CN110636549B

CN110636549B - Data transmission method, network equipment and terminal equipment

Info

Publication number: CN110636549B
Application number: CN201810649847.0A
Authority: CN
Inventors: 袁世通; 朱元萍; 李铕; 戴明增; 刘菁
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-06-21
Filing date: 2018-06-21
Publication date: 2022-04-12
Anticipated expiration: 2038-06-21
Also published as: WO2019242755A1; CN110636549A

Abstract

The embodiment of the application discloses a data transmission method, network equipment and terminal equipment, wherein the method comprises the following steps: the first network equipment receives first configuration information of the second network equipment, wherein the first configuration information comprises at least one of the following information: an ARQ feedback mode of a first bearer, a node identifier of first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier; the first network equipment determines whether to perform ARQ feedback according to the first configuration information. Data transmission can be efficiently performed under different ARQ mechanisms.

Description

Data transmission method, network equipment and terminal equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a data transmission method, a network device, and a terminal device.

Background

A Long Term Evolution (LTE) relay (relay) technology is a technology for forwarding data between a base station (evolved non-radio access network node B, eNB) and User Equipment (UE) by deploying a Relay Node (RN) in a network, and can enhance network capacity, solve backhaul connection between base stations, and solve coverage holes.

In a wireless relay networking scene facing 5G (5th generation mobile networks or 5th generation wireless systems, 5G), a multi-hop wireless relay and multi-connection scene are supported. In a networking scene of multi-hop wireless relay, the number of relay nodes participating in data forwarding between user equipment and a base station is one or more, and the number of the relay nodes is the hop count.

In a multi-hop wireless relay networking scenario, the relay nodes may adopt Radio Link Control (RLC) management on a hop-by-hop basis, that is, each relay node may directly adopt a 5G/NR (new radio, NR) manner to process data destined for a next hop or a previous hop, and may also adopt end-to-end RLC management. In order to ensure the reliability of data transmission, an Automatic Repeat Request (ARQ) function is supported in the RLC layer.

In 5G, the ARQ mechanism may be a hop-by-hop ARQ or an end-to-end ARQ, different ARQ mechanisms have different data operation modes, and how to ensure effective data transmission under different ARQ mechanisms is a problem to be solved.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present application is to provide a data transmission method, a network device, and a terminal device, which can effectively perform data transmission under different ARQ mechanisms.

In a first aspect, an embodiment of the present application provides a data transmission method, where a first network device receives first configuration information of a second network device, where the first configuration information includes at least one of the following information: ARQ feedback information of a first bearer, a node identifier of the first network device, an identifier of the first bearer, an identifier of a terminal device, a logical channel identifier, and an ARQ target node identifier; and the first network equipment determines whether to perform ARQ feedback according to the first configuration information.

In this implementation, the first network device determines whether to perform ARQ feedback based on the first configuration information of the second network device, and may efficiently perform data transmission under different ARQ mechanisms.

In one possible implementation, the ARQ feedback information of the first bearer includes: one of end-to-end feedback, hop-by-hop feedback, and a feedback indication; the feedback indication is used for indicating the first network device to perform ARQ feedback on the data of the first bearer or not to perform ARQ feedback on the data of the first bearer.

In a possible implementation manner, the ARQ feedback information of the first configuration information corresponds to one or more first bearers of the terminal device, or corresponds to all bearers of the terminal device.

In a possible implementation manner, the first configuration information may further include a transmission direction indication, where the transmission direction indication includes uplink transmission or downlink transmission.

In a possible implementation manner, the determining, by the first network device, whether to perform ARQ feedback according to the first configuration information includes:

if the ARQ feedback information comprises end-to-end feedback, if the identifier of the first network equipment is the same as the identifier of the ARQ target node, the first network equipment sends the ARQ feedback, and if the identifier of the first network equipment is different from the identifier of the ARQ target node, the first network equipment does not carry out the ARQ feedback and forwards the data of the first bearer;

if the ARQ feedback information comprises hop-by-hop feedback, the first network equipment sends the ARQ feedback when receiving the data of the first bearer;

if the ARQ feedback information comprises the feedback indication, the first network equipment determines whether to perform ARQ feedback on the data of the first bearer according to the feedback indication.

In a second aspect, an embodiment of the present application provides a data transmission method, where a second network device determines first configuration information, and the second network device sends the first configuration information to a first network device, where the first configuration information includes at least one of the following information: the ARQ feedback information of the first bearer, the node identifier of the first network device, the identifier of the first bearer, the identifier of the terminal device, the identifier of the logical channel, and the identifier of the ARQ target node.

In this implementation, the second network device sends the first configuration information to the first network device, and the first network device determines whether to perform ARQ feedback based on the first configuration information, so that data transmission can be efficiently performed under different ARQ mechanisms.

In a third aspect, an embodiment of the present application provides a data transmission method, where a first network device sends backhaul indication information to a third network device, where the backhaul indication information is used to notify the third network device to receive backhaul data, and the backhaul data is data that the first network device fails to send and belongs to the third network device; the first network device sends the backhaul data to the third network device; the first network device is a superior node of the third network device.

In this implementation, the third network device forwards the data to the upper node of the first network device via the first network device, the upper node of the first network device fails to decode the data, and the first network device may send the backhaul indication information to the third network device and send the data to the third network device, so that the third network device transmits the data to the receiving end through another path, and retransmission and recovery of the data across multiple hops may be implemented.

In a possible implementation manner, after the first network device sends the backhaul indication information, the first network device receives feedback information sent by the third network device.

In a possible implementation manner, after receiving the feedback information, the first network device stops receiving the uplink data sent by the third network device.

In a fourth aspect, an embodiment of the present application provides a data transmission method, where a terminal device receives third configuration information from a second network device, where the third configuration information includes retransmission indication information, where the retransmission indication information is used to indicate the terminal device to perform data retransmission, and the retransmission indication information includes a sequence number SN of a packet data unit PDU of a packet data convergence protocol PDCP layer; and the terminal equipment retransmits the data of the PDCP PDU according to the retransmission indication information.

In this implementation manner, the second network device sends the third configuration information to the terminal device, and the terminal device performs data retransmission of the PDCP PDU according to the retransmission indication information, so that data retransmission can be effectively implemented and the utilization rate of air interface resources is improved.

In one possible implementation, the retransmission indication information includes a cause value and/or a number K of retransmission packets.

In a possible implementation manner, the performing, by the terminal device, data retransmission of the PDCP PDU according to the retransmission indication information includes:

the terminal equipment retransmits data after all SNs according to the SNs;

the data after all SNs includes a data packet to which packet data of all PDCP PDUs is assigned a PDCP packet sequence number after the SNs.

and the terminal equipment retransmits the K data packets with the sequence number of the PDCP PDU being after the SN.

In a fifth aspect, an embodiment of the present application provides a computer storage medium, where the computer storage medium stores a program, and the program, when executed, causes a terminal device to execute any one of the data transmission methods described in the first aspect.

In a sixth aspect, an embodiment of the present application provides a computer storage medium, where the computer storage medium stores a program, and the program, when executed, causes a terminal device to execute any one of the data transmission methods described in the second aspect.

In a seventh aspect, an embodiment of the present application provides a computer storage medium, where the computer storage medium stores a program, and the program, when executed, causes a terminal device to execute any one of the data transmission methods described in the third aspect.

In an eighth aspect, an embodiment of the present application provides a computer storage medium, where the computer storage medium stores a program, and the program, when executed, causes a terminal device to execute any one of the data transmission methods described in the fourth aspect.

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

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

In an eleventh aspect, an embodiment of the present application provides a first network device, where the first network device has a function of implementing a behavior of the first network device in the example of the data transmission method in the third aspect. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units or modules corresponding to the above functions.

In a twelfth aspect, an embodiment of the present application provides a terminal device, where the terminal device has a function of implementing a behavior of the terminal device in the example of the data transmission method described in the fourth aspect. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units or modules corresponding to the above functions.

In a thirteenth aspect, an embodiment of the present application provides a first network device, where the first network device may include a receiver, a processor, and a memory, where the processor is configured to support the first network device to perform a function corresponding to the first network device in the data transmission method according to the first aspect. The receiver is used for communicating with other devices. The memory is for coupling with the processor and holds program instructions and data necessary for the first network device.

In a fourteenth aspect, the present embodiment provides a second network device, where the second network device may include a transmitter, a processor, and a memory, where the processor is configured to support the second network device to perform a function corresponding to the second network device in the data transmission method according to the second aspect. The transmitter is used for communicating with other devices. The memory is for coupling with the processor and holds program instructions and data necessary for the second network device.

In a fifteenth aspect, the present application provides a first network device, where the first network device may include a transmitter, a processor, and a memory, where the processor is configured to support the first network device to perform a function corresponding to the first network device in the data transmission method according to the third aspect. The transmitter is used for communicating with other devices. The memory is for coupling with the processor and holds program instructions and data necessary for the first network device.

In a sixteenth aspect, an embodiment of the present application provides a terminal device, where the terminal device may include a receiver, a processor, and a memory, where the processor is configured to support the terminal device to perform a corresponding function of the terminal device in the data transmission method according to the fourth aspect. The receiver is used for communicating with other devices. The memory is for coupling with the processor and holds program instructions and data necessary for the first network device.

In a seventeenth aspect, embodiments of the present application provide a computer program product containing instructions, which when run on a computer, causes the computer to execute the data transmission method according to the first aspect.

In an eighteenth aspect, embodiments of the present application provide a computer program product containing instructions that, when executed on a computer, cause the computer to perform the data transmission method of the second aspect.

In a nineteenth aspect, embodiments of the present application provide a computer program product containing instructions that, when executed on a computer, cause the computer to perform the data transmission method of the third aspect.

