CN110278058B

CN110278058B - Redundant information feedback method and communication device

Info

Publication number: CN110278058B
Application number: CN201910488397.6A
Authority: CN
Inventors: 汤德龙; 仇力炜
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2020-11-03
Anticipated expiration: 2039-06-05
Also published as: WO2020244642A1; CN110278058A

Abstract

The embodiment of the application discloses a redundant information feedback method and a communication device. The method comprises the following steps: the method comprises the steps that a first node sends one or more data packets to a second node, wherein each data packet comprises a packet data convergence protocol sequence number PDCP SN of the data packet; then, the first node sends redundant information to the second node, the redundant information comprises the PDCP SN of the one or more data packets, and the second node can determine whether the data packets are lost on a transmission path between the first node and the second node according to the redundant information.

Description

Redundant information feedback method and communication device

Technical Field

The embodiment of the application relates to the field of communication, and in particular relates to a redundant information feedback method and a communication device.

Background

Fifth generation (5)^thgeneration, 5G) non-independent (NSA) networking, uplink dynamic offloading is a common user plane data transmission mode. In this mode, uplink data of a User Equipment (UE) may be shunted and arrive at an evolved node B (eNB) through a 4G air interface, and arrive at a next generation base station (gNB) through a 5G air interface. The data are finally converged at an anchor base station (gNB or eNB), the received data are reordered by the anchor, and the data are transmitted to a core network.

When the anchor base station receives the discontinuous data packet, a timer is started. Before the timer is overtime, if the data packet is completely supplemented, the anchor base station continuously transmits the data packet to the core network; otherwise, the anchor base station needs to wait for the timeout of the timer to continue to transmit the data packet.

If the timer is set too small, the data packet which is delayed and not received may be regarded as a packet loss, which causes abnormal processing at the application layer and results in poor experience of the upper layer application. Therefore, a relatively large timer is generally set, the anchor base station stops transmitting data packets during the running period of the timer, and the bandwidth between the anchor base station and the core network is in an idle state during the period, so that the bandwidth waste is serious.

Disclosure of Invention

The embodiment of the application provides a redundant information feedback method and a communication device, which can accurately determine whether a data packet is lost on an air interface or a transmission path between nodes, and perform different processing on two different lost data packets, so as to timely terminate a packet loss waiting timer or not start the packet loss waiting timer, avoid long-time packet loss waiting, reduce bandwidth waste, save cost, and improve communication benefits.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, a redundant information feedback method is disclosed, where the method may be executed by a first communication device (a first node or a chip in the first node), and the first node is taken as an example to be described below, and it should be noted that an execution subject of the method may be replaced by the first communication device. The method comprises the following steps: a first node transmitting one or more (e.g., N) data packets to a second node, each of the one or more data packets including a PDCP SN of the data packet; the first node sends redundant information to the second node, the redundant information including the one or more (e.g., N) PDCP SNs, the one or more (e.g., N) PDCP SNs and the one or more (e.g., N) data packets being in a one-to-one correspondence.

After one or more data packets are sent, the PDCP SNs of the one or more data packets are sent, so that the second node can determine which data packets are lost on a transmission path between the nodes, and therefore except the data packets lost on the transmission path between the first node and the second node, the second node finds that other packets which are not received are lost on an air interface when carrying out PDCP reordering, and further the second node can carry out different processing on the two different lost data packets.

In the method provided by the embodiment of the present application, when the PDCP entity of the second node finds that the data packet received from the first node is discontinuous, a timer is started to wait for the data packet. Meanwhile, the second node may determine whether packet loss occurs when the first node transmits a plurality of data packets to the second node according to the redundant information from the first node. Once the second node judges that packet loss occurs on the transmission path of the first node and the second node, the second node skips the data packet when reordering the data packet, for example, if a timer waiting for the data packet is started, the timer waiting for the data packet is terminated, and the second node can continue to deliver the data packet to the core network; or, if the timer for waiting the data packet has not started yet, the timer for waiting the data packet is not started, and after the currently running timer (waiting for other data packets) expires, the second node may continue to deliver the data packet to the core network. Therefore, the method provided by the embodiment of the application can avoid the waste of bandwidth caused by waiting for the lost data packet for a long time, can reduce the time delay of the second node for sending data to the core network element, and is beneficial to improving the communication performance.

With reference to the first aspect, in a first possible implementation manner of the first aspect, each of the one or more (e.g., N) data packets further includes an identification sequence number of the data packet; the redundant information further includes the one or more (e.g., N) identification sequence numbers, which are in a one-to-one correspondence with the one or more (e.g., N) PDCP SNs.

In this embodiment of the application, after receiving a plurality of data packets, the second node analyzes the data packets to obtain the identification sequence numbers therein, and further may determine whether the received data packets are consecutive according to the identification sequence numbers, or may determine whether a packet is lost on a transmission path between the first node and the second node. In addition, the second node can also determine PDCPSN of packet loss according to the redundant information.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the plurality of identification sequence numbers are consecutive.

In this embodiment of the application, the first node sends a plurality of data packets with consecutive identification sequence numbers to the second node, and after the second node receives the data packets from the first node, whether to lose the packets or not can be determined according to the continuity of the data packets. For example, the data packets received by the second node from the first node are consecutive, which indicates that there is no packet loss on the transmission path between the first node and the second node; the data packet received by the second node from the first node is discontinuous, which indicates that there is a packet loss on the transmission path between the first node and the second node.

With reference to the first or second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the one or more identification sequence numbers in one-to-one correspondence with the one or more data packets are consecutive according to a transmission sequence of the one or more data packets.

In this embodiment of the present application, the first node may determine the identification sequence numbers of the data packets according to the packet sending sequence, and when the first node sends packets continuously, the identification sequence numbers of the multiple data packets sent by the first node are also continuous. Correspondingly, the second node may determine whether to lose the packet according to whether the received data packets are consecutive.

With reference to the first aspect or any one of the first to third possible implementation manners of the first aspect, in a fourth possible implementation manner of the first aspect, the redundant information is sent periodically.

In the embodiment of the application, after sending one or more data packets, the first node sends a redundant message at least indicating the PDCP SN of the data packet sent this time, so that the second node can determine whether there is a packet loss according to the redundant message, and terminate the timer waiting for the packet loss, or not start the timer waiting for the packet loss, thereby avoiding that the second node occupies the bandwidth for a long time but does not transmit the data packet, which results in wasting the bandwidth resources.

With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, a sending cycle of the redundant information is less than a duration of a PDCP discard timer.

In the embodiment of the application, the sending period of the redundant information is shorter than the time length of the PDCP discard timer, the second node can receive the redundant information before the PDCP discard timer is overtime, and once the data packet triggering the PDCP discard timer is lost, the timer is stopped in time, so that the bandwidth resource is prevented from being wasted for a long time.

With reference to the fifth or sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the redundant information includes the one or more PDCP SNs corresponding to the one or more data packets sent by the first node one to one after the redundant information is sent last time.

In this embodiment of the application, after sending one or more data packets, the first node sends the redundancy information to the second node to indicate the PDCP SNs of the one or more data packets, so that the second node can determine whether the one or more data packets sent by the first node are lost according to the redundancy information. Once the data packet triggering the PDCP discard timer is lost, the timer is stopped in time, and the bandwidth resource is prevented from being wasted for a long time.

With reference to the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the redundancy information further includes the redundancy information sent last time.

In the embodiment of the application, the first node can also send redundant information in a redundant manner, so that the reliability of the redundant information is improved. For example, the first node may also include the redundancy information sent the ith time in the redundancy information sent the (i + 1) th time, and when a continuous packet loss occurs, the second node may still determine the packet loss according to the redundancy information.

With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, the method further includes: the first node receives duration information of the PDCP discard timer from the second node.

In the embodiment of the application, the second node is responsible for converging data, and delivering the data packets to the core network after reordering the data packets, so that the second node maintains the duration information of the PDCP discard timer. The second node may transmit a duration of the PDCP discard timer to the first node, and the first node may set a period for transmitting the redundant information according to the duration of the PDCP discard timer, so that the second node receives the redundant information before the PDCP discard timer expires.

With reference to the first aspect or any one of the first to third possible implementation manners of the first aspect, in a ninth possible implementation manner of the first aspect, a difference between a time when the first node sends the redundant information and a time when the first node completes sending of the one or more data packets is a first threshold.

In the embodiment of the present application, it is assumed that the second node receives the redundant information associated with the data packet first and then receives the data packet, which may cause the second node to misunderstand that the data packet is lost and skip the data packet during reordering. The first node sends the data packet and the redundant information at a certain time interval, and ensures that the second node receives the redundant information associated with the data packet after receiving a certain data packet as far as possible, so that the second node can be prevented from mistakenly considering that the data packet is lost, and the erroneous reordering operation is avoided.

With reference to the first aspect or any one of the first to third possible implementation manners of the first aspect, in a tenth possible implementation manner of the first aspect, the sending, by the first node, the redundant information to the second node specifically includes:

after the first node completes the sending of the one or more data packets, one or more other data packets are sent first, and then the redundant information is sent to the second node.

In the embodiment of the present application, it is assumed that the second node receives the redundant information associated with the data packet first and then receives the data packet, which may cause the second node to misunderstand that the data packet is lost and skip the data packet during reordering. The first node sends the data packets and the redundant information at intervals of N data packets, and ensures that the second node receives the redundant information associated with the data packets after receiving a certain data packet as far as possible, so that the second node can be prevented from mistakenly considering that the data packets are lost, and the wrong reordering operation is avoided.

With reference to the first aspect or any one of the first to third possible implementation manners of the first aspect, in an eleventh possible implementation manner of the first aspect, the sending, by the first node, the redundant information to the second node specifically includes: and the first node repeatedly sends the redundant information until receiving confirmation information from the second node, wherein the confirmation information is used for confirming the receipt of the redundant information.

In the embodiment of the application, the reliability of the redundant information can be improved through repeated transmission.

With reference to the first aspect, in a twelfth possible implementation manner of the first aspect, the redundant information is carried in a service data packet, and the service data packet is different from the one or more data packets.

In this embodiment of the present application, the redundant information may be carried in other data packets (the same type as the first one or more data packets sent by the first node, including service data) and sent to the gNB. When the eNB transmits the data packet, the PDCP SN of one or more data packets transmitted before is attached to the path.

With reference to the first aspect, in a thirteenth possible implementation manner of the first aspect, the redundant information is carried in a data packet except for a service data packet.

In this embodiment of the present application, the first node may further construct a dedicated data packet to send the redundant information, and such a data packet may not include service data and is only used to carry the redundant information.

In a second aspect, a redundant information feedback method is disclosed, where the redundant information feedback method may be executed by a second communication device (a second node or a chip in the second node), and the second node is taken as an example to be described below, and it should be noted that an execution subject of the method may be replaced by the second communication device. The method comprises the following steps: the second node receiving redundancy information from the first node, the redundancy information comprising one or more (e.g. N) packet data convergence protocol sequence numbers, PDCP SNs; the one or more (e.g., N) PDCP SNs correspond one-to-one with one or more (e.g., N) data packets sent by the first node to the second node, each of the one or more (e.g., N) data packets including a PDCP SN of the data packet.

It is understood that N is greater than or equal to M, the first node sends N packets to the second node, the second node may receive some or all of the one or more packets, and there may be some packets that the second node does not receive.

The above method may further comprise: the second node receives M data packets from the first node, wherein each data packet in the M data packets comprises a Packet Data Convergence Protocol (PDCP) sequence number SN of the data packet, and M is an integer greater than or equal to 1. Or, the second node may not receive the data packet from the first node, and it can be understood that N data packets sent by the first node are lost, and at this time, the second node only receives the redundant information, which includes N PDCP SN numbers, but does not include the service data packet.

With reference to the second aspect, in a first possible implementation manner of the second aspect, each of the one or more (e.g., N) data packets sent by the first node further includes an identification sequence number of the data packet, and each of the M data packets received by the second node includes an identification sequence number of the data packet. The redundant information further includes the one or more (e.g., N) identification sequence numbers, which are in a one-to-one correspondence with the one or more (e.g., N) PDCP SNs.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the identification sequence numbers are consecutive.

With reference to the first or second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, according to the sending order of the one or more (e.g., N) data packets, the one or more (e.g., N) identification sequence numbers in one-to-one correspondence with the one or more (e.g., N) data packets are consecutive. However, since the second node receives only M data packets, the identification sequence numbers of the M data packets may not be consecutive.

With reference to the second aspect or any one of the first to third possible implementations of the second aspect, in a fourth possible implementation of the second aspect, the redundant information is received periodically. Or, the first node sends the redundant information periodically, but the second node receives the redundant information at some time and does not receive the redundant information at other time, and the second node receives the redundant information not periodically.

With reference to the fourth possible implementation manner of the second aspect, in a fifth possible implementation manner of the second aspect, a receiving period of the redundant information is less than a duration of the PDCP discard timer. Alternatively, the second node is not periodic in receiving the redundant information, but the time interval between two adjacent times of receiving the redundant information is less than the time length of the PDCP discard timer.

