WO2018049652A1

WO2018049652A1 - Data retransmission method and device

Info

Publication number: WO2018049652A1
Application number: PCT/CN2016/099223
Authority: WO
Inventors: 薛冰; 杨小虎; 尤中乾
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2016-09-18
Filing date: 2016-09-18
Publication date: 2018-03-22
Also published as: CN108476097B; CN108476097A

Abstract

Provided in an embodiment of the invention are a data retransmission method and device. The method comprises: determining that a data packet transmitted by a transmitting end at the n^th time is lost, where N is an integer greater than or equal to 1; transmitting a packet lost message to the transmitting end, the packet lost message being used to indicate failure of reception of the data packet transmitted at the n^th time; and receiving a data packet transmitted by the transmitting end at the N+1^th time, wherein the data packet transmitted at the N+1^th time is a data packet transmitted by the transmitting end according to the packet lost message. The invention ensures continuity of data transmission, thereby reducing data transmission delay, and increasing a transmission bandwidth.

Description

Data retransmission method and device

Technical field

The embodiments of the present invention relate to the field of communications technologies, and in particular, to a data retransmission method and apparatus.

Background technique

In the field of drones, it is necessary to transmit the camera image of the sky end to the ground end in real time, and the image is mainly transmitted through the Wi-Fi network. At present, the data transmission is basically based on a Transmission Control Protocol (English: Transmission Control Protocol, TCP for short) or a User Datagram Protocol (UDP) protocol, through a sliding window and a network congestion mechanism. A reliable data transmission is implemented. Specifically, the transmitting end sends a data packet carrying the packet sequence number to the receiving end. When the receiving end finds that the sequence number is not continuous, it sends a negative response message to the sending end (English: Negative Acknowledgment, referred to as NAK) If the sender receives the NAK, it will retransmit the corresponding packet. If the sender does not receive the acknowledgment response message (English: Acknowledgement, ACK for short), the sender will continue according to the retransmission interval. The corresponding packet is retransmitted, and in the case of continuous retransmission, the delay of the packet transmission is multiplied. Wi-Fi networks are susceptible to interference, and packet loss may occur. If multiple retransmissions occur on the retransmission mechanism described above, image transmission delays may occur, and transmission bandwidth may decrease.

Summary of the invention

Embodiments of the present invention provide a data retransmission method and apparatus, which are used to ensure continuity of data transmission, reduce data transmission delay, and improve transmission bandwidth.

In a first aspect, an embodiment of the present invention provides a data retransmission method, including:

Determining, by the sending end, that the first data packet sent by the Nth time is lost, and the N is an integer greater than or equal to 1;

Sending a first lost message to the sending end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received;

And receiving, by the sending end, the first data packet sent by the N+1th time, where the first data packet sent by the N+1th time is the first data packet sent by the sending end according to the first lost message.

Optionally, when N≥2, determining that the first data packet sent by the sending end is lost, including:

Receiving, by the sending end, a first sending indication, where the first sending indication is used to indicate that the first data packet sent by the Nth time has been sent;

Determining, according to the first sending indication, that the first data packet sent by the Nth time is lost.

Optionally, the first sending indication includes a first sequence number of the data packet sent by the Nth time, where the first sequence number is used to indicate that the data packet whose Nth transmission sequence number is less than or equal to the first sequence number has been sent. ;

Determining, according to the first sending indication, that the first data packet sent by the Nth time is lost, including: determining, when the first data packet is not received, determining, according to the first sequence number, an Nth transmission The first data packet whose sequence number is less than or equal to the first serial number is lost.

Optionally, the first sending indication includes a number of sending times N and a first sequence number, where the first sequence number and the number of sending times N are used to indicate that the sequence number of the Nth transmission is less than or equal to the data packet of the first sequence number. Has been sent;

Determining, according to the first sending indication, that the first data packet sent by the Nth time is lost, including: determining, according to the first sequence number and the number of sending times N, that the sequence number of the Nth transmission is less than or equal to The first serial number packet is lost.

Optionally, before the receiving the first sending indication sent by the sending end, the method further includes:

Transmitting, to the sending end, a second lost message, where the second lost message is used to indicate that the first data packet sent by the (N-1)th transmission is not received;

The receiving the first sending indication sent by the sending end includes: receiving a first ping packet sent by the sending end, where the first ping packet includes the first sending indication.

Optionally, when N=1, determining that the first data packet sent by the sending end is the Nth time, including:

And determining, according to the received sequence number of the data packet sent by the sending end, that the first data packet sent by the first time is lost, and the sequence number of the first data packet is a missing sequence number.

Optionally, the sending the first lost message to the sending end includes: sending a negative response message to the sending end, where the negative response message includes a previous serial number of the sequence number of the first data packet, where the first The previous sequence number of the sequence number of the data packet is used by the sender to determine the first data packet loss sent for the first time.

When the data packet is not received within the preset time, the third lost message is sent to the sending end, The third lost message is used to indicate that the data packet is not received;

Receiving, by the sending end, a second sending indication, where the second sending indication is used to indicate that the sending end has sent the first data packet that is sent for the first time;

Determining, according to the second sending instruction, that the first data packet sent by the first time is lost.

Optionally, receiving the second sending indication sent by the sending end, including: receiving a second ping packet sent by the sending end, where the second ping packet includes a left end serial number and a right end serial number of the current sliding window;

Determining, according to the second sending indication, that the first data packet sent by the first time is lost, including: determining, according to a left end number and a right end number of the current sliding window, that the serial number is located in the current sliding window The first packet is lost.

Optionally, before the receiving, by the sending end, the first data packet sent by the sending end of the N+1th time, the method further includes:

Receiving a second data packet sent by the sending end, where the second data packet carries a sequence number of the second data packet, a left end serial number and a right end serial number of the current sliding window;

After the receiving, by the sending end, the first data packet sent by the N+1th time, the method further includes:

When the sequence number of the second data packet is equal to the right end number of the current sliding window, and the data packet corresponding to the right end number of the current sliding window to the right end serial number has been received, send the first to the sending end. And confirming the response message, where the first acknowledgement response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the second data packet in the current sliding window has been received.

Optionally, the first data packet sent by the (N+1)th time carries the number of transmissions N+1 of the first data packet.

Optionally, if the N+1 is the maximum number of transmissions, after the sending the first lost message to the sending end, the method further includes:

Receiving a third data packet sent by the sending end, where the third data packet carries a sequence number of the third data packet;

And sending, by the sending end, a second acknowledgement response message, where the second acknowledgement response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the third data packet has been received.

The data retransmission method provided in this embodiment is determined by not determining that the data packet sent by the transmitting end is sent by the transmitting end (i.e., N times), and then sending the sending end to indicate that the Nth sending is not received. The lost message of the packet, and the packet sent by the receiving end according to the lost message, The received data packet is the data packet sent by the sender at the N+1th time. In this embodiment, the number of times of the lost data packet can be determined, and the lost message is sent to the sender to notify the data packet that the number of times of the transmission is not received, so that the sender sends the data packet again after receiving the lost message. The continuity of data transmission is guaranteed, the data transmission delay is reduced, and the transmission bandwidth is improved.

In a second aspect, an embodiment of the present invention provides a data retransmission method, including:

Receiving a first lost message sent by the receiving end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received, where the N is an integer greater than or equal to 1;

And sending, according to the first lost message, the first data packet sent by the N+1th time to the receiving end.

Optionally, when N≥2, before receiving the first lost message sent by the receiving end, the method includes:

Sending, by the receiving end, a first sending indication, where the first sending indication is used to indicate that the first data packet sent by the Nth time has been sent.

Optionally, the first sending indication includes a first sequence number of the data packet sent by the Nth time, where the first sequence number is used to indicate that the data packet whose Nth transmission sequence number is less than or equal to the first sequence number has been sent. .

Optionally, the first sending indication includes a number of sending times N and a first sequence number, where the number of sending times N and the first sequence number are used to indicate that the sequence number of the Nth transmission is less than or equal to the data packet of the first sequence number has been sent. .

Optionally, before the sending the first sending indication to the receiving end, the method further includes:

Receiving a second lost message sent by the receiving end, where the second lost message is used to indicate that the first data packet that is not received by the N-1th transmission is received;

Transmitting, according to the second lost message, the first data packet sent by the Nth time to the receiving end;

Sending the first sending indication to the receiving end, including:

When it is determined that the message sent by the receiving end to indicate that the first data packet sent by the Nth transmission has been received or lost is received within a preset time, sending the first ping packet to the receiving end The first ping packet includes the first sending indication.

Optionally, the receiving, by the receiving end, the first lost message, comprising: receiving a negative response message sent by the receiving end, where the negative response message includes a previous sequence number of the sequence number of the first data packet;

The method further includes:

And changing, according to the previous serial number of the sequence number of the first data packet, the left end number of the current sliding window to the previous serial number of the serial number of the first data packet.