In a twentieth aspect, embodiments of the present application provide a computer program product containing instructions that, when executed on a computer, cause the computer to perform the data transmission method according to the fourth aspect.

In a twenty-first aspect, the present application provides a chip system, where the chip system includes a processor, configured to implement the functions referred to in the foregoing first aspect, for example, to generate or process data and/or information referred to in the foregoing method.

In one design, the system-on-chip further includes a memory to hold program instructions and data necessary for the first network device. The chip system may be formed by a chip, or may include a chip and other discrete devices.

In a twenty-second aspect, embodiments of the present application provide a chip system, where the chip system includes a processor, and is configured to implement the functions referred to in the foregoing second aspect, for example, to generate or process data and/or information referred to in the foregoing method.

In one design, the system-on-chip further includes a memory to hold program instructions and data necessary for the second network device. The chip system may be formed by a chip, or may include a chip and other discrete devices.

In a twenty-third aspect, embodiments of the present application provide a chip system, where the chip system includes a processor, configured to implement the functions referred to in the foregoing third aspect, for example, to generate or process data and/or information referred to in the foregoing method.

In a twenty-fourth aspect, the present application provides a chip system, where the chip system includes a processor, and is used for implementing the functions referred to in the foregoing fourth aspect, for example, generating or processing data and/or information referred to in the foregoing method.

In one embodiment, the chip system further includes a memory for storing program instructions and data necessary for the terminal device. The chip system may be formed by a chip, or may include a chip and other discrete devices.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present application, the drawings required to be used in the embodiments or the background art of the present application will be described below.

Fig. 1 is a schematic structural diagram of a data transmission system disclosed in an embodiment of the present application;

fig. 2 is a schematic flow chart of a data transmission method disclosed in an embodiment of the present application;

fig. 3 is a schematic structural diagram of another data transmission system disclosed in the embodiment of the present application;

fig. 4 is a schematic flow chart of another data transmission method disclosed in the embodiments of the present application;

fig. 5 is a schematic structural diagram of a user plane protocol stack disclosed in an embodiment of the present application;

fig. 6 is a schematic structural diagram of another user plane protocol stack disclosed in the embodiment of the present application;

fig. 7 is a schematic flow chart of another data transmission method disclosed in the embodiments of the present application;

fig. 8 is a schematic flow chart of another data transmission method disclosed in the embodiments of the present application;

fig. 9 is a schematic structural diagram of a first network device disclosed in an embodiment of the present application;

fig. 10 is a schematic structural diagram of another first network device disclosed in an embodiment of the present application;

fig. 11 is a schematic structural diagram of a second network device disclosed in an embodiment of the present application;

fig. 12 is a schematic structural diagram of another second network device disclosed in an embodiment of the present application;

fig. 13 is a schematic structural diagram of a terminal device disclosed in an embodiment of the present application;

fig. 14 is a schematic structural diagram of another terminal device disclosed in the embodiment of the present application.

Detailed Description

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

In order to better understand the data transmission method, the network device, and the terminal device disclosed in the embodiments of the present application, first, a data transmission system implemented in the present application is described below. Referring to fig. 1, fig. 1 is a schematic structural diagram of a data transmission system disclosed in an embodiment of the present application, where the data transmission system may include a terminal device, an integrated access and backhaul node (IAB node), and an anchor base station (e.g., an IAB node), and for example, the relay node in fig. 1 includes: a first relay node (e.g., IAB node 1), a second relay node (e.g., IAB node 2), a third relay node (e.g., IAB node 3), and a fourth relay node (e.g., IAB node 4). The terminal equipment establishes communication connection with an IAB node1, the IAB node1 establishes communication connection with an IAB node 2 and an IAB node3 respectively, the IAB node 2 establishes communication connection with an IAB node4, the IAB node3 establishes communication connection with the IAB node4, and the IAB node4 establishes communication connection with an IAB node. The link between the IAB node4 and the IAB node may be a Backhaul (BH) link, and the link between the terminal device and the IAB node1 may be an Access (AC) link.

For convenience of description, the meanings of the terms in the present application are defined as follows:

and (3) uplink transmission: the device transmits data or signals to the network, and the device comprises a terminal, an IAB node and the like.

Downlink transmission: the device receives data or signals transmitted by the network, and similarly, the device comprises a terminal, an IAB node and the like.

The upper node: in uplink transmission, a node receiving data or a signal, or a node sending data or a signal in downlink transmission, for example, IAB node1 is an upper node of a terminal device, IAB node 2 is an upper node of IAB node1, and so on. It should be understood that, in the uplink transmission, the node which performs data forwarding after the sending node is all referred to as the upper node, that is, the upper node is not limited to the direct upper node, which refers to the node which directly receives data in the uplink transmission without forwarding through other nodes, or in the downlink transmission, the node which directly receives data is directly transmitted by the data receiving node without forwarding through other nodes.

A subordinate node: for example, the IAB node1 is a lower node of the IAB node 2, and the IAB node 2 is a lower node of the IAB node4, and the like. It should be understood that all nodes that transmit or forward data to a data receiving node through a data transmitting node at the time of uplink transmission are referred to as subordinate nodes, i.e., the subordinate nodes are not limited to direct subordinate nodes, which means nodes that transmit data directly received by a receiving node at the time of uplink transmission without passing through forwarding of other nodes, or nodes that receive data directly at the time of downlink transmission without passing through forwarding of other nodes.

When the terminal device transmits uplink data to the IAB node, in a possible implementation manner, the terminal device may transmit the data to the IAB node sequentially via the IAB node1, the IAB node 2, and the IAB node4, where the IAB node1 is a superior node (i.e., a parent node) of the terminal device, the IAB node 2 is the superior node of the IAB node1, the IAB node4 is the superior node of the IAB node 2, and the IAB node is the superior node of the IAB node 4. In another possible implementation manner, the terminal device may transmit data to the IAB node sequentially via the IAB node1, the IAB node3, and the IAB node4, where the IAB node1 is an upper node of the terminal device, the IAB node3 is an upper node of the IAB node1, the IAB node4 is an upper node of the IAB node3, and the IAB node4 is an upper node of the IAB node 4. Further, the network device sends the data to one or more of a User Plane Function (UPF), a Serving Gateway (SGW) device, or a public data network gateway (PGW) device in the 5G network.

In a possible implementation manner, the IAB node may transmit data to the terminal device sequentially via an IAB node4, an IAB node 2, and an IAB node1, where the IAB node4 is an upper node of the IAB node4, the IAB node 2 is an upper node of the IAB node4, the IAB node1 is an upper node of the IAB node 2, and the terminal device is an upper node of the IAB node 1. In another possible implementation manner, the IAB node may transmit data to the terminal device sequentially via the IAB node4, the IAB node3, and the IAB node1, where the IAB node4 is an upper node of the IAB node, the IAB node3 is an upper node of the IAB node4, the IAB node1 is an upper node of the IAB node3, and the terminal device is an upper node of the IAB node 1.

Generally, in order to guarantee reliable transmission of data, an ARQ function is included in the RLC protocol. ARQ confirms whether transmission is correct by checking data of a transmitting side at a data receiving side, transmits an Acknowledgement (ACK) signal to the transmitting side if the data of the transmitting side is correctly received, and transmits a non-Acknowledgement (NACK) signal to the transmitting side if the receiving side cannot correctly receive the data transmitted by the transmitting side. Checking the data may include performing a CRC check on the data or not receiving a packet within a certain time. For example, if the second relay node does not successfully receive the data sent by the first relay node, a NACK signal is sent to the first node to the second relay node, and the first node retransmits the data through ARQ after receiving the NACK signal. Automatic repeat requests may include hop-by-hop ARQ and end-to-end ARQ.

The hop-by-hop ARQ is to immediately feed back a transmission result to a sender for each received data packet, for example, a second relay node decodes first data from a first relay node after receiving the first data, and if the decoding is successful, an ACK signal is returned; if the decoding fails, a NACK signal is returned. After the first relay node receives the ACK signal from the second relay node, second data is sent to the second relay node, and the first data is deleted from the cache of the first relay node; when the first relay node receives the NACK signal from the second relay node, the first relay node retransmits the first data. For example, the buffer in the embodiment of the present application may be an RLC buffer.

The end-to-end ARQ means that the intermediate node does not decode and feed back the received data, the intermediate node forwards the received data after receiving the data, and the target node for receiving the data checks the received data after receiving the data and feeds back the receiving result to the sending source of the data. If the target node of data reception fails to check or waits for too long time, NACK is fed back, and if the data is correctly received, ACK is fed back.

In the hop-by-hop ARQ, when a first relay node receives an ACK signal from a second relay node, the data decoded successfully by the second relay node is deleted from the cache of the first relay node, and if the link of the second relay node is abnormal after ACK feedback, the data decoded successfully by the second relay node cannot be continuously sent to a superior node, that is, the data sent to the second relay node by the first relay node cannot be recovered or retransmitted by the first relay node.

For end-to-end ARQ, because the intermediate node does not feed back the ACK/NACK signal, only the receiving end feeds back the ACK/NACK signal, if the target node receiving the data feeds back the NACK signal, the transmitting end cannot determine the specific failed link, and if the data is continuously retransmitted to the target node through the original intermediate nodes, data failure may also be caused, which may cause waste of air interface transmission resources of the intermediate node and reduce utilization rate of air interface resources.

In the embodiment of the application, a first network device receives first configuration information of a second network device, and the first network device determines whether to perform ARQ feedback according to the first configuration information. The first network device may be the IAB node in fig. 1, for example, IAB node1 or IAB node4, and the second network device may be the IAB node in fig. 1. The first configuration information includes at least one of the following information: the ARQ feedback information of the first bearer, the node identifier of the first network device, the identifier of the first bearer, the identifier of the terminal device, the logical channel identifier, and the identifier of the ARQ target node. According to the embodiment of the application, the relay nodes which need to perform ARQ feedback can be configured based on the IAB donor, other relay nodes in the transmission path can directly forward the data sent by the subordinate nodes to the superior nodes, the multi-hop-crossing data retransmission recovery can be performed, the sending end is not required to send the data to the receiving end again through each intermediate node, and the utilization rate of air interface resources is improved. When the sending end is a terminal device, the receiving end can be an IAB donor; when the sending end is an IAB donor, the receiving end may be a terminal device.

