CN107484183B

CN107484183B - Distributed base station system, CU, DU and data transmission method

Info

Publication number: CN107484183B
Application number: CN201610405936.1A
Authority: CN
Inventors: 孙军帅; 王莹莹; 陈卓; 陈锋; 黄学艳; 易芝玲
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2016-06-08
Filing date: 2016-06-08
Publication date: 2020-12-29
Anticipated expiration: 2036-06-08
Also published as: CN107484183A

Abstract

The invention discloses a distributed base station system, a CU, a DU and a data transmission method. The distributed base station system provided by the invention comprises a CU and M DUs connected with the CU, wherein M is a positive integer, and the CU comprises a C-RLC protocol unit and a D-RLC protocol unit for receiving data; the D-RLC protocol unit for data transmission is included in the DU. The invention provides a distributed structure of RLC protocol stack function in a distributed network architecture.

Description

Distributed base station system, CU, DU and data transmission method

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a distributed base station system, a CU, a DU, and a data transmission method.

Background

Based on Centralized, Cooperative, Cloud-architecture, and green Radio Access Network (C-RAN) Cloud platform, a Next Generation front end transmission Interface (NGFI) Network architecture completes coverage of various scenes through a flexible forward Interface for various 2G/3G/4G and 5G scenes.

Compared with the conventional Long Term Evolution (LTE) network design, in a desired Distributed network architecture in a 5G scenario, a baseband centralized Unit is introduced, which does not introduce a high-level network element, but performs configuration reconstruction between a baseband Unit (BBU) and a Radio Remote Unit (RRU), moves a part of processing functions of the conventional BBU onto the RRU, and defines the reconstructed BBU as a Centralized Unit (CU) and a Distributed Unit (DU) (or in some specific Distributed network architecture scenarios, CU is also referred to as a Radio Cloud Center (RCC), and DU is also referred to as a Radio Remote System (RRS), where the DU may include an antenna, an RRU, and a part of baseband processing function Radio Aggregation Unit (Radio Aggregation Unit) of the conventional BBU, RAU), the CU may include a remaining function of the conventional BBU excluding the RAU, a high-level management function, and the like.

Figure 1 illustrates an RCC-RRS distributed network architecture. The distributed network architecture shown in fig. 1 includes: RRS 101, RCC 102, NGFI 103, and back-end transmission 104 and core network 105. One or more RRS 101 may be connected to one RCC 102, and the RRS 101 and the RCC 102 are connected through a transmission network. Based on the architecture, one desirable interaction process between the RCC and the RRS is: and the RCC completes big data operation, then sends the instruction to the RRS, and the RRS completes resource allocation of a corresponding air interface on the basis of the operation result of the RCC. Similarly, each RRS performs certain processing on information collected from the air interface and reports the processed information to the RCC. The RCC and the RRS both have an air interface protocol stack and a baseband processing function, and in order to reduce the data transmission pressure between the RCC and the RRS, the functions between the RCC and the RRS can be flexibly divided.

Since air interface protocol stacks in the distributed network architecture proposed in the 5G scenario operate on different distributed entities, a protocol stack function of a Radio Link Control (RLC) layer of a conventional or ideal transmission network cannot be directly applied to the distributed network architecture. For the distributed network architecture, the distribution of the RLC protocol stack function on the distributed network architecture needs to be redesigned to meet various performance indexes such as the transmission network requirement, the data processing delay requirement, and the data control (for example, data out-of-order delivery during reconstruction) requirement in the distributed network architecture.

Disclosure of Invention

The embodiment of the invention provides a distributed base station system, a CU, a DU and a data transmission method, which are used for providing a distributed structure of the RLC protocol stack function in a distributed network architecture.

In a distributed base station system provided in an embodiment of the present invention, the distributed base station system includes a central unit CU and M distribution units DU connected to the CU, where M is a positive integer;

the CU comprises a centralized radio link control (C-RLC) protocol unit and a distributed radio link control (D-RLC) protocol unit for receiving data;

the DU comprises a D-RLC protocol unit used for data transmission.

Optionally, one C-RLC protocol unit corresponds to one unidirectional or bidirectional radio bearer RB;

according to the number of empty links occupied by unidirectional RBs corresponding to the C-RLC protocol units, one C-RLC protocol unit corresponds to the same number of D-RLC protocol units for data transmission, wherein each D-RLC protocol unit for data transmission corresponds to one empty link;

according to the number of empty links occupied by the bidirectional RB corresponding to the C-RLC protocol unit, one C-RLC protocol unit corresponds to the same number of D-RLC protocol units used for data transmission and the same number of D-RLC protocol units used for data reception, wherein one D-RLC protocol unit used for data transmission and one D-RLC protocol unit used for data reception correspond to one empty link.

Optionally, the C-RLC protocol unit is configured to buffer data sent by a protocol unit in a layer higher than the C-RLC protocol unit, and allocate the buffered data to a D-RLC protocol unit corresponding to the C-RLC protocol unit and used for sending the data; and/or the presence of a gas in the gas,

and the D-RLC protocol unit is used for receiving the data sent by the D-RLC protocol unit corresponding to the C-RLC protocol unit and used for receiving the data, recombining the received data and sending the recombined data to the upper layer protocol unit of the C-RLC protocol unit.

Optionally, the C-RLC protocol unit is specifically configured to:

after receiving the data sent by the upper layer protocol unit of the C-RLC protocol unit, sending a data distribution request to a Media Access Control (MAC) protocol unit;

receiving a data allocation indication fed back by the MAC protocol unit;

and according to the data distribution indication, distributing the buffered data to the D-RLC protocol unit which is corresponding to the C-RLC protocol unit and used for data transmission.

Optionally, the D-RLC protocol unit for data transmission is configured to transmit the received data allocated by the C-RLC protocol unit to an MAC protocol unit;

the D-RLC protocol unit for data reception is used for transmitting the data sent by the received MAC protocol unit to the C-RLC protocol unit corresponding to the D-RLC protocol unit for data reception.

Optionally, the DU further includes: and the routing unit corresponds to the D-RLC protocol unit used for data transmission in the DU.

Optionally, the routing unit is configured to, after receiving data sent by the MAC protocol unit, send the received data to a D-RLC protocol unit in the DU for data transmission, or send the received data to a D-RLC protocol unit in a CU connected to the DU for data reception.

Optionally, the C-RLC protocol unit is configured to: according to the configuration information of the RRC protocol unit, configuring a D-RLC protocol unit for data transmission; and/or the presence of a gas in the gas,

and activating or deactivating the D-RLC protocol unit which is used for data transmission and corresponds to the C-RLC functional entity according to the data distribution indication of the MAC protocol unit.

One embodiment of the invention provides a CU, wherein the CU comprises a C-RLC protocol unit and a D-RLC protocol unit for data receiving; the CU is connected to M DUs that include D-RLC protocol units for data transmission, M being a positive integer.

Optionally, the C-RLC protocol unit is specifically configured to:

receiving a data allocation indication fed back by the MAC protocol unit;

In an embodiment of the present invention, a DU is provided, where the DU includes a D-RLC protocol unit for data transmission; the DU is connected to a CU comprising a C-RLC protocol unit and a D-RLC protocol unit for data reception.

