CN111585723A

CN111585723A - Auxiliary information and method and device for transmitting auxiliary information

Info

Publication number: CN111585723A
Application number: CN201910117795.7A
Authority: CN
Inventors: 韩锋; 杨旭东; 晋英豪; 杨水根; 谭巍
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-02-15
Filing date: 2019-02-15
Publication date: 2020-08-25
Anticipated expiration: 2039-02-15
Also published as: CN111585723B; WO2020164614A1

Abstract

The embodiment of the application provides an auxiliary information transfer method for data packet repetition. The method comprises the following steps: a first Radio Access Network (RAN) device determines first information, wherein the first information comprises information of at least one logical channel in the first RAN device; the first RAN device sends the first information to a second RAN device, where the first information is used to indicate packet repetition assistance information of the first RAN device. By using the method, the second RAN equipment can be effectively supported to carry out data packet repeated decision.

Description

Auxiliary information and method and device for transmitting auxiliary information

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method and an apparatus for auxiliary information and its delivery.

Background

With the rapid development of wireless communication technology, the fifth Generation (5th Generation,5G) wireless communication technology has been a hot spot in the industry. The 5G will support diverse application requirements including access capability supporting higher rate experience and larger bandwidth, lower latency and highly reliable information interaction, and access and management of larger-scale and low-cost machine type communication devices, etc. In addition, 5G can support various vertical industry application scenes such as vehicle networking, emergency communication, industrial internet and the like.

High-reliability Low-Latency Communications (URLLC) is an important type of Communications in 5G. URLLC is a communication service with high requirements on delay and reliability, and is applied in situations such as unmanned driving and telemedicine. The delay requirement of the type of service to the user plane needs to reach 0.5ms of uplink/downlink transmission; for 32 byte length transmission, the reliability needs to reach 1-10 under the condition that the user plane delay is 1ms^-5And the like. In order to support URLLC service, the same data packet may be repeatedly transmitted over the air interface to improve the reliability and robustness of data transmission. For example, a terminal device may be wirelessly connected to two base stations at the same time, over which the same data packets are transmitted simultaneously with the two base station wireless links. How to fully utilize the capability of the base station to realize efficient repeated transmission has not been a proper solution at present.

Disclosure of Invention

The embodiment of the application provides auxiliary information and a method for transmitting the auxiliary information, and the method effectively supports RAN equipment to make repeated decision on data packets.

The present application is described below in a number of aspects, it being readily understood that implementations of the following aspects may be referred to one another.

In a first aspect, the present application provides an information delivery method for data packet repetition, including: determining first information by a first Radio Access Network (RAN) device, wherein the first information comprises information of at least one logical channel in the first RAN device; the first RAN device sends the first information to a second RAN device, where the first information is used to indicate packet duplication assistance information of the first RAN device.

Therefore, the method provided by the embodiment of the application realizes that the first RAN device sends the data packet repetition auxiliary information to the second RAN device at the granularity of the logical channel, so that the second RAN device can obtain richer information of the first RAN device, and can make a decision of data packet repetition more effectively. For example, the second RAN device may decide to activate one or more logical channels of the first RAN device for packet repetition based on the packet repetition assistance information.

In one possible implementation, the information of the at least one logical channel includes at least one of the following information: a logical channel identifier of the at least one logical channel, a logical channel index of the at least one logical channel, radio quality assistance information of the at least one logical channel, a tunnel identifier of at least one tunnel corresponding to the at least one logical channel, a tunnel index of the at least one tunnel, and a downlink tunneling layer address and a tunnel endpoint identifier TEID of the at least one tunnel. Wherein one logical channel corresponds to one tunnel.

In one possible implementation, the first information is auxiliary information data (assistance information data) containing at least one of packet data convergence layer protocol PDCP (packet data convergence activity notification) repetition activation notification (PDCP activation notification) and radio quality assistance information (radio quality assistance notification).

The data packet repeated auxiliary information is transmitted by using the auxiliary information data of the existing standard, so that the existing standard can be better compatible.

In one possible implementation, the PDCP repetition activation recommendation is used to indicate the at least one logical channel or the at least one tunnel for which the first RAN device recommends an activation packet repetition.

In one possible implementation, the radio quality assistance information includes radio quality assistance information of the at least one logical channel of the first RAN device or radio quality assistance information of at least one logical channel corresponding to the at least one tunnel.

In one possible implementation, the PDCP repetition activation suggestion is used to indicate the at least one logical channel or the at least one tunnel for which the first RAN device suggests activation packet repetition, including: the PDCP repetition activation proposal comprises at least two bits of information indicating the at least one logical channel or the at least one tunnel for which the activation packet is proposed by the first RAN device.

By modifying the PDCP re-activation proposal field of the side information data in the existing standard, the identification information of the activated logical channel or tunnel can be delivered with as little modification and information overhead as possible.

In one possible implementation, the second RAN device is a hosting PDCP entity node, and the first RAN device is a corresponding node; or the second RAN equipment is a central unit CU and the first RAN equipment is a distributed unit DU.

In a possible implementation manner, the first RAN device receives the downlink data packet sent by the second RAN device through the at least one tunnel. And under the condition that the first RAN equipment receives downlink data packets sent by the second RAN equipment through at least two tunnels, the downlink data packets have the same PDCP sequence number.

Therefore, the first RAN device receives the downlink data packet from the second RAN device through the corresponding tunnel, and it can be ensured that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In one possible implementation manner, the sending, by the first RAN device, the first information to the second RAN device includes: the first RAN device sends the first information to the second RAN device via a third RAN device.

In one possible implementation, the second RAN equipment is a centralized unit control plane network element CU-CP, the first RAN equipment is a distributed unit DU, and the third RAN equipment is a centralized unit user plane network element CU-UP.

In a possible implementation manner, the first RAN device receives the downlink data packet sent by the third RAN device through the at least one tunnel. And in the case that the first RAN device receives downlink data packets sent by the third RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

Therefore, under the condition that the second RAN device only executes the function of the control plane, the first RAN device receives the downlink data packet from the third RAN device executing the function of the user plane through the corresponding tunnel, so that the corresponding RLC entity in the first RAN device can be ensured to correctly receive the data packet which needs to be repeated.

In a second aspect, the present application provides an information delivery method for data packet repetition, including: determining first information by a first Radio Access Network (RAN) device, wherein the first information comprises information of at least one logical channel group in the first RAN device, and the logical channel group comprises at least one logical channel; the first RAN device sends the first information to a second RAN device, where the first information is used to indicate packet duplication assistance information of the first RAN device.

Therefore, the method provided by the embodiment of the application realizes that the first RAN device sends the data packet repetition auxiliary information to the second RAN device at the granularity of the logical channel group, so that the second RAN device can acquire richer information of the first RAN device and can make a decision of data packet repetition more effectively. For example, the second RAN apparatus may decide to activate a certain logical channel group of the first RAN apparatus for packet duplication based on the packet duplication assistance information. In addition, the auxiliary information is repeated by forming data packets with the granularity of the logical channel groups, so that the information overhead can be effectively reduced.

In one possible implementation, the information of the at least one logical channel group comprises at least one of the following information: a logical channel group identification of the at least one logical channel group, a logical channel group index of the at least one logical channel group, radio quality assistance information of the at least one logical channel group, a tunnel identification of at least one tunnel group corresponding to the at least one logical channel group, a tunnel group index of the at least one tunnel group, and a downlink tunneling layer address and a tunnel endpoint identification TEID of the at least one tunnel group. Wherein one logical channel group corresponds to one tunnel group.

In one possible implementation, a logical channel group may be any combination of logical channels in the first RAN device; alternatively, a tunnel group may be any combination of tunnels of the first RAN device.

In one possible implementation, a logical channel group may be any combination of one or more specific logical channels and other logical channels in the first RAN device; alternatively, a tunnel group may be any combination of one or more specific tunnels of the first RAN device with other tunnels.

It can be seen that the division of the logical channel groups or tunnel groups may be flexible to adapt to the application of the network in various scenarios.

In one possible implementation, the PDCP repetition activation recommendation is used to indicate the at least one logical channel group or the at least one tunnel group of the first RAN device recommended activation packet repetitions.

In one possible implementation, the radio quality assistance information includes radio quality assistance information of the at least one logical channel group of the first RAN device or radio quality assistance information of at least one logical channel group corresponding to the at least one tunnel group.

In one possible implementation, the PDCP repetition activation proposal is used to indicate the at least one logical channel group or the at least one tunnel group of the activation packet repetition proposed by the first RAN device, and includes: the PDCP repetition activation proposal comprises at least two bits of information indicating the at least one logical channel group or the at least one tunnel group of the activation packet repetition proposed by the first RAN device.

In a possible implementation manner, the radio quality assistance information of the at least one logical channel group includes radio quality assistance information of each logical channel in the at least one logical channel group or radio quality assistance information obtained by performing mathematical operation on the radio quality assistance information of each logical channel.

By modifying the PDCP re-activation proposal field of the side information data in the existing standard, the identification information of the activated logical channel group or tunnel group can be delivered with as little modification and information overhead as possible.

In a possible implementation manner, the first RAN device receives the downlink data packet sent by the second RAN device through the at least one tunnel group. And in the case that the first RAN device receives downlink data packets sent by the second RAN device through at least two tunnels in the at least one tunnel group, the downlink data packets have the same PDCP sequence number.

Therefore, the first RAN device receives the downlink data packet from the second RAN device through the corresponding tunnel group, and it can be ensured that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In a possible implementation manner, the first RAN device receives the downlink data packet sent by the third RAN device through the at least one tunnel group. And in the case that the first RAN device receives downlink data packets sent by the third RAN device through at least two tunnels in the at least one tunnel group, the downlink data packets have the same PDCP sequence number.

Therefore, under the condition that the second RAN device only executes the function of the control plane, the first RAN device receives the downlink data packet from the third RAN device executing the function of the user plane through the corresponding tunnel group, and can ensure that the corresponding RLC entity in the first RAN device correctly receives the data packet which needs to be repeated.

In a third aspect, the present application provides an information delivery method for data packet repetition, including: receiving, by a second radio access network RAN device, first information sent by a first RAN device, where the first information includes information of at least one logical channel in the first RAN device, and the first information is used to indicate packet repetition assistance information of the first RAN device; the second RAN device decides packet duplication based on the first information.

Therefore, the method provided by the embodiment of the application realizes that the second RAN device receives the data packet repetition auxiliary information sent by the first RAN device at the granularity of the logical channel, so that the second RAN device can acquire richer information of the first RAN device and can make a decision of data packet repetition more effectively. For example, the second RAN device may decide to activate one or more logical channels of the first RAN device for packet repetition based on the packet repetition assistance information.

In one possible implementation, the second RAN device deciding the packet repetition according to the first information includes: the second RAN device decides to activate packet repetition of the at least one logical channel or the at least one tunnel according to the first information.

It can be seen that the second RAN device makes a finer decision on packet repetition at the granularity of logical channels or tunnels, and can better utilize the resources of the first RAN device for packet repetition.

In one possible implementation, the second RAN apparatus sends the downlink data packet to the first RAN apparatus through the at least one tunnel. And in the case that the second RAN device sends downlink data packets to the first RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

Therefore, the second RAN device sends the downlink data packet to the first RAN device through the corresponding tunnel, which can ensure that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In a possible implementation manner, the receiving, by the second RAN device, the first information sent by the first RAN device includes: the second RAN device receives the first information sent by the first RAN device via a third RAN device.

In a possible implementation manner, the second RAN device sends packet retransmission information to the third RAN device, where the packet retransmission information includes transmission information of the at least one logical channel, and the packet retransmission information is used to instruct the third RAN device to send downlink data to the first RAN device according to the packet retransmission information.