Optionally, before the receiving the first lost message sent by the receiving end, the method further includes:

Transmitting a data packet to the receiving end according to a sliding window;

Receiving, by the receiving end, a third lost message, where the third lost message is used to indicate that the data packet is not received;

And sending, by the third lost message, a second sending indication to the receiving end, where the second sending indication is used to indicate that the first data packet that is sent the first time is sent.

Optionally, sending the second sending indication to the receiving end according to the third lost message, including: sending a second ping packet to the receiving end, where the second ping packet includes a left end sequence number of the current sliding window, and The right end serial number; the left end serial number and the right end serial number of the current sliding window product are used to indicate that the first data packet in the current sliding window has been sent.

Optionally, the N+1 is a maximum number of transmissions, and after the sending, by the first sending message, the first data packet sent by the N+1th time according to the first lost message, the method further includes:

Adjusting the current sliding window according to the sequence number of the first data packet.

The data retransmission method provided in this embodiment receives the lost message sent by the receiving end to indicate that the Nth transmitted data packet is not received, and then sends the data packet again according to the lost message. In this embodiment, the transmitting end sends the data packet again after receiving the lost message, thereby ensuring continuity of data transmission, reducing data transmission delay, and improving transmission bandwidth.

In a third aspect, an embodiment of the present invention provides a data retransmission device, including:

a determining module, configured to determine, by the sending end, the first data packet sent by the Nth time, where the N is an integer greater than or equal to 1;

a sending module, configured to send a first lost message to the sending end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received;

a receiving module, configured to receive, by the sending end, the first data packet sent by the N+1th time, where the first data packet sent by the N+1th time is sent by the sending end according to the first lost message A packet of data.

Optionally, when N≥2, the receiving module is further configured to receive a first sending indication sent by the sending end, where the first sending indication is used to indicate the first data packet sent by the Nth time Has been sent;

The determining module is specifically configured to: determine, according to the first sending indication, that the first data packet sent by the Nth time is lost.

The determining module is configured to: when the receiving module does not receive the first data packet, determine, according to the first serial number, that the sequence number of the Nth transmission is less than or equal to the first sequence number The packet is lost.

The determining module is specifically configured to: determine, according to the first serial number and the number of transmissions N, that the sequence number sent by the Nth time is less than or equal to the data packet loss of the first sequence number.

Optionally, the sending module is further configured to: before the receiving module receives the first sending indication sent by the sending end, send a second lost message to the sending end, where the second lost message is used to indicate Not receiving the first data packet sent by the N-1th time;

The receiving module, when receiving the first sending indication sent by the sending end, is specifically configured to: receive the first ping packet sent by the sending end, where the first ping packet includes the first sending indication.

Optionally, the determining module is configured to: determine, according to the received serial number discontinuity of the data packet sent by the sending end, that the first data packet sent by the first time is lost, The serial number of the first data packet is the missing serial number.

Optionally, when the sending module sends the first lost message to the sending end, the sending module specifically includes: sending a negative response message to the sending end, where the negative response message includes a sequence number of the first data packet. a sequence number, the previous sequence number of the sequence number of the first data packet is used by the sender to determine the first data packet loss sent for the first time.

Optionally, when N=1, the sending module is further configured to: when a data packet is not received within a preset time, send a third lost message to the sending end, where the third lost message is used. Indicates that no data packet has been received;

The receiving module is further configured to receive a second sending indication sent by the sending end, where the second sending indication is used to indicate that the sending end has sent the first data packet that is sent for the first time;

The determining module is specifically configured to: determine, according to the second sending indication, that the first data packet sent by the first time is lost.

Optionally, the receiving module, when receiving the second sending indication sent by the sending end, is specifically configured to: receive a second ping packet sent by the sending end, where the second ping packet includes a current sliding window. Left end number and right end number;

The determining module is specifically configured to: determine, according to the left end number and the right end serial number of the current sliding window, that the first data packet whose serial number is located in the current sliding window is lost.

Optionally, the receiving module is further configured to: before receiving the first data packet sent by the sending end by the N+1th, receive the second data packet sent by the sending end, where the second data is The packet carries the serial number of the second data packet, the left end serial number and the right end serial number of the current sliding window;

The sending module is further configured to: after the receiving module receives the first data packet sent by the sending end of the N+1th time, when the sequence number of the second data packet is equal to the right end of the current sliding window a sequence number, and the data packet corresponding to the right end of the current sliding window is received, and the first acknowledgement response message is sent to the sending end, where the first acknowledgement response message is used to indicate the current The data packet corresponding to the sequence number before the serial number of the second data packet in the sliding window has been received.

Optionally, if the N+1 is the maximum number of transmissions, the receiving module is further configured to: after the sending module sends the first lost message to the sending end, receive the third data packet sent by the sending end, where The third data packet carries the sequence number of the third data packet;

The sending module is further configured to send a second acknowledgment response message to the sending end, where the second acknowledgment response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the third data packet has been received.

The data retransmission device provided in this embodiment is configured to determine that the data packet sent by the transmitting end is not sent by the transmitting end, and then sent to the transmitting end to indicate that the Nth transmission is not received. The lost message of the data packet, and the data packet sent by the receiving and transmitting end according to the lost message, and the received data packet is the data packet sent by the transmitting end for the N+1th time. In this embodiment, the number of times of the lost data packet can be determined, and the lost message is sent to the sender to notify the data packet that the number of times of the transmission is not received, so that the sender sends the data packet again after receiving the lost message. Guaranteed number According to the continuity of transmission, the data transmission delay is reduced and the transmission bandwidth is increased.

In a fourth aspect, an embodiment of the present invention provides a data retransmission device, including:

a receiving module, configured to receive a first lost message sent by the receiving end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received, where the N is an integer greater than or equal to 1;

And a sending module, configured to send, according to the first lost message, the first data packet sent by the N+1th time to the receiving end.

Optionally, the sending module is further configured to: before the receiving module receives the first lost message sent by the receiving end, send a first sending indication to the receiving end, where the A sending indication is used to indicate that the first data packet sent by the Nth time has been transmitted.

Optionally, the receiving module is further configured to: before the transmitting module sends the first sending indication to the receiving end, receive a second lost message sent by the receiving end, where the second lost message is used to indicate that Receiving the first data packet sent by the N-1th time;

The sending module is further configured to send, according to the second lost message, the first data packet sent by the Nth time to the receiving end;

When the sending module sends the first sending indication to the receiving end, the sending module is specifically configured to: when it is determined that the first data sent by the receiving end to indicate the Nth sending is not received within a preset time When the packet has received or lost, the first ping packet is sent to the receiving end, and the first ping packet includes the first sending indication.

Optionally, the receiving module, when receiving the first lost message sent by the receiving end, is specifically configured to: receive a negative response message sent by the receiving end, where the negative response message includes a sequence number of the first data packet. The previous serial number;

The device further includes:

The change module is configured to change the left end number of the current sliding window to the previous serial number of the first data packet according to the previous serial number of the first data packet.

Optionally, the sending module is further configured to: before the receiving module receives the first lost message sent by the receiving end, send the data packet to the receiving end according to the sliding window;

The receiving module is further configured to receive a third lost message sent by the receiving end, where the third lost message is used to indicate that the data packet is not received;

The sending module is further configured to send, according to the third lost message, a second sending indication to the receiving end, where the second sending indication is used to indicate that the first data packet that is sent the first time is sent.

Optionally, the sending module is configured to send a second ping packet to the receiving end, where the second ping packet is sent to the receiving end according to the third lost message. The left end serial number and the right end serial number of the current sliding window are included; the left end serial number and the right end serial number of the current sliding window product are used to indicate that the first data packet in the current sliding window has been sent.

Optionally, the device further includes:

And an adjusting module, configured to: after the sending, by the sending module, send the first data packet sent by the N+1th time to the receiving end according to the first lost message, adjust according to the sequence number of the first data packet Current sliding window; the N+1 is the maximum number of transmissions.