With reference to the fourth or fifth possible implementation manner of the second aspect, in a sixth possible implementation manner of the second aspect, the redundant information includes the one or more (e.g., M) PDCP SNs corresponding to the one or more (e.g., M) data packets received from the first node after the redundant information is received last time.

With reference to the sixth possible implementation manner of the second aspect, in a seventh possible implementation manner of the second aspect, the redundant information further includes the redundant information received last time.

With reference to the fifth possible implementation manner of the second aspect, in an eighth possible implementation manner of the second aspect, the duration information of the PDCP discard timer is sent to the first node.

With reference to the second aspect or any one of the first to eighth possible implementation manners of the second aspect, in a ninth possible implementation manner of the second aspect, the method further includes: and when the second node determines that the data packet corresponding to the first PDCP SN in the redundant information is not received and the second node performs PDCP reordering, skipping the data packet corresponding to the first PDCP SN, wherein the first PDCP SN is one PDCP SN in the one or more PDCP SNs.

With reference to the second possible implementation manner of the second aspect, in a tenth possible implementation manner of the second aspect, the N identification sequence numbers that are one-to-one corresponding to the N data packets sent by the first node are consecutive, but since the second node only receives M data packets, M identification sequence numbers that are respectively corresponding to the M data packets are discontinuous, the method further includes: and when the second node determines that a first identification sequence number is not received according to the continuity of the identification sequence numbers of the plurality of (for example, M) identification sequence numbers, wherein the first identification sequence number is one of the plurality of (for example, N) identification sequence numbers, and the PDCP SN corresponding to the first identification sequence number is the first PDCP SN, skipping the data packet corresponding to the first PDCP SN when the second node performs PDCP reordering.

With reference to the tenth possible implementation manner of the second aspect, in an eleventh possible implementation manner of the second aspect, when the second node performs PDCP reordering, skipping a data packet corresponding to the first PDCP SN includes: if the PDCP discard timer of the data packet corresponding to the first PDCP SN is started, stopping the PDCP discard timer of the data packet corresponding to the first PDCP SN; or, if the PDCP discard timer of the data packet corresponding to the first PDCP SN is not started, the PDCP discard timer of the data packet corresponding to the first PDCP SN is discarded to be started.

With reference to the tenth or eleventh possible implementation manner of the second aspect, in a twelfth possible implementation manner of the second aspect, the method further includes: and sending a data packet with the PDCP SN larger than the first PDCP SN to a core network.

With reference to the second aspect or any one of the first to twelfth possible implementation manners of the second aspect, in a thirteenth possible implementation manner of the second aspect, the method further includes: and sending confirmation information to the first node, wherein the confirmation information is used for confirming the receipt of the redundant information.

With reference to the second aspect or the first aspect, in a possible implementation manner, the one or more data packets are data packets of a first data radio bearer, a radio link control, RLC, layer of the first data radio bearer is at the first node, and a PDCP layer of the first data radio bearer is at the second node.

In the embodiment of the application, the data packets sent by the first node to the second node may have disorder, and the second node may sequence the data packets received from the first node; or, the PDCP SN of the data packet sent by the first node to the second node via the first data radio bearer is discontinuous, the second node may further receive data packets from other bearers (e.g., the second bearer), and the second node may mix and order the data packets received via the first data radio bearer and the second bearer.

It should be noted that, the communication between the MN and the UE may be achieved through the first data radio bearer, and the communication between the SN and the UE may also be achieved through the first data radio bearer. The first data radio bearer may be a data radio bearer, and the first data radio bearer may correspond to only one PDCP entity on the network side, but the first data radio bearer may correspond to two RLC bearers on the network side, and the two RLC bearers are respectively on the MN and the SN (i.e. a offload bearer).

With reference to the second aspect or the first aspect, in a possible implementation manner, the first data radio bearer is an auxiliary cell group SCG bearer terminated by a master node MN, or a offload bearer terminated by the master node MN, or a master cell group MCG bearer terminated by an auxiliary node SN, or a offload bearer terminated by an SN.

With reference to the second aspect or the first aspect, in a possible implementation manner, the first node is a distribution unit DU, and the second node is a centralized CU.

In a third aspect, a communication device is disclosed, which may be a first node or a chip in the first node. The communication device may comprise means corresponding to the steps in the method of the first aspect, to which reference may be made. The communication device includes: a communication unit, configured to transmit one or more (e.g., N) data packets to a second node, each of the one or more data packets including a PDCP SN of the data packet; the communication unit is further configured to send redundant information to the second node, where the redundant information includes the one or more PDCP SNs, and the one or more PDCP SNs and the one or more data packets are in a one-to-one correspondence.

With reference to the third aspect, in a first possible implementation manner of the third aspect, each of the one or more data packets further includes an identification sequence number of the data packet; the redundant information further includes the one or more identification sequence numbers, which are in one-to-one correspondence with the one or more PDCP SNs.

With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the multiple identification sequence numbers are consecutive.

With reference to the first or second possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect, according to a transmission sequence of the one or more data packets, the one or more identification sequence numbers in one-to-one correspondence with the one or more data packets are consecutive.

With reference to the third aspect or any one of the first to third possible implementation manners of the third aspect, in a fourth possible implementation manner of the third aspect, the redundant information is sent periodically.

With reference to the fifth possible implementation manner of the third aspect, in a sixth possible implementation manner of the third aspect, a sending cycle of the redundant information is less than a duration of a PDCP discard timer.

With reference to the fifth or sixth possible implementation manner of the third aspect, in a seventh possible implementation manner of the third aspect, the redundant information includes the one or more PDCP SNs corresponding to the one or more data packets sent by the first node in a one-to-one manner after the redundant information is sent last time.

With reference to the sixth possible implementation manner of the third aspect, in a seventh possible implementation manner of the third aspect, the redundancy information further includes the redundancy information that was sent last time.

With reference to the fifth possible implementation manner of the third aspect, in a sixth possible implementation manner of the third aspect, the communication unit is further configured to receive, from the second node, duration information of the PDCP discard timer.

With reference to the third aspect or any one of the first to third possible implementation manners of the third aspect, in a ninth possible implementation manner of the third aspect, a difference between a time when the first node sends the redundant information and a time when the first node completes sending of the one or more data packets is a first threshold.

With reference to the third aspect or any one of the first to third possible implementation manners of the third aspect, in a tenth possible implementation manner of the third aspect, the communication unit is specifically configured to, after completing the sending of the one or more data packets, send N other data packets first, and then send the redundant information to the second node.

With reference to the third aspect or any one of the first to third possible implementation manners of the third aspect, in an eleventh possible implementation manner of the third aspect, the communication unit is specifically configured to repeatedly send the redundant information until receiving acknowledgement information from the second node, where the acknowledgement information is used to acknowledge receipt of the redundant information.

With reference to the third aspect, in a twelfth possible implementation manner of the third aspect, the redundant information is carried in a service data packet, and the service data packet is different from the one or more data packets.

With reference to the third aspect, in a thirteenth possible implementation manner of the third aspect, the redundant information is carried in a data packet except for a service data packet.

In the third aspect of the embodiment of the present application, one or more data packets sent by the first node to the second node may be recorded as N data packets, where N is an integer greater than or equal to 1.

In a fourth aspect, a communication device is disclosed, which may be a first node or a chip in the first node. The communication device may comprise elements corresponding to the steps in the method of the second aspect, which may be referred to. The communication device includes: a communication interface to transmit one or more data packets to a second node, each of the one or more data packets including a PDCP SN of the data packet; the communication interface is further configured to send redundant information to the second node, where the redundant information includes the one or more PDCP SNs, and the one or more PDCP SNs and the one or more data packets are in a one-to-one correspondence.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, each of the one or more data packets further includes an identification sequence number of the data packet; the redundant information further includes the one or more identification sequence numbers, which are in one-to-one correspondence with the one or more PDCP SNs.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, the plurality of identification numbers are consecutive.

With reference to the first or second possible implementation manner of the fourth aspect, in a third possible implementation manner of the fourth aspect, the one or more identification sequence numbers in one-to-one correspondence with the one or more data packets are consecutive according to a transmission sequence of the one or more data packets.

With reference to the fourth aspect or any one of the first to third possible implementation manners of the fourth aspect, in a fourth possible implementation manner of the fourth aspect, the redundant information is sent periodically.

With reference to the fifth possible implementation manner of the fourth aspect, in a sixth possible implementation manner of the fourth aspect, a sending cycle of the redundant information is less than a duration of a PDCP discard timer.

With reference to the fifth or sixth possible implementation manner of the fourth aspect, in a seventh possible implementation manner of the fourth aspect, the redundant information includes the one or more PDCP SNs, which are in one-to-one correspondence with the one or more data packets sent by the first node after the redundant information is sent last time.

With reference to the sixth possible implementation manner of the fourth aspect, in a seventh possible implementation manner of the fourth aspect, the redundancy information further includes the redundancy information sent last time.

With reference to the fifth possible implementation manner of the fourth aspect, in a sixth possible implementation manner of the fourth aspect, the communication interface is further configured to receive, from the second node, duration information of the PDCP discard timer.

With reference to the fourth aspect or any one of the first to third possible implementation manners of the fourth aspect, in a ninth possible implementation manner of the fourth aspect, a difference between a time when the first node sends the redundant information and a time when the first node completes sending the one or more data packets is a first threshold.

With reference to the fourth aspect or any one of the first to third possible implementation manners of the fourth aspect, in a tenth possible implementation manner of the fourth aspect, the communication interface is specifically configured to, after the sending of the one or more data packets is completed, send one or more other data packets first, and then send the redundant information to the second node.

With reference to the fourth aspect or any one of the first to third possible implementation manners of the fourth aspect, in an eleventh possible implementation manner of the fourth aspect, the communication interface is specifically configured to repeatedly send the redundant information until receiving an acknowledgement information from the second node, where the acknowledgement information is used to acknowledge receipt of the redundant information.

With reference to the fourth aspect, in a twelfth possible implementation manner of the fourth aspect, the redundant information is carried in a service data packet, and the service data packet is different from the one or more data packets.

With reference to the fourth aspect, in a thirteenth possible implementation manner of the fourth aspect, the redundant information is carried in a data packet other than a service data packet.

In the fourth aspect of the embodiment of the present application, one or more data packets sent by the first node to the second node through the communication interface may be referred to as N data packets, where N is an integer greater than or equal to 1.

In a fifth aspect, a communication device is disclosed, which may be a second node or a chip in the second node. The method comprises the following steps: a communication unit configured to receive redundancy information from a first node, the redundancy information including one or more packet data convergence protocol sequence numbers PDCP SN; the one or more PDCP SNs are in one-to-one correspondence with one or more data packets sent by the first node to the second node, and each data packet of the one or more data packets comprises a PDCP SN of the data packet.

It should be noted that, when the first node sends N data packets to the second node, the second node may receive some or all of the one or more data packets, and there may be some data packets that the second node does not receive.

In one possible implementation manner, the communication unit receives M data packets from the first node, where each data packet in the M data packets includes a packet data convergence protocol PDCP sequence number SN of the data packet, and M is an integer greater than or equal to 1. Or, the second node may not receive the data packet from the first node, and it can be understood that N data packets sent by the first node are lost, and at this time, the second node only receives the redundant information, which includes N PDCP SN numbers, but does not include the service data packet.

With reference to the fifth aspect, in a first possible implementation manner of the fifth aspect, each of the one or more data packets further includes an identification sequence number of the data packet; the redundant information further includes the one or more identification sequence numbers, and the one or more identification sequence numbers are in one-to-one correspondence with the one or more PDCP SNs.

With reference to the first possible implementation manner of the fifth aspect, in a second possible implementation manner of the fifth aspect, the identification sequence numbers are consecutive.

With reference to the first or second possible implementation manner of the fifth aspect, in a third possible implementation manner of the fifth aspect, the one or more identification sequence numbers in one-to-one correspondence with the one or more data packets are consecutive according to a transmission sequence of the one or more data packets.

With reference to the fifth aspect or any one of the first to third possible implementations of the fifth aspect, in a fourth possible implementation of the fifth aspect, the redundant information is received periodically.

With reference to the fourth possible implementation manner of the fifth aspect, in a fifth possible implementation manner of the fifth aspect, a receiving period of the redundant information is less than a duration of the PDCP discard timer.

With reference to the fourth or fifth possible implementation manner of the fifth aspect, in a sixth possible implementation manner of the fifth aspect, the redundant information includes the one or more PDCP SNs that are in one-to-one correspondence with the one or more data packets received from the first node after the redundant information is received last time.

With reference to the sixth possible implementation manner of the fifth aspect, in a seventh possible implementation manner of the fifth aspect, the redundant information further includes the redundant information received last time.

With reference to the fifth possible implementation manner of the fifth aspect, in an eighth possible implementation manner of the fifth aspect, the communication unit is further configured to send duration information of the PDCP discard timer to the first node.

