CN114928430A

CN114928430A - System supporting PDCP (packet data convergence protocol) repeat function, data transmission method and network equipment

Info

Publication number: CN114928430A
Application number: CN202210615670.9A
Authority: CN
Inventors: 汪巍崴; 柯小婉; 王弘; 许丽香
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2017-06-16
Filing date: 2018-01-10
Publication date: 2022-08-19

Abstract

The invention discloses a system, a data transmission method and network equipment for supporting a Packet Data Convergence Protocol (PDCP) repeating function, wherein the data transmission method for supporting the PDCP repeating function comprises the following steps: the first network equipment sends a configuration instruction message of a radio bearer supporting a PDCP (packet data convergence protocol) repeat function to the second network equipment; and the first network equipment and the second network equipment carry out transmission of data packets of the radio bearer configured with the PDCP repeated function. According to the invention, through the interface between the first network equipment and the second network equipment, the repeated data packets are transmitted between the first network equipment and the second network equipment, and the reliability of data transmission is improved.

Description

System supporting PDCP (packet data convergence protocol) repeating function, data transmission method and network equipment

The application is a divisional application of an invention patent application with the application number of 201810024386.8, the application date of 2018, 1 month and 10 days, and the name of the invention is 'a system for supporting a PDCP (packet data convergence protocol) repeat function, a data transmission method and a network device'.

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a system, a data transmission method, and a network device for supporting a PDCP (packet data convergence protocol) repeat function.

Background

In the next generation network or the fifth generation 5G network, in order to support network function virtualization, more efficient resource management and scheduling, a base station (gNB) providing a radio network interface for terminals (UEs) may be further divided into a centralized unit gNB-cu (gNB Central unit) and a Distributed unit gNB-du (gNB Distributed unit). The gNB-CU has a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, and optionally includes a Service Data Adaptation Protocol (SDAP) layer, etc. The gNB-DU has a Radio Link Control protocol (RLC), a Medium Access Control (MAC), a physical layer, and the like. Between the gNB-CU and the gNB-DU is a standardized public interface F1. The F1 interface is divided into a control plane F1-C and a user plane F1-U. The transport network layer of F1-C is based on IP transport. For more reliable transport signaling, the SCTP protocol is added on top of IP. The protocol of the application layer is F1 AP. SCTP can provide reliable application layer message transport. The transport layer of F1-U is UDP/IP, and GTP-U is used to carry user plane PDU (Protocol Data Unit) on top of UDP/IP. Fig. 1 shows the structure of a gNB-CU and a gNB-DU. In addition, in a new generation network, in order to improve reliability of data or signaling transmission, the PDCP protocol layer may support a PDCP Duplication function (i.e., PDCP Duplication), which is characterized in that each PDCP PDU of a Radio Bearer (Radio Bearer) supporting the function is transmitted to at least two RLC entities, transmitted to the MAC layer through two different logical channels or the same logical channel, and then transmitted through two different cells, respectively. The Radio Bearer may be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB). This function can be applied to the scenario of carrier aggregation and the scenario of dual connectivity.

For the carrier aggregation scenario, fig. 2 shows a schematic diagram including a transmitting end and a receiving end. At a sending end, a PDCP SDU (Service Data Unit) (which may be a Data packet from a Data radio bearer DRB or a Data packet from a signaling radio bearer SRB) is processed by a PDCP protocol layer (including a PDCP Duplication function) to obtain two identical PDCP PDUs (e.g., PDCP PDU1), which are sent to two different RLC entities (i.e., RLC1 and RLC2), and then sent to a MAC layer via two different logical channels (i.e., logical channel 1 and logical channel 2). At the MAC layer, packets from the two logical channels are sent through physical layers serving different cells (i.e., cell 1 and cell 2, which may use different carriers or may use the same carrier). At a receiving end, after being processed by the MAC layer, data packets from different carriers are respectively sent to two different RLC entities (e.g., RLC1 and RLC2) through different logical channels, and then the data packets after RLC processing are sent to the PDCP layer, and the PDCP layer processes repeated PDCP PDUs (e.g., discards one repeated PDCP PDU), and finally obtains PDCP SDUs. In fig. 2, examples of the transmitting end and the receiving end may be a gNB and a UE, or a UE and a gNB, or a UE and a UE, etc.

For the dual connectivity scenario, fig. 3 shows a schematic diagram for downlink transmission (gNB to UE). At the gNB, one PDCP SDU is processed by the PDCP protocol layer (including PDCP repetition function) to obtain two identical PDCP PDUs (e.g., PDCP PDU 1). The two identical PDCP PDUs are respectively sent to two different RLC entities on two different gnbs (i.e., gNB1 and gNB2), then sent to the MAC layer corresponding to each RLC entity, and finally sent to the user through the physical layers of two different cells (i.e., cell 1 and cell 2, which may use different carriers or the same carrier). At a user side, packets received by two different cells are sent to two different MAC entities and then sent to two different RLC entities, data packets output by the two RLC entities are sent to the same PDCP entity, the PDCP entity processes a repeated PDCP PDU (for example, discards one repeated PDCP PDU), and finally PDCP SDUs are obtained. Similarly, fig. 4 gives a schematic diagram for uplink transmission (UE to gNB).

In addition, in the next generation network or the fifth generation 5G network, one UE may also receive services of two base stations (a main base station and an auxiliary base station), where the two base stations may be two base stations of the same type, such as a base station that is both 4G, i.e., eNB, or a base station that is both 5G, i.e., gNB; or may be different types of base stations, such as an eNB, a gNB, or other types of base stations. In one case, when the two base stations serve a radio bearer (e.g., data bearer, signaling bearer) of the UE, the PDCP Layer serving the radio bearer is located at one base station (e.g., base station 1, which may be a primary base station or a secondary base station), and the other protocol layers (e.g., RLC, MAC, PHY, Physical Layer) serving the radio bearer are located at the other base station (e.g., base station 2, which may be a primary base station or a secondary base station, if base station 1 is a primary base station, base station 2 is a secondary base station, and if base station 1 is a secondary base station, base station 2 is a primary base station). The data of the radio bearer is transmitted over the interface (e.g., X2 interface, Xn interface) between the two base stations, as shown in fig. 4 a.

In the above description of the PDCP repetition function, the PDCP PDU obtained after the PDCP repetition may belong to one radio bearer or may belong to multiple radio bearers. The radio bearer may be a Data Radio Bearer (DRB) for transmitting data, or a Signaling Radio Bearer (SRB) for transmitting signaling by a user. These radio bearers may belong to one user or to multiple users. If belonging to one user, it means that only the user is configured with the PDCP repeat function, and if belonging to a plurality of different users, it means that the plurality of users are all configured with the PDCP repeat function.

In the above description of the PDCP repetition function, one PDCP PDU is transmitted twice via different RLC entity transmissions, respectively. The function may also transmit one PDCP PDU multiple times via multiple different RLC entity transmissions. In the following description of the present invention, the case of transmitting one PDCP PDU twice is described as an example, and the case of transmitting a plurality of times is similar.

In a 5G system, however, the gNB may be composed of two separate functional entities, namely a gNB-CU and a gNB-DU, with the interface between the two being standardized F1. In a conventional LTE network, a base station is a functional entity, and interaction among all functions of the entity can be regarded as an internal implementation. However, in 5G, if one gNB is composed of a gNB-CU and a gNB-DU, how to implement the transmission of duplicate PDCP PDUs between the gNB-CU and the gNB-DU becomes a problem to be solved urgently.

Disclosure of Invention

The invention provides a system supporting a PDCP (packet data convergence protocol) repeat function, a data transmission method and network equipment, which are used for realizing the transmission of repeated data packets between first network equipment and second network equipment and improving the reliability of data transmission.

A first network device, comprising:

a sending subunit, configured to send a configuration instruction message of a radio bearer supporting a PDCP repetition function to the second network device;

a processing subunit, configured to perform, with the second network device, transmission of a data packet of a radio bearer configured with a PDCP repetition function.

When the data packet of the radio bearer configured with the PDCP repetition function is downlink data,

the sending subunit is configured to send, through an interface with the second network device, the data packet of the radio bearer configured with the PDCP duplication function.

When the first network device and the second network device activate PDCP repetition functionality for a radio bearer supporting PDCP repetition functionality,

the sending subunit is specifically configured to send, to the second network device, the data packet of the radio bearer configured with the PDCP duplication function through a tunnel on an interface between the first network device and the second network device; or the like, or, alternatively,

the sending subunit is specifically configured to copy the data packet of the radio bearer configured with the PDCP repetition function to obtain two identical data packets of the radio bearer configured with the PDCP repetition function; sending the two same data packets of the radio bearer configured with the PDCP repeat function through a tunnel on an interface between the first network device and the second network device; or, specifically, the method is configured to send the data packet of the radio bearer configured with the PDCP repetition function twice through a tunnel on an interface between the first network device and the second network device; or the like, or a combination thereof,

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repetition function to the second network device twice through two different tunnels on an interface between the first network device and the second network device; or the like, or, alternatively,

the sending subunit is specifically configured to send, to the second network device, two identical data packets of the radio bearer configured with the PDCP repeat function through a control plane message on an interface between the first network device and the second network device, respectively.

When the first network device does not activate PDCP repetition functionality for a radio bearer supporting PDCP repetition functionality,

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP duplicate function to the second network device through an interface between the first network device and the second network device, so that the second network device sends the data packet to the user terminal sequentially through an assigned or self-selected RLC entity, a logical channel corresponding to the RLC entity, an MAC layer, and a cell.

When the sending subunit sends the data packet of the radio bearer configured with the PDCP repeat function to the second network device, sending the data packet through a tunnel on an interface between the first network device and the second network device or a control plane message on an interface between the first network device and the second network device;

and when the sending subunit sends the data packet of the radio bearer configured with the PDCP repeat function to the second network device, one tunnel on an interface between the first network device and the second network device includes a designated tunnel or an optional tunnel.

When the data packet of the radio bearer configured with the PDCP repeat function is uplink data, the first network device further includes:

a receiving subunit, configured to receive the data packet of the radio bearer configured with the PDCP repetition function, sent by the second network device;

and the processing subunit is configured to process the received data packet of the radio bearer configured with the PDCP repetition function through a PDCP layer to obtain a PDCP service data unit SDU of the radio bearer configured with the PDCP repetition function.

The configuration instruction message of the radio bearer supporting the PDCP repetition function, which is sent by the sending subunit to the second network device, includes at least one of the following information:

information supporting a PDCP repetition function;

partial or complete configuration information of at least one radio link control protocol, RLC, entity corresponding to the data bearer;

identification information and/or configuration information of a logical channel corresponding to at least one RLC entity;

configuration information of at least one tunnel on an interface between the first network device and the second network device;

information of correspondence between at least one tunnel and at least one RLC entity on an interface between the first network device and the second network device;

identifying indication information of duplicate packets.

The first network device further comprises:

a receiving subunit, configured to receive a configuration response message returned by the second network device; wherein the configuration response message includes configuration information of at least one tunnel on an interface between the first network device and the second network device.

The configuration information of at least one tunnel on the interface between the first network device and the second network device, which is included in the configuration instruction message, is specifically address information of a data packet of the radio bearer supporting the PDCP repetition function, which is received or sent by the first network device; the configuration information of at least one tunnel on the interface between the first network device and the second network device included in the configuration response message is specifically address information of a data packet of the radio bearer supporting the PDCP repetition function, which is received or sent by the second network device side.

Preferably, the first and second electrodes are formed of a metal,

the first network equipment is a first base station, and the second network equipment is a second base station; or

The first network device is a centralized unit in the base station, and the second network device is a distributed unit in the base station.

The present invention also provides a second network device, including:

a receiving subunit, configured to receive a configuration instruction message of a radio bearer that supports a PDCP repetition function and is sent by a first network device;

a processing subunit, configured to perform, with the first network device, transmission of a data packet of the radio bearer configured with the PDCP repetition function.

When the data packet of the radio bearer configured with the PDCP repeat function is downlink data, the second network device further includes:

the receiving subunit is configured to receive, through an interface with the first network device, the data packet of the radio bearer configured with the PDCP duplication function;

a sending subunit, configured to send the data packets of the radio bearer configured with the PDCP repetition function to two different cells, respectively.

When the first network device and the second network device activate PDCP repetition capability for a radio bearer supporting PDCP repetition capability,

the receiving subunit is configured to receive, through a tunnel on an interface between the second network device and the first network device, the data packet of the radio bearer configured with the PDCP repeat function and sent by the first network device;

the processing subunit is specifically configured to copy the data packet of the radio bearer configured with the PDCP repetition function, and obtain two identical data packets of the radio bearer configured with the PDCP repetition function;

the sending subunit is specifically configured to send two identical data packets of the radio bearer configured with the PDCP repeat function to two different cells through two different RLC entities and their respective corresponding logical channels via the MAC layer.

the receiving subunit is configured to receive, through a tunnel on an interface between the second network device and the first network device, the data packet of the radio bearer configured with the PDCP repeat function sent by the first network device;

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repetition function to two different cells once through two different RLC entities and respective corresponding logical channels via the MAC layer.

the receiving subunit is configured to receive, twice through one or two tunnels on an interface between the second network device and the first network device, two identical data packets of the radio bearer configured with the PDCP repeat function and sent by the first network device;

the sending subunit is specifically configured to send the same two data packets of the radio bearer configured with the PDCP repeat function to two different cells through two different RLC entities and corresponding logical channels via an MAC layer, respectively.

the receiving subunit is configured to receive, by a control plane message on an interface between the second network device and the first network device, two identical data packets of the radio bearer configured with the PDCP repeat function sent by the first network device in two times;

the sending subunit is specifically configured to send the two identical data packets of the radio bearer configured with the PDCP repetition function to two different cells through two different RLC entities and corresponding logical channels via an MAC layer, respectively.

When the first network device and the second network device do not activate PDCP repetition functionality for a radio bearer supporting PDCP repetition functionality,

the receiving sub-unit is specifically configured to receive the data packet of the radio bearer configured with the PDCP repeat function, where the data packet is sent by the first network device through an interface between the second network device and the first network device;

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repetition function to the user equipment after sequentially passing through the designated or self-selected RLC entity, the logical channel corresponding to the RLC entity, the MAC layer, and a cell.

When the data packet of the radio bearer configured with the PDCP repetition function is uplink data, the second network device further includes:

a sending subunit, configured to send, to the first network device, the data packet of the radio bearer configured with the PDCP repetition function.

the sending subunit is specifically configured to send two identical data packets, which are acquired from two different cells and configured with the radio bearer with the PDCP duplication function, to the first network device through one tunnel or two tunnels on an interface between the second network device and the first network device or a control plane message on an interface between the second network device and the first network device, where the two identical data packets are obtained through a physical layer, an MAC layer, two different logical channels of each cell, and an RLC entity corresponding to each logical channel.

the sending subunit is specifically configured to send, to the first network device through an interface between the second network device and the first network device, the data packet of the radio bearer configured with the PDCP repetition function, which is obtained from one cell, where the data packet is obtained through a physical layer, an MAC layer, a logical channel, and an RLC entity corresponding to the logical channel of the cell.