The data retransmission device provided by the embodiment of the present invention receives the lost message sent by the receiving end to indicate that the Nth transmitted data packet is not received, and then sends the data packet again according to the lost message. In this embodiment, the transmitting end sends the data packet again after receiving the lost message, thereby ensuring continuity of data transmission, reducing data transmission delay, and improving transmission bandwidth. Guaranteed continuity of data transmission, reduced data transmission delay, and improved transmission bandwidth

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

1 is a flowchart of Embodiment 1 of a data retransmission method according to the present invention;

2 is a flowchart of Embodiment 2 of a data retransmission method according to the present invention;

3 is a flowchart of Embodiment 3 of a data retransmission method according to the present invention;

4 is a flowchart of Embodiment 4 of a data retransmission method according to the present invention;

5 is a flowchart of Embodiment 5 of a data retransmission method according to the present invention;

6 is a flowchart of Embodiment 6 of a data retransmission method according to the present invention;

7 is a flowchart of Embodiment 7 of a data retransmission method according to the present invention;

8 is a flowchart of Embodiment 8 of a data retransmission method according to the present invention;

FIG. 9 is a schematic diagram of a structure of a data packet according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of an application of a data retransmission method according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of an application of a data retransmission method according to an embodiment of the present invention;

FIG. 12 is a schematic diagram of an application of a data retransmission method according to an embodiment of the present invention;

13 is a schematic structural diagram of Embodiment 1 of a data retransmission apparatus according to the present invention;

14 is a schematic structural diagram of Embodiment 2 of a data retransmission apparatus according to the present invention;

FIG. 15 is a schematic structural diagram of Embodiment 1 of a data retransmission system according to the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The data retransmission method provided by the embodiments of the present invention can be applied to a drone. The following transmitting end can be a drone, and the receiving end can be a control device for controlling the drone. For example, the control device can include a remote controller and The ground station, the ground station can be a smart phone or a tablet computer, and the following data packet can be a picture taken by the camera device in the drone.

1 is a flowchart of Embodiment 1 of a data retransmission method according to the present invention. As shown in FIG. 1, the method in this embodiment may include:

S101. Determine that the data packet sent by the sender at the Nth time is lost.

S102. Send a lost message to the sending end, where the lost message is used to indicate that the data packet sent by the Nth time is not received.

S103. Receive a data packet that is sent by the sending end to the N+1th time, where the data packet sent by the N+1th time is a data packet sent by the sending end according to the lost message.

The executor of this embodiment is a receiving end, and the receiving end may determine that the data packet sent by the transmitting end is lost for the Nth time, and the N is an integer greater than or equal to 1, that is, the receiving end may determine that the sending end sends the sending end. The sent packet is lost and it can also be determined that the lost packet was sent by the sender several times. Then, it is required to notify the sending end that the data packet receiving end sent by the sending end is not received, and the transmitting end needs to send the data packet again, that is, in this embodiment, the receiving end sends a lost message to the sending end, and the lost message is used. The receiving end does not receive the data packet sent by the transmitting end for the Nth time, and then the receiving end can receive the data packet that is sent by the sending end according to the lost message, and the data packet is the data packet sent by the transmitting end for the N+1th time.

The data retransmission method provided in this embodiment is determined by not determining that the data packet sent by the transmitting end is sent by the transmitting end (i.e., N times), and then sending the sending end to indicate that the Nth sending is not received. The lost message of the data packet, and the data packet sent by the receiving and transmitting end according to the lost message, and the received data packet is the data packet sent by the transmitting end for the N+1th time. In this embodiment, the number of times of the lost data packet can be determined, and the lost message is sent to the sender to notify the data packet that the number of times of the transmission is not received, so that the sender sends the data packet again after receiving the lost message. The continuity of data transmission is guaranteed, the data transmission delay is reduced, and the transmission bandwidth is improved.

2 is a flowchart of Embodiment 2 of a data retransmission method according to the present invention. As shown in FIG. 2, the method in this embodiment may include:

S201: Receive a lost message sent by the receiving end, where the lost message is used to indicate that the data packet sent by the Nth time is not received, and N is an integer greater than or equal to 1.

S202. Send, according to the lost message, the data packet sent by the N+1th time to the receiving end.

The execution body of this embodiment is a transmitting end, and the transmitting end receives the lost message sent by the receiving end, and the transmitting end can determine that the receiving end does not receive the data packet sent by the sending end according to the received lost message, and the unreceived data packet is the transmitting end. The data packet sent in the Nth time is then sent to the receiving end again, and the data packet sent again is the data packet sent by the N+1th time, so that the receiving end can receive the data packet transmitted by the N+1th time.

FIG. 3 is a flowchart of Embodiment 3 of the data retransmission method of the present invention. As shown in FIG. 3, in this embodiment, N is greater than or equal to 2, and the method in this embodiment may include:

S301. The sending end sends a sending indication to the receiving end.

The sending indication is used to indicate that the data packet sent by the Nth time has been sent. N is an integer greater than or equal to 2.

In this embodiment, after transmitting the data packet sent by the Nth time to the receiving end, the transmitting end sends the sending indication to the receiving end; correspondingly, the receiving end receives the sending indication sent by the sending end. Optionally, the sending end may carry the sending indication in a data packet and send the signal to the receiving end.

S302. The receiving end determines, according to the sending indication, that the data packet sent by the Nth time is lost.

In this embodiment, after receiving the transmission indication, the receiving end has not received the data packet so far, and then determines, according to the sending indication, that the data packet sent by the transmitting end is lost for the Nth time, that is, the Nth time of the transmitting end is not received. The packet sent.

In a possible implementation manner of S301 and S302, the foregoing sending indication includes a first sequence number of the data packet sent by the Nth time, where the first sequence number is used to indicate that the sequence number of the Nth transmission is less than or equal to the number Correspondingly, when the receiving end does not receive the data packet whose sequence number is less than or equal to the first sequence number, the receiving end determines, according to the first sequence number in the sending indication, that the sequence number sent by the Nth time is less than or equal to the first number. The data packet of the serial number is lost, that is, the receiving end determines, according to the first sequence number, that the data packet whose sequence number sent by the transmitting end is less than or equal to the first sequence number sent by the transmitting end is determined, and the receiving end determines that the data packet is not received. Therefore, the receiving end determines the Nth. The packet sent with the sequence number less than or equal to the first sequence number is lost. Optionally, the sending indication may include multiple fields, where a first field of the multiple field indicates a sequence number of the data packet sent for the second time, and a second field indicates a sequence number of the data packet sent for the third time. In the embodiment, the N-1 field may be filled with a value indicating the sequence number of the data packet transmitted by the N+1th time, and the positions of the other fields are invalid. If the sending indication is carried in the data packet transmission, the structure for transmitting the indication may be as shown in Table 1, and the multiple fields in the sending indication are the fields (including the fifth bit field) after the fifth bit field in Table 1.

Table 1

In another feasible implementation manner of S301 and S302, the foregoing sending indication includes sending The number of times N and the first sequence number, the first sequence number and the number of transmissions N are used to indicate that the data packet whose sequence number of the Nth transmission is less than or equal to the first sequence number has been sent; correspondingly, the sender end is not received. When the data packet whose sequence number is less than or equal to the first sequence number, according to the first sequence number and the number of transmission times N in the sending indication, it is determined that the data packet whose Nth transmission sequence number is less than or equal to the first sequence number is lost, that is, the receiving end is according to the first The sequence number and the number of transmissions N determine that the data transmission end of the Nth transmission sequence number less than or equal to the first sequence number has been transmitted, and the receiving end determines that it has not been received, and therefore, the receiving end determines that the data packet is lost. Optionally, the sending indication may include a sending times field and a sequence number field, and determining, according to the number of the sending times field and the serial number field, which data packet is sent in the first few times, so in this embodiment, the number of times of sending may be filled in the field. The upper value N, the first serial number is added to the serial number field. If the sending indication is carried in the data packet transmission, the structure for sending the indication may be as shown in Table 2. The number of transmission times in the transmission indication is the second bit field in Table 2, and the sequence number field is the fifth bit field in Table 2. .

Table 2

S303. The receiving end sends a lost message to the sending end.

The lost message is used to indicate that the data packet sent by the Nth time is not received.

S304. The sending end sends, according to the lost message, the data packet sent by the N+1th time to the receiving end.

For the specific implementation process of S303 and S304 in this embodiment, refer to the related description in the embodiment shown in FIG. 1 or FIG. 2, and details are not described herein again.

In the data retransmission method provided by the embodiment, the sending end indicates that the data packet sent by the Nth transmission to the receiving end is sent by sending the indication; and then the receiving end does not receive the data packet, and determines that the data packet sent by the Nth time has been lost, and The sender sends a lost message; the sender sends the packet again after receiving the lost message, ensuring continuity of data transmission, reducing data transmission delay, and improving transmission bandwidth.

4 is a flowchart of Embodiment 4 of the data retransmission method of the present invention. As shown in FIG. 4, in this embodiment, N is greater than or equal to 2, and the method in this embodiment may include:

S401. The receiving end sends a first lost message to the sending end.

The first lost message is used to indicate that the data packet sent by the (N-1)th transmission is not received.

In this embodiment, the receiving end may determine that the data packet sent by the N-1th time is lost, and then send the first lost message to the transmitting end. For a specific implementation process of the S401, refer to the related description in the foregoing embodiment or the following embodiments, and details are not described herein again.

S402. The sending end sends, according to the first lost message, the data packet sent by the Nth time to the receiving end.

In this embodiment, the transmitting end determines, according to the first lost message, that the data packet sent by the N-1th time is lost, and then sends the data packet to the receiving end again, and the data packet sent this time is called the data packet sent by the Nth time. .