Optionally, the D-RLC protocol unit for data transmission is configured to transmit the received data allocated by the C-RLC protocol unit in the CU to the MAC protocol unit.

Optionally, the method further comprises: and the routing unit corresponds to the D-RLC protocol unit used for data transmission in the DU.

The data transmission method provided by one embodiment of the invention is applied to a distributed base station system, wherein the distributed base station system comprises a CU and M DUs connected with the CU, and M is a positive integer;

the method comprises the following steps:

a C-RLC protocol unit in the CU buffers data sent by a protocol unit of a layer above the C-RLC protocol unit;

the C-RLC protocol unit in the CU distributes the buffered data to a D-RLC protocol unit which is used for data transmission and corresponds to the C-RLC protocol unit in a DU connected to the CU;

and the D-RLC protocol unit used for data transmission in the DU transmits the received data distributed by the C-RLC protocol unit to the MAC protocol unit.

the method comprises the following steps:

a D-RLC protocol unit used for data receiving in the CU receives data sent by an MAC protocol unit;

the D-RLC protocol unit for data reception in the CU transmits the received data to the C-RLC protocol unit corresponding to the D-RLC protocol unit for data reception in the CU;

and the C-RLC protocol unit recombines the data transmitted by the D-RLC protocol unit which is used for receiving the data and corresponds to the C-RLC protocol unit and then sends the recombined data to the upper layer protocol unit of the C-RLC protocol unit.

Optionally, the data sent by the MAC protocol unit is transmitted to a D-RLC protocol unit for data reception in the CU by a routing unit in a DU connected to the CU after receiving the data sent by the MAC protocol unit and determining that the data sent by the received MAC protocol unit is transmitted to the D-RLC protocol unit for data reception in the CU connected to the DU.

In the foregoing embodiment of the present invention, the distributed base station system mainly includes a CU and M DUs connected to the CU, where M is a positive integer, and in the foregoing embodiment of the present invention, the CU mainly includes a C-RLC protocol unit and a D-RLC protocol unit for data reception; D-RLC protocol units for data transmission are mainly included in the DU, thereby providing a distributed structure of the protocol stack functions of the RLC in the distributed network architecture.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic diagram of an RCC-RRS distributed network architecture in a 5G scenario in the prior art;

FIG. 2 is a diagram illustrating the basic concept of the present invention for separating RLC protocol units into different sub-divisions;

fig. 3 is a schematic structural diagram of RLC protocol units separated according to general divisions in the embodiment of the present invention;

fig. 4 is a schematic structural diagram of a distributed base station system according to an embodiment of the present invention;

fig. 5 is an exploded view of the RLC protocol stack function in the distributed base station system according to the embodiment of the present invention;

fig. 6 is a schematic diagram illustrating decomposition and placement of RLC protocol stack functions in a distributed base station system according to an embodiment of the present invention;

fig. 7 is a schematic diagram illustrating decomposition and placement of RLC protocol stack functions in an integrated platform of a distributed base station system according to an embodiment of the present invention;

fig. 8 is a schematic diagram illustrating functional division and placement of RLC protocol stack functions in a distributed base station system in a TM mode according to an embodiment of the present invention;

FIG. 9 is a diagram of a distributed structure based on the TM C-RCL and TM D-RLC shown in FIG. 8 according to an embodiment of the present invention_TxAnd TM D-RLC_RxSchematic diagram of the data transmission process implemented;

FIG. 10 is a CU provided in accordance with some embodiments of the invention;

fig. 11 is a DU provided by some embodiments of the present invention;

fig. 12 illustrates a data transmission method according to some embodiments of the invention;

fig. 13 is a data transmission method according to some embodiments of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In a conventional LTE network, an architecture of an LTE Protocol stack is designed according to a natural hierarchy of protocols, and includes a Radio Resource Control (RRC) Layer, a Packet Data Convergence Protocol (PDCP) Layer, a Radio Link Control (RLC) Layer, a Media Access Control (MAC) Layer, a Physical Layer (PHY) Layer, and the like. The conventional LTE protocol stack is planned in units of cells, and processing between the cells is performed independently.

Regarding the functions of each protocol layer, it is well known to those skilled in the art, since the present application mainly focuses on the distribution design of the protocol stack function of the RLC in the distributed base station system, the protocol layers related to the present application are only briefly described below, and the other protocol layers will not be described in detail. It should be noted that, regarding the processing of each protocol layer, for example, PDCP protocol processing and MAC protocol processing, may be evolved together with the standard protocol, and the improvement of the present application is not limited thereto, and the specific operation content thereof does not constitute a limitation of the present application.

For convenience of description, in the description of the present application, the functions of the respective protocol layers are performed by the protocol units corresponding to the respective protocol layers. For example: the RLC protocol unit is a protocol unit for executing the function of a protocol stack of the RLC and belongs to an RLC layer; the RRC protocol unit is a protocol unit for executing the functions of the RRC layer and belongs to the RRC layer; the PDCP protocol unit is a protocol unit for executing the function of the PDCP layer and belongs to the PDCP layer; the MAC protocol unit is a protocol unit that performs a function of the MAC layer, and belongs to the MAC layer.

It should be understood that the protocol units corresponding to the respective protocol layers may also be referred to as functional modules, entities, functional entities, logical entities, or virtual entities, etc.; the implementation method may specifically be in a software form, and may implement the corresponding functions by executing the program codes through the processor, or may also be in a hardware form.

In a conventional LTE network, the RLC layer is mainly used for transmitting data to the RLC layer of a peer end, and particularly, at a transmitting end, the RLC layer is mainly used for data segmentation and/or reassembly and can be used for Automatic Repeat-reQuest (ARQ) related operations, such as retransmission detection or sequence transfer to an upper layer; accordingly, at the receiving end, the RLC layer is mainly used for data re-assembly, ARQ-related operations.

In the present application, a sending end refers to a device that sends a data packet, and specifically may be a base station eNB, or a terminal UE, etc.; the receiving end refers to a device that receives the data packet, and may specifically be an eNB, a UE, or the like. For example, the sending end is an eNB, the receiving end is a UE, the eNB side is configured with an RLC protocol unit, and the UE side is configured with a peer RLC protocol unit; or for another example, the sending end is a UE, the receiving end is an eNB, the UE side is configured with an RLC protocol unit, and the eNB side is configured with a peer RLC protocol unit; and the like.

RLC protocol units are established before the RLC layer provides service. In the control plane, the service provided by the RLC layer to the upper layer is a Signaling Radio Bearer (SRB), and in the user plane, the service provided by the RLC layer to the upper layer is a Radio Bearer (RB). A plurality of different RLC protocol units may be established in one RLC layer, one RLC protocol unit being responsible for transmitting RLC PDUs to or receiving RLC PDUs of the RLC protocol unit of the peer.