And the second network equipment sends the data packet of the radio bearer configured with the PDCP repeat function, acquired from a cell, to the first network equipment through a tunnel on an interface between the second network equipment and the first network equipment or a control plane message on the interface between the second network equipment and the first network equipment, wherein the data packet is acquired through a physical layer, an MAC layer, a logical channel and an RLC entity corresponding to the logical channel of the cell.

One tunnel on the interface between the second network device and the first network device comprises a designated tunnel or a self-selection tunnel, and the RLC entity comprises a designated RLC entity or a self-selection RLC entity.

The second network device further comprises:

a sending subunit, configured to send, to the first network device, a configuration response message carrying configuration information of at least one tunnel on an interface between the second network device and the first network device.

The configuration information of at least one tunnel on the interface between the second network device and the first network device, which is included in the configuration response message, is specifically address information of a data packet of the radio bearer supporting the PDCP repeat function, which is received by the receiving subunit or sent by the sending subunit.

Preferably, the first and second liquid crystal display panels are,

The invention discloses a system for supporting the repeat function of packet data convergence protocol PDCP, which comprises a first base station and a second base station or a centralized unit and a distributed unit in the base stations,

the data packet of the radio bearer configured with the PDCP repeat function comprises: data packets configured with PDCP repetition capability data radio bearer and/or data packets configured with PDCP repetition capability signaling radio bearer.

The invention discloses a data transmission method supporting PDCP (packet data convergence protocol) repeat function, which comprises the following steps:

the first network equipment sends a configuration instruction message of a radio bearer supporting a PDCP (packet data convergence protocol) repeat function to the second network equipment;

and the first network equipment perform transmission of data packets of the radio bearer configured with the PDCP repeat function.

Preferably, the first and second electrodes are formed of a metal,

Compared with the prior art, the invention has at least the following advantages:

through the interface between the first network equipment and the second network equipment, the repeated data packets are transmitted between the first network equipment and the second network equipment, and the reliability of data transmission is improved.

Drawings

FIG. 1 is a diagram of the structure of a gNB-CU and a gNB-DU in the prior art;

FIG. 2 is a schematic diagram illustrating a PDCP repeat process in a carrier aggregation scenario in the prior art;

FIG. 3 is a schematic diagram illustrating a PDCP duplication process in a dual-connection downlink scenario in the prior art;

FIG. 4 is a schematic diagram illustrating a process of PDCP duplication in a dual connectivity uplink scenario in the prior art;

FIG. 4a is a schematic diagram illustrating a PDCP duplication process in a dual base station scenario in the prior art;

fig. 5 is a flowchart illustrating a data transmission method supporting PDCP repetition function at the first network device according to the present invention.

Detailed Description

The present invention provides a system, a data transmission method and a network device for supporting PDCP repetition function, and the following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the system for supporting the PDCP repetition function provided by the present invention, the base station may be a base station gNB in a new generation network, which includes a gNB-CU and a gNB-DU, or a base station in another network (e.g., an eNB in an LTE system). For convenience of understanding, the following embodiments a to five each exemplify a base station supporting the PDCP repeating function, which includes a central unit (central unit) and a distributed unit (distributed unit), and in the embodiments a to five each exemplify a gNB-CU (first network device) and a gNB-DU (second network device), and the centralized units and the distributed units included in the base stations in other networks are also applicable to the present invention.

In the method for transmitting a data packet of a radio bearer supporting the PDCP repeat function between a central unit and a distribution unit according to the present invention, for convenience of understanding, the following embodiments of the present invention use PDCP PDUs as the data packet to make specific explanation, and certainly, in an actual system, the format of the data packet is not limited thereto.

The PDCP repetition function mentioned in the present invention is an example of repeatedly sending a data packet of a radio bearer supporting the PDCP repetition function twice, and the data packet may also be repeatedly sent many times in an actual system. In this case, the data packets of the radio bearer may be sent in multiple cells through multiple RLC entities and their corresponding channels, and may be sent through multiple tunnels or one tunnel on the F1 interface. In the following embodiments one to five of the present invention, for convenience, the detailed description is made only by using an example of repeating transmission twice.

In the invention, the tunnel is used for transmitting data of the user plane.

In a base station supporting a PDCP repetition function, the base station comprises a centralized unit and a distributed unit; wherein the content of the first and second substances,

the concentration unit includes:

a configuration instruction message for sending a radio bearer supporting a PDCP repetition function to the distribution unit; wherein, the configuration instruction message of the radio bearer supporting the PDCP repetition function sent by the central unit to the distributing unit includes at least one of the following information:

information supporting a PDCP repetition function;

partial or full configuration information of at least one RLC entity corresponding to the data bearer;

configuration information of at least one tunnel on the F1 interface;

corresponding relation information of at least one tunnel and at least one RLC entity on an F1 interface;

identifying indication information of duplicate packets.

Further, the central unit is further configured to receive a configuration response message returned by the distribution unit; wherein the configuration response message includes configuration information of at least one tunnel on the F1 interface; the configuration message includes address information of the tunnel, which may be one address information or two address information.

The centralized unit is further configured to perform, with the distribution unit, transmission of data packets of the radio bearer configured with the PDCP repeat function;

the distribution unit is configured to receive a configuration instruction message of a radio bearer supporting a PDCP repetition function, which is sent by the central unit; sending a configuration response message carrying configuration information of at least one tunnel on an F1 interface to the central unit, where the configuration information includes address information of the tunnel, and may be one address information or two address information; and transmitting the data packet of the radio bearer configured with the PDCP repeat function with the centralized unit.

The configuration information of at least one tunnel on the F1 interface included in the configuration instruction message of the radio bearer supporting the PDCP repetition function sent by the central unit to the distributing unit is specifically address information of the radio bearer supporting the PDCP repetition function received or sent by the central unit; the configuration information of at least one tunnel on the F1 interface included in the configuration response message returned by the distribution unit is specifically the address information of the radio bearer supporting the PDCP repeat function received or sent by the distribution unit side.

The data packets of the radio bearer configured with the PDCP repeat function comprise data packets of a data radio bearer configured with the PDCP repeat function and/or data packets of a signaling radio bearer configured with the PDCP repeat function.

Specifically, for the transmission of the data packet of the radio bearer configured with the PDCP repetition function by the central unit and the distribution unit, two cases, namely, uplink data and downlink data, of the data packet of the radio bearer configured with the PDCP repetition function are described.

the central unit is configured to send the data packet of the radio bearer configured with the PDCP repeat function through an F1 interface with the distribution unit;

the distribution unit is configured to send the data packets of the radio bearer configured with the PDCP repeat function to two different cells, respectively.

When the central unit and the distribution unit activate a PDCP repetition function of a radio bearer supporting the PDCP repetition function,

the central unit is specifically configured to send the data packet of the radio bearer configured with the PDCP entity to the distribution unit through a tunnel on an F1 interface;

the distribution unit is specifically configured to copy the data packet of the radio bearer configured with the PDCP repetition function to obtain two identical data packets of the radio bearer configured with the PDCP repetition function; and respectively sending the data packets of the two same radio bearers configured with the PDCP repeat function to two different cells through two different RLC entities and respective corresponding logical channels thereof via an MAC layer. Or, the RLC layer is specifically configured to send the data packet of the radio bearer configured with the PDCP repetition function to two different cells once through two different RLC entities and corresponding logical channels via the MAC layer.

When the concentration unit and the distribution unit activate a PDCP repetition function of a radio bearer supporting the PDCP repetition function,

the centralized unit is specifically configured to copy the data packet of the radio bearer configured with the PDCP repetition function to obtain two identical data packets of the radio bearer configured with the PDCP repetition function; respectively sending data packets of the two same radio bearers configured with the PDCP repeat function to the distribution unit through one tunnel of an F1 interface; or, specifically, the method is configured to send the data packet of the radio bearer configured with the PDCP repetition function to the distribution unit twice through one tunnel of the F1 interface;

the distribution unit is specifically configured to send two identical data packets of the radio bearer configured with the PDCP repetition function to two different cells through two different RLC entities and respective corresponding logical channels via an MAC layer.

When the concentration unit and the distribution unit activate a PDCP repetition function of a radio bearer configured with the PDCP repetition function,

the central unit is specifically configured to send two identical data packets of the radio bearer configured with the PDCP repeat function to the distribution unit through two different tunnels on an F1 interface, respectively; or, respectively sending data packets of two identical radio bearers configured with the PDCP repetition function to the distribution unit through a control plane message on an F1 interface.

When the concentration unit and the distribution unit do not activate the PDCP repetition function of the radio bearer supporting the PDCP repetition function,

the central unit is specifically configured to send the data packet of the radio bearer configured with the PDCP repeat function to the distribution unit through an F1 interface, where the distribution unit sends the data packet to a user equipment after passing through an RLC entity, a logical channel corresponding to the RLC entity, an MAC layer, and a cell in sequence;

the distribution unit is specifically configured to receive the data packet of the radio bearer configured with the PDCP repeat function, which is sent by the central unit through an F1 interface; and the data packet of the radio bearer configured with the PDCP repeat function is sent to the user terminal after sequentially passing through the appointed or self-selected RLC entity, the corresponding logical channel, the MAC layer and one cell.

When the data packets of the radio bearer configured with the PDCP repetition function are sent to the user equipment, the central unit sends the data packets through a tunnel on an F1 interface or a control plane message on an F1 interface;

and, when the central unit sends the data packet of the radio bearer configured with the PDCP duplicate function to the user equipment, one tunnel on the F1 interface includes a designated tunnel or an optional tunnel.

When the data packet of the radio bearer configured with the PDCP repetition function is uplink data,

the distribution unit is configured to send the data packet of the radio bearer configured with the PDCP repeat function to the central unit;

the centralized unit is configured to process the received data packet of the radio bearer configured with the PDCP repeat function through a PDCP layer to obtain PDCP SDUs of the radio bearer configured with the PDCP repeat function.

the distribution unit is specifically configured to send two identical data packets of the radio bearer configured with the PDCP duplication function, acquired from two different cells, to the central unit through one tunnel or two tunnels on an F1 interface or a control plane message on an F1 interface, where the two identical data packets are obtained through a physical layer, an MAC layer, two different logical channels of each cell and its corresponding RLC entity.

When the concentration unit and the distribution unit do not activate a PDCP repetition function of a radio bearer supporting the PDCP repetition function,

the distribution unit is specifically configured to send, to the central unit through an F1 interface, the data packet of the radio bearer configured with the PDCP repetition function, acquired from one cell, where the data packet is obtained through a physical layer, an MAC layer, a logical channel of the cell, and a corresponding RLC entity of the cell;

the central unit is specifically configured to process the received data packet of the radio bearer configured with the PDCP repetition function through a PDCP layer to obtain the data packet of the radio bearer configured with the PDCP repetition function.

The distribution unit sends the data packet of the radio bearer configured with the PDCP repeat function, acquired from a cell, to the central unit through a tunnel on an F1 interface or a control plane message on an F1 interface, where the data packet is obtained through a physical layer, an MAC layer, a logical channel of the cell and an RLC entity corresponding to the logical channel.

Wherein, one tunnel on the F1 interface includes a designated tunnel or an optional tunnel, and the RLC entity includes a designated RLC entity or an optional RLC entity.

The data packets of the radio bearer configured with the PDCP repeat function comprise data packets of a Data Radio Bearer (DRB) configured with the PDCP repeat function and/or data packets of a Signaling Radio Bearer (SRB) configured with the PDCP repeat function.

Based on the base station including the centralized unit and the distributed unit provided by the present invention, the following explains that the centralized unit and the distributed unit are respectively subdivided into each functional module for processing.

A hub unit, comprising:

a sending subunit, configured to send a configuration instruction message of a radio bearer supporting the PDCP repetition function to the distribution unit;

and the processing subunit is configured to perform, with the distribution unit, transmission of a data packet of a radio bearer configured with a PDCP repeat function.

the sending subunit is configured to send, through an F1 interface with the distribution unit, the data packet of the radio bearer configured with the PDCP duplication function.

the sending subunit is specifically configured to send, to the distribution unit, the data packet of the radio bearer configured with the PDCP repetition function through a tunnel on the F1 interface; or the like, or, alternatively,

the sending subunit is specifically configured to copy the data packet of the radio bearer configured with the PDCP repetition function to obtain two identical data packets of the radio bearer configured with the PDCP repetition function; and respectively sending the data packets of the two identical radio bearers configured with the PDCP repeat function through a tunnel on an F1 interface; or, specifically, the method is configured to send the data packet of the radio bearer configured with the PDCP repetition function twice through one tunnel on the F1 interface; or the like, or a combination thereof,

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repetition function to the distribution unit twice through two different tunnels on an F1 interface; or the like, or, alternatively,

the sending subunit is specifically configured to send, to the distribution unit, two identical data packets of the radio bearer configured with the PDCP duplicate function through a control plane message on an F1 interface, respectively.

When the centralized unit does not activate the PDCP repetition function of the radio bearer supporting the PDCP repetition function,

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repeat function to the distribution unit through an F1 interface, so that the distribution unit sequentially sends the data packet to the user equipment via an assigned or selected RLC entity, a corresponding logical channel of the RLC entity, an MAC layer, and a cell.

The sending subunit sends the data packet of the radio bearer configured with the PDCP repetition function to the distribution unit through a tunnel on an F1 interface or a control plane message on an F1 interface;

and, when the sending subunit sends the data packet of the radio bearer configured with the PDCP repetition function to the distribution unit, one tunnel on the F1 interface includes a designated tunnel or an optional tunnel.

When the data packet of the radio bearer configured with the PDCP repeat function is uplink data, the central unit further includes:

a receiving subunit, configured to receive the data packet of the radio bearer configured with the PDCP repeat function sent by the distributing unit;

the processing subunit is configured to process the received data packet of the radio bearer configured with the PDCP repetition function through a PDCP layer to obtain a PDCP service data unit SDU of the radio bearer configured with the PDCP repetition function.

The configuration instruction message of the radio bearer supporting the PDCP repetition function, which is sent by the sending subunit to the distributing unit, includes at least one of the following information:

information supporting a PDCP repetition function;

configuration information of at least one tunnel on the F1 interface;

identifying an indication of a duplicate packet.

The concentration unit further comprises:

a receiving subunit, configured to receive the configuration response message returned by the distribution unit; wherein the configuration response message includes configuration information of at least one tunnel on the F1 interface.

The configuration information of at least one tunnel on the F1 interface included in the configuration instruction message is specifically address information of a data packet of the radio bearer supporting the PDCP repetition function, which is received or sent by the central unit; the configuration information of the at least one tunnel on the F1 interface included in the configuration response message is specifically address information of a data packet of the radio bearer supporting the PDCP repetition function, which is received or sent by the distribution unit side.

The data packet of the radio bearer configured with the PDCP repetition function includes: data packets configured with a PDCP repetition function data radio bearer and/or data packets configured with a PDCP repetition function signaling radio bearer.

The present invention also provides a distribution unit, comprising:

a receiving subunit, configured to receive a configuration instruction message of a radio bearer supporting the PDCP repetition function sent by the central unit;

a processing subunit, configured to perform, with the central unit, transmission of data packets of the radio bearer configured with the PDCP repeat function.