S403. When the sending end determines that the message sent by the receiving end to indicate that the Nth transmitted data packet has been received or lost is not received within the preset time, the sending end sends a ping packet to the receiving end.

The ping packet includes a sending indication.

In this embodiment, after the transmitting end sends the data packet sent by the Nth time, the message sent by the receiving end to indicate that the data packet sent by the Nth time has been received is not received within the preset time, and the receiving message is not received. When the terminal sends a message indicating that the data packet sent by the Nth time has been lost, the sending end sends a ping packet to the receiving end, and the ping packet carries a sending indication. For a description of the sending indication, refer to the related description in the embodiment shown in FIG. 3, and details are not described herein again.

S404. The receiving end determines, according to the sending indication, that the data packet sent by the Nth time is lost.

S405. The receiving end sends a second lost message to the sending end.

S406. The sending end sends, according to the second lost message, the data packet sent by the N+1th time to the receiving end.

For the specific implementation process of the S404-S406 in this embodiment, refer to the related description in the embodiment shown in FIG. 3, and details are not described herein again.

In the data retransmission method provided by the embodiment, the sending end sends an indication to the receiving end through the ping packet, to indicate to the receiving end that the data packet sent by the Nth time has been sent; and then the receiving end determines the Nth sending time when the data packet is not received. The data packet has been lost, and the lost message is sent to the sending end; the transmitting end sends the data packet again after receiving the lost message, which ensures the continuity of data transmission, reduces the data transmission delay, and improves the transmission bandwidth.

FIG. 5 is a flowchart of Embodiment 5 of a data retransmission method according to the present invention. As shown in FIG. 5, this embodiment is shown in FIG. Taking N equal to 1 as an example, the method in this embodiment may include:

S501. The receiving end determines, according to the discontinuous sequence number of the data packet sent by the receiving end, that the data packet sent by the first time is lost.

The sequence number of the lost data packet is a missing sequence number.

In this embodiment, the sending end sequentially sends a data packet to the receiving end according to the serial number of the data packet, and each data packet carries the serial number of the data packet. Correspondingly, the receiving end receives the data packet sent by the transmitting end, and when the receiving end receives the data packet, but the serial number of the data packet received in sequence is not continuous, according to which it can be determined that the data packet corresponding to the missing serial number is lost. For example, the receiving end receives the data packet with

sequence numbers

2 and 3, and can determine that the data packet with the sequence number 1 is lost; for example, the receiving end receives the data packet with the

sequence number

1, 2, and 4, and accordingly, the sequence number is determined to be 3 packets are lost.

Then, the receiving end of the embodiment needs to send a lost message to the sending end, and the lost message is used to indicate that the first sent data packet is lost. In a feasible implementation manner, the receiving end sending the lost message to the sending end may include S502.

S502. The receiving end sends a negative response message to the sending end.

The negative response message includes a previous sequence number of the sequence number of the data packet, and the previous sequence number of the sequence number of the data packet is used by the sender to determine that the data packet is lost for the first time.

In this embodiment, the sequence number of the lost data packet is a missing sequence number, and the data packet receiving end corresponding to the previous sequence number of the missing sequence number is received, so the negative response message sent by the receiving end to the sending end includes the The previous sequence number of the sequence number of the lost data packet, for example, the sequence number of the lost data packet is 3, and the sequence number included in the negative response message is 2.

S503. The sending end sends the second transmitted data packet to the receiving end according to the negative response message.

In this embodiment, after receiving the negative acknowledgement message, the sender determines that the first sent data packet has been lost according to the previous sequence number of the lost data packet in the negative acknowledgement message, for example, in the negative acknowledgement message. If the previous sequence number of the lost data packet is 2, the sender determines that the data packet with sequence number 3 has been lost according to the sequence number 2, and then sends the data packet to the receiving end again. The data packet sent this time is the second time. The packet sent.

S504. The sending end changes the left end number of the current sliding window to the previous serial number of the lost serial number of the data packet according to the previous serial number of the lost serial number of the data packet.

In this embodiment, the sending end may determine that the previous sequence number and the data packet corresponding to the previous sequence number have been successfully received according to the previous sequence number of the lost data packet in the negative response message. Therefore, the left end number of the current sliding window is changed to the previous serial number of the missing serial number of the data packet. For example, if the previous serial number of the serial number of the lost data packet is 3, the transmitting end of the embodiment changes the left end serial number of the current sliding window to 3.

The data retransmission method provided in this embodiment, by using the foregoing solution, the receiving end may determine that the data packet sent by the first time is lost, and then send a negative acknowledgement message to the sending end; the transmitting end sends the data packet again after receiving the negative acknowledgement message. , to ensure the continuity of data transmission, reduce the data transmission delay, and improve the transmission bandwidth.

FIG. 6 is a flowchart of Embodiment 6 of the data retransmission method of the present invention. As shown in FIG. 6 , in this embodiment, N is equal to 1. The method in this embodiment may include:

S601. The sending end sends a data packet to the receiving end according to the sliding window.

S602. When the data packet is not received within the preset time, the receiving end sends the first lost message to the sending end.

The first lost message is used to indicate that a data packet has not been received.

In this embodiment, the transmitting end sends a data packet to the receiving end according to the sliding window, and when the receiving end does not receive any data packet within the preset time, the receiving end sends the first lost message to the sending end.

S603. The sending end sends a first sending indication to the receiving end according to the first lost message.

The first sending indication is used to indicate that the data packet sent for the first time has been sent.

S604. The receiving end determines, according to the first sending indication, that the data packet sent by the first time is lost.

In this embodiment, after receiving the first lost message, the transmitting end determines that all the transmitted data packets are lost according to the first lost message, and then sends a first sending indication to the receiving end, where the first sending indication is used to indicate the first time. Which packets were sent, that is, lost packets. After receiving the first sending indication, the receiving end may determine that the first sent data packet is lost.

Optionally, a feasible implementation manner of the S603 is: the sending end sends a ping packet to the receiving end, where the ping packet includes a left end number and a right end serial number of the current sliding window; and a left end serial number of the current sliding window product And the right end sequence number is used to indicate that the data packet in the current sliding window has been sent. Correspondingly, a feasible implementation manner of S604 is: determining, according to the left end number and the right end number of the current sliding window, that the data packet whose serial number is located in the current sliding window is lost. For example, the left end of the current sliding window included in the ping packet is 0, and the right end is 2, and the receiving end is determined according to the left end number is 0, the right end number is 2, and the sequence number is 1 and the sequence number 2 is lost.

S605. The receiving end sends a second lost message to the sending end.

The second lost message is used to indicate that the first transmitted data packet is not received.

S606. The sending end sends, according to the second lost message, the data packet sent for the second time to the receiving end.

For the specific implementation process of S605 and S606 in this embodiment, refer to the related description in the embodiment shown in FIG. 1 or FIG. 2, and details are not described herein again.

FIG. 7 is a flowchart of Embodiment 7 of the data retransmission method of the present invention. As shown in FIG. 7, the method in this embodiment may include:

S701. The receiving end determines that the first data packet sent by the sending end is lost.

The N is an integer greater than or equal to 1;

S702. The receiving end sends a lost message to the sending end.

The lost message is used to indicate that the first data packet sent by the Nth time is not received.

For the specific implementation process of S701 and S702 in this embodiment, reference may be made to related descriptions in the foregoing embodiments, and details are not described herein again.

S703. The sending end sends the second data packet to the receiving end.

The second data packet carries a sequence number of the second data packet, a left end sequence number and a right end sequence number of the current sliding window.

S704. The sending end sends, according to the lost message, the first data packet sent by the N+1th time to the receiving end.

For the specific implementation process of S704, refer to related descriptions in the foregoing embodiments, and details are not described herein again.

It should be noted that the execution order of S703 and S704 is in no particular order.

S705. When the sequence number of the second data packet is equal to the right end number of the current sliding window, and the data packet corresponding to the left end serial number of the current sliding window to the right end serial number has been received, the receiving end sends the data packet to the sending end. The end sends an acknowledgement response message.

The acknowledgement response message is used to indicate that a data packet corresponding to the sequence number before the sequence number of the second data packet in the current sliding window has been received.

In this embodiment, when the sequence number of the second data packet is equal to the right end number of the current sliding window, it is indicated that all the data packet sending ends in the current sliding window are sent to the receiving end, and the left end number of the current sliding window is within the right end serial number. When all the data packets corresponding to the sequence number are received by the receiving end, the receiving end sends an acknowledgement response message to the sender, and the current sliding window of the sender is notified by the acknowledgement response message. All packets in the port have been received. Optionally, the sending end receives the confirmation response message to update the current sliding window, for example, changing the left end number of the current sliding window to the serial number of the second data packet.