Specifically, the RLC protocol unit may receive an RLC Service data unit (RLC SDU) from an upper layer protocol unit (an RRC protocol unit for a common control channel CCCH, or a PDCP protocol unit otherwise) through a Service Access Point (SAP), and then construct an RLC protocol data unit (RLC PDU) from the received RLC SDU, and then distribute the RLC PDU to a lower layer protocol unit (MAC protocol unit) through a logical channel; the RLC protocol unit may receive RLC PDUs from the MAC protocol unit through a logical channel, and after constructing RLC SDUs from the received RLC PDUs, deliver the RLC SDUs to the PDCP protocol unit through the SAP. The RLC PDU formed by the RLC SDU from the PDCP layer is transmitted only when the MAC layer notifies that there is a transmission opportunity.

The configuration of the RLC layer is generally controlled by the RRC layer, and in particular, the RRC layer may configure relevant parameters of the RLC layer, such as RLC protocol units, data transmission modes, sizes of SNs, coding schemes, and the like.

With the continuous evolution of communication network architectures, 5G network architectures provide a distributed architecture of an access network, air interface protocol stacks are respectively operated on different device entities, and transmission between the distributed entities can be non-ideal transmission, so that the segmentation and reconfiguration of the protocol stack functions need to be considered.

In this application, for convenience of description, a distributed network architecture proposed in a 5G scenario is denoted as a CU-DU distributed network architecture, it should be understood that a CU may specifically be also denoted as an RCC, a DU may specifically be denoted as an RRS, and a CU-DU distributed network architecture may specifically be the RCC-RRS distributed network architecture shown in fig. 1.

For the CU-DU distributed network architecture, the distribution of the RLC protocol stack function on the CU-DU distributed network architecture needs to be redesigned to meet various performance indexes such as the transmission network requirement, the data processing delay requirement, and the data control (e.g., data out-of-order delivery during reconstruction) requirement in the CU-DU distributed network architecture.

The existing technical scheme is that segmentation reconstruction is carried out between PDCP and RLC, the reordering function of PDCP PDU is added in the function of PDCP protocol, and the function of RLC is kept unchanged. The technical scheme has a plurality of defects, for example, the function of sequencing data packets needs to be added in the PDCP protocol; a complete set of in-sequence sending and receiving reordering mechanism needs to be added in the PDCP protocol, the PDCP protocol is changed greatly, and the like, which not only confuses the functional division of the RLC and PDCP, but also destroys the principle of functional division of the protocol stack in which the RLC takes charge of packet ordering.

Aiming at the segmentation and reconstruction requirements of the distributed network architecture on the protocol stack function and the problems of the current functional segmentation and reconstruction between the PDCP and the RLC, the invention provides a distributed base station system, a CU, a DU and a data transmission method, so as to provide a technical scheme for distributively setting the protocol stack function of the RLC, which is suitable for the distributed network architecture.

The technical scheme provided by the embodiment of the invention mainly carries out the separation and the placement of the whole function and the data transceiving function of the RLC protocol stack in the distributed network architecture, and can also be understood as the distributed structure which divides and reconstructs the RLC protocol stack function in the distributed network architecture into a general form and separates the data transceiving function.

In various embodiments of the present invention, the overall integration of RLC protocol stack functions in a Distributed network architecture and the separate placement of data transceiving functions are achieved primarily by separating RLC protocol units into Centralized radio link control (C-RLC) protocol units, Distributed radio link control (D-RLC) protocol units for data reception, and D-RLC protocol units for data transmission, and placing the separated C-RLC protocol units and D-RLC protocol units for data reception on CUs, and placing D-RLC protocol units for data transmission on DUs.

Or more specifically, it can also be understood that the technical solution provided in the embodiment of the present invention implements the overall and partial separate placement of RLC protocol stack functions and the separate placement of data transceiving functions in a distributed network architecture by first performing the overall separate placement of RLC protocol unit functions according to the basic function settings of the C-RLC protocol unit and the D-RLC protocol unit, and then performing the function separate placement of the data receiving function module and the data transmitting function module (or the D-RLC function module for data receiving and the D-RLC function module for data transmitting) of the D-RLC protocol unit.

The following describes embodiments of the present invention in detail with reference to the accompanying drawings.

In order to more clearly illustrate the technical solutions of the distributed base station system, the CU, the DU and the data transmission method provided by the embodiments of the present invention, the basic concept of performing overall fractional separation on the RLC protocol unit function in the present invention will be first briefly described, and it should be understood that the concept of the overall fractional separation of the RLC protocol unit is a part of the technical concept of the present invention.

Fig. 2 shows a schematic diagram of the basic concept of the RLC protocol unit population split separation in the embodiment of the present invention. As shown in FIG. 2, the protocol stack functionality of the RLC is divided into two parts, a C-RLC protocol unit (C-RLC 201 as shown) and a D-RLC protocol unit (D-RLC 202 as shown). Each D-RLC protocol unit 202 is a Branch Link (Branch of the Radio Link), one C-RLC protocol unit 201 may correspond to a plurality of D-RLC protocol units 202, the C-RLC protocol unit 201 corresponds to one RB of each UE, and each D-RLC protocol unit 202 is responsible for providing a data transceiving function for an air interface Link of the UE.

Specifically, as shown in fig. 2, the PDCP protocol unit (PDCP 203 as shown in the figure) transmits data to the C-RLC protocol unit 201, the C-RLC protocol unit 201 allocates the received data to each D-RLC protocol unit 202, and each D-RLC protocol unit 202 transmits the allocated data to the MAC protocol unit (MAC 204 as shown in the figure); the MAC protocol unit 204 transmits data to each D-RLC protocol unit 202, each D-RLC protocol unit 202 transmits the received data to the C-RLC protocol unit 201, and the C-RLC protocol unit 201 combines the received data and transmits the combined data to the PDCP protocol unit 203. The connection between the C-RLC protocol unit and the D-RLC protocol unit can be interacted through a non-ideal transmission network of the NGFI, and can be interacted through an ideal transmission network.

Further, fig. 3 shows a schematic structural diagram of the RLC protocol unit separated according to the general division in the embodiment of the present invention according to the distribution of the protocol stack functions of the RLC of the C-RLC protocol unit and the D-RLC protocol unit shown in fig. 2.

As shown in fig. 3, the RLC protocol unit is separated into a C-RLC protocol unit 301 and a plurality of D-RLC protocol units 302 according to a general formula, specifically, the C-RLC protocol unit is added on the basis of the original RLC protocol unit, and the D-RLC protocol unit has the function of the original RLC protocol unit. It can be seen that the technical concept of separating the RLC protocol units into different parts as shown in fig. 2 and fig. 3 is to add a C-RLC protocol unit on the basis of the original RLC protocol entity, and a D-RLC protocol unit performs the function of the original RLC protocol entity, that is, add a new processing function on the basis of being compatible with the existing RLC protocol stack function, and have no influence on the PDCP protocol function.

In combination with the function of the current RLC protocol unit and the CU-DU distributed network architecture, the embodiment of the present invention provides a technical solution of a distributed structure in which the RLC protocol stack function in the distributed network structure is segmented and reconstructed into a general sub-formula and the data transceiving function is separately located, based on the basic technical concepts shown in fig. 2 and fig. 3.

Fig. 4 is a schematic structural diagram of a distributed base station system according to an embodiment of the present invention.

The distributed base station system provided in the embodiment of the present invention shown in fig. 4 includes a CU 401 and M DUs 402 connected to the CU 401, where M is a positive integer.

