CN115701173A

CN115701173A - Data retransmission method, equipment, device and storage medium

Info

Publication number: CN115701173A
Application number: CN202110860129.XA
Authority: CN
Inventors: 张惠英
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2023-02-07

Abstract

An embodiment of the application provides a data retransmission method, device, apparatus and storage medium, wherein the method includes: the target communication equipment determines the PDCP SDU which is not successfully transmitted based on the PDCP status report sent by the first receiving end or the second receiving end; and the target communication equipment retransmits the PDCP SDU which is not successfully transmitted. The embodiment of the application determines the unsuccessfully transmitted PDCP SDU through the PDCP status report, and retransmits the unsuccessfully transmitted PDCP SDU, thereby ensuring the lossless transmission of data under the relay scene.

Description

Data retransmission method, equipment, device and storage medium

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a data retransmission method, device, apparatus, and storage medium.

Background

The traditional wireless communication adopts a cellular network communication mode, namely, a terminal and network side equipment transmit uplink and downlink data/control information through a Uu interface. In order to extend Network coverage, one solution is to introduce a UE (User Equipment) -to-Network Relay. The UE-to-Network Relay may be a terminal having a Relay function, an interface between the Relay and the Network uses a Uu interface for the UE-to-Network Relay, and a direct communication interface between a relayed terminal (which may be referred to as a Remote UE, remote UE) is used, and a link between the Relay and the Network may be referred to as a Backhaul link (BH) for the Remote UE.

In the prior art, for a PDCP (Packet Data Convergence Protocol) reconstruction or PDCP Data recovery process caused by a handover or a path switch of a UE, a PDCP layer sequentially transmits PDCP Data PDUs that have not been successfully transmitted by an RLC layer in an ascending order based on a successful transmission confirmation indication of the RLC layer.

However, in a Relay scenario, especially in an L2 Relay scenario, peer entities of the RLC layer and the PDCP layer are located at different nodes, and when a handover or a path transfer occurs between a remote UE of an L2U 2N (UE-to-Network) Relay or a source or target UE of the L2U (UE-to-UE, terminal-to-terminal) Relay, since the RLC layer is based on each hop, a successful transmission acknowledgement indication of the RLC layer only represents that data is successfully transmitted in a first hop, and cannot represent that data is successfully transmitted in a next hop, that is, it cannot be determined that a receiving end successfully receives data. If data retransmission is still performed according to the successful transmission confirmation indication of the RLC layer, there may be some data packets that are successfully transmitted only in the first hop, and the next hop is not successfully transmitted, and these data packets are not retransmitted, thereby resulting in data loss. Therefore, how to implement lossless transmission of data in a relay scenario becomes a problem that needs to be solved urgently.

Disclosure of Invention

In order to solve the problems in the prior art, embodiments of the present application provide a data retransmission method, device, apparatus, and storage medium.

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

the target communication equipment determines a packet data convergence protocol service data unit PDCP SDU which is not successfully transmitted based on a packet data convergence protocol PDCP status report sent by a first receiving end or a second receiving end;

the target communication device retransmits the unsuccessfully transmitted PDCP SDUs.

Optionally, according to a data retransmission method in an embodiment of the present application, the determining, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, that a packet data convergence protocol service data unit PDCP SDU which is not successfully transmitted includes:

determining the related information of the PDCP SDU which is not successfully transmitted based on the PDCP status report sent by the first receiving end or the second receiving end;

wherein the relevant information comprises at least one of:

first correlation information including a first unsuccessfully transmitted PDCP SDU and a first bitmap indicating whether a PDCP SDU following the first unsuccessfully transmitted PDCP SDU was successfully transmitted;

second correlation information including non-discarded PDCP SDUs including the unsuccessfully transmitted PDCP SDU;

wherein the first receiving end is a receiving end of the PDCP SDU before the retransmission of the unsuccessfully transmitted PDCP SDU;

the second receiving end is a receiving end connected with the target communication device at the moment of retransmitting the PDCP SDU which is not successfully transmitted;

the first receiving end and the second receiving end are the same or different.

Optionally, according to a data retransmission method according to an embodiment of the present application, the PDCP status report includes the first related information.

Optionally, according to a data retransmission method in an embodiment of the present application, in a case that the related information includes the first related information, the target communication device retransmits the PDCP SDU which is not successfully transmitted, including:

and the target communication equipment retransmits the PDCP SDUs which are not successfully transmitted in sequence from the first PDCP SDU which is not successfully transmitted based on the first bitmap.

Optionally, according to a data retransmission method in an embodiment of the present application, the determining, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, related information of a PDCP SDU that is not successfully transmitted includes:

discarding the PDCP SDUs before the first unsuccessfully transmitted PDCP SDU;

discarding the PDCP SDU with the value of 1 corresponding to the COUNT value in the PDCP SDU after the first unsuccessfully transmitted PDCP SDU;

determining a PDCP SDU that is not discarded as the second related information.

Optionally, according to a data retransmission method in an embodiment of the present application, in a case that the related information includes the second related information, the target communication device retransmits the PDCP SDU which is not successfully transmitted, including:

the target communication device retransmits the non-discarded PDCP SDUs.

Optionally, according to a data retransmission method in an embodiment of the present application, the retransmitting the PDCP SDU that is not successfully transmitted includes:

determining to retransmit the unsuccessfully transmitted PDCP SDU based on the relevant information based on retransmission configuration information;

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

Optionally, according to a data retransmission method according to an embodiment of the present application, in a case that the retransmission configuration information includes the link requirement and/or the service requirement, the determining, based on the retransmission configuration information, to retransmit the PDCP SDU that is not successfully transmitted based on the relevant information includes:

and determining to retransmit the successfully transmitted PDCP SDU based on the relevant information under the condition that the requirement of the link requirement and/or the service requirement on the transmission reliability is higher than a first threshold.

Optionally, according to a data retransmission method according to an embodiment of the present application, in a case that the retransmission configuration information includes the link type, the determining, based on the retransmission configuration information, to retransmit the unsuccessfully transmitted PDCP SDU based on the related information includes:

determining to retransmit the unsuccessfully transmitted PDCP SDU based on the related information, in case that the link type includes an L2 Relay type.

Optionally, according to a data retransmission method in an embodiment of the present application, in a case that the target communication device is a first terminal and the first terminal is handed over from the first receiving end or reestablished to the second receiving end, the retransmitting the PDCP SDU that is not successfully transmitted includes:

retransmitting the PDCP SDU which is not successfully transmitted to the second receiving end;

the first receiving end and the second receiving end are different base station equipment; or

The first receiving end and the second receiving end are different terminal devices.

Optionally, according to a data retransmission method in an embodiment of the present application, in a case that the target communication device is a first base station, the first receiving end and the second receiving end are both second terminals, and the second terminal corresponding to the unsuccessfully transmitted PDCP SDU is switched from the first base station or is reestablished to the second base station, the retransmitting the unsuccessfully transmitted PDCP SDU includes:

and sending the unsuccessfully transmitted PDCP SDUs to the second base station so that the second base station retransmits the unsuccessfully transmitted PDCP SDUs to the second terminal.

Optionally, according to a data retransmission method in an embodiment of the present application, when the target communication device is a third base station, the first receiving end and the second receiving end are both third terminals, and the third terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over from the fourth base station or is reestablished to the third base station, the retransmitting the unsuccessfully transmitted PDCP SDU includes:

receiving the unsuccessfully transmitted PDCP SDU sent by the fourth base station;

and retransmitting the PDCP SDU which is not successfully transmitted to the third terminal.

Optionally, according to a data retransmission method in an embodiment of the present application, in a case that the target communication device is a fourth terminal and a relay device in a relay link where the fourth terminal is located is switched from a first relay device or is reestablished to a second relay device, the retransmitting a PDCP SDU that is not successfully transmitted includes:

retransmitting, by the second relay device, the unsuccessfully transmitted PDCP SDU to the first receiving end or the second receiving end;

wherein the PDCP status report is transmitted by the first relay device or the second relay device;

the first receiving end and the second receiving end are the same base station equipment; or

The first receiving end and the second receiving end are the same terminal equipment.