In one possible implementation, the transmission information of the at least one logical channel includes at least one of the following information: the logical channel identifier of the at least one logical channel, the logical channel index of the at least one logical channel, the tunnel identifier of the at least one tunnel corresponding to the at least one logical channel, the tunnel index of the at least one tunnel, and the downlink tunneling layer address and TEID of the at least one tunnel.

As can be seen, in the case that the second RAN device only executes the function of the control plane, the second RAN device instructs the third RAN device executing the user plane function to send the downlink data packet to the first RAN device through the corresponding tunnel, which can ensure that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In a fourth aspect, the present application provides an information delivery method for data packet repetition, including: receiving, by a second radio access network RAN device, first information sent by a first RAN device, where the first information includes information of at least one logical channel group in the first RAN device, and the logical channel group includes at least one logical channel; the first information is used for indicating data packet repetition assistance information of the first RAN equipment; the second RAN device decides packet duplication based on the first information.

Therefore, the method provided by the embodiment of the application realizes that the second RAN device receives the data packet repetition auxiliary information sent by the first RAN device at the granularity of the logical channel group, so that the second RAN device can acquire richer information of the first RAN device and can make a decision of data packet repetition more effectively. For example, the second RAN device may decide to activate one or more logical channels of the first RAN device for packet repetition based on the packet repetition assistance information. In addition, the auxiliary information is repeated by forming data packets with the granularity of the logical channel groups, so that the information overhead can be effectively reduced.

In one possible implementation, the information of the at least one logical channel group comprises at least one of the following information: a logical channel group identification of the at least one logical channel group, a logical channel group index of the at least one logical channel group, radio quality assistance information of the at least one logical channel group, a tunnel group identification of at least one tunnel group corresponding to the at least one logical channel group, a tunnel group index of the at least one tunnel group, and a downlink tunneling layer address and a tunnel endpoint identification TEID of the at least one tunnel group. Wherein one logical channel group corresponds to one tunnel group.

In one possible implementation, the second RAN device deciding the packet repetition according to the first information includes: the second RAN device decides to activate packet repetition of the at least one logical channel group or the at least one tunnel group according to the first information.

It can be seen that the second RAN device makes a finer decision on packet duplication at the granularity of logical channel groups or tunnel groups, and can better utilize the resources of the first RAN device for packet duplication.

In one possible implementation, the second RAN device sends the downlink data packet to the first RAN device through the at least one tunnel group. And in the case that the second RAN device sends downlink data packets to the first RAN device through at least two tunnels in the at least one tunnel group, the downlink data packets have the same PDCP sequence number.

Therefore, the second RAN device sends the downlink data packet to the first RAN device through the corresponding tunnel group, which can ensure that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In a possible implementation manner, the second RAN device sends packet retransmission information to the third RAN device, where the packet retransmission information includes transmission information of the at least one logical channel group, and the packet retransmission information is used to instruct the third RAN device to send downlink data to the first RAN device according to the packet retransmission information.

In one possible implementation, the transmission information of the at least one logical channel group includes at least one of the following information: a logical channel group identification of the at least one logical channel group, a logical channel group index of the at least one logical channel group, a tunnel group identification of at least one tunnel group corresponding to the at least one logical channel group, a tunnel group index of the at least one tunnel group, and a downlink tunneling layer address and TEID of the at least one tunnel group.

As can be seen, in the case that the second RAN device only executes the function of the control plane, the second RAN device instructs the third RAN device executing the user plane function to send a downlink data packet to the first RAN device through the corresponding tunnel group, so as to ensure that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In a fifth aspect, the present application provides an information delivery method for data packet repetition, including: the third radio access network RAN equipment receives first information sent by the first RAN equipment, wherein the first information comprises information of at least one logical channel in the first RAN equipment; the first information is used for indicating data packet repetition assistance information of the first RAN equipment; the third RAN device sends the first information to the second RAN device.

Therefore, the method provided by the embodiment of the present application enables the first RAN device to send the packet duplication auxiliary information to the second RAN device through the third RAN device at the granularity of the logical channel, so that the second RAN device can obtain richer information of the first RAN device, and can make a decision on packet duplication more effectively.

In a possible implementation manner, the third RAN device receives data packet retransmission information sent by the second RAN device, where the data packet retransmission information includes transmission information of the at least one logical channel, and the data packet retransmission information is used to instruct the third RAN device to send downlink data to the first RAN device according to the data packet retransmission information.

In one possible implementation, the third RAN apparatus sends the downlink data packet to the first RAN apparatus through the at least one tunnel. And in the case that the third RAN device sends downlink data packets to the first RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

Therefore, under the condition that the second RAN device only executes the function of the control plane, the third RAN device executing the function of the user plane receives the indication of the second RAN device, and sends the downlink data packet to the first RAN device through the corresponding tunnel, so that the corresponding RLC entity in the first RAN device can be ensured to correctly receive the data packet which needs to be repeated.

In a sixth aspect, the present application provides an information delivery method for data packet repetition, including: receiving, by a third radio access network RAN device, first information sent by a first RAN device, where the first information includes information of at least one logical channel group in the first RAN device, and the logical channel group includes at least one logical channel; the first information is used for indicating data packet repetition assistance information of the first RAN equipment; the third RAN device sends the first information to the second RAN device.

Therefore, the method provided by the embodiment of the present application enables the first RAN device to send the packet duplication auxiliary information to the second RAN device through the third RAN device at the granularity of the logical channel group, so that the second RAN device can obtain richer information of the first RAN device, and can make a decision on packet duplication more effectively. In addition, the auxiliary information is repeated by forming data packets with the granularity of the logical channel groups, so that the information overhead can be effectively reduced.

In a possible implementation manner, the third RAN device receives data packet retransmission information sent by the second RAN device, where the data packet retransmission information includes transmission information of the at least one logical channel group, and the data packet retransmission information is used to instruct the third RAN device to send downlink data to the first RAN device according to the data packet retransmission information.

In one possible implementation, the third RAN device sends the downlink data packet to the first RAN device through the at least one tunnel group. In the case that the third RAN device sends downlink data packets to the first RAN device through two tunnels of the at least one tunnel group, the downlink data packets have the same PDCP sequence number.

It can be seen that, under the condition that the second RAN device only executes the function of the control plane, the third RAN device executing the function of the user plane receives the indication of the second RAN device, and sends the downlink data packet to the first RAN device through the corresponding tunnel group, so as to ensure that the corresponding RLC entity in the first RAN device correctly receives the data packet that needs to be repeated.

In a seventh aspect, an access network RAN apparatus is provided for performing the method in the first aspect or any possible implementation manner of the first aspect, or any possible implementation manner of the second aspect, and in particular, the RAN apparatus may include means for performing the method in the first aspect or any possible implementation manner of the first aspect, or any possible implementation manner of the second aspect.

In an eighth aspect, another access network RAN apparatus is provided for performing the method in any possible implementation manner of the third aspect or the third aspect, or any possible implementation manner of the fourth aspect or the fourth aspect, and in particular, the RAN apparatus may include means for performing the method in any possible implementation manner of the third aspect or the third aspect, or any possible implementation manner of the fourth aspect or the fourth aspect.

A ninth aspect provides a further access network RAN apparatus for performing the method of any possible implementation manner of the fifth aspect or the fifth aspect, or any possible implementation manner of the sixth aspect or the sixth aspect, and in particular, the RAN apparatus may include means for performing the method of any possible implementation manner of the fifth aspect or the fifth aspect, or any possible implementation manner of the sixth aspect or the sixth aspect.

In a tenth aspect, there is provided a computer program product comprising: computer program code which, when run by a communication unit, a processing unit or a transceiver, a processor of a communication device (e.g. an access network device or a terminal device), causes the communication device to perform the method of the first to sixth aspect or any of the possible implementations of the first to sixth aspects.

In an eleventh aspect, there is provided a computer-readable storage medium storing a program for causing a computer to execute the method of the first to sixth aspects or any one of the possible implementations of the first to sixth aspects.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

Drawings

The drawings that accompany the detailed description can be briefly described as follows:

fig. 1 is a schematic diagram of a wireless communication system according to an embodiment of the present application;

fig. 2 is a schematic diagram of an architecture of a gNB divided into a CU and a DU according to an embodiment of the present disclosure;

fig. 3 is a schematic diagram of a protocol stack of a user plane layer 2 of a RAN device according to an embodiment of the present application;

fig. 4 is a schematic diagram of a user plane L2 protocol stack for packet repetition in a case that each RAN device has a carrier aggregation function in a dual connectivity scenario according to an embodiment of the present application;

fig. 5 is a schematic flowchart of an improved auxiliary information and a method for transferring the improved auxiliary information in a dual connectivity scenario according to an embodiment of the present application;

fig. 6 is a schematic diagram of a user plane layer 2 protocol stack for data packet repetition under a RAN device architecture divided into CUs and DUs according to an embodiment of the present application;

fig. 7 is a schematic flowchart of an improved auxiliary information and a method for delivering the improved auxiliary information in another dual-connectivity scenario provided by an embodiment of the present application;

fig. 8 is a schematic flowchart of an improved assistance information and a method for delivering the improved assistance information in a dual connectivity scenario provided by an embodiment of the present application;

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

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

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

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

fig. 13 is a schematic block diagram of a third network device provided in an embodiment of the present application;

fig. 14 is another schematic block diagram of a third network device provided in an embodiment of the present application.

Detailed Description

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

In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the invention. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and processes are not shown in detail to avoid obscuring the description of the invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The terms "system" and "network" are often used interchangeably herein.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

The technical solution of the embodiment of the present application can be applied to various wireless communication systems, for example: a Long Term Evolution (LTE) system, a fifth generation (5G) mobile communication system, a New Radio (NR) communication system, a Next Generation (NG) communication system, a future mobile communication system, and the like.

In a wireless communication system, a terminal device is connected to a Radio Access Network (RAN) device through a wireless link, and realizes communication with other terminal devices or access to a wireless internet, etc. through a Core Network (CN) device connected to the RAN device. Typically, a terminal device is wirelessly connected to a RAN device to enable communication. Further, one terminal device may also be wirelessly connected to two RAN devices to enable communication. Fig. 1 is a diagram illustrating a wireless communication system 100 according to an embodiment of the present application. The terminal device 120 is wirelessly connected to the RAN device 140 through an air interface 160. Optionally, the wireless communication system further includes the terminal device 120 wirelessly connecting with the RAN device 142 through the air interface 162. In this case, the RAN device 140 is referred to as a Master Node (MN), and the RAN device 142 is referred to as a Secondary Node (SN). The RAN device 140 implements transmission of User Plane (UP) data with the 5G core network (5G core,5GC)180 through an NG user plane (NG-U) interface, and implements transmission of Control Plane (CP) data with the 5GC through an NG control plane (NG-C) interface. The RAN device 142 enables transmission of user plane data with the 5GC device 180 through the NG-U interface. The RAN device 140 and the RAN device 142 implement interaction of control plane data through an Xn control plane (Xn-C) interface, and implement interaction of user plane data through an Xn user plane (Xn-U) interface. Illustratively, MN 140 is connected to an access and mobility management function (AMF) network element in 5GC180 through an NG-C interface, and MN 140 and SN 142 are respectively connected to a User Plane Function (UPF) network element in 5GC180 through an NG-U interface. Under the condition that the terminal device and the two RAN devices are in wireless connection, user plane data sent by the two RAN devices to the terminal device can be transmitted through a plurality of wireless links on an air interface, and each wireless link can transmit the same data packet, so that the reliability of data transmission is improved.