Wherein, CU 401 and DU 402 are connected via a transmission network, and the interaction process can refer to the foregoing description of the distributed network architecture shown in fig. 1. Both CU 401 and DU 402 have air interface protocol stack and baseband processing functions.

Specifically, in the distributed base station system provided by the embodiment of the present invention shown in fig. 4, a CU 401 includes a C-RLC protocol unit 403, and a D-RLC protocol unit 404 for data reception; the D-RLC protocol unit 405 for data transmission is included in the DU 402.

It should be understood that, since the CU and the DU also include protocol units corresponding to other protocol layers, since the improvement point of the present invention is not involved, only the protocol units corresponding to the RLC protocol layers in the CU and the DU will be described in the present invention, and the protocol units corresponding to other protocol layers are not specifically described.

In particular, one C-RLC protocol unit 403 may correspond to one unidirectional or bidirectional radio bearer RB.

Further, each D-RLC protocol unit 405 for data transmission is responsible for providing a data transmission function for an air interface link of the UE; each D-RLC protocol unit 404 for data reception is responsible for providing a reception function of data for one air interface link of the UE.

Wherein, since each RB in the existing RLC protocol is associated with one PDCP protocol unit, each PDCP protocol unit is associated with one or two (uplink and downlink) RLC protocol units, depending on the characteristics (unidirectional or bidirectional) of the RB and the transmission mode of the RLC layer. Therefore, in the embodiment of the present invention, when the original RLC protocol unit is divided into the C-RLC protocol unit 403, the D-RLC protocol unit 404 for data reception, and the D-RLC protocol unit 405 for data transmission, the correspondence relationship between the PDCP protocol unit and the RLC protocol unit changes accordingly.

Further, since one CU may correspond to a plurality of DUs, for a bidirectional RB, the D-RLC protocol units 404 for data reception and the D-RLC protocol units 405 for data transmission on the CU correspond one to one, one D-RLC protocol unit 405 for data transmission is provided on each DU, and a plurality of D-RLC protocol units 404 for data reception are provided on the CU, and the total number of the two D-RLC protocol units 404 is the same. For unidirectional RBs, the D-RLC protocol units 404 for data reception and the D-RLC protocol units 405 for data transmission will not have a pairing constraint relationship, and the number between the two has no relationship.

Specifically, according to the number of air interface links occupied by unidirectional RBs corresponding to the C-RLC protocol unit 403, one C-RLC protocol unit 403 may correspond to the same number of D-RLC protocol units 405 for data transmission, where each D-RLC protocol unit 405 for data transmission corresponds to one air interface link.

Specifically, according to the number of air interface links occupied by the bidirectional RB corresponding to the C-RLC protocol unit 403, one C-RLC protocol unit 403 may correspond to the same number of D-RLC protocol units 405 for data transmission and the same number of D-RLC protocol units 404 for data reception, where one D-RLC protocol unit 405 for data transmission and one D-RLC protocol unit 404 for data reception correspond to one air interface link.

In some embodiments of the present invention, the C-RLC protocol unit 403 may be configured to buffer data transmitted by a protocol unit of a layer higher than the C-RLC protocol unit 403, and may allocate the buffered data to the D-RLC protocol unit 405 corresponding to the C-RLC protocol unit 403 for data transmission.

In some embodiments of the present invention, the C-RLC protocol unit 403 may be configured to receive data sent by the D-RLC protocol unit 404 for data reception corresponding to the C-RLC protocol unit 403, and reassemble the received data and send the reassembled data to a protocol unit in a higher layer of the C-RLC protocol unit 403.

In some embodiments of the present invention, the C-RLC protocol unit 403 may specifically include a Centralized Transmission buffer pool (Centralized Transmission buffer), and when data is transmitted, buffer data transmitted by a higher layer protocol unit of the C-RLC protocol unit 403, and when data is allocated to the D-RLC protocol unit 405 for data Transmission, form an RLC SDU cluster from SDUs transmitted to each D-RLC protocol unit 405 for data Transmission, where the RLC SDUs in the RLC SDU cluster are transmitted to each D-RLC protocol unit 405 for data Transmission according to a receiving order, and the RLC SDUs are not cut, so that all transmitted RLC SDUs are guaranteed to be complete RLC SDUs; when receiving data, the data sorting of the RLC SDU cluster reported by the D-RLC protocol unit 404 for data reception is completed, and the data is reported to the upper layer in the correct order.

In some embodiments of the invention, the D-RLC protocol unit 405 for data transmission may be configured to transmit the data allocated by the received C-RLC protocol unit 403 to the MAC protocol unit 406.

In some embodiments of the present invention, the D-RLC protocol unit 404 for data reception is configured to transmit data sent by the received MAC protocol unit 406 to the C-RLC protocol unit 403 corresponding to the D-RLC protocol unit 404 for data reception.

In some embodiments of the present invention, the D-RLC protocol unit 405 for data Transmission may specifically include a Transmission buffer pool (Transmission buffer) for performing in-order Transmission of data after receiving a plurality of RLC SDU packets in the RLC SDU cluster from the C-RLC protocol unit 403, including functions of data concatenation, header addition, retransmission, and the like; accordingly, the D-RLC protocol unit 404 for data reception, in particular for performing in-sequence reception and reassembly of data, delivers the data to the C-RLC protocol unit 403 in the correct order of RLC SDU cluster.

Specifically, in some embodiments of the present invention, any data amount control information does not need to be interacted between the C-RLC protocol unit 403 and the D-RLC protocol unit 405 for data transmission, and between the C-RLC protocol unit 403 and the D-RLC protocol unit 404 for data reception, and the interaction is performed directly by transceiving data packets. The D-RLC protocol unit 405 for data transmission does not need to send a data request to the C-RLC protocol unit 403, and the C-RLC protocol unit 403 allocates data according to the data throughput sent by each D-RLC protocol unit 405 for data transmission. Each D-RLC protocol unit 404 for data reception transmits the received data to the C-RLC protocol unit 403, and the C-RLC protocol unit 403 is ordered in the order specified by the protocol and then handed to the PDCP protocol unit in order. Each D-RLC protocol unit 404 for data reception is handed over to the C-RLC protocol unit 403 in the order of transmission as it receives data, and the C-RLC protocol unit 403 is only responsible for combining the ordering of packets received from the D-RLC protocol unit 404 for data reception with the ordering of packets received from a different D-RLC protocol unit 404 for data reception.

Further, in some embodiments of the present invention, the C-RLC protocol unit 403 may be specifically configured to send a data allocation request to the MAC protocol unit after receiving data sent by a higher-layer protocol unit of the C-RLC protocol unit 403; receiving a data distribution indication fed back by the MAC protocol unit; and according to the data allocation indication, allocating the buffered data to the D-RLC protocol unit 405 corresponding to the C-RLC protocol unit 403 and used for data transmission.

Optionally, in some embodiments of the present invention, the C-RLC protocol unit 403 is specifically configured to: configuring a D-RLC protocol unit 405 for data transmission according to the configuration information of the RRC protocol unit; and/or activating or deactivating the D-RLC protocol unit 405 corresponding to the C-RLC protocol unit and used for data transmission according to the data allocation indication of the MAC protocol unit.