With reference to the fifth aspect or any one of the first to eighth possible implementation manners of the fifth aspect, in a ninth possible implementation manner of the fifth aspect, the method further includes a processing unit, where the processing unit is configured to skip a data packet corresponding to a first PDCP SN when the second node determines that a data packet corresponding to the first PDCP SN in the redundant information is not received, and the second node performs PDCP reordering, where the first PDCP SN is one PDCP SN of the one or more PDCP SNs.

With reference to the second possible implementation manner of the fifth aspect, in a tenth possible implementation manner of the fifth aspect, the multiple identification sequence numbers are consecutive, and the processing unit is specifically configured to, when the second node determines that a first identification sequence number is not received according to the continuity of the multiple identification sequence numbers, where the first identification sequence number is one of the multiple identification sequence numbers, and the PDCP SN corresponding to the first identification sequence number is a first PDCP SN, skip the data packet corresponding to the first PDCP SN when the second node performs PDCP reordering.

With reference to the tenth possible implementation manner of the fifth aspect, in an eleventh possible implementation manner of the fifth aspect, when the second node performs PDCP reordering, the processing unit is specifically configured to stop the PDCP discard timer of the data packet corresponding to the first PDCP SN if the PDCP discard timer of the data packet corresponding to the first PDCP SN is started; or, if the PDCP discard timer of the data packet corresponding to the first PDCP SN is not started, the PDCP discard timer of the data packet corresponding to the first PDCP SN is discarded from being started.

With reference to the tenth or eleventh possible implementation manner of the fifth aspect, in a twelfth possible implementation manner of the fifth aspect, the communication unit is further configured to send, to the core network, a data packet with a PDCP SN greater than the first PDCP SN.

With reference to the fifth aspect or any one of the first to twelfth possible implementation manners of the fifth aspect, in a thirteenth possible implementation manner of the fifth aspect, the communication unit is further configured to send acknowledgement information to the first node, where the acknowledgement information is used to acknowledge receipt of the redundant information.

In a sixth aspect, a communication device is disclosed, which may be a second node or a chip in the second node. The method comprises the following steps: a communication unit configured to receive redundancy information from a first node, the redundancy information including one or more packet data convergence protocol sequence numbers PDCP SN; the one or more PDCP SNs are in one-to-one correspondence with one or more data packets sent by the first node to the second node, and each data packet of the one or more data packets comprises a PDCP SN of the data packet.

In one possible implementation manner, M data packets are received from a first node through a communication interface, each of the M data packets includes a packet data convergence protocol PDCP sequence number SN of the data packet, and M is an integer greater than or equal to 1. Or, the second node may not receive the data packet from the first node, and it can be understood that N data packets sent by the first node are lost, and at this time, the second node only receives the redundant information, which includes N PDCP SN numbers, but does not include the service data packet.

With reference to the sixth aspect, in a first possible implementation manner of the sixth aspect, each of the one or more data packets further includes an identification sequence number of the data packet; the redundant information further includes the one or more identification sequence numbers, and the one or more identification sequence numbers are in one-to-one correspondence with the one or more PDCP SNs.

With reference to the first possible implementation manner of the sixth aspect, in a second possible implementation manner of the sixth aspect, the identification sequence numbers are consecutive.

With reference to the first or second possible implementation manner of the sixth aspect, in a third possible implementation manner of the sixth aspect, the one or more identification sequence numbers in one-to-one correspondence with the one or more data packets are consecutive according to a transmission order of the one or more data packets.

With reference to the sixth aspect or any one of the first to third possible implementations of the sixth aspect, in a fourth possible implementation of the sixth aspect, the redundant information is received periodically.

With reference to the fourth possible implementation manner of the sixth aspect, in a fifth possible implementation manner of the sixth aspect, a receiving period of the redundant information is less than a duration of a PDCP discard timer.

With reference to the fourth or fifth possible implementation manner of the sixth aspect, in a sixth possible implementation manner of the sixth aspect, the redundant information includes the one or more PDCP SNs that are in one-to-one correspondence with the one or more data packets received from the first node after the redundant information is received last time.

With reference to the sixth possible implementation manner of the sixth aspect, in a seventh possible implementation manner of the sixth aspect, the redundant information further includes the redundant information received last time.

With reference to the fifth possible implementation manner of the sixth aspect, in an eighth possible implementation manner of the sixth aspect, the communication unit is further configured to send duration information of the PDCP discard timer to the first node.

With reference to the sixth aspect or any one of the first to eighth possible implementation manners of the sixth aspect, in a ninth possible implementation manner of the sixth aspect, the method further includes a processing unit, where the processing unit is configured to skip a data packet corresponding to a first PDCP SN when the second node determines that a data packet corresponding to the first PDCP SN in the redundant information is not received, and the second node performs PDCP reordering, where the first PDCP SN is one PDCP SN of the one or more PDCP SNs.

With reference to the second possible implementation manner of the sixth aspect, in a tenth possible implementation manner of the sixth aspect, the multiple identification sequence numbers are consecutive, and the processing unit is specifically configured to, when the second node determines that a first identification sequence number is not received according to the continuity of the multiple identification sequence numbers, where the first identification sequence number is one of the multiple identification sequence numbers, and the PDCP SN corresponding to the first identification sequence number is a first PDCP SN, skip the data packet corresponding to the first PDCP SN when the second node performs PDCP reordering.

With reference to the tenth possible implementation manner of the sixth aspect, in an eleventh possible implementation manner of the sixth aspect, when the second node performs PDCP reordering, the processing unit is specifically configured to stop the PDCP discard timer of the data packet corresponding to the first PDCP SN if the PDCP discard timer of the data packet corresponding to the first PDCP SN is started; or, if the PDCP discard timer of the data packet corresponding to the first PDCP SN is not started, the PDCP discard timer of the data packet corresponding to the first PDCP SN is discarded from being started.

With reference to the tenth or eleventh possible implementation manner of the sixth aspect, in a twelfth possible implementation manner of the sixth aspect, the communication unit is further configured to send, to the core network, a data packet with a PDCP SN greater than the first PDCP SN.

With reference to the sixth aspect or any one of the first to twelfth possible implementation manners of the sixth aspect, in a thirteenth possible implementation manner of the sixth aspect, the communication unit is further configured to send acknowledgement information to the first node, where the acknowledgement information is used to acknowledge receipt of the redundant information.

In a seventh aspect, a communication device is disclosed that includes a processor coupled to a memory; a memory for storing a computer program. A processor configured to execute a computer program stored in a memory to cause an apparatus to perform a method as described in the first aspect, any one of the possible implementations of the first aspect, the second aspect, and any one of the possible implementations of the second aspect.

In an eighth aspect, a readable storage medium is disclosed, which comprises a program or instructions, which when executed by a processor, is the method according to any one of the possible implementations of the first aspect, the second aspect and any one of the possible implementations of the second aspect.

In a ninth aspect, a computer-readable storage medium is disclosed, comprising instructions which, when executed on a computer, cause the computer to perform the method of any one of the possible implementations of the first aspect and the first aspect, the second aspect, and the second aspect.

In a tenth aspect, a computer program product is disclosed, comprising instructions which, when run on a computer, cause the computer to perform the method according to any one of the possible implementations of the first aspect and the first aspect, the second aspect, and the second aspect as described above.

In an eleventh aspect, a wireless communications apparatus is disclosed that includes: instructions are stored in the wireless communication device; when the wireless communication device is operated on the device according to the third to sixth aspects, the device is caused to perform the method according to any one of the above-mentioned first aspect and any one of the above-mentioned possible implementation manners of the first aspect, the second aspect, and the wireless communication device is a chip.

In a twelfth aspect, embodiments of the present application provide a chip, where the chip includes a processor and an interface circuit, where the interface circuit is coupled to the processor, and the processor is configured to execute a computer program or instructions to implement the method according to the first aspect and any one of the possible implementations of the first aspect, the second aspect, and any one of the possible implementations of the second aspect, and the interface circuit is configured to communicate with other modules outside the chip.

In a thirteenth aspect, an embodiment of the present application provides a communication system, which includes a first node and a second node. Illustratively, a first node sends one or more data packets to a second node, each of the one or more data packets including a PDCP SN of the data packet; the first node sends redundant information to the second node, the redundant information includes the one or more PDCP SNs, and the one or more PDCP SNs and the one or more data packets are in one-to-one correspondence.

Drawings

Fig. 1A is an architecture diagram of a communication system provided in an embodiment of the present application;

fig. 1B is another architecture diagram of a communication system according to an embodiment of the present application;

fig. 1C is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1D is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1E is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1F is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1G is a schematic diagram of a protocol architecture of a network side angle according to an embodiment of the present application;

fig. 1H is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1I is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1J is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 1K is another architecture diagram of a communication system provided by an embodiment of the present application;

fig. 2A is a block diagram of a communication device according to an embodiment of the present disclosure;

fig. 2B is a block diagram of the structures of the DU and CU according to the embodiment of the present disclosure;

fig. 3 is a schematic flowchart of a redundant information feedback method according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a data packet provided by an embodiment of the present application;

FIG. 5 is another schematic diagram of a data packet provided by an embodiment of the present application;

FIG. 6 is another diagram of a data packet provided by an embodiment of the present application;

fig. 7 is another schematic flow chart of a redundant information feedback method according to an embodiment of the present application;

fig. 8 is a schematic diagram of a redundant information feedback method according to an embodiment of the present application;

fig. 9 is another schematic diagram of a redundant information feedback method according to an embodiment of the present application;

fig. 10 is another block diagram of a communication device according to an embodiment of the present disclosure;

fig. 11 is another block diagram of a communication device according to an embodiment of the present disclosure.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

First, terms related to the embodiments of the present application are explained:

(1) packet Data Convergence Protocol (PDCP) layer

The PDCP layer mainly processes RRC messages from the control plane and IP packets from the data plane, and includes: the received data is subjected to header compression and decompression, encryption/decryption, integrity protection, transmission of user data and control plane data, reordering and retransmission processing, and the like.

(2) PDCP data packet

For the PDCP layer, both the received packet and the transmitted packet are considered to be PDCP packets. The data packets received by the PDCP layer may be referred to as a PDCP Service Data Unit (SDU), and the data packets sent by the PDCP layer may be referred to as a PDCP Protocol Data Unit (PDU).

(3) PDCP Sequence Number (SN)

The PDCP SNs are numbers of PDCP data packets, and different PDCP SNs are used to identify different PDCP data packets. In case of good network conditions, the PDCP SNs of the PDCP data received by the PDCP layer may be continuous; under the condition of bad network conditions, packet loss may occur, and the PDCP SN of the PDCP data packet received by the PDCP layer is discontinuous. If the network delay is large, the PDCP SNs of the PDCP data packets received by the PDCP layer may be out of order.

The embodiment of the application provides a communication system, which can comprise at least two nodes, wherein the two nodes can be connected through an interface between the two nodes. The two nodes may be two different access network devices, or may be different units on the same access network device, for example, the two nodes are a Centralized Unit (CU) and a Distributed Unit (DU) in the access network device. After a node receives a data packet from a UE, the node can send the data packet to another node through an interface, and the other node can reorder the data packet and then send the data packet to a core network. For example, after a node receives a data packet from an air interface, the RLC layer of the node may send the data packet to the PDCP layer of another node through an interface between the nodes, and the PDCP layer of another node may reorder the data packet and then send the reordered data packet to the core network.

The communication system described above is exemplified below with reference to fig. 1A to 1K.

The method provided by the embodiment of the application is suitable for the communication system shown in fig. 1A. Referring to fig. 1A, a plurality of transmitting nodes (two transmitting nodes are taken as an example in fig. 1A) transmit data to one receiving node. Wherein, the sending node 1 sends data to the receiving node through the transmission link 1, and the sending node 2 sends data to the receiving node through the transmission link 2. Due to different time delays of the transmission link 1 and the transmission link 2, the PDCP SNs of the PDCP data packets received by the receiving node may be out of order, and the receiving node needs to reorder the received PDCP data packets. In addition, packet loss may also occur in the transmission link 1 and the transmission link 2, that is, in a reordering scenario of the receiving node, packet loss may occur in a transmission path between the transmitting node and the receiving node. In fig. 1A, a sending node 1 may be a terminal, an access network device, or an element in an access network device; the sending node 2 may be a terminal, an access network device or an element in an access network device; the receiving node may be an access network device or an element in an access network device. The communication system shown in fig. 1A supports Dual Connectivity (DC).

The method provided by the embodiment of the application is suitable for the communication system shown in fig. 1B. Only one transmitting node in fig. 1B transmits data to a receiving node. Data packets sent by a sending node to a receiving node are out of order, and the receiving node needs to reorder the received data packets. In addition, there may be packet loss on the transmission link between the sending node and the receiving node, that is, under the reordering scenario of the receiving node, there is a possibility that the transmission link has packet loss. In fig. 1B, the sending node may be an access network device or an element in an access network device; the receiving node may be an access network device or an element in an access network device. The communication system shown in fig. 1B supports DC or single connection.