In a second aspect, an embodiment of the present application further provides a target communication device, including a memory, a transceiver, and a processor, where:

a memory for storing a computer program; a transceiver for transceiving data under control of the processor; a processor for reading the computer program in the memory and performing the following operations:

Optionally, according to the target communication device in an embodiment of the present application, the determining, based on the packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, that the packet data convergence protocol service data unit PDCP SDU which is not successfully transmitted includes:

wherein the relevant information comprises at least one of:

the first receiving end is the receiving end of the PDCP SDUs before the retransmission of the PDCP SDUs which are not successfully transmitted;

the first receiving end and the second receiving end are the same or different.

Optionally, according to the target communication device in an embodiment of the present application, the PDCP status report includes the first related information.

Optionally, according to the target communication device in an embodiment of the present application, in a case that the related information includes the first related information, the target communication device retransmits the PDCP SDU which is not successfully transmitted, including:

Optionally, according to the target communication device in an embodiment of the present application, the determining, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, relevant information of a PDCP SDU that is not successfully transmitted includes:

discarding the PDCP SDU preceding the first unsuccessfully transmitted PDCP SDU;

determining the non-discarded PDCP SDUs as the second related information.

Optionally, according to the target communication device in an embodiment of the present application, in a case that the related information includes the second related information, the target communication device retransmits the PDCP SDU that is not successfully transmitted, including:

the target communication device retransmits the non-discarded PDCP SDUs.

Optionally, according to the target communication device in an embodiment of the present application, the retransmitting the PDCP SDU that is not successfully transmitted includes:

based on retransmission configuration information, determining to retransmit PDCP SDUs which are not successfully transmitted based on the relevant information;

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

Optionally, according to the target communication device in an embodiment of the present application, in a case that the retransmission configuration information includes the link requirement and/or the service requirement, the determining, based on the retransmission configuration information, to retransmit the PDCP SDU that is not successfully transmitted based on the relevant information includes:

and under the condition that the requirement of the link requirement and/or the service requirement on the transmission reliability is higher than a first threshold, determining to retransmit the PDCP SDU which is not successfully transmitted based on the relevant information.

Optionally, according to the target communication device in an embodiment of the present application, in a case that the retransmission configuration information includes the link type, the determining, based on the retransmission configuration information, to retransmit the PDCP SDU that is not successfully transmitted based on the relevant information includes:

Optionally, according to the target communications device in an embodiment of the present application, in a case that the target communications device is a first terminal and the first terminal is handed over from the first receiving end or reestablished to the second receiving end, the retransmitting the PDCP SDU that is not successfully transmitted includes:

Optionally, according to the target communications device in an embodiment of the present application, the target communications device is a first base station, the first receiving end and the second receiving end are both second terminals, and the second terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over from the first base station or is re-established to the second base station, the retransmitting the unsuccessfully transmitted PDCP SDU includes:

Optionally, according to the target communication device in an embodiment of the present application, when the target communication device is a third base station, the first receiving end and the second receiving end are both third terminals, and the third terminal corresponding to the unsuccessfully transmitted PDCP SDU is switched from the fourth base station or is reestablished to the third base station, the retransmitting the unsuccessfully transmitted PDCP SDU, includes:

Optionally, according to the target communication device in an embodiment of the present application, in a case that the target communication device is a fourth terminal and a relay device in a relay link where the fourth terminal is located is switched from a first relay device or reestablished to a second relay device, the retransmitting the PDCP SDU that is not successfully transmitted includes:

In a third aspect, an embodiment of the present application further provides a data retransmission apparatus, including:

a determining unit, configured to determine a packet data convergence protocol service data unit PDCP SDU that is not successfully transmitted based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end;

and the retransmission unit is used for retransmitting the PDCP SDU which is not successfully transmitted.

In a fourth aspect, an embodiment of the present application further provides a processor-readable storage medium, where a computer program is stored, where the computer program is configured to enable the processor to execute the steps of the data retransmission method according to the first aspect described above.

According to the data retransmission method, the data retransmission device, the data retransmission apparatus and the storage medium provided by the embodiment of the application, the target communication device determines the PDCP SDU which is not successfully transmitted in the relay link through the PDCP status report, and retransmits the PDCP SDU which is not successfully transmitted, so that lossless transmission of data under a relay scene is effectively ensured.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following descriptions are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic diagram of a conventional wireless communication manner provided by the prior art;

FIG. 2 is a diagram of a prior art device-to-device direct communication scheme;

fig. 3 is a schematic diagram of a UE-to-Network Relay provided in the prior art;

fig. 4 is a schematic diagram of an L2 UE-to-Network Relay user plane protocol stack provided in the prior art;

FIG. 5 is a diagram of a user plane protocol stack of an L2UE-to-UE Relay provided in the prior art;

FIG. 6 is a diagram of a PDCP status report format provided by the prior art;

fig. 7 is a flowchart illustrating a data retransmission method according to an embodiment of the present application;

fig. 8 is a second flowchart of a data retransmission method according to an embodiment of the present application;

fig. 9 is a third flowchart illustrating a data retransmission method according to an embodiment of the present application;

fig. 10 is a fourth flowchart illustrating a data retransmission method according to an embodiment of the present application;

fig. 11 is a fifth flowchart illustrating a data retransmission method according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a target communication device according to an embodiment of the present application;

fig. 13 is a second schematic structural diagram of a target communication device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present application.

Detailed Description

In the embodiment of the present application, the term "and/or" describes an association relationship of associated objects, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the embodiments of the present application, the term "plurality" means two or more, and other terms are similar thereto.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

To facilitate a clearer understanding of the embodiments of the present application, some relevant background information is first presented below.

(1) Cellular network communications;

fig. 1 is a schematic diagram of a conventional wireless communication method provided in the prior art, and as shown in fig. 1, the conventional wireless communication method adopts a cellular network communication method, that is, a terminal and a network side device perform uplink and downlink data/control information transmission through a Uu interface.

(2) Direct communication;

fig. 2 is a schematic diagram of a device-to-device direct Communication manner provided by the prior art, and as shown in fig. 2, the direct Communication refers to a manner in which a nearby terminal can perform data transmission through a direct Communication link (also called Sidelink or PC5 (Proximity Communication Port 5)) in a short distance range. The wireless interface to which the Sidelink link corresponds is referred to as the Sidelink interface (also referred to as the direct communication interface or PC5 interface).

(3)UE-to-Network Relay；

Fig. 3 is a schematic diagram of a UE-to-Network Relay provided in the prior art, and as shown in fig. 3, in order to extend Network coverage, one solution is to introduce the UE-to-Network Relay. The UE-to-Network Relay may be a terminal with a Relay function, where an Uu interface is used for an interface between the Relay and a Network for the UE-to-Network Relay, and a direct communication interface is used between a relayed terminal (which may be referred to as a Remote UE, remote UE), and a link between the Relay and the Network may be referred to as a Backhaul link (BH) for the Remote UE.

(4) An L2 UE-to-Network Relay and UE-to-UE Relay user plane protocol stack;

fig. 4 is a schematic diagram of an L2 UE-to-Network Relay user plane protocol stack provided in the prior art, fig. 5 is a schematic diagram of an L2UE-to-UE Relay user plane protocol stack provided in the prior art, and as shown in fig. 4 and fig. 5, regardless of whether the L2 UE-to-Network Relay or the L2UE-to-UE Relay, the PDCP and the above layers are end-to-end protocol stacks, and the adaptation layer and the RLC and the below layers are hop-by-hop protocol stacks.

(5) Packet data convergence protocol PDCP status report (PDCP status report).