When the data packet of the radio bearer configured with the PDCP repeat function is downlink data, the distributing unit further includes:

the receiving subunit is configured to receive, through an F1 interface with the central unit, a packet of the radio bearer configured with the PDCP duplication function;

a sending subunit, configured to send the data packets of the radio bearer configured with the PDCP repeat function to two different cells, respectively.

the receiving subunit is configured to receive, through a tunnel on an F1 interface, the data packet of the radio bearer configured with the PDCP repeat function sent by the central unit;

the sending subunit is specifically configured to send two identical data packets of the radio bearer configured with the PDCP repetition function to two different cells through two different RLC entities and their respective corresponding logical channels via an MAC layer, respectively.

the receiving subunit is configured to receive, by two times through one or two tunnels on an F1 interface, two identical data packets of the radio bearer configured with the PDCP duplicate function sent by the central unit;

the receiving subunit is configured to receive, through a control plane message on an F1 interface, two times the same data packets of the radio bearer configured with the PDCP repeat function sent by the central unit;

the receiving subunit is specifically configured to receive the data packet of the radio bearer configured with the PDCP repeat function, which is sent by the central unit through an F1 interface;

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repeat function to the user equipment after passing through the designated or selected RLC entity, the corresponding logical channel, the MAC layer, and a cell in sequence.

When the data packet of the radio bearer configured with the PDCP repetition function is uplink data, the distributing unit further includes:

a sending subunit, configured to send, to the central unit, the data packet of the radio bearer configured with the PDCP repetition function.

the sending subunit is specifically configured to send, to the central unit, two identical data packets of the radio bearer configured with the PDCP repetition function, acquired from two different cells, through one tunnel or two tunnels on the F1 interface or a control plane message on the F1 interface, where the two identical data packets are acquired through a physical layer, an MAC layer, two different logical channels of each cell, and its corresponding RLC entity.

the sending subunit is specifically configured to send, to the central unit, the data packet of the radio bearer configured with the PDCP repetition function, acquired from one cell, through an F1 interface, where the data packet is obtained through a physical layer, an MAC layer, a logical channel of the cell, and an RLC entity corresponding to the logical channel.

The distribution unit sends the data packet of the radio bearer configured with the PDCP duplicate function, which is obtained from a cell via the physical layer, MAC layer, logical channel of the cell and its corresponding RLC entity, to the concentration unit through a tunnel on the F1 interface or a control plane message on the F1 interface.

One tunnel on the F1 interface includes a designated tunnel or an optional tunnel, and the RLC entities include designated RLC entities or optional RLC entities.

The distribution unit further includes:

a sending subunit, configured to send, to the central unit, a configuration response message carrying configuration information of at least one tunnel on the F1 interface.

The configuration information of at least one tunnel on the F1 interface included in the configuration response message is specifically address information of a data packet of the radio bearer supporting the PDCP repetition function, which is received by the receiving subunit or sent by the sending subunit.

The data packet of the radio bearer configured with the PDCP repeat function comprises: data packets configured with a PDCP repetition function data radio bearer and/or data packets configured with a PDCP repetition function signaling radio bearer.

In the above embodiment, the transmission of the bearer supporting the PDCP repetition function between the central unit and the distributed unit in one base station over the F1 interface is mainly discussed, but in an actual system, the bearer supporting the PDCP repetition function may also be transmitted over an interface (e.g., X2 interface, Xn interface) between two base stations (e.g., between an eNB and a gNB, between two enbs, between two gnbs, etc.), and for the transmission of the bearer supporting the PDCP repetition function between the two base stations over the interface, since the processing procedure is the same as the transmission processing of the bearer supporting the PDCP repetition function between the central unit and the distributed unit in one base station over the F1 interface, the detailed description is not repeated here.

Based on this, the present invention further provides a data transmission method supporting the PDCP repeat function, as shown in fig. 5, the method includes:

in step 501, a first network device sends a configuration instruction message of a radio bearer supporting a PDCP repeat function to a second network device.

Step 502, the first network device and the second network device perform transmission of data packets of the radio bearer configured with the PDCP repeat function.

The first network equipment is a first base station, and the second network equipment is a second base station; or, the first network device is a centralized unit in the base station, and the second network device is a distributed unit in the base station.

Based on the system and the data transmission method supporting the PDCP repetition function provided by the present invention, five embodiments are specifically described below, and of course, the five embodiments are mainly described with respect to the central unit and the distribution unit in the base station.

Example one

In the first embodiment, the method includes the following steps:

step A: the gNB-CU sends a request message for configuring the data radio bearer supporting the PDCP repeat function to the gNB-DU, and the message at least contains one or more of the following information for each data radio bearer supporting the PDCP repeat function:

1) the information supporting the PDCP repetition function may be implemented in a manner that:

mode 1: indication information supporting the PDCP repeat function, wherein the indication information indicates that the data radio bearer supports the PDCP repeat function;

the method comprises the following steps: type information of a data radio bearer, the type information indicating that the data radio bearer is a data radio bearer supporting a PDCP repetition function;

mode 3: identification information of the data radio bearer, predefining or preconfiguring one or more identifications of the data radio bearer for supporting the PDCP repetition function, if the identification of the data radio bearer indicates that it belongs to the data radio bearer for supporting the PDCP repetition function, the data radio bearer supports the PDCP repetition function.

Further, the information supporting the PDCP repetition function may further include an indication information of uplink and downlink, where the indication information indicates that the uplink supports the PDCP repetition function, or the downlink supports the PDCP repetition function, or both the uplink and the downlink support the PDCP repetition function; if the indication information of the uplink and the downlink is not included, the information supporting the PDCP repetition function may indicate that both the uplink and the downlink support the PDCP repetition function, or the downlink supports the PDCP repetition function, or the uplink supports the PDCP repetition function, or the PDCP repetition function is supported in a default direction (uplink or downlink or uplink and downlink).

2) Some or all of configuration information of at least one RLC entity corresponding to the data radio bearer. The data radio bearer supporting the PDCP repetition function has two RLC entities, but the configuration message may include part or all of configuration information of one RLC entity, or may include part or all of configuration information of two RLC entities. For example, in the case of including configuration information of an RLC entity, a configuration message indicating that the existing RLC entity of the data radio bearer can be multiplexed, and the included configuration information of the RLC entity is for a newly added RLC entity; for the case of containing configuration information of two RLC entities, if the gNB-DU already has configuration information of at least one RLC entity of the data radio bearer, the newly received configuration information of the two RLC entities may overwrite the existing information, and if the gNB-DU does not have any information about the RLC entity corresponding to the data radio bearer, the gNB-DU directly uses the newly received configuration information of the two RLC entities. In addition, the configuration information of each RLC entity may include indication information of whether the RLC entity is a main RLC entity (or referred to as a default RLC entity) (if one RLC entity is not configured as a main RLC entity, the indication information may not be included; alternatively, the main RLC entity does not include indication information, and the non-main RLC entity adds an indication information indicating that the non-main RLC entity is not configured as a main RLC entity). The indication information may be optional or mandatory. The indication information has the functions of: for downlink data transmission, the indication message is used to indicate how the gNB-DU distributes the received PDCP PDUs to two RLC entities configured for the data radio bearer; for uplink data transmission, the indication message is used to indicate how the gNB-DU distributes data belonging to the data radio bearer received from different cells to the two RLC entities configured for the data radio bearer. The indication information may indicate the RLC entity (e.g., primary RLC entity) that the gNB-DU needs to use when only one RLC entity needs to be used. For example, if one RLC entity is indicated as the primary RLC entity, when the data radio bearer is configured to support the PDCP repetition function and the function is not activated yet, for downlink data, the PDCP PDUs belonging to the data radio bearer from the gNB-CU are sent to the primary RLC entity only, and for uplink data, the data belonging to the data radio bearer received by the gNB-DU are sent to the primary RLC entity through the logical channel corresponding to the primary RLC entity. For another example, when the data radio bearer is configured to support PDCP repetition function and the function has been activated for use, for downlink data, each time a PDCP PDU belonging to the data radio bearer is received from a gbb-CU, it is sent to the primary RLC entity if it is received for the first time and to another RLC entity (non-primary RLC entity) if it is received for the second time.

3) For the data radio bearer, identification information and/or configuration information of a logical channel corresponding to at least one configured RLC entity, where the configuration information includes restriction information mapped to the logical channel, which indicates that data of the logical channel can only be sent to a cell or a carrier indicated by the restriction information.

4) Configuration information for at least one tunnel of the data radio bearer. This information provides information of the tunnel established for sending the data of the data radio bearer over the F1 interface. The data radio bearer supporting the PDCP repetition function may have two tunnels, where the information includes information of at least one Tunnel on the side of the gNB-CU, and the information of each Tunnel includes information or address information on the side of the gNB-CU, such as a gNB-CU GTP Tunnel Endpoint information (gNB-CU GTP Tunnel Endpoint) (including a transport layer address and a GTP TEID). For the case of containing the configuration information of a tunnel, the configuration message indicating that the data radio bearer has the tunnel can be multiplexed, and the contained tunnel configuration information is for a newly added tunnel; for the case of containing the configuration information of two tunnels, if there is already configuration information of at least one tunnel of the data radio bearer, the newly received configuration information of the two tunnels may overwrite the existing information, and if there is no configuration information about the tunnel corresponding to the data radio bearer, the newly received configuration information of the two tunnels is directly used. The method also comprises indication information of whether the tunnel is a main tunnel (or a default tunnel) (if one tunnel is not configured as a main tunnel, the indication information can also not be included; or in another way, if one tunnel is a main tunnel, the indication information is not included, but the indication information is added into the configuration information of the non-main tunnel to indicate that the tunnel is not a main tunnel), and the indication information can be optional or optional. The indication information has the functions of: for downlink data transmission, the indication message is used to indicate how the gNB-CU sends PDCP PDUs to the gNB-DU; for uplink data transmission, the indication message is used to indicate how the gNB-DU sends PDCP PDUs to the gNB-CU. The indication information may indicate a tunnel (e.g., a primary tunnel) that needs to be used between the gNB-CU and the gNB-DU when only one tunnel needs to be used. For example, if one tunnel is indicated as the primary tunnel, when the data radio bearer is configured to support the PDCP repetition function and the function is not yet activated for use, for downlink data, PDCP PDUs belonging to the data radio bearer from the gNB-CU are sent to the gNB-DU through the tunnel, and for uplink data, data belonging to the data radio bearer received by the gNB-DU are sent to the gNB-CU only through the tunnel. For another example, when the data radio bearer is configured to support PDCP repetition function and the function has been activated for use, for uplink data, whenever one RLC entity gets one PDCP PDU of the data radio bearer, it is sent to the gNB-CU via the primary tunnel if it is the first time, and via another tunnel (non-primary tunnel) if it is the second time.

5) And the corresponding relation information of the tunnel and the RLC entity. As can be seen from the above description, each data radio bearer has two corresponding tunnels, two RLC entities and the identification and configuration information of the logical channel corresponding to each RLC entity.

The corresponding relationship between the RLC entity and the tunnel of the F1 interface may be as follows:

mode 1: each RLC entity has a tunnel on the F1 interface, for example, tunnel 1 corresponds to RLC entity 1, tunnel 2 corresponds to RLC entity 2, the main tunnel corresponds to the main RLC entity, the main tunnel corresponds to the non-main RLC entity, and the non-main tunnel corresponds to the main RLC entity;

mode 2: the RLC entity has no correspondence with the tunnel on the F1 interface.

According to the above description about the information in the request message in step a, the structure of the configuration information of the data radio bearer may be as follows:

when the RLC entity has a corresponding tunnel on the F1 interface

1) Information supporting a PDCP repetition function;

2) configuration information of RLC entity 1;

3) identification and/or configuration information of a logical channel corresponding to the RLC entity 1;

4) the gNB-CU side information or address information of the tunnel 1 corresponding to the RLC entity 1;

5) configuration information of RLC entity 2;

6) identification and/or configuration information of a logical channel corresponding to the RLC entity 2; (ii) a

7) The gNB-CU side information or address information of the tunnel 2 corresponding to the RLC entity 2;

when the RLC entity has no corresponding relation with the tunnel on the F1 interface

1) Information supporting a PDCP repetition function;

2) configuration information of RLC entity 1;

4) configuration information of RLC entity 2;

5) identification and/or configuration information of a logical channel corresponding to the RLC entity 2;

6) gNB-CU side information or address information of tunnel 1;

7) the gbb-CU side information or address information of the tunnel 2.

And B: if the gNB-DU accepts the configuration of the data radio bearer in step A, the gNB-DU performs the relevant configuration, and feeds back a response message to the gNB-CU for configuring the data radio bearer supporting the PDCP repeat function, wherein the message at least contains the following information:

for the tunnel information of the data radio bearer, it provides information of the tunnel established for transmitting the data of the data radio bearer over the F1 interface. The information includes information of the gbb-DU side of at least one established Tunnel (e.g., information of the DU side of Tunnel 1, and information of the DU side of Tunnel 2), and the information of each Tunnel includes address information of the DU side, such as gbb-DU GTP Tunnel Endpoint information (gbb-DU GTP Tunnel Endpoint) (including a transport layer address and a GTP TEID).

And C: the PDCP repetition function is activated. This step is an optional step. The step includes activating a gNB-CU, a gNB-DU and a PDCP repeat function at the UE side, and possible implementation manners include:

mode 1: the gNB-CU activates the gNB-DU and/or the PDCP repeat function of the data radio bearer at the UE side. And the gNB-CU sends PDCP repeat function activation information to the gNB-DU and/or the UE, the gNB-DU side activates the PDCP repeat function of the data radio bearer, the PDCP repeat function of the data radio bearer can be carried out according to the configuration information in the steps A and B, the UE side also activates the PDCP repeat function of the data radio bearer, and the PDCP repeat function of the data radio bearer can be carried out according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates activation of the uplink and downlink PDCP repetition function, or indicates activation of the uplink PDCP repetition function, or indicates activation of the downlink PDCP repetition function, or indicates activation of the PDCP repetition function in the default direction (uplink or downlink or uplink and downlink). The activation order here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated, the UE side may be activated first and then the gNB-DU side may be activated, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-CU, the gNB-DU may reply whether activation is successful. And if the reply activation is successful, activating the PDCP repeat function on the gNB-DU side, otherwise, not activating. Further, after the PDCP repetition function is activated, the gNB-CU may also send deactivation information to the gNB-DU and/or the UE, optionally, the gNB-DU may reply whether the deactivation is successful, if the deactivation is successful, the gNB-DU side stops the PDCP repetition function, and otherwise, the PDCP repetition function is continuously used.

Mode 2: the gNB-DU activates a PDCP repeat function of the gNB-CU and/or the data radio bearer at the UE side. And the gNB-DU sends PDCP repeat function activation information to the gNB-CU and/or the UE, the gNB-CU side activates the PDCP repeat function of the data radio bearer, performs data transmission of the data radio bearer according to the configuration information in the steps A and B (sends the repeated PDCP PDU to the gNB-DU through an F1 interface or receives the repeated PDCP PDU sent by the gNB-DU), and the UE side also activates the PDCP repeat function of the data radio bearer, and performs data transmission of the data radio bearer according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates activation of the uplink and downlink PDCP repetition function, or indicates activation of the uplink PDCP repetition function, or indicates activation of the downlink PDCP repetition function, or indicates activation of the PDCP repetition function in a default direction (uplink or downlink). The activation order here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated, the UE side may be activated first and then the gNB-DU side may be activated, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-DU, the gNB-CU may reply whether activation is successful. And if the reply activation is successful, activating the PDCP repeat function by the gNB-CU side, and otherwise, not activating. Further, after the PDCP repetition function is activated, the gNB-DU may also send deactivation information to the gNB-CU and/or the UE, optionally, the gNB-CU may reply whether the deactivation is successful, if the deactivation is successful, the side of the gNB-CU stops the PDCP repetition function, and otherwise, the PDCP repetition function continues to be used.