Fig. 1C is a DC scenario to which the method provided in the embodiment of the present application is applied, and fig. 1C shows an Evolved Universal Terrestrial Radio Access (E-UTRA-NR Dual Connectivity, EN-DC) of an Evolved Universal Terrestrial Radio Access (E-UTRA) and a new air interface (new Radio, NR). As shown in fig. 1C, the core network element is an Evolved Packet Core (EPC) element, the primary node (MN) is an eNB, and the Secondary Node (SN) is a gNB. The interface between the eNB, the gNB and the EPC network element is an s1 interface.

MN and SN can connect through X2interface, there can be user interface connection between MN and SN; the MN and the core network element can be connected through an S1 interface, and the MN and the core network element can be connected through a user plane; the SN11 can be connected with the core network elements through an S1-U interface, and the SN core network elements can have user plane connection.

Fig. 1D is a DC scenario to which the method provided in the embodiment of the present application is applied, and fig. 1D shows an evolved universal terrestrial radio access (E-UTRA) and NR Dual Connectivity (NG-range-UTRA-NR Dual Connectivity, NGEN-DC) of a Next Generation (NG) Radio Access Network (RAN). As shown in fig. 1G, the core network element is a fifth generation (5G, 5th generation) core network (5G core, 5GC) element, the primary node (MN) is an eNB, and the Secondary Node (SN) is a gNB. The interface between the eNB, the gNB and the EPC network element is an s1 interface.

MN and SN can be connected through Xn interface, MN and SN can have user interface connection; MN can connect with the network element of the core network through NG interface, MN can have user plane connection with network element of the core network; the SN and the core network elements can be connected through the NG-U interface, and the SN core network elements can be connected with each other through a user plane.

Fig. 1E is a DC scenario to which the method provided in the embodiment of the present application is applied, and fig. 1E shows an NR-E-UTRA dual connectivity (NE-DC) network architecture of NR and E-UTRA. Referring to fig. 1E, the core network element is a 5GC network element, the MN is a gNB, and the SN is an eNB. The MN and SN may be connected, for example, via an Xn interface. User interface connection can be arranged between the MN and the SN; the MN and the core network element may be connected, for example, via an NG interface. User interface connection can be arranged between the MN and the network element of the core network; the SN and the core network elements may be connected, for example, via a NG-U interface, and there may be a user plane connection between the SN core network elements.

Fig. 1F is a DC scenario to which the method provided in the embodiment of the present application is applied, and fig. 1F illustrates a Dual connection between NR and NR (NR-NR Dual Connectivity, NR-DC). Referring to fig. 1I, the core network element is a 5GC network element, the MN is a gNB, and the SN11 is a gNB. The MN and SN may be connected, for example, via an Xn interface. User interface connection can be arranged between the MN and the SN; the MN and the core network element may be connected, for example, through an NG interface, and there may be a user plane connection between the MN and the core network element; the SN and the core network elements may be connected, for example, via a NG-U interface, and there may be a user plane connection between the SN core network elements.

It is emphasized that the communication system to which the embodiment of the present application is applied includes, but is not limited to, the communication systems shown in fig. 1A to 1F described above. The receiving node needs to reorder the data packets, and the scenario that there is packet loss on the transmission link between the receiving and transmitting nodes is applicable to the method provided by the embodiment of the present application, which is not limited in the present application.

Fig. 1G shows a schematic diagram of a protocol architecture in a network side perspective, from the perspective of the network side (MN01 and SN11), there may be 6 types of user plane bearers as follows. The following behavior examples respectively describe the data flow direction of each bearer type, and those skilled in the art can understand that the uplink is similar to the downlink, and details are not described herein again.

1. MN terminated Master Cell Group (MCG) bearers.

Data is sent from a core network element to the MN, and is sent to the terminal sequentially through a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Media Access Control (MAC) layer of the MN.

2. MN terminated Secondary Cell Group (SCG) bearers.

And the data is transmitted from the core network element to the MN, is transmitted to the RLC layer of the SN through the PDCP layer of the MN, and is transmitted to the terminal through the RLC layer and the MAC layer of the SN in sequence.

3. MN terminated Split (Split) bearers.

Data is sent to the MN from a core network element, a PDCP layer of the MN shunts the data, one part of the data is sent to the terminal through an RLC layer and an MAC layer of the MN in sequence, and the other part of the data is sent to the RLC layer of the SN and sent to the terminal through the RLC layer and the MAC layer of the SN in sequence.

4. SN terminated Split bearers.

Data is sent to the SN from a core network element, the PDCP layer of the SN shunts the data, one part of the data is sent to the terminal through the RLC layer and the MAC layer of the SN in sequence, the other part of the data is sent to the RLC layer of the MN and is sent to the terminal through the RLC layer and the MAC layer of the MN in sequence.

5. SN terminated MCG bearers.

And the data is sent to the SN from the network element of the core network, sent to the RLC layer of the MN through the PDCP layer of the SN, and sent to the terminal through the RLC layer and the MAC layer of the MN in sequence.

6. SN terminated SCG bearers.

And the data is transmitted from the core network element to the SN and is sequentially transmitted to the terminal through the PDCP layer, the RLC layer and the MAC layer of the SN.

The MCG bearer relates to an MCG air interface resource, the SCG bearer relates to an SCG air interface resource, and the Split bearer relates to an MCG air interface resource and an SCG air interface resource.

Optionally, in the multiple bearer types, the PDCP entities of the MN and the SN may be NR PDCP entities, and in an MN-terminated MCG bearer under EN-DC, the PDCP entity of the MN may also be E-UTRA PDCP. When the core network element is a 5GC network element, an SDAP layer can be arranged on the PDCP layer of the MN, and data is transmitted to the MN from the core network element and reaches the PDCP layer of the MN through the SDAP layer of the MN; the PDCP layer of the SN may have an SDAP layer, and data is sent from the network element of the core network to the SN11, and reaches the PDCP layer of S1 through the SDAP layer of the SN.

The following describes a communication system related to embodiments of the present application with reference to specific bearer types. Fig. 1H is a DC scenario to which the method provided in the embodiment of the present application is applicable, and fig. 1H shows an NSA DC Option3 networking architecture, where a bearer type involved in the scenario is a Split bearer terminated by an MN. In NSA DC Option3 networking, the dynamic offload mechanism is turned on. For example, data sent by the UE arrives at the eNB through an LTE air interface, and arrives at the gNB through an NR air interface. The gNB needs to send the received data packets to the eNB through an X2interface between the base station and the base station, the eNB needs to reorder the data packets received by the air interface and the data packets transmitted by the gNB, and then the eNB transmits the data packets to the core network. It should be noted that a packet loss may occur when the gNB sends a data packet to the eNB, that is, in a reordering scenario of the eNB, a transmission path between the gNB and the eNB may have a packet loss, and it may also be considered that the X2interface has a packet loss possibility.

The method provided by the embodiment of the application is suitable for the communication system shown in fig. 1I. Fig. 1I shows a non-independent (NSA) Dual Connectivity (DC) Option3x networking architecture. In the NSA DC Option3x networking, a dynamic offloading mechanism is started, and the bearer type related to the scenario is a Split bearer terminated by an SN. For example, referring to fig. 1B, data sent by the UE arrives at an evolved node base station (eNB) through a Long Term Evolution (LTE) air interface, and arrives at a next generation base station (gNB) through an NR air interface. The eNB needs to send the received data packets to the gNB through an X2interface between the base station and the base station, the gNB needs to reorder the data packets received by the air interface and the data packets transmitted by the eNB, and then the gNB transmits the data packets to the core network. It should be noted that a packet loss may occur when the eNB sends a data packet to the gNB, that is, in a scenario of reordering by the gNB, a transmission path between the gNB and the eNB may have a packet loss, and it may also be considered that the X2interface has a packet loss possibility.

Fig. 1J is a DC scenario to which the method provided in the embodiment of the present application is applicable, and in the NSA DC Option3 networking shown in fig. 1J, a dynamic offloading mechanism is not started, and a bearer type related to the scenario is an SCG bearer terminated by an MN. Referring to fig. 1J, a data packet sent by the UE arrives at the gNB over the NR air interface. Because of the error code on the air interface, some data packets need to be retransmitted, and some data packets are successfully transmitted once, so that the data packets may be out of order after arriving at the NR Radio Link Control (RLC) entity. The NR RLC entity does not reorder the data packets, and the data packets are delivered to the LTE PDCP entity after being received, and the LTE PDCP reorders the messages. That is, at this time, the data packets sent by the gNB to the eNB are out of order, and the eNB needs to reorder the received data packets and then deliver the data packets to the core network. When the gNB sends a data packet to the eNB, a packet loss may occur, that is, in a reordering scenario of the eNB, a transmission path between the gNB and the eNB may have a packet loss, and it may also be considered that a packet loss may exist in the X2 interface.

For example, fig. 1K is a networking structure to which the method provided in the embodiment of the present application is applied, and fig. 1K shows a pure 5G networking. Under a Cloud radio access network (Cloud RAN) architecture, a RAN base station is separated into two components, namely a CU and a DU, and an interface between the CU and the DU may be referred to as an F1 interface. Data packets sent by the UE under the Cloud RAN architecture arrive at a Distributed Unit (DU) of the gNB through NR air interfaces in a disordered manner, the DU of the gNB forwards the disordered data packets to a Central Unit (CU) of the gNB through an F1 interface, and the CU of the gNB reorders the received data packets. That is to say, in a scenario where the receiving node reorders, there is a possibility of packet loss on a transmission path between the transmitting and receiving nodes, and it may also be considered that there is a possibility of packet loss on the F1 interface.

In addition, the transmission interface between the NSA networking architecture eNB and the gNB is referred to as an X2interface (X2 interface); the air Interface between the UE and the base station is called UU Interface (UU Interface).

It should be noted that a transmission path between nodes may be understood as a link between nodes, for example, nodes may be connected by an interface, and a transmission path between nodes may be understood as an interface between nodes, and a transmission path between an access network device and a terminal may be understood as an air interface between an access network device and a terminal.

Taking the communication system shown in fig. 1I as an example, suppose that the UE needs to send data packets with PDCP SNs 1 to 9 to the core network, where the UE sends data packets with

PDCP SNs

3, 6, and 9 to the eNB through an air interface, and the eNB sends data packets with

PDCP SNs

3, 6, and 9 to the gNB through an X2 interface. And the UE sends other messages to the gNB through an air interface. Assuming that the transmission delay of the transmission link between the UE and the eNB is large, the data packets with

PDCP SNs

3, 6, and 9 arrive at the gNB later than other packets. When the packet data with PDCP SN1 and PDCP SN2 arrives at the gNB, the packet data is directly transmitted to the core network by the gNB. When the data packet with the PDCP SN of 4 arrives at the gNB, the data packet with the PDCP SN of 3 does not arrive at the gNB, the PDCP SN is discontinuous, and the gNB starts a timer to wait for the data packet with the PDCP SN of 3 and stops sending the data packet to the core network.

If the data packet with the PDCP SN of 3 arrives at the gNB before the time-out of the timer, the gNB delivers the data packet with the PDCP SN of 3 to the core network, and then delivers the data packets with the PDCP SNs of 4 and 5 to the core network.

If the timer is overtime, the data packet with PDCP SN 3 still reaches gNB, and the gNB directly delivers the data packets with

PDCP SN

4 and 5 to the core network without waiting for the data packet with PDCP SN 3. During the process of waiting for the PDCP SN 3 packet, no data is transmitted between the gNB and the core network, i.e., the transmission bandwidth is wasted during this time.

The embodiment of the present application provides a method, where after a first node sends one or more data packets to a second node, the first node also sends redundant information to the second node, where the redundant information includes PDCPSNs of the one or more data packets. First, the second node may determine, according to the redundant information, whether a packet loss occurs when the first node sends a plurality of data packets to the second node, so that the second node may accurately determine whether the lost data packet occurs at an air interface or an interface between nodes, and the second node may select different policies to cope with the lost data packet when reordering. Secondly, once the second node determines that a packet loss occurs on the transmission path between the first node and the second node, the second node may skip the data packet when reordering the data packet, for example, if a timer waiting for the data packet is started, the timer waiting for the data packet is terminated, and the second node may continue to deliver the data packet to the core network; or, the timer waiting for the data packet is not started, after the currently running timer (waiting for other data packets) is overtime, the second node may continue to deliver the data packet to the core network, when the second node determines that packet loss does not occur on the transmission path between the first node and the second node, which indicates that packet loss may occur on an air interface, the second node may start the timer waiting for the data packet, wait for the lost data packet, and deliver the data packet to the core network until the timer is overtime. Therefore, the method provided by the embodiment of the application can accurately judge the transmission path with the lost packet, avoids the bandwidth waste caused by long-time waiting of the lost data packet, and is beneficial to improving the communication performance.

Fig. 2A is a block diagram of a communication apparatus according to an embodiment of the present application, where the communication apparatus shown in fig. 2A may be an access network device, for example, a first node or a second node according to the embodiment of the present application.