Fig. 6 is a schematic diagram of a PDCP status report format provided in the prior art, and as shown in fig. 6, the PDCP status report is used for a receiving situation where a receiving end reports Data to a transmitting end, where D/C is 0, which indicates a control PDU (Protocol Data Unit), PDU Type is set to 000, which represents that this PDCP control PDU is a PDCP status report. FMC (Fist Missing COUNT, COUNT value of first Missing packet data convergence protocol service data unit) is set to the COUNT value of first Missing PDCP SDU. Table 1 is a Bitmap (Bitmap) provided in the prior art, which is used to indicate whether each PDCP SDU was correctly received after FMC, as shown in table 1. And when the PDCP at the sending end receives the PDCP status report, discarding the PDCP SDUs with the COUNT value smaller than the FMC and the PDCP SDUs with the corresponding position value of the COUNT value of 1 in the Bitmap.

TABLE 1 Bitmap (Bitmap)

At present, no clear solution exists for lossless data transmission in a relay scenario, and for this reason, embodiments of the present application provide a data retransmission method applied in a relay scenario, so as to implement lossless data transmission in U2N and U2U relay communication systems.

Fig. 7 is a schematic flow diagram of a data retransmission method provided in an embodiment of the present application, and as shown in fig. 7, the embodiment of the present application provides a data retransmission method, where the method includes:

step 700, the target communication device determines a packet data convergence protocol service data unit PDCP SDU which is not successfully transmitted, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end.

Specifically, in this embodiment of the present application, the target communication device may be a base station or a remote UE, and similarly, the first receiving end or the second receiving end may be a base station or a remote UE.

In particular, in case the target communication device is a base station, the first or second receiving end may be a far end UE.

Specifically, in the case that the target communication device is a remote UE, the first receiving end or the second receiving end may be a base station, or may be a remote UE.

Specifically, when the target communication device performs data transmission over the relay link, for example, after the packet data convergence protocol service data unit PDCP SDU is transmitted over the relay link, the first receiving end or the second receiving end may send a PDCP status report to the target communication device, and the target communication device may determine the unsuccessfully transmitted PDCP SDU based on the received PDCP status report.

Step 701, the target communication device retransmits the PDCP SDU which was not successfully transmitted.

Specifically, after determining the unsuccessfully transmitted PDCP SDUs, the target communication device may retransmit the unsuccessfully transmitted PDCP SDUs to the first receiving end or the second receiving end.

Specifically, in the prior art, data retransmission is performed according to a successful transmission acknowledgement indication of the RLC layer. Since the RLC layer is based on each hop, the successful transmission acknowledgement indication of the RLC layer only represents that data is successfully transmitted in the first hop, and cannot represent that data is successfully transmitted in the next hop, so that the receiving end cannot be determined to successfully receive data in a relay scenario. Therefore, when data retransmission is performed according to the successful transmission acknowledgement indication of the RLC layer, there may be some data packets that are successfully transmitted only in the first hop and are not successfully transmitted in the next hop, and these data packets are not retransmitted, which results in data loss.

Therefore, in the embodiment of the present application, after determining the unsuccessfully transmitted PDCP SDUs based on the PDCP status report sent by the first receiving end or the second receiving end, the unsuccessfully transmitted PDCP SDUs may be retransmitted, for the sending end of the PDCP SDUs (i.e., the target communication device), the unsuccessfully transmitted PDCP SDUs may be accurately determined based on the PDCP status report, and the unsuccessfully transmitted PDCP SDUs are retransmitted, for the first receiving end or the second receiving end, it may be ensured that the unsuccessfully received PDCP SDUs are retransmitted and then received again, thereby reducing data loss.

According to the data retransmission method provided by the embodiment of the application, the target communication equipment determines the PDCP SDU which is not successfully transmitted in the relay link through the PDCP status report, and retransmits the PDCP SDU which is not successfully transmitted, so that the lossless transmission of data under a relay scene is effectively ensured.

Optionally, the determining, based on the packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, the unsuccessfully transmitted packet data convergence protocol service data unit PDCP SDU includes:

wherein the relevant information comprises at least one of:

first correlation information including a first unsuccessfully transmitted PDCP SDU and a first bitmap for indicating whether a PDCP SDU following the first unsuccessfully transmitted PDCP SDU is successfully transmitted;

the first receiving end and the second receiving end are the same or different.

Specifically, in this embodiment, the target communication device may first determine, based on the PDCP status report sent by the first receiving end or the second receiving end, related information of the unsuccessfully transmitted PDCP SDUs, where the related information may include at least the first related information and/or the second related information.

Specifically, the first related information may include a first unsuccessfully transmitted PDCP SDU and a first bitmap, wherein the first bitmap may be used to indicate whether a PDCP SDU after the first unsuccessfully transmitted PDCP SDU was successfully transmitted.

Specifically, in the first bitmap, in the case where the COUNT value is 1, it indicates that the corresponding PDCP SDU is successfully transmitted, and in the case where the COUNT value is 0, it indicates that the corresponding PDCP SDU is lost.

Specifically, the second related information may include PDCP SDUs that are not discarded, i.e., unsuccessfully transmitted PDCP SDUs; that is, the target communication device may determine the successfully transmitted PDCP SDUs based on the PDCP status report, and discard the successfully transmitted PDCP SDUs, so that the PDCP SDUs that are not discarded in the target communication device are the unsuccessfully transmitted PDCP SDUs.

In particular, the first receiving end may be a receiving end of PDCP SDUs by the target communication device prior to retransmission of unsuccessfully transmitted PDCP SDUs.

Specifically, the second receiving end may be a communication apparatus to which the target communication apparatus is connected at a time when the target communication apparatus retransmits the PDCP SDU which has not been successfully transmitted.

Specifically, the first receiving end and the second receiving end may be the same communication device or different communication devices.

For example, the first receiving end and the second receiving end may both be the base station 1 at the same time.

For example, the first receiving end may be base station 1 and the second receiving end may be base station 2.

For example, the first receiving end and the second receiving end may both be the far end UE1 at the same time.

For example, the first receiving end may be the far-end UE1, and the second receiving end may be the far-end UE2.

Optionally, the PDCP status report includes the first related information.

Specifically, in the embodiment of the present application, the PDCP status report may include the first related information, that is, the PDCP status report may include the first unsuccessfully transmitted PDCP SDU and the first bitmap.

Optionally, in a case that the related information includes the first related information, the retransmitting, by the target communication device, the PDCP SDU which is not successfully transmitted, including:

Specifically, in the embodiment of the present application, in the case that the related information includes the first related information, the unsuccessfully transmitted PDCP SDUs may be retransmitted in sequence from the first unsuccessfully transmitted PDCP SDU based on the first bitmap in the PDCP status report.

Specifically, the retransmission may be performed sequentially from the FMC indicated by the PDCP status report based on the PDCP SDUs corresponding to the case where the COUNT value indicated by the first bitmap is 0.

Optionally, the determining, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, related information of a PDCP SDU that is not successfully transmitted includes:

determining the non-discarded PDCP SDUs as the second related information.

Specifically, in this embodiment of the present application, after receiving a PDCP status report sent by a first receiving end or a second receiving end, a target communication device may discard a successfully transmitted PDCP SDU based on the PDCP status report, specifically, first discard a PDCP SDU before a first unsuccessfully transmitted PDCP SDU, and discard a PDCP SDU whose value is 1 and corresponding to a COUNT value in a first bitmap in the PDCP SDU after the first unsuccessfully transmitted PDCP SDU, where the remaining unsuccessfully transmitted PDCP SDUs are PDCP SDUs, that is, the unsuccessfully transmitted PDCP SDUs may be used as second related information.

Optionally, in a case that the related information includes the second related information, the retransmitting, by the target communication device, the PDCP SDU which is not successfully transmitted, including:

the target communication device retransmits the non-discarded PDCP SDUs.

Specifically, in the embodiment of the present application, in the case that the related information includes the second related information, the PDCP SDU which is not discarded may be directly retransmitted.