The technical scheme of the embodiment of the invention can be applied to various communication systems, such as: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (Long Term Evolution, LTE) System, an LTE Frequency Division Duplex (FDD) System, an LTE Time Division Duplex (TDD), a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication System, a fifth-Generation Mobile communication technology (5th-Generation, 5G) communication System, or a New Radio System (NR).

In the embodiment of the present invention, the IAB donor may be a device for communicating with a Mobile Station, and specifically may be any one of an Access Point (AP) in a Wireless Local Area Network (WLAN), a Global System for Mobile Communication (GSM) or a Base Transceiver Station (BTS) in Code Division Multiple Access (CDMA), a Base Station (NB) in a Wideband Code Division Multiple Access (WCDMA), an evolved Node B (eNB) in an LTE System, a relay Station or an Access Point, a vehicle-mounted device, a wearable device, an Access Network device in a NodeB 5G Network, and an Access Network device in a future evolved Public Land Mobile Network (PLMN).

The terminal device may also be referred to as a User Equipment (UE), a mobile Station, an access terminal, a subscriber unit, a subscriber Station, a mobile Station, a remote terminal, a mobile device, a terminal, a Wireless communication device, a User agent, a User Equipment, or the like, and may specifically be any one of a Station (ST) in a WLAN, a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) Station, a Personal Digital Assistant (PDA), a handheld device with a Wireless communication function, a computing device, other processing devices connected to a Wireless modem, a vehicle-mounted device, a wearable device, a mobile Station in a future 5G network, a terminal device in a future evolved PLMN network, and the like.

Based on the data transmission system shown in fig. 1, please refer to fig. 2, and fig. 2 is a data transmission method provided in the embodiment of the present application, which includes, but is not limited to, the following steps:

step S201: the second network device sends the first configuration information to the first network device.

Taking the data transmission system shown in fig. 1 as an example, if the terminal device transmits uplink data to the IAB node (i.e., the second network device) via the IAB node1, the IAB node 2, and the IAB node4, the first network device may be the IAB node1, and the third network device may be the IAB node 2 or the IAB node 4; or the first network device may be an IAB node 2, the third network device may be an IAB node4, and the third network device is a superior node of the first network device. Before the terminal device transmits uplink data to the IAB donor, the IAB donor may send the first configuration information to the first network device. In a possible implementation manner, before the terminal device transmits uplink data to the IAB node, the IAB node may send the first configuration information to all or part of the intermediate nodes (i.e., one or more of the IAB node1, the IAB node 2, and the IAB node 4), respectively.

Taking the data transmission system shown in fig. 1 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node4, the IAB node 2, and the IAB node1, the first network device may be the IAB node4, and the third network device may be the IAB node 2 or the IAB node 1; or the first network device may be an IAB node 2, the third network device may be an IAB node1, and the third network device is a subordinate node of the first network device. Before the IAB node transmits downlink data to the terminal device, the IAB node may send first configuration information to the IAB node 4. In a possible implementation manner, before the IAB node transmits downlink data to the terminal device, the IAB node may send the first configuration information to all or part of the intermediate nodes (i.e., one or more of the IAB node4, the IAB node 2, and the IAB node 1), respectively.

Wherein the first configuration information may include at least one of the following information: the ARQ feedback information of the first bearer, the node identifier of the first network device, the identifier of the first bearer, the identifier of the terminal device, the logical channel identifier, and the identifier of the ARQ target node. The first bearer may include a Data Radio Bearer (DRB) for the terminal device, a Signaling Radio Bearer (SRB) for the terminal device, or a Radio Bearer (RB) for the IAB donor. The node identifier of the first network device may be an Internet Protocol (IP) address or a Media Access Control (MAC) address, and the like, which are used to uniquely identify the first network device, and the node identifier is not limited in this application. The identifier of the first bearer may be an identification number (ID) of the first bearer, and is used to uniquely identify the first bearer. The identifier of the terminal device may be an IP address, an MAC address, an International Mobile Equipment Identity (IMEI), an International Mobile Subscriber Identity (IMSI), or the like of the terminal device, and is used to uniquely identify the terminal device. The logical channel identifier may be an ID of a logical channel, and is used to uniquely identify the logical channel, and the logical channels of the terminal device correspond to bearers one to one. The ARQ target node Identifier may include a node Identifier of an intermediate node that needs ARQ feedback, where the node Identifier may be a node name, an IP address, an MAC address, a Physical Cell Identifier (PCI), a Global Cell Identifier (CGI), a number Global Cell Identifier (NR Cell Global Identifier, NCGI), or the like, and is used to uniquely identify the intermediate node.

The ARQ feedback information of the first bearer may include one of end-to-end feedback, hop-by-hop feedback, and a feedback indication, where the feedback indication is used to instruct the first network device to perform ARQ feedback on the data of the first bearer or not perform ARQ feedback on the data of the first bearer. The end-to-end feedback or the hop-by-hop feedback may be configured by a default of the system, or may be configured by the second network device, and is not specifically limited by the embodiment of the present application.

Because the first configuration information is configured for the first bearer and can be configured for each IAB node, two IAB nodes can be used as end points on the first bearer, that is, the two IAB nodes perform the sender and the receiver of the ARQ feedback, and the IAB node between the two IAB nodes does not need to perform the ARQ feedback and only needs to perform data forwarding, so that the ARQ configuration is more flexible. For example, IAB node1 and IAB node4 may be configured as a receiver and a sender of ARQ feedback, after receiving data of a first bearer sent by IAB node1, IAB node4 determines to perform ARQ feedback according to first configuration information, and IAB node1 receives feedback sent by IAB node4, whereas IAB node 2 between IAB node1 and IAB node4 does not need to perform feedback but only needs to perform data forwarding.

The ARQ feedback information of the first configuration information corresponds to one or more first bearers of the terminal device, or corresponds to all bearers of the terminal device. The number of the terminal devices in the embodiment of the present application may be one or more, and the present application is not limited. Since one terminal device may have multiple bearers, one or a part of the bearers may be designated to perform ARQ feedback and/or reception on a certain IAB node, or may also be designated to perform ARQ feedback and/or reception on all bearers of a certain terminal device, that is, the granularity of ARQ feedback and/or reception may be configurable, which depends on implementation specifically, and is not limited in this application.

Step S202: the first network device receives data of the third network device.

Taking the data transmission system shown in fig. 1 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node1, the IAB node 2, and the IAB node4, the first network device is the IAB node1, the third network device is the terminal device, and the IAB node sends the first configuration information to the IAB node 1. After the terminal device sends the uplink data of the first bearer to the IAB node1, the IAB node1 may receive the uplink data of the first bearer of the terminal device. If the terminal equipment transmits uplink data to the IAB node through the IAB node1, the IAB node 2 and the IAB node4, the first network equipment is the IAB node 2, the third network equipment is the IAB node1, and the IAB node sends first configuration information to the IAB node 2. After the terminal device sends the uplink data of the first bearer to the IAB node 2 through the IAB node1, the IAB node 2 may receive the uplink data of the first bearer of the IAB node 1.

Taking the data transmission system shown in fig. 1 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node4, the IAB node 2, and the IAB node1, the first network device is the IAB node4, the third network device is the IAB node, and the IAB node sends the first configuration information to the IAB node 4. After the IAB node sends the downlink data of the first bearer to the IAB node4, the IAB node4 receives the downlink data of the first bearer of the IAB node. If the IAB node transmits downlink data to the terminal device via the IAB node4, the IAB node 2, and the IAB node1, the first network device is the IAB node 2, the third network device is the IAB node4, and the IAB node transmits the first configuration information to the IAB node 2. After the IAB node sends the downlink data of the first bearer to the IAB node 2 through the IAB node4, the IAB node 2 receives the downlink data of the first bearer of the IAB node 4.

Step S203: the first network equipment determines whether to perform ARQ feedback according to the first configuration information.

In a possible implementation manner, if the ARQ feedback information includes end-to-end feedback, if the identifier of the first network device is the same as the identifier of the ARQ target node, the first network device sends the ARQ feedback, and if the identifier of the first network device is different from the identifier of the ARQ target node, the first network device does not perform the ARQ feedback and forwards the data of the first bearer.

Specifically, after receiving the data sent by the third network device, the first network device determines whether the bearer corresponding to the received data is configured according to the first configuration information. If the bearer corresponding to the data is configured, determining whether ARQ feedback is needed according to ARQ feedback information of the first bearer of the first configuration information, and if the ARQ feedback is needed, performing ARQ ACK or NACK feedback according to a data receiving result; or, if the ARQ target node identifier in the first configuration information is the same as the node identifier of the first network device, feedback is also required. And if the first network equipment does not need to perform ARQ feedback on the received data, performing data forwarding according to the ARQ target node identification in the first configuration information.

It should be understood that if the ARQ feedback mode of the first network device is default, that is, the ARQ feedback mode using end-to-end ARQ feedback or hop-by-hop ARQ feedback mode is default, as defined by the protocol, the ARQ feedback information of the first bearer is not necessary, and the IAB node only needs to determine whether to feedback through the ARQ target node identifier and the default ARQ feedback mode. Specifically, if the default ARQ feedback mode is an end-to-end mode, when the node identifier of the IAB node and the ARQ target node identifier are different, forwarding the data; if the default ARQ feedback mode is hop-by-hop feedback, the IAB node performs ARQ feedback for all data.