If step C is performed, indicating that the PDCP repeat function of the data radio bearer is already activated on the gNB-CU, gNB-DU and UE sides, step D is performed. Without step C, there are two possibilities: 1) after steps a and B are finished, the PDCP repetition function of the data radio bearer is already activated on the gNB-CU, gNB-DU and UE side (the UE side activation has been activated by a separate signaling), and for this possibility, step D is executed; 2) after the end of steps a and B, the gbb-CU, the gbb-DU and the UE side have completed the configuration of the PDCP duplicate function, but the function has not been activated, and E is performed for this possibility.

Step D: data of the data radio bearer in which the PDCP repetition function is activated is transmitted. This step is performed after the PDCP repetition function of the data radio bearer is activated (i.e., data of the data radio bearer is transmitted between the gbb-CU, the gbb-DU, and the UE according to the configuration of the corresponding PDCP repetition function). If the data radio bearer is downlink, the step comprises the sub-steps of:

substep D-a (down): the gNB-CU copies one PDCP PDU to obtain two identical PDCP PDUs, or sends one PDCP PDU twice;

substep D-b (Down): the two same PDCP PDUs obtained in the step D-a (downlink) are respectively sent to the gNB-DU through two different tunnels (tunnels) on an F1 interface (such as an F1-U Tunnel 1 and an F1-U Tunnel 2);

substeps D-c (Down): the gNB-DU sends the received two identical PDCP PDUs to two different RLC entities (e.g., RLC1 and RLC2), and then sends the two identical PDCP PDUs to the MAC layer through two different logical channels (e.g., logical channel 1 and logical channel 2), and finally the MAC layer sends the data from the two different logical channels to two different cells (e.g., cell 1 and cell 2, which may be different in frequency or the same in frequency) through two different cells, respectively. How the data received by the gNB-DU from the two tunnels is distributed to the two RLC entities may be implemented as follows:

mode 1: if each tunnel has a specified corresponding relation with the RLC entity, the data on each tunnel is sent to the specified RLC entity according to the specified relation, for example, the data on the tunnel 1 is sent to the RLC1, and the data on the tunnel 2 is sent to the RLC 2;

mode 2: if each tunnel has no assigned corresponding relation with the RLC entity, the gNB-DU can be set by itself. One embodiment is: the gNB-DU sets the data on the tunnel 1 to be sent to the RLC1, and the data on the tunnel 2 to be sent to the RLC 2; another embodiment is: for two identical PDCP PDUs received from two tunnels, the first received is sent to RLC1 and the second received is sent to RLC2, in this way the gNB-DU needs to identify if the two PDCP PDUs received from two tunnels are identical; yet another embodiment is: once a gNB-DU receives a data packet (such as a PDCP PDU1) from one of the two tunnels, the gNB-DU copies the data packet by itself to obtain two identical data packets, and then sends the data packets to two RLC entities (RLC1 and RLC2) respectively, or sends the data packets twice by itself to two RLC entities (RLC1 and RLC2) respectively; thereafter, if the gNB-DU receives a same data packet (e.g., PDCP PDU1) again (it is also required that the gNB-DU has a function of recognizing whether the two PDCP PDUs received from the two tunnels are the same or not), the gNB-DU may discard the data packet because the data packet has been transmitted to different RLC entities, or may copy the data packet so as to obtain two same data packets, and then transmit the data packets to the two RLC entities (RLC1 and RLC2), respectively, or may transmit the data packets twice by itself to the two RLC entities (RLC1 and RLC2), respectively. It may also be determined by the gNB-DU based on existing configuration, for example, for two identical PDCP PDUs, for the first received PDU, the DU is sent to a specific RLC entity (e.g., RLC1), which may be the configured primary RLC entity (or default RLC entity), and for the second received PDU, the gNB-DU is sent to another RLC entity (non-primary RLC entity), in such a way that the gNB-DU needs to identify whether the two PDCP PDUs received from the two tunnels are identical;

if the data radio bearer is uplink, the step includes the sub-steps of:

substep D-a (upper row): the gNB-DU receives data from two different cells (such as cell 1 and cell 2, which may have different or same frequency) respectively, and after the data is processed by a physical layer and an MAC layer, the data of the two different cells are sent to two different RLC entities (such as RLC1 and RLC2) by two different logical channels (such as logical channel 1 and logical channel 2) respectively;

substep D-b (upper line): the data processed by the two RLC entities are respectively sent to the CU through two different tunnels (e.g., tunnel 1 and tunnel 2) of the F1 interface; how the gNB-DU distributes data output by two RLC entities to two tunnels, possible implementations are:

mode 1: if each tunnel has a specified corresponding relationship with the RLC entity, transmitting data output by each RLC entity to the specified tunnel according to the corresponding relationship, for example, transmitting data output by RLC1 to CU through tunnel 1, and transmitting data output by RLC2 to CU through tunnel 2;

mode 2: if each tunnel has no corresponding relation with the RLC entity, the gNB-DU can be set by itself. One embodiment is: the gNB-DU sets that data output by RLC1 is sent to the CU through a tunnel 1, and data output by RLC2 is sent to the CU through a tunnel 2; another embodiment is: for two identical PDCP PDUs output from two RLC entities, the first one is output to tunnel 1 and the second one is output to tunnel 2, in this way, the gNB-DU needs to identify whether the two PDCP PDUs output from the two RLC entities are identical; yet another embodiment is: once a packet (e.g., PDCP PDU1) is output by one of the two RLC entities on the gbb-DU, the packet is copied by itself to obtain two identical packets and then sent to the two tunnels (tunnel 1 and tunnel 2), and then if the gbb-DU obtains another identical packet (e.g., PDCP PDU1) (here, it is also required that the gbb-DU has the function of identifying whether the two PDCP PDUs output from the two RLC entities are identical) because the packet has already been sent to the gbb-CU, the gbb-DU can discard the packet, or the packet can be copied to obtain two identical packets and then sent to the two tunnels (tunnel 1 and tunnel 2). The gNB-DU may also determine according to the existing configuration, for example, for two identical PDCP PDUs output from two RLC entities, for the first output PDU, the gNB-DU will be sent to a specified tunnel (e.g., tunnel 1), which may be a primary tunnel (or referred to as a default tunnel), and for the second output PDU, the gNB-DU will be sent to another tunnel (e.g., a non-primary tunnel), in this way, the gNB-DU needs to identify whether the two PDCP PDUs output from the two RLC entities are identical;

substeps D-c (upper row): the CU processes the received PDCP PDU through a PDCP layer (such as discarding repeated PDCP PDUs) to obtain PDCP SDUs.

Step E: data of the data radio bearer configured but not activated for the PDCP repetition function is transmitted. For downlink data transmission, the following implementation manners may be included:

mode 1: if a tunnel (such as a main tunnel or a default tunnel) that should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, an RLC entity (such as a main RLC entity or a default RLC entity) is configured, the gNB-CU sends PDCP PDUs of the data radio bearer to the specified RLC entity (such as the main RLC entity or the default RLC entity) through the specified tunnel (such as the main tunnel or the default tunnel) on the F1 interface, and then sends the PDCP PDUs to the MAC layer via a logical channel corresponding to the specified RLC entity, and then sends the PDCP PDUs to the user via one cell.

Mode 2: if the tunnel (such as the main tunnel or the default tunnel) which should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, but the RLC entity which should be used is not specified, the CU sends the PDCP PDU of the data radio bearer to the gNB-DU through the specified tunnel (such as the main tunnel or the default tunnel) on the F1 interface, and the gNB-DU selects a configured RLC entity by itself, and then sends the selected RLC entity to the MAC layer via the logical channel corresponding to the RLC entity, and then sends the selected RLC entity to the user via a cell.

Mode 3: if the RLC entity (such as the main RLC entity or the default RLC entity) which is adopted when the PDCP repeat function is configured but not activated is specified in the step A and/or the step B, but a tunnel is not specified, the gNB-CU determines a configured tunnel by itself, sends the PDCP PDUs of the data radio bearer to the gNB-DU through the tunnel, then the gNB-DU delivers the received PDCP PDUs to the specified RLC entity (such as the main RLC entity or the default RLC entity), then sends the PDCP PDUs to the MAC layer through the corresponding logical channel of the specified RLC entity, and then sends the PDCP PDUs to a user through a cell.

Mode 4: if the tunnel and the RLC entity which are used when the PDCP repeat function is configured but not activated are not specified in the step A and/or the step B, the CU determines a configured tunnel by itself, sends the PDCP PDUs of the data radio bearer to the gNB-DU through the tunnel, selects a configured RLC entity by itself by the gNB-DU, sends the selected RLC entity to the MAC layer through a corresponding logical channel of the RLC entity, and sends the selected RLC entity to the user through a cell.

For uplink data transmission, the following implementation manners may be included:

mode 1: if the tunnel (such as the main tunnel or the default tunnel) that should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, the RLC entity (such as the main RLC entity or the default RLC entity) is configured, the gbb-DU sends the data of the data radio bearer received from a cell to the specified RLC entity (the main RLC entity or the default RLC entity) for processing after being processed by the physical layer and the MAC layer, the processed PDCP PDU is sent to the gbb-CU by the specified tunnel (such as the main tunnel or the default tunnel) on the F1 interface, and finally, the PDCP SDU is obtained after being processed by the PDCP layer.

Mode 2: if the tunnel (such as the main tunnel or the default tunnel) which should be used when the PDCP repeat function is configured but not activated is specified in the step a and/or B, but the RLC entity is not specified, the gbb-DU sends the data of the data radio bearer received from a cell to the corresponding RLC entity for processing after being processed by the physical layer and the MAC layer, the processed PDCP PDU is sent to the gbb-CU by the specified tunnel (such as the main tunnel or the default tunnel) on the F1 interface, and finally, the PDCP SDU is obtained after being processed by the PDCP layer.

Mode 3: if the RLC entity (such as the main RLC entity or the default RLC entity) which should be used when the PDCP repetition function is configured but not activated is specified in the step a and/or B, but a tunnel is not specified, the gbb-DU will send data received from a cell to the specified RLC entity (the specified logical channel corresponds to the specified RLC entity) for processing after being processed by the physical layer and the MAC layer, the processed PDCP PDU is sent to the gbb-CU by the gbb-DU selecting a tunnel on the F1 interface, and finally the PDCP SDU is obtained after being processed by the PDCP layer.

Mode 4: if the tunnel and the RLC entity which should be used when the PDCP repeat function is configured but not activated are not specified in the step a and/or B, the gbb-DU sends the data of the data radio bearer received from a cell to the corresponding RLC entity for processing after being processed by the physical layer and the MAC layer, the processed PDCP PDU is sent to the gbb-CU by the gbb-DU selecting a tunnel on the F1 interface, and finally the PDCP SDU is obtained after being processed by the PDCP layer.

The message names in steps a and B are only examples, and the configuration information related to the above steps may be sent in other messages. Such as UE context setup request and UE context setup response, bearer setup request and bearer setup response, DL RRC message transfer and UL RRC message transfer, etc.

In addition, steps a and B may be used to modify the existing configuration of the data radio bearer. If the data radio bearer is already configured as a normal bearer that does not support the PDCP repetition function, but needs to be configured as a data radio bearer that supports the PDCP repetition function in order to improve the reliability of data transmission of the data radio bearer, steps a and B may be used to change the configuration of the data radio bearer, that is, the configuration messages in steps a and B are sent through a bearer modification request message and a bearer modification response message; alternatively, only the newly added information or the configuration information that needs to be modified is included in steps a and B, for example, for the data radio bearer, the following information is already configured when the PDCP repetition function is not supported:

RLC entity 1 configuration information;

identification information of a logical channel corresponding to the RLC entity 1;

configuration information of a logical channel corresponding to the RLC entity 1;

and tunnel information of the gNB-CU side and the gNB-DU side of the tunnel 1 established for the data radio bearer on the F1 interface.

When the data radio bearer is to be configured as a data radio bearer supporting the PDCP repeat function, the modified existing configuration information and the newly added information are sent to the gNB-DU in step a based on the existing configuration information, for example, the modified existing configuration information includes:

an update part of the configuration information of the RLC entity 1, for example, indication information indicating whether the entity is a main RLC entity is added;

an update part of configuration information of a logical channel corresponding to the RLC entity 1, such as restriction information added with logical channel mapping;

an updated part of the information of the tunnel 1 established for the data radio bearer on the F1 interface, for example, indication information indicating whether the tunnel is a main tunnel is added;

the newly added information includes:

configuration information of RLC entity 2;

identification information of a logical channel corresponding to the RLC entity 2;

configuration information of a logical channel corresponding to the RLC entity 2;

CU side tunnel information of tunnel 2 established for the data radio bearer on F1 interface.

The information sent by the gNB-DU in step B includes:

tunnel information on the gbb-DU side of tunnel 2 established for the data radio bearer on the F1 interface.

Example two

In the first embodiment, two tunnels are established for each data radio bearer, and the two identical duplicated PDCP PDUs (or two PDCP PDUs obtained by sending one PDCP PDU twice) are transmitted through two different tunnels, respectively, whereas in the second embodiment, the two identical duplicated PDCP PDUs (or two PDCP PDUs obtained by sending one PDCP PDU twice) are transmitted through the same tunnel, and two RLC entities and logical channel identifiers and/or configurations corresponding to each RLC entity are configured in the gNB-DU for the data radio bearer. The method comprises the following steps:

step A: the gNB-CU sends a request message for configuring the data radio bearers supporting the PDCP repeat function to the gNB-DU, and the message at least contains one or more of the following information for each data radio bearer supporting the PDCP repeat function:

the method comprises the following steps: type information of a data radio bearer, the type information indicating that the data radio bearer supports a data radio bearer of a PDCP repeat function;

mode 3: identification information of a data radio bearer, predefining or preconfiguring one or more identifications on the data radio bearer supporting the PDCP repetition function, if the identification of the data radio bearer indicates that it belongs to the data radio bearer supporting the PDCP repetition function, the data radio bearer supporting the PDCP repetition function.

Further, the information for supporting the PDCP repetition function may further include indication information of uplink and downlink, where the indication information indicates that the uplink supports the PDCP repetition function, or the downlink supports the PDCP repetition function, or both the uplink and the downlink support the PDCP repetition function, and if the indication information is not included, the information for supporting the PDCP repetition function may indicate that both the uplink and the downlink support the PDCP repetition function, or the downlink supports the PDCP repetition function, or the uplink supports the PDCP repetition function, or the PDCP repetition function is supported in a default direction (uplink or downlink or uplink and downlink).