Optionally, the retransmitting the unsuccessfully transmitted PDCP SDU includes:

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

Specifically, in the embodiment of the present application, when retransmitting a PDCP SDU that has not been successfully transmitted, it may be determined to retransmit the PDCP SDU that has not been successfully transmitted based on the relevant information based on retransmission configuration information.

Specifically, the target retransmission mode may be determined to be a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information based on the configuration information of the network side device or the receiving end.

For example, when the base station configures the terminal through an RRC (Radio Resource Control) message to perform data retransmission, data transfer, or data recovery, the base station may retransmit the data based on a PDCP status report or based on a retransmission mode that is not discarded, that is, may retransmit the PDCP SDU that is not successfully transmitted based on a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information through configuration information of the network side device or the receiving end.

Specifically, the target retransmission mode may be determined to be a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information based on the link requirement and/or the service requirement.

For example, the terminal is a far-end UE of an L2U 2N Relay, and service transmission carried by one AM DRB (Data Resource Bearer) requires lossless transmission, the terminal may select that the PDCP retransmits the DRB based on a PDCP status report or based on a PDCP SDU that is not discarded, that is, may retransmit the PDCP SDU that is not successfully transmitted based on a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information.

Specifically, the target retransmission mode may be determined to be a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information based on the link type.

For example, for the remote terminal of L2 Relay, a retransmission based on PDCP status report or based on not discarded is used, that is, in the case that the link type includes the L2 Relay type, the PDCP SDU that is not successfully transmitted may be retransmitted based on the retransmission corresponding to the first related information or the retransmission corresponding to the second related information.

According to the data retransmission method provided by the embodiment of the application, the target retransmission mode is determined by providing multiple selection bases, and the flexibility of selection of the target retransmission mode is improved.

Optionally, in a case that the retransmission configuration information includes the link requirement and/or the service requirement, the determining, based on the retransmission configuration information, to retransmit the PDCP SDU that is not successfully transmitted based on the related information includes:

Specifically, in this embodiment of the present application, the first threshold may be configured or preconfigured by the network, or may be determined by the target communication device itself, which is not specifically limited in this application.

Specifically, the size of the first threshold may be set based on the size of the transmission reliability requirement required by the link requirement and/or the traffic requirement, for example, the size of the first threshold may be 0.8 or 0.9 or 0.95 or 0.99, and the like, which is not specifically limited in this application.

Specifically, when the link requirement and/or the service requirement for transmission reliability is higher than a first threshold, it is determined that the unsuccessfully transmitted PDCP SDU is retransmitted based on the related information, that is, it may be determined that the target retransmission mode is a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information.

According to the data retransmission method provided by the embodiment of the application, the target retransmission mode is determined according to the size of the transmission reliability requirement based on the link requirement and/or the service requirement, so that different retransmission modes can be flexibly selected according to different requirements of the transmission reliability to realize lossless transmission of data.

Optionally, in a case that the retransmission configuration information includes the link type, the determining, based on the retransmission configuration information, to retransmit the unsuccessfully transmitted PDCP SDU based on the related information includes:

Specifically, in this embodiment of the present application, when the link type includes an L2 Relay type, it may be determined that the unsuccessfully transmitted PDCP SDU is retransmitted based on the related information, that is, it may be determined that the target retransmission mode is a retransmission mode corresponding to the first related information or a retransmission mode corresponding to the second related information.

In the data retransmission method provided in the embodiment of the present application, when the link type includes the L2 Relay type, the PDCP SDU that is not successfully transmitted is retransmitted based on the retransmission mode corresponding to the first related information or the retransmission mode corresponding to the second related information, so that lossless transmission of data in the L2 Relay scenario is achieved.

Optionally, when the target communication device is a first terminal and the first terminal is handed over from the first receiving end or reestablished to the second receiving end, the retransmitting the PDCP SDU that is not successfully transmitted includes:

Specifically, in the embodiment of the present application, the first receiving end and the second receiving end may be base stations.

Specifically, in the embodiment of the present application, the first receiving end and the second receiving end may be terminals, that is, U2U (UE-to-UE) scenarios.

Specifically, in case of handover or re-establishment at the receiving end, i.e. from a first receiving end to a second receiving end, the unsuccessfully transmitted PDCP SDUs may be retransmitted to the second receiving end.

For example, in a case where the remote UE1 accesses the base station 1 through the L2 relay UE1 and the remote UE1 switches to the direct access base station 2, the remote UE1 may retransmit the unsuccessfully transmitted PDCP SDU to the base station 2 based on the received information in the PDCP status report to avoid data loss.

According to the data retransmission method provided by the embodiment of the application, under the condition that receiving end switching or rebuilding occurs, the terminal retransmits the PDCP SDU which is not successfully transmitted to the target receiving end, and lossless transmission of data is effectively achieved.

Optionally, when the target communication device is a first base station, the first receiving end and the second receiving end are both second terminals, and the second terminal corresponding to the unsuccessfully transmitted PDCP SDU is switched from the first base station or reestablished to the second base station, the retransmitting the unsuccessfully transmitted PDCP SDU, including:

Specifically, in the embodiment of the present application, in the case that the base station is handed over or reestablished, that is, in the case of being handed over or reestablished from the first base station to the second base station, the unsuccessfully transmitted PDCP SDUs may be retransmitted to the second base station, so that the second base station may retransmit the unsuccessfully transmitted PDCP SDUs to the second terminal.

For example, in a case where the remote UE1 accesses the base station 1 through the L2 relay UE1 and the remote UE1 switches to the direct access base station 2, the base station 1 may retransmit the unsuccessfully transmitted PDCP SDU to the base station 2 based on the received information in the PDCP status report, so that the base station 2 may retransmit the unsuccessfully transmitted PDCP SDU to the remote UE1 to avoid data loss.

According to the data retransmission method provided by the embodiment of the application, under the condition that the base station is switched or rebuilt, the source base station retransmits the unsuccessfully transmitted PDCP SDU to the target base station, so that the target base station can retransmit the unsuccessfully transmitted PDCP SDU to the terminal, and lossless transmission of data is effectively achieved.

Optionally, when the target communication device is a third base station, the first receiving end and the second receiving end are both third terminals, and the third terminal corresponding to the unsuccessfully transmitted PDCP SDU is switched from the fourth base station or is reestablished to the third base station, the retransmitting the unsuccessfully transmitted PDCP SDU includes:

Specifically, in the embodiment of the present application, in a case that the base station is handed over or reestablished, that is, in a case that the base station is handed over or reestablished from the fourth base station to the third base station, the unsuccessfully transmitted PDCP SDU sent by the fourth base station is received, and then the unsuccessfully transmitted PDCP SDU may be retransmitted to the third terminal.

For example, in the case that the remote UE1 accesses the base station 1 through the L2 relay UE1 and the remote UE1 switches to the direct access base station 2, the base station 2 may receive the unsuccessfully transmitted PDCP SDU sent by the base station 1, and then the base station 2 retransmits the unsuccessfully transmitted PDCP SDU to the remote UE1, so as to avoid data loss.

According to the data retransmission method provided by the embodiment of the application, under the condition that the base station is switched or rebuilt, the target base station receives the unsuccessfully transmitted PDCP SDU sent by the source base station, and retransmits the unsuccessfully transmitted PDCP SDU to the terminal, so that lossless transmission of data is effectively realized.

Optionally, when the target communication device is a fourth terminal and a relay device in a relay link where the fourth terminal is located is switched from the first relay device or reestablished to the second relay device, the retransmitting the PDCP SDU that is not successfully transmitted includes:

Specifically, in this embodiment of the present application, when a relay link is switched or reestablished, that is, when the relay link is switched or reestablished from a first relay device to a second relay device, a terminal may retransmit a PDCP SDU that is not successfully transmitted to a receiving end through the second relay device.