Taking the data transmission system shown in fig. 1 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node1, the IAB node 2, and the IAB node4, the first network device is the IAB node1, the third network device is the terminal device, the IAB node1 determines that the ARQ feedback information includes end-to-end feedback based on the first configuration information, and the ARQ target node is identified as the IAB node. After the IAB node1 receives the uplink data of the first bearer of the terminal device, the ARQ feedback is not performed, but the uplink data of the first bearer is directly forwarded to the IAB node 2. Since the IAB node 2 is not a target node, the IAB node 2 does not perform ARQ feedback, but directly forwards the uplink data of the first bearer to the IAB node4, and similarly, after receiving the data, the IAB node4 forwards the data to the IAB node, and the IAB node can decode the received data, and if the decoding is successful, the IAB node sends an ACK signal to the terminal device; if the decoding fails, the IAB node sends a NACK signal to the terminal equipment, and the IAB node1 can select a new transmission path for data retransmission.

In the embodiment of the present application, since the sending end of the data may store the sent data in the buffer, if the non-acknowledgement feedback is received, the retransmission of the data may be performed, thereby ensuring reliable transmission of the data.

Taking the data transmission system shown in fig. 1 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node4, the IAB node 2, and the IAB node1, the first network device is the IAB node4, the third network device is the IAB node, the IAB node4 determines that the ARQ feedback information includes end-to-end feedback based on the first configuration information, and the ARQ target node is identified as the terminal device. After the IAB node4 receives the downlink data of the first bearer of the IAB node, the IAB node4 does not perform ARQ feedback, but forwards the downlink data of the first bearer to the IAB node 2. The IAB node 2 does not perform ARQ feedback, and forwards the downlink data of the first bearer to the IAB node 1. After receiving the data, the IAB node1 similarly forwards the data to the terminal equipment, the terminal equipment decodes the received data, and if the decoding is successful, the terminal equipment sends an ACK signal to the IAB node; and if the decoding fails, the terminal equipment sends a NACK signal to the IAB donor. And retransmitting the data after the IAB donor receives the NACK signal.

In the embodiment of the application, reliable transmission of end-to-end data can be ensured.

In one possible implementation, if the ARQ feedback information includes hop-by-hop feedback, the first network device sends the ARQ feedback when receiving data of the first bearer.

Taking the data transmission system shown in fig. 1 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node1, the IAB node 2, and the IAB node4, the first network device is the IAB node4, the third network device is the IAB node 2, the IAB node sends first configuration information to the IAB node4, the IAB node4 determines that the ARQ feedback information includes hop-by-hop feedback based on the first configuration information, and the ARQ target node is identified as the IAB node. After the terminal equipment sends the uplink data of the first bearer to the IAB node1, the IAB node1 feeds back ACK or NACK to the terminal equipment, and if the decoding is successful, the IAB node1 forwards the uplink data of the first bearer to the IAB node 2. The IAB node 2 feeds back ACK or NACK to the IAB node1, and if decoding is successful, the IAB node 2 forwards the uplink data of the first bearer to the IAB node 4. And after receiving the data, the IAB node4 sends ACK or NACK to the IAB node 2, and if the decoding is successful, the data is forwarded to the IAB node. And when each IAB node receives the ACK signal sent by the superior node, deleting the corresponding data in the cache, and if the NACK signal sent by the superior node is received, retransmitting the data.

In the embodiment of the application, due to the fact that ARQ feedback is carried out hop by hop, retransmission on the whole transmission path can be avoided, transmission resources are saved, and transmission efficiency is improved.

Taking the data transmission system shown in fig. 1 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node4, the IAB node 2, and the IAB node1, the first network device is the IAB node1, the IAB node sends first configuration information to the IAB node1, the IAB node1 determines that the ARQ feedback information includes hop-by-hop feedback based on the first configuration information, and the ARQ target node is identified as the terminal device. After the IAB node sends the downlink data of the first bearer to the IAB node4, the IAB node4 feeds back ACK or NACK to the IAB node, and if the decoding is successful, the downlink data of the first bearer is forwarded to the IAB node 2. The IAB node 2 feeds back ACK or NACK to the IAB node4, and if decoding is successful, the downlink data of the first bearer is forwarded to the IAB node 1. After receiving the data, the IAB node1 feeds back ACK or NACK to the IAB node 2, and if the decoding is successful, forwards the downlink data of the first bearer to the terminal device. And when each IAB node receives the ACK signal sent by the superior node, deleting the corresponding data in the cache, and if the NACK signal sent by the superior node is received, retransmitting the data.

In one possible implementation, if the ARQ feedback information includes a feedback indication, the first network device determines whether to perform ARQ feedback on the data of the first bearer according to the feedback indication. At this time, the IAB node determines whether to feed back the data of the first bearer according to the feedback indication. Different from end-to-end and hop-by-hop feedback, the ARQ feedback based on the feedback indication can configure any node, some two IAB nodes can be configured as the end nodes of the ARQ feedback, and the IAB nodes between the two end nodes do not need to perform the ARQ feedback. The end node refers to a pair of nodes that need ARQ feedback and ARQ reception. The end node may make the determination by the identity of the first bearer, the identity of the terminal device, and the ARQ feedback information of the first bearer. An IAB node is an end node if it is configured to ARQ feedback for a certain bearer of a certain terminal device.

Taking the data transmission system shown in fig. 1 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node1, the IAB node 2, and the IAB node4, the first network device is the IAB node1, and the IAB node1 determines, based on the first configuration information, that the ARQ feedback information includes a feedback instruction, where the feedback instruction is used to instruct the first network device to perform ARQ feedback on the first bearer of the terminal device. After receiving the uplink data of the first bearer of the terminal device, the IAB node1 feeds back ACK or NACK to the terminal device, and if the decoding is successful, the IAB node1 forwards the uplink data of the first bearer to the IAB node 2, and buffers the received data. Since the feedback indication is used to indicate that the IAB node 2 does not perform ARQ feedback, the IAB node 2 may not perform ARQ feedback, but directly forward the uplink data of the first bearer to the IAB node 4. Because the feedback indication is used for indicating the IAB node4 to perform ARQ feedback, after the IAB node4 receives the data, the received data can be decoded, and if the decoding is successful, the IAB node4 sends an ACK signal to the IAB node 2 or the IAB node 1; if the decoding fails, the IAB node4 sends a NACK signal to the IAB node 2 or the IAB node1, and the IAB node1 may select a new transmission path for data retransmission.

In this embodiment of the present application, if IAB node4 sends a NACK signal to IAB node 2, IAB node 2 may send the NACK signal to IAB node1, and IAB node1 may select a new transmission path to perform data retransmission, for example, IAB node1 transmits data to IAB node via IAB node3 and IAB node4, and does not need to retransmit the data to IAB node via each intermediate node by a terminal device, which may improve the utilization rate of air interface resources.

Taking the data transmission system shown in fig. 1 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node4, the IAB node 2, and the IAB node1, the first network device is the IAB node4, and the IAB node4 determines, based on the first configuration information, that the ARQ feedback information includes a feedback instruction, where the feedback instruction is used to instruct the first network device to perform ARQ feedback. After receiving the downlink data of the first bearer of the IAB node, the IAB node4 feeds back ACK or NACK to the IAB node, and if the decoding of the IAB node4 is successful, forwards the downlink data of the first bearer to the IAB node 2, and buffers the data. Since the feedback indication is used to indicate that the IAB node 2 does not perform ARQ feedback, the IAB node 2 may not perform ARQ feedback, but directly forward the downlink data of the first bearer to the IAB node 1. Because the feedback indication is used for indicating the IAB node1 to perform ARQ feedback, after the IAB node1 receives the data, the received data can be decoded, and if the decoding is successful, the IAB node1 sends an ACK signal to the IAB node 2 or the IAB node 4; if the decoding fails, the IAB node1 sends a NACK signal to the IAB node 2 or the IAB node4, and the IAB node4 may select a new transmission path for data retransmission.

In this embodiment of the present application, if IAB node1 sends a NACK signal to IAB node 2, IAB node 2 may send the NACK signal to IAB node4, and IAB node4 may select a new transmission path to perform data retransmission, for example, IAB node4 transmits data to terminal equipment via IAB node3 and IAB node1, and does not need to retransmit the data to the terminal equipment via each intermediate node, so that the utilization rate of air interface resources may be improved.

In a possible implementation manner, the first configuration information may further include a transmission direction indication, where the transmission direction indication includes uplink transmission or downlink transmission. If the transmission direction indication includes uplink transmission, the first network device determines whether to perform ARQ feedback according to the first configuration information only when receiving uplink data. And if the transmission direction indication comprises downlink transmission, the first network equipment determines whether to perform ARQ feedback according to the first configuration information only when receiving downlink data. The transmission direction indication may be configured for one bearer, or multiple bearers, or all bearers of one terminal device. It should be understood that due to the difference of the transmission directions, the uplink transmission path and the downlink transmission path of the device for the same terminal may be different, and the feedback of ARQ and the transmission direction of data should be the same but opposite. Since the paths for uplink data transmission and downlink data transmission may not have the same IAB node, and the feedback is for data transmission, the path for ARQ feedback needs to be the same as the path for data transmission, but in the opposite direction.

In the method described in fig. 2, the second network device sends the first configuration information to the first network device, the first network device receives data of the third network device, and the first network device determines whether to perform ARQ feedback according to the first configuration information, so that data retransmission can be effectively implemented, and the utilization rate of air interface resources is improved.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a data transmission system disclosed in an embodiment of the present application, where the data transmission system may include a terminal device, an IAB node, and a donor base station (e.g., an IAB node), for example, a relay node in fig. 1 includes: a first relay node (e.g., IAB node 1), a second relay node (e.g., IAB node 2), and a third relay node (e.g., IAB node 3). The terminal equipment establishes communication connection with the IAB node3, the IAB node3 establishes communication connection with the IAB node 2 and the IAB node1 respectively, the IAB node 2 establishes communication connection with the IAB node, and the IAB node1 establishes communication connection with the IAB node. The link between IAB node 2 and IAB node may be a BH link, the link between IAB node1 and IAB node may be a BH link, and the link between the terminal device and IAB node3 may be an AC link.