In an actual system, the RAN device shown in fig. 1 may be a next generation base station, such as a next-generation Node B (gNB) or a next-generation evolved Node B (ng-eNB), and may also be an Access Point (AP) in a Wireless Local Area Network (WLAN), an evolved Node B (eNB) or eNodeB in LTE, or a relay or an access point, or a vehicle-mounted device, a wearable device, and a Transmission and Reception Point (TRP). It should be understood that the terminal device communicates with the RAN device through transmission resources (e.g., frequency domain resources, time domain resources, code domain resources, etc.) used by one or more cells managed by the RAN device, where the cells may belong to a macro cell (macro cell), a super cell (super cell), or a small cell (small cell), where the small cell may include: urban cell (metro cell), micro cell (microcell), pico cell (pico cell), femto cell (femtocell), etc., which have the characteristics of small coverage and low transmission power, and are suitable for providing high-rate data transmission service. The terminal equipment in fig. 1 may also be referred to as User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device may be a Station (ST) in a WLAN, and may be a cellular phone, a cordless phone, a SIP phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a handheld device with wireless communication capability, a relay device, a computing device or other processing device coupled to a wireless modem, a vehicle-mounted device, a wearable device, and a next generation communication system, for example, a terminal device in a 5G network or a terminal device in a future evolved Public Land Mobile Network (PLMN) network, and so on. By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable equipment can also be called wearable intelligent equipment, is the general term of applying wearable technique to carry out intelligent design, develop the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

Generally, an air interface user plane protocol stack of a RAN device at least includes a packet data convergence layer protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Media Access Control (MAC) layer, and a Physical (PHY) layer; in the NR system, an air interface user plane protocol stack of the RAN device further includes a Service Data Adaptation Protocol (SDAP) layer, where the SDAP layer is an upper layer of the PDCP layer. An air interface control plane protocol stack of a RAN device includes a Radio Resource Control (RRC) layer, a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. It can be seen that the PDCP layer, the RLC layer, the MAC layer, and the PHY layer have both control plane and user plane functions. Accordingly, a terminal device also has an air interface user plane and control plane protocol stack corresponding to the RAN device.

Optionally, in the 5G system, one RAN device (e.g. the gNB) may be further divided into a Central Unit (CU) and a Distributed Unit (DU) according to a protocol stack, where the CU and the DU may be respectively deployed on different physical devices. The CU is responsible for the operation of the RRC layer, the SDAP layer, and the PDCP layer, and the DU is responsible for the operation of the RLC layer, the MAC layer, and the PHY layer. Fig. 2(a) shows an architecture of a gbb divided into CUs and DUs. A gNB may include a CU and one or more DUs controlled by the CU. One DU is connected to the CU via a control plane interface (e.g., F1-C) for transmitting control plane data; a DU is connected to the CU via a user plane interface (e.g., F1-U) for transmitting user plane data. Further, the CUs may be further divided into a centralized unit of the control plane (i.e. a centralized unit control plane CU-CP network element) and a centralized unit of the user plane (i.e. a centralized unit user plane CU-UP network element), wherein the CU-CP and the CU-UP may also be deployed on different physical devices, respectively, the CU-CP is responsible for handling of the control plane of the RRC layer and the PDCP layer, and the CU-UP is responsible for handling of the user plane of the SDAP layer and the PDCP layer. FIG. 2(b) shows an architecture of a gNB divided into CU-CP, CU-UP and DU. Wherein, a gNB may comprise a CU-CP, one or more CU-UP and one or more DU. One CP-UP is connected with only one CU-CP through a control plane interface (e.g., E1) for transmitting control plane data; one DU is connected to only one CU-CP through a control plane interface (e.g., F1-C) for transmitting control plane data; under the control of the CU-CP, a DU may be connected with one or more CU-UP, and a CU-UP may also be connected with one or more DU, and the CU-UP and DU are connected through a user plane interface (such as F1-U) for transmitting user plane data. It is worth mentioning that one DU or one CU-UP may also be connected to multiple CUs-CPs in order to keep the network resilient. At this time, the plurality of CU-CPs act as backups to each other; in practical applications, only one CU-CP is in operation at a time. It should be understood that, for the RAN device architecture divided into CUs and DUs, the protocol stack division manner according to which the RAN device divides the CUs and DUs is only exemplary, and the RAN device may also divide the CUs and DUs according to other division manners, for example, the CU may be responsible for the operations of the RRC layer, the SDAP layer, the PDCP layer, and the RLC layer, and the DU may be responsible for the operations of the MAC layer and the PHY layer; or the CU is responsible for the operations of the RRC layer and the SDAP layer, and the DU is responsible for the operations of the PDCP layer, the RLC layer, the MAC layer, and the PHY layer; similarly, the protocol stack partitioning between CU-CP and CU-UP in a CU is also variable; the application is not specifically limited thereto.

For ease of understanding, several concepts involved in the embodiments of the present application will be described first. It should be understood that the following conceptual explanations may be limited by the specific details of the embodiments of the present application, but do not represent that the present application is limited to only those specific details, and that the following conceptual explanations may also vary from one embodiment to another.

Packet repetition (packet repetition): data packet repetition is the transmission of the same data packet between the RAN device and the terminal device over two radio links. Generally, data transmission between the RAN equipment and the terminal equipment is based on radio bearers (DRBs), i.e. data bearers with similar quality of service (QoS) requirements will also be transmitted on one DRB. When a DRB is established, the RAN device and the terminal device configure a PDCP entity, an RLC entity, an MAC entity, and the like for the DRB. When the RAN device is to send a downlink data packet, the PDCP entity that processes the DRB carried by the downlink data packet allocates a PDCP sequence number to the downlink data packet, and includes the PDCP sequence number in a PDCP Protocol Data Unit (PDU) header and sends the PDCP sequence number to the RLC entity for processing. When data packets are repeated, the PDCP entity corresponding to the DRB should be configured with two RLC entities, and the PDCP entity sends two downlink data packets with the same PDCP sequence number to the two RLC entities corresponding to two Logical Channels (LCs), respectively, where the two RLC entities may be on one physical device or different physical devices. Then, the common MAC entity or the respective MAC entities corresponding to the two RLC entities schedule the downlink data packets having the same PDCP sequence number to a plurality of radio links for transmission to the terminal device. After receiving the downlink data packets through the plurality of radio links, the terminal device performs repeated detection by the PDCP entity. It should be understood that for packet repetition of one DRB, the terminal device also has two RLC entities and one PDCP entity for that DRB. Under one condition, if the terminal equipment correctly receives the PDCP PDU on one of the logic channels, the PDCP entity carries out subsequent processing such as data packet analysis on the received PDCP PDU; in another case, the terminal device correctly receives PDCP PDUs on both logical channels, the PDCP entity detects whether the PDCP sequence numbers of the two received PDCP PDUs are the same, if the PDCP PDUs with the same PDCP sequence numbers are received, one of the PDCP PDUs is reserved, and the PDCP entity performs subsequent processing such as data packet analysis on the reserved PDCP PDUs.

Carrier aggregation (carrier aggregation): carrier aggregation is that one RAN device communicates with a terminal device through multiple carriers, that is, downlink data between the RAN device and the terminal device can be transmitted on multiple wireless links through multiple carriers, respectively, so as to improve data transmission rate. One carrier may correspond to one cell, and when one RAN device communicates with a terminal device through multiple carriers, the RAN device correspondingly uses a group of cells, which may be referred to as a Cell Group (CG). The plurality of carriers and the bandwidth of each carrier used by the RAN device and the terminal device to communicate are determined by network configuration or by RAN device and terminal device negotiation. For transmission of a DRB in a carrier aggregation scenario, the RAN device configures a PDCP entity, an RLC entity, and a MAC entity for the DRB, and one RLC entity corresponds to one logical channel. The MAC entity schedules each downlink data packet in the downlink data of the logical channel to different carriers respectively and sends the downlink data packets to the terminal device, that is, the MAC entity schedules the downlink data of one logical channel to a plurality of carriers and sends the downlink data of the logical channel to the terminal device through a plurality of wireless links. For packet repetition in the carrier aggregation scenario, fig. 3(a) shows a protocol stack diagram of the user plane Layer 2(Layer 2, L2) of the RAN device. The RRC entity of the RAN device configures one PDCP entity, two RLC entities, and one MAC entity for one DRB. The PDCP entity corresponding to the DRB sends the PDCP PDUs with the same PDCP sequence numbers to two RLC entities, the PDCP PDUs are transmitted to an MAC entity through two logic channels, and then the MAC entity schedules downlink data packets with the same PDCP sequence numbers of the two logic channels to a plurality of carriers to be sent to the terminal equipment.

Double connection (dual connectivity): a dual connection is where the end device is in wireless communication with two RAN devices simultaneously (e.g., RAN device 140 and RAN device 142 in fig. 1). The two RAN devices may use the same Radio Access Technology (RAT), e.g., both use NR; different RATs may also be used, e.g. one using LTE technology and the other NR technology. Each RAN equipment manages a respective group of cells, each group of cells having at least one cell. Fig. 3(b) shows a schematic diagram of a user plane L2 protocol stack of a RAN device under dual connectivity. For one DRB, the RAN device corresponding to the CG1 has a PDCP entity corresponding to the DRB, which is also called a host PDCP entity, and the RAN device corresponding to the CG2 does not have a PDCP entity. Generally, a RAN device hosting a PDCP entity is referred to as a hosting PDCP entity node, and a RAN device without a PDCP entity is referred to as a corresponding (ciphering) node. In addition, the user plane L2 of the RAN device corresponding to CG1 further includes an RLC layer and a MAC layer; the user plane L2 of the RAN device to which the CG2 corresponds includes an RLC layer and a MAC layer, but does not include a PDCP layer. Illustratively, for one DRB, the managed PDCP entity node configures one RLC entity and one MAC entity for itself and the corresponding node, respectively. During downlink data transmission, the managed PDCP entity node sends part of downlink data of the DRB to the terminal equipment; in addition, the managed PDCP entity node sends another part of downlink data of the DRB to the corresponding node through a tunnel (tunnel) between the managed PDCP entity node and the corresponding node, and the corresponding node sends the another part of downlink data to the terminal device. In a dual-connection scenario, the managed PDCP entity node determines how downlink data for the DRB is allocated to the managed PDCP entity node and a corresponding node for transmission. The managed PDCP entity node can map a part of PDCP PDUs of the DRB to its own logical channel, map another part of PDCP PDUs of the DRB to a logical channel of a corresponding node, and schedule downlink data of the respective logical channels to respective radio links between the respective nodes and the terminal device for transmission by respective MAC entities of the managed PDCP entity node and the corresponding node. It should be noted that, during the process of establishing the dual connection, a tunnel is established between the node hosting the PDCP entity and the corresponding node so that the data of the DRB can be transmitted between the two nodes. Illustratively, the node hosting the PDCP entity sends uplink tunnel information (i.e., receiving endpoint information of the receiving endpoint of the tunnel as the hosting PDCP entity) to the corresponding node; the corresponding node sends the downlink tunnel information (i.e. the receiving endpoint information of the corresponding node as the receiving endpoint of the tunnel) to the managed PDCP entity node. For downlink data transmission, the managed PDCP entity node sends downlink data to the corresponding node according to the downlink tunnel information provided by the corresponding node; for uplink data transmission, the corresponding node sends uplink data to the managed PDCP entity node according to the uplink tunnel information provided by the managed PDCP entity node. The uplink tunnel information may be an uplink tunnel transport layer address and a Tunnel End Identifier (TEID) of the tunnel, an index of the tunnel, an identifier or Identity (ID) of the tunnel, or the like; accordingly, the downlink tunnel information may be a downlink tunneling layer address and TEID of the tunnel, an index of the tunnel, or an identification of the tunnel, etc. For data packet repetition under a double-connection scene, the PDCP entity of the managed PDCP entity node maps the data packets with the same PDCP sequence number to the logical channels of the managed PDCP entity node and the corresponding node, and the MAC entities of the respective nodes schedule the downlink data packets to respective radio links respectively for transmission to the terminal device.

It is worth noting that the terms RLC entity and logical channel are used interchangeably herein.