For example, when the remote UE1 communicates with the remote UE2 through the L2 relay UE1, and the remote UE1 and the remote UE2 switch to the link where the relay UE2 is located according to the link quality to continue communicating, before the remote UE1 communicates with the remote UE2 through the link where the relay UE2 is located, the remote UE1 may retransmit the PDCP SDU that is not successfully transmitted to the remote UE2 through the relay link where the relay UE2 is located, based on the received information in the PDCP status report, so as to avoid data loss.

It should be noted that the embodiment of the present application is applicable to a multi-hop Relay, that is, a scenario that a remote UE may access a network through a Relay of multiple relays, or 2 remote UEs may communicate through a Relay of multiple relays, which is not specifically limited in the present application.

According to the data retransmission method provided by the embodiment of the application, under the condition that the relay link is switched or rebuilt, the PDCP SDU which is not successfully transmitted is retransmitted to the receiving end through the target relay link, so that lossless transmission of data is effectively realized.

Fig. 8 is a second schematic flowchart of the data retransmission method provided in the embodiment of the present application, and as shown in fig. 8, an initial remote UE1 resides in a cell 1 controlled by a base station 1 through a relay UE1, the remote UE1 accesses the base station 1 through an L2 relay UE1, the remote UE1 is switched to a direct access base station 2, and the remote UE1 adopts a retransmission method corresponding to the first relevant information provided in the embodiment of the present application based on the base station configuration. Wherein, the detailed description of each step is as follows:

step 800, the base station 1 configures the PDCP of the remote UE1 to adopt the retransmission method corresponding to the first relevant information provided in the embodiment of the present application;

step 801, the remote UE1 replies a reconfiguration complete message to the base station 1;

step 802, the remote UE1 triggers a measurement report and reports that the quality of the Uu interface signal of the base station 2 is higher than a threshold;

step 803, carrying out switching preparation interaction between the base station 1 and the base station 2;

step 804, the base station 1 reconfigures the remote UE1 to switch to the base station 2;

step 805, the far-end UE1 sends a PDCP status report of downlink data to the base station 1;

step 806, the base station 1 sends PDCP status report of uplink data to the remote UE 1;

specifically, the above step 805 and step 806 do not distinguish the sequence, and may be executed in parallel.

Step 807, the base station 1 sends PDCP SDUs that the remote UE1 did not correctly receive to the base station 2 according to the FMC and bitmap instructions based on the received information in the PDCP status report;

step 808, the remote UE1 executes a handover process;

step 809, the remote UE1 sends a reconfiguration complete message to the base station 2;

step 810, the far-end UE1 retransmits the PDCP SDU which the base station 1 did not correctly receive to the base station 2 according to the FMC and bitmap instruction based on the received information in the PDCP status report;

step 811, data transmission is performed between the remote UE1 and the base station 2;

step 812, releasing the PC5 connection between the remote UE1 and the relay UE1.

Specifically, there is no timing relationship between step 812 and steps 809-811, and the PC5 connection with the relay UE1 can be released after the remote UE1 performs handover.

Specifically, the embodiment of the present application is also applicable to a scenario where a target base station for remote UE handover is also accessed through relay UE, and the process is basically unchanged, and only the PC5 connection with the target relay UE needs to be established before the remote UE handover is completed.

Optionally, in an embodiment, the remote UE1 accesses the base station 1 through the L2 relay UE1, the remote UE1 switches to the direct access base station 2, and the remote UE1 adopts a retransmission method corresponding to the second relevant information provided in the embodiment of the present application based on the base station configuration.

Specifically, the flow of the data retransmission method provided in this embodiment of the present application is substantially the same as the flow shown in fig. 8, except that the base station 1 discards downlink PDCP SDUs whose COUNT value is smaller than FMC and PDCP SDUs whose corresponding COUNT value position is 1 in Bitmap after receiving the PDCP status report in step 805, and forwards all the transmitted non-discarded PDCP SDUs to the base station 2 in step 807; correspondingly, after receiving the PDCP status report of step 806, the remote UE1 discards the uplink PDCP SDU with the COUNT value smaller than FMC and the PDCP SDU with the corresponding COUNT value position value of 1 in the Bitmap, and retransmits all the transmitted uplink PDCP SDUs that are not discarded to the base station 2 in step 810 and step 811.

Specifically, the embodiment of the present application is also applicable to a scenario in which a target base station for remote UE handover is accessed through relay UE, and the process is basically unchanged, but a PC5 connection with the target relay UE needs to be established before the remote UE handover is completed.

Fig. 9 is a third flowchart of the data retransmission method provided in the embodiment of the present application, and as shown in fig. 9, an initial remote UE2 resides in a cell 2 controlled by a base station 3 through a relay UE2, the remote UE2 accesses the base station 3 through an L2 relay UE2, the remote UE2 is switched to a direct access base station 4, and the remote UE2 adopts a retransmission mode corresponding to the first relevant information provided in the embodiment of the present application based on base station configuration. Wherein, the specific description of each step is as follows:

step 900, the base station 3 configures the PDCP of the remote UE2 to use the retransmission method corresponding to the first relevant information provided in the embodiment of the present application;

step 901, the remote UE2 replies a reconfiguration complete message to the base station 3;

step 902, the remote UE2 triggers a measurement report to report that the Uu interface signal quality of the base station 4 is higher than a threshold;

step 903, carrying out switching preparation interaction between the base station 3 and the base station 4;

step 904, base station 3 reconfigures remote UE2 to switch to base station 4;

step 905, the remote UE2 executes a handover process;

step 906, the remote UE2 sends a reconfiguration complete message to the base station 4;

step 907, the far-end UE2 sends PDCP status report of downlink data to the base station 4;

step 908, the base station 4 sends the received PDCP status report to the base station 3, the base station 3 determines, based on the information in the received PDCP status report, PDCP SDUs that the remote UE2 did not correctly receive, and sends PDCP SDUs that the remote UE2 did not correctly receive to the base station 4 according to the FMC and bitmap indication;

step 909, the base station 4 sends PDCP status report of downlink data to the far UE 2;

step 910, the remote UE2 retransmits the PDCP SDU that the base station 3 did not correctly receive to the base station 4 according to the FMC and bitmap instructions based on the received information in the PDCP status report;

911, data transmission is carried out between the remote UE2 and the base station 4;

step 912, release the PC5 connection between the remote UE2 and the relay UE2.

Specifically, there is no timing relationship between step 912 and steps 906 to 911, and the PC5 connection with the relay UE2 may be released after the remote UE2 performs handover.

Specifically, the embodiment of the present application may also be applicable to a scenario where a target base station for remote UE handover is accessed through relay UE as well, where the flow may refer to the flow shown in fig. 9, and only before the remote UE handover is completed, the PC5 connection with the target relay UE needs to be established.

Fig. 10 is a fourth flowchart of the data retransmission method provided in the embodiment of the present application, and as shown in fig. 10, an initial remote UE3 resides in a cell 3 controlled by a base station 5 through a relay UE3, the remote UE3 accesses the base station 5 through an L2 relay UE3, the relay UE3 has a Uu interface radio link failure, the relay UE3 accesses the base station 5 through a reestablishment, and the remote UE3 adopts a retransmission mode corresponding to the first relevant information provided in the embodiment of the present application based on base station configuration. Wherein, the specific description of each step is as follows:

step 1000, the relay UE3 generates a Uu interface radio link failure;

step 1001, the relay UE3 sends Uu RLF (Radio Link Failure) indication to the remote UE3 connected thereto;

step 1002, the relay UE3 initiates RRC reestablishment at the base station 5, and reestablishes the RRC reestablishment;

step 1003, the relay UE3 sends a Uu reestablishment success indication to the connected remote UE3;

step 1004, the remote UE3 initiates RRC reestablishment to the base station 5, and reestablishes the RRC reestablishment;

step 1005, the far-end UE3 sends PDCP status report of downlink data to the base station 5;

step 1006, the base station 5 sends a PDCP status report of uplink data to the remote UE3;

specifically, the step 1005 and the step 1006 are not in sequence, and may be executed in parallel.