When the terminal device transmits uplink data to the IAB node, in a possible implementation manner, the terminal device may transmit the data to the IAB node sequentially via the IAB node3 and the IAB node 2, where the IAB node3 is a higher node (i.e., a parent node) of the terminal device, the IAB node 2 is a higher node of the IAB node3, and the IAB node is a higher node of the IAB node 2. In another possible implementation manner, the terminal device may transmit data to the IAB node sequentially via the IAB node3 and the IAB node1, where the IAB node3 is an upper node of the terminal device, the IAB node1 is an upper node of the IAB node3, and the IAB node is an upper node of the IAB node 1. Further, the IAB donor may send the uplink data to the GW device.

In a possible implementation manner, the IAB node may transmit data to the terminal device sequentially via an IAB node 2 and an IAB node3, where the IAB node 2 is a higher node of the IAB node 2, the IAB node3 is a higher node of the IAB node 2, and the terminal device is a higher node of the IAB node 3. In another possible implementation manner, the IAB node may transmit data to the terminal device sequentially via the IAB node1 and the IAB node3, where the IAB node1 is an upper node of the IAB node, the IAB node3 is an upper node of the IAB node1, and the terminal device is an upper node of the IAB node 3.

Generally, in order to ensure reliable transmission of data, an automatic repeat request ARQ function is included in the RLC protocol. ARQ confirms whether transmission is correct by checking data of a transmitting side at a data receiving side, and transmits an ACK signal to the transmitting side if the data of the transmitting side is correctly received, and transmits a NACK signal to the transmitting side if the receiving side cannot correctly receive the data transmitted by the transmitting side. Checking the data may include performing a CRC check on the data or not receiving a packet within a certain time. For example, if the second relay node does not successfully receive the data sent by the first relay node, a NACK signal is sent to the first node to the second relay node, and the first node retransmits the data through ARQ after receiving the NACK signal. Automatic repeat requests may include hop-by-hop ARQ and end-to-end ARQ.

The hop-by-hop ARQ is to immediately feed back a transmission result to a sender for each received data packet, for example, a second relay node decodes first data from a first relay node after receiving the first data, and if the decoding is successful, an ACK signal is returned; if the decoding fails, a NACK signal is returned. After the first relay node receives the ACK signal from the second relay node, second data is sent to the second relay node, and the first data is deleted from the cache of the first relay node; when the first relay node receives the NACK signal from the second relay node, the first relay node retransmits the first data.

In the embodiment of the application, the first network device sends backhaul indication information to the third network device, where the backhaul indication information is used to notify the third network device to receive backhaul data, and the backhaul data is data belonging to the third network device, and the backhaul data is failed to be sent by the first network device; the first network equipment sends the return data to the third network equipment; the first network device is a superior node of the third network device. The first network device may be the IAB node 2 in fig. 1, and the third network device may be the IAB node3 in fig. 1. IAB node 2 is a superordinate node of IAB node 3. In the hop-by-hop feedback, the IAB node3 sends data to the IAB node 2, the IAB node 2 successfully decodes the data, the IAB node 2 sends an ACK signal to the IAB node3, and the IAB node3 deletes the data stored in the buffer of the IAB node 3. The IAB node 2 forwards the data to the IAB node, the IAB node fails to decode the data, the IAB node sends a NACK signal to the IAB node 2, the IAB node 2 may send back indication information to the IAB node3, and send the data to the IAB node3, so that the IAB node3 transmits the data to the IAB node through another path, for example, the IAB node3 transmits the data to the IAB node through the IAB node1, and the data retransmission recovery across multiple hops can be performed.

Based on the data transmission system shown in fig. 3, please refer to fig. 4, and fig. 4 is a data transmission method provided in the embodiment of the present application, which includes, but is not limited to, the following steps:

step S401: the first network device sends the backhaul indication information to the third network device.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the first network device may be the IAB node 2, the third network device may be the IAB node3, and the first network device is a superior node of the third network device. In the hop-by-hop feedback, the IAB node3 sends the uplink data to the IAB node 2, the IAB node 2 successfully decodes the uplink data, the IAB node 2 sends an ACK signal to the IAB node3, and the IAB node3 deletes the uplink data stored in the buffer of the IAB node 3. The IAB node 2 forwards the uplink data to the IAB node, the IAB node fails to decode the uplink data, the IAB node sends a NACK signal to the IAB node 2, the IAB node 2 may send return indication information to the IAB node3, the return indication information is used for notifying the IAB node3 to receive return data, and the return data is the uplink data.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the first network device may be the IAB node 2, the third network device may be the IAB node, and the first network device is a lower node of the third network device. In the hop-by-hop feedback, the IAB node sends downlink data to the IAB node 2, the IAB node 2 successfully decodes the downlink data, the IAB node 2 sends an ACK signal to the IAB node, and the IAB node deletes the downlink data stored in the buffer of the IAB node. The IAB node 2 forwards the downlink data to the IAB node3, the IAB node3 fails to decode the downlink data, the IAB node3 sends a NACK signal to the IAB node 2, the IAB node 2 may send return indication information to the IAB node, and the return indication information is used to notify the IAB node to receive return data, where the return data is the downlink data.

In a possible implementation manner, before the first network device sends the backhaul indication information to the third network device, the first network device may receive second configuration information forwarded by the IAB donor via the third network device, where the second configuration information includes first indication information, and the first indication information is used to indicate that the first network device sends the backhaul indication information when receiving a NACK signal.

In a specific implementation, when the IAB donor determines that the link is abnormal, the IAB donor actively generates second configuration information, transmits the second configuration information to the third network device, and transmits the second configuration information to the first network device; or the first network device sends the link abnormality indication information to the third network device, after the third network device forwards the link abnormality indication information to the IAB donor, the IAB donor generates the second configuration information, transmits the second configuration information to the third network device, and the third network device transmits the second configuration information to the first network device.

In a possible implementation manner, when the third network device sends the second configuration information to the first network device, it needs to send the configuration indication information to the first network device, otherwise the first network device may refuse to schedule the third network device for uplink transmission because its uplink has failed. Specifically, the configuration indication information may be Random Access (RACH), Scheduling Request (SR), Buffer Status Report (BSR), or pre-configured uplink grant (pre-configured UL grant), which is not specifically limited by the embodiment of the present application.

Step S402: the third network device sends the feedback information to the first network device.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the first network device is the IAB node 2, the third network device is the IAB node3, and after the IAB node 2 sends the backhaul indication information to the IAB node3, the IAB node3 may detect whether to receive the second configuration information of the IAB node, where the second configuration information is used to indicate that the intermediate node is allowed to send the backhaul indication information when receiving a NACK signal, and if the IAB node3 receives the second configuration information, the IAB node3 may send feedback information to the IAB node 2, and the IAB node 2 receives the feedback information.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the first network device is the IAB node 2, the third network device is the IAB node, after the IAB node 2 sends the backhaul indication information to the IAB node, the IAB node may detect whether the second configuration information exists, where the second configuration information is used to indicate that the intermediate node is allowed to send the backhaul indication information when receiving a NACK signal, and if the second configuration information exists, the IAB node may send feedback information to the IAB node 2, and the IAB node 2 receives the feedback information.

Step S403: the first network device stops receiving the data sent by the third network device.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the IAB node3 sends feedback information to the IAB node 2, and the IAB node 2 may stop receiving the uplink data sent by the IAB node 3.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the IAB node sends feedback information to the IAB node 2, and the IAB node 2 may stop receiving the downlink data sent by the IAB node.

Step S404: the first network device sends the backhaul data to the third network device.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the IAB node3 sends feedback information to the IAB node 2, and the IAB node 2 may send return data to the IAB node3, where the return data is uplink data belonging to the IAB node3 and failed to be sent by the IAB node 2.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the IAB node sends feedback information to the IAB node 2, and the IAB node 2 may send return data to the IAB node, where the return data is the downlink data belonging to the IAB node that the IAB node 2 failed to send.

In a possible implementation manner, the third network device may transmit the backhaul data to the receiving end through another path, specifically, the third network device may reconfigure a routing path according to existing routing information on a data packet containing the backhaul data, for example, add new routing information on the basis of the existing routing information; and if the original routing information is deleted, replacing the original routing information with the new routing information. Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, after the IAB node 2 sends the backhaul data to the IAB node3, the IAB node3 may transmit the backhaul data to the IAB node via the IAB node 1. Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, after the IAB node 2 sends the backhaul data to the IAB node, the IAB node may transmit the backhaul data to the terminal device via the IAB node1 and the IAB node 3.

In a possible implementation manner, the first network device may reselect the upper node according to the network topology and the routing information of the existing data transmission system, and transmit the data to the receiving end via the new upper node. Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the first network device may be the IAB node 2. In the hop-by-hop feedback, the terminal equipment sends the uplink data to the IAB node3, the IAB node3 forwards the uplink data to the IAB node 2, and if the IAB node 2 fails to decode the uplink data, the IAB node 2 sends a NACK signal to the IAB node 3. The IAB node3 may reselect the superordinate node, for example, the IAB node1 is used as a new superordinate node of the IAB node3, and the IAB node3 transmits the uplink data to the IAB node via the IAB node 1. Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the first network device may be the IAB node 2. In the hop-by-hop feedback, the IAB node sends downlink data to the IAB node 2, the IAB node 2 fails to decode the downlink data, and the IAB node 2 sends a NACK signal to the IAB node. The IAB node may reselect the subordinate node, for example, the IAB node1 is used as a new subordinate node of the IAB node, and the IAB node transmits the downlink data to the terminal device via the IAB node1 and the IAB node 3.