2) Some or all of configuration information of at least one RLC entity corresponding to the data radio bearer. The data radio bearer supporting the PDCP repeat function has two RLC entities, but the configuration message may include part or all of configuration information of one RLC entity, or may include part or all of configuration information of two RLC entities (if only part of configuration information is included, it indicates that the configuration information not included may multiplex the existing configuration). For example, in the case of including configuration information of an RLC entity, a configuration message indicating that the existing RLC entity of the data radio bearer can be multiplexed, and the included configuration information of the RLC entity is for a newly added RLC entity; for the case of containing configuration information of two RLC entities, if the gNB-DU already has configuration information of at least one RLC entity of the data radio bearer, the newly received configuration information of the two RLC entities may overwrite the existing information, and if the gNB-DU does not have any information about the RLC entity corresponding to the data radio bearer, the gNB-DU directly uses the newly received configuration information of the two RLC entities. In addition, the configuration information of each RLC entity may include indication information of whether the RLC entity is a main RLC entity (or referred to as a default RLC entity) (if one RLC entity is not configured as a main RLC entity, the indication information may not be included; alternatively, the main RLC entity does not include indication information, and the non-main RLC entity adds an indication information indicating that the non-main RLC entity is not configured as a main RLC entity). The indication information may be optional or mandatory. The indication information has the functions of: for downlink data transmission, the indication message is used to indicate how the gNB-DU distributes the received PDCP PDUs to two RLC entities configured for the data radio bearer; for uplink data transmission, the indication message is used to indicate how the gNB-DU distributes data received from different cells belonging to the data radio bearer to the two RLC entities configured for the data radio bearer. The indication information may indicate the RLC entity (e.g., primary RLC entity) that the gNB-DU needs to use when only one RLC entity needs to be used. For example, if one RLC entity is indicated as the primary RLC entity, when the data radio bearer is configured to support the PDCP repetition function and the function is not yet activated for use, for downlink data, the PDCP PDUs belonging to the data radio bearer from the gNB-CU are sent to the primary RLC entity only, and for uplink data, the data belonging to the data radio bearer received by the DU is sent to the primary RLC entity. Another example is when the data radio bearer is configured to support PDCP repetition functionality and this functionality has been activated for use, for downlink data, each time a PDCP PDU belonging to the data radio bearer is received from a gbb-CU, it is sent to the primary RLC entity if it was received for the first time and to another RLC entity (non-primary RLC entity) if it was received for the second time.

3) For the data radio bearer, the identification information and/or configuration information of the logical channel corresponding to at least one configured RLC entity includes restriction information mapped to the logical channel in the configuration information, which indicates that data of the logical channel can only be sent to a cell or a carrier indicated by the restriction information.

4) Configuration information for one tunnel of the data radio bearer. This information provides information of the tunnel established for sending the data of the data radio bearer over the F1 interface. The information includes information of a Tunnel on the side of the gNB-CU, such as gNB-CU GTP Tunnel Endpoint information (gNB-CU GTP Tunnel Endpoint) (including transport layer address and GTP TEID).

5) Identifying indication information of the duplicate PDCP PDUs. The indication information indicates the gNB-DU which identifies whether the received PDCP PDUs are identical or not according to what kind of information. For example, the indication information indicates that the gNB-DU identifies whether the received two PDCP PDUs are two identical PDUs according to the sequence number of the G-PDU, or according to the sequence number of the F1 interface user plane, or according to the PDCP SNs in the extension header included in the GTP-PDU. This information is optionally identified by the gNB-DU by default settings if this information is not included, which default settings may be identified by default from the sequence number of the G-PDU or by default from the sequence number of the F1 interface user plane, or by default from the PDCP SN in the extension header included in the GTP-PDU, or by default from comparing each PDCP PDU received.

And B: if the gNB-DU accepts the configuration of the data radio bearer in the step A, the gNB-DU performs the relevant configuration, and feeds back a response message for configuring the data radio bearer supporting the PDCP repeat function to the gNB-CU, which indicates whether the gNB-DU accepts the configuration of the data radio bearer in the step A, and the response message is optional. The response message contains information of a Tunnel on the gbb-DU side, such as the gbb-DU GTP Tunnel Endpoint information (gbb-DU GTP Tunnel Endpoint) (containing the transport layer address and GTP TEID).

mode 1: the gNB-CU activates the gNB-DU and/or the PDCP repeat function of the data radio bearer at the UE side. And the gNB-CU sends PDCP repeat function activation information to the gNB-DU and/or the UE, the gNB-DU side activates the PDCP repeat function of the data radio bearer, the data transmission of the data radio bearer is carried out according to the configuration information in the steps A and B, and the UE side also activates the PDCP repeat function of the data radio bearer, and the data transmission of the data radio bearer is carried out according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates activation of the uplink and downlink PDCP repetition function, or indicates activation of the uplink PDCP repetition function, or indicates activation of the downlink PDCP repetition function, or indicates activation of the PDCP repetition function in the default direction (uplink or downlink or uplink and downlink). The activation order here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated, the UE side may be activated first and then the gNB-DU side may be activated, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-CU, the gNB-DU may reply whether the activation is successful. If the reply activation is successful, the gNB-DU side activates the PDCP repeat function, otherwise, the PDCP repeat function is not activated. Further, after the PDCP repetition function is activated, the gNB-CU may also send deactivation information to the gNB-DU and/or the UE, optionally, the gNB-DU may reply whether the deactivation is successful, if the deactivation is successful, the side of the gNB-DU stops the PDCP repetition function, and otherwise, the PDCP repetition function is continuously used.

Mode 2: the gNB-DU activates a PDCP repeat function of the gNB-CU and/or the data radio bearer at the UE side. And the gNB-DU sends PDCP repeat function activation information to the gNB-CU and/or the UE, the gNB-CU side activates the PDCP repeat function of the data radio bearer, performs data transmission of the data radio bearer according to the configuration information in the steps A and B (sends the repeated PDCP PDU to the gNB-DU through an F1 interface or receives the repeated PDCP PDU sent by the gNB-DU), and the UE side also activates the PDCP repeat function of the data radio bearer, and performs data transmission of the data radio bearer according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates that the uplink and downlink PDCP repeat function is activated, or indicates that the uplink PDCP repeat function is activated, or indicates that the downlink PDCP repeat function is activated, or indicates that the PDCP repeat function in the default direction (uplink or downlink or uplink and downlink) is activated. The activation order here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated, the UE side may be activated first and then the gNB-DU side may be activated, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-DU, the gNB-CU may reply whether activation is successful. And if the reply activation is successful, activating the PDCP repeat function by the gNB-CU side, and otherwise, not activating. Further, after the PDCP repetition function is activated, the gNB-DU may also send deactivation information to the gNB-CU and/or the UE, optionally, the gNB-CU may reply whether the deactivation is successful, if the deactivation is successful, the side of the gNB-CU stops the PDCP repetition function, and otherwise, the PDCP repetition function continues to be used.

If step C is performed, indicating that the PDCP repeat function of the data radio bearer is already activated at the gNB-CU, the gNB-DU and the UE side, step D is performed. Without step C, there are two possibilities: 1) after steps a and B are finished, the PDCP repetition function of the data radio bearer is already activated on the gNB-CU, gNB-DU and UE side (the UE side is activated by a separate signaling), and for this possibility, step D is executed; 2) after the steps A and B are finished, the gNB-CU, the gNB-DU and the UE side have already finished the configuration of the PDCP repeat function, but the function is not activated, and E is executed for the possibility.

Step D: data of the data radio bearer in which the PDCP repetition function is activated is transmitted. This step is performed after the PDCP repetition function of the data radio bearer is activated (i.e., the data of the data radio bearer is transmitted among the gNB-CU, gNB-DU, and UE according to the configuration of the corresponding PDCP repetition function). If the data radio bearer is downlink, the step comprises the sub-steps of:

substep D-a (lower): the gNB-CU copies one PDCP PDU to obtain two same PDCP PDUs, or sends one PDCP PDU twice to obtain two same PDCP PDUs;

substep D-b (Down): and D, sending the two identical PDCP PDUs obtained in the step D-a (downlink) to the gNB-DU through one Tunnel (Tunnel) on the F1 interface, and adding the same identifier to the two identical PDCP PDUs to assist the gNB-DU in identifying the two identical PDCP PDUs. For example, two identical PDCP PDUs can be identified by a G-PDU sequence number, and the two identical PDCP PDUs are assigned the same G-PDU sequence number when the G-PDU is generated; two identical PDCP PDUs can also be identified by the sequence number of the F1 interface user plane, then the sequence number of the F1 interface user plane is distributed to the two identical PDCP PDUs when the data packet of the F1 interface user plane is generated, or the PDCP SN in the extension header contained in the GTP PDU is used for identifying the two identical PDCP PDUs, then the extension header with the PDCP SN identification is contained in the GTP PDU. In addition, the gNB-CU may not add any identifier to two identical PDCP PDUs, and may determine the identical PDCP PDUs by the gNB-DU.

Substeps D-c (Down): the gNB-DU identifies two identical PDCP PDUs, which can be identified from the indication information identifying the duplicate PDCP PDUs contained in the configuration information in step A, or from default settings (which can be identified by default from the sequence number of the G-PDU, or by default from the sequence number of the F1 interface user plane, or by default from the PDCP SN in the extension header contained in the GTP-PDU), or from comparing the two received PDCP PDUs to determine whether they are identical. The DU sends the received two identical PDCP PDUs to two different RLC entities (e.g., RLC1 and RLC2), and then sends the two identical PDCP PDUs to the MAC layer through two different logical channels (e.g., logical channel 1 and logical channel 2), and finally the MAC layer sends the data from the two different logical channels to two different cells (e.g., cell 1 and cell 2, which may be different in frequency or the same in frequency) through the physical layers of the two different cells, respectively. How the data received by the gNB-DU is distributed to two RLC entities can be realized by the following methods:

mode 1: the gNB-DU may be determined based on existing configuration, e.g., for two identical PDCP PDUs, for the first received PDU the gNB-DU may be sent to a specific RLC entity (e.g., RLC1), which may be the configured primary RLC entity (or default RLC entity), for the second received PDU the gNB-DU may be sent to another RLC entity (non-primary RLC entity)

Mode 2: set by the gNB-DU itself. One embodiment is: for two identical PDCP PDUs, the first received transmission is to RLC1, the second received transmission is to RLC 2; yet another embodiment is: once a packet (such as PDCP PDU1) is received from the tunnel by the gNB-DU, the packet is copied by itself to obtain two identical packets, and then the two identical packets are sent to two RLC entities (RLC1 and RLC2), or the packet is sent twice by itself to two RLC entities (RLC1 and RLC 2); thereafter, if the gNB-DU receives a same data packet (e.g., PDCP PDU1) again, because the data packet has already been transmitted to a different RLC entity, the gNB-DU may discard the data packet, or may copy the data packet to obtain two identical data packets, which are then transmitted to two RLC entities (RLC1 and RLC2), respectively, or may transmit the data packet twice in a self-organized manner to two RLC entities (RLC1 and RLC2), respectively.

If the data radio bearer is uplink, the step includes the sub-steps of:

substep D-a (upper line): the gNB-DU receives data from two different cells (e.g., cell 1 and cell 2, which may be different in frequency or same in frequency) respectively, and after processing by the physical layer and the MAC layer, the data of the two different cells are sent to two different RLC entities (e.g., RLC1 and RLC2) by two different logical channels (e.g., logical channel 1 and logical channel 2) respectively;

substep D-b (upper line): the data processed by the two RLC entities can be sent to the gNB-CU through a tunnel on an F1 interface;

substeps D-c (up): and the gNB-CU processes the received PDCP PDU through a PDCP layer (such as dropping repeated PDCP PDUs) to obtain the PDCP SDU.

And E, step E: data of the data radio bearer configured but not activated for the PDCP repetition function is transmitted. For downlink data transmission, the following implementation manners may be included:

mode 1: if the RLC entity (e.g., the main RLC entity or the default RLC entity) that should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, the gNB-CU sends PDCP PDUs of the data radio bearer to the specified RLC entity (e.g., the main RLC entity or the default RLC entity) through a tunnel over the F1 interface, and then sends the PDCP PDUs to the MAC layer via the logical channel corresponding to the specified RLC entity, and then sends the PDCP PDUs to the user via one cell.

Mode 2: if the RLC entity which should be adopted when the PDCP repeat function is configured but not activated is not specified in the step A and/or the step B, the gNB-CU sends the PDCP PDU of the data radio bearer to the gNB-DU through a tunnel, then the gNB-DU selects a configured RLC entity by itself, and then the configured RLC entity is sent to the MAC layer through a corresponding logical channel of the RLC entity and then sent to the user through a cell.

mode 1: if the RLC entity (such as the main RLC entity or the default RLC entity) which should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, the gbb-DU sends the data of the data radio bearer received from a cell to the specified RLC entity (the specified logical channel is corresponding to the specified RLC entity) for processing after being processed by the physical layer and the MAC layer, the processed PDCP PDU is sent to the gbb-CU by a tunnel on the F1 interface, and finally the PDCP PDU is obtained after being processed by the PDCP layer.

Mode 2: if the RLC entity which should be used when the PDCP repetition function is configured but not activated is not specified in step a and/or B, the gNB-DU processes the data of the data radio bearer received from a cell through the physical layer and the MAC layer, and sends the processed data to a corresponding RLC entity through a logical channel (the logical channel and the RLC entity are determined by the gNB-DU), the processed PDCP PDU is sent to the gNB-CU through a tunnel on the F1 interface by the gNB-DU, and finally the PDCP layer processes the processed PDCP PDU to obtain the PDCP SDU.

The message names in the above steps a and B are only examples, and the configuration information related thereto may be sent in other messages. Such as UE context setup request and UE context setup response, bearer setup request and bearer setup response, DL RRC message transfer and UL RRC message transfer, etc.

In addition, steps a and B may be used to modify the existing configuration of the data radio bearer. If the data radio bearer has been configured as a normal bearer that does not support the PDCP repetition function, but needs to be configured as a data radio bearer that supports the PDCP repetition function in order to improve the reliability of data transmission of the data radio bearer, steps a and B may be used to change the configuration of the data radio bearer, that is, the configuration messages in steps a and B are sent through a bearer modification request and a bearer modification response message; alternatively, only the newly added information or the configuration information that needs to be modified is included in steps a and B, for example, for the data radio bearer, the following information is already configured when the PDCP repetition function is not supported:

RLC entity 1 configuration information;

identification information and/or configuration information of a logical channel corresponding to the RLC entity 1;

and the tunnel information of the gNB-CU side and the gNB-DU side of the tunnel established for the data radio bearer on the F1 interface.

When the data radio bearer is to be configured as a data radio bearer supporting the PDCP repetition function, step a sends the modified existing configuration information and the newly added information to the gNB-DU on the basis of the existing configuration information, for example, the modified existing configuration information includes:

an update part of the configuration information of the logical channel corresponding to the RLC entity 1, such as restriction information added with logical channel mapping;

the newly added information includes:

configuration information of RLC entity 2;

identification information and/or configuration information of a logical channel corresponding to the RLC entity 2.