Step 1007, the far-end UE3 retransmits the PDCP SDU which the base station 5 did not correctly receive to the base station 5 according to the FMC and bitmap instruction based on the received information in the PDCP status report;

step 1008, the base station 5 retransmits PDCP SDUs that the remote UE3 did not receive correctly to the remote UE3 according to the FMC and bitmap indication based on the information in the received PDCP status report;

step 1009, data transmission is performed between the remote UE3 and the base station 5.

Specifically, in this embodiment of the present application, after receiving the Uu RLF indication of the relay UE3, the remote UE3 may perform relay reselection or cell selection, and after passing through a new relay UE or directly accessing a cell, initiate an RRC reestablishment procedure, that is, step 1004 and the subsequent procedures.

Specifically, the cell reconstructed by the relay UE and the remote UE may be a source cell or a new cell, and for the case that the new cell is successfully reconstructed, the new cell needs to acquire uplink PDCP data receiving status information of the remote UE from the source cell, and the subsequent step 1004 and the subsequent steps are executed in the new cell.

Optionally, in an embodiment, the remote UE1 accesses the base station 1 through the L2 relay UE1, the remote UE1 is switched to the direct access base station 2, and the remote UE1 determines to use the retransmission method corresponding to the second relevant information provided in the embodiment of the present application based on the link (through the L2 relay access network) and the service requirement (lossless transmission).

Specifically, the embodiment of the present application is also applicable to a scenario where a target base station for remote UE handover is accessed through relay UE, and the process is basically unchanged, but a PC5 connection with the target relay UE needs to be established before the remote UE handover is completed.

Fig. 11 is a fifth flowchart of a data retransmission method provided in the embodiment of the present application, and as shown in fig. 11, a remote UE4 communicates with a remote UE5 through an L2 relay UE4, the remote UE4 and the remote UE5 switch to the relay UE5 to continue communicating according to link quality, and the remote UE4 and the remote UE5 determine to use a retransmission method corresponding to the first relevant information provided in the embodiment of the present application based on a link (communicating through an L2 relay) and a service requirement (lossless transmission). Wherein, the specific description of each step is as follows:

step 1100, the initial remote UE4 performs data transmission with the remote UE5 through the relay UE4;

step 1101, the remote UE4 and the remote UE5 switch to the relay UE5 according to the channel quality transformation negotiation;

step 1102, the far-end UE4 sends a PDCP status report of downlink data to the far-end UE5;

step 1103, the remote UE5 sends a PDCP status report of uplink data to the remote UE4;

specifically, the step 1102 and the step 1103 are not in sequence, and may be executed in parallel.

Step 1104, the remote UE4 establishes PC5 connection with the relay UE5;

step 1105, the remote UE5 establishes PC5 connection with the relay UE5;

specifically, the step 1104 and the step 1105 are not in sequence, and may be executed in parallel.

Step 1106, performing end-to-end signaling interaction between the remote UE4 and the remote UE5 through the relay UE5 to establish end-to-end connection;

step 1107, the remote UE4 sends PDCP SDUs that the remote UE5 did not correctly receive to the remote UE5 according to the FMC and bitmap indication based on the received information in the PDCP status report; correspondingly, the far-end UE5 sends PDCP SDU which is not correctly received by the far-end UE4 to the far-end UE4 according to the FMC and bitmap indication based on the received information in the PDCP status report;

step 1108, releasing the PC5 connection between the remote UE4 and the relay UE4;

step 1109, releasing the PC5 connection between the remote UE5 and the relay UE 4.

Specifically, there is no timing relationship between steps 1108 and 1109 and steps 1102-1107, and the remote UE4 and the remote UE5 may release the PC5 connection with the relay UE4 before or after establishing the PC5 connection with the relay UE 5.

Optionally, in an embodiment, the remote UE4 may communicate with the remote UE5 through the L2 relay UE4, and the serving base stations of the remote UE4 and the remote UE5 configure the remote UE4 and the remote UE5 to use the retransmission mode corresponding to the second relevant information.

Specifically, the flow of the data retransmission method provided in this embodiment of the present application is substantially the same as the flow shown in fig. 11, except that the serving base stations (which may be the same base station or different base stations) of the remote UE4 and the remote UE5 configure the retransmission method corresponding to the second relevant information provided in this embodiment of the present application. After step 1102 and step 1103, the remote UE4 and the remote UE5 discard the uplink PDCP SDU with the COUNT value smaller than FMC and the PDCP SDU with the corresponding COUNT value position value of 1 in Bitmap, and retransmit all the uplink PDCP SDUs that are transmitted and not discarded to the UE at the opposite end in step 1107.

Alternatively, the target communication device may be a base station, and the first receiving end or the second receiving end may be a remote terminal.

Alternatively, the target communication device may be a remote terminal, and the first receiving end or the second receiving end may be a base station.

The technical scheme provided by the embodiment of the application can be suitable for various systems, particularly 5G systems. For example, the applicable system may be a global system for mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) General Packet Radio Service (GPRS) system, a long term evolution (long term evolution, LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, an LTE-a (long term evolution) system, a universal mobile system (universal mobile telecommunications system, UMTS), a universal internet Access (WiMAX) system, a New Radio Network (NR) system, etc. These various systems include terminal devices and network devices. The System may further include a core network portion, such as an Evolved Packet System (EPS), a 5G System (5 GS), and the like.

The network device according to the embodiment of the present application may be a base station, and the base station may include a plurality of cells for serving a terminal. A base station may also be referred to as an access point, or a device in an access network that communicates over the air-interface, through one or more sectors, with wireless terminal devices, or by other names, depending on the particular application. The network device may be configured to exchange received air frames with Internet Protocol (IP) packets as a router between the wireless terminal device and the rest of the access network, which may include an Internet Protocol (IP) communication network. The network device may also coordinate attribute management for the air interface. For example, the network device according to the embodiment of the present application may be a Base Transceiver Station (BTS) in a Global System for Mobile communications (GSM) or a Code Division Multiple Access (CDMA), may also be a network device (NodeB) in a Wide-band Code Division Multiple Access (WCDMA), may also be an evolved Node B (eNB or e-NodeB) in a Long Term Evolution (LTE) System, a 5G Base Station (gNB) in a 5G network architecture (next generation System), may also be a Home evolved Node B (HeNB), a relay Node (relay Node), a Home Base Station (femto), a pico Base Station (pico) and the like, and the present application is not limited in this embodiment. In some network architectures, a network device may include a Centralized Unit (CU) node and a Distributed Unit (DU) node, which may also be geographically separated.

A terminal as referred to in embodiments of the present application may refer to a device providing voice and/or data connectivity to a user, a handheld device having a wireless connection capability, or other processing device connected to a wireless modem, etc. In different systems, the names of terminals may be different, for example, in a 5G system, a terminal may be called a User terminal or User Equipment (UE). A wireless terminal device, which may be a mobile terminal device such as a mobile telephone (or "cellular" telephone) and a computer having a mobile terminal device, e.g., a portable, pocket, hand-held, computer-included or vehicle-mounted mobile device, may communicate with one or more Core Networks (CNs) via a Radio Access Network (RAN), and may exchange language and/or data with the RAN. Examples of such devices include Personal Communication Service (PCS) phones, cordless phones, session Initiation Protocol (SIP) phones, wireless Local Loop (WLL) stations, and Personal Digital Assistants (PDAs). The wireless terminal device may also be referred to as a system, a subscriber unit (subscriber unit), a subscriber station (subscriber station), a mobile station (mobile station), a remote station (remote station), an access point (access point), a remote terminal (remote terminal), an access terminal (access terminal), a user terminal (user terminal), a user agent (user agent), and a user device (user device), which is not limited in this embodiment.

The network device and the terminal may each use one or more antennas for Multiple Input Multiple Output (MIMO) transmission, and the MIMO transmission may be Single User MIMO (SU-MIMO) or Multi-User MIMO (MU-MIMO). The MIMO transmission may be 2D-MIMO, 3D-MIMO, FD-MIMO, or massive-MIMO, or may be diversity transmission, precoding transmission, beamforming transmission, or the like, depending on the form and number of root antenna combinations.