The access network equipment includes at least one processor 2101, at least one memory 2102, at least one transceiver 2103, at least one network interface 2104, and one or more antennas 2105. The processor 2101, the memory 2102, the transceiver 2103 and the network interface 2104 are connected, for example, by a bus, and in this embodiment, the connection may include various interfaces, transmission lines, or buses, which is not limited in this embodiment. The antenna 2105 is connected to the transceiver 2103. The network interface 2104 is used to enable the access network device to connect to other communication devices via a communication link, for example, the network interface 2104 may include a network interface between the access network device and a core network element, for example, an S1 interface, and the network interface may include a network interface between the access network device and other network devices (for example, other access network devices or core network elements), for example, an X2 or Xn interface.

The processor 2101 is mainly used to process communication protocols and communication data, and to control the entire access network device, execute software programs, and process data of the software programs, for example, to support the access network device to perform the actions described in the embodiments. The access network device may include a baseband processor and a central processing unit, the baseband processor is mainly used for processing the communication protocol and the communication data, and the central processing unit is mainly used for controlling the whole terminal device, executing the software program, and processing the data of the software program. The processor 2101 in fig. 2A may integrate the functions of a baseband processor and a central processing unit, and those skilled in the art will understand that the baseband processor and the central processing unit may also be independent processors, and are interconnected by a bus or the like. Those skilled in the art will appreciate that the terminal device may include a plurality of baseband processors to accommodate different network formats, the terminal device may include a plurality of central processors to enhance its processing capability, and various components of the terminal device may be connected by various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processing unit can also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and the communication data may be built in the processor, or may be stored in the memory in the form of a software program, and the processor executes the software program to realize the baseband processing function.

The memory is used primarily for storing software programs and data. The memory 2102 may be separate and coupled to the processor 2101. Alternatively, the memory 2102 may be integrated with the processor 2101, for example, within one chip. The memory 2102 can store program codes for executing the technical solutions of the embodiments of the present application, and is controlled by the processor 2101, and various executed computer program codes can also be regarded as drivers of the processor 2101.

Fig. 2A shows only one memory and one processor. In an actual terminal device, there may be multiple processors and multiple memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be a memory element on the same chip as the processor, that is, an on-chip memory element, or a separate memory element, which is not limited in this embodiment.

The transceiver 2103 may be used to support the reception or transmission of radio frequency signals between the access network device and the terminal, and the transceiver 2103 may be connected to the antenna 2105. The transceiver 2103 comprises a transmitter Tx and a receiver Rx. Specifically, one or more antennas 2105 may receive a radio frequency signal, and the receiver Rx of the transceiver 2103 is configured to receive the radio frequency signal from the antennas, convert the radio frequency signal into a digital baseband signal or a digital intermediate frequency signal, and provide the digital baseband signal or the digital intermediate frequency signal to the processor 2101, so that the processor 2101 may further process the digital baseband signal or the digital intermediate frequency signal, such as demodulation processing and decoding processing. The transmitter Tx in the transceiver 2103 is also used to receive a modulated digital baseband signal or digital intermediate frequency signal from the processor 2101, convert the modulated digital baseband signal or digital intermediate frequency signal into a radio frequency signal, and transmit the radio frequency signal via one or more antennas 2105. Specifically, the receiver Rx may selectively perform one or more stages of down-mixing and analog-to-digital conversion processes on the rf signal to obtain a digital baseband signal or a digital intermediate frequency signal, wherein the order of the down-mixing and analog-to-digital conversion processes is adjustable. The transmitter Tx may selectively perform one or more stages of up-mixing and digital-to-analog conversion processes on the modulated digital baseband signal or the modulated digital intermediate frequency signal to obtain the rf signal, where the order of the up-mixing and the digital-to-analog conversion processes is adjustable. The digital baseband signal and the digital intermediate frequency signal may be collectively referred to as a digital signal.

A transceiver may also be referred to as a transceiver unit, transceiver, transceiving means, etc. Optionally, a device for implementing a receiving function in the transceiver unit may be regarded as a receiving unit, and a device for implementing a sending function in the transceiver unit may be regarded as a sending unit, that is, the transceiver unit includes a receiving unit and a sending unit, the receiving unit may also be referred to as a receiver, an input port, a receiving circuit, and the like, and the sending unit may be referred to as a transmitter, a sending circuit, and the like.

In one possible implementation, the processor 2101 may invoke the code stored in the memory 2102 to perform the following functions: the method comprises the steps that a first node is supported to send one or more data packets to a second node, wherein each data packet in the one or more data packets comprises a packet data convergence protocol sequence number PDCP SN of the data packet;

and supporting the first node to send redundant information to the second node, wherein the redundant information comprises the one or more PDCP SNs, and the one or more PDCP SNs and the one or more data packets are in one-to-one correspondence.

And the supporting second node receives the one or more data packets from the first node, and determines whether the data packets are lost on a transmission path between the first node and the second node according to the redundant information.

Fig. 2B is a block diagram of structures of a CU and a DU provided in this embodiment, where the CU may be the second node in this embodiment, and the DU may be the first node in this embodiment.

For example, referring to fig. 2B, a base station may include one or more DUs 221 and one or more CUs 222. The CU222 may communicate with an NG core (Next Generation core network, NC).

The DU221 may include at least one antenna 2211, at least one radio frequency unit 2212, at least one processor 2213 and at least one memory 2214. The DU221 part is mainly used for transceiving radio frequency signals, converting radio frequency signals and baseband signals, and partially processing baseband. The CU222 may include at least one processor 2222 and at least one memory 2221. CU222 and DU221 may communicate via an interface, wherein a Control plane (Control plane) interface may be Fs-C, such as F1-C, and a User plane (User plane) interface may be Fs-U, such as F1-U.

The CU222 is mainly used for baseband processing, base station control, and the like. The DU221 and CU222 may be physically located together or physically separated, i.e. distributed base stations. The CU222 is a control center of the base station, and may also be referred to as a processing unit, and is mainly used for performing a baseband processing function. For example, the CU222 may be used to control the base station to perform the operation flow related to the network device in the above method embodiment.

Specifically, the baseband processing on the CU and the DU may be divided according to protocol layers of the wireless network, for example, functions of a Packet Data Convergence Protocol (PDCP) layer and protocol layers above the PDCP layer are set in the CU, and functions of protocol layers below the PDCP layer, for example, functions of a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer, are set in the DU. For another example, a CU implements Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) functions, and a DU implements Radio Link Control (RLC), Medium Access Control (MAC) and Physical (PHY) functions.

Further, optionally, the base station 60 may include one or more radio frequency units (RUs), one or more DUs, and one or more CUs. Wherein a DU may include at least one processor 2213 and at least one memory 2214, an RU may include at least one antenna 2211 and at least one radio unit 2212, and a CU may include at least one processor 2222 and at least one memory 2221.

In an example, the CU222 may be formed by one or more boards, and the multiple boards may jointly support a radio access network with a single access indication (e.g., a 5G network), or may respectively support radio access networks with different access schemes (e.g., an LTE network, a 5G network, or other networks). The memory 2221 and the processor 2222 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits. The DU221 may be formed by one or more boards, and the boards may jointly support a radio access network with a single access instruction (e.g., a 5G network), or may respectively support radio access networks with different access schemes (e.g., an LTE network, a 5G network, or other networks). The memory 2214 and the processor 2213 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits.

The embodiment of the present application provides a method for feeding back redundant information, which is applied to communication systems shown in fig. 1A to 1F and fig. 1H to 1K, and as shown in fig. 3, the method includes the following steps:

301. the first node transmits one or more data packets to the second node, each of the one or more data packets including a PDCP SN of the data packet.

In this embodiment of the present application, one or more data packets sent by a first node to a second node may be recorded as N data packets, where each data packet in the N data packets includes a PDCP SN of the data packet. The second node may receive N data packets sent by the first node, or the second node may receive only a part of the N data packets, for example, one or more data packets received by the second node may be referred to as M data packets, each of the M data packets includes a PDCP SN of the data packet, N and M are integers greater than or equal to 1, and N is greater than or equal to M. Alternatively, the second node may not receive any of the N data packets, which are lost on the transmission path between the first node and the second node.

It should be noted that the first node may send a data packet to the second node, and the second node may sequence the received data packet and then deliver the data packet to the core network. The first node and the second node may be access network devices, for example, the first node may be a sending node 1 or a sending node 2in the communication system shown in fig. 1A, and the second node is a receiving node in the communication system shown in fig. 1A; or, the first node is a sending node in the communication system shown in fig. 1B, and the second node is a receiving node in the communication system shown in fig. 1B; or, the first node is an SN in the communication system shown in fig. 1C to 1F, and the second node is an MN in the communication system shown in fig. 1C to 1E; or, the first node is MN in the communication system shown in fig. 1C to 1F, and the second node is SN in the communication system shown in fig. 1C to 1F; or, the first node is a gbb in the communication system shown in fig. 1H, and the second node is an eNB in the communication system shown in fig. 1H; or, the first node is an eNB in the communication system shown in fig. 1I, and the second node is a gNB in the communication system shown in fig. 1I; alternatively, the first node is a gNB in the communication system shown in fig. 1J, and the second node is a gNB in the communication system shown in fig. 1J. Alternatively, the first node and the second node may be different units in one access network device, the first node may be a CU, and the second node may be a DU, for example, the first node is a DU in the communication system shown in fig. 1K, and the second node is a CU in the communication system shown in fig. 1K.

In a data offloading scenario, the first node and the second node may respectively receive a data packet through an air interface, and the first node may send the data packet received by itself through the air interface to the second node. The data packets are finally aggregated at the second node, and the second node may reorder the data packets received by the air interface and the data packets sent by the first node, and transmit the data packets to the core network after reordering. For example, the first node may be an eNB in the communication system shown in fig. 1B, and the second node may be a gNB in the communication system shown in fig. 1B; alternatively, the first node may be a gbb in the communication system shown in fig. 1C, and the second node may be an eNB in the communication system shown in fig. 1C.

In a scenario where data is not split, the first node may receive a data packet through an air interface, and the first node may send the data packet received by the air interface to the second node. Due to air interface error codes, the data packet received by the first node may be out of order, so the data packet sent by the first node to the second node is out of order. After receiving the data packet from the first node, the second node may reorder the received data packet, and after reordering, deliver the data packet to the core network. For example, the first node may be a gNB in the communication system shown in fig. 1E, and the second node may be an eNB in the communication system shown in fig. 1E. Alternatively, the first node may be a DU in the architecture shown in fig. 1F, and the second node may be a CU in the communication system shown in fig. 1F.

In a possible implementation manner, the data packet described in this embodiment of the present application is a PDCP data packet, and a PDCP layer (PDCP entity) of the second node receives the data packet sent by the first node and reorders the received data packet. For example, the packet format of the PDCP packet may be the format shown in fig. 4. Referring to fig. 4, the PDCP packet includes an Internet Protocol (IP) header, a User Datagram Protocol (UDP) header, a general packet radio service tunneling protocol (GTPU) header, a PDCP header, an extension header, and a traffic data field. Wherein, the PDCP header includes a "PDCP sequence number field" for filling the PDCP SN of the data packet.

Illustratively, a first node transmits one or more data packets to a second node, each data packet including a PDCP SN of the data packet. Illustratively, the first node sends a packet with PDCP SN of 1 to the second node, where the packet includes PDCP SN "1", e.g., the "PDCP sequence number field" of the packet with PDCP SN of 1 is filled with "1".

302. The first node sends redundant information to the second node, the redundant information comprises the one or more PDCP SNs, and the one or more PDCP SNs and the one or more data packets are in one-to-one correspondence.

The redundant information may be other names, such as the first information, and the like, and this is not limited in this embodiment of the application.

In a specific implementation, the first node sends one or more data packets to the second node, and also sends the PDCP SN of each of the one or more data packets to the second node, that is, the first node sends the one or more PDCP SNs to the second node. It is understood that the one or more PDCP SNs sent by the first node in step 302 are in one-to-one correspondence with the one or more data packets sent by the first node in step 301.

The one or more PDCP SNs included in the redundant information may be denoted as N PDCP SNs, and correspond to N data packets sent by the first node to the second node in S301 one to one.

In a possible implementation manner, after receiving the redundant information, the second node may determine whether a packet is lost on a transmission path between the first node and the second node according to the redundant information, and after determining that the packet is lost, may skip (ignore) the data packet in the reordering.

Illustratively, the second node may compare N PDCP SNs in the redundant information with the PDCP SNs of the M received data packets, and for any one PDCP SN in the redundant information, the second node may determine whether a data packet corresponding to the PDCP SN is received. For example, the redundant information includes PDCP SN "1", the second node may determine whether there is a data packet corresponding to PDCP SN "1" (i.e., a data packet with PDCP SN of "1") in the M received data packets, and if the M received data packets include a data packet with PDCP SN of "1", it represents that the second node receives the data packet with PDCP SN of "1"; and if the M data packets received by the second node do not include the data packet with the PDCP SN of "1", the second node does not receive the data packet with the PDCP SN of "1".

Illustratively, when the second node determines that the data packet corresponding to the first PDCP SN in the redundant information is not received and the second node performs PDCP reordering, the data packet corresponding to the first PDCP SN is skipped. Wherein the first PDCP SN is any one of one or more PDCP SNs included in the redundant information.