Optionally, the C-RLC protocol unit, and the D-RLC protocol unit for data transmission and the D-RLC protocol unit for data reception corresponding to the C-RLC protocol unit may be created, configured, and released by the RRC protocol unit.

Further, it is contemplated that the RLC protocol unit may be configured with one of three data transmission modes to perform data transmission: transparent Mode (TM), Unacknowledged Mode (UM), or Acknowledged Mode (AM). The RLC protocol unit may be classified as a TM RLC protocol unit, a UM RLC protocol unit, or an AM RLC protocol unit, depending on the data transmission mode in which the RLC protocol unit is configured.

Specifically, one TM RLC protocol unit may be configured to transmit TM RLC protocol units (transmitting TM RLC entity) or receive TM RLC protocol units (receiving TM RLC entity); one UM RLC protocol unit may be configured to transmit UM RLC protocol unit (transmitting UM RLC entity) or receive UM RLC protocol unit (receiving UM RLC entity); an AM RLC protocol unit may include a transmitting side and a receiving side; the AM RLC protocol unit also comprises a Routing function part. Accordingly, it can be appreciated that the RLC protocol units configured to operate in the TM mode or the UM mode for data transmission, the receiving function and the transmitting function are performed separately from each other without interaction with each other, the RLC protocol units configured to operate in the AM mode for data transmission have both receiving and transmitting functions, and interaction is required between the receiving part and the transmitting part.

In addition, for the CU-DU distributed network architecture, the RLC protocol unit may be further divided into a Low RLC functional part and a High RLC functional part according to the functional division of the RLC protocol stack function, where the Low RLC functional part is located in the DU and the High RLC functional part is located in the CU. The Low RLC functional part and the High RLC functional part jointly complete the whole function of the RLC protocol stack.

Specifically, the High RLC functional part may include a receiving part of a TM RLC protocol unit, a UM RLC protocol unit, and an AM RLC protocol unit, which may be respectively denoted as TM High RLC, UM High RLC, and AM High RLC; the Low RLC functional part may include a transmitting part in a TM RLC protocol unit, a UM RLC protocol unit, and an AM RLC protocol unit, and accordingly, may be respectively denoted as TM Low RLC, UM Low RLC, and AM Low RLC; in particular, for AM RLC protocol units, the Routing function part in AM RLC protocol units may be located in the DU together with AM Low RLC.

Further, the C-RLC protocol unit and the D-RLC protocol unit for data transmission and the D-RLC protocol unit for data reception provided in some embodiments of the present invention may be configured based on the three data transmission modes and the corresponding RLC protocol units, for example, the C-RLC protocol unit and the D-RLC protocol unit for data transmission and the D-RLC protocol unit for data reception provided in some embodiments of the present invention are configured by the RRC protocol unit to perform data transmission in any one of the three data transmission modes, so as to ensure compatibility of the three data transmission modes.

Specifically, when configured in any one of the three data transmission modes, the C-RLC protocol unit may be configured to buffer data transmitted by an upper layer protocol unit and distribute the data to the D-RLC protocol unit for data transmission, and may be configured to receive data transmitted by each D-RLC protocol unit for data reception, and reassemble and deliver the received data to the upper layer protocol unit.

Further, for the case of data transmission configured in TM mode or UM mode, in some embodiments of the present invention configured in TM mode for data transmission, the D-RLC protocol unit for data transmission may be configured to perform a function (such as transmission buffering) possessed by the TM RLC protocol unit for transmission, and the D-RLC protocol unit for data reception may be configured to perform a function possessed by the TM RLC protocol unit for reception; in some embodiments of the present invention configured for UM mode data transmission, D-RLC protocol units for data transmission may be used to perform functions that the transmitting UM RLC protocol units have (such as transmission buffering, segmentation and concatenation, adding RLC headers), and D-RLC protocol units for data reception may be used to perform functions that the receiving UM RLC protocol units have (such as reception buffering and HARQ reordering, RLC header removal, SDU reassembly).

Further, for the case of data transmission configured in the AM mode, since the AM RLC protocol unit may specifically include a transmitting part and a receiving part, the Routing function part implements interaction between the receiving part and the transmitting part, and accordingly, in some embodiments of the present invention, interaction also needs to be implemented between the D-RLC protocol unit for data reception and the D-RLC protocol unit for data transmission.

Optionally, in some embodiments of the present invention, a routing unit is further included in the DU, and the routing unit corresponds to a D-RLC protocol unit for data transmission in the DU.

Specifically, the routing unit may be configured to, after receiving the data sent by the MAC protocol unit, send the received data to a D-RLC protocol unit in the DU for data transmission, or send the received data to a D-RLC protocol unit in a CU connected to the DU for data reception.

In particular, in some embodiments of the invention configured for AM mode data transmission, D-RLC protocol units for data transmission may be used to perform functions of the transmitting part of the AM RLC protocol units (such as transmission buffering, segmentation and concatenation, adding RLC headers, retransmission buffering), Routing function parts of the AM RLC protocol units (such as being responsible for deciding whether received data is to be transmitted to D-RLC protocol units for data transmission or to D-RLC protocol units for data reception), and D-RLC protocol units for data reception may be used to perform functions of the receiving part of the AM RLC protocol units (such as reception buffering and HARQ reordering, removal of RLC headers, SDU reassembly).

In view of the above-mentioned functional division of the RLC protocol stack in the CU-DU distributed network architecture, in some embodiments of the present invention, the functional division may be performed in a manner that is internal to the RLC protocol stack function. For example, in some embodiments of the present invention, the High RLC functional part may include a C-RLC protocol unit and a D-RLC protocol unit for data reception, and the Low RLC functional part may include a D-RLC protocol unit for data transmission; for another example, in some embodiments of the present invention, the D-RLC protocol unit for data transmission and the D-RLC protocol unit for data reception interact via the routing unit, the High RLC function portion may include the C-RLC protocol unit and the D-RLC protocol unit for data reception, and the Low RLC function portion may include the D-RLC protocol unit for data transmission and the routing unit.

Fig. 5 is an exploded view of the RLC protocol stack function in the distributed base station system according to an embodiment of the present invention. Wherein, D-RLC_TxIndicating D-RLC protocol units, D-RLC, for data transmission_RxIndicating D-RLC protocol units for data reception and Routing indicating Routing units.

Wherein the functional definition of the C-RLC protocol unit may be the same as the functional definition of the C-RLC protocol unit shown in fig. 3. D-RLC_Tx，D-RLC_RxAnd Routing may be understood as respective parts obtained by decomposing the function of the D-RLC protocol unit shown in fig. 3. C-RLC protocol unit and D-RLC_Tx，D-RLC_RxThe logical relationship of the D-RLC protocol unit formed with Routing is the same as that shown in fig. 2. D-RLC_TxResponsible for the transmission processing of data, D-RLC_RxIs responsible for the receiving process of the data, and the Routing function is responsible for deciding whether to send the received data to the D-RLC_TxOr D-RLC_Rx。

For TM/UM mode, because of D-RLC_TxAnd D-RLC_RxNo interaction is required between them, so Routing function may not be required. For AM mode, because D-RLC_TxAnd D-RLC_RxInteraction is needed, so Routing function is needed.