In a possible implementation manner, the first network device may use a node with a higher priority as an upper node of the first network device, and the first network device may also use a neighboring node specified by the IAB donor as an upper node of the first network device. For example, the shorter the link distance to the IAB donor is, the higher the priority of the node is, the first network device may use the node having the shorter link distance to the IAB donor as the upper node of the first network device.

In a possible implementation manner, in a random access process or a first message after access is completed, the first network device may send a cache state of the first network device, such as original routing information and a cause of a link anomaly, to a new upper node of the first network device, where the cause may be indicated by a cause value (cause value), and a definition of a specific cause value depends on a protocol, which is not limited in this application.

In a possible implementation manner, the first network device determines whether to start the corresponding process described in fig. 4 according to one or more possible conditions: in a preset time period, the first network equipment determines that the sum of the data volume of all data currently stored in the cache of the first network equipment is greater than a preset data volume threshold; or within a preset time period, the quality of the return link of the first network equipment is less than a preset quality threshold; or all candidate beams are smaller than a preset beam threshold; or a beam failure; or the radio link fails.

In the method described in fig. 4, the first network device sends the backhaul indication information to the third network device, the third network device sends the feedback information to the first network device, and the first network device stops receiving the uplink data sent by the third network device and sends the backhaul data to the third network device, so that data retransmission can be effectively implemented.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a user plane protocol stack disclosed in an embodiment of the present application, where a user plane of the user plane protocol stack includes UE, IAB-node 1, IAB-node 2, and IAB-donor. The Protocol stack of the UE includes, from top to bottom, a Service Data Attachment Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and an MAC layer. The protocol stack of communication between the IAB-node 2 and the UE comprises an RLC Layer and an MAC Layer from top to bottom, and the protocol stack of communication between the IAB-node 2 and the IAB-node 1 comprises the RLC Layer, an Adaptation Layer (Adpt) and the MAC Layer from top to bottom. The protocol stack of the communication between the IAB-node 1 and the IAB-node 2 comprises an RLC layer, an Adapt layer and an MAC layer from top to bottom, and the protocol stack of the communication between the IAB-node 1 and the IAB-node comprises the RLC layer, the Adpt layer and the MAC layer from top to bottom.

Referring to fig. 6, fig. 6 is a schematic structural diagram of another user plane protocol stack disclosed in this embodiment, where the user plane protocol stack has a partial layer 2 protocol stack, for example, forwarding of Data between a terminal device, L2RN and a base station is based on PDCP/RLC/MAC Packet Data Unit (PDU), and the base station is, for example, a Donor base station (Donor nodeb, DgNB) in fig. 5. Accordingly, data transmission in the intermediate node can be processed by a few protocol layers, the time delay is shorter, and the signaling overhead is smaller. The following figure shows a possible implementation of L2relay, where the peer entity of the PDCP of the terminal device is at the base station and the peer entities of the RLC, MAC and PHY of the terminal device are at the RN. The nodes forward PDCP PDUs, and the PDCP PDUs are processed by the added Adpt between the PDCP layer and the RLC layer. Taking downlink transmission as an example: and the DgNB encapsulates the PDCP PDU into an adaptation layer PDU, and then delivers the adaptation layer PDU to the RLC layer, and the adaptation layer adds information such as the identification of the terminal equipment, the identification of the first bearer and the like. And the RN selects the corresponding UE DRB to process the data according to the identifier of the terminal equipment and the identifier of the first bearer, and then sends the data to the terminal equipment. The Adpt is used for identifying the terminal device to which the data belongs and the DRB of the terminal device when the RN and the DgNB forward the data. Service Data Adaptation Protocol (SDAP) is a new Protocol hierarchy introduced by NR with respect to LTE for handling Quality of Service (QoS flow) to DRB mapping. The interface between the RN and the base station may also be an F1AP, a GTP tunnel, or an F1 Application Protocol (AP) with extended functionality, where F1 is an interface connecting a Central Unit (CU) and a Distributed Unit (DU), a GPRS Tunneling Protocol (GTP) tunnel, and the like. General Packet Radio Service (GPRS) is a Packet-based transmission.

Referring to fig. 7 based on the user plane protocol stacks shown in fig. 5 and 6, fig. 7 is another data transmission method provided in the embodiment of the present application, where the method includes, but is not limited to, the following steps:

step S701: and the second network equipment sends the third configuration information to the terminal equipment or the fourth network equipment.

The third configuration information includes retransmission indication information, where the retransmission indication information is used to indicate the terminal device or the fourth network device to perform data retransmission, and the retransmission indication information includes a Serial Number (SN) of a PDU of the PDCP layer. Wherein the fourth network device includes PDCP and is capable of processing PDCP data of its upper node or lower node.

In one possible implementation, the retransmission indication information may include a cause value, and/or a number K of retransmission packets.

Taking fig. 3 as an example, the IAB donor may send the third configuration information to the terminal device.

In a possible implementation manner, the second network device may send third configuration information to the first network device, and the first network device forwards the third configuration information to the terminal device or the fourth network device.

In the above implementation, since the fourth network device includes the PDCP layer, the terminal device may send data to the fourth network device, and the fourth network device processes the PDCP data of the terminal device and buffers the sent data in a buffer of the PDCP layer. It should be understood that the fourth network device does not necessarily have to be a direct superior node of the terminal device, and the direct superior node means that the terminal device directly transmits data to the fourth network device without forwarding through other network devices.

Step S702: and the terminal equipment or the fourth network equipment retransmits the data of the PDCP PDU according to the retransmission indication information.

In one possible implementation, the terminal device or the fourth network device may retransmit data after all SNs according to the SNs. Wherein the data after all SNs includes a data packet to which packet data of all PDCP PDUs is assigned a PDCP packet sequence number after the SNs.

In a possible implementation manner, the terminal device or the fourth network device retransmits K data packets after the PDCP PDU sequence number is SN.

In the embodiment of the present application, the PDCP layer discards the data packet in the buffer only in the following two cases: receiving a PDCP status report fed back by a receiving end, and deleting the PDCP packet which is fed back and successfully sent in the report; or a timeout timer (discardTimer) expires. That is, in the scenario of hop-by-hop feedback, if the SDU of the PDCP has not been discarded yet, the PDCP may be utilized for retransmission.

In the method described in fig. 7, the second network device sends the third configuration information to the terminal device or the fourth network device, and the terminal device performs data retransmission of the PDCP PDU according to the retransmission indication information, so that data retransmission can be effectively implemented, and the utilization rate of air interface resources is improved.

Based on the data transmission system shown in fig. 3, please refer to fig. 8, fig. 8 is another data transmission method provided in the embodiment of the present application, which includes, but is not limited to, the following steps:

step S801: the third network device receives fourth configuration information of the second network device.

The third network device may receive fourth configuration information of the second network device. The fourth configuration information includes second indication information, and the second indication information is used for indicating to configure a buffer memory of data related to the terminal device or the first bearer.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the third network device may be the IAB node3, and the second network device may be the IAB node. The IAB node may send fourth configuration information to the IAB node3, where the fourth configuration information is used to instruct the IAB node3 to establish a buffer for storing data related to the terminal device or data of the first bearer.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the third network device may be the IAB node 2, and the second network device may be the IAB node. The IAB node may send fourth configuration information to the IAB node 2, where the fourth configuration information is used to instruct the IAB node 2 to establish a buffer for storing data related to the terminal device or data of the first bearer.

Step S802: the third network device sends the data to the first network device.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the IAB node3 may send the uplink data to the IAB node 2 after receiving the uplink data from the terminal device.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, after the IAB node transmits the downlink data to the IAB node 2, the IAB node 2 may transmit the downlink data to the IAB node 3.

Step S803: the first network device sends the data to the receiving end.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits the uplink data to the IAB node via the IAB node3 and the IAB node 2, after the IAB node3 sends the uplink data to the IAB node 2, the IAB node 2 may forward the uplink data to the IAB node.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, after the IAB node 2 sends the downlink data to the IAB node3, the IAB node3 may forward the downlink data to the terminal device.

Step S804: and when the receiving end successfully decodes the data, the receiving end sends an ACK signal to the first network equipment.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, the IAB node 2 forwards the uplink data to the IAB node, and if the IAB node successfully decodes the uplink data, the IAB node sends an ACK signal to the IAB node 2.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, the IAB node3 forwards the downlink data to the terminal device, and if the terminal device successfully decodes the downlink data, the terminal device sends an ACK signal to the IAB node 3.

Step S805: the first network device forwards the ACK signal to the third network device.

In a possible implementation manner, the first network device may further receive fifth configuration information of the second network device, where the fifth configuration information includes third indication information, and the third indication information is used to forward the ACK signal to the third network device when indicating that the ACK signal of the receiving end is received.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, after the IAB node sends an ACK signal to the IAB node 2, the IAB node 2 forwards the ACK signal to the IAB node 3.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, after the terminal device sends an ACK signal to the IAB node3, the IAB node3 forwards the ACK signal to the IAB node 2.

Step S806: the third network device deletes the data stored in the cache of the third network device.

After the third network device receives the ACK signal of the receiving end, it may be determined that the receiving end successfully decodes the data, and then delete the data stored in the cache of the third network device.

Taking the data transmission system shown in fig. 3 as an example, if the terminal device transmits uplink data to the IAB node via the IAB node3 and the IAB node 2, after the IAB node 2 forwards the ACK signal to the IAB node3, the IAB node3 may determine that the IAB node successfully decodes the uplink data, and further delete the uplink data stored in the buffer of the IAB node 3.