The method and the device provided by the embodiments of the application are based on the same application concept, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not described again.

Fig. 12 is a schematic structural diagram of a target communication device according to an embodiment of the present application, where, as shown in fig. 12, in a case that the target communication device is a base station, the base station includes a memory 1220, a transceiver 1210, and a processor 1200, where:

a memory 1220 for storing computer programs; a transceiver 1210 for transceiving data under the control of the processor 1200; a processor 1200 for reading the computer program in the memory and performing the following operations:

The base station provided by the embodiment of the application determines the PDCP SDUs which are not successfully transmitted in the relay link through the PDCP status report, retransmits the PDCP SDUs which are not successfully transmitted, and effectively ensures the lossless transmission of data in a relay scene.

wherein the relevant information comprises at least one of:

the first receiving end and the second receiving end are the same or different.

Optionally, the PDCP status report includes the first related information.

determining the non-discarded PDCP SDUs as the second related information.

the target communication device retransmits the non-discarded PDCP SDUs.

Optionally, the retransmitting the PDCP SDU that is not successfully transmitted includes:

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

Optionally, when the target communications device is a third base station, the first receiving end and the second receiving end are both third terminals, and the third terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over from the fourth base station or is reestablished to the third base station, the retransmitting the unsuccessfully transmitted PDCP SDU includes:

The base station provided by the embodiment of the application determines the PDCP SDU which is not successfully transmitted in the relay link through the PDCP status report, and retransmits the PDCP SDU which is not successfully transmitted, thereby effectively ensuring the lossless transmission of data under the relay scene.

Where in fig. 12, the bus architecture may include any number of interconnected buses and bridges, with various circuits of one or more processors represented by processor 1200 and memory represented by memory 1220 being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 1210 may be a number of elements including a transmitter and receiver that provide a means for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like.

The processor 1200 is responsible for managing the bus architecture and general processing, and the memory 1220 may store data used by the processor 1200 in performing operations.

Alternatively, the processor 1200 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and may also adopt a multi-core architecture.

The processor 1200 calls the computer program stored in the memory 1220 to execute any of the methods provided by the embodiments of the present application according to the obtained executable instructions. The processor 1200 and the memory 1220 may also be physically separated.

Fig. 13 is a second schematic structural diagram of a target communication device according to an embodiment of the present application, and as shown in fig. 13, in the case that the target communication device is a remote terminal, the terminal includes a memory 1320, a transceiver 1310 and a processor 1300, where:

a memory 1320 for storing computer programs; a transceiver 1310 for transceiving data under the control of the processor 1300; a processor 1300 for reading the computer program in the memory and performing the following operations:

The remote terminal provided by the embodiment of the application determines the PDCP SDU which is not successfully transmitted in the relay link through the PDCP status report, retransmits the PDCP SDU which is not successfully transmitted, and effectively ensures the lossless transmission of data under the relay scene

wherein the relevant information comprises at least one of:

the first receiving end and the second receiving end are the same or different.

Optionally, the PDCP status report includes the first related information.

Optionally, the determining, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end, relevant information of a PDCP SDU that is not successfully transmitted includes:

determining a PDCP SDU that is not discarded as the second related information.

Optionally, in a case that the related information includes the second related information, the retransmitting, by the target communication device, the PDCP SDU that is not successfully transmitted, includes:

the target communication device retransmits the non-discarded PDCP SDUs.

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

Optionally, when the target communication device is a first terminal and the first terminal is handed over from the first receiving end or reestablished to the second receiving end, the retransmitting the PDCP SDU which is not successfully transmitted includes:

The first receiving end and the second receiving end are the same terminal equipment. The remote terminal provided by the embodiment of the application determines the PDCP SDU which is not successfully transmitted in the relay link through the PDCP status report, and retransmits the PDCP SDU which is not successfully transmitted, thereby effectively ensuring the lossless transmission of data in a relay scene.

In fig. 13, among other things, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by the processor 1300, and various circuits, represented by the memory 1320, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 1310 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over transmission media including wireless channels, wired channels, fiber optic cables, and the like. User interface 1330 may also be an interface capable of interfacing with a desired device for different user devices, including but not limited to a keypad, display, speaker, microphone, joystick, etc.

The processor 1300 is responsible for managing the bus architecture and general processing, and the memory 1320 may store data used by the processor 1300 in performing operations.

Alternatively, the processor 1300 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and may also adopt a multi-core architecture.

The processor 1300 is used for executing any of the methods provided by the embodiments of the present application according to the obtained executable instructions by calling the computer program stored in the memory 1320. The processor 1300 and the memory 1320 may also be physically separated.

It should be noted that, the target network device provided in the embodiment of the present application can implement all the method steps implemented by the method embodiment and achieve the same technical effect, and detailed descriptions of the same parts and beneficial effects as the method embodiment in this embodiment are not repeated herein.

Fig. 14 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present application, and as shown in fig. 14, the apparatus includes: a determination unit 1400 and a retransmission unit 1410, wherein:

the determining unit 1400 is configured to determine a packet data convergence protocol service data unit PDCP SDU that is not successfully transmitted, based on a packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end;

the retransmission unit 1410 is configured to retransmit the unsuccessfully transmitted PDCP SDUs.

The data retransmission device provided by the embodiment of the application determines the PDCP SDU which is not successfully transmitted in the relay link through the PDCP status report, and retransmits the PDCP SDU which is not successfully transmitted, thereby effectively ensuring the lossless transmission of data in a relay scene.

Optionally, the determining unit 1400 is further configured to:

determining the related information of the PDCP SDU which is not successfully transmitted based on a PDCP status report sent by the first receiving terminal or the second receiving terminal;

wherein the relevant information comprises at least one of:

the first receiving end and the second receiving end are the same or different.

Optionally, the PDCP status report includes the first related information.

Optionally, the retransmission unit 1410 is further configured to:

and under the condition that the relevant information comprises the first relevant information, retransmitting the unsuccessfully transmitted PDCP SDUs in turn from the first unsuccessfully transmitted PDCP SDU based on the first bitmap.

Optionally, the determining unit 1400 is further configured to:

discarding the PDCP SDUs with the value 1 of a first bitmap corresponding to the COUNT value in the PDCP SDUs after the first unsuccessfully transmitted PDCP SDU;

determining the non-discarded PDCP SDUs as the second related information.

Optionally, the retransmission unit 1410 is further configured to:

in a case where the correlation information includes the second correlation information, the target communication device retransmits the non-discarded PDCP SDU.

Optionally, the retransmission unit 1410 is further configured to:

the retransmission of the unsuccessfully transmitted PDCP SDUs includes:

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

Optionally, the retransmission unit 1410 is further configured to:

and under the condition that the retransmission configuration information comprises the link requirement and/or the service requirement, determining to retransmit the successfully transmitted PDCP SDU based on the relevant information under the condition that the link requirement and/or the service requirement have higher requirement on transmission reliability than a first threshold.

Optionally, the retransmission unit 1410 is further configured to:

and under the condition that the retransmission configuration information comprises the link type, under the condition that the link type comprises an L2 Relay type, determining to retransmit the PDCP SDU which is not successfully transmitted based on the relevant information.

Optionally, the retransmission unit 1410 is further configured to:

under the condition that the target communication equipment is a first terminal and the first terminal is switched or rebuilt from the first receiving end to the second receiving end, retransmitting the PDCP SDU which is not successfully transmitted to the second receiving end;

Optionally, the retransmission unit 1410 is further configured to:

the target communication device is a first base station, the first receiving terminal and the second receiving terminal are second terminals, and the second terminals corresponding to the unsuccessfully transmitted PDCP SDUs are switched from the first base station or rebuilt to the second base station, and the unsuccessfully transmitted PDCP SDUs are sent to the second base station, so that the second base station retransmits the unsuccessfully transmitted PDCP SDUs to the second terminals.