The data retransmission method provided in this embodiment ensures the continuity of data transmission, reduces the data transmission delay, improves the transmission bandwidth, and enables the receiving end to receive all the data packets in the current sliding window. The acknowledgment response message is sent to the sender to ensure that the data transmission sequence is not disturbed.

FIG. 8 is a flowchart of Embodiment 8 of the data retransmission method of the present invention. As shown in FIG. 8, the method in this embodiment may include:

S801. The receiving end determines that the first data packet sent by the sending end is lost.

The N is an integer greater than or equal to 1;

S802. The receiving end sends a lost message to the sending end.

For the specific implementation process of S801 and S802 in this embodiment, refer to related descriptions in the foregoing embodiments, and details are not described herein again.

S803. The sending end sends the second data packet to the receiving end.

The second data packet carries a sequence number of the second data packet.

S804. The sending end sends, according to the lost message, the first data packet sent by the N+1th time to the receiving end.

For the specific implementation process of the S804 in this embodiment, refer to the related description in the foregoing embodiments, and details are not described herein again.

Among them, the execution order of S803 and S804 is in no particular order.

S805. If the N+1 is the maximum number of transmissions, the receiving end sends an acknowledgement response message to the sending end.

The acknowledgement response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the second data packet has been received.

In this embodiment, if N+1 is the maximum number of transmissions of the first data packet, it means that the sender does not send the first data packet again, regardless of whether the receiving end receives the first data packet sent by the N+1th time. Therefore, the receiving end considers that the first data packet sent by the N+1th transmission has been received, and after receiving the second data packet sent by the transmitting end, the receiving end sends an acknowledgement response message to the transmitting end, and acknowledges the response message by The sender notifies the data packet corresponding to the sequence number before the sequence number of the second data packet has been received. Can Alternatively, the sender adjusts the current sliding window after receiving the confirmation response message.

S806. If the N+1 is the maximum number of transmissions, the sending end adjusts the current sliding window according to the sequence number of the first data packet.

In this embodiment, after the sending end sends the first data packet sent by the N+1th to the receiving end, if the N+1 is the maximum number of times of sending the first data packet, the sending end does not send the first data packet again. The sender considers that the receiving end has received the first data packet sent by the N+1th time, and then adjusts the current sliding window according to the sequence number of the first data packet, for example, changing the left end number of the current sliding window to the sequence number of the first data packet.

The execution order of S805 and S806 is in no particular order.

The data retransmission method provided in this embodiment ensures the continuity of data transmission, reduces the delay of data transmission, and improves the transmission bandwidth through the above solution; and the limitation of the maximum number of transmissions can tolerate loss of part of data and improve The overall data transmission efficiency.

Optionally, in the foregoing embodiments, the data packet sent by the (N+1)th time carries the number of times of sending the data packet N+1, so that the receiving end receives the N+1th transmission. After the data packet is described, it can be determined that the data packet is sent by the sender at the N+1th time.

Optionally, the number of times of sending may be represented by the number of retransmissions, that is, the number of transmissions is equal to the number of retransmissions +1, for example, the number of retransmissions is 1, indicating that the number of transmissions is 2.

It should be noted that the current sliding window refers to the maximum amount of data packets currently transmitted, and the data packet in the current sliding window is a data packet that has been sent but has not been confirmed to be received; the left end serial number refers to the first in the current sliding window. The serial number of the transmitted data packet is decremented by 1, that is, the serial number of the currently received data packet has been confirmed; the right end serial number is the serial number of the latest data packet sent in the current sliding window.

FIG. 9 is a schematic diagram of a structure of a data packet according to an embodiment of the present invention. As shown in FIG. 9 , the maximum number of retransmissions is 2 (that is, the maximum number of transmissions is 3), and the structure includes: a sequence number and data of a data packet. The number of retransmissions of the packet, the left end number of the current sliding window, the right end number, and the serial number of the first retransmitted data packet.

FIG. 10 is a schematic diagram of an application of a data retransmission method according to an embodiment of the present invention. As shown in FIG. 10, the embodiment is described based on the structure shown in FIG. 9.

The sliding window of the embodiment is exemplified by 5, and the transmitting end sequentially sends a data packet with sequence number 1, a data packet with sequence number 2, and a data packet with sequence number 3 to the receiving end according to the sliding window of 5. The data with sequence number 4 and the data packet with sequence number 5. The structure of the data packet with sequence number 1 includes: 1 (number of data packets), 0 (first transmission, no retransmission, so the number of retransmissions is 0), 0 (the first packet sent by the current sliding window) The serial number (which is 1) minus 1), 1 (the serial number of the data packet sent by the current sliding window), and none (the data packet currently not retransmitted); the structure of the data packet with the serial number 2 includes: 2, 0, 0 2, no; the structure of the data packet with sequence number 3 includes: 3, 0, 0, 3, and none; the structure of the data packet with sequence number 4 includes: 4, 0, 0, 4, and none; The structure of the data packet includes: 5, 0, 0, 5, and none. The receiving end receives the data packet with the sequence number of 1, 4, and the receiving end determines that the data packet with the

sequence number

2 and 3 is lost according to the discontinuity of the sequence number of 1, 4, and the receiving end sends the data packet with the acknowledgement sequence number 1 to the transmitting end. And the 0th retransmission (that is, the first transmission) the message whose sequence number is 2 or 3 is not received; after receiving the message, the sender retransmits the data packet of sequence number 2 to the receiving end (referred to as 2.1) And retransmitting the data packet of sequence number 3 (referred to as 3.1), and the structure of the data packet of 2.1 includes: 2, 1 (the first retransmission of the data packet with sequence number 2), 1 (the serial number received by the receiving end is 1 data packet, the current sliding window is adjusted), 5 (the serial number of the data packet to which the current sliding window has been sent), 2 (the serial number of the first retransmitted data packet is 2); The structure includes: 3, 1 (the first retransmission of the data packet with sequence number 3), 1, 5 (the sequence number of the data packet to which the current sliding window has been sent), and 3 (the data of the first retransmission at this time) The sequence number of the packet is 3); then the sender continues to send the data packet with sequence number 6 according to the sliding window of 5. The structure of the data packet with sequence number 6 is: 6, 0. 1,6,3 (case No. 1st retransmission data packet is 3). When the receiving end receives the data packet of 3.1 and does not receive the data packet of 2.1, the receiving end continues to send to the transmitting end that the data packet with the acknowledgement sequence number 1 has been received and the sequence number of the first retransmission (ie, the second transmission) is The message received by the data packet of 2; after receiving the message, the transmitting end retransmits the data packet of sequence number 2 (referred to as 2.2) to the receiving end, and the structure of the data packet of 2.2 includes: 2, 2 (the serial number is 2) The second retransmission of the data packet), 1 (the receiving end has received the data packet with sequence number 1, the current sliding window has been adjusted), 6 (the serial number of the data packet to which the current sliding window has been sent), 3 (this The serial number of the data packet retransmitted for the first time is 3). The receiving end receives the data packet with the sequence number of 6 and the data packet of 2.2, and then sends the message that the data packet with the sequence number 6 is received to the transmitting end, and after receiving the message, the transmitting end determines the corresponding data packet with the sequence number 6 All have been received, then adjust the current sliding window, continue to send subsequent data, such as sending a serial number 7 packet.

According to the embodiment of the present invention, the continuity of data transmission is ensured, the defect of continuously retransmitting the first data packet before the acknowledgement response message of the first data packet is not received is avoided, and the data transmission is reduced. Delay, increasing the transmission bandwidth.

FIG. 11 is a schematic diagram of an application of a data retransmission method according to an embodiment of the present invention. As shown in FIG. 11, the embodiment is described based on the structure shown in FIG. 9.

The sliding window of this embodiment is exemplified. The transmitting end sequentially sends a data packet of sequence number 1 and a data packet of sequence number 2 to the receiving end according to the sliding window of 2. The structure of the data packet with sequence number 1 includes: 1 (number of data packets), 0 (first transmission, no retransmission, so the number of retransmissions is 0), 0 (the first packet sent by the current sliding window) The serial number (which is 1) minus 1), 1 (the serial number of the data packet sent by the current sliding window), and none (the data packet currently not retransmitted); the structure of the data packet with the serial number 2 includes: 2, 0, 0 2, no. If the receiving end does not receive any data packet within the preset time, it may determine that the data packet is lost, and the receiving end sends a message to the transmitting end that the data packet with the sequence number of 0 (not present) has been received; after receiving the message, the transmitting end receives the message. It can be determined that the receiving end does not receive any data packet, and then sends a ping packet to the receiving end. The structure of the ping packet includes: no (the ping packet does not allocate a sequence number), none (currently no retransmission), 0 (the current sliding window The sequence number of the first packet is decremented by 1), 2 (the sequence number of the packet to which the current sliding window has been sent), and none (currently no retransmission). After receiving the ping packet, the receiving end determines, according to 0 and 2 in the ping packet, that the data packet with the

sequence number

1 and 2 sent in the first transmission is not received, and the receiving end sends the data packet with the acknowledgement sequence number 0 to the transmitting end. And the 0th retransmission (ie, the first transmission) is a message whose sequence number is 1, 2 is not received; after receiving the message, the sender retransmits the data packet with the sequence number 1 to the receiving end (referred to as 1.1) And the data packet with sequence number 2 (referred to as 2.1), the structure of the data packet of 1.1 includes: 1, 1 (the first retransmission of the data packet with sequence number 1), 0, 2, 1 (the first time at this time) The serial number of the retransmitted data packet is 1), and the structure of the data packet of 2.1 includes: 2, 1 (the first retransmission of the data packet with sequence number 2), 0, 2, 2 (the first retransmission at this time) The serial number of the data packet is 2). The receiving end receives the data packet of 1.1 and the data packet of 2.1, and then sends a message to the sending end that the data packet with the sequence number 2 is received. After receiving the message, the transmitting end determines that the corresponding data packet before the sequence number 2 has been receive.