In the prior art, when data packet repetition is implemented in a dual-connection scenario, a corresponding node needs to provide auxiliary information to a managed PDCP entity node, so that the managed PDCP entity node can make a decision on how to perform data packet repetition. Specifically, the auxiliary information may be a suggestion of whether the corresponding node activates data packet repetition or wireless quality information of the corresponding node, and the like. The inventors have found that, in the case that the corresponding node has a carrier aggregation function, the corresponding node may configure multiple logical channels to further optimize the packet duplication, whereas the corresponding node in the prior art cannot provide enough assistance information for the PDCP entity node to make the decision of the packet duplication. Therefore, the embodiment of the application provides an improved auxiliary information and a technical scheme for transferring the auxiliary information. Further, the technical solution of the embodiment of the present application is also applied to a RAN device architecture having CUs and DUs, where CUs may also include a case where CU-CP and CU-UP are separated.

The following embodiments are specifically provided, and the technical solution of the present application is described in detail with reference to fig. 4 to 8. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. It should be understood that fig. 5, 7 and 8 are schematic flow charts of the communication method of the embodiment of the present application, showing detailed communication steps or operations of the method, but these steps or operations are merely examples, and the embodiment of the present application may also perform other operations or variations of the various operations in fig. 5, 7 and 8. Moreover, the various steps in fig. 5, 7, and 8 may be performed in a different order presented in fig. 5, 7, and 8, respectively, and it is possible that not all of the operations in fig. 5, 7, and 8 may be performed.

Fig. 4 is a schematic diagram of a user plane L2 protocol stack for packet repetition in a case that each RAN device has a carrier aggregation function in a dual connectivity scenario, where M is an integer greater than or equal to 1, and N is an integer greater than or equal to 2. The RAN device corresponding to the CG1 has a PDCP entity, that is, is a node hosting the PDCP entity, and the RAN device corresponding to the CG2 is a corresponding node. It is noted that, unlike fig. 3(b), a plurality of RLC entities are configured in the corresponding node for one DRB. Correspondingly, a plurality of tunnels are established between the managed PDCP entity node and the corresponding node, wherein the RLC entities and the tunnels are in a one-to-one correspondence relationship, that is, the number of the tunnels between the managed PDCP entity node and the corresponding node is the same as the number of the RLC entities of the corresponding node. In a possible implementation manner, a managed PDCP entity node configures a plurality of RLC entities of a corresponding node through control plane signaling of an Xn-C interface; the method comprises the steps that a managed PDCP entity node sends information of a plurality of uplink tunnels to a corresponding node, and the corresponding node sends the information of a plurality of corresponding downlink tunnels to the managed PDCP entity node; wherein the number of RLC entities or tunnels of the corresponding node is determined by the hosting PDCP entity node. In another possible implementation manner, the managed PDCP entity node corresponding to the DRB notifies the corresponding node of the maximum number of RLC entities or tunnels that the corresponding node allows to establish through control plane signaling of the Xn-C interface, and the corresponding node determines the number of RLC entities or tunnels by itself accordingly and sends corresponding downlink tunnel information to the managed PDCP entity node. The number of RLC entities or tunnels of the corresponding node is not particularly limited herein. Optionally, the configuration of the RLC entity or the tunnel of the corresponding node by the PDCP entity node is carried on a secondary node addition requirement (SN addition requirement) message or a secondary node modification requirement (SN modification requirement) message.

Fig. 5 shows a flowchart of auxiliary information in a dual connectivity scenario and a method for transferring the auxiliary information according to an embodiment of the present application. The method 500 may be applied to information interaction between MN 140 and SN 142 shown in fig. 1. Wherein, when the MN is a managed PDCP entity node, the SN is a corresponding node; when the SN is a managed PDCP entity node, the MN is a correspondent node. The process illustrated in FIG. 5 includes the following steps:

501. the corresponding node determines the packet repetition assistance information.

The packet repetition assistance information includes information of at least one logical channel of the corresponding node, and the packet repetition assistance information is used for assisting the managed PDCP entity node in making a packet repetition decision. The information of the at least one logical channel may be at least one logical channel for which the activation packet proposed by the corresponding node is repeated, or may be radio quality assistance information of the at least one logical channel for the corresponding node, or may be at least one logical channel for which the activation packet proposed by the corresponding node is repeated and radio quality assistance information corresponding to the at least one logical channel, or may be any other combination of the at least one logical channel for which the activation packet proposed by the corresponding node is repeated and the radio quality assistance information corresponding to the at least one logical channel. Illustratively, for one DRB, three RLC entities RLC1, RLC2 and RLC3 (corresponding to three logical channels: LC1, LC2 and LC3) are configured in the corresponding node, i.e. there are three tunnels between the node hosting the PDCP entity and the corresponding node, corresponding to LC1, LC2 and LC3 being a first tunnel, a second tunnel and a third tunnel, respectively. The logical channel of the activation packet repetition may be any one of LC1 to LC3, or any two of LC1 to LC3, or LC1 to LC 3. In one possible implementation, the packet repetition assistance information may include a logical channel identifier or a logical channel index of a logical channel for which the corresponding node proposes to activate packet repetition. It should be noted that, since one logical channel corresponds to one tunnel, the packet repetition assistance information may include information of at least one downlink tunnel that the corresponding node proposes to activate packet repetition. Specifically, the packet repetition assistance information may include at least one tunnel identifier, or at least one tunnel index, or a transport layer address and TEID of at least one downlink tunnel that the corresponding node proposes to activate packet repetition. For example, when the corresponding node suggests to activate packet duplication of LC1 and LC3, the packet duplication assistance information may include the first tunnel identification and the third tunnel identification, or the first tunnel index and the third tunnel index, or the transport layer address and TEID of the first downlink tunnel and the transport layer address and TEID of the third downlink tunnel. It should be understood that the information indicating the tunnel in which manner may be determined by negotiation between the managed PDCP entity node and the corresponding node, may also be defined by the 3GPP standard, and may also be configured by the network management system, which is not specifically limited herein. In another possible implementation, the packet repetition assistance information may include wireless quality assistance information of some or all of the logical channels in the LCs 1-3 of the corresponding node. The radio quality assistance information of one of the logical channels may be at least one of a downlink radio quality index (DL radio quality index), an uplink radio quality index (UL radio quality index), an average CQI, an average HARQ failure, an average HARQ retransmission, and a Power Headroom Report (PHR). In yet another possible implementation, the packet repetition assistance information may include logical channels (e.g., LC1 and LC2) for which the corresponding node proposes to activate packet repetition, and wireless quality assistance information for each of these logical channels (LC1 and LC 2). It should be understood that if the downlink tunnel information is used to indicate the packet repetition side information, the radio quality side information of one logical channel is the radio quality side information of the logical channel corresponding to one tunnel.

502. The corresponding node sends the data packet repetition assistance information to the managed PDCP entity node. Accordingly, the managed PDCP entity node receives the data packet repetition auxiliary information sent by the corresponding node.

In this step, the correspondent node provides the packet duplication assistance information to the managed PDCP entity node using an assistance information forwarding procedure. The auxiliary information forwarding process is used for the corresponding node to provide auxiliary information to the managed PDCP entity node, so that the managed PDCP entity node can be used for management and optimization of a user plane. Illustratively, the corresponding node sends the packet repetition assistance information to the managed PDCP entity node through NR user plane protocol frames. The NR user plane protocol frame format specified in the current 3GPP standard may be referred to the 3GPP ts38.425v15.4.0 technical specification. Table 1 gives the NR user plane protocol frame format of the side information data in the technical specification. In the technical specification, the corresponding node has a logical channel, and auxiliary information such as whether to activate the logical channel of the corresponding node or radio quality auxiliary information of the logical channel can be provided for the managed PDCP entity node.

Table 13 GPP3GPP ts38.425v15.4.0 NR user plane protocol frame format for side information data

Wherein the value of the PDU type field is 2, which indicates that the NR user plane protocol data is used to represent the auxiliary information data. The "PDCP repetition Indication (PDCP repetition Indication)" field is used to identify whether the "PDCP repetition Activation proposal (PDCP repetition Activation completion)" field exists. If the value of the PDCP repeat indication field is 0, the PDCP repeat activation suggestion field does not exist; the PDCP repeat indication field takes a value of 1 to indicate that the PDCP repeat activation proposal field exists. The "Assistance Information Indication" Field is used to identify whether or not the "Number of Assistance Information Field" Field exists. If the value of the auxiliary information indication field is 0, indicating that no auxiliary information field number field exists; the value of the "auxiliary information indication" field is 1, indicating that the "number of auxiliary information fields" field exists. The "spare" field is typically taken to be 0, for reservation to be used by subsequent versions. The "PDCP repetition activation proposal" field is used to identify whether the corresponding node activates PDCP repetition. If the field of the PDCP repeated activation suggestion is 0, the PDCP repeated activation is not activated; the PDCP repetition activation proposal field takes a value of 1 to indicate activation of PDCP repetition. The "auxiliary information field number" field is used to indicate the number of the "auxiliary information Type (assistance information Type)" field and the concatenated "Radio Quality assistance information (Radio Quality assistance information)" field; the "assistance information type" field is used to describe the type of radio quality assistance information provided by the corresponding node to the managed NR PDCP entity node. Wherein, the downlink Radio quality index (DL Radio quality index) is a numerical index for indicating the downlink DRB Radio quality, where a value of 0 represents the lowest quality; an uplink Radio Quality Index (UL Radio Quality Index) is a numerical Index for indicating the uplink DRB Radio Quality, where a value of 0 represents the lowest Quality; the average CQI, average HARQ failure, and average window of average HARQ retransmission are set by configuration; the power headroom report is a reported PHR MAC CE defined by the 3GPP standard specification. The "number of radio quality assistance information fields" field is used to indicate the number of bytes needed to be used by the radio quality assistance information field. For average CQI, average HARQ failure, average HARQ retransmission, downlink radio quality index, and uplink radio quality index, this field should be indicated as "1"; for power headroom reporting, this field should indicate the number of bytes used for power headroom reporting. The "wireless quality assistance information" field is used to indicate one item of assistance information indicated by the type of assistance information. It should be understood that the auxiliary information data in table 1 is data of packet repetition auxiliary information in the embodiment of the present application, and the PDCP repetition in table 1 is data packet repetition in the embodiment of the present application.

In the embodiment of the present application, the corresponding node has a plurality of logical channels, and thus, in the assistance information data, the corresponding node may indicate not only whether to activate PDCP duplication, but also which logical channel or channels to activate. As in the above example, the corresponding node may indicate whether to activate any combination of packet duplication in LC1, LC2, and LC 3. For this reason, the 1-bit length of the "PDCP repeated activation proposal" field in table 1 is not adapted any more. In the embodiment of the present application, the length of the "PDCP repetition activation proposal" field may be set according to the number of logical channels of the corresponding node. Similarly, in the "wireless quality assistance information" field, the corresponding node may also indicate wireless quality assistance information of different logical channels. To this end, the wireless quality assistance information for one assistance information type in table 1 may be wireless quality assistance information of one or more logical channels under the assistance information type. As in the above example, the corresponding node may indicate the wireless quality assistance information of each of LC1, LC2, and LC3 whose assistance information type is "downlink wireless quality index".