Taking the data transmission system shown in fig. 3 as an example, if the IAB node transmits downlink data to the terminal device via the IAB node 2 and the IAB node3, after the IAB node3 forwards the ACK signal to the IAB node 2, the IAB node 2 may determine that the terminal device successfully decodes the uplink data, and further delete the uplink data stored in the buffer of the IAB node 2.

In the method described in fig. 8, the third network device receives the fourth configuration information of the second network device, and deletes the data stored in the cache of the third network device after determining that the receiving end successfully decodes the data, so that data retransmission can be effectively implemented.

The method of the embodiments of the present application is explained in detail above, and the related apparatus of the embodiments of the present application is provided below.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a first network device provided in an embodiment of the present application, for implementing functions of the first network device in the embodiment of fig. 2, where functional blocks of the first network device may be implemented by hardware, software, or a combination of hardware and software. Those skilled in the art will appreciate that the functional blocks described in FIG. 9 may be combined or separated into sub-blocks to implement the application scheme. Thus, the above description in this application may support any possible combination or separation or further definition of the functional blocks described below.

As shown in fig. 9, the first network device may include: a receiving module 901 and a processing module 902, wherein the detailed description of each module is as follows.

A receiving module 901, configured to receive first configuration information of a second network device, where the first configuration information includes at least one of the following information: ARQ feedback information of a first bearer, a node identifier of the first network device, an identifier of the first bearer, an identifier of a terminal device, a logical channel identifier, and an ARQ target node identifier;

a processing module 902, configured to determine whether to perform ARQ feedback according to the first configuration information.

In one possible implementation manner, the ARQ feedback information of the first bearer includes: one of end-to-end feedback, hop-by-hop feedback, and a feedback indication; the feedback indication is used for indicating the first network device to perform ARQ feedback on the data of the first bearer or not to perform ARQ feedback on the data of the first bearer.

In a possible implementation manner, the processing module 902 determines whether to perform ARQ feedback according to the first configuration information, and is specifically configured to:

if the ARQ feedback information comprises end-to-end feedback, if the identifier of the first network equipment is the same as the identifier of the ARQ target node, the first network equipment sends ARQ feedback, and if the identifier of the first network equipment is different from the identifier of the ARQ target node, the first network equipment does not carry out ARQ feedback and forwards the data of the first bearer;

if the ARQ feedback information comprises hop-by-hop feedback, the first network equipment sends ARQ feedback when receiving the data of the first bearer;

and if the ARQ feedback information comprises a feedback indication, the first network equipment determines whether to perform ARQ feedback on the data of the first bearer according to the feedback indication.

It should be noted that the implementation of each module may also correspond to the corresponding description of the embodiment shown in fig. 2.

It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation. Each functional module in the embodiments of the present application may be integrated into one processing module, or each module may exist alone physically, or two or more modules are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode.

Another first network device provided in this embodiment of the present application is configured to implement the functions of the first network device in fig. 4, and the functional blocks of the first network device may be implemented by hardware, software, or a combination of hardware and software. Those skilled in the art will appreciate that the functional blocks described in the embodiments of the present application may be combined or separated into sub-blocks to implement the schemes of the present application. Thus, the above description in this application may support any possible combination or separation or further definition of the functional blocks described below.

Referring to fig. 9, the first network device may include: a sending module 903, wherein each module is described in detail as follows.

A sending module 903, configured to send backhaul indication information to a third network device, where the backhaul indication information is used to notify the third network device to receive backhaul data, and the backhaul data is data that is failed to be sent by the first network device and belongs to the third network device;

the sending module 903 is further configured to send the backhaul data to the third network device;

the first network device is a superior node of the third network device.

In one possible implementation manner, the first network device further includes:

a receiving module 901, configured to receive the feedback information sent by the third network device after the sending module 903 sends the backhaul indication information.

a processing module 902, configured to stop receiving the uplink data sent by the third network device after the receiving module 901 receives the feedback information.

It should be noted that the implementation of each module may also correspond to the corresponding description of the embodiment shown in fig. 4.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a first network device disclosed in the embodiment of the present application. As shown in fig. 10, the first network device may include: at least one processor 1001, bus 1002, receiver 1003, transmitter 1004, and memory 1005. Wherein, the receiver 1003, the transmitter 1004, the memory 1005 and the processor 1001 are connected to each other through a bus 1002; the bus 1002 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 10, but this is not intended to represent only one bus or type of bus. The Processor 1001 may be a Central Processing Unit (CPU), a Network Processor (NP), a general-purpose Processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, a transistor logic device, a hardware component, or any combination thereof. In the case where the processor 1001 is one CPU, the CPU may be a single-core CPU or a multi-core CPU. The receiver 1003 and the transmitter 1004 may be integrated as a transceiver. The memory 1005 may store program code, and first configuration information, wherein:

the receiver 1003 receives first configuration information of the second network device, where the first configuration information includes at least one of the following information: automatic repeat request ARQ feedback information of a first bearer, a node identifier of the first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier;

the processor 1001 determines whether to perform ARQ feedback according to the first configuration information.

In a possible implementation manner, the processor 1001 determines whether to perform ARQ feedback according to the first configuration information, and specifically may be:

if the ARQ feedback information includes end-to-end feedback, if the identifier of the first network device is the same as the identifier of the ARQ target node, the transmitter 1004 sends ARQ feedback, if the identifier of the first network device is different from the identifier of the ARQ target node, the transmitter 1004 does not perform ARQ feedback, and the receiver 1003 forwards the data of the first bearer;

if the ARQ feedback information includes hop-by-hop feedback, the transmitter 1004 transmits ARQ feedback when the receiver 1003 receives the data of the first bearer;

if the ARQ feedback information includes a feedback indication, the processor 1001 determines whether to perform ARQ feedback on the data of the first bearer according to the feedback indication.

It should be understood that the first network device is only one example provided by the embodiments of the present application, and that the first network device may have more or less components than shown, may combine two or more components, or may have a different configuration implementation of the components.

Specifically, the first network device described in this embodiment may be configured to implement part or all of the processes in the method embodiment described in this application with reference to fig. 2.

In another embodiment of the present application, as shown in fig. 10, the memory 1005 may store the program code, the backhaul indication information, and the backhaul data, wherein:

the transmitter 1004 transmits backhaul indication information to a third network device, where the backhaul indication information is used to notify the third network device to receive backhaul data, where the backhaul data is data belonging to the third network device and failed to be transmitted by the first network device;

the transmitter 1004 transmits the backhaul data to the third network device;

the first network device is a superior node of the third network device.

In one possible implementation manner, after the transmitter 1004 transmits the backhaul indication information, the receiver 1003 receives feedback information transmitted by the third network device.

In a possible implementation manner, after the receiver 1003 receives the feedback information, the processor 1001 stops receiving the uplink data sent by the third network device.

Specifically, the first network device described in this embodiment may be configured to implement part or all of the processes in the method embodiment described in this application with reference to fig. 4.

Referring to fig. 11, fig. 11 is a schematic structural diagram of a second network device provided in an embodiment of the present application, for implementing functions of the second network device in the embodiment of fig. 2, where functional blocks of the second network device may be implemented by hardware, software, or a combination of hardware and software. Those skilled in the art will appreciate that the functional blocks described in FIG. 11 may be combined or separated into sub-blocks to implement the application scheme. Thus, the above description in this application may support any possible combination or separation or further definition of the functional blocks described below.

As shown in fig. 11, the second network device may include: a processing module 1101 and a sending module 1102, wherein the detailed description of each module is as follows.

A processing module 1101, configured to determine first configuration information, where the first configuration information includes at least one of the following information: an automatic repeat request (ARQ) feedback mode of a first bearer, a node identifier of the first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier;

a sending module 1102, configured to send the first configuration information to the first network device.

Referring to fig. 12, fig. 12 is a schematic structural diagram of a second network device disclosed in the embodiment of the present application. As shown in fig. 10, the second network device may include: at least one processor 1201, a bus 1202, a receiver 1203, a transmitter 1204, and a memory 1205. Wherein the receiver 1203, the transmitter 1204, the memory 1205 and the processor 1201 are interconnected via a bus 1202; the bus 1202 may be a PCI bus or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 12, but this is not intended to represent only one bus or type of bus. The processor 1201 may be a CPU, NP, general processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component, or any combination thereof. In the case where the processor 1201 is one CPU, the CPU may be a single-core CPU or a multi-core CPU. The receiver 1203 and the transmitter 1204 may be integrated as a transceiver. The memory 1205 may store program code, and first configuration information, wherein:

a processor 1201 configured to determine first configuration information, the first configuration information including at least one of: automatic repeat request ARQ feedback information of a first bearer, a node identifier of the first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier;

a transmitter 1204, configured to send the first configuration information to the first network device.

It should be understood that the second network device is only one example provided by the embodiments of the present application, and that the second network device may have more or less components than shown, may combine two or more components, or may have a different configuration implementation of the components.

Specifically, the second network device described in this embodiment may be used to implement part or all of the process in the embodiment of the method described in this application in conjunction with fig. 2.

Referring to fig. 13, fig. 13 is a schematic structural diagram of a terminal device or a fourth network device provided in an embodiment of the present application, configured to implement the functions of the terminal device or the fourth network device in the embodiment of fig. 7, where functional blocks of the terminal device or the fourth network device may be implemented by hardware, software, or a combination of hardware and software. Those skilled in the art will appreciate that the functional blocks described in FIG. 13 may be combined or separated into sub-blocks to implement the application scheme. Thus, the above description in this application may support any possible combination or separation or further definition of the functional blocks described below.

As shown in fig. 13, the terminal device or the fourth network device may include: a receiving module 1301 and a processing module 1302, wherein the detailed description of each module is as follows.

A receiving module 1301, configured to receive third configuration information from a second network device, where the third configuration information includes retransmission indication information, where the retransmission indication information is used to indicate the terminal device or a fourth network device to perform data retransmission, and the retransmission indication information includes a SN of a packet data unit PDU of a packet data convergence protocol PDCP layer;

a processing module 1302, configured to perform data retransmission of the PDCP PDU according to the retransmission indication information.