For example, the second node may compare one or more PDCP SNs in the redundant information with one or more PDCP psns corresponding to the received one or more data packets, and determine whether there is a data packet corresponding to a PDCP SN in the redundant information that has not been received.

In a specific implementation, the second node may skip the data packet corresponding to the first PDCP SN by the following two methods:

firstly, if the PDCP discard timer of the data packet corresponding to the first PDCP SN is started, the PDCP discard timer of the data packet corresponding to the first PDCP SN is stopped.

And the second node receives the data packets from the first node, can acquire the PDCP SN of each received data packet by analyzing the data packets, and delivers the received data packets to the core network when the acquired PDCP SNs are continuous, namely the received data packets are continuous. When the acquired PDCP SN is discontinuous, the second node may determine that the received data packet is discontinuous, for example, the missing PDCP SN is the data packet of the first PDCP SN.

And the second node determines that the received data packet is discontinuous, and then starts a timer to wait for the data packet which is not received, namely the data packet of which the PDCP SN is the first PDCP SN. It should be noted that the timer may be a PDCP discard timer, which is used to wait for a data packet that is not received, and stop waiting for the data packet once the timer expires. The embodiment of the application does not limit the duration of the timer.

When the second node receives the redundant information, a plurality of PDCP SNs are obtained from the redundant information. The second node can also compare the PDCP SNs in the redundant information with the resolved PDCP SNs to determine whether the unreceived data packet is lost. For example, the second node may determine that the first node has sent the data packet corresponding to the first PDCP SN to the second node, but the second node has not received the data packet corresponding to the first PDCP SN, and then the second node may determine that the data packet is a lost data packet, if the second node analyzes the redundant information and obtains the first PDCP SN but does not receive the data packet whose PDCP SN is the first PDCP SN. Upon determining that the unreceived packet is a missing packet, the timer waiting for the packet is terminated and the packet is no longer waiting. For example, the second node may terminate the timer, no longer wait for a packet with a PDCP SN that is the first PDCP SN, continue reordering packets, ignore (skip) a packet with a PDCP SN that is the first PDCP SN when reordering, reorder other received packets, and transmit the reordered packet to the core network, that is, send a packet with a PDCP SN that is greater than the first PDCP SN to the core network.

In another example, assume that the second node receives the data packet from the first node as: and after the data packet with the PDCP SN of "4" is received, the second node finds that the received data packet is discontinuous, then a PDCP discard timer is started, and the data packet with the PDCP SN of "3" is waited.

And then, the second node receives the redundant information from the first node, acquires 5 PDCP SNs from the redundant information, wherein the PDCP SNs are respectively 1, 2, 3, 4 and 5, determines that packet loss occurs on a transmission path of the first node and the second node and a data packet with the PDCP SN of 3 is lost, immediately terminates the PDCP discard timer, and does not wait for the data packet with the PDCP SN of 3. And reordering the data packets with the PDCP SNs of 4 and 5, and transmitting the reordered data packets with the PDCP SNs of 4 and 5 to a core network. Because the data packet with the PDCP SN of 3 is lost on the transmission paths of the first node and the second node, the second node does not need to spend too long time waiting for the data packet, and terminates timing in time, and continues to deliver the data packet to the core network, thereby avoiding wasting bandwidth resources and improving the system performance.

And secondly, if the PDCP discard timer of the data packet corresponding to the first PDCP SN is not started, the PDCP discard timer of the data packet corresponding to the first PDCP SN is abandoned to be started.

When the second node receives the data packet from the first node, the PDCP SN of each received data packet can be obtained by parsing the data packet, and when the obtained PDCP SN is discontinuous, the second node can determine that the received data packet is discontinuous, for example, a missing PDCP SN is a data packet of the second PDCP SN, and the second node starts the timer 1 to wait for a data packet of which the PDCP SN is the second PDCP SN.

When the second node receives the redundant information, the second node may determine that the data packet corresponding to the second PDCP SN is a lost data packet because the redundant information includes the second PDCP SN. The subsequent second node continues to receive the data packet from the first node, and finds again the PDCP SN discontinuity, for example, missing the data packet corresponding to the first PDCP SN. Assuming that the redundant information includes the first PDCP SN, the second node may determine that the data packet corresponding to the first PDCP SN is a lost data packet, and the second node no longer starts the timer to wait for the data packet corresponding to the first PDCP SN, and may also wait for the data packet corresponding to the first PDCP SN within the effective duration of the timer 1. The method can avoid wasting the data packets waiting for loss for a long time and causing the waste of bandwidth resources.

Subsequently, the second node receives the redundant information from the first node, acquires 6 PDCP SNs, which are respectively "1, 2, 3, 4, 5, and 6" from the redundant information, determines that packet loss occurs on the transmission paths of the first node and the second node, and that a packet with PDCP SN of "3" is lost, and waits for a packet with PDCP SN of "3" within the effective duration of the PDCP discard timer.

The second node then receives a packet with PDCP SN of "7" from the first node, the PDCP SN is discontinuous, and the second node does not receive a packet with PDCP SN of "6", but the redundant information includes PDCP SN of "6", and the packet with PDCP SN of "6" is a lost packet. The second node no longer starts a new timer to wait for the packet with the PDCP SN of "6", and may wait for the packet with the PDCP SN of "6" within the valid duration of the timer waiting for the packet with the PDCP SN of "3". The method and the device avoid that the second node spends a long time waiting for the lost data packet and does not transmit the data packet to the core network for a long time, thereby wasting the bandwidth resource between the second node and the core network.

The carrying manner of the redundant information will be further described below.

In one possible implementation, the first node may redundantly send PDCP SNs of the data packets to the second node via the same type of data packets. For example, one or more data packets sent by the first node to the second node are PDCP data packets, and the PDCP data packets carry service data. The first node may also send the respective PDCP SNs of the one or more data packets to the second node via other PDCP data packets. The other PDCP data packet is different from the one or more data packets. It can be understood that after the first node sends one or more data packets to the second node, the redundant information is carried by other PDCP data packets.

It is to be understood that the redundant information carrying may be in a data packet comprising service data, which is different from the one or more data packets, i.e. the data packet carrying the redundant information is different from the one or more data packets sent by the first node in step 301.

For example, referring to the packet format shown in fig. 4, the redundancy information may be filled in the extension header of the packet.

In another possible implementation manner, the first node sends redundant information to the second node through different types of data packets, for example, the data packet carrying the redundant information does not include service data, and one or more data packets sent by the first node in step 301 include service data, which are different types of data packets.

For example, the first node may construct a data packet (e.g., redundant information as described in embodiments herein) in a dedicated format to send the PDCP SN of one or more data packets. Fig. 5 shows an example of a possible format of a data packet carrying redundant information, and referring to fig. 5, the data packet is, from outside to inside, an IP header, a UDP header, a GTPU header, and redundant information. Referring to fig. 5, the redundancy information includes a first PDCP SN field, a second PDCP SN field …, an nth PDCP SN field. The first PDCP SN field, the second PDCP SN field …, the nth PDCP SN field, and one-to-one correspondence between one or more data packets sent by the first node, are used to fill the PDCP SNs of the corresponding data packets. In one possible implementation, the first PDCP SN field, the second PDCP SN field …, the nth PDCP SN field is included in a PDCP header of a data packet.

Illustratively, the first PDCP SN field is for populating a PDCP SN of a first data packet of the one or more data packets. Assuming that the PDCP SN of the first packet is 3, the first PDCP SN field may be padded with "11".

Optionally, when the first node sends the data packet, the first node may carry an identification sequence number of the data packet, and the redundant information may also carry an identification sequence number of the data packet, which is further described below.

Optionally, the data packet sent by the first node in step 301 further includes an identification sequence number of the data packet. The identification sequence number is used to identify the data packet, and may be any sequence number different from the PDCP SN for identifying the data packet. In a possible implementation, the first node numbers the packets according to the packet sending sequence to the second node, and determines the identification sequence number of each data packet, and the second node may determine whether there is a packet loss on the transmission path between the first node and the second node according to the continuity of the identification sequence number.

For example, a first node sends one or more data packets to a second node through an X2interface, and the identification sequence number determined by the first node according to the packet data may be referred to as an X2 sequence number. Each packet sent by the first node may also include the X2 sequence number of the packet. The X2 sequence number is used to identify the data packets sent by the first node through the X2interface, and the second node may sort the data packets received from the first node according to the X2 sequence number, and determine whether there is a packet loss according to the continuity of the X2 sequence number.

In one possible implementation, the identification sequence number of the data packet may be filled in the extension header of the data packet. For example, in the data packet structure shown in fig. 3, the first node may fill the identification sequence number of the data packet in the extension header when packaging the packet.

Optionally, the redundant information sent by the first node to the second node further includes one or more identification sequence numbers, where the one or more identification sequence numbers are in one-to-one correspondence with the one or more PDCP SNs. It should be noted that one identification sequence number and its corresponding PDCP SN are used to identify the same data packet.

In a possible implementation manner, the PDCP SN and the identification sequence number in the redundant information also exist correspondingly. By way of example, FIG. 6 is one possible format for redundant information. Fig. 6 shows a possible format of a data packet carrying redundant information, and referring to fig. 6, the data packet includes an IP header, a UDP header, a GTPU header, and redundant information in sequence from inside to outside. The redundant information may include, among other things, an identification sequence number range and a first field, a second field … nth field. The identification sequence number range is used for indicating the range of the identification sequence numbers of the plurality of data packets corresponding to the PDCP SNs in the redundant information. For example, the identification sequence number range is "1 to 10", which represents that the redundant information includes PDCP SNs of 10 packets with

identification sequence numbers

1, 2, and 3 … 10. In addition, the first field and the nth field of the second field … are in one-to-one correspondence with one or more data packets sent by the first node, and are used for filling the PDCP SNs and the identification sequence numbers of the corresponding data packets. For example, the first field is used to fill the PDCP SN "110" of the first packet and the identification sequence number "1" of the first packet.

Optionally, it is assumed that the data packet sent by the first node carries the identification sequence number of the data packet, and the redundant information sent by the first node carries the identification sequence number of the data packet and the PDCP SN of the data packet. For example, the first node may send one or more data packets to the second node, and may also send redundant information to the second node, where the redundant information includes one or more PDCP SNs corresponding to the one or more data packets and one or more identification sequence numbers corresponding to the one or more data packets. Because the one or more data packets are continuously sent by the first node, the identification sequence number is determined according to the sending sequence of the data packets, and the identification sequence numbers of the multiple data packets sent by the first node are also continuous. It is understood that the plurality of identification numbers in the redundant information are also consecutive.

After receiving the data packet, the second node may analyze the identification sequence number of the data packet from the data packet, and may determine whether the received data packet is continuous according to the continuity of the identification sequence number. In addition, the PDCP SNs of the data packets which are not received can be determined by combining the redundant information.

For example, the second node receives a data packet, analyzes the data packet, finds that the data packet corresponding to the first identification sequence number is not received, and determines that the data packet corresponding to the first PDCP SN is not received if the PDCP SN corresponding to the first identification sequence number in the redundant information is the first PDCP SN. For example, the second node receives the data packets with the identification sequence numbers "1, 3, 4, and 5", that is, the data packet with the identification sequence number "2" is not received, and analyzes the redundant information to determine that the PDCP SN corresponding to the identification sequence number "2" is "110", that is, the second node does not receive the data packet with the PDCP SN of "110".

The transmission timing of the redundant information will be further described below.

Optionally, the first node sends the redundant information periodically, and a sending period of the redundant information is less than a duration of the PDCP discard timer. The PDCP discard timer is a timer started when the first node finds out that the received data packets are out of order (or missing), and the first node waits for the data packets that are not received within the valid duration of the PDCP discard timer.

It can be understood that, because the sending period of the redundant information is less than the time length of the PDCP discard timer, the second node can receive the redundant information before the PDCP discard timer expires, and can also determine that packet loss occurs on the transmission paths of the first node and the second node according to the redundant information, thereby terminating the PDCP discard timer waiting for the data packet, so that the second node can continue to deliver the data packet to the core network, avoid waiting for the lost data packet for a long time, leave the bandwidth for a long time, reasonably utilize the bandwidth resources, and improve the communication performance.

Optionally, the redundant information includes the one or more PDCP SNs corresponding to the one or more data packets sent by the first node after the redundant information is sent last time.

For example, the redundant information sent by the first node each time is the PDCP SN of the data packet sent by the first node to the second node after the redundant information is sent to the second node last time. For example, after the first node sends the data packets 1 to 4 to the second node, the redundancy information indicates the PDCPSN of each of the data packets 1 to 4 to the second node. And then, the first node sends the data packets 5 to 8 to the second node, and then sends redundancy information to the second node to indicate the PDCP SN of each data packet in the data packets 5 to 8.

Optionally, the redundant information further includes redundant information sent last time. For example, after the first node sends the data packets 1 to 4 to the second node, the redundancy information is sent to the second node to indicate the PDCP SN of each of the data packets 1 to 4. Then, the first node sends data packets 5 to 8 to the second node, and then sends redundancy information to the second node to indicate the PDCP SN of each of data packets 1 to 4 and the PDCP SN of each of data packets 5 to 8.