Illustratively, table 2 shows the NR user plane protocol frame format of the side information data according to the embodiment of the present application. As in the above example, when the packet repetition assistance information is at least one logical channel corresponding to an activation packet repetition proposed by the node, in one possible implementation, the length of the "PDCP repetition activation proposal" field may be set to 2 bits (as shown in table 2), for example, when the field takes a value of 00, the activation LC1 is instructed to perform PDCP repetition; when the field is 01, indicating that the LC2 is recommended to be activated for PDCP repetition; when this field takes the value 10, it indicates that the LC3 is recommended to be activated for PDCP repetition. Or when the field takes a value of 00, indicating that the first tunnel is recommended to be activated for PDCP repetition; when the field is 01, indicating that the second tunnel is recommended to be activated for PDCP repetition; when this field takes the value 10, it indicates that it is recommended to activate the third tunnel for PDCP repetition. In another possible implementation, the length of the "PDCP repetition activation proposal" field may be set to 3 bits, for example, when the field takes a value of 001, it indicates that the activation LC1 is proposed to perform PDCP repetition; when the field takes a value of 010, indicating that the LC2 is recommended to be activated for PDCP repetition; when the field takes a value of 100, indicating that the LC3 is recommended to be activated for PDCP repetition; when the field is 011, indicating that LC1 and LC2 are recommended to be activated for PDCP repetition; when the field takes the value of 110, indicating that LC2 and LC3 are recommended to be activated for PDCP repetition; when the field is 101, indicating that LC1 and LC3 are recommended to be activated for PDCP repetition; when the field takes the value of 111, it indicates that LC 1-LC 3 are recommended to be activated for PDCP repetition. Or when the field takes a value of 001, indicating that the first tunnel is recommended to be activated for PDCP repetition; when the field value is 010, indicating that the second tunnel is recommended to be activated for PDCP repetition; when the field takes a value of 100, indicating that the third tunnel is recommended to be activated for PDCP repetition; when the field is 011, indicating to recommend to activate the first tunnel and the second tunnel for PDCP repetition; when the field is 110, indicating that the second tunnel and the third tunnel are recommended to be activated for PDCP repetition; when the field is 101, indicating that the first tunnel and the third tunnel are recommended to be activated for PDCP repetition; and when the field is 111, indicating that the first tunnel to the third tunnel are recommended to be activated for PDCP repetition. When the packet repetition assistance information is wireless quality assistance information of at least one logical channel of the corresponding node, as an example, the "wireless quality assistance information" field may contain wireless quality assistance information of LC1, or wireless quality assistance information of LC2, or wireless quality assistance information of LC3, or wireless quality assistance information of LC1 and LC2, or wireless quality assistance information of LC1 and LC3, or wireless quality assistance information of LC2 and LC3, or wireless quality assistance information of LC1 to LC3 for any one type of assistance information. When the packet repetition assistance information is at least one logical channel which is proposed by the corresponding node and activates packet repetition and the radio quality assistance information corresponding to the at least one logical channel, as an example, the "PDCP repetition activation proposal" field takes a value of 010, which indicates that the LC2 is activated for PDCP repetition, and the "radio quality assistance information" field contains the radio quality assistance information of the LC 2; or, the activation of the second tunnel for PDCP repetition is indicated, and the "radio quality assistance information" field contains radio quality assistance information of a logical channel corresponding to the second tunnel. As another example, the "PDCP repetition activation proposal" field takes value 110, indicating that LCs 2 and LC3 are activated for PDCP repetition, and the "radio quality assistance information" field contains the radio quality assistance information of LCs 2 and 3; or, the activation of the second tunnel and the third tunnel for PDCP repetition is indicated, and the "radio quality assistance information" field contains radio quality assistance information of logical channels corresponding to the second tunnel and the third tunnel, respectively. It should be noted that the radio quality auxiliary information of a logical channel may be radio quality auxiliary information obtained by performing mathematical operation (such as taking an arithmetic average or a weighted average) on the radio quality auxiliary information of each carrier corresponding to the logical channel group; the radio quality assistance information of one logical channel may also be unprocessed radio quality assistance information of each carrier corresponding to the logical channel.

Optionally, the correspondence between various values of the "PDCP duplicate activation proposal" field and the logical channel or tunnel is carried on a secondary node addition requirement (SN addition requirement) message or a secondary node modification requirement (SNmodification requirement) message.

Table 2 NR user plane protocol frame format of auxiliary information data according to an embodiment of the present application

Optionally, the corresponding node sends the packet repetition assistance information to the managed PDCP entity node through the assistance information data of the Xn-U interface.

Optionally, before step 501, the correspondent node also acquires its logical channel packet. The logical channel grouping is to divide the logical channels of the corresponding nodes into a plurality of groups, wherein one Logical Channel Group (LCG) includes one or more logical channels. It should be noted that one logical channel corresponds to one RLC entity, and thus one logical channel group corresponds to one or more RLC entities, i.e., a group of RLC entities. In a possible implementation manner, the managed PDCP entity node groups the logical channels of the corresponding nodes and notifies the corresponding nodes of the grouping condition; the corresponding node can store and use the logic channel grouping information after obtaining the logic channel grouping information. In another possible implementation manner, the corresponding node groups its own logical channel and notifies the managed PDCP entity node of the grouping situation; the managed PDCP entity node can store and use the logic channel grouping information after acquiring the logic channel grouping information. There are many ways in which logical channels may be grouped, and in one possible implementation, an LCG is any combination of LCs for a corresponding node. Illustratively, corresponding nodes are provided with LC1, LC2 and LC3, logical channels of which can be divided into four groups, and particularly, LCG1 comprises LC1 and LC2, LCG2 comprises LC2 and LC3, LCG3 comprises LC1 and LC3, and LCG4 comprises LC1 to LC 3. In another possible implementation, an LCG may be any combination of a particular LC and other LCs of a corresponding node. In other words, in this manner, any one LCG will always contain the particular LC of the corresponding node, which may also be referred to as primary LC. In the above example, in the case where LC1 is a master LC, its logical channels may be divided into three groups, specifically, LCG1 includes LC1 and LC2, LCG2 includes LC1 and LC3, and LCG3 includes LC1 to LC 3. It is worth noting that the master LC may be determined by the hosting PDCP entity node or the corresponding node, and the master LC may contain a plurality of LCs. For example, the managed PDCP entity node sets LC1 and LC2 as master LCs, and its logical channels may be divided into two groups, specifically, LCG1 includes LC1 and LC2, and LCG2 includes LC1 to LC 3. Tables 3 and 4 show the logical channel grouping information sent to the corresponding node after the managed PDCP entity node determines the logical channel grouping of the corresponding node, or the logical channel grouping information sent to the managed PDCP entity node after the corresponding node determines the logical channel grouping of the corresponding node. Optionally, the logical channel packet information is carried on a secondary node addition requirement (SN addition requirement) message or a secondary node modification requirement (SNmodification requirement) message.

TABLE 3 logical channel grouping information

>DRB ID
	>LCID grouping list
>>LCG1 ID
	>>>LC1 ID,LC2 ID
>>LCG2 ID
	>>>LC2 ID,LC3 ID
>>LCG3ID
	>>>LC1 ID,LC3 ID
…

Table 4 logical channel grouping information with main logical channel

>DRB ID
	>LCID grouping list
>>LCG1ID
	>>>LC1 ID,LC2 ID
>>LCG2ID
	>>>LC1 ID,LC3 ID
>>LCG3ID
	>>>LC1 ID,LC2 ID,LC3 ID
…

Wherein, the DRB ID represents an identity of a DRB served by the corresponding node. The LCID grouping list represents a logical channel group identification list, which contains a plurality of logical channel group identifications (LCG IDs). In the case where the corresponding node will have three logical channels, table 3 gives an illustration of dividing the logical channels of the corresponding node into three logical channel groups. Wherein, LCG1 ID identifies LCG1 consisting of LC1 and LC2, LCG2 ID identifies LCG2 consisting of LC2 and LC3, and LCG3 ID identifies LCG3 consisting of LC1 and LC 3. In the case where the corresponding node has a primary logical channel (e.g., LC1), table 4 gives an illustration of dividing the logical channels of the corresponding node into three logical channel groups. LCG1 ID identifies LCG1 consisting of LC1 and LC2, LCG2 ID identifies LCG2 consisting of LC1 and LC3, and LCG3 ID identifies LCG3 consisting of LC1, LC2, and LC 3.

It should be noted that, in the case that the corresponding node has a logical channel group, in step 501, the packet repetition assistance information generated by the corresponding node is granular with the logical channel group. Illustratively, the packet repetition assistance information may be at least one logical channel group for which the activation packet repetition proposed by the corresponding node is performed, wireless quality assistance information for each of some or all of the logical channel groups of the corresponding node, or at least one logical channel group for which the activation packet repetition proposed by the corresponding node is performed and wireless quality assistance information corresponding to the at least one logical channel group. The radio quality auxiliary information of a logical channel group may be radio quality auxiliary information obtained by performing mathematical operation (such as taking an arithmetic average or a weighted average) on the radio quality auxiliary information of each logical channel in the logical channel group; the radio quality assistance information for a logical channel group may also be unprocessed radio quality assistance information for individual logical channels in the logical channel group. Accordingly, in step 502, the data packet repetition assistance information sent by the corresponding node is also granular in terms of logical channel group.

It is worth noting that, since one logical channel corresponds to one tunnel, the corresponding node can also acquire its tunnel packet before step 501. Similar to the logical channel group-to-logical channel correspondence, a tunnel group may contain one or more tunnels. The tunnel packet information may be carried on a secondary node addition demand (SN addition demand) message or a secondary node modification demand (SN modification demand) message. In one possible implementation, a tunnel group is any combination of tunnels. In another possible implementation, a tunnel group may be any combination of a particular tunnel and other tunnels. Under the condition of Tunnel grouping, the table 3 and the table 4 correspond to Tunnel grouping information, wherein an LCID grouping list corresponds to a Tunnel ID grouping list and represents a Tunnel group identification list; and corresponding to any one tunnel group identifier in the list, the downlink tunnel information of each tunnel included in the tunnel group is included, such as the tunnel identifier of each tunnel, or the tunnel index of each tunnel, or the transport layer address and TEID of each downlink tunnel.

Because one logical channel group comprises one or more logical channels, the data packet repetition auxiliary information with the logical channel group or the tunnel group as the granularity can effectively reduce the data volume of the auxiliary information and reduce the information overhead.

503. The managed PDCP entity node decides packet repetition.

The managed PDCP entity node receives the packet repetition assistance information sent by the corresponding node, and may decide packet repetition in accordance with the conditions of the managed PDCP entity node (e.g., the radio quality of each logical channel of the managed PDCP entity node, the load of the managed PDCP entity node, etc.). Specifically, the managed PDCP entity node decides to activate at least two logical channels for packet repetition. The at least two logical channels may be composed of logical channels of the managed PDCP entity node, or of logical channels of the corresponding node, or of logical channels of both the managed PDCP entity node and the corresponding node. Illustratively, the managed PDCP entity node activates at least one logic channel of the managed PDCP entity node and at least one logic channel of the corresponding node for data packet repetition according to the data packet repetition suggestion of the corresponding node and the self condition decision; or the managed PDCP entity node decides to activate a plurality of logic channels of the corresponding node for data packet repetition according to the wireless quality auxiliary information of the plurality of logic channels of the corresponding node; or the managed PDCP entity node only activates a plurality of self logic channels to repeat the data packet according to the data packet repetition auxiliary information decision of the corresponding node, and the like. Similarly, if the information of the tunnel is included in the packet repetition assistance information, the managed PDCP entity node decides whether to activate the tunnel with the corresponding node or activate several tunnels with the corresponding node for packet repetition.

Through the steps of the embodiment of the application, the corresponding node sends the data packet repetition auxiliary information to the managed PDCP entity node at the granularity of the logic channel, so that the auxiliary managed PDCP entity node can effectively make the decision of data packet repetition. For example, the managed PDCP entity node may decide to activate multiple logical channels of the corresponding node for packet repetition according to the packet repetition assistance information.

Optionally, the embodiment of the present application further includes step 504.

504. And the managed PDCP entity node sends a downlink data packet to the corresponding node through at least one tunnel.