Optionally, the retransmission unit 1410 is further configured to:

receiving the unsuccessfully transmitted PDCP SDU sent by the fourth base station when the target communication device is a third base station, the first receiving end and the second receiving end are both third terminals, and the third terminal corresponding to the unsuccessfully transmitted PDCP SDU is switched or reestablished from the fourth base station to the third base station; and retransmitting the PDCP SDU which is not successfully transmitted to the third terminal.

Optionally, the retransmission unit 1410 is further configured to:

under the condition that the target communication device is a fourth terminal and the relay device in the relay link where the fourth terminal is located is switched or reestablished from the first relay device to a second relay device, retransmitting the unsuccessfully transmitted PDCP SDU to the first receiving terminal or the second receiving terminal through the second relay device;

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

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a processor readable storage medium. Based on such understanding, the technical solutions of the present application, which are essential or contributing to the prior art, or all or part of the technical solutions may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It should be noted that the apparatus provided in the embodiment of the present application can implement all the method steps implemented by the method embodiment and achieve the same technical effect, and detailed descriptions of the same parts and beneficial effects as the method embodiment in this embodiment are omitted here.

On the other hand, an embodiment of the present application further provides a processor-readable storage medium, where the processor-readable storage medium stores a computer program, where the computer program is configured to enable the processor to execute the data retransmission method provided in each of the foregoing embodiments, where the method includes:

The processor-readable storage medium may be any available medium or data storage device that can be accessed by a processor, including, but not limited to, magnetic memory (e.g., floppy disks, hard disks, magnetic tape, magneto-optical disks (MOs), etc.), optical memory (e.g., CDs, DVDs, BDs, HVDs, etc.), and semiconductor memory (e.g., ROMs, EPROMs, EEPROMs, non-volatile memories (NAND FLASH), solid State Disks (SSDs)), etc.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method for retransmitting data, comprising:

2. The method of claim 1, wherein the determining the unsuccessfully transmitted packet data convergence protocol service data unit PDCP SDU based on the packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end comprises:

wherein the relevant information comprises at least one of:

the first receiving end and the second receiving end are the same or different.

3. The data retransmission method according to claim 2, wherein the PDCP status report comprises the first related information.

4. The data retransmission method according to claim 3, wherein in case that the relevant information includes the first relevant information, the target communication device retransmits the unsuccessfully transmitted PDCP SDU, comprising:

5. The method according to claim 2, wherein the determining the information related to the unsuccessfully transmitted PDCP SDUs based on the PDCP status report of the packet data convergence protocol sent by the first receiver or the second receiver comprises:

determining the non-discarded PDCP SDUs as the second related information.

6. The data retransmission method according to claim 5, wherein in case that the related information includes the second related information, the target communication device retransmits the unsuccessfully transmitted PDCP SDUs, including:

the target communication device retransmits the non-discarded PDCP SDUs.

7. The data retransmission method according to claim 2, wherein the retransmitting the unsuccessfully transmitted PDCP SDUs comprises:

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

8. The method according to claim 7, wherein in case that the retransmission configuration information includes the link requirement and/or the service requirement, the determining, based on the retransmission configuration information, to retransmit the unsuccessfully transmitted PDCP SDU based on the relevant information comprises:

9. The method according to claim 7, wherein in case that the retransmission configuration information includes the link type, the determining, based on the retransmission configuration information, to retransmit the unsuccessfully transmitted PDCP SDU based on the relevant information comprises:

and under the condition that the link type comprises the L2 Relay type, determining to retransmit the PDCP SDU which is not successfully transmitted based on the relevant information.

10. The method according to any of claims 1-9, wherein in case that the target communication device is a first terminal and the first terminal is handed over from the first receiving end or reestablished to the second receiving end, the retransmitting the unsuccessfully transmitted PDCP SDU, comprises:

11. The method according to any of claims 1 to 9, wherein in a case that the target communication device is a first base station, the first receiving end and the second receiving end are both second terminals, and the second terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over from the first base station or is re-established to a second base station, the retransmitting the unsuccessfully transmitted PDCP SDU, includes:

12. The method according to any one of claims 1 to 9, wherein in a case that the target communication device is a third base station, the first receiving end and the second receiving end are both third terminals, and the third terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over or reestablished from the fourth base station to the third base station, the retransmitting the unsuccessfully transmitted PDCP SDU comprises:

13. The data retransmission method according to any one of claims 1 to 9, wherein in a case that the target communication device is a fourth terminal and a relay device in a relay link where the fourth terminal is located is handed over from a first relay device or reestablished to a second relay device, the retransmitting the PDCP SDU which is not successfully transmitted includes:

14. A target communication device comprising a memory, a transceiver, a processor:

a memory for storing a computer program; a transceiver for transceiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following:

15. The target communications device of claim 14, wherein the determining of unsuccessfully transmitted packet data convergence protocol service data units PDCP SDUs based on the packet data convergence protocol PDCP status report sent by the first receiving end or the second receiving end comprises:

wherein the relevant information comprises at least one of:

the first receiving end and the second receiving end are the same or different.

16. The target communications device of claim 15, wherein the PDCP status report includes the first related information.

17. The target communications device of claim 16, wherein in case that the correlation information includes the first correlation information, the target communications device retransmits the unsuccessfully transmitted PDCP SDUs, comprising:

18. The target communications device of claim 15, wherein the determining the information related to the unsuccessfully transmitted PDCP SDUs based on the status report of the PDCP SDU sent by the first receiving end or the second receiving end comprises:

determining the non-discarded PDCP SDUs as the second related information.

19. The target communications device of claim 18, wherein in case that the related information includes the second related information, the target communications device retransmits the unsuccessfully transmitted PDCP SDUs, comprising:

the target communication device retransmits the non-discarded PDCP SDUs.

20. The target communications device of claim 15, wherein the retransmitting the unsuccessfully transmitted PDCP SDUs comprises:

the retransmission configuration information includes at least one of:

configuration information of network side equipment;

configuration information of a receiving end;

link requirements and/or traffic requirements;

the type of link.

21. The target communications device of claim 19, wherein in case that the retransmission configuration information includes the link requirement and/or service requirement, the determining, based on the retransmission configuration information, to retransmit PDCP SDUs that were not successfully transmitted based on the relevant information comprises:

22. The target communications device of claim 19, wherein in the case that the retransmission configuration information includes the link type, the determining, based on the retransmission configuration information, to retransmit the unsuccessfully transmitted PDCP SDUs based on the related information comprises:

23. The target communications device according to any of claims 14-22, wherein in case the target communications device is a first terminal and the first terminal is handed over or re-established from the first receiving end to the second receiving end, the retransmitting the unsuccessfully transmitted PDCP SDUs, comprises:

24. The target communications device according to any one of claims 14-22, wherein in a case that the target communications device is a first base station, the first receiving end and the second receiving end are both second terminals, and the second terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over from the first base station or is re-established to a second base station, the retransmitting the unsuccessfully transmitted PDCP SDU comprises:

25. The target communications device according to any one of claims 14 to 22, wherein in a case that the target communications device is a third base station, the first receiving end and the second receiving end are both third terminals, and a third terminal corresponding to the unsuccessfully transmitted PDCP SDU is handed over from the fourth base station or is re-established to the third base station, the retransmitting the unsuccessfully transmitted PDCP SDU comprises:

26. The target communications device according to any one of claims 14 to 22, wherein in a case that the target communications device is a fourth terminal and a relay device in a relay link where the fourth terminal is located is handed over from a first relay device or reestablished to a second relay device, the retransmitting the PDCP SDU which is not successfully transmitted includes:

27. A data retransmission apparatus, comprising:

28. A processor-readable storage medium, characterized in that the processor-readable storage medium stores a computer program for causing a processor to perform the method of any one of claims 1 to 13.