EXAMPLE III

In this embodiment, a PDCP repetition function is configured for a data radio bearer, and a tunnel is established for the data radio bearer on the F1 interface to transmit data of the data radio bearer, two RLC entities and a logical channel identifier and/or configuration corresponding to each RLC entity are configured for the data radio bearer in a DU, and for downlink, the DU copies each received PDCP PDU to obtain two identical PDCP PDUs or sends each PDCP PDU twice (in this method, the CU does not copy the PDCP PDUs). The method comprises the following steps:

the method comprises the following steps: type information of a data radio bearer, the type information indicating that the data radio bearer supports a data radio bearer of a PDCP repetition function;

Further, the information supporting the PDCP repeat function may further include uplink and downlink indication information, where the indication information indicates that the uplink supports the PDCP repeat function, or the downlink supports the PDCP repeat function, or both the uplink and the downlink support the PDCP repeat function; if the indication information is not included, the information for supporting the PDCP repeat function may indicate that both uplink and downlink support the PDCP repeat function, or uplink support the PDCP repeat function, or a default direction (uplink or downlink or uplink and downlink) support the PDCP repeat function.

2) Some or all of configuration information of at least one RLC entity corresponding to the data radio bearer. The data radio bearer supporting the PDCP repeat function has two RLC entities, but the configuration message may include part or all of configuration information of one RLC entity, or may include part or all of configuration information of two RLC entities (if only part of configuration information is included, it indicates that the configuration information not included may multiplex the existing configuration). For example, in the case of including configuration information of an RLC entity, a configuration message indicating that the existing RLC entity of the data radio bearer can be multiplexed, and the included configuration information of the RLC entity is for a newly added RLC entity; for the case of containing configuration information of two RLC entities, if the gNB-DU already has configuration information of at least one RLC entity of the data radio bearer, the newly received configuration information of the two RLC entities may overwrite the existing information, and if the gNB-DU does not have any information about the RLC entity corresponding to the data radio bearer, the gNB-DU directly uses the newly received configuration information of the two RLC entities. In addition, the configuration information of each RLC entity may include indication information indicating whether the RLC entity is a primary RLC entity (or referred to as a default RLC entity) (or may not include the indication information if one RLC entity is not configured as the primary RLC entity; alternatively, the primary RLC entity does not include the indication information, and the non-primary RLC entity adds an indication information indicating that the non-primary RLC entity is the non-primary RLC entity). The indication information may be optional or mandatory. The indication information has the functions of: for downlink data transmission, the indication message is used to indicate how the gNB-DU distributes the received PDCP PDUs to two RLC entities configured for the data radio bearer; for uplink data transmission, the indication message is used to indicate how the gNB-DU distributes data received from different cells belonging to the data radio bearer to the two RLC entities configured for the data radio bearer. The indication information may indicate the RLC entity (e.g., primary RLC entity) that the gNB-DU needs to use when only one RLC entity needs to be used. For example, if one RLC entity is indicated as the primary RLC entity, when the data radio bearer is configured to support the PDCP repetition function and the function is not yet activated for use, for downlink data, the PDCP PDUs belonging to the data radio bearer from the gNB-CU are sent to the primary RLC entity only, and for uplink data, the data belonging to the data radio bearer received by the gNB-DU are sent to the primary RLC entity. Another example is when the data radio bearer is configured to support PDCP repetition function and the function has been activated for use, for downlink data, each time a PDCP PDU belonging to the data radio bearer is received from the gNB-CU, it is sent to the primary RLC entity if it is received for the first time and to another RLC entity (non-primary RLC entity) if it is received for the second time.

And B: and if the gNB-DU accepts the configuration of the data radio bearer in the step A, performing relevant configuration, and feeding back a response message for configuring the data radio bearer supporting the PDCP repeat function to the gNB-CU by the gNB-DU, wherein the response message indicates whether the gNB-DU accepts the configuration of the data radio bearer in the step A, and the response message is optional. The response message may contain information of a Tunnel on the gbb-DU side, such as gbb-DU GTP Tunnel Endpoint information (gbb-DU GTP Tunnel Endpoint) (containing the transport layer address and GTP TEID).

Step C: the PDCP repetition function is activated. This step is an optional step. This step includes activating the PDCP repetition function of the DU and UE sides, and possible implementations thereof include:

mode 1: the gNB-CU activates the gNB-DU and/or the PDCP repeat function of the data radio bearer at the UE side. And the gNB-CU sends PDCP repeat function activation information to the gNB-DU and/or the UE, the gNB-DU side activates the PDCP repeat function of the data radio bearer, the data transmission of the data radio bearer is carried out according to the configuration information in the steps A and B, and the UE side also activates the PDCP repeat function of the data radio bearer, and the data transmission of the data radio bearer is carried out according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates that the uplink and downlink PDCP repeat function is activated, or indicates that the uplink PDCP repeat function is activated, or indicates that the downlink PDCP repeat function is activated, or indicates that the PDCP repeat function in the default direction (uplink or downlink or uplink and downlink) is activated. The activation sequence here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated first, or the UE side may be activated first and then the gNB-DU side may be activated first, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-CU, the gNB-DU may reply whether activation is successful. If the reply activation is successful, the gNB-DU side activates the PDCP repeat function, otherwise, the PDCP repeat function is not activated. Further, after the PDCP repetition function is activated, the gNB-CU may also send deactivation information to the gNB-DU and/or the UE, optionally, the gNB-DU may reply whether the deactivation is successful, if the deactivation is successful, the gNB-DU side stops the PDCP repetition function, and otherwise, the PDCP repetition function is continuously used.

Mode 2: the gNB-DU activates the PDCP repeat function of the data radio bearer at the UE side. And the gNB-DU sends PDCP repeat function activation information to the UE, so that the UE side activates the PDCP repeat function of the data radio bearer, and the UE side can transmit the data of the data radio bearer according to the received RRC configuration message.

If step C is performed, indicating that the PDCP repeat function of the data radio bearer is already activated at the gNB-DU and UE sides, step D is performed. Without step C, there are two possibilities: 1) after steps a and B are finished, the PDCP repetition function of the data radio bearer is already activated in the gNB-DU and UE side (the UE side is activated by a separate signaling), and for this possibility, step D is executed; 2) after steps a and B are finished, the gbb-DU and the UE side have already completed the configuration of the PDCP repetition function, but the function has not yet been activated, and step E is performed for this possibility.

Step D: data of the data radio bearer in which the PDCP repetition function is activated is transmitted. This step is performed after the PDCP repetition function of the data radio bearer is activated (i.e. the data of the data radio bearer is transmitted between the gNB-DU and the UE according to the configuration of the corresponding PDCP repetition function).

If the data radio bearer is downlink, the step comprises the sub-steps of:

substep D-a (lower): the gNB-CU generates PDCP PDUs for the data radio bearer without copying each PDCP PDU.

Substep D-b (Down): the PDCP PDU obtained in the step D-a (downlink) is sent to the gNB-DU through a Tunnel (Tunnel) on an F1 interface; alternatively, for data radio bearers supporting PDCP repetition function, the data may be transmitted over the F1 interface using SCTP/rudp (reusable udp) protocol, or may be sent using messages of the control plane of the F1 interface.

Substeps D-c (Down): the gNB-DU duplicates each received PDCP PDU to obtain two identical PDCP PDUs, and then transmits the PDCP PDUs to two different RLC entities (such as RLC1 and RLC2), or transmits each received PDCP PDU twice, the two times are respectively transmitted to two different RLC entities (such as RLC1 and RLC2), and then transmitted to the MAC layer through two different logical channels (such as logical channel 1 and logical channel 2), and finally the MAC layer transmits data from the two different logical channels to two different cells (such as cell 1 and cell 2, which may be different in frequency or same in frequency) through physical layers of the two different cells.

If the data radio bearer is uplink, the step includes the sub-steps of:

substep D-a (upper row): the gNB-DU receives data from two different cells (e.g., cell 1 and cell 2, which may be different in frequency or same in frequency) respectively, and after processing by the physical layer and the MAC layer, the data of the two different cells are sent to two different RLC entities (e.g., RLC1 and RLC2) by two different logical channels (e.g., logical channel 1 and logical channel 2) respectively;

substep D-b (upper row): data processed by two RLC entities is sent to the gNB-CU through one tunnel over the F1 interface, or if the gNB-DU finds two identical PDCP PDUs in the data output by the RLC entity (the gNB-DU can identify whether the two PDCP PDUs output by the RLC entity are identical), one is discarded, and the remaining one PDCP PDU is sent to the gNB-CU through one tunnel over the F1 interface.

Substeps D-c (upper row): and the gNB-CU processes the received PDCP PDU through a PDCP layer (such as dropping repeated PDCP PDUs) to obtain the PDCP SDU.

mode 1: if the RLC entity (such as the main RLC entity or the default RLC entity) which should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, the gbb-CU sends PDCP PDUs of the data radio bearer to the gbb-DU through a tunnel over the F1 interface, and then the gbb-DU sends the PDUs to the specified RLC entity (such as the main RLC entity or the default RLC entity), and then sends the PDUs to the MAC layer via a logical channel corresponding to the specified RLC entity, and then sends the PDUs to the user via a cell.

Mode 2: if the RLC entity which should be used when the PDCP repeat function is configured but not activated is not specified in the step A and/or the step B, the gNB-CU sends the PDCP PDU of the data radio bearer to the gNB-DU through a tunnel, the gNB-DU selects a configured RLC entity by itself, and then the configured RLC entity is sent to the MAC layer through a logical channel corresponding to the RLC entity and then sent to the user through a cell.

Mode 2: if the RLC entity which should be used when the PDCP repetition function is configured but not activated is not specified in step a and/or B, the gNB-DU processes the data of the data radio bearer received from a cell by the physical layer and the MAC layer, and sends the processed data to the corresponding RLC entity by the logical channel (the logical channel and the RLC entity are determined by the gNB-DU), the processed PDCP PDU is sent to the CU by the DU through a tunnel on the F1 interface, and finally the PDCP SDU is obtained after the PDCP layer processing.

Additionally, steps a and B may be used to modify the existing configuration of the data radio bearer. If the data radio bearer is already configured as a normal bearer that does not support the PDCP repetition function, but needs to be configured as a data radio bearer that supports the PDCP repetition function in order to improve the reliability of data transmission of the data radio bearer, steps a and B may be used to change the configuration of the data radio bearer, that is, the configuration messages in steps a and B are sent through a bearer modification request message and a bearer modification response message; alternatively, only the newly added information or the configuration information that needs to be modified is included in steps a and B, for example, for the data radio bearer, the following information is already configured when the PDCP repetition function is not supported:

RLC entity 1 configuration information;

tunnel information of a gNB-CU side and a gNB-DU side of a tunnel established for the data radio bearer on an F1 interface;

the newly added information includes:

configuration information of RLC entity 2;

Example four

In this embodiment, a PDCP repetition function is configured for a signaling radio bearer (SRB, such as SRB1/SRB1S, SRB2/SRB2S, SRB3, etc.), two RLC entities and a logical channel identifier and/or configuration corresponding to each RLC entity are configured for the signaling radio bearer in a DU, for downlink, a PDCP layer on a CU copies each PDCP PDU of the signaling radio bearer to obtain two identical PDCP PDUs or sends each PDCP PDU twice to obtain two identical PDCP PDUs, and sends a message (F1-C message) of a control plane of F1 to the DU, and the DU sends the received two identical PDCP PDUs belonging to the same signaling radio bearer to the two configured RLC entities respectively. In this embodiment, the method comprises the steps of:

step A: the gNB-CU sends a request message for configuring a signaling radio bearer supporting the PDCP repeat function to the gNB-DU, wherein the message at least contains one or more of the following information:

mode 1: indication information supporting the PDCP repeat function, wherein the indication information indicates that the signaling radio bearer supports the PDCP repeat function;

the method comprises the following steps: type information of a signaling radio bearer, the type information indicating that the signaling radio bearer supports a signaling radio bearer of a PDCP repeat function;

mode 3: identification information of the signaling radio bearer, predefining or pre-configuring one or more identifications of the signaling radio bearer for supporting the PDCP repeat function, and if the identification of the signaling radio bearer indicates that the signaling radio bearer belongs to the signaling radio bearer for supporting the PDCP repeat function, the signaling radio bearer supports the PDCP repeat function.

Further, the information for supporting the PDCP repetition function may further include an indication information of uplink and downlink, where the indication information indicates that the uplink supports the PDCP repetition function, or the downlink supports the PDCP repetition function, or both the uplink and the downlink support the PDCP repetition function. If the indication information is not included, the information for supporting the PDCP repeat function may indicate that both uplink and downlink support the PDCP repeat function, or uplink support the PDCP repeat function, or a default direction (uplink or downlink or uplink and downlink) support the PDCP repeat function.

2) Some or all of configuration information of at least one RLC entity corresponding to the signaling radio bearer. The signaling radio bearer supporting the PDCP repetition function has two RLC entities, but the configuration message may include part or all of configuration information of one RLC entity, or may include part or all of configuration information of two RLC entities (if only part of configuration information is included, it indicates that the configuration information not included may reuse the existing configuration). For example, in the case of including configuration information of an RLC entity, the configuration message indicating that the signaling radio bearer has an existing RLC entity may be multiplexed, and the included configuration information of the RLC entity is for a newly added RLC entity; for the case of containing configuration information of two RLC entities, if the gNB-DU already has configuration information of at least one RLC entity of the signaling radio bearer, the newly received configuration information of the two RLC entities may overwrite the existing information, and if the gNB-DU does not have any information about the RLC entity corresponding to the signaling radio bearer, the gNB-DU directly uses the newly received configuration information of the two RLC entities. In addition, the configuration information of each RLC entity may include indication information of whether the RLC entity is a main RLC entity (or referred to as a default RLC entity) (if one RLC entity is not configured as a main RLC entity, the indication information may not be included; alternatively, the main RLC entity does not include indication information, and the non-main RLC entity adds an indication information indicating that the non-main RLC entity is not configured as a main RLC entity). The indication information may be optional or mandatory. The indication information has the functions of: for downlink data transmission, the indication message is used to indicate how the gNB-DU distributes the received PDCP PDU to two RLC entities configured for the signaling radio bearer; for uplink data transmission, the indication message is used to indicate how the gNB-DU distributes data belonging to the signaling radio bearer received from different cells to the two RLC entities configured for the signaling radio bearer. The indication information may indicate the RLC entity (e.g., primary RLC entity) that the gNB-DU needs to use when only one RLC entity needs to be used. For example, if one RLC entity is indicated as the primary RLC entity, when the signaling radio bearer is configured to support the PDCP repetition function and the function is not yet activated for use, for downlink data, the PDCP PDUs belonging to the signaling radio bearer from the gNB-CU are sent to the primary RLC entity only, and for uplink data, the data belonging to the signaling radio bearer received by the gNB-DU are sent to the primary RLC entity. Another example is when the signaling radio bearer is configured to support PDCP repetition functionality and this functionality has been activated for use, for downlink data, each time a PDCP PDU belonging to the signaling radio bearer is received from a gbb-CU, it is sent to the primary RLC entity if it was received for the first time and to another RLC entity (non-primary RLC entity) if it was received for the second time.

3) For the signaling radio bearer, the identification information and/or configuration information of the logical channel corresponding to at least one configured RLC entity includes, in the configuration information, restriction information of logical channel mapping, which indicates that data of the logical channel can only be sent to a cell or carrier indicated by the restriction information, or mapping restriction information corresponding to at least one configured RLC entity, such as data from the RLC entity 1 is sent to the cell 1 or carrier 1 indicated by the restriction information, and data from the RLC entity 2 is sent to the cell 2 or carrier 2 indicated by the restriction information.