Optionally, the second node is a node that aggregates the data packet and performs packet reordering, and the second node maintains the duration information of the PDCP discard timer. The second node may further send the duration information of the PDCP discard timer to the first node, the first node receives the duration information of the PDCP discard timer from the second node, and may determine the duration of the PDCP discard timer according to the duration information of the PDCP discard timer, thereby setting a sending period of the redundant information to be less than the duration of the PDCP discard timer.

Optionally, a difference between a time when the first node sends the redundant information and a time when the first node completes sending the one or more data packets is a first threshold. That is, after completing the transmission of the one or more data packets, the first node transmits redundancy information to the second node at a certain time interval, indicating the PDCP SNs of the one or more data packets.

It can be appreciated that, assuming the network delay affects, the second node receives the redundant information associated with the data packet before receiving the data packet, which may cause the second node to misunderstand that the data packet is lost and skip the data packet when reordering. The first node sends the data packet and the redundant information at a certain time interval, and ensures that the second node receives the redundant information associated with the data packet after receiving a certain data packet as far as possible, so that the second node can be prevented from mistakenly considering that the data packet is lost, and the erroneous reordering operation is avoided.

Optionally, after the first node completes sending the one or more data packets, the first node sends N data packets including service data, and then sends the redundant information to the second node.

It can be appreciated that, assuming the network delay affects, the second node receives the redundant information associated with the data packet before receiving the data packet, which may cause the second node to misunderstand that the data packet is lost and skip the data packet when reordering. The first node sends the data packets and the redundant information at intervals of a plurality of data packets, and ensures that the second node receives the redundant information associated with the data packets after receiving a certain data packet as far as possible, so that the second node can be prevented from mistakenly considering that the data packets are lost, and the erroneous reordering operation is avoided.

Optionally, the first node may repeatedly send the redundant information.

Optionally, the first node may repeatedly send the redundant information until receiving an acknowledgement from the second node, where the acknowledgement is used to acknowledge receipt of the redundant information. That is, the first node may repeatedly transmit the redundant information, and stop transmitting the redundant information if the acknowledgement information fed back by the second node is received.

It should be noted that the one or more data packets sent by the first node are data packets of the first data radio bearer. In addition, the RLC layer of the first data radio bearer is at the first node and the PDCP layer of the first data radio bearer is at the second node. That is, the RLC layer of the first node packetizes and transmits data packets, and the PDCP layer of the second node receives data packets from the RLC layer of the first node and reorders the data packets when the data packets are discontinuous.

In a possible implementation manner, the first data radio bearer is a Secondary Cell Group (SCG) bearer terminated by a Master Node (MN), or a Split bearer terminated by the MN, or a Master Cell Group (MCG) bearer terminated by a Secondary Node (SN), or a Split bearer terminated by an SN.

In one possible implementation, the processor 2101 in the apparatus (first node) shown in FIG. 2A calls code in the memory 2102 to perform the method shown in FIG. 3.

Alternatively, the processor 2213 of the DU shown in fig. 2B calls the code in the memory 2214 to execute the method shown in fig. 3.

The solution presented in fig. 3 is further explained below in connection with fig. 7 to 9, the contents of fig. 7 to 9 being mutually referenced and referred to with the contents of fig. 3.

In a possible implementation manner, for example, the NSA DC Option3X networking, when the eNB sends a data packet to the gNB, the eNB numbers the data packet continuously (hereinafter referred to as an X2 sequence number, which is an identification number described in this embodiment), and indicates a correspondence between the X2 sequence number of the data packet and the PDCP SN through redundant information. And the gNB can judge whether packet loss occurs or not according to the continuity of the serial numbers of the receiving end, find out the PDCP serial number of the packet loss according to the state report, and find out the corresponding serial number in the PDCP reordering queue to avoid reordering. Specifically, referring to fig. 7, the method provided by the embodiment of the present application includes the following steps:

801. the gNB receives all data packets except the PDCP SNs 110, 120, 130-190, 200 before receiving the PDCP SN200 from the NR air interface.

It should be noted that the UE sends 10 data packets, i.e., the PDCP SN110, the PDCP SN120, and the PDCP SN130 … PDCP SN200, to the eNB through an LTE air interface, and the eNB receives the data packets from the LTE air interface.

In the embodiment of the present application, "PDCP SN XX" represents a packet with PDCP SN of "XX".

802. The eNB receives the PDCP SN110, adds X2 sequence number 1 to the PDCP SN110, and sends the processed data packet to the gNB.

803. The gNB receives the PDCP SN110 and transmits the previous data packet of the PDCP SN110 buffered by the gNB and the PDCP SN110 to a core network.

804. The eNB receives the PDCP SN120, adds X2 sequence number 2 to the PDCP SN120, and sends the processed data packet to the gNB.

805. The gNB receives the PDCP SN120, and the gNB delivers the buffered previous data packet of the PDCP SN120 and the PDCP SN120 to the core network.

806. The eNB receives the PDCP SN130, adds X2 sequence number 3 to the PDCP SN130, and sends the processed data packet to the gNB. The PDCP SN130 loses packets on the X2interface and fails to reach the gbb.

807. And the eNB continues to increase the X2 serial number in the transmitted data packet and transmits the processed data packet to the gNB until 10 data packets are transmitted.

808. After receiving the data packet, the gNB finds the missing PDCP SN130, starts a timer to wait for the PDCP SN130, and stops delivering the data packet to the core network.

809. After transmitting 10 packets from PDCP SN110 to PDCP SN200, the eNB transmits redundant information to the gNB. The redundant information includes X2 serial numbers 1-10 of 10 data packets from PDCP SN110 to PDCP SN200, and 10 PDCP SNs corresponding to X2 serial numbers 1-10, namely 110-200.

In a specific implementation, the eNB may analyze the data packet, obtain the PDCP SN of the data packet from the data packet, and add the PDCP SN of the data packet to the redundant information.

The eNB may also copy the 3 bytes in the header of the data packet to fill in the corresponding position in the redundant information. Referring to the PDCP protocols (3GPP 36.323 and 3GPP 38.323), a PDCP SN exists within the header 3 bytes of a PDCP packet. The embodiment of the application is not limited to this, and is suitable for adjusting the PDCP protocol, and the number of bytes copied can be adjusted accordingly. For example, the PDCP protocol specifies that PDCP SNs exist in the first 4 bytes of the PDCP data packet, and the first 4 bytes of the copied PDCP data packet are filled to the corresponding location of the redundant information.

In addition, the redundancy information may be sent periodically according to the number of data packets, for example, the eNB sends one redundancy information every 10 data packets, which carries the PDCP SN and the X2 sequence number of the 10 data packets.

Alternatively, the redundant information is transmitted periodically at time intervals, for example, one redundant information is transmitted at intervals of 10 ms.

It should be noted that the first node may set different sending periods according to factors such as packet loss probability and transmission delay of the network. The transmission period may be N data packets or a time interval.

810. And the gNB stops waiting for the timer of the PDCP SN130 according to the data packet lost by the redundant information PDCP SN130 message on the X2interface, reorders the buffered other data packets except the PDCP SN130 and transmits the reordered data packets to the core network.

In a specific implementation, if the redundant information includes the PDCP SN of "130", it indicates that the eNB sends the packet of the PDCP SN130 to the gNB on the X2interface, but packet loss occurs between the eNB and the gNB, and the gNB does not receive the packet of the PDCP SN 130.

Still taking NSA DC Option3x networking as an example, assuming that an eNB sends redundant information to a gNB every other data packet, the sending period of the redundant information may include a number of data packets greater than the number of PDCP SNs of the redundant information, i.e., the redundant information is sent after delay. Illustratively, the redundant information includes PDCP SNs of 6 data packets, and the eNB sends the redundant information to the gNB after completing sending 8 data packets.

In one possible implementation, the gNB maintains a queue for packet loss monitoring, where the queue identifies packets with their X2 sequence number and the queue pointer points to the X2 sequence number of the pending packet. The specific monitoring process is described with reference to fig. 8. As shown in fig. 8, eNB sends data packets with sequence numbers 1 to 8 of X2 to gNB, and when the gNB receives the 8 data packets, the queue pointer slides to 9. The eNB sends redundant information 1 to the gNB, wherein the redundant information comprises PDCP SNs of data packets with X2 serial numbers of 1-6, and the PDCP SNs are respectively 110, 120 and 130 … 160. And the gNB determines that no packet is lost according to the redundant information 1.

Then, the eNB sends data packets with the sequence numbers of X2 being 9-16 to the gNB, the data packet with the sequence number of X2 being 10 is lost at the port X2, the gNB does not receive the data packet with the sequence number of X2 being 10, and the queue pointer stops at 10. The eNB sends redundant information 2 to the gNB, wherein the redundant information comprises PDCP SNs of data packets with X2 serial numbers of 7-12, and the PDCP SNs are respectively 170, 180 and 190 … 230. And the gNB analyzes the redundant information 2, and acquires that the PDCP SN corresponding to the data packet with the X2 serial number of 10 is 1000.

If the PDCP discard timer is started currently and the timer is triggered by the data packet with the PDCP SN of 1000, namely the timer is used for waiting the data packet with the PDCP SN of 1000, the gNB stops the timer and transmits the continuous data packets with the PDCP SN of 1000 to the core network; if the timer is not triggered by the PDCP SN 1000 data packet, a new timer is not started, and the PDCP SN 1000 data packet is waited.

It can be understood that if the eNB sends the redundant information 1 immediately after the packet with the sequence number of X2 being 6, assuming that the packet with the sequence number of X2 reaching the gNB later than the redundant information 1 due to disorder of transmission, an erroneous packet skipping action will be caused, that is, the packet with the sequence number of X2 being mistaken after the gNB analyzes the redundant information 1 is lost on the X2 port, and the packet with the sequence number of X2 being 6 is skipped during reordering, which results in an erroneous operation of the upper layer protocol, for example, the packet with the sequence number of X2 being 6 is mistakenly lost, and the service layer is retransmitted.

When the eNB finishes transmitting the data packet with the sequence number of X2 being 8, the eNB finishes transmitting the redundancy information 1, and assumes that the data packet with the sequence number of X2 being 6 is out of order, and will arrive at the gNB after the data packet with the sequence number of X2 being 7, and will still arrive at the gNB earlier than the redundancy information 1, which will not cause an erroneous packet hopping action.

It should be noted that the degree of delayed sending of the redundant information may be set according to an out-of-order condition of actual networking (for example, the X2 sequence number of a data packet received by the gNB is disordered due to the time delay of an X2 transmission link), and if the out-of-order condition is more serious, the number of the delayed data packets may be set to be larger, and a plurality of delayed data packets may be sent with the redundant information; if the disorder degree is very low, the number of delayed data packets can be set to be smaller, and a few messages can be delayed; if it is determined that no out-of-order exists on the network, the delayed sending of the status report may not be performed, that is, the number of data packets included in the sending period of the redundant information may be equal to the number of PDCP SNs of the redundant information.

The method provided by the embodiment of the application can avoid the waste of bandwidth caused by waiting for lost data packets for a long time, and is beneficial to the characteristic communication performance. Meanwhile, the problem of misoperation caused by disorder of the X2 port can be solved, and the fault tolerance of the system is improved by optimizing the sending mode of redundant information.

Still taking NSA DC Option3X networking as an example, the eNB may also solve the influence caused by packet loss of redundant information at the X2 port by the following two ways, which specifically include:

in the first method, when the eNB sends the jth redundant information, the jth-1 redundant information is repeatedly sent.

For example, after the eNB sends the X2 data packets with sequence numbers of 1-10 to the gbb at the X2 port, the eNB sends redundancy information 1 to the gbb, including 10 PDCP SNs corresponding to the X2 data packets with sequence numbers of 1-10.

And the eNB sends a data packet with an X2 sequence number of 11-20 to the gNB at an X2 port, and sends redundant information 1 and redundant information 2, wherein the redundant information 2 comprises 10 PDCP SNs corresponding to the data packet with the X2 sequence number of 11-20.

And the eNB sends a data packet with the sequence number of 21-30 of X2 to the gNB at an X2 port, and sends redundant information 2 and redundant information 3, wherein the redundant information 3 comprises 10 PDCP SNs corresponding to the data packet with the sequence number of 21-30 of X2.

The subsequent processes are analogized in turn, and details are not repeated in the embodiments of the present application.

Secondly, the eNB repeatedly sends the redundant information until receiving the acknowledgement information of the gNB.

For example, after the eNB sends the X2 data packets with sequence numbers of 1-10 to the gbb at the X2 port, the eNB repeatedly sends redundancy information 1 to the gbb, including 10 PDCP SNs corresponding to the X2 data packets with sequence numbers of 1-10.

The eNB receives the acknowledgement information sent by the gNB, and the acknowledgement information is used to confirm that the gNB received the redundant information 1, and the eNB stops sending the redundant information 1.