In this step, when the managed PDCP entity node decides to activate at least one logical channel of the corresponding node for packet repetition, the managed PDCP entity node sends a downlink packet to the corresponding node through at least one tunnel corresponding to the at least one logical channel, so that the corresponding node can schedule the downlink packet on the corresponding at least one logical channel to at least one radio link and send the downlink packet to the terminal device. Illustratively, the hosting PDCP entity node, when configuring the DRB, configures LH1 and LH2 of the hosting PDCP entity node and LH3 and LH4 of the corresponding node, and configures two tunnels between the hosting PDCP entity node and the corresponding node corresponding to LH3 and LH4, such as a first tunnel and a second tunnel, where the first tunnel corresponds to LH3 and the second tunnel corresponds to LH 4. Accordingly, if the hosting PDCP entity node decides to activate its LH1 and the LH3 of the corresponding node for packet repetition in step 503, the hosting PDCP entity node transmits a downlink packet to the corresponding node through the first tunnel in this step. In addition, the managed PDCP entity node also transmits the downlink packet to its RLC 1. If the managed PDCP entity node decides to activate LH3 and LH4 of the corresponding node for packet repetition in step 503, the managed PDCP entity node transmits downlink packets having the same PDCP sequence number to the corresponding node through the first tunnel and the second tunnel, respectively, in this step. Similarly, if the managed PDCP entity node decides to activate its at least one tunnel with the corresponding node for packet repetition in step 503 above, the managed PDCP entity node sends the downlink packet to the corresponding node through the at least one tunnel in this step.

Through the steps, the managed PDCP entity node sends the downlink data packet to the corresponding node through the corresponding tunnel according to the decision of data packet repetition, and the corresponding RLC entity in the corresponding node correctly receives the downlink data packet, so that the corresponding node can correctly repeat the data packet.

Further, the wireless communication system shown in fig. 1 may also include a terminal device wirelessly connected to three or more RAN devices, which may also be referred to as multi-connection. It should be understood that when the terminal device is wirelessly connected to three or more RAN devices, one of the RAN devices is the MN and the other RAN devices are SNs. The MN realizes the transmission of control plane data and user plane data of the 5GC equipment through NG-C and NG-U interfaces respectively, the SN realizes the transmission of the user plane data of the 5GC equipment through the NG-U interface, and the MN and the SN can realize the transmission of the control plane data and the user plane data through Xn-C and Xn-U interfaces respectively. In this case, one RAN device is a managed PDCP entity node, and the other RAN devices are correspondent nodes. For one DRB, a plurality of RLC entities are configured in part or all of the corresponding nodes. In the case that multiple corresponding nodes exist, the method flow shown in fig. 5 is applicable to the interaction between each corresponding node configured with multiple RLC entities and the node hosting the PDCP entity. The managed PDCP entity node acquires the data packet repetition auxiliary information of a plurality of corresponding nodes, and can further optimize the decision of data packet repetition, such as activating a proper logical link with greater freedom degree to repeat the data packet and the like.

In the architecture that the RAN device is divided into CUs and DUs according to the protocol stack, for one DRB, a CU includes a PDCP entity corresponding to the DRB. In order to implement packet repetition, the DU needs to send packet repetition assistance information to the CUs, and the CU decides packet repetition. Fig. 6 shows a schematic diagram of a user plane L2 protocol stack for packet repetition under a RAN device architecture divided into CUs and DUs according to an embodiment of the present application. Wherein, fig. 6(a) shows a case where the RAN device is composed of one CU and one DU, where L is an integer greater than 2; fig. 6(b) shows a case where the RAN device is composed of one CU and two DUs, where P is an integer greater than or equal to 2 and Q is an integer greater than or equal to 2. It should be understood that for one DRB, a plurality of RLC entities are configured in the DU. Accordingly, a plurality of tunnels are established between the CU and one DU, and the number of tunnels is the same as the number of RLC entities of one DU. In one possible implementation, CU configures DU multiple RLC entities through control plane signaling of F1-C interface; the CU sends information of a plurality of uplink tunnels to the DU, and the DU sends the information of a plurality of corresponding downlink tunnels to the CU; wherein the number of RLC entities or tunnels of the DU is determined by the CU. In another possible implementation, the CU informs the DU of the maximum number of RLC entities or tunnels it allows to establish through control plane signaling of the F1-C interface, and the DU determines the number of RLC entities or tunnels by itself and sends corresponding downlink tunnel information to the CU. The number of RLC entities of the DU is not particularly limited herein. Optionally, the configuration of the RLC entity or tunnel of the DU by the CU is carried on a terminal device context setup request (UE context setup request) message or a terminal device context modification request (UE context modification request) message.

Fig. 7 is a schematic diagram illustrating a flow of an improved assistance information and its delivery method under a RAN device architecture divided into CUs and DUs according to an embodiment of the present application. The method 700 may be applied to the scenarios of fig. 6(a) or fig. 6 (b). It should be understood that the CU in fig. 7 is similar to the hosting PDCP entity node in fig. 5 and the DU in fig. 7 is similar to the corresponding node in fig. 5. The process illustrated in FIG. 7 includes the following steps:

701. the DU determines packet duplication assistance information.

In this step, the DU, which may be any one of the DUs in fig. 6(a) or fig. 6(b), determines the packet repetition assistance information.

The data packet repetition auxiliary information determined by the DU is similar to the data packet repetition auxiliary information determined by the corresponding node in step 501 in the foregoing embodiment, and is not described herein again.

702. The DU sends packet repetition side information to the CUs. Accordingly, the CU receives the packet repetition side information transmitted by the DU.

This step is similar to step 502 of the previous embodiment and will not be described again.

Alternatively, the DU sends packet repetition side information to the CUs via side information data of the F1-U interface.

Optionally, before step 701, the DU also acquires its logical channel packets or tunnel packets. In a possible implementation manner, a CU groups a logical channel of a DU or a tunnel between the CU and the DU, and notifies the DU of the grouping situation; the DU may obtain the packet information and then save it for subsequent use. In another possible implementation, the DU groups its own logical channels or tunnels between itself and the CUs, and notifies the CUs of the grouping; the CU may obtain the packet information and then save it for subsequent use.

Alternatively, the logical channel packet information or the tunnel packet information may be carried on a terminal device context setup request (UE context setup request) message or a terminal device context modification request (UE context modification request) message.

It should be understood that, similar to the foregoing embodiment, in the case that there exists a logical channel packet or a tunnel packet in the DU, in step 701, the data packet repetition assistance information generated by the DU is granular in the logical channel group or the tunnel group; in step 702, the packet repetition assistance information sent by the DU is also granular in terms of logical channel groups or tunnel groups.

703. The CU decides packet repetition.

In this step, the CU decides packet repetition according to the received packet repetition assistance information sent by the DU. In a scenario that a CU connects a DU, the CU activates at least two logical channels proposed by the DU for packet repetition according to a packet repetition proposal decision of the DU, for example; or the CU decides to activate at least two logical channels of the DU for data packet repetition according to the plurality of logical channel wireless quality auxiliary information of the DU, and the like. In a scenario where a CU connects two DUs, the CU activates some or all logical channels in any one DU or two DUs for packet repetition according to a packet repetition proposal decision of the two DUs, for example; or the CU decides to activate some or all logical channels in any DU for packet repetition according to multiple logical channel wireless quality side information of the two DUs, and so on.

Through the steps of the embodiment of the application, the DU is used for sending the data packet repetition auxiliary information to the CU in the granularity of the logical channel, so that the CU can effectively make the decision of data packet repetition. For example, a CU may decide to activate multiple logical channels of at least one DU for packet repetition based on packet repetition assistance information.

Optionally, this embodiment of the present application further includes step 704.

704. The CU sends downstream packets to the DU through at least one tunnel.

In this step, when the CU decides to activate at least one logical channel of a DU for packet repetition, the CU sends a downlink packet to the DU through at least one tunnel corresponding to the at least one logical channel, so that the DU can schedule the downlink packet on the corresponding at least one logical channel to at least one wireless link for sending to the terminal device. Illustratively, in a scenario where a CU is connected to a DU, when configuring a DRB, the CU configures the DRB in LH1, LH2, and LH3 of the DU, and configures three tunnels between the CU and the DU corresponding to LH1 to LH3, such as a first tunnel, a second tunnel, and a third tunnel, where the first tunnel corresponds to LH1, the second tunnel corresponds to LH2, and the third tunnel corresponds to LH 3. Accordingly, if the CU decides to activate LH1 and LH3 of the DU for packet duplication in step 703, the CU sends a downlink packet with the same PDCP sequence number to the DU through the first tunnel and the third tunnel in this step. In a scenario where a CU connects two DUs, when configuring a DRB, the CU configures LH1 and LH2 of the DRB at DU1 and LH3 and LH4 of DU2, and configures four tunnels between the CU and the two DUs corresponding to LH1 to LH4, such as a first tunnel, a second tunnel, a third tunnel and a fourth tunnel, where the first tunnel corresponds to LH1, the second tunnel corresponds to LH2, and so on. Accordingly, if the CU decides to activate LH1 of DU1 and LH3 and LH4 of DU2 for packet duplication in step 703, the CU sends a downlink packet with the same PDCP sequence number to DU1 through the first tunnel and to DU2 through the third tunnel and the fourth tunnel, respectively, in this step.

Through the steps, the CU sends the downlink data packet to at least one DU through the corresponding tunnel according to the decision of data packet repetition, and the corresponding RLC entity in the at least one DU correctly receives the downlink data packet, so that the at least one DU can correctly repeat the data packet.

Further, one RAN device may also be composed of one CU and three or more DUs. In this case, the method flow shown in fig. 7 also applies to the interaction between the respective DU and CU. The CU obtains packet repetition assistance information of three or more DUs, and can further optimize the decision of packet repetition, such as activating a suitable logical link with a greater degree of freedom to perform packet repetition.

In the architecture where the RAN device is divided into CUs and DUs by protocol stack, further, CUs are divided into one CU-CP and one or more CU-UPs. For a DRB, the CU-CP contains the control plane entity in the CU that handles the DRB, and the CU-UP contains the user plane entity in the CU that handles the DRB. Thus, for the user plane, the L2 protocol stack of the present scenario is similar to fig. 6, except that the CU in fig. 6 becomes CU-UP. Since the CU-UP has only user plane functions, the DU and CU-UP also need to be connected to and provide control plane functions by the CU-CP. In order to implement packet duplication, the DU needs to send auxiliary information to the CU-UP, and to the CU-CP by the CU-UP, and then the CU-CP decides packet duplication. It should be understood that for one DRB, a plurality of RLC entities are configured in the DU. Accordingly, a plurality of tunnels are established between one CU-UP and one DU, and the number of tunnels is the same as the number of RLC entities of the DU. In one possible implementation, the CU-CP configures a plurality of RLC entities of the DU through control plane signaling of the F1-C interface and informs a configuration result to a CU-UP to which the DU is connected through control plane signaling of the E1 interface; the CU-CP transmits information of a plurality of uplink tunnels of the CU-UP to the DU, and transmits information of a plurality of downlink tunnels of the DU to the CU-UP. Wherein the number of RLC entities or tunnels of the DU is determined by the CU-CP. In another possible implementation, the CU-CP informs the DU of the maximum number of RLC entities or tunnels it allows to establish through control plane signaling of the F1-C interface, determines the number of RLC entities or tunnels by itself by the DU, and sends corresponding downlink tunnel information to the CU-UP. The number of RLC entities of the DU is not particularly limited herein. Optionally, the configuration of the CU-CP at the RLC entity of the DU is carried on a terminal device context setup request (UE context setup request) message or a terminal device context modification request (UE context modification request) message.

Fig. 8 is a schematic diagram illustrating a method for delivering supplementary information under RAN device architecture divided into CU-CP, CU-UP and DU according to an embodiment of the present application. The method 800 is applicable to the RAN device architecture corresponding to fig. 2(b), where one DU is connected to one CU-UP, the CU-UP is connected to the CU-CP, and the DU is also connected to the CU-CP. The process illustrated in FIG. 8 includes the following steps:

801. the DU determines packet duplication assistance information.

The data packet repetition auxiliary information determined by the DU is similar to the data packet repetition auxiliary information determined by the DU in step 701 of the foregoing embodiment, and is not described herein again.

802. The DU sends packet repetition side information to the CU-UP. Accordingly, the CU-UP receives the packet repetition assistance information sent by the DU.

