparatus of claim 9,
the specified divisor is equal to 2n-k，1≤k＜n。
11. The apparatus of claim 8, further comprising:
the timing module is used for timing the sending waiting time length of the PDU when the PDU to be sent is obtained;
a cancellation module, configured to restart timing of the transmission waiting duration when the transmission waiting duration of the PDU reaches a waiting duration threshold and the PDU is the key PDU, or cancel the timing of the transmission waiting duration;
and the first release module is used for releasing the PDU when the sending waiting time of the PDU reaches a waiting time threshold and the PDU is not a key PDU.
12. The apparatus according to any of claims 8 to 11, wherein the feedback information comprises positive feedback information or negative feedback information,
the second determining module is configured to:
determining that the critical PDU failed to receive when W consecutive negative feedback information for the critical PDU is received, W being an integer greater than 1.
13. The apparatus according to any one of claims 8 to 11, characterized in that it further comprises:
a first detection module, configured to detect whether the key PDU meets a retransmission condition before the retransmission module retransmits the key PDU to the receiving end;
the retransmission module is configured to:
when the key PDU meets the retransmission condition, retransmitting the key PDU to the receiving end;
wherein the retransmission condition comprises at least one of:
the retransmission times of the key PDU are less than a specified time threshold value;
the critical PDU is in a retransmission capable period.
14. The apparatus of claim 13, further comprising:
a second releasing module, configured to release the key PDU when the key PDU does not satisfy the retransmission condition after the first detecting module detects whether the key PDU satisfies the retransmission condition.
15. A data transmission device, comprising:
a processor;
a memory for storing executable instructions of the processor;
wherein the processor, when executing the executable instructions, is capable of implementing the data transmission method of any one of claims 1 to 7.
16. A computer-readable storage medium having stored therein instructions which, when run on a processing component, cause the processing component to perform the data transmission method of any of claims 1 to 7.
17. A data transmission system, comprising: a transmitting device and a receiving device, the transmitting device comprising the data transmission device of any one of claims 8 to 14.
18. A data transmission system, comprising: a transmitting device and a receiving device, the transmitting device comprising the data transmission device of claim 15.
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