In a possible implementation manner, the retransmission indication information includes a cause value and/or a number K of retransmission packets.

In a possible implementation manner, the processing module 1302 is specifically configured to:

retransmitting data after all SNs according to the SNs;

and retransmitting K data packets with the sequence number of the PDCP PDU being after the SN.

It should be noted that the implementation of each module may also correspond to the corresponding description of the embodiment shown in fig. 7.

Referring to fig. 14, fig. 14 is a schematic structural diagram of a terminal device or a fourth network device disclosed in the embodiment of the present application. As shown in fig. 14, the terminal device or the fourth network device may include: at least one processor 1401, a bus 1402, a receiver 1403, a transmitter 1404, and a memory 1405. Wherein the receiver 1403, the transmitter 1404, the memory 1405 and the processor 1401 are connected to each other through a bus 1402; the bus 1402 may be a PCI bus or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 14, but this is not intended to represent only one bus or type of bus. Processor 1401 may be a CPU, NP, general purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component, or any combination thereof, among others. In the case where the processor 1401 is one CPU, the CPU may be a single-core CPU or a multi-core CPU. The receiver 1403 and the transmitter 1404 may be integrated as a transceiver. The memory 1405 may store program code, and third configuration information, wherein:

the receiver 1403 receives third configuration information from the second network device, where the third configuration information includes retransmission indication information, where the retransmission indication information is used to indicate the terminal device or the fourth network device to perform data retransmission, and the retransmission indication information includes a SN of a packet data unit PDU of a packet data convergence protocol PDCP layer;

the processor 1401 retransmits the data of the PDCP PDU according to the retransmission indication information.

In one possible implementation, processor 1401 retransmits all data following the SN in accordance with the SN;

In one possible implementation, the processor 1401 retransmits K data packets after the PDCP PDU with sequence number SN.

It should be understood that the terminal device or the fourth network device is only one example provided by the embodiments of the present application, and the terminal device or the fourth network device may have more or less components than those shown, may combine two or more components, or may have a different configuration implementation of the components.

Specifically, the second network device described in this embodiment may be used to implement part or all of the process in the method embodiment described in this application with reference to fig. 7.

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

Claims

1. A method of data transmission, the method comprising:

the method comprises the steps that a first network device receives first configuration information of a second network device, wherein the first configuration information comprises at least one of the following information: automatic repeat request ARQ feedback information of a first bearer, a node identifier of the first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier;

the first network equipment determines whether to perform ARQ feedback according to the first configuration information;

the ARQ feedback information of the first bearer includes: one of end-to-end feedback, hop-by-hop feedback, and a feedback indication, where the feedback indication is used to indicate that the first network device performs ARQ feedback on the data of the first bearer or does not perform ARQ feedback on the data of the first bearer;

the determining, by the first network device according to the first configuration information, whether to perform ARQ feedback includes:

2. The method of claim 1, wherein the ARQ feedback information for the first configuration information corresponds to one or more of the first bearers for the terminal device or to all bearers for the terminal device.

3. The method of any of claims 1-2, wherein the first configuration information further comprises a transmission direction indication, the transmission direction indication comprising an uplink transmission or a downlink transmission.

4. A method of data transmission, the method comprising:

the second network equipment determines first configuration information, wherein the first configuration information comprises at least one of the following information: the method comprises the steps that automatic repeat request ARQ feedback information of a first bearer, a node identifier of first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier are obtained;

the second network device sends the first configuration information to the first network device;

the ARQ feedback information of the first bearer includes: one of end-to-end feedback, hop-by-hop feedback, and a feedback indication; the feedback indication is used for indicating the first network device to perform ARQ feedback on the data of the first bearer or not to perform ARQ feedback on the data of the first bearer.

5. The method of claim 4, wherein the first configuration information further comprises a transmission direction indication, and the transmission direction indication comprises an uplink transmission or a downlink transmission.

6. A method of data transmission, the method comprising:

the method comprises the steps that a first network device sends back transmission indicating information to a third network device, wherein the back transmission indicating information is used for informing the third network device to receive back transmission data, and the back transmission data is data which is failed to be sent to a superior node by the first network device and belongs to the third network device;

the first network device sends the backhaul data to the third network device;

the first network device is a superior node of the third network device.

7. The method of claim 6, further comprising: and after the first network equipment sends the return indication information, receiving feedback information sent by the third network equipment.

8. The method of claim 7, further comprising: and after receiving the feedback information, the first network equipment stops receiving the uplink data sent by the third network equipment.

9. A method of data transmission, the method comprising:

the terminal equipment receives third configuration information from second network equipment, wherein the third configuration information comprises retransmission indication information, the retransmission indication information is used for indicating the terminal equipment to carry out data retransmission, and the retransmission indication information comprises a serial number SN of a packet data unit PDU of a packet data convergence protocol PDCP layer;

the terminal equipment retransmits the data of the PDCP PDU according to the retransmission indication information;

the terminal equipment performs data retransmission of the PDCP PDU according to the retransmission indication information, and comprises the following steps:

the terminal equipment retransmits data after all SNs according to the SNs;

10. The method of claim 9, wherein the retransmission indication information comprises a cause value, and/or a number of retransmitted packets, K.

11. The method of claim 10, wherein the terminal device performing data retransmission of PDCP PDUs according to the retransmission indication information comprises:

the terminal equipment retransmits data after all SNs according to the SNs;

12. The method of claim 10, wherein the terminal device performing data retransmission of PDCP PDUs according to the retransmission indication information comprises:

13. A first network device, the device comprising:

a receiving module, configured to receive first configuration information of a second network device, where the first configuration information includes at least one of the following information: automatic repeat request ARQ feedback information of a first bearer, a node identifier of the first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier;

a processing module, configured to determine whether to perform ARQ feedback according to the first configuration information;

the ARQ feedback information of the first bearer includes: one of end-to-end feedback, hop-by-hop feedback, and a feedback indication; the feedback indication is used for indicating the first network device to perform ARQ feedback on the data of the first bearer or not to perform ARQ feedback on the data of the first bearer;

the processing module determining whether to perform ARQ feedback according to the first configuration information includes:

if the ARQ feedback information comprises end-to-end feedback, if the identifier of the first network equipment is the same as the identifier of the ARQ target node, sending ARQ feedback, if the identifier of the first network equipment is different from the identifier of the ARQ target node, not carrying out ARQ feedback, and forwarding the data of the first bearer;

if the ARQ feedback information comprises hop-by-hop feedback, transmitting ARQ feedback when receiving the data of the first bearer;

and if the ARQ feedback information comprises a feedback indication, determining whether to perform ARQ feedback on the data of the first bearer according to the feedback indication.

14. The apparatus of claim 13, wherein the ARQ feedback information for the first configuration information corresponds to one or more of the first bearers for the terminal device or to all bearers for the terminal device.

15. The apparatus of any one of claims 13-14, wherein the first configuration information further comprises a transmission direction indication, the transmission direction indication comprising an uplink transmission or a downlink transmission.

16. A second network device, the device comprising:

a processing module, configured to determine first configuration information, where the first configuration information includes at least one of: the method comprises the steps that automatic repeat request ARQ feedback information of a first bearer, a node identifier of first network equipment, an identifier of the first bearer, an identifier of terminal equipment, a logical channel identifier and an ARQ target node identifier are obtained;

a sending module, configured to send the first configuration information to the first network device;

17. The apparatus of claim 16, wherein the first configuration information further comprises a transmission direction indication, the transmission direction indication comprising an uplink transmission or a downlink transmission.

18. A first network device, the device comprising:

a sending module, configured to send backhaul indication information to a third network device, where the backhaul indication information is used to notify the third network device to receive backhaul data, and the backhaul data is data that the first network device fails to send to a superior node and belongs to the third network device;

the sending module is further configured to send the backhaul data to the third network device;

the first network device is a superior node of the third network device.

19. The apparatus of claim 18, wherein the apparatus further comprises:

and the receiving module is used for receiving the feedback information sent by the third network equipment after the sending module sends the return indication information.

20. The apparatus of claim 19, wherein the apparatus further comprises:

and the processing module is used for stopping receiving the uplink data sent by the third network equipment after the receiving module receives the feedback information.

21. A terminal device, characterized in that the device comprises:

a receiving module, configured to receive third configuration information from a second network device, where the third configuration information includes retransmission indication information, the retransmission indication information is used to indicate the terminal device to perform data retransmission, and the retransmission indication information includes a SN of a packet data unit PDU of a packet data convergence protocol PDCP layer;

a processing module, configured to perform data retransmission of the PDCP PDU according to the retransmission indication information;

the processing module is specifically configured to:

retransmitting data after all SNs according to the SNs;

22. The apparatus of claim 21, wherein the retransmission indication information comprises a cause value, and/or a number of retransmission packets, K.

23. The device according to claim 22, wherein the processing module is specifically configured to:

24. A first network device, comprising a receiver, a processor, and a memory, the processor establishing communication with the receiver and the memory, respectively;

the receiver for performing the method of any one of claims 1-3;

the processor configured to perform the method of any one of claims 1-3.

25. A second network device, wherein the first network device comprises a transmitter and a memory, wherein the transmitter and the memory establish communication;

the transmitter for performing the method of any one of claims 4-5.

26. A first network device, wherein the first network device comprises a transmitter and a memory, wherein the transmitter and the memory establish communication;

the transmitter for performing the method of any one of claims 6-8.

27. A terminal device, characterized in that the terminal device comprises a receiver, a processor and a memory, the processor establishing communication with the receiver and the memory, respectively;

the receiver for performing the method of any one of claims 9-12;

the processor configured to perform the method of any one of claims 9-12.