According to the embodiment of the present invention, the continuity of data transmission is ensured, the defect of continuously retransmitting the first data packet before the acknowledgement response message of the first data packet is not received is avoided, and the data transmission delay is reduced, and the transmission bandwidth is improved. .

FIG. 12 is a schematic diagram of an application of a data retransmission method according to an embodiment of the present invention. As shown in FIG. 12, the embodiment is described based on the structure shown in FIG. 9.

In the embodiment, the sliding window is 2, and the maximum number of transmissions is 3. For example, the transmitting end sequentially sends a data packet of sequence number 1 and a data packet of sequence number 2 to the receiving end according to the sliding window of 2. The structure of the data packet with sequence number 1 includes: 1, 0, 0, 1, and none; the structure of the data packet with sequence number 2 includes: 2, 0, 0, 2, and none. The data packet with sequence number 1 is lost, and the receiving end receives the data packet with sequence number 2, and the receiving end sends a message to the transmitting end that the data packet with the confirmation sequence number 0 (not present) has been received and the data packet with sequence number 1 has not been received; After receiving the message, the transmitting end retransmits the data packet with the sequence number 1 (referred to as 1.1) to the receiving end, and the structure of the data packet of 1.1 includes: 1, 1, 0, 2, 1. The receiving end does not receive the data packet of 1.1. The receiving end does not send any message to the sending end temporarily. When the sending end does not receive any message within the preset time, the sending end sends a ping packet to the receiving end. The structure of the ping packet includes: None, none, 0, 2, 1 (the sequence number of the first retransmission packet is 1). After receiving the ping packet, the receiving end determines that the data packet with the sequence number 1 of the first retransmission is not received according to the ping packet, and the receiving end sends the data packet with the acknowledgment sequence number 0 to the transmitting end and the first packet. The message of the sequence number 1 of the secondary retransmission (that is, the second transmission) is not received; after receiving the message, the transmitting end retransmits the data packet of sequence number 1 (referred to as 1.2), data of 1.2 to the receiving end. The structure of the packet includes: 1, 2 (the second retransmission of the data packet with sequence number 1), 0, 2, and 1 (the sequence number of the data packet retransmitted for the first time is 1), due to the maximum number of retransmissions. It is 2, so the sequence number of the packet including the second retransmission can be omitted here. Then, the sender can consider that the data packet with sequence number 1 has been received, adjust the current sliding window, and continue to send the data packet with sequence number 3 to the receiving end, and the structure of the data packet with sequence number 3 includes: 3, 0, 1, 3, None (no retransmissions in the current sliding window). For the receiving end, the data packet of 1.2 is still not received, and the data packet with sequence number 3 is received. Since the maximum number of retransmissions is 2, the sender will not send any data packet regardless of whether it receives 1.2 packets. The data packet of 1.3, therefore, the receiving end receives the data packet of 1.2 by default, and sends a message to the sending end that the data packet with the sequence number 3 is received, so that the sending end determines the data packet before the sequence number 3 according to the message. Received.

FIG. 13 is a schematic structural diagram of Embodiment 1 of a data retransmission apparatus according to the present invention. As shown in FIG. 13, the apparatus in this embodiment may include: a determining module 110, a sending module 120, and a receiving module 130, where

a determining module 110, configured to determine, by the sending end, that the first data packet sent by the Nth end is lost, the N An integer greater than or equal to 1;

The sending module 120 is configured to send, to the sending end, a first lost message, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received;

The receiving module 130 is configured to receive, by the sending end, the first data packet sent by the N+1th time, where the first data packet sent by the N+1th time is sent by the sending end according to the first lost message. The first packet.

Optionally, when N≥2, the receiving module 130 is further configured to receive a first sending indication sent by the sending end, where the first sending indication is used to indicate the first data sent by the Nth time The package has been sent;

The determining module 110 is specifically configured to: determine, according to the first sending indication, that the first data packet sent by the Nth time is lost.

The determining module 110 is specifically configured to: determine, according to the first sequence number, that the first sequence sent by the Nth time is less than or equal to the first packet loss of the first sequence number.

The determining module 110 is configured to: when the receiving module 130 does not receive the first data packet, determine, according to the first serial number and the number of transmissions N, that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number is lost.

Optionally, the sending module 120 is further configured to: before the receiving module 130 receives the first sending indication sent by the sending end, send a second lost message to the sending end, where the second lost message is used by the receiving module The first data packet indicating that the N-1th transmission is not received;

When receiving the first sending indication sent by the sending end, the receiving module 130 is specifically configured to: receive the first ping packet sent by the sending end, where the first ping packet includes the first sending indication.

Optionally, when N=1, the determining module 110 is specifically configured to: determine, according to the received serial number discontinuity of the data packet sent by the sending end, that the first data packet sent by the first time is lost, The sequence number of the first data packet is a missing sequence number.

Optionally, when the transmitting module 120 sends the first lost message to the sending end, the sending module 120 is specifically configured to: send a negative response message to the sending end, where the negative response message includes a sequence number of the first data packet. The previous serial number, the previous serial number of the sequence number of the first data packet is used by the transmitting end to determine that the first data packet is sent for the first time.

Optionally, when N=1, the sending module 120 is further configured to: when a data packet is not received within a preset time, send a third lost message to the sending end, where the third lost message is used. Indicates that no data packet has been received;

The receiving module 130 is further configured to receive a second sending indication sent by the sending end, where the second sending indication is used to indicate that the sending end has sent the first data packet that is sent for the first time;

The determining module 110 is specifically configured to: determine, according to the second sending indication, that the first data packet sent by the first time is lost.

Optionally, when receiving the second sending indication sent by the sending end, the receiving module 130 is specifically configured to: receive a second ping packet sent by the sending end, where the second ping packet includes a current sliding window. The left end number and the right end number;

The determining module 110 is specifically configured to: according to the left end number and the right end serial number of the current sliding window, determine that the first data packet whose serial number is located in the current sliding window is lost.

Optionally, the receiving module 130 is further configured to: before receiving the first data packet sent by the sending end of the N+1th time, receive the second data packet sent by the sending end, where the second The data packet carries the sequence number of the second data packet, the left end sequence number and the right end sequence number of the current sliding window;

The sending module 120 is further configured to: after the receiving module 130 receives the first data packet sent by the sending end of the N+1th time, when the sequence number of the second data packet is equal to the current sliding window And the first acknowledgement message is sent to the sending end, and the first acknowledgement response message is used to indicate that the data packet corresponding to the right end number of the current sliding window has been received. A data packet corresponding to the sequence number preceding the sequence number of the second data packet in the current sliding window has been received.

Optionally, if the N+1 is the maximum number of transmissions, the receiving module 130 is further configured to: after the sending module 120 sends the first lost message to the sending end, receive the third sent by the sending end. a data packet, where the third data packet carries a sequence number of the third data packet;

The sending module 120 is further configured to send a second acknowledgement response message to the sending end, where the second acknowledgement response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the third data packet has been received.

The device in this embodiment may be used to perform the technical solution executed by the receiving end in the foregoing method embodiments of the present invention. The implementation principle and technical effects are similar, and details are not described herein again.

FIG. 14 is a schematic structural diagram of Embodiment 2 of a data retransmission apparatus according to the present invention. As shown in FIG. 14, the apparatus in this embodiment may include: a receiving module 210 and a sending module 220, where

The receiving module 210 is configured to receive a first lost message sent by the receiving end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received, where the N is an integer greater than or equal to 1;

The sending module 220 is configured to send, according to the first lost message, the first data packet that is sent by the N+1th time to the receiving end.

Optionally, when N≥2, the sending module 220 is further configured to: before the receiving module 210 receives the first lost message sent by the receiving end, send a first sending indication to the receiving end, where The first sending indication is used to indicate that the first data packet sent by the Nth time has been sent.