4) Indication information to help the gNB-DU identify whether or not to transmit PDCP PDUs belonging to the same signaling radio bearer to different RLC entities, the indication information indicating to the gNB-DU that two PDCP PDUs received from the F1 interface for the signaling radio bearer should be transmitted to different RLC entities.

And B: if the gNB-DU accepts the configuration of the signaling radio bearer in the step A, the gNB-DU performs the corresponding configuration, and the gNB-DU feeds back a response message of the signaling radio bearer for configuring the support PDCP repeat function to the gNB-CU, which indicates whether the gNB-DU accepts the configuration of the signaling radio bearer in the step A, and the response message is optional.

mode 1: the gNB-CU activates the gNB-DU and/or the PDCP repeat function of the signaling radio bearer at the UE side. And the gNB-CU sends PDCP repeat function activation information to the gNB-DU and/or the UE, so that the gNB-DU side activates the PDCP repeat function of the signaling radio bearer, the PDCP repeat function of the signaling radio bearer can be used for carrying out data transmission of the signaling radio bearer according to the configuration information in the steps A and B, and the UE side also activates the PDCP repeat function of the signaling radio bearer, and the PDCP repeat function of the signaling radio bearer can be used for carrying out data transmission of the signaling radio bearer according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates that the uplink and downlink PDCP repeat function is activated, or indicates that the uplink PDCP repeat function is activated, or indicates that the downlink PDCP repeat function is activated, or indicates that the PDCP repeat function in the default direction (uplink or downlink or uplink and downlink) is activated. The activation sequence here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated first, or the UE side may be activated first and then the gNB-DU side may be activated first, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-CU, the gNB-DU may reply whether the activation is successful. If the reply activation is successful, the gNB-DU side activates the PDCP repeat function, otherwise, the PDCP repeat function is not activated. Further, after the PDCP repetition function is activated, the gNB-CU may also send deactivation information to the gNB-DU and/or the UE, optionally, the gNB-DU may reply whether the deactivation is successful, if the deactivation is successful, the gNB-DU side stops the PDCP repetition function, and otherwise, the PDCP repetition function is continuously used.

Mode 2: the gNB-DU activates the PDCP repeat function of the signaling radio bearer on the gNB-CU and/or the UE side. And the gNB-DU sends PDCP repeat function activation information to the gNB-CU and/or the UE, the gNB-CU side activates the PDCP repeat function of the signaling radio bearer, performs data transmission of the signaling radio bearer according to the configuration information in the steps A and B (sends the repeated PDCP PDU to the gNB-DU through an F1 interface or receives the repeated PDCP PDU sent by the gNB-DU), and the UE side also activates the PDCP repeat function of the signaling radio bearer, and performs data transmission of the signaling radio bearer according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates that the uplink and downlink PDCP repeat function is activated, or indicates that the uplink PDCP repeat function is activated, or indicates that the downlink PDCP repeat function is activated, or indicates that the PDCP repeat function in the default direction (uplink or downlink or uplink and downlink) is activated. The activation order here is not limited, and the gNB-CU side may be activated first and then the UE side may be activated first, or the UE side may be activated first and then the gNB-CU side may be activated first, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-DU, the gNB-CU may reply whether activation is successful. And if the reply activation is successful, activating the PDCP repeat function by the gNB-CU side, and otherwise, not activating. Further, after the PDCP repetition function is activated, the gNB-DU may also send deactivation information to the gNB-CU and/or the UE, optionally, the gNB-CU may reply whether the deactivation is successful, if the deactivation is successful, the side of the gNB-CU stops the PDCP repetition function, and otherwise, the PDCP repetition function continues to be used.

If step C is performed, indicating that the PDCP repeat function of the signaling radio bearer is already activated on the gNB-CU, the gNB-DU and the UE side, step D is performed. Without step C, there are two possibilities: 1) after steps a and B are finished, the PDCP repetition function of the signaling radio bearer is already activated on the gNB-CU, gNB-DU and UE side (the UE side is already activated by a separate signaling), and for this possibility, step D is executed; 2) after the steps A and B are finished, the gNB-CU, the gNB-DU and the UE side have already finished the configuration of the PDCP repeat function, but the function is not activated, and E is executed for the possibility.

Step D: data of the signaling radio bearer in which the PDCP repetition function is activated is transmitted using the F1-C message. This step is performed after the PDCP repetition function of the signaling radio bearer is activated (i.e., data of the signaling radio bearer is transmitted among the gNB-CU, gNB-DU, and UE according to the configuration of the corresponding PDCP repetition function). If the signaling radio bearer is downlink, the step comprises the sub-steps of:

substep D-a (down): the gNB-CU copies one PDCP PDU of one signaling radio bearer to obtain two same PDCP PDUs, or repeats one PDCP PDU of one signaling radio bearer twice to obtain two same PDCP PDUs;

substep D-b (Down): two identical PDCP PDUs obtained in step D-a (downlink) are sent to the gNB-DU through a message (F1-C message) of the control plane on the F1 interface, which may include:

mode 1: placing the two identical PDCP PDUs of the signaling radio bearer in an F1-C message (e.g., RRC MESSAGE TRANSFER); optionally, the F1-C message further instructs the gNB-DU to send the two PDCP PDUs to different RLC entities or through different logical channels or through different cells, or instructs the gNB-DU to send the two PDCP PDUs to a specified RLC entity and/or through a specified logical channel and/or through a specified cell, respectively.

Mode 2: placing the two identical PDCP PDUs of the signaling radio bearer in two F1-C messages (e.g., RRC MESSAGE TRANSFER), each message containing an indication that helps the gNB-DU identify that PDCP PDUs from the two F1-C messages should be sent to different RLC entities, e.g., the indication contained in each F1-C message indicates to which RLC entity or over which logical channel or over which cell the PDCP PDUs of the signaling bearer contained in the F1-C message should be sent, or indicates whether the PDCP PDUs of the signaling bearer contained in the F1-C message are duplicate PDUs (non-original PDCP PDUs), or indicates whether the PDCP PDUs of the signaling bearer contained in the F1-C messages are an original PDCP PDU (non-duplicate PDCP PDUs), or indicates from the two F1 PDUs by containing two different indication messages in two F1-C messages The PDCP PDUs of this signaling bearer in the C message should be sent to a different RLC entity; in another embodiment, an indication message is added to each F1-C message to help identify whether the PDCP PDU belonging to the signaling radio bearer contained in the message is the same as the PDCP PDU belonging to the same signaling radio bearer contained in another message. Possible indications are: assigning a number to the PDCP PDUs belonging to a signaling radio bearer contained in each F1-C message, if two messages contain the same number, indicating that the two PDCP PDUs contained in the two messages are two same PDUs belonging to the same signaling radio bearer; or if there are two F1-C messages, one containing an odd number (or even number) and the other containing an even number (or odd number) and being 1 greater than the odd number (or even number), it means that the two PDCP PDUs contained in the two messages are two identical PDUs belonging to the same signaling radio bearer. In another embodiment, a new F1-C message is defined, which is specifically used to send the duplicated PDCP PDU, for example, an original PDCP PDU, and is repeatedly sent twice after PDCP repetition, one time through RRC MESSAGE TRANSFER at F1 interface and the other time through a newly defined F1-C message (e.g., RRC MESSAGE COPY TRANSFER). Thus, PDCP PDUs transmitted by RRC MESSAGE TRANSFER and RRC MESSAGE COPY TRANSFER need to be transmitted in the gNB-DU by different cells via different RLC entities.

Substeps D-c (Down): the gNB-DU transmits two identical PDCP PDUs received from the same signaling radio bearer to two different RLC entities (such as RLC1 and RLC2), and then transmits the two identical PDCP PDUs to an MAC layer through one logical channel or two different logical channels (such as logical channel 1 and logical channel 2), and finally the MAC layer transmits data from the one logical channel or the two different logical channels to two different cells (such as cell 1 and cell 2, which may be different in frequency or common in frequency) through physical layers of the two different cells, respectively. In this step, the gNB-DU may receive two identical PDCP PDUs belonging to the same signaling bearer. How to distribute data received by the gNB-DU to two RLC entities can be realized by the following methods:

mode 1: the gNB-DU determines according to the existing configuration, for example, the gNB-DU transmits the received PDCP PDU belonging to the signaling bearer to the designated RLC entity according to the indication message in the F1-C message in the sub-step D-b (downlink), or transmits the PDCP PDU through the designated logical channel, or transmits the PDCP PDU to the designated cell; as another example, for two identical PDCP PDUs, for the first received PDU, the gNB-DU would be sent to a specific RLC entity (e.g., RLC1), which may be the configured primary RLC entity (or default RLC entity), and for the second received PDU, the gNB-DU would be sent to another RLC entity (non-primary RLC entity);

mode 2: set by the gNB-DU itself. One embodiment is: if the gNB-DU identifies that two PDCP PDUs belonging to the signaling bearer need to be sent to different RLC entities, the gNB-DU respectively sends the two PDCP PDUs to the two different RLC entities by itself; in another embodiment, for two identical PDCP PDUs, the first received transmission is to RLC1, the second received transmission is to RLC 2; yet another embodiment is: once a packet (e.g., PDCP PDU1) is received by the gNB-DU, the packet is copied by itself to obtain two identical packets, and then sent to two RLC entities (RLC1 and RLC2), or the packet is sent twice to obtain two identical packets, and then sent to two different RLC entities. Thereafter, if the gNB-DU receives a same data packet (e.g., PDCP PDU1) because the data packet has been transmitted to a different RLC entity, the gNB-DU may discard the data packet, or may copy the data packet into one copy to obtain two identical data packets, which are then transmitted to the two RLC entities (RLC1 and RLC2), or transmit the data packet twice to obtain two identical data packets, which are then transmitted to the two different RLC entities.

If the signaling radio bearer is uplink, the step includes the sub-steps of:

substep D-a (upper line): the gNB-DU respectively receives data from two different cells (such as cell 1 and cell 2, which may have different or same frequency), and after the data is processed by a physical layer and an MAC layer, the data of the two different cells are respectively sent to two different RLC entities (such as RLC1 and RLC2) by one logical channel or two different logical channels (such as logical channel 1 and logical channel 2);

substep D-b (upper line): the data processed by the two RLC entities can be sent to the gNB-CU through the F1-C message (the data can be put in the same F1-C message or different F1-C messages, one of the two identical PDCP PDUs can be discarded, and then the rest one PDCP PDU is sent to the gNB-CU through one F1-C message);

substeps D-c (up): and the gNB-CU processes the received PDCP PDUs through a PDCP layer (such as dropping repeated PDCP PDUs) to obtain PDCP SDUs.

Step E: data of the signaling radio bearer configured but not activated for PDCP repetition function is transmitted. For downlink data transmission, the following implementation manners may be included:

mode 1: if the RLC entity (such as the main RLC entity or the default RLC entity) which should be used when the PDCP repetition function is configured but not activated is specified in step a and/or B, the gNB-CU sends the PDCP PDUs of the signaling radio bearer to the specified RLC entity (such as the main RLC entity or the default RLC entity) through the F1-C message, and then sends the PDCP PDUs to the MAC layer via the logical channel corresponding to the specified RLC entity, and then sends the PDCP PDUs to the user via one cell.

Mode 2: if the RLC entity which should be used when the PDCP repeat function is configured but not activated is not specified in the step A and/or the step B, the gNB-CU sends the PDCP PDU of the signaling radio bearer to the gNB-DU through an F1-C message, and then the DU selects a configured RLC entity by itself, and then the configured RLC entity is sent to the MAC layer through a logical channel corresponding to the RLC entity and then sent to the user through a cell.

mode 1: if the RLC entity (such as the main RLC entity or the default RLC entity) which should be used when the PDCP repetition function is configured but not activated is specified in the step a and/or B, the gbb-DU processes the data of the signaling radio bearer received from a cell by the physical layer and the MAC layer, and sends the data to the specified RLC entity (the specified logical channel corresponds to the specified RLC entity) for processing, the processed PDCP PDU is sent to the gbb-CU by an F1-C message, and finally the PDCP SDU is obtained after the PDCP layer processes.

Mode 2: if the RLC entity which should be used when the PDCP repetition function is configured but not activated is not specified in step a and/or B, the gNB-DU processes the data of the signaling radio bearer received from a cell through the physical layer and the MAC layer, and sends the processed data to the corresponding RLC entity through the logical channel (the logical channel and the RLC entity are determined by the gNB-DU), the processed PDCP PDU is sent to the gNB-CU through the F1-C message by the gNB-DU, and finally the PDCP SDU is obtained after the PDCP layer processing.

The message names in the above steps a and B are only examples, and may be other messages.

In addition, steps a and B may be used to modify the existing configuration of the signaling radio bearer. If the signaling radio bearer is already configured as a normal bearer that does not support the PDCP repetition function, but needs to be configured as the signaling radio bearer that supports the PDCP repetition function in order to improve the reliability of data transmission of the signaling radio bearer, steps a and B may be used to change the configuration of the signaling radio bearer; alternatively, only the newly added information or the configuration information that needs to be modified is included in steps a and B, for example, for the signaling radio bearer, the following information is already configured when the PDCP repetition function is not supported:

RLC entity 1 configuration information;

identification information and/or configuration information of a logical channel corresponding to the RLC entity 1.

When the signaling radio bearer is to be configured as a signaling radio bearer supporting the PDCP repetition function, the modified existing configuration information and the newly added information are sent to the gNB-DU in step a based on the existing configuration information, for example, the modified existing configuration information includes:

the newly added information includes:

configuration information of RLC entity 2;

EXAMPLE five

In this embodiment, a PDCP repetition function is configured for a signaling bearer (SRB, such as SRB1/SRB1S, SRB2/SRB2S, SRB3, etc.), two RLC entities and a logical channel identifier and/or configuration corresponding to each RLC entity are configured in a DU for the signaling bearer, and for a downlink, a CU sends each PDCP PDU of the signaling bearer to the DU through a message of an F1 control plane (the CU does not repeat the PDCP PDU), and copies the received PDCP PDU of the signaling bearer and sends the copied PDU to the two configured RLC entities or repeats the sending twice, which are sent to the two configured RLC entities respectively. In this embodiment, the method comprises the steps of:

the method comprises the following steps: type information of the signaling radio bearer, the type information indicating the signaling radio bearer supporting the PDCP repeat function;

Further, the information supporting the PDCP repetition function may further include indication information of uplink and downlink, where the indication information indicates that the uplink supports the PDCP repetition function, or the downlink supports the PDCP repetition function, or both the uplink and the downlink support the PDCP repetition function, and if the indication information is not included, the information supporting the PDCP repetition function may indicate that both the uplink and the downlink support the PDCP repetition function, or the downlink supports the PDCP repetition function, or the uplink supports the PDCP repetition function, or the default direction (uplink or downlink or uplink and downlink) supports the PDCP repetition function.