Further, fig. 6 is a schematic diagram illustrating the decomposition and placement of the RLC protocol stack function in the distributed base station system according to the embodiment of the present invention.

As shown in fig. 6, a routing unit 601 is further included in addition to fig. 4. Among them, a C-RLC protocol unit 403 and a D-RLC protocol unit 405 (D-RLC) for data transmission_Rx) D-RLC placed on CU for data receptionProtocol unit 405 (D-RLC)_Tx) The functions are placed on the DUs, and the routing units 601 are placed on the DUs in one-to-one correspondence with the D-RLC protocol units 405 for data reception.

As shown in FIG. 6 in particular, one CU may correspond to multiple DUs, and for a bidirectional RB, D-RLC of the CU_TxAnd D-RLC_RxOne for one, with one D-RLC on each DU_TxFunctional entity, having multiple D-RLC on CU_RxEntities, the total number of which is the same. For unidirectional RB, D-RLC_TxAnd D-RLC_RxThere is no pairing-constraint relationship, and the number between the two has no relationship. For the Routing unit 601(Routing function), there is a configuration in AM mode, there may be no configuration in TM or UM mode, and it is also placed on DU and on D-RLC_TxOne-to-one correspondence, which is responsible for deciding whether the received data is left on the DU for processing or sent to the CU for processing.

Furthermore, the C-RLC protocol unit and the D-RLC protocol unit used for data transmission and the C-RLC protocol unit and the D-RLC protocol unit used for data reception can interact through an imperfect transmission network of the NGFI and can also interact through an ideal transmission network.

For the distributed base station system as shown in fig. 6, there may be two specific connection modes between the CU and the DU, one is a requirement that the time delay between the CU and the DU is lower than a certain index threshold, that is, so-called ideal transmission; another requirement is that the time delay between the two is higher than a certain index threshold, namely the requirement of non-ideal transmission; the ideal transmission may refer to an integrated base station, the protocol stack is not partitioned, or although partitioned, the transmission is optical fiber direct connection, the transmission delay is in an order of magnitude with the transmission delay of the current CPRI (Common Public Radio Interface), or other transmissions meeting the data interaction requirements between protocol entities of the protocol stack in real time; otherwise, it is a non-ideal transmission. The placement scheme shown in fig. 6 is fully compatible for both transmission modes.

Specifically, under ideal transmission, D-RLC is the C-RLC protocol unit shown in FIG. 6_Tx，D-RLC_RxThe real-time interaction between the four Routing methods is better, and the redundancy measures are simpler; in non-ideal transmission, C-RLC protocol unit, D-RLC_Tx，D-RLC_RxThe real-time performance of the interaction between the four methods is poor, but the newly added redundancy measure can completely meet the requirement.

Fig. 7 is a schematic diagram illustrating the decomposition and placement of the RLC protocol stack function in the integrated platform of the distributed base station system according to the embodiment of the present invention. It can be seen that the C-RLC protocol unit, D-RLC_Tx，D-RLC_RxAnd Routing functions are all placed on an integrated platform, and the logical relationship is the same as that of the distributed network architecture.

In combination with the above description, it can be seen that the technical solution provided by the embodiments of the present invention mainly provides a technical solution for reconstructing the function segmentation of the original RLC protocol unit into a distributed structure that is adaptive to the overall form of the distributed network architecture and has a data transceiving function separately. To more clearly illustrate the distributed base station system provided by the embodiment of the present invention, the technical solution provided by the embodiment of the present invention will be used to configure the original RLC protocol unit as a function in TM mode, which is divided into C-RLC protocol units and D-RLC protocol units for data transmission_TxAnd D-RLC for data reception_RxThe structure and the process of data transmission are taken as examples and exemplary descriptions are given.

Fig. 8 shows a schematic diagram of functional partitioning and placement of RLC protocol stack functions in a distributed base station system in a configuration in TM mode according to some embodiments of the present invention.

As shown in FIG. 8, the original TM RLC protocol unit is divided into a TM C-RLC protocol unit (TMC-RLC 801), a TM D-RLC protocol unit for data transmission (TM D-RLC)_Tx802) And TM D-RLC protocol unit (TM D-RLC) for data reception_Rx803). Wherein, TM C-RLC801 and TM D-RLC _Rx803 is placed on the CU; TM D-RLC _Tx802 are placed onto the DU.

The TM C-RLC801 includes a newly added Centralized Transmission buffer 804(Centralized Transmission buffer), and the Centralized Transmission buffer 804 is responsible for transmitting data according to the priorityThe order of upper layer data is sent to each TMD-RLC_TxData distribution over 802 and control of TM D-RLC _Tx802, creation and deletion.

TM D-RLC _Tx802 includes the same Transmission buffer 805(Transmission buffer) function as the existing TM D-RLC protocol unit, i.e., the conventional TM RLC data Transmission function.

TM D-RLC _Rx803 is a conventional TM RLC data reception function, and the data packet is directly delivered to an upper layer.

It can be seen that TM C-RLC801 is placed on a CU, and TM C-RLC can coordinate and control multiple TM D-RLC simultaneously_Tx802 reception of data. TM D-RLC _Tx802 are all placed on the DUs, so that real-time data transmission support can be provided for a bottom layer, and the whole downlink transmission is all on the DUs, so that the influence of transmission delay brought by a transmission network between CUs and DUs can be avoided.

Further, for the integrated platform, TM C-RLC801 and TM D-RLC _Tx802 and TM D-RLC _Rx803 may be all placed in an integrated distributed base station system, or may be understood as placing all of the Centralized Transmission buffer and the Transmission buffer shown in fig. 8 in an integrated base station.

FIG. 9 illustrates a distributed structure based on the TM C-RCL and TM D-RLC shown in FIG. 8_TxAnd TM D-RLC_RxSchematic diagram of the implemented data transmission process.

As shown in FIG. 9, for the transmitting end (Tx), when the Centralized Transmission buffer of the TM C-RLC receives the RRC_cellAfter the Data is transmitted (step 9001), the Centralized Transmission buffer of the TM C-RLC transmits the Data to the MAC_cellInitiate a data Allocation request Allocation Req (step 9002), MAC_cellSending a data Allocation response (Allocation Resp) to a Centralized Transmission buffer of the TM C-RLC according to the monitored quality of the air interface on each Cell (step 9003), wherein each carrier unit CC is only visible in an MAC layer, and the RLC layer does not distinguish a primary carrier PCC and a secondary carrier SCC, so the RLC layer needs to start RLC processing according to the MAC scheduling result of each CC of the terminal to generate an RLC PDU, and then the RLC PDU is generated and sent to the central Transmission buffer of the TM C-RLC (Cell-to-Cell) according to the monitored quality of the air interface on each CellAnd sending the data to a MAC layer for distribution to each CC, wherein the MAC layer can distinguish each CC and can also understand that a MAC entity independently exists for each CC. The Centralized Transmission buffer of the TM C-RLC respectively gives the corresponding TM D-RLC with the indication of the distribution response_TxThe Transmission buffer of (1) transmits a number of RLC SDUs (buffer data) (step 9004), each TM D-RLC_TxSending RLC PDUs to the MAC on each Carrier Unit CC in a conventional manner_CC(step 9005).