This step is similar to step 702 of the previous embodiment and will not be described again.

Alternatively, the DU may transmit packet repetition side information to the CU-UP via side information data of the F1-U interface.

Optionally, before step 801, the DU also acquires its logical channel packets or tunnel packets. In one possible implementation, the CU-CP groups logical channels of the DUs or tunnels between the CU-UP and the DUs and informs the CU-UP and the DUs of the grouping situation; the CU-UP and DU may obtain the packet information and then save it for later use. In another possible implementation, the DU groups the own logical channel or the tunnel between itself and the CU-UP, and informs the CU-UP and CU-CP of the grouping situation; the logical channel grouping information can be stored and used by the CU-UP and the CU-CP after being acquired.

Optionally, the CU-CP sends the logical channel packet information or the tunnel packet information to the CU-UP over a bearer context setup request (bearer context setup request) message or a bearer context modification request (bearer context modification request) message; the CU-CP carries the logical channel packet information or the tunnel packet information on a terminal device context setup request (UE context setup request) message or a terminal device context modification request (UE context modification request) message, and transmits the same to the DU.

803. The CU-UP sends packet repetition side information to the CU-CP. Accordingly, the CU-CP receives the packet repetition side information transmitted by the CU-UP.

In this step, the CU-UP sends packet duplicate assistance information received from the DU to the CU-CP. Illustratively, the CU-UP sends the auxiliary information data to the CU-CP through the E1 interface. Optionally, the side information data is carried in a bearer context modification request (requested) message.

It should be understood that in the case that there is a logical channel packet or a tunnel packet in the DU, in step 801, the data packet repetition assistance information generated by the DU is granular in terms of the logical channel group or the tunnel group; in step 802, the data packet repetition assistance information sent by the DU is also granular in terms of logical channel groups or tunnel groups; in step 803, the packet repetition side information sent by the CU-UP is also granular in logical channel group or tunnel group.

804. The CU-CP decides packet repetition.

In this step, the CU-CP decides packet repetition based on the received packet repetition assistance information sent by the CU-UP. This step is similar to step 703 of the previous embodiment and will not be described again.

Through the steps of the embodiment of the application, the DU is used for sending the data packet repetition auxiliary information to the CU-CP through the CU-UP with the granularity of the logical channel, so that the CU-CP can effectively make the decision of data packet repetition. For example, the CU-CP may decide to activate multiple logical channels of at least one DU for packet repetition based on the packet repetition assistance information.

Optionally, the embodiment of the present application further includes steps 805 and 806.

805. The CU-CP sends packet duplicate information to the CU-UP. Accordingly, the CU-UP receives the data packet repetitive transmission information sent by the CU-CP.

In this step, in case the CU decides to activate at least one logical channel of one DU for packet repetition, the CU-CP sends packet repetition transmission information indicating transmission information of the at least one logical channel activating DU packet repetition to the CU-UP. The transmission information of one logical channel may be at least one of the following parameters: the logical channel identifier of the logical channel, the logical channel index of the logical channel, the tunnel identifier of the tunnel corresponding to the logical channel, the tunnel index of the tunnel, and the downlink tunnel transport layer address and TEID of the tunnel. Illustratively, after the CU-CP decides which logical channels to activate for packet repetition, the CU-CP sends the downlink tunnel information corresponding to the logical channels to the CU-UP, so that the CU-UP knows which tunnels to send downlink packets to corresponding DUs. For example, when configuring DRB, CU-CP configures the DRB with LH1, LH2, and LH3 of DU1 and LH4, LH5, and LH6 of DU2, and configures six tunnels corresponding to LH1 to LH6 between CU-UP and DU1 and DU2, such as a first tunnel to a sixth tunnel, where the first tunnel corresponds to LH1, the second tunnel corresponds to LH2, and so on. If the CU-CP receives packet duplication auxiliary information for packet duplication at LH1 and LH3 suggested by DU1 and packet duplication at LH5 suggested by DU2 in step 803, and decides to activate LH2, LH3, and LH5 for packet duplication in step 804, the CU-CP sends downlink tunnel information of each of the second tunnel, the third tunnel, and the fifth tunnel between the CU-UP and the DU corresponding to LH2, LH3, and LH5 to the CU-UP in this step.

It should be understood that if the packet repetition assistance information is granular in terms of logical channel groups or tunnel groups, in this step, in case the CU decides to activate at least one logical channel group of one DU for packet repetition, the packet repetition transmission information sent by the CU-CP to the CU-UP contains transmission information of the at least one logical channel group or the at least one tunnel group. The transmission information of a logical channel group or a tunnel group may be transmission information of each logical channel in the logical channel group or each logical channel corresponding to the tunnel group.

806. The CU-UP sends downstream packets to the DU over at least one tunnel.

In this step, the CU-UP transmits a downlink packet to the DU according to the packet retransmission information received in the above-described step 805. Specifically, the data packet retransmission information includes downlink tunnel information of at least one tunnel. In this step, the CU-UP sends the downlink packet to the at least one DU through the at least one tunnel. In the above example of step 805, in this step, the CU-UP transmits downlink packets having the same PDCP sequence number to DU1 through the second tunnel and the third tunnel, and to DU2 through the fifth tunnel, respectively.

Through steps 805 and 806, the CU instructs, according to the decision of packet repetition, the CU-UP to send the downlink packet to the at least one DU through the corresponding tunnel, and the corresponding RLC entity in the at least one DU correctly receives the downlink packet, so that the at least one DU can correctly perform packet repetition.

Further, the method flow shown in FIG. 8 also applies to the CU-UP to which each DU is connected and the interaction between the CU-UP and the CU in the case where the CU-CP is connected to three or more DUs. It should be noted that in the RAN device architecture shown in fig. 2(b), one DU may also be connected to multiple CUs-UPs, and one CU-UP may also be connected to multiple DUs. For a DRB, during configuration of the DRB, the CU-CP configures DUs and CUs-UP that handle the DRB. Therefore, before step 801, the CU-UPs to which a DU is connected and the connections between the CU-UPs and the CU-CP are determined, and the tunnels between the RLC entities in the DU and the CU-UPs to which the DU is connected are also determined. In the method flow shown in fig. 8, after the DU determines the packet duplication auxiliary information, the packet duplication auxiliary information of the corresponding logical channel is transmitted to the CU-UP connected to the logical channel and transmitted from the CU-UP to the CU-CP. Illustratively, if one DU is connected to the first CU-UP and the second CU-UP, and RLC1 and RLC2 in the DU are connected to the first CU-UP and RLC3 and RLC4 in the DU are connected to the second CU-UP, the DU transmits the wireless quality assistance information of LC1 and LC2 to the first CU-UP and the wireless quality assistance information of LC4 to the second CU-UP when determining to transmit the wireless quality assistance information of LC1, LC2 and LC 4.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present patent application.

Method embodiments of the present application are described in detail above in conjunction with fig. 5, 7, and 8, and apparatus embodiments of the present application are described in detail below in conjunction with fig. 9-14. It is to be understood that the apparatus embodiments correspond to the method embodiments and similar descriptions may be made with reference to the method embodiments. It is noted that the device embodiments may be used in conjunction with the above-described methods, or may be used alone.

Fig. 9 shows a schematic block diagram of a first network device 900 according to an embodiment of the present application, where the first network device 900 may correspond to (e.g., may be configured as or be itself) a corresponding node described in the method 500 above, or a distributed unit described in the method 700 above, or a distributed unit described in the method 800 above. The first network device 900 may include: a processor 901 and a transceiver 902, the processor 901 and the transceiver 902 being communicatively coupled. Optionally, the first network device 900 further comprises a memory 903, the memory 903 being communicatively coupled to the processor 901. Optionally, a processor 901, a memory 903 and a transceiver 902 may be communicatively coupled, the memory 903 may be used to store instructions, and the processor 901 is used to execute the instructions stored by the memory 903 to control the transceiver 902 to receive and/or transmit information or signals. The processor 901 and the transceiver 902 are respectively configured to execute each action or processing procedure executed by a corresponding node described in the method 500, or a distributed unit described in the method 700, or a distributed unit described in the method 800. Here, detailed description thereof is omitted in order to avoid redundancy.

Fig. 10 shows another schematic block diagram of a first network device 1000 according to an embodiment of the present application, where the first network device 1000 may correspond to (e.g., may be configured as or be itself) a corresponding node described in the method 500, or a distributed unit described in the method 700, or a distributed unit described in the method 800. The first network device 1000 may include: a receiving module 1001, a processing module 1002, and a transmitting module 1003, the processing module 1002 being communicatively coupled to the receiving module 1001 and the transmitting module 1003, respectively. The first network device 1000 may take the form shown in fig. 9. The processing module 1002 may be implemented by the processor 901 in fig. 9, and the receiving module 1001 and/or the transmitting module 1003 may be implemented by the transceiver 902 in fig. 9. The first network device 1000 may further include a storage unit for storing a program or data to be executed by the processing module 1002, or storing information received by the receiving module 1001 and/or transmitted by the transmitting module 1003. Each module or unit in the first network device 1000 is configured to execute each action or process performed by the corresponding node described in the method 500, the distributed unit described in the method 700, or the distributed unit described in the method 800, respectively. Here, detailed description thereof is omitted in order to avoid redundancy.

Fig. 11 shows a schematic block diagram of a second network device 1100 according to an embodiment of the present application, where the second network device 1100 may correspond to (e.g., may be configured to or be itself) the managed PDCP entity node described in the method 500, or the centralized unit described in the method 700, or the centralized unit control plane network element described in the method 800. The second network device 1100 may include: a processor 1101 and a transceiver 1102, the processor 1101 and the transceiver 1102 being communicatively coupled. Optionally, the second network device 1100 further comprises a memory 1103, the memory 1103 being communicatively coupled to the processor 1101. Optionally, a processor 1101, a memory 1103 and a transceiver 1102 may be communicatively coupled, the memory 1103 may be configured to store instructions, and the processor 1101 is configured to execute the instructions stored by the memory 1103 to control the transceiver 1102 to receive and/or transmit information or signals. The processor 1101 and the transceiver 1102 are respectively configured to perform actions or processes performed by the managed PDCP entity node described in the method 500, or the central unit described in the method 700, or the central unit control plane network element described in the method 800. Here, detailed description thereof is omitted in order to avoid redundancy.

Fig. 12 shows another schematic block diagram of a second network device 1200 according to an embodiment of the present application, where the second network device 1200 may correspond to (e.g., may be configured as or be itself) the managed PDCP entity node described in the method 500, or the central unit described in the method 700, or the central unit control plane network element described in the method 800. The second network device 1200 may include: a receiving module 1201, a processing module 1202, and a transmitting module 1203, the processing module 1202 being communicatively coupled to the receiving module 1201 and the transmitting module 1203, respectively. Second network device 1200 may take the form shown in fig. 11. The processing module 1202 may be implemented by the processor 1101 in fig. 11, and the receiving module 1201 and/or the transmitting module 1203 may be implemented by the transceiver 1102 in fig. 11. The second network device 1200 may further include a storage unit for storing a program or data to be executed by the processing module 1202, or storing information received by the receiving module 1201 and/or transmitted by the transmitting module 1203. The modules or units in the second network device 1200 are respectively configured to perform the actions or processes performed by the managed PDCP entity node described in the method 500, the centralized unit described in the method 700, or the centralized unit control plane network element described in the method 800. Here, detailed description thereof is omitted in order to avoid redundancy.