2) Some or all of configuration information of at least one RLC entity corresponding to the signaling radio bearer. The signaling radio bearer supporting the PDCP repetition function has two RLC entities, but the configuration message may include part or all of configuration information of one RLC entity, or may include part or all of configuration information of two RLC entities (if only part of configuration information is included, it indicates that the configuration information not included may reuse the existing configuration). For example, in the case of including configuration information of an RLC entity, a configuration message indicating that the signaling radio bearer has an existing RLC entity may be multiplexed, and the included configuration information of the RLC entity is for a newly added RLC entity; for the case of containing configuration information of two RLC entities, if the gNB-DU already has configuration information of at least one RLC entity of the signaling radio bearer, the newly received configuration information of the two RLC entities may overwrite the existing information, and if the gNB-DU does not have any information about the RLC entity corresponding to the signaling radio bearer, the gNB-DU directly uses the newly received configuration information of the two RLC entities. In addition, the configuration information of each RLC entity may include indication information indicating whether the RLC entity is a primary RLC entity (or referred to as a default RLC entity) (or may not include the indication information if one RLC entity is not configured as the primary RLC entity; alternatively, the primary RLC entity does not include the indication information, and the non-primary RLC entity adds an indication information indicating that the non-primary RLC entity is the non-primary RLC entity). The indication information may be optional or mandatory. The indication information has the functions of: for downlink data transmission, the indication message is used to indicate how the gNB-DU distributes the received PDCP PDU to two RLC entities configured for the signaling radio bearer; for uplink data transmission, the indication message is used to indicate how the gNB-DU distributes data belonging to the signaling radio bearer received from different cells to the two RLC entities configured for the signaling radio bearer. The indication information may indicate the RLC entity (e.g., primary RLC entity) that the gNB-DU needs to use when only one RLC entity needs to be used. For example, if one RLC entity is indicated as the primary RLC entity, when the signaling radio bearer is configured to support the PDCP repetition function and the function is not yet activated for use, for downlink data, the PDCP PDUs belonging to the signaling radio bearer from the gNB-CU are sent to the primary RLC entity only, and for uplink data, the data belonging to the signaling radio bearer received by the gNB-DU are sent to the primary RLC entity. Another example is when the signaling radio bearer is configured to support PDCP repetition function and the function has been activated for use, for downlink data, each time a PDCP PDU belonging to the signaling radio bearer is received from the gNB-CU, it is sent to the primary RLC entity if it is received for the first time and to another RLC entity (non-primary RLC entity) if it is received for the second time.

And B, step B: if the gNB-DU accepts the configuration of the signaling radio bearer in the step A, the relevant configuration is performed, and the gNB-DU feeds back a response message of the signaling radio bearer for configuring the support PDCP repeat function to the gNB-CU, indicating whether the gNB-DU accepts the configuration of the signaling radio bearer in the step A, wherein the response message is optional.

And C: the PDCP repetition function is activated. This step is an optional step. The step includes activating a gNB-DU and PDCP repetition function at the UE side, and possible implementation modes thereof include:

mode 1: the gNB-CU activates the gNB-DU and/or the PDCP repeat function of the signaling radio bearer at the UE side. And the gNB-CU sends PDCP repeat function activation information to the gNB-DU and/or the UE, the gNB-DU side activates the PDCP repeat function of the signaling radio bearer, the PDCP repeat function of the signaling radio bearer can be carried out according to the configuration information in the steps A and B, the UE side also activates the PDCP repeat function of the signaling radio bearer, and the PDCP repeat function of the signaling radio bearer can be carried out according to the received RRC configuration information. Further, the activation information may indicate activation of an uplink PDCP repetition function, or activation of a downlink PDCP repetition function, or activation of uplink and downlink PDCP repetition functions. If the activation information does not have the indication information, the activation information indicates that the uplink and downlink PDCP repeat function is activated, or indicates that the uplink PDCP repeat function is activated, or indicates that the downlink PDCP repeat function is activated, or indicates that the PDCP repeat function in the default direction (uplink or downlink or uplink and downlink) is activated. The activation sequence here is not limited, and the gNB-DU side may be activated first and then the UE side may be activated first, or the UE side may be activated first and then the gNB-DU side may be activated first, or the activation may be performed simultaneously. In addition, optionally, after receiving the activation information sent by the gNB-CU, the gNB-DU may reply whether the activation is successful. If the reply activation is successful, the gNB-DU side activates the PDCP repeat function, otherwise, the PDCP repeat function is not activated. Further, after the PDCP repetition function is activated, the gNB-CU may also send deactivation information to the gNB-DU and/or the UE, optionally, the gNB-DU may reply whether the deactivation is successful, if the deactivation is successful, the gNB-DU side stops the PDCP repetition function, and otherwise, the PDCP repetition function is continuously used.

Mode 2: the gNB-DU activates the PDCP repeat function of the signaling radio bearer at the UE side. And the gNB-DU sends PDCP repeat function activation information to the UE, so that the UE side activates the PDCP repeat function of the signaling radio bearer, and the UE side can perform data transmission of the signaling radio bearer according to the received RRC configuration message.

If step C is performed, indicating that the PDCP repetition function of the signaling radio bearer is already activated at the gNB-DU and UE sides, step D is performed. Without step C, there are two possibilities: 1) after steps a and B are finished, the PDCP repetition function of the signaling radio bearer is already activated on the gbb-DU and UE side (the UE side is already activated by a separate signaling), and for this possibility, step D is executed; 2) after steps a and B are finished, the gbb-DU and the UE side have already completed the configuration of the PDCP repetition function, but the function has not been activated yet, and E is performed for this possibility.

Step D: data of the signaling radio bearer in which the PDCP repetition function is activated is transmitted using the F1-C message. This step is performed after the PDCP repetition function of the signaling radio bearer is activated (i.e. the data of the signaling radio bearer will be transmitted between the gNB-DU and the UE according to the configuration of the corresponding PDCP repetition function). If the signaling radio bearer is downlink, the step comprises the sub-steps of:

substep D-a (down): the gNB-CU generates a PDCP PDU of the signaling radio bearer, and does not copy the PDU;

substep D-b (Down): the PDCP PDU obtained in the step D-a (downlink) is sent to the gNB-DU through a message (F1-C message) of a control plane on an F1 interface;

substeps D-c (Down): the gNB-DU duplicates the received PDCP PDU of the signaling radio bearer to obtain two identical PDUs, and sends the two identical PDCP PDUs to two different RLC entities (such as RLC1 and RLC2), or sends the PDCP PDU twice, the two times are respectively sent to the two different RLC entities (such as RLC1 and RLC2), and then sent to the MAC layer through one logical channel or two different logical channels (such as logical channel 1 and logical channel 2), and finally the MAC layer sends the data from the one logical channel or the two different logical channels to two different cells (such as cell 1 and cell 2, which may be different in frequency or the same in frequency) through the physical layers of the two different cells.

If the signaling radio bearer is uplink, the step includes the sub-steps of:

substep D-a (upper line): the gNB-DU receives data from two different cells (e.g., cell 1 and cell 2, which may be different in frequency or may be the same in frequency) respectively, and after being processed by the physical layer and the MAC layer, the data of the two different cells has one logical channel or is sent to two different RLC entities (e.g., RLC1 and RLC2) by two different logical channels (e.g., logical channel 1 and logical channel 2) respectively;

substep D-b (upper line): the data processed by the two RLC entities is sent to the gNB-CU through the F1-C message (the data can be placed in the same F1-C message or different F1-C messages, one of the two same PDCP PDUs can be lost, and then the rest one PDCP PDU is sent to the gNB-CU through one F1-C message);

substeps D-c (upper row): and the gNB-CU processes the received PDCP PDUs through a PDCP layer (such as dropping repeated PDCP PDUs) to obtain PDCP SDUs.

Mode 2: if the RLC entity which should be used when the PDCP repeat function is configured but not activated is not specified in the step A and/or the step B, the gNB-CU sends the PDCP PDU of the signaling radio bearer to the gNB-DU through an F1-C message, and then the gNB-DU selects a configured RLC entity by itself, and then the configured RLC entity is sent to the MAC layer through a logical channel corresponding to the RLC entity and then is sent to the user through a cell.

Mode 2: if the RLC entity which should be used when the PDCP repetition function is configured but not activated is not specified in step a and/or B, the gbb-DU processes the data of the signaling radio bearer received from a cell through the physical layer and the MAC layer, and then delivers the processed data to the corresponding RLC entity through the logical channel (the logical channel and the RLC entity are determined by the gbb-DU), the processed PDCP PDU is sent to the CU through the F1-C message from the gbb-DU, and finally the PDCP SDU is obtained after the PDCP layer processing.

The message names in steps a and B are only examples, and may be other messages.

In addition, steps a and B may be used to modify the existing configuration of the signaling radio bearer. If the signaling radio bearer is already configured as a normal bearer that does not support PDCP repetition function, but needs to be configured as a signaling radio bearer that supports PDCP repetition function in order to improve the reliability of data transmission of the signaling radio bearer, steps a and B may be used to change the configuration of the signaling radio bearer; alternatively, only the newly added information or the configuration information that needs to be modified is included in steps a and B, for example, for the signaling radio bearer, the following information is already configured when the PDCP repetition function is not supported:

RLC entity 1 configuration information;

When the signaling radio bearer is to be configured as a signaling radio bearer supporting the PDCP repetition function, step a sends the modified existing configuration information and the newly added information to the gNB-DU on the basis of the existing configuration information, for example, the modified existing configuration information includes:

the newly added information includes:

configuration information of RLC entity 2;

In the invention, the repeated PDCP PDUs are transmitted between the gNB-CU and the gNB-DU through the F1 interface between the gNB-CU and the gNB-DU, thereby improving the reliability of data transmission.

In the above embodiments, the transmission of the bearer supporting the PDCP repetition function between the central unit and the distributed unit in one base station over the F1 interface is mainly discussed, but in an actual system, the bearer supporting the PDCP repetition function may also be transmitted over an interface (e.g., an X2 interface, an Xn interface) between two base stations (e.g., between an eNB and a gNB, between two enbs, between two gnbs, etc.).

For example, a data bearer (DRB) supporting PDCP repetition function, the PDCP layer used for transmitting the data of the bearer is located in the base station 1, and other protocol layers (e.g., RLC layer, MAC layer, PHY layer) used for transmitting the data of the bearer are located in the base station 2. In order to support transmission of the data bearer between the base station 1 and the base station 2, the mechanisms described in the first to third embodiments may be applied between the base station 1 and the base station 2 (an interface between the two base stations may be an X2 interface or an Xn interface), that is, replacing the gNB-CU in the description of the first to third embodiments with the base station 1, replacing the gNB-DU in the description of the first to third embodiments with the base station 2, and replacing the F1 interface in the description of the first to third embodiments with an interface between the base station 1 and the base station 2 (e.g., an X2 interface or an Xn interface).

For example, a signaling bearer (SRB) supporting PDCP repetition function, the PDCP layer used for transmitting the data of the bearer is located in the base station 1, and other protocol layers (such as RLC layer, MAC layer, PHY layer) used for transmitting the data of the bearer are located in the base station 2. In order to support the transmission of the signaling bearer between the base station 1 and the base station 2, the mechanisms described in the fourth to fifth embodiments may be applied between the base station 1 and the base station 2 (the interface between the two base stations may be an X2 interface or an Xn interface), that is, replacing the gNB-CU in the description of the fourth to fifth embodiments with the base station 1, replacing the gNB-DU in the description of the fourth to fifth embodiments with the base station 2, and replacing the F1 interface in the description of the fourth to fifth embodiments with the interface between the base station 1 and the base station 2 (e.g., an X2 interface or an Xn interface).

The invention also provides a system for supporting the repeated function of the packet data convergence protocol PDCP, which comprises a first base station and a second base station, or a centralized unit and a distributed unit in the base stations,

It will be understood by those within the art that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. Those skilled in the art will appreciate that the computer program instructions may be implemented by a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, implement the aspects specified in the block diagrams and/or flowchart block or blocks of the present disclosure.

The modules of the device can be integrated into a whole or can be separately deployed. The modules can be combined into one module, and can also be further split into a plurality of sub-modules.

Those skilled in the art will appreciate that the drawings are merely schematic representations of preferred embodiments and that the blocks or flowchart illustrations are not necessary to practice the present invention.

Those skilled in the art will appreciate that the modules in the devices in the embodiments may be distributed in the devices in the embodiments according to the description of the embodiments, and may be correspondingly changed in one or more devices different from the embodiments. The modules of the above embodiments may be combined into one module, or further split into multiple sub-modules.

The above-mentioned serial numbers of the present invention are for description only and do not represent the merits of the embodiments.

The above disclosure is only for a few specific embodiments of the present invention, but the present invention is not limited thereto, and any variations that can be made by those skilled in the art are intended to fall within the scope of the present invention.

Claims

1. A first network device, comprising:

2. The first network device of claim 1, wherein when the data packet of the radio bearer configured with the PDCP repeat function is downlink data,

the sending subunit is specifically configured to send, to the second network device, the data packet of the radio bearer configured with the PDCP repetition function through a tunnel on an interface with the second network device; or the like, or, alternatively,

the sending subunit is specifically configured to copy the data packet of the radio bearer configured with the PDCP repetition function, and obtain two identical data packets of the radio bearer configured with the PDCP repetition function; respectively sending the two same data packets of the radio bearer configured with the PDCP repeat function through a tunnel on an interface between the first network device and the second network device; or, specifically, the method is configured to send the data packet of the radio bearer configured with the PDCP repetition function twice through one tunnel on the interface between the first network device and the second network device; or the like, or, alternatively,

the sending subunit is specifically configured to send the data packet of the radio bearer configured with the PDCP repetition function to the second network device twice through two different tunnels on an interface between the first network device and the second network device; or the like, or a combination thereof,

the sending subunit is specifically configured to send, to the second network device, two identical data packets of the radio bearer configured with the PDCP duplicate function through a control plane message on an interface between the first network device and the second network device, respectively.

3. The first network device of claim 1, wherein when the data packet of the radio bearer configured with the PDCP repetition function is uplink data, the first network device further comprises:

a receiving subunit, configured to receive the data packet of the radio bearer configured with the PDCP duplicate function sent by the second network device;

4. The first network device of claim 1, wherein the configuration instruction message for the radio bearer supporting the PDCP repetition function sent by the sending subunit to the second network device includes at least one of:

information supporting a PDCP repetition function;

partial or full configuration information of at least one radio link control protocol, RLC, entity corresponding to the data bearer;

identifying indication information of duplicate packets.

5. The first network device of claim 4, wherein the first network device further comprises:

6. The first network device of claim 5, wherein the configuration information of the at least one tunnel on the interface between the first network device and the second network device included in the configuration instruction message is specifically address information of a packet of the radio bearer supporting the PDCP repetition function received or sent by the first network device; the configuration information of at least one tunnel on the interface between the first network device and the second network device included in the configuration response message is specifically address information of a data packet of the radio bearer supporting the PDCP repetition function received or sent by the second network device side.

7. The first network device of any one of claims 1-6,

8. A second network device, the second network device comprising:

a receiving subunit, configured to receive a configuration instruction message of a radio bearer supporting a PDCP repetition function sent by a first network device;

9. A data transmission method for supporting PDCP repetition function, the method comprising:

and the first network equipment and the second network equipment carry out transmission of data packets of the radio bearer configured with the PDCP repeat function.

10. The data transmission method of claim 9,