As shown in fig. 9, for the receiving end (Rx), MAC on the carrier component CC of the terminal_CCSending RLC PDUs directly to TM D-RLC on a CU_RxProceed to processing (step 9011), TM D-RLC_RxThe data packet is delivered directly to the upper layer (step 9012).

In summary, the distributed base station system provided in the embodiment of the present invention mainly includes a CU and M DUs connected to the CU, where M is a positive integer; the method mainly comprises the steps that C-RLC protocol units and D-RLC protocol units used for data receiving are mainly included in a CU; the D-RLC protocol unit for data transmission is mainly included in the DU. As can be seen from the description of the above embodiments of the present invention, the distributed base station system provided in the embodiments of the present invention implements a distributed structure in which the RLC protocol stack function is decomposed and placed in a distributed network architecture.

It can be seen that, in the distributed base station system provided in the embodiment of the present invention, the original RLC protocol units are divided into C-RLC protocol units, and functional portions of D-RLC protocol units for data transmission and D-RLC protocol units for data reception, where the functions of the C-RLC protocol units may be understood as newly added functions (buffering, allocation (downlink) and reassembly (uplink)), and the functions of the D-RLC protocol units for data transmission and the D-RLC protocol units for data reception may be understood as being consistent with the functions of the existing RLC protocol units. The C-RLC protocol unit directly distributes data to the D-RLC protocol unit for data transmission when the data are transmitted, and the D-RLC protocol unit for data reception directly transmits the data to the C-RLC protocol unit when the data are received, and data flow control information does not need to be interacted with each other. Therefore, the technical scheme provided by the embodiment of the invention has good compatibility, can be compatible with the existing RLC protocol stack function, namely can be compatible with the RLC protocol unit in the 4G or 5G network, and realizes the combination of the total-divided RLC and the CU-DU distributed network architecture, which can effectively support the requirements of various 4G/5G scenes.

Meanwhile, the technical scheme provided by the embodiment of the invention does not involve any change on the function of the PDCP layer, does not influence the function of the PDCP protocol, and overcomes the defects of the technical scheme for carrying out segmentation reconstruction between the PDCP layer and the RLC layer in the prior art.

Further, according to the technical solution provided by the embodiment of the present invention, the RLC protocol stack function is placed on the CU-DU distributed network architecture, that is, the C-RLC is placed on the CU, the C-RLC coordinates and controls the plurality of D-RLC protocol units for data transmission and/or the plurality of D-RLC protocol units for data reception, and the D-RLC protocol units for data transmission are placed on the DU, so that real-time data transmission support can be provided for the bottom layer, and the whole downlink transmission is completely performed on the DU, which can avoid the influence of transmission delay caused by the transmission network between the CU and the DU, i.e., can be compatible with the delay caused by discontinuous transmission, has good extensibility, can quickly support a large number of users, and can be applied to the distributed network architecture in the 5G scenario shown in fig. 1, and can meet the requirements of the transmission network of the CU-DU distributed network architecture, Various performance indexes such as data processing delay requirements, data control requirements and the like.

Based on the same technical concept, an embodiment of the present invention further provides a CU, where the CU may specifically be a CU in the distributed base station system provided in the foregoing embodiment, and the CU may be applied to the distributed base station system provided in the foregoing embodiment.

Fig. 10 shows a CU1001 provided by some embodiments of the present invention, the CU1001 including therein a C-RLC protocol unit 1002, and a D-RLC protocol unit 1003 for data reception; the CU1001 is connected to M DUs that include D-RLC protocol units for data transmission, M being a positive integer.

Wherein, one C-RLC protocol unit 1002 corresponds to one unidirectional or bidirectional radio bearer RB;

according to the number of empty links occupied by unidirectional RBs corresponding to the C-RLC protocol unit 1002, one C-RLC protocol unit corresponds to the same number of D-RLC protocol units for data transmission, wherein each D-RLC protocol unit for data transmission corresponds to one empty link;

according to the number of air interface links occupied by the bidirectional RB corresponding to the C-RLC protocol unit 1002, one C-RLC protocol unit corresponds to the same number of D-RLC protocol units for data transmission and the same number of D-RLC protocol units 1003 for data reception, wherein one D-RLC protocol unit for data transmission and one D-RLC protocol unit for data reception correspond to one air interface link.

Specifically, the C-RLC protocol unit 1002 is configured to buffer data sent by a protocol unit in an upper layer of the C-RLC protocol unit, and allocate the buffered data to a D-RLC protocol unit corresponding to the C-RLC protocol unit and used for data sending; and/or the data processing device is used for receiving data sent by a D-RLC protocol unit which is corresponding to the C-RLC protocol unit and used for receiving the data, recombining the received data and sending the recombined data to a previous layer protocol unit of the C-RLC protocol unit.

Optionally, the C-RLC protocol unit 1002 is specifically configured to send a data allocation request to the MAC protocol unit after receiving data sent by a protocol unit in a higher layer of the C-RLC protocol unit; receiving a data distribution indication fed back by the MAC protocol unit; and according to the data allocation indication, allocating the buffered data to a D-RLC protocol unit corresponding to the C-RLC protocol unit and used for data transmission.

Optionally, the C-RLC protocol unit 1002 is configured to configure a D-RLC protocol unit for data transmission according to the configuration information of the RRC protocol unit; and/or activating or deactivating the D-RLC protocol unit corresponding to the C-RLC functional entity and used for data transmission according to the data allocation indication of the MAC protocol unit.

Specifically, as shown in fig. 10, the CU provided in some embodiments of the present invention may specifically refer to the description related to the CU in the distributed base station system provided in the foregoing embodiments.

Based on the same technical concept, an embodiment of the present invention further provides a DU, where the CU may specifically be a DU in the distributed base station system provided in the foregoing embodiment, and the DU may be applied to the distributed base station system provided in the foregoing embodiment.

Fig. 11 illustrates a DU1101 provided by some embodiments of the present invention, where the DU1101 includes a D-RLC protocol unit 1102 for data transmission; the DU1101 is connected to a CU comprising a C-RLC protocol unit and a D-RLC protocol unit for data reception.

Specifically, the D-RLC protocol unit 1102 is configured to transmit the received data allocated by the C-RLC protocol unit in the CU to the MAC protocol unit.

Optionally, the DU1101 further includes: a routing unit 1103, where the routing unit 1103 corresponds to the D-RLC protocol unit 1102 in the DU1101 for data transmission.

Optionally, the routing unit 1103 in the DU1101 is configured to, after receiving data sent by the MAC protocol unit, send the received data to a D-RLC protocol unit in the DU for data transmission, or send the received data to a D-RLC protocol unit in a CU connected to the DU for data reception.

Specifically, as shown in fig. 11, the DU provided by some embodiments of the present invention may specifically refer to the description related to the DU in the distributed base station system provided in the foregoing embodiments.