Fig. 13 shows a schematic block diagram of a third network device 1300 according to an embodiment of the present application, where the third network device 1300 may correspond to (e.g., may be configured as or itself is) the centralized-unit user plane network element described in the method 800. The third network device 1300 may include: processor 1301 and transceiver 1302, processor 1301 and transceiver 1302 being communicatively coupled. Optionally, the third network device 1300 further comprises a memory 1303, and the memory 1303 is communicatively coupled to the processor 1301. Optionally, the processor 1301, the memory 1303 and the transceiver 1302 may be communicatively coupled, the memory 1303 may be configured to store instructions, and the processor 1301 is configured to execute the instructions stored in the memory 1303 to control the transceiver 1302 to receive and/or transmit information or signals. The processor 1301 and the transceiver 1302 are respectively configured to perform each action or process performed by the centralized unit user plane network element described in the method 800. Here, detailed description thereof is omitted in order to avoid redundancy.

Fig. 14 shows another schematic block diagram of a third network device 1400 according to an embodiment of the present application, where the third network device 1400 may correspond to (e.g., may be configured as or itself is) the centralized element user plane network element described in the method 800. The third network device 1400 may include: a receiving module 1401, a processing module 1402 and a transmitting module 1403, the processing module 1402 being communicatively coupled to the receiving module 1401 and the transmitting module 1403, respectively. The third network device 1400 may take the form shown in fig. 13. Wherein the processing module 1402 may be implemented by the processor 1301 in fig. 13, and the receiving module 1401 and/or the transmitting module 1403 may be implemented by the transceiver 1302 in fig. 13. The third network device 1400 may further include a storage unit for storing programs or data to be executed by the processing module 1402, or storing information received by the receiving module 1401 and/or transmitted by the transmitting module 1403. The modules or units in the third network device 1400 are respectively configured to perform the actions or processes performed by the centralized element user plane network element described in the method 800. Here, detailed description thereof is omitted in order to avoid redundancy.

It should be understood that the processors (901, 1101, 1301) in the apparatus embodiments of the present application may be Central Processing Units (CPUs), Network Processors (NPs), hardware chips, or any combination thereof. The hardware chip may be an application-specific integrated circuit (ASIC), a Programmable Logic Device (PLD), or a combination thereof. The PLD may be a Complex Programmable Logic Device (CPLD), a field-programmable gate array (FPGA), a General Array Logic (GAL), or any combination thereof.

The memory (903, 1103, 1303) in the device embodiments of the present application may be a volatile memory (volatile memory), such as a random-access memory (RAM); a non-volatile memory (non-volatile memory) such as a read-only memory (ROM), a flash memory (flash memory), a Hard Disk Drive (HDD) or a solid-state drive (SSD); combinations of the above types of memories are also possible.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of a unit is merely a logical division, and an actual implementation may have another division, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication coupling may be an indirect coupling or communication coupling of devices or units through some interfaces, and may be in an electrical, mechanical or other form.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. 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 functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present patent application or a part of the technical solution that substantially contributes to the prior art may be embodied in the form of a software product stored in a storage medium and containing instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present patent application. And the aforementioned storage medium comprises: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present patent application shall be subject to the protection scope of the claims.

Claims

1. An information delivery method for packet duplication, comprising:

a first Radio Access Network (RAN) device determines first information, wherein the first information comprises information of at least one logical channel in the first RAN device;

the first RAN device sends the first information to a second RAN device, where the first information is used to indicate packet repetition assistance information of the first RAN device.

2. An information delivery method for packet duplication, comprising:

receiving, by a second radio access network RAN device, first information sent by a first RAN device, where the first information includes information of at least one logical channel in the first RAN device, and the first information is used to indicate packet repetition assistance information of the first RAN device;

the second RAN device decides packet duplication according to the first information.

3. The method according to claim 1 or 2, wherein the information of the at least one logical channel comprises at least one of the following information: a logical channel identifier of the at least one logical channel, a logical channel index of the at least one logical channel, radio quality assistance information of the at least one logical channel, a tunnel identifier of at least one tunnel corresponding to the at least one logical channel, a tunnel index of the at least one tunnel, and a downlink tunnel transport layer address and a tunnel endpoint identifier TEID of the at least one tunnel.

4. The method according to claim 1 or 3, or the method according to claim 2 or 3, wherein the first information is assistance information data comprising at least one of packet data convergence layer protocol, PDCP, duplicate activation suggestions and radio quality assistance information.

5. The method of claim 4, wherein the PDCP duplicate activation suggestion indicates the at least one logical channel or the at least one tunnel for which the activation packet is suggested by the first RAN device.

6. The method of claim 4, wherein the radio quality assistance information comprises radio quality assistance information for the at least one logical channel of the first RAN device or radio quality assistance information for at least one logical channel corresponding to the at least one tunnel.

7. The method of claim 5, wherein the PDCP duplicate activation suggestion indicates the at least one logical channel or the at least one tunnel for the first RAN device suggested activation packet duplication, comprising:

the PDCP repetition activation proposal comprises at least two bits of information indicating the at least one logical channel or the at least one tunnel for which the activation packet is proposed by the first RAN device.

8. The method of claim 2 or 3, wherein the second RAN device deciding packet repetition based on the first information comprises:

the second RAN device decides to activate packet repetition of the at least one logical channel or the at least one tunnel according to the first information.

9. The method of claim 1, or the method of claims 2 or 8, wherein the second RAN device is a hosting PDCP entity node and the first RAN device is a corresponding node.

10. The method according to claim 1 or claim 2 or 8, wherein the second RAN device is a central unit, CU, and wherein the first RAN device is a distributed unit, DU.

11. The method of claim 1, wherein sending the first information from the first RAN device to a second RAN device comprises:

the first RAN device sends the first information to the second RAN device via a third RAN device.

12. The method of claim 2, wherein the second RAN device receives the first information sent by the first RAN device, and wherein the receiving comprises:

the second RAN device receives the first information sent by the first RAN device via a third RAN device.

13. The method according to claim 11 or 12, wherein said second RAN equipment is a centralized unit control plane network element CU-CP, said first RAN equipment is a distributed unit DU, and said third RAN equipment is a centralized unit user plane network element CU-UP.

14. The method of claim 1, 9 or 10, further comprising:

and the first RAN equipment receives the downlink data packet sent by the second RAN equipment through the at least one tunnel.

15. The method of claim 14, wherein in the case that the first RAN device receives downlink data packets sent by the second RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

16. The method of claim 11 or 13, further comprising:

and the first RAN equipment receives the downlink data packet sent by the third RAN equipment through the at least one tunnel.

17. The method of claim 16, wherein in the case that the first RAN device receives downlink data packets sent by the third RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

18. The method of claim 2, 9 or 10, further comprising:

and the second RAN equipment sends a downlink data packet to the first RAN equipment through the at least one tunnel.

19. The method of claim 18, wherein downlink data packets have the same PDCP sequence number if the second RAN device sends the downlink data packets to the first RAN device through at least two tunnels.

20. The method of claim 12 or 13, further comprising:

the second RAN device sends packet retransmission information to the third RAN device, where the packet retransmission information includes transmission information of the at least one logical channel, and the packet retransmission information is used to instruct the third RAN device to send downlink data to the first RAN device according to the packet retransmission information.

21. The method according to claim 20, wherein the transmission information of the at least one logical channel comprises at least one of the following information: the logical channel identifier of the at least one logical channel, the logical channel index of the at least one logical channel, the tunnel identifier of the at least one tunnel corresponding to the at least one logical channel, the tunnel index of the at least one tunnel, and the downlink tunnel transport layer address and TEID of the at least one tunnel.

22. A network device, wherein the network device is a first Radio Access Network (RAN) device comprising a processor and a transceiver, wherein,

the processor configured to determine first information, the first information including information of at least one logical channel in the first RAN device;

the transceiver is communicatively coupled to the processor and configured to send the first information to a second RAN device, where the first information is used to indicate packet repetition assistance information of the first RAN device.

23. A network device, wherein the network device is a second Radio Access Network (RAN) device, wherein the second RAN device comprises a processor and a transceiver, wherein,

the transceiver is configured to receive first information sent by a first RAN device, where the first information includes information of at least one logical channel in the first RAN device, and the first information is used to indicate packet repetition assistance information of the first RAN device;

the processor is communicatively coupled to the transceiver for deciding packet repetition based on the first information.

24. The network device according to claim 22 or 23, wherein the information of the at least one logical channel comprises at least one of the following information: a logical channel identifier of the at least one logical channel, a logical channel index of the at least one logical channel, radio quality assistance information of the at least one logical channel, a tunnel identifier of at least one tunnel corresponding to the at least one logical channel, a tunnel index of the at least one tunnel, and a downlink tunnel transport layer address and a tunnel endpoint identifier TEID of the at least one tunnel.

25. The network device of claim 22 or 24, or the network device of claim 23 or 24, wherein the first information is assistance information data comprising at least one of a packet data convergence layer protocol, PDCP, reactivation proposal and radio quality assistance information.

26. The network device of claim 25, wherein the PDCP repetition activation recommendation is for the at least one logical channel or the at least one tunnel indicating the first RAN device proposed activation packet repetition.

27. The network device of claim 25, wherein the radio quality assistance information comprises radio quality assistance information for the at least one logical channel of the first RAN device or radio quality assistance information for at least one logical channel corresponding to the at least one tunnel.

28. The network device of claim 26, wherein the PDCP repetition activation recommendation is for the at least one logical channel or the at least one tunnel indicating the first RAN device proposed activation packet repetition, comprising:

29. The network device of claim 23 or 24, wherein the processor is configured to decide packet repetition according to the first information, and comprises:

the processor is configured to decide to activate packet repetition of the at least one logical channel or the at least one tunnel according to the first information.

30. The network device of claim 22, or the network device of claim 23 or 29, wherein the second RAN device is a hosting PDCP entity node and the first RAN device is a corresponding node.

31. The network device of claim 22, or the network device of claim 23 or 29, wherein the second RAN device is a central unit, CU, and wherein the first RAN device is a distributed unit, DU.

32. The network device of claim 22, wherein the transceiver is configured to send the first information to a second RAN device, comprising:

the transceiver is configured to send the first information to the second RAN device via a third RAN device.

33. The network device of claim 23, wherein the transceiver is configured to receive first information sent by a first RAN device, and wherein the first information comprises:

the transceiver is configured to receive, via a third RAN device, the first information sent by the first RAN device.

34. The network device of claim 32 or 33, wherein the second RAN device is a central unit control plane network element CU-CP, wherein the first RAN device is a distributed unit DU, and wherein the third RAN device is a central unit user plane network element CU-UP.

35. Network device according to claim 22, 30 or 31, comprising:

the transceiver is further configured to receive, through the at least one tunnel, a downlink data packet sent by the second RAN device.

36. The network device of claim 35, wherein in the case that the transceiver is configured to receive downlink data packets sent by the second RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

37. Network device according to claim 32 or 34, comprising:

the transceiver is further configured to receive, through the at least one tunnel, a downlink data packet sent by the third RAN device.

38. The network device of claim 37, wherein in the case that the transceiver is configured to receive downlink data packets sent by the third RAN device through at least two tunnels, the downlink data packets have the same PDCP sequence number.

39. A network device as claimed in claim 23, 30 or 31, comprising:

the transceiver is further configured to send a downlink data packet to the first RAN device through the at least one tunnel.

40. The network device of claim 39, wherein if the transceiver is configured to send downlink packets to the first RAN device via at least two tunnels, the downlink packets have the same PDCP sequence number.

41. Network device according to claim 33 or 34, comprising:

the transceiver is further configured to send data packet retransmission information to the third RAN device, where the data packet retransmission information includes transmission information of the at least one logical channel, and the data packet retransmission information is used to instruct the third RAN device to send downlink data to the first RAN device according to the data packet retransmission information.

42. The network device of claim 41, wherein the transmission information of the at least one logical channel comprises at least one of the following information: the logical channel identifier of the at least one logical channel, the logical channel index of the at least one logical channel, the tunnel identifier of the at least one tunnel corresponding to the at least one logical channel, the tunnel index of the at least one tunnel, and the downlink tunnel transport layer address and TEID of the at least one tunnel.

43. A computer-readable storage medium storing computer instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 21.