It should be noted that the eNB may decide to select the first or second manner to send the redundant information according to the transmission quality of the X2 port. If the transmission quality is slightly poor and the packet loss rate of the X2 port is not high, the redundant information can be sent by adopting a first mode; if the transmission quality is poor and the packet loss rate of the X2 port is high, the redundant information can be sent in the second mode.

The method provided by the embodiment of the application can avoid the waste of bandwidth caused by waiting for lost data packets for a long time, and is beneficial to the characteristic communication performance. Meanwhile, the problem caused by packet loss of the X2 port can be solved, and the fault tolerance of the system is improved by optimizing the sending mode of the redundant information.

Still taking NSA DC Option3X networking as an example, the eNB numbers the data packets according to the transmission order of the X2 port, and does not need to transmit redundant information separately, but carries the redundant information in other data packets to transmit to the gNB. When the eNB transmits the data packet, the PDCP SN of one or more data packets transmitted before is attached to the path. Referring to fig. 4, one or more PDCP SNs attached to a channel may be filled in an extension header of a message. The number of PDCP SNs carried depends on the transmission quality. When the transmission quality is better, the probability of continuous packet loss is small, and the number of carried PDCP SNs is less; when the transmission quality is poor, the probability of continuous packet loss is high, and the number of the carried PDCP SNs is larger.

For example, referring to fig. 9 (in the figure, the number is a PDCP SN of a data packet), a first data packet (that is, a data packet with a PDCP SN of 1 in the figure) sent by an eNB does not carry PDCP SNs of other data packets, and after receiving the data packet with the PDCP SN of 1, a gNB analyzes and finds that the data packet with the PDCP SN of 1 does not carry the PDCP SNs of other data packets, for example, an extension header of the data packet is null, and then, according to the existing flow processing, transfers consecutive data packets to a core network.

And the gNB receives the second data packet, namely the data packet with the PDCP SN of 5 in the figure, analyzes the data packet, acquires the PDCP SN of 1 at the extension head of the gNB, confirms that the data packet with the PDCP SN of 1 is received, continues to process according to the existing flow, and transmits continuous data packets to the core network.

And the gNB receives the third data packet, namely the data packet with the PDCP SN of 8 in the figure, analyzes the data packet, acquires the PDCP SN of 3 at the extension head, confirms that the data packet with the PDCP SN of 3 is not received, starts a timer to wait for the data packet with the PDCP SN of 3, and suspends the transmission of the data packet to the core network.

And the gNB receives the fourth message, namely the data packet with the PDCP SN of 3 in the figure, and stops the timer when monitoring that the timer waiting for the data packet with the PDCP SN of 3 is running. In addition, the packet with PDCP SN of 3 is analyzed, and the extension header of the packet acquires PDCP SN of "5", and it is confirmed that the packet with PDCP SN of 5 has been received.

The PDCP receives a fifth message: that is, the packet with PDCP SN of 12 in the figure is analyzed, the extension header of the packet acquires PDCP SN "9", it is confirmed that the packet with PDCP SN of 9 is not received, the timer is started to wait for the packet with PDCP SN of 9, and the transmission of the packet to the core network is suspended. After the timer for waiting the data packet with the PDCP SN of 9 is overtime, constructing a virtual packet for reordering, and transmitting the reordered data packet to a core network.

The method provided by the embodiment of the application can avoid the waste of bandwidth caused by waiting for lost data packets for a long time, and is beneficial to the characteristic communication performance. Meanwhile, the transmission resource of the X2 port can be reduced. By using the method, the problem of waste of bandwidth caused by PDCP reordering due to disorder of the X2 ports and packet loss is solved with less cost.

Fig. 10 shows a schematic diagram of a possible structure of the communication device according to the above-described embodiment, in a case where each functional module is divided according to each function. The communication device shown in fig. 10 may be the first node or the second node described in the embodiment of the present application, may also be a component in the first node or the second node, which implements the foregoing method, or may also be a chip applied to the first node or the second node. The Chip may be a System-On-a-Chip (SOC) or a baseband Chip with a communication function. As shown in fig. 10, the communication apparatus includes a processing unit 1101 and a communication unit 1102. The processing unit may be one or more processors and the communication unit may be a transceiver.

A processing unit 1101 for supporting the first node or the second node to perform internal processing, e.g., assembling a data packet; processing unit 1101 is also used to support the second node (e.g., the gNB) in performing step 808, and/or other processes for the techniques described herein.

A communication unit 1102 for supporting communication between the communication apparatus and other communication apparatuses, e.g. supporting the first node, the second node to perform

steps

301 and 302, supporting the first node to perform steps 802, 804, 806, 807 and 809, and/or other processes for the techniques described herein.

It should be noted that all relevant contents of each step related to the above method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

For example, in the case of using an integrated unit, a schematic structural diagram of a communication device provided in an embodiment of the present application is shown in fig. 11. In fig. 11, the communication apparatus includes: a processing module 1201 and a communication module 1202. The processing module 1201 is used to control and manage the actions of the communication device, e.g., to perform the steps performed by the processing unit 1101 described above, and/or to perform other processes for the techniques described herein. The communication module 1202 is configured to perform the steps performed by the communication unit 1102, and support interaction between the communication apparatus and other devices, such as interaction with other terminal apparatuses. As shown in fig. 11, the communication device may further include a storage module 1203, and the storage module 1203 is used for storing program codes and data of the communication device.

When the processing module 1201 is a processor, the communication module 1202 is a transceiver, and the storage module 1203 is a memory, the communication device is the communication device shown in fig. 2A.

The embodiment of the application provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium; the instructions are for performing the method as shown in fig. 3.

Embodiments of the present application provide a computer program product comprising instructions which, when run on a communication apparatus, cause the communication apparatus to perform the method as shown in fig. 3.

An embodiment of the present application provides a wireless communication apparatus, including: instructions are stored in the wireless communication device; when the wireless communication device is operating on the communication device shown in fig. 2A, 2B, 10, 11, the communication device is caused to perform the method as shown in fig. 3. The wireless communication device may be a chip.

An embodiment of the present application further provides a communication system, including: a first node and a second node. Illustratively, the first node may be the communication device shown in fig. 2A, 10, 11 or the DU shown in fig. 2B, and the second node may be the communication device shown in fig. 2A, 10, 11 or the CU shown in fig. 2B.

Through the description of the above embodiments, it is clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely used as an example, and in practical applications, the above functions may be distributed by different functional modules according to needs, that is, the internal structure of the database access apparatus may be divided into different functional modules to complete all or part of the above described functions.

The processor in the embodiment of the present application may include, but is not limited to, at least one of the following: various computing devices that run software, such as a Central Processing Unit (CPU), a microprocessor, a Digital Signal Processor (DSP), a Microcontroller (MCU), or an artificial intelligence processor, may each include one or more cores for executing software instructions to perform operations or processing. The processor may be a single semiconductor chip or integrated with other circuits to form a semiconductor chip, for example, an SoC (system on chip) with other circuits (such as a codec circuit, a hardware acceleration circuit, or various buses and interface circuits), or may be integrated in the ASIC as a built-in processor of the ASIC, which may be packaged separately or together with other circuits. The processor may further include necessary hardware accelerators such as Field Programmable Gate Arrays (FPGAs), PLDs (programmable logic devices), or logic circuits implementing dedicated logic operations, in addition to the core for executing software instructions to perform operations or processing.

The memory in the embodiment of the present application may include at least one of the following types: read-only memory (ROM) or other types of static memory devices that may store static information and instructions, Random Access Memory (RAM) or other types of dynamic memory devices that may store information and instructions, and Electrically erasable programmable read-only memory (EEPROM). In some scenarios, the memory may also be, but is not limited to, a compact disk-read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

In the present application, "at least one" means one or more. "plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. In addition, in order to facilitate clear description of technical solutions of the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.

In the several embodiments provided in the present application, it should be understood that the disclosed database access apparatus and method may be implemented in other ways. For example, the above-described database access device embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, multiple units or components may be combined or integrated into another device, or some features may be omitted, or not executed. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be an indirect coupling or communication connection through some interfaces, database access devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may be one physical unit or a plurality of physical units, that is, may be located in one place, or may be distributed in a plurality of different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

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 in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially or partially contributed to by the prior art, or all or part of the technical solutions may be embodied in the form of a software product, where the software product is stored in a storage medium and includes several instructions to enable a device (which may be a single chip microcomputer, a chip, or the like) or a 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 U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for feeding back redundant information, comprising:

a first node sends N data packets to a second node, wherein each data packet in the N data packets comprises a Packet Data Convergence Protocol (PDCP) sequence number SN of the data packet, and N is an integer greater than or equal to 1;

the first node sends redundant information to the second node, wherein the redundant information comprises N PDCP SNs, and the N PDCP SNs are in one-to-one correspondence with the N data packets; the redundant information is sent periodically, and the sending period of the redundant information is less than the time length of the PDCP discarding timer.

2. The method of claim 1, wherein each of said N data packets further comprises an identification sequence number of said data packet;

the redundant information further comprises N identification sequence numbers, and the N identification sequence numbers are in one-to-one correspondence with the N PDCP SNs.

3. The method of claim 2, wherein the N identification sequence numbers corresponding to the N data packets one to one are consecutive according to a transmission order of the N data packets.

4. The method according to any of claims 1-3, wherein said N packets are sent by said first node to said second node after said first node last sent redundant information to said second node.

5. The method of any of claims 1-3, wherein the redundant information further comprises redundant information last sent.

6. The method according to any one of claims 1-3, further comprising: the first node receives duration information of the PDCP discard timer from the second node.

7. The method according to any one of claims 1 to 3,

the difference between the time when the first node sends the redundant information and the time when the first node finishes sending the N data packets is a first threshold value; alternatively, the first and second electrodes may be,

and after the first node finishes sending the N data packets, sending one or more other data packets, and then sending the redundant information to the second node.

8. A method according to any of claims 1-3, wherein the N data packets are data packets of a first data radio bearer, wherein a radio link control, RLC, layer of the first data radio bearer is at the first node and wherein a PDCP layer of the first data radio bearer is at the second node.

9. A method for feeding back redundant information, comprising:

the method comprises the steps that a second node receives M data packets from a first node, wherein each data packet in the M data packets comprises a Packet Data Convergence Protocol (PDCP) sequence number SN of the data packet, and M is an integer larger than or equal to 1;

the second node receives redundant information from the first node, wherein the redundant information comprises N PDCP SNs, N is an integer greater than or equal to 1, N is greater than or equal to M, and the N PDCP SNs comprise M PDCP SNs which are in one-to-one correspondence with the M data packets; the redundant information is received periodically, and the receiving period of the redundant information is less than the time length of a PDCP discarding timer;

and when the second node determines that the data packet corresponding to the first PDCP SN in the redundant information is not received and the second node performs PDCP reordering, skipping the data packet corresponding to the first PDCP SN, wherein the first PDCP SN is one of the N PDCP SNs.

10. The method of claim 9, wherein each of said M data packets further comprises an identification sequence number of said data packet;

11. The method of claim 10, wherein the M packets are received by the second node from the first node after the second node last received redundant information from the second node.

12. The method of claim 11, wherein the redundant information further comprises redundant information last received.

13. The method according to any of claims 9-12, wherein the duration information of the PDCP discard timer is sent to the first node.

14. The method of claim 10, further comprising:

and when the second node determines that the data packet corresponding to the first identification sequence number is not received according to the continuity of the identification sequence numbers of the M data packets, wherein the first identification sequence number is one of the N identification sequence numbers, and the PDCP SN corresponding to the first identification sequence number is the first PDCP SN, skipping the data packet corresponding to the first PDCP SN when the second node performs PDCP reordering.

15. The method of claim 9, wherein skipping the data packet corresponding to the first PDCP SN when the second node performs PDCP reordering comprises:

if the PDCP discard timer of the data packet corresponding to the first PDCP SN is started, stopping the PDCP discard timer of the data packet corresponding to the first PDCP SN; alternatively, the first and second electrodes may be,

and if the PDCP discard timer of the data packet corresponding to the first PDCP SN is not started, the PDCP discard timer of the data packet corresponding to the first PDCP SN is abandoned to be started.

16. The method of claim 9, further comprising:

and sending a data packet with the PDCP SN larger than the first PDCP SN to a core network.

17. The method of claim 9, wherein the M data packets are data packets of a first data radio bearer, wherein a radio link control, RLC, layer of the first data radio bearer is at the first node, and wherein a PDCP layer of the first data radio bearer is at the second node.

18. The method of claim 17, wherein the first data radio bearer is a Secondary Cell Group (SCG) bearer terminated by a primary node (MN), or a breakout bearer terminated by a primary node (MN), or a primary cell group (MCG) bearer terminated by a Secondary Node (SN), or a breakout bearer terminated by an SN.

19. The method of claim 18, wherein the first node is a Distribution Unit (DU) and the second node is a centralized CU.

20. A communications apparatus comprising a processor coupled with a memory;

a memory for storing a computer program;

a processor for executing a computer program stored in the memory to cause the apparatus to perform the method of any of claims 1 to 19.