Based on the same technical concept, embodiments of the present invention further provide a data transmission method, and fig. 12 illustrates a data transmission method provided in some embodiments of the present invention, which may be specifically executed by the distributed base station system provided in the foregoing embodiments, and the method may be applied to the distributed base station system provided in the foregoing embodiments. The distributed base station system comprises a CU and M DUs connected with the CU, wherein M is a positive integer;

as shown in fig. 12, the method includes:

step 1201: a C-RLC protocol unit in a CU buffers data sent by a protocol unit of a previous layer of the C-RLC protocol unit;

step 1202: the C-RLC protocol unit in the CU distributes the buffered data to the D-RLC protocol unit which corresponds to the C-RLC protocol unit and is used for data transmission in the DU connected to the CU;

step 1203: the D-RLC protocol unit for data transmission in the DU transfers the data allocated by the received C-RLC protocol unit to the MAC protocol unit.

Specifically, as shown in fig. 12, the data transmission method provided by some embodiments of the present invention may specifically refer to the description related to downlink data transmission in the distributed base station system provided in the foregoing embodiments.

Based on the same technical concept, embodiments of the present invention further provide a data transmission method, and fig. 13 illustrates a data transmission method provided in some embodiments of the present invention, which may be specifically executed by the distributed base station system provided in the foregoing embodiments, and the method may be applied to the distributed base station system provided in the foregoing embodiments. The distributed base station system comprises a CU and M DUs connected with the CU, wherein M is a positive integer;

as shown in fig. 13, the method includes:

step 1301: a D-RLC protocol unit used for data reception in the CU receives data sent by the MAC protocol unit;

step 1302: the D-RLC protocol unit for data reception in the CU transmits the received data to the C-RLC protocol unit corresponding to the D-RLC protocol unit for data reception in the CU;

step 1303: the C-RLC protocol unit recombines data transmitted by the D-RLC protocol unit which is used for receiving the data and corresponds to the received C-RLC protocol unit and then sends the recombined data to a protocol unit of the upper layer of the C-RLC protocol unit.

Optionally, the data sent by the MAC protocol unit is transmitted to the D-RLC protocol unit for data reception in the CU by the routing unit in the DU connected to the CU after receiving the data sent by the MAC protocol unit and determining that the data sent by the received MAC protocol unit is transmitted to the D-RLC protocol unit for data reception in the CU connected to the DU.

Specifically, the data transmission method provided by some embodiments of the present invention as shown in fig. 13 may specifically refer to the description related to the uplink data transmission process in the distributed base station system provided in the foregoing embodiments.

For a software implementation, the techniques may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor or external to the processor.

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

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

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

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

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

Claims

1. A distributed base station system is characterized in that the distributed base station system comprises a central unit CU and M distribution units DU connected with the CU, wherein M is a positive integer;

the DU comprises a D-RLC protocol unit used for data transmission; the C-RLC protocol unit and the D-RLC protocol unit are obtained by dividing the RLC protocol units, and one C-RLC protocol unit corresponds to a plurality of D-RLC protocol units.

2. The distributed base station system of claim 1, wherein one C-RLC protocol unit corresponds to one unidirectional or bidirectional radio bearer RB;

3. The distributed base station system according to claim 1, wherein the C-RLC protocol unit is configured to buffer data sent by a protocol unit of a layer higher than the C-RLC protocol unit, and allocate the buffered data to a D-RLC protocol unit corresponding to the C-RLC protocol unit for data transmission; and/or the presence of a gas in the gas,

4. The distributed base station system of claim 3, wherein the C-RLC protocol unit is specifically configured to:

receiving a data allocation indication fed back by the MAC protocol unit;

5. The distributed base station system of claim 3, wherein the D-RLC protocol unit for data transmission is configured to transmit the received data allocated by the C-RLC protocol unit to a MAC protocol unit;

6. The distributed base station system of any of claims 1 through 5, wherein the DU further comprises: and the routing unit corresponds to the D-RLC protocol unit used for data transmission in the DU.

7. The distributed base station system according to claim 6, wherein the routing unit, after receiving the data transmitted by the MAC protocol unit, transmits the received data to the D-RLC protocol unit for data transmission in the DU or transmits the received data to the D-RLC protocol unit for data reception in the CU connected to the DU.

8. The distributed base station system of claim 1, wherein the C-RLC protocol unit is to: according to the configuration information of the RRC protocol unit, configuring a D-RLC protocol unit for data transmission; and/or the presence of a gas in the gas,

9. A CU comprising a C-RLC protocol unit and a D-RLC protocol unit for data reception; the CU is connected with M DUs comprising D-RLC protocol units used for data transmission, wherein M is a positive integer; the C-RLC protocol unit and the D-RLC protocol unit are obtained by dividing the RLC protocol units, and one C-RLC protocol unit corresponds to a plurality of D-RLC protocol units.

10. The CU of claim 9, wherein one C-RLC protocol unit corresponds to one unidirectional or bidirectional radio bearer RB;

11. The CU of claim 9, wherein the C-RLC protocol unit is configured to buffer data transmitted by a higher layer protocol unit of the C-RLC protocol unit, and to allocate the buffered data to a D-RLC protocol unit corresponding to the C-RLC protocol unit for data transmission; and/or the presence of a gas in the gas,

12. The CU of claim 11, wherein the C-RLC protocol unit is further configured to:

receiving a data allocation indication fed back by the MAC protocol unit;

13. The CU of claim 9, wherein the C-RLC protocol unit is to: according to the configuration information of the RRC protocol unit, configuring a D-RLC protocol unit for data transmission; and/or the presence of a gas in the gas,

14. A DU, wherein the DU includes a D-RLC protocol unit for data transmission; the DU is connected to a CU comprising a C-RLC protocol unit and a D-RLC protocol unit for data reception; the C-RLC protocol unit and the D-RLC protocol unit are obtained by dividing the RLC protocol units, and one C-RLC protocol unit corresponds to a plurality of D-RLC protocol units.

15. The DU of claim 14, wherein the D-RLC protocol units for data transmission transmit received data allocated by C-RLC protocol units in the CUs to MAC protocol units.

16. The DU of claim 14 or 15, further comprising: and the routing unit corresponds to the D-RLC protocol unit used for data transmission in the DU.

17. The DU of claim 16, wherein the routing unit is configured to send the received data to a D-RLC protocol unit in the DU for data transmission or to a D-RLC protocol unit in a CU connected to the DU for data reception after receiving data sent by a MAC protocol unit.

18. A data transmission method is characterized in that the method is applied to a distributed base station system, wherein the distributed base station system comprises a CU and M DUs connected with the CU, and M is a positive integer;

the method comprises the following steps:

19. A data transmission method is characterized in that the method is applied to a distributed base station system, wherein the distributed base station system comprises a CU and M DUs connected with the CU, and M is a positive integer;

the method comprises the following steps:

20. The data transmission method according to claim 19, wherein the data transmitted by the MAC protocol unit is transmitted to the D-RLC protocol unit for data reception in the CU after the routing unit in the DU connected to the CU receives the data transmitted by the MAC protocol unit and determines to transmit the data transmitted by the received MAC protocol unit to the D-RLC protocol unit for data reception in the CU connected to the DU.