Optionally, the receiving module 210 is further configured to receive, after the sending module 220 sends the first sending indication to the receiving end, a second lost message sent by the receiving end, where the second lost message is used. Instructing that the first data packet of the N-1th transmission is not received;

The sending module 220 is further configured to send, according to the second lost message, the first data packet sent by the Nth time to the receiving end;

When the sending module 220 sends the first sending indication to the receiving end, the sending module 220 is specifically configured to: when it is determined that the first sending of the Nth sending is not received by the receiving end, Sending the first ping packet to the receiving end when the data packet has received or lost the message, The first sending indication is included in the first ping packet.

Optionally, when receiving the first lost message sent by the receiving end, the receiving module 210 is specifically configured to: receive a negative response message sent by the receiving end, where the negative response message includes a sequence number of the first data packet. The previous serial number;

The device further includes: a change module 230, wherein the change module 230 is configured to change the left end number of the current sliding window to the front of the first data packet according to the previous serial number of the first data packet A serial number.

Optionally, the sending module 220 is further configured to: before the receiving module 210 receives the first lost message sent by the receiving end, send the data packet to the receiving end according to the sliding window;

The receiving module 210 is further configured to receive a third lost message sent by the receiving end, where the third lost message is used to indicate that the data packet is not received;

The sending module 220 is further configured to send, according to the third lost message, a second sending indication to the receiving end, where the second sending indication is used to indicate that the first data packet sent by the first sending is sent.

Optionally, the sending module 220 is configured to send a second ping packet to the receiving end, where the second ping packet is sent to the receiving end according to the third lost message. The packet includes a left end number and a right end number of the current sliding window; the left end number and the right end number of the current sliding window are used to indicate that the first data packet in the current sliding window has been sent.

Optionally, the apparatus in this embodiment further includes: an adjustment module 240, configured to send, by the sending module 220, the N+1th transmission to the receiving end according to the first lost message. After the first data packet is described, the current sliding window is adjusted according to the sequence number of the first data packet; and the N+1 is the maximum number of transmissions.

The device in this embodiment may be used to perform the technical solution executed by the sending end in the foregoing method embodiments, and the implementation principle and technical effects are similar, and details are not described herein again.

FIG. 15 is a schematic structural diagram of Embodiment 1 of the data retransmission system of the present invention. As shown in FIG. 15, the system of this embodiment may include: a control device 10 and a drone 20. The transceiver 21 of the drone 20 can communicate with the transceiver 11 of the control device 10, and the mounting table 22 of the drone is equipped with the imaging device 23, and the rotary wing 24 of the drone can change the steering so that the imaging device 23 can take a picture. To a different screen, the drone 20 can transmit the picture captured by the imaging device 23 to the transceiver 11 of the control device 10 via the transceiver 21. It should be noted that FIG. 15 is from one side of the drone 20. Two rotating wings of the drone 20 are shown, but the drone 20 can have four rotating wings.

It should be noted that the control device 10 can execute the technical solution executed by the receiving end, and the drone 20 can execute the technical solution executed by the transmitting end.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to the program instructions. The foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing storage medium includes: read-only memory (English: Read-Only Memory, ROM for short), random access memory (English: Random Access Memory, RAM), disk or A variety of media such as optical discs that can store program code.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A data retransmission method, comprising:

Determining, by the sending end, that the first data packet sent by the Nth time is lost, and the N is an integer greater than or equal to 1;

Sending a first lost message to the sending end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received;

And receiving, by the sending end, the first data packet sent by the N+1th time, where the first data packet sent by the N+1th time is the first data packet sent by the sending end according to the first lost message.
The method according to claim 1, wherein when N ≥ 2, determining that the first data packet sent by the transmitting end is lost for the Nth time comprises:

Receiving, by the sending end, a first sending indication, where the first sending indication is used to indicate that the first data packet sent by the Nth time has been sent;

Determining, according to the first sending indication, that the first data packet sent by the Nth time is lost.
The method according to claim 2, wherein the first transmission indication comprises a first sequence number of the data packet sent by the Nth time, and the first sequence number is used to indicate that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number has been sent;

Determining, according to the first sending indication, that the first data packet sent by the Nth time is lost, including: determining, when the first data packet is not received, determining, according to the first sequence number, an Nth transmission The first data packet whose sequence number is less than or equal to the first serial number is lost.
The method according to claim 2, wherein the first transmission indication comprises a number of transmissions N and a first sequence number, and the first sequence number and the number of transmissions N are used to indicate that the sequence number of the Nth transmission is less than or a data packet equal to the first serial number has been sent;

Determining, according to the first sending indication, that the first data packet sent by the Nth time is lost, including: determining, according to the first sequence number and the number of sending times N, that the sequence number of the Nth transmission is less than or equal to The first serial number packet is lost.
The method according to any one of claims 2-4, wherein before the receiving the first sending indication sent by the sending end, the method further includes:

Transmitting, to the sending end, a second lost message, where the second lost message is used to indicate that the first data packet sent by the (N-1)th transmission is not received;

Receiving the first sending indication sent by the sending end, comprising: receiving, sending, by the sending end The first ping packet includes the first sending indication in the first ping packet.
The method according to claim 1, wherein when N=1, determining that the first data packet sent by the transmitting end is lost, including:

And determining, according to the received sequence number of the data packet sent by the sending end, that the first data packet sent by the first time is lost, and the sequence number of the first data packet is a missing sequence number.
The method according to claim 6, wherein the sending the first lost message to the transmitting end comprises: sending a negative response message to the sending end, where the negative response message includes a sequence number of the first data packet The previous serial number, the previous serial number of the serial number of the first data packet is used by the transmitting end to determine that the first data packet is sent for the first time.
The method according to claim 1, wherein when N=1, determining that the first data packet sent by the transmitting end is lost, including:

When the data packet is not received within the preset time, sending a third lost message to the sending end, where the third lost message is used to indicate that the data packet is not received;

Receiving, by the sending end, a second sending indication, where the second sending indication is used to indicate that the sending end has sent the first data packet that is sent for the first time;

Determining, according to the second sending instruction, that the first data packet sent by the first time is lost.
The method according to claim 8, wherein receiving the second sending indication sent by the sending end comprises: receiving a second ping packet sent by the sending end, where the second ping packet includes a current sliding window The left end number and the right end number;

Determining, according to the second sending indication, that the first data packet sent by the first time is lost, including: determining, according to a left end number and a right end number of the current sliding window, that the serial number is located in the current sliding window The first packet is lost.
The method according to any one of claims 1-9, wherein before receiving the first data packet sent by the transmitting end by the N+1th time, the method further includes:

Receiving a second data packet sent by the sending end, where the second data packet carries a sequence number of the second data packet, a left end serial number and a right end serial number of the current sliding window;

After the receiving, by the sending end, the first data packet sent by the N+1th time, the method further includes:

When the sequence number of the second data packet is equal to the right end number of the current sliding window, and the data packet corresponding to the right end number of the current sliding window to the right end serial number has been received, send the first to the sending end. Confirming a response message, the first confirmation response message is used to indicate the current slip The data packet corresponding to the sequence number before the sequence number of the second data packet in the window has been received.
The method according to any one of claims 1 to 10, wherein the first data packet sent by the (N+1)th time carries the number of transmissions N+1 of the first data packet.
The method according to any one of claims 1 to 11, wherein, if the N+1 is the maximum number of transmissions, after the sending the first lost message to the transmitting end, the method further includes:

Receiving a third data packet sent by the sending end, where the third data packet carries a sequence number of the third data packet;

And sending, by the sending end, a second acknowledgement response message, where the second acknowledgement response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the third data packet has been received.
A data retransmission method, comprising:

Receiving a first lost message sent by the receiving end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received, where the N is an integer greater than or equal to 1;

And sending, according to the first lost message, the first data packet sent by the N+1th time to the receiving end.
The method according to claim 13, wherein when N≥2, the receiving the first lost message sent by the receiving end comprises:

Sending, by the receiving end, a first sending indication, where the first sending indication is used to indicate that the first data packet sent by the Nth time has been sent.
The method according to claim 14, wherein the first transmission indication comprises a first sequence number of the data packet transmitted by the Nth time, and the first sequence number is used to indicate that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number has been sent.
The method according to claim 14, wherein the first transmission indication comprises a number of transmissions N and a first sequence number, and the number of transmissions N and the first sequence number are used to indicate that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number has been sent.
The method according to any one of claims 14-16, wherein before the sending the first sending indication to the receiving end, the method further includes:

Receiving a second lost message sent by the receiving end, where the second lost message is used to indicate that the first data packet that is not received by the N-1th transmission is received;

Transmitting, according to the second lost message, the first data packet sent by the Nth time to the receiving end;

Sending the first sending indication to the receiving end, including:

When it is determined that the message sent by the receiving end to indicate that the first data packet sent by the Nth transmission has been received or lost is received within a preset time, sending the first ping packet to the receiving end The first ping packet includes the first sending indication.
The method according to claim 13, wherein the receiving the first lost message sent by the receiving end comprises: receiving a negative response message sent by the receiving end, where the negative response message includes the first data packet The previous serial number of the serial number;

The method further includes:

And changing, according to the previous serial number of the sequence number of the first data packet, the left end number of the current sliding window to the previous serial number of the serial number of the first data packet.
The method according to claim 13, wherein before receiving the first lost message sent by the receiving end, the method further includes:

Transmitting a data packet to the receiving end according to a sliding window;

Receiving, by the receiving end, a third lost message, where the third lost message is used to indicate that the data packet is not received;

And sending, by the third lost message, a second sending indication to the receiving end, where the second sending indication is used to indicate that the first data packet that is sent the first time is sent.
The method according to claim 19, wherein the sending the second sending indication to the receiving end according to the third lost message comprises: sending a second ping packet to the receiving end, the second ping packet The left end serial number and the right end serial number of the current sliding window are included; the left end serial number and the right end serial number of the current sliding window product are used to indicate that the first data packet in the current sliding window has been sent.
The method according to any one of claims 13 to 20, wherein the N+1 is the maximum number of transmissions, and the sending the N+1th transmission to the receiving end according to the first lost message After the first data packet, the method further includes:

Adjusting the current sliding window according to the sequence number of the first data packet.
A data retransmission device, comprising:

a determining module, configured to determine, by the sending end, the first data packet sent by the Nth time, where the N is an integer greater than or equal to 1;

a sending module, configured to send a first lost message to the sending end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received;

a receiving module, configured to receive, by the sending end, the first data packet sent by the N+1th time, where the first data packet sent by the N+1th time is sent by the sending end according to the first lost message A packet of data.
The device according to claim 22, wherein, when N≥2, the receiving module is further configured to receive a first sending indication sent by the sending end, where the first sending indication is used to indicate the Nth The first data packet sent once is sent;

The determining module is specifically configured to: determine, according to the first sending indication, that the first data packet sent by the Nth time is lost.
The apparatus according to claim 23, wherein the first transmission indication comprises a first sequence number of the data packet transmitted by the Nth time, and the first sequence number is used to indicate that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number has been sent;

The determining module is configured to: when the receiving module does not receive the first data packet, determine, according to the first serial number, that the sequence number of the Nth transmission is less than or equal to the first sequence number The packet is lost.
The apparatus according to claim 23, wherein the first transmission indication comprises a number of transmissions N and a first sequence number, and the first sequence number and the number of transmissions N are used to indicate that the sequence number of the Nth transmission is less than or a data packet equal to the first serial number has been sent;

The determining module is specifically configured to: determine, according to the first serial number and the number of transmissions N, that the sequence number sent by the Nth time is less than or equal to the data packet loss of the first sequence number.
The device according to any one of claims 23-25, wherein the sending module is further configured to send, to the sending end, before the receiving module receives the first sending indication sent by the sending end a second lost message, where the second lost message is used to indicate that the first data packet that is not received by the (N-1)th transmission is received;

The receiving module, when receiving the first sending indication sent by the sending end, is specifically configured to: receive the first ping packet sent by the sending end, where the first ping packet includes the first sending indication.
The apparatus according to claim 22, wherein, when N=1, the determining module is configured to: determine, according to the received sequence number of the data packet sent by the sending end, that the first sending is performed The first data packet is lost, and the sequence number of the first data packet is a missing serial number.
The device according to claim 27, wherein the sending module, when transmitting the first lost message to the sending end, is specifically configured to: send a negative response message to the sending end, The negative response message includes a previous sequence number of the sequence number of the first data packet, and the previous sequence number of the sequence number of the first data packet is used by the sender to determine that the first data packet is sent for the first time. .
The device according to claim 22, wherein, when N=1, the sending module is further configured to: when the data packet is not received within a preset time, send a third lost message to the sending end. The third lost message is used to indicate that the data packet is not received;

The receiving module is further configured to receive a second sending indication sent by the sending end, where the second sending indication is used to indicate that the sending end has sent the first data packet that is sent for the first time;

The determining module is specifically configured to: determine, according to the second sending indication, that the first data packet sent by the first time is lost.
The device according to claim 29, wherein the receiving module, when receiving the second sending indication sent by the sending end, is specifically configured to: receive a second ping packet sent by the sending end, where the The second ping packet includes the left end serial number and the right end serial number of the current sliding window;

The determining module is specifically configured to: determine, according to the left end number and the right end serial number of the current sliding window, that the first data packet whose serial number is located in the current sliding window is lost.
The device according to any one of claims 22-30, wherein the receiving module is further configured to receive the first data packet sent by the transmitting end before the N+1th transmission. a second data packet sent by the sending end, where the second data packet carries a sequence number of the second data packet, a left end serial number and a right end serial number of the current sliding window;

The sending module is further configured to: after the receiving module receives the first data packet sent by the sending end of the N+1th time, when the sequence number of the second data packet is equal to the right end of the current sliding window a sequence number, and the data packet corresponding to the right end of the current sliding window is received, and the first acknowledgement response message is sent to the sending end, where the first acknowledgement response message is used to indicate the current The data packet corresponding to the sequence number before the serial number of the second data packet in the sliding window has been received.
The device according to any one of claims 22 to 31, wherein the first data packet sent by the (N+1)th time carries the number of transmissions N+1 of the first data packet.
The device according to any one of claims 22 to 32, wherein, if the N+1 is the maximum number of transmissions, the receiving module is further configured to: after the sending module sends the first lost message to the sending end, Receiving a third data packet sent by the sending end, where the third data packet carries the The serial number of the third data packet;

The sending module is further configured to send a second acknowledgment response message to the sending end, where the second acknowledgment response message is used to indicate that the data packet corresponding to the sequence number before the sequence number of the third data packet has been received.
A data retransmission device, comprising:

a receiving module, configured to receive a first lost message sent by the receiving end, where the first lost message is used to indicate that the first data packet sent by the Nth time is not received, where the N is an integer greater than or equal to 1;

And a sending module, configured to send, according to the first lost message, the first data packet sent by the N+1th time to the receiving end.
The device according to claim 34, wherein, when N≥2, the sending module is further configured to: before the receiving module receives the first lost message sent by the receiving end, to the receiving end Sending a first sending indication, where the first sending indication is used to indicate that the first data packet sent by the Nth time has been sent.
The apparatus according to claim 35, wherein the first transmission indication comprises a first sequence number of the data packet transmitted by the Nth time, and the first sequence number is used to indicate that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number has been sent.
The apparatus according to claim 35, wherein the first transmission indication comprises a number of transmissions N and a first sequence number, and the number of transmissions N and the first sequence number are used to indicate that the sequence number of the Nth transmission is less than or equal to The data packet of the first serial number has been sent.
The device according to any one of claims 35 to 37, wherein the receiving module is further configured to: before the sending module sends the first sending indication to the receiving end, receive the first sending by the receiving end a second lost message, the second lost message is used to indicate that the first data packet that is not received by the N-1th transmission is received;

The sending module is further configured to send, according to the second lost message, the first data packet sent by the Nth time to the receiving end;

When the sending module sends the first sending indication to the receiving end, the sending module is specifically configured to: when it is determined that the first data sent by the receiving end to indicate the Nth sending is not received within a preset time When the packet has received or lost, the first ping packet is sent to the receiving end, and the first ping packet includes the first sending indication.
The device according to claim 34, wherein said receiving module is receiving When the first lost message is sent by the receiving end, it is specifically used to: receive a negative response message sent by the receiving end, where the negative response message includes a previous serial number of the sequence number of the first data packet;

The device further includes:

The change module is configured to change the left end number of the current sliding window to the previous serial number of the first data packet according to the previous serial number of the first data packet.
The device according to claim 34, wherein the sending module is further configured to: before the receiving module receives the first lost message sent by the receiving end, send the data packet to the receiving end according to the sliding window;

The receiving module is further configured to receive a third lost message sent by the receiving end, where the third lost message is used to indicate that the data packet is not received;

The sending module is further configured to send, according to the third lost message, a second sending indication to the receiving end, where the second sending indication is used to indicate that the first data packet that is sent the first time is sent.
The device according to claim 40, wherein the sending module is configured to: send a second to the receiving end when sending a second sending indication to the receiving end according to the third lost message a ping packet, where the second ping packet includes a left end number and a right end number of the current sliding window; the left end number and the right end number of the current sliding window are used to indicate that the first data packet in the current sliding window has been sent.
The device according to any one of claims 34 to 41, further comprising:

And an adjusting module, configured to: after the sending, by the sending module, send the first data packet sent by the N+1th time to the receiving end according to the first lost message, adjust according to the sequence number of the first data packet Current sliding window; the N+1 is the maximum